Re: [PATCH v2] media: ov8856: Add runtime PM callbacks

From: Sakari Ailus
Date: Wed Sep 21 2022 - 04:20:57 EST


Hi Hidenori,

On Wed, Sep 21, 2022 at 05:15:35PM +0900, Hidenori Kobayashi wrote:
> There were no runtime PM callbacks registered, leaving regulators being
> enabled while the device is suspended on DT systems. Add callbacks that
> call existing power controlling functions to turn them off/on.
>
> To simplify the code with this addition, change the argument of the
> power controlling functions.
>
> Signed-off-by: Hidenori Kobayashi <hidenorik@xxxxxxxxxxxx>
> ---
> V1 -> V2: Change argument of power controlling functions
> ---
> drivers/media/i2c/ov8856.c | 41 ++++++++++++++++++++++++++------------
> 1 file changed, 28 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/media/i2c/ov8856.c b/drivers/media/i2c/ov8856.c
> index a9728afc81d4..188699455fdf 100644
> --- a/drivers/media/i2c/ov8856.c
> +++ b/drivers/media/i2c/ov8856.c
> @@ -2110,17 +2110,18 @@ static int ov8856_set_stream(struct v4l2_subdev *sd, int enable)
> return ret;
> }
>
> -static int __ov8856_power_on(struct ov8856 *ov8856)
> +static int __ov8856_power_on(struct device *dev)
> {
> - struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct ov8856 *ov8856 = to_ov8856(sd);
> int ret;
>
> - if (is_acpi_node(dev_fwnode(&client->dev)))
> + if (is_acpi_node(dev_fwnode(dev)))
> return 0;
>
> ret = clk_prepare_enable(ov8856->xvclk);
> if (ret < 0) {
> - dev_err(&client->dev, "failed to enable xvclk\n");
> + dev_err(dev, "failed to enable xvclk\n");
> return ret;
> }
>
> @@ -2132,7 +2133,7 @@ static int __ov8856_power_on(struct ov8856 *ov8856)
> ret = regulator_bulk_enable(ARRAY_SIZE(ov8856_supply_names),
> ov8856->supplies);
> if (ret < 0) {
> - dev_err(&client->dev, "failed to enable regulators\n");
> + dev_err(dev, "failed to enable regulators\n");
> goto disable_clk;
> }
>
> @@ -2148,11 +2149,12 @@ static int __ov8856_power_on(struct ov8856 *ov8856)
> return ret;
> }
>
> -static void __ov8856_power_off(struct ov8856 *ov8856)
> +static void __ov8856_power_off(struct device *dev)
> {
> - struct i2c_client *client = v4l2_get_subdevdata(&ov8856->sd);
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct ov8856 *ov8856 = to_ov8856(sd);
>
> - if (is_acpi_node(dev_fwnode(&client->dev)))
> + if (is_acpi_node(dev_fwnode(dev)))
> return;
>
> gpiod_set_value_cansleep(ov8856->reset_gpio, 1);
> @@ -2170,7 +2172,7 @@ static int __maybe_unused ov8856_suspend(struct device *dev)
> if (ov8856->streaming)
> ov8856_stop_streaming(ov8856);
>
> - __ov8856_power_off(ov8856);
> + __ov8856_power_off(dev);
> mutex_unlock(&ov8856->mutex);
>
> return 0;
> @@ -2184,7 +2186,7 @@ static int __maybe_unused ov8856_resume(struct device *dev)
>
> mutex_lock(&ov8856->mutex);
>
> - __ov8856_power_on(ov8856);
> + __ov8856_power_on(dev);
> if (ov8856->streaming) {
> ret = ov8856_start_streaming(ov8856);
> if (ret) {
> @@ -2200,6 +2202,18 @@ static int __maybe_unused ov8856_resume(struct device *dev)
> return 0;
> }
>
> +static int __maybe_unused ov8856_runtime_suspend(struct device *dev)
> +{
> + __ov8856_power_off(dev);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused ov8856_runtime_resume(struct device *dev)
> +{
> + return __ov8856_power_on(dev);
> +}

These two functions are redundant now, you can call __ov8856_power_on /
__ov8856_power_off directly. The return type of __ov8856_power_off needs to
be changed to int. You could also remove the underscores from the names at
the same time.

> +
> static int ov8856_set_format(struct v4l2_subdev *sd,
> struct v4l2_subdev_state *sd_state,
> struct v4l2_subdev_format *fmt)
> @@ -2451,7 +2465,7 @@ static int ov8856_remove(struct i2c_client *client)
> pm_runtime_disable(&client->dev);
> mutex_destroy(&ov8856->mutex);
>
> - __ov8856_power_off(ov8856);
> + __ov8856_power_off(&client->dev);
>
> return 0;
> }
> @@ -2477,7 +2491,7 @@ static int ov8856_probe(struct i2c_client *client)
>
> full_power = acpi_dev_state_d0(&client->dev);
> if (full_power) {
> - ret = __ov8856_power_on(ov8856);
> + ret = __ov8856_power_on(&client->dev);
> if (ret) {
> dev_err(&client->dev, "failed to power on\n");
> return ret;
> @@ -2533,13 +2547,14 @@ static int ov8856_probe(struct i2c_client *client)
> mutex_destroy(&ov8856->mutex);
>
> probe_power_off:
> - __ov8856_power_off(ov8856);
> + __ov8856_power_off(&client->dev);
>
> return ret;
> }
>
> static const struct dev_pm_ops ov8856_pm_ops = {
> SET_SYSTEM_SLEEP_PM_OPS(ov8856_suspend, ov8856_resume)
> + SET_RUNTIME_PM_OPS(ov8856_runtime_suspend, ov8856_runtime_resume, NULL)
> };
>
> #ifdef CONFIG_ACPI

--
Kind regards,

Sakari Ailus