regulator: pwm: add support for setting voltage time sel

The pwm voltage ramp for each level is not linear in nature sometimes
and it can be exponential. In this case, the voltage ramp time which is
independent of amount of voltage levels need to be provided to calculate
the proper ramp time.

Change-Id: Idfa17b3bc0a565e66104091090f4fcdb32882be5
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/393889

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index aa813933ed41a5ae2afe9b3deca9de1e262298fb..aeb36fd3b528fb08d54b8b75ddd0052e5aeaab5e 100644 (file)
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -46,6 +46,7 @@ struct pwm_regulator {
        int                     enable_gpio;
        int                     idle_gpio;
        int                     standby_gpio;
+       unsigned int            voltage_time_sel;
 };
 
 static int pwm_regulator_set_voltage_sel(
@@ -118,12 +119,22 @@ static unsigned int pwm_regulator_get_mode(struct regulator_dev *rdev)
                return REGULATOR_MODE_IDLE;
 }
 
+static int pwm_regulator_set_voltage_time_sel(struct regulator_dev *rdev,
+               unsigned int old_selector, unsigned int new_selector)
+{
+       struct pwm_regulator *preg = rdev_get_drvdata(rdev);
+
+       if (preg->voltage_time_sel)
+               return preg->voltage_time_sel;
+       return regulator_set_voltage_time_sel(rdev, old_selector, new_selector);
+}
+
 static struct regulator_ops pwm_regulator_ops = {
        .set_voltage_sel = pwm_regulator_set_voltage_sel,
        .get_voltage_sel = pwm_regulator_get_voltage_sel,
        .list_voltage = regulator_list_voltage_linear,
        .map_voltage = regulator_map_voltage_linear,
-       .set_voltage_time_sel   = regulator_set_voltage_time_sel,
+       .set_voltage_time_sel   = pwm_regulator_set_voltage_time_sel,
        .set_mode = pwm_regulator_set_mode,
        .get_mode = pwm_regulator_get_mode,
 };
@@ -149,6 +160,10 @@ static int pwm_regulator_parse_dt(struct device *dev,
                return ret;
        }
 
+       ret = of_property_read_u32(node, "voltage-time-sel", &pval);
+       if (!ret)
+               preg->voltage_time_sel = pval;
+
        preg->enable_gpio = of_get_named_gpio(node, "enable-gpio", 0);
        if ((preg->enable_gpio < 0) && (preg->enable_gpio != -ENOENT)) {
                dev_err(dev, "Enable gpio not available, %d\n",