/*
 * Copyright © 2006-2017 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"

/**
 * DOC: CDCLK / RAWCLK
 *
 * The display engine uses several different clocks to do its work. There
 * are two main clocks involved that aren't directly related to the actual
 * pixel clock or any symbol/bit clock of the actual output port. These
 * are the core display clock (CDCLK) and RAWCLK.
 *
 * CDCLK clocks most of the display pipe logic, and thus its frequency
 * must be high enough to support the rate at which pixels are flowing
 * through the pipes. Downscaling must also be accounted as that increases
 * the effective pixel rate.
 *
 * On several platforms the CDCLK frequency can be changed dynamically
 * to minimize power consumption for a given display configuration.
 * Typically changes to the CDCLK frequency require all the display pipes
 * to be shut down while the frequency is being changed.
 *
 * On SKL+ the DMC will toggle the CDCLK off/on during DC5/6 entry/exit.
 * DMC will not change the active CDCLK frequency however, so that part
 * will still be performed by the driver directly.
 *
 * RAWCLK is a fixed frequency clock, often used by various auxiliary
 * blocks such as AUX CH or backlight PWM. Hence the only thing we
 * really need to know about RAWCLK is its frequency so that various
 * dividers can be programmed correctly.
 */

static void fixed_133mhz_get_cdclk(struct drm_i915_private *dev_priv,
                                   struct intel_cdclk_state *cdclk_state)
{
        cdclk_state->cdclk = 133333;
}

static void fixed_200mhz_get_cdclk(struct drm_i915_private *dev_priv,
                                   struct intel_cdclk_state *cdclk_state)
{
        cdclk_state->cdclk = 200000;
}

static void fixed_266mhz_get_cdclk(struct drm_i915_private *dev_priv,
                                   struct intel_cdclk_state *cdclk_state)
{
        cdclk_state->cdclk = 266667;
}

static void fixed_333mhz_get_cdclk(struct drm_i915_private *dev_priv,
                                   struct intel_cdclk_state *cdclk_state)
{
        cdclk_state->cdclk = 333333;
}

static void fixed_400mhz_get_cdclk(struct drm_i915_private *dev_priv,
                                   struct intel_cdclk_state *cdclk_state)
{
        cdclk_state->cdclk = 400000;
}

static void fixed_450mhz_get_cdclk(struct drm_i915_private *dev_priv,
                                   struct intel_cdclk_state *cdclk_state)
{
        cdclk_state->cdclk = 450000;
}

static void i85x_get_cdclk(struct drm_i915_private *dev_priv,
                           struct intel_cdclk_state *cdclk_state)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        u16 hpllcc = 0;

        /*
         * 852GM/852GMV only supports 133 MHz and the HPLLCC
         * encoding is different :(
         * FIXME is this the right way to detect 852GM/852GMV?
         */
        if (pdev->revision == 0x1) {
                cdclk_state->cdclk = 133333;
                return;
        }

        pci_bus_read_config_word(pdev->bus,
                                 PCI_DEVFN(0, 3), HPLLCC, &hpllcc);

        /* Assume that the hardware is in the high speed state.  This
         * should be the default.
         */
        switch (hpllcc & GC_CLOCK_CONTROL_MASK) {
        case GC_CLOCK_133_200:
        case GC_CLOCK_133_200_2:
        case GC_CLOCK_100_200:
                cdclk_state->cdclk = 200000;
                break;
        case GC_CLOCK_166_250:
                cdclk_state->cdclk = 250000;
                break;
        case GC_CLOCK_100_133:
                cdclk_state->cdclk = 133333;
                break;
        case GC_CLOCK_133_266:
        case GC_CLOCK_133_266_2:
        case GC_CLOCK_166_266:
                cdclk_state->cdclk = 266667;
                break;
        }
}

static void i915gm_get_cdclk(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_state *cdclk_state)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        u16 gcfgc = 0;

        pci_read_config_word(pdev, GCFGC, &gcfgc);

        if (gcfgc & GC_LOW_FREQUENCY_ENABLE) {
                cdclk_state->cdclk = 133333;
                return;
        }

        switch (gcfgc & GC_DISPLAY_CLOCK_MASK) {
        case GC_DISPLAY_CLOCK_333_320_MHZ:
                cdclk_state->cdclk = 333333;
                break;
        default:
        case GC_DISPLAY_CLOCK_190_200_MHZ:
                cdclk_state->cdclk = 190000;
                break;
        }
}

static void i945gm_get_cdclk(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_state *cdclk_state)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        u16 gcfgc = 0;

        pci_read_config_word(pdev, GCFGC, &gcfgc);

        if (gcfgc & GC_LOW_FREQUENCY_ENABLE) {
                cdclk_state->cdclk = 133333;
                return;
        }

        switch (gcfgc & GC_DISPLAY_CLOCK_MASK) {
        case GC_DISPLAY_CLOCK_333_320_MHZ:
                cdclk_state->cdclk = 320000;
                break;
        default:
        case GC_DISPLAY_CLOCK_190_200_MHZ:
                cdclk_state->cdclk = 200000;
                break;
        }
}

static unsigned int intel_hpll_vco(struct drm_i915_private *dev_priv)
{
        static const unsigned int blb_vco[8] = {
                [0] = 3200000,
                [1] = 4000000,
                [2] = 5333333,
                [3] = 4800000,
                [4] = 6400000,
        };
        static const unsigned int pnv_vco[8] = {
                [0] = 3200000,
                [1] = 4000000,
                [2] = 5333333,
                [3] = 4800000,
                [4] = 2666667,
        };
        static const unsigned int cl_vco[8] = {
                [0] = 3200000,
                [1] = 4000000,
                [2] = 5333333,
                [3] = 6400000,
                [4] = 3333333,
                [5] = 3566667,
                [6] = 4266667,
        };
        static const unsigned int elk_vco[8] = {
                [0] = 3200000,
                [1] = 4000000,
                [2] = 5333333,
                [3] = 4800000,
        };
        static const unsigned int ctg_vco[8] = {
                [0] = 3200000,
                [1] = 4000000,
                [2] = 5333333,
                [3] = 6400000,
                [4] = 2666667,
                [5] = 4266667,
        };
        const unsigned int *vco_table;
        unsigned int vco;
        uint8_t tmp = 0;

