drm/i915: Implement color management on bdw/skl/bxt/kbl

Patch based on a previous series by Shashank Sharma.

v2: Do not read GAMMA_MODE register to figure what mode we're in

v3: Program PREC_PAL_GC_MAX to clamp pixel values > 1.0

    Add documentation on how the Broadcast RGB property is affected by CTM

v4: Update contributors

v5: Refactor degamma/gamma LUTs load into a single function

v6: Fix missing intel_crtc variable (bisect issue)

v7: Fix & simplify limited range matrix multiplication (Matt Roper's
    comment)

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Kumar, Kiran S <kiran.s.kumar@intel.com>
Signed-off-by: Kausal Malladi <kausalmalladi@gmail.com>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Acknowledged-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458125837-2576-4-git-send-email-lionel.g.landwerlin@intel.com

Documentation/DocBook/gpu.tmpl

@@ -2153,7 +2153,11 @@ void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >ENUM</td>
 	<td valign="top" >{ "Automatic", "Full", "Limited 16:235" }</td>
 	<td valign="top" >Connector</td>
-	<td valign="top" >TBD</td>
+	<td valign="top" >When this property is set to Limited 16:235
+		and CTM is set, the hardware will be programmed with the
+		result of the multiplication of CTM by the limited range
+		matrix to ensure the pixels normaly in the range 0..1.0 are
+		remapped to the range 16/255..235/255.</td>
 	</tr>
 	<tr>
 	<td valign="top" >“audio”</td>

drivers/gpu/drm/i915/i915_drv.c

@@ -66,6 +66,9 @@ static struct drm_driver driver;
 #define IVB_CURSOR_OFFSETS \
 	.cursor_offsets = { CURSOR_A_OFFSET, IVB_CURSOR_B_OFFSET, IVB_CURSOR_C_OFFSET }
 
+#define BDW_COLORS \
+	.color = { .degamma_lut_size = 512, .gamma_lut_size = 512 }
+
 static const struct intel_device_info intel_i830_info = {
 	.gen = 2, .is_mobile = 1, .cursor_needs_physical = 1, .num_pipes = 2,
 	.has_overlay = 1, .overlay_needs_physical = 1,
@@ -288,24 +291,28 @@ static const struct intel_device_info intel_haswell_m_info = {
 	.is_mobile = 1,
 };
 
+#define BDW_FEATURES \
+	HSW_FEATURES, \
+	BDW_COLORS
+
 static const struct intel_device_info intel_broadwell_d_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.gen = 8,
 };
 
 static const struct intel_device_info intel_broadwell_m_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.gen = 8, .is_mobile = 1,
 };
 
 static const struct intel_device_info intel_broadwell_gt3d_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.gen = 8,
 	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING | BSD2_RING,
 };
 
 static const struct intel_device_info intel_broadwell_gt3m_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.gen = 8, .is_mobile = 1,
 	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING | BSD2_RING,
 };
@@ -321,13 +328,13 @@ static const struct intel_device_info intel_cherryview_info = {
 };
 
 static const struct intel_device_info intel_skylake_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.is_skylake = 1,
 	.gen = 9,
 };
 
 static const struct intel_device_info intel_skylake_gt3_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.is_skylake = 1,
 	.gen = 9,
 	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING | BSD2_RING,
@@ -345,17 +352,18 @@ static const struct intel_device_info intel_broxton_info = {
 	.has_fbc = 1,
 	GEN_DEFAULT_PIPEOFFSETS,
 	IVB_CURSOR_OFFSETS,
+	BDW_COLORS,
 };
 
 static const struct intel_device_info intel_kabylake_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.is_preliminary = 1,
 	.is_kabylake = 1,
 	.gen = 9,
 };
 
 static const struct intel_device_info intel_kabylake_gt3_info = {
-	HSW_FEATURES,
+	BDW_FEATURES,
 	.is_preliminary = 1,
 	.is_kabylake = 1,
 	.gen = 9,

drivers/gpu/drm/i915/i915_drv.h

@@ -630,6 +630,7 @@ struct drm_i915_display_funcs {
 	/* display clock increase/decrease */
 	/* pll clock increase/decrease */
 
+	void (*load_csc_matrix)(struct drm_crtc *crtc);
 	void (*load_luts)(struct drm_crtc *crtc);
 };
 
