[PATCH] parport: add parallel port support for SGI O2

Add support for the built-in parallel port on SGI O2 (a.k.a.  IP32).
Define a new configuration option: PARPORT_IP32.  The module is named
parport_ip32.

Hardware support for SPP, EPP and ECP modes along with DMA support when
available are currently implemented.

Signed-off-by: Arnaud Giersch <arnaud.giersch@free.fr>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2253 insertions, 0 deletions

diff --git a/drivers/parport/parport_ip32.c b/drivers/parport/parport_ip32.c
new file mode 100644
index 000000000000..46e06e596d73
--- /dev/null
+++ b/drivers/parport/parport_ip32.c
@@ -0,0 +1,2253 @@
+/* Low-level parallel port routines for built-in port on SGI IP32
+ *
+ * Author: Arnaud Giersch <arnaud.giersch@free.fr>
+ *
+ * Based on parport_pc.c by
+ *	Phil Blundell, Tim Waugh, Jose Renau, David Campbell,
+ *	Andrea Arcangeli, et al.
+ *
+ * Thanks to Ilya A. Volynets-Evenbakh for his help.
+ *
+ * Copyright (C) 2005, 2006 Arnaud Giersch.
+ *
+ * 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., 59
+ * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/* Current status:
+ *
+ *	Basic SPP and PS2 modes are supported.
+ *	Support for parallel port IRQ is present.
+ *	Hardware SPP (a.k.a. compatibility), EPP, and ECP modes are
+ *	supported.
+ *	SPP/ECP FIFO can be driven in PIO or DMA mode.  PIO mode can work with
+ *	or without interrupt support.
+ *
+ *	Hardware ECP mode is not fully implemented (ecp_read_data and
+ *	ecp_write_addr are actually missing).
+ *
+ * To do:
+ *
+ *	Fully implement ECP mode.
+ *	EPP and ECP mode need to be tested.  I currently do not own any
+ *	peripheral supporting these extended mode, and cannot test them.
+ *	If DMA mode works well, decide if support for PIO FIFO modes should be
+ *	dropped.
+ *	Use the io{read,write} family functions when they become available in
+ *	the linux-mips.org tree.  Note: the MIPS specific functions readsb()
+ *	and writesb() are to be translated by ioread8_rep() and iowrite8_rep()
+ *	respectively.
+ */
+
+/* The built-in parallel port on the SGI 02 workstation (a.k.a. IP32) is an
+ * IEEE 1284 parallel port driven by a Texas Instrument TL16PIR552PH chip[1].
+ * This chip supports SPP, bidirectional, EPP and ECP modes.  It has a 16 byte
+ * FIFO buffer and supports DMA transfers.
+ *
+ * [1] http://focus.ti.com/docs/prod/folders/print/tl16pir552.html
+ *
+ * Theoretically, we could simply use the parport_pc module.  It is however
+ * not so simple.  The parport_pc code assumes that the parallel port
+ * registers are port-mapped.  On the O2, they are memory-mapped.
+ * Furthermore, each register is replicated on 256 consecutive addresses (as
+ * it is for the built-in serial ports on the same chip).
+ */
+
+/*--- Some configuration defines ---------------------------------------*/
+
+/* DEBUG_PARPORT_IP32
+ *	0	disable debug
+ *	1	standard level: pr_debug1 is enabled
+ *	2	parport_ip32_dump_state is enabled
+ *	>=3	verbose level: pr_debug is enabled
+ */
+#if !defined(DEBUG_PARPORT_IP32)
+#	define DEBUG_PARPORT_IP32  0	/* 0 (disabled) for production */
+#endif
+
+/*----------------------------------------------------------------------*/
+
+/* Setup DEBUG macros.  This is done before any includes, just in case we
+ * activate pr_debug() with DEBUG_PARPORT_IP32 >= 3.
+ */
+#if DEBUG_PARPORT_IP32 == 1
+#	warning DEBUG_PARPORT_IP32 == 1
+#elif DEBUG_PARPORT_IP32 == 2
+#	warning DEBUG_PARPORT_IP32 == 2
+#elif DEBUG_PARPORT_IP32 >= 3
+#	warning DEBUG_PARPORT_IP32 >= 3
+#	if !defined(DEBUG)
+#		define DEBUG /* enable pr_debug() in kernel.h */
+#	endif
+#endif
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/parport.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+#include <asm/io.h>
+#include <asm/ip32/ip32_ints.h>
+#include <asm/ip32/mace.h>
+
+/*--- Global variables -------------------------------------------------*/
+
+/* Verbose probing on by default for debugging. */
+#if DEBUG_PARPORT_IP32 >= 1
+#	define DEFAULT_VERBOSE_PROBING	1
+#else
+#	define DEFAULT_VERBOSE_PROBING	0
+#endif
+
+/* Default prefix for printk */
+#define PPIP32 "parport_ip32: "
+
+/*
+ * These are the module parameters:
+ * @features:		bit mask of features to enable/disable
+ *			(all enabled by default)
+ * @verbose_probing:	log chit-chat during initialization
+ */
+#define PARPORT_IP32_ENABLE_IRQ	(1U << 0)
+#define PARPORT_IP32_ENABLE_DMA	(1U << 1)
+#define PARPORT_IP32_ENABLE_SPP	(1U << 2)
+#define PARPORT_IP32_ENABLE_EPP	(1U << 3)
+#define PARPORT_IP32_ENABLE_ECP	(1U << 4)
+static unsigned int features =	~0U;
+static int verbose_probing =	DEFAULT_VERBOSE_PROBING;
+
+/* We do not support more than one port. */
+static struct parport *this_port = NULL;
+
+/* Timing constants for FIFO modes.  */
+#define FIFO_NFAULT_TIMEOUT	100	/* milliseconds */
+#define FIFO_POLLING_INTERVAL	50	/* microseconds */
+
+/*--- I/O register definitions -----------------------------------------*/
+
+/**
+ * struct parport_ip32_regs - virtual addresses of parallel port registers
+ * @data:	Data Register
+ * @dsr:	Device Status Register
+ * @dcr:	Device Control Register
+ * @eppAddr:	EPP Address Register
+ * @eppData0:	EPP Data Register 0
+ * @eppData1:	EPP Data Register 1
+ * @eppData2:	EPP Data Register 2
+ * @eppData3:	EPP Data Register 3
+ * @ecpAFifo:	ECP Address FIFO
+ * @fifo:	General FIFO register.  The same address is used for:
+ *		- cFifo, the Parallel Port DATA FIFO
+ *		- ecpDFifo, the ECP Data FIFO
+ *		- tFifo, the ECP Test FIFO
+ * @cnfgA:	Configuration Register A
+ * @cnfgB:	Configuration Register B
+ * @ecr:	Extended Control Register
+ */
+struct parport_ip32_regs {
+	void __iomem *data;
+	void __iomem *dsr;
+	void __iomem *dcr;
+	void __iomem *eppAddr;
+	void __iomem *eppData0;
+	void __iomem *eppData1;
+	void __iomem *eppData2;
+	void __iomem *eppData3;
+	void __iomem *ecpAFifo;
+	void __iomem *fifo;
+	void __iomem *cnfgA;
+	void __iomem *cnfgB;
+	void __iomem *ecr;
+};
+
+/* Device Status Register */
+#define DSR_nBUSY		(1U << 7)	/* PARPORT_STATUS_BUSY */
+#define DSR_nACK		(1U << 6)	/* PARPORT_STATUS_ACK */
+#define DSR_PERROR		(1U << 5)	/* PARPORT_STATUS_PAPEROUT */
+#define DSR_SELECT		(1U << 4)	/* PARPORT_STATUS_SELECT */
+#define DSR_nFAULT		(1U << 3)	/* PARPORT_STATUS_ERROR */
+#define DSR_nPRINT		(1U << 2)	/* specific to TL16PIR552 */
+/* #define DSR_reserved		(1U << 1) */
+#define DSR_TIMEOUT		(1U << 0)	/* EPP timeout */
+
+/* Device Control Register */
+/* #define DCR_reserved		(1U << 7) | (1U <<  6) */
+#define DCR_DIR			(1U << 5)	/* direction */
+#define DCR_IRQ			(1U << 4)	/* interrupt on nAck */
+#define DCR_SELECT		(1U << 3)	/* PARPORT_CONTROL_SELECT */
+#define DCR_nINIT		(1U << 2)	/* PARPORT_CONTROL_INIT */
+#define DCR_AUTOFD		(1U << 1)	/* PARPORT_CONTROL_AUTOFD */
+#define DCR_STROBE		(1U << 0)	/* PARPORT_CONTROL_STROBE */
+
+/* ECP Configuration Register A */
+#define CNFGA_IRQ		(1U << 7)
+#define CNFGA_ID_MASK		((1U << 6) | (1U << 5) | (1U << 4))
+#define CNFGA_ID_SHIFT		4
+#define CNFGA_ID_16		(00U << CNFGA_ID_SHIFT)
+#define CNFGA_ID_8		(01U << CNFGA_ID_SHIFT)
+#define CNFGA_ID_32		(02U << CNFGA_ID_SHIFT)
+/* #define CNFGA_reserved	(1U << 3) */
+#define CNFGA_nBYTEINTRANS	(1U << 2)
+#define CNFGA_PWORDLEFT		((1U << 1) | (1U << 0))
+
+/* ECP Configuration Register B */
+#define CNFGB_COMPRESS		(1U << 7)
+#define CNFGB_INTRVAL		(1U << 6)
+#define CNFGB_IRQ_MASK		((1U << 5) | (1U << 4) | (1U << 3))
+#define CNFGB_IRQ_SHIFT		3
+#define CNFGB_DMA_MASK		((1U << 2) | (1U << 1) | (1U << 0))
+#define CNFGB_DMA_SHIFT		0
+
+/* Extended Control Register */
+#define ECR_MODE_MASK		((1U << 7) | (1U << 6) | (1U << 5))
+#define ECR_MODE_SHIFT		5
+#define ECR_MODE_SPP		(00U << ECR_MODE_SHIFT)
+#define ECR_MODE_PS2		(01U << ECR_MODE_SHIFT)
+#define ECR_MODE_PPF		(02U << ECR_MODE_SHIFT)
+#define ECR_MODE_ECP		(03U << ECR_MODE_SHIFT)
+#define ECR_MODE_EPP		(04U << ECR_MODE_SHIFT)
+/* #define ECR_MODE_reserved	(05U << ECR_MODE_SHIFT) */
+#define ECR_MODE_TST		(06U << ECR_MODE_SHIFT)
+#define ECR_MODE_CFG		(07U << ECR_MODE_SHIFT)
+#define ECR_nERRINTR		(1U << 4)
+#define ECR_DMAEN		(1U << 3)
+#define ECR_SERVINTR		(1U << 2)
+#define ECR_F_FULL		(1U << 1)
+#define ECR_F_EMPTY		(1U << 0)
+
+/*--- Private data -----------------------------------------------------*/
+
+/**
+ * enum parport_ip32_irq_mode - operation mode of interrupt handler
+ * @PARPORT_IP32_IRQ_FWD:	forward interrupt to the upper parport layer
+ * @PARPORT_IP32_IRQ_HERE:	interrupt is handled locally
+ */
+enum parport_ip32_irq_mode { PARPORT_IP32_IRQ_FWD, PARPORT_IP32_IRQ_HERE };
+
+/**
+ * struct parport_ip32_private - private stuff for &struct parport
+ * @regs:		register addresses
+ * @dcr_cache:		cached contents of DCR
+ * @dcr_writable:	bit mask of writable DCR bits
+ * @pword:		number of bytes per PWord
+ * @fifo_depth:		number of PWords that FIFO will hold
+ * @readIntrThreshold:	minimum number of PWords we can read
+ *			if we get an interrupt
+ * @writeIntrThreshold:	minimum number of PWords we can write
+ *			if we get an interrupt
+ * @irq_mode:		operation mode of interrupt handler for this port
+ * @irq_complete:	mutex used to wait for an interrupt to occur
+ */
+struct parport_ip32_private {
+	struct parport_ip32_regs	regs;
+	unsigned int			dcr_cache;
+	unsigned int			dcr_writable;
+	unsigned int			pword;
+	unsigned int			fifo_depth;
+	unsigned int			readIntrThreshold;
+	unsigned int			writeIntrThreshold;
+	enum parport_ip32_irq_mode	irq_mode;
+	struct completion		irq_complete;
+};
+
+/*--- Debug code -------------------------------------------------------*/
+
+/*
+ * pr_debug1 - print debug messages
+ *
+ * This is like pr_debug(), but is defined for %DEBUG_PARPORT_IP32 >= 1
+ */
+#if DEBUG_PARPORT_IP32 >= 1
+#	define pr_debug1(...)	printk(KERN_DEBUG __VA_ARGS__)
+#else /* DEBUG_PARPORT_IP32 < 1 */
+#	define pr_debug1(...)	do { } while (0)
+#endif
+
+/*
+ * pr_trace, pr_trace1 - trace function calls
+ * @p:		pointer to &struct parport
+ * @fmt:	printk format string
+ * @...:	parameters for format string
+ *
+ * Macros used to trace function calls.  The given string is formatted after
+ * function name.  pr_trace() uses pr_debug(), and pr_trace1() uses
+ * pr_debug1().  __pr_trace() is the low-level macro and is not to be used
+ * directly.
