|
@@ -11,61 +11,27 @@
|
|
|
*/
|
|
|
#include <linux/init.h>
|
|
|
#include <linux/module.h>
|
|
|
-#include <linux/interrupt.h>
|
|
|
#include <linux/spinlock.h>
|
|
|
#include <linux/proc_fs.h>
|
|
|
#include <linux/list.h>
|
|
|
#include <linux/platform_device.h>
|
|
|
+#include <linux/mm.h>
|
|
|
#include <asm/dma.h>
|
|
|
|
|
|
DEFINE_SPINLOCK(dma_spin_lock);
|
|
|
static LIST_HEAD(registered_dmac_list);
|
|
|
|
|
|
-/*
|
|
|
- * A brief note about the reasons for this API as it stands.
|
|
|
- *
|
|
|
- * For starters, the old ISA DMA API didn't work for us for a number of
|
|
|
- * reasons, for one, the vast majority of channels on the SH DMAC are
|
|
|
- * dual-address mode only, and both the new and the old DMA APIs are after the
|
|
|
- * concept of managing a DMA buffer, which doesn't overly fit this model very
|
|
|
- * well. In addition to which, the new API is largely geared at IOMMUs and
|
|
|
- * GARTs, and doesn't even support the channel notion very well.
|
|
|
- *
|
|
|
- * The other thing that's a marginal issue, is the sheer number of random DMA
|
|
|
- * engines that are present (ie, in boards like the Dreamcast), some of which
|
|
|
- * cascade off of the SH DMAC, and others do not. As such, there was a real
|
|
|
- * need for a scalable subsystem that could deal with both single and
|
|
|
- * dual-address mode usage, in addition to interoperating with cascaded DMACs.
|
|
|
- *
|
|
|
- * There really isn't any reason why this needs to be SH specific, though I'm
|
|
|
- * not aware of too many other processors (with the exception of some MIPS)
|
|
|
- * that have the same concept of a dual address mode, or any real desire to
|
|
|
- * actually make use of the DMAC even if such a subsystem were exposed
|
|
|
- * elsewhere.
|
|
|
- *
|
|
|
- * The idea for this was derived from the ARM port, which acted as an excellent
|
|
|
- * reference when trying to address these issues.
|
|
|
- *
|
|
|
- * It should also be noted that the decision to add Yet Another DMA API(tm) to
|
|
|
- * the kernel wasn't made easily, and was only decided upon after conferring
|
|
|
- * with jejb with regards to the state of the old and new APIs as they applied
|
|
|
- * to these circumstances. Philip Blundell was also a great help in figuring
|
|
|
- * out some single-address mode DMA semantics that were otherwise rather
|
|
|
- * confusing.
|
|
|
- */
|
|
|
-
|
|
|
struct dma_info *get_dma_info(unsigned int chan)
|
|
|
{
|
|
|
struct dma_info *info;
|
|
|
- unsigned int total = 0;
|
|
|
|
|
|
/*
|
|
|
* Look for each DMAC's range to determine who the owner of
|
|
|
* the channel is.