@@ -781,6 +782,11 @@ struct intel_device_info {
 	u8 has_slice_pg:1;
 	u8 has_subslice_pg:1;
 	u8 has_eu_pg:1;
+
+	struct color_luts {
+		u16 degamma_lut_size;
+		u16 gamma_lut_size;
+	} color;
 };
 
 #undef DEFINE_FLAG

drivers/gpu/drm/i915/i915_reg.h

@@ -7663,6 +7663,28 @@ enum skl_disp_power_wells {
 #define PIPE_CSC_POSTOFF_ME(pipe)	_MMIO_PIPE(pipe, _PIPE_A_CSC_POSTOFF_ME, _PIPE_B_CSC_POSTOFF_ME)
 #define PIPE_CSC_POSTOFF_LO(pipe)	_MMIO_PIPE(pipe, _PIPE_A_CSC_POSTOFF_LO, _PIPE_B_CSC_POSTOFF_LO)
 
+/* pipe degamma/gamma LUTs on IVB+ */
+#define _PAL_PREC_INDEX_A	0x4A400
+#define _PAL_PREC_INDEX_B	0x4AC00
+#define _PAL_PREC_INDEX_C	0x4B400
+#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_DATA_A	0x4A404
+#define _PAL_PREC_DATA_B	0x4AC04
+#define _PAL_PREC_DATA_C	0x4B404
+#define _PAL_PREC_GC_MAX_A	0x4A410
+#define _PAL_PREC_GC_MAX_B	0x4AC10
+#define _PAL_PREC_GC_MAX_C	0x4B410
+#define _PAL_PREC_EXT_GC_MAX_A	0x4A420
+#define _PAL_PREC_EXT_GC_MAX_B	0x4AC20
+#define _PAL_PREC_EXT_GC_MAX_C	0x4B420
+
+#define PREC_PAL_INDEX(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_INDEX_A, _PAL_PREC_INDEX_B)
+#define PREC_PAL_DATA(pipe)		_MMIO_PIPE(pipe, _PAL_PREC_DATA_A, _PAL_PREC_DATA_B)
+#define PREC_PAL_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_GC_MAX_A, _PAL_PREC_GC_MAX_B) + (i) * 4)
+#define PREC_PAL_EXT_GC_MAX(pipe, i)	_MMIO(_PIPE(pipe, _PAL_PREC_EXT_GC_MAX_A, _PAL_PREC_EXT_GC_MAX_B) + (i) * 4)
+
 /* MIPI DSI registers */
 
 #define _MIPI_PORT(port, a, c)	_PORT3(port, a, 0, c)	/* ports A and C only */

drivers/gpu/drm/i915/intel_color.c

@@ -24,39 +24,155 @@
 
 #include "intel_drv.h"
 
