[v3,04/10] dmaengine: edma: Add support for DMA_PAUSE/RESUME operation

Commit Message

Peter Ujfalusi April 14, 2014, 11:41 a.m. UTC

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 <[e-mail]>
Acked-by: Joel Fernandes <[e-mail]>
---
 drivers/dma/edma.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

Patch

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 2742867fd1e6..7891378a03f0 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;
 	}