summaryrefslogtreecommitdiff
path: root/drivers/dma/dmaengine.h
diff options
context:
space:
mode:
authorDave Jiang <dave.jiang@intel.com>2016-07-20 13:10:31 -0700
committerVinod Koul <vinod.koul@intel.com>2016-08-08 08:11:37 +0530
commitf083f557186d77de5f14bf90aec1bfe2503cf513 (patch)
tree19dd371b7dd76dc3a29c953168453a44cc35ed03 /drivers/dma/dmaengine.h
parent29b4817d4018df78086157ea3a55c1d9424a7cfc (diff)
dmaengine: Add helper function to prep for error reporting
Dmaengine does not provide a way to pass back the result from a DMA transaction through the callback function. We are adding dmaengine helper function in order to prep for a mechanism that allow result status and other information through the callback. The initial conversion will make the existing driver use these new helper functions but retain the original behavior of the code. However, the helper functions paves a way towards adding the result parameter through callback. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/dmaengine.h')
-rw-r--r--drivers/dma/dmaengine.h72
1 files changed, 72 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h
index 17f983a4e9ba..94a4379c7639 100644
--- a/drivers/dma/dmaengine.h
+++ b/drivers/dma/dmaengine.h
@@ -86,4 +86,76 @@ static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
state->residue = residue;
}
+struct dmaengine_desc_callback {
+ dma_async_tx_callback callback;
+ void *callback_param;
+};
+
+/**
+ * dmaengine_desc_get_callback - get the passed in callback function
+ * @tx: tx descriptor
+ * @cb: temp struct to hold the callback info
+ *
+ * Fill the passed in cb struct with what's available in the passed in
+ * tx descriptor struct
+ * No locking is required.
+ */
+static inline void
+dmaengine_desc_get_callback(struct dma_async_tx_descriptor *tx,
+ struct dmaengine_desc_callback *cb)
+{
+ cb->callback = tx->callback;
+ cb->callback_param = tx->callback_param;
+}
+
+/**
+ * dmaengine_desc_callback_invoke - call the callback function in cb struct
+ * @cb: temp struct that is holding the callback info
+ * @result: dummy pointer for now
+ *
+ * Call the callback function provided in the cb struct with the parameter
+ * in the cb struct.
+ * Locking is dependent on the driver.
+ */
+static inline void
+dmaengine_desc_callback_invoke(struct dmaengine_desc_callback *cb,
+ const void *result)
+{
+ if (cb->callback)
+ cb->callback(cb->callback_param);
+}
+
+/**
+ * dmaengine_desc_get_callback_invoke - get the callback in tx descriptor and
+ * then immediately call the callback.
+ * @tx: dma async tx descriptor
+ * @result: dummy pointer for now
+ *
+ * Call dmaengine_desc_get_callback() and dmaengine_desc_callback_invoke()
+ * in a single function since no work is necessary in between for the driver.
+ * Locking is dependent on the driver.
+ */
+static inline void
+dmaengine_desc_get_callback_invoke(struct dma_async_tx_descriptor *tx,
+ const void *result)
+{
+ struct dmaengine_desc_callback cb;
+
+ dmaengine_desc_get_callback(tx, &cb);
+ dmaengine_desc_callback_invoke(&cb, result);
+}
+
+/**
+ * dmaengine_desc_callback_valid - verify the callback is valid in cb
+ * @cb: callback info struct
+ *
+ * Return a bool that verifies whether callback in cb is valid or not.
+ * No locking is required.
+ */
+static inline bool
+dmaengine_desc_callback_valid(struct dmaengine_desc_callback *cb)
+{
+ return (cb->callback) ? true : false;
+}
+
#endif