+#define CTM_COEFF_SIGN	(1ULL << 63)
+
+#define CTM_COEFF_1_0	(1ULL << 32)
+#define CTM_COEFF_2_0	(CTM_COEFF_1_0 << 1)
+#define CTM_COEFF_4_0	(CTM_COEFF_2_0 << 1)
+#define CTM_COEFF_0_5	(CTM_COEFF_1_0 >> 1)
+#define CTM_COEFF_0_25	(CTM_COEFF_0_5 >> 1)
+#define CTM_COEFF_0_125	(CTM_COEFF_0_25 >> 1)
+
+#define CTM_COEFF_LIMITED_RANGE ((235ULL - 16ULL) * CTM_COEFF_1_0 / 255)
+
+#define CTM_COEFF_NEGATIVE(coeff)	(((coeff) & CTM_COEFF_SIGN) != 0)
+#define CTM_COEFF_ABS(coeff)		((coeff) & (CTM_COEFF_SIGN - 1))
+
+#define LEGACY_LUT_LENGTH		(sizeof(struct drm_color_lut) * 256)
+
 /*
- * Set up the pipe CSC unit.
+ * Extract the CSC coefficient from a CTM coefficient (in U32.32 fixed point
+ * format). This macro takes the coefficient we want transformed and the
+ * number of fractional bits.
  *
- * Currently only full range RGB to limited range RGB conversion
- * is supported, but eventually this should handle various
- * RGB<->YCbCr scenarios as well.
+ * We only have a 9 bits precision window which slides depending on the value
+ * of the CTM coefficient and we write the value from bit 3. We also round the
+ * value.
  */
+#define I9XX_CSC_COEFF_FP(coeff, fbits)	\
+	(clamp_val(((coeff) >> (32 - (fbits) - 3)) + 4, 0, 0xfff) & 0xff8)
+
+#define I9XX_CSC_COEFF_LIMITED_RANGE	\
+	I9XX_CSC_COEFF_FP(CTM_COEFF_LIMITED_RANGE, 9)
+#define I9XX_CSC_COEFF_1_0		\
+	((7 << 12) | I9XX_CSC_COEFF_FP(CTM_COEFF_1_0, 8))
+
+static bool crtc_state_is_legacy(struct drm_crtc_state *state)
+{
+	return !state->degamma_lut &&
+		!state->ctm &&
+		state->gamma_lut &&
+		state->gamma_lut->length == LEGACY_LUT_LENGTH;
+}
+
+/*
+ * When using limited range, multiply the matrix given by userspace by
+ * the matrix that we would use for the limited range. We do the
+ * multiplication in U2.30 format.
+ */
+static void ctm_mult_by_limited(uint64_t *result, int64_t *input)
+{
+	int i;
+
+	for (i = 0; i < 9; i++)
+		result[i] = 0;
+
+	for (i = 0; i < 3; i++) {
+		int64_t user_coeff = input[i * 3 + i];
+		uint64_t limited_coeff = CTM_COEFF_LIMITED_RANGE >> 2;
+		uint64_t abs_coeff = clamp_val(CTM_COEFF_ABS(user_coeff),
+					       0,
+					       CTM_COEFF_4_0 - 1) >> 2;
+
+		result[i * 3 + i] = (limited_coeff * abs_coeff) >> 27;
+		if (CTM_COEFF_NEGATIVE(user_coeff))
+			result[i * 3 + i] |= CTM_COEFF_SIGN;
+	}
+}
+
+/* Set up the pipe CSC unit. */
 static void i9xx_load_csc_matrix(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
+	struct drm_crtc_state *crtc_state = crtc->state;
 	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... */
+	int i, pipe = intel_crtc->pipe;
+	uint16_t coeffs[9] = { 0, };
+
+	if (crtc_state->ctm) {
+		struct drm_color_ctm *ctm =
+			(struct drm_color_ctm *)crtc_state->ctm->data;
+		uint64_t input[9] = { 0, };
+
+		if (intel_crtc->config->limited_color_range) {
+			ctm_mult_by_limited(input, ctm->matrix);
+		} else {
+			for (i = 0; i < ARRAY_SIZE(input); i++)
+				input[i] = ctm->matrix[i];
+		}
+
+		/*
+		 * Convert fixed point S31.32 input to format supported by the
+		 * hardware.
+		 */
+		for (i = 0; i < ARRAY_SIZE(coeffs); i++) {
+			uint64_t abs_coeff = ((1ULL << 63) - 1) & input[i];
+
+			/*
+			 * Clamp input value to min/max supported by
+			 * hardware.
+			 */
+			abs_coeff = clamp_val(abs_coeff, 0, CTM_COEFF_4_0 - 1);
+
+			/* sign bit */
+			if (CTM_COEFF_NEGATIVE(input[i]))
+				coeffs[i] |= 1 << 15;
+
+			if (abs_coeff < CTM_COEFF_0_125)
+				coeffs[i] |= (3 << 12) |
+					I9XX_CSC_COEFF_FP(abs_coeff, 12);
+			else if (abs_coeff < CTM_COEFF_0_25)
+				coeffs[i] |= (2 << 12) |
+					I9XX_CSC_COEFF_FP(abs_coeff, 11);
+			else if (abs_coeff < CTM_COEFF_0_5)
+				coeffs[i] |= (1 << 12) |
+					I9XX_CSC_COEFF_FP(abs_coeff, 10);
+			else if (abs_coeff < CTM_COEFF_1_0)
+				coeffs[i] |= I9XX_CSC_COEFF_FP(abs_coeff, 9);
+			else if (abs_coeff < CTM_COEFF_2_0)
+				coeffs[i] |= (7 << 12) |
+					I9XX_CSC_COEFF_FP(abs_coeff, 8);
+			else
+				coeffs[i] |= (6 << 12) |
+					I9XX_CSC_COEFF_FP(abs_coeff, 7);
+		}
+	} else {
+		/*
+		 * Load an identity matrix if no coefficients are provided.
+		 *
+		 * 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.
+		 */
+		for (i = 0; i < 3; i++) {
+			if (intel_crtc->config->limited_color_range)
+				coeffs[i * 3 + i] =
+					I9XX_CSC_COEFF_LIMITED_RANGE;
+			else
+				coeffs[i * 3 + i] = I9XX_CSC_COEFF_1_0;
+		}
+	}
 
