int s3c_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 == S3C_DMALOAD_1LOADED) {
if (s3c_dma_waitforload(chan, __LINE__) == 0) {
pr_debug("%s: buff not yet loaded, no more todo\n",
__FUNCTION__);
} else {
chan->load_state = S3C_DMALOAD_1RUNNING;
s3c_dma_loadbuffer(chan, chan->next);
}
} else if (chan->load_state == S3C_DMALOAD_1RUNNING) {
s3c_dma_loadbuffer(chan, chan->next);
}
}
local_irq_restore(flags);
return 0;
}
/* s3c_dma_start
*
* start a dma channel going
*/
static int s3c_dma_start(struct s3c2410_dma_chan *chan)
{
unsigned long flags;
pr_debug("s3c_start_dma: channel number=%d, index=%d\n", chan->number, chan->index);
local_irq_save(flags);
if (chan->state == S3C_DMA_RUNNING) {
pr_debug("s3c_start_dma: already running (%d)\n", chan->state);
local_irq_restore(flags);
return 0;
}
chan->state = S3C_DMA_RUNNING;
/* check wether there is anything to load, and if not, see
* if we can find anything to load
*/
if (chan->load_state == S3C_DMALOAD_NONE) {
if (chan->next == NULL) {
printk(KERN_ERR "dma%d: dcon_num has nothing loaded\n", chan->number);
chan->state = S3C_DMA_IDLE;
local_irq_restore(flags);
return -EINVAL;
}
s3c_dma_loadbuffer(chan, chan->next);
}
dbg_showchan(chan);
/* enable the channel */
if (!chan->irq_enabled) {
enable_irq(chan->irq);
chan->irq_enabled = 1;
}
/* Get the DMA channel started ...*/
dma_wrreg(chan, S3C_DMAC_CxCONFIGURATION, chan->config_flags);
pr_debug("%s:wrote %08lx to S3C_DMAC_CxCONFIGURATION.\n",__FUNCTION__, chan->config_flags);
/* Start the DMA operation on Peripheral */
s3c_dma_call_op(chan, S3C2410_DMAOP_START);
dbg_showchan(chan);
local_irq_restore(flags);
return 0;
}
/* s3c_dma_start
*
* start a dma channel going
*/
static int s3c_dma_start(struct s3c2410_dma_chan *chan)
{
unsigned long flags;
pr_debug("s3c_start_dma: channel number=%d, index=%d\n", chan->number, chan->index);
local_irq_save(flags);
if (chan->state == S3C_DMA_RUNNING) {
pr_debug("s3c_start_dma: already running (%d)\n", chan->state);
local_irq_restore(flags);
return 0;
}
chan->state = S3C_DMA_RUNNING;
/* check wether there is anything to load, and if not, see
* if we can find anything to load
*/
if (chan->load_state == S3C_DMALOAD_NONE) {
if (chan->next == NULL) {
printk(KERN_ERR "dma CH %d: dcon_num has nothing loaded\n", chan->number);
chan->state = S3C_DMA_IDLE;
local_irq_restore(flags);
return -EINVAL;
}
s3c_dma_loadbuffer(chan, chan->next);
}
dbg_showchan(chan);
/* enable the channel */
if (!chan->irq_enabled) {
enable_irq(chan->irq);
chan->irq_enabled = 1;
}
start_DMA_channel(dma_regaddr(chan->dma_con, S3C_DMAC_DBGSTATUS), chan->number,
chan->curr->mcptr, PL330_NON_SECURE_DMA);
/* Start the DMA operation on Peripheral */
s3c_dma_call_op(chan, S3C2410_DMAOP_START);
dbg_showchan(chan);
local_irq_restore(flags);
return 0;
}
static irqreturn_t s3c_dma_irq(int irq, void *devpw)
{
unsigned int channel = 0, dcon_num, i;
unsigned long tmp;
s3c_dma_controller_t *dma_controller = (s3c_dma_controller_t *) devpw;
struct s3c2410_dma_chan *chan=NULL;
struct s3c_dma_buf *buf;
dcon_num = dma_controller->number;
tmp = dma_rdreg(dma_controller, S3C_DMAC_INTSTATUS);
pr_debug("# s3c_dma_irq: IRQ status : 0x%x\n", tmp);
if (tmp == 0)
return IRQ_HANDLED;
for (i = 0; i < S3C_CHANNELS_PER_DMA; i++) {
if (tmp & 0x01) {
pr_debug("# DMAC %d: requestor %d\n", dcon_num, i);
channel = i;
chan = &s3c_dma_chans[channel + dcon_num * S3C_CHANNELS_PER_DMA];
pr_debug("# DMA CH:%d, index:%d load_state:%d\n", chan->number, chan->index, chan->load_state);
buf = chan->curr;
dbg_showchan(chan);
/* modify the channel state */
switch (chan->load_state) {
case S3C_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 = S3C_DMALOAD_NONE;
break;
case S3C_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 = S3C_DMALOAD_NONE;
break;
case S3C_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 = S3C_DMALOAD_1LOADED;
break;
case S3C_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 CH %d: %s: buf %p incorrect magic\n",
chan->number, __FUNCTION__, buf);
goto next_channel;
}
s3c_dma_buffdone(chan, buf, S3C2410_RES_OK);
/* free resouces */
s3c_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... */
if (chan->next != NULL && chan->state != S3C_DMA_IDLE) {
unsigned long flags;
switch (chan->load_state) {
case S3C_DMALOAD_1RUNNING:
/* don't need to do anything for this state */
break;
case S3C_DMALOAD_NONE:
/* can load buffer immediately */
break;
case S3C_DMALOAD_1LOADED:
if (s3c_dma_waitforload(chan, __LINE__) == 0) {
/* flag error? */
printk(KERN_ERR "dma CH %d: timeout waiting for load\n",
chan->number);
goto next_channel;
}
break;
case S3C_DMALOAD_1LOADED_1RUNNING:
goto next_channel;
default:
printk(KERN_ERR "dma CH %d: unknown load_state in irq, %d\n",
chan->number, chan->load_state);
goto next_channel;
}
local_irq_save(flags);
s3c_dma_loadbuffer(chan, chan->next);
start_DMA_channel(dma_regaddr(chan->dma_con, S3C_DMAC_DBGSTATUS), chan->number,
chan->curr->mcptr, PL330_NON_SECURE_DMA);
local_irq_restore(flags);
} else {
s3c_dma_lastxfer(chan);
/* see if we can stop this channel.. */
if (chan->load_state == S3C_DMALOAD_NONE) {
pr_debug("# DMA CH %d - (index:%d): end of transfer, stopping channel (%ld)\n",
chan->number, chan->index, jiffies);
s3c2410_dma_ctrl(chan->index | DMACH_LOW_LEVEL, S3C2410_DMAOP_STOP);
}
}
s3c_clear_interrupts(chan->dma_con->number, chan->number);
}
next_channel:
tmp >>= 1;
}
return IRQ_HANDLED;
}