        /* FIXME other chipsets? */
        if (IS_GM45(dev_priv))
                vco_table = ctg_vco;
        else if (IS_G45(dev_priv))
                vco_table = elk_vco;
        else if (IS_I965GM(dev_priv))
                vco_table = cl_vco;
        else if (IS_PINEVIEW(dev_priv))
                vco_table = pnv_vco;
        else if (IS_G33(dev_priv))
                vco_table = blb_vco;
        else
                return 0;

        tmp = I915_READ(IS_MOBILE(dev_priv) ? HPLLVCO_MOBILE : HPLLVCO);

        vco = vco_table[tmp & 0x7];
        if (vco == 0)
                DRM_ERROR("Bad HPLL VCO (HPLLVCO=0x%02x)\n", tmp);
        else
                DRM_DEBUG_KMS("HPLL VCO %u kHz\n", vco);

        return vco;
}

static void g33_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        static const uint8_t div_3200[] = { 12, 10,  8,  7, 5, 16 };
        static const uint8_t div_4000[] = { 14, 12, 10,  8, 6, 20 };
        static const uint8_t div_4800[] = { 20, 14, 12, 10, 8, 24 };
        static const uint8_t div_5333[] = { 20, 16, 12, 12, 8, 28 };
        const uint8_t *div_table;
        unsigned int cdclk_sel;
        uint16_t tmp = 0;

        cdclk_state->vco = intel_hpll_vco(dev_priv);

        pci_read_config_word(pdev, GCFGC, &tmp);

        cdclk_sel = (tmp >> 4) & 0x7;

        if (cdclk_sel >= ARRAY_SIZE(div_3200))
                goto fail;

        switch (cdclk_state->vco) {
        case 3200000:
                div_table = div_3200;
                break;
        case 4000000:
                div_table = div_4000;
                break;
        case 4800000:
                div_table = div_4800;
                break;
        case 5333333:
                div_table = div_5333;
                break;
        default:
                goto fail;
        }

        cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco,
                                               div_table[cdclk_sel]);
        return;

fail:
        DRM_ERROR("Unable to determine CDCLK. HPLL VCO=%u kHz, CFGC=0x%08x\n",
                  cdclk_state->vco, tmp);
        cdclk_state->cdclk = 190476;
}

static void pnv_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        u16 gcfgc = 0;

        pci_read_config_word(pdev, GCFGC, &gcfgc);

        switch (gcfgc & GC_DISPLAY_CLOCK_MASK) {
        case GC_DISPLAY_CLOCK_267_MHZ_PNV:
                cdclk_state->cdclk = 266667;
                break;
        case GC_DISPLAY_CLOCK_333_MHZ_PNV:
                cdclk_state->cdclk = 333333;
                break;
        case GC_DISPLAY_CLOCK_444_MHZ_PNV:
                cdclk_state->cdclk = 444444;
                break;
        case GC_DISPLAY_CLOCK_200_MHZ_PNV:
                cdclk_state->cdclk = 200000;
                break;
        default:
                DRM_ERROR("Unknown pnv display core clock 0x%04x\n", gcfgc);
                /* fall through */
        case GC_DISPLAY_CLOCK_133_MHZ_PNV:
                cdclk_state->cdclk = 133333;
                break;
        case GC_DISPLAY_CLOCK_167_MHZ_PNV:
                cdclk_state->cdclk = 166667;
                break;
        }
}

static void i965gm_get_cdclk(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_state *cdclk_state)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        static const uint8_t div_3200[] = { 16, 10,  8 };
        static const uint8_t div_4000[] = { 20, 12, 10 };
        static const uint8_t div_5333[] = { 24, 16, 14 };
        const uint8_t *div_table;
        unsigned int cdclk_sel;
        uint16_t tmp = 0;

        cdclk_state->vco = intel_hpll_vco(dev_priv);

        pci_read_config_word(pdev, GCFGC, &tmp);

        cdclk_sel = ((tmp >> 8) & 0x1f) - 1;

        if (cdclk_sel >= ARRAY_SIZE(div_3200))
                goto fail;

        switch (cdclk_state->vco) {
        case 3200000:
                div_table = div_3200;
                break;
        case 4000000:
                div_table = div_4000;
                break;
        case 5333333:
                div_table = div_5333;
                break;
        default:
                goto fail;
        }

        cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco,
                                               div_table[cdclk_sel]);
        return;

fail:
        DRM_ERROR("Unable to determine CDCLK. HPLL VCO=%u kHz, CFGC=0x%04x\n",
                  cdclk_state->vco, tmp);
        cdclk_state->cdclk = 200000;
}

static void gm45_get_cdclk(struct drm_i915_private *dev_priv,
                           struct intel_cdclk_state *cdclk_state)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        unsigned int cdclk_sel;
        uint16_t tmp = 0;

        cdclk_state->vco = intel_hpll_vco(dev_priv);

        pci_read_config_word(pdev, GCFGC, &tmp);

        cdclk_sel = (tmp >> 12) & 0x1;

        switch (cdclk_state->vco) {
        case 2666667:
        case 4000000:
        case 5333333:
                cdclk_state->cdclk = cdclk_sel ? 333333 : 222222;
                break;
        case 3200000:
                cdclk_state->cdclk = cdclk_sel ? 320000 : 228571;
                break;
        default:
                DRM_ERROR("Unable to determine CDCLK. HPLL VCO=%u, CFGC=0x%04x\n",
                          cdclk_state->vco, tmp);
                cdclk_state->cdclk = 222222;
                break;
        }
}

static void hsw_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        uint32_t lcpll = I915_READ(LCPLL_CTL);
        uint32_t freq = lcpll & LCPLL_CLK_FREQ_MASK;

        if (lcpll & LCPLL_CD_SOURCE_FCLK)
                cdclk_state->cdclk = 800000;
        else if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
                cdclk_state->cdclk = 450000;
        else if (freq == LCPLL_CLK_FREQ_450)
                cdclk_state->cdclk = 450000;
        else if (IS_HSW_ULT(dev_priv))
                cdclk_state->cdclk = 337500;
        else
                cdclk_state->cdclk = 540000;
}

static int vlv_calc_cdclk(struct drm_i915_private *dev_priv, int min_cdclk)
{
        int freq_320 = (dev_priv->hpll_freq <<  1) % 320000 != 0 ?
                333333 : 320000;