-	I915_WRITE(PIPE_CSC_COEFF_RY_GY(pipe), coeff << 16);
-	I915_WRITE(PIPE_CSC_COEFF_BY(pipe), 0);
+	I915_WRITE(PIPE_CSC_COEFF_RY_GY(pipe), coeffs[0] << 16 | coeffs[1]);
+	I915_WRITE(PIPE_CSC_COEFF_BY(pipe), coeffs[2] << 16);
 
-	I915_WRITE(PIPE_CSC_COEFF_RU_GU(pipe), coeff);
-	I915_WRITE(PIPE_CSC_COEFF_BU(pipe), 0);
+	I915_WRITE(PIPE_CSC_COEFF_RU_GU(pipe), coeffs[3] << 16 | coeffs[4]);
+	I915_WRITE(PIPE_CSC_COEFF_BU(pipe), coeffs[5] << 16);
 
-	I915_WRITE(PIPE_CSC_COEFF_RV_GV(pipe), 0);
-	I915_WRITE(PIPE_CSC_COEFF_BV(pipe), coeff << 16);
+	I915_WRITE(PIPE_CSC_COEFF_RV_GV(pipe), coeffs[6] << 16 | coeffs[7]);
+	I915_WRITE(PIPE_CSC_COEFF_BV(pipe), coeffs[8] << 16);
 
 	I915_WRITE(PIPE_CSC_PREOFF_HI(pipe), 0);
 	I915_WRITE(PIPE_CSC_PREOFF_ME(pipe), 0);
@@ -85,13 +201,18 @@ static void i9xx_load_csc_matrix(struct drm_crtc *crtc)
 
 void intel_color_set_csc(struct drm_crtc *crtc)
 {
-	i9xx_load_csc_matrix(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (dev_priv->display.load_csc_matrix)
+		dev_priv->display.load_csc_matrix(crtc);
 }
 
-/* Loads the palette/gamma unit for the CRTC with the prepared values. */
+/* Loads the legacy palette/gamma unit for the CRTC. */
 static void i9xx_load_luts(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
+	struct drm_crtc_state *state = crtc->state;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	enum pipe pipe = intel_crtc->pipe;
@@ -104,18 +225,33 @@ static void i9xx_load_luts(struct drm_crtc *crtc)
 			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);
+	if (state->gamma_lut) {
+		struct drm_color_lut *lut =
+			(struct drm_color_lut *) state->gamma_lut->data;
+		for (i = 0; i < 256; i++) {
+			uint32_t word =
+				(drm_color_lut_extract(lut[i].red, 8) << 16) |
+				(drm_color_lut_extract(lut[i].green, 8) << 8) |
+				drm_color_lut_extract(lut[i].blue, 8);
+
+			if (HAS_GMCH_DISPLAY(dev))
+				I915_WRITE(PALETTE(pipe, i), word);
+			else
+				I915_WRITE(LGC_PALETTE(pipe, i), word);
+		}
+	} else {
+		for (i = 0; i < 256; i++) {
+			uint32_t word = (i << 16) | (i << 8) | 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+. */
+/* 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;
@@ -144,6 +280,89 @@ static void haswell_load_luts(struct drm_crtc *crtc)
 		hsw_enable_ips(intel_crtc);
 }
 
