Re: [PATCH 04/10] drm/fourcc: Add DRM_FORMAT_Y10_LE32

[Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>]

Hi,

On 04/12/2024 11:31, Tomi Valkeinen wrote:
> Add Y10_LE32, a 10 bit greyscale format, with 3 pixels packed into
> 32-bit container.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>   drivers/gpu/drm/drm_fourcc.c  | 4 ++++
>   include/uapi/drm/drm_fourcc.h | 1 +
>   2 files changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index d721d9fdbe98..6048e0a191dc 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -327,6 +327,10 @@ const struct drm_format_info *__drm_format_info(u32 format)
>   		  .num_planes = 2, .char_per_block = { 4, 8, 0 },
>   		  .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 }, .hsub = 2,
>   		  .vsub = 1, .is_yuv = true },
> +		{ .format = DRM_FORMAT_Y10_LE32,        .depth = 0,
> +		  .num_planes = 1, .char_per_block =  { 4, 0, 0 },
> +		  .block_w = { 3, 0, 0 }, .block_h = { 1, 0, 0 }, .hsub = 1,
> +		  .vsub = 1, .is_yuv = true },
>   	};
>   
>   	unsigned int i;
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index f79ee3b93f09..82f255eb3d1b 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -408,6 +408,7 @@ extern "C" {
>   /* Greyscale formats */
>   
>   #define DRM_FORMAT_Y8		fourcc_code('G', 'R', 'E', 'Y')  /* 8-bit Y-only */
> +#define DRM_FORMAT_Y10_LE32	fourcc_code('Y', '1', '0', 'P')  /* [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian */

I realized that V4L2 already has "Y10P" fourcc: V4L2_PIX_FMT_Y10P, which 
is MIPI CSI style packed 10-bit format.

While it's not strictly speaking a problem, maybe it's best to try to 
avoid overlapping fourccs. So... "Y04P"? I'm being a bit inventive here 
=). 0 would be for "10". 4 as in 4 bytes. P for packed.

  Tomi