summaryrefslogtreecommitdiffstats
path: root/arch/blackfin/kernel/bfin_dma.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/blackfin/kernel/bfin_dma.c')
-rw-r--r--arch/blackfin/kernel/bfin_dma.c542
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 0000000..40c2ed6
--- /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, );