regulator: palmas: disable bypass when the LDO is enabled

Some LDOs have a bypass capability. Make sure that the bypass is disabled
when is the LDO is enabled (otherwise the voltage can't be changed).

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/power/regulator/palmas_regulator.c b/drivers/power/regulator/palmas_regulator.c
index 99614b0..24a7977 100644
--- a/drivers/power/regulator/palmas_regulator.c
+++ b/drivers/power/regulator/palmas_regulator.c
@@ -163,6 +163,38 @@
 	return pmic_reg_write(dev->parent, adr, ret);
 }
 
+static int palmas_ldo_bypass_enable(struct udevice *dev, bool enabled)
+{
+	int type = dev_get_driver_data(dev_get_parent(dev));
+	struct dm_regulator_uclass_platdata *p;
+	unsigned int adr;
+	int reg;
+
+	if (type == TPS65917) {
+		/* bypass available only on LDO1 and LDO2 */
+		if (dev->driver_data > 2)
+			return -ENOTSUPP;
+	} else if (type == TPS659038) {
+		/* bypass available only on LDO9 */
+		if (dev->driver_data != 9)
+			return -ENOTSUPP;
+	}
+
+	p = dev_get_uclass_platdata(dev);
+	adr = p->ctrl_reg;
+
+	reg = pmic_reg_read(dev->parent, adr);
+	if (reg < 0)
+		return reg;
+
+	if (enabled)
+		reg |= PALMAS_LDO_BYPASS_EN;
+	else
+		reg &= ~PALMAS_LDO_BYPASS_EN;
+
+	return pmic_reg_write(dev->parent, adr, reg);
+}
+
 static int palmas_ldo_enable(struct udevice *dev, int op, bool *enable)
 {
 	int ret;
@@ -194,6 +226,10 @@
 		ret = pmic_reg_write(dev->parent, adr, ret);
 		if (ret)
 			return ret;
+
+		ret = palmas_ldo_bypass_enable(dev, false);
+		if (ret && (ret != -ENOTSUPP))
+			return ret;
 	}
 
 	return 0;