Re: [PATCH v2 1/3] drm: Add some new format DRM_FORMAT_NVXX_10

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Thu, Sep 26, 2019 at 04:24:47PM +0800, Sandy Huang wrote:
> These new format is supported by some rockchip socs:
> 
> DRM_FORMAT_NV12_10/DRM_FORMAT_NV21_10
> DRM_FORMAT_NV16_10/DRM_FORMAT_NV61_10
> DRM_FORMAT_NV24_10/DRM_FORMAT_NV42_10
> 
> Signed-off-by: Sandy Huang <hjc@rock-chips.com>
> ---
>  drivers/gpu/drm/drm_fourcc.c  | 18 ++++++++++++++++++
>  include/uapi/drm/drm_fourcc.h | 14 ++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index c630064..ccd78a3 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -261,6 +261,24 @@ const struct drm_format_info *__drm_format_info(u32 format)
>  		{ .format = DRM_FORMAT_P016,		.depth = 0,  .num_planes = 2,
>  		  .char_per_block = { 2, 4, 0 }, .block_w = { 1, 0, 0 }, .block_h = { 1, 0, 0 },
>  		  .hsub = 2, .vsub = 2, .is_yuv = true},
> +		{ .format = DRM_FORMAT_NV12_10,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 5, 10, 0 }, .block_w = { 4, 4, 0 }, .block_h = { 4, 4, 0 },
> +		  .hsub = 2, .vsub = 2, .is_yuv = true},
> +		{ .format = DRM_FORMAT_NV21_10,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 5, 10, 0 }, .block_w = { 4, 4, 0 }, .block_h = { 4, 4, 0 },
> +		  .hsub = 2, .vsub = 2, .is_yuv = true},
> +		{ .format = DRM_FORMAT_NV16_10,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 5, 10, 0 }, .block_w = { 4, 4, 0 }, .block_h = { 4, 4, 0 },
> +		  .hsub = 2, .vsub = 1, .is_yuv = true},
> +		{ .format = DRM_FORMAT_NV61_10,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 5, 10, 0 }, .block_w = { 4, 4, 0 }, .block_h = { 4, 4, 0 },
> +		  .hsub = 2, .vsub = 1, .is_yuv = true},
> +		{ .format = DRM_FORMAT_NV24_10,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 5, 10, 0 }, .block_w = { 4, 4, 0 }, .block_h = { 4, 4, 0 },
> +		  .hsub = 1, .vsub = 1, .is_yuv = true},
> +		{ .format = DRM_FORMAT_NV42_10,		.depth = 0,  .num_planes = 2,
> +		  .char_per_block = { 5, 10, 0 }, .block_w = { 4, 4, 0 }, .block_h = { 4, 4, 0 },
> +		  .hsub = 1, .vsub = 1, .is_yuv = true},
>  		{ .format = DRM_FORMAT_P210,		.depth = 0,
>  		  .num_planes = 2, .char_per_block = { 2, 4, 0 },
>  		  .block_w = { 1, 0, 0 }, .block_h = { 1, 0, 0 }, .hsub = 2,
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index 3feeaa3..08e2221 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -238,6 +238,20 @@ extern "C" {
>  #define DRM_FORMAT_NV42		fourcc_code('N', 'V', '4', '2') /* non-subsampled Cb:Cr plane */
>  
>  /*
> + * 2 plane YCbCr
> + * index 0 = Y plane, Y3:Y2:Y1:Y0 10:10:10:10
> + * index 1 = Cb:Cr plane, Cb3:Cr3:Cb2:Cr2:Cb1:Cr1:Cb0:Cr0 10:10:10:10:10:10:10:10
> + * or
> + * index 1 = Cr:Cb plane, Cr3:Cb3:Cr2:Cb2:Cr1:Cb1:Cr0:Cb0 10:10:10:10:10:10:10:10

So now you're defining it as some kind of byte aligned block.
With that specifying endianness would now make sense since
otherwise this tells us absolutely nothing about the memory
layout.

So I'd either do that, or go back to not specifying anything and
use some weasel words like "mamory layout is implementation defined"
which of course means no one can use it for anything that involves
any kind of cross vendor stuff.

> + */
> +#define DRM_FORMAT_NV12_10	fourcc_code('N', 'A', '1', '2') /* 2x2 subsampled Cr:Cb plane */
> +#define DRM_FORMAT_NV21_10	fourcc_code('N', 'A', '2', '1') /* 2x2 subsampled Cb:Cr plane */
> +#define DRM_FORMAT_NV16_10	fourcc_code('N', 'A', '1', '6') /* 2x1 subsampled Cr:Cb plane */
> +#define DRM_FORMAT_NV61_10	fourcc_code('N', 'A', '6', '1') /* 2x1 subsampled Cb:Cr plane */
> +#define DRM_FORMAT_NV24_10	fourcc_code('N', 'A', '2', '4') /* non-subsampled Cr:Cb plane */
> +#define DRM_FORMAT_NV42_10	fourcc_code('N', 'A', '4', '2') /* non-subsampled Cb:Cr plane */
> +
> +/*
>   * 2 plane YCbCr MSB aligned
>   * index 0 = Y plane, [15:0] Y:x [10:6] little endian
>   * index 1 = Cr:Cb plane, [31:0] Cr:x:Cb:x [10:6:10:6] little endian
> -- 
> 2.7.4
> 
> 
> 
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-- 
Ville Syrjälä
Intel