+ */
+#define __pr_trace(pr, p, fmt, ...)					\
+	pr("%s: %s" fmt "\n",						\
+	   ({ const struct parport *__p = (p);				\
+		   __p ? __p->name : "parport_ip32"; }),		\
+	   __func__ , ##__VA_ARGS__)
+#define pr_trace(p, fmt, ...)	__pr_trace(pr_debug, p, fmt , ##__VA_ARGS__)
+#define pr_trace1(p, fmt, ...)	__pr_trace(pr_debug1, p, fmt , ##__VA_ARGS__)
+
+/*
+ * __pr_probe, pr_probe - print message if @verbose_probing is true
+ * @p:		pointer to &struct parport
+ * @fmt:	printk format string
+ * @...:	parameters for format string
+ *
+ * For new lines, use pr_probe().  Use __pr_probe() for continued lines.
+ */
+#define __pr_probe(...)							\
+	do { if (verbose_probing) printk(__VA_ARGS__); } while (0)
+#define pr_probe(p, fmt, ...)						\
+	__pr_probe(KERN_INFO PPIP32 "0x%lx: " fmt, (p)->base , ##__VA_ARGS__)
+
+/*
+ * parport_ip32_dump_state - print register status of parport
+ * @p:		pointer to &struct parport
+ * @str:	string to add in message
+ * @show_ecp_config:	shall we dump ECP configuration registers too?
+ *
+ * This function is only here for debugging purpose, and should be used with
+ * care.  Reading the parallel port registers may have undesired side effects.
+ * Especially if @show_ecp_config is true, the parallel port is resetted.
+ * This function is only defined if %DEBUG_PARPORT_IP32 >= 2.
+ */
+#if DEBUG_PARPORT_IP32 >= 2
+static void parport_ip32_dump_state(struct parport *p, char *str,
+				    unsigned int show_ecp_config)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	unsigned int i;
+
+	printk(KERN_DEBUG PPIP32 "%s: state (%s):\n", p->name, str);
+	{
+		static const char ecr_modes[8][4] = {"SPP", "PS2", "PPF",
+						     "ECP", "EPP", "???",
+						     "TST", "CFG"};
+		unsigned int ecr = readb(priv->regs.ecr);
+		printk(KERN_DEBUG PPIP32 "    ecr=0x%02x", ecr);
+		printk(" %s",
+		       ecr_modes[(ecr & ECR_MODE_MASK) >> ECR_MODE_SHIFT]);
+		if (ecr & ECR_nERRINTR)
+			printk(",nErrIntrEn");
+		if (ecr & ECR_DMAEN)
+			printk(",dmaEn");
+		if (ecr & ECR_SERVINTR)
+			printk(",serviceIntr");
+		if (ecr & ECR_F_FULL)
+			printk(",f_full");
+		if (ecr & ECR_F_EMPTY)
+			printk(",f_empty");
+		printk("\n");
+	}
+	if (show_ecp_config) {
+		unsigned int oecr, cnfgA, cnfgB;
+		oecr = readb(priv->regs.ecr);
+		writeb(ECR_MODE_PS2, priv->regs.ecr);
+		writeb(ECR_MODE_CFG, priv->regs.ecr);
+		cnfgA = readb(priv->regs.cnfgA);
+		cnfgB = readb(priv->regs.cnfgB);
+		writeb(ECR_MODE_PS2, priv->regs.ecr);
+		writeb(oecr, priv->regs.ecr);
+		printk(KERN_DEBUG PPIP32 "    cnfgA=0x%02x", cnfgA);
+		printk(" ISA-%s", (cnfgA & CNFGA_IRQ) ? "Level" : "Pulses");
+		switch (cnfgA & CNFGA_ID_MASK) {
+		case CNFGA_ID_8:
+			printk(",8 bits");
+			break;
+		case CNFGA_ID_16:
+			printk(",16 bits");
+			break;
+		case CNFGA_ID_32:
+			printk(",32 bits");
+			break;
+		default:
+			printk(",unknown ID");
+			break;
+		}
+		if (!(cnfgA & CNFGA_nBYTEINTRANS))
+			printk(",ByteInTrans");
+		if ((cnfgA & CNFGA_ID_MASK) != CNFGA_ID_8)
+			printk(",%d byte%s left", cnfgA & CNFGA_PWORDLEFT,
+			       ((cnfgA & CNFGA_PWORDLEFT) > 1) ? "s" : "");
+		printk("\n");
+		printk(KERN_DEBUG PPIP32 "    cnfgB=0x%02x", cnfgB);
+		printk(" irq=%u,dma=%u",
+		       (cnfgB & CNFGB_IRQ_MASK) >> CNFGB_IRQ_SHIFT,
+		       (cnfgB & CNFGB_DMA_MASK) >> CNFGB_DMA_SHIFT);
+		printk(",intrValue=%d", !!(cnfgB & CNFGB_INTRVAL));
+		if (cnfgB & CNFGB_COMPRESS)
+			printk(",compress");
+		printk("\n");
+	}
+	for (i = 0; i < 2; i++) {
+		unsigned int dcr = i ? priv->dcr_cache : readb(priv->regs.dcr);
+		printk(KERN_DEBUG PPIP32 "    dcr(%s)=0x%02x",
+		       i ? "soft" : "hard", dcr);
+		printk(" %s", (dcr & DCR_DIR) ? "rev" : "fwd");
+		if (dcr & DCR_IRQ)
+			printk(",ackIntEn");
+		if (!(dcr & DCR_SELECT))
+			printk(",nSelectIn");
+		if (dcr & DCR_nINIT)
+			printk(",nInit");
+		if (!(dcr & DCR_AUTOFD))
+			printk(",nAutoFD");
+		if (!(dcr & DCR_STROBE))
+			printk(",nStrobe");
+		printk("\n");
+	}
+#define sep (f++ ? ',' : ' ')
+	{
+		unsigned int f = 0;
+		unsigned int dsr = readb(priv->regs.dsr);
+		printk(KERN_DEBUG PPIP32 "    dsr=0x%02x", dsr);
+		if (!(dsr & DSR_nBUSY))
+			printk("%cBusy", sep);
+		if (dsr & DSR_nACK)
+			printk("%cnAck", sep);
+		if (dsr & DSR_PERROR)
+			printk("%cPError", sep);
+		if (dsr & DSR_SELECT)
+			printk("%cSelect", sep);
+		if (dsr & DSR_nFAULT)
+			printk("%cnFault", sep);
+		if (!(dsr & DSR_nPRINT))
+			printk("%c(Print)", sep);
+		if (dsr & DSR_TIMEOUT)
+			printk("%cTimeout", sep);
+		printk("\n");
+	}
+#undef sep
+}
+#else /* DEBUG_PARPORT_IP32 < 2 */
+#define parport_ip32_dump_state(...)	do { } while (0)
+#endif
+
+/*
+ * CHECK_EXTRA_BITS - track and log extra bits
+ * @p:		pointer to &struct parport
+ * @b:		byte to inspect
+ * @m:		bit mask of authorized bits
+ *
+ * This is used to track and log extra bits that should not be there in
+ * parport_ip32_write_control() and parport_ip32_frob_control().  It is only
+ * defined if %DEBUG_PARPORT_IP32 >= 1.
+ */
+#if DEBUG_PARPORT_IP32 >= 1
+#define CHECK_EXTRA_BITS(p, b, m)					\
+	do {								\
+		unsigned int __b = (b), __m = (m);			\
+		if (__b & ~__m)						\
+			pr_debug1(PPIP32 "%s: extra bits in %s(%s): "	\
+				  "0x%02x/0x%02x\n",			\
+				  (p)->name, __func__, #b, __b, __m);	\
+	} while (0)
+#else /* DEBUG_PARPORT_IP32 < 1 */
+#define CHECK_EXTRA_BITS(...)	do { } while (0)
+#endif
+
+/*--- IP32 parallel port DMA operations --------------------------------*/
+
+/**
+ * struct parport_ip32_dma_data - private data needed for DMA operation
+ * @dir:	DMA direction (from or to device)
+ * @buf:	buffer physical address
+ * @len:	buffer length
+ * @next:	address of next bytes to DMA transfer
+ * @left:	number of bytes remaining
+ * @ctx:	next context to write (0: context_a; 1: context_b)
+ * @irq_on:	are the DMA IRQs currently enabled?
