[PATCH v3 07/59] dmaengine: split out pause/resume operations from device_control

Maxime Ripard
2014-10-22T15:45:14Z

Split out the pause and resume operations to callbacks of their own. In order
to preserve some backwark compatibility, the dmaengine_pause/dmaengine_resume
are still falling back on dmaengine_device_control.

Eventually, that will allow to get the device capabilities in a generic way,
removing the need to implement device_slave_caps.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
include/linux/dmaengine.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index f797cb81355f..4583c55f3355 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -611,6 +611,10 @@ struct dma_tx_state {
* code
* @device_control: manipulate all pending operations on a channel, returns
* zero or error code
+ * @device_pause: Pauses any transfer happening on a channel. Returns
+ * 0 or an error code
+ * @device_resume: Resumes any transfer on a channel previously
+ * paused. Returns 0 or an error code
* @device_tx_status: poll for transaction completion, the optional
* txstate parameter can be supplied with a pointer to get a
* struct with auxiliary transfer status information, otherwise the call
@@ -680,6 +684,8 @@ struct dma_device {
struct dma_slave_config *config);
int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg);
+ int (*device_pause)(struct dma_chan *chan);
+ int (*device_resume)(struct dma_chan *chan);

enum dma_status (*device_tx_status)(struct dma_chan *chan,
dma_cookie_t cookie,
@@ -794,11 +800,17 @@ static inline int dmaengine_terminate_all(struct dma_chan *chan)

static inline int dmaengine_pause(struct dma_chan *chan)
{
+ if (chan->device->device_pause)
+ return chan->device->device_pause(chan);
+
return dmaengine_device_control(chan, DMA_PAUSE, 0);
}

static inline int dmaengine_resume(struct dma_chan *chan)
{
+ if (chan->device->device_resume)
+ return chan->device->device_resume(chan);
+
return dmaengine_device_control(chan, DMA_RESUME, 0);
}

--
2.1.1