/*
 * 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"

#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_8_0   (CTM_COEFF_4_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               256

/* Post offset values for RGB->YCBCR conversion */
#define POSTOFF_RGB_TO_YUV_HI 0x800
#define POSTOFF_RGB_TO_YUV_ME 0x100
#define POSTOFF_RGB_TO_YUV_LO 0x800

/*
 * These values are direct register values specified in the Bspec,
 * for RGB->YUV conversion matrix (colorspace BT709)
 */
#define CSC_RGB_TO_YUV_RU_GU 0x2ba809d8
#define CSC_RGB_TO_YUV_BU 0x37e80000
#define CSC_RGB_TO_YUV_RY_GY 0x1e089cc0
#define CSC_RGB_TO_YUV_BY 0xb5280000
#define CSC_RGB_TO_YUV_RV_GV 0xbce89ad8
#define CSC_RGB_TO_YUV_BV 0x1e080000

/*
 * 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.
 *
 * 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 ILK_CSC_COEFF_FP(coeff, fbits)  \
        (clamp_val(((coeff) >> (32 - (fbits) - 3)) + 4, 0, 0xfff) & 0xff8)

#define ILK_CSC_COEFF_LIMITED_RANGE     \
        ILK_CSC_COEFF_FP(CTM_COEFF_LIMITED_RANGE, 9)
#define ILK_CSC_COEFF_1_0               \
        ((7 << 12) | ILK_CSC_COEFF_FP(CTM_COEFF_1_0, 8))

static bool crtc_state_is_legacy_gamma(struct drm_crtc_state *state)
{
        return !state->degamma_lut &&
                !state->ctm &&
                state->gamma_lut &&
                drm_color_lut_size(state->gamma_lut) == LEGACY_LUT_LENGTH;
}

/*
 * When using limited range, multiply the matrix given by userspace by
 * the matrix that we would use for the limited range.
 */
static u64 *ctm_mult_by_limited(u64 *result, const u64 *input)
{
        int i;

        for (i = 0; i < 9; i++) {
                u64 user_coeff = input[i];
                u32 limited_coeff = CTM_COEFF_LIMITED_RANGE;
                u32 abs_coeff = clamp_val(CTM_COEFF_ABS(user_coeff), 0,
                                          CTM_COEFF_4_0 - 1) >> 2;

                /*
                 * By scaling every co-efficient with limited range (16-235)
                 * vs full range (0-255) the final o/p will be scaled down to
                 * fit in the limited range supported by the panel.
                 */
                result[i] = mul_u32_u32(limited_coeff, abs_coeff) >> 30;
                result[i] |= user_coeff & CTM_COEFF_SIGN;
        }

        return result;
}

static void ilk_load_ycbcr_conversion_matrix(struct intel_crtc *intel_crtc)
{
        int pipe = intel_crtc->pipe;
        struct drm_i915_private *dev_priv = to_i915(intel_crtc->base.dev);

        I915_WRITE(PIPE_CSC_PREOFF_HI(pipe), 0);
        I915_WRITE(PIPE_CSC_PREOFF_ME(pipe), 0);
        I915_WRITE(PIPE_CSC_PREOFF_LO(pipe), 0);

        I915_WRITE(PIPE_CSC_COEFF_RU_GU(pipe), CSC_RGB_TO_YUV_RU_GU);
        I915_WRITE(PIPE_CSC_COEFF_BU(pipe), CSC_RGB_TO_YUV_BU);

        I915_WRITE(PIPE_CSC_COEFF_RY_GY(pipe), CSC_RGB_TO_YUV_RY_GY);
        I915_WRITE(PIPE_CSC_COEFF_BY(pipe), CSC_RGB_TO_YUV_BY);

        I915_WRITE(PIPE_CSC_COEFF_RV_GV(pipe), CSC_RGB_TO_YUV_RV_GV);
        I915_WRITE(PIPE_CSC_COEFF_BV(pipe), CSC_RGB_TO_YUV_BV);

