mfd: Add WM8994 bulk register write operation

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

drivers/mfd/wm8994-core.c

@@ -137,6 +137,29 @@ int wm8994_reg_write(struct wm8994 *wm8994, unsigned short reg,
 }
 EXPORT_SYMBOL_GPL(wm8994_reg_write);
 
+/**
+ * wm8994_bulk_write: Write multiple WM8994 registers
+ *
+ * @wm8994: Device to write to
+ * @reg: First register
+ * @count: Number of registers
+ * @buf: Buffer to write from.
+ */
+int wm8994_bulk_write(struct wm8994 *wm8994, unsigned short reg,
+		      int count, u16 *buf)
+{
+	int ret;
+
+	mutex_lock(&wm8994->io_lock);
+
+	ret = wm8994_write(wm8994, reg, count * 2, buf);
+
+	mutex_unlock(&wm8994->io_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(wm8994_bulk_write);
+
 /**
  * wm8994_set_bits: Set the value of a bitfield in a WM8994 register
  *

include/linux/mfd/wm8994/core.h

@@ -88,6 +88,8 @@ int wm8994_set_bits(struct wm8994 *wm8994, unsigned short reg,
 		    unsigned short mask, unsigned short val);
 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);
 
 
 /* Helper to save on boilerplate */