+ * @lock:	spinlock to protect access to the structure
+ */
+struct parport_ip32_dma_data {
+	enum dma_data_direction		dir;
+	dma_addr_t			buf;
+	dma_addr_t			next;
+	size_t				len;
+	size_t				left;
+	unsigned int			ctx;
+	unsigned int			irq_on;
+	spinlock_t			lock;
+};
+static struct parport_ip32_dma_data parport_ip32_dma;
+
+/**
+ * parport_ip32_dma_setup_context - setup next DMA context
+ * @limit:	maximum data size for the context
+ *
+ * The alignment constraints must be verified in caller function, and the
+ * parameter @limit must be set accordingly.
+ */
+static void parport_ip32_dma_setup_context(unsigned int limit)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&parport_ip32_dma.lock, flags);
+	if (parport_ip32_dma.left > 0) {
+		/* Note: ctxreg is "volatile" here only because
+		 * mace->perif.ctrl.parport.context_a and context_b are
+		 * "volatile".  */
+		volatile u64 __iomem *ctxreg = (parport_ip32_dma.ctx == 0) ?
+			&mace->perif.ctrl.parport.context_a :
+			&mace->perif.ctrl.parport.context_b;
+		u64 count;
+		u64 ctxval;
+		if (parport_ip32_dma.left <= limit) {
+			count = parport_ip32_dma.left;
+			ctxval = MACEPAR_CONTEXT_LASTFLAG;
+		} else {
+			count = limit;
+			ctxval = 0;
+		}
+
+		pr_trace(NULL,
+			 "(%u): 0x%04x:0x%04x, %u -> %u%s",
+			 limit,
+			 (unsigned int)parport_ip32_dma.buf,
+			 (unsigned int)parport_ip32_dma.next,
+			 (unsigned int)count,
+			 parport_ip32_dma.ctx, ctxval ? "*" : "");
+
+		ctxval |= parport_ip32_dma.next &
+			MACEPAR_CONTEXT_BASEADDR_MASK;
+		ctxval |= ((count - 1) << MACEPAR_CONTEXT_DATALEN_SHIFT) &
+			MACEPAR_CONTEXT_DATALEN_MASK;
+		writeq(ctxval, ctxreg);
+		parport_ip32_dma.next += count;
+		parport_ip32_dma.left -= count;
+		parport_ip32_dma.ctx ^= 1U;
+	}
+	/* If there is nothing more to send, disable IRQs to avoid to
+	 * face an IRQ storm which can lock the machine.  Disable them
+	 * only once. */
+	if (parport_ip32_dma.left == 0 && parport_ip32_dma.irq_on) {
+		pr_debug(PPIP32 "IRQ off (ctx)\n");
+		disable_irq_nosync(MACEISA_PAR_CTXA_IRQ);
+		disable_irq_nosync(MACEISA_PAR_CTXB_IRQ);
+		parport_ip32_dma.irq_on = 0;
+	}
+	spin_unlock_irqrestore(&parport_ip32_dma.lock, flags);
+}
+
+/**
+ * parport_ip32_dma_interrupt - DMA interrupt handler
+ * @irq:	interrupt number
+ * @dev_id:	unused
+ * @regs:	pointer to &struct pt_regs
+ */
+static irqreturn_t parport_ip32_dma_interrupt(int irq, void *dev_id,
+					      struct pt_regs *regs)
+{
+	if (parport_ip32_dma.left)
+		pr_trace(NULL, "(%d): ctx=%d", irq, parport_ip32_dma.ctx);
+	parport_ip32_dma_setup_context(MACEPAR_CONTEXT_DATA_BOUND);
+	return IRQ_HANDLED;
+}
+
+#if DEBUG_PARPORT_IP32
+static irqreturn_t parport_ip32_merr_interrupt(int irq, void *dev_id,
+					       struct pt_regs *regs)
+{
+	pr_trace1(NULL, "(%d)", irq);
+	return IRQ_HANDLED;
+}
+#endif
+
+/**
+ * parport_ip32_dma_start - begins a DMA transfer
+ * @dir:	DMA direction: DMA_TO_DEVICE or DMA_FROM_DEVICE
+ * @addr:	pointer to data buffer
+ * @count:	buffer size
+ *
+ * Calls to parport_ip32_dma_start() and parport_ip32_dma_stop() must be
+ * correctly balanced.
+ */
+static int parport_ip32_dma_start(enum dma_data_direction dir,
+				  void *addr, size_t count)
+{
+	unsigned int limit;
+	u64 ctrl;
+
+	pr_trace(NULL, "(%d, %lu)", dir, (unsigned long)count);
+
+	/* FIXME - add support for DMA_FROM_DEVICE.  In this case, buffer must
+	 * be 64 bytes aligned. */
+	BUG_ON(dir != DMA_TO_DEVICE);
+
+	/* Reset DMA controller */
+	ctrl = MACEPAR_CTLSTAT_RESET;
+	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
+
+	/* DMA IRQs should normally be enabled */
+	if (!parport_ip32_dma.irq_on) {
+		WARN_ON(1);
+		enable_irq(MACEISA_PAR_CTXA_IRQ);
+		enable_irq(MACEISA_PAR_CTXB_IRQ);
+		parport_ip32_dma.irq_on = 1;
+	}
+
+	/* Prepare DMA pointers */
+	parport_ip32_dma.dir = dir;
+	parport_ip32_dma.buf = dma_map_single(NULL, addr, count, dir);
+	parport_ip32_dma.len = count;
+	parport_ip32_dma.next = parport_ip32_dma.buf;
+	parport_ip32_dma.left = parport_ip32_dma.len;
+	parport_ip32_dma.ctx = 0;
+
+	/* Setup DMA direction and first two contexts */
+	ctrl = (dir == DMA_TO_DEVICE) ? 0 : MACEPAR_CTLSTAT_DIRECTION;
+	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
+	/* Single transfer should not cross a 4K page boundary */
+	limit = MACEPAR_CONTEXT_DATA_BOUND -
+		(parport_ip32_dma.next & (MACEPAR_CONTEXT_DATA_BOUND - 1));
+	parport_ip32_dma_setup_context(limit);
+	parport_ip32_dma_setup_context(MACEPAR_CONTEXT_DATA_BOUND);
+
+	/* Real start of DMA transfer */
+	ctrl |= MACEPAR_CTLSTAT_ENABLE;
+	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
+
+	return 0;
+}
+
+/**
+ * parport_ip32_dma_stop - ends a running DMA transfer
+ *
+ * Calls to parport_ip32_dma_start() and parport_ip32_dma_stop() must be
+ * correctly balanced.
+ */
+static void parport_ip32_dma_stop(void)
+{
+	u64 ctx_a;
+	u64 ctx_b;
+	u64 ctrl;
+	u64 diag;
+	size_t res[2];	/* {[0] = res_a, [1] = res_b} */
+
+	pr_trace(NULL, "()");
+
+	/* Disable IRQs */
+	spin_lock_irq(&parport_ip32_dma.lock);
+	if (parport_ip32_dma.irq_on) {
+		pr_debug(PPIP32 "IRQ off (stop)\n");
+		disable_irq_nosync(MACEISA_PAR_CTXA_IRQ);
+		disable_irq_nosync(MACEISA_PAR_CTXB_IRQ);
+		parport_ip32_dma.irq_on = 0;
+	}
+	spin_unlock_irq(&parport_ip32_dma.lock);
+	/* Force IRQ synchronization, even if the IRQs were disabled
+	 * elsewhere. */
+	synchronize_irq(MACEISA_PAR_CTXA_IRQ);
+	synchronize_irq(MACEISA_PAR_CTXB_IRQ);
+
+	/* Stop DMA transfer */
+	ctrl = readq(&mace->perif.ctrl.parport.cntlstat);
+	ctrl &= ~MACEPAR_CTLSTAT_ENABLE;
+	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
+
+	/* Adjust residue (parport_ip32_dma.left) */
+	ctx_a = readq(&mace->perif.ctrl.parport.context_a);
+	ctx_b = readq(&mace->perif.ctrl.parport.context_b);
+	ctrl = readq(&mace->perif.ctrl.parport.cntlstat);
+	diag = readq(&mace->perif.ctrl.parport.diagnostic);
+	res[0] = (ctrl & MACEPAR_CTLSTAT_CTXA_VALID) ?
+		1 + ((ctx_a & MACEPAR_CONTEXT_DATALEN_MASK) >>
+		     MACEPAR_CONTEXT_DATALEN_SHIFT) :
+		0;
+	res[1] = (ctrl & MACEPAR_CTLSTAT_CTXB_VALID) ?
+		1 + ((ctx_b & MACEPAR_CONTEXT_DATALEN_MASK) >>
+		     MACEPAR_CONTEXT_DATALEN_SHIFT) :
+		0;
+	if (diag & MACEPAR_DIAG_DMACTIVE)
+		res[(diag & MACEPAR_DIAG_CTXINUSE) != 0] =
+			1 + ((diag & MACEPAR_DIAG_CTRMASK) >>
+			     MACEPAR_DIAG_CTRSHIFT);
+	parport_ip32_dma.left += res[0] + res[1];
+
+	/* Reset DMA controller, and re-enable IRQs */
+	ctrl = MACEPAR_CTLSTAT_RESET;
+	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
+	pr_debug(PPIP32 "IRQ on (stop)\n");
+	enable_irq(MACEISA_PAR_CTXA_IRQ);
+	enable_irq(MACEISA_PAR_CTXB_IRQ);
+	parport_ip32_dma.irq_on = 1;
+
+	dma_unmap_single(NULL, parport_ip32_dma.buf, parport_ip32_dma.len,
+			 parport_ip32_dma.dir);
+}
+
+/**
+ * parport_ip32_dma_get_residue - get residue from last DMA transfer
+ *
+ * Returns the number of bytes remaining from last DMA transfer.
+ */
+static inline size_t parport_ip32_dma_get_residue(void)
+{
+	return parport_ip32_dma.left;
+}
+
+/**
+ * parport_ip32_dma_register - initialize DMA engine
+ *
+ * Returns zero for success.
