[PATCH 12/14] regulator: pwm: Retrieve correct voltage

Boris Brezillon
2016-06-03T08:23:10Z

The continuous PWM voltage regulator is caching the voltage value in
the ->volt_uV field. While most of the time this value should reflect the
real voltage, sometime it can be sightly different if the PWM device
rounded the set_duty_cycle request.
Moreover, this value is not valid until someone has modified the regulator
output.

Remove the ->volt_uV field and always rely on the PWM state to calculate
the regulator output.

Signed-off-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
Mark,

I know you already added your Tested-by/Acked-by tags on this patch
but this version has slightly change and is now making use of the
pwm_get_relative_duty_cycle() helper instead of manually converting
the absolute duty_cycle value into a relative one.
---
drivers/regulator/pwm-regulator.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 8c56e16..c39ecd1 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -35,9 +35,6 @@ struct pwm_regulator_data {
struct regulator_ops ops;

int state;
-
- /* Continuous voltage */
- int volt_uV;
};

struct pwm_voltages {
@@ -135,8 +132,13 @@ static int pwm_regulator_is_enabled(struct regulator_dev *dev)
static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
{
struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+ int min_uV = rdev->constraints->min_uV;
+ int diff = rdev->constraints->max_uV - min_uV;
+ struct pwm_state pstate;

- return drvdata->volt_uV;
+ pwm_get_state(drvdata->pwm, &pstate);
+
+ return min_uV + pwm_get_relative_duty_cycle(&pstate, diff);
}

static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
@@ -162,8 +164,6 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
return ret;
}

- drvdata->volt_uV = min_uV;
-
/* Delay required by PWM regulator to settle to the new voltage */
usleep_range(ramp_delay, ramp_delay + 1000);

--
2.7.4