        /*
         * We seem to get an unstable or solid color picture at 200MHz.
         * Not sure what's wrong. For now use 200MHz only when all pipes
         * are off.
         */
        if (IS_VALLEYVIEW(dev_priv) && min_cdclk > freq_320)
                return 400000;
        else if (min_cdclk > 266667)
                return freq_320;
        else if (min_cdclk > 0)
                return 266667;
        else
                return 200000;
}

static u8 vlv_calc_voltage_level(struct drm_i915_private *dev_priv, int cdclk)
{
        if (IS_VALLEYVIEW(dev_priv)) {
                if (cdclk >= 320000) /* jump to highest voltage for 400MHz too */
                        return 2;
                else if (cdclk >= 266667)
                        return 1;
                else
                        return 0;
        } else {
                /*
                 * Specs are full of misinformation, but testing on actual
                 * hardware has shown that we just need to write the desired
                 * CCK divider into the Punit register.
                 */
                return DIV_ROUND_CLOSEST(dev_priv->hpll_freq << 1, cdclk) - 1;
        }
}

static void vlv_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        u32 val;

        cdclk_state->vco = vlv_get_hpll_vco(dev_priv);
        cdclk_state->cdclk = vlv_get_cck_clock(dev_priv, "cdclk",
                                               CCK_DISPLAY_CLOCK_CONTROL,
                                               cdclk_state->vco);

        mutex_lock(&dev_priv->pcu_lock);
        val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
        mutex_unlock(&dev_priv->pcu_lock);

        if (IS_VALLEYVIEW(dev_priv))
                cdclk_state->voltage_level = (val & DSPFREQGUAR_MASK) >>
                        DSPFREQGUAR_SHIFT;
        else
                cdclk_state->voltage_level = (val & DSPFREQGUAR_MASK_CHV) >>
                        DSPFREQGUAR_SHIFT_CHV;
}

static void vlv_program_pfi_credits(struct drm_i915_private *dev_priv)
{
        unsigned int credits, default_credits;

        if (IS_CHERRYVIEW(dev_priv))
                default_credits = PFI_CREDIT(12);
        else
                default_credits = PFI_CREDIT(8);

        if (dev_priv->cdclk.hw.cdclk >= dev_priv->czclk_freq) {
                /* CHV suggested value is 31 or 63 */
                if (IS_CHERRYVIEW(dev_priv))
                        credits = PFI_CREDIT_63;
                else
                        credits = PFI_CREDIT(15);
        } else {
                credits = default_credits;
        }

        /*
         * WA - write default credits before re-programming
         * FIXME: should we also set the resend bit here?
         */
        I915_WRITE(GCI_CONTROL, VGA_FAST_MODE_DISABLE |
                   default_credits);

        I915_WRITE(GCI_CONTROL, VGA_FAST_MODE_DISABLE |
                   credits | PFI_CREDIT_RESEND);

        /*
         * FIXME is this guaranteed to clear
         * immediately or should we poll for it?
         */
        WARN_ON(I915_READ(GCI_CONTROL) & PFI_CREDIT_RESEND);
}

static void vlv_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_state *cdclk_state)
{
        int cdclk = cdclk_state->cdclk;
        u32 val, cmd = cdclk_state->voltage_level;

        switch (cdclk) {
        case 400000:
        case 333333:
        case 320000:
        case 266667:
        case 200000:
                break;
        default:
                MISSING_CASE(cdclk);
                return;
        }

        /* There are cases where we can end up here with power domains
         * off and a CDCLK frequency other than the minimum, like when
         * issuing a modeset without actually changing any display after
         * a system suspend.  So grab the PIPE-A domain, which covers
         * the HW blocks needed for the following programming.
         */
        intel_display_power_get(dev_priv, POWER_DOMAIN_PIPE_A);

        mutex_lock(&dev_priv->pcu_lock);
        val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
        val &= ~DSPFREQGUAR_MASK;
        val |= (cmd << DSPFREQGUAR_SHIFT);
        vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);
        if (wait_for((vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ) &
                      DSPFREQSTAT_MASK) == (cmd << DSPFREQSTAT_SHIFT),
                     50)) {
                DRM_ERROR("timed out waiting for CDclk change\n");
        }
        mutex_unlock(&dev_priv->pcu_lock);

        mutex_lock(&dev_priv->sb_lock);

        if (cdclk == 400000) {
                u32 divider;

                divider = DIV_ROUND_CLOSEST(dev_priv->hpll_freq << 1,
                                            cdclk) - 1;

                /* adjust cdclk divider */
                val = vlv_cck_read(dev_priv, CCK_DISPLAY_CLOCK_CONTROL);
                val &= ~CCK_FREQUENCY_VALUES;
                val |= divider;
                vlv_cck_write(dev_priv, CCK_DISPLAY_CLOCK_CONTROL, val);

                if (wait_for((vlv_cck_read(dev_priv, CCK_DISPLAY_CLOCK_CONTROL) &
                              CCK_FREQUENCY_STATUS) == (divider << CCK_FREQUENCY_STATUS_SHIFT),
                             50))
                        DRM_ERROR("timed out waiting for CDclk change\n");
        }

        /* adjust self-refresh exit latency value */
        val = vlv_bunit_read(dev_priv, BUNIT_REG_BISOC);
        val &= ~0x7f;

        /*
         * For high bandwidth configs, we set a higher latency in the bunit
         * so that the core display fetch happens in time to avoid underruns.
         */
        if (cdclk == 400000)
                val |= 4500 / 250; /* 4.5 usec */
        else
                val |= 3000 / 250; /* 3.0 usec */
        vlv_bunit_write(dev_priv, BUNIT_REG_BISOC, val);

        mutex_unlock(&dev_priv->sb_lock);

        intel_update_cdclk(dev_priv);

        vlv_program_pfi_credits(dev_priv);

        intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE_A);
}

static void chv_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_state *cdclk_state)
{
        int cdclk = cdclk_state->cdclk;
        u32 val, cmd = cdclk_state->voltage_level;

        switch (cdclk) {
        case 333333:
        case 320000:
        case 266667:
        case 200000:
                break;
        default:
                MISSING_CASE(cdclk);
                return;
        }