+ */
+static int parport_ip32_dma_register(void)
+{
+	int err;
+
+	spin_lock_init(&parport_ip32_dma.lock);
+	parport_ip32_dma.irq_on = 1;
+
+	/* Reset DMA controller */
+	writeq(MACEPAR_CTLSTAT_RESET, &mace->perif.ctrl.parport.cntlstat);
+
+	/* Request IRQs */
+	err = request_irq(MACEISA_PAR_CTXA_IRQ, parport_ip32_dma_interrupt,
+			  0, "parport_ip32", NULL);
+	if (err)
+		goto fail_a;
+	err = request_irq(MACEISA_PAR_CTXB_IRQ, parport_ip32_dma_interrupt,
+			  0, "parport_ip32", NULL);
+	if (err)
+		goto fail_b;
+#if DEBUG_PARPORT_IP32
+	/* FIXME - what is this IRQ for? */
+	err = request_irq(MACEISA_PAR_MERR_IRQ, parport_ip32_merr_interrupt,
+			  0, "parport_ip32", NULL);
+	if (err)
+		goto fail_merr;
+#endif
+	return 0;
+
+#if DEBUG_PARPORT_IP32
+fail_merr:
+	free_irq(MACEISA_PAR_CTXB_IRQ, NULL);
+#endif
+fail_b:
+	free_irq(MACEISA_PAR_CTXA_IRQ, NULL);
+fail_a:
+	return err;
+}
+
+/**
+ * parport_ip32_dma_unregister - release and free resources for DMA engine
+ */
+static void parport_ip32_dma_unregister(void)
+{
+#if DEBUG_PARPORT_IP32
+	free_irq(MACEISA_PAR_MERR_IRQ, NULL);
+#endif
+	free_irq(MACEISA_PAR_CTXB_IRQ, NULL);
+	free_irq(MACEISA_PAR_CTXA_IRQ, NULL);
+}
+
+/*--- Interrupt handlers and associates --------------------------------*/
+
+/**
+ * parport_ip32_wakeup - wakes up code waiting for an interrupt
+ * @p:		pointer to &struct parport
+ */
+static inline void parport_ip32_wakeup(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	complete(&priv->irq_complete);
+}
+
+/**
+ * parport_ip32_interrupt - interrupt handler
+ * @irq:	interrupt number
+ * @dev_id:	pointer to &struct parport
+ * @regs:	pointer to &struct pt_regs
+ *
+ * Caught interrupts are forwarded to the upper parport layer if IRQ_mode is
+ * %PARPORT_IP32_IRQ_FWD.
+ */
+static irqreturn_t parport_ip32_interrupt(int irq, void *dev_id,
+					  struct pt_regs *regs)
+{
+	struct parport * const p = dev_id;
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	enum parport_ip32_irq_mode irq_mode = priv->irq_mode;
+	switch (irq_mode) {
+	case PARPORT_IP32_IRQ_FWD:
+		parport_generic_irq(irq, p, regs);
+		break;
+	case PARPORT_IP32_IRQ_HERE:
+		parport_ip32_wakeup(p);
+		break;
+	}
+	return IRQ_HANDLED;
+}
+
+/*--- Some utility function to manipulate ECR register -----------------*/
+
+/**
+ * parport_ip32_read_econtrol - read contents of the ECR register
+ * @p:		pointer to &struct parport
+ */
+static inline unsigned int parport_ip32_read_econtrol(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return readb(priv->regs.ecr);
+}
+
+/**
+ * parport_ip32_write_econtrol - write new contents to the ECR register
+ * @p:		pointer to &struct parport
+ * @c:		new value to write
+ */
+static inline void parport_ip32_write_econtrol(struct parport *p,
+					       unsigned int c)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	writeb(c, priv->regs.ecr);
+}
+
+/**
+ * parport_ip32_frob_econtrol - change bits from the ECR register
+ * @p:		pointer to &struct parport
+ * @mask:	bit mask of bits to change
+ * @val:	new value for changed bits
+ *
+ * Read from the ECR, mask out the bits in @mask, exclusive-or with the bits
+ * in @val, and write the result to the ECR.
+ */
+static inline void parport_ip32_frob_econtrol(struct parport *p,
+					      unsigned int mask,
+					      unsigned int val)
+{
+	unsigned int c;
+	c = (parport_ip32_read_econtrol(p) & ~mask) ^ val;
+	parport_ip32_write_econtrol(p, c);
+}
+
+/**
+ * parport_ip32_set_mode - change mode of ECP port
+ * @p:		pointer to &struct parport
+ * @mode:	new mode to write in ECR
+ *
+ * ECR is reset in a sane state (interrupts and DMA disabled), and placed in
+ * mode @mode.  Go through PS2 mode if needed.
+ */
+static void parport_ip32_set_mode(struct parport *p, unsigned int mode)
+{
+	unsigned int omode;
+
+	mode &= ECR_MODE_MASK;
+	omode = parport_ip32_read_econtrol(p) & ECR_MODE_MASK;
+
+	if (!(mode == ECR_MODE_SPP || mode == ECR_MODE_PS2
+	      || omode == ECR_MODE_SPP || omode == ECR_MODE_PS2)) {
+		/* We have to go through PS2 mode */
+		unsigned int ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
+		parport_ip32_write_econtrol(p, ecr);
+	}
+	parport_ip32_write_econtrol(p, mode | ECR_nERRINTR | ECR_SERVINTR);
+}
+
+/*--- Basic functions needed for parport -------------------------------*/
+
+/**
+ * parport_ip32_read_data - return current contents of the DATA register
+ * @p:		pointer to &struct parport
+ */
+static inline unsigned char parport_ip32_read_data(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return readb(priv->regs.data);
+}
+
+/**
+ * parport_ip32_write_data - set new contents for the DATA register
+ * @p:		pointer to &struct parport
+ * @d:		new value to write
+ */
+static inline void parport_ip32_write_data(struct parport *p, unsigned char d)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	writeb(d, priv->regs.data);
+}
+
+/**
+ * parport_ip32_read_status - return current contents of the DSR register
+ * @p:		pointer to &struct parport
+ */
+static inline unsigned char parport_ip32_read_status(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return readb(priv->regs.dsr);
+}
+
+/**
+ * __parport_ip32_read_control - return cached contents of the DCR register
+ * @p:		pointer to &struct parport
+ */
+static inline unsigned int __parport_ip32_read_control(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return priv->dcr_cache; /* use soft copy */
+}
+
+/**
+ * __parport_ip32_write_control - set new contents for the DCR register
+ * @p:		pointer to &struct parport
+ * @c:		new value to write
+ */
+static inline void __parport_ip32_write_control(struct parport *p,
+						unsigned int c)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	CHECK_EXTRA_BITS(p, c, priv->dcr_writable);
+	c &= priv->dcr_writable; /* only writable bits */
+	writeb(c, priv->regs.dcr);
+	priv->dcr_cache = c;		/* update soft copy */
+}
+
+/**
+ * __parport_ip32_frob_control - change bits from the DCR register
+ * @p:		pointer to &struct parport
+ * @mask:	bit mask of bits to change
+ * @val:	new value for changed bits
+ *
+ * This is equivalent to read from the DCR, mask out the bits in @mask,
+ * exclusive-or with the bits in @val, and write the result to the DCR.
+ * Actually, the cached contents of the DCR is used.
+ */
+static inline void __parport_ip32_frob_control(struct parport *p,
+					       unsigned int mask,
+					       unsigned int val)
+{
+	unsigned int c;
+	c = (__parport_ip32_read_control(p) & ~mask) ^ val;
+	__parport_ip32_write_control(p, c);
+}
+
+/**
+ * parport_ip32_read_control - return cached contents of the DCR register
+ * @p:		pointer to &struct parport
+ *
+ * The return value is masked so as to only return the value of %DCR_STROBE,
+ * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
+ */
+static inline unsigned char parport_ip32_read_control(struct parport *p)
+{
+	const unsigned int rm =
+		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
+	return __parport_ip32_read_control(p) & rm;
+}
+
+/**
+ * parport_ip32_write_control - set new contents for the DCR register
+ * @p:		pointer to &struct parport
+ * @c:		new value to write
+ *
+ * The value is masked so as to only change the value of %DCR_STROBE,
+ * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
+ */
+static inline void parport_ip32_write_control(struct parport *p,
+					      unsigned char c)
+{
+	const unsigned int wm =
+		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
+	CHECK_EXTRA_BITS(p, c, wm);
+	__parport_ip32_frob_control(p, wm, c & wm);
+}
+
+/**
+ * parport_ip32_frob_control - change bits from the DCR register
+ * @p:		pointer to &struct parport
+ * @mask:	bit mask of bits to change
+ * @val:	new value for changed bits
+ *
+ * This differs from __parport_ip32_frob_control() in that it only allows to
+ * change the value of %DCR_STROBE, %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
+ */
+static inline unsigned char parport_ip32_frob_control(struct parport *p,
+						      unsigned char mask,
+						      unsigned char val)
+{
+	const unsigned int wm =
+		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
+	CHECK_EXTRA_BITS(p, mask, wm);
+	CHECK_EXTRA_BITS(p, val, wm);
+	__parport_ip32_frob_control(p, mask & wm, val & wm);
+	return parport_ip32_read_control(p);
+}
+
+/**
+ * parport_ip32_disable_irq - disable interrupts on the rising edge of nACK
+ * @p:		pointer to &struct parport
+ */
+static inline void parport_ip32_disable_irq(struct parport *p)
+{
+	__parport_ip32_frob_control(p, DCR_IRQ, 0);
+}
+
+/**
+ * parport_ip32_enable_irq - enable interrupts on the rising edge of nACK
+ * @p:		pointer to &struct parport
+ */
+static inline void parport_ip32_enable_irq(struct parport *p)
+{
+	__parport_ip32_frob_control(p, DCR_IRQ, DCR_IRQ);
+}
+
+/**
+ * parport_ip32_data_forward - enable host-to-peripheral communications
+ * @p:		pointer to &struct parport
+ *
+ * Enable the data line drivers, for 8-bit host-to-peripheral communications.
+ */
+static inline void parport_ip32_data_forward(struct parport *p)
+{
+	__parport_ip32_frob_control(p, DCR_DIR, 0);
+}
+
+/**
+ * parport_ip32_data_reverse - enable peripheral-to-host communications
+ * @p:		pointer to &struct parport
+ *
+ * Place the data bus in a high impedance state, if @p->modes has the
+ * PARPORT_MODE_TRISTATE bit set.
