usb: host: Faraday fotg210-hcd driver

FOTG210 is an OTG controller which can be configured as an
USB2.0 host. FOTG210 host is an ehci-like controller with
some differences. First, register layout of FOTG210 is
incompatible with EHCI. Furthermore, FOTG210 is lack of
siTDs which means iTDs are used for both HS and FS ISO
transfer.

Signed-off-by: Feng-Hsin Chiang <john453@faraday-tech.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6049 insertions, 0 deletions

diff --git a/drivers/usb/host/fotg210-hcd.c b/drivers/usb/host/fotg210-hcd.c
new file mode 100644
index 000000000000..fce13bcc4a3e
--- /dev/null
+++ b/drivers/usb/host/fotg210-hcd.c
@@ -0,0 +1,6049 @@
+/*
+ * Faraday FOTG210 EHCI-like driver
+ *
+ * Copyright (c) 2013 Faraday Technology Corporation
+ *
+ * Author: Yuan-Hsin Chen <yhchen@faraday-tech.com>
+ *	   Feng-Hsin Chiang <john453@faraday-tech.com>
+ *	   Po-Yu Chuang <ratbert.chuang@gmail.com>
+ *
+ * Most of code borrowed from the Linux-3.7 EHCI driver
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/hrtimer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/moduleparam.h>
+#include <linux/dma-mapping.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#include <asm/byteorder.h>
+#include <asm/irq.h>
+#include <asm/unaligned.h>
+
+/*-------------------------------------------------------------------------*/
+#define DRIVER_AUTHOR "Yuan-Hsin Chen"
+#define DRIVER_DESC "FOTG210 Host Controller (EHCI) Driver"
+
+static const char	hcd_name[] = "fotg210_hcd";
+
+#undef VERBOSE_DEBUG
+#undef FOTG210_URB_TRACE
+
+#ifdef DEBUG
+#define FOTG210_STATS
+#endif
+
+/* magic numbers that can affect system performance */
+#define	FOTG210_TUNE_CERR		3 /* 0-3 qtd retries; 0 == don't stop */
+#define	FOTG210_TUNE_RL_HS		4 /* nak throttle; see 4.9 */
+#define	FOTG210_TUNE_RL_TT		0
+#define	FOTG210_TUNE_MULT_HS	1	/* 1-3 transactions/uframe; 4.10.3 */
+#define	FOTG210_TUNE_MULT_TT	1
+/*
+ * Some drivers think it's safe to schedule isochronous transfers more than
+ * 256 ms into the future (partly as a result of an old bug in the scheduling
+ * code).  In an attempt to avoid trouble, we will use a minimum scheduling
+ * length of 512 frames instead of 256.
+ */
+#define	FOTG210_TUNE_FLS		1 /* (medium) 512-frame schedule */
+
+/* Initial IRQ latency:  faster than hw default */
+static int log2_irq_thresh;		/* 0 to 6 */
+module_param(log2_irq_thresh, int, S_IRUGO);
+MODULE_PARM_DESC(log2_irq_thresh, "log2 IRQ latency, 1-64 microframes");
+
+/* initial park setting:  slower than hw default */
+static unsigned park;
+module_param(park, uint, S_IRUGO);
+MODULE_PARM_DESC(park, "park setting; 1-3 back-to-back async packets");
+
+/* for link power management(LPM) feature */
+static unsigned int hird;
+module_param(hird, int, S_IRUGO);
+MODULE_PARM_DESC(hird, "host initiated resume duration, +1 for each 75us");
+
+#define	INTR_MASK (STS_IAA | STS_FATAL | STS_PCD | STS_ERR | STS_INT)
+
+#include "fotg210.h"
+
+/*-------------------------------------------------------------------------*/
+
+#define fotg210_dbg(fotg210, fmt, args...) \
+	dev_dbg(fotg210_to_hcd(fotg210)->self.controller , fmt , ## args)
+#define fotg210_err(fotg210, fmt, args...) \
+	dev_err(fotg210_to_hcd(fotg210)->self.controller , fmt , ## args)
+#define fotg210_info(fotg210, fmt, args...) \
+	dev_info(fotg210_to_hcd(fotg210)->self.controller , fmt , ## args)
+#define fotg210_warn(fotg210, fmt, args...) \
+	dev_warn(fotg210_to_hcd(fotg210)->self.controller , fmt , ## args)
+
+#ifdef VERBOSE_DEBUG
+#	define fotg210_vdbg fotg210_dbg
+#else
+	static inline void fotg210_vdbg(struct fotg210_hcd *fotg210, ...) {}
+#endif
+
+#ifdef	DEBUG
+
+/* check the values in the HCSPARAMS register
+ * (host controller _Structural_ parameters)
+ * see EHCI spec, Table 2-4 for each value
+ */
+static void dbg_hcs_params(struct fotg210_hcd *fotg210, char *label)
+{
+	u32	params = fotg210_readl(fotg210, &fotg210->caps->hcs_params);
+
+	fotg210_dbg(fotg210,
+		"%s hcs_params 0x%x ports=%d\n",
+		label, params,
+		HCS_N_PORTS(params)
+		);
+}
+#else
+
+static inline void dbg_hcs_params(struct fotg210_hcd *fotg210, char *label) {}
+
+#endif
+
+#ifdef	DEBUG
+
+/* check the values in the HCCPARAMS register
+ * (host controller _Capability_ parameters)
+ * see EHCI Spec, Table 2-5 for each value
+ * */
+static void dbg_hcc_params(struct fotg210_hcd *fotg210, char *label)
+{
+	u32	params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+
+	fotg210_dbg(fotg210,
+		"%s hcc_params %04x uframes %s%s\n",
+		label,
+		params,
+		HCC_PGM_FRAMELISTLEN(params) ? "256/512/1024" : "1024",
+		HCC_CANPARK(params) ? " park" : "");
+}
+#else
+
+static inline void dbg_hcc_params(struct fotg210_hcd *fotg210, char *label) {}
+
+#endif
+
+#ifdef	DEBUG
+
+static void __maybe_unused
+dbg_qtd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd)
+{
+	fotg210_dbg(fotg210, "%s td %p n%08x %08x t%08x p0=%08x\n", label, qtd,
+		hc32_to_cpup(fotg210, &qtd->hw_next),
+		hc32_to_cpup(fotg210, &qtd->hw_alt_next),
+		hc32_to_cpup(fotg210, &qtd->hw_token),
+		hc32_to_cpup(fotg210, &qtd->hw_buf[0]));
+	if (qtd->hw_buf[1])
+		fotg210_dbg(fotg210, "  p1=%08x p2=%08x p3=%08x p4=%08x\n",
+			hc32_to_cpup(fotg210, &qtd->hw_buf[1]),
+			hc32_to_cpup(fotg210, &qtd->hw_buf[2]),
+			hc32_to_cpup(fotg210, &qtd->hw_buf[3]),
+			hc32_to_cpup(fotg210, &qtd->hw_buf[4]));
+}
+
+static void __maybe_unused
+dbg_qh(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	struct fotg210_qh_hw *hw = qh->hw;
+
+	fotg210_dbg(fotg210, "%s qh %p n%08x info %x %x qtd %x\n", label,
+		qh, hw->hw_next, hw->hw_info1, hw->hw_info2, hw->hw_current);
+	dbg_qtd("overlay", fotg210, (struct fotg210_qtd *) &hw->hw_qtd_next);
+}
+
+static void __maybe_unused
+dbg_itd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_itd *itd)
+{
+	fotg210_dbg(fotg210, "%s[%d] itd %p, next %08x, urb %p\n",
+		label, itd->frame, itd, hc32_to_cpu(fotg210, itd->hw_next),
+		itd->urb);
+	fotg210_dbg(fotg210,
+		"  trans: %08x %08x %08x %08x %08x %08x %08x %08x\n",
+		hc32_to_cpu(fotg210, itd->hw_transaction[0]),
+		hc32_to_cpu(fotg210, itd->hw_transaction[1]),
+		hc32_to_cpu(fotg210, itd->hw_transaction[2]),
+		hc32_to_cpu(fotg210, itd->hw_transaction[3]),
+		hc32_to_cpu(fotg210, itd->hw_transaction[4]),
+		hc32_to_cpu(fotg210, itd->hw_transaction[5]),
+		hc32_to_cpu(fotg210, itd->hw_transaction[6]),
+		hc32_to_cpu(fotg210, itd->hw_transaction[7]));
+	fotg210_dbg(fotg210,
+		"  buf:   %08x %08x %08x %08x %08x %08x %08x\n",
+		hc32_to_cpu(fotg210, itd->hw_bufp[0]),
+		hc32_to_cpu(fotg210, itd->hw_bufp[1]),
+		hc32_to_cpu(fotg210, itd->hw_bufp[2]),
+		hc32_to_cpu(fotg210, itd->hw_bufp[3]),
+		hc32_to_cpu(fotg210, itd->hw_bufp[4]),
+		hc32_to_cpu(fotg210, itd->hw_bufp[5]),
+		hc32_to_cpu(fotg210, itd->hw_bufp[6]));
+	fotg210_dbg(fotg210, "  index: %d %d %d %d %d %d %d %d\n",
+		itd->index[0], itd->index[1], itd->index[2],
+		itd->index[3], itd->index[4], itd->index[5],
+		itd->index[6], itd->index[7]);
+}
+
+static int __maybe_unused
+dbg_status_buf(char *buf, unsigned len, const char *label, u32 status)
+{
+	return scnprintf(buf, len,
+		"%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s",
+		label, label[0] ? " " : "", status,
+		(status & STS_ASS) ? " Async" : "",
+		(status & STS_PSS) ? " Periodic" : "",
+		(status & STS_RECL) ? " Recl" : "",
+		(status & STS_HALT) ? " Halt" : "",
+		(status & STS_IAA) ? " IAA" : "",
+		(status & STS_FATAL) ? " FATAL" : "",
+		(status & STS_FLR) ? " FLR" : "",
+		(status & STS_PCD) ? " PCD" : "",
+		(status & STS_ERR) ? " ERR" : "",
+		(status & STS_INT) ? " INT" : ""
+		);
+}
+
+static int __maybe_unused
+dbg_intr_buf(char *buf, unsigned len, const char *label, u32 enable)
+{
+	return scnprintf(buf, len,
+		"%s%sintrenable %02x%s%s%s%s%s%s",
+		label, label[0] ? " " : "", enable,
+		(enable & STS_IAA) ? " IAA" : "",
+		(enable & STS_FATAL) ? " FATAL" : "",
+		(enable & STS_FLR) ? " FLR" : "",
+		(enable & STS_PCD) ? " PCD" : "",
+		(enable & STS_ERR) ? " ERR" : "",
+		(enable & STS_INT) ? " INT" : ""
+		);
+}
+
+static const char *const fls_strings[] = { "1024", "512", "256", "??" };
+
+static int
+dbg_command_buf(char *buf, unsigned len, const char *label, u32 command)
+{
+	return scnprintf(buf, len,
+		"%s%scommand %07x %s=%d ithresh=%d%s%s%s "
+		"period=%s%s %s",
+		label, label[0] ? " " : "", command,
+		(command & CMD_PARK) ? " park" : "(park)",
+		CMD_PARK_CNT(command),
+		(command >> 16) & 0x3f,
+		(command & CMD_IAAD) ? " IAAD" : "",
+		(command & CMD_ASE) ? " Async" : "",
+		(command & CMD_PSE) ? " Periodic" : "",
+		fls_strings[(command >> 2) & 0x3],
+		(command & CMD_RESET) ? " Reset" : "",
+		(command & CMD_RUN) ? "RUN" : "HALT"
+		);
+}
+
+static int
+dbg_port_buf(char *buf, unsigned len, const char *label, int port, u32 status)
+{
+	char	*sig;
+
+	/* signaling state */
+	switch (status & (3 << 10)) {
+	case 0 << 10:
+		sig = "se0";
+		break;
+	case 1 << 10:
+		sig = "k";
+		break; /* low speed */
+	case 2 << 10:
+		sig = "j";
+		break;
+	default:
+		sig = "?";
+		break;
+	}
+
+	return scnprintf(buf, len,
+		"%s%sport:%d status %06x %d "
+		"sig=%s%s%s%s%s%s%s%s",
+		label, label[0] ? " " : "", port, status,
+		status>>25,/*device address */
+		sig,
+		(status & PORT_RESET) ? " RESET" : "",
+		(status & PORT_SUSPEND) ? " SUSPEND" : "",
+		(status & PORT_RESUME) ? " RESUME" : "",
+		(status & PORT_PEC) ? " PEC" : "",
+		(status & PORT_PE) ? " PE" : "",
+		(status & PORT_CSC) ? " CSC" : "",
+		(status & PORT_CONNECT) ? " CONNECT" : "");
+}
+
+#else
+static inline void __maybe_unused
+dbg_qh(char *label, struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{}
+
+static inline int __maybe_unused
+dbg_status_buf(char *buf, unsigned len, const char *label, u32 status)
+{ return 0; }
+
+static inline int __maybe_unused
+dbg_command_buf(char *buf, unsigned len, const char *label, u32 command)
+{ return 0; }
+
+static inline int __maybe_unused
+dbg_intr_buf(char *buf, unsigned len, const char *label, u32 enable)
+{ return 0; }
+
+static inline int __maybe_unused
+dbg_port_buf(char *buf, unsigned len, const char *label, int port, u32 status)
+{ return 0; }
+
+#endif	/* DEBUG */
+
+/* functions have the "wrong" filename when they're output... */
+#define dbg_status(fotg210, label, status) { \
+	char _buf[80]; \
+	dbg_status_buf(_buf, sizeof(_buf), label, status); \
+	fotg210_dbg(fotg210, "%s\n", _buf); \
+}
+
+#define dbg_cmd(fotg210, label, command) { \
+	char _buf[80]; \
+	dbg_command_buf(_buf, sizeof(_buf), label, command); \
+	fotg210_dbg(fotg210, "%s\n", _buf); \
+}
+
+#define dbg_port(fotg210, label, port, status) { \
+	char _buf[80]; \
+	dbg_port_buf(_buf, sizeof(_buf), label, port, status); \
+	fotg210_dbg(fotg210, "%s\n", _buf); \
+}
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef STUB_DEBUG_FILES
+
+static inline void create_debug_files(struct fotg210_hcd *bus) { }
+static inline void remove_debug_files(struct fotg210_hcd *bus) { }
+
+#else
+
+/* troubleshooting help: expose state in debugfs */
+
+static int debug_async_open(struct inode *, struct file *);
+static int debug_periodic_open(struct inode *, struct file *);
+static int debug_registers_open(struct inode *, struct file *);
+static int debug_async_open(struct inode *, struct file *);
+
+static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);
+static int debug_close(struct inode *, struct file *);
+
+static const struct file_operations debug_async_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debug_async_open,
+	.read		= debug_output,
+	.release	= debug_close,
+	.llseek		= default_llseek,
+};
+static const struct file_operations debug_periodic_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debug_periodic_open,
+	.read		= debug_output,
+	.release	= debug_close,
+	.llseek		= default_llseek,
+};
+static const struct file_operations debug_registers_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debug_registers_open,
+	.read		= debug_output,
+	.release	= debug_close,
+	.llseek		= default_llseek,
+};
+
+static struct dentry *fotg210_debug_root;
+
+struct debug_buffer {
+	ssize_t (*fill_func)(struct debug_buffer *);	/* fill method */
+	struct usb_bus *bus;
+	struct mutex mutex;	/* protect filling of buffer */
+	size_t count;		/* number of characters filled into buffer */
+	char *output_buf;
+	size_t alloc_size;
+};
+
+#define speed_char(info1)({ char tmp; \
+		switch (info1 & (3 << 12)) { \
+		case QH_FULL_SPEED:	\
+			tmp = 'f'; break; \
+		case QH_LOW_SPEED:	\
+			tmp = 'l'; break; \
+		case QH_HIGH_SPEED:	\
+			tmp = 'h'; break; \
+		default:		\
+			tmp = '?'; break; \
+		}; tmp; })
+
+static inline char token_mark(struct fotg210_hcd *fotg210, __hc32 token)
+{
+	__u32 v = hc32_to_cpu(fotg210, token);
+
+	if (v & QTD_STS_ACTIVE)
+		return '*';
+	if (v & QTD_STS_HALT)
+		return '-';
+	if (!IS_SHORT_READ(v))
+		return ' ';
+	/* tries to advance through hw_alt_next */
+	return '/';
+}
+
+static void qh_lines(
+	struct fotg210_hcd *fotg210,
+	struct fotg210_qh *qh,
+	char **nextp,
+	unsigned *sizep
+)
+{
+	u32			scratch;
+	u32			hw_curr;
+	struct fotg210_qtd	*td;
+	unsigned		temp;
+	unsigned		size = *sizep;
+	char			*next = *nextp;
+	char			mark;
+	__le32			list_end = FOTG210_LIST_END(fotg210);
+	struct fotg210_qh_hw	*hw = qh->hw;
+
+	if (hw->hw_qtd_next == list_end)	/* NEC does this */
+		mark = '@';
+	else
+		mark = token_mark(fotg210, hw->hw_token);
+	if (mark == '/') {	/* qh_alt_next controls qh advance? */
+		if ((hw->hw_alt_next & QTD_MASK(fotg210))
+				== fotg210->async->hw->hw_alt_next)
+			mark = '#';	/* blocked */
+		else if (hw->hw_alt_next == list_end)
+			mark = '.';	/* use hw_qtd_next */
+		/* else alt_next points to some other qtd */
+	}
+	scratch = hc32_to_cpup(fotg210, &hw->hw_info1);
+	hw_curr = (mark == '*') ? hc32_to_cpup(fotg210, &hw->hw_current) : 0;
+	temp = scnprintf(next, size,
+			"qh/%p dev%d %cs ep%d %08x %08x(%08x%c %s nak%d)",
+			qh, scratch & 0x007f,
+			speed_char(scratch),
+			(scratch >> 8) & 0x000f,
+			scratch, hc32_to_cpup(fotg210, &hw->hw_info2),
+			hc32_to_cpup(fotg210, &hw->hw_token), mark,
+			(cpu_to_hc32(fotg210, QTD_TOGGLE) & hw->hw_token)
+				? "data1" : "data0",
+			(hc32_to_cpup(fotg210, &hw->hw_alt_next) >> 1) & 0x0f);
+	size -= temp;
+	next += temp;
+
+	/* hc may be modifying the list as we read it ... */
+	list_for_each_entry(td, &qh->qtd_list, qtd_list) {
+		scratch = hc32_to_cpup(fotg210, &td->hw_token);
+		mark = ' ';
+		if (hw_curr == td->qtd_dma)
+			mark = '*';
+		else if (hw->hw_qtd_next == cpu_to_hc32(fotg210, td->qtd_dma))
+			mark = '+';
+		else if (QTD_LENGTH(scratch)) {
+			if (td->hw_alt_next == fotg210->async->hw->hw_alt_next)
+				mark = '#';
+			else if (td->hw_alt_next != list_end)
+				mark = '/';
+		}
+		temp = snprintf(next, size,
+				"\n\t%p%c%s len=%d %08x urb %p",
+				td, mark, ({ char *tmp;
+				 switch ((scratch>>8)&0x03) {
+				 case 0:
+					tmp = "out";
+					break;
+				 case 1:
+					tmp = "in";
+					break;
+				 case 2:
+					tmp = "setup";
+					break;
+				 default:
+					tmp = "?";
+					break;
+				 } tmp; }),
+				(scratch >> 16) & 0x7fff,
+				scratch,
+				td->urb);
+		if (size < temp)
+			temp = size;
+		size -= temp;
+		next += temp;
+		if (temp == size)
+			goto done;
+	}
+
+	temp = snprintf(next, size, "\n");
+	if (size < temp)
+		temp = size;
+	size -= temp;
+	next += temp;
+
+done:
+	*sizep = size;
+	*nextp = next;
+}
+
+static ssize_t fill_async_buffer(struct debug_buffer *buf)
+{
+	struct usb_hcd		*hcd;
+	struct fotg210_hcd	*fotg210;
+	unsigned long		flags;
+	unsigned		temp, size;
+	char			*next;
+	struct fotg210_qh		*qh;
+
+	hcd = bus_to_hcd(buf->bus);
+	fotg210 = hcd_to_fotg210(hcd);
+	next = buf->output_buf;
+	size = buf->alloc_size;
+
+	*next = 0;
+
+	/* dumps a snapshot of the async schedule.
+	 * usually empty except for long-term bulk reads, or head.
+	 * one QH per line, and TDs we know about
+	 */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	for (qh = fotg210->async->qh_next.qh; size > 0 && qh;
+	     qh = qh->qh_next.qh)
+		qh_lines(fotg210, qh, &next, &size);
+	if (fotg210->async_unlink && size > 0) {
+		temp = scnprintf(next, size, "\nunlink =\n");
+		size -= temp;
+		next += temp;
+
+		for (qh = fotg210->async_unlink; size > 0 && qh;
+				qh = qh->unlink_next)
+			qh_lines(fotg210, qh, &next, &size);
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+
+	return strlen(buf->output_buf);
+}
+
+#define DBG_SCHED_LIMIT 64
+static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
+{
+	struct usb_hcd		*hcd;
+	struct fotg210_hcd		*fotg210;
+	unsigned long		flags;
+	union fotg210_shadow	p, *seen;
+	unsigned		temp, size, seen_count;
+	char			*next;
+	unsigned		i;
+	__hc32			tag;
+
+	seen = kmalloc(DBG_SCHED_LIMIT * sizeof(*seen), GFP_ATOMIC);
+	if (!seen)
+		return 0;
+	seen_count = 0;
+
+	hcd = bus_to_hcd(buf->bus);
+	fotg210 = hcd_to_fotg210(hcd);
+	next = buf->output_buf;
+	size = buf->alloc_size;
+
+	temp = scnprintf(next, size, "size = %d\n", fotg210->periodic_size);
+	size -= temp;
+	next += temp;
+
+	/* dump a snapshot of the periodic schedule.
+	 * iso changes, interrupt usually doesn't.
