mfd: wm8994: Reset device during probe

Ensure that the device is in a known good state. This should have little
practical impact as the runtime PM will reset the device shortly after
probe but it's neater.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index 00e4fe2..ccdddf9 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -652,6 +652,17 @@
 		return ret;
 	}
 
+	/* Explicitly put the device into reset in case regulators
+	 * don't get disabled in order to ensure we know the device
+	 * state.
+	 */
+	ret = wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET,
+			       wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET));
+	if (ret != 0) {
+		dev_err(wm8994->dev, "Failed to reset device: %d\n", ret);
+		return ret;
+	}
+
 	if (regmap_patch) {
 		ret = regmap_register_patch(wm8994->regmap, regmap_patch,
 					    patch_regs);