Add greyscale Y8 format.
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
drivers/gpu/drm/drm_fourcc.c | 1 +
include/uapi/drm/drm_fourcc.h | 10 ++++++++++
2 files changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index b22ef86428a1..a39b9d7a5b62 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
{ .format = DRM_FORMAT_YVU422, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
{ .format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
{ .format = DRM_FORMAT_YVU444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
+ { .format = DRM_FORMAT_Y8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
{ .format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
{ .format = DRM_FORMAT_NV21, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
{ .format = DRM_FORMAT_NV16, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index 6c786701238e..5cfc188c4e72 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -459,6 +459,16 @@ extern "C" {
#define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
#define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
+/*
+ * Y-only (greyscale) formats
+ *
+ * The Y-only formats are handled similarly to the YCbCr formats in the display
+ * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
+ * also means that COLOR_RANGE property applies to the Y-only formats.
+ *
+ */
+
+#define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */
/*
* Format Modifiers:
--
2.43.0Hi Tomi,
Thank you for the patch.
On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
> Add greyscale Y8 format.
I would explain here why we need a new format and can't just use
DRM_FORMAT_R8. You don't need to convince me, but I think it's important
to summarize the rationale should someone later wonder why we introduced
this.
> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
> drivers/gpu/drm/drm_fourcc.c | 1 +
> include/uapi/drm/drm_fourcc.h | 10 ++++++++++
> 2 files changed, 11 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index b22ef86428a1..a39b9d7a5b62 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
> { .format = DRM_FORMAT_YVU422, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> { .format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> { .format = DRM_FORMAT_YVU444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> + { .format = DRM_FORMAT_Y8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> { .format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> { .format = DRM_FORMAT_NV21, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> { .format = DRM_FORMAT_NV16, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> index 6c786701238e..5cfc188c4e72 100644
> --- a/include/uapi/drm/drm_fourcc.h
> +++ b/include/uapi/drm/drm_fourcc.h
> @@ -459,6 +459,16 @@ extern "C" {
> #define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
> #define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
>
> +/*
> + * Y-only (greyscale) formats
> + *
> + * The Y-only formats are handled similarly to the YCbCr formats in the display
> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
> + * also means that COLOR_RANGE property applies to the Y-only formats.
> + *
Extra blank line.
> + */
> +
> +#define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */
I would have gone for 'Y', '8', ' ', ' '
>
> /*
> * Format Modifiers:
--
Regards,
Laurent Pinchart
Hi,
On 28/01/2026 13:49, Laurent Pinchart wrote:
> Hi Tomi,
>
> Thank you for the patch.
>
> On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
>> Add greyscale Y8 format.
>
> I would explain here why we need a new format and can't just use
> DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> to summarize the rationale should someone later wonder why we introduced
> this.
>
>> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
>> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>> drivers/gpu/drm/drm_fourcc.c | 1 +
>> include/uapi/drm/drm_fourcc.h | 10 ++++++++++
>> 2 files changed, 11 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
>> index b22ef86428a1..a39b9d7a5b62 100644
>> --- a/drivers/gpu/drm/drm_fourcc.c
>> +++ b/drivers/gpu/drm/drm_fourcc.c
>> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
>> { .format = DRM_FORMAT_YVU422, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>> { .format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> { .format = DRM_FORMAT_YVU444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> + { .format = DRM_FORMAT_Y8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> { .format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>> { .format = DRM_FORMAT_NV21, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>> { .format = DRM_FORMAT_NV16, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
>> index 6c786701238e..5cfc188c4e72 100644
>> --- a/include/uapi/drm/drm_fourcc.h
>> +++ b/include/uapi/drm/drm_fourcc.h
>> @@ -459,6 +459,16 @@ extern "C" {
>> #define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
>> #define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
>>
>> +/*
>> + * Y-only (greyscale) formats
>> + *
>> + * The Y-only formats are handled similarly to the YCbCr formats in the display
>> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
>> + * also means that COLOR_RANGE property applies to the Y-only formats.
>> + *
>
> Extra blank line.
I'll drop.
>> + */
>> +
>> +#define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */
>
> I would have gone for 'Y', '8', ' ', ' '
Missed these comments earlier...
Yes, "Y8 " makes sense. But I was trying to be nice, as there are
already users for Y8 ("GREY") with BSP kernels, and changing the fourcc
code would break their userspace...
Tomi
On Wed, Jan 28, 2026 at 05:38:11PM +0200, Tomi Valkeinen wrote:
> On 28/01/2026 13:49, Laurent Pinchart wrote:
> > On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
> >> Add greyscale Y8 format.
> >
> > I would explain here why we need a new format and can't just use
> > DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> > to summarize the rationale should someone later wonder why we introduced
> > this.
