1 files changed, 542 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/bfin_dma.c b/arch/blackfin/kernel/bfin_dma.c
new file mode 100644
index 000000000000..40c2ed61258e
--- /dev/null
+++ b/arch/blackfin/kernel/bfin_dma.c
@@ -0,0 +1,542 @@
+/*
+ * bfin_dma.c - Blackfin DMA implementation
+ *
+ * Copyright 2004-2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+
+#include <asm/blackfin.h>
+#include <asm/cacheflush.h>
+#include <asm/dma.h>
+#include <asm/uaccess.h>
+#include <asm/early_printk.h>
+
+/*
+ * To make sure we work around 05000119 - we always check DMA_DONE bit,
+ * never the DMA_RUN bit
+ */
+
+struct dma_channel dma_ch[MAX_DMA_CHANNELS];
+EXPORT_SYMBOL(dma_ch);
+
+static int __init blackfin_dma_init(void)
+{
+	int i;
+
+	printk(KERN_INFO "Blackfin DMA Controller\n");
+
+
+#if ANOMALY_05000480
+	bfin_write_DMAC_TC_PER(0x0111);
+#endif
+
+	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
+		atomic_set(&dma_ch[i].chan_status, 0);
+		dma_ch[i].regs = dma_io_base_addr[i];
+	}
+	/* Mark MEMDMA Channel 0 as requested since we're using it internally */
+	request_dma(CH_MEM_STREAM0_DEST, "Blackfin dma_memcpy");
+	request_dma(CH_MEM_STREAM0_SRC, "Blackfin dma_memcpy");
+
+#if defined(CONFIG_DEB_DMA_URGENT)
+	bfin_write_EBIU_DDRQUE(bfin_read_EBIU_DDRQUE()
+			 | DEB1_URGENT | DEB2_URGENT | DEB3_URGENT);
+#endif
+
+	return 0;
+}
+arch_initcall(blackfin_dma_init);
+
+#ifdef CONFIG_PROC_FS
+static int proc_dma_show(struct seq_file *m, void *v)
+{
+	int i;
+
+	for (i = 0; i < MAX_DMA_CHANNELS; ++i)
+		if (dma_channel_active(i))
+			seq_printf(m, "%2d: %s\n", i, dma_ch[i].device_id);
+
+	return 0;
+}
+
+static int proc_dma_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, proc_dma_show, NULL);
+}
+
+static const struct file_operations proc_dma_operations = {
+	.open		= proc_dma_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init proc_dma_init(void)
+{
+	return proc_create("dma", 0, NULL, &proc_dma_operations) != NULL;
+}
+late_initcall(proc_dma_init);
+#endif
+
+static void set_dma_peripheral_map(unsigned int channel, const char *device_id)
+{
+#ifdef CONFIG_BF54x
+	unsigned int per_map;
+
+	switch (channel) {
+		case CH_UART2_RX: per_map = 0xC << 12; break;
+		case CH_UART2_TX: per_map = 0xD << 12; break;
+		case CH_UART3_RX: per_map = 0xE << 12; break;
+		case CH_UART3_TX: per_map = 0xF << 12; break;
+		default:          return;
+	}
+
+	if (strncmp(device_id, "BFIN_UART", 9) == 0)
+		dma_ch[channel].regs->peripheral_map = per_map;
+#endif
+}
+
+/**
+ *	request_dma - request a DMA channel
+ *
+ * Request the specific DMA channel from the system if it's available.
