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authorRalf Baechle <ralf@linux-mips.org>2000-07-21 22:00:56 +0000
committerRalf Baechle <ralf@linux-mips.org>2000-07-21 22:00:56 +0000
commit168660f24dfc46c2702acbe4701a446f42a59578 (patch)
treef431368afbf6b1b71809cf3fd904d800ea126f4d /arch/arm/kernel/dma.c
parent6420f767924fa73b0ea267864d96820815f4ba5a (diff)
Merge with Linux 2.4.0-test5-pre3.
Diffstat (limited to 'arch/arm/kernel/dma.c')
-rw-r--r--arch/arm/kernel/dma.c307
1 files changed, 180 insertions, 127 deletions
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c
index ff8322d34..7ed4c28ca 100644
--- a/arch/arm/kernel/dma.c
+++ b/arch/arm/kernel/dma.c
@@ -1,130 +1,123 @@
/*
* linux/arch/arm/kernel/dma.c
*
- * Copyright (C) 1995-1998 Russell King
+ * Copyright (C) 1995-2000 Russell King
*
- * Front-end to the DMA handling. You must provide the following
- * architecture-specific routines:
- *
- * int arch_request_dma(dmach_t channel, dma_t *dma, const char *dev_id);
- * void arch_free_dma(dmach_t channel, dma_t *dma);
- * void arch_enable_dma(dmach_t channel, dma_t *dma);
- * void arch_disable_dma(dmach_t channel, dma_t *dma);
- * int arch_get_dma_residue(dmach_t channel, dma_t *dma);
- *
- * Moved DMA resource allocation here...
+ * Front-end to the DMA handling. This handles the allocation/freeing
+ * of DMA channels, and provides a unified interface to the machines
+ * DMA facilities.
*/
+#include <linux/module.h>
#include <linux/malloc.h>
#include <linux/sched.h>
-#include <linux/module.h>
#include <linux/mman.h>
#include <linux/init.h>
#include <linux/spinlock.h>
-#include <asm/page.h>
-#include <asm/irq.h>
-#include <asm/hardware.h>
-#include <asm/io.h>
#include <asm/dma.h>
-
-/* A note on resource allocation:
- *
- * All drivers needing DMA channels, should allocate and release them
- * through the public routines `request_dma()' and `free_dma()'.
- *
- * In order to avoid problems, all processes should allocate resources in
- * the same sequence and release them in the reverse order.
- *
- * So, when allocating DMAs and IRQs, first allocate the IRQ, then the DMA.
- * When releasing them, first release the DMA, then release the IRQ.
- * If you don't, you may cause allocation requests to fail unnecessarily.
- * This doesn't really matter now, but it will once we get real semaphores
- * in the kernel.
- */
-
+#include "dma.h"
spinlock_t dma_spin_lock = SPIN_LOCK_UNLOCKED;
-#include "dma.h"
-
-const char dma_str[] = "%s: dma %d not supported\n";
+#if MAX_DMA_CHANNELS > 0
static dma_t dma_chan[MAX_DMA_CHANNELS];
-/* Get dma list
- * for /proc/dma
+/*
+ * Get dma list for /proc/dma
*/
int get_dma_list(char *buf)
{
- int i, len = 0;
+ dma_t *dma;
+ char *p = buf;
+ int i;
- for (i = 0; i < MAX_DMA_CHANNELS; i++) {
- if (dma_chan[i].lock)
- len += sprintf(buf + len, "%2d: %s\n",
- i, dma_chan[i].device_id);
- }
- return len;
+ for (i = 0, dma = dma_chan; i < MAX_DMA_CHANNELS; i++, dma++)
+ if (dma->lock)
+ p += sprintf(p, "%2d: %14s %s\n", i,
+ dma->d_ops->type, dma->device_id);
+
+ return p - buf;
}
-/* Request DMA channel
+/*
+ * Request DMA channel
*
* On certain platforms, we have to allocate an interrupt as well...
