drm/i915: Extract out gamma table and CSC to their own file

The moves a couple of functions programming the gamma LUT and CSC
units into their own file.

On generations prior to Haswell there is only a gamma LUT. From
haswell on there is also a new enhanced color correction unit that
isn't used yet. This is why we need to set the GAMMA_MODE register,
either we're using the legacy 8bits LUT or enhanced LUTs (of 10 or
12bits).

The CSC unit is only available from Haswell on.

We also need to make a special case for CherryView which is recognized
as a gen 8 but doesn't have the same enhanced color correction unit
from Haswell on.

v2: Fix access to GAMMA_MODE register on older generations than
    Haswell (from Matt Roper's comments)

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1458125837-2576-2-git-send-email-lionel.g.landwerlin@intel.com

drivers/gpu/drm/i915/Makefile

@@ -55,6 +55,7 @@ i915-y += intel_audio.o \
 	  intel_atomic.o \
 	  intel_atomic_plane.o \
 	  intel_bios.o \
+	  intel_color.o \
 	  intel_display.o \
 	  intel_dpll_mgr.o \
 	  intel_fbc.o \

drivers/gpu/drm/i915/i915_drv.h

@@ -629,6 +629,8 @@ struct drm_i915_display_funcs {
 	/* render clock increase/decrease */
 	/* display clock increase/decrease */
 	/* pll clock increase/decrease */
+
+	void (*load_luts)(struct drm_crtc *crtc);
 };
 
 enum forcewake_domain_id {

drivers/gpu/drm/i915/intel_color.c

@@ -0,0 +1,191 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include "intel_drv.h"
+
+/*
+ * Set up the pipe CSC unit.
+ *
+ * Currently only full range RGB to limited range RGB conversion
+ * is supported, but eventually this should handle various
+ * RGB<->YCbCr scenarios as well.
+ */
+static void i9xx_load_csc_matrix(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int pipe = intel_crtc->pipe;
+	uint16_t coeff = 0x7800; /* 1.0 */
+
+	/*
+	 * TODO: Check what kind of values actually come out of the pipe
+	 * with these coeff/postoff values and adjust to get the best
+	 * accuracy. Perhaps we even need to take the bpc value into
+	 * consideration.
+	 */
+
+	if (intel_crtc->config->limited_color_range)
+		coeff = ((235 - 16) * (1 << 12) / 255) & 0xff8; /* 0.xxx... */
+
+	I915_WRITE(PIPE_CSC_COEFF_RY_GY(pipe), coeff << 16);
+	I915_WRITE(PIPE_CSC_COEFF_BY(pipe), 0);
+
+	I915_WRITE(PIPE_CSC_COEFF_RU_GU(pipe), coeff);
+	I915_WRITE(PIPE_CSC_COEFF_BU(pipe), 0);
+
+	I915_WRITE(PIPE_CSC_COEFF_RV_GV(pipe), 0);
+	I915_WRITE(PIPE_CSC_COEFF_BV(pipe), coeff << 16);
+
+	I915_WRITE(PIPE_CSC_PREOFF_HI(pipe), 0);
+	I915_WRITE(PIPE_CSC_PREOFF_ME(pipe), 0);
+	I915_WRITE(PIPE_CSC_PREOFF_LO(pipe), 0);
+
+	if (INTEL_INFO(dev)->gen > 6) {
+		uint16_t postoff = 0;
+
+		if (intel_crtc->config->limited_color_range)
+			postoff = (16 * (1 << 12) / 255) & 0x1fff;
+
+		I915_WRITE(PIPE_CSC_POSTOFF_HI(pipe), postoff);
+		I915_WRITE(PIPE_CSC_POSTOFF_ME(pipe), postoff);
+		I915_WRITE(PIPE_CSC_POSTOFF_LO(pipe), postoff);
+
+		I915_WRITE(PIPE_CSC_MODE(pipe), 0);
+	} else {
+		uint32_t mode = CSC_MODE_YUV_TO_RGB;
+
+		if (intel_crtc->config->limited_color_range)
+			mode |= CSC_BLACK_SCREEN_OFFSET;
+
+		I915_WRITE(PIPE_CSC_MODE(pipe), mode);
+	}
+}
+
+void intel_color_set_csc(struct drm_crtc *crtc)
+{
+	i9xx_load_csc_matrix(crtc);
+}
+
+/* Loads the palette/gamma unit for the CRTC with the prepared values. */
+static void i9xx_load_luts(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	enum pipe pipe = intel_crtc->pipe;
+	int i;
+
+	if (HAS_GMCH_DISPLAY(dev)) {
+		if (intel_crtc->config->has_dsi_encoder)
+			assert_dsi_pll_enabled(dev_priv);
+		else
+			assert_pll_enabled(dev_priv, pipe);
+	}
+
+	for (i = 0; i < 256; i++) {
+		uint32_t word = (intel_crtc->lut_r[i] << 16) |
+			(intel_crtc->lut_g[i] << 8) |
+			intel_crtc->lut_b[i];
+		if (HAS_GMCH_DISPLAY(dev))
+			I915_WRITE(PALETTE(pipe, i), word);
+		else
+			I915_WRITE(LGC_PALETTE(pipe, i), word);
+	}
+}
+
+/* Loads the legacy palette/gamma unit for the CRTC on Haswell+. */
+static void haswell_load_luts(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	bool reenable_ips = false;
+
+	/*
+	 * Workaround : Do not read or write the pipe palette/gamma data while
+	 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
+	 */
+	if (IS_HASWELL(dev) && intel_crtc->config->ips_enabled &&
+	    ((I915_READ(GAMMA_MODE(intel_crtc->pipe)) & GAMMA_MODE_MODE_MASK) ==
+	     GAMMA_MODE_MODE_SPLIT)) {
+		hsw_disable_ips(intel_crtc);
+		reenable_ips = true;
+	}
+	I915_WRITE(GAMMA_MODE(intel_crtc->pipe), GAMMA_MODE_MODE_8BIT);
+
+	i9xx_load_luts(crtc);
+
+	if (reenable_ips)
+		hsw_enable_ips(intel_crtc);
+}
+
+void intel_color_load_luts(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	/* The clocks have to be on to load the palette. */
+	if (!crtc->state->active)
+		return;
+
+	dev_priv->display.load_luts(crtc);
+}
+
+void intel_color_legacy_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				  u16 *blue, uint32_t start, uint32_t size)
+{
+	int end = (start + size > 256) ? 256 : start + size, i;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+
+	for (i = start; i < end; i++) {
+		intel_crtc->lut_r[i] = red[i] >> 8;
+		intel_crtc->lut_g[i] = green[i] >> 8;
+		intel_crtc->lut_b[i] = blue[i] >> 8;
+	}
+
+	intel_color_load_luts(crtc);
+}
+
+void intel_color_init(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int i;
+
+	drm_mode_crtc_set_gamma_size(crtc, 256);
+	for (i = 0; i < 256; i++) {
+		intel_crtc->lut_r[i] = i;
+		intel_crtc->lut_g[i] = i;
+		intel_crtc->lut_b[i] = i;
+	}
+
+	if (IS_HASWELL(dev) ||
+	    (INTEL_INFO(dev)->gen >= 8 && !IS_CHERRYVIEW(dev))) {
+		dev_priv->display.load_luts = haswell_load_luts;
+	} else {
+		dev_priv->display.load_luts = i9xx_load_luts;
+	}
+}