+ */
+int request_dma(unsigned int channel, const char *device_id)
+{
+	pr_debug("request_dma() : BEGIN\n");
+
+	if (device_id == NULL)
+		printk(KERN_WARNING "request_dma(%u): no device_id given\n", channel);
+
+#if defined(CONFIG_BF561) && ANOMALY_05000182
+	if (channel >= CH_IMEM_STREAM0_DEST && channel <= CH_IMEM_STREAM1_DEST) {
+		if (get_cclk() > 500000000) {
+			printk(KERN_WARNING
+			       "Request IMDMA failed due to ANOMALY 05000182\n");
+			return -EFAULT;
+		}
+	}
+#endif
+
+	if (atomic_cmpxchg(&dma_ch[channel].chan_status, 0, 1)) {
+		pr_debug("DMA CHANNEL IN USE\n");
+		return -EBUSY;
+	}
+
+	set_dma_peripheral_map(channel, device_id);
+	dma_ch[channel].device_id = device_id;
+	dma_ch[channel].irq = 0;
+
+	/* This is to be enabled by putting a restriction -
+	 * you have to request DMA, before doing any operations on
+	 * descriptor/channel
+	 */
+	pr_debug("request_dma() : END\n");
+	return 0;
+}
+EXPORT_SYMBOL(request_dma);
+
+int set_dma_callback(unsigned int channel, irq_handler_t callback, void *data)
+{
+	int ret;
+	unsigned int irq;
+
+	BUG_ON(channel >= MAX_DMA_CHANNELS || !callback ||
+			!atomic_read(&dma_ch[channel].chan_status));
+
+	irq = channel2irq(channel);
+	ret = request_irq(irq, callback, 0, dma_ch[channel].device_id, data);
+	if (ret)
+		return ret;
+
+	dma_ch[channel].irq = irq;
+	dma_ch[channel].data = data;
+
+	return 0;
+}
+EXPORT_SYMBOL(set_dma_callback);
+
+/**
+ *	clear_dma_buffer - clear DMA fifos for specified channel
+ *
+ * Set the Buffer Clear bit in the Configuration register of specific DMA
+ * channel. This will stop the descriptor based DMA operation.
+ */
+static void clear_dma_buffer(unsigned int channel)
+{
+	dma_ch[channel].regs->cfg |= RESTART;
+	SSYNC();
+	dma_ch[channel].regs->cfg &= ~RESTART;
+}
+
+void free_dma(unsigned int channel)
+{
+	pr_debug("freedma() : BEGIN\n");
+	BUG_ON(channel >= MAX_DMA_CHANNELS ||
+			!atomic_read(&dma_ch[channel].chan_status));
+
+	/* Halt the DMA */
+	disable_dma(channel);
+	clear_dma_buffer(channel);
+
+	if (dma_ch[channel].irq)
+		free_irq(dma_ch[channel].irq, dma_ch[channel].data);
+
+	/* Clear the DMA Variable in the Channel */
+	atomic_set(&dma_ch[channel].chan_status, 0);
+
+	pr_debug("freedma() : END\n");
+}
+EXPORT_SYMBOL(free_dma);
+
+#ifdef CONFIG_PM
+# ifndef MAX_DMA_SUSPEND_CHANNELS
+#  define MAX_DMA_SUSPEND_CHANNELS MAX_DMA_CHANNELS
+# endif
+int blackfin_dma_suspend(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_DMA_CHANNELS; ++i) {
+		if (dma_ch[i].regs->cfg & DMAEN) {
+			printk(KERN_ERR "DMA Channel %d failed to suspend\n", i);
+			return -EBUSY;
+		}
+
+		if (i < MAX_DMA_SUSPEND_CHANNELS)
+			dma_ch[i].saved_peripheral_map = dma_ch[i].regs->peripheral_map;
+	}
+
+#if ANOMALY_05000480
+	bfin_write_DMAC_TC_PER(0x0);
+#endif
+	return 0;
+}
+
+void blackfin_dma_resume(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_DMA_CHANNELS; ++i) {
+		dma_ch[i].regs->cfg = 0;
+
+		if (i < MAX_DMA_SUSPEND_CHANNELS)
+			dma_ch[i].regs->peripheral_map = dma_ch[i].saved_peripheral_map;
+	}
+#if ANOMALY_05000480
+	bfin_write_DMAC_TC_PER(0x0111);
+#endif
+}
+#endif
+
+/**
+ *	blackfin_dma_early_init - minimal DMA init
+ *
+ * Setup a few DMA registers so we can safely do DMA transfers early on in
+ * the kernel booting process.  Really this just means using dma_memcpy().