> >
> >> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> >> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> >> ---
> >> drivers/gpu/drm/drm_fourcc.c | 1 +
> >> include/uapi/drm/drm_fourcc.h | 10 ++++++++++
> >> 2 files changed, 11 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> >> index b22ef86428a1..a39b9d7a5b62 100644
> >> --- a/drivers/gpu/drm/drm_fourcc.c
> >> +++ b/drivers/gpu/drm/drm_fourcc.c
> >> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
> >> { .format = DRM_FORMAT_YVU422, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >> { .format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> { .format = DRM_FORMAT_YVU444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> + { .format = DRM_FORMAT_Y8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> { .format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >> { .format = DRM_FORMAT_NV21, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >> { .format = DRM_FORMAT_NV16, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> >> index 6c786701238e..5cfc188c4e72 100644
> >> --- a/include/uapi/drm/drm_fourcc.h
> >> +++ b/include/uapi/drm/drm_fourcc.h
> >> @@ -459,6 +459,16 @@ extern "C" {
> >> #define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
> >> #define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
> >>
> >> +/*
> >> + * Y-only (greyscale) formats
> >> + *
> >> + * The Y-only formats are handled similarly to the YCbCr formats in the display
> >> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
> >> + * also means that COLOR_RANGE property applies to the Y-only formats.
> >> + *
> >
> > Extra blank line.
>
> I'll drop.
>
> >> + */
> >> +
> >> +#define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */
> >
> > I would have gone for 'Y', '8', ' ', ' '
>
> Missed these comments earlier...
>
> Yes, "Y8 " makes sense. But I was trying to be nice, as there are
> already users for Y8 ("GREY") with BSP kernels, and changing the fourcc
> code would break their userspace...
That's a more compeling argument than matching the V4L2 4CC. I have a
slight preference for 'Y8 ' for how it would appear in debug messages,
but I'm also fine being nice :-)
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
--
Regards,
Laurent Pinchart
Hi,
On 28/01/2026 13:49, Laurent Pinchart wrote:
> Hi Tomi,
>
> Thank you for the patch.
>
> On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
>> Add greyscale Y8 format.
>
> I would explain here why we need a new format and can't just use
> DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> to summarize the rationale should someone later wonder why we introduced
> this.
Good point. I can take the text from the cover letter to this commit's
description.
Would this be fine:
==
Add greyscale Y8 format.
The 8-bit greyscale format has been discussed before, and the
earlier guidance was to use DRM_FORMAT_R8, as a single-channel 8-bit pixel.
However, adding DRM_FORMAT_Y8 makes sense, as:
1) We can mark it as 'is_yuv' in the drm_format_info, and this can help
the drivers handle e.g. full/limited range. Probably some hardware
handles grayscale as a value used for all RGB components, in which case
R8 makes sense, but when the hardware handles the Y-only pixels as YCbCr,
where Cb and Cr are "neutral", it makes more sense to consider the
format as an YUV format rather than RGB.
2) We can have the same fourcc as in v4l2. While not strictly necessary,
it's a constant source of confusion when the fourccs differ.
3) It (possibly) makes more sense for the user to use Y8/GREY format
instead of R8, as, in my experience, the documentation usually refers
to gray(scale) format or Y-only format.
4) We have other Y-only formats, like the Y10_P32 added in the following
patches, with "Y" in the fourcc name.
==
Tomi
>> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
>> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
>> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
>> ---
>> drivers/gpu/drm/drm_fourcc.c | 1 +
>> include/uapi/drm/drm_fourcc.h | 10 ++++++++++
>> 2 files changed, 11 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
>> index b22ef86428a1..a39b9d7a5b62 100644
>> --- a/drivers/gpu/drm/drm_fourcc.c
>> +++ b/drivers/gpu/drm/drm_fourcc.c
>> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
>> { .format = DRM_FORMAT_YVU422, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>> { .format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> { .format = DRM_FORMAT_YVU444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> + { .format = DRM_FORMAT_Y8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
>> { .format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>> { .format = DRM_FORMAT_NV21, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
>> { .format = DRM_FORMAT_NV16, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
>> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
>> index 6c786701238e..5cfc188c4e72 100644
>> --- a/include/uapi/drm/drm_fourcc.h
>> +++ b/include/uapi/drm/drm_fourcc.h
>> @@ -459,6 +459,16 @@ extern "C" {
>> #define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
>> #define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
>>
>> +/*
>> + * Y-only (greyscale) formats
>> + *
>> + * The Y-only formats are handled similarly to the YCbCr formats in the display
>> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
>> + * also means that COLOR_RANGE property applies to the Y-only formats.
>> + *
>
> Extra blank line.