+/* Loads the palette/gamma unit for the CRTC on Broadwell+. */
+static void broadwell_load_luts(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_crtc_state *state = crtc->state;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc_state *intel_state = to_intel_crtc_state(state);
+	enum pipe pipe = to_intel_crtc(crtc)->pipe;
+	uint32_t i, lut_size = INTEL_INFO(dev)->color.degamma_lut_size;
+
+	if (crtc_state_is_legacy(state)) {
+		haswell_load_luts(crtc);
+		return;
+	}
+
+	I915_WRITE(PREC_PAL_INDEX(pipe),
+		   PAL_PREC_SPLIT_MODE | PAL_PREC_AUTO_INCREMENT);
+
+	if (state->degamma_lut) {
+		struct drm_color_lut *lut =
+			(struct drm_color_lut *) state->degamma_lut->data;
+
+		for (i = 0; i < lut_size; i++) {
+			uint32_t word =
+			drm_color_lut_extract(lut[i].red, 10) << 20 |
+			drm_color_lut_extract(lut[i].green, 10) << 10 |
+			drm_color_lut_extract(lut[i].blue, 10);
+
+			I915_WRITE(PREC_PAL_DATA(pipe), word);
+		}
+	} else {
+		for (i = 0; i < lut_size; i++) {
+			uint32_t v = (i * ((1 << 10) - 1)) / (lut_size - 1);
+
+			I915_WRITE(PREC_PAL_DATA(pipe),
+				   (v << 20) | (v << 10) | v);
+		}
+	}
+
+	if (state->gamma_lut) {
+		struct drm_color_lut *lut =
+			(struct drm_color_lut *) state->gamma_lut->data;
+
+		for (i = 0; i < lut_size; i++) {
+			uint32_t word =
+			(drm_color_lut_extract(lut[i].red, 10) << 20) |
+			(drm_color_lut_extract(lut[i].green, 10) << 10) |
+			drm_color_lut_extract(lut[i].blue, 10);
+
+			I915_WRITE(PREC_PAL_DATA(pipe), word);
+		}
+
+		/* Program the max register to clamp values > 1.0. */
+		I915_WRITE(PREC_PAL_GC_MAX(pipe, 0),
+			   drm_color_lut_extract(lut[i].red, 16));
+		I915_WRITE(PREC_PAL_GC_MAX(pipe, 1),
+			   drm_color_lut_extract(lut[i].green, 16));
+		I915_WRITE(PREC_PAL_GC_MAX(pipe, 2),
+			   drm_color_lut_extract(lut[i].blue, 16));
+	} else {
+		for (i = 0; i < lut_size; i++) {
+			uint32_t v = (i * ((1 << 10) - 1)) / (lut_size - 1);
+
+			I915_WRITE(PREC_PAL_DATA(pipe),
+				   (v << 20) | (v << 10) | v);
+		}
+
+		I915_WRITE(PREC_PAL_GC_MAX(pipe, 0), (1 << 16) - 1);
+		I915_WRITE(PREC_PAL_GC_MAX(pipe, 1), (1 << 16) - 1);
+		I915_WRITE(PREC_PAL_GC_MAX(pipe, 2), (1 << 16) - 1);
+	}
+
+	intel_state->gamma_mode = GAMMA_MODE_MODE_SPLIT;
+	I915_WRITE(GAMMA_MODE(pipe), GAMMA_MODE_MODE_SPLIT);
+	POSTING_READ(GAMMA_MODE(pipe));
+
+	/*
+	 * Reset the index, otherwise it prevents the legacy palette to be
+	 * written properly.
+	 */
+	I915_WRITE(PREC_PAL_INDEX(pipe), 0);
+}
+
 void intel_color_load_luts(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
@@ -156,39 +375,61 @@ void intel_color_load_luts(struct drm_crtc *crtc)
 	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 intel_color_check(struct drm_crtc *crtc,
+		      struct drm_crtc_state *crtc_state)
 {
-	int end = (start + size > 256) ? 256 : start + size, i;
-	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	size_t gamma_length, degamma_length;
 
-	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;
-	}
+	degamma_length = INTEL_INFO(dev)->color.degamma_lut_size *
+		sizeof(struct drm_color_lut);
+	gamma_length = INTEL_INFO(dev)->color.gamma_lut_size *
+		sizeof(struct drm_color_lut);
 
-	intel_color_load_luts(crtc);
+	/*
+	 * We allow both degamma & gamma luts at the right size or
+	 * NULL.
+	 */
+	if ((!crtc_state->degamma_lut ||
+	     crtc_state->degamma_lut->length == degamma_length) &&
+	    (!crtc_state->gamma_lut ||
+	     crtc_state->gamma_lut->length == gamma_length))
+		return 0;
+
+	/*
+	 * We also allow no degamma lut and a gamma lut at the legacy
+	 * size (256 entries).
+	 */
+	if (!crtc_state->degamma_lut &&
+	    crtc_state->gamma_lut &&
+	    crtc_state->gamma_lut->length == LEGACY_LUT_LENGTH)
+		return 0;
+
+	return -EINVAL;
 }
 
