DMAENGINE: generic channel status v2

Convert the device_is_tx_complete() operation on the
DMA engine to a generic device_tx_status()operation which
can return three states, DMA_TX_RUNNING, DMA_TX_COMPLETE,
DMA_TX_PAUSED.

[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, 33 insertions, 5 deletions

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 0731802f876f..55b08e84ac8d 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -40,11 +40,13 @@ typedef s32 dma_cookie_t;
  * enum dma_status - DMA transaction status
  * @DMA_SUCCESS: transaction completed successfully
  * @DMA_IN_PROGRESS: transaction not yet processed
+ * @DMA_PAUSED: transaction is paused
  * @DMA_ERROR: transaction failed
  */
 enum dma_status {
         DMA_SUCCESS,
         DMA_IN_PROGRESS,
+        DMA_PAUSED,
         DMA_ERROR,
 };
 
@@ -249,6 +251,21 @@ struct dma_async_tx_descriptor {
 };
 
 /**
+ * struct dma_tx_state - filled in to report the status of
+ * a transfer.
+ * @last: last completed DMA cookie
+ * @used: last issued DMA cookie (i.e. the one in progress)
+ * @residue: the remaining number of bytes left to transmit
+ *      on the selected transfer for states DMA_IN_PROGRESS and
+ *      DMA_PAUSED if this is implemented in the driver, else 0
+ */
+struct dma_tx_state {
+        dma_cookie_t last;
+        dma_cookie_t used;
+        u32 residue;
+};
+
+/**
  * struct dma_device - info on the entity supplying DMA services
  * @chancnt: how many DMA channels are supported
  * @privatecnt: how many DMA channels are requested by dma_request_channel
@@ -276,7 +293,10 @@ struct dma_async_tx_descriptor {
  * @device_prep_slave_sg: prepares a slave dma operation
  * @device_control: manipulate all pending operations on a channel, returns
  *      zero or error code
- * @device_is_tx_complete: poll for transaction completion
+ * @device_tx_status: poll for transaction completion, the optional
+ *      txstate parameter can be supplied with a pointer to get a
+ *      struct with auxilary transfer status information, otherwise the call
+ *      will just return a simple status code
  * @device_issue_pending: push pending transactions to hardware
  */
 struct dma_device {
@@ -329,9 +349,9 @@ struct dma_device {
                 unsigned long flags);
         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,
-                        dma_cookie_t *used);
+        enum dma_status (*device_tx_status)(struct dma_chan *chan,
+                                            dma_cookie_t cookie,
+                                            struct dma_tx_state *txstate);
         void (*device_issue_pending)(struct dma_chan *chan);
 };
 
@@ -572,7 +592,15 @@ static inline void dma_async_issue_pending(struct dma_chan *chan)
 static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
         dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
 {
-        return chan->device->device_is_tx_complete(chan, cookie, last, used);
+        struct dma_tx_state state;
+        enum dma_status status;
+
+        status = chan->device->device_tx_status(chan, cookie, &state);
+        if (last)
+                *last = state.last;
+        if (used)
+                *used = state.used;
+        return status;
 }
 
 #define dma_async_memcpy_complete(chan, cookie, last, used)\