+ */
+static inline void parport_ip32_data_reverse(struct parport *p)
+{
+	__parport_ip32_frob_control(p, DCR_DIR, DCR_DIR);
+}
+
+/**
+ * parport_ip32_init_state - for core parport code
+ * @dev:	pointer to &struct pardevice
+ * @s:		pointer to &struct parport_state to initialize
+ */
+static void parport_ip32_init_state(struct pardevice *dev,
+				    struct parport_state *s)
+{
+	s->u.ip32.dcr = DCR_SELECT | DCR_nINIT;
+	s->u.ip32.ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
+}
+
+/**
+ * parport_ip32_save_state - for core parport code
+ * @p:		pointer to &struct parport
+ * @s:		pointer to &struct parport_state to save state to
+ */
+static void parport_ip32_save_state(struct parport *p,
+				    struct parport_state *s)
+{
+	s->u.ip32.dcr = __parport_ip32_read_control(p);
+	s->u.ip32.ecr = parport_ip32_read_econtrol(p);
+}
+
+/**
+ * parport_ip32_restore_state - for core parport code
+ * @p:		pointer to &struct parport
+ * @s:		pointer to &struct parport_state to restore state from
+ */
+static void parport_ip32_restore_state(struct parport *p,
+				       struct parport_state *s)
+{
+	parport_ip32_set_mode(p, s->u.ip32.ecr & ECR_MODE_MASK);
+	parport_ip32_write_econtrol(p, s->u.ip32.ecr);
+	__parport_ip32_write_control(p, s->u.ip32.dcr);
+}
+
+/*--- EPP mode functions -----------------------------------------------*/
+
+/**
+ * parport_ip32_clear_epp_timeout - clear Timeout bit in EPP mode
+ * @p:		pointer to &struct parport
+ *
+ * Returns 1 if the Timeout bit is clear, and 0 otherwise.
+ */
+static unsigned int parport_ip32_clear_epp_timeout(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	unsigned int cleared;
+
+	if (!(parport_ip32_read_status(p) & DSR_TIMEOUT))
+		cleared = 1;
+	else {
+		unsigned int r;
+		/* To clear timeout some chips require double read */
+		parport_ip32_read_status(p);
+		r = parport_ip32_read_status(p);
+		/* Some reset by writing 1 */
+		writeb(r | DSR_TIMEOUT, priv->regs.dsr);
+		/* Others by writing 0 */
+		writeb(r & ~DSR_TIMEOUT, priv->regs.dsr);
+
+		r = parport_ip32_read_status(p);
+		cleared = !(r & DSR_TIMEOUT);
+	}
+
+	pr_trace(p, "(): %s", cleared ? "cleared" : "failed");
+	return cleared;
+}
+
+/**
+ * parport_ip32_epp_read - generic EPP read function
+ * @eppreg:	I/O register to read from
+ * @p:		pointer to &struct parport
+ * @buf:	buffer to store read data
+ * @len:	length of buffer @buf
+ * @flags:	may be PARPORT_EPP_FAST
+ */
+static size_t parport_ip32_epp_read(void __iomem *eppreg,
+				    struct parport *p, void *buf,
+				    size_t len, int flags)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	size_t got;
+	parport_ip32_set_mode(p, ECR_MODE_EPP);
+	parport_ip32_data_reverse(p);
+	parport_ip32_write_control(p, DCR_nINIT);
+	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
+		readsb(eppreg, buf, len);
+		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
+			parport_ip32_clear_epp_timeout(p);
+			return -EIO;
+		}
+		got = len;
+	} else {
+		u8 *bufp = buf;
+		for (got = 0; got < len; got++) {
+			*bufp++ = readb(eppreg);
+			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
+				parport_ip32_clear_epp_timeout(p);
+				break;
+			}
+		}
+	}
+	parport_ip32_data_forward(p);
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	return got;
+}
+
+/**
+ * parport_ip32_epp_write - generic EPP write function
+ * @eppreg:	I/O register to write to
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ * @flags:	may be PARPORT_EPP_FAST
+ */
+static size_t parport_ip32_epp_write(void __iomem *eppreg,
+				     struct parport *p, const void *buf,
+				     size_t len, int flags)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	size_t written;
+	parport_ip32_set_mode(p, ECR_MODE_EPP);
+	parport_ip32_data_forward(p);
+	parport_ip32_write_control(p, DCR_nINIT);
+	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
+		writesb(eppreg, buf, len);
+		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
+			parport_ip32_clear_epp_timeout(p);
+			return -EIO;
+		}
+		written = len;
+	} else {
+		const u8 *bufp = buf;
+		for (written = 0; written < len; written++) {
+			writeb(*bufp++, eppreg);
+			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
+				parport_ip32_clear_epp_timeout(p);
+				break;
+			}
+		}
+	}
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	return written;
+}
+
+/**
+ * parport_ip32_epp_read_data - read a block of data in EPP mode
+ * @p:		pointer to &struct parport
+ * @buf:	buffer to store read data
+ * @len:	length of buffer @buf
+ * @flags:	may be PARPORT_EPP_FAST
+ */
+static size_t parport_ip32_epp_read_data(struct parport *p, void *buf,
+					 size_t len, int flags)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return parport_ip32_epp_read(priv->regs.eppData0, p, buf, len, flags);
+}
+
+/**
+ * parport_ip32_epp_write_data - write a block of data in EPP mode
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ * @flags:	may be PARPORT_EPP_FAST
+ */
+static size_t parport_ip32_epp_write_data(struct parport *p, const void *buf,
+					  size_t len, int flags)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return parport_ip32_epp_write(priv->regs.eppData0, p, buf, len, flags);
+}
+
+/**
+ * parport_ip32_epp_read_addr - read a block of addresses in EPP mode
+ * @p:		pointer to &struct parport
+ * @buf:	buffer to store read data
+ * @len:	length of buffer @buf
+ * @flags:	may be PARPORT_EPP_FAST
+ */
+static size_t parport_ip32_epp_read_addr(struct parport *p, void *buf,
+					 size_t len, int flags)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return parport_ip32_epp_read(priv->regs.eppAddr, p, buf, len, flags);
+}
+
+/**
+ * parport_ip32_epp_write_addr - write a block of addresses in EPP mode
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ * @flags:	may be PARPORT_EPP_FAST
+ */
+static size_t parport_ip32_epp_write_addr(struct parport *p, const void *buf,
+					  size_t len, int flags)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	return parport_ip32_epp_write(priv->regs.eppAddr, p, buf, len, flags);
+}
+
+/*--- ECP mode functions (FIFO) ----------------------------------------*/
+
+/**
+ * parport_ip32_fifo_wait_break - check if the waiting function should return
+ * @p:		pointer to &struct parport
+ * @expire:	timeout expiring date, in jiffies
+ *
+ * parport_ip32_fifo_wait_break() checks if the waiting function should return
+ * immediately or not.  The break conditions are:
+ *	- expired timeout;
+ *	- a pending signal;
+ *	- nFault asserted low.
+ * This function also calls cond_resched().
+ */
+static unsigned int parport_ip32_fifo_wait_break(struct parport *p,
+						 unsigned long expire)
+{
+	cond_resched();
+	if (time_after(jiffies, expire)) {
+		pr_debug1(PPIP32 "%s: FIFO write timed out\n", p->name);
+		return 1;
+	}
+	if (signal_pending(current)) {
+		pr_debug1(PPIP32 "%s: Signal pending\n", p->name);
+		return 1;
+	}
+	if (!(parport_ip32_read_status(p) & DSR_nFAULT)) {
+		pr_debug1(PPIP32 "%s: nFault asserted low\n", p->name);
+		return 1;
+	}
+	return 0;
+}
+
+/**
+ * parport_ip32_fwp_wait_polling - wait for FIFO to empty (polling)
+ * @p:		pointer to &struct parport
+ *
+ * Returns the number of bytes that can safely be written in the FIFO.  A
+ * return value of zero means that the calling function should terminate as
+ * fast as possible.
+ */
+static unsigned int parport_ip32_fwp_wait_polling(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	struct parport * const physport = p->physport;
+	unsigned long expire;
+	unsigned int count;
+	unsigned int ecr;
+
+	expire = jiffies + physport->cad->timeout;
+	count = 0;
+	while (1) {
+		if (parport_ip32_fifo_wait_break(p, expire))
+			break;
+
+		/* Check FIFO state.  We do nothing when the FIFO is nor full,
+		 * nor empty.  It appears that the FIFO full bit is not always
+		 * reliable, the FIFO state is sometimes wrongly reported, and
+		 * the chip gets confused if we give it another byte. */
+		ecr = parport_ip32_read_econtrol(p);
+		if (ecr & ECR_F_EMPTY) {
+			/* FIFO is empty, fill it up */
+			count = priv->fifo_depth;
+			break;
+		}
+
+		/* Wait a moment... */
+		udelay(FIFO_POLLING_INTERVAL);
+	} /* while (1) */
+
+	return count;
+}
+
+/**
+ * parport_ip32_fwp_wait_interrupt - wait for FIFO to empty (interrupt-driven)
+ * @p:		pointer to &struct parport
+ *
+ * Returns the number of bytes that can safely be written in the FIFO.  A
+ * return value of zero means that the calling function should terminate as
+ * fast as possible.
+ */
+static unsigned int parport_ip32_fwp_wait_interrupt(struct parport *p)
+{
+	static unsigned int lost_interrupt = 0;
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	struct parport * const physport = p->physport;
+	unsigned long nfault_timeout;
+	unsigned long expire;
+	unsigned int count;
+	unsigned int ecr;
+
+	nfault_timeout = min((unsigned long)physport->cad->timeout,
+			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
+	expire = jiffies + physport->cad->timeout;
+	count = 0;
+	while (1) {
+		if (parport_ip32_fifo_wait_break(p, expire))
+			break;
+
+		/* Initialize mutex used to take interrupts into account */
+		INIT_COMPLETION(priv->irq_complete);
+
+		/* Enable serviceIntr */
+		parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
+
+		/* Enabling serviceIntr while the FIFO is empty does not
+		 * always generate an interrupt, so check for emptiness
+		 * now. */
+		ecr = parport_ip32_read_econtrol(p);
+		if (!(ecr & ECR_F_EMPTY)) {
+			/* FIFO is not empty: wait for an interrupt or a
+			 * timeout to occur */
+			wait_for_completion_interruptible_timeout(
+				&priv->irq_complete, nfault_timeout);
+			ecr = parport_ip32_read_econtrol(p);
+			if ((ecr & ECR_F_EMPTY) && !(ecr & ECR_SERVINTR)
+			    && !lost_interrupt) {
+				printk(KERN_WARNING PPIP32
+				       "%s: lost interrupt in %s\n",
+				       p->name, __func__);
+				lost_interrupt = 1;
+			}
+		}
+
+		/* Disable serviceIntr */
+		parport_ip32_frob_econtrol(p, ECR_SERVINTR, ECR_SERVINTR);
+
+		/* Check FIFO state */
+		if (ecr & ECR_F_EMPTY) {
+			/* FIFO is empty, fill it up */
+			count = priv->fifo_depth;
+			break;
+		} else if (ecr & ECR_SERVINTR) {
+			/* FIFO is not empty, but we know that can safely push
+			 * writeIntrThreshold bytes into it */
+			count = priv->writeIntrThreshold;
+			break;
+		}
+		/* FIFO is not empty, and we did not get any interrupt.
