Re: [PATCH v5 3/3] media: ov7670: Add the s_power operation

From: Sakari Ailus
Date: Tue Sep 19 2017 - 03:36:52 EST


Hi Wenyou,

On Tue, Sep 19, 2017 at 08:45:09AM +0800, Wenyou Yang wrote:
> Add the s_power operation which is responsible for manipulating the
> power dowm mode through the PWDN pin and the reset operation through
> the RESET pin.

This is still broken: accessing controls through the sub-device node won't
work when the device is powered off. The options are what I suggested the
previous time: keep it powered at all times, fix it or convert to runtime
PM.

>
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxxxxxx>
> ---
>
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2:
> - Add the patch to support the get_fmt ops.
> - Remove the redundant invoking ov7670_init_gpio().
>
> drivers/media/i2c/ov7670.c | 32 +++++++++++++++++++++++++++-----
> 1 file changed, 27 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
> index 73ceec63a8ca..8e86479d8a24 100644
> --- a/drivers/media/i2c/ov7670.c
> +++ b/drivers/media/i2c/ov7670.c
> @@ -1544,6 +1544,22 @@ static int ov7670_s_register(struct v4l2_subdev *sd, const struct v4l2_dbg_regis
> }
> #endif
>
> +static int ov7670_s_power(struct v4l2_subdev *sd, int on)
> +{
> + struct ov7670_info *info = to_state(sd);
> +
> + if (info->pwdn_gpio)
> + gpiod_direction_output(info->pwdn_gpio, !on);
> + if (on && info->resetb_gpio) {
> + gpiod_set_value(info->resetb_gpio, 1);
> + usleep_range(500, 1000);
> + gpiod_set_value(info->resetb_gpio, 0);
> + usleep_range(3000, 5000);
> + }
> +
> + return 0;
> +}
> +
> static void ov7670_get_default_format(struct v4l2_subdev *sd,
> struct v4l2_mbus_framefmt *format)
> {
> @@ -1577,6 +1593,7 @@ static const struct v4l2_subdev_core_ops ov7670_core_ops = {
> .g_register = ov7670_g_register,
> .s_register = ov7670_s_register,
> #endif
> + .s_power = ov7670_s_power,
> };
>
> static const struct v4l2_subdev_video_ops ov7670_video_ops = {
> @@ -1694,23 +1711,25 @@ static int ov7670_probe(struct i2c_client *client,
> if (ret)
> return ret;
>
> - ret = ov7670_init_gpio(client, info);
> - if (ret)
> - goto clk_disable;
> -
> info->clock_speed = clk_get_rate(info->clk) / 1000000;
> if (info->clock_speed < 10 || info->clock_speed > 48) {
> ret = -EINVAL;
> goto clk_disable;
> }
>
> + ret = ov7670_init_gpio(client, info);
> + if (ret)
> + goto clk_disable;
> +
> + ov7670_s_power(sd, 1);
> +
> /* Make sure it's an ov7670 */
> ret = ov7670_detect(sd);
> if (ret) {
> v4l_dbg(1, debug, client,
> "chip found @ 0x%x (%s) is not an ov7670 chip.\n",
> client->addr << 1, client->adapter->name);
> - goto clk_disable;
> + goto power_off;
> }
> v4l_info(client, "chip found @ 0x%02x (%s)\n",
> client->addr << 1, client->adapter->name);
> @@ -1789,6 +1808,8 @@ static int ov7670_probe(struct i2c_client *client,
> #endif
> hdl_free:
> v4l2_ctrl_handler_free(&info->hdl);
> +power_off:
> + ov7670_s_power(sd, 0);
> clk_disable:
> clk_disable_unprepare(info->clk);
> return ret;
> @@ -1806,6 +1827,7 @@ static int ov7670_remove(struct i2c_client *client)
> #if defined(CONFIG_MEDIA_CONTROLLER)
> media_entity_cleanup(&info->sd.entity);
> #endif
> + ov7670_s_power(sd, 0);
> return 0;
> }
>
> --
> 2.13.0
>

--
Regards,

Sakari Ailus
e-mail: sakari.ailus@xxxxxx