drm/i915: Precompute/readout/check CHV CGM mode

Let's precompute the CGM mode for CHV. And naturally we
also read it out and check it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190218193137.22914-3-ville.syrjala@linux.intel.comReviewed-by: Uma Shankar <uma.shankar@intel.com>

drivers/gpu/drm/i915/intel_color.c

@@ -294,7 +294,6 @@ static void cherryview_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);
 	enum pipe pipe = crtc->pipe;
-	u32 mode;
 
 	if (crtc_state->base.ctm) {
 		const struct drm_color_ctm *ctm = crtc_state->base.ctm->data;
@@ -328,12 +327,7 @@ static void cherryview_load_csc_matrix(const struct intel_crtc_state *crtc_state
 		I915_WRITE(CGM_PIPE_CSC_COEFF8(pipe), coeffs[8]);
 	}
 
-	mode = (crtc_state->base.ctm ? CGM_PIPE_MODE_CSC : 0);
-	if (!crtc_state_is_legacy_gamma(crtc_state)) {
-		mode |= (crtc_state->base.degamma_lut ? CGM_PIPE_MODE_DEGAMMA : 0) |
-			(crtc_state->base.gamma_lut ? CGM_PIPE_MODE_GAMMA : 0);
-	}
-	I915_WRITE(CGM_PIPE_MODE(pipe), mode);
+	I915_WRITE(CGM_PIPE_MODE(pipe), crtc_state->cgm_mode);
 }
 
 /* Loads the legacy palette/gamma unit for the CRTC. */
@@ -753,6 +747,23 @@ static int check_lut_size(const struct drm_property_blob *lut, int expected)
 	return 0;
 }
 
+static u32 chv_cgm_mode(const struct intel_crtc_state *crtc_state)
+{
+	u32 cgm_mode = 0;
+
+	if (crtc_state_is_legacy_gamma(crtc_state))
+		return 0;
+
+	if (crtc_state->base.degamma_lut)
+		cgm_mode |= CGM_PIPE_MODE_DEGAMMA;
+	if (crtc_state->base.ctm)
+		cgm_mode |= CGM_PIPE_MODE_CSC;
+	if (crtc_state->base.gamma_lut)
+		cgm_mode |= CGM_PIPE_MODE_GAMMA;
+
+	return cgm_mode;
+}
+
 int intel_color_check(struct intel_crtc_state *crtc_state)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc_state->base.crtc->dev);
@@ -790,6 +801,9 @@ int intel_color_check(struct intel_crtc_state *crtc_state)
 
 	crtc_state->csc_mode = 0;
 
+	if (IS_CHERRYVIEW(dev_priv))
+		crtc_state->cgm_mode = chv_cgm_mode(crtc_state);
+
 	/* Always allow legacy gamma LUT with no further checking. */
 	if (!crtc_state->gamma_enable ||
 	    crtc_state_is_legacy_gamma(crtc_state)) {

drivers/gpu/drm/i915/intel_display.c

@@ -8216,6 +8216,9 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 	pipe_config->gamma_mode = (tmp & PIPECONF_GAMMA_MODE_MASK_I9XX) >>
 		PIPECONF_GAMMA_MODE_SHIFT;
 
+	if (IS_CHERRYVIEW(dev_priv))
+		pipe_config->cgm_mode = I915_READ(CGM_PIPE_MODE(crtc->pipe));
+
 	i9xx_get_pipe_color_config(pipe_config);
 
 	if (INTEL_GEN(dev_priv) < 4)
@@ -12238,7 +12241,10 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
 		PIPE_CONF_CHECK_CLOCK_FUZZY(pixel_rate);
 
 		PIPE_CONF_CHECK_X(gamma_mode);
-		PIPE_CONF_CHECK_X(csc_mode);
+		if (IS_CHERRYVIEW(dev_priv))
+			PIPE_CONF_CHECK_X(cgm_mode);
+		else
+			PIPE_CONF_CHECK_X(csc_mode);
 		PIPE_CONF_CHECK_BOOL(gamma_enable);
 		PIPE_CONF_CHECK_BOOL(csc_enable);
 	}

drivers/gpu/drm/i915/intel_drv.h

@@ -1021,8 +1021,13 @@ struct intel_crtc_state {
 	/* Gamma mode programmed on the pipe */
 	u32 gamma_mode;
 
-	/* CSC mode programmed on the pipe */
-	u32 csc_mode;
+	union {
+		/* CSC mode programmed on the pipe */
+		u32 csc_mode;
+
+		/* CHV CGM mode */
+		u32 cgm_mode;
+	};
 
 	/* bitmask of visible planes (enum plane_id) */
 	u8 active_planes;