[PATCH 1/3] video: Introduce video_sync call

[Simon Glass]

Hi Michal,

On Thu, 3 Dec 2020 at 02:13, Michal Simek <michal.simek at xilinx.com> wrote:
>
> Some drivers like LCD connected via SPI requires explicit sync function
> which copy framebuffer content over SPI to controller to display.
> This hook doesn't exist yet that's why introduce it via video operations.
>
> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
> ---
>
> Simon: Please review this. I didn't find existing way how this can be done
> that's why I am introducing this hook. Also maybe name can be named a
> little bit differently. That's why waiting for better suggestion.
> ---
>  drivers/video/video-uclass.c |  5 +++++
>  include/video.h              | 13 +++++++++++++
>  2 files changed, 18 insertions(+)

> diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
> index 650891e49dd0..ba52a6c7125b 100644
> --- a/drivers/video/video-uclass.c
> +++ b/drivers/video/video-uclass.c
> @@ -174,6 +174,11 @@ void video_set_default_colors(struct udevice *dev, bool invert)
>  /* Flush video activity to the caches */
>  void video_sync(struct udevice *vid, bool force)
>  {
> +       struct video_ops *ops = video_get_ops(vid);
> +
> +       if (ops && ops->video_sync)
> +               (void)ops->video_sync(vid);

We should update video_sync() to return an error.

> +
>         /*
>          * flush_dcache_range() is declared in common.h but it seems that some
>          * architectures do not actually implement it. Is there a way to find
> diff --git a/include/video.h b/include/video.h
> index 9d09d2409af6..acac3f6b3c8d 100644
> --- a/include/video.h
> +++ b/include/video.h
> @@ -115,7 +115,20 @@ struct video_priv {
>  };
>
>  /* Placeholder - there are no video operations at present */

Need to update comment

> +/**
> + * struct video_ops - structure for keeping video operations
> + */
>  struct video_ops {
> +       /**
> +        * video_sync - Synchronize FB with device
> +        *
> +        * Some device like SPI based LCD displays needs synchronization when
> +        * data in an FB is available. For these devices implement video_sync
> +        * hook to call a sync function
> +        *
> +        * @vid:        Video device udevice structure

@return

> +        */
> +       int (*video_sync)(struct udevice *vid);
>  };
>
>  #define video_get_ops(dev)        ((struct video_ops *)(dev)->driver->ops)
> --
> 2.29.2
>

Regards,
Simon