regulator: Report actual configured voltage to set_voltage()

Change the interface used by set_voltage() to report the selected value
to the regulator core in terms of a selector used by list_voltage().
This allows the regulator core to know the voltage that was chosen
without having to do an explict get_voltage(), which would be much more
expensive as it will generally access hardware.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/wm831x-dcdc.c b/drivers/regulator/wm831x-dcdc.c
index dbfaf59..71da6b2 100644
--- a/drivers/regulator/wm831x-dcdc.c
+++ b/drivers/regulator/wm831x-dcdc.c
@@ -302,7 +302,7 @@
 }
 
 static int wm831x_buckv_set_voltage(struct regulator_dev *rdev,
-				    int min_uV, int max_uV)
+				    int min_uV, int max_uV, unsigned *selector)
 {
 	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
 	struct wm831x *wm831x = dcdc->wm831x;
@@ -314,6 +314,8 @@
 	if (vsel < 0)
 		return vsel;
 
+	*selector = vsel;
+
 	/* If this value is already set then do a GPIO update if we can */
 	if (dcdc->dvs_gpio && dcdc->on_vsel == vsel)
 		return wm831x_buckv_set_dvs(rdev, 0);
@@ -636,7 +638,7 @@
 }
 
 static int wm831x_buckp_set_voltage_int(struct regulator_dev *rdev, int reg,
-					int min_uV, int max_uV)
+					int min_uV, int max_uV, int *selector)
 {
 	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
 	struct wm831x *wm831x = dcdc->wm831x;
@@ -650,16 +652,20 @@
 	if (wm831x_buckp_list_voltage(rdev, vsel) > max_uV)
 		return -EINVAL;
 
+	*selector = vsel;
+
 	return wm831x_set_bits(wm831x, reg, WM831X_DC3_ON_VSEL_MASK, vsel);
 }
 
 static int wm831x_buckp_set_voltage(struct regulator_dev *rdev,
-				    int min_uV, int max_uV)
+				    int min_uV, int max_uV,
+				    unsigned *selector)
 {
 	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
 	u16 reg = dcdc->base + WM831X_DCDC_ON_CONFIG;
 
-	return wm831x_buckp_set_voltage_int(rdev, reg, min_uV, max_uV);
+	return wm831x_buckp_set_voltage_int(rdev, reg, min_uV, max_uV,
+					    selector);
 }
 
 static int wm831x_buckp_set_suspend_voltage(struct regulator_dev *rdev,
@@ -667,8 +673,9 @@
 {
 	struct wm831x_dcdc *dcdc = rdev_get_drvdata(rdev);
 	u16 reg = dcdc->base + WM831X_DCDC_SLEEP_CONTROL;
+	unsigned selector;
 
-	return wm831x_buckp_set_voltage_int(rdev, reg, uV, uV);
+	return wm831x_buckp_set_voltage_int(rdev, reg, uV, uV, &selector);
 }
 
 static int wm831x_buckp_get_voltage(struct regulator_dev *rdev)