+	 */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	for (i = 0; i < fotg210->periodic_size; i++) {
+		p = fotg210->pshadow[i];
+		if (likely(!p.ptr))
+			continue;
+		tag = Q_NEXT_TYPE(fotg210, fotg210->periodic[i]);
+
+		temp = scnprintf(next, size, "%4d: ", i);
+		size -= temp;
+		next += temp;
+
+		do {
+			struct fotg210_qh_hw *hw;
+
+			switch (hc32_to_cpu(fotg210, tag)) {
+			case Q_TYPE_QH:
+				hw = p.qh->hw;
+				temp = scnprintf(next, size, " qh%d-%04x/%p",
+						p.qh->period,
+						hc32_to_cpup(fotg210,
+							&hw->hw_info2)
+							/* uframe masks */
+							& (QH_CMASK | QH_SMASK),
+						p.qh);
+				size -= temp;
+				next += temp;
+				/* don't repeat what follows this qh */
+				for (temp = 0; temp < seen_count; temp++) {
+					if (seen[temp].ptr != p.ptr)
+						continue;
+					if (p.qh->qh_next.ptr) {
+						temp = scnprintf(next, size,
+							" ...");
+						size -= temp;
+						next += temp;
+					}
+					break;
+				}
+				/* show more info the first time around */
+				if (temp == seen_count) {
+					u32	scratch = hc32_to_cpup(fotg210,
+							&hw->hw_info1);
+					struct fotg210_qtd	*qtd;
+					char		*type = "";
+
+					/* count tds, get ep direction */
+					temp = 0;
+					list_for_each_entry(qtd,
+							&p.qh->qtd_list,
+							qtd_list) {
+						temp++;
+						switch (0x03 & (hc32_to_cpu(
+							fotg210,
+							qtd->hw_token) >> 8)) {
+						case 0:
+							type = "out";
+							continue;
+						case 1:
+							type = "in";
+							continue;
+						}
+					}
+
+					temp = scnprintf(next, size,
+						"(%c%d ep%d%s "
+						"[%d/%d] q%d p%d)",
+						speed_char(scratch),
+						scratch & 0x007f,
+						(scratch >> 8) & 0x000f, type,
+						p.qh->usecs, p.qh->c_usecs,
+						temp,
+						0x7ff & (scratch >> 16));
+
+					if (seen_count < DBG_SCHED_LIMIT)
+						seen[seen_count++].qh = p.qh;
+				} else
+					temp = 0;
+				tag = Q_NEXT_TYPE(fotg210, hw->hw_next);
+				p = p.qh->qh_next;
+				break;
+			case Q_TYPE_FSTN:
+				temp = scnprintf(next, size,
+					" fstn-%8x/%p", p.fstn->hw_prev,
+					p.fstn);
+				tag = Q_NEXT_TYPE(fotg210, p.fstn->hw_next);
+				p = p.fstn->fstn_next;
+				break;
+			case Q_TYPE_ITD:
+				temp = scnprintf(next, size,
+					" itd/%p", p.itd);
+				tag = Q_NEXT_TYPE(fotg210, p.itd->hw_next);
+				p = p.itd->itd_next;
+				break;
+			}
+			size -= temp;
+			next += temp;
+		} while (p.ptr);
+
+		temp = scnprintf(next, size, "\n");
+		size -= temp;
+		next += temp;
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	kfree(seen);
+
+	return buf->alloc_size - size;
+}
+#undef DBG_SCHED_LIMIT
+
+static const char *rh_state_string(struct fotg210_hcd *fotg210)
+{
+	switch (fotg210->rh_state) {
+	case FOTG210_RH_HALTED:
+		return "halted";
+	case FOTG210_RH_SUSPENDED:
+		return "suspended";
+	case FOTG210_RH_RUNNING:
+		return "running";
+	case FOTG210_RH_STOPPING:
+		return "stopping";
+	}
+	return "?";
+}
+
+static ssize_t fill_registers_buffer(struct debug_buffer *buf)
+{
+	struct usb_hcd		*hcd;
+	struct fotg210_hcd	*fotg210;
+	unsigned long		flags;
+	unsigned		temp, size, i;
+	char			*next, scratch[80];
+	static const char	fmt[] = "%*s\n";
+	static const char	label[] = "";
+
+	hcd = bus_to_hcd(buf->bus);
+	fotg210 = hcd_to_fotg210(hcd);
+	next = buf->output_buf;
+	size = buf->alloc_size;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	if (!HCD_HW_ACCESSIBLE(hcd)) {
+		size = scnprintf(next, size,
+			"bus %s, device %s\n"
+			"%s\n"
+			"SUSPENDED(no register access)\n",
+			hcd->self.controller->bus->name,
+			dev_name(hcd->self.controller),
+			hcd->product_desc);
+		goto done;
+	}
+
+	/* Capability Registers */
+	i = HC_VERSION(fotg210, fotg210_readl(fotg210,
+					      &fotg210->caps->hc_capbase));
+	temp = scnprintf(next, size,
+		"bus %s, device %s\n"
+		"%s\n"
+		"EHCI %x.%02x, rh state %s\n",
+		hcd->self.controller->bus->name,
+		dev_name(hcd->self.controller),
+		hcd->product_desc,
+		i >> 8, i & 0x0ff, rh_state_string(fotg210));
+	size -= temp;
+	next += temp;
+
+	/* FIXME interpret both types of params */
+	i = fotg210_readl(fotg210, &fotg210->caps->hcs_params);
+	temp = scnprintf(next, size, "structural params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	i = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+	temp = scnprintf(next, size, "capability params 0x%08x\n", i);
+	size -= temp;
+	next += temp;
+
+	/* Operational Registers */
+	temp = dbg_status_buf(scratch, sizeof(scratch), label,
+			fotg210_readl(fotg210, &fotg210->regs->status));
+	temp = scnprintf(next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_command_buf(scratch, sizeof(scratch), label,
+			fotg210_readl(fotg210, &fotg210->regs->command));
+	temp = scnprintf(next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = dbg_intr_buf(scratch, sizeof(scratch), label,
+			fotg210_readl(fotg210, &fotg210->regs->intr_enable));
+	temp = scnprintf(next, size, fmt, temp, scratch);
+	size -= temp;
+	next += temp;
+
+	temp = scnprintf(next, size, "uframe %04x\n",
+			fotg210_read_frame_index(fotg210));
+	size -= temp;
+	next += temp;
+
+	if (fotg210->async_unlink) {
+		temp = scnprintf(next, size, "async unlink qh %p\n",
+				fotg210->async_unlink);
+		size -= temp;
+		next += temp;
+	}
+
+#ifdef FOTG210_STATS
+	temp = scnprintf(next, size,
+		"irq normal %ld err %ld iaa %ld(lost %ld)\n",
+		fotg210->stats.normal, fotg210->stats.error, fotg210->stats.iaa,
+		fotg210->stats.lost_iaa);
+	size -= temp;
+	next += temp;
+
+	temp = scnprintf(next, size, "complete %ld unlink %ld\n",
+		fotg210->stats.complete, fotg210->stats.unlink);
+	size -= temp;
+	next += temp;
+#endif
+
+done:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+
+	return buf->alloc_size - size;
+}
+
+static struct debug_buffer *alloc_buffer(struct usb_bus *bus,
+				ssize_t (*fill_func)(struct debug_buffer *))
+{
+	struct debug_buffer *buf;
+
+	buf = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);
+
+	if (buf) {
+		buf->bus = bus;
+		buf->fill_func = fill_func;
+		mutex_init(&buf->mutex);
+		buf->alloc_size = PAGE_SIZE;
+	}
+
+	return buf;
+}
+
+static int fill_buffer(struct debug_buffer *buf)
+{
+	int ret = 0;
+
+	if (!buf->output_buf)
+		buf->output_buf = vmalloc(buf->alloc_size);
+
+	if (!buf->output_buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = buf->fill_func(buf);
+
+	if (ret >= 0) {
+		buf->count = ret;
+		ret = 0;
+	}
+
+out:
+	return ret;
+}
+
+static ssize_t debug_output(struct file *file, char __user *user_buf,
+			    size_t len, loff_t *offset)
+{
+	struct debug_buffer *buf = file->private_data;
+	int ret = 0;
+
+	mutex_lock(&buf->mutex);
+	if (buf->count == 0) {
+		ret = fill_buffer(buf);
+		if (ret != 0) {
+			mutex_unlock(&buf->mutex);
+			goto out;
+		}
+	}
+	mutex_unlock(&buf->mutex);
+
+	ret = simple_read_from_buffer(user_buf, len, offset,
+				      buf->output_buf, buf->count);
+
+out:
+	return ret;
+
+}
+
+static int debug_close(struct inode *inode, struct file *file)
+{
+	struct debug_buffer *buf = file->private_data;
+
+	if (buf) {
+		vfree(buf->output_buf);
+		kfree(buf);
+	}
+
+	return 0;
+}
+static int debug_async_open(struct inode *inode, struct file *file)
+{
+	file->private_data = alloc_buffer(inode->i_private, fill_async_buffer);
+
+	return file->private_data ? 0 : -ENOMEM;
+}
+
+static int debug_periodic_open(struct inode *inode, struct file *file)
+{
+	struct debug_buffer *buf;
+	buf = alloc_buffer(inode->i_private, fill_periodic_buffer);
+	if (!buf)
+		return -ENOMEM;
+
+	buf->alloc_size = (sizeof(void *) == 4 ? 6 : 8)*PAGE_SIZE;
+	file->private_data = buf;
+	return 0;
+}
+
+static int debug_registers_open(struct inode *inode, struct file *file)
+{
+	file->private_data = alloc_buffer(inode->i_private,
+					  fill_registers_buffer);
+
+	return file->private_data ? 0 : -ENOMEM;
+}
+
+static inline void create_debug_files(struct fotg210_hcd *fotg210)
+{
+	struct usb_bus *bus = &fotg210_to_hcd(fotg210)->self;
+
+	fotg210->debug_dir = debugfs_create_dir(bus->bus_name,
+						fotg210_debug_root);
+	if (!fotg210->debug_dir)
+		return;
+
+	if (!debugfs_create_file("async", S_IRUGO, fotg210->debug_dir, bus,
+						&debug_async_fops))
+		goto file_error;
+
+	if (!debugfs_create_file("periodic", S_IRUGO, fotg210->debug_dir, bus,
+						&debug_periodic_fops))
+		goto file_error;
+
+	if (!debugfs_create_file("registers", S_IRUGO, fotg210->debug_dir, bus,
+						    &debug_registers_fops))
+		goto file_error;
+
+	return;
+
+file_error:
+	debugfs_remove_recursive(fotg210->debug_dir);
+}
+
+static inline void remove_debug_files(struct fotg210_hcd *fotg210)
+{
+	debugfs_remove_recursive(fotg210->debug_dir);
+}
+
+#endif /* STUB_DEBUG_FILES */
+/*-------------------------------------------------------------------------*/
+
+/*
+ * handshake - spin reading hc until handshake completes or fails
+ * @ptr: address of hc register to be read
+ * @mask: bits to look at in result of read
+ * @done: value of those bits when handshake succeeds
+ * @usec: timeout in microseconds
+ *
+ * Returns negative errno, or zero on success
+ *
+ * Success happens when the "mask" bits have the specified value (hardware
+ * handshake done).  There are two failure modes:  "usec" have passed (major
+ * hardware flakeout), or the register reads as all-ones (hardware removed).
+ *
+ * That last failure should_only happen in cases like physical cardbus eject
+ * before driver shutdown. But it also seems to be caused by bugs in cardbus
+ * bridge shutdown:  shutting down the bridge before the devices using it.
+ */
+static int handshake(struct fotg210_hcd *fotg210, void __iomem *ptr,
+		      u32 mask, u32 done, int usec)
+{
+	u32	result;
+
+	do {
+		result = fotg210_readl(fotg210, ptr);
+		if (result == ~(u32)0)		/* card removed */
+			return -ENODEV;
+		result &= mask;
+		if (result == done)
+			return 0;
+		udelay(1);
+		usec--;
+	} while (usec > 0);
+	return -ETIMEDOUT;
+}
+
+/*
+ * Force HC to halt state from unknown (EHCI spec section 2.3).
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static int fotg210_halt(struct fotg210_hcd *fotg210)
+{
+	u32	temp;
+
+	spin_lock_irq(&fotg210->lock);
+
+	/* disable any irqs left enabled by previous code */
+	fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
+
+	/*
+	 * This routine gets called during probe before fotg210->command
+	 * has been initialized, so we can't rely on its value.
+	 */
+	fotg210->command &= ~CMD_RUN;
+	temp = fotg210_readl(fotg210, &fotg210->regs->command);
+	temp &= ~(CMD_RUN | CMD_IAAD);
+	fotg210_writel(fotg210, temp, &fotg210->regs->command);
+
+	spin_unlock_irq(&fotg210->lock);
+	synchronize_irq(fotg210_to_hcd(fotg210)->irq);
+
+	return handshake(fotg210, &fotg210->regs->status,
+			  STS_HALT, STS_HALT, 16 * 125);
+}
+
+/*
+ * Reset a non-running (STS_HALT == 1) controller.
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static int fotg210_reset(struct fotg210_hcd *fotg210)
+{
+	int	retval;
+	u32	command = fotg210_readl(fotg210, &fotg210->regs->command);
+
+	/* If the EHCI debug controller is active, special care must be
+	 * taken before and after a host controller reset */
+	if (fotg210->debug && !dbgp_reset_prep(fotg210_to_hcd(fotg210)))
+		fotg210->debug = NULL;
+
+	command |= CMD_RESET;
+	dbg_cmd(fotg210, "reset", command);
+	fotg210_writel(fotg210, command, &fotg210->regs->command);
+	fotg210->rh_state = FOTG210_RH_HALTED;
+	fotg210->next_statechange = jiffies;
+	retval = handshake(fotg210, &fotg210->regs->command,
+			    CMD_RESET, 0, 250 * 1000);
+
+	if (retval)
+		return retval;
+
+	if (fotg210->debug)
+		dbgp_external_startup(fotg210_to_hcd(fotg210));
+
+	fotg210->port_c_suspend = fotg210->suspended_ports =
+			fotg210->resuming_ports = 0;
+	return retval;
+}
+
+/*
+ * Idle the controller (turn off the schedules).
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static void fotg210_quiesce(struct fotg210_hcd *fotg210)
+{
+	u32	temp;
+
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	/* wait for any schedule enables/disables to take effect */
+	temp = (fotg210->command << 10) & (STS_ASS | STS_PSS);
+	handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, temp,
+		  16 * 125);
+
+	/* then disable anything that's still active */
+	spin_lock_irq(&fotg210->lock);
+	fotg210->command &= ~(CMD_ASE | CMD_PSE);
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+	spin_unlock_irq(&fotg210->lock);
+
+	/* hardware can take 16 microframes to turn off ... */
+	handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, 0,
+		  16 * 125);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void end_unlink_async(struct fotg210_hcd *fotg210);
+static void unlink_empty_async(struct fotg210_hcd *fotg210);
+static void fotg210_work(struct fotg210_hcd *fotg210);
+static void start_unlink_intr(struct fotg210_hcd *fotg210,
+			      struct fotg210_qh *qh);
+static void end_unlink_intr(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
+
+/*-------------------------------------------------------------------------*/
+
+/* Set a bit in the USBCMD register */
+static void fotg210_set_command_bit(struct fotg210_hcd *fotg210, u32 bit)
+{
+	fotg210->command |= bit;
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+
+	/* unblock posted write */
+	fotg210_readl(fotg210, &fotg210->regs->command);
+}
+
+/* Clear a bit in the USBCMD register */
+static void fotg210_clear_command_bit(struct fotg210_hcd *fotg210, u32 bit)
+{
+	fotg210->command &= ~bit;
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+
+	/* unblock posted write */
+	fotg210_readl(fotg210, &fotg210->regs->command);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * EHCI timer support...  Now using hrtimers.
+ *
+ * Lots of different events are triggered from fotg210->hrtimer.  Whenever
+ * the timer routine runs, it checks each possible event; events that are
+ * currently enabled and whose expiration time has passed get handled.
+ * The set of enabled events is stored as a collection of bitflags in
+ * fotg210->enabled_hrtimer_events, and they are numbered in order of
+ * increasing delay values (ranging between 1 ms and 100 ms).
+ *
+ * Rather than implementing a sorted list or tree of all pending events,
+ * we keep track only of the lowest-numbered pending event, in
+ * fotg210->next_hrtimer_event.  Whenever fotg210->hrtimer gets restarted, its
+ * expiration time is set to the timeout value for this event.
+ *
+ * As a result, events might not get handled right away; the actual delay
+ * could be anywhere up to twice the requested delay.  This doesn't
+ * matter, because none of the events are especially time-critical.  The
+ * ones that matter most all have a delay of 1 ms, so they will be
+ * handled after 2 ms at most, which is okay.  In addition to this, we
+ * allow for an expiration range of 1 ms.
+ */
+
+/*
+ * Delay lengths for the hrtimer event types.
+ * Keep this list sorted by delay length, in the same order as
+ * the event types indexed by enum fotg210_hrtimer_event in fotg210.h.
+ */
+static unsigned event_delays_ns[] = {
+	1 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_POLL_ASS */
+	1 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_POLL_PSS */
+	1 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_POLL_DEAD */
+	1125 * NSEC_PER_USEC,	/* FOTG210_HRTIMER_UNLINK_INTR */
+	2 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_FREE_ITDS */
+	6 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_ASYNC_UNLINKS */
+	10 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_IAA_WATCHDOG */
+	10 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_DISABLE_PERIODIC */
+	15 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_DISABLE_ASYNC */
+	100 * NSEC_PER_MSEC,	/* FOTG210_HRTIMER_IO_WATCHDOG */
+};
+
+/* Enable a pending hrtimer event */
+static void fotg210_enable_event(struct fotg210_hcd *fotg210, unsigned event,
+		bool resched)
+{
+	ktime_t		*timeout = &fotg210->hr_timeouts[event];
+
+	if (resched)
+		*timeout = ktime_add(ktime_get(),
+				ktime_set(0, event_delays_ns[event]));
+	fotg210->enabled_hrtimer_events |= (1 << event);
+
+	/* Track only the lowest-numbered pending event */
+	if (event < fotg210->next_hrtimer_event) {
+		fotg210->next_hrtimer_event = event;
+		hrtimer_start_range_ns(&fotg210->hrtimer, *timeout,
+				NSEC_PER_MSEC, HRTIMER_MODE_ABS);
+	}
+}
+
+
+/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
+static void fotg210_poll_ASS(struct fotg210_hcd *fotg210)
+{
+	unsigned	actual, want;
+
+	/* Don't enable anything if the controller isn't running (e.g., died) */
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	want = (fotg210->command & CMD_ASE) ? STS_ASS : 0;
+	actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_ASS;
+
+	if (want != actual) {
+
+		/* Poll again later, but give up after about 20 ms */
+		if (fotg210->ASS_poll_count++ < 20) {
+			fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_ASS,
+					     true);
+			return;
+		}
+		fotg210_dbg(fotg210, "Waited too long for the async schedule status (%x/%x), giving up\n",
+				want, actual);
+	}
+	fotg210->ASS_poll_count = 0;
+
+	/* The status is up-to-date; restart or stop the schedule as needed */
+	if (want == 0) {	/* Stopped */
+		if (fotg210->async_count > 0)
+			fotg210_set_command_bit(fotg210, CMD_ASE);
+
+	} else {		/* Running */
+		if (fotg210->async_count == 0) {
+
+			/* Turn off the schedule after a while */
+			fotg210_enable_event(fotg210,
+					     FOTG210_HRTIMER_DISABLE_ASYNC,
+					     true);
+		}
+	}
+}
+
+/* Turn off the async schedule after a brief delay */
+static void fotg210_disable_ASE(struct fotg210_hcd *fotg210)
+{
+	fotg210_clear_command_bit(fotg210, CMD_ASE);
+}
+
+
+/* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
+static void fotg210_poll_PSS(struct fotg210_hcd *fotg210)
+{
+	unsigned	actual, want;
+
+	/* Don't do anything if the controller isn't running (e.g., died) */
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	want = (fotg210->command & CMD_PSE) ? STS_PSS : 0;
+	actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_PSS;
+
+	if (want != actual) {
+
+		/* Poll again later, but give up after about 20 ms */
+		if (fotg210->PSS_poll_count++ < 20) {
+			fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_PSS,
+					     true);
+			return;
+		}
+		fotg210_dbg(fotg210, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
+				want, actual);
+	}
+	fotg210->PSS_poll_count = 0;
+
+	/* The status is up-to-date; restart or stop the schedule as needed */
+	if (want == 0) {	/* Stopped */
+		if (fotg210->periodic_count > 0)
+			fotg210_set_command_bit(fotg210, CMD_PSE);
+
+	} else {		/* Running */
+		if (fotg210->periodic_count == 0) {
+
+			/* Turn off the schedule after a while */
+			fotg210_enable_event(fotg210,
+					     FOTG210_HRTIMER_DISABLE_PERIODIC,
+					     true);
+		}
+	}
+}
+
+/* Turn off the periodic schedule after a brief delay */
+static void fotg210_disable_PSE(struct fotg210_hcd *fotg210)
+{
+	fotg210_clear_command_bit(fotg210, CMD_PSE);
+}
+
+
+/* Poll the STS_HALT status bit; see when a dead controller stops */
+static void fotg210_handle_controller_death(struct fotg210_hcd *fotg210)
+{
+	if (!(fotg210_readl(fotg210, &fotg210->regs->status) & STS_HALT)) {
+
+		/* Give up after a few milliseconds */
+		if (fotg210->died_poll_count++ < 5) {
+			/* Try again later */
+			fotg210_enable_event(fotg210,
+					     FOTG210_HRTIMER_POLL_DEAD, true);
+			return;
+		}
+		fotg210_warn(fotg210, "Waited too long for the controller to stop, giving up\n");
+	}
+
+	/* Clean up the mess */
+	fotg210->rh_state = FOTG210_RH_HALTED;
+	fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
+	fotg210_work(fotg210);
+	end_unlink_async(fotg210);
+
+	/* Not in process context, so don't try to reset the controller */
+}
+
+
+/* Handle unlinked interrupt QHs once they are gone from the hardware */
+static void fotg210_handle_intr_unlinks(struct fotg210_hcd *fotg210)
+{
+	bool		stopped = (fotg210->rh_state < FOTG210_RH_RUNNING);
+
+	/*
+	 * Process all the QHs on the intr_unlink list that were added
+	 * before the current unlink cycle began.  The list is in
+	 * temporal order, so stop when we reach the first entry in the
+	 * current cycle.  But if the root hub isn't running then
+	 * process all the QHs on the list.
+	 */
+	fotg210->intr_unlinking = true;
+	while (fotg210->intr_unlink) {
+		struct fotg210_qh	*qh = fotg210->intr_unlink;
+
+		if (!stopped && qh->unlink_cycle == fotg210->intr_unlink_cycle)
+			break;
+		fotg210->intr_unlink = qh->unlink_next;
+		qh->unlink_next = NULL;
+		end_unlink_intr(fotg210, qh);
+	}
+
+	/* Handle remaining entries later */
+	if (fotg210->intr_unlink) {
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_UNLINK_INTR,
+				     true);
+		++fotg210->intr_unlink_cycle;
+	}
+	fotg210->intr_unlinking = false;
+}
+
+
+/* Start another free-iTDs/siTDs cycle */
+static void start_free_itds(struct fotg210_hcd *fotg210)
+{
+	if (!(fotg210->enabled_hrtimer_events &
+			BIT(FOTG210_HRTIMER_FREE_ITDS))) {
+		fotg210->last_itd_to_free = list_entry(
+				fotg210->cached_itd_list.prev,
+				struct fotg210_itd, itd_list);
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_FREE_ITDS, true);
+	}
+}
+
+/* Wait for controller to stop using old iTDs and siTDs */
+static void end_free_itds(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_itd		*itd, *n;
+
+	if (fotg210->rh_state < FOTG210_RH_RUNNING)
+		fotg210->last_itd_to_free = NULL;
+
+	list_for_each_entry_safe(itd, n, &fotg210->cached_itd_list, itd_list) {
+		list_del(&itd->itd_list);
+		dma_pool_free(fotg210->itd_pool, itd, itd->itd_dma);
+		if (itd == fotg210->last_itd_to_free)
+			break;
+	}
+
+	if (!list_empty(&fotg210->cached_itd_list))
+		start_free_itds(fotg210);
+}
+
+
+/* Handle lost (or very late) IAA interrupts */
+static void fotg210_iaa_watchdog(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->rh_state != FOTG210_RH_RUNNING)
+		return;
+
+	/*
+	 * Lost IAA irqs wedge things badly; seen first with a vt8235.
+	 * So we need this watchdog, but must protect it against both
+	 * (a) SMP races against real IAA firing and retriggering, and
+	 * (b) clean HC shutdown, when IAA watchdog was pending.
+	 */
+	if (fotg210->async_iaa) {
+		u32 cmd, status;
+
+		/* If we get here, IAA is *REALLY* late.  It's barely
+		 * conceivable that the system is so busy that CMD_IAAD
+		 * is still legitimately set, so let's be sure it's
+		 * clear before we read STS_IAA.  (The HC should clear
+		 * CMD_IAAD when it sets STS_IAA.)
+		 */
+		cmd = fotg210_readl(fotg210, &fotg210->regs->command);
+
+		/*
+		 * If IAA is set here it either legitimately triggered
+		 * after the watchdog timer expired (_way_ late, so we'll
+		 * still count it as lost) ... or a silicon erratum:
+		 * - VIA seems to set IAA without triggering the IRQ;
+		 * - IAAD potentially cleared without setting IAA.
+		 */
+		status = fotg210_readl(fotg210, &fotg210->regs->status);
+		if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
+			COUNT(fotg210->stats.lost_iaa);
+			fotg210_writel(fotg210, STS_IAA,
+				       &fotg210->regs->status);
+		}
+
+		fotg210_vdbg(fotg210, "IAA watchdog: status %x cmd %x\n",
+				status, cmd);
+		end_unlink_async(fotg210);
+	}
+}
+
+
+/* Enable the I/O watchdog, if appropriate */
+static void turn_on_io_watchdog(struct fotg210_hcd *fotg210)
+{
+	/* Not needed if the controller isn't running or it's already enabled */
+	if (fotg210->rh_state != FOTG210_RH_RUNNING ||
+			(fotg210->enabled_hrtimer_events &
+				BIT(FOTG210_HRTIMER_IO_WATCHDOG)))
+		return;
+
+	/*
+	 * Isochronous transfers always need the watchdog.
+	 * For other sorts we use it only if the flag is set.
+	 */
+	if (fotg210->isoc_count > 0 || (fotg210->need_io_watchdog &&
+			fotg210->async_count + fotg210->intr_count > 0))
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_IO_WATCHDOG,
+				     true);
+}
+
+
+/*
+ * Handler functions for the hrtimer event types.
+ * Keep this array in the same order as the event types indexed by
+ * enum fotg210_hrtimer_event in fotg210.h.
+ */
+static void (*event_handlers[])(struct fotg210_hcd *) = {
+	fotg210_poll_ASS,			/* FOTG210_HRTIMER_POLL_ASS */
+	fotg210_poll_PSS,			/* FOTG210_HRTIMER_POLL_PSS */
+	fotg210_handle_controller_death,	/* FOTG210_HRTIMER_POLL_DEAD */
+	fotg210_handle_intr_unlinks,	/* FOTG210_HRTIMER_UNLINK_INTR */
+	end_free_itds,			/* FOTG210_HRTIMER_FREE_ITDS */
+	unlink_empty_async,		/* FOTG210_HRTIMER_ASYNC_UNLINKS */
+	fotg210_iaa_watchdog,		/* FOTG210_HRTIMER_IAA_WATCHDOG */
+	fotg210_disable_PSE,		/* FOTG210_HRTIMER_DISABLE_PERIODIC */
+	fotg210_disable_ASE,		/* FOTG210_HRTIMER_DISABLE_ASYNC */
+	fotg210_work,			/* FOTG210_HRTIMER_IO_WATCHDOG */
+};
+
+static enum hrtimer_restart fotg210_hrtimer_func(struct hrtimer *t)
+{
+	struct fotg210_hcd *fotg210 =
+			container_of(t, struct fotg210_hcd, hrtimer);
+	ktime_t		now;
+	unsigned long	events;
+	unsigned long	flags;
+	unsigned	e;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	events = fotg210->enabled_hrtimer_events;
+	fotg210->enabled_hrtimer_events = 0;
+	fotg210->next_hrtimer_event = FOTG210_HRTIMER_NO_EVENT;
+
+	/*
+	 * Check each pending event.  If its time has expired, handle
+	 * the event; otherwise re-enable it.
+	 */
+	now = ktime_get();
+	for_each_set_bit(e, &events, FOTG210_HRTIMER_NUM_EVENTS) {
+		if (now.tv64 >= fotg210->hr_timeouts[e].tv64)
+			event_handlers[e](fotg210);
+		else
+			fotg210_enable_event(fotg210, e, false);
+	}
+
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return HRTIMER_NORESTART;
+}
+
+/*-------------------------------------------------------------------------*/
+
+#define fotg210_bus_suspend	NULL
+#define fotg210_bus_resume	NULL
+
+/*-------------------------------------------------------------------------*/
+
+static int check_reset_complete(
+	struct fotg210_hcd	*fotg210,
+	int		index,
+	u32 __iomem	*status_reg,
+	int		port_status
+) {
+	if (!(port_status & PORT_CONNECT))
+		return port_status;
+
+	/* if reset finished and it's still not enabled -- handoff */
+	if (!(port_status & PORT_PE)) {
+		/* with integrated TT, there's nobody to hand it to! */
+		fotg210_dbg(fotg210,
+			"Failed to enable port %d on root hub TT\n",
+			index+1);
+		return port_status;
+	} else {
+		fotg210_dbg(fotg210, "port %d reset complete, port enabled\n",
+			index + 1);
+	}
+
+	return port_status;
+}
+
+/*-------------------------------------------------------------------------*/
+
+
+/* build "status change" packet (one or two bytes) from HC registers */
+
+static int
+fotg210_hub_status_data(struct usb_hcd *hcd, char *buf)
+{
+	struct fotg210_hcd	*fotg210 = hcd_to_fotg210(hcd);
+	u32		temp, status;
+	u32		mask;
+	int		retval = 1;
+	unsigned long	flags;
+
+	/* init status to no-changes */
+	buf[0] = 0;
+
+	/* Inform the core about resumes-in-progress by returning
+	 * a non-zero value even if there are no status changes.
