static int s3c2410_dma_started(struct s3c2410_dma_chan *chan)
{
unsigned long flags;
local_irq_save(flags);
dbg_showchan(chan);
/* if we've only loaded one buffer onto the channel, then chec
* to see if we have another, and if so, try and load it so when
* the first buffer is finished, the new one will be loaded onto
* the channel */
if (chan->next != NULL) {
if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
pr_debug("%s: buff not yet loaded, no more todo\n",
__func__);
} else {
chan->load_state = S3C2410_DMALOAD_1RUNNING;
s3c2410_dma_loadbuffer(chan, chan->next);
}
} else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) {
s3c2410_dma_loadbuffer(chan, chan->next);
}
}
local_irq_restore(flags);
return 0;
}
static inline void
s3c2410_dma_lastxfer(s3c2410_dma_chan_t *chan)
{
pr_debug("dma%d: s3c2410_dma_lastxfer: load_state %d\n",
chan->number, chan->load_state);
switch (chan->load_state) {
case S3C2410_DMALOAD_NONE:
break;
case S3C2410_DMALOAD_1LOADED:
if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
/* flag error? */
printk(KERN_ERR "dma%d: timeout waiting for load\n",
chan->number);
return;
}
break;
default:
pr_debug("dma%d: lastxfer: unhandled load_state %d with no next",
chan->number, chan->load_state);
return;
}
/* hopefully this'll shut the damned thing up after the transfer... */
dma_wrreg(chan, S3C2410_DMA_DCON, chan->dcon | S3C2410_DCON_NORELOAD);
}
static inline void
s3c2410_dma_lastxfer(struct s3c2410_dma_chan *chan)
{
switch (chan->load_state) {
case S3C2410_DMALOAD_NONE:
break;
case S3C2410_DMALOAD_1LOADED:
if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
/* flag error? */
printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n",
chan->number, __func__);
return;
}
break;
case S3C2410_DMALOAD_1LOADED_1RUNNING:
/* I belive in this case we do not have anything to do
* until the next buffer comes along, and we turn off the
* reload */
return;
default:
pr_debug("dma%d: lastxfer: unhandled load_state %d with no next\n",
chan->number, chan->load_state);
return;
}
/* hopefully this'll shut the damned thing up after the transfer... */
dma_wrreg(chan, S3C2410_DMA_DCON, chan->dcon | S3C2410_DCON_NORELOAD);
}
static irqreturn_t
s3c2410_dma_irq(int irq, void *devpw)
{
struct s3c2410_dma_chan *chan = (struct s3c2410_dma_chan *)devpw;
struct s3c2410_dma_buf *buf;
buf = chan->curr;
dbg_showchan(chan);
/* modify the channel state */
switch (chan->load_state) {
case S3C2410_DMALOAD_1RUNNING:
/* TODO - if we are running only one buffer, we probably
* want to reload here, and then worry about the buffer
* callback */
chan->load_state = S3C2410_DMALOAD_NONE;
break;
case S3C2410_DMALOAD_1LOADED:
/* iirc, we should go back to NONE loaded here, we
* had a buffer, and it was never verified as being
* loaded.
*/
chan->load_state = S3C2410_DMALOAD_NONE;
break;
case S3C2410_DMALOAD_1LOADED_1RUNNING:
/* we'll worry about checking to see if another buffer is
* ready after we've called back the owner. This should
* ensure we do not wait around too long for the DMA
* engine to start the next transfer
*/
chan->load_state = S3C2410_DMALOAD_1LOADED;
break;
case S3C2410_DMALOAD_NONE:
printk(KERN_ERR "dma%d: IRQ with no loaded buffer?\n",
chan->number);
break;
default:
printk(KERN_ERR "dma%d: IRQ in invalid load_state %d\n",
chan->number, chan->load_state);
break;
}
if (buf != NULL) {
/* update the chain to make sure that if we load any more
* buffers when we call the callback function, things should
* work properly */
chan->curr = buf->next;
buf->next = NULL;
if (buf->magic != BUF_MAGIC) {
printk(KERN_ERR "dma%d: %s: buf %p incorrect magic\n",
chan->number, __func__, buf);
return IRQ_HANDLED;
}
s3c2410_dma_buffdone(chan, buf, S3C2410_RES_OK);
/* free resouces */
s3c2410_dma_freebuf(buf);
} else {
}
/* only reload if the channel is still running... our buffer done
* routine may have altered the state by requesting the dma channel
* to stop or shutdown... */
/* todo: check that when the channel is shut-down from inside this
* function, we cope with unsetting reload, etc */
if (chan->next != NULL && chan->state != S3C2410_DMA_IDLE) {
unsigned long flags;
switch (chan->load_state) {
case S3C2410_DMALOAD_1RUNNING:
/* don't need to do anything for this state */
break;
case S3C2410_DMALOAD_NONE:
/* can load buffer immediately */
break;
case S3C2410_DMALOAD_1LOADED:
if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
/* flag error? */
printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n",
