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dmaengine: omap: Add support for pause/resume in cyclic dma mode 

The audio stack used omap_stop_dma/omap_start_dma to pause/resume the DMA.
This method has been used for years on OMAP based products.
We only allow pause/resume when the DMA has been configured in cyclic mode
which is used by the audio stack.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Vinod Koul <vinod.koul@linux.intel.com>
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
hifive-unleashed-5.1
Peter Ujfalusi 2012-09-14 15:05:45 +03:00 committed by Mark Brown
parent ccffa3870a
commit 2dcdf57093
1 changed files with 25 additions and 5 deletions
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30
drivers/dma/omap-dma.c
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@ -34,6 +34,7 @@ struct omap_chan {
struct dma_slave_config cfg;
unsigned dma_sig;
bool cyclic;
bool paused;
int dma_ch;
struct omap_desc *desc;
@ -470,11 +471,14 @@ static int omap_dma_terminate_all(struct omap_chan *c)
*/
if (c->desc) {
c->desc = NULL;
omap_stop_dma(c->dma_ch);
/* Avoid stopping the dma twice */
if (!c->paused)
omap_stop_dma(c->dma_ch);
}
if (c->cyclic) {
c->cyclic = false;
c->paused = false;
omap_dma_unlink_lch(c->dma_ch, c->dma_ch);
}
@ -487,14 +491,30 @@ static int omap_dma_terminate_all(struct omap_chan *c)
static int omap_dma_pause(struct omap_chan *c)
{
/* FIXME: not supported by platform private API */
return -EINVAL;
/* Pause/Resume only allowed with cyclic mode */
if (!c->cyclic)
return -EINVAL;
if (!c->paused) {
omap_stop_dma(c->dma_ch);
c->paused = true;
}
return 0;
}
static int omap_dma_resume(struct omap_chan *c)
{
/* FIXME: not supported by platform private API */
return -EINVAL;
/* Pause/Resume only allowed with cyclic mode */
if (!c->cyclic)
return -EINVAL;
if (c->paused) {
omap_start_dma(c->dma_ch);
c->paused = false;
}
return 0;
}
static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,