+		 * Either it's time to check for nFault, or a signal is
+		 * pending.  This is verified in
+		 * parport_ip32_fifo_wait_break(), so we continue the loop. */
+	} /* while (1) */
+
+	return count;
+}
+
+/**
+ * parport_ip32_fifo_write_block_pio - write a block of data (PIO mode)
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ *
+ * Uses PIO to write the contents of the buffer @buf into the parallel port
+ * FIFO.  Returns the number of bytes that were actually written.  It can work
+ * with or without the help of interrupts.  The parallel port must be
+ * correctly initialized before calling parport_ip32_fifo_write_block_pio().
+ */
+static size_t parport_ip32_fifo_write_block_pio(struct parport *p,
+						const void *buf, size_t len)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	const u8 *bufp = buf;
+	size_t left = len;
+
+	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
+
+	while (left > 0) {
+		unsigned int count;
+
+		count = (p->irq == PARPORT_IRQ_NONE) ?
+			parport_ip32_fwp_wait_polling(p) :
+			parport_ip32_fwp_wait_interrupt(p);
+		if (count == 0)
+			break;	/* Transmission should be stopped */
+		if (count > left)
+			count = left;
+		if (count == 1) {
+			writeb(*bufp, priv->regs.fifo);
+			bufp++, left--;
+		} else {
+			writesb(priv->regs.fifo, bufp, count);
+			bufp += count, left -= count;
+		}
+	}
+
+	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
+
+	return len - left;
+}
+
+/**
+ * parport_ip32_fifo_write_block_dma - write a block of data (DMA mode)
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ *
+ * Uses DMA to write the contents of the buffer @buf into the parallel port
+ * FIFO.  Returns the number of bytes that were actually written.  The
+ * parallel port must be correctly initialized before calling
+ * parport_ip32_fifo_write_block_dma().
+ */
+static size_t parport_ip32_fifo_write_block_dma(struct parport *p,
+						const void *buf, size_t len)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	struct parport * const physport = p->physport;
+	unsigned long nfault_timeout;
+	unsigned long expire;
+	size_t written;
+	unsigned int ecr;
+
+	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
+
+	parport_ip32_dma_start(DMA_TO_DEVICE, (void *)buf, len);
+	INIT_COMPLETION(priv->irq_complete);
+	parport_ip32_frob_econtrol(p, ECR_DMAEN | ECR_SERVINTR, ECR_DMAEN);
+
+	nfault_timeout = min((unsigned long)physport->cad->timeout,
+			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
+	expire = jiffies + physport->cad->timeout;
+	while (1) {
+		if (parport_ip32_fifo_wait_break(p, expire))
+			break;
+		wait_for_completion_interruptible_timeout(&priv->irq_complete,
+							  nfault_timeout);
+		ecr = parport_ip32_read_econtrol(p);
+		if (ecr & ECR_SERVINTR)
+			break;	/* DMA transfer just finished */
+	}
+	parport_ip32_dma_stop();
+	written = len - parport_ip32_dma_get_residue();
+
+	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
+
+	return written;
+}
+
+/**
+ * parport_ip32_fifo_write_block - write a block of data
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ *
+ * Uses PIO or DMA to write the contents of the buffer @buf into the parallel
+ * p FIFO.  Returns the number of bytes that were actually written.
+ */
+static size_t parport_ip32_fifo_write_block(struct parport *p,
+					    const void *buf, size_t len)
+{
+	size_t written = 0;
+	if (len)
+		/* FIXME - Maybe some threshold value should be set for @len
+		 * under which we revert to PIO mode? */
+		written = (p->modes & PARPORT_MODE_DMA) ?
+			parport_ip32_fifo_write_block_dma(p, buf, len) :
+			parport_ip32_fifo_write_block_pio(p, buf, len);
+	return written;
+}
+
+/**
+ * parport_ip32_drain_fifo - wait for FIFO to empty
+ * @p:		pointer to &struct parport
+ * @timeout:	timeout, in jiffies
+ *
+ * This function waits for FIFO to empty.  It returns 1 when FIFO is empty, or
+ * 0 if the timeout @timeout is reached before, or if a signal is pending.
+ */
+static unsigned int parport_ip32_drain_fifo(struct parport *p,
+					    unsigned long timeout)
+{
+	unsigned long expire = jiffies + timeout;
+	unsigned int polling_interval;
+	unsigned int counter;
+
+	/* Busy wait for approx. 200us */
+	for (counter = 0; counter < 40; counter++) {
+		if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
+			break;
+		if (time_after(jiffies, expire))
+			break;
+		if (signal_pending(current))
+			break;
+		udelay(5);
+	}
+	/* Poll slowly.  Polling interval starts with 1 millisecond, and is
+	 * increased exponentially until 128.  */
+	polling_interval = 1; /* msecs */
+	while (!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY)) {
+		if (time_after_eq(jiffies, expire))
+			break;
+		msleep_interruptible(polling_interval);
+		if (signal_pending(current))
+			break;
+		if (polling_interval < 128)
+			polling_interval *= 2;
+	}
+
+	return !!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY);
+}
+
+/**
+ * parport_ip32_get_fifo_residue - reset FIFO
+ * @p:		pointer to &struct parport
+ * @mode:	current operation mode (ECR_MODE_PPF or ECR_MODE_ECP)
+ *
+ * This function resets FIFO, and returns the number of bytes remaining in it.
+ */
+static unsigned int parport_ip32_get_fifo_residue(struct parport *p,
+						  unsigned int mode)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	unsigned int residue;
+	unsigned int cnfga;
+
+	/* FIXME - We are missing one byte if the printer is off-line.  I
+	 * don't know how to detect this.  It looks that the full bit is not
+	 * always reliable.  For the moment, the problem is avoided in most
+	 * cases by testing for BUSY in parport_ip32_compat_write_data().
+	 */
+	if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
+		residue = 0;
+	else {
+		pr_debug1(PPIP32 "%s: FIFO is stuck\n", p->name);
+
+		/* Stop all transfers.
+		 *
+		 * Microsoft's document instructs to drive DCR_STROBE to 0,
+		 * but it doesn't work (at least in Compatibility mode, not
+		 * tested in ECP mode).  Switching directly to Test mode (as
+		 * in parport_pc) is not an option: it does confuse the port,
+		 * ECP service interrupts are no more working after that.  A
+		 * hard reset is then needed to revert to a sane state.
+		 *
+		 * Let's hope that the FIFO is really stuck and that the
+		 * peripheral doesn't wake up now.
+		 */
+		parport_ip32_frob_control(p, DCR_STROBE, 0);
+
+		/* Fill up FIFO */
+		for (residue = priv->fifo_depth; residue > 0; residue--) {
+			if (parport_ip32_read_econtrol(p) & ECR_F_FULL)
+				break;
+			writeb(0x00, priv->regs.fifo);
+		}
+	}
+	if (residue)
+		pr_debug1(PPIP32 "%s: %d PWord%s left in FIFO\n",
+			  p->name, residue,
+			  (residue == 1) ? " was" : "s were");
+
+	/* Now reset the FIFO */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+
+	/* Host recovery for ECP mode */
+	if (mode == ECR_MODE_ECP) {
+		parport_ip32_data_reverse(p);
+		parport_ip32_frob_control(p, DCR_nINIT, 0);
+		if (parport_wait_peripheral(p, DSR_PERROR, 0))
+			pr_debug1(PPIP32 "%s: PEerror timeout 1 in %s\n",
+				  p->name, __func__);
+		parport_ip32_frob_control(p, DCR_STROBE, DCR_STROBE);
+		parport_ip32_frob_control(p, DCR_nINIT, DCR_nINIT);
+		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR))
+			pr_debug1(PPIP32 "%s: PEerror timeout 2 in %s\n",
+				  p->name, __func__);
+	}
+
+	/* Adjust residue if needed */
+	parport_ip32_set_mode(p, ECR_MODE_CFG);
+	cnfga = readb(priv->regs.cnfgA);
+	if (!(cnfga & CNFGA_nBYTEINTRANS)) {
+		pr_debug1(PPIP32 "%s: cnfgA contains 0x%02x\n",
+			  p->name, cnfga);
+		pr_debug1(PPIP32 "%s: Accounting for extra byte\n",
+			  p->name);
+		residue++;
+	}
+
+	/* Don't care about partial PWords since we do not support
+	 * PWord != 1 byte. */
+
+	/* Back to forward PS2 mode. */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	parport_ip32_data_forward(p);
+
+	return residue;
+}
+
+/**
+ * parport_ip32_compat_write_data - write a block of data in SPP mode
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ * @flags:	ignored
+ */
+static size_t parport_ip32_compat_write_data(struct parport *p,
+					     const void *buf, size_t len,
+					     int flags)
+{
+	static unsigned int ready_before = 1;
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	struct parport * const physport = p->physport;
+	size_t written = 0;
+
+	/* Special case: a timeout of zero means we cannot call schedule().
+	 * Also if O_NONBLOCK is set then use the default implementation. */
+	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
+		return parport_ieee1284_write_compat(p, buf, len, flags);
+
+	/* Reset FIFO, go in forward mode, and disable ackIntEn */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
+	parport_ip32_data_forward(p);
+	parport_ip32_disable_irq(p);
+	parport_ip32_set_mode(p, ECR_MODE_PPF);
+	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
+
+	/* Wait for peripheral to become ready */
+	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
+				       DSR_nBUSY | DSR_nFAULT)) {
+		/* Avoid to flood the logs */
+		if (ready_before)
+			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
+			       p->name, __func__);
+		ready_before = 0;
+		goto stop;
+	}
+	ready_before = 1;
+
+	written = parport_ip32_fifo_write_block(p, buf, len);
+
+	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
+	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
+
+	/* Check for a potential residue */
+	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_PPF);
+
+	/* Then, wait for BUSY to get low. */
+	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
+		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
+		       p->name, __func__);
+
+stop:
+	/* Reset FIFO */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
+
+	return written;
+}
+
+/*
+ * FIXME - Insert here parport_ip32_ecp_read_data().
