Re: [RFC PATCH 14/15] regulator: pwm: implement ->enable(), ->disable() and ->is_enabled methods

Boris Brezillon
2015-07-01T12:05:31Z

Hi Heiko,

On Wed, 01 Jul 2015 13:58:09 +0200
Heiko Stübner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org> wrote:

> Am Mittwoch, 1. Juli 2015, 10:22:00 schrieb Boris Brezillon:
> > 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 <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> > ---
> > 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