+ */
+void __init blackfin_dma_early_init(void)
+{
+	early_shadow_stamp();
+	bfin_write_MDMA_S0_CONFIG(0);
+	bfin_write_MDMA_S1_CONFIG(0);
+}
+
+void __init early_dma_memcpy(void *pdst, const void *psrc, size_t size)
+{
+	unsigned long dst = (unsigned long)pdst;
+	unsigned long src = (unsigned long)psrc;
+	struct dma_register *dst_ch, *src_ch;
+
+	early_shadow_stamp();
+
+	/* We assume that everything is 4 byte aligned, so include
+	 * a basic sanity check
+	 */
+	BUG_ON(dst % 4);
+	BUG_ON(src % 4);
+	BUG_ON(size % 4);
+
+	src_ch = 0;
+	/* Find an avalible memDMA channel */
+	while (1) {
+		if (src_ch == (struct dma_register *)MDMA_S0_NEXT_DESC_PTR) {
+			dst_ch = (struct dma_register *)MDMA_D1_NEXT_DESC_PTR;
+			src_ch = (struct dma_register *)MDMA_S1_NEXT_DESC_PTR;
+		} else {
+			dst_ch = (struct dma_register *)MDMA_D0_NEXT_DESC_PTR;
+			src_ch = (struct dma_register *)MDMA_S0_NEXT_DESC_PTR;
+		}
+
+		if (!bfin_read16(&src_ch->cfg))
+			break;
+		else if (bfin_read16(&dst_ch->irq_status) & DMA_DONE) {
+			bfin_write16(&src_ch->cfg, 0);
+			break;
+		}
+	}
+
+	/* Force a sync in case a previous config reset on this channel
+	 * occurred.  This is needed so subsequent writes to DMA registers
+	 * are not spuriously lost/corrupted.
+	 */
+	__builtin_bfin_ssync();
+
+	/* Destination */
+	bfin_write32(&dst_ch->start_addr, dst);
+	bfin_write16(&dst_ch->x_count, size >> 2);
+	bfin_write16(&dst_ch->x_modify, 1 << 2);
+	bfin_write16(&dst_ch->irq_status, DMA_DONE | DMA_ERR);
+
+	/* Source */
+	bfin_write32(&src_ch->start_addr, src);
+	bfin_write16(&src_ch->x_count, size >> 2);
+	bfin_write16(&src_ch->x_modify, 1 << 2);
+	bfin_write16(&src_ch->irq_status, DMA_DONE | DMA_ERR);
+
+	/* Enable */
+	bfin_write16(&src_ch->cfg, DMAEN | WDSIZE_32);
+	bfin_write16(&dst_ch->cfg, WNR | DI_EN | DMAEN | WDSIZE_32);
+
+	/* Since we are atomic now, don't use the workaround ssync */
+	__builtin_bfin_ssync();
+}
+
+void __init early_dma_memcpy_done(void)
+{
+	early_shadow_stamp();
+
+	while ((bfin_read_MDMA_S0_CONFIG() && !(bfin_read_MDMA_D0_IRQ_STATUS() & DMA_DONE)) ||
+	       (bfin_read_MDMA_S1_CONFIG() && !(bfin_read_MDMA_D1_IRQ_STATUS() & DMA_DONE)))
+		continue;
+
+	bfin_write_MDMA_D0_IRQ_STATUS(DMA_DONE | DMA_ERR);
+	bfin_write_MDMA_D1_IRQ_STATUS(DMA_DONE | DMA_ERR);
+	/*
+	 * Now that DMA is done, we would normally flush cache, but
+	 * i/d cache isn't running this early, so we don't bother,
+	 * and just clear out the DMA channel for next time
+	 */
+	bfin_write_MDMA_S0_CONFIG(0);
+	bfin_write_MDMA_S1_CONFIG(0);
+	bfin_write_MDMA_D0_CONFIG(0);
+	bfin_write_MDMA_D1_CONFIG(0);
+
+	__builtin_bfin_ssync();
+}
+
+/**
+ *	__dma_memcpy - program the MDMA registers
+ *
+ * Actually program MDMA0 and wait for the transfer to finish.  Disable IRQs
+ * while programming registers so that everything is fully configured.  Wait
+ * for DMA to finish with IRQs enabled.  If interrupted, the initial DMA_DONE
+ * check will make sure we don't clobber any existing transfer.
