Re: [PATCH 2/2] media: ov2740: Add support for external clock

[Bingbu Cao <bingbu.cao@linux.intel.com>]

Hans,

On 11/15/23 8:38 PM, Hans de Goede wrote:
> On some ACPI platforms, such as Chromebooks the ACPI methods to
> change the power-state (_PS0 and _PS3) fully take care of powering
> on/off the sensor.
> 
> On other ACPI platforms, such as e.g. various ThinkPad models with
> IPU6 + ov2740 sensor, the sensor driver must control the reset GPIO
> and the sensor's clock itself.
> 
> Add support for having the driver control an optional clock.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/media/i2c/ov2740.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/media/i2c/ov2740.c b/drivers/media/i2c/ov2740.c
> index e5f9569a229d..0a87d0920eb8 100644
> --- a/drivers/media/i2c/ov2740.c
> +++ b/drivers/media/i2c/ov2740.c
> @@ -3,6 +3,7 @@
>  
>  #include <asm/unaligned.h>
>  #include <linux/acpi.h>
> +#include <linux/clk.h>
>  #include <linux/delay.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/i2c.h>
> @@ -336,6 +337,7 @@ struct ov2740 {
>  
>  	/* GPIOs, clocks */
>  	struct gpio_desc *reset_gpio;
> +	struct clk *clk;
>  
>  	/* Current mode */
>  	const struct ov2740_mode *cur_mode;
> @@ -1068,6 +1070,7 @@ static int ov2740_suspend(struct device *dev)
>  	struct ov2740 *ov2740 = to_ov2740(sd);
>  
>  	gpiod_set_value_cansleep(ov2740->reset_gpio, 1);
> +	clk_disable_unprepare(ov2740->clk);
>  	return 0;
>  }
>  
> @@ -1075,6 +1078,11 @@ static int ov2740_resume(struct device *dev)
>  {
>  	struct v4l2_subdev *sd = dev_get_drvdata(dev);
>  	struct ov2740 *ov2740 = to_ov2740(sd);
> +	int ret;
> +
> +	ret = clk_prepare_enable(ov2740->clk);
> +	if (ret)
> +		return ret;
>  
>  	gpiod_set_value_cansleep(ov2740->reset_gpio, 0);
>  	msleep(20);
> @@ -1102,6 +1110,10 @@ static int ov2740_probe(struct i2c_client *client)
>  		return dev_err_probe(dev, PTR_ERR(ov2740->reset_gpio),
>  				     "failed to get reset GPIO\n");
>  
> +	ov2740->clk = devm_clk_get_optional(dev, "clk");
> +	if (IS_ERR(ov2740->clk))
> +		return dev_err_probe(dev, PTR_ERR(ov2740->clk), "failed to get clock\n");
> +

I am not very sure that the 80-char rule is still valid for checkpatch.pl.


>  	v4l2_i2c_subdev_init(&ov2740->sd, client, &ov2740_subdev_ops);
>  	full_power = acpi_dev_state_d0(&client->dev);
>  	if (full_power) {
>

Reviewed-by: Bingbu Cao <bingbu.cao@intel.com>

-- 
Best regards,
Bingbu Cao