drm/i915: Extract ilk_color_check()

With everything else moved out of the way only ilk+
remains using _intel_color_check(). Streamline the logic
into ilk_color_check().

v2: Add some comments explaining we that we don't expose
    the full hardware capabilities currently (Matt)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190327155045.28446-9-ville.syrjala@linux.intel.comReviewed-by: Matt Roper <matthew.d.roper@intel.com>

drivers/gpu/drm/i915/intel_color.c

@@ -883,6 +883,38 @@ static int chv_color_check(struct intel_crtc_state *crtc_state)
 	return 0;
 }
 
+static int ilk_color_check(struct intel_crtc_state *crtc_state)
+{
+	int ret;
+
+	ret = check_luts(crtc_state);
+	if (ret)
+		return ret;
+
+	crtc_state->gamma_enable =
+		crtc_state->base.gamma_lut &&
+		!crtc_state->c8_planes;
+
+	/*
+	 * We don't expose the ctm on ilk-hsw currently,
+	 * nor do we enable YCbCr output. Only hsw uses
+	 * the csc for RGB limited range output.
+	 */
+	crtc_state->csc_enable =
+		ilk_csc_limited_range(crtc_state);
+
+	/* We don't expose fancy gamma modes on ilk-hsw currently */
+	crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
+
+	crtc_state->csc_mode = 0;
+
+	ret = intel_color_add_affected_planes(crtc_state);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static u32 bdw_gamma_mode(const struct intel_crtc_state *crtc_state)
 {
 	if (!crtc_state->gamma_enable ||
@@ -1007,48 +1039,6 @@ static int icl_color_check(struct intel_crtc_state *crtc_state)
 	return 0;
 }
 
-static int _intel_color_check(struct intel_crtc_state *crtc_state)
-{
-	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
-	const struct drm_property_blob *gamma_lut = crtc_state->base.gamma_lut;
-	const struct drm_property_blob *degamma_lut = crtc_state->base.degamma_lut;
-	bool limited_color_range = false;
-	int ret;
-
-	ret = check_luts(crtc_state);
-	if (ret)
-		return ret;
-
-	crtc_state->gamma_enable = (gamma_lut || degamma_lut) &&
-		!crtc_state->c8_planes;
-
-	if (INTEL_GEN(dev_priv) >= 9 ||
-	    IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
-		limited_color_range = crtc_state->limited_color_range;
-
-	crtc_state->csc_enable =
-		crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB ||
-		crtc_state->base.ctm || limited_color_range;
-
-	ret = intel_color_add_affected_planes(crtc_state);
-	if (ret)
-		return ret;
-
-	crtc_state->csc_mode = 0;
-
-	if (!crtc_state->gamma_enable ||
-	    crtc_state_is_legacy_gamma(crtc_state))
-		crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
-	else if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
-		crtc_state->gamma_mode = GAMMA_MODE_MODE_10BIT;
-	else if (INTEL_GEN(dev_priv) >= 9 || IS_BROADWELL(dev_priv))
-		crtc_state->gamma_mode = GAMMA_MODE_MODE_SPLIT;
-	else
-		crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
-
-	return 0;
-}
-
 void intel_color_init(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
@@ -1073,7 +1063,7 @@ void intel_color_init(struct intel_crtc *crtc)
 		else if (INTEL_GEN(dev_priv) >= 8)
 			dev_priv->display.color_check = bdw_color_check;
 		else
-			dev_priv->display.color_check = _intel_color_check;
+			dev_priv->display.color_check = ilk_color_check;
 
 		if (INTEL_GEN(dev_priv) >= 9)
 			dev_priv->display.color_commit = skl_color_commit;