DMAENGINE: generic slave control v2

Convert the device_terminate_all() operation on the
DMA engine to a generic device_control() operation
which can now optionally support also pausing and
resuming DMA on a certain channel. Implemented for the
COH 901 318 DMAC as an example.

[dan.j.williams@intel.com: update for timberdale]
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Li Yang <leoli@freescale.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Liam Girdwood <lrg@slimlogic.co.uk>
Cc: Joe Perches <joe@perches.com>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 20ea12c86fd0..0731802f876f 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -107,6 +107,19 @@ enum dma_ctrl_flags {
 };
 
 /**
+ * enum dma_ctrl_cmd - DMA operations that can optionally be exercised
+ * on a running channel.
+ * @DMA_TERMINATE_ALL: terminate all ongoing transfers
+ * @DMA_PAUSE: pause ongoing transfers
+ * @DMA_RESUME: resume paused transfer
+ */
+enum dma_ctrl_cmd {
+	DMA_TERMINATE_ALL,
+	DMA_PAUSE,
+	DMA_RESUME,
+};
+
+/**
  * enum sum_check_bits - bit position of pq_check_flags
  */
 enum sum_check_bits {
@@ -261,7 +274,8 @@ struct dma_async_tx_descriptor {
  * @device_prep_dma_memset: prepares a memset operation
  * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
  * @device_prep_slave_sg: prepares a slave dma operation
- * @device_terminate_all: terminate all pending operations
+ * @device_control: manipulate all pending operations on a channel, returns
+ *	zero or error code
  * @device_is_tx_complete: poll for transaction completion
  * @device_issue_pending: push pending transactions to hardware
  */
@@ -313,7 +327,7 @@ struct dma_device {
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_data_direction direction,
 		unsigned long flags);
-	void (*device_terminate_all)(struct dma_chan *chan);
+	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd);
 
 	enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
 			dma_cookie_t cookie, dma_cookie_t *last,