mfd: Constify WM8994 write path

Allow const buffers to be passed in without type safety issues.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/wm8994-core.c

@@ -97,9 +97,9 @@ int wm8994_bulk_read(struct wm8994 *wm8994, unsigned short reg,
 EXPORT_SYMBOL_GPL(wm8994_bulk_read);
 
 static int wm8994_write(struct wm8994 *wm8994, unsigned short reg,
-			int bytes, void *src)
+			int bytes, const void *src)
 {
-	u16 *buf = src;
+	const u16 *buf = src;
 	int i;
 
 	BUG_ON(bytes % 2);
@@ -146,7 +146,7 @@ EXPORT_SYMBOL_GPL(wm8994_reg_write);
  * @buf: Buffer to write from.  Data must be big-endian formatted.
  */
 int wm8994_bulk_write(struct wm8994 *wm8994, unsigned short reg,
-		      int count, u16 *buf)
+		      int count, const u16 *buf)
 {
 	int ret;
 
@@ -583,7 +583,7 @@ static int wm8994_i2c_read_device(struct wm8994 *wm8994, unsigned short reg,
 }
 
 static int wm8994_i2c_write_device(struct wm8994 *wm8994, unsigned short reg,
-				   int bytes, void *src)
+				   int bytes, const void *src)
 {
 	struct i2c_client *i2c = wm8994->control_data;
 	struct i2c_msg xfer[2];

include/linux/mfd/wm8994/core.h

@@ -59,7 +59,7 @@ struct wm8994 {
 	int (*read_dev)(struct wm8994 *wm8994, unsigned short reg,
 			int bytes, void *dest);
 	int (*write_dev)(struct wm8994 *wm8994, unsigned short reg,
-			 int bytes, void *src);
+			 int bytes, const void *src);
 
 	void *control_data;
 
@@ -89,7 +89,7 @@ int wm8994_set_bits(struct wm8994 *wm8994, unsigned short reg,
 int wm8994_bulk_read(struct wm8994 *wm8994, unsigned short reg,
 		     int count, u16 *buf);
 int wm8994_bulk_write(struct wm8994 *wm8994, unsigned short reg,
-		     int count, u16 *buf);
+		     int count, const u16 *buf);
 
 
 /* Helper to save on boilerplate */