drm/i915: Split broadwell_load_luts() into smaller functions

Split the logic for progamming each LUT out of broadwell_load_luts(), so
we can reuse part of it for geminilake.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1485429865-10687-4-git-send-email-ander.conselvan.de.oliveira@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -8166,6 +8166,7 @@ enum {
 #define   PAL_PREC_10_12_BIT		(0 << 31)
 #define   PAL_PREC_SPLIT_MODE		(1 << 31)
 #define   PAL_PREC_AUTO_INCREMENT	(1 << 15)
+#define   PAL_PREC_INDEX_VALUE_MASK	(0x3ff << 0)
 #define _PAL_PREC_DATA_A	0x4A404
 #define _PAL_PREC_DATA_B	0x4AC04
 #define _PAL_PREC_DATA_C	0x4B404

drivers/gpu/drm/i915/intel_color.c

@@ -340,20 +340,12 @@ static void haswell_load_luts(struct drm_crtc_state *crtc_state)
 		hsw_enable_ips(intel_crtc);
 }
 
-/* Loads the palette/gamma unit for the CRTC on Broadwell+. */
-static void broadwell_load_luts(struct drm_crtc_state *state)
+static void bdw_load_degamma_lut(struct drm_crtc_state *state)
 {
-	struct drm_crtc *crtc = state->crtc;
-	struct drm_i915_private *dev_priv = to_i915(crtc->dev);
-	struct intel_crtc_state *intel_state = to_intel_crtc_state(state);
-	enum pipe pipe = to_intel_crtc(crtc)->pipe;
+	struct drm_i915_private *dev_priv = to_i915(state->crtc->dev);
+	enum pipe pipe = to_intel_crtc(state->crtc)->pipe;
 	uint32_t i, lut_size = INTEL_INFO(dev_priv)->color.degamma_lut_size;
 
-	if (crtc_state_is_legacy(state)) {
-		haswell_load_luts(state);
-		return;
-	}
-
 	I915_WRITE(PREC_PAL_INDEX(pipe),
 		   PAL_PREC_SPLIT_MODE | PAL_PREC_AUTO_INCREMENT);
 
@@ -377,6 +369,18 @@ static void broadwell_load_luts(struct drm_crtc_state *state)
 				   (v << 20) | (v << 10) | v);
 		}
 	}
+}
+
+static void bdw_load_gamma_lut(struct drm_crtc_state *state, u32 offset)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->crtc->dev);
+	enum pipe pipe = to_intel_crtc(state->crtc)->pipe;
+	uint32_t i, lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
+
+	WARN_ON(offset & ~PAL_PREC_INDEX_VALUE_MASK);
+
+	I915_WRITE(PREC_PAL_INDEX(pipe),
+		   PAL_PREC_SPLIT_MODE | PAL_PREC_AUTO_INCREMENT | offset);
 
 	if (state->gamma_lut) {
 		struct drm_color_lut *lut =
@@ -410,6 +414,23 @@ static void broadwell_load_luts(struct drm_crtc_state *state)
 		I915_WRITE(PREC_PAL_GC_MAX(pipe, 1), (1 << 16) - 1);
 		I915_WRITE(PREC_PAL_GC_MAX(pipe, 2), (1 << 16) - 1);
 	}
+}
+
+/* Loads the palette/gamma unit for the CRTC on Broadwell+. */
+static void broadwell_load_luts(struct drm_crtc_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->crtc->dev);
+	struct intel_crtc_state *intel_state = to_intel_crtc_state(state);
+	enum pipe pipe = to_intel_crtc(state->crtc)->pipe;
+
+	if (crtc_state_is_legacy(state)) {
+		haswell_load_luts(state);
+		return;
+	}
+
+	bdw_load_degamma_lut(state);
+	bdw_load_gamma_lut(state,
+			   INTEL_INFO(dev_priv)->color.degamma_lut_size);
 
 	intel_state->gamma_mode = GAMMA_MODE_MODE_SPLIT;
 	I915_WRITE(GAMMA_MODE(pipe), GAMMA_MODE_MODE_SPLIT);