UPSTREAM: regulator: pwm: Properly initialize the ->state field

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>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
(cherry picked from commit 87248991a1de28e73dc30057e82d831bc11cdd44)

Change-Id: I179395dc7bad7aa867e68c92be7ce92b03ae7112
Signed-off-by: David Wu <david.wu@rock-chips.com>

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 7920411057af301a25b6c0a0d6a686c11e871935..7d26d3b0eed6122f1ee720db64b23121d36f0103 100644 (file)
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -52,10 +52,31 @@ 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;
 }
 
@@ -221,6 +242,7 @@ 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));