AFBC is a proprietary lossless image compression protocol and format. It provides fine-grained random access and minimizes the amount of data transferred between IP blocks. AFBC has several features which may be supported and/or used, which are represented using bits in the modifier. Not all combinations are valid, and different devices or use-cases may support different combinations.

Signed-off-by: Rosen Zhelev rosen.zhelev@arm.com Signed-off-by: Ayan Kumar halder ayan.halder@arm.com Reviewed-by: Brian Starkey brian.starkey@arm.com Reviewed-by: Liviu Dudau liviu.dudau@arm.com Reviewed-by: James (Qian) Wang james.qian.wang@arm.com --- include/uapi/drm/drm_fourcc.h | 83 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+)

diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index e04613d..af7e9ab 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -183,6 +183,7 @@ extern "C" { #define DRM_FORMAT_MOD_VENDOR_QCOM 0x05 #define DRM_FORMAT_MOD_VENDOR_VIVANTE 0x06 #define DRM_FORMAT_MOD_VENDOR_BROADCOM 0x07 +#define DRM_FORMAT_MOD_VENDOR_ARM 0x08 /* add more to the end as needed */

#define DRM_FORMAT_RESERVED ((1ULL << 56) - 1) @@ -405,6 +406,88 @@ extern "C" { */ #define DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED fourcc_mod_code(BROADCOM, 1)

+/* + * Arm Framebuffer Compression (AFBC) modifiers + * + * AFBC is a proprietary lossless image compression protocol and format. + * It provides fine-grained random access and minimizes the amount of data + * transferred between IP blocks. + * + * AFBC has several features which may be supported and/or used, which are + * represented using bits in the modifier. Not all combinations are valid, + * and different devices or use-cases may support different combinations. + */ +#define DRM_FORMAT_MOD_ARM_AFBC(__afbc_mode) fourcc_mod_code(ARM, __afbc_mode) + +/* + * AFBC superblock size + * + * Indicates the superblock size(s) used for the AFBC buffer. The buffer + * size (in pixels) must be aligned to a multiple of the superblock size. + * Four lowest significant bits(LSBs) are reserved for block size. + */ +#define AFBC_FORMAT_MOD_BLOCK_SIZE_MASK 0xf +#define AFBC_FORMAT_MOD_BLOCK_SIZE_16x16 (1ULL) +#define AFBC_FORMAT_MOD_BLOCK_SIZE_32x8 (2ULL) + +/* + * AFBC lossless colorspace transform + * + * Indicates that the buffer makes use of the AFBC lossless colorspace + * transform. + */ +#define AFBC_FORMAT_MOD_YTR (1ULL << 4) + +/* + * AFBC block-split + * + * Indicates that the payload of each superblock is split. The second + * half of the payload is positioned at a predefined offset from the start + * of the superblock payload. + */ +#define AFBC_FORMAT_MOD_SPLIT (1ULL << 5) + +/* + * AFBC sparse layout + * + * This flag indicates that the payload of each superblock must be stored at a + * predefined position relative to the other superblocks in the same AFBC + * buffer. This order is the same order used by the header buffer. In this mode + * each superblock is given the same amount of space as an uncompressed + * superblock of the particular format would require, rounding up to the next + * multiple of 128 bytes in size. + */ +#define AFBC_FORMAT_MOD_SPARSE (1ULL << 6) + +/* + * AFBC copy-block restrict + * + * Buffers with this flag must obey the copy-block restriction. The restriction + * is such that there are no copy-blocks referring across the border of 8x8 + * blocks. For the subsampled data the 8x8 limitation is also subsampled. + */ +#define AFBC_FORMAT_MOD_CBR (1ULL << 7) + +/* + * AFBC tiled layout + * + * The tiled layout groups superblocks in 8x8 or 4x4 tiles, where all + * superblocks inside a tile are stored together in memory. 8x8 tiles are used + * for pixel formats up to and including 32 bpp while 4x4 tiles are used for + * larger bpp formats. The order between the tiles is scan line. + * When the tiled layout is used, the buffer size (in pixels) must be aligned + * to the tile size. + */ +#define AFBC_FORMAT_MOD_TILED (1ULL << 8) + +/* + * AFBC solid color blocks + * + * Indicates that the buffer makes use of solid-color blocks, whereby bandwidth + * can be reduced if a whole superblock is a single color. + */ +#define AFBC_FORMAT_MOD_SC (1ULL << 9) + #if defined(__cplusplus) } #endif -- 2.7.4

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