drm/fourcc: Add packed 10bit YUV 4:2:0 format

Adds a format that is 3 10bit YUV 4:2:0 samples packed into
a 32bit word (with 2 spare bits).

Supported on Broadcom BCM2711 chips.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20211215091739.135042-2-maxime@cerno.tech

drivers/gpu/drm/drm_fourcc.c

@@ -269,6 +269,9 @@ const struct drm_format_info *__drm_format_info(u32 format)
 		  .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_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},
 	};
 
 	unsigned int i;

include/uapi/drm/drm_fourcc.h

@@ -314,6 +314,13 @@ extern "C" {
  */
 #define DRM_FORMAT_P016		fourcc_code('P', '0', '1', '6') /* 2x2 subsampled Cr:Cb plane 16 bits per channel */
 
+/* 2 plane YCbCr420.
+ * 3 10 bit components and 2 padding bits packed into 4 bytes.
+ * index 0 = Y plane, [31:0] x:Y2:Y1:Y0 2:10:10:10 little endian
+ * index 1 = Cr:Cb plane, [63:0] x:Cr2:Cb2:Cr1:x:Cb1:Cr0:Cb0 [2:10:10:10:2:10:10:10] little endian
+ */
+#define DRM_FORMAT_P030		fourcc_code('P', '0', '3', '0') /* 2x2 subsampled Cr:Cb plane 10 bits per channel packed */
+
 /* 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
@@ -854,6 +861,10 @@ drm_fourcc_canonicalize_nvidia_format_mod(__u64 modifier)
  * and UV.  Some SAND-using hardware stores UV in a separate tiled
  * image from Y to reduce the column height, which is not supported
  * with these modifiers.
+ *
+ * The DRM_FORMAT_MOD_BROADCOM_SAND128_COL_HEIGHT modifier is also
+ * supported for DRM_FORMAT_P030 where the columns remain as 128 bytes
+ * wide, but as this is a 10 bpp format that translates to 96 pixels.
  */
 
 #define DRM_FORMAT_MOD_BROADCOM_SAND32_COL_HEIGHT(v) \