        /* There are cases where we can end up here with power domains
         * off and a CDCLK frequency other than the minimum, like when
         * issuing a modeset without actually changing any display after
         * a system suspend.  So grab the PIPE-A domain, which covers
         * the HW blocks needed for the following programming.
         */
        intel_display_power_get(dev_priv, POWER_DOMAIN_PIPE_A);

        mutex_lock(&dev_priv->pcu_lock);
        val = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
        val &= ~DSPFREQGUAR_MASK_CHV;
        val |= (cmd << DSPFREQGUAR_SHIFT_CHV);
        vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, val);
        if (wait_for((vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ) &
                      DSPFREQSTAT_MASK_CHV) == (cmd << DSPFREQSTAT_SHIFT_CHV),
                     50)) {
                DRM_ERROR("timed out waiting for CDclk change\n");
        }
        mutex_unlock(&dev_priv->pcu_lock);

        intel_update_cdclk(dev_priv);

        vlv_program_pfi_credits(dev_priv);

        intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE_A);
}

static int bdw_calc_cdclk(int min_cdclk)
{
        if (min_cdclk > 540000)
                return 675000;
        else if (min_cdclk > 450000)
                return 540000;
        else if (min_cdclk > 337500)
                return 450000;
        else
                return 337500;
}

static u8 bdw_calc_voltage_level(int cdclk)
{
        switch (cdclk) {
        default:
        case 337500:
                return 2;
        case 450000:
                return 0;
        case 540000:
                return 1;
        case 675000:
                return 3;
        }
}

static void bdw_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        uint32_t lcpll = I915_READ(LCPLL_CTL);
        uint32_t freq = lcpll & LCPLL_CLK_FREQ_MASK;

        if (lcpll & LCPLL_CD_SOURCE_FCLK)
                cdclk_state->cdclk = 800000;
        else if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
                cdclk_state->cdclk = 450000;
        else if (freq == LCPLL_CLK_FREQ_450)
                cdclk_state->cdclk = 450000;
        else if (freq == LCPLL_CLK_FREQ_54O_BDW)
                cdclk_state->cdclk = 540000;
        else if (freq == LCPLL_CLK_FREQ_337_5_BDW)
                cdclk_state->cdclk = 337500;
        else
                cdclk_state->cdclk = 675000;

        /*
         * Can't read this out :( Let's assume it's
         * at least what the CDCLK frequency requires.
         */
        cdclk_state->voltage_level =
                bdw_calc_voltage_level(cdclk_state->cdclk);
}

static void bdw_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_state *cdclk_state)
{
        int cdclk = cdclk_state->cdclk;
        uint32_t val;
        int ret;

        if (WARN((I915_READ(LCPLL_CTL) &
                  (LCPLL_PLL_DISABLE | LCPLL_PLL_LOCK |
                   LCPLL_CD_CLOCK_DISABLE | LCPLL_ROOT_CD_CLOCK_DISABLE |
                   LCPLL_CD2X_CLOCK_DISABLE | LCPLL_POWER_DOWN_ALLOW |
                   LCPLL_CD_SOURCE_FCLK)) != LCPLL_PLL_LOCK,
                 "trying to change cdclk frequency with cdclk not enabled\n"))
                return;

        mutex_lock(&dev_priv->pcu_lock);
        ret = sandybridge_pcode_write(dev_priv,
                                      BDW_PCODE_DISPLAY_FREQ_CHANGE_REQ, 0x0);
        mutex_unlock(&dev_priv->pcu_lock);
        if (ret) {
                DRM_ERROR("failed to inform pcode about cdclk change\n");
                return;
        }

        val = I915_READ(LCPLL_CTL);
        val |= LCPLL_CD_SOURCE_FCLK;
        I915_WRITE(LCPLL_CTL, val);

        /*
         * According to the spec, it should be enough to poll for this 1 us.
         * However, extensive testing shows that this can take longer.
         */
        if (wait_for_us(I915_READ(LCPLL_CTL) &
                        LCPLL_CD_SOURCE_FCLK_DONE, 100))
                DRM_ERROR("Switching to FCLK failed\n");

        val = I915_READ(LCPLL_CTL);
        val &= ~LCPLL_CLK_FREQ_MASK;

        switch (cdclk) {
        default:
                MISSING_CASE(cdclk);
                /* fall through */
        case 337500:
                val |= LCPLL_CLK_FREQ_337_5_BDW;
                break;
        case 450000:
                val |= LCPLL_CLK_FREQ_450;
                break;
        case 540000:
                val |= LCPLL_CLK_FREQ_54O_BDW;
                break;
        case 675000:
                val |= LCPLL_CLK_FREQ_675_BDW;
                break;
        }

        I915_WRITE(LCPLL_CTL, val);

        val = I915_READ(LCPLL_CTL);
        val &= ~LCPLL_CD_SOURCE_FCLK;
        I915_WRITE(LCPLL_CTL, val);

        if (wait_for_us((I915_READ(LCPLL_CTL) &
                        LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
                DRM_ERROR("Switching back to LCPLL failed\n");

        mutex_lock(&dev_priv->pcu_lock);
        sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
                                cdclk_state->voltage_level);
        mutex_unlock(&dev_priv->pcu_lock);

        I915_WRITE(CDCLK_FREQ, DIV_ROUND_CLOSEST(cdclk, 1000) - 1);

        intel_update_cdclk(dev_priv);
}

static int skl_calc_cdclk(int min_cdclk, int vco)
{
        if (vco == 8640000) {
                if (min_cdclk > 540000)
                        return 617143;
                else if (min_cdclk > 432000)
                        return 540000;
                else if (min_cdclk > 308571)
                        return 432000;
                else
                        return 308571;
        } else {
                if (min_cdclk > 540000)
                        return 675000;
                else if (min_cdclk > 450000)
                        return 540000;
                else if (min_cdclk > 337500)
                        return 450000;
                else
                        return 337500;
        }
}

static u8 skl_calc_voltage_level(int cdclk)
{
        switch (cdclk) {
        default:
        case 308571:
        case 337500:
                return 0;
        case 450000:
        case 432000:
                return 1;
        case 540000:
                return 2;
        case 617143:
        case 675000:
                return 3;
        }
}

static void skl_dpll0_update(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_state *cdclk_state)
{
        u32 val;

        cdclk_state->ref = 24000;
        cdclk_state->vco = 0;

        val = I915_READ(LCPLL1_CTL);
        if ((val & LCPLL_PLL_ENABLE) == 0)
                return;

        if (WARN_ON((val & LCPLL_PLL_LOCK) == 0))
                return;

        val = I915_READ(DPLL_CTRL1);

        if (WARN_ON((val & (DPLL_CTRL1_HDMI_MODE(SKL_DPLL0) |
                            DPLL_CTRL1_SSC(SKL_DPLL0) |
                            DPLL_CTRL1_OVERRIDE(SKL_DPLL0))) !=
                    DPLL_CTRL1_OVERRIDE(SKL_DPLL0)))
                return;