|
|
|
*/
|
|
|
list_for_each_entry(info, ®istered_dmac_list, list) {
|
|
|
- total += info->nr_channels;
|
|
|
- if (chan > total)
|
|
|
+ if ((chan < info->first_channel_nr) ||
|
|
|
+ (chan >= info->first_channel_nr + info->nr_channels))
|
|
|
continue;
|
|
|
|
|
|
return info;
|
|
@@ -73,6 +39,22 @@ struct dma_info *get_dma_info(unsigned int chan)
|
|
|
|
|
|
return NULL;
|
|
|
}
|
|
|
+EXPORT_SYMBOL(get_dma_info);
|
|
|
+
|
|
|
+struct dma_info *get_dma_info_by_name(const char *dmac_name)
|
|
|
+{
|
|
|
+ struct dma_info *info;
|
|
|
+
|
|
|
+ list_for_each_entry(info, ®istered_dmac_list, list) {
|
|
|
+ if (dmac_name && (strcmp(dmac_name, info->name) != 0))
|
|
|
+ continue;
|
|
|
+ else
|
|
|
+ return info;
|
|
|
+ }
|
|
|
+
|
|
|
+ return NULL;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(get_dma_info_by_name);
|
|
|
|
|
|
static unsigned int get_nr_channels(void)
|
|
|
{
|
|
@@ -91,63 +73,161 @@ static unsigned int get_nr_channels(void)
|
|
|
struct dma_channel *get_dma_channel(unsigned int chan)
|
|
|
{
|
|
|
struct dma_info *info = get_dma_info(chan);
|
|
|
+ struct dma_channel *channel;
|
|
|
+ int i;
|
|
|
|
|
|
- if (!info)
|
|
|
+ if (unlikely(!info))
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
|
- return info->channels + chan;
|
|
|
+ for (i = 0; i < info->nr_channels; i++) {
|
|
|
+ channel = &info->channels[i];
|
|
|
+ if (channel->chan == chan)
|
|
|
+ return channel;
|
|
|
+ }
|
|
|
+
|
|
|
+ return NULL;
|
|
|
}
|
|
|
+EXPORT_SYMBOL(get_dma_channel);
|
|
|
|
|
|
int get_dma_residue(unsigned int chan)
|
|
|
{
|
|
|
struct dma_info *info = get_dma_info(chan);
|
|
|
- struct dma_channel *channel = &info->channels[chan];
|
|
|
+ struct dma_channel *channel = get_dma_channel(chan);
|
|
|
|
|
|
if (info->ops->get_residue)
|
|
|
return info->ops->get_residue(channel);
|
|
|
|
|
|
return 0;
|
|
|
}
|
|
|
+EXPORT_SYMBOL(get_dma_residue);
|
|
|
|
|
|
-int request_dma(unsigned int chan, const char *dev_id)
|
|
|
+static int search_cap(const char **haystack, const char *needle)
|
|
|
{
|
|
|
- struct dma_info *info = get_dma_info(chan);
|
|
|
- struct dma_channel *channel = &info->channels[chan];
|
|
|
+ const char **p;
|
|
|
+
|
|
|
+ for (p = haystack; *p; p++)
|
|
|
+ if (strcmp(*p, needle) == 0)
|
|
|
+ return 1;
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * request_dma_bycap - Allocate a DMA channel based on its capabilities
|
|
|
+ * @dmac: List of DMA controllers to search
|
|
|
+ * @caps: List of capabilites
|
|
|
+ *
|
|
|
+ * Search all channels of all DMA controllers to find a channel which
|
|
|
+ * matches the requested capabilities. The result is the channel
|
|
|
+ * number if a match is found, or %-ENODEV if no match is found.
|
|
|
+ *
|
|
|
+ * Note that not all DMA controllers export capabilities, in which
|
|
|
+ * case they can never be allocated using this API, and so
|
|
|
+ * request_dma() must be used specifying the channel number.