        I915_WRITE(PIPE_CSC_POSTOFF_HI(pipe), POSTOFF_RGB_TO_YUV_HI);
        I915_WRITE(PIPE_CSC_POSTOFF_ME(pipe), POSTOFF_RGB_TO_YUV_ME);
        I915_WRITE(PIPE_CSC_POSTOFF_LO(pipe), POSTOFF_RGB_TO_YUV_LO);
        I915_WRITE(PIPE_CSC_MODE(pipe), 0);
}

static void ilk_load_csc_matrix(struct drm_crtc_state *crtc_state)
{
        struct drm_crtc *crtc = crtc_state->crtc;
        struct drm_i915_private *dev_priv = to_i915(crtc->dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        int i, pipe = intel_crtc->pipe;
        uint16_t coeffs[9] = { 0, };
        struct intel_crtc_state *intel_crtc_state = to_intel_crtc_state(crtc_state);
        bool limited_color_range = false;

        /*
         * FIXME if there's a gamma LUT after the CSC, we should
         * do the range compression using the gamma LUT instead.
         */
        if (INTEL_GEN(dev_priv) >= 8 || IS_HASWELL(dev_priv))
                limited_color_range = intel_crtc_state->limited_color_range;

        if (intel_crtc_state->ycbcr420) {
                ilk_load_ycbcr_conversion_matrix(intel_crtc);
                return;
        } else if (crtc_state->ctm) {
                struct drm_color_ctm *ctm = crtc_state->ctm->data;
                const u64 *input;
                u64 temp[9];

                if (limited_color_range)
                        input = ctm_mult_by_limited(temp, ctm->matrix);
                else
                        input = ctm->matrix;

                /*
                 * 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) |
                                        ILK_CSC_COEFF_FP(abs_coeff, 12);
                        else if (abs_coeff < CTM_COEFF_0_25)
                                coeffs[i] |= (2 << 12) |
                                        ILK_CSC_COEFF_FP(abs_coeff, 11);
                        else if (abs_coeff < CTM_COEFF_0_5)
                                coeffs[i] |= (1 << 12) |
                                        ILK_CSC_COEFF_FP(abs_coeff, 10);
                        else if (abs_coeff < CTM_COEFF_1_0)
                                coeffs[i] |= ILK_CSC_COEFF_FP(abs_coeff, 9);
                        else if (abs_coeff < CTM_COEFF_2_0)
                                coeffs[i] |= (7 << 12) |
                                        ILK_CSC_COEFF_FP(abs_coeff, 8);
                        else
                                coeffs[i] |= (6 << 12) |
                                        ILK_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 (limited_color_range)
                                coeffs[i * 3 + i] =
                                        ILK_CSC_COEFF_LIMITED_RANGE;
                        else
                                coeffs[i * 3 + i] = ILK_CSC_COEFF_1_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), coeffs[3] << 16 | coeffs[4]);
        I915_WRITE(PIPE_CSC_COEFF_BU(pipe), coeffs[5] << 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);
        I915_WRITE(PIPE_CSC_PREOFF_LO(pipe), 0);

        if (INTEL_GEN(dev_priv) > 6) {
                uint16_t postoff = 0;

                if (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 (limited_color_range)
                        mode |= CSC_BLACK_SCREEN_OFFSET;

                I915_WRITE(PIPE_CSC_MODE(pipe), mode);
        }
}

/*
 * Set up the pipe CSC unit on CherryView.
 */
static void cherryview_load_csc_matrix(struct drm_crtc_state *state)
{
        struct drm_crtc *crtc = state->crtc;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        int pipe = to_intel_crtc(crtc)->pipe;
        uint32_t mode;

        if (state->ctm) {
                struct drm_color_ctm *ctm = state->ctm->data;
                uint16_t coeffs[9] = { 0, };
                int i;

                for (i = 0; i < ARRAY_SIZE(coeffs); i++) {
                        uint64_t abs_coeff =
                                ((1ULL << 63) - 1) & ctm->matrix[i];

                        /* Round coefficient. */
                        abs_coeff += 1 << (32 - 13);
                        /* Clamp to hardware limits. */
                        abs_coeff = clamp_val(abs_coeff, 0, CTM_COEFF_8_0 - 1);

