drm/i915: Extract ilk_csc_convert_ctm()

Start splitting low level nuts and bolts stuff from
ilk_load_csc_matrix(). The goal is to leave only the clear
high level logic in place.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190218193137.22914-6-ville.syrjala@linux.intel.comReviewed-by: Uma Shankar <uma.shankar@intel.com>

drivers/gpu/drm/i915/intel_color.c

@@ -188,41 +188,15 @@ static bool ilk_csc_limited_range(const struct intel_crtc_state *crtc_state)
 		 IS_GEN_RANGE(dev_priv, 9, 10));
 }
 
-static void ilk_load_csc_matrix(const struct intel_crtc_state *crtc_state)
+static void ilk_csc_convert_ctm(const struct intel_crtc_state *crtc_state,
+				u16 coeffs[9])
 {
-	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
-	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
-	bool limited_color_range = ilk_csc_limited_range(crtc_state);
-	enum pipe pipe = crtc->pipe;
-	u16 coeffs[9] = {};
-	int i;
-
-	if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
-	    crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444) {
-		if (INTEL_GEN(dev_priv) >= 11)
-			icl_update_output_csc(crtc, ilk_csc_off_zero,
-					      ilk_csc_coeff_rgb_to_ycbcr,
-					      ilk_csc_postoff_rgb_to_ycbcr);
-		else
-			ilk_update_pipe_csc(crtc, ilk_csc_off_zero,
-					    ilk_csc_coeff_rgb_to_ycbcr,
-					    ilk_csc_postoff_rgb_to_ycbcr);
-
-		I915_WRITE(PIPE_CSC_MODE(pipe), crtc_state->csc_mode);
-		/*
-		 * On pre GEN11 output CSC is not there, so with 1 pipe CSC
-		 * RGB to YUV conversion can be done. No need to go further
-		 */
-		if (INTEL_GEN(dev_priv) < 11)
-			return;
-	}
-
-	if (crtc_state->base.ctm) {
-		struct drm_color_ctm *ctm = crtc_state->base.ctm->data;
+	const struct drm_color_ctm *ctm = crtc_state->base.ctm->data;
 	const u64 *input;
 	u64 temp[9];
+	int i;
 
-		if (limited_color_range)
+	if (ilk_csc_limited_range(crtc_state))
 		input = ctm_mult_by_limited(temp, ctm->matrix);
 	else
 		input = ctm->matrix;
@@ -231,7 +205,7 @@ static void ilk_load_csc_matrix(const struct intel_crtc_state *crtc_state)
 	 * Convert fixed point S31.32 input to format supported by the
 	 * hardware.
 	 */
-		for (i = 0; i < ARRAY_SIZE(coeffs); i++) {
+	for (i = 0; i < 9; i++) {
 		u64 abs_coeff = ((1ULL << 63) - 1) & input[i];
 
 		/*
@@ -240,6 +214,8 @@ static void ilk_load_csc_matrix(const struct intel_crtc_state *crtc_state)
 		 */
 		abs_coeff = clamp_val(abs_coeff, 0, CTM_COEFF_4_0 - 1);
 
+		coeffs[i] = 0;
+
 		/* sign bit */
 		if (CTM_COEFF_NEGATIVE(input[i]))
 			coeffs[i] |= 1 << 15;
@@ -262,6 +238,39 @@ static void ilk_load_csc_matrix(const struct intel_crtc_state *crtc_state)
 			coeffs[i] |= (6 << 12) |
 				ILK_CSC_COEFF_FP(abs_coeff, 7);
 	}
+}
+
+static void ilk_load_csc_matrix(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	bool limited_color_range = ilk_csc_limited_range(crtc_state);
+	enum pipe pipe = crtc->pipe;
+	u16 coeffs[9] = {};
+	int i;
+
+	if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ||
+	    crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444) {
+		if (INTEL_GEN(dev_priv) >= 11)
+			icl_update_output_csc(crtc, ilk_csc_off_zero,
+					      ilk_csc_coeff_rgb_to_ycbcr,
+					      ilk_csc_postoff_rgb_to_ycbcr);
+		else
+			ilk_update_pipe_csc(crtc, ilk_csc_off_zero,
+					    ilk_csc_coeff_rgb_to_ycbcr,
+					    ilk_csc_postoff_rgb_to_ycbcr);
+
+		I915_WRITE(PIPE_CSC_MODE(pipe), crtc_state->csc_mode);
+		/*
+		 * On pre GEN11 output CSC is not there, so with 1 pipe CSC
+		 * RGB to YUV conversion can be done. No need to go further
+		 */
+		if (INTEL_GEN(dev_priv) < 11)
+			return;
+	}
+
+	if (crtc_state->base.ctm) {
+		ilk_csc_convert_ctm(crtc_state, coeffs);
 	} else {
 		/*
 		 * Load an identity matrix if no coefficients are provided.