linux-kernel - Re: [PATCH v3 2/2] drm/bridge: anx7625: disable regulators when power off

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Message-ID: <CAG3jFytPDLWygTGeyCYEqJYcwD=UDAe6hagL5zTjrSKXoN5aMA@mail.gmail.com>
Date:   Tue, 23 Feb 2021 16:23:10 +0100
From:   Robert Foss <robert.foss@...aro.org>
To:     Hsin-Yi Wang <hsinyi@...omium.org>
Cc:     Xin Ji <xji@...logixsemi.com>, David Airlie <airlied@...ux.ie>,
        Sam Ravnborg <sam@...nborg.org>,
        Rob Herring <robh+dt@...nel.org>,
        Daniel Vetter <daniel@...ll.ch>,
        dri-devel <dri-devel@...ts.freedesktop.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>,
        linux-kernel <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 v3 2/2] drm/bridge: anx7625: disable regulators when power off

Hey Hsin-Yi,

This patch looks good to me, feel free to add my r-b.
Reviewed-by: Robert Foss <robert.foss@...aro.org>

On Fri, 15 Jan 2021 at 08:05, 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>
> ---
> Change:
> v3: add delays between regulators power on
> ---
>  drivers/gpu/drm/bridge/analogix/anx7625.c | 34 +++++++++++++++++++++++
>  drivers/gpu/drm/bridge/analogix/anx7625.h |  1 +
>  2 files changed, 35 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
> index 65cc05982f82..23283ba0c4f9 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 +876,25 @@ 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, i;
>
>         if (!ctx->pdata.low_power_mode) {
>                 DRM_DEV_DEBUG_DRIVER(dev, "not low power mode!\n");
>                 return;
>         }
>
> +       for (i = 0; i < ARRAY_SIZE(ctx->pdata.supplies); i++) {
> +               ret = regulator_enable(ctx->pdata.supplies[i].consumer);
> +               if (ret < 0) {
> +                       DRM_DEV_DEBUG_DRIVER(dev, "cannot enable supply %d: %d\n",
> +                                            i, ret);
> +                       goto reg_err;
> +               }
> +               usleep_range(2000, 2100);
> +       }
> +
> +       usleep_range(4000, 4100);
> +
>         /* Power on pin enable */
>         gpiod_set_value(ctx->pdata.gpio_p_on, 1);
>         usleep_range(10000, 11000);
> @@ -889,11 +903,16 @@ static void anx7625_power_on(struct anx7625_data *ctx)
>         usleep_range(10000, 11000);
>
>         DRM_DEV_DEBUG_DRIVER(dev, "power on !\n");
> +       return;
> +reg_err:
> +       for (--i; i >= 0; i--)
> +               regulator_disable(ctx->pdata.supplies[i].consumer);
>  }
>
>  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 +923,12 @@ 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 supplies %d\n", ret);
> +
>         DRM_DEV_DEBUG_DRIVER(dev, "power down\n");
>  }
>
> @@ -1742,6 +1767,15 @@ 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;
> --
> 2.30.0.284.gd98b1dd5eaa7-goog
>