*/
int request_dma(dmach_t channel, const char *device_id)
{
- if (channel < MAX_DMA_CHANNELS) {
- int ret;
-
- if (xchg(&dma_chan[channel].lock, 1) != 0)
- return -EBUSY;
-
- ret = arch_request_dma(channel, &dma_chan[channel], device_id);
- if (!ret) {
- dma_chan[channel].device_id = device_id;
- dma_chan[channel].active = 0;
- dma_chan[channel].invalid = 1;
- } else
- xchg(&dma_chan[channel].lock, 0);
-
- return ret;
- } else {
- printk (KERN_ERR "Trying to allocate DMA%d\n", channel);
- return -EINVAL;
- }
+ dma_t *dma = dma_chan + channel;
+ int ret;
+
+ if (channel >= MAX_DMA_CHANNELS || !dma->d_ops)
+ goto bad_dma;
+
+ if (xchg(&dma->lock, 1) != 0)
+ goto busy;
+
+ dma->device_id = device_id;
+ dma->active = 0;
+ dma->invalid = 1;
+
+ ret = 0;
+ if (dma->d_ops->request)
+ ret = dma->d_ops->request(channel, dma);
+
+ if (ret)
+ xchg(&dma->lock, 0);
+
+ return ret;
+
+bad_dma:
+ printk(KERN_ERR "dma: trying to allocate DMA%d\n", channel);
+ return -EINVAL;
+
+busy:
+ return -EBUSY;
}
-/* Free DMA channel
+/*
+ * Free DMA channel
*
* On certain platforms, we have to free interrupt as well...
*/
void free_dma(dmach_t channel)
{
- if (channel >= MAX_DMA_CHANNELS) {
- printk (KERN_ERR "Trying to free DMA%d\n", channel);
- return;
- }
+ dma_t *dma = dma_chan + channel;
+
+ if (channel >= MAX_DMA_CHANNELS || !dma->d_ops)
+ goto bad_dma;
- if (xchg(&dma_chan[channel].lock, 0) == 0) {
- if (dma_chan[channel].active) {
- printk (KERN_ERR "Freeing active DMA%d\n", channel);
- arch_disable_dma(channel, &dma_chan[channel]);
- dma_chan[channel].active = 0;
- }
+ if (dma->active) {
+ printk(KERN_ERR "dma%d: freeing active DMA\n", channel);
+ dma->d_ops->disable(channel, dma);
+ dma->active = 0;
+ }
- printk (KERN_ERR "Trying to free free DMA%d\n", channel);
+ if (xchg(&dma->lock, 0) != 0) {
+ if (dma->d_ops->free)
+ dma->d_ops->free(channel, dma);
return;
}
- arch_free_dma(channel, &dma_chan[channel]);
+
+ printk(KERN_ERR "dma%d: trying to free free DMA\n", channel);
+ return;
+
+bad_dma:
+ printk(KERN_ERR "dma: trying to free DMA%d\n", channel);
}
/* Set DMA Scatter-Gather list
*/
void set_dma_sg (dmach_t channel, dmasg_t *sg, int nr_sg)
{
- dma_chan[channel].sg = sg;
- dma_chan[channel].sgcount = nr_sg;
- dma_chan[channel].invalid = 1;
+ dma_t *dma = dma_chan + channel;
+
+ dma->sg = sg;
+ dma->sgcount = nr_sg;
+ dma->invalid = 1;
}
/* Set DMA address
@@ -133,15 +126,16 @@ void set_dma_sg (dmach_t channel, dmasg_t *sg, int nr_sg)
*/
void set_dma_addr (dmach_t channel, unsigned long physaddr)
{
- if (dma_chan[channel].active)
- printk(KERN_ERR "set_dma_addr: altering DMA%d"
- " address while DMA active\n",
- channel);
-
- dma_chan[channel].sg = &dma_chan[channel].buf;
- dma_chan[channel].sgcount = 1;
- dma_chan[channel].buf.address = physaddr;
- dma_chan[channel].invalid = 1;
+ dma_t *dma = dma_chan + channel;
+
+ if (dma->active)
+ printk(KERN_ERR "dma%d: altering DMA address while "
+ "DMA active\n", channel);
+
+ dma->sg = &dma->buf;
+ dma->sgcount = 1;
+ dma->buf.address = physaddr;
+ dma->invalid = 1;
}
/* Set DMA byte count
@@ -150,78 +144,137 @@ void set_dma_addr (dmach_t channel, unsigned long physaddr)
*/
void set_dma_count (dmach_t channel, unsigned long count)
{
- if (dma_chan[channel].active)
- printk(KERN_ERR "set_dma_count: altering DMA%d"
- " count while DMA active\n",
- channel);
-
- dma_chan[channel].sg = &dma_chan[channel].buf;
- dma_chan[channel].sgcount = 1;
- dma_chan[channel].buf.length = count;
- dma_chan[channel].invalid = 1;
