[PATCH] drm: drm_fourcc: add 10/12bit software decoder YCbCr formats

[Robert Mader]

This adds FOURCCs for 10/12bit YCbCr formats used by software decoders
like ffmpeg, dav1d and libvpx. The intended use-case is buffer sharing
between SW-decoders and GPUs by allocating buffers with udmabuf or
dma-heaps, avoiding unnecessary copies or format conversions.

Unlike formats typically used by hardware decoders these formats
use a LSB alignment. In order to allow fast implementations in GL
and Vulkan the padding must contain only zeros, so the float
representation can calculated by simple multiplicating with 2^6=64
or 2^4=16.

WIP MRs for Mesa, Vulkan and Gstreamer can be found at:
 - https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34303
 - https://github.com/rmader/Vulkan-Docs/commits/ycbcr-16bit-lsb-formats/
 - https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8540

The values where inspired by the corresponding VA_FOURCC_I010, however
suggestions are very welcome.

Signed-off-by: Robert Mader <robert.mader at collabora.com>
---
 drivers/gpu/drm/drm_fourcc.c  | 18 ++++++++++++++++++
 include/uapi/drm/drm_fourcc.h | 20 ++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
index 3a94ca211f9c..917f77703645 100644
--- a/drivers/gpu/drm/drm_fourcc.c
+++ b/drivers/gpu/drm/drm_fourcc.c
@@ -346,6 +346,24 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_P030,            .depth = 0,  .num_planes = 2,
 		  .char_per_block = { 4, 8, 0 }, .block_w = { 3, 3, 0 }, .block_h = { 1, 1, 0 },
 		  .hsub = 2, .vsub = 2, .is_yuv = true},
+		{ .format = DRM_FORMAT_I010,            .depth = 0,  .num_planes = 3,
+		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
+		  .hsub = 2, .vsub = 2, .is_yuv = true},
+		{ .format = DRM_FORMAT_I210,            .depth = 0,  .num_planes = 3,
+		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
+		  .hsub = 2, .vsub = 1, .is_yuv = true},
+		{ .format = DRM_FORMAT_I410,            .depth = 0,  .num_planes = 3,
+		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
+		  .hsub = 1, .vsub = 1, .is_yuv = true},
+		{ .format = DRM_FORMAT_I012,            .depth = 0,  .num_planes = 3,
+		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
+		  .hsub = 2, .vsub = 2, .is_yuv = true},
+		{ .format = DRM_FORMAT_I212,            .depth = 0,  .num_planes = 3,
+		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
+		  .hsub = 2, .vsub = 1, .is_yuv = true},
+		{ .format = DRM_FORMAT_I412,            .depth = 0,  .num_planes = 3,
+		  .char_per_block = { 2, 2, 2 }, .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 },
+		  .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 e41a3cec6a9e..f22c80031595 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -397,6 +397,26 @@ 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 */
 
+/*
+ * 3 plane YCbCr LSB aligned
+ * index 0 = Y plane, [15:0] x:Y [6:10] little endian
+ * index 1 = Cr plane, [15:0] x:Cr [6:10] little endian
+ * index 2 = Cb plane, [15:0] x:Cb [6:10] little endian
+ */
+#define DRM_FORMAT_I010	fourcc_code('I', '0', '1', '0') /* 2x2 subsampled Cb (1) and Cr (2) planes 10 bits per channel */
+#define DRM_FORMAT_I210	fourcc_code('I', '2', '1', '0') /* 2x1 subsampled Cb (1) and Cr (2) planes 10 bits per channel */
+#define DRM_FORMAT_I410	fourcc_code('I', '4', '1', '0') /* non-subsampled Cb (1) and Cr (2) planes 10 bits per channel */
+
+/*
+ * 3 plane YCbCr LSB aligned
+ * index 0 = Y plane, [15:0] x:Y [4:12] little endian
+ * index 1 = Cr plane, [15:0] x:Cr [4:12] little endian
+ * index 2 = Cb plane, [15:0] x:Cb [4:12] little endian
+ */
+#define DRM_FORMAT_I012	fourcc_code('I', '0', '1', '2') /* 2x2 subsampled Cb (1) and Cr (2) planes 12 bits per channel */
+#define DRM_FORMAT_I212	fourcc_code('I', '2', '1', '2') /* 2x1 subsampled Cb (1) and Cr (2) planes 12 bits per channel */
+#define DRM_FORMAT_I412	fourcc_code('I', '4', '1', '2') /* non-subsampled Cb (1) and Cr (2) planes 12 bits per channel */
+
 
 /*
  * Format Modifiers:
-- 
2.49.0