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    Subject[PATCH v5 30/46] regulator: pwm: retrieve correct voltage
    Date
    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@free-electrons.com>
    ---
    drivers/regulator/pwm-regulator.c | 23 +++++++++++++++++------
    1 file changed, 17 insertions(+), 6 deletions(-)

    diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
    index 9374796..77f42d8 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 {
    @@ -167,11 +164,27 @@ static int pwm_voltage_to_duty_cycle_percentage(struct regulator_dev *rdev, int
    return ((req_uV * 100) - (min_uV * 100)) / diff;
    }

    +static int pwm_duty_cycle_percentage_to_voltage(struct regulator_dev *rdev,
    + int dutycycle)
    +{
    + int min_uV = rdev->constraints->min_uV;
    + int max_uV = rdev->constraints->max_uV;
    + int diff = max_uV - min_uV;
    +
    + return min_uV + ((diff * dutycycle) / 100);
    +}
    +
    static int pwm_regulator_get_voltage(struct regulator_dev *rdev)
    {
    struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
    + struct pwm_state pstate;
    + u64 dutycycle;

    - return drvdata->volt_uV;
    + pwm_get_state(drvdata->pwm, &pstate);
    + dutycycle = pstate.duty_cycle * 100;
    + do_div(dutycycle, pstate.period);
    +
    + return pwm_duty_cycle_percentage_to_voltage(rdev, dutycycle);
    }

    static int pwm_regulator_set_voltage(struct regulator_dev *rdev,
    @@ -196,8 +209,6 @@ 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);

    --
    2.5.0
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