 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))) {
+	if (IS_HASWELL(dev)) {
+		dev_priv->display.load_csc_matrix = i9xx_load_csc_matrix;
 		dev_priv->display.load_luts = haswell_load_luts;
+	} else if (IS_BROADWELL(dev) || IS_SKYLAKE(dev) ||
+		   IS_BROXTON(dev) || IS_KABYLAKE(dev)) {
+		dev_priv->display.load_csc_matrix = i9xx_load_csc_matrix;
+		dev_priv->display.load_luts = broadwell_load_luts;
 	} else {
 		dev_priv->display.load_luts = i9xx_load_luts;
 	}
+
+	/* Enable color management support when we have degamma & gamma LUTs. */
+	if (INTEL_INFO(dev)->color.degamma_lut_size != 0 &&
+	    INTEL_INFO(dev)->color.gamma_lut_size != 0)
+		drm_helper_crtc_enable_color_mgmt(crtc,
+					INTEL_INFO(dev)->color.degamma_lut_size,
+					INTEL_INFO(dev)->color.gamma_lut_size);
 }

drivers/gpu/drm/i915/intel_display.c

@@ -11911,6 +11911,12 @@ static int intel_crtc_atomic_check(struct drm_crtc *crtc,
 			return ret;
 	}
 
+	if (crtc_state->color_mgmt_changed) {
+		ret = intel_color_check(crtc, crtc_state);
+		if (ret)
+			return ret;
+	}
+
 	ret = 0;
 	if (dev_priv->display.compute_pipe_wm) {
 		ret = dev_priv->display.compute_pipe_wm(pipe_config);
@@ -11953,7 +11959,6 @@ static int intel_crtc_atomic_check(struct drm_crtc *crtc,
 
 static const struct drm_crtc_helper_funcs intel_helper_funcs = {
 	.mode_set_base_atomic = intel_pipe_set_base_atomic,
-	.load_lut = intel_color_load_luts,
 	.atomic_begin = intel_begin_crtc_commit,
 	.atomic_flush = intel_finish_crtc_commit,
 	.atomic_check = intel_crtc_atomic_check,
@@ -13576,6 +13581,18 @@ static int intel_atomic_commit(struct drm_device *dev,
 			dev_priv->display.crtc_enable(crtc);
 		}
 
+		if (!modeset &&
+		    crtc->state->active &&
+		    crtc->state->color_mgmt_changed) {
+			/*
+			 * Only update color management when not doing
+			 * a modeset as this will be done by
+			 * crtc_enable already.
+			 */
+			intel_color_set_csc(crtc);
+			intel_color_load_luts(crtc);
+		}
+
 		if (!modeset)
 			intel_pre_plane_update(to_intel_crtc_state(old_crtc_state));
 
@@ -13686,8 +13703,9 @@ out:
 #undef for_each_intel_crtc_masked
 
 static const struct drm_crtc_funcs intel_crtc_funcs = {
-	.gamma_set = intel_color_legacy_gamma_set,
+	.gamma_set = drm_atomic_helper_legacy_gamma_set,
 	.set_config = drm_atomic_helper_set_config,
+	.set_property = drm_atomic_helper_crtc_set_property,
 	.destroy = intel_crtc_destroy,
 	.page_flip = intel_crtc_page_flip,
 	.atomic_duplicate_state = intel_crtc_duplicate_state,

drivers/gpu/drm/i915/intel_drv.h

@@ -1668,9 +1668,8 @@ extern const struct drm_plane_helper_funcs intel_plane_helper_funcs;
 
 /* intel_color.c */
 void intel_color_init(struct drm_crtc *crtc);
+int intel_color_check(struct drm_crtc *crtc, struct drm_crtc_state *state);
 void intel_color_set_csc(struct drm_crtc *crtc);
 void intel_color_load_luts(struct drm_crtc *crtc);
-void intel_color_legacy_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-				  u16 *blue, uint32_t start, uint32_t size);
 
 #endif /* __INTEL_DRV_H__ */

drivers/gpu/drm/i915/intel_fbdev.c

@@ -379,6 +379,7 @@ retry:
 		struct drm_connector *connector;
 		struct drm_encoder *encoder;
 		struct drm_fb_helper_crtc *new_crtc;
+		struct intel_crtc *intel_crtc;
 
 		fb_conn = fb_helper->connector_info[i];
 		connector = fb_conn->connector;
@@ -420,6 +421,13 @@ retry:
 
 		num_connectors_enabled++;
 
+		intel_crtc = to_intel_crtc(connector->state->crtc);
+		for (j = 0; j < 256; j++) {
+			intel_crtc->lut_r[j] = j;
+			intel_crtc->lut_g[j] = j;
+			intel_crtc->lut_b[j] = j;
+		}
+
 		new_crtc = intel_fb_helper_crtc(fb_helper, connector->state->crtc);
 
 		/*