+	 */
+	status = fotg210->resuming_ports;
+
+	mask = PORT_CSC | PORT_PEC;
+	/* PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND */
+
+	/* no hub change reports (bit 0) for now (power, ...) */
+
+	/* port N changes (bit N)? */
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	temp = fotg210_readl(fotg210, &fotg210->regs->port_status);
+
+	/*
+	 * Return status information even for ports with OWNER set.
+	 * Otherwise khubd wouldn't see the disconnect event when a
+	 * high-speed device is switched over to the companion
+	 * controller by the user.
+	 */
+
+	if ((temp & mask) != 0 || test_bit(0, &fotg210->port_c_suspend)
+			|| (fotg210->reset_done[0] && time_after_eq(
+				jiffies, fotg210->reset_done[0]))) {
+		buf[0] |= 1 << 1;
+		status = STS_PCD;
+	}
+	/* FIXME autosuspend idle root hubs */
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return status ? retval : 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void
+fotg210_hub_descriptor(
+	struct fotg210_hcd		*fotg210,
+	struct usb_hub_descriptor	*desc
+) {
+	int		ports = HCS_N_PORTS(fotg210->hcs_params);
+	u16		temp;
+
+	desc->bDescriptorType = 0x29;
+	desc->bPwrOn2PwrGood = 10;	/* fotg210 1.0, 2.3.9 says 20ms max */
+	desc->bHubContrCurrent = 0;
+
+	desc->bNbrPorts = ports;
+	temp = 1 + (ports / 8);
+	desc->bDescLength = 7 + 2 * temp;
+
+	/* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
+	memset(&desc->u.hs.DeviceRemovable[0], 0, temp);
+	memset(&desc->u.hs.DeviceRemovable[temp], 0xff, temp);
+
+	temp = 0x0008;		/* per-port overcurrent reporting */
+	temp |= 0x0002;		/* no power switching */
+	desc->wHubCharacteristics = cpu_to_le16(temp);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int fotg210_hub_control(
+	struct usb_hcd	*hcd,
+	u16		typeReq,
+	u16		wValue,
+	u16		wIndex,
+	char		*buf,
+	u16		wLength
+) {
+	struct fotg210_hcd	*fotg210 = hcd_to_fotg210(hcd);
+	int		ports = HCS_N_PORTS(fotg210->hcs_params);
+	u32 __iomem	*status_reg = &fotg210->regs->port_status;
+	u32		temp, temp1, status;
+	unsigned long	flags;
+	int		retval = 0;
+	unsigned	selector;
+
+	/*
+	 * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
+	 * HCS_INDICATOR may say we can change LEDs to off/amber/green.
+	 * (track current state ourselves) ... blink for diagnostics,
+	 * power, "this is the one", etc.  EHCI spec supports this.
+	 */
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	switch (typeReq) {
+	case ClearHubFeature:
+		switch (wValue) {
+		case C_HUB_LOCAL_POWER:
+		case C_HUB_OVER_CURRENT:
+			/* no hub-wide feature/status flags */
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case ClearPortFeature:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		temp = fotg210_readl(fotg210, status_reg);
+		temp &= ~PORT_RWC_BITS;
+
+		/*
+		 * Even if OWNER is set, so the port is owned by the
+		 * companion controller, khubd needs to be able to clear
+		 * the port-change status bits (especially
+		 * USB_PORT_STAT_C_CONNECTION).
+		 */
+
+		switch (wValue) {
+		case USB_PORT_FEAT_ENABLE:
+			fotg210_writel(fotg210, temp & ~PORT_PE, status_reg);
+			break;
+		case USB_PORT_FEAT_C_ENABLE:
+			fotg210_writel(fotg210, temp | PORT_PEC, status_reg);
+			break;
+		case USB_PORT_FEAT_SUSPEND:
+			if (temp & PORT_RESET)
+				goto error;
+			if (!(temp & PORT_SUSPEND))
+				break;
+			if ((temp & PORT_PE) == 0)
+				goto error;
+
+			/* resume signaling for 20 msec */
+			fotg210_writel(fotg210, temp | PORT_RESUME, status_reg);
+			fotg210->reset_done[wIndex] = jiffies
+					+ msecs_to_jiffies(20);
+			break;
+		case USB_PORT_FEAT_C_SUSPEND:
+			clear_bit(wIndex, &fotg210->port_c_suspend);
+			break;
+		case USB_PORT_FEAT_C_CONNECTION:
+			fotg210_writel(fotg210, temp | PORT_CSC, status_reg);
+			break;
+		case USB_PORT_FEAT_C_OVER_CURRENT:
+			fotg210_writel(fotg210, temp | OTGISR_OVC,
+				       &fotg210->regs->otgisr);
+			break;
+		case USB_PORT_FEAT_C_RESET:
+			/* GetPortStatus clears reset */
+			break;
+		default:
+			goto error;
+		}
+		fotg210_readl(fotg210, &fotg210->regs->command);
+		break;
+	case GetHubDescriptor:
+		fotg210_hub_descriptor(fotg210, (struct usb_hub_descriptor *)
+			buf);
+		break;
+	case GetHubStatus:
+		/* no hub-wide feature/status flags */
+		memset(buf, 0, 4);
+		/*cpu_to_le32s ((u32 *) buf); */
+		break;
+	case GetPortStatus:
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		status = 0;
+		temp = fotg210_readl(fotg210, status_reg);
+
+		/* wPortChange bits */
+		if (temp & PORT_CSC)
+			status |= USB_PORT_STAT_C_CONNECTION << 16;
+		if (temp & PORT_PEC)
+			status |= USB_PORT_STAT_C_ENABLE << 16;
+
+		temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
+		if (temp1 & OTGISR_OVC)
+			status |= USB_PORT_STAT_C_OVERCURRENT << 16;
+
+		/* whoever resumes must GetPortStatus to complete it!! */
+		if (temp & PORT_RESUME) {
+
+			/* Remote Wakeup received? */
+			if (!fotg210->reset_done[wIndex]) {
+				/* resume signaling for 20 msec */
+				fotg210->reset_done[wIndex] = jiffies
+						+ msecs_to_jiffies(20);
+				/* check the port again */
+				mod_timer(&fotg210_to_hcd(fotg210)->rh_timer,
+						fotg210->reset_done[wIndex]);
+			}
+
+			/* resume completed? */
+			else if (time_after_eq(jiffies,
+					fotg210->reset_done[wIndex])) {
+				clear_bit(wIndex, &fotg210->suspended_ports);
+				set_bit(wIndex, &fotg210->port_c_suspend);
+				fotg210->reset_done[wIndex] = 0;
+
+				/* stop resume signaling */
+				temp = fotg210_readl(fotg210, status_reg);
+				fotg210_writel(fotg210,
+					temp & ~(PORT_RWC_BITS | PORT_RESUME),
+					status_reg);
+				clear_bit(wIndex, &fotg210->resuming_ports);
+				retval = handshake(fotg210, status_reg,
+					   PORT_RESUME, 0, 2000 /* 2msec */);
+				if (retval != 0) {
+					fotg210_err(fotg210,
+						"port %d resume error %d\n",
+						wIndex + 1, retval);
+					goto error;
+				}
+				temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
+			}
+		}
+
+		/* whoever resets must GetPortStatus to complete it!! */
+		if ((temp & PORT_RESET)
+				&& time_after_eq(jiffies,
+					fotg210->reset_done[wIndex])) {
+			status |= USB_PORT_STAT_C_RESET << 16;
+			fotg210->reset_done[wIndex] = 0;
+			clear_bit(wIndex, &fotg210->resuming_ports);
+
+			/* force reset to complete */
+			fotg210_writel(fotg210,
+				       temp & ~(PORT_RWC_BITS | PORT_RESET),
+				       status_reg);
+			/* REVISIT:  some hardware needs 550+ usec to clear
+			 * this bit; seems too long to spin routinely...
+			 */
+			retval = handshake(fotg210, status_reg,
+					PORT_RESET, 0, 1000);
+			if (retval != 0) {
+				fotg210_err(fotg210, "port %d reset error %d\n",
+					wIndex + 1, retval);
+				goto error;
+			}
+
+			/* see what we found out */
+			temp = check_reset_complete(fotg210, wIndex, status_reg,
+					fotg210_readl(fotg210, status_reg));
+		}
+
+		if (!(temp & (PORT_RESUME|PORT_RESET))) {
+			fotg210->reset_done[wIndex] = 0;
+			clear_bit(wIndex, &fotg210->resuming_ports);
+		}
+
+		/* transfer dedicated ports to the companion hc */
+		if ((temp & PORT_CONNECT) &&
+				test_bit(wIndex, &fotg210->companion_ports)) {
+			temp &= ~PORT_RWC_BITS;
+			fotg210_writel(fotg210, temp, status_reg);
+			fotg210_dbg(fotg210, "port %d --> companion\n",
+				    wIndex + 1);
+			temp = fotg210_readl(fotg210, status_reg);
+		}
+
+		/*
+		 * Even if OWNER is set, there's no harm letting khubd
+		 * see the wPortStatus values (they should all be 0 except
+		 * for PORT_POWER anyway).
+		 */
+
+		if (temp & PORT_CONNECT) {
+			status |= USB_PORT_STAT_CONNECTION;
+			status |= fotg210_port_speed(fotg210, temp);
+		}
+		if (temp & PORT_PE)
+			status |= USB_PORT_STAT_ENABLE;
+
+		/* maybe the port was unsuspended without our knowledge */
+		if (temp & (PORT_SUSPEND|PORT_RESUME)) {
+			status |= USB_PORT_STAT_SUSPEND;
+		} else if (test_bit(wIndex, &fotg210->suspended_ports)) {
+			clear_bit(wIndex, &fotg210->suspended_ports);
+			clear_bit(wIndex, &fotg210->resuming_ports);
+			fotg210->reset_done[wIndex] = 0;
+			if (temp & PORT_PE)
+				set_bit(wIndex, &fotg210->port_c_suspend);
+		}
+
+		temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
+		if (temp1 & OTGISR_OVC)
+			status |= USB_PORT_STAT_OVERCURRENT;
+		if (temp & PORT_RESET)
+			status |= USB_PORT_STAT_RESET;
+		if (test_bit(wIndex, &fotg210->port_c_suspend))
+			status |= USB_PORT_STAT_C_SUSPEND << 16;
+
+#ifndef	VERBOSE_DEBUG
+	if (status & ~0xffff)	/* only if wPortChange is interesting */
+#endif
+		dbg_port(fotg210, "GetStatus", wIndex + 1, temp);
+		put_unaligned_le32(status, buf);
+		break;
+	case SetHubFeature:
+		switch (wValue) {
+		case C_HUB_LOCAL_POWER:
+		case C_HUB_OVER_CURRENT:
+			/* no hub-wide feature/status flags */
+			break;
+		default:
+			goto error;
+		}
+		break;
+	case SetPortFeature:
+		selector = wIndex >> 8;
+		wIndex &= 0xff;
+
+		if (!wIndex || wIndex > ports)
+			goto error;
+		wIndex--;
+		temp = fotg210_readl(fotg210, status_reg);
+		temp &= ~PORT_RWC_BITS;
+		switch (wValue) {
+		case USB_PORT_FEAT_SUSPEND:
+			if ((temp & PORT_PE) == 0
+					|| (temp & PORT_RESET) != 0)
+				goto error;
+
+			/* After above check the port must be connected.
+			 * Set appropriate bit thus could put phy into low power
+			 * mode if we have hostpc feature
+			 */
+			fotg210_writel(fotg210, temp | PORT_SUSPEND,
+				       status_reg);
+			set_bit(wIndex, &fotg210->suspended_ports);
+			break;
+		case USB_PORT_FEAT_RESET:
+			if (temp & PORT_RESUME)
+				goto error;
+			/* line status bits may report this as low speed,
+			 * which can be fine if this root hub has a
+			 * transaction translator built in.
+			 */
+			fotg210_vdbg(fotg210, "port %d reset\n", wIndex + 1);
+			temp |= PORT_RESET;
+			temp &= ~PORT_PE;
+
+			/*
+			 * caller must wait, then call GetPortStatus
+			 * usb 2.0 spec says 50 ms resets on root
+			 */
+			fotg210->reset_done[wIndex] = jiffies
+					+ msecs_to_jiffies(50);
+			fotg210_writel(fotg210, temp, status_reg);
+			break;
+
+		/* For downstream facing ports (these):  one hub port is put
+		 * into test mode according to USB2 11.24.2.13, then the hub
+		 * must be reset (which for root hub now means rmmod+modprobe,
+		 * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
+		 * about the EHCI-specific stuff.
+		 */
+		case USB_PORT_FEAT_TEST:
+			if (!selector || selector > 5)
+				goto error;
+			spin_unlock_irqrestore(&fotg210->lock, flags);
+			fotg210_quiesce(fotg210);
+			spin_lock_irqsave(&fotg210->lock, flags);
+
+			/* Put all enabled ports into suspend */
+			temp = fotg210_readl(fotg210, status_reg) &
+				~PORT_RWC_BITS;
+			if (temp & PORT_PE)
+				fotg210_writel(fotg210, temp | PORT_SUSPEND,
+						status_reg);
+
+			spin_unlock_irqrestore(&fotg210->lock, flags);
+			fotg210_halt(fotg210);
+			spin_lock_irqsave(&fotg210->lock, flags);
+
+			temp = fotg210_readl(fotg210, status_reg);
+			temp |= selector << 16;
+			fotg210_writel(fotg210, temp, status_reg);
+			break;
+
+		default:
+			goto error;
+		}
+		fotg210_readl(fotg210, &fotg210->regs->command);
+		break;
+
+	default:
+error:
+		/* "stall" on error */
+		retval = -EPIPE;
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return retval;
+}
+
+static void __maybe_unused fotg210_relinquish_port(struct usb_hcd *hcd,
+		int portnum)
+{
+	return;
+}
+
+static int __maybe_unused fotg210_port_handed_over(struct usb_hcd *hcd,
+		int portnum)
+{
+	return 0;
+}
+/*-------------------------------------------------------------------------*/
+/*
+ * There's basically three types of memory:
+ *	- data used only by the HCD ... kmalloc is fine
+ *	- async and periodic schedules, shared by HC and HCD ... these
+ *	  need to use dma_pool or dma_alloc_coherent
+ *	- driver buffers, read/written by HC ... single shot DMA mapped
+ *
+ * There's also "register" data (e.g. PCI or SOC), which is memory mapped.
+ * No memory seen by this driver is pageable.
+ */
+
+/*-------------------------------------------------------------------------*/
+
+/* Allocate the key transfer structures from the previously allocated pool */
+
+static inline void fotg210_qtd_init(struct fotg210_hcd *fotg210,
+				    struct fotg210_qtd *qtd, dma_addr_t dma)
+{
+	memset(qtd, 0, sizeof(*qtd));
+	qtd->qtd_dma = dma;
+	qtd->hw_token = cpu_to_hc32(fotg210, QTD_STS_HALT);
+	qtd->hw_next = FOTG210_LIST_END(fotg210);
+	qtd->hw_alt_next = FOTG210_LIST_END(fotg210);
+	INIT_LIST_HEAD(&qtd->qtd_list);
+}
+
+static struct fotg210_qtd *fotg210_qtd_alloc(struct fotg210_hcd *fotg210,
+					     gfp_t flags)
+{
+	struct fotg210_qtd		*qtd;
+	dma_addr_t		dma;
+
+	qtd = dma_pool_alloc(fotg210->qtd_pool, flags, &dma);
+	if (qtd != NULL)
+		fotg210_qtd_init(fotg210, qtd, dma);
+
+	return qtd;
+}
+
+static inline void fotg210_qtd_free(struct fotg210_hcd *fotg210,
+				    struct fotg210_qtd *qtd)
+{
+	dma_pool_free(fotg210->qtd_pool, qtd, qtd->qtd_dma);
+}
+
+
+static void qh_destroy(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	/* clean qtds first, and know this is not linked */
+	if (!list_empty(&qh->qtd_list) || qh->qh_next.ptr) {
+		fotg210_dbg(fotg210, "unused qh not empty!\n");
+		BUG();
+	}
+	if (qh->dummy)
+		fotg210_qtd_free(fotg210, qh->dummy);
+	dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
+	kfree(qh);
+}
+
+static struct fotg210_qh *fotg210_qh_alloc(struct fotg210_hcd *fotg210,
+					   gfp_t flags)
+{
+	struct fotg210_qh		*qh;
+	dma_addr_t		dma;
+
+	qh = kzalloc(sizeof(*qh), GFP_ATOMIC);
+	if (!qh)
+		goto done;
+	qh->hw = (struct fotg210_qh_hw *)
+		dma_pool_alloc(fotg210->qh_pool, flags, &dma);
+	if (!qh->hw)
+		goto fail;
+	memset(qh->hw, 0, sizeof(*qh->hw));
+	qh->qh_dma = dma;
+	INIT_LIST_HEAD(&qh->qtd_list);
+
+	/* dummy td enables safe urb queuing */
+	qh->dummy = fotg210_qtd_alloc(fotg210, flags);
+	if (qh->dummy == NULL) {
+		fotg210_dbg(fotg210, "no dummy td\n");
+		goto fail1;
+	}
+done:
+	return qh;
+fail1:
+	dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
+fail:
+	kfree(qh);
+	return NULL;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* The queue heads and transfer descriptors are managed from pools tied
+ * to each of the "per device" structures.
+ * This is the initialisation and cleanup code.
+ */
+
+static void fotg210_mem_cleanup(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->async)
+		qh_destroy(fotg210, fotg210->async);
+	fotg210->async = NULL;
+
+	if (fotg210->dummy)
+		qh_destroy(fotg210, fotg210->dummy);
+	fotg210->dummy = NULL;
+
+	/* DMA consistent memory and pools */
+	if (fotg210->qtd_pool)
+		dma_pool_destroy(fotg210->qtd_pool);
+	fotg210->qtd_pool = NULL;
+
+	if (fotg210->qh_pool) {
+		dma_pool_destroy(fotg210->qh_pool);
+		fotg210->qh_pool = NULL;
+	}
+
+	if (fotg210->itd_pool)
+		dma_pool_destroy(fotg210->itd_pool);
+	fotg210->itd_pool = NULL;
+
+	if (fotg210->periodic)
+		dma_free_coherent(fotg210_to_hcd(fotg210)->self.controller,
+			fotg210->periodic_size * sizeof(u32),
+			fotg210->periodic, fotg210->periodic_dma);
+	fotg210->periodic = NULL;
+
+	/* shadow periodic table */
+	kfree(fotg210->pshadow);
+	fotg210->pshadow = NULL;
+}
+
+/* remember to add cleanup code (above) if you add anything here */
+static int fotg210_mem_init(struct fotg210_hcd *fotg210, gfp_t flags)
+{
+	int i;
+
+	/* QTDs for control/bulk/intr transfers */
+	fotg210->qtd_pool = dma_pool_create("fotg210_qtd",
+			fotg210_to_hcd(fotg210)->self.controller,
+			sizeof(struct fotg210_qtd),
+			32 /* byte alignment (for hw parts) */,
+			4096 /* can't cross 4K */);
+	if (!fotg210->qtd_pool)
+		goto fail;
+
+	/* QHs for control/bulk/intr transfers */
+	fotg210->qh_pool = dma_pool_create("fotg210_qh",
+			fotg210_to_hcd(fotg210)->self.controller,
+			sizeof(struct fotg210_qh_hw),
+			32 /* byte alignment (for hw parts) */,
+			4096 /* can't cross 4K */);
+	if (!fotg210->qh_pool)
+		goto fail;
+
+	fotg210->async = fotg210_qh_alloc(fotg210, flags);
+	if (!fotg210->async)
+		goto fail;
+
+	/* ITD for high speed ISO transfers */
+	fotg210->itd_pool = dma_pool_create("fotg210_itd",
+			fotg210_to_hcd(fotg210)->self.controller,
+			sizeof(struct fotg210_itd),
+			64 /* byte alignment (for hw parts) */,
+			4096 /* can't cross 4K */);
+	if (!fotg210->itd_pool)
+		goto fail;
+
+	/* Hardware periodic table */
+	fotg210->periodic = (__le32 *)
+		dma_alloc_coherent(fotg210_to_hcd(fotg210)->self.controller,
+			fotg210->periodic_size * sizeof(__le32),
+			&fotg210->periodic_dma, 0);
+	if (fotg210->periodic == NULL)
+		goto fail;
+
+	for (i = 0; i < fotg210->periodic_size; i++)
+		fotg210->periodic[i] = FOTG210_LIST_END(fotg210);
+
+	/* software shadow of hardware table */
+	fotg210->pshadow = kcalloc(fotg210->periodic_size, sizeof(void *),
+				   flags);
+	if (fotg210->pshadow != NULL)
+		return 0;
+
+fail:
+	fotg210_dbg(fotg210, "couldn't init memory\n");
+	fotg210_mem_cleanup(fotg210);
+	return -ENOMEM;
+}
+/*-------------------------------------------------------------------------*/
+/*
+ * EHCI hardware queue manipulation ... the core.  QH/QTD manipulation.
+ *
+ * Control, bulk, and interrupt traffic all use "qh" lists.  They list "qtd"
+ * entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
+ * buffers needed for the larger number).  We use one QH per endpoint, queue
+ * multiple urbs (all three types) per endpoint.  URBs may need several qtds.
+ *
+ * ISO traffic uses "ISO TD" (itd) records, and (along with
+ * interrupts) needs careful scheduling.  Performance improvements can be
+ * an ongoing challenge.  That's in "ehci-sched.c".
+ *
+ * USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
+ * or otherwise through transaction translators (TTs) in USB 2.0 hubs using
+ * (b) special fields in qh entries or (c) split iso entries.  TTs will
+ * buffer low/full speed data so the host collects it at high speed.
+ */
+
+/*-------------------------------------------------------------------------*/
+
+/* fill a qtd, returning how much of the buffer we were able to queue up */
+
+static int
+qtd_fill(struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd, dma_addr_t buf,
+		  size_t len, int token, int maxpacket)
+{
+	int	i, count;
+	u64	addr = buf;
+
+	/* one buffer entry per 4K ... first might be short or unaligned */
+	qtd->hw_buf[0] = cpu_to_hc32(fotg210, (u32)addr);
+	qtd->hw_buf_hi[0] = cpu_to_hc32(fotg210, (u32)(addr >> 32));
+	count = 0x1000 - (buf & 0x0fff);	/* rest of that page */
+	if (likely(len < count))		/* ... iff needed */
+		count = len;
+	else {
+		buf +=  0x1000;
+		buf &= ~0x0fff;
+
+		/* per-qtd limit: from 16K to 20K (best alignment) */
+		for (i = 1; count < len && i < 5; i++) {
+			addr = buf;
+			qtd->hw_buf[i] = cpu_to_hc32(fotg210, (u32)addr);
+			qtd->hw_buf_hi[i] = cpu_to_hc32(fotg210,
+					(u32)(addr >> 32));
+			buf += 0x1000;
+			if ((count + 0x1000) < len)
+				count += 0x1000;
+			else
+				count = len;
+		}
+
+		/* short packets may only terminate transfers */
+		if (count != len)
+			count -= (count % maxpacket);
+	}
+	qtd->hw_token = cpu_to_hc32(fotg210, (count << 16) | token);
+	qtd->length = count;
+
+	return count;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline void
+qh_update(struct fotg210_hcd *fotg210, struct fotg210_qh *qh,
+	  struct fotg210_qtd *qtd)
+{
+	struct fotg210_qh_hw *hw = qh->hw;
+
+	/* writes to an active overlay are unsafe */
+	BUG_ON(qh->qh_state != QH_STATE_IDLE);
+
+	hw->hw_qtd_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+	hw->hw_alt_next = FOTG210_LIST_END(fotg210);
+
+	/* Except for control endpoints, we make hardware maintain data
+	 * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
+	 * and set the pseudo-toggle in udev. Only usb_clear_halt() will
+	 * ever clear it.
+	 */
+	if (!(hw->hw_info1 & cpu_to_hc32(fotg210, QH_TOGGLE_CTL))) {
+		unsigned	is_out, epnum;
+
+		is_out = qh->is_out;
+		epnum = (hc32_to_cpup(fotg210, &hw->hw_info1) >> 8) & 0x0f;
+		if (unlikely(!usb_gettoggle(qh->dev, epnum, is_out))) {
+			hw->hw_token &= ~cpu_to_hc32(fotg210, QTD_TOGGLE);
+			usb_settoggle(qh->dev, epnum, is_out, 1);
+		}
+	}
+
+	hw->hw_token &= cpu_to_hc32(fotg210, QTD_TOGGLE | QTD_STS_PING);
+}
+
+/* if it weren't for a common silicon quirk (writing the dummy into the qh
+ * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
+ * recovery (including urb dequeue) would need software changes to a QH...
+ */
+static void
+qh_refresh(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	struct fotg210_qtd *qtd;
+
+	if (list_empty(&qh->qtd_list))
+		qtd = qh->dummy;
+	else {
+		qtd = list_entry(qh->qtd_list.next,
+				struct fotg210_qtd, qtd_list);
+		/*
+		 * first qtd may already be partially processed.
+		 * If we come here during unlink, the QH overlay region
+		 * might have reference to the just unlinked qtd. The
+		 * qtd is updated in qh_completions(). Update the QH
+		 * overlay here.
