linux-kernel - Re: [PATCH v2 2/2] drm/bridge: anx7625: disable regulators when power off

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Date:   Fri, 25 Dec 2020 13:41:36 +0800
From:   Hsin-Yi Wang <hsinyi@...omium.org>
To:     Xin Ji <xji@...logixsemi.com>, Sam Ravnborg <sam@...nborg.org>,
        Rob Herring <robh+dt@...nel.org>
Cc:     David Airlie <airlied@...ux.ie>, Daniel Vetter <daniel@...ll.ch>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        Devicetree List <devicetree@...r.kernel.org>,
        lkml <linux-kernel@...r.kernel.org>,
        Andrzej Hajda <a.hajda@...sung.com>,
        Neil Armstrong <narmstrong@...libre.com>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...l.net>
Subject: Re: [PATCH v2 2/2] drm/bridge: anx7625: disable regulators when power off

On Wed, Dec 9, 2020 at 12:43 PM Hsin-Yi Wang <hsinyi@...omium.org> wrote:
>
> On Mon, Nov 23, 2020 at 11:47 AM Hsin-Yi Wang <hsinyi@...omium.org> wrote:
> >
> > When suspending the driver, anx7625_power_standby() will be called to
> > turn off reset-gpios and enable-gpios. However, power supplies are not
> > disabled. To save power, the driver can get the power supply regulators
> > and turn off them in anx7625_power_standby().
> >
> > Signed-off-by: Hsin-Yi Wang <hsinyi@...omium.org>
>
> Gentle ping on the patch
>

After some testing, the powering sequence has some issue and would
cause i2c failures. The powering sequence needs to be rechecked.

> > ---
> > Change:
> > v2: none
> > ---
> >  drivers/gpu/drm/bridge/analogix/anx7625.c | 25 +++++++++++++++++++++++
> >  drivers/gpu/drm/bridge/analogix/anx7625.h |  1 +
> >  2 files changed, 26 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > index 65cc05982f82..eb9c4cc2504a 100644
> > --- a/drivers/gpu/drm/bridge/analogix/anx7625.c
> > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
> > @@ -11,6 +11,7 @@
> >  #include <linux/kernel.h>
> >  #include <linux/module.h>
> >  #include <linux/mutex.h>
> > +#include <linux/regulator/consumer.h>
> >  #include <linux/slab.h>
> >  #include <linux/types.h>
> >  #include <linux/workqueue.h>
> > @@ -875,12 +876,20 @@ static int sp_tx_edid_read(struct anx7625_data *ctx,
> >  static void anx7625_power_on(struct anx7625_data *ctx)
> >  {
> >         struct device *dev = &ctx->client->dev;
> > +       int ret;
> >
> >         if (!ctx->pdata.low_power_mode) {
> >                 DRM_DEV_DEBUG_DRIVER(dev, "not low power mode!\n");
> >                 return;
> >         }
> >
> > +       ret = regulator_bulk_enable(ARRAY_SIZE(ctx->pdata.supplies),
> > +                                   ctx->pdata.supplies);
> > +       if (ret < 0) {
> > +               DRM_DEV_DEBUG_DRIVER(dev, "cannot enable regulators %d\n", ret);
> > +               return;
> > +       }
> > +
> >         /* Power on pin enable */
> >         gpiod_set_value(ctx->pdata.gpio_p_on, 1);
> >         usleep_range(10000, 11000);
> > @@ -894,6 +903,7 @@ static void anx7625_power_on(struct anx7625_data *ctx)
> >  static void anx7625_power_standby(struct anx7625_data *ctx)
> >  {
> >         struct device *dev = &ctx->client->dev;
> > +       int ret;
> >
> >         if (!ctx->pdata.low_power_mode) {
> >                 DRM_DEV_DEBUG_DRIVER(dev, "not low power mode!\n");
> > @@ -904,6 +914,12 @@ static void anx7625_power_standby(struct anx7625_data *ctx)
> >         usleep_range(1000, 1100);
> >         gpiod_set_value(ctx->pdata.gpio_p_on, 0);
> >         usleep_range(1000, 1100);
> > +
> > +       ret = regulator_bulk_disable(ARRAY_SIZE(ctx->pdata.supplies),
> > +                                    ctx->pdata.supplies);
> > +       if (ret < 0)
> > +               DRM_DEV_DEBUG_DRIVER(dev, "cannot disable regulators %d\n", ret);
> > +
> >         DRM_DEV_DEBUG_DRIVER(dev, "power down\n");
> >  }
> >
> > @@ -1742,6 +1758,15 @@ static int anx7625_i2c_probe(struct i2c_client *client,
> >         platform->client = client;
> >         i2c_set_clientdata(client, platform);
> >
> > +       pdata->supplies[0].supply = "vdd10";
> > +       pdata->supplies[1].supply = "vdd18";
> > +       pdata->supplies[2].supply = "vdd33";
> > +       ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(pdata->supplies),
> > +                                     pdata->supplies);
> > +       if (ret) {
> > +               DRM_DEV_ERROR(dev, "fail to get power supplies: %d\n", ret);
> > +               return ret;
> > +       }
> >         anx7625_init_gpio(platform);
> >
> >         atomic_set(&platform->power_status, 0);
> > diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.h b/drivers/gpu/drm/bridge/analogix/anx7625.h
> > index 193ad86c5450..e4a086b3a3d7 100644
> > --- a/drivers/gpu/drm/bridge/analogix/anx7625.h
> > +++ b/drivers/gpu/drm/bridge/analogix/anx7625.h
> > @@ -350,6 +350,7 @@ struct s_edid_data {
> >  struct anx7625_platform_data {
> >         struct gpio_desc *gpio_p_on;
> >         struct gpio_desc *gpio_reset;
> > +       struct regulator_bulk_data supplies[3];
> >         struct drm_bridge *panel_bridge;
> >         int intp_irq;
> >         u32 low_power_mode;
> > --
> > 2.29.2.454.gaff20da3a2-goog
> >