[1/3] dt-bindings: adv7180: Introduce the 'reset-gpios' property

Introduce the 'reset-gpios' property to describe the GPIO that connects
to the ADV7180 reset pin.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 Documentation/devicetree/bindings/media/i2c/adv7180.yaml | 3 +++
 1 file changed, 3 insertions(+)

On 30.05.21 22:44, Fabio Estevam wrote:
> On a design where the ADV7180 pin is pulled down, it is not possible
> to make it functional unless the GPIO connected to this pin goes
> high.
> 
> Add support for the reset GPIO by introducing an optional property
> called 'reset-gpios'.
> 
> Note: the reset operation is still performed via software as recommended
> by the Analog Devices, but the reset GPIO still needs to go high to make
> the chip operational.
> 
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> ---
>  drivers/media/i2c/adv7180.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/i2c/adv7180.c b/drivers/media/i2c/adv7180.c
> index 44bb6fe85644..2811f2c337fa 100644
> --- a/drivers/media/i2c/adv7180.c
> +++ b/drivers/media/i2c/adv7180.c
> @@ -205,6 +205,7 @@ struct adv7180_state {
>  	struct mutex		mutex; /* mutual excl. when accessing chip */
>  	int			irq;
>  	struct gpio_desc	*pwdn_gpio;
> +	struct gpio_desc	*reset_gpio;
>  	v4l2_std_id		curr_norm;
>  	bool			powered;
>  	bool			streaming;
> @@ -473,13 +474,15 @@ static int adv7180_g_frame_interval(struct v4l2_subdev *sd,
>  
>  static void adv7180_set_power_pin(struct adv7180_state *state, bool on)
>  {
> -	if (!state->pwdn_gpio)
> +	if (!state->pwdn_gpio && !state->reset_gpio)
>  		return;
>  
>  	if (on) {
> +		gpiod_set_value_cansleep(state->reset_gpio, 0);
>  		gpiod_set_value_cansleep(state->pwdn_gpio, 0);

The datasheet specifies a delay of 5 ms between deasserting the PWRDWN and the RESET GPIO. Also this function is named adv7180_set_power_pin() which doesn't fit anymore if we also handle the RESET GPIO here.

As I was recently working with the ADV7280-M, I came up with a similar patch: https://git.kontron-electronics.de/linux/linux/-/commit/3619ed166140a0499ada7b14e5f1846a0ed7d18d.

What do you think?

>  		usleep_range(5000, 10000);
>  	} else {
> +		gpiod_set_value_cansleep(state->reset_gpio, 1);
>  		gpiod_set_value_cansleep(state->pwdn_gpio, 1);
>  	}
>  }
> @@ -1338,6 +1341,15 @@ static int adv7180_probe(struct i2c_client *client,
>  		return ret;
>  	}
>  
> +	state->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
> +						     GPIOD_OUT_HIGH);
> +	if (IS_ERR(state->reset_gpio)) {
> +		ret = PTR_ERR(state->reset_gpio);
> +		v4l_err(client, "request for reset pin failed: %d\n", ret);
> +		return ret;
> +	}
> +
> +
>  	if (state->chip_info->flags & ADV7180_FLAG_MIPI_CSI2) {
>  		state->csi_client = i2c_new_dummy_device(client->adapter,
>  				ADV7180_DEFAULT_CSI_I2C_ADDR);
>

On 30.05.21 22:44, Fabio Estevam wrote:
> Improve the probe message by printing the chip ID version.
> 
> Signed-off-by: Fabio Estevam <festevam@gmail.com>

Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>

> ---
>  drivers/media/i2c/adv7180.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/i2c/adv7180.c b/drivers/media/i2c/adv7180.c
> index 2811f2c337fa..e5ef99f0460c 100644
> --- a/drivers/media/i2c/adv7180.c
> +++ b/drivers/media/i2c/adv7180.c
> @@ -1404,11 +1404,19 @@ static int adv7180_probe(struct i2c_client *client,
>  	if (ret)
>  		goto err_free_irq;
>  
> -	v4l_info(client, "chip found @ 0x%02x (%s)\n",
> -		 client->addr, client->adapter->name);
> +	mutex_lock(&state->mutex);
> +	ret = adv7180_read(state, ADV7180_REG_IDENT);
> +	mutex_unlock(&state->mutex);
> +	if (ret < 0)
> +		goto err_v4l2_async_unregister;
> +
> +	v4l_info(client, "chip id 0x%x found @ 0x%02x (%s)\n",
> +		 ret, client->addr, client->adapter->name);
>  
>  	return 0;
>  
> +err_v4l2_async_unregister:
> +	v4l2_async_unregister_subdev(sd);
>  err_free_irq:
>  	if (state->irq > 0)
>  		free_irq(client->irq, state);
>

Hi Frieder,

On Mon, May 31, 2021 at 4:02 AM Frieder Schrempf
<frieder.schrempf@kontron.de> wrote:

> The datasheet specifies a delay of 5 ms between deasserting the PWRDWN and the RESET GPIO. Also this function is named adv7180_set_power_pin() which doesn't fit anymore if we also handle the RESET GPIO here.
>
> As I was recently working with the ADV7280-M, I came up with a similar patch: https://git.kontron-electronics.de/linux/linux/-/commit/3619ed166140a0499ada7b14e5f1846a0ed7d18d.
>
> What do you think?

Thanks for the review. I will send a v2 using your patch instead of mine.

Thanks,

Fabio Estevam