+		 */
+		if (cpu_to_hc32(fotg210, qtd->qtd_dma) == qh->hw->hw_current) {
+			qh->hw->hw_qtd_next = qtd->hw_next;
+			qtd = NULL;
+		}
+	}
+
+	if (qtd)
+		qh_update(fotg210, qh, qtd);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void qh_link_async(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
+
+static void fotg210_clear_tt_buffer_complete(struct usb_hcd *hcd,
+		struct usb_host_endpoint *ep)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	struct fotg210_qh		*qh = ep->hcpriv;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	qh->clearing_tt = 0;
+	if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
+			&& fotg210->rh_state == FOTG210_RH_RUNNING)
+		qh_link_async(fotg210, qh);
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+}
+
+static void fotg210_clear_tt_buffer(struct fotg210_hcd *fotg210,
+				    struct fotg210_qh *qh,
+				    struct urb *urb, u32 token)
+{
+
+	/* If an async split transaction gets an error or is unlinked,
+	 * the TT buffer may be left in an indeterminate state.  We
+	 * have to clear the TT buffer.
+	 *
+	 * Note: this routine is never called for Isochronous transfers.
+	 */
+	if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
+#ifdef DEBUG
+		struct usb_device *tt = urb->dev->tt->hub;
+		dev_dbg(&tt->dev,
+			"clear tt buffer port %d, a%d ep%d t%08x\n",
+			urb->dev->ttport, urb->dev->devnum,
+			usb_pipeendpoint(urb->pipe), token);
+#endif /* DEBUG */
+		if (urb->dev->tt->hub !=
+		    fotg210_to_hcd(fotg210)->self.root_hub) {
+			if (usb_hub_clear_tt_buffer(urb) == 0)
+				qh->clearing_tt = 1;
+		}
+	}
+}
+
+static int qtd_copy_status(
+	struct fotg210_hcd *fotg210,
+	struct urb *urb,
+	size_t length,
+	u32 token
+)
+{
+	int	status = -EINPROGRESS;
+
+	/* count IN/OUT bytes, not SETUP (even short packets) */
+	if (likely(QTD_PID(token) != 2))
+		urb->actual_length += length - QTD_LENGTH(token);
+
+	/* don't modify error codes */
+	if (unlikely(urb->unlinked))
+		return status;
+
+	/* force cleanup after short read; not always an error */
+	if (unlikely(IS_SHORT_READ(token)))
+		status = -EREMOTEIO;
+
+	/* serious "can't proceed" faults reported by the hardware */
+	if (token & QTD_STS_HALT) {
+		if (token & QTD_STS_BABBLE) {
+			/* FIXME "must" disable babbling device's port too */
+			status = -EOVERFLOW;
+		/* CERR nonzero + halt --> stall */
+		} else if (QTD_CERR(token)) {
+			status = -EPIPE;
+
+		/* In theory, more than one of the following bits can be set
+		 * since they are sticky and the transaction is retried.
+		 * Which to test first is rather arbitrary.
+		 */
+		} else if (token & QTD_STS_MMF) {
+			/* fs/ls interrupt xfer missed the complete-split */
+			status = -EPROTO;
+		} else if (token & QTD_STS_DBE) {
+			status = (QTD_PID(token) == 1) /* IN ? */
+				? -ENOSR  /* hc couldn't read data */
+				: -ECOMM; /* hc couldn't write data */
+		} else if (token & QTD_STS_XACT) {
+			/* timeout, bad CRC, wrong PID, etc */
+			fotg210_dbg(fotg210, "devpath %s ep%d%s 3strikes\n",
+				urb->dev->devpath,
+				usb_pipeendpoint(urb->pipe),
+				usb_pipein(urb->pipe) ? "in" : "out");
+			status = -EPROTO;
+		} else {	/* unknown */
+			status = -EPROTO;
+		}
+
+		fotg210_vdbg(fotg210,
+			"dev%d ep%d%s qtd token %08x --> status %d\n",
+			usb_pipedevice(urb->pipe),
+			usb_pipeendpoint(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out",
+			token, status);
+	}
+
+	return status;
+}
+
+static void
+fotg210_urb_done(struct fotg210_hcd *fotg210, struct urb *urb, int status)
+__releases(fotg210->lock)
+__acquires(fotg210->lock)
+{
+	if (likely(urb->hcpriv != NULL)) {
+		struct fotg210_qh	*qh = (struct fotg210_qh *) urb->hcpriv;
+
+		/* S-mask in a QH means it's an interrupt urb */
+		if ((qh->hw->hw_info2 & cpu_to_hc32(fotg210, QH_SMASK)) != 0) {
+
+			/* ... update hc-wide periodic stats (for usbfs) */
+			fotg210_to_hcd(fotg210)->self.bandwidth_int_reqs--;
+		}
+	}
+
+	if (unlikely(urb->unlinked)) {
+		COUNT(fotg210->stats.unlink);
+	} else {
+		/* report non-error and short read status as zero */
+		if (status == -EINPROGRESS || status == -EREMOTEIO)
+			status = 0;
+		COUNT(fotg210->stats.complete);
+	}
+
+#ifdef FOTG210_URB_TRACE
+	fotg210_dbg(fotg210,
+		"%s %s urb %p ep%d%s status %d len %d/%d\n",
+		__func__, urb->dev->devpath, urb,
+		usb_pipeendpoint(urb->pipe),
+		usb_pipein(urb->pipe) ? "in" : "out",
+		status,
+		urb->actual_length, urb->transfer_buffer_length);
+#endif
+
+	/* complete() can reenter this HCD */
+	usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+	spin_unlock(&fotg210->lock);
+	usb_hcd_giveback_urb(fotg210_to_hcd(fotg210), urb, status);
+	spin_lock(&fotg210->lock);
+}
+
+static int qh_schedule(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
+
+/*
+ * Process and free completed qtds for a qh, returning URBs to drivers.
+ * Chases up to qh->hw_current.  Returns number of completions called,
+ * indicating how much "real" work we did.
+ */
+static unsigned
+qh_completions(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	struct fotg210_qtd		*last, *end = qh->dummy;
+	struct list_head	*entry, *tmp;
+	int			last_status;
+	int			stopped;
+	unsigned		count = 0;
+	u8			state;
+	struct fotg210_qh_hw	*hw = qh->hw;
+
+	if (unlikely(list_empty(&qh->qtd_list)))
+		return count;
+
+	/* completions (or tasks on other cpus) must never clobber HALT
+	 * till we've gone through and cleaned everything up, even when
+	 * they add urbs to this qh's queue or mark them for unlinking.
+	 *
+	 * NOTE:  unlinking expects to be done in queue order.
+	 *
+	 * It's a bug for qh->qh_state to be anything other than
+	 * QH_STATE_IDLE, unless our caller is scan_async() or
+	 * scan_intr().
+	 */
+	state = qh->qh_state;
+	qh->qh_state = QH_STATE_COMPLETING;
+	stopped = (state == QH_STATE_IDLE);
+
+ rescan:
+	last = NULL;
+	last_status = -EINPROGRESS;
+	qh->needs_rescan = 0;
+
+	/* remove de-activated QTDs from front of queue.
+	 * after faults (including short reads), cleanup this urb
+	 * then let the queue advance.
+	 * if queue is stopped, handles unlinks.
+	 */
+	list_for_each_safe(entry, tmp, &qh->qtd_list) {
+		struct fotg210_qtd	*qtd;
+		struct urb	*urb;
+		u32		token = 0;
+
+		qtd = list_entry(entry, struct fotg210_qtd, qtd_list);
+		urb = qtd->urb;
+
+		/* clean up any state from previous QTD ...*/
+		if (last) {
+			if (likely(last->urb != urb)) {
+				fotg210_urb_done(fotg210, last->urb,
+						 last_status);
+				count++;
+				last_status = -EINPROGRESS;
+			}
+			fotg210_qtd_free(fotg210, last);
+			last = NULL;
+		}
+
+		/* ignore urbs submitted during completions we reported */
+		if (qtd == end)
+			break;
+
+		/* hardware copies qtd out of qh overlay */
+		rmb();
+		token = hc32_to_cpu(fotg210, qtd->hw_token);
+
+		/* always clean up qtds the hc de-activated */
+ retry_xacterr:
+		if ((token & QTD_STS_ACTIVE) == 0) {
+
+			/* Report Data Buffer Error: non-fatal but useful */
+			if (token & QTD_STS_DBE)
+				fotg210_dbg(fotg210,
+					"detected DataBufferErr for urb %p ep%d%s len %d, qtd %p [qh %p]\n",
+					urb,
+					usb_endpoint_num(&urb->ep->desc),
+					usb_endpoint_dir_in(&urb->ep->desc)
+						? "in" : "out",
+					urb->transfer_buffer_length,
+					qtd,
+					qh);
+
+			/* on STALL, error, and short reads this urb must
+			 * complete and all its qtds must be recycled.
+			 */
+			if ((token & QTD_STS_HALT) != 0) {
+
+				/* retry transaction errors until we
+				 * reach the software xacterr limit
+				 */
+				if ((token & QTD_STS_XACT) &&
+					QTD_CERR(token) == 0 &&
+					++qh->xacterrs < QH_XACTERR_MAX &&
+					!urb->unlinked) {
+					fotg210_dbg(fotg210,
+	"detected XactErr len %zu/%zu retry %d\n",
+	qtd->length - QTD_LENGTH(token), qtd->length, qh->xacterrs);
+
+					/* reset the token in the qtd and the
+					 * qh overlay (which still contains
+					 * the qtd) so that we pick up from
+					 * where we left off
+					 */
+					token &= ~QTD_STS_HALT;
+					token |= QTD_STS_ACTIVE |
+						 (FOTG210_TUNE_CERR << 10);
+					qtd->hw_token = cpu_to_hc32(fotg210,
+							token);
+					wmb();
+					hw->hw_token = cpu_to_hc32(fotg210,
+							token);
+					goto retry_xacterr;
+				}
+				stopped = 1;
+
+			/* magic dummy for some short reads; qh won't advance.
+			 * that silicon quirk can kick in with this dummy too.
+			 *
+			 * other short reads won't stop the queue, including
+			 * control transfers (status stage handles that) or
+			 * most other single-qtd reads ... the queue stops if
+			 * URB_SHORT_NOT_OK was set so the driver submitting
+			 * the urbs could clean it up.
+			 */
+			} else if (IS_SHORT_READ(token)
+					&& !(qtd->hw_alt_next
+						& FOTG210_LIST_END(fotg210))) {
+				stopped = 1;
+			}
+
+		/* stop scanning when we reach qtds the hc is using */
+		} else if (likely(!stopped
+				&& fotg210->rh_state >= FOTG210_RH_RUNNING)) {
+			break;
+
+		/* scan the whole queue for unlinks whenever it stops */
+		} else {
+			stopped = 1;
+
+			/* cancel everything if we halt, suspend, etc */
+			if (fotg210->rh_state < FOTG210_RH_RUNNING)
+				last_status = -ESHUTDOWN;
+
+			/* this qtd is active; skip it unless a previous qtd
+			 * for its urb faulted, or its urb was canceled.
+			 */
+			else if (last_status == -EINPROGRESS && !urb->unlinked)
+				continue;
+
+			/* qh unlinked; token in overlay may be most current */
+			if (state == QH_STATE_IDLE
+					&& cpu_to_hc32(fotg210, qtd->qtd_dma)
+						== hw->hw_current) {
+				token = hc32_to_cpu(fotg210, hw->hw_token);
+
+				/* An unlink may leave an incomplete
+				 * async transaction in the TT buffer.
+				 * We have to clear it.
+				 */
+				fotg210_clear_tt_buffer(fotg210, qh, urb,
+							token);
+			}
+		}
+
+		/* unless we already know the urb's status, collect qtd status
+		 * and update count of bytes transferred.  in common short read
+		 * cases with only one data qtd (including control transfers),
+		 * queue processing won't halt.  but with two or more qtds (for
+		 * example, with a 32 KB transfer), when the first qtd gets a
+		 * short read the second must be removed by hand.
+		 */
+		if (last_status == -EINPROGRESS) {
+			last_status = qtd_copy_status(fotg210, urb,
+					qtd->length, token);
+			if (last_status == -EREMOTEIO
+					&& (qtd->hw_alt_next
+						& FOTG210_LIST_END(fotg210)))
+				last_status = -EINPROGRESS;
+
+			/* As part of low/full-speed endpoint-halt processing
+			 * we must clear the TT buffer (11.17.5).
+			 */
+			if (unlikely(last_status != -EINPROGRESS &&
+					last_status != -EREMOTEIO)) {
+				/* The TT's in some hubs malfunction when they
+				 * receive this request following a STALL (they
+				 * stop sending isochronous packets).  Since a
+				 * STALL can't leave the TT buffer in a busy
+				 * state (if you believe Figures 11-48 - 11-51
+				 * in the USB 2.0 spec), we won't clear the TT
+				 * buffer in this case.  Strictly speaking this
+				 * is a violation of the spec.
+				 */
+				if (last_status != -EPIPE)
+					fotg210_clear_tt_buffer(fotg210, qh,
+								urb, token);
+			}
+		}
+
+		/* if we're removing something not at the queue head,
+		 * patch the hardware queue pointer.
+		 */
+		if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
+			last = list_entry(qtd->qtd_list.prev,
+					struct fotg210_qtd, qtd_list);
+			last->hw_next = qtd->hw_next;
+		}
+
+		/* remove qtd; it's recycled after possible urb completion */
+		list_del(&qtd->qtd_list);
+		last = qtd;
+
+		/* reinit the xacterr counter for the next qtd */
+		qh->xacterrs = 0;
+	}
+
+	/* last urb's completion might still need calling */
+	if (likely(last != NULL)) {
+		fotg210_urb_done(fotg210, last->urb, last_status);
+		count++;
+		fotg210_qtd_free(fotg210, last);
+	}
+
+	/* Do we need to rescan for URBs dequeued during a giveback? */
+	if (unlikely(qh->needs_rescan)) {
+		/* If the QH is already unlinked, do the rescan now. */
+		if (state == QH_STATE_IDLE)
+			goto rescan;
+
+		/* Otherwise we have to wait until the QH is fully unlinked.
+		 * Our caller will start an unlink if qh->needs_rescan is
+		 * set.  But if an unlink has already started, nothing needs
+		 * to be done.
+		 */
+		if (state != QH_STATE_LINKED)
+			qh->needs_rescan = 0;
+	}
+
+	/* restore original state; caller must unlink or relink */
+	qh->qh_state = state;
+
+	/* be sure the hardware's done with the qh before refreshing
+	 * it after fault cleanup, or recovering from silicon wrongly
+	 * overlaying the dummy qtd (which reduces DMA chatter).
+	 */
+	if (stopped != 0 || hw->hw_qtd_next == FOTG210_LIST_END(fotg210)) {
+		switch (state) {
+		case QH_STATE_IDLE:
+			qh_refresh(fotg210, qh);
+			break;
+		case QH_STATE_LINKED:
+			/* We won't refresh a QH that's linked (after the HC
+			 * stopped the queue).  That avoids a race:
+			 *  - HC reads first part of QH;
+			 *  - CPU updates that first part and the token;
+			 *  - HC reads rest of that QH, including token
+			 * Result:  HC gets an inconsistent image, and then
+			 * DMAs to/from the wrong memory (corrupting it).
+			 *
+			 * That should be rare for interrupt transfers,
+			 * except maybe high bandwidth ...
+			 */
+
+			/* Tell the caller to start an unlink */
+			qh->needs_rescan = 1;
+			break;
+		/* otherwise, unlink already started */
+		}
+	}
+
+	return count;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
+#define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
+/* ... and packet size, for any kind of endpoint descriptor */
+#define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
+
+/*
+ * reverse of qh_urb_transaction:  free a list of TDs.
+ * used for cleanup after errors, before HC sees an URB's TDs.
+ */
+static void qtd_list_free(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	struct list_head	*qtd_list
+) {
+	struct list_head	*entry, *temp;
+
+	list_for_each_safe(entry, temp, qtd_list) {
+		struct fotg210_qtd	*qtd;
+
+		qtd = list_entry(entry, struct fotg210_qtd, qtd_list);
+		list_del(&qtd->qtd_list);
+		fotg210_qtd_free(fotg210, qtd);
+	}
+}
+
+/*
+ * create a list of filled qtds for this URB; won't link into qh.
+ */
+static struct list_head *
+qh_urb_transaction(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	struct list_head	*head,
+	gfp_t			flags
+) {
+	struct fotg210_qtd		*qtd, *qtd_prev;
+	dma_addr_t		buf;
+	int			len, this_sg_len, maxpacket;
+	int			is_input;
+	u32			token;
+	int			i;
+	struct scatterlist	*sg;
+
+	/*
+	 * URBs map to sequences of QTDs:  one logical transaction
+	 */
+	qtd = fotg210_qtd_alloc(fotg210, flags);
+	if (unlikely(!qtd))
+		return NULL;
+	list_add_tail(&qtd->qtd_list, head);
+	qtd->urb = urb;
+
+	token = QTD_STS_ACTIVE;
+	token |= (FOTG210_TUNE_CERR << 10);
+	/* for split transactions, SplitXState initialized to zero */
+
+	len = urb->transfer_buffer_length;
+	is_input = usb_pipein(urb->pipe);
+	if (usb_pipecontrol(urb->pipe)) {
+		/* SETUP pid */
+		qtd_fill(fotg210, qtd, urb->setup_dma,
+				sizeof(struct usb_ctrlrequest),
+				token | (2 /* "setup" */ << 8), 8);
+
+		/* ... and always at least one more pid */
+		token ^= QTD_TOGGLE;
+		qtd_prev = qtd;
+		qtd = fotg210_qtd_alloc(fotg210, flags);
+		if (unlikely(!qtd))
+			goto cleanup;
+		qtd->urb = urb;
+		qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+		list_add_tail(&qtd->qtd_list, head);
+
+		/* for zero length DATA stages, STATUS is always IN */
+		if (len == 0)
+			token |= (1 /* "in" */ << 8);
+	}
+
+	/*
+	 * data transfer stage:  buffer setup
+	 */
+	i = urb->num_mapped_sgs;
+	if (len > 0 && i > 0) {
+		sg = urb->sg;
+		buf = sg_dma_address(sg);
+
+		/* urb->transfer_buffer_length may be smaller than the
+		 * size of the scatterlist (or vice versa)
+		 */
+		this_sg_len = min_t(int, sg_dma_len(sg), len);
+	} else {
+		sg = NULL;
+		buf = urb->transfer_dma;
+		this_sg_len = len;
+	}
+
+	if (is_input)
+		token |= (1 /* "in" */ << 8);
+	/* else it's already initted to "out" pid (0 << 8) */
+
+	maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
+
+	/*
+	 * buffer gets wrapped in one or more qtds;
+	 * last one may be "short" (including zero len)
+	 * and may serve as a control status ack
+	 */
+	for (;;) {
+		int this_qtd_len;
+
+		this_qtd_len = qtd_fill(fotg210, qtd, buf, this_sg_len, token,
+				maxpacket);
+		this_sg_len -= this_qtd_len;
+		len -= this_qtd_len;
+		buf += this_qtd_len;
+
+		/*
+		 * short reads advance to a "magic" dummy instead of the next
+		 * qtd ... that forces the queue to stop, for manual cleanup.
+		 * (this will usually be overridden later.)
+		 */
+		if (is_input)
+			qtd->hw_alt_next = fotg210->async->hw->hw_alt_next;
+
+		/* qh makes control packets use qtd toggle; maybe switch it */
+		if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
+			token ^= QTD_TOGGLE;
+
+		if (likely(this_sg_len <= 0)) {
+			if (--i <= 0 || len <= 0)
+				break;
+			sg = sg_next(sg);
+			buf = sg_dma_address(sg);
+			this_sg_len = min_t(int, sg_dma_len(sg), len);
+		}
+
+		qtd_prev = qtd;
+		qtd = fotg210_qtd_alloc(fotg210, flags);
+		if (unlikely(!qtd))
+			goto cleanup;
+		qtd->urb = urb;
+		qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+		list_add_tail(&qtd->qtd_list, head);
+	}
+
+	/*
+	 * unless the caller requires manual cleanup after short reads,
+	 * have the alt_next mechanism keep the queue running after the
+	 * last data qtd (the only one, for control and most other cases).
+	 */
+	if (likely((urb->transfer_flags & URB_SHORT_NOT_OK) == 0
+				|| usb_pipecontrol(urb->pipe)))
+		qtd->hw_alt_next = FOTG210_LIST_END(fotg210);
+
+	/*
+	 * control requests may need a terminating data "status" ack;
+	 * other OUT ones may need a terminating short packet
+	 * (zero length).
+	 */
+	if (likely(urb->transfer_buffer_length != 0)) {
+		int	one_more = 0;
+
+		if (usb_pipecontrol(urb->pipe)) {
+			one_more = 1;
+			token ^= 0x0100;	/* "in" <--> "out"  */
+			token |= QTD_TOGGLE;	/* force DATA1 */
+		} else if (usb_pipeout(urb->pipe)
+				&& (urb->transfer_flags & URB_ZERO_PACKET)
+				&& !(urb->transfer_buffer_length % maxpacket)) {
+			one_more = 1;
+		}
+		if (one_more) {
+			qtd_prev = qtd;
+			qtd = fotg210_qtd_alloc(fotg210, flags);
+			if (unlikely(!qtd))
+				goto cleanup;
+			qtd->urb = urb;
+			qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
+			list_add_tail(&qtd->qtd_list, head);
+
+			/* never any data in such packets */
+			qtd_fill(fotg210, qtd, 0, 0, token, 0);
+		}
+	}
+
+	/* by default, enable interrupt on urb completion */
+	if (likely(!(urb->transfer_flags & URB_NO_INTERRUPT)))
+		qtd->hw_token |= cpu_to_hc32(fotg210, QTD_IOC);
+	return head;
+
+cleanup:
+	qtd_list_free(fotg210, urb, head);
+	return NULL;
+}
+
+/*-------------------------------------------------------------------------*/
+/*
+ * Would be best to create all qh's from config descriptors,
+ * when each interface/altsetting is established.  Unlink
+ * any previous qh and cancel its urbs first; endpoints are
+ * implicitly reset then (data toggle too).
+ * That'd mean updating how usbcore talks to HCDs. (2.7?)
+*/
+
+
+/*
+ * Each QH holds a qtd list; a QH is used for everything except iso.
+ *
+ * For interrupt urbs, the scheduler must set the microframe scheduling
+ * mask(s) each time the QH gets scheduled.  For highspeed, that's
+ * just one microframe in the s-mask.  For split interrupt transactions
+ * there are additional complications: c-mask, maybe FSTNs.
+ */
+static struct fotg210_qh *
+qh_make(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	gfp_t			flags
+) {
+	struct fotg210_qh		*qh = fotg210_qh_alloc(fotg210, flags);
+	u32			info1 = 0, info2 = 0;
+	int			is_input, type;
+	int			maxp = 0;
+	struct usb_tt		*tt = urb->dev->tt;
+	struct fotg210_qh_hw	*hw;
+
+	if (!qh)
+		return qh;
+
+	/*
+	 * init endpoint/device data for this QH
+	 */
+	info1 |= usb_pipeendpoint(urb->pipe) << 8;
+	info1 |= usb_pipedevice(urb->pipe) << 0;
+
+	is_input = usb_pipein(urb->pipe);
+	type = usb_pipetype(urb->pipe);
+	maxp = usb_maxpacket(urb->dev, urb->pipe, !is_input);
+
+	/* 1024 byte maxpacket is a hardware ceiling.  High bandwidth
+	 * acts like up to 3KB, but is built from smaller packets.
+	 */
+	if (max_packet(maxp) > 1024) {
+		fotg210_dbg(fotg210, "bogus qh maxpacket %d\n",
+			    max_packet(maxp));
+		goto done;
+	}
+
+	/* Compute interrupt scheduling parameters just once, and save.
+	 * - allowing for high bandwidth, how many nsec/uframe are used?
+	 * - split transactions need a second CSPLIT uframe; same question
+	 * - splits also need a schedule gap (for full/low speed I/O)
+	 * - qh has a polling interval
+	 *
+	 * For control/bulk requests, the HC or TT handles these.
+	 */
+	if (type == PIPE_INTERRUPT) {
+		qh->usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
+				is_input, 0,
+				hb_mult(maxp) * max_packet(maxp)));
+		qh->start = NO_FRAME;
+
+		if (urb->dev->speed == USB_SPEED_HIGH) {
+			qh->c_usecs = 0;
+			qh->gap_uf = 0;
+
+			qh->period = urb->interval >> 3;
+			if (qh->period == 0 && urb->interval != 1) {
+				/* NOTE interval 2 or 4 uframes could work.
+				 * But interval 1 scheduling is simpler, and
+				 * includes high bandwidth.
+				 */
+				urb->interval = 1;
+			} else if (qh->period > fotg210->periodic_size) {
+				qh->period = fotg210->periodic_size;
+				urb->interval = qh->period << 3;
+			}
+		} else {
+			int		think_time;
+
+			/* gap is f(FS/LS transfer times) */
+			qh->gap_uf = 1 + usb_calc_bus_time(urb->dev->speed,
+					is_input, 0, maxp) / (125 * 1000);
+
+			/* FIXME this just approximates SPLIT/CSPLIT times */
+			if (is_input) {		/* SPLIT, gap, CSPLIT+DATA */
+				qh->c_usecs = qh->usecs + HS_USECS(0);
+				qh->usecs = HS_USECS(1);
+			} else {		/* SPLIT+DATA, gap, CSPLIT */
+				qh->usecs += HS_USECS(1);
+				qh->c_usecs = HS_USECS(0);
+			}
+
+			think_time = tt ? tt->think_time : 0;
+			qh->tt_usecs = NS_TO_US(think_time +
+					usb_calc_bus_time(urb->dev->speed,
+					is_input, 0, max_packet(maxp)));
+			qh->period = urb->interval;
+			if (qh->period > fotg210->periodic_size) {
+				qh->period = fotg210->periodic_size;
+				urb->interval = qh->period;
+			}
+		}
+	}
+
+	/* support for tt scheduling, and access to toggles */
+	qh->dev = urb->dev;
+
+	/* using TT? */
+	switch (urb->dev->speed) {
+	case USB_SPEED_LOW:
+		info1 |= QH_LOW_SPEED;
+		/* FALL THROUGH */
+
+	case USB_SPEED_FULL:
+		/* EPS 0 means "full" */
+		if (type != PIPE_INTERRUPT)
+			info1 |= (FOTG210_TUNE_RL_TT << 28);
+		if (type == PIPE_CONTROL) {
+			info1 |= QH_CONTROL_EP;		/* for TT */
+			info1 |= QH_TOGGLE_CTL;		/* toggle from qtd */
+		}
+		info1 |= maxp << 16;
+
+		info2 |= (FOTG210_TUNE_MULT_TT << 30);
+
+		/* Some Freescale processors have an erratum in which the
+		 * port number in the queue head was 0..N-1 instead of 1..N.
