static int s3c2410_dma_dostop(struct s3c2410_dma_chan *chan)
{
unsigned long flags;
unsigned long tmp;
pr_debug("%s:\n", __func__);
dbg_showchan(chan);
local_irq_save(flags);
s3c2410_dma_call_op(chan, S3C2410_DMAOP_STOP);
tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
tmp |= S3C2410_DMASKTRIG_STOP;
//tmp &= ~S3C2410_DMASKTRIG_ON;
dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
#if 0
/* should also clear interrupts, according to WinCE BSP */
tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
tmp |= S3C2410_DCON_NORELOAD;
dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
#endif
/* should stop do this, or should we wait for flush? */
chan->state = S3C2410_DMA_IDLE;
chan->load_state = S3C2410_DMALOAD_NONE;
local_irq_restore(flags);
return 0;
}
static int s3c2410_dma_dostop(s3c2410_dma_chan_t *chan)
{
unsigned long tmp;
unsigned long flags;
pr_debug("%s:\n", __FUNCTION__);
dbg_showchan(chan);
local_irq_save(flags);
s3c2410_dma_call_op(chan, S3C2410_DMAOP_STOP);
tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
tmp |= S3C2410_DMASKTRIG_STOP;
dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
#if 0
/* should also clear interrupts, according to WinCE BSP */
tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
tmp |= S3C2410_DCON_NORELOAD;
dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
#endif
chan->state = S3C2410_DMA_IDLE;
chan->load_state = S3C2410_DMALOAD_NONE;
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;
}
static int s3c2410_dma_start(s3c2410_dma_chan_t *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("wrote %08lx to DMASKTRIG\n", 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);
local_irq_restore(flags);
return 0;
}
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;
unsigned long tmp;
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:
/* printk(KERN_INFO "DMA: 1 LOADED\n"); */
//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;
}
/*
* Since we are not using the auto-reload feature, we must restart
* the DMA-channel at this point
* (Luis Galdos)
*/
local_irq_save(flags);
chan->load_state = S3C2410_DMALOAD_NONE;
s3c2410_dma_loadbuffer(chan, chan->curr);
tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
tmp &= ~S3C2410_DMASKTRIG_STOP;
tmp |= S3C2410_DMASKTRIG_ON;
dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
s3c2410_dma_call_op(chan, S3C2410_DMAOP_START);
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;
}