drm/komeda: Add drm_lut_to_fgamma_coeffs()

This function is used to convert drm color lut to komeda HW required curve
coeffs values.
Signed-off-by: james qian wang (Arm Technology China) <james.qian.wang@arm.com>
Reviewed-by: Mihail Atanassov <mihail.atanassov@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191112110927.20931-3-james.qian.wang@arm.com

drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c

@@ -65,3 +65,55 @@ const s32 *komeda_select_yuv2rgb_coeffs(u32 color_encoding, u32 color_range)
 
 	return coeffs;
 }
+
+struct gamma_curve_sector {
+	u32 boundary_start;
+	u32 num_of_segments;
+	u32 segment_width;
+};
+
+struct gamma_curve_segment {
+	u32 start;
+	u32 end;
+};
+
+static struct gamma_curve_sector sector_tbl[] = {
+	{ 0,    4,  4   },
+	{ 16,   4,  4   },
+	{ 32,   4,  8   },
+	{ 64,   4,  16  },
+	{ 128,  4,  32  },
+	{ 256,  4,  64  },
+	{ 512,  16, 32  },
+	{ 1024, 24, 128 },
+};
+
+static void
+drm_lut_to_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs,
+		  struct gamma_curve_sector *sector_tbl, u32 num_sectors)
+{
+	struct drm_color_lut *lut;
+	u32 i, j, in, num = 0;
+
+	if (!lut_blob)
+		return;
+
+	lut = lut_blob->data;
+
+	for (i = 0; i < num_sectors; i++) {
+		for (j = 0; j < sector_tbl[i].num_of_segments; j++) {
+			in = sector_tbl[i].boundary_start +
+			     j * sector_tbl[i].segment_width;
+
+			coeffs[num++] = drm_color_lut_extract(lut[in].red,
+						KOMEDA_COLOR_PRECISION);
+		}
+	}
+
+	coeffs[num] = BIT(KOMEDA_COLOR_PRECISION);
+}
+
+void drm_lut_to_fgamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs)
+{
+	drm_lut_to_coeffs(lut_blob, coeffs, sector_tbl, ARRAY_SIZE(sector_tbl));
+}

drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h

@@ -11,7 +11,14 @@
 #include <drm/drm_color_mgmt.h>
 
 #define KOMEDA_N_YUV2RGB_COEFFS		12
+#define KOMEDA_N_RGB2YUV_COEFFS		12
+#define KOMEDA_COLOR_PRECISION		12
+#define KOMEDA_N_GAMMA_COEFFS		65
+#define KOMEDA_COLOR_LUT_SIZE		BIT(KOMEDA_COLOR_PRECISION)
+#define KOMEDA_N_CTM_COEFFS		9
+
+void drm_lut_to_fgamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs);
 
 const s32 *komeda_select_yuv2rgb_coeffs(u32 color_encoding, u32 color_range);
 
-#endif
+#endif /*_KOMEDA_COLOR_MGMT_H_*/