Hi Heiko,

On Wed, 01 Jul 2015 13:58:09 +0200
Heiko St?bner [off-list ref] wrote:

Am Mittwoch, 1. Juli 2015, 10:22:00 schrieb Boris Brezillon:

quoted

Implement the ->enable(), ->disable() and ->is_enabled methods and remove
the PWM call in ->set_voltage_sel().
This is particularly important for critical regulators tagged as always-on,
because not claiming the PWM (and its dependencies) might lead to
unpredictable behavior (like a system hang because the PWM clk is only
claimed when the PWM device is enabled).

Signed-off-by: Boris Brezillon <redacted>
---
 drivers/regulator/pwm-regulator.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/regulator/pwm-regulator.c

b/drivers/regulator/pwm-regulator.c index 12b4d9d..8159518 100644

--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c

@@ -59,12 +59,6 @@ static int pwm_regulator_set_voltage_sel(struct

regulator_dev *rdev,

 	drvdata->state = selector;

-	ret = pwm_enable(drvdata->pwm);
-	if (ret) {
-		dev_err(&rdev->dev, "Failed to enable PWM\n");
-		return ret;
-	}
-
 	return 0;
 }

@@ -79,11 +73,37 @@ static int pwm_regulator_list_voltage(struct

regulator_dev *rdev, return drvdata->duty_cycle_table[selector].uV;
 }

+static int pwm_regulator_enable(struct regulator_dev *dev)
+{
+	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+
+	return pwm_enable(drvdata->pwm);
+}
+
+static int pwm_regulator_disable(struct regulator_dev *dev)
+{
+	struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+
+	pwm_disable(drvdata->pwm);
+
+	return 0;
+}
+
+static int pwm_regulator_is_enabled(struct regulator_dev *dev)
+{
+       struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev);
+
+       return pwm_is_enabled(drvdata->pwm);
+}

nit: indentation is wrong in pwm_regulator_is_enabled (spaces instead of tabs)

Yep, I noticed checkpatch warnings/errors before sending the patch, but
since this is just an RFC I decided to fix them for the next version ;-)

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com