media: Add NV12_4L4 tiled format

This format is produced by VeriSilicon Hantro G2 and VC8000D cores.
It is a simple 4x4 tiling layout in a linear way.

The pixel format was introduced by GStreamer using FourCC VT12,
so let's stick to it.

Link: https://gstreamer.freedesktop.org/documentation/video/video-format.htmlSigned-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst

@@ -254,6 +254,7 @@ of the luma plane.
 
 .. _V4L2-PIX-FMT-NV12MT:
 .. _V4L2-PIX-FMT-NV12MT-16X16:
+.. _V4L2-PIX-FMT-NV12-4L4:
 .. _V4L2-PIX-FMT-NV12-16L16:
 .. _V4L2-PIX-FMT-NV12-32L32:
 
@@ -279,6 +280,11 @@ If the vertical resolution is an odd number of macroblocks, the last row of
 macroblocks is stored in linear order. The layouts of the luma and chroma
 planes are identical.
 
+``V4L2_PIX_FMT_NV12_4L4`` stores pixel in 4x4 tiles, and stores
+tiles linearly in memory. The line stride and image height must be
+aligned to a multiple of 4. The layouts of the luma and chroma planes are
+identical.
+
 ``V4L2_PIX_FMT_NV12_16L16`` stores pixel in 16x16 tiles, and stores
 tiles linearly in memory. The line stride and image height must be
 aligned to a multiple of 16. The layouts of the luma and chroma planes are

drivers/media/v4l2-core/v4l2-common.c

@@ -275,6 +275,9 @@ const struct v4l2_format_info *v4l2_format_info(u32 format)
 		{ .format = V4L2_PIX_FMT_YUV422P, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 3, .bpp = { 1, 1, 1, 0 }, .hdiv = 2, .vdiv = 1 },
 		{ .format = V4L2_PIX_FMT_GREY,    .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 1, .bpp = { 1, 0, 0, 0 }, .hdiv = 1, .vdiv = 1 },
 
+		/* Tiled YUV formats */
+		{ .format = V4L2_PIX_FMT_NV12_4L4, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 1, .comp_planes = 2, .bpp = { 1, 2, 0, 0 }, .hdiv = 2, .vdiv = 2 },
+
 		/* YUV planar formats, non contiguous variant */
 		{ .format = V4L2_PIX_FMT_YUV420M, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 3, .comp_planes = 3, .bpp = { 1, 1, 1, 0 }, .hdiv = 2, .vdiv = 2 },
 		{ .format = V4L2_PIX_FMT_YVU420M, .pixel_enc = V4L2_PIXEL_ENC_YUV, .mem_planes = 3, .comp_planes = 3, .bpp = { 1, 1, 1, 0 }, .hdiv = 2, .vdiv = 2 },

drivers/media/v4l2-core/v4l2-ioctl.c

@@ -1281,6 +1281,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 	case V4L2_PIX_FMT_NV61:		descr = "Y/CrCb 4:2:2"; break;
 	case V4L2_PIX_FMT_NV24:		descr = "Y/CbCr 4:4:4"; break;
 	case V4L2_PIX_FMT_NV42:		descr = "Y/CrCb 4:4:4"; break;
+	case V4L2_PIX_FMT_NV12_4L4:	descr = "Y/CbCr 4:2:0 (4x4 Linear)"; break;
 	case V4L2_PIX_FMT_NV12_16L16:	descr = "Y/CbCr 4:2:0 (16x16 Linear)"; break;
 	case V4L2_PIX_FMT_NV12_32L32:   descr = "Y/CbCr 4:2:0 (32x32 Linear)"; break;
 	case V4L2_PIX_FMT_NV12M:	descr = "Y/CbCr 4:2:0 (N-C)"; break;

include/uapi/linux/videodev2.h

@@ -627,6 +627,7 @@ struct v4l2_pix_format {
 #define V4L2_PIX_FMT_YVU444M v4l2_fourcc('Y', 'M', '4', '2') /* 24  YVU444 planar */
 
 /* Tiled YUV formats */
+#define V4L2_PIX_FMT_NV12_4L4 v4l2_fourcc('V', 'T', '1', '2')   /* 12  Y/CbCr 4:2:0  4x4 tiles */
 #define V4L2_PIX_FMT_NV12_16L16 v4l2_fourcc('H', 'M', '1', '2') /* 12  Y/CbCr 4:2:0 16x16 tiles */
 #define V4L2_PIX_FMT_NV12_32L32 v4l2_fourcc('S', 'T', '1', '2') /* 12  Y/CbCr 4:2:0 32x32 tiles */