+ */
+static void __dma_memcpy(u32 daddr, s16 dmod, u32 saddr, s16 smod, size_t cnt, u32 conf)
+{
+	static DEFINE_SPINLOCK(mdma_lock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&mdma_lock, flags);
+
+	/* Force a sync in case a previous config reset on this channel
+	 * occurred.  This is needed so subsequent writes to DMA registers
+	 * are not spuriously lost/corrupted.  Do it under irq lock and
+	 * without the anomaly version (because we are atomic already).
+	 */
+	__builtin_bfin_ssync();
+
+	if (bfin_read_MDMA_S0_CONFIG())
+		while (!(bfin_read_MDMA_D0_IRQ_STATUS() & DMA_DONE))
+			continue;
+
+	if (conf & DMA2D) {
+		/* For larger bit sizes, we've already divided down cnt so it
+		 * is no longer a multiple of 64k.  So we have to break down
+		 * the limit here so it is a multiple of the incoming size.
+		 * There is no limitation here in terms of total size other
+		 * than the hardware though as the bits lost in the shift are
+		 * made up by MODIFY (== we can hit the whole address space).
+		 * X: (2^(16 - 0)) * 1 == (2^(16 - 1)) * 2 == (2^(16 - 2)) * 4
+		 */
+		u32 shift = abs(dmod) >> 1;
+		size_t ycnt = cnt >> (16 - shift);
+		cnt = 1 << (16 - shift);
+		bfin_write_MDMA_D0_Y_COUNT(ycnt);
+		bfin_write_MDMA_S0_Y_COUNT(ycnt);
+		bfin_write_MDMA_D0_Y_MODIFY(dmod);
+		bfin_write_MDMA_S0_Y_MODIFY(smod);
+	}
+
+	bfin_write_MDMA_D0_START_ADDR(daddr);
+	bfin_write_MDMA_D0_X_COUNT(cnt);
+	bfin_write_MDMA_D0_X_MODIFY(dmod);
+	bfin_write_MDMA_D0_IRQ_STATUS(DMA_DONE | DMA_ERR);
+
+	bfin_write_MDMA_S0_START_ADDR(saddr);
+	bfin_write_MDMA_S0_X_COUNT(cnt);
+	bfin_write_MDMA_S0_X_MODIFY(smod);
+	bfin_write_MDMA_S0_IRQ_STATUS(DMA_DONE | DMA_ERR);
+
+	bfin_write_MDMA_S0_CONFIG(DMAEN | conf);
+	bfin_write_MDMA_D0_CONFIG(WNR | DI_EN | DMAEN | conf);
+
+	spin_unlock_irqrestore(&mdma_lock, flags);
+
+	SSYNC();
+
+	while (!(bfin_read_MDMA_D0_IRQ_STATUS() & DMA_DONE))
+		if (bfin_read_MDMA_S0_CONFIG())
+			continue;
+		else
+			return;
+
+	bfin_write_MDMA_D0_IRQ_STATUS(DMA_DONE | DMA_ERR);
+
+	bfin_write_MDMA_S0_CONFIG(0);
+	bfin_write_MDMA_D0_CONFIG(0);
+}
+
+/**
+ *	_dma_memcpy - translate C memcpy settings into MDMA settings
+ *
+ * Handle all the high level steps before we touch the MDMA registers.  So
+ * handle direction, tweaking of sizes, and formatting of addresses.
+ */
+static void *_dma_memcpy(void *pdst, const void *psrc, size_t size)
+{
+	u32 conf, shift;
+	s16 mod;
+	unsigned long dst = (unsigned long)pdst;
+	unsigned long src = (unsigned long)psrc;
+
+	if (size == 0)
+		return NULL;
+
+	if (dst % 4 == 0 && src % 4 == 0 && size % 4 == 0) {
+		conf = WDSIZE_32;
+		shift = 2;
+	} else if (dst % 2 == 0 && src % 2 == 0 && size % 2 == 0) {
+		conf = WDSIZE_16;
+		shift = 1;
+	} else {
+		conf = WDSIZE_8;
+		shift = 0;
+	}
+
+	/* If the two memory regions have a chance of overlapping, make
+	 * sure the memcpy still works as expected.  Do this by having the
+	 * copy run backwards instead.
