drm: drm_fourcc: add NV15, Q410, Q401 YUV formats

DRM_FORMAT_NV15 is a 2 plane format suitable for linear and 16x16
block-linear memory layouts (DRM_FORMAT_MOD_SAMSUNG_16_16_TILE). The
format is similar to P010 with 4:2:0 sub-sampling but has no padding
between components. Instead, luminance and chrominance samples are
grouped into 4s so that each group is packed into an integer number
of bytes:

YYYY = UVUV = 4 * 10 bits = 40 bits = 5 bytes

The '15' suffix refers to the optimum effective bits per pixel which is
achieved when the total number of luminance samples is a multiple of 8.

Q410 and Q401 are both 3 plane non-subsampled formats with 16 bits per
component, but only 10 bits are used and 6 are padded. 'Q' is chosen
as the first letter to denote 3 plane YUV444, (and is the next letter
along from P which is usually 2 plane).

V2: Updated block_w of NV15 to {4, 2, 0}
V3: Updated commit message to include specific modifier name

NV15:
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Signed-off-by: Ben Davis <ben.davis@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200601162817.18230-1-ben.davis@arm.com

drivers/gpu/drm/drm_fourcc.c

@@ -274,6 +274,18 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		{ .format = DRM_FORMAT_YUV420_10BIT,    .depth = 0,
 		  .num_planes = 1, .cpp = { 0, 0, 0 }, .hsub = 2, .vsub = 2,
 		  .is_yuv = true },
+		{ .format = DRM_FORMAT_NV15,		.depth = 0,
+		  .num_planes = 2, .char_per_block = { 5, 5, 0 },
+		  .block_w = { 4, 2, 0 }, .block_h = { 1, 1, 0 }, .hsub = 2,
+		  .vsub = 2, .is_yuv = true },
+		{ .format = DRM_FORMAT_Q410,		.depth = 0,
+		  .num_planes = 3, .char_per_block = { 2, 2, 2 },
+		  .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 }, .hsub = 0,
+		  .vsub = 0, .is_yuv = true },
+		{ .format = DRM_FORMAT_Q401,		.depth = 0,
+		  .num_planes = 3, .char_per_block = { 2, 2, 2 },
+		  .block_w = { 1, 1, 1 }, .block_h = { 1, 1, 1 }, .hsub = 0,
+		  .vsub = 0, .is_yuv = true },
 	};
 
 	unsigned int i;

include/uapi/drm/drm_fourcc.h

@@ -236,6 +236,12 @@ extern "C" {
 #define DRM_FORMAT_NV61		fourcc_code('N', 'V', '6', '1') /* 2x1 subsampled Cb:Cr plane */
 #define DRM_FORMAT_NV24		fourcc_code('N', 'V', '2', '4') /* non-subsampled Cr:Cb plane */
 #define DRM_FORMAT_NV42		fourcc_code('N', 'V', '4', '2') /* non-subsampled Cb:Cr plane */
+/*
+ * 2 plane YCbCr
+ * index 0 = Y plane, [39:0] Y3:Y2:Y1:Y0 little endian
+ * index 1 = Cr:Cb plane, [39:0] Cr1:Cb1:Cr0:Cb0 little endian
+ */
+#define DRM_FORMAT_NV15		fourcc_code('N', 'V', '1', '5') /* 2x2 subsampled Cr:Cb plane */
 
 /*
  * 2 plane YCbCr MSB aligned
@@ -265,6 +271,22 @@ extern "C" {
  */
 #define DRM_FORMAT_P016		fourcc_code('P', '0', '1', '6') /* 2x2 subsampled Cr:Cb plane 16 bits per channel */
 
+/* 3 plane non-subsampled (444) YCbCr
+ * 16 bits per component, but only 10 bits are used and 6 bits are padded
+ * index 0: Y plane, [15:0] Y:x [10:6] little endian
+ * index 1: Cb plane, [15:0] Cb:x [10:6] little endian
+ * index 2: Cr plane, [15:0] Cr:x [10:6] little endian
+ */
+#define DRM_FORMAT_Q410		fourcc_code('Q', '4', '1', '0')
+
+/* 3 plane non-subsampled (444) YCrCb
+ * 16 bits per component, but only 10 bits are used and 6 bits are padded
+ * index 0: Y plane, [15:0] Y:x [10:6] little endian
+ * index 1: Cr plane, [15:0] Cr:x [10:6] little endian
+ * index 2: Cb plane, [15:0] Cb:x [10:6] little endian
+ */
+#define DRM_FORMAT_Q401		fourcc_code('Q', '4', '0', '1')
+
 /*
  * 3 plane YCbCr
  * index 0: Y plane, [7:0] Y