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>
diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
index c7552c0..071834b 100644
--- a/drivers/mfd/wm8350-core.c
+++ b/drivers/mfd/wm8350-core.c
@@ -388,7 +388,8 @@
 }
 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 @@
 		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: