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

From: Krzysztof Kozlowski
Date: Mon Oct 27 2014 - 05:46:15 EST


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@xxxxxxxxxxx>
---
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

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