        switch (val & DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0)) {
        case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_810, SKL_DPLL0):
        case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1350, SKL_DPLL0):
        case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1620, SKL_DPLL0):
        case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2700, SKL_DPLL0):
                cdclk_state->vco = 8100000;
                break;
        case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1080, SKL_DPLL0):
        case DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2160, SKL_DPLL0):
                cdclk_state->vco = 8640000;
                break;
        default:
                MISSING_CASE(val & DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0));
                break;
        }
}

static void skl_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        u32 cdctl;

        skl_dpll0_update(dev_priv, cdclk_state);

        cdclk_state->cdclk = cdclk_state->bypass = cdclk_state->ref;

        if (cdclk_state->vco == 0)
                goto out;

        cdctl = I915_READ(CDCLK_CTL);

        if (cdclk_state->vco == 8640000) {
                switch (cdctl & CDCLK_FREQ_SEL_MASK) {
                case CDCLK_FREQ_450_432:
                        cdclk_state->cdclk = 432000;
                        break;
                case CDCLK_FREQ_337_308:
                        cdclk_state->cdclk = 308571;
                        break;
                case CDCLK_FREQ_540:
                        cdclk_state->cdclk = 540000;
                        break;
                case CDCLK_FREQ_675_617:
                        cdclk_state->cdclk = 617143;
                        break;
                default:
                        MISSING_CASE(cdctl & CDCLK_FREQ_SEL_MASK);
                        break;
                }
        } else {
                switch (cdctl & CDCLK_FREQ_SEL_MASK) {
                case CDCLK_FREQ_450_432:
                        cdclk_state->cdclk = 450000;
                        break;
                case CDCLK_FREQ_337_308:
                        cdclk_state->cdclk = 337500;
                        break;
                case CDCLK_FREQ_540:
                        cdclk_state->cdclk = 540000;
                        break;
                case CDCLK_FREQ_675_617:
                        cdclk_state->cdclk = 675000;
                        break;
                default:
                        MISSING_CASE(cdctl & CDCLK_FREQ_SEL_MASK);
                        break;
                }
        }

 out:
        /*
         * Can't read this out :( Let's assume it's
         * at least what the CDCLK frequency requires.
         */
        cdclk_state->voltage_level =
                skl_calc_voltage_level(cdclk_state->cdclk);
}

/* convert from kHz to .1 fixpoint MHz with -1MHz offset */
static int skl_cdclk_decimal(int cdclk)
{
        return DIV_ROUND_CLOSEST(cdclk - 1000, 500);
}

static void skl_set_preferred_cdclk_vco(struct drm_i915_private *dev_priv,
                                        int vco)
{
        bool changed = dev_priv->skl_preferred_vco_freq != vco;

        dev_priv->skl_preferred_vco_freq = vco;

        if (changed)
                intel_update_max_cdclk(dev_priv);
}

static void skl_dpll0_enable(struct drm_i915_private *dev_priv, int vco)
{
        u32 val;

        WARN_ON(vco != 8100000 && vco != 8640000);

        /*
         * We always enable DPLL0 with the lowest link rate possible, but still
         * taking into account the VCO required to operate the eDP panel at the
         * desired frequency. The usual DP link rates operate with a VCO of
         * 8100 while the eDP 1.4 alternate link rates need a VCO of 8640.
         * The modeset code is responsible for the selection of the exact link
         * rate later on, with the constraint of choosing a frequency that
         * works with vco.
         */
        val = I915_READ(DPLL_CTRL1);

        val &= ~(DPLL_CTRL1_HDMI_MODE(SKL_DPLL0) | DPLL_CTRL1_SSC(SKL_DPLL0) |
                 DPLL_CTRL1_LINK_RATE_MASK(SKL_DPLL0));
        val |= DPLL_CTRL1_OVERRIDE(SKL_DPLL0);
        if (vco == 8640000)
                val |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1080,
                                            SKL_DPLL0);
        else
                val |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_810,
                                            SKL_DPLL0);

        I915_WRITE(DPLL_CTRL1, val);
        POSTING_READ(DPLL_CTRL1);

        I915_WRITE(LCPLL1_CTL, I915_READ(LCPLL1_CTL) | LCPLL_PLL_ENABLE);

        if (intel_wait_for_register(dev_priv,
                                    LCPLL1_CTL, LCPLL_PLL_LOCK, LCPLL_PLL_LOCK,
                                    5))
                DRM_ERROR("DPLL0 not locked\n");

        dev_priv->cdclk.hw.vco = vco;

        /* We'll want to keep using the current vco from now on. */
        skl_set_preferred_cdclk_vco(dev_priv, vco);
}

static void skl_dpll0_disable(struct drm_i915_private *dev_priv)
{
        I915_WRITE(LCPLL1_CTL, I915_READ(LCPLL1_CTL) & ~LCPLL_PLL_ENABLE);
        if (intel_wait_for_register(dev_priv,
                                   LCPLL1_CTL, LCPLL_PLL_LOCK, 0,
                                   1))
                DRM_ERROR("Couldn't disable DPLL0\n");

        dev_priv->cdclk.hw.vco = 0;
}

static void skl_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_state *cdclk_state)
{
        int cdclk = cdclk_state->cdclk;
        int vco = cdclk_state->vco;
        u32 freq_select, cdclk_ctl;
        int ret;

        /*
         * Based on WA#1183 CDCLK rates 308 and 617MHz CDCLK rates are
         * unsupported on SKL. In theory this should never happen since only
         * the eDP1.4 2.16 and 4.32Gbps rates require it, but eDP1.4 is not
         * supported on SKL either, see the above WA. WARN whenever trying to
         * use the corresponding VCO freq as that always leads to using the
         * minimum 308MHz CDCLK.
         */
        WARN_ON_ONCE(IS_SKYLAKE(dev_priv) && vco == 8640000);

        mutex_lock(&dev_priv->pcu_lock);
        ret = skl_pcode_request(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                SKL_CDCLK_PREPARE_FOR_CHANGE,
                                SKL_CDCLK_READY_FOR_CHANGE,
                                SKL_CDCLK_READY_FOR_CHANGE, 3);
        mutex_unlock(&dev_priv->pcu_lock);
        if (ret) {
                DRM_ERROR("Failed to inform PCU about cdclk change (%d)\n",
                          ret);
                return;
        }

