[PATCH 02/18] dma: edma: Add support for DMA_PAUSE/RESUME operation

From: Peter Ujfalusi
Date: Thu Mar 13 2014 - 05:25:13 EST


Pause/Resume can be used by the audio stack when the stream is paused/resumed
The edma platform code has support for this and the legacy audio stack used
this.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---
drivers/dma/edma.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index cd04eb7b182e..b54cd2dedde0 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -240,6 +240,26 @@ static int edma_slave_config(struct edma_chan *echan,
return 0;
}

+static int edma_dma_pause(struct edma_chan *echan)
+{
+ /* Pause/Resume only allowed with cyclic mode */
+ if (!echan->edesc->cyclic)
+ return -EINVAL;
+
+ edma_pause(echan->ch_num);
+ return 0;
+}
+
+static int edma_dma_resume(struct edma_chan *echan)
+{
+ /* Pause/Resume only allowed with cyclic mode */
+ if (!echan->edesc->cyclic)
+ return -EINVAL;
+
+ edma_resume(echan->ch_num);
+ return 0;
+}
+
static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
@@ -255,6 +275,14 @@ static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
config = (struct dma_slave_config *)arg;
ret = edma_slave_config(echan, config);
break;
+ case DMA_PAUSE:
+ ret = edma_dma_pause(echan);
+ break;
+
+ case DMA_RESUME:
+ ret = edma_dma_resume(echan);
+ break;
+
default:
ret = -ENOSYS;
}
--
1.9.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/