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References: <20220927201634.750141-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
In-Reply-To: <20220927201634.750141-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
From:   "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Date:   Mon, 10 Oct 2022 21:04:22 +0100
Message-ID: <CA+V-a8vQce5+my5nQr=CiJf9KtuHgzmt18PT1kwp9Nq8ADHYFw@mail.gmail.com>
Subject: Re: [PATCH] media: i2c: ov5645: Use runtime PM
To:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Hans Verkuil <hverkuil@xs4all.nl>
Cc:     Shawn Tu <shawnx.tu@intel.com>, Jacopo Mondi <jacopo@jmondi.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-renesas-soc@vger.kernel.org,
        Biju Das <biju.das.jz@bp.renesas.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi,

On Tue, Sep 27, 2022 at 9:16 PM Prabhakar <prabhakar.csengg@gmail.com> wrote:
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Switch to using runtime PM for power management.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  drivers/media/i2c/Kconfig  |   2 +-
>  drivers/media/i2c/ov5645.c | 135 +++++++++++++++++++------------------
>  2 files changed, 69 insertions(+), 68 deletions(-)
>
I know it's too early, but I dont want to miss the v6.2 window for
RZ/G2L CRU driver [0].

Gentle ping for review.

[0] https://patchwork.kernel.org/project/linux-renesas-soc/cover/20221004234343.54777-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