        /* Choose frequency for this cdclk */
        switch (cdclk) {
        default:
                WARN_ON(cdclk != dev_priv->cdclk.hw.bypass);
                WARN_ON(vco != 0);
                /* fall through */
        case 308571:
        case 337500:
                freq_select = CDCLK_FREQ_337_308;
                break;
        case 450000:
        case 432000:
                freq_select = CDCLK_FREQ_450_432;
                break;
        case 540000:
                freq_select = CDCLK_FREQ_540;
                break;
        case 617143:
        case 675000:
                freq_select = CDCLK_FREQ_675_617;
                break;
        }

        if (dev_priv->cdclk.hw.vco != 0 &&
            dev_priv->cdclk.hw.vco != vco)
                skl_dpll0_disable(dev_priv);

        cdclk_ctl = I915_READ(CDCLK_CTL);

        if (dev_priv->cdclk.hw.vco != vco) {
                /* Wa Display #1183: skl,kbl,cfl */
                cdclk_ctl &= ~(CDCLK_FREQ_SEL_MASK | CDCLK_FREQ_DECIMAL_MASK);
                cdclk_ctl |= freq_select | skl_cdclk_decimal(cdclk);
                I915_WRITE(CDCLK_CTL, cdclk_ctl);
        }

        /* Wa Display #1183: skl,kbl,cfl */
        cdclk_ctl |= CDCLK_DIVMUX_CD_OVERRIDE;
        I915_WRITE(CDCLK_CTL, cdclk_ctl);
        POSTING_READ(CDCLK_CTL);

        if (dev_priv->cdclk.hw.vco != vco)
                skl_dpll0_enable(dev_priv, vco);

        /* Wa Display #1183: skl,kbl,cfl */
        cdclk_ctl &= ~(CDCLK_FREQ_SEL_MASK | CDCLK_FREQ_DECIMAL_MASK);
        I915_WRITE(CDCLK_CTL, cdclk_ctl);

        cdclk_ctl |= freq_select | skl_cdclk_decimal(cdclk);
        I915_WRITE(CDCLK_CTL, cdclk_ctl);

        /* Wa Display #1183: skl,kbl,cfl */
        cdclk_ctl &= ~CDCLK_DIVMUX_CD_OVERRIDE;
        I915_WRITE(CDCLK_CTL, cdclk_ctl);
        POSTING_READ(CDCLK_CTL);

        /* inform PCU of the change */
        mutex_lock(&dev_priv->pcu_lock);
        sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                cdclk_state->voltage_level);
        mutex_unlock(&dev_priv->pcu_lock);

        intel_update_cdclk(dev_priv);
}

static void skl_sanitize_cdclk(struct drm_i915_private *dev_priv)
{
        uint32_t cdctl, expected;

        /*
         * check if the pre-os initialized the display
         * There is SWF18 scratchpad register defined which is set by the
         * pre-os which can be used by the OS drivers to check the status
         */
        if ((I915_READ(SWF_ILK(0x18)) & 0x00FFFFFF) == 0)
                goto sanitize;

        intel_update_cdclk(dev_priv);
        intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");

        /* Is PLL enabled and locked ? */
        if (dev_priv->cdclk.hw.vco == 0 ||
            dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.bypass)
                goto sanitize;

        /* DPLL okay; verify the cdclock
         *
         * Noticed in some instances that the freq selection is correct but
         * decimal part is programmed wrong from BIOS where pre-os does not
         * enable display. Verify the same as well.
         */
        cdctl = I915_READ(CDCLK_CTL);
        expected = (cdctl & CDCLK_FREQ_SEL_MASK) |
                skl_cdclk_decimal(dev_priv->cdclk.hw.cdclk);
        if (cdctl == expected)
                /* All well; nothing to sanitize */
                return;

sanitize:
        DRM_DEBUG_KMS("Sanitizing cdclk programmed by pre-os\n");

        /* force cdclk programming */
        dev_priv->cdclk.hw.cdclk = 0;
        /* force full PLL disable + enable */
        dev_priv->cdclk.hw.vco = -1;
}

/**
 * skl_init_cdclk - Initialize CDCLK on SKL
 * @dev_priv: i915 device
 *
 * Initialize CDCLK for SKL and derivatives. This is generally
 * done only during the display core initialization sequence,
 * after which the DMC will take care of turning CDCLK off/on
 * as needed.
 */
void skl_init_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state cdclk_state;

        skl_sanitize_cdclk(dev_priv);

        if (dev_priv->cdclk.hw.cdclk != 0 &&
            dev_priv->cdclk.hw.vco != 0) {
                /*
                 * Use the current vco as our initial
                 * guess as to what the preferred vco is.
                 */
                if (dev_priv->skl_preferred_vco_freq == 0)
                        skl_set_preferred_cdclk_vco(dev_priv,
                                                    dev_priv->cdclk.hw.vco);
                return;
        }

        cdclk_state = dev_priv->cdclk.hw;

        cdclk_state.vco = dev_priv->skl_preferred_vco_freq;
        if (cdclk_state.vco == 0)
                cdclk_state.vco = 8100000;
        cdclk_state.cdclk = skl_calc_cdclk(0, cdclk_state.vco);
        cdclk_state.voltage_level = skl_calc_voltage_level(cdclk_state.cdclk);

        skl_set_cdclk(dev_priv, &cdclk_state);
}

/**
 * skl_uninit_cdclk - Uninitialize CDCLK on SKL
 * @dev_priv: i915 device
 *
 * Uninitialize CDCLK for SKL and derivatives. This is done only
 * during the display core uninitialization sequence.
 */
void skl_uninit_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state cdclk_state = dev_priv->cdclk.hw;

        cdclk_state.cdclk = cdclk_state.bypass;
        cdclk_state.vco = 0;
        cdclk_state.voltage_level = skl_calc_voltage_level(cdclk_state.cdclk);

        skl_set_cdclk(dev_priv, &cdclk_state);
}

static int bxt_calc_cdclk(int min_cdclk)
{
        if (min_cdclk > 576000)
                return 624000;
        else if (min_cdclk > 384000)
                return 576000;
        else if (min_cdclk > 288000)
                return 384000;
        else if (min_cdclk > 144000)
                return 288000;
        else
                return 144000;
}

static int glk_calc_cdclk(int min_cdclk)
{
        if (min_cdclk > 158400)
                return 316800;
        else if (min_cdclk > 79200)
                return 158400;
        else
                return 79200;
}

