DMA: of: Constant names

No DMA of-function alters the name, so this patch changes the name arguments
to be constant. Most drivers will probably request DMA channels using a
constant name.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

drivers/dma/dmaengine.c

@@ -555,7 +555,7 @@ EXPORT_SYMBOL_GPL(__dma_request_channel);
  * @dev:	pointer to client device structure
  * @name:	slave channel name
  */
-struct dma_chan *dma_request_slave_channel(struct device *dev, char *name)
+struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name)
 {
 	/* If device-tree is present get slave info from here */
 	if (dev->of_node)

drivers/dma/of-dma.c

@@ -172,8 +172,8 @@ EXPORT_SYMBOL_GPL(of_dma_controller_free);
  * specifiers, matches the name provided. Returns 0 if the name matches and
  * a valid pointer to the DMA specifier is found. Otherwise returns -ENODEV.
  */
-static int of_dma_match_channel(struct device_node *np, char *name, int index,
-				struct of_phandle_args *dma_spec)
+static int of_dma_match_channel(struct device_node *np, const char *name,
+				int index, struct of_phandle_args *dma_spec)
 {
 	const char *s;
 
@@ -198,7 +198,7 @@ static int of_dma_match_channel(struct device_node *np, char *name, int index,
  * Returns pointer to appropriate dma channel on success or NULL on error.
  */
 struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
-					      char *name)
+					      const char *name)
 {
 	struct of_phandle_args	dma_spec;
 	struct of_dma		*ofdma;

include/linux/dmaengine.h

@@ -968,7 +968,7 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
 enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
 void dma_issue_pending_all(void);
 struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
-struct dma_chan *dma_request_slave_channel(struct device *dev, char *name);
+struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name);
 void dma_release_channel(struct dma_chan *chan);
 #else
 static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
@@ -984,7 +984,7 @@ static inline struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask,
 	return NULL;
 }
 static inline struct dma_chan *dma_request_slave_channel(struct device *dev,
-							 char *name)
+							 const char *name)
 {
 	return NULL;
 }

include/linux/of_dma.h

@@ -40,7 +40,7 @@ extern int of_dma_controller_register(struct device_node *np,
 		void *data);
 extern int of_dma_controller_free(struct device_node *np);
 extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
-						     char *name);
+						     const char *name);
 extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
 		struct of_dma *ofdma);
 #else
@@ -58,7 +58,7 @@ static inline int of_dma_controller_free(struct device_node *np)
 }
 
 static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
-						     char *name)
+						     const char *name)
 {
 	return NULL;
 }