|
|
|
+ */
|
|
|
+int request_dma_bycap(const char **dmac, const char **caps, const char *dev_id)
|
|
|
+{
|
|
|
+ unsigned int found = 0;
|
|
|
+ struct dma_info *info;
|
|
|
+ const char **p;
|
|
|
+ int i;
|
|
|
+
|
|
|
+ BUG_ON(!dmac || !caps);
|
|
|
+
|
|
|
+ list_for_each_entry(info, ®istered_dmac_list, list)
|
|
|
+ if (strcmp(*dmac, info->name) == 0) {
|
|
|
+ found = 1;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (!found)
|
|
|
+ return -ENODEV;
|
|
|
+
|
|
|
+ for (i = 0; i < info->nr_channels; i++) {
|
|
|
+ struct dma_channel *channel = &info->channels[i];
|
|
|
+
|
|
|
+ if (unlikely(!channel->caps))
|
|
|
+ continue;
|
|
|
+
|
|
|
+ for (p = caps; *p; p++) {
|
|
|
+ if (!search_cap(channel->caps, *p))
|
|
|
+ break;
|
|
|
+ if (request_dma(channel->chan, dev_id) == 0)
|
|
|
+ return channel->chan;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ return -EINVAL;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(request_dma_bycap);
|
|
|
+
|
|
|
+int dmac_search_free_channel(const char *dev_id)
|
|
|
+{
|
|
|
+ struct dma_channel *channel = { 0 };
|
|
|
+ struct dma_info *info = get_dma_info(0);
|
|
|
+ int i;
|
|
|
+
|
|
|
+ for (i = 0; i < info->nr_channels; i++) {
|
|
|
+ channel = &info->channels[i];
|
|
|
+ if (unlikely(!channel))
|
|
|
+ return -ENODEV;
|
|
|
+
|
|
|
+ if (atomic_read(&channel->busy) == 0)
|
|
|
+ break;
|
|
|
+ }
|
|
|
|
|
|
- down(&channel->sem);
|
|
|
+ if (info->ops->request) {
|
|
|
+ int result = info->ops->request(channel);
|
|
|
+ if (result)
|
|
|
+ return result;
|
|
|
|
|
|
- if (!info->ops || chan >= MAX_DMA_CHANNELS) {
|
|
|
- up(&channel->sem);
|
|
|
- return -EINVAL;
|
|
|
+ atomic_set(&channel->busy, 1);
|
|
|
+ return channel->chan;
|
|
|
}
|
|
|
|
|
|
- atomic_set(&channel->busy, 1);
|
|
|
+ return -ENOSYS;
|
|
|
+}
|
|
|
+
|
|
|
+int request_dma(unsigned int chan, const char *dev_id)
|
|
|
+{
|
|
|
+ struct dma_channel *channel = { 0 };
|
|
|
+ struct dma_info *info = get_dma_info(chan);
|
|
|
+ int result;
|
|
|
+
|
|
|
+ channel = get_dma_channel(chan);
|
|
|
+ if (atomic_xchg(&channel->busy, 1))
|
|
|
+ return -EBUSY;
|
|
|
|
|
|
strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
|
|
|
|
|
|
- up(&channel->sem);
|
|
|
+ if (info->ops->request) {
|
|
|
+ result = info->ops->request(channel);
|
|
|
+ if (result)
|
|
|
+ atomic_set(&channel->busy, 0);
|
|
|
|
|
|
- if (info->ops->request)
|
|
|
- return info->ops->request(channel);
|
|
|
+ return result;
|
|
|
+ }
|
|
|
|
|
|
return 0;
|
|
|
}
|
|
|
+EXPORT_SYMBOL(request_dma);
|
|
|
|
|
|
void free_dma(unsigned int chan)
|
|
|
{
|
|
|
struct dma_info *info = get_dma_info(chan);
|
|
|
- struct dma_channel *channel = &info->channels[chan];
|
|
|
+ struct dma_channel *channel = get_dma_channel(chan);
|
|
|
|
|
|
if (info->ops->free)
|
|
|
info->ops->free(channel);
|
|
|
|
|
|
atomic_set(&channel->busy, 0);