+		 */
+		if (fotg210_has_fsl_portno_bug(fotg210))
+			info2 |= (urb->dev->ttport-1) << 23;
+		else
+			info2 |= urb->dev->ttport << 23;
+
+		/* set the address of the TT; for TDI's integrated
+		 * root hub tt, leave it zeroed.
+		 */
+		if (tt && tt->hub != fotg210_to_hcd(fotg210)->self.root_hub)
+			info2 |= tt->hub->devnum << 16;
+
+		/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets c-mask } */
+
+		break;
+
+	case USB_SPEED_HIGH:		/* no TT involved */
+		info1 |= QH_HIGH_SPEED;
+		if (type == PIPE_CONTROL) {
+			info1 |= (FOTG210_TUNE_RL_HS << 28);
+			info1 |= 64 << 16;	/* usb2 fixed maxpacket */
+			info1 |= QH_TOGGLE_CTL;	/* toggle from qtd */
+			info2 |= (FOTG210_TUNE_MULT_HS << 30);
+		} else if (type == PIPE_BULK) {
+			info1 |= (FOTG210_TUNE_RL_HS << 28);
+			/* The USB spec says that high speed bulk endpoints
+			 * always use 512 byte maxpacket.  But some device
+			 * vendors decided to ignore that, and MSFT is happy
+			 * to help them do so.  So now people expect to use
+			 * such nonconformant devices with Linux too; sigh.
+			 */
+			info1 |= max_packet(maxp) << 16;
+			info2 |= (FOTG210_TUNE_MULT_HS << 30);
+		} else {		/* PIPE_INTERRUPT */
+			info1 |= max_packet(maxp) << 16;
+			info2 |= hb_mult(maxp) << 30;
+		}
+		break;
+	default:
+		fotg210_dbg(fotg210, "bogus dev %p speed %d\n", urb->dev,
+			urb->dev->speed);
+done:
+		qh_destroy(fotg210, qh);
+		return NULL;
+	}
+
+	/* NOTE:  if (PIPE_INTERRUPT) { scheduler sets s-mask } */
+
+	/* init as live, toggle clear, advance to dummy */
+	qh->qh_state = QH_STATE_IDLE;
+	hw = qh->hw;
+	hw->hw_info1 = cpu_to_hc32(fotg210, info1);
+	hw->hw_info2 = cpu_to_hc32(fotg210, info2);
+	qh->is_out = !is_input;
+	usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), !is_input, 1);
+	qh_refresh(fotg210, qh);
+	return qh;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void enable_async(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->async_count++)
+		return;
+
+	/* Stop waiting to turn off the async schedule */
+	fotg210->enabled_hrtimer_events &= ~BIT(FOTG210_HRTIMER_DISABLE_ASYNC);
+
+	/* Don't start the schedule until ASS is 0 */
+	fotg210_poll_ASS(fotg210);
+	turn_on_io_watchdog(fotg210);
+}
+
+static void disable_async(struct fotg210_hcd *fotg210)
+{
+	if (--fotg210->async_count)
+		return;
+
+	/* The async schedule and async_unlink list are supposed to be empty */
+	WARN_ON(fotg210->async->qh_next.qh || fotg210->async_unlink);
+
+	/* Don't turn off the schedule until ASS is 1 */
+	fotg210_poll_ASS(fotg210);
+}
+
+/* move qh (and its qtds) onto async queue; maybe enable queue.  */
+
+static void qh_link_async(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	__hc32		dma = QH_NEXT(fotg210, qh->qh_dma);
+	struct fotg210_qh	*head;
+
+	/* Don't link a QH if there's a Clear-TT-Buffer pending */
+	if (unlikely(qh->clearing_tt))
+		return;
+
+	WARN_ON(qh->qh_state != QH_STATE_IDLE);
+
+	/* clear halt and/or toggle; and maybe recover from silicon quirk */
+	qh_refresh(fotg210, qh);
+
+	/* splice right after start */
+	head = fotg210->async;
+	qh->qh_next = head->qh_next;
+	qh->hw->hw_next = head->hw->hw_next;
+	wmb();
+
+	head->qh_next.qh = qh;
+	head->hw->hw_next = dma;
+
+	qh->xacterrs = 0;
+	qh->qh_state = QH_STATE_LINKED;
+	/* qtd completions reported later by interrupt */
+
+	enable_async(fotg210);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * For control/bulk/interrupt, return QH with these TDs appended.
+ * Allocates and initializes the QH if necessary.
+ * Returns null if it can't allocate a QH it needs to.
+ * If the QH has TDs (urbs) already, that's great.
+ */
+static struct fotg210_qh *qh_append_tds(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	struct list_head	*qtd_list,
+	int			epnum,
+	void			**ptr
+)
+{
+	struct fotg210_qh		*qh = NULL;
+	__hc32			qh_addr_mask = cpu_to_hc32(fotg210, 0x7f);
+
+	qh = (struct fotg210_qh *) *ptr;
+	if (unlikely(qh == NULL)) {
+		/* can't sleep here, we have fotg210->lock... */
+		qh = qh_make(fotg210, urb, GFP_ATOMIC);
+		*ptr = qh;
+	}
+	if (likely(qh != NULL)) {
+		struct fotg210_qtd	*qtd;
+
+		if (unlikely(list_empty(qtd_list)))
+			qtd = NULL;
+		else
+			qtd = list_entry(qtd_list->next, struct fotg210_qtd,
+					qtd_list);
+
+		/* control qh may need patching ... */
+		if (unlikely(epnum == 0)) {
+			/* usb_reset_device() briefly reverts to address 0 */
+			if (usb_pipedevice(urb->pipe) == 0)
+				qh->hw->hw_info1 &= ~qh_addr_mask;
+		}
+
+		/* just one way to queue requests: swap with the dummy qtd.
+		 * only hc or qh_refresh() ever modify the overlay.
+		 */
+		if (likely(qtd != NULL)) {
+			struct fotg210_qtd		*dummy;
+			dma_addr_t		dma;
+			__hc32			token;
+
+			/* to avoid racing the HC, use the dummy td instead of
+			 * the first td of our list (becomes new dummy).  both
+			 * tds stay deactivated until we're done, when the
+			 * HC is allowed to fetch the old dummy (4.10.2).
+			 */
+			token = qtd->hw_token;
+			qtd->hw_token = HALT_BIT(fotg210);
+
+			dummy = qh->dummy;
+
+			dma = dummy->qtd_dma;
+			*dummy = *qtd;
+			dummy->qtd_dma = dma;
+
+			list_del(&qtd->qtd_list);
+			list_add(&dummy->qtd_list, qtd_list);
+			list_splice_tail(qtd_list, &qh->qtd_list);
+
+			fotg210_qtd_init(fotg210, qtd, qtd->qtd_dma);
+			qh->dummy = qtd;
+
+			/* hc must see the new dummy at list end */
+			dma = qtd->qtd_dma;
+			qtd = list_entry(qh->qtd_list.prev,
+					struct fotg210_qtd, qtd_list);
+			qtd->hw_next = QTD_NEXT(fotg210, dma);
+
+			/* let the hc process these next qtds */
+			wmb();
+			dummy->hw_token = token;
+
+			urb->hcpriv = qh;
+		}
+	}
+	return qh;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int
+submit_async(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	struct list_head	*qtd_list,
+	gfp_t			mem_flags
+) {
+	int			epnum;
+	unsigned long		flags;
+	struct fotg210_qh		*qh = NULL;
+	int			rc;
+
+	epnum = urb->ep->desc.bEndpointAddress;
+
+#ifdef FOTG210_URB_TRACE
+	{
+		struct fotg210_qtd *qtd;
+		qtd = list_entry(qtd_list->next, struct fotg210_qtd, qtd_list);
+		fotg210_dbg(fotg210,
+			 "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
+			 __func__, urb->dev->devpath, urb,
+			 epnum & 0x0f, (epnum & USB_DIR_IN) ? "in" : "out",
+			 urb->transfer_buffer_length,
+			 qtd, urb->ep->hcpriv);
+	}
+#endif
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
+		rc = -ESHUTDOWN;
+		goto done;
+	}
+	rc = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
+	if (unlikely(rc))
+		goto done;
+
+	qh = qh_append_tds(fotg210, urb, qtd_list, epnum, &urb->ep->hcpriv);
+	if (unlikely(qh == NULL)) {
+		usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+		rc = -ENOMEM;
+		goto done;
+	}
+
+	/* Control/bulk operations through TTs don't need scheduling,
+	 * the HC and TT handle it when the TT has a buffer ready.
+	 */
+	if (likely(qh->qh_state == QH_STATE_IDLE))
+		qh_link_async(fotg210, qh);
+ done:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	if (unlikely(qh == NULL))
+		qtd_list_free(fotg210, urb, qtd_list);
+	return rc;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void single_unlink_async(struct fotg210_hcd *fotg210,
+				struct fotg210_qh *qh)
+{
+	struct fotg210_qh		*prev;
+
+	/* Add to the end of the list of QHs waiting for the next IAAD */
+	qh->qh_state = QH_STATE_UNLINK;
+	if (fotg210->async_unlink)
+		fotg210->async_unlink_last->unlink_next = qh;
+	else
+		fotg210->async_unlink = qh;
+	fotg210->async_unlink_last = qh;
+
+	/* Unlink it from the schedule */
+	prev = fotg210->async;
+	while (prev->qh_next.qh != qh)
+		prev = prev->qh_next.qh;
+
+	prev->hw->hw_next = qh->hw->hw_next;
+	prev->qh_next = qh->qh_next;
+	if (fotg210->qh_scan_next == qh)
+		fotg210->qh_scan_next = qh->qh_next.qh;
+}
+
+static void start_iaa_cycle(struct fotg210_hcd *fotg210, bool nested)
+{
+	/*
+	 * Do nothing if an IAA cycle is already running or
+	 * if one will be started shortly.
+	 */
+	if (fotg210->async_iaa || fotg210->async_unlinking)
+		return;
+
+	/* Do all the waiting QHs at once */
+	fotg210->async_iaa = fotg210->async_unlink;
+	fotg210->async_unlink = NULL;
+
+	/* If the controller isn't running, we don't have to wait for it */
+	if (unlikely(fotg210->rh_state < FOTG210_RH_RUNNING)) {
+		if (!nested)		/* Avoid recursion */
+			end_unlink_async(fotg210);
+
+	/* Otherwise start a new IAA cycle */
+	} else if (likely(fotg210->rh_state == FOTG210_RH_RUNNING)) {
+		/* Make sure the unlinks are all visible to the hardware */
+		wmb();
+
+		fotg210_writel(fotg210, fotg210->command | CMD_IAAD,
+				&fotg210->regs->command);
+		fotg210_readl(fotg210, &fotg210->regs->command);
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_IAA_WATCHDOG,
+				     true);
+	}
+}
+
+/* the async qh for the qtds being unlinked are now gone from the HC */
+
+static void end_unlink_async(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh		*qh;
+
+	/* Process the idle QHs */
+ restart:
+	fotg210->async_unlinking = true;
+	while (fotg210->async_iaa) {
+		qh = fotg210->async_iaa;
+		fotg210->async_iaa = qh->unlink_next;
+		qh->unlink_next = NULL;
+
+		qh->qh_state = QH_STATE_IDLE;
+		qh->qh_next.qh = NULL;
+
+		qh_completions(fotg210, qh);
+		if (!list_empty(&qh->qtd_list) &&
+				fotg210->rh_state == FOTG210_RH_RUNNING)
+			qh_link_async(fotg210, qh);
+		disable_async(fotg210);
+	}
+	fotg210->async_unlinking = false;
+
+	/* Start a new IAA cycle if any QHs are waiting for it */
+	if (fotg210->async_unlink) {
+		start_iaa_cycle(fotg210, true);
+		if (unlikely(fotg210->rh_state < FOTG210_RH_RUNNING))
+			goto restart;
+	}
+}
+
+static void unlink_empty_async(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh *qh, *next;
+	bool stopped = (fotg210->rh_state < FOTG210_RH_RUNNING);
+	bool check_unlinks_later = false;
+
+	/* Unlink all the async QHs that have been empty for a timer cycle */
+	next = fotg210->async->qh_next.qh;
+	while (next) {
+		qh = next;
+		next = qh->qh_next.qh;
+
+		if (list_empty(&qh->qtd_list) &&
+				qh->qh_state == QH_STATE_LINKED) {
+			if (!stopped && qh->unlink_cycle ==
+					fotg210->async_unlink_cycle)
+				check_unlinks_later = true;
+			else
+				single_unlink_async(fotg210, qh);
+		}
+	}
+
+	/* Start a new IAA cycle if any QHs are waiting for it */
+	if (fotg210->async_unlink)
+		start_iaa_cycle(fotg210, false);
+
+	/* QHs that haven't been empty for long enough will be handled later */
+	if (check_unlinks_later) {
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_ASYNC_UNLINKS,
+				     true);
+		++fotg210->async_unlink_cycle;
+	}
+}
+
+/* makes sure the async qh will become idle */
+/* caller must own fotg210->lock */
+
+static void start_unlink_async(struct fotg210_hcd *fotg210,
+			       struct fotg210_qh *qh)
+{
+	/*
+	 * If the QH isn't linked then there's nothing we can do
+	 * unless we were called during a giveback, in which case
+	 * qh_completions() has to deal with it.
+	 */
+	if (qh->qh_state != QH_STATE_LINKED) {
+		if (qh->qh_state == QH_STATE_COMPLETING)
+			qh->needs_rescan = 1;
+		return;
+	}
+
+	single_unlink_async(fotg210, qh);
+	start_iaa_cycle(fotg210, false);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void scan_async(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh		*qh;
+	bool			check_unlinks_later = false;
+
+	fotg210->qh_scan_next = fotg210->async->qh_next.qh;
+	while (fotg210->qh_scan_next) {
+		qh = fotg210->qh_scan_next;
+		fotg210->qh_scan_next = qh->qh_next.qh;
+ rescan:
+		/* clean any finished work for this qh */
+		if (!list_empty(&qh->qtd_list)) {
+			int temp;
+
+			/*
+			 * Unlinks could happen here; completion reporting
+			 * drops the lock.  That's why fotg210->qh_scan_next
+			 * always holds the next qh to scan; if the next qh
+			 * gets unlinked then fotg210->qh_scan_next is adjusted
+			 * in single_unlink_async().
+			 */
+			temp = qh_completions(fotg210, qh);
+			if (qh->needs_rescan) {
+				start_unlink_async(fotg210, qh);
+			} else if (list_empty(&qh->qtd_list)
+					&& qh->qh_state == QH_STATE_LINKED) {
+				qh->unlink_cycle = fotg210->async_unlink_cycle;
+				check_unlinks_later = true;
+			} else if (temp != 0)
+				goto rescan;
+		}
+	}
+
+	/*
+	 * Unlink empty entries, reducing DMA usage as well
+	 * as HCD schedule-scanning costs.  Delay for any qh
+	 * we just scanned, there's a not-unusual case that it
+	 * doesn't stay idle for long.
+	 */
+	if (check_unlinks_later && fotg210->rh_state == FOTG210_RH_RUNNING &&
+			!(fotg210->enabled_hrtimer_events &
+				BIT(FOTG210_HRTIMER_ASYNC_UNLINKS))) {
+		fotg210_enable_event(fotg210,
+				     FOTG210_HRTIMER_ASYNC_UNLINKS, true);
+		++fotg210->async_unlink_cycle;
+	}
+}
+/*-------------------------------------------------------------------------*/
+/*
+ * EHCI scheduled transaction support:  interrupt, iso, split iso
+ * These are called "periodic" transactions in the EHCI spec.
+ *
+ * Note that for interrupt transfers, the QH/QTD manipulation is shared
+ * with the "asynchronous" transaction support (control/bulk transfers).
+ * The only real difference is in how interrupt transfers are scheduled.
+ *
+ * For ISO, we make an "iso_stream" head to serve the same role as a QH.
+ * It keeps track of every ITD (or SITD) that's linked, and holds enough
+ * pre-calculated schedule data to make appending to the queue be quick.
+ */
+
+static int fotg210_get_frame(struct usb_hcd *hcd);
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * periodic_next_shadow - return "next" pointer on shadow list
+ * @periodic: host pointer to qh/itd
+ * @tag: hardware tag for type of this record
+ */
+static union fotg210_shadow *
+periodic_next_shadow(struct fotg210_hcd *fotg210,
+		     union fotg210_shadow *periodic, __hc32 tag)
+{
+	switch (hc32_to_cpu(fotg210, tag)) {
+	case Q_TYPE_QH:
+		return &periodic->qh->qh_next;
+	case Q_TYPE_FSTN:
+		return &periodic->fstn->fstn_next;
+	default:
+		return &periodic->itd->itd_next;
+	}
+}
+
+static __hc32 *
+shadow_next_periodic(struct fotg210_hcd *fotg210,
+		     union fotg210_shadow *periodic, __hc32 tag)
+{
+	switch (hc32_to_cpu(fotg210, tag)) {
+	/* our fotg210_shadow.qh is actually software part */
+	case Q_TYPE_QH:
+		return &periodic->qh->hw->hw_next;
+	/* others are hw parts */
+	default:
+		return periodic->hw_next;
+	}
+}
+
+/* caller must hold fotg210->lock */
+static void periodic_unlink(struct fotg210_hcd *fotg210, unsigned frame,
+			    void *ptr)
+{
+	union fotg210_shadow	*prev_p = &fotg210->pshadow[frame];
+	__hc32			*hw_p = &fotg210->periodic[frame];
+	union fotg210_shadow	here = *prev_p;
+
+	/* find predecessor of "ptr"; hw and shadow lists are in sync */
+	while (here.ptr && here.ptr != ptr) {
+		prev_p = periodic_next_shadow(fotg210, prev_p,
+				Q_NEXT_TYPE(fotg210, *hw_p));
+		hw_p = shadow_next_periodic(fotg210, &here,
+				Q_NEXT_TYPE(fotg210, *hw_p));
+		here = *prev_p;
+	}
+	/* an interrupt entry (at list end) could have been shared */
+	if (!here.ptr)
+		return;
+
+	/* update shadow and hardware lists ... the old "next" pointers
+	 * from ptr may still be in use, the caller updates them.
+	 */
+	*prev_p = *periodic_next_shadow(fotg210, &here,
+			Q_NEXT_TYPE(fotg210, *hw_p));
+
+	*hw_p = *shadow_next_periodic(fotg210, &here,
+				Q_NEXT_TYPE(fotg210, *hw_p));
+}
+
+/* how many of the uframe's 125 usecs are allocated? */
+static unsigned short
+periodic_usecs(struct fotg210_hcd *fotg210, unsigned frame, unsigned uframe)
+{
+	__hc32			*hw_p = &fotg210->periodic[frame];
+	union fotg210_shadow	*q = &fotg210->pshadow[frame];
+	unsigned		usecs = 0;
+	struct fotg210_qh_hw	*hw;
+
+	while (q->ptr) {
+		switch (hc32_to_cpu(fotg210, Q_NEXT_TYPE(fotg210, *hw_p))) {
+		case Q_TYPE_QH:
+			hw = q->qh->hw;
+			/* is it in the S-mask? */
+			if (hw->hw_info2 & cpu_to_hc32(fotg210, 1 << uframe))
+				usecs += q->qh->usecs;
+			/* ... or C-mask? */
+			if (hw->hw_info2 & cpu_to_hc32(fotg210,
+					1 << (8 + uframe)))
+				usecs += q->qh->c_usecs;
+			hw_p = &hw->hw_next;
+			q = &q->qh->qh_next;
+			break;
+		/* case Q_TYPE_FSTN: */
+		default:
+			/* for "save place" FSTNs, count the relevant INTR
+			 * bandwidth from the previous frame
+			 */
+			if (q->fstn->hw_prev != FOTG210_LIST_END(fotg210))
+				fotg210_dbg(fotg210, "ignoring FSTN cost ...\n");
+
+			hw_p = &q->fstn->hw_next;
+			q = &q->fstn->fstn_next;
+			break;
+		case Q_TYPE_ITD:
+			if (q->itd->hw_transaction[uframe])
+				usecs += q->itd->stream->usecs;
+			hw_p = &q->itd->hw_next;
+			q = &q->itd->itd_next;
+			break;
+		}
+	}
+#ifdef	DEBUG
+	if (usecs > fotg210->uframe_periodic_max)
+		fotg210_err(fotg210, "uframe %d sched overrun: %d usecs\n",
+			frame * 8 + uframe, usecs);
+#endif
+	return usecs;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int same_tt(struct usb_device *dev1, struct usb_device *dev2)
+{
+	if (!dev1->tt || !dev2->tt)
+		return 0;
+	if (dev1->tt != dev2->tt)
+		return 0;
+	if (dev1->tt->multi)
+		return dev1->ttport == dev2->ttport;
+	else
+		return 1;
+}
+
+/* return true iff the device's transaction translator is available
+ * for a periodic transfer starting at the specified frame, using
+ * all the uframes in the mask.
+ */
+static int tt_no_collision(
+	struct fotg210_hcd		*fotg210,
+	unsigned		period,
+	struct usb_device	*dev,
+	unsigned		frame,
+	u32			uf_mask
+)
+{
+	if (period == 0)	/* error */
+		return 0;
+
+	/* note bandwidth wastage:  split never follows csplit
+	 * (different dev or endpoint) until the next uframe.
+	 * calling convention doesn't make that distinction.
+	 */
+	for (; frame < fotg210->periodic_size; frame += period) {
+		union fotg210_shadow	here;
+		__hc32			type;
+		struct fotg210_qh_hw	*hw;
+
+		here = fotg210->pshadow[frame];
+		type = Q_NEXT_TYPE(fotg210, fotg210->periodic[frame]);
+		while (here.ptr) {
+			switch (hc32_to_cpu(fotg210, type)) {
+			case Q_TYPE_ITD:
+				type = Q_NEXT_TYPE(fotg210, here.itd->hw_next);
+				here = here.itd->itd_next;
+				continue;
+			case Q_TYPE_QH:
+				hw = here.qh->hw;
+				if (same_tt(dev, here.qh->dev)) {
+					u32		mask;
+
+					mask = hc32_to_cpu(fotg210,
+							hw->hw_info2);
+					/* "knows" no gap is needed */
+					mask |= mask >> 8;
+					if (mask & uf_mask)
+						break;
+				}
+				type = Q_NEXT_TYPE(fotg210, hw->hw_next);
+				here = here.qh->qh_next;
+				continue;
+			/* case Q_TYPE_FSTN: */
+			default:
+				fotg210_dbg(fotg210,
+					"periodic frame %d bogus type %d\n",
+					frame, type);
+			}
+
+			/* collision or error */
+			return 0;
+		}
+	}
+
+	/* no collision */
+	return 1;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void enable_periodic(struct fotg210_hcd *fotg210)
+{
+	if (fotg210->periodic_count++)
+		return;
+
+	/* Stop waiting to turn off the periodic schedule */
+	fotg210->enabled_hrtimer_events &=
+		~BIT(FOTG210_HRTIMER_DISABLE_PERIODIC);
+
+	/* Don't start the schedule until PSS is 0 */
+	fotg210_poll_PSS(fotg210);
+	turn_on_io_watchdog(fotg210);
+}
+
+static void disable_periodic(struct fotg210_hcd *fotg210)
+{
+	if (--fotg210->periodic_count)
+		return;
+
+	/* Don't turn off the schedule until PSS is 1 */
+	fotg210_poll_PSS(fotg210);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* periodic schedule slots have iso tds (normal or split) first, then a
+ * sparse tree for active interrupt transfers.
+ *
+ * this just links in a qh; caller guarantees uframe masks are set right.
