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-rw-r--r--arch/arm/plat-pxa/dma.c392
1 files changed, 392 insertions, 0 deletions
diff --git a/arch/arm/plat-pxa/dma.c b/arch/arm/plat-pxa/dma.c
new file mode 100644
index 00000000..2d3c19d7
--- /dev/null
+++ b/arch/arm/plat-pxa/dma.c
@@ -0,0 +1,392 @@
+/*
+ * linux/arch/arm/plat-pxa/dma.c
+ *
+ * PXA DMA registration and IRQ dispatching
+ *
+ * Author: Nicolas Pitre
+ * Created: Nov 15, 2001
+ * Copyright: MontaVista Software Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/memory.h>
+#include <mach/hardware.h>
+#include <mach/dma.h>
+
+#define DMA_DEBUG_NAME "pxa_dma"
+#define DMA_MAX_REQUESTERS 64
+
+struct dma_channel {
+ char *name;
+ pxa_dma_prio prio;
+ void (*irq_handler)(int, void *);
+ void *data;
+ spinlock_t lock;
+};
+
+static struct dma_channel *dma_channels;
+static int num_dma_channels;
+
+/*
+ * Debug fs
+ */
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
+
+static struct dentry *dbgfs_root, *dbgfs_state, **dbgfs_chan;
+
+static int dbg_show_requester_chan(struct seq_file *s, void *p)
+{
+ int pos = 0;
+ int chan = (int)s->private;
+ int i;
+ u32 drcmr;
+
+ pos += seq_printf(s, "DMA channel %d requesters list :\n", chan);
+ for (i = 0; i < DMA_MAX_REQUESTERS; i++) {
+ drcmr = DRCMR(i);
+ if ((drcmr & DRCMR_CHLNUM) == chan)
+ pos += seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
+ !!(drcmr & DRCMR_MAPVLD));
+ }
+ return pos;
+}
+
+static inline int dbg_burst_from_dcmd(u32 dcmd)
+{
+ int burst = (dcmd >> 16) & 0x3;
+
+ return burst ? 4 << burst : 0;
+}
+
+static int is_phys_valid(unsigned long addr)
+{
+ return pfn_valid(__phys_to_pfn(addr));
+}
+
+#define DCSR_STR(flag) (dcsr & DCSR_##flag ? #flag" " : "")
+#define DCMD_STR(flag) (dcmd & DCMD_##flag ? #flag" " : "")
+
+static int dbg_show_descriptors(struct seq_file *s, void *p)
+{
+ int pos = 0;
+ int chan = (int)s->private;
+ int i, max_show = 20, burst, width;
+ u32 dcmd;
+ unsigned long phys_desc;
+ struct pxa_dma_desc *desc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dma_channels[chan].lock, flags);
+ phys_desc = DDADR(chan);
+
+ pos += seq_printf(s, "DMA channel %d descriptors :\n", chan);
+ pos += seq_printf(s, "[%03d] First descriptor unknown\n", 0);
+ for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) {
+ desc = phys_to_virt(phys_desc);
+ dcmd = desc->dcmd;
+ burst = dbg_burst_from_dcmd(dcmd);
+ width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
+
+ pos += seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n",
+ i, phys_desc, desc);
+ pos += seq_printf(s, "\tDDADR = %08x\n", desc->ddadr);
+ pos += seq_printf(s, "\tDSADR = %08x\n", desc->dsadr);
+ pos += seq_printf(s, "\tDTADR = %08x\n", desc->dtadr);
+ pos += seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d"
+ " width=%d len=%d)\n",
+ dcmd,
+ DCMD_STR(INCSRCADDR), DCMD_STR(INCTRGADDR),
+ DCMD_STR(FLOWSRC), DCMD_STR(FLOWTRG),
+ DCMD_STR(STARTIRQEN), DCMD_STR(ENDIRQEN),
+ DCMD_STR(ENDIAN), burst, width,
+ dcmd & DCMD_LENGTH);
+ phys_desc = desc->ddadr;
+ }
+ if (i == max_show)
+ pos += seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n",
+ i, phys_desc);
+ else
+ pos += seq_printf(s, "[%03d] Desc at %08lx is %s\n",
+ i, phys_desc, phys_desc == DDADR_STOP ?
