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author | Matt Roper <matthew.d.roper@intel.com> | 2018-12-17 14:44:14 -0800 |
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committer | Matt Roper <matthew.d.roper@intel.com> | 2019-01-23 16:29:32 -0800 |
commit | 3c8861d84a4d2c6cd7221d18e49bf9201c6c6115 (patch) | |
tree | 0325843f3a148f53e299e505073fa280c9f9aa9b /include/drm/drm_color_mgmt.h | |
parent | 6e062b60b0b1bd82cac475e63cdb8c451647182b (diff) | |
download | linux-stable-3c8861d84a4d2c6cd7221d18e49bf9201c6c6115.tar.gz linux-stable-3c8861d84a4d2c6cd7221d18e49bf9201c6c6115.tar.bz2 linux-stable-3c8861d84a4d2c6cd7221d18e49bf9201c6c6115.zip |
drm: Add color management LUT validation helper (v4)
Some hardware may place additional restrictions on the gamma/degamma
curves described by our LUT properties. E.g., that a gamma curve never
decreases or that the red/green/blue channels of a LUT's entries must be
equal. Let's add a helper function that drivers can use to test that a
userspace-provided LUT is valid and doesn't violate hardware
requirements.
v2:
- Combine into a single helper that just takes a bitmask of the tests
to apply. (Brian Starkey)
- Add additional check (always performed) that LUT property blob size
is always a multiple of the LUT entry size. (stolen from ARM driver)
v3:
- Drop the LUT size check again since
drm_atomic_replace_property_blob_from_id() already covers this for
us. (Alexandru Gheorghe)
v4:
- Use an enum to describe possible test values rather than #define's;
this is cleaner to provide kerneldoc for. (Daniel Vetter)
- s/DRM_COLOR_LUT_INCREASING/DRM_COLOR_LUT_NON_DECREASING/. (Ville)
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Swati Sharma <swati2.sharma@intel.com>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Brian Starkey <brian.starkey@arm.com>
Reviewed-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20181217224415.12848-1-matthew.d.roper@intel.com
Diffstat (limited to 'include/drm/drm_color_mgmt.h')
-rw-r--r-- | include/drm/drm_color_mgmt.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h index 90ef9996d9a4..6affbda6d9cb 100644 --- a/include/drm/drm_color_mgmt.h +++ b/include/drm/drm_color_mgmt.h @@ -69,4 +69,33 @@ int drm_plane_create_color_properties(struct drm_plane *plane, u32 supported_ranges, enum drm_color_encoding default_encoding, enum drm_color_range default_range); + +/** + * enum drm_color_lut_tests - hw-specific LUT tests to perform + * + * The drm_color_lut_check() function takes a bitmask of the values here to + * determine which tests to apply to a userspace-provided LUT. + */ +enum drm_color_lut_tests { + /** + * @DRM_COLOR_LUT_EQUAL_CHANNELS: + * + * Checks whether the entries of a LUT all have equal values for the + * red, green, and blue channels. Intended for hardware that only + * accepts a single value per LUT entry and assumes that value applies + * to all three color components. + */ + DRM_COLOR_LUT_EQUAL_CHANNELS = BIT(0), + + /** + * @DRM_COLOR_LUT_NON_DECREASING: + * + * Checks whether the entries of a LUT are always flat or increasing + * (never decreasing). + */ + DRM_COLOR_LUT_NON_DECREASING = BIT(1), +}; + +int drm_color_lut_check(struct drm_property_blob *lut, + uint32_t tests); #endif |