| Message ID | 20220215165226.2738568-8-geert@linux-m68k.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: Add support for low-color frame buffer formats | expand |
On Tue, 15 Feb 2022 17:52:25 +0100 Geert Uytterhoeven <geert@linux-m68k.org> wrote: > Introduce fourcc codes for single-channel frame buffer formats with two, > four, and sixteen intensity levels. Traditionally, the first channel > has been called the "red" channel, but the fourcc can also be used for > other light-on-dark displays. > > As the number of bits per pixel is less than eight, these rely on proper > block handling for the calculation of bits per pixel and pitch. > > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> > --- > drivers/gpu/drm/drm_fourcc.c | 6 ++++++ > include/uapi/drm/drm_fourcc.h | 9 +++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c > index 5c77ce10f53e3a64..c12e48ecb1ab8aad 100644 > --- a/drivers/gpu/drm/drm_fourcc.c > +++ b/drivers/gpu/drm/drm_fourcc.c > @@ -151,6 +151,12 @@ const struct drm_format_info *__drm_format_info(u32 format) > { .format = DRM_FORMAT_C4, .depth = 4, .num_planes = 1, > .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, > { .format = DRM_FORMAT_C8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 }, > + { .format = DRM_FORMAT_R1, .depth = 1, .num_planes = 1, > + .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, > + { .format = DRM_FORMAT_R2, .depth = 2, .num_planes = 1, > + .char_per_block = { 1, }, .block_w = { 4, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, > + { .format = DRM_FORMAT_R4, .depth = 4, .num_planes = 1, > + .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, > { .format = DRM_FORMAT_R8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 }, > { .format = DRM_FORMAT_R10, .depth = 10, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > { .format = DRM_FORMAT_R12, .depth = 12, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, > diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h > index 3f09174670b3cce6..8605a1acc6813e6c 100644 > --- a/include/uapi/drm/drm_fourcc.h > +++ b/include/uapi/drm/drm_fourcc.h > @@ -104,6 +104,15 @@ extern "C" { > #define DRM_FORMAT_C4 fourcc_code('C', '4', ' ', ' ') /* [3:0] C */ > #define DRM_FORMAT_C8 fourcc_code('C', '8', ' ', ' ') /* [7:0] C */ > > +/* 1 bpp Red */ > +#define DRM_FORMAT_R1 fourcc_code('R', '1', ' ', ' ') /* [0] R */ > + > +/* 2 bpp Red */ > +#define DRM_FORMAT_R2 fourcc_code('R', '2', ' ', ' ') /* [1:0] R */ > + > +/* 4 bpp Red */ > +#define DRM_FORMAT_R4 fourcc_code('R', '4', ' ', ' ') /* [3:0] R */ > + > /* 8 bpp Red */ > #define DRM_FORMAT_R8 fourcc_code('R', '8', ' ', ' ') /* [7:0] R */ > Hi Geert, I have the same comment here as for C1/C2/C4: these need to specify the ordering inside a byte. Otherwise this reads as one byte of storage per pixel, but using only 1/2/4 bits of each byte. The idea of having Cx and Rx formats separately sounds good to me. Thanks, pq
diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c index 5c77ce10f53e3a64..c12e48ecb1ab8aad 100644 --- a/drivers/gpu/drm/drm_fourcc.c +++ b/drivers/gpu/drm/drm_fourcc.c @@ -151,6 +151,12 @@ const struct drm_format_info *__drm_format_info(u32 format) { .format = DRM_FORMAT_C4, .depth = 4, .num_planes = 1, .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, { .format = DRM_FORMAT_C8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 }, + { .format = DRM_FORMAT_R1, .depth = 1, .num_planes = 1, + .char_per_block = { 1, }, .block_w = { 8, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, + { .format = DRM_FORMAT_R2, .depth = 2, .num_planes = 1, + .char_per_block = { 1, }, .block_w = { 4, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, + { .format = DRM_FORMAT_R4, .depth = 4, .num_planes = 1, + .char_per_block = { 1, }, .block_w = { 2, }, .block_h = { 1, }, .hsub = 1, .vsub = 1 }, { .format = DRM_FORMAT_R8, .depth = 8, .num_planes = 1, .cpp = { 1, 0, 0 }, .hsub = 1, .vsub = 1 }, { .format = DRM_FORMAT_R10, .depth = 10, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, { .format = DRM_FORMAT_R12, .depth = 12, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 }, diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h index 3f09174670b3cce6..8605a1acc6813e6c 100644 --- a/include/uapi/drm/drm_fourcc.h +++ b/include/uapi/drm/drm_fourcc.h @@ -104,6 +104,15 @@ extern "C" { #define DRM_FORMAT_C4 fourcc_code('C', '4', ' ', ' ') /* [3:0] C */ #define DRM_FORMAT_C8 fourcc_code('C', '8', ' ', ' ') /* [7:0] C */ +/* 1 bpp Red */ +#define DRM_FORMAT_R1 fourcc_code('R', '1', ' ', ' ') /* [0] R */ + +/* 2 bpp Red */ +#define DRM_FORMAT_R2 fourcc_code('R', '2', ' ', ' ') /* [1:0] R */ + +/* 4 bpp Red */ +#define DRM_FORMAT_R4 fourcc_code('R', '4', ' ', ' ') /* [3:0] R */ + /* 8 bpp Red */ #define DRM_FORMAT_R8 fourcc_code('R', '8', ' ', ' ') /* [7:0] R */
Introduce fourcc codes for single-channel frame buffer formats with two, four, and sixteen intensity levels. Traditionally, the first channel has been called the "red" channel, but the fourcc can also be used for other light-on-dark displays. As the number of bits per pixel is less than eight, these rely on proper block handling for the calculation of bits per pixel and pitch. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> --- drivers/gpu/drm/drm_fourcc.c | 6 ++++++ include/uapi/drm/drm_fourcc.h | 9 +++++++++ 2 files changed, 15 insertions(+)