+ "DDADR_STOP" : "invalid");
+
+ spin_unlock_irqrestore(&dma_channels[chan].lock, flags);
+ return pos;
+}
+
+static int dbg_show_chan_state(struct seq_file *s, void *p)
+{
+ int pos = 0;
+ int chan = (int)s->private;
+ u32 dcsr, dcmd;
+ int burst, width;
+ static char *str_prio[] = { "high", "normal", "low" };
+
+ dcsr = DCSR(chan);
+ dcmd = DCMD(chan);
+ burst = dbg_burst_from_dcmd(dcmd);
+ width = (1 << ((dcmd >> 14) & 0x3)) >> 1;
+
+ pos += seq_printf(s, "DMA channel %d\n", chan);
+ pos += seq_printf(s, "\tPriority : %s\n",
+ str_prio[dma_channels[chan].prio]);
+ pos += seq_printf(s, "\tUnaligned transfer bit: %s\n",
+ DALGN & (1 << chan) ? "yes" : "no");
+ pos += seq_printf(s, "\tDCSR = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
+ dcsr, DCSR_STR(RUN), DCSR_STR(NODESC),
+ DCSR_STR(STOPIRQEN), DCSR_STR(EORIRQEN),
+ DCSR_STR(EORJMPEN), DCSR_STR(EORSTOPEN),
+ DCSR_STR(SETCMPST), DCSR_STR(CLRCMPST),
+ DCSR_STR(CMPST), DCSR_STR(EORINTR), DCSR_STR(REQPEND),
+ DCSR_STR(STOPSTATE), DCSR_STR(ENDINTR),
+ DCSR_STR(STARTINTR), DCSR_STR(BUSERR));
+
+ pos += seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d width=%d"
+ " len=%d)\n",
+ dcmd,
+ DCMD_STR(INCSRCADDR), DCMD_STR(INCTRGADDR),
+ DCMD_STR(FLOWSRC), DCMD_STR(FLOWTRG),
+ DCMD_STR(STARTIRQEN), DCMD_STR(ENDIRQEN),
+ DCMD_STR(ENDIAN), burst, width, dcmd & DCMD_LENGTH);
+ pos += seq_printf(s, "\tDSADR = %08x\n", DSADR(chan));
+ pos += seq_printf(s, "\tDTADR = %08x\n", DTADR(chan));
+ pos += seq_printf(s, "\tDDADR = %08x\n", DDADR(chan));
+ return pos;
+}
+
+static int dbg_show_state(struct seq_file *s, void *p)
+{
+ int pos = 0;
+
+ /* basic device status */
+ pos += seq_printf(s, "DMA engine status\n");
+ pos += seq_printf(s, "\tChannel number: %d\n", num_dma_channels);
+
+ return pos;
+}
+
+#define DBGFS_FUNC_DECL(name) \
+static int dbg_open_##name(struct inode *inode, struct file *file) \
+{ \
+ return single_open(file, dbg_show_##name, inode->i_private); \
+} \
+static const struct file_operations dbg_fops_##name = { \
+ .owner = THIS_MODULE, \
+ .open = dbg_open_##name, \
+ .llseek = seq_lseek, \
+ .read = seq_read, \
+ .release = single_release, \
+}
+
+DBGFS_FUNC_DECL(state);
+DBGFS_FUNC_DECL(chan_state);
+DBGFS_FUNC_DECL(descriptors);
+DBGFS_FUNC_DECL(requester_chan);
+
+static struct dentry *pxa_dma_dbg_alloc_chan(int ch, struct dentry *chandir)
+{
+ char chan_name[11];
+ struct dentry *chan, *chan_state = NULL, *chan_descr = NULL;
+ struct dentry *chan_reqs = NULL;
+ void *dt;
+
+ scnprintf(chan_name, sizeof(chan_name), "%d", ch);
+ chan = debugfs_create_dir(chan_name, chandir);
+ dt = (void *)ch;
+
+ if (chan)
+ chan_state = debugfs_create_file("state", 0400, chan, dt,
+ &dbg_fops_chan_state);
+ if (chan_state)
+ chan_descr = debugfs_create_file("descriptors", 0400, chan, dt,
+ &dbg_fops_descriptors);
+ if (chan_descr)
+ chan_reqs = debugfs_create_file("requesters", 0400, chan, dt,
+ &dbg_fops_requester_chan);
+ if (!chan_reqs)
+ goto err_state;
+
+ return chan;
+
+err_state:
+ debugfs_remove_recursive(chan);
+ return NULL;
+}
+
+static void pxa_dma_init_debugfs(void)
+{
+ int i;
+ struct dentry *chandir;
+
+ dbgfs_root = debugfs_create_dir(DMA_DEBUG_NAME, NULL);
+ if (IS_ERR(dbgfs_root) || !dbgfs_root)
+ goto err_root;
+
+ dbgfs_state = debugfs_create_file("state", 0400, dbgfs_root, NULL,
+ &dbg_fops_state);
+ if (!dbgfs_state)
+ goto err_state;
+
+ dbgfs_chan = kmalloc(sizeof(*dbgfs_state) * num_dma_channels,