|
|
|
}
|
|
|
+EXPORT_SYMBOL(free_dma);
|
|
|
|
|
|
void dma_wait_for_completion(unsigned int chan)
|
|
|
{
|
|
|
struct dma_info *info = get_dma_info(chan);
|
|
|
- struct dma_channel *channel = &info->channels[chan];
|
|
|
+ struct dma_channel *channel = get_dma_channel(chan);
|
|
|
|
|
|
if (channel->flags & DMA_TEI_CAPABLE) {
|
|
|
wait_event(channel->wait_queue,
|
|
@@ -158,21 +238,52 @@ void dma_wait_for_completion(unsigned int chan)
|
|
|
while (info->ops->get_residue(channel))
|
|
|
cpu_relax();
|
|
|
}
|
|
|
+EXPORT_SYMBOL(dma_wait_for_completion);
|
|
|
+
|
|
|
+int register_chan_caps(const char *dmac, struct dma_chan_caps *caps)
|
|
|
+{
|
|
|
+ struct dma_info *info;
|
|
|
+ unsigned int found = 0;
|
|
|
+ int i;
|
|
|
+
|
|
|
+ list_for_each_entry(info, ®istered_dmac_list, list)
|
|
|
+ if (strcmp(dmac, info->name) == 0) {
|
|
|
+ found = 1;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (unlikely(!found))
|
|
|
+ return -ENODEV;
|
|
|
+
|
|
|
+ for (i = 0; i < info->nr_channels; i++, caps++) {
|
|
|
+ struct dma_channel *channel;
|
|
|
+
|
|
|
+ if ((info->first_channel_nr + i) != caps->ch_num)
|
|
|
+ return -EINVAL;
|
|
|
+
|
|
|
+ channel = &info->channels[i];
|
|
|
+ channel->caps = caps->caplist;
|
|
|
+ }
|
|
|
+
|
|
|
+ return 0;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(register_chan_caps);
|
|
|
|
|
|
void dma_configure_channel(unsigned int chan, unsigned long flags)
|
|
|
{
|
|
|
struct dma_info *info = get_dma_info(chan);
|
|
|
- struct dma_channel *channel = &info->channels[chan];
|
|
|
+ struct dma_channel *channel = get_dma_channel(chan);
|
|
|
|
|
|
if (info->ops->configure)
|
|
|
info->ops->configure(channel, flags);
|
|
|
}
|
|
|
+EXPORT_SYMBOL(dma_configure_channel);
|
|
|
|
|
|
int dma_xfer(unsigned int chan, unsigned long from,
|
|
|
unsigned long to, size_t size, unsigned int mode)
|
|
|
{
|
|
|
struct dma_info *info = get_dma_info(chan);
|
|
|
- struct dma_channel *channel = &info->channels[chan];
|
|
|
+ struct dma_channel *channel = get_dma_channel(chan);
|
|
|
|
|
|
channel->sar = from;
|
|
|
channel->dar = to;
|
|
@@ -181,8 +292,20 @@ int dma_xfer(unsigned int chan, unsigned long from,
|
|
|
|
|
|
return info->ops->xfer(channel);
|
|
|
}
|
|
|
+EXPORT_SYMBOL(dma_xfer);
|
|
|
+
|
|
|
+int dma_extend(unsigned int chan, unsigned long op, void *param)
|
|
|
+{
|
|
|
+ struct dma_info *info = get_dma_info(chan);
|
|
|
+ struct dma_channel *channel = get_dma_channel(chan);
|
|
|
+
|
|
|
+ if (info->ops->extend)
|
|
|
+ return info->ops->extend(channel, op, param);
|
|
|
+
|
|
|
+ return -ENOSYS;
|
|
|
+}
|
|
|
+EXPORT_SYMBOL(dma_extend);
|
|
|
|
|
|
-#ifdef CONFIG_PROC_FS
|
|
|
static int dma_read_proc(char *buf, char **start, off_t off,
|
|
|
int len, int *eof, void *data)
|
|
|
{
|
|
@@ -214,8 +337,6 @@ static int dma_read_proc(char *buf, char **start, off_t off,
