Re: [PATCH v3 2/4] rcar-vin: Add control for alpha component

[Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>]

Hi Niklas,

On 04/07/2019 02:58, Niklas Söderlund wrote:
> In preparation to adding support for RGB pixel formats with an alpha
> component add a control to allow the user to control which alpha value
> should be used.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Comment/Question below, but:

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>



> ---
>  drivers/media/platform/rcar-vin/rcar-core.c | 53 ++++++++++++++++++++-
>  drivers/media/platform/rcar-vin/rcar-dma.c  |  5 ++
>  drivers/media/platform/rcar-vin/rcar-vin.h  |  5 ++
>  3 files changed, 61 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
> index 64f9cf790445d14e..ee6e6cb39c749675 100644
> --- a/drivers/media/platform/rcar-vin/rcar-core.c
> +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> @@ -389,6 +389,28 @@ static void rvin_group_put(struct rvin_dev *vin)
>  	kref_put(&group->refcount, rvin_group_release);
>  }
>  
> +/* -----------------------------------------------------------------------------
> + * Controls
> + */
> +
> +static int rvin_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct rvin_dev *vin =
> +		container_of(ctrl->handler, struct rvin_dev, ctrl_handler);
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_ALPHA_COMPONENT:
> +		rvin_set_alpha(vin, ctrl->val);
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ctrl_ops rvin_ctrl_ops = {
> +	.s_ctrl = rvin_s_ctrl,
> +};
> +
>  /* -----------------------------------------------------------------------------
>   * Async notifier
>   */
> @@ -478,6 +500,15 @@ static int rvin_parallel_subdevice_attach(struct rvin_dev *vin,
>  	if (ret < 0)
>  		return ret;
>  
> +	v4l2_ctrl_new_std(&vin->ctrl_handler, &rvin_ctrl_ops,
> +			  V4L2_CID_ALPHA_COMPONENT, 0, 255, 1, 255);
> +
> +	if (vin->ctrl_handler.error) {
> +		ret = vin->ctrl_handler.error;
> +		v4l2_ctrl_handler_free(&vin->ctrl_handler);
> +		return ret;
> +	}
> +
>  	ret = v4l2_ctrl_add_handler(&vin->ctrl_handler, subdev->ctrl_handler,
>  				    NULL, true);
>  	if (ret < 0) {
> @@ -870,6 +901,21 @@ static int rvin_mc_init(struct rvin_dev *vin)
>  	if (ret)
>  		rvin_group_put(vin);
>  
> +	ret = v4l2_ctrl_handler_init(&vin->ctrl_handler, 1);
> +	if (ret < 0)
> +		return ret;
> +
> +	v4l2_ctrl_new_std(&vin->ctrl_handler, &rvin_ctrl_ops,
> +			  V4L2_CID_ALPHA_COMPONENT, 0, 255, 1, 255);
> +
> +	if (vin->ctrl_handler.error) {
> +		ret = vin->ctrl_handler.error;
> +		v4l2_ctrl_handler_free(&vin->ctrl_handler);
> +		return ret;
> +	}
> +
> +	vin->vdev.ctrl_handler = &vin->ctrl_handler;

There's quite a few lines duplicated between rvin_mc_init() and
rvin_parallel_subdevice_attach() to instantiate the controls. Could that
code be shared in a single function, which would make it easier to
extend with new controls?

Perhaps no other controls are expected though.

Anyway, that's not so crucial - so RB tag added above.



> +
>  	return ret;
>  }
>  
> @@ -1245,6 +1291,7 @@ static int rcar_vin_probe(struct platform_device *pdev)
>  
>  	vin->dev = &pdev->dev;
>  	vin->info = of_device_get_match_data(&pdev->dev);
> +	vin->alpha = 0xff;
>  
>  	/*
>  	 * Special care is needed on r8a7795 ES1.x since it
> @@ -1288,6 +1335,8 @@ static int rcar_vin_probe(struct platform_device *pdev)
>  	return 0;
>  
>  error_group_unregister:
> +	v4l2_ctrl_handler_free(&vin->ctrl_handler);
> +
>  	if (vin->info->use_mc) {
>  		mutex_lock(&vin->group->lock);
>  		if (&vin->v4l2_dev == vin->group->notifier.v4l2_dev) {
> @@ -1323,10 +1372,10 @@ static int rcar_vin_remove(struct platform_device *pdev)
>  		}
>  		mutex_unlock(&vin->group->lock);
>  		rvin_group_put(vin);
> -	} else {
> -		v4l2_ctrl_handler_free(&vin->ctrl_handler);
>  	}
>  
> +	v4l2_ctrl_handler_free(&vin->ctrl_handler);
> +
>  	rvin_dma_unregister(vin);
>  
>  	return 0;
> diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
> index 2d146ecf93d66ad5..4e991cce5fb56a90 100644
> --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> @@ -1343,3 +1343,8 @@ int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel)
>  
>  	return 0;
>  }
> +
> +void rvin_set_alpha(struct rvin_dev *vin, unsigned int alpha)
> +{
> +	vin->alpha = alpha;
> +}
> diff --git a/drivers/media/platform/rcar-vin/rcar-vin.h b/drivers/media/platform/rcar-vin/rcar-vin.h
> index 0b13b34d03e3dce4..365dfde06ec25add 100644
> --- a/drivers/media/platform/rcar-vin/rcar-vin.h
> +++ b/drivers/media/platform/rcar-vin/rcar-vin.h
> @@ -178,6 +178,8 @@ struct rvin_info {
>   * @compose:		active composing
>   * @source:		active size of the video source
>   * @std:		active video standard of the video source
> + *
> + * @alpha:		Alpha component to fill in for supported pixel formats
>   */
>  struct rvin_dev {
>  	struct device *dev;
> @@ -215,6 +217,8 @@ struct rvin_dev {
>  	struct v4l2_rect compose;
>  	struct v4l2_rect source;
>  	v4l2_std_id std;
> +
> +	unsigned int alpha;
>  };
>  
>  #define vin_to_source(vin)		((vin)->parallel->subdev)
> @@ -266,5 +270,6 @@ const struct rvin_video_format *rvin_format_from_pixel(u32 pixelformat);
>  void rvin_crop_scale_comp(struct rvin_dev *vin);
>  
>  int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel);
> +void rvin_set_alpha(struct rvin_dev *vin, unsigned int alpha);
>  
>  #endif
>