+ */
+
+/**
+ * parport_ip32_ecp_write_data - write a block of data in ECP mode
+ * @p:		pointer to &struct parport
+ * @buf:	buffer of data to write
+ * @len:	length of buffer @buf
+ * @flags:	ignored
+ */
+static size_t parport_ip32_ecp_write_data(struct parport *p,
+					  const void *buf, size_t len,
+					  int flags)
+{
+	static unsigned int ready_before = 1;
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	struct parport * const physport = p->physport;
+	size_t written = 0;
+
+	/* Special case: a timeout of zero means we cannot call schedule().
+	 * Also if O_NONBLOCK is set then use the default implementation. */
+	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
+		return parport_ieee1284_ecp_write_data(p, buf, len, flags);
+
+	/* Negotiate to forward mode if necessary. */
+	if (physport->ieee1284.phase != IEEE1284_PH_FWD_IDLE) {
+		/* Event 47: Set nInit high. */
+		parport_ip32_frob_control(p, DCR_nINIT | DCR_AUTOFD,
+					     DCR_nINIT | DCR_AUTOFD);
+
+		/* Event 49: PError goes high. */
+		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR)) {
+			printk(KERN_DEBUG PPIP32 "%s: PError timeout in %s",
+			       p->name, __func__);
+			physport->ieee1284.phase = IEEE1284_PH_ECP_DIR_UNKNOWN;
+			return 0;
+		}
+	}
+
+	/* Reset FIFO, go in forward mode, and disable ackIntEn */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
+	parport_ip32_data_forward(p);
+	parport_ip32_disable_irq(p);
+	parport_ip32_set_mode(p, ECR_MODE_ECP);
+	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
+
+	/* Wait for peripheral to become ready */
+	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
+				       DSR_nBUSY | DSR_nFAULT)) {
+		/* Avoid to flood the logs */
+		if (ready_before)
+			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
+			       p->name, __func__);
+		ready_before = 0;
+		goto stop;
+	}
+	ready_before = 1;
+
+	written = parport_ip32_fifo_write_block(p, buf, len);
+
+	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
+	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
+
+	/* Check for a potential residue */
+	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_ECP);
+
+	/* Then, wait for BUSY to get low. */
+	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
+		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
+		       p->name, __func__);
+
+stop:
+	/* Reset FIFO */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
+
+	return written;
+}
+
+/*
+ * FIXME - Insert here parport_ip32_ecp_write_addr().
+ */
+
+/*--- Default parport operations ---------------------------------------*/
+
+static __initdata struct parport_operations parport_ip32_ops = {
+	.write_data		= parport_ip32_write_data,
+	.read_data		= parport_ip32_read_data,
+
+	.write_control		= parport_ip32_write_control,
+	.read_control		= parport_ip32_read_control,
+	.frob_control		= parport_ip32_frob_control,
+
+	.read_status		= parport_ip32_read_status,
+
+	.enable_irq		= parport_ip32_enable_irq,
+	.disable_irq		= parport_ip32_disable_irq,
+
+	.data_forward		= parport_ip32_data_forward,
+	.data_reverse		= parport_ip32_data_reverse,
+
+	.init_state		= parport_ip32_init_state,
+	.save_state		= parport_ip32_save_state,
+	.restore_state		= parport_ip32_restore_state,
+
+	.epp_write_data		= parport_ieee1284_epp_write_data,
+	.epp_read_data		= parport_ieee1284_epp_read_data,
+	.epp_write_addr		= parport_ieee1284_epp_write_addr,
+	.epp_read_addr		= parport_ieee1284_epp_read_addr,
+
+	.ecp_write_data		= parport_ieee1284_ecp_write_data,
+	.ecp_read_data		= parport_ieee1284_ecp_read_data,
+	.ecp_write_addr		= parport_ieee1284_ecp_write_addr,
+
+	.compat_write_data	= parport_ieee1284_write_compat,
+	.nibble_read_data	= parport_ieee1284_read_nibble,
+	.byte_read_data		= parport_ieee1284_read_byte,
+
+	.owner			= THIS_MODULE,
+};
+
+/*--- Device detection -------------------------------------------------*/
+
+/**
+ * parport_ip32_ecp_supported - check for an ECP port
+ * @p:		pointer to the &parport structure
+ *
+ * Returns 1 if an ECP port is found, and 0 otherwise.  This function actually
+ * checks if an Extended Control Register seems to be present.  On successful
+ * return, the port is placed in SPP mode.
+ */
+static __init unsigned int parport_ip32_ecp_supported(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	unsigned int ecr;
+
+	ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
+	writeb(ecr, priv->regs.ecr);
+	if (readb(priv->regs.ecr) != (ecr | ECR_F_EMPTY))
+		goto fail;
+
+	pr_probe(p, "Found working ECR register\n");
+	parport_ip32_set_mode(p, ECR_MODE_SPP);
+	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
+	return 1;
+
+fail:
+	pr_probe(p, "ECR register not found\n");
+	return 0;
+}
+
+/**
+ * parport_ip32_fifo_supported - check for FIFO parameters
+ * @p:		pointer to the &parport structure
+ *
+ * Check for FIFO parameters of an Extended Capabilities Port.  Returns 1 on
+ * success, and 0 otherwise.  Adjust FIFO parameters in the parport structure.
+ * On return, the port is placed in SPP mode.
+ */
+static __init unsigned int parport_ip32_fifo_supported(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	unsigned int configa, configb;
+	unsigned int pword;
+	unsigned int i;
+
+	/* Configuration mode */
+	parport_ip32_set_mode(p, ECR_MODE_CFG);
+	configa = readb(priv->regs.cnfgA);
+	configb = readb(priv->regs.cnfgB);
+
+	/* Find out PWord size */
+	switch (configa & CNFGA_ID_MASK) {
+	case CNFGA_ID_8:
+		pword = 1;
+		break;
+	case CNFGA_ID_16:
+		pword = 2;
+		break;
+	case CNFGA_ID_32:
+		pword = 4;
+		break;
+	default:
+		pr_probe(p, "Unknown implementation ID: 0x%0x\n",
+			 (configa & CNFGA_ID_MASK) >> CNFGA_ID_SHIFT);
+		goto fail;
+		break;
+	}
+	if (pword != 1) {
+		pr_probe(p, "Unsupported PWord size: %u\n", pword);
+		goto fail;
+	}
+	priv->pword = pword;
+	pr_probe(p, "PWord is %u bits\n", 8 * priv->pword);
+
+	/* Check for compression support */
+	writeb(configb | CNFGB_COMPRESS, priv->regs.cnfgB);
+	if (readb(priv->regs.cnfgB) & CNFGB_COMPRESS)
+		pr_probe(p, "Hardware compression detected (unsupported)\n");
+	writeb(configb & ~CNFGB_COMPRESS, priv->regs.cnfgB);
+
+	/* Reset FIFO and go in test mode (no interrupt, no DMA) */
+	parport_ip32_set_mode(p, ECR_MODE_TST);
+
+	/* FIFO must be empty now */
+	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
+		pr_probe(p, "FIFO not reset\n");
+		goto fail;
+	}
+
+	/* Find out FIFO depth. */
+	priv->fifo_depth = 0;
+	for (i = 0; i < 1024; i++) {
+		if (readb(priv->regs.ecr) & ECR_F_FULL) {
+			/* FIFO full */
+			priv->fifo_depth = i;
+			break;
+		}
+		writeb((u8)i, priv->regs.fifo);
+	}
+	if (i >= 1024) {
+		pr_probe(p, "Can't fill FIFO\n");
+		goto fail;
+	}
+	if (!priv->fifo_depth) {
+		pr_probe(p, "Can't get FIFO depth\n");
+		goto fail;
+	}
+	pr_probe(p, "FIFO is %u PWords deep\n", priv->fifo_depth);
+
+	/* Enable interrupts */
+	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
+
+	/* Find out writeIntrThreshold: number of PWords we know we can write
+	 * if we get an interrupt. */
+	priv->writeIntrThreshold = 0;
+	for (i = 0; i < priv->fifo_depth; i++) {
+		if (readb(priv->regs.fifo) != (u8)i) {
+			pr_probe(p, "Invalid data in FIFO\n");
+			goto fail;
+		}
+		if (!priv->writeIntrThreshold
+		    && readb(priv->regs.ecr) & ECR_SERVINTR)
+			/* writeIntrThreshold reached */
+			priv->writeIntrThreshold = i + 1;
+		if (i + 1 < priv->fifo_depth
+		    && readb(priv->regs.ecr) & ECR_F_EMPTY) {
+			/* FIFO empty before the last byte? */
+			pr_probe(p, "Data lost in FIFO\n");
+			goto fail;
+		}
+	}
+	if (!priv->writeIntrThreshold) {
+		pr_probe(p, "Can't get writeIntrThreshold\n");
+		goto fail;
+	}
+	pr_probe(p, "writeIntrThreshold is %u\n", priv->writeIntrThreshold);
+
+	/* FIFO must be empty now */
+	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
+		pr_probe(p, "Can't empty FIFO\n");
+		goto fail;
+	}
+
+	/* Reset FIFO */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	/* Set reverse direction (must be in PS2 mode) */
+	parport_ip32_data_reverse(p);
+	/* Test FIFO, no interrupt, no DMA */
+	parport_ip32_set_mode(p, ECR_MODE_TST);
+	/* Enable interrupts */
+	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
+
+	/* Find out readIntrThreshold: number of PWords we can read if we get
+	 * an interrupt. */
+	priv->readIntrThreshold = 0;
+	for (i = 0; i < priv->fifo_depth; i++) {
+		writeb(0xaa, priv->regs.fifo);
+		if (readb(priv->regs.ecr) & ECR_SERVINTR) {
+			/* readIntrThreshold reached */
+			priv->readIntrThreshold = i + 1;
+			break;
+		}
+	}
+	if (!priv->readIntrThreshold) {
+		pr_probe(p, "Can't get readIntrThreshold\n");
+		goto fail;
+	}
+	pr_probe(p, "readIntrThreshold is %u\n", priv->readIntrThreshold);
+
+	/* Reset ECR */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	parport_ip32_data_forward(p);
+	parport_ip32_set_mode(p, ECR_MODE_SPP);
+	return 1;
+
+fail:
+	priv->fifo_depth = 0;
+	parport_ip32_set_mode(p, ECR_MODE_SPP);
+	return 0;
+}
+
+/*--- Initialization code ----------------------------------------------*/
+
+/**
+ * parport_ip32_make_isa_registers - compute (ISA) register addresses
+ * @regs:	pointer to &struct parport_ip32_regs to fill
+ * @base:	base address of standard and EPP registers
+ * @base_hi:	base address of ECP registers
+ * @regshift:	how much to shift register offset by
+ *
+ * Compute register addresses, according to the ISA standard.  The addresses
+ * of the standard and EPP registers are computed from address @base.  The
+ * addresses of the ECP registers are computed from address @base_hi.
