Adds R16_UINT and RG1616_UINT DRM formats that represent unsigned integer formats.
Although these formats are not used at this moment, they would need to be exposed in the future for applications that need to use raw formats suitable for camera ISPs
Signed-off-by: Dennis Tsiang dennis.tsiang@arm.com Signed-off-by: Normunds Rieksts normunds.rieksts@arm.com --- include/uapi/drm/drm_fourcc.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index f1972154a594..fdb7d2a76507 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -112,14 +112,16 @@ extern "C" {
/* 16 bpp Red */ #define DRM_FORMAT_R16 fourcc_code('R', '1', '6', ' ') /* [15:0] R little endian */ +#define DRM_FORMAT_R16_UINT fourcc_code('R', '1', '6', 'U') /* [15:0] R little endian, unsigned */
/* 16 bpp RG */ #define DRM_FORMAT_RG88 fourcc_code('R', 'G', '8', '8') /* [15:0] R:G 8:8 little endian */ #define DRM_FORMAT_GR88 fourcc_code('G', 'R', '8', '8') /* [15:0] G:R 8:8 little endian */
/* 32 bpp RG */ -#define DRM_FORMAT_RG1616 fourcc_code('R', 'G', '3', '2') /* [31:0] R:G 16:16 little endian */ -#define DRM_FORMAT_GR1616 fourcc_code('G', 'R', '3', '2') /* [31:0] G:R 16:16 little endian */ +#define DRM_FORMAT_RG1616 fourcc_code('R', 'G', '3', '2') /* [31:0] R:G 16:16 little endian */ +#define DRM_FORMAT_RG1616_UINT fourcc_code('R', 'G', '3', 'U') /* [31:0] R:G 16:16 little endian, unsigned */ +#define DRM_FORMAT_GR1616 fourcc_code('G', 'R', '3', '2') /* [31:0] G:R 16:16 little endian */
/* 8 bpp RGB */ #define DRM_FORMAT_RGB332 fourcc_code('R', 'G', 'B', '8') /* [7:0] R:G:B 3:3:2 */ -- 2.36.1
From: Dennis Tsiang Sent: Monday, June 27, 2022 2:40 PM To: dri-devel@lists.freedesktop.org dri-devel@lists.freedesktop.org Cc: maarten.lankhorst@linux.intel.com maarten.lankhorst@linux.intel.com; mripard@kernel.org mripard@kernel.org; tzimmermann@suse.de tzimmermann@suse.de; airlied@linux.ie airlied@linux.ie; daniel@ffwll.ch daniel@ffwll.ch; sumit.semwal@linaro.org sumit.semwal@linaro.org; christian.koenig@amd.com christian.koenig@amd.com; linux-kernel@vger.kernel.org linux-kernel@vger.kernel.org; linux-media@vger.kernel.org linux-media@vger.kernel.org; linaro-mm-sig@lists.linaro.org linaro-mm-sig@lists.linaro.org; Liviu Dudau Liviu.Dudau@arm.com; Brian Starkey Brian.Starkey@arm.com; Lisa Wu lisa.wu@arm.com; Normunds Rieksts Normunds.Rieksts@arm.com; Dennis Tsiang Dennis.Tsiang@arm.com; nd nd@arm.com Subject: [PATCH 0/1] [RFC] drm/fourcc: Add new unsigned R16_UINT/RG1616_UINT formats
This patch is an early RFC to discuss the viable options and alternatives for inclusion of unsigned integer formats for the DRM API.
This patch adds a new single component 16-bit and a two component 32-bit DRM fourcc’s that represent unsigned integer formats. The use case for needing UINT formats, in our case, would be to support using raw buffers for camera ISPs.
For images imported with DRM fourcc + modifier combination, the GPU driver needs a way to determine the datatype of the format which currently the DRM API does not provide explicitly with a notable exception of the floating-point fourccs such as DRM_FORMAT_XRGB16161616F as an example. As the DRM fourccs do not currently define the interpretation of the data, should the information be made explicit in the DRM API similarly to how it is already done in Vulkan?
The reason for introducing datatype to the DRM fourcc's is that the alternative, for any API (e.g., EGL) that lacks the format datatype information for fourcc/modifier combination for dma_buf interop would be to introduce explicit additional metadata/attributes that encode this information which then would be passed to the GPU driver but the drawback of this is that it would require extending multiple graphics APIs to support every single platform.
By having the DRM API expose the datatype information for formats saves a lot of integration/verification work for all of the different graphics APIs and platforms as this information could be determined by the DRM triple alone for dma_buf interop.
It would be good to gather some opinions on what others think about introducing datatypes to the DRM API.
Any feedback and suggestions are highly appreciated.
Dennis Tsiang (1): [RFC] drm/fourcc: Add new unsigned R16_UINT/RG1616_UINT formats
include/uapi/drm/drm_fourcc.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
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