+ GFP_KERNEL);
+ if (!dbgfs_chan)
+ goto err_alloc;
+
+ chandir = debugfs_create_dir("channels", dbgfs_root);
+ if (!chandir)
+ goto err_chandir;
+
+ for (i = 0; i < num_dma_channels; i++) {
+ dbgfs_chan[i] = pxa_dma_dbg_alloc_chan(i, chandir);
+ if (!dbgfs_chan[i])
+ goto err_chans;
+ }
+
+ return;
+err_chans:
+err_chandir:
+ kfree(dbgfs_chan);
+err_alloc:
+err_state:
+ debugfs_remove_recursive(dbgfs_root);
+err_root:
+ pr_err("pxa_dma: debugfs is not available\n");
+}
+
+static void __exit pxa_dma_cleanup_debugfs(void)
+{
+ debugfs_remove_recursive(dbgfs_root);
+}
+#else
+static inline void pxa_dma_init_debugfs(void) {}
+static inline void pxa_dma_cleanup_debugfs(void) {}
+#endif
+
+int pxa_request_dma (char *name, pxa_dma_prio prio,
+ void (*irq_handler)(int, void *),
+ void *data)
+{
+ unsigned long flags;
+ int i, found = 0;
+
+ /* basic sanity checks */
+ if (!name || !irq_handler)
+ return -EINVAL;
+
+ local_irq_save(flags);
+
+ do {
+ /* try grabbing a DMA channel with the requested priority */
+ for (i = 0; i < num_dma_channels; i++) {
+ if ((dma_channels[i].prio == prio) &&
+ !dma_channels[i].name) {
+ found = 1;
+ break;
+ }
+ }
+ /* if requested prio group is full, try a hier priority */
+ } while (!found && prio--);
+
+ if (found) {
+ DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
+ dma_channels[i].name = name;
+ dma_channels[i].irq_handler = irq_handler;
+ dma_channels[i].data = data;
+ } else {
+ printk (KERN_WARNING "No more available DMA channels for %s\n", name);
+ i = -ENODEV;
+ }
+
+ local_irq_restore(flags);
+ return i;
+}
+EXPORT_SYMBOL(pxa_request_dma);
+
+void pxa_free_dma (int dma_ch)
+{
+ unsigned long flags;
+
+ if (!dma_channels[dma_ch].name) {
+ printk (KERN_CRIT
+ "%s: trying to free channel %d which is already freed\n",
+ __func__, dma_ch);
+ return;
+ }
+
+ local_irq_save(flags);
+ DCSR(dma_ch) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
+ dma_channels[dma_ch].name = NULL;
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(pxa_free_dma);
+
+static irqreturn_t dma_irq_handler(int irq, void *dev_id)
+{
+ int i, dint = DINT;
+ struct dma_channel *channel;
+
+ while (dint) {
+ i = __ffs(dint);
+ dint &= (dint - 1);
+ channel = &dma_channels[i];
+ if (channel->name && channel->irq_handler) {
+ channel->irq_handler(i, channel->data);
+ } else {
+ /*
+ * IRQ for an unregistered DMA channel:
+ * let's clear the interrupts and disable it.
+ */
+ printk (KERN_WARNING "spurious IRQ for DMA channel %d\n", i);
+ DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
+ }
+ }
+ return IRQ_HANDLED;
+}
+
+int __init pxa_init_dma(int irq, int num_ch)
+{
+ int i, ret;
+
+ dma_channels = kzalloc(sizeof(struct dma_channel) * num_ch, GFP_KERNEL);
+ if (dma_channels == NULL)
+ return -ENOMEM;
+
+ /* dma channel priorities on pxa2xx processors:
+ * ch 0 - 3, 16 - 19 <--> (0) DMA_PRIO_HIGH
+ * ch 4 - 7, 20 - 23 <--> (1) DMA_PRIO_MEDIUM
+ * ch 8 - 15, 24 - 31 <--> (2) DMA_PRIO_LOW
+ */
+ for (i = 0; i < num_ch; i++) {
+ DCSR(i) = 0;
+ dma_channels[i].prio = min((i & 0xf) >> 2, DMA_PRIO_LOW);
+ spin_lock_init(&dma_channels[i].lock);
+ }
+
+ ret = request_irq(irq, dma_irq_handler, IRQF_DISABLED, "DMA", NULL);
+ if (ret) {
+ printk (KERN_CRIT "Wow! Can't register IRQ for DMA\n");
+ kfree(dma_channels);
+ return ret;
+ }
+ num_dma_channels = num_ch;
+
+ pxa_dma_init_debugfs();
+
+ return 0;
+}
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