Cheers,
Prabhakar

> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 7806d4b81716..c0edd1017fe8 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -459,7 +459,7 @@ config VIDEO_OV5640
>  config VIDEO_OV5645
>         tristate "OmniVision OV5645 sensor support"
>         depends on OF
> -       depends on I2C && VIDEO_DEV
> +       depends on I2C && PM && VIDEO_DEV
>         select MEDIA_CONTROLLER
>         select VIDEO_V4L2_SUBDEV_API
>         select V4L2_FWNODE
> diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
> index 81e4e87e1821..3c3b30338328 100644
> --- a/drivers/media/i2c/ov5645.c
> +++ b/drivers/media/i2c/ov5645.c
> @@ -27,6 +27,7 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_graph.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
>  #include <linux/types.h>
> @@ -108,7 +109,6 @@ struct ov5645 {
>         u8 timing_tc_reg21;
>
>         struct mutex power_lock; /* lock to protect power state */
> -       int power_count;
>
>         struct gpio_desc *enable_gpio;
>         struct gpio_desc *rst_gpio;
> @@ -635,8 +635,24 @@ static int ov5645_set_register_array(struct ov5645 *ov5645,
>         return 0;
>  }
>
> -static int ov5645_set_power_on(struct ov5645 *ov5645)
> +static int ov5645_set_power_off(struct device *dev)
>  {
> +       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +       struct ov5645 *ov5645 = to_ov5645(sd);
> +
> +       ov5645_write_reg(ov5645, OV5645_IO_MIPI_CTRL00, 0x58);
> +       gpiod_set_value_cansleep(ov5645->rst_gpio, 1);
> +       gpiod_set_value_cansleep(ov5645->enable_gpio, 0);
> +       clk_disable_unprepare(ov5645->xclk);
> +       regulator_bulk_disable(OV5645_NUM_SUPPLIES, ov5645->supplies);
> +
> +       return 0;
> +}
> +
> +static int ov5645_set_power_on(struct device *dev)
> +{
> +       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +       struct ov5645 *ov5645 = to_ov5645(sd);
>         int ret;
>
>         ret = regulator_bulk_enable(OV5645_NUM_SUPPLIES, ov5645->supplies);
> @@ -658,57 +674,19 @@ static int ov5645_set_power_on(struct ov5645 *ov5645)
>
>         msleep(20);
>
> -       return 0;
> -}
> -
> -static void ov5645_set_power_off(struct ov5645 *ov5645)
> -{
> -       gpiod_set_value_cansleep(ov5645->rst_gpio, 1);
> -       gpiod_set_value_cansleep(ov5645->enable_gpio, 0);
> -       clk_disable_unprepare(ov5645->xclk);
> -       regulator_bulk_disable(OV5645_NUM_SUPPLIES, ov5645->supplies);
> -}
> -
> -static int ov5645_s_power(struct v4l2_subdev *sd, int on)
> -{
> -       struct ov5645 *ov5645 = to_ov5645(sd);
> -       int ret = 0;
> -
> -       mutex_lock(&ov5645->power_lock);
> -
> -       /* If the power count is modified from 0 to != 0 or from != 0 to 0,
> -        * update the power state.
> -        */
> -       if (ov5645->power_count == !on) {
> -               if (on) {
> -                       ret = ov5645_set_power_on(ov5645);
> -                       if (ret < 0)
> -                               goto exit;
> -
> -                       ret = ov5645_set_register_array(ov5645,
> -                                       ov5645_global_init_setting,
> +       ret = ov5645_set_register_array(ov5645, ov5645_global_init_setting,
>                                         ARRAY_SIZE(ov5645_global_init_setting));
> -                       if (ret < 0) {
> -                               dev_err(ov5645->dev,
> -                                       "could not set init registers\n");
> -                               ov5645_set_power_off(ov5645);
> -                               goto exit;
> -                       }
> -
> -                       usleep_range(500, 1000);
> -               } else {
> -                       ov5645_write_reg(ov5645, OV5645_IO_MIPI_CTRL00, 0x58);
> -                       ov5645_set_power_off(ov5645);
> -               }
> +       if (ret < 0) {
> +               dev_err(ov5645->dev, "could not set init registers\n");
> +               goto exit;
>         }
>
> -       /* Update the power count. */
> -       ov5645->power_count += on ? 1 : -1;
> -       WARN_ON(ov5645->power_count < 0);
> +       usleep_range(500, 1000);
>
> -exit:
> -       mutex_unlock(&ov5645->power_lock);
> +       return 0;
>
> +exit:
> +       ov5645_set_power_off(dev);
>         return ret;
>  }
>
> @@ -795,7 +773,7 @@ static int ov5645_s_ctrl(struct v4l2_ctrl *ctrl)
>         int ret;
>
>         mutex_lock(&ov5645->power_lock);
> -       if (!ov5645->power_count) {
> +       if (!pm_runtime_get_if_in_use(ov5645->dev)) {
>                 mutex_unlock(&ov5645->power_lock);
>                 return 0;
>         }
> @@ -827,6 +805,7 @@ static int ov5645_s_ctrl(struct v4l2_ctrl *ctrl)
>                 break;
>         }
>
> +       pm_runtime_put_autosuspend(ov5645->dev);
>         mutex_unlock(&ov5645->power_lock);
>
>         return ret;
> @@ -991,6 +970,10 @@ static int ov5645_s_stream(struct v4l2_subdev *subdev, int enable)
>         int ret;
>
>         if (enable) {
> +               ret = pm_runtime_resume_and_get(ov5645->dev);
> +               if (ret < 0)
> +                       return ret;
> +
>                 ret = ov5645_set_register_array(ov5645,
>                                         ov5645->current_mode->data,
>                                         ov5645->current_mode->data_size);
> @@ -998,22 +981,22 @@ static int ov5645_s_stream(struct v4l2_subdev *subdev, int enable)
>                         dev_err(ov5645->dev, "could not set mode %dx%d\n",
>                                 ov5645->current_mode->width,
>                                 ov5645->current_mode->height);
