diff options
| author | Louis Chauvet <louis.chauvet@bootlin.com> | 2024-11-18 19:28:22 +0100 |
|---|---|---|
| committer | Louis Chauvet <louis.chauvet@bootlin.com> | 2024-11-22 14:00:08 +0100 |
| commit | b52fd27356af947f80b0c0855691e42a4c02ee79 (patch) | |
| tree | cc60ad1905089ed5290894f70f9ebc469831419d /drivers/gpu/drm/vkms/vkms_formats.c | |
| parent | cb6de83faa9049bf40e7dc6821d903016bec2337 (diff) | |
drm/vkms: Introduce pixel_read_direction enum
The pixel_read_direction enum is useful to describe the reading direction
in a plane. It avoids using the rotation property of DRM, which not
practical to know the direction of reading.
This patch also introduce two helpers, one to compute the
pixel_read_direction from the DRM rotation property, and one to compute
the step, in byte, between two successive pixel in a specific direction.
Acked-by: Maíra Canal <mairacanal@riseup.net>
Reviewed-by: José Expósito <jose.exposito89@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241118-yuv-v14-7-2dbc2f1e222c@bootlin.com
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
Diffstat (limited to 'drivers/gpu/drm/vkms/vkms_formats.c')
| -rw-r--r-- | drivers/gpu/drm/vkms/vkms_formats.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c index f9045a80aceb..5dad7bcec0a6 100644 --- a/drivers/gpu/drm/vkms/vkms_formats.c +++ b/drivers/gpu/drm/vkms/vkms_formats.c @@ -80,6 +80,38 @@ static void packed_pixels_addr(const struct vkms_frame_info *frame_info, } /** + * get_block_step_bytes() - Common helper to compute the correct step value between each pixel block + * to read in a certain direction. + * + * @fb: Framebuffer to iter on + * @direction: Direction of the reading + * @plane_index: Plane to get the step from + * + * As the returned count is the number of bytes between two consecutive blocks in a direction, + * the caller may have to read multiple pixels before using the next one (for example, to read from + * left to right in a DRM_FORMAT_R1 plane, each block contains 8 pixels, so the step must be used + * only every 8 pixels). + */ +static int get_block_step_bytes(struct drm_framebuffer *fb, enum pixel_read_direction direction, + int plane_index) +{ + switch (direction) { + case READ_LEFT_TO_RIGHT: + return fb->format->char_per_block[plane_index]; + case READ_RIGHT_TO_LEFT: + return -fb->format->char_per_block[plane_index]; + case READ_TOP_TO_BOTTOM: + return (int)fb->pitches[plane_index] * drm_format_info_block_width(fb->format, + plane_index); + case READ_BOTTOM_TO_TOP: + return -(int)fb->pitches[plane_index] * drm_format_info_block_width(fb->format, + plane_index); + } + + return 0; +} + +/** * packed_pixels_addr_1x1() - Get the pointer to the block containing the pixel at the given * coordinates * |