mfd: Add initialisation callback for WM8350

Some functions of the WM8350 require board-specific initialisation on
startup. Provide a callback to the WM8350 driver in platform data
for platforms to use to configure the chip.  Use of a callback allows
platforms to control the ordering of initialisation which can be
important.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@openedhand.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/mfd/wm8350-core.c

@@ -388,7 +388,8 @@ static int wm8350_create_cache(struct wm8350 *wm8350, int mode)
 }
 EXPORT_SYMBOL_GPL(wm8350_create_cache);
 
-int wm8350_device_init(struct wm8350 *wm8350)
+int wm8350_device_init(struct wm8350 *wm8350,
+		       struct wm8350_platform_data *pdata)
 {
 	int ret = -EINVAL;
 	u16 id1, id2, mask, mode;
@@ -439,6 +440,15 @@ int wm8350_device_init(struct wm8350 *wm8350)
 		return ret;
 	}
 
+	if (pdata->init) {
+		ret = pdata->init(wm8350);
+		if (ret != 0) {
+			dev_err(wm8350->dev, "Platform init() failed: %d\n",
+				ret);
+			goto err;
+		}
+	}
+
 	return 0;
 
 err:

drivers/mfd/wm8350-i2c.c

@@ -65,7 +65,7 @@ static int wm8350_i2c_probe(struct i2c_client *i2c,
 	wm8350->read_dev = wm8350_i2c_read_device;
 	wm8350->write_dev = wm8350_i2c_write_device;
 
-	ret = wm8350_device_init(wm8350);
+	ret = wm8350_device_init(wm8350, i2c->dev.platform_data);
 	if (ret < 0)
 		goto err;
 

include/linux/mfd/wm8350/core.h

@@ -564,10 +564,22 @@ struct wm8350 {
 	u16 *reg_cache;
 };
 
+/**
+ * Data to be supplied by the platform to initialise the WM8350.
+ *
+ * @init: Function called during driver initialisation.  Should be
+ *        used by the platform to configure GPIO functions and similar.
+ */
+struct wm8350_platform_data {
+	int (*init)(struct wm8350 *wm8350);
+};
+
+
 /*
  * WM8350 device initialisation and exit.
  */
-int wm8350_device_init(struct wm8350 *wm8350);
+int wm8350_device_init(struct wm8350 *wm8350,
+		       struct wm8350_platform_data *pdata);
 void wm8350_device_exit(struct wm8350 *wm8350);
 
 /*