+ * no FSTN support (yet; fotg210 0.96+)
+ */
+static void qh_link_periodic(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	unsigned	i;
+	unsigned	period = qh->period;
+
+	dev_dbg(&qh->dev->dev,
+		"link qh%d-%04x/%p start %d [%d/%d us]\n",
+		period, hc32_to_cpup(fotg210, &qh->hw->hw_info2)
+			& (QH_CMASK | QH_SMASK),
+		qh, qh->start, qh->usecs, qh->c_usecs);
+
+	/* high bandwidth, or otherwise every microframe */
+	if (period == 0)
+		period = 1;
+
+	for (i = qh->start; i < fotg210->periodic_size; i += period) {
+		union fotg210_shadow	*prev = &fotg210->pshadow[i];
+		__hc32			*hw_p = &fotg210->periodic[i];
+		union fotg210_shadow	here = *prev;
+		__hc32			type = 0;
+
+		/* skip the iso nodes at list head */
+		while (here.ptr) {
+			type = Q_NEXT_TYPE(fotg210, *hw_p);
+			if (type == cpu_to_hc32(fotg210, Q_TYPE_QH))
+				break;
+			prev = periodic_next_shadow(fotg210, prev, type);
+			hw_p = shadow_next_periodic(fotg210, &here, type);
+			here = *prev;
+		}
+
+		/* sorting each branch by period (slow-->fast)
+		 * enables sharing interior tree nodes
+		 */
+		while (here.ptr && qh != here.qh) {
+			if (qh->period > here.qh->period)
+				break;
+			prev = &here.qh->qh_next;
+			hw_p = &here.qh->hw->hw_next;
+			here = *prev;
+		}
+		/* link in this qh, unless some earlier pass did that */
+		if (qh != here.qh) {
+			qh->qh_next = here;
+			if (here.qh)
+				qh->hw->hw_next = *hw_p;
+			wmb();
+			prev->qh = qh;
+			*hw_p = QH_NEXT(fotg210, qh->qh_dma);
+		}
+	}
+	qh->qh_state = QH_STATE_LINKED;
+	qh->xacterrs = 0;
+
+	/* update per-qh bandwidth for usbfs */
+	fotg210_to_hcd(fotg210)->self.bandwidth_allocated += qh->period
+		? ((qh->usecs + qh->c_usecs) / qh->period)
+		: (qh->usecs * 8);
+
+	list_add(&qh->intr_node, &fotg210->intr_qh_list);
+
+	/* maybe enable periodic schedule processing */
+	++fotg210->intr_count;
+	enable_periodic(fotg210);
+}
+
+static void qh_unlink_periodic(struct fotg210_hcd *fotg210,
+			       struct fotg210_qh *qh)
+{
+	unsigned	i;
+	unsigned	period;
+
+	/*
+	 * If qh is for a low/full-speed device, simply unlinking it
+	 * could interfere with an ongoing split transaction.  To unlink
+	 * it safely would require setting the QH_INACTIVATE bit and
+	 * waiting at least one frame, as described in EHCI 4.12.2.5.
+	 *
+	 * We won't bother with any of this.  Instead, we assume that the
+	 * only reason for unlinking an interrupt QH while the current URB
+	 * is still active is to dequeue all the URBs (flush the whole
+	 * endpoint queue).
+	 *
+	 * If rebalancing the periodic schedule is ever implemented, this
+	 * approach will no longer be valid.
+	 */
+
+	/* high bandwidth, or otherwise part of every microframe */
+	period = qh->period;
+	if (!period)
+		period = 1;
+
+	for (i = qh->start; i < fotg210->periodic_size; i += period)
+		periodic_unlink(fotg210, i, qh);
+
+	/* update per-qh bandwidth for usbfs */
+	fotg210_to_hcd(fotg210)->self.bandwidth_allocated -= qh->period
+		? ((qh->usecs + qh->c_usecs) / qh->period)
+		: (qh->usecs * 8);
+
+	dev_dbg(&qh->dev->dev,
+		"unlink qh%d-%04x/%p start %d [%d/%d us]\n",
+		qh->period,
+		hc32_to_cpup(fotg210, &qh->hw->hw_info2) &
+		(QH_CMASK | QH_SMASK), qh, qh->start, qh->usecs, qh->c_usecs);
+
+	/* qh->qh_next still "live" to HC */
+	qh->qh_state = QH_STATE_UNLINK;
+	qh->qh_next.ptr = NULL;
+
+	if (fotg210->qh_scan_next == qh)
+		fotg210->qh_scan_next = list_entry(qh->intr_node.next,
+				struct fotg210_qh, intr_node);
+	list_del(&qh->intr_node);
+}
+
+static void start_unlink_intr(struct fotg210_hcd *fotg210,
+			      struct fotg210_qh *qh)
+{
+	/* If the QH isn't linked then there's nothing we can do
+	 * unless we were called during a giveback, in which case
+	 * qh_completions() has to deal with it.
+	 */
+	if (qh->qh_state != QH_STATE_LINKED) {
+		if (qh->qh_state == QH_STATE_COMPLETING)
+			qh->needs_rescan = 1;
+		return;
+	}
+
+	qh_unlink_periodic(fotg210, qh);
+
+	/* Make sure the unlinks are visible before starting the timer */
+	wmb();
+
+	/*
+	 * The EHCI spec doesn't say how long it takes the controller to
+	 * stop accessing an unlinked interrupt QH.  The timer delay is
+	 * 9 uframes; presumably that will be long enough.
+	 */
+	qh->unlink_cycle = fotg210->intr_unlink_cycle;
+
+	/* New entries go at the end of the intr_unlink list */
+	if (fotg210->intr_unlink)
+		fotg210->intr_unlink_last->unlink_next = qh;
+	else
+		fotg210->intr_unlink = qh;
+	fotg210->intr_unlink_last = qh;
+
+	if (fotg210->intr_unlinking)
+		;	/* Avoid recursive calls */
+	else if (fotg210->rh_state < FOTG210_RH_RUNNING)
+		fotg210_handle_intr_unlinks(fotg210);
+	else if (fotg210->intr_unlink == qh) {
+		fotg210_enable_event(fotg210, FOTG210_HRTIMER_UNLINK_INTR,
+				     true);
+		++fotg210->intr_unlink_cycle;
+	}
+}
+
+static void end_unlink_intr(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	struct fotg210_qh_hw	*hw = qh->hw;
+	int			rc;
+
+	qh->qh_state = QH_STATE_IDLE;
+	hw->hw_next = FOTG210_LIST_END(fotg210);
+
+	qh_completions(fotg210, qh);
+
+	/* reschedule QH iff another request is queued */
+	if (!list_empty(&qh->qtd_list) &&
+	    fotg210->rh_state == FOTG210_RH_RUNNING) {
+		rc = qh_schedule(fotg210, qh);
+
+		/* An error here likely indicates handshake failure
+		 * or no space left in the schedule.  Neither fault
+		 * should happen often ...
+		 *
+		 * FIXME kill the now-dysfunctional queued urbs
+		 */
+		if (rc != 0)
+			fotg210_err(fotg210, "can't reschedule qh %p, err %d\n",
+					qh, rc);
+	}
+
+	/* maybe turn off periodic schedule */
+	--fotg210->intr_count;
+	disable_periodic(fotg210);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int check_period(
+	struct fotg210_hcd *fotg210,
+	unsigned	frame,
+	unsigned	uframe,
+	unsigned	period,
+	unsigned	usecs
+) {
+	int		claimed;
+
+	/* complete split running into next frame?
+	 * given FSTN support, we could sometimes check...
+	 */
+	if (uframe >= 8)
+		return 0;
+
+	/* convert "usecs we need" to "max already claimed" */
+	usecs = fotg210->uframe_periodic_max - usecs;
+
+	/* we "know" 2 and 4 uframe intervals were rejected; so
+	 * for period 0, check _every_ microframe in the schedule.
+	 */
+	if (unlikely(period == 0)) {
+		do {
+			for (uframe = 0; uframe < 7; uframe++) {
+				claimed = periodic_usecs(fotg210, frame,
+							 uframe);
+				if (claimed > usecs)
+					return 0;
+			}
+		} while ((frame += 1) < fotg210->periodic_size);
+
+	/* just check the specified uframe, at that period */
+	} else {
+		do {
+			claimed = periodic_usecs(fotg210, frame, uframe);
+			if (claimed > usecs)
+				return 0;
+		} while ((frame += period) < fotg210->periodic_size);
+	}
+
+	/* success! */
+	return 1;
+}
+
+static int check_intr_schedule(
+	struct fotg210_hcd		*fotg210,
+	unsigned		frame,
+	unsigned		uframe,
+	const struct fotg210_qh	*qh,
+	__hc32			*c_maskp
+)
+{
+	int		retval = -ENOSPC;
+	u8		mask = 0;
+
+	if (qh->c_usecs && uframe >= 6)		/* FSTN territory? */
+		goto done;
+
+	if (!check_period(fotg210, frame, uframe, qh->period, qh->usecs))
+		goto done;
+	if (!qh->c_usecs) {
+		retval = 0;
+		*c_maskp = 0;
+		goto done;
+	}
+
+	/* Make sure this tt's buffer is also available for CSPLITs.
+	 * We pessimize a bit; probably the typical full speed case
+	 * doesn't need the second CSPLIT.
+	 *
+	 * NOTE:  both SPLIT and CSPLIT could be checked in just
+	 * one smart pass...
+	 */
+	mask = 0x03 << (uframe + qh->gap_uf);
+	*c_maskp = cpu_to_hc32(fotg210, mask << 8);
+
+	mask |= 1 << uframe;
+	if (tt_no_collision(fotg210, qh->period, qh->dev, frame, mask)) {
+		if (!check_period(fotg210, frame, uframe + qh->gap_uf + 1,
+					qh->period, qh->c_usecs))
+			goto done;
+		if (!check_period(fotg210, frame, uframe + qh->gap_uf,
+					qh->period, qh->c_usecs))
+			goto done;
+		retval = 0;
+	}
+done:
+	return retval;
+}
+
+/* "first fit" scheduling policy used the first time through,
+ * or when the previous schedule slot can't be re-used.
+ */
+static int qh_schedule(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
+{
+	int		status;
+	unsigned	uframe;
+	__hc32		c_mask;
+	unsigned	frame;		/* 0..(qh->period - 1), or NO_FRAME */
+	struct fotg210_qh_hw	*hw = qh->hw;
+
+	qh_refresh(fotg210, qh);
+	hw->hw_next = FOTG210_LIST_END(fotg210);
+	frame = qh->start;
+
+	/* reuse the previous schedule slots, if we can */
+	if (frame < qh->period) {
+		uframe = ffs(hc32_to_cpup(fotg210, &hw->hw_info2) & QH_SMASK);
+		status = check_intr_schedule(fotg210, frame, --uframe,
+				qh, &c_mask);
+	} else {
+		uframe = 0;
+		c_mask = 0;
+		status = -ENOSPC;
+	}
+
+	/* else scan the schedule to find a group of slots such that all
+	 * uframes have enough periodic bandwidth available.
+	 */
+	if (status) {
+		/* "normal" case, uframing flexible except with splits */
+		if (qh->period) {
+			int		i;
+
+			for (i = qh->period; status && i > 0; --i) {
+				frame = ++fotg210->random_frame % qh->period;
+				for (uframe = 0; uframe < 8; uframe++) {
+					status = check_intr_schedule(fotg210,
+							frame, uframe, qh,
+							&c_mask);
+					if (status == 0)
+						break;
+				}
+			}
+
+		/* qh->period == 0 means every uframe */
+		} else {
+			frame = 0;
+			status = check_intr_schedule(fotg210, 0, 0, qh,
+						     &c_mask);
+		}
+		if (status)
+			goto done;
+		qh->start = frame;
+
+		/* reset S-frame and (maybe) C-frame masks */
+		hw->hw_info2 &= cpu_to_hc32(fotg210, ~(QH_CMASK | QH_SMASK));
+		hw->hw_info2 |= qh->period
+			? cpu_to_hc32(fotg210, 1 << uframe)
+			: cpu_to_hc32(fotg210, QH_SMASK);
+		hw->hw_info2 |= c_mask;
+	} else
+		fotg210_dbg(fotg210, "reused qh %p schedule\n", qh);
+
+	/* stuff into the periodic schedule */
+	qh_link_periodic(fotg210, qh);
+done:
+	return status;
+}
+
+static int intr_submit(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	struct list_head	*qtd_list,
+	gfp_t			mem_flags
+) {
+	unsigned		epnum;
+	unsigned long		flags;
+	struct fotg210_qh		*qh;
+	int			status;
+	struct list_head	empty;
+
+	/* get endpoint and transfer/schedule data */
+	epnum = urb->ep->desc.bEndpointAddress;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
+		status = -ESHUTDOWN;
+		goto done_not_linked;
+	}
+	status = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
+	if (unlikely(status))
+		goto done_not_linked;
+
+	/* get qh and force any scheduling errors */
+	INIT_LIST_HEAD(&empty);
+	qh = qh_append_tds(fotg210, urb, &empty, epnum, &urb->ep->hcpriv);
+	if (qh == NULL) {
+		status = -ENOMEM;
+		goto done;
+	}
+	if (qh->qh_state == QH_STATE_IDLE) {
+		status = qh_schedule(fotg210, qh);
+		if (status)
+			goto done;
+	}
+
+	/* then queue the urb's tds to the qh */
+	qh = qh_append_tds(fotg210, urb, qtd_list, epnum, &urb->ep->hcpriv);
+	BUG_ON(qh == NULL);
+
+	/* ... update usbfs periodic stats */
+	fotg210_to_hcd(fotg210)->self.bandwidth_int_reqs++;
+
+done:
+	if (unlikely(status))
+		usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+done_not_linked:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	if (status)
+		qtd_list_free(fotg210, urb, qtd_list);
+
+	return status;
+}
+
+static void scan_intr(struct fotg210_hcd *fotg210)
+{
+	struct fotg210_qh		*qh;
+
+	list_for_each_entry_safe(qh, fotg210->qh_scan_next,
+				 &fotg210->intr_qh_list, intr_node) {
+ rescan:
+		/* clean any finished work for this qh */
+		if (!list_empty(&qh->qtd_list)) {
+			int temp;
+
+			/*
+			 * Unlinks could happen here; completion reporting
+			 * drops the lock.  That's why fotg210->qh_scan_next
+			 * always holds the next qh to scan; if the next qh
+			 * gets unlinked then fotg210->qh_scan_next is adjusted
+			 * in qh_unlink_periodic().
+			 */
+			temp = qh_completions(fotg210, qh);
+			if (unlikely(qh->needs_rescan ||
+					(list_empty(&qh->qtd_list) &&
+					 qh->qh_state == QH_STATE_LINKED)))
+				start_unlink_intr(fotg210, qh);
+			else if (temp != 0)
+				goto rescan;
+		}
+	}
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* fotg210_iso_stream ops work with both ITD and SITD */
+
+static struct fotg210_iso_stream *
+iso_stream_alloc(gfp_t mem_flags)
+{
+	struct fotg210_iso_stream *stream;
+
+	stream = kzalloc(sizeof(*stream), mem_flags);
+	if (likely(stream != NULL)) {
+		INIT_LIST_HEAD(&stream->td_list);
+		INIT_LIST_HEAD(&stream->free_list);
+		stream->next_uframe = -1;
+	}
+	return stream;
+}
+
+static void
+iso_stream_init(
+	struct fotg210_hcd		*fotg210,
+	struct fotg210_iso_stream	*stream,
+	struct usb_device	*dev,
+	int			pipe,
+	unsigned		interval
+)
+{
+	u32			buf1;
+	unsigned		epnum, maxp;
+	int			is_input;
+	long			bandwidth;
+	unsigned		multi;
+
+	/*
+	 * this might be a "high bandwidth" highspeed endpoint,
+	 * as encoded in the ep descriptor's wMaxPacket field
+	 */
+	epnum = usb_pipeendpoint(pipe);
+	is_input = usb_pipein(pipe) ? USB_DIR_IN : 0;
+	maxp = usb_maxpacket(dev, pipe, !is_input);
+	if (is_input)
+		buf1 = (1 << 11);
+	else
+		buf1 = 0;
+
+	maxp = max_packet(maxp);
+	multi = hb_mult(maxp);
+	buf1 |= maxp;
+	maxp *= multi;
+
+	stream->buf0 = cpu_to_hc32(fotg210, (epnum << 8) | dev->devnum);
+	stream->buf1 = cpu_to_hc32(fotg210, buf1);
+	stream->buf2 = cpu_to_hc32(fotg210, multi);
+
+	/* usbfs wants to report the average usecs per frame tied up
+	 * when transfers on this endpoint are scheduled ...
+	 */
+	if (dev->speed == USB_SPEED_FULL) {
+		interval <<= 3;
+		stream->usecs = NS_TO_US(usb_calc_bus_time(dev->speed,
+				is_input, 1, maxp));
+		stream->usecs /= 8;
+	} else {
+		stream->highspeed = 1;
+		stream->usecs = HS_USECS_ISO(maxp);
+	}
+	bandwidth = stream->usecs * 8;
+	bandwidth /= interval;
+
+	stream->bandwidth = bandwidth;
+	stream->udev = dev;
+	stream->bEndpointAddress = is_input | epnum;
+	stream->interval = interval;
+	stream->maxp = maxp;
+}
+
+static struct fotg210_iso_stream *
+iso_stream_find(struct fotg210_hcd *fotg210, struct urb *urb)
+{
+	unsigned		epnum;
+	struct fotg210_iso_stream	*stream;
+	struct usb_host_endpoint *ep;
+	unsigned long		flags;
+
+	epnum = usb_pipeendpoint(urb->pipe);
+	if (usb_pipein(urb->pipe))
+		ep = urb->dev->ep_in[epnum];
+	else
+		ep = urb->dev->ep_out[epnum];
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	stream = ep->hcpriv;
+
+	if (unlikely(stream == NULL)) {
+		stream = iso_stream_alloc(GFP_ATOMIC);
+		if (likely(stream != NULL)) {
+			ep->hcpriv = stream;
+			stream->ep = ep;
+			iso_stream_init(fotg210, stream, urb->dev, urb->pipe,
+					urb->interval);
+		}
+
+	/* if dev->ep[epnum] is a QH, hw is set */
+	} else if (unlikely(stream->hw != NULL)) {
+		fotg210_dbg(fotg210, "dev %s ep%d%s, not iso??\n",
+			urb->dev->devpath, epnum,
+			usb_pipein(urb->pipe) ? "in" : "out");
+		stream = NULL;
+	}
+
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return stream;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* fotg210_iso_sched ops can be ITD-only or SITD-only */
+
+static struct fotg210_iso_sched *
+iso_sched_alloc(unsigned packets, gfp_t mem_flags)
+{
+	struct fotg210_iso_sched	*iso_sched;
+	int			size = sizeof(*iso_sched);
+
+	size += packets * sizeof(struct fotg210_iso_packet);
+	iso_sched = kzalloc(size, mem_flags);
+	if (likely(iso_sched != NULL))
+		INIT_LIST_HEAD(&iso_sched->td_list);
+
+	return iso_sched;
+}
+
+static inline void
+itd_sched_init(
+	struct fotg210_hcd		*fotg210,
+	struct fotg210_iso_sched	*iso_sched,
+	struct fotg210_iso_stream	*stream,
+	struct urb		*urb
+)
+{
+	unsigned	i;
+	dma_addr_t	dma = urb->transfer_dma;
+
+	/* how many uframes are needed for these transfers */
+	iso_sched->span = urb->number_of_packets * stream->interval;
+
+	/* figure out per-uframe itd fields that we'll need later
+	 * when we fit new itds into the schedule.
+	 */
+	for (i = 0; i < urb->number_of_packets; i++) {
+		struct fotg210_iso_packet	*uframe = &iso_sched->packet[i];
+		unsigned		length;
+		dma_addr_t		buf;
+		u32			trans;
+
+		length = urb->iso_frame_desc[i].length;
+		buf = dma + urb->iso_frame_desc[i].offset;
+
+		trans = FOTG210_ISOC_ACTIVE;
+		trans |= buf & 0x0fff;
+		if (unlikely(((i + 1) == urb->number_of_packets))
+				&& !(urb->transfer_flags & URB_NO_INTERRUPT))
+			trans |= FOTG210_ITD_IOC;
+		trans |= length << 16;
+		uframe->transaction = cpu_to_hc32(fotg210, trans);
+
+		/* might need to cross a buffer page within a uframe */
+		uframe->bufp = (buf & ~(u64)0x0fff);
+		buf += length;
+		if (unlikely((uframe->bufp != (buf & ~(u64)0x0fff))))
+			uframe->cross = 1;
+	}
+}
+
+static void
+iso_sched_free(
+	struct fotg210_iso_stream	*stream,
+	struct fotg210_iso_sched	*iso_sched
+)
+{
+	if (!iso_sched)
+		return;
+	/* caller must hold fotg210->lock!*/
+	list_splice(&iso_sched->td_list, &stream->free_list);
+	kfree(iso_sched);
+}
+
+static int
+itd_urb_transaction(
+	struct fotg210_iso_stream	*stream,
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	gfp_t			mem_flags
+)
+{
+	struct fotg210_itd		*itd;
+	dma_addr_t		itd_dma;
+	int			i;
+	unsigned		num_itds;
+	struct fotg210_iso_sched	*sched;
+	unsigned long		flags;
+
+	sched = iso_sched_alloc(urb->number_of_packets, mem_flags);
+	if (unlikely(sched == NULL))
+		return -ENOMEM;
+
+	itd_sched_init(fotg210, sched, stream, urb);
+
+	if (urb->interval < 8)
+		num_itds = 1 + (sched->span + 7) / 8;
+	else
+		num_itds = urb->number_of_packets;
+
+	/* allocate/init ITDs */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	for (i = 0; i < num_itds; i++) {
+
+		/*
+		 * Use iTDs from the free list, but not iTDs that may
+		 * still be in use by the hardware.
+		 */
+		if (likely(!list_empty(&stream->free_list))) {
+			itd = list_first_entry(&stream->free_list,
+					struct fotg210_itd, itd_list);
+			if (itd->frame == fotg210->now_frame)
+				goto alloc_itd;
+			list_del(&itd->itd_list);
+			itd_dma = itd->itd_dma;
+		} else {
+ alloc_itd:
+			spin_unlock_irqrestore(&fotg210->lock, flags);
+			itd = dma_pool_alloc(fotg210->itd_pool, mem_flags,
+					&itd_dma);
+			spin_lock_irqsave(&fotg210->lock, flags);
+			if (!itd) {
+				iso_sched_free(stream, sched);
+				spin_unlock_irqrestore(&fotg210->lock, flags);
+				return -ENOMEM;
+			}
+		}
+
+		memset(itd, 0, sizeof(*itd));
+		itd->itd_dma = itd_dma;
+		list_add(&itd->itd_list, &sched->td_list);
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+
+	/* temporarily store schedule info in hcpriv */
+	urb->hcpriv = sched;
+	urb->error_count = 0;
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline int
+itd_slot_ok(
+	struct fotg210_hcd		*fotg210,
+	u32			mod,
+	u32			uframe,
+	u8			usecs,
+	u32			period
+)
+{
+	uframe %= period;
+	do {
+		/* can't commit more than uframe_periodic_max usec */
+		if (periodic_usecs(fotg210, uframe >> 3, uframe & 0x7)
+				> (fotg210->uframe_periodic_max - usecs))
+			return 0;
+
+		/* we know urb->interval is 2^N uframes */
+		uframe += period;
+	} while (uframe < mod);
+	return 1;
+}
+
+/*
+ * This scheduler plans almost as far into the future as it has actual
+ * periodic schedule slots.  (Affected by TUNE_FLS, which defaults to
+ * "as small as possible" to be cache-friendlier.)  That limits the size
+ * transfers you can stream reliably; avoid more than 64 msec per urb.
+ * Also avoid queue depths of less than fotg210's worst irq latency (affected
+ * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
+ * and other factors); or more than about 230 msec total (for portability,
+ * given FOTG210_TUNE_FLS and the slop).  Or, write a smarter scheduler!
+ */
+
+#define SCHEDULE_SLOP	80	/* microframes */
+
+static int
+iso_stream_schedule(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	struct fotg210_iso_stream	*stream
+)
+{
+	u32			now, next, start, period, span;
+	int			status;
+	unsigned		mod = fotg210->periodic_size << 3;
+	struct fotg210_iso_sched	*sched = urb->hcpriv;
+
+	period = urb->interval;
+	span = sched->span;
+
+	if (span > mod - SCHEDULE_SLOP) {
+		fotg210_dbg(fotg210, "iso request %p too long\n", urb);
+		status = -EFBIG;
+		goto fail;
+	}
+
+	now = fotg210_read_frame_index(fotg210) & (mod - 1);
+
+	/* Typical case: reuse current schedule, stream is still active.
+	 * Hopefully there are no gaps from the host falling behind
+	 * (irq delays etc), but if there are we'll take the next
+	 * slot in the schedule, implicitly assuming URB_ISO_ASAP.
+	 */
+	if (likely(!list_empty(&stream->td_list))) {
+		u32	excess;
+
+		/* For high speed devices, allow scheduling within the
+		 * isochronous scheduling threshold.  For full speed devices
+		 * and Intel PCI-based controllers, don't (work around for
+		 * Intel ICH9 bug).
+		 */
+		if (!stream->highspeed && fotg210->fs_i_thresh)
+			next = now + fotg210->i_thresh;
+		else
+			next = now;
+
+		/* Fell behind (by up to twice the slop amount)?
+		 * We decide based on the time of the last currently-scheduled
+		 * slot, not the time of the next available slot.
+		 */
+		excess = (stream->next_uframe - period - next) & (mod - 1);
+		if (excess >= mod - 2 * SCHEDULE_SLOP)
+			start = next + excess - mod + period *
+					DIV_ROUND_UP(mod - excess, period);
+		else
+			start = next + excess + period;
+		if (start - now >= mod) {
+			fotg210_dbg(fotg210, "request %p would overflow (%d+%d >= %d)\n",
+					urb, start - now - period, period,
+					mod);
+			status = -EFBIG;
+			goto fail;
+		}
+	}
+
+	/* need to schedule; when's the next (u)frame we could start?
+	 * this is bigger than fotg210->i_thresh allows; scheduling itself
+	 * isn't free, the slop should handle reasonably slow cpus.  it
+	 * can also help high bandwidth if the dma and irq loads don't
+	 * jump until after the queue is primed.
+	 */
+	else {
+		int done = 0;
+		start = SCHEDULE_SLOP + (now & ~0x07);
+
+		/* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
+
+		/* find a uframe slot with enough bandwidth.
+		 * Early uframes are more precious because full-speed
+		 * iso IN transfers can't use late uframes,
+		 * and therefore they should be allocated last.