>
>> + */
>> +
>> +#define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */
>
> I would have gone for 'Y', '8', ' ', ' '
>
>>
>> /*
>> * Format Modifiers:
>
On Wed, Jan 28, 2026 at 02:31:57PM +0200, Tomi Valkeinen wrote:
> On 28/01/2026 13:49, Laurent Pinchart wrote:
> > On Mon, Dec 01, 2025 at 02:18:45PM +0200, Tomi Valkeinen wrote:
> >> Add greyscale Y8 format.
> >
> > I would explain here why we need a new format and can't just use
> > DRM_FORMAT_R8. You don't need to convince me, but I think it's important
> > to summarize the rationale should someone later wonder why we introduced
> > this.
>
> Good point. I can take the text from the cover letter to this commit's
> description.
>
> Would this be fine:
>
> ==
>
> Add greyscale Y8 format.
>
> The 8-bit greyscale format has been discussed before, and the
> earlier guidance was to use DRM_FORMAT_R8, as a single-channel 8-bit pixel.
>
> However, adding DRM_FORMAT_Y8 makes sense, as:
>
> 1) We can mark it as 'is_yuv' in the drm_format_info, and this can help
> the drivers handle e.g. full/limited range. Probably some hardware
> handles grayscale as a value used for all RGB components, in which case
> R8 makes sense, but when the hardware handles the Y-only pixels as YCbCr,
> where Cb and Cr are "neutral", it makes more sense to consider the
> format as an YUV format rather than RGB.
>
> 2) We can have the same fourcc as in v4l2. While not strictly necessary,
> it's a constant source of confusion when the fourccs differ.
I wouldn't consider that as a goal (see my comment below about the 4CC
value). V4L2 and DRM 4CCs differ, and applications must handle them
separately. Implying we can take shortcuts for a subset of formats will
in my opinion generate more harm than good.
> 3) It (possibly) makes more sense for the user to use Y8/GREY format
> instead of R8, as, in my experience, the documentation usually refers
> to gray(scale) format or Y-only format.
>
> 4) We have other Y-only formats, like the Y10_P32 added in the following
> patches, with "Y" in the fourcc name.
If those two were the only reasons, I'd tell you to use R8 :-) I would
drop 2-4 and only document 1, that's the real reason.
> >> Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.com>
> >> Reviewed-by: Vishal Sagar <vishal.sagar@amd.com>
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> >> ---
> >> drivers/gpu/drm/drm_fourcc.c | 1 +
> >> include/uapi/drm/drm_fourcc.h | 10 ++++++++++
> >> 2 files changed, 11 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> >> index b22ef86428a1..a39b9d7a5b62 100644
> >> --- a/drivers/gpu/drm/drm_fourcc.c
> >> +++ b/drivers/gpu/drm/drm_fourcc.c
> >> @@ -275,6 +275,7 @@ const struct drm_format_info *__drm_format_info(u32 format)
> >> { .format = DRM_FORMAT_YVU422, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >> { .format = DRM_FORMAT_YUV444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> { .format = DRM_FORMAT_YVU444, .depth = 0, .num_planes = 3, .cpp = { 1, 1, 1 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> + { .format = DRM_FORMAT_Y8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1, .is_yuv = true },
> >> { .format = DRM_FORMAT_NV12, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >> { .format = DRM_FORMAT_NV21, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 2, .is_yuv = true },
> >> { .format = DRM_FORMAT_NV16, .depth = 0, .num_planes = 2, .cpp = { 1, 2, 0 }, .hsub = 2, .vsub = 1, .is_yuv = true },
> >> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> >> index 6c786701238e..5cfc188c4e72 100644
> >> --- a/include/uapi/drm/drm_fourcc.h
> >> +++ b/include/uapi/drm/drm_fourcc.h
> >> @@ -459,6 +459,16 @@ extern "C" {
> >> #define DRM_FORMAT_YUV444 fourcc_code('Y', 'U', '2', '4') /* non-subsampled Cb (1) and Cr (2) planes */
> >> #define DRM_FORMAT_YVU444 fourcc_code('Y', 'V', '2', '4') /* non-subsampled Cr (1) and Cb (2) planes */
> >>
> >> +/*
> >> + * Y-only (greyscale) formats
> >> + *
> >> + * The Y-only formats are handled similarly to the YCbCr formats in the display
> >> + * pipeline, with the Cb and Cr implicitly neutral (0.0 in nominal values). This
> >> + * also means that COLOR_RANGE property applies to the Y-only formats.
> >> + *
> >
> > Extra blank line.
> >
> >> + */
> >> +
> >> +#define DRM_FORMAT_Y8 fourcc_code('G', 'R', 'E', 'Y') /* 8-bit Y-only */
> >
> > I would have gone for 'Y', '8', ' ', ' '
> >
> >>
> >> /*
> >> * Format Modifiers:
--
Regards,
Laurent Pinchart
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