                        /* Write coefficients in S3.12 format. */
                        if (ctm->matrix[i] & (1ULL << 63))
                                coeffs[i] = 1 << 15;
                        coeffs[i] |= ((abs_coeff >> 32) & 7) << 12;
                        coeffs[i] |= (abs_coeff >> 20) & 0xfff;
                }

                I915_WRITE(CGM_PIPE_CSC_COEFF01(pipe),
                           coeffs[1] << 16 | coeffs[0]);
                I915_WRITE(CGM_PIPE_CSC_COEFF23(pipe),
                           coeffs[3] << 16 | coeffs[2]);
                I915_WRITE(CGM_PIPE_CSC_COEFF45(pipe),
                           coeffs[5] << 16 | coeffs[4]);
                I915_WRITE(CGM_PIPE_CSC_COEFF67(pipe),
                           coeffs[7] << 16 | coeffs[6]);
                I915_WRITE(CGM_PIPE_CSC_COEFF8(pipe), coeffs[8]);
        }

        mode = (state->ctm ? CGM_PIPE_MODE_CSC : 0);
        if (!crtc_state_is_legacy_gamma(state)) {
                mode |= (state->degamma_lut ? CGM_PIPE_MODE_DEGAMMA : 0) |
                        (state->gamma_lut ? CGM_PIPE_MODE_GAMMA : 0);
        }
        I915_WRITE(CGM_PIPE_MODE(pipe), mode);
}

void intel_color_set_csc(struct drm_crtc_state *crtc_state)
{
        struct drm_device *dev = crtc_state->crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);

        if (dev_priv->display.load_csc_matrix)
                dev_priv->display.load_csc_matrix(crtc_state);
}

/* Loads the legacy palette/gamma unit for the CRTC. */
static void i9xx_load_luts_internal(struct drm_crtc *crtc,
                                    struct drm_property_blob *blob,
                                    struct intel_crtc_state *crtc_state)
{
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        enum i915_pipe pipe = intel_crtc->pipe;
        int i;

        if (HAS_GMCH_DISPLAY(dev_priv)) {
                if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI))
                        assert_dsi_pll_enabled(dev_priv);
                else
                        assert_pll_enabled(dev_priv, pipe);
        }

        if (blob) {
                struct drm_color_lut *lut = blob->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_priv))
                                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_priv))
                                I915_WRITE(PALETTE(pipe, i), word);
                        else
                                I915_WRITE(LGC_PALETTE(pipe, i), word);
                }
        }
}

static void i9xx_load_luts(struct drm_crtc_state *crtc_state)
{
        i9xx_load_luts_internal(crtc_state->crtc, crtc_state->gamma_lut,
                                to_intel_crtc_state(crtc_state));
}

/* Loads the legacy palette/gamma unit for the CRTC on Haswell. */
static void haswell_load_luts(struct drm_crtc_state *crtc_state)
{
        struct drm_crtc *crtc = crtc_state->crtc;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
        struct intel_crtc_state *intel_crtc_state =
                to_intel_crtc_state(crtc_state);
        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_priv) && intel_crtc_state->ips_enabled &&
            (intel_crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)) {
                hsw_disable_ips(intel_crtc_state);
                reenable_ips = true;
        }

        intel_crtc_state->gamma_mode = GAMMA_MODE_MODE_8BIT;
        I915_WRITE(GAMMA_MODE(intel_crtc->pipe), GAMMA_MODE_MODE_8BIT);

        i9xx_load_luts(crtc_state);

        if (reenable_ips)
                hsw_enable_ips(intel_crtc_state);
}

static void bdw_load_degamma_lut(struct drm_crtc_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->crtc->dev);
        enum i915_pipe pipe = to_intel_crtc(state->crtc)->pipe;
        uint32_t i, lut_size = INTEL_INFO(dev_priv)->color.degamma_lut_size;

        I915_WRITE(PREC_PAL_INDEX(pipe),
                   PAL_PREC_SPLIT_MODE | PAL_PREC_AUTO_INCREMENT);

        if (state->degamma_lut) {
                struct drm_color_lut *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);
                }
        }
}

static void bdw_load_gamma_lut(struct drm_crtc_state *state, u32 offset)
{
        struct drm_i915_private *dev_priv = to_i915(state->crtc->dev);
        enum i915_pipe pipe = to_intel_crtc(state->crtc)->pipe;
        uint32_t i, lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;

