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| author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2012-09-14 15:05:45 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2012-09-22 11:12:40 -0400 |
| commit | 2dcdf570936168d488acf90be9b04a3d32dafce7 (patch) | |
| tree | db98bbd4b10906b6148510f6719d479e635a889f /drivers | |
| parent | ccffa3870a7ec2b59cf051b745220c56f423d182 (diff) | |
| download | linux-2dcdf570936168d488acf90be9b04a3d32dafce7.tar.gz linux-2dcdf570936168d488acf90be9b04a3d32dafce7.tar.bz2 linux-2dcdf570936168d488acf90be9b04a3d32dafce7.zip | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/dma/omap-dma.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c index b77a40db2856..71d786973dfd 100644 --- a/drivers/dma/omap-dma.c +++ b/drivers/dma/omap-dma.c @@ -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, |