+	 */
+	mod = 1 << shift;
+	if (src < dst) {
+		mod *= -1;
+		dst += size + mod;
+		src += size + mod;
+	}
+	size >>= shift;
+
+	if (size > 0x10000)
+		conf |= DMA2D;
+
+	__dma_memcpy(dst, mod, src, mod, size, conf);
+
+	return pdst;
+}
+
+/**
+ *	dma_memcpy - DMA memcpy under mutex lock
+ *
+ * Do not check arguments before starting the DMA memcpy.  Break the transfer
+ * up into two pieces.  The first transfer is in multiples of 64k and the
+ * second transfer is the piece smaller than 64k.
+ */
+void *dma_memcpy(void *pdst, const void *psrc, size_t size)
+{
+	unsigned long dst = (unsigned long)pdst;
+	unsigned long src = (unsigned long)psrc;
+
+	if (bfin_addr_dcacheable(src))
+		blackfin_dcache_flush_range(src, src + size);
+
+	if (bfin_addr_dcacheable(dst))
+		blackfin_dcache_invalidate_range(dst, dst + size);
+
+	return dma_memcpy_nocache(pdst, psrc, size);
+}
+EXPORT_SYMBOL(dma_memcpy);
+
+/**
+ *	dma_memcpy_nocache - DMA memcpy under mutex lock
+ *	- No cache flush/invalidate
+ *
+ * Do not check arguments before starting the DMA memcpy.  Break the transfer
+ * up into two pieces.  The first transfer is in multiples of 64k and the
+ * second transfer is the piece smaller than 64k.
+ */
+void *dma_memcpy_nocache(void *pdst, const void *psrc, size_t size)
+{
+	size_t bulk, rest;
+
+	bulk = size & ~0xffff;
+	rest = size - bulk;
+	if (bulk)
+		_dma_memcpy(pdst, psrc, bulk);
+	_dma_memcpy(pdst + bulk, psrc + bulk, rest);
+	return pdst;
+}
+EXPORT_SYMBOL(dma_memcpy_nocache);
+
+/**
+ *	safe_dma_memcpy - DMA memcpy w/argument checking
+ *
+ * Verify arguments are safe before heading to dma_memcpy().
+ */
+void *safe_dma_memcpy(void *dst, const void *src, size_t size)
+{
+	if (!access_ok(VERIFY_WRITE, dst, size))
+		return NULL;
+	if (!access_ok(VERIFY_READ, src, size))
+		return NULL;
+	return dma_memcpy(dst, src, size);
+}
+EXPORT_SYMBOL(safe_dma_memcpy);
+
+static void _dma_out(unsigned long addr, unsigned long buf, unsigned short len,
+                     u16 size, u16 dma_size)
+{
+	blackfin_dcache_flush_range(buf, buf + len * size);
+	__dma_memcpy(addr, 0, buf, size, len, dma_size);
+}
+
+static void _dma_in(unsigned long addr, unsigned long buf, unsigned short len,
+                    u16 size, u16 dma_size)
+{
+	blackfin_dcache_invalidate_range(buf, buf + len * size);
+	__dma_memcpy(buf, size, addr, 0, len, dma_size);
+}
+
+#define MAKE_DMA_IO(io, bwl, isize, dmasize, cnst) \
+void dma_##io##s##bwl(unsigned long addr, cnst void *buf, unsigned short len) \
+{ \
+	_dma_##io(addr, (unsigned long)buf, len, isize, WDSIZE_##dmasize); \
+} \
+EXPORT_SYMBOL(dma_##io##s##bwl)
+MAKE_DMA_IO(out, b, 1,  8, const);
+MAKE_DMA_IO(in,  b, 1,  8, );
+MAKE_DMA_IO(out, w, 2, 16, const);
+MAKE_DMA_IO(in,  w, 2, 16, );
+MAKE_DMA_IO(out, l, 4, 32, const);
+MAKE_DMA_IO(in,  l, 4, 32, );