drm/i915: Clean up legacy palette defines

Use consistent bit definitions for the legacy gamma LUT. We just
define these alongside the pre-ilk register definitions and point
to those from the ilk+ defines.

Also use the these appropriately in the LUT entry pack/unpack
functions.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221114153732.11773-2-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/display/intel_color.c

@@ -425,32 +425,32 @@ static u32 intel_color_lut_pack(u32 val, int bit_precision)
 
 static u32 i9xx_lut_8(const struct drm_color_lut *color)
 {
-	return drm_color_lut_extract(color->red, 8) << 16 |
-		drm_color_lut_extract(color->green, 8) << 8 |
-		drm_color_lut_extract(color->blue, 8);
+	return REG_FIELD_PREP(PALETTE_RED_MASK, drm_color_lut_extract(color->red, 8)) |
+		REG_FIELD_PREP(PALETTE_GREEN_MASK, drm_color_lut_extract(color->green, 8)) |
+		REG_FIELD_PREP(PALETTE_BLUE_MASK, drm_color_lut_extract(color->blue, 8));
 }
 
 static void i9xx_lut_8_pack(struct drm_color_lut *entry, u32 val)
 {
-	entry->red = intel_color_lut_pack(REG_FIELD_GET(LGC_PALETTE_RED_MASK, val), 8);
-	entry->green = intel_color_lut_pack(REG_FIELD_GET(LGC_PALETTE_GREEN_MASK, val), 8);
-	entry->blue = intel_color_lut_pack(REG_FIELD_GET(LGC_PALETTE_BLUE_MASK, val), 8);
+	entry->red = intel_color_lut_pack(REG_FIELD_GET(PALETTE_RED_MASK, val), 8);
+	entry->green = intel_color_lut_pack(REG_FIELD_GET(PALETTE_GREEN_MASK, val), 8);
+	entry->blue = intel_color_lut_pack(REG_FIELD_GET(PALETTE_BLUE_MASK, val), 8);
 }
 
 /* i965+ "10.6" bit interpolated format "even DW" (low 8 bits) */
 static u32 i965_lut_10p6_ldw(const struct drm_color_lut *color)
 {
-	return (color->red & 0xff) << 16 |
-		(color->green & 0xff) << 8 |
-		(color->blue & 0xff);
+	return REG_FIELD_PREP(PALETTE_RED_MASK, color->red & 0xff) |
+		REG_FIELD_PREP(PALETTE_GREEN_MASK, color->green & 0xff) |
+		REG_FIELD_PREP(PALETTE_BLUE_MASK, color->blue & 0xff);
 }
 
 /* i965+ "10.6" interpolated format "odd DW" (high 8 bits) */
 static u32 i965_lut_10p6_udw(const struct drm_color_lut *color)
 {
-	return (color->red >> 8) << 16 |
-		(color->green >> 8) << 8 |
-		(color->blue >> 8);
+	return REG_FIELD_PREP(PALETTE_RED_MASK, color->red >> 8) |
+		REG_FIELD_PREP(PALETTE_GREEN_MASK, color->green >> 8) |
+		REG_FIELD_PREP(PALETTE_BLUE_MASK, color->blue >> 8);
 }
 
 static void i965_lut_10p6_pack(struct drm_color_lut *entry, u32 ldw, u32 udw)

drivers/gpu/drm/i915/i915_reg.h

@@ -1708,6 +1708,7 @@
 #define _PALETTE_A		0xa000
 #define _PALETTE_B		0xa800
 #define _CHV_PALETTE_C		0xc000
+/* 8bit mode / i965+ 10.6 interpolated mode ldw/udw */
 #define   PALETTE_RED_MASK		REG_GENMASK(23, 16)
 #define   PALETTE_GREEN_MASK		REG_GENMASK(15, 8)
 #define   PALETTE_BLUE_MASK		REG_GENMASK(7, 0)
@@ -5306,9 +5307,7 @@
 /* legacy palette */
 #define _LGC_PALETTE_A           0x4a000
 #define _LGC_PALETTE_B           0x4a800
-#define LGC_PALETTE_RED_MASK     REG_GENMASK(23, 16)
-#define LGC_PALETTE_GREEN_MASK   REG_GENMASK(15, 8)
-#define LGC_PALETTE_BLUE_MASK    REG_GENMASK(7, 0)
+/* see PALETTE_* for the bits */
 #define LGC_PALETTE(pipe, i) _MMIO(_PIPE(pipe, _LGC_PALETTE_A, _LGC_PALETTE_B) + (i) * 4)
 
 /* ilk/snb precision palette */