Hi Paul,
Thank you for the patch.
On Fri, Mar 11, 2022 at 08:12:59PM +0900, Paul Elder wrote:
> Switch to using runtime PM for power management.
>
> Signed-off-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx>
>
> ---
> Changes in v2:
> - replace manual tracking of power status with pm_runtime_get_if_in_use
> - power on the sensor before reading the checking the chip id
> - add dependency on PM to Kconfig
> ---
> drivers/media/i2c/Kconfig | 1 +
> drivers/media/i2c/ov5640.c | 112 ++++++++++++++++++++++---------------
> 2 files changed, 67 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index e7194c1be4d2..97c3611d9304 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -1025,6 +1025,7 @@ config VIDEO_OV5640
> tristate "OmniVision OV5640 sensor support"
> depends on OF
> depends on GPIOLIB && VIDEO_V4L2 && I2C
> + depends on PM
> select MEDIA_CONTROLLER
> select VIDEO_V4L2_SUBDEV_API
> select V4L2_FWNODE
> diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
> index 4de83d0ef85d..454ffd3c6d59 100644
> --- a/drivers/media/i2c/ov5640.c
> +++ b/drivers/media/i2c/ov5640.c
> @@ -15,6 +15,7 @@
> #include <linux/init.h>
> #include <linux/module.h>
> #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/regulator/consumer.h>
> #include <linux/slab.h>
> #include <linux/types.h>
> @@ -445,8 +446,6 @@ struct ov5640_dev {
> /* lock to protect all members below */
> struct mutex lock;
>
> - int power_count;
> -
> struct v4l2_mbus_framefmt fmt;
> bool pending_fmt_change;
>
> @@ -2693,37 +2692,6 @@ static int ov5640_set_power(struct ov5640_dev *sensor, bool on)
>
> /* --------------- Subdev Operations --------------- */
>
> -static int ov5640_s_power(struct v4l2_subdev *sd, int on)
> -{
> - struct ov5640_dev *sensor = to_ov5640_dev(sd);
> - int ret = 0;
> -
> - mutex_lock(&sensor->lock);
> -
> - /*
> - * If the power count is modified from 0 to != 0 or from != 0 to 0,
> - * update the power state.
> - */
> - if (sensor->power_count == !on) {
> - ret = ov5640_set_power(sensor, !!on);
> - if (ret)
> - goto out;
> - }
> -
> - /* Update the power count. */
> - sensor->power_count += on ? 1 : -1;
> - WARN_ON(sensor->power_count < 0);
> -out:
> - mutex_unlock(&sensor->lock);
> -
> - if (on && !ret && sensor->power_count == 1) {
> - /* restore controls */
> - ret = v4l2_ctrl_handler_setup(&sensor->ctrls.handler);
> - }
> -
> - return ret;
> -}
> -
> static int ov5640_try_frame_interval(struct ov5640_dev *sensor,
> struct v4l2_fract *fi,
> u32 width, u32 height)
> @@ -3288,6 +3256,9 @@ static int ov5640_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
>
> /* v4l2_ctrl_lock() locks our own mutex */
>
> + if (!pm_runtime_get_if_in_use(&sensor->i2c_client->dev))
> + return 0;
I'm afraid this won't work as intended :-S This function is called by
v4l2_ctrl_handler_setup(), itself called from ov5640_sensor_resume(). At
that point, runtime PM isn't flagged as in use yet, we're still in the
process of resuming.
There are a few ways around this. The simplest one may be to move the
v4l2_ctrl_handler_setup() call from ov5640_sensor_resume() to
ov5640_s_stream(). Sakari, any opinion ?
> +
> switch (ctrl->id) {
> case V4L2_CID_AUTOGAIN:
> val = ov5640_get_gain(sensor);
> @@ -3303,6 +3274,8 @@ static int ov5640_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
> break;
> }
>
> + pm_runtime_put_autosuspend(&sensor->i2c_client->dev);
> +
> return 0;
> }
>
> @@ -3334,7 +3307,7 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
> * not apply any controls to H/W at this time. Instead
> * the controls will be restored right after power-up.