+		 */
+		next = start;
+		start += period;
+		do {
+			start--;
+			/* check schedule: enough space? */
+			if (itd_slot_ok(fotg210, mod, start,
+					stream->usecs, period))
+				done = 1;
+		} while (start > next && !done);
+
+		/* no room in the schedule */
+		if (!done) {
+			fotg210_dbg(fotg210, "iso resched full %p (now %d max %d)\n",
+				urb, now, now + mod);
+			status = -ENOSPC;
+			goto fail;
+		}
+	}
+
+	/* Tried to schedule too far into the future? */
+	if (unlikely(start - now + span - period
+				>= mod - 2 * SCHEDULE_SLOP)) {
+		fotg210_dbg(fotg210, "request %p would overflow (%d+%d >= %d)\n",
+				urb, start - now, span - period,
+				mod - 2 * SCHEDULE_SLOP);
+		status = -EFBIG;
+		goto fail;
+	}
+
+	stream->next_uframe = start & (mod - 1);
+
+	/* report high speed start in uframes; full speed, in frames */
+	urb->start_frame = stream->next_uframe;
+	if (!stream->highspeed)
+		urb->start_frame >>= 3;
+
+	/* Make sure scan_isoc() sees these */
+	if (fotg210->isoc_count == 0)
+		fotg210->next_frame = now >> 3;
+	return 0;
+
+ fail:
+	iso_sched_free(stream, sched);
+	urb->hcpriv = NULL;
+	return status;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static inline void
+itd_init(struct fotg210_hcd *fotg210, struct fotg210_iso_stream *stream,
+		struct fotg210_itd *itd)
+{
+	int i;
+
+	/* it's been recently zeroed */
+	itd->hw_next = FOTG210_LIST_END(fotg210);
+	itd->hw_bufp[0] = stream->buf0;
+	itd->hw_bufp[1] = stream->buf1;
+	itd->hw_bufp[2] = stream->buf2;
+
+	for (i = 0; i < 8; i++)
+		itd->index[i] = -1;
+
+	/* All other fields are filled when scheduling */
+}
+
+static inline void
+itd_patch(
+	struct fotg210_hcd		*fotg210,
+	struct fotg210_itd		*itd,
+	struct fotg210_iso_sched	*iso_sched,
+	unsigned		index,
+	u16			uframe
+)
+{
+	struct fotg210_iso_packet	*uf = &iso_sched->packet[index];
+	unsigned		pg = itd->pg;
+
+	uframe &= 0x07;
+	itd->index[uframe] = index;
+
+	itd->hw_transaction[uframe] = uf->transaction;
+	itd->hw_transaction[uframe] |= cpu_to_hc32(fotg210, pg << 12);
+	itd->hw_bufp[pg] |= cpu_to_hc32(fotg210, uf->bufp & ~(u32)0);
+	itd->hw_bufp_hi[pg] |= cpu_to_hc32(fotg210, (u32)(uf->bufp >> 32));
+
+	/* iso_frame_desc[].offset must be strictly increasing */
+	if (unlikely(uf->cross)) {
+		u64	bufp = uf->bufp + 4096;
+
+		itd->pg = ++pg;
+		itd->hw_bufp[pg] |= cpu_to_hc32(fotg210, bufp & ~(u32)0);
+		itd->hw_bufp_hi[pg] |= cpu_to_hc32(fotg210, (u32)(bufp >> 32));
+	}
+}
+
+static inline void
+itd_link(struct fotg210_hcd *fotg210, unsigned frame, struct fotg210_itd *itd)
+{
+	union fotg210_shadow	*prev = &fotg210->pshadow[frame];
+	__hc32			*hw_p = &fotg210->periodic[frame];
+	union fotg210_shadow	here = *prev;
+	__hc32			type = 0;
+
+	/* skip any iso nodes which might belong to previous microframes */
+	while (here.ptr) {
+		type = Q_NEXT_TYPE(fotg210, *hw_p);
+		if (type == cpu_to_hc32(fotg210, Q_TYPE_QH))
+			break;
+		prev = periodic_next_shadow(fotg210, prev, type);
+		hw_p = shadow_next_periodic(fotg210, &here, type);
+		here = *prev;
+	}
+
+	itd->itd_next = here;
+	itd->hw_next = *hw_p;
+	prev->itd = itd;
+	itd->frame = frame;
+	wmb();
+	*hw_p = cpu_to_hc32(fotg210, itd->itd_dma | Q_TYPE_ITD);
+}
+
+/* fit urb's itds into the selected schedule slot; activate as needed */
+static void itd_link_urb(
+	struct fotg210_hcd		*fotg210,
+	struct urb		*urb,
+	unsigned		mod,
+	struct fotg210_iso_stream	*stream
+)
+{
+	int			packet;
+	unsigned		next_uframe, uframe, frame;
+	struct fotg210_iso_sched	*iso_sched = urb->hcpriv;
+	struct fotg210_itd		*itd;
+
+	next_uframe = stream->next_uframe & (mod - 1);
+
+	if (unlikely(list_empty(&stream->td_list))) {
+		fotg210_to_hcd(fotg210)->self.bandwidth_allocated
+				+= stream->bandwidth;
+		fotg210_vdbg(fotg210,
+			"schedule devp %s ep%d%s-iso period %d start %d.%d\n",
+			urb->dev->devpath, stream->bEndpointAddress & 0x0f,
+			(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
+			urb->interval,
+			next_uframe >> 3, next_uframe & 0x7);
+	}
+
+	/* fill iTDs uframe by uframe */
+	for (packet = 0, itd = NULL; packet < urb->number_of_packets;) {
+		if (itd == NULL) {
+			/* ASSERT:  we have all necessary itds */
+
+			/* ASSERT:  no itds for this endpoint in this uframe */
+
+			itd = list_entry(iso_sched->td_list.next,
+					struct fotg210_itd, itd_list);
+			list_move_tail(&itd->itd_list, &stream->td_list);
+			itd->stream = stream;
+			itd->urb = urb;
+			itd_init(fotg210, stream, itd);
+		}
+
+		uframe = next_uframe & 0x07;
+		frame = next_uframe >> 3;
+
+		itd_patch(fotg210, itd, iso_sched, packet, uframe);
+
+		next_uframe += stream->interval;
+		next_uframe &= mod - 1;
+		packet++;
+
+		/* link completed itds into the schedule */
+		if (((next_uframe >> 3) != frame)
+				|| packet == urb->number_of_packets) {
+			itd_link(fotg210, frame & (fotg210->periodic_size - 1),
+				 itd);
+			itd = NULL;
+		}
+	}
+	stream->next_uframe = next_uframe;
+
+	/* don't need that schedule data any more */
+	iso_sched_free(stream, iso_sched);
+	urb->hcpriv = NULL;
+
+	++fotg210->isoc_count;
+	enable_periodic(fotg210);
+}
+
+#define	ISO_ERRS (FOTG210_ISOC_BUF_ERR | FOTG210_ISOC_BABBLE |\
+		  FOTG210_ISOC_XACTERR)
+
+/* Process and recycle a completed ITD.  Return true iff its urb completed,
+ * and hence its completion callback probably added things to the hardware
+ * schedule.
+ *
+ * Note that we carefully avoid recycling this descriptor until after any
+ * completion callback runs, so that it won't be reused quickly.  That is,
+ * assuming (a) no more than two urbs per frame on this endpoint, and also
+ * (b) only this endpoint's completions submit URBs.  It seems some silicon
+ * corrupts things if you reuse completed descriptors very quickly...
+ */
+static bool itd_complete(struct fotg210_hcd *fotg210, struct fotg210_itd *itd)
+{
+	struct urb				*urb = itd->urb;
+	struct usb_iso_packet_descriptor	*desc;
+	u32					t;
+	unsigned				uframe;
+	int					urb_index = -1;
+	struct fotg210_iso_stream			*stream = itd->stream;
+	struct usb_device			*dev;
+	bool					retval = false;
+
+	/* for each uframe with a packet */
+	for (uframe = 0; uframe < 8; uframe++) {
+		if (likely(itd->index[uframe] == -1))
+			continue;
+		urb_index = itd->index[uframe];
+		desc = &urb->iso_frame_desc[urb_index];
+
+		t = hc32_to_cpup(fotg210, &itd->hw_transaction[uframe]);
+		itd->hw_transaction[uframe] = 0;
+
+		/* report transfer status */
+		if (unlikely(t & ISO_ERRS)) {
+			urb->error_count++;
+			if (t & FOTG210_ISOC_BUF_ERR)
+				desc->status = usb_pipein(urb->pipe)
+					? -ENOSR  /* hc couldn't read */
+					: -ECOMM; /* hc couldn't write */
+			else if (t & FOTG210_ISOC_BABBLE)
+				desc->status = -EOVERFLOW;
+			else /* (t & FOTG210_ISOC_XACTERR) */
+				desc->status = -EPROTO;
+
+			/* HC need not update length with this error */
+			if (!(t & FOTG210_ISOC_BABBLE)) {
+				desc->actual_length =
+					fotg210_itdlen(urb, desc, t);
+				urb->actual_length += desc->actual_length;
+			}
+		} else if (likely((t & FOTG210_ISOC_ACTIVE) == 0)) {
+			desc->status = 0;
+			desc->actual_length = fotg210_itdlen(urb, desc, t);
+			urb->actual_length += desc->actual_length;
+		} else {
+			/* URB was too late */
+			desc->status = -EXDEV;
+		}
+	}
+
+	/* handle completion now? */
+	if (likely((urb_index + 1) != urb->number_of_packets))
+		goto done;
+
+	/* ASSERT: it's really the last itd for this urb
+	list_for_each_entry (itd, &stream->td_list, itd_list)
+		BUG_ON (itd->urb == urb);
+	 */
+
+	/* give urb back to the driver; completion often (re)submits */
+	dev = urb->dev;
+	fotg210_urb_done(fotg210, urb, 0);
+	retval = true;
+	urb = NULL;
+
+	--fotg210->isoc_count;
+	disable_periodic(fotg210);
+
+	if (unlikely(list_is_singular(&stream->td_list))) {
+		fotg210_to_hcd(fotg210)->self.bandwidth_allocated
+				-= stream->bandwidth;
+		fotg210_vdbg(fotg210,
+			"deschedule devp %s ep%d%s-iso\n",
+			dev->devpath, stream->bEndpointAddress & 0x0f,
+			(stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
+	}
+
+done:
+	itd->urb = NULL;
+
+	/* Add to the end of the free list for later reuse */
+	list_move_tail(&itd->itd_list, &stream->free_list);
+
+	/* Recycle the iTDs when the pipeline is empty (ep no longer in use) */
+	if (list_empty(&stream->td_list)) {
+		list_splice_tail_init(&stream->free_list,
+				&fotg210->cached_itd_list);
+		start_free_itds(fotg210);
+	}
+
+	return retval;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int itd_submit(struct fotg210_hcd *fotg210, struct urb *urb,
+	gfp_t mem_flags)
+{
+	int			status = -EINVAL;
+	unsigned long		flags;
+	struct fotg210_iso_stream	*stream;
+
+	/* Get iso_stream head */
+	stream = iso_stream_find(fotg210, urb);
+	if (unlikely(stream == NULL)) {
+		fotg210_dbg(fotg210, "can't get iso stream\n");
+		return -ENOMEM;
+	}
+	if (unlikely(urb->interval != stream->interval &&
+		      fotg210_port_speed(fotg210, 0) ==
+				USB_PORT_STAT_HIGH_SPEED)) {
+			fotg210_dbg(fotg210, "can't change iso interval %d --> %d\n",
+				stream->interval, urb->interval);
+			goto done;
+	}
+
+#ifdef FOTG210_URB_TRACE
+	fotg210_dbg(fotg210,
+		"%s %s urb %p ep%d%s len %d, %d pkts %d uframes[%p]\n",
+		__func__, urb->dev->devpath, urb,
+		usb_pipeendpoint(urb->pipe),
+		usb_pipein(urb->pipe) ? "in" : "out",
+		urb->transfer_buffer_length,
+		urb->number_of_packets, urb->interval,
+		stream);
+#endif
+
+	/* allocate ITDs w/o locking anything */
+	status = itd_urb_transaction(stream, fotg210, urb, mem_flags);
+	if (unlikely(status < 0)) {
+		fotg210_dbg(fotg210, "can't init itds\n");
+		goto done;
+	}
+
+	/* schedule ... need to lock */
+	spin_lock_irqsave(&fotg210->lock, flags);
+	if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
+		status = -ESHUTDOWN;
+		goto done_not_linked;
+	}
+	status = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
+	if (unlikely(status))
+		goto done_not_linked;
+	status = iso_stream_schedule(fotg210, urb, stream);
+	if (likely(status == 0))
+		itd_link_urb(fotg210, urb, fotg210->periodic_size << 3, stream);
+	else
+		usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
+ done_not_linked:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+ done:
+	return status;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void scan_isoc(struct fotg210_hcd *fotg210)
+{
+	unsigned	uf, now_frame, frame;
+	unsigned	fmask = fotg210->periodic_size - 1;
+	bool		modified, live;
+
+	/*
+	 * When running, scan from last scan point up to "now"
+	 * else clean up by scanning everything that's left.
+	 * Touches as few pages as possible:  cache-friendly.
+	 */
+	if (fotg210->rh_state >= FOTG210_RH_RUNNING) {
+		uf = fotg210_read_frame_index(fotg210);
+		now_frame = (uf >> 3) & fmask;
+		live = true;
+	} else  {
+		now_frame = (fotg210->next_frame - 1) & fmask;
+		live = false;
+	}
+	fotg210->now_frame = now_frame;
+
+	frame = fotg210->next_frame;
+	for (;;) {
+		union fotg210_shadow	q, *q_p;
+		__hc32			type, *hw_p;
+
+restart:
+		/* scan each element in frame's queue for completions */
+		q_p = &fotg210->pshadow[frame];
+		hw_p = &fotg210->periodic[frame];
+		q.ptr = q_p->ptr;
+		type = Q_NEXT_TYPE(fotg210, *hw_p);
+		modified = false;
+
+		while (q.ptr != NULL) {
+			switch (hc32_to_cpu(fotg210, type)) {
+			case Q_TYPE_ITD:
+				/* If this ITD is still active, leave it for
+				 * later processing ... check the next entry.
+				 * No need to check for activity unless the
+				 * frame is current.
+				 */
+				if (frame == now_frame && live) {
+					rmb();
+					for (uf = 0; uf < 8; uf++) {
+						if (q.itd->hw_transaction[uf] &
+							    ITD_ACTIVE(fotg210))
+							break;
+					}
+					if (uf < 8) {
+						q_p = &q.itd->itd_next;
+						hw_p = &q.itd->hw_next;
+						type = Q_NEXT_TYPE(fotg210,
+							q.itd->hw_next);
+						q = *q_p;
+						break;
+					}
+				}
+
+				/* Take finished ITDs out of the schedule
+				 * and process them:  recycle, maybe report
+				 * URB completion.  HC won't cache the
+				 * pointer for much longer, if at all.
+				 */
+				*q_p = q.itd->itd_next;
+				*hw_p = q.itd->hw_next;
+				type = Q_NEXT_TYPE(fotg210, q.itd->hw_next);
+				wmb();
+				modified = itd_complete(fotg210, q.itd);
+				q = *q_p;
+				break;
+			default:
+				fotg210_dbg(fotg210, "corrupt type %d frame %d shadow %p\n",
+					type, frame, q.ptr);
+				/* FALL THROUGH */
+			case Q_TYPE_QH:
+			case Q_TYPE_FSTN:
+				/* End of the iTDs and siTDs */
+				q.ptr = NULL;
+				break;
+			}
+
+			/* assume completion callbacks modify the queue */
+			if (unlikely(modified && fotg210->isoc_count > 0))
+				goto restart;
+		}
+
+		/* Stop when we have reached the current frame */
+		if (frame == now_frame)
+			break;
+		frame = (frame + 1) & fmask;
+	}
+	fotg210->next_frame = now_frame;
+}
+/*-------------------------------------------------------------------------*/
+/*
+ * Display / Set uframe_periodic_max
+ */
+static ssize_t show_uframe_periodic_max(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct fotg210_hcd		*fotg210;
+	int			n;
+
+	fotg210 = hcd_to_fotg210(bus_to_hcd(dev_get_drvdata(dev)));
+	n = scnprintf(buf, PAGE_SIZE, "%d\n", fotg210->uframe_periodic_max);
+	return n;
+}
+
+
+static ssize_t store_uframe_periodic_max(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	struct fotg210_hcd	*fotg210;
+	unsigned		uframe_periodic_max;
+	unsigned		frame, uframe;
+	unsigned short		allocated_max;
+	unsigned long		flags;
+	ssize_t			ret;
+
+	fotg210 = hcd_to_fotg210(bus_to_hcd(dev_get_drvdata(dev)));
+	if (kstrtouint(buf, 0, &uframe_periodic_max) < 0)
+		return -EINVAL;
+
+	if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
+		fotg210_info(fotg210, "rejecting invalid request for uframe_periodic_max=%u\n",
+			     uframe_periodic_max);
+		return -EINVAL;
+	}
+
+	ret = -EINVAL;
+
+	/*
+	 * lock, so that our checking does not race with possible periodic
+	 * bandwidth allocation through submitting new urbs.
+	 */
+	spin_lock_irqsave(&fotg210->lock, flags);
+
+	/*
+	 * for request to decrease max periodic bandwidth, we have to check
+	 * every microframe in the schedule to see whether the decrease is
+	 * possible.
+	 */
+	if (uframe_periodic_max < fotg210->uframe_periodic_max) {
+		allocated_max = 0;
+
+		for (frame = 0; frame < fotg210->periodic_size; ++frame)
+			for (uframe = 0; uframe < 7; ++uframe)
+				allocated_max = max(allocated_max,
+						    periodic_usecs(fotg210, frame, uframe));
+
+		if (allocated_max > uframe_periodic_max) {
+			fotg210_info(fotg210,
+				"cannot decrease uframe_periodic_max becase "
+				"periodic bandwidth is already allocated "
+				"(%u > %u)\n",
+				allocated_max, uframe_periodic_max);
+			goto out_unlock;
+		}
+	}
+
+	/* increasing is always ok */
+
+	fotg210_info(fotg210, "setting max periodic bandwidth to %u%% (== %u usec/uframe)\n",
+		     100 * uframe_periodic_max/125, uframe_periodic_max);
+
+	if (uframe_periodic_max != 100)
+		fotg210_warn(fotg210, "max periodic bandwidth set is non-standard\n");
+
+	fotg210->uframe_periodic_max = uframe_periodic_max;
+	ret = count;
+
+out_unlock:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return ret;
+}
+
+static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max,
+		   store_uframe_periodic_max);
+
+static inline int create_sysfs_files(struct fotg210_hcd *fotg210)
+{
+	struct device	*controller = fotg210_to_hcd(fotg210)->self.controller;
+	int	i = 0;
+
+	if (i)
+		goto out;
+
+	i = device_create_file(controller, &dev_attr_uframe_periodic_max);
+out:
+	return i;
+}
+
+static inline void remove_sysfs_files(struct fotg210_hcd *fotg210)
+{
+	struct device	*controller = fotg210_to_hcd(fotg210)->self.controller;
+
+	device_remove_file(controller, &dev_attr_uframe_periodic_max);
+}
+/*-------------------------------------------------------------------------*/
+
+/* On some systems, leaving remote wakeup enabled prevents system shutdown.
+ * The firmware seems to think that powering off is a wakeup event!
+ * This routine turns off remote wakeup and everything else, on all ports.
+ */
+static void fotg210_turn_off_all_ports(struct fotg210_hcd *fotg210)
+{
+	u32 __iomem *status_reg = &fotg210->regs->port_status;
+
+	fotg210_writel(fotg210, PORT_RWC_BITS, status_reg);
+}
+
+/*
+ * Halt HC, turn off all ports, and let the BIOS use the companion controllers.
+ * Must be called with interrupts enabled and the lock not held.
+ */
+static void fotg210_silence_controller(struct fotg210_hcd *fotg210)
+{
+	fotg210_halt(fotg210);
+
+	spin_lock_irq(&fotg210->lock);
+	fotg210->rh_state = FOTG210_RH_HALTED;
+	fotg210_turn_off_all_ports(fotg210);
+	spin_unlock_irq(&fotg210->lock);
+}
+
+/* fotg210_shutdown kick in for silicon on any bus (not just pci, etc).
+ * This forcibly disables dma and IRQs, helping kexec and other cases
+ * where the next system software may expect clean state.
+ */
+static void fotg210_shutdown(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd	*fotg210 = hcd_to_fotg210(hcd);
+
+	spin_lock_irq(&fotg210->lock);
+	fotg210->shutdown = true;
+	fotg210->rh_state = FOTG210_RH_STOPPING;
+	fotg210->enabled_hrtimer_events = 0;
+	spin_unlock_irq(&fotg210->lock);
+
+	fotg210_silence_controller(fotg210);
+
+	hrtimer_cancel(&fotg210->hrtimer);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * fotg210_work is called from some interrupts, timers, and so on.
+ * it calls driver completion functions, after dropping fotg210->lock.
+ */
+static void fotg210_work(struct fotg210_hcd *fotg210)
+{
+	/* another CPU may drop fotg210->lock during a schedule scan while
+	 * it reports urb completions.  this flag guards against bogus
+	 * attempts at re-entrant schedule scanning.
+	 */
+	if (fotg210->scanning) {
+		fotg210->need_rescan = true;
+		return;
+	}
+	fotg210->scanning = true;
+
+ rescan:
+	fotg210->need_rescan = false;
+	if (fotg210->async_count)
+		scan_async(fotg210);
+	if (fotg210->intr_count > 0)
+		scan_intr(fotg210);
+	if (fotg210->isoc_count > 0)
+		scan_isoc(fotg210);
+	if (fotg210->need_rescan)
+		goto rescan;
+	fotg210->scanning = false;
+
+	/* the IO watchdog guards against hardware or driver bugs that
+	 * misplace IRQs, and should let us run completely without IRQs.
+	 * such lossage has been observed on both VT6202 and VT8235.
+	 */
+	turn_on_io_watchdog(fotg210);
+}
+
+/*
+ * Called when the fotg210_hcd module is removed.
+ */
+static void fotg210_stop(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+
+	fotg210_dbg(fotg210, "stop\n");
+
+	/* no more interrupts ... */
+
+	spin_lock_irq(&fotg210->lock);
+	fotg210->enabled_hrtimer_events = 0;
+	spin_unlock_irq(&fotg210->lock);
+
+	fotg210_quiesce(fotg210);
+	fotg210_silence_controller(fotg210);
+	fotg210_reset(fotg210);
+
+	hrtimer_cancel(&fotg210->hrtimer);
+	remove_sysfs_files(fotg210);
+	remove_debug_files(fotg210);
+
+	/* root hub is shut down separately (first, when possible) */
+	spin_lock_irq(&fotg210->lock);
+	end_free_itds(fotg210);
+	spin_unlock_irq(&fotg210->lock);
+	fotg210_mem_cleanup(fotg210);
+
+#ifdef	FOTG210_STATS
+	fotg210_dbg(fotg210, "irq normal %ld err %ld iaa %ld (lost %ld)\n",
+		fotg210->stats.normal, fotg210->stats.error, fotg210->stats.iaa,
+		fotg210->stats.lost_iaa);
+	fotg210_dbg(fotg210, "complete %ld unlink %ld\n",
+		fotg210->stats.complete, fotg210->stats.unlink);
+#endif
+
+	dbg_status(fotg210, "fotg210_stop completed",
+		    fotg210_readl(fotg210, &fotg210->regs->status));
+}
+
+/* one-time init, only for memory state */
+static int hcd_fotg210_init(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	u32			temp;
+	int			retval;
+	u32			hcc_params;
+	struct fotg210_qh_hw	*hw;
+
+	spin_lock_init(&fotg210->lock);
+
+	/*
+	 * keep io watchdog by default, those good HCDs could turn off it later
+	 */
+	fotg210->need_io_watchdog = 1;
+
+	hrtimer_init(&fotg210->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	fotg210->hrtimer.function = fotg210_hrtimer_func;
+	fotg210->next_hrtimer_event = FOTG210_HRTIMER_NO_EVENT;
+
+	hcc_params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+
+	/*
+	 * by default set standard 80% (== 100 usec/uframe) max periodic
+	 * bandwidth as required by USB 2.0
+	 */
+	fotg210->uframe_periodic_max = 100;
+
+	/*
+	 * hw default: 1K periodic list heads, one per frame.
+	 * periodic_size can shrink by USBCMD update if hcc_params allows.
+	 */
+	fotg210->periodic_size = DEFAULT_I_TDPS;
+	INIT_LIST_HEAD(&fotg210->intr_qh_list);
+	INIT_LIST_HEAD(&fotg210->cached_itd_list);
+
+	if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
+		/* periodic schedule size can be smaller than default */
+		switch (FOTG210_TUNE_FLS) {
+		case 0:
+			fotg210->periodic_size = 1024;
+			break;
+		case 1:
+			fotg210->periodic_size = 512;
+			break;
+		case 2:
+			fotg210->periodic_size = 256;
+			break;
+		default:
+			BUG();
+		}
+	}
+	retval = fotg210_mem_init(fotg210, GFP_KERNEL);
+	if (retval < 0)
+		return retval;
+
+	/* controllers may cache some of the periodic schedule ... */
+	fotg210->i_thresh = 2;
+
+	/*
+	 * dedicate a qh for the async ring head, since we couldn't unlink
+	 * a 'real' qh without stopping the async schedule [4.8].  use it
+	 * as the 'reclamation list head' too.
+	 * its dummy is used in hw_alt_next of many tds, to prevent the qh
+	 * from automatically advancing to the next td after short reads.
+	 */
+	fotg210->async->qh_next.qh = NULL;
+	hw = fotg210->async->hw;
+	hw->hw_next = QH_NEXT(fotg210, fotg210->async->qh_dma);
+	hw->hw_info1 = cpu_to_hc32(fotg210, QH_HEAD);
+	hw->hw_token = cpu_to_hc32(fotg210, QTD_STS_HALT);
+	hw->hw_qtd_next = FOTG210_LIST_END(fotg210);
+	fotg210->async->qh_state = QH_STATE_LINKED;
+	hw->hw_alt_next = QTD_NEXT(fotg210, fotg210->async->dummy->qtd_dma);
+
+	/* clear interrupt enables, set irq latency */
+	if (log2_irq_thresh < 0 || log2_irq_thresh > 6)
+		log2_irq_thresh = 0;
+	temp = 1 << (16 + log2_irq_thresh);
+	if (HCC_CANPARK(hcc_params)) {
+		/* HW default park == 3, on hardware that supports it (like
+		 * NVidia and ALI silicon), maximizes throughput on the async
+		 * schedule by avoiding QH fetches between transfers.