+ */
+static void __init
+parport_ip32_make_isa_registers(struct parport_ip32_regs *regs,
+				void __iomem *base, void __iomem *base_hi,
+				unsigned int regshift)
+{
+#define r_base(offset)    ((u8 __iomem *)base    + ((offset) << regshift))
+#define r_base_hi(offset) ((u8 __iomem *)base_hi + ((offset) << regshift))
+	*regs = (struct parport_ip32_regs){
+		.data		= r_base(0),
+		.dsr		= r_base(1),
+		.dcr		= r_base(2),
+		.eppAddr	= r_base(3),
+		.eppData0	= r_base(4),
+		.eppData1	= r_base(5),
+		.eppData2	= r_base(6),
+		.eppData3	= r_base(7),
+		.ecpAFifo	= r_base(0),
+		.fifo		= r_base_hi(0),
+		.cnfgA		= r_base_hi(0),
+		.cnfgB		= r_base_hi(1),
+		.ecr		= r_base_hi(2)
+	};
+#undef r_base_hi
+#undef r_base
+}
+
+/**
+ * parport_ip32_probe_port - probe and register IP32 built-in parallel port
+ *
+ * Returns the new allocated &parport structure.  On error, an error code is
+ * encoded in return value with the ERR_PTR function.
+ */
+static __init struct parport *parport_ip32_probe_port(void)
+{
+	struct parport_ip32_regs regs;
+	struct parport_ip32_private *priv = NULL;
+	struct parport_operations *ops = NULL;
+	struct parport *p = NULL;
+	int err;
+
+	parport_ip32_make_isa_registers(&regs, &mace->isa.parallel,
+					&mace->isa.ecp1284, 8 /* regshift */);
+
+	ops = kmalloc(sizeof(struct parport_operations), GFP_KERNEL);
+	priv = kmalloc(sizeof(struct parport_ip32_private), GFP_KERNEL);
+	p = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, ops);
+	if (ops == NULL || priv == NULL || p == NULL) {
+		err = -ENOMEM;
+		goto fail;
+	}
+	p->base = MACE_BASE + offsetof(struct sgi_mace, isa.parallel);
+	p->base_hi = MACE_BASE + offsetof(struct sgi_mace, isa.ecp1284);
+	p->private_data = priv;
+
+	*ops = parport_ip32_ops;
+	*priv = (struct parport_ip32_private){
+		.regs			= regs,
+		.dcr_writable		= DCR_DIR | DCR_SELECT | DCR_nINIT |
+					  DCR_AUTOFD | DCR_STROBE,
+		.irq_mode		= PARPORT_IP32_IRQ_FWD,
+	};
+	init_completion(&priv->irq_complete);
+
+	/* Probe port. */
+	if (!parport_ip32_ecp_supported(p)) {
+		err = -ENODEV;
+		goto fail;
+	}
+	parport_ip32_dump_state(p, "begin init", 0);
+
+	/* We found what looks like a working ECR register.  Simply assume
+	 * that all modes are correctly supported.  Enable basic modes. */
+	p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
+	p->modes |= PARPORT_MODE_TRISTATE;
+
+	if (!parport_ip32_fifo_supported(p)) {
+		printk(KERN_WARNING PPIP32
+		       "%s: error: FIFO disabled\n", p->name);
+		/* Disable hardware modes depending on a working FIFO. */
+		features &= ~PARPORT_IP32_ENABLE_SPP;
+		features &= ~PARPORT_IP32_ENABLE_ECP;
+		/* DMA is not needed if FIFO is not supported.  */
+		features &= ~PARPORT_IP32_ENABLE_DMA;
+	}
+
+	/* Request IRQ */
+	if (features & PARPORT_IP32_ENABLE_IRQ) {
+		int irq = MACEISA_PARALLEL_IRQ;
+		if (request_irq(irq, parport_ip32_interrupt, 0, p->name, p)) {
+			printk(KERN_WARNING PPIP32
+			       "%s: error: IRQ disabled\n", p->name);
+			/* DMA cannot work without interrupts. */
+			features &= ~PARPORT_IP32_ENABLE_DMA;
+		} else {
+			pr_probe(p, "Interrupt support enabled\n");
+			p->irq = irq;
+			priv->dcr_writable |= DCR_IRQ;
+		}
+	}
+
+	/* Allocate DMA resources */
+	if (features & PARPORT_IP32_ENABLE_DMA) {
+		if (parport_ip32_dma_register())
+			printk(KERN_WARNING PPIP32
+			       "%s: error: DMA disabled\n", p->name);
+		else {
+			pr_probe(p, "DMA support enabled\n");
+			p->dma = 0; /* arbitrary value != PARPORT_DMA_NONE */
+			p->modes |= PARPORT_MODE_DMA;
+		}
+	}
+
+	if (features & PARPORT_IP32_ENABLE_SPP) {
+		/* Enable compatibility FIFO mode */
+		p->ops->compat_write_data = parport_ip32_compat_write_data;
+		p->modes |= PARPORT_MODE_COMPAT;
+		pr_probe(p, "Hardware support for SPP mode enabled\n");
+	}
+	if (features & PARPORT_IP32_ENABLE_EPP) {
+		/* Set up access functions to use EPP hardware. */
+		p->ops->epp_read_data = parport_ip32_epp_read_data;
+		p->ops->epp_write_data = parport_ip32_epp_write_data;
+		p->ops->epp_read_addr = parport_ip32_epp_read_addr;
+		p->ops->epp_write_addr = parport_ip32_epp_write_addr;
+		p->modes |= PARPORT_MODE_EPP;
+		pr_probe(p, "Hardware support for EPP mode enabled\n");
+	}
+	if (features & PARPORT_IP32_ENABLE_ECP) {
+		/* Enable ECP FIFO mode */
+		p->ops->ecp_write_data = parport_ip32_ecp_write_data;
+		/* FIXME - not implemented */
+/*		p->ops->ecp_read_data  = parport_ip32_ecp_read_data; */
+/*		p->ops->ecp_write_addr = parport_ip32_ecp_write_addr; */
+		p->modes |= PARPORT_MODE_ECP;
+		pr_probe(p, "Hardware support for ECP mode enabled\n");
+	}
+
+	/* Initialize the port with sensible values */
+	parport_ip32_set_mode(p, ECR_MODE_PS2);
+	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
+	parport_ip32_data_forward(p);
+	parport_ip32_disable_irq(p);
+	parport_ip32_write_data(p, 0x00);
+	parport_ip32_dump_state(p, "end init", 0);
+
+	/* Print out what we found */
+	printk(KERN_INFO "%s: SGI IP32 at 0x%lx (0x%lx)",
+	       p->name, p->base, p->base_hi);
+	if (p->irq != PARPORT_IRQ_NONE)
+		printk(", irq %d", p->irq);
+	printk(" [");
+#define printmode(x)	if (p->modes & PARPORT_MODE_##x)		\
+				printk("%s%s", f++ ? "," : "", #x)
+	{
+		unsigned int f = 0;
+		printmode(PCSPP);
+		printmode(TRISTATE);
+		printmode(COMPAT);
+		printmode(EPP);
+		printmode(ECP);
+		printmode(DMA);
+	}
+#undef printmode
+	printk("]\n");
+
+	parport_announce_port(p);
+	return p;
+
+fail:
+	if (p)
+		parport_put_port(p);
+	kfree(priv);
+	kfree(ops);
+	return ERR_PTR(err);
+}
+
+/**
+ * parport_ip32_unregister_port - unregister a parallel port
+ * @p:		pointer to the &struct parport
+ *
+ * Unregisters a parallel port and free previously allocated resources
+ * (memory, IRQ, ...).
+ */
+static __exit void parport_ip32_unregister_port(struct parport *p)
+{
+	struct parport_ip32_private * const priv = p->physport->private_data;
+	struct parport_operations *ops = p->ops;
+
+	parport_remove_port(p);
+	if (p->modes & PARPORT_MODE_DMA)
+		parport_ip32_dma_unregister();
+	if (p->irq != PARPORT_IRQ_NONE)
+		free_irq(p->irq, p);
+	parport_put_port(p);
+	kfree(priv);
+	kfree(ops);
+}
+
+/**
+ * parport_ip32_init - module initialization function
+ */
+static int __init parport_ip32_init(void)
+{
+	pr_info(PPIP32 "SGI IP32 built-in parallel port driver v0.6\n");
+	pr_debug1(PPIP32 "Compiled on %s, %s\n", __DATE__, __TIME__);
+	this_port = parport_ip32_probe_port();
+	return IS_ERR(this_port) ? PTR_ERR(this_port) : 0;
+}
+
+/**
+ * parport_ip32_exit - module termination function
+ */
+static void __exit parport_ip32_exit(void)
+{
+	parport_ip32_unregister_port(this_port);
+}
+
+/*--- Module stuff -----------------------------------------------------*/
+
+MODULE_AUTHOR("Arnaud Giersch <arnaud.giersch@free.fr>");
+MODULE_DESCRIPTION("SGI IP32 built-in parallel port driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.6");		/* update in parport_ip32_init() too */
+
+module_init(parport_ip32_init);
+module_exit(parport_ip32_exit);
+
+module_param(verbose_probing, bool, S_IRUGO);
+MODULE_PARM_DESC(verbose_probing, "Log chit-chat during initialization");
+
+module_param(features, uint, S_IRUGO);
+MODULE_PARM_DESC(features,
+		 "Bit mask of features to enable"
+		 ", bit 0: IRQ support"
+		 ", bit 1: DMA support"
+		 ", bit 2: hardware SPP mode"
+		 ", bit 3: hardware EPP mode"
+		 ", bit 4: hardware ECP mode");
+
+/*--- Inform (X)Emacs about preferred coding style ---------------------*/
+/*
+ * Local Variables:
+ * mode: c
+ * c-file-style: "linux"
+ * indent-tabs-mode: t
+ * tab-width: 8
+ * fill-column: 78
+ * ispell-local-dictionary: "american"
+ * End:
+ */