static u8 bxt_calc_voltage_level(int cdclk)
{
        return DIV_ROUND_UP(cdclk, 25000);
}

static int bxt_de_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
{
        int ratio;

        if (cdclk == dev_priv->cdclk.hw.bypass)
                return 0;

        switch (cdclk) {
        default:
                MISSING_CASE(cdclk);
                /* fall through */
        case 144000:
        case 288000:
        case 384000:
        case 576000:
                ratio = 60;
                break;
        case 624000:
                ratio = 65;
                break;
        }

        return dev_priv->cdclk.hw.ref * ratio;
}

static int glk_de_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
{
        int ratio;

        if (cdclk == dev_priv->cdclk.hw.bypass)
                return 0;

        switch (cdclk) {
        default:
                MISSING_CASE(cdclk);
                /* fall through */
        case  79200:
        case 158400:
        case 316800:
                ratio = 33;
                break;
        }

        return dev_priv->cdclk.hw.ref * ratio;
}

static void bxt_de_pll_update(struct drm_i915_private *dev_priv,
                              struct intel_cdclk_state *cdclk_state)
{
        u32 val;

        cdclk_state->ref = 19200;
        cdclk_state->vco = 0;

        val = I915_READ(BXT_DE_PLL_ENABLE);
        if ((val & BXT_DE_PLL_PLL_ENABLE) == 0)
                return;

        if (WARN_ON((val & BXT_DE_PLL_LOCK) == 0))
                return;

        val = I915_READ(BXT_DE_PLL_CTL);
        cdclk_state->vco = (val & BXT_DE_PLL_RATIO_MASK) * cdclk_state->ref;
}

static void bxt_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        u32 divider;
        int div;

        bxt_de_pll_update(dev_priv, cdclk_state);

        cdclk_state->cdclk = cdclk_state->bypass = cdclk_state->ref;

        if (cdclk_state->vco == 0)
                goto out;

        divider = I915_READ(CDCLK_CTL) & BXT_CDCLK_CD2X_DIV_SEL_MASK;

        switch (divider) {
        case BXT_CDCLK_CD2X_DIV_SEL_1:
                div = 2;
                break;
        case BXT_CDCLK_CD2X_DIV_SEL_1_5:
                WARN(IS_GEMINILAKE(dev_priv), "Unsupported divider\n");
                div = 3;
                break;
        case BXT_CDCLK_CD2X_DIV_SEL_2:
                div = 4;
                break;
        case BXT_CDCLK_CD2X_DIV_SEL_4:
                div = 8;
                break;
        default:
                MISSING_CASE(divider);
                return;
        }

        cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco, div);

 out:
        /*
         * Can't read this out :( Let's assume it's
         * at least what the CDCLK frequency requires.
         */
        cdclk_state->voltage_level =
                bxt_calc_voltage_level(cdclk_state->cdclk);
}

static void bxt_de_pll_disable(struct drm_i915_private *dev_priv)
{
        I915_WRITE(BXT_DE_PLL_ENABLE, 0);

        /* Timeout 200us */
        if (intel_wait_for_register(dev_priv,
                                    BXT_DE_PLL_ENABLE, BXT_DE_PLL_LOCK, 0,
                                    1))
                DRM_ERROR("timeout waiting for DE PLL unlock\n");

        dev_priv->cdclk.hw.vco = 0;
}

static void bxt_de_pll_enable(struct drm_i915_private *dev_priv, int vco)
{
        int ratio = DIV_ROUND_CLOSEST(vco, dev_priv->cdclk.hw.ref);
        u32 val;

        val = I915_READ(BXT_DE_PLL_CTL);
        val &= ~BXT_DE_PLL_RATIO_MASK;
        val |= BXT_DE_PLL_RATIO(ratio);
        I915_WRITE(BXT_DE_PLL_CTL, val);

        I915_WRITE(BXT_DE_PLL_ENABLE, BXT_DE_PLL_PLL_ENABLE);

        /* Timeout 200us */
        if (intel_wait_for_register(dev_priv,
                                    BXT_DE_PLL_ENABLE,
                                    BXT_DE_PLL_LOCK,
                                    BXT_DE_PLL_LOCK,
                                    1))
                DRM_ERROR("timeout waiting for DE PLL lock\n");

        dev_priv->cdclk.hw.vco = vco;
}

static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_state *cdclk_state)
{
        int cdclk = cdclk_state->cdclk;
        int vco = cdclk_state->vco;
        u32 val, divider;
        int ret;

        /* cdclk = vco / 2 / div{1,1.5,2,4} */
        switch (DIV_ROUND_CLOSEST(vco, cdclk)) {
        default:
                WARN_ON(cdclk != dev_priv->cdclk.hw.bypass);
                WARN_ON(vco != 0);
                /* fall through */
        case 2:
                divider = BXT_CDCLK_CD2X_DIV_SEL_1;
                break;
        case 3:
                WARN(IS_GEMINILAKE(dev_priv), "Unsupported divider\n");
                divider = BXT_CDCLK_CD2X_DIV_SEL_1_5;
                break;
        case 4:
                divider = BXT_CDCLK_CD2X_DIV_SEL_2;
                break;
        case 8:
                divider = BXT_CDCLK_CD2X_DIV_SEL_4;
                break;
        }

        /*
         * Inform power controller of upcoming frequency change. BSpec
         * requires us to wait up to 150usec, but that leads to timeouts;
         * the 2ms used here is based on experiment.
         */
        mutex_lock(&dev_priv->pcu_lock);
        ret = sandybridge_pcode_write_timeout(dev_priv,
                                              HSW_PCODE_DE_WRITE_FREQ_REQ,
                                              0x80000000, 150, 2);
        mutex_unlock(&dev_priv->pcu_lock);

        if (ret) {
                DRM_ERROR("PCode CDCLK freq change notify failed (err %d, freq %d)\n",
                          ret, cdclk);
                return;
        }

        if (dev_priv->cdclk.hw.vco != 0 &&
            dev_priv->cdclk.hw.vco != vco)
                bxt_de_pll_disable(dev_priv);

        if (dev_priv->cdclk.hw.vco != vco)
                bxt_de_pll_enable(dev_priv, vco);