chan->number, __func__);
return IRQ_HANDLED;
}
break;
case S3C2410_DMALOAD_1LOADED_1RUNNING:
goto no_load;
default:
printk(KERN_ERR "dma%d: unknown load_state in irq, %d\n",
chan->number, chan->load_state);
return IRQ_HANDLED;
}
local_irq_save(flags);
s3c2410_dma_loadbuffer(chan, chan->next);
local_irq_restore(flags);
} else {
s3c2410_dma_lastxfer(chan);
/* see if we can stop this channel.. */
if (chan->load_state == S3C2410_DMALOAD_NONE) {
pr_debug("dma%d: end of transfer, stopping channel (%ld)\n",
chan->number, jiffies);
s3c2410_dma_ctrl(chan->number | DMACH_LOW_LEVEL,
S3C2410_DMAOP_STOP);
}
}
no_load:
return IRQ_HANDLED;
}
int s3c2410_dma_enqueue(unsigned int channel, void *id,
dma_addr_t data, int size)
{
struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
struct s3c2410_dma_buf *buf;
unsigned long flags;
if (chan == NULL)
return -EINVAL;
pr_debug("%s: id=%p, data=%08x, size=%d\n",
__func__, id, (unsigned int)data, size);
buf = kmem_cache_alloc(dma_kmem, GFP_ATOMIC);
if (buf == NULL) {
pr_debug("%s: out of memory (%ld alloc)\n",
__func__, (long)sizeof(*buf));
return -ENOMEM;
}
//pr_debug("%s: new buffer %p\n", __func__, buf);
//dbg_showchan(chan);
buf->next = NULL;
buf->data = buf->ptr = data;
buf->size = size;
buf->id = id;
buf->magic = BUF_MAGIC;
local_irq_save(flags);
if (chan->curr == NULL) {
/* we've got nothing loaded... */
pr_debug("%s: buffer %p queued onto empty channel\n",
__func__, buf);
chan->curr = buf;
chan->end = buf;
chan->next = NULL;
} else {
pr_debug("dma%d: %s: buffer %p queued onto non-empty channel\n",
chan->number, __func__, buf);
if (chan->end == NULL)
pr_debug("dma%d: %s: %p not empty, and chan->end==NULL?\n",
chan->number, __func__, chan);
chan->end->next = buf;
chan->end = buf;
}
/* if necessary, update the next buffer field */
if (chan->next == NULL)
chan->next = buf;
/* check to see if we can load a buffer */
if (chan->state == S3C2410_DMA_RUNNING) {
if (chan->load_state == S3C2410_DMALOAD_1LOADED && 1) {
if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
printk(KERN_ERR "dma%d: loadbuffer:"
"timeout loading buffer\n",
chan->number);
dbg_showchan(chan);
local_irq_restore(flags);
return -EINVAL;
}
}
while (s3c2410_dma_canload(chan) && chan->next != NULL) {
s3c2410_dma_loadbuffer(chan, chan->next);
}
} else if (chan->state == S3C2410_DMA_IDLE) {
if (chan->flags & S3C2410_DMAF_AUTOSTART) {
s3c2410_dma_ctrl(chan->number | DMACH_LOW_LEVEL,
S3C2410_DMAOP_START);
}
}
local_irq_restore(flags);
return 0;
}
static int s3c2410_dma_start(struct s3c2410_dma_chan *chan)
{
unsigned long tmp;
unsigned long flags;
pr_debug("s3c2410_start_dma: channel=%d\n", chan->number);
local_irq_save(flags);
if (chan->state == S3C2410_DMA_RUNNING) {
pr_debug("s3c2410_start_dma: already running (%d)\n", chan->state);
local_irq_restore(flags);
return 0;
}
chan->state = S3C2410_DMA_RUNNING;
/* check wether there is anything to load, and if not, see
* if we can find anything to load
*/
if (chan->load_state == S3C2410_DMALOAD_NONE) {
if (chan->next == NULL) {
printk(KERN_ERR "dma%d: channel has nothing loaded\n",
chan->number);
chan->state = S3C2410_DMA_IDLE;
local_irq_restore(flags);
return -EINVAL;
}
s3c2410_dma_loadbuffer(chan, chan->next);
}
dbg_showchan(chan);
/* enable the channel */
if (!chan->irq_enabled) {
enable_irq(chan->irq);
chan->irq_enabled = 1;
}
/* start the channel going */
tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
tmp &= ~S3C2410_DMASKTRIG_STOP;
tmp |= S3C2410_DMASKTRIG_ON;
dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
pr_debug("dma%d: %08lx to DMASKTRIG\n", chan->number, tmp);
#if 0
/* the dma buffer loads should take care of clearing the AUTO
* reloading feature */
tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
tmp &= ~S3C2410_DCON_NORELOAD;
dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
#endif
s3c2410_dma_call_op(chan, S3C2410_DMAOP_START);
dbg_showchan(chan);
/* if we've only loaded one buffer onto the channel, then chec
* to see if we have another, and if so, try and load it so when
* the first buffer is finished, the new one will be loaded onto
* the channel */
if (chan->next != NULL) {
if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
pr_debug("%s: buff not yet loaded, no more todo\n",
__func__);
} else {
chan->load_state = S3C2410_DMALOAD_1RUNNING;
s3c2410_dma_loadbuffer(chan, chan->next);
}
} else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) {
s3c2410_dma_loadbuffer(chan, chan->next);
}
}
local_irq_restore(flags);
return 0;
}