+		 *
+		 * With fast usb storage devices and NForce2, "park" seems to
+		 * make problems:  throughput reduction (!), data errors...
+		 */
+		if (park) {
+			park = min_t(unsigned, park, 3);
+			temp |= CMD_PARK;
+			temp |= park << 8;
+		}
+		fotg210_dbg(fotg210, "park %d\n", park);
+	}
+	if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
+		/* periodic schedule size can be smaller than default */
+		temp &= ~(3 << 2);
+		temp |= (FOTG210_TUNE_FLS << 2);
+	}
+	fotg210->command = temp;
+
+	/* Accept arbitrarily long scatter-gather lists */
+	if (!(hcd->driver->flags & HCD_LOCAL_MEM))
+		hcd->self.sg_tablesize = ~0;
+	return 0;
+}
+
+/* start HC running; it's halted, hcd_fotg210_init() has been run (once) */
+static int fotg210_run(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	u32			temp;
+	u32			hcc_params;
+
+	hcd->uses_new_polling = 1;
+
+	/* EHCI spec section 4.1 */
+
+	fotg210_writel(fotg210, fotg210->periodic_dma,
+		       &fotg210->regs->frame_list);
+	fotg210_writel(fotg210, (u32)fotg210->async->qh_dma,
+		       &fotg210->regs->async_next);
+
+	/*
+	 * hcc_params controls whether fotg210->regs->segment must (!!!)
+	 * be used; it constrains QH/ITD/SITD and QTD locations.
+	 * pci_pool consistent memory always uses segment zero.
+	 * streaming mappings for I/O buffers, like pci_map_single(),
+	 * can return segments above 4GB, if the device allows.
+	 *
+	 * NOTE:  the dma mask is visible through dma_supported(), so
+	 * drivers can pass this info along ... like NETIF_F_HIGHDMA,
+	 * Scsi_Host.highmem_io, and so forth.  It's readonly to all
+	 * host side drivers though.
+	 */
+	hcc_params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
+
+	/*
+	 * Philips, Intel, and maybe others need CMD_RUN before the
+	 * root hub will detect new devices (why?); NEC doesn't
+	 */
+	fotg210->command &= ~(CMD_IAAD|CMD_PSE|CMD_ASE|CMD_RESET);
+	fotg210->command |= CMD_RUN;
+	fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
+	dbg_cmd(fotg210, "init", fotg210->command);
+
+	/*
+	 * Start, enabling full USB 2.0 functionality ... usb 1.1 devices
+	 * are explicitly handed to companion controller(s), so no TT is
+	 * involved with the root hub.  (Except where one is integrated,
+	 * and there's no companion controller unless maybe for USB OTG.)
+	 *
+	 * Turning on the CF flag will transfer ownership of all ports
+	 * from the companions to the EHCI controller.  If any of the
+	 * companions are in the middle of a port reset at the time, it
+	 * could cause trouble.  Write-locking ehci_cf_port_reset_rwsem
+	 * guarantees that no resets are in progress.  After we set CF,
+	 * a short delay lets the hardware catch up; new resets shouldn't
+	 * be started before the port switching actions could complete.
+	 */
+	down_write(&ehci_cf_port_reset_rwsem);
+	fotg210->rh_state = FOTG210_RH_RUNNING;
+	/* unblock posted writes */
+	fotg210_readl(fotg210, &fotg210->regs->command);
+	msleep(5);
+	up_write(&ehci_cf_port_reset_rwsem);
+	fotg210->last_periodic_enable = ktime_get_real();
+
+	temp = HC_VERSION(fotg210,
+			  fotg210_readl(fotg210, &fotg210->caps->hc_capbase));
+	fotg210_info(fotg210,
+		"USB %x.%x started, EHCI %x.%02x\n",
+		((fotg210->sbrn & 0xf0)>>4), (fotg210->sbrn & 0x0f),
+		temp >> 8, temp & 0xff);
+
+	fotg210_writel(fotg210, INTR_MASK,
+		    &fotg210->regs->intr_enable); /* Turn On Interrupts */
+
+	/* GRR this is run-once init(), being done every time the HC starts.
+	 * So long as they're part of class devices, we can't do it init()
+	 * since the class device isn't created that early.
+	 */
+	create_debug_files(fotg210);
+	create_sysfs_files(fotg210);
+
+	return 0;
+}
+
+static int fotg210_setup(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
+	int retval;
+
+	fotg210->regs = (void __iomem *)fotg210->caps +
+	    HC_LENGTH(fotg210,
+		      fotg210_readl(fotg210, &fotg210->caps->hc_capbase));
+	dbg_hcs_params(fotg210, "reset");
+	dbg_hcc_params(fotg210, "reset");
+
+	/* cache this readonly data; minimize chip reads */
+	fotg210->hcs_params = fotg210_readl(fotg210,
+					    &fotg210->caps->hcs_params);
+
+	fotg210->sbrn = HCD_USB2;
+
+	/* data structure init */
+	retval = hcd_fotg210_init(hcd);
+	if (retval)
+		return retval;
+
+	retval = fotg210_halt(fotg210);
+	if (retval)
+		return retval;
+
+	fotg210_reset(fotg210);
+
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static irqreturn_t fotg210_irq(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	u32			status, masked_status, pcd_status = 0, cmd;
+	int			bh;
+
+	spin_lock(&fotg210->lock);
+
+	status = fotg210_readl(fotg210, &fotg210->regs->status);
+
+	/* e.g. cardbus physical eject */
+	if (status == ~(u32) 0) {
+		fotg210_dbg(fotg210, "device removed\n");
+		goto dead;
+	}
+
+	/*
+	 * We don't use STS_FLR, but some controllers don't like it to
+	 * remain on, so mask it out along with the other status bits.
+	 */
+	masked_status = status & (INTR_MASK | STS_FLR);
+
+	/* Shared IRQ? */
+	if (!masked_status ||
+	    unlikely(fotg210->rh_state == FOTG210_RH_HALTED)) {
+		spin_unlock(&fotg210->lock);
+		return IRQ_NONE;
+	}
+
+	/* clear (just) interrupts */
+	fotg210_writel(fotg210, masked_status, &fotg210->regs->status);
+	cmd = fotg210_readl(fotg210, &fotg210->regs->command);
+	bh = 0;
+
+#ifdef	VERBOSE_DEBUG
+	/* unrequested/ignored: Frame List Rollover */
+	dbg_status(fotg210, "irq", status);
+#endif
+
+	/* INT, ERR, and IAA interrupt rates can be throttled */
+
+	/* normal [4.15.1.2] or error [4.15.1.1] completion */
+	if (likely((status & (STS_INT|STS_ERR)) != 0)) {
+		if (likely((status & STS_ERR) == 0))
+			COUNT(fotg210->stats.normal);
+		else
+			COUNT(fotg210->stats.error);
+		bh = 1;
+	}
+
+	/* complete the unlinking of some qh [4.15.2.3] */
+	if (status & STS_IAA) {
+
+		/* Turn off the IAA watchdog */
+		fotg210->enabled_hrtimer_events &=
+			~BIT(FOTG210_HRTIMER_IAA_WATCHDOG);
+
+		/*
+		 * Mild optimization: Allow another IAAD to reset the
+		 * hrtimer, if one occurs before the next expiration.
+		 * In theory we could always cancel the hrtimer, but
+		 * tests show that about half the time it will be reset
+		 * for some other event anyway.
+		 */
+		if (fotg210->next_hrtimer_event == FOTG210_HRTIMER_IAA_WATCHDOG)
+			++fotg210->next_hrtimer_event;
+
+		/* guard against (alleged) silicon errata */
+		if (cmd & CMD_IAAD)
+			fotg210_dbg(fotg210, "IAA with IAAD still set?\n");
+		if (fotg210->async_iaa) {
+			COUNT(fotg210->stats.iaa);
+			end_unlink_async(fotg210);
+		} else
+			fotg210_dbg(fotg210, "IAA with nothing unlinked?\n");
+	}
+
+	/* remote wakeup [4.3.1] */
+	if (status & STS_PCD) {
+		int pstatus;
+		u32 __iomem *status_reg = &fotg210->regs->port_status;
+
+		/* kick root hub later */
+		pcd_status = status;
+
+		/* resume root hub? */
+		if (fotg210->rh_state == FOTG210_RH_SUSPENDED)
+			usb_hcd_resume_root_hub(hcd);
+
+		pstatus = fotg210_readl(fotg210, status_reg);
+
+		if (test_bit(0, &fotg210->suspended_ports) &&
+				((pstatus & PORT_RESUME) ||
+					!(pstatus & PORT_SUSPEND)) &&
+				(pstatus & PORT_PE) &&
+				fotg210->reset_done[0] == 0) {
+
+			/* start 20 msec resume signaling from this port,
+			 * and make khubd collect PORT_STAT_C_SUSPEND to
+			 * stop that signaling.  Use 5 ms extra for safety,
+			 * like usb_port_resume() does.
+			 */
+			fotg210->reset_done[0] = jiffies + msecs_to_jiffies(25);
+			set_bit(0, &fotg210->resuming_ports);
+			fotg210_dbg(fotg210, "port 1 remote wakeup\n");
+			mod_timer(&hcd->rh_timer, fotg210->reset_done[0]);
+		}
+	}
+
+	/* PCI errors [4.15.2.4] */
+	if (unlikely((status & STS_FATAL) != 0)) {
+		fotg210_err(fotg210, "fatal error\n");
+		dbg_cmd(fotg210, "fatal", cmd);
+		dbg_status(fotg210, "fatal", status);
+dead:
+		usb_hc_died(hcd);
+
+		/* Don't let the controller do anything more */
+		fotg210->shutdown = true;
+		fotg210->rh_state = FOTG210_RH_STOPPING;
+		fotg210->command &= ~(CMD_RUN | CMD_ASE | CMD_PSE);
+		fotg210_writel(fotg210, fotg210->command,
+			       &fotg210->regs->command);
+		fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
+		fotg210_handle_controller_death(fotg210);
+
+		/* Handle completions when the controller stops */
+		bh = 0;
+	}
+
+	if (bh)
+		fotg210_work(fotg210);
+	spin_unlock(&fotg210->lock);
+	if (pcd_status)
+		usb_hcd_poll_rh_status(hcd);
+	return IRQ_HANDLED;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * non-error returns are a promise to giveback() the urb later
+ * we drop ownership so next owner (or urb unlink) can get it
+ *
+ * urb + dev is in hcd.self.controller.urb_list
+ * we're queueing TDs onto software and hardware lists
+ *
+ * hcd-specific init for hcpriv hasn't been done yet
+ *
+ * NOTE:  control, bulk, and interrupt share the same code to append TDs
+ * to a (possibly active) QH, and the same QH scanning code.
+ */
+static int fotg210_urb_enqueue(
+	struct usb_hcd	*hcd,
+	struct urb	*urb,
+	gfp_t		mem_flags
+) {
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	struct list_head	qtd_list;
+
+	INIT_LIST_HEAD(&qtd_list);
+
+	switch (usb_pipetype(urb->pipe)) {
+	case PIPE_CONTROL:
+		/* qh_completions() code doesn't handle all the fault cases
+		 * in multi-TD control transfers.  Even 1KB is rare anyway.
+		 */
+		if (urb->transfer_buffer_length > (16 * 1024))
+			return -EMSGSIZE;
+		/* FALLTHROUGH */
+	/* case PIPE_BULK: */
+	default:
+		if (!qh_urb_transaction(fotg210, urb, &qtd_list, mem_flags))
+			return -ENOMEM;
+		return submit_async(fotg210, urb, &qtd_list, mem_flags);
+
+	case PIPE_INTERRUPT:
+		if (!qh_urb_transaction(fotg210, urb, &qtd_list, mem_flags))
+			return -ENOMEM;
+		return intr_submit(fotg210, urb, &qtd_list, mem_flags);
+
+	case PIPE_ISOCHRONOUS:
+		return itd_submit(fotg210, urb, mem_flags);
+	}
+}
+
+/* remove from hardware lists
+ * completions normally happen asynchronously
+ */
+
+static int fotg210_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	struct fotg210_qh		*qh;
+	unsigned long		flags;
+	int			rc;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
+	if (rc)
+		goto done;
+
+	switch (usb_pipetype(urb->pipe)) {
+	/* case PIPE_CONTROL: */
+	/* case PIPE_BULK:*/
+	default:
+		qh = (struct fotg210_qh *) urb->hcpriv;
+		if (!qh)
+			break;
+		switch (qh->qh_state) {
+		case QH_STATE_LINKED:
+		case QH_STATE_COMPLETING:
+			start_unlink_async(fotg210, qh);
+			break;
+		case QH_STATE_UNLINK:
+		case QH_STATE_UNLINK_WAIT:
+			/* already started */
+			break;
+		case QH_STATE_IDLE:
+			/* QH might be waiting for a Clear-TT-Buffer */
+			qh_completions(fotg210, qh);
+			break;
+		}
+		break;
+
+	case PIPE_INTERRUPT:
+		qh = (struct fotg210_qh *) urb->hcpriv;
+		if (!qh)
+			break;
+		switch (qh->qh_state) {
+		case QH_STATE_LINKED:
+		case QH_STATE_COMPLETING:
+			start_unlink_intr(fotg210, qh);
+			break;
+		case QH_STATE_IDLE:
+			qh_completions(fotg210, qh);
+			break;
+		default:
+			fotg210_dbg(fotg210, "bogus qh %p state %d\n",
+					qh, qh->qh_state);
+			goto done;
+		}
+		break;
+
+	case PIPE_ISOCHRONOUS:
+		/* itd... */
+
+		/* wait till next completion, do it then. */
+		/* completion irqs can wait up to 1024 msec, */
+		break;
+	}
+done:
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+	return rc;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* bulk qh holds the data toggle */
+
+static void
+fotg210_endpoint_disable(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	unsigned long		flags;
+	struct fotg210_qh		*qh, *tmp;
+
+	/* ASSERT:  any requests/urbs are being unlinked */
+	/* ASSERT:  nobody can be submitting urbs for this any more */
+
+rescan:
+	spin_lock_irqsave(&fotg210->lock, flags);
+	qh = ep->hcpriv;
+	if (!qh)
+		goto done;
+
+	/* endpoints can be iso streams.  for now, we don't
+	 * accelerate iso completions ... so spin a while.
+	 */
+	if (qh->hw == NULL) {
+		struct fotg210_iso_stream	*stream = ep->hcpriv;
+
+		if (!list_empty(&stream->td_list))
+			goto idle_timeout;
+
+		/* BUG_ON(!list_empty(&stream->free_list)); */
+		kfree(stream);
+		goto done;
+	}
+
+	if (fotg210->rh_state < FOTG210_RH_RUNNING)
+		qh->qh_state = QH_STATE_IDLE;
+	switch (qh->qh_state) {
+	case QH_STATE_LINKED:
+	case QH_STATE_COMPLETING:
+		for (tmp = fotg210->async->qh_next.qh;
+				tmp && tmp != qh;
+				tmp = tmp->qh_next.qh)
+			continue;
+		/* periodic qh self-unlinks on empty, and a COMPLETING qh
+		 * may already be unlinked.
+		 */
+		if (tmp)
+			start_unlink_async(fotg210, qh);
+		/* FALL THROUGH */
+	case QH_STATE_UNLINK:		/* wait for hw to finish? */
+	case QH_STATE_UNLINK_WAIT:
+idle_timeout:
+		spin_unlock_irqrestore(&fotg210->lock, flags);
+		schedule_timeout_uninterruptible(1);
+		goto rescan;
+	case QH_STATE_IDLE:		/* fully unlinked */
+		if (qh->clearing_tt)
+			goto idle_timeout;
+		if (list_empty(&qh->qtd_list)) {
+			qh_destroy(fotg210, qh);
+			break;
+		}
+		/* else FALL THROUGH */
+	default:
+		/* caller was supposed to have unlinked any requests;
+		 * that's not our job.  just leak this memory.
+		 */
+		fotg210_err(fotg210, "qh %p (#%02x) state %d%s\n",
+			qh, ep->desc.bEndpointAddress, qh->qh_state,
+			list_empty(&qh->qtd_list) ? "" : "(has tds)");
+		break;
+	}
+ done:
+	ep->hcpriv = NULL;
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+}
+
+static void
+fotg210_endpoint_reset(struct usb_hcd *hcd, struct usb_host_endpoint *ep)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	struct fotg210_qh		*qh;
+	int			eptype = usb_endpoint_type(&ep->desc);
+	int			epnum = usb_endpoint_num(&ep->desc);
+	int			is_out = usb_endpoint_dir_out(&ep->desc);
+	unsigned long		flags;
+
+	if (eptype != USB_ENDPOINT_XFER_BULK && eptype != USB_ENDPOINT_XFER_INT)
+		return;
+
+	spin_lock_irqsave(&fotg210->lock, flags);
+	qh = ep->hcpriv;
+
+	/* For Bulk and Interrupt endpoints we maintain the toggle state
+	 * in the hardware; the toggle bits in udev aren't used at all.
+	 * When an endpoint is reset by usb_clear_halt() we must reset
+	 * the toggle bit in the QH.
+	 */
+	if (qh) {
+		usb_settoggle(qh->dev, epnum, is_out, 0);
+		if (!list_empty(&qh->qtd_list)) {
+			WARN_ONCE(1, "clear_halt for a busy endpoint\n");
+		} else if (qh->qh_state == QH_STATE_LINKED ||
+				qh->qh_state == QH_STATE_COMPLETING) {
+
+			/* The toggle value in the QH can't be updated
+			 * while the QH is active.  Unlink it now;
+			 * re-linking will call qh_refresh().
+			 */
+			if (eptype == USB_ENDPOINT_XFER_BULK)
+				start_unlink_async(fotg210, qh);
+			else
+				start_unlink_intr(fotg210, qh);
+		}
+	}
+	spin_unlock_irqrestore(&fotg210->lock, flags);
+}
+
+static int fotg210_get_frame(struct usb_hcd *hcd)
+{
+	struct fotg210_hcd		*fotg210 = hcd_to_fotg210(hcd);
+	return (fotg210_read_frame_index(fotg210) >> 3) %
+		fotg210->periodic_size;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * The EHCI in ChipIdea HDRC cannot be a separate module or device,
+ * because its registers (and irq) are shared between host/gadget/otg
+ * functions  and in order to facilitate role switching we cannot
+ * give the fotg210 driver exclusive access to those.
+ */
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_LICENSE("GPL");
+
+static const struct hc_driver fotg210_fotg210_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "Faraday USB2.0 Host Controller",
+	.hcd_priv_size		= sizeof(struct fotg210_hcd),
+
+	/*
+	 * generic hardware linkage
+	 */
+	.irq			= fotg210_irq,
+	.flags			= HCD_MEMORY | HCD_USB2,
+
+	/*
+	 * basic lifecycle operations
+	 */
+	.reset			= hcd_fotg210_init,
+	.start			= fotg210_run,
+	.stop			= fotg210_stop,
+	.shutdown		= fotg210_shutdown,
+
+	/*
+	 * managing i/o requests and associated device resources
+	 */
+	.urb_enqueue		= fotg210_urb_enqueue,
+	.urb_dequeue		= fotg210_urb_dequeue,
+	.endpoint_disable	= fotg210_endpoint_disable,
+	.endpoint_reset		= fotg210_endpoint_reset,
+
+	/*
+	 * scheduling support
+	 */
+	.get_frame_number	= fotg210_get_frame,
+
+	/*
+	 * root hub support
+	 */
+	.hub_status_data	= fotg210_hub_status_data,
+	.hub_control		= fotg210_hub_control,
+	.bus_suspend		= fotg210_bus_suspend,
+	.bus_resume		= fotg210_bus_resume,
+
+	.relinquish_port	= fotg210_relinquish_port,
+	.port_handed_over	= fotg210_port_handed_over,
+
+	.clear_tt_buffer_complete = fotg210_clear_tt_buffer_complete,
+};
+
+static void fotg210_init(struct fotg210_hcd *fotg210)
+{
+	u32 value;
+
+	iowrite32(GMIR_MDEV_INT | GMIR_MOTG_INT | GMIR_INT_POLARITY,
+		  &fotg210->regs->gmir);
+
+	value = ioread32(&fotg210->regs->otgcsr);
+	value &= ~OTGCSR_A_BUS_DROP;
+	value |= OTGCSR_A_BUS_REQ;
+	iowrite32(value, &fotg210->regs->otgcsr);
+}
+
+/**
+ * fotg210_hcd_probe - initialize faraday FOTG210 HCDs
+ *
+ * Allocates basic resources for this USB host controller, and
+ * then invokes the start() method for the HCD associated with it
+ * through the hotplug entry's driver_data.
+ */
+static int fotg210_hcd_probe(struct platform_device *pdev)
+{
+	struct device			*dev = &pdev->dev;
+	struct usb_hcd			*hcd;
+	struct resource			*res;
+	int				irq;
+	int				retval = -ENODEV;
+	struct fotg210_hcd		*fotg210;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	pdev->dev.power.power_state = PMSG_ON;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(dev,
+			"Found HC with no IRQ. Check %s setup!\n",
+			dev_name(dev));
+		return -ENODEV;
+	}
+
+	irq = res->start;
+
+	hcd = usb_create_hcd(&fotg210_fotg210_hc_driver, dev,
+			dev_name(dev));
+	if (!hcd) {
+		dev_err(dev, "failed to create hcd with err %d\n", retval);
+		retval = -ENOMEM;
+		goto fail_create_hcd;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev,
+			"Found HC with no register addr. Check %s setup!\n",
+			dev_name(dev));
+		retval = -ENODEV;
+		goto fail_request_resource;
+	}
+
+	hcd->rsrc_start = res->start;
+	hcd->rsrc_len = resource_size(res);
+	hcd->has_tt = 1;
+
+	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len,
+				fotg210_fotg210_hc_driver.description)) {
+		dev_dbg(dev, "controller already in use\n");
+		retval = -EBUSY;
+		goto fail_request_resource;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+	if (!res) {
+		dev_err(dev,
+			"Found HC with no register addr. Check %s setup!\n",
+			dev_name(dev));
+		retval = -ENODEV;
+		goto fail_request_resource;
+	}
+
+	hcd->regs = ioremap_nocache(res->start, resource_size(res));
+	if (hcd->regs == NULL) {
+		dev_dbg(dev, "error mapping memory\n");
+		retval = -EFAULT;
+		goto fail_ioremap;
+	}
+
+	fotg210 = hcd_to_fotg210(hcd);
+
+	fotg210->caps = hcd->regs;
+
+	retval = fotg210_setup(hcd);
+	if (retval)
+		goto fail_add_hcd;
+
+	fotg210_init(fotg210);
+
+	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
+	if (retval) {
+		dev_err(dev, "failed to add hcd with err %d\n", retval);
+		goto fail_add_hcd;
+	}
+
+	return retval;
+
+fail_add_hcd:
+	iounmap(hcd->regs);
+fail_ioremap:
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+fail_request_resource:
+	usb_put_hcd(hcd);
+fail_create_hcd:
+	dev_err(dev, "init %s fail, %d\n", dev_name(dev), retval);
+	return retval;
+}
+
+/**
+ * fotg210_hcd_remove - shutdown processing for EHCI HCDs
+ * @dev: USB Host Controller being removed
+ *
+ */
+static int fotg210_hcd_remove(struct platform_device *pdev)
+{
+	struct device *dev	= &pdev->dev;
+	struct usb_hcd *hcd	= dev_get_drvdata(dev);
+
+	if (!hcd)
+		return 0;
+
+	usb_remove_hcd(hcd);
+	iounmap(hcd->regs);
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+	usb_put_hcd(hcd);
+
+	return 0;
+}
+
+static struct platform_driver fotg210_hcd_driver = {
+	.driver = {
+		.name   = "fotg210-hcd",
+	},
+	.probe  = fotg210_hcd_probe,
+	.remove = fotg210_hcd_remove,
+};
+
+static int __init fotg210_hcd_init(void)
+{
+	int retval = 0;
+
+	if (usb_disabled())
+		return -ENODEV;
+
+	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
+	set_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
+	if (test_bit(USB_UHCI_LOADED, &usb_hcds_loaded) ||
+			test_bit(USB_OHCI_LOADED, &usb_hcds_loaded))
+		pr_warn(KERN_WARNING "Warning! fotg210_hcd should always be loaded before uhci_hcd and ohci_hcd, not after\n");
+
+	pr_debug("%s: block sizes: qh %Zd qtd %Zd itd %Zd\n",
+		 hcd_name,
+		 sizeof(struct fotg210_qh), sizeof(struct fotg210_qtd),
+		 sizeof(struct fotg210_itd));
+
+#ifdef DEBUG
+	fotg210_debug_root = debugfs_create_dir("fotg210", usb_debug_root);
+	if (!fotg210_debug_root) {
+		retval = -ENOENT;
+		goto err_debug;
+	}
+#endif
+
+	retval = platform_driver_register(&fotg210_hcd_driver);
+	if (retval < 0)
+		goto clean;
+	return retval;
+
+	platform_driver_unregister(&fotg210_hcd_driver);
+clean:
+#ifdef DEBUG
+	debugfs_remove(fotg210_debug_root);
+	fotg210_debug_root = NULL;
+err_debug:
+#endif
+	clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
+	return retval;
+}
+module_init(fotg210_hcd_init);
+
+static void __exit fotg210_hcd_cleanup(void)
+{
+	platform_driver_unregister(&fotg210_hcd_driver);
+#ifdef DEBUG
+	debugfs_remove(fotg210_debug_root);
+#endif
+	clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
+}
+module_exit(fotg210_hcd_cleanup);