From: Chaitanya Kumar Borah Date: Sat, 15 Nov 2025 00:02:01 +0000 (-0700) Subject: drm: Add helper to extract lut from struct drm_color_lut32 X-Git-Url: https://gentwo.org/gitweb/?a=commitdiff_plain;h=94529775135c301efff78373310102f47f3c8671;p=linux%2F.git drm: Add helper to extract lut from struct drm_color_lut32 Add helper to extract lut values in 32-bit precision needed by hardware. Signed-off-by: Alex Hung Signed-off-by: Uma Shankar Signed-off-by: Chaitanya Kumar Borah Reviewed-by: Sebastian Wick Signed-off-by: Simon Ser Link: https://patch.msgid.link/20251115000237.3561250-37-alex.hung@amd.com --- diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h index 527582c20885..5140691f476a 100644 --- a/include/drm/drm_color_mgmt.h +++ b/include/drm/drm_color_mgmt.h @@ -50,6 +50,22 @@ static inline u32 drm_color_lut_extract(u32 user_input, int bit_precision) (1 << 16) - 1); } +/** + * drm_color_lut32_extract - clamp and round LUT entries + * @user_input: input value + * @bit_precision: number of bits the hw LUT supports + * + * Extract U0.bit_precision from a U0.32 LUT value. + * + */ +static inline u32 drm_color_lut32_extract(u32 user_input, int bit_precision) +{ + u64 max = (bit_precision >= 64) ? ~0ULL : (1ULL << bit_precision) - 1; + + return DIV_ROUND_CLOSEST_ULL((u64)user_input * max, + (1ULL << 32) - 1); +} + u64 drm_color_ctm_s31_32_to_qm_n(u64 user_input, u32 m, u32 n); void drm_crtc_enable_color_mgmt(struct drm_crtc *crtc,