        WARN_ON(offset & ~PAL_PREC_INDEX_VALUE_MASK);

        I915_WRITE(PREC_PAL_INDEX(pipe),
                   (offset ? PAL_PREC_SPLIT_MODE : 0) |
                   PAL_PREC_AUTO_INCREMENT |
                   offset);

        if (state->gamma_lut) {
                struct drm_color_lut *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. */
                i = lut_size - 1;
                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);
        }
}

/* Loads the palette/gamma unit for the CRTC on Broadwell+. */
static void broadwell_load_luts(struct drm_crtc_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->crtc->dev);
        struct intel_crtc_state *intel_state = to_intel_crtc_state(state);
        enum i915_pipe pipe = to_intel_crtc(state->crtc)->pipe;

        if (crtc_state_is_legacy_gamma(state)) {
                haswell_load_luts(state);
                return;
        }

        bdw_load_degamma_lut(state);
        bdw_load_gamma_lut(state,
                           INTEL_INFO(dev_priv)->color.degamma_lut_size);

        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);
}

static void glk_load_degamma_lut(struct drm_crtc_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->crtc->dev);
        enum i915_pipe pipe = to_intel_crtc(state->crtc)->pipe;
        const uint32_t lut_size = 33;
        uint32_t i;

        /*
         * When setting the auto-increment bit, the hardware seems to
         * ignore the index bits, so we need to reset it to index 0
         * separately.
         */
        I915_WRITE(PRE_CSC_GAMC_INDEX(pipe), 0);
        I915_WRITE(PRE_CSC_GAMC_INDEX(pipe), PRE_CSC_GAMC_AUTO_INCREMENT);

        /*
         *  FIXME: The pipe degamma table in geminilake doesn't support
         *  different values per channel, so this just loads a linear table.
         */
        for (i = 0; i < lut_size; i++) {
                uint32_t v = (i * (1 << 16)) / (lut_size - 1);

                I915_WRITE(PRE_CSC_GAMC_DATA(pipe), v);
        }

        /* Clamp values > 1.0. */
        while (i++ < 35)
                I915_WRITE(PRE_CSC_GAMC_DATA(pipe), (1 << 16));
}

static void glk_load_luts(struct drm_crtc_state *state)
{
        struct drm_crtc *crtc = state->crtc;
        struct drm_device *dev = crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_crtc_state *intel_state = to_intel_crtc_state(state);
        enum i915_pipe pipe = to_intel_crtc(crtc)->pipe;

        glk_load_degamma_lut(state);

        if (crtc_state_is_legacy_gamma(state)) {
                haswell_load_luts(state);
                return;
        }

        bdw_load_gamma_lut(state, 0);

        intel_state->gamma_mode = GAMMA_MODE_MODE_10BIT;
        I915_WRITE(GAMMA_MODE(pipe), GAMMA_MODE_MODE_10BIT);
        POSTING_READ(GAMMA_MODE(pipe));
}

/* Loads the palette/gamma unit for the CRTC on CherryView. */
static void cherryview_load_luts(struct drm_crtc_state *state)
{
        struct drm_crtc *crtc = state->crtc;
        struct drm_i915_private *dev_priv = to_i915(crtc->dev);
        enum i915_pipe pipe = to_intel_crtc(crtc)->pipe;
        struct drm_color_lut *lut;
        uint32_t i, lut_size;
        uint32_t word0, word1;

        if (crtc_state_is_legacy_gamma(state)) {
                /* Turn off degamma/gamma on CGM block. */
                I915_WRITE(CGM_PIPE_MODE(pipe),
                           (state->ctm ? CGM_PIPE_MODE_CSC : 0));
                i9xx_load_luts_internal(crtc, state->gamma_lut,
                                        to_intel_crtc_state(state));
                return;
        }

        if (state->degamma_lut) {
                lut = state->degamma_lut->data;
                lut_size = INTEL_INFO(dev_priv)->color.degamma_lut_size;
                for (i = 0; i < lut_size; i++) {
                        /* Write LUT in U0.14 format. */
                        word0 =
                        (drm_color_lut_extract(lut[i].green, 14) << 16) |
                        drm_color_lut_extract(lut[i].blue, 14);
                        word1 = drm_color_lut_extract(lut[i].red, 14);