+ dma_t *dma = dma_chan + channel;
+
+ if (dma->active)
+ printk(KERN_ERR "dma%d: altering DMA count while "
+ "DMA active\n", channel);
+
+ dma->sg = &dma->buf;
+ dma->sgcount = 1;
+ dma->buf.length = count;
+ dma->invalid = 1;
}
/* Set DMA direction mode
*/
void set_dma_mode (dmach_t channel, dmamode_t mode)
{
- if (dma_chan[channel].active)
- printk(KERN_ERR "set_dma_mode: altering DMA%d"
- " mode while DMA active\n",
- channel);
+ dma_t *dma = dma_chan + channel;
+
+ if (dma->active)
+ printk(KERN_ERR "dma%d: altering DMA mode while "
+ "DMA active\n", channel);
- dma_chan[channel].dma_mode = mode;
- dma_chan[channel].invalid = 1;
+ dma->dma_mode = mode;
+ dma->invalid = 1;
}
/* Enable DMA channel
*/
void enable_dma (dmach_t channel)
{
- if (dma_chan[channel].lock) {
- if (dma_chan[channel].active == 0) {
- dma_chan[channel].active = 1;
- arch_enable_dma(channel, &dma_chan[channel]);
- }
- } else
- printk (KERN_ERR "Trying to enable free DMA%d\n", channel);
+ dma_t *dma = dma_chan + channel;
+
+ if (!dma->lock)
+ goto free_dma;
+
+ if (dma->active == 0) {
+ dma->active = 1;
+ dma->d_ops->enable(channel, dma);
+ }
+ return;
+
+free_dma:
+ printk(KERN_ERR "dma%d: trying to enable free DMA\n", channel);
+ BUG();
}
/* Disable DMA channel
*/
void disable_dma (dmach_t channel)
{
- if (dma_chan[channel].lock) {
- if (dma_chan[channel].active == 1) {
- dma_chan[channel].active = 0;
- arch_disable_dma(channel, &dma_chan[channel]);
- }
- } else
- printk (KERN_ERR "Trying to disable free DMA%d\n", channel);
+ dma_t *dma = dma_chan + channel;
+
+ if (!dma->lock)
+ goto free_dma;
+
+ if (dma->active == 1) {
+ dma->active = 0;
+ dma->d_ops->disable(channel, dma);
+ }
+ return;
+
+free_dma:
+ printk(KERN_ERR "dma%d: trying to disable free DMA\n", channel);
+ BUG();
+}
+
+void set_dma_page(dmach_t channel, char pagenr)
+{
+ printk(KERN_ERR "dma%d: trying to set_dma_page\n", channel);
}
void set_dma_speed(dmach_t channel, int cycle_ns)
{
- dma_chan[channel].speed =
- arch_set_dma_speed(channel, &dma_chan[channel], cycle_ns);
+ dma_t *dma = dma_chan + channel;
+ int ret = 0;
+
+ if (dma->d_ops->setspeed)
+ ret = dma->d_ops->setspeed(channel, dma, cycle_ns);
+ dma->speed = ret;
}
int get_dma_residue(dmach_t channel)
{
- return arch_get_dma_residue(channel, &dma_chan[channel]);
+ dma_t *dma = dma_chan + channel;
+ int ret = 0;
+
+ if (dma->d_ops->residue)
+ ret = dma->d_ops->residue(channel, dma);
+
+ return ret;
+}
+
+void __init init_dma(void)
+{
+ arch_dma_init(dma_chan);
+}
+
+#else
+
+int request_dma(dmach_t channel, const char *device_id)
+{
+ return -EINVAL;
+}
+
+static int no_dma(void)
+{
+ return 0;
}
-EXPORT_SYMBOL(dma_str);
+#define GLOBAL_ALIAS(_a,_b) asm (".set " #_a "," #_b "; .globl " #_a)
+GLOBAL_ALIAS(disable_dma, no_dma);
+GLOBAL_ALIAS(enable_dma, no_dma);
+GLOBAL_ALIAS(free_dma, no_dma);
+GLOBAL_ALIAS(get_dma_residue, no_dma);
+GLOBAL_ALIAS(get_dma_list, no_dma);
+GLOBAL_ALIAS(set_dma_mode, no_dma);
+GLOBAL_ALIAS(set_dma_page, no_dma);
+GLOBAL_ALIAS(set_dma_count, no_dma);
+GLOBAL_ALIAS(set_dma_addr, no_dma);
+GLOBAL_ALIAS(set_dma_sg, no_dma);
+GLOBAL_ALIAS(set_dma_speed, no_dma);
+GLOBAL_ALIAS(init_dma, no_dma);
+
+#endif
+
EXPORT_SYMBOL(enable_dma);
EXPORT_SYMBOL(disable_dma);
EXPORT_SYMBOL(set_dma_addr);
EXPORT_SYMBOL(set_dma_count);
EXPORT_SYMBOL(set_dma_mode);
+EXPORT_SYMBOL(set_dma_page);
EXPORT_SYMBOL(get_dma_residue);
EXPORT_SYMBOL(set_dma_sg);
EXPORT_SYMBOL(set_dma_speed);
-
-void __init init_dma(void)
-{
- arch_dma_init(dma_chan);
-}