Hi Paul,
On Mon, Apr 25, 2022 at 03:10:22PM +0900, Paul Elder wrote:
> Switch to using runtime PM for power management.
>
> Signed-off-by: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> ---
> Changes in v5:
> - fix compilation warning
>
> Changes in v4:
> - replace pm_runtime_put* with pm_runtime_put_autosuspend
> - remove the manual initial call to ov5640_set_power()
>
> Changes in v3:
> - Move v4l2_ctrl_handler_setup() from ov5640_sensor_resume to
> ov5640_s_stream()
>
> 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 | 120 +++++++++++++++++++++----------------
> 2 files changed, 71 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index fae2baabb773..0bd53f8198f1 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -433,6 +433,7 @@ config VIDEO_OV5640
> tristate "OmniVision OV5640 sensor support"
> depends on OF
> depends on GPIOLIB && VIDEO_DEV && 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 db5a19babe67..e8e53e954db0 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>
> @@ -240,8 +241,6 @@ struct ov5640_dev {
> /* lock to protect all members below */
> struct mutex lock;
>
> - int power_count;
> -
> struct v4l2_mbus_framefmt fmt;
> bool pending_fmt_change;
>
> @@ -2157,37 +2156,6 @@ 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)
> @@ -2663,6 +2631,9 @@ 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;
> +
> switch (ctrl->id) {
> case V4L2_CID_AUTOGAIN:
> val = ov5640_get_gain(sensor);
> @@ -2678,6 +2649,8 @@ static int ov5640_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
> break;
> }
>
> + pm_runtime_put_autosuspend(&sensor->i2c_client->dev);
> +
> return 0;
> }
>
> @@ -2692,9 +2665,9 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
> /*
> * If the device is not powered up by the host driver do
> * not apply any controls to H/W at this time. Instead
> - * the controls will be restored right after power-up.
> + * the controls will be restored at start streaming time.
> */
> - if (sensor->power_count == 0)
> + if (!pm_runtime_get_if_in_use(&sensor->i2c_client->dev))
> return 0;
>
> switch (ctrl->id) {
> @@ -2733,6 +2706,8 @@ static int ov5640_s_ctrl(struct v4l2_ctrl *ctrl)
> break;
> }
>
> + pm_runtime_put_autosuspend(&sensor->i2c_client->dev);
> +
> return ret;
> }
>
> @@ -2945,6 +2920,18 @@ 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;
> +
> + ret = v4l2_ctrl_handler_setup(&sensor->ctrls.handler);
> + if (ret) {
> + pm_runtime_put(&sensor->i2c_client->dev);
> + return ret;
> + }
> + }
> +
> mutex_lock(&sensor->lock);
>
> if (sensor->streaming == !enable) {
> @@ -2969,13 +2956,17 @@ 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_autosuspend(&sensor->i2c_client->dev);
> +
> return ret;
> }
>
> 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,
> @@ -3019,26 +3010,20 @@ 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) {
> dev_err(&client->dev, "%s: wrong chip identifier, expected 0x5640, got 0x%x\n",
> __func__, chip_id);
> - ret = -ENXIO;
> + return -ENXIO;
> }
>
> -power_off:
> - ov5640_set_power_off(sensor);
> - return ret;
> + return 0;
> }
>
> static int ov5640_probe(struct i2c_client *client)
> @@ -3158,21 +3143,31 @@ 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);
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> + pm_runtime_get(dev);
You could on DT but the driver but the driver could be used on ACPI systems
as well.
Please see drivers/media/i2c/ccs/ccs-core.c for an example. You'll still
need explicit callbacks powering on and off the sensor in probe and remove.
> +
> + ret = ov5640_check_chip_id(sensor);
> if (ret)
> - goto entity_cleanup;
> + 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;
>
> -free_ctrls:
> +err_pm_runtime:
> + pm_runtime_disable(dev);
> + pm_runtime_put_autosuspend(dev);
> v4l2_ctrl_handler_free(&sensor->ctrls.handler);
> entity_cleanup:
> media_entity_cleanup(&sensor->sd.entity);
> @@ -3184,6 +3179,10 @@ static int ov5640_remove(struct i2c_client *client)
> {
> struct v4l2_subdev *sd = i2c_get_clientdata(client);
> struct ov5640_dev *sensor = to_ov5640_dev(sd);
> + struct device *dev = &client->dev;
> +
> + pm_runtime_disable(dev);
> + pm_runtime_put_autosuspend(dev);
>
> v4l2_async_unregister_subdev(&sensor->sd);
> media_entity_cleanup(&sensor->sd.entity);
> @@ -3193,6 +3192,26 @@ 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);
> +
> + return ov5640_set_power(ov5640, true);
> +}
> +
> +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},
> {},
> @@ -3209,6 +3228,7 @@ 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,
Sakari Ailus
