diff options
Diffstat (limited to 'include/uapi/drm/drm_fourcc.h')
| -rw-r--r-- | include/uapi/drm/drm_fourcc.h | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index 82f327801267..9f7e19c9416c 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -58,6 +58,30 @@ extern "C" { * may preserve meaning - such as number of planes - from the fourcc code, * whereas others may not. * + * Modifiers must uniquely encode buffer layout. In other words, a buffer must + * match only a single modifier. A modifier must not be a subset of layouts of + * another modifier. For instance, it's incorrect to encode pitch alignment in + * a modifier: a buffer may match a 64-pixel aligned modifier and a 32-pixel + * aligned modifier. That said, modifiers can have implicit minimal + * requirements. + * + * For modifiers where the combination of fourcc code and modifier can alias, + * a canonical pair needs to be defined and used by all drivers. Preferred + * combinations are also encouraged where all combinations might lead to + * confusion and unnecessarily reduced interoperability. An example for the + * latter is AFBC, where the ABGR layouts are preferred over ARGB layouts. + * + * There are two kinds of modifier users: + * + * - Kernel and user-space drivers: for drivers it's important that modifiers + * don't alias, otherwise two drivers might support the same format but use + * different aliases, preventing them from sharing buffers in an efficient + * format. + * - Higher-level programs interfacing with KMS/GBM/EGL/Vulkan/etc: these users + * see modifiers as opaque tokens they can check for equality and intersect. + * These users musn't need to know to reason about the modifier value + * (i.e. they are not expected to extract information out of the modifier). + * * Vendors should document their modifier usage in as much detail as * possible, to ensure maximum compatibility across devices, drivers and * applications. @@ -155,6 +179,12 @@ extern "C" { #define DRM_FORMAT_ARGB16161616F fourcc_code('A', 'R', '4', 'H') /* [63:0] A:R:G:B 16:16:16:16 little endian */ #define DRM_FORMAT_ABGR16161616F fourcc_code('A', 'B', '4', 'H') /* [63:0] A:B:G:R 16:16:16:16 little endian */ +/* + * RGBA format with 10-bit components packed in 64-bit per pixel, with 6 bits + * of unused padding per component: + */ +#define DRM_FORMAT_AXBXGXRX106106106106 fourcc_code('A', 'B', '1', '0') /* [63:0] A:x:B:x:G:x:R:x 10:6:10:6:10:6:10:6 little endian */ + /* packed YCbCr */ #define DRM_FORMAT_YUYV fourcc_code('Y', 'U', 'Y', 'V') /* [31:0] Cr0:Y1:Cb0:Y0 8:8:8:8 little endian */ #define DRM_FORMAT_YVYU fourcc_code('Y', 'V', 'Y', 'U') /* [31:0] Cb0:Y1:Cr0:Y0 8:8:8:8 little endian */ @@ -320,7 +350,6 @@ extern "C" { */ /* Vendor Ids: */ -#define DRM_FORMAT_MOD_NONE 0 #define DRM_FORMAT_MOD_VENDOR_NONE 0 #define DRM_FORMAT_MOD_VENDOR_INTEL 0x01 #define DRM_FORMAT_MOD_VENDOR_AMD 0x02 @@ -392,6 +421,16 @@ extern "C" { */ #define DRM_FORMAT_MOD_LINEAR fourcc_mod_code(NONE, 0) +/* + * Deprecated: use DRM_FORMAT_MOD_LINEAR instead + * + * The "none" format modifier doesn't actually mean that the modifier is + * implicit, instead it means that the layout is linear. Whether modifiers are + * used is out-of-band information carried in an API-specific way (e.g. in a + * flag for drm_mode_fb_cmd2). + */ +#define DRM_FORMAT_MOD_NONE 0 + /* Intel framebuffer modifiers */ /* |