                        I915_WRITE(CGM_PIPE_DEGAMMA(pipe, i, 0), word0);
                        I915_WRITE(CGM_PIPE_DEGAMMA(pipe, i, 1), word1);
                }
        }

        if (state->gamma_lut) {
                lut = state->gamma_lut->data;
                lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
                for (i = 0; i < lut_size; i++) {
                        /* Write LUT in U0.10 format. */
                        word0 =
                        (drm_color_lut_extract(lut[i].green, 10) << 16) |
                        drm_color_lut_extract(lut[i].blue, 10);
                        word1 = drm_color_lut_extract(lut[i].red, 10);

                        I915_WRITE(CGM_PIPE_GAMMA(pipe, i, 0), word0);
                        I915_WRITE(CGM_PIPE_GAMMA(pipe, i, 1), word1);
                }
        }

        I915_WRITE(CGM_PIPE_MODE(pipe),
                   (state->ctm ? CGM_PIPE_MODE_CSC : 0) |
                   (state->degamma_lut ? CGM_PIPE_MODE_DEGAMMA : 0) |
                   (state->gamma_lut ? CGM_PIPE_MODE_GAMMA : 0));

        /*
         * Also program a linear LUT in the legacy block (behind the
         * CGM block).
         */
        i9xx_load_luts_internal(crtc, NULL, to_intel_crtc_state(state));
}

void intel_color_load_luts(struct drm_crtc_state *crtc_state)
{
        struct drm_device *dev = crtc_state->crtc->dev;
        struct drm_i915_private *dev_priv = to_i915(dev);

        dev_priv->display.load_luts(crtc_state);
}

int intel_color_check(struct drm_crtc *crtc,
                      struct drm_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->dev);
        size_t gamma_length, degamma_length;

        degamma_length = INTEL_INFO(dev_priv)->color.degamma_lut_size;
        gamma_length = INTEL_INFO(dev_priv)->color.gamma_lut_size;

        /*
         * We allow both degamma & gamma luts at the right size or
         * NULL.
         */
        if ((!crtc_state->degamma_lut ||
             drm_color_lut_size(crtc_state->degamma_lut) == degamma_length) &&
            (!crtc_state->gamma_lut ||
             drm_color_lut_size(crtc_state->gamma_lut) == gamma_length))
                return 0;

        /*
         * We also allow no degamma lut/ctm and a gamma lut at the legacy
         * size (256 entries).
         */
        if (crtc_state_is_legacy_gamma(crtc_state))
                return 0;

        return -EINVAL;
}

void intel_color_init(struct drm_crtc *crtc)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->dev);

        drm_mode_crtc_set_gamma_size(crtc, 256);

        if (IS_CHERRYVIEW(dev_priv)) {
                dev_priv->display.load_csc_matrix = cherryview_load_csc_matrix;
                dev_priv->display.load_luts = cherryview_load_luts;
        } else if (IS_HASWELL(dev_priv)) {
                dev_priv->display.load_csc_matrix = ilk_load_csc_matrix;
                dev_priv->display.load_luts = haswell_load_luts;
        } else if (IS_BROADWELL(dev_priv) || IS_GEN9_BC(dev_priv) ||
                   IS_BROXTON(dev_priv)) {
                dev_priv->display.load_csc_matrix = ilk_load_csc_matrix;
                dev_priv->display.load_luts = broadwell_load_luts;
        } else if (IS_GEMINILAKE(dev_priv) || IS_CANNONLAKE(dev_priv)) {
                dev_priv->display.load_csc_matrix = ilk_load_csc_matrix;
                dev_priv->display.load_luts = glk_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_priv)->color.degamma_lut_size != 0 &&
            INTEL_INFO(dev_priv)->color.gamma_lut_size != 0)
                drm_crtc_enable_color_mgmt(crtc,
                                           INTEL_INFO(dev_priv)->color.degamma_lut_size,
                                           true,
                                           INTEL_INFO(dev_priv)->color.gamma_lut_size);
}