*
* SuperH-specific DMA management API
*
- * Copyright (C) 2003 Paul Mundt
+ * Copyright (C) 2003, 2004 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
- */
+ */
#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 <asm/dma.h>
-struct dma_info dma_info[MAX_DMA_CHANNELS] = { { 0, } };
spinlock_t dma_spin_lock = SPIN_LOCK_UNLOCKED;
+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
struct dma_info *get_dma_info(unsigned int chan)
{
- return dma_info + chan;
+ struct list_head *pos, *tmp;
+ unsigned int total = 0;
+
+ /*
+ * Look for each DMAC's range to determine who the owner of
+ * the channel is.
+ */
+ list_for_each_safe(pos, tmp, ®istered_dmac_list) {
+ struct dma_info *info = list_entry(pos, struct dma_info, list);
+
+ total += info->nr_channels;
+ if (chan > total)
+ continue;
+
+ return info;
+ }
+
+ return NULL;
+}
+
+struct dma_channel *get_dma_channel(unsigned int chan)
+{
+ struct dma_info *info = get_dma_info(chan);
+
+ if (!info)
+ return ERR_PTR(-EINVAL);
+
+ return info->channels + chan;
}
int get_dma_residue(unsigned int chan)
{
struct dma_info *info = get_dma_info(chan);
+ struct dma_channel *channel = &info->channels[chan];
if (info->ops->get_residue)
- return info->ops->get_residue(info);
-
+ return info->ops->get_residue(channel);
+
return 0;
}
int request_dma(unsigned int chan, const char *dev_id)
{
struct dma_info *info = get_dma_info(chan);
+ struct dma_channel *channel = &info->channels[chan];
- down(&info->sem);
+ down(&channel->sem);
if (!info->ops || chan >= MAX_DMA_CHANNELS) {
- up(&info->sem);
+ up(&channel->sem);
return -EINVAL;
}
-
- atomic_set(&info->busy, 1);
- info->dev_id = dev_id;
+ atomic_set(&channel->busy, 1);
- up(&info->sem);
+ strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id));
+
+ up(&channel->sem);
if (info->ops->request)
- return info->ops->request(info);
-
+ return info->ops->request(channel);
+
return 0;
}
void free_dma(unsigned int chan)
{
struct dma_info *info = get_dma_info(chan);
+ struct dma_channel *channel = &info->channels[chan];
if (info->ops->free)
- info->ops->free(info);
-
- atomic_set(&info->busy, 0);
+ info->ops->free(channel);
+
+ atomic_set(&channel->busy, 0);
}
void dma_wait_for_completion(unsigned int chan)
{
struct dma_info *info = get_dma_info(chan);
+ struct dma_channel *channel = &info->channels[chan];
- if (info->tei_capable) {
- wait_event(info->wait_queue, (info->ops->get_residue(info) == 0));
+ if (channel->flags & DMA_TEI_CAPABLE) {
+ wait_event(channel->wait_queue,
+ (info->ops->get_residue(channel) == 0));
return;
}
- while (info->ops->get_residue(info))
+ while (info->ops->get_residue(channel))
cpu_relax();
}
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];
if (info->ops->configure)
- info->ops->configure(info, flags);
+ info->ops->configure(channel, flags);
}
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];
- info->sar = from;
- info->dar = to;
- info->count = size;
- info->mode = mode;
+ channel->sar = from;
+ channel->dar = to;
+ channel->count = size;
+ channel->mode = mode;
- return info->ops->xfer(info);
+ return info->ops->xfer(channel);
}
#ifdef CONFIG_PROC_FS
static int dma_read_proc(char *buf, char **start, off_t off,
int len, int *eof, void *data)
{
- struct dma_info *info;
+ struct list_head *pos, *tmp;
char *p = buf;
- int i;
- for (i = 0, info = dma_info; i < MAX_DMA_CHANNELS; i++, info++) {
- if (!atomic_read(&info->busy))
- continue;
+ if (list_empty(®istered_dmac_list))
+ return 0;
+
+ /*
+ * Iterate over each registered DMAC
+ */
+ list_for_each_safe(pos, tmp, ®istered_dmac_list) {
+ struct dma_info *info = list_entry(pos, struct dma_info, list);
+ int i;
- p += sprintf(p, "%2d: %14s %s\n", i,
- info->ops->name, info->dev_id);
+ /*
+ * Iterate over each channel
+ */
+ for (i = 0; i < info->nr_channels; i++) {
+ struct dma_channel *channel = info->channels + i;
+
+ if (!(channel->flags & DMA_CONFIGURED))
+ continue;
+
+ p += sprintf(p, "%2d: %14s %s\n", i,
+ info->name, channel->dev_id);
+ }
}
return p - buf;
}
#endif
-int __init register_dmac(struct dma_ops *ops)
+
+int __init register_dmac(struct dma_info *info)
{
int i;
- printk("DMA: Registering %s handler.\n", ops->name);
+ INIT_LIST_HEAD(&info->list);
+
+ printk(KERN_INFO "DMA: Registering %s handler (%d channels).\n",
+ info->name, info->nr_channels);
+
+ BUG_ON((info->flags & DMAC_CHANNELS_CONFIGURED) && !info->channels);
- for (i = 0; i < MAX_DMA_CHANNELS; i++) {
- struct dma_info *info = get_dma_info(i);
+ /*
+ * Don't touch pre-configured channels
+ */
+ if (!(info->flags & DMAC_CHANNELS_CONFIGURED)) {
+ unsigned int size;
- info->chan = i;
+ size = sizeof(struct dma_channel) * info->nr_channels;
- init_MUTEX(&info->sem);
- init_waitqueue_head(&info->wait_queue);
+ info->channels = kmalloc(size, GFP_KERNEL);
+ if (!info->channels)
+ return -ENOMEM;
+
+ memset(info->channels, 0, size);
}
+ for (i = 0; i < info->nr_channels; i++) {
+ struct dma_channel *chan = info->channels + i;
+
+ chan->chan = i;
+
+ 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);
+
+#ifdef CONFIG_SYSFS
+ dma_create_sysfs_files(chan);
+#endif
+ }
+
+ list_add(&info->list, ®istered_dmac_list);
+
return 0;
}
+void __exit unregister_dmac(struct dma_info *info)
+{
+ if (!(info->flags & DMAC_CHANNELS_CONFIGURED))
+ kfree(info->channels);
+
+ list_del(&info->list);
+}
+
static int __init dma_api_init(void)
{
printk("DMA: Registering DMA API.\n");
EXPORT_SYMBOL(request_dma);
EXPORT_SYMBOL(free_dma);
+EXPORT_SYMBOL(register_dmac);
+EXPORT_SYMBOL(unregister_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);
git://git.onelab.eu / linux-2.6.git / blobdiff