Existing LUT precision structure is having only 16 bit precision. This is not enough for upcoming enhanced hardwares and advance usecases like HDR processing. Hence added a new structure with 32 bit precision values. Also added the code, for extracting the same from values passed from userspace.
Signed-off-by: Uma Shankar uma.shankar@intel.com --- drivers/gpu/drm/drm_plane.c | 19 +++++++++++++++++++ include/uapi/drm/drm_mode.h | 15 +++++++++++++++ 2 files changed, 34 insertions(+)
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c index a5d1fc7..e706da6 100644 --- a/drivers/gpu/drm/drm_plane.c +++ b/drivers/gpu/drm/drm_plane.c @@ -426,6 +426,25 @@ void drm_plane_force_disable(struct drm_plane *plane) } EXPORT_SYMBOL(drm_plane_force_disable);
+/* + * Added to accommodate enhanced LUT precision. + * Max LUT precision is 32 bits. + */ +uint32_t drm_color_lut_extract_ext(uint32_t user_input, uint32_t bit_precision) +{ + uint32_t val = user_input; + uint32_t max = 0xffffffff >> (32 - bit_precision); + + /* Round only if we're not using full precision. */ + if (bit_precision < 32) { + val += 1UL << (32 - bit_precision - 1); + val >>= 32 - bit_precision; + } + + return clamp_val(val, 0, max); +} +EXPORT_SYMBOL(drm_color_lut_extract_ext); + /** * drm_mode_plane_set_obj_prop - set the value of a property * @plane: drm plane object to set property value for diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index b5d7d9e..5f3ed88 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -615,6 +615,21 @@ struct drm_color_lut { __u16 reserved; };
+/* + * Creating 32 bit palette entries for better data + * precision. This will be required for HDR and + * similar color processing usecases. + */ +struct drm_color_lut_ext { + /* + * Data is U0.32 fixed point format. + */ + __u32 red; + __u32 green; + __u32 blue; + __u32 reserved; +}; + #define DRM_MODE_PAGE_FLIP_EVENT 0x01 #define DRM_MODE_PAGE_FLIP_ASYNC 0x02 #define DRM_MODE_PAGE_FLIP_TARGET_ABSOLUTE 0x4