|
|
|
|
|
|
return p - buf;
|
|
|
}
|
|
|
-#endif
|
|
|
-
|
|
|
|
|
|
int register_dmac(struct dma_info *info)
|
|
|
{
|
|
@@ -224,8 +345,7 @@ int register_dmac(struct dma_info *info)
|
|
|
INIT_LIST_HEAD(&info->list);
|
|
|
|
|
|
printk(KERN_INFO "DMA: Registering %s handler (%d channel%s).\n",
|
|
|
- info->name, info->nr_channels,
|
|
|
- info->nr_channels > 1 ? "s" : "");
|
|
|
+ info->name, info->nr_channels, info->nr_channels > 1 ? "s" : "");
|
|
|
|
|
|
BUG_ON((info->flags & DMAC_CHANNELS_CONFIGURED) && !info->channels);
|
|
|
|
|
@@ -242,28 +362,26 @@ int register_dmac(struct dma_info *info)
|
|
|
|
|
|
size = sizeof(struct dma_channel) * info->nr_channels;
|
|
|
|
|
|
- info->channels = kmalloc(size, GFP_KERNEL);
|
|
|
+ info->channels = kzalloc(size, GFP_KERNEL);
|
|
|
if (!info->channels)
|
|
|
return -ENOMEM;
|
|
|
-
|
|
|
- memset(info->channels, 0, size);
|
|
|
}
|
|
|
|
|
|
total_channels = get_nr_channels();
|
|
|
for (i = 0; i < info->nr_channels; i++) {
|
|
|
- struct dma_channel *chan = info->channels + i;
|
|
|
+ struct dma_channel *chan = &info->channels[i];
|
|
|
+
|
|
|
+ atomic_set(&chan->busy, 0);
|
|
|
|
|
|
- chan->chan = i;
|
|
|
- chan->vchan = i + total_channels;
|
|
|
+ chan->chan = info->first_channel_nr + i;
|
|
|
+ chan->vchan = info->first_channel_nr + i + total_channels;
|
|
|
|
|
|
memcpy(chan->dev_id, "Unused", 7);
|
|
|
|
|
|
if (info->flags & DMAC_CHANNELS_TEI_CAPABLE)
|
|
|
chan->flags |= DMA_TEI_CAPABLE;
|
|
|
|
|
|
- init_MUTEX(&chan->sem);
|
|
|
init_waitqueue_head(&chan->wait_queue);
|
|
|
-
|
|
|
dma_create_sysfs_files(chan, info);
|
|
|
}
|
|
|
|
|
@@ -271,6 +389,7 @@ int register_dmac(struct dma_info *info)
|
|
|
|
|
|
return 0;
|
|
|
}
|
|
|
+EXPORT_SYMBOL(register_dmac);
|
|
|
|
|
|
void unregister_dmac(struct dma_info *info)
|
|
|
{
|
|
@@ -285,31 +404,16 @@ void unregister_dmac(struct dma_info *info)
|
|
|
list_del(&info->list);
|
|
|
platform_device_unregister(info->pdev);
|
|
|
}
|
|
|
+EXPORT_SYMBOL(unregister_dmac);
|
|
|
|
|
|
static int __init dma_api_init(void)
|
|
|
{
|
|
|
- printk("DMA: Registering DMA API.\n");
|
|
|
-
|
|
|
-#ifdef CONFIG_PROC_FS
|
|
|
+ printk(KERN_NOTICE "DMA: Registering DMA API.\n");
|
|
|
create_proc_read_entry("dma", 0, 0, dma_read_proc, 0);
|
|
|
-#endif
|
|
|
-
|
|
|
return 0;
|
|
|
}
|
|
|
-
|
|
|
subsys_initcall(dma_api_init);
|
|
|
|
|
|
MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
|
|
|
MODULE_DESCRIPTION("DMA API for SuperH");
|
|
|
MODULE_LICENSE("GPL");
|
|
|
-
|
|
|
-EXPORT_SYMBOL(request_dma);
|
|
|
-EXPORT_SYMBOL(free_dma);
|
|
|
-EXPORT_SYMBOL(register_dmac);
|
|
|
-EXPORT_SYMBOL(get_dma_residue);
|
|
|
-EXPORT_SYMBOL(get_dma_info);
|
|
|
-EXPORT_SYMBOL(get_dma_channel);
|
|
|
-EXPORT_SYMBOL(dma_xfer);
|
|
|
-EXPORT_SYMBOL(dma_wait_for_completion);
|
|
|
-EXPORT_SYMBOL(dma_configure_channel);
|
|
|
-
|