> */
> - if (sensor->power_count == 0)
> + if (!pm_runtime_get_if_in_use(&sensor->i2c_client->dev))
> return 0;
>
> switch (ctrl->id) {
> @@ -3376,6 +3349,8 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
> break;
> }
>
> + pm_runtime_put_autosuspend(&sensor->i2c_client->dev);
> +
> return ret;
> }
>
> @@ -3657,6 +3632,12 @@ static int ov5640_s_stream(struct v4l2_subdev *sd, int enable)
> struct ov5640_dev *sensor = to_ov5640_dev(sd);
> int ret = 0;
>
> + if (enable) {
> + ret = pm_runtime_resume_and_get(&sensor->i2c_client->dev);
> + if (ret < 0)
> + return ret;
> + }
> +
> mutex_lock(&sensor->lock);
>
> if (sensor->streaming == !enable) {
> @@ -3681,8 +3662,13 @@ static int ov5640_s_stream(struct v4l2_subdev *sd, int enable)
> if (!ret)
> sensor->streaming = enable;
> }
> +
> out:
> mutex_unlock(&sensor->lock);
> +
> + if (!enable || ret)
> + pm_runtime_put(&sensor->i2c_client->dev);
> +
> return ret;
> }
>
> @@ -3704,7 +3690,6 @@ static int ov5640_init_cfg(struct v4l2_subdev *sd,
> }
>
> static const struct v4l2_subdev_core_ops ov5640_core_ops = {
> - .s_power = ov5640_s_power,
> .log_status = v4l2_ctrl_subdev_log_status,
> .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> .unsubscribe_event = v4l2_event_subdev_unsubscribe,
> @@ -3750,15 +3735,11 @@ static int ov5640_check_chip_id(struct ov5640_dev *sensor)
> int ret = 0;
> u16 chip_id;
>
> - ret = ov5640_set_power_on(sensor);
> - if (ret)
> - return ret;
> -
> ret = ov5640_read_reg16(sensor, OV5640_REG_CHIP_ID, &chip_id);
> if (ret) {
> dev_err(&client->dev, "%s: failed to read chip identifier\n",
> __func__);
> - goto power_off;
> + return ret;
> }
>
> if (chip_id != 0x5640) {
> @@ -3767,8 +3748,6 @@ static int ov5640_check_chip_id(struct ov5640_dev *sensor)
> ret = -ENXIO;
> }
>
> -power_off:
> - ov5640_set_power_off(sensor);
> return ret;
> }
>
> @@ -3863,20 +3842,35 @@ static int ov5640_probe(struct i2c_client *client)
>
> mutex_init(&sensor->lock);
>
> - ret = ov5640_check_chip_id(sensor);
> + ret = ov5640_init_controls(sensor);
> if (ret)
> goto entity_cleanup;
>
> - ret = ov5640_init_controls(sensor);
> + ret = ov5640_set_power(sensor, true);
> if (ret)
> - goto entity_cleanup;
> + goto free_ctrls;
> +
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> + pm_runtime_get(dev);
> +
> + ret = ov5640_check_chip_id(sensor);
> + if (ret)
> + goto err_pm_runtime;
>
> ret = v4l2_async_register_subdev_sensor(&sensor->sd);
> if (ret)
> - goto free_ctrls;
> + goto err_pm_runtime;
> +
> + pm_runtime_set_autosuspend_delay(dev, 1000);
> + pm_runtime_use_autosuspend(dev);
> + pm_runtime_put_autosuspend(dev);
>
> return 0;
>
> +err_pm_runtime:
> + pm_runtime_disable(dev);
> + pm_runtime_put_noidle(dev);
> free_ctrls:
> v4l2_ctrl_handler_free(&sensor->ctrls.handler);
> entity_cleanup:
> @@ -3898,6 +3892,31 @@ static int ov5640_remove(struct i2c_client *client)
> return 0;
> }
>
> +static int __maybe_unused ov5640_sensor_suspend(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct ov5640_dev *ov5640 = to_ov5640_dev(sd);
> +
> + return ov5640_set_power(ov5640, false);
> +}
> +
> +static int __maybe_unused ov5640_sensor_resume(struct device *dev)
> +{
> + struct v4l2_subdev *sd = dev_get_drvdata(dev);
> + struct ov5640_dev *ov5640 = to_ov5640_dev(sd);
> + int ret;
> +
> + ret = ov5640_set_power(ov5640, true);
> + if (ret)
> + return ret;
> +
> + return v4l2_ctrl_handler_setup(&ov5640->ctrls.handler);
> +}
> +
> +static const struct dev_pm_ops ov5640_pm_ops = {
> + SET_RUNTIME_PM_OPS(ov5640_sensor_suspend, ov5640_sensor_resume, NULL)
> +};
> +
> static const struct i2c_device_id ov5640_id[] = {
> {"ov5640", 0},
> {},
> @@ -3914,6 +3933,7 @@ static struct i2c_driver ov5640_i2c_driver = {
> .driver = {
> .name = "ov5640",
> .of_match_table = ov5640_dt_ids,
> + .pm = &ov5640_pm_ops,
> },
> .id_table = ov5640_id,
> .probe_new = ov5640_probe,
--
Regards,
Laurent Pinchart