> -                       return ret;
> +                       goto err_rpm_put;
>                 }
>                 ret = v4l2_ctrl_handler_setup(&ov5645->ctrls);
>                 if (ret < 0) {
>                         dev_err(ov5645->dev, "could not sync v4l2 controls\n");
> -                       return ret;
> +                       goto err_rpm_put;
>                 }
>
>                 ret = ov5645_write_reg(ov5645, OV5645_IO_MIPI_CTRL00, 0x45);
>                 if (ret < 0)
> -                       return ret;
> +                       goto err_rpm_put;
>
>                 ret = ov5645_write_reg(ov5645, OV5645_SYSTEM_CTRL0,
>                                        OV5645_SYSTEM_CTRL0_START);
>                 if (ret < 0)
> -                       return ret;
> +                       goto err_rpm_put;
>         } else {
>                 ret = ov5645_write_reg(ov5645, OV5645_IO_MIPI_CTRL00, 0x40);
>                 if (ret < 0)
> @@ -1023,14 +1006,15 @@ static int ov5645_s_stream(struct v4l2_subdev *subdev, int enable)
>                                        OV5645_SYSTEM_CTRL0_STOP);
>                 if (ret < 0)
>                         return ret;
> +               pm_runtime_put(ov5645->dev);
>         }
>
>         return 0;
> -}
>
> -static const struct v4l2_subdev_core_ops ov5645_core_ops = {
> -       .s_power = ov5645_s_power,
> -};
> +err_rpm_put:
> +       pm_runtime_put(ov5645->dev);
> +       return ret;
> +}
>
>  static const struct v4l2_subdev_video_ops ov5645_video_ops = {
>         .s_stream = ov5645_s_stream,
> @@ -1046,7 +1030,6 @@ static const struct v4l2_subdev_pad_ops ov5645_subdev_pad_ops = {
>  };
>
>  static const struct v4l2_subdev_ops ov5645_subdev_ops = {
> -       .core = &ov5645_core_ops,
>         .video = &ov5645_video_ops,
>         .pad = &ov5645_subdev_pad_ops,
>  };
> @@ -1188,11 +1171,9 @@ static int ov5645_probe(struct i2c_client *client)
>                 goto free_ctrl;
>         }
>
> -       ret = ov5645_s_power(&ov5645->sd, true);
> -       if (ret < 0) {
> -               dev_err(dev, "could not power up OV5645\n");
> +       ret = ov5645_set_power_on(dev);
> +       if (ret)
>                 goto free_entity;
> -       }
>
>         ret = ov5645_read_reg(ov5645, OV5645_CHIP_ID_HIGH, &chip_id_high);
>         if (ret < 0 || chip_id_high != OV5645_CHIP_ID_HIGH_BYTE) {
> @@ -1209,12 +1190,16 @@ static int ov5645_probe(struct i2c_client *client)
>
>         dev_info(dev, "OV5645 detected at address 0x%02x\n", client->addr);
>
> +       pm_runtime_set_active(dev);
> +       pm_runtime_get_noresume(dev);
> +       pm_runtime_enable(dev);
> +
>         ret = ov5645_read_reg(ov5645, OV5645_AEC_PK_MANUAL,
>                               &ov5645->aec_pk_manual);
>         if (ret < 0) {
>                 dev_err(dev, "could not read AEC/AGC mode\n");
>                 ret = -ENODEV;
> -               goto power_down;
> +               goto err_pm_runtime;
>         }
>
>         ret = ov5645_read_reg(ov5645, OV5645_TIMING_TC_REG20,
> @@ -1222,7 +1207,7 @@ static int ov5645_probe(struct i2c_client *client)
>         if (ret < 0) {
>                 dev_err(dev, "could not read vflip value\n");
>                 ret = -ENODEV;
> -               goto power_down;
> +               goto err_pm_runtime;
>         }
>
>         ret = ov5645_read_reg(ov5645, OV5645_TIMING_TC_REG21,
> @@ -1230,14 +1215,18 @@ static int ov5645_probe(struct i2c_client *client)
>         if (ret < 0) {
>                 dev_err(dev, "could not read hflip value\n");
>                 ret = -ENODEV;
> -               goto power_down;
> +               goto err_pm_runtime;
>         }
>
> -       ov5645_s_power(&ov5645->sd, false);
> +       pm_runtime_set_autosuspend_delay(dev, 1000);
> +       pm_runtime_use_autosuspend(dev);
> +       pm_runtime_put_autosuspend(dev);
>
>         ret = v4l2_async_register_subdev(&ov5645->sd);
>         if (ret < 0) {
>                 dev_err(dev, "could not register v4l2 device\n");
> +               pm_runtime_disable(dev);
> +               pm_runtime_set_suspended(dev);
>                 goto free_entity;
>         }
>
> @@ -1245,8 +1234,11 @@ static int ov5645_probe(struct i2c_client *client)
>
>         return 0;
>
> +err_pm_runtime:
> +       pm_runtime_disable(dev);
> +       pm_runtime_put_noidle(dev);
>  power_down:
> -       ov5645_s_power(&ov5645->sd, false);
> +       ov5645_set_power_off(dev);
>  free_entity:
>         media_entity_cleanup(&ov5645->sd.entity);
>  free_ctrl:
> @@ -1264,6 +1256,10 @@ static void ov5645_remove(struct i2c_client *client)
>         v4l2_async_unregister_subdev(&ov5645->sd);
>         media_entity_cleanup(&ov5645->sd.entity);
>         v4l2_ctrl_handler_free(&ov5645->ctrls);
> +       pm_runtime_disable(ov5645->dev);
> +       if (!pm_runtime_status_suspended(ov5645->dev))
> +               ov5645_set_power_off(ov5645->dev);
> +       pm_runtime_set_suspended(ov5645->dev);
>         mutex_destroy(&ov5645->power_lock);
>  }
>
> @@ -1279,10 +1275,15 @@ static const struct of_device_id ov5645_of_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, ov5645_of_match);
>
> +static const struct dev_pm_ops ov5645_pm_ops = {
> +       SET_RUNTIME_PM_OPS(ov5645_set_power_off, ov5645_set_power_on, NULL)
> +};
> +
>  static struct i2c_driver ov5645_i2c_driver = {
>         .driver = {
>                 .of_match_table = ov5645_of_match,
>                 .name  = "ov5645",
> +               .pm = &ov5645_pm_ops,
>         },
>         .probe_new = ov5645_probe,
>         .remove = ov5645_remove,
> --
> 2.25.1
>