Re: [PATCH 10/15] drm/panfrost: add regulators to devfreq

From: ClÃment PÃron
Date: Fri May 29 2020 - 08:37:17 EST


Hi Steven,

On Thu, 28 May 2020 at 15:23, Steven Price <steven.price@xxxxxxx> wrote:
>
> On 10/05/2020 17:55, ClÃment PÃron wrote:
> > Some OPP tables specify voltage for each frequency. Devfreq can
> > handle these regulators but they should be get only 1 time to avoid
> > issue and know who is in charge.
> >
> > If OPP table is probe don't init regulator.
> >
> > Signed-off-by: ClÃment PÃron <peron.clem@xxxxxxxxx>
>
> This looks like it should work - thanks for doing this!

Yes but I'm not really happy how it's implemented.

Looks like a bit a workaround but didn't found a better solution.

Thanks for your review,
Clement

>
> Reviewed-by: Steven Price <steven.price@xxxxxxx>
>
> > ---
> > drivers/gpu/drm/panfrost/panfrost_devfreq.c | 19 +++++++++++++++++++
> > drivers/gpu/drm/panfrost/panfrost_devfreq.h | 2 ++
> > drivers/gpu/drm/panfrost/panfrost_device.c | 11 +++++++----
> > 3 files changed, 28 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > index fce21c682414..9ffea0d4a087 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> > @@ -93,6 +93,7 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
> > unsigned long cur_freq;
> > struct device *dev = &pfdev->pdev->dev;
> > struct devfreq *devfreq;
> > + struct opp_table *opp_table;
> > struct thermal_cooling_device *cooling;
> > struct panfrost_devfreq *pfdevfreq = &pfdev->pfdevfreq;
> >
> > @@ -102,6 +103,19 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
> >
> > spin_lock_init(&pfdevfreq->lock);
> >
> > + opp_table = dev_pm_opp_set_regulators(dev, pfdev->comp->supply_names,
> > + pfdev->comp->num_supplies);
> > + if (IS_ERR(opp_table)) {
> > + ret = PTR_ERR(opp_table);
> > + /* Continue if the optional regulator is missing */
> > + if (ret != -ENODEV) {
> > + DRM_DEV_ERROR(dev, "Couldn't set OPP regulators\n");
> > + goto err_fini;
> > + }
> > + } else {
> > + pfdevfreq->regulators_opp_table = opp_table;
> > + }
> > +
> > ret = dev_pm_opp_of_add_table(dev);
> > if (ret) {
> > DRM_DEV_ERROR(dev, "Couldn't add OPP table\n");
> > @@ -157,6 +171,11 @@ void panfrost_devfreq_fini(struct panfrost_device *pfdev)
> > dev_pm_opp_of_remove_table(&pfdev->pdev->dev);
> > pfdevfreq->opp_of_table_added = false;
> > }
> > +
> > + if (pfdevfreq->regulators_opp_table) {
> > + dev_pm_opp_put_regulators(pfdevfreq->regulators_opp_table);
> > + pfdevfreq->regulators_opp_table = NULL;
> > + }
> > }
> >
> > void panfrost_devfreq_resume(struct panfrost_device *pfdev)
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.h b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> > index add203cb00c2..347cde4786cf 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> > +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.h
> > @@ -8,12 +8,14 @@
> > #include <linux/ktime.h>
> >
> > struct devfreq;
> > +struct opp_table;
> > struct thermal_cooling_device;
> >
> > struct panfrost_device;
> >
> > struct panfrost_devfreq {
> > struct devfreq *devfreq;
> > + struct opp_table *regulators_opp_table;
> > struct thermal_cooling_device *cooling;
> > bool opp_of_table_added;
> >
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> > index 67eedf64e82d..8b17fb2e3369 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> > @@ -222,10 +222,13 @@ int panfrost_device_init(struct panfrost_device *pfdev)
> > goto err_out0;
> > }
> >
> > - err = panfrost_regulator_init(pfdev);
> > - if (err) {
> > - dev_err(pfdev->dev, "regulator init failed %d\n", err);
> > - goto err_out1;
> > + /* OPP will handle regulators */
> > + if (!pfdev->pfdevfreq.opp_of_table_added) {
> > + err = panfrost_regulator_init(pfdev);
> > + if (err) {
> > + dev_err(pfdev->dev, "regulator init failed %d\n", err);
> > + goto err_out1;
> > + }
> > }
> >
> > err = panfrost_reset_init(pfdev);
> >
>