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.
Signed-off-by: Uma Shankar <uma.shankar@xxxxxxxxx>
Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@xxxxxxxxx>
---
include/drm/drm_color_mgmt.h | 23 +++++++++++++++++++++++
include/uapi/drm/drm_mode.h | 17 +++++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h
index ed81741036d7..72a08b5f7d14 100644
--- a/include/drm/drm_color_mgmt.h
+++ b/include/drm/drm_color_mgmt.h
@@ -50,6 +50,29 @@ static inline u32 drm_color_lut_extract(u32 user_input, int bit_precision)
(1 << 16) - 1);
}
+/* TODO: Add uapi documentation
+ * Added to accommodate enhanced LUT precision.
+ * Max LUT precision is 32 bits.
+ */
+static inline u64 drm_color_lut_extract_ext(u64 user_input, u32 bit_precision)
+{
+ u64 val = user_input & 0xffffffff;
+ u32 max;
+
+ if (bit_precision > 32)
+ return 0;
+
+ 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 ((user_input & 0xffffffff00000000) |
+ clamp_val(val, 0, max));
+}
+
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,
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index 68696253867e..bbc5be97c80f 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -866,6 +866,23 @@ struct drm_color_lut {
__u16 reserved;
};
+/**
+ * struct drm_color_lut_ext - Represents high precision lut values
+ *
+ * Creating 64 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 U32.32 fixed point format.
+ */
+ __u64 red;
+ __u64 green;
+ __u64 blue;
+ __u64 reserved;
+};
+
enum drm_colorop_type {
DRM_COLOROP_1D_CURVE,
DRM_COLOROP_CTM_3X3,
--
2.42.0
