diff options
Diffstat (limited to 'drivers/gpu/drm/drm_color_mgmt.c')
-rw-r--r-- | drivers/gpu/drm/drm_color_mgmt.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index 07dcf47daafe..d5d34d0c79c7 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -462,3 +462,46 @@ int drm_plane_create_color_properties(struct drm_plane *plane, return 0; } EXPORT_SYMBOL(drm_plane_create_color_properties); + +/** + * drm_color_lut_check - check validity of lookup table + * @lut: property blob containing LUT to check + * @tests: bitmask of tests to run + * + * Helper to check whether a userspace-provided lookup table is valid and + * satisfies hardware requirements. Drivers pass a bitmask indicating which of + * the tests in &drm_color_lut_tests should be performed. + * + * Returns 0 on success, -EINVAL on failure. + */ +int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests) +{ + const struct drm_color_lut *entry; + int i; + + if (!lut || !tests) + return 0; + + entry = lut->data; + for (i = 0; i < drm_color_lut_size(lut); i++) { + if (tests & DRM_COLOR_LUT_EQUAL_CHANNELS) { + if (entry[i].red != entry[i].blue || + entry[i].red != entry[i].green) { + DRM_DEBUG_KMS("All LUT entries must have equal r/g/b\n"); + return -EINVAL; + } + } + + if (i > 0 && tests & DRM_COLOR_LUT_NON_DECREASING) { + if (entry[i].red < entry[i - 1].red || + entry[i].green < entry[i - 1].green || + entry[i].blue < entry[i - 1].blue) { + DRM_DEBUG_KMS("LUT entries must never decrease.\n"); + return -EINVAL; + } + } + } + + return 0; +} +EXPORT_SYMBOL(drm_color_lut_check); |