[PATCH v3 11/14] regulator: pwm: Properly initialize the ->state field

[Boris Brezillon <boris.brezillon@free-electrons.com>]

The ->state field is currently initialized to 0, thus referencing the
voltage selector at index 0, which might not reflect the current
voltage value.
If possible, retrieve the current voltage selector from the PWM state,
else return -EINVAL.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Brian Norris <briannorris@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Mark,

I know you already added your Acked-by tag 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 | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index ad75360..2000118 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -48,10 +48,31 @@ struct pwm_voltages {
 /**
  * Voltage table call-backs
  */
+static void pwm_regulator_init_state(struct regulator_dev *rdev)
+{
+	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	struct pwm_state pwm_state;
+	unsigned int dutycycle;
+	int i;
+
+	pwm_get_state(drvdata->pwm, &pwm_state);
+	dutycycle = pwm_get_relative_duty_cycle(&pwm_state, 100);
+
+	for (i = 0; i < rdev->desc->n_voltages; i++) {
+		if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) {
+			drvdata->state = i;
+			return;
+		}
+	}
+}
+
 static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 
+	if (drvdata->state < 0)
+		pwm_regulator_init_state(rdev);
+
 	return drvdata->state;
 }
 
@@ -203,6 +224,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev,
 		return ret;
 	}
 
+	drvdata->state			= -EINVAL;
 	drvdata->duty_cycle_table	= duty_cycle_table;
 	memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops,
 	       sizeof(drvdata->ops));
-- 
2.7.4