[PATCH v4 2/3] regulator: max77686: Implement suspend disable for some LDOs

[Krzysztof Kozlowski]

Some LDOs of Maxim 77686 PMIC support disabling during system suspend
(LDO{2,6,7,8,10,11,12,14,15,16}). This was already implemented as part
of set_suspend_mode function. In that case the mode was one of:
 - disable,
 - normal mode,
 - low power mode.
However there are no bindings for setting the mode during suspend.

Add suspend disable for LDO regulators supporting this to the existing
max77686_buck_set_suspend_disable() function. This helps reducing
energy consumption during system sleep.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
---
 drivers/regulator/max77686.c | 75 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 66 insertions(+), 9 deletions(-)

diff --git a/drivers/regulator/max77686.c b/drivers/regulator/max77686.c
index 3d0922051488..4b35c19c9286 100644
--- a/drivers/regulator/max77686.c
+++ b/drivers/regulator/max77686.c
@@ -87,18 +87,31 @@ struct max77686_data {
 	unsigned int opmode[MAX77686_REGULATORS];
 };
 
-/* Some BUCKS supports Normal[ON/OFF] mode during suspend */
-static int max77686_buck_set_suspend_disable(struct regulator_dev *rdev)
+/* Some BUCKs and LDOs supports Normal[ON/OFF] mode during suspend */
+static int max77686_set_suspend_disable(struct regulator_dev *rdev)
 {
 	unsigned int val;
 	struct max77686_data *max77686 = rdev_get_drvdata(rdev);
 	int ret, id = rdev_get_id(rdev);
 
-	if (id == MAX77686_BUCK1)
+	switch (id) {
+	case MAX77686_BUCK1:
 		val = MAX77686_BUCK_OFF_PWRREQ;
-	else
-		val = MAX77686_BUCK_OFF_PWRREQ
-			<< MAX77686_OPMODE_BUCK234_SHIFT;
+		break;
+	case MAX77686_BUCK2 ...	MAX77686_BUCK4:
+		val = MAX77686_BUCK_OFF_PWRREQ << MAX77686_OPMODE_BUCK234_SHIFT;
+		break;
+	case MAX77686_LDO2:
+	case MAX77686_LDO6 ... MAX77686_LDO8:
+	case MAX77686_LDO10 ... MAX77686_LDO12:
+	case MAX77686_LDO14 ... MAX77686_LDO16:
+		val = MAX77686_LDO_OFF_PWRREQ << MAX77686_OPMODE_SHIFT;
+		break;
+	default:
+		pr_warn("%s: regulator_suspend_disable not supported\n",
+			rdev->desc->name);
+		return -EINVAL;
+	}
 
 	ret = regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
 				 rdev->desc->enable_mask, val);
@@ -176,13 +189,53 @@ static int max77686_ldo_set_suspend_mode(struct regulator_dev *rdev,
 	return 0;
 }
 
+/*
+ * For regulators supporting disabled in suspend it checks if opmode
+ * is 'off_pwrreq' mode (disabled in suspend) and changes it to 'enable'.
+ * For other regulators does nothing.
+ */
+static void max77686_set_opmode_enable(struct max77686_data *max77686, int id)
+{
+	unsigned int opmode_shift;
+
+	/*
+	 * Same enable function is used for LDO and bucks. Assuming
+	 * the same values are used for enable registers.
+	 */
+	BUILD_BUG_ON(MAX77686_LDO_OFF_PWRREQ != MAX77686_BUCK_OFF_PWRREQ);
+	BUILD_BUG_ON(MAX77686_LDO_NORMAL != MAX77686_BUCK_NORMAL);
+
+	switch (id) {
+	case MAX77686_BUCK1:
+		opmode_shift = 0;
+		break;
+	case MAX77686_BUCK2 ...	MAX77686_BUCK4:
+		opmode_shift = MAX77686_OPMODE_BUCK234_SHIFT;
+		break;
+	case MAX77686_LDO2:
+	case MAX77686_LDO6 ... MAX77686_LDO8:
+	case MAX77686_LDO10 ... MAX77686_LDO12:
+	case MAX77686_LDO14 ... MAX77686_LDO16:
+		opmode_shift = MAX77686_OPMODE_SHIFT;
+		break;
+	default:
+		return;
+	}
+
+	if (max77686->opmode[id] == (MAX77686_LDO_OFF_PWRREQ << opmode_shift))
+		max77686->opmode[id] = MAX77686_LDO_NORMAL << opmode_shift;
+}
+
 static int max77686_enable(struct regulator_dev *rdev)
 {
 	struct max77686_data *max77686 = rdev_get_drvdata(rdev);
+	int id = rdev_get_id(rdev);
+
+	max77686_set_opmode_enable(max77686, id);
 
 	return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
 				  rdev->desc->enable_mask,
-				  max77686->opmode[rdev_get_id(rdev)]);
+				  max77686->opmode[id]);
 }
 
 static int max77686_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
@@ -232,6 +285,8 @@ static struct regulator_ops max77686_ldo_ops = {
 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
 	.set_suspend_mode	= max77686_ldo_set_suspend_mode,
+	.set_suspend_disable	= max77686_set_suspend_disable,
+	.set_suspend_enable	= max77686_enable,
 };
 
 static struct regulator_ops max77686_buck1_ops = {
@@ -243,7 +298,8 @@ static struct regulator_ops max77686_buck1_ops = {
 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
-	.set_suspend_disable	= max77686_buck_set_suspend_disable,
+	.set_suspend_disable	= max77686_set_suspend_disable,
+	.set_suspend_enable	= max77686_enable,
 };
 
 static struct regulator_ops max77686_buck_dvs_ops = {
@@ -256,7 +312,8 @@ static struct regulator_ops max77686_buck_dvs_ops = {
 	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
 	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
 	.set_ramp_delay		= max77686_set_ramp_delay,
-	.set_suspend_disable	= max77686_buck_set_suspend_disable,
+	.set_suspend_disable	= max77686_set_suspend_disable,
+	.set_suspend_enable	= max77686_enable,
 };
 
 #define regulator_desc_ldo(num)		{				\
-- 
1.9.1