        val = divider | skl_cdclk_decimal(cdclk);
        /*
         * FIXME if only the cd2x divider needs changing, it could be done
         * without shutting off the pipe (if only one pipe is active).
         */
        val |= BXT_CDCLK_CD2X_PIPE_NONE;
        /*
         * Disable SSA Precharge when CD clock frequency < 500 MHz,
         * enable otherwise.
         */
        if (cdclk >= 500000)
                val |= BXT_CDCLK_SSA_PRECHARGE_ENABLE;
        I915_WRITE(CDCLK_CTL, val);

        mutex_lock(&dev_priv->pcu_lock);
        /*
         * The timeout isn't specified, the 2ms used here is based on
         * experiment.
         * FIXME: Waiting for the request completion could be delayed until
         * the next PCODE request based on BSpec.
         */
        ret = sandybridge_pcode_write_timeout(dev_priv,
                                              HSW_PCODE_DE_WRITE_FREQ_REQ,
                                              cdclk_state->voltage_level, 150, 2);
        mutex_unlock(&dev_priv->pcu_lock);

        if (ret) {
                DRM_ERROR("PCode CDCLK freq set failed, (err %d, freq %d)\n",
                          ret, cdclk);
                return;
        }

        intel_update_cdclk(dev_priv);
}

static void bxt_sanitize_cdclk(struct drm_i915_private *dev_priv)
{
        u32 cdctl, expected;

        intel_update_cdclk(dev_priv);
        intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");

        if (dev_priv->cdclk.hw.vco == 0 ||
            dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.bypass)
                goto sanitize;

        /* DPLL okay; verify the cdclock
         *
         * Some BIOS versions leave an incorrect decimal frequency value and
         * set reserved MBZ bits in CDCLK_CTL at least during exiting from S4,
         * so sanitize this register.
         */
        cdctl = I915_READ(CDCLK_CTL);
        /*
         * Let's ignore the pipe field, since BIOS could have configured the
         * dividers both synching to an active pipe, or asynchronously
         * (PIPE_NONE).
         */
        cdctl &= ~BXT_CDCLK_CD2X_PIPE_NONE;

        expected = (cdctl & BXT_CDCLK_CD2X_DIV_SEL_MASK) |
                skl_cdclk_decimal(dev_priv->cdclk.hw.cdclk);
        /*
         * Disable SSA Precharge when CD clock frequency < 500 MHz,
         * enable otherwise.
         */
        if (dev_priv->cdclk.hw.cdclk >= 500000)
                expected |= BXT_CDCLK_SSA_PRECHARGE_ENABLE;

        if (cdctl == expected)
                /* All well; nothing to sanitize */
                return;

sanitize:
        DRM_DEBUG_KMS("Sanitizing cdclk programmed by pre-os\n");

        /* force cdclk programming */
        dev_priv->cdclk.hw.cdclk = 0;

        /* force full PLL disable + enable */
        dev_priv->cdclk.hw.vco = -1;
}

/**
 * bxt_init_cdclk - Initialize CDCLK on BXT
 * @dev_priv: i915 device
 *
 * Initialize CDCLK for BXT and derivatives. This is generally
 * done only during the display core initialization sequence,
 * after which the DMC will take care of turning CDCLK off/on
 * as needed.
 */
void bxt_init_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state cdclk_state;

        bxt_sanitize_cdclk(dev_priv);

        if (dev_priv->cdclk.hw.cdclk != 0 &&
            dev_priv->cdclk.hw.vco != 0)
                return;

        cdclk_state = dev_priv->cdclk.hw;

        /*
         * FIXME:
         * - The initial CDCLK needs to be read from VBT.
         *   Need to make this change after VBT has changes for BXT.
         */
        if (IS_GEMINILAKE(dev_priv)) {
                cdclk_state.cdclk = glk_calc_cdclk(0);
                cdclk_state.vco = glk_de_pll_vco(dev_priv, cdclk_state.cdclk);
        } else {
                cdclk_state.cdclk = bxt_calc_cdclk(0);
                cdclk_state.vco = bxt_de_pll_vco(dev_priv, cdclk_state.cdclk);
        }
        cdclk_state.voltage_level = bxt_calc_voltage_level(cdclk_state.cdclk);

        bxt_set_cdclk(dev_priv, &cdclk_state);
}

/**
 * bxt_uninit_cdclk - Uninitialize CDCLK on BXT
 * @dev_priv: i915 device
 *
 * Uninitialize CDCLK for BXT and derivatives. This is done only
 * during the display core uninitialization sequence.
 */
void bxt_uninit_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state cdclk_state = dev_priv->cdclk.hw;

        cdclk_state.cdclk = cdclk_state.bypass;
        cdclk_state.vco = 0;
        cdclk_state.voltage_level = bxt_calc_voltage_level(cdclk_state.cdclk);

        bxt_set_cdclk(dev_priv, &cdclk_state);
}

static int cnl_calc_cdclk(int min_cdclk)
{
        if (min_cdclk > 336000)
                return 528000;
        else if (min_cdclk > 168000)
                return 336000;
        else
                return 168000;
}

static u8 cnl_calc_voltage_level(int cdclk)
{
        switch (cdclk) {
        default:
        case 168000:
                return 0;
        case 336000:
                return 1;
        case 528000:
                return 2;
        }
}

static void cnl_cdclk_pll_update(struct drm_i915_private *dev_priv,
                                 struct intel_cdclk_state *cdclk_state)
{
        u32 val;

        if (I915_READ(SKL_DSSM) & CNL_DSSM_CDCLK_PLL_REFCLK_24MHz)
                cdclk_state->ref = 24000;
        else
                cdclk_state->ref = 19200;

        cdclk_state->vco = 0;

        val = I915_READ(BXT_DE_PLL_ENABLE);
        if ((val & BXT_DE_PLL_PLL_ENABLE) == 0)
                return;

        if (WARN_ON((val & BXT_DE_PLL_LOCK) == 0))
                return;

        cdclk_state->vco = (val & CNL_CDCLK_PLL_RATIO_MASK) * cdclk_state->ref;
}

static void cnl_get_cdclk(struct drm_i915_private *dev_priv,
                         struct intel_cdclk_state *cdclk_state)
{
        u32 divider;
        int div;

        cnl_cdclk_pll_update(dev_priv, cdclk_state);

        cdclk_state->cdclk = cdclk_state->bypass = cdclk_state->ref;

        if (cdclk_state->vco == 0)
                goto out;

        divider = I915_READ(CDCLK_CTL) & BXT_CDCLK_CD2X_DIV_SEL_MASK;

        switch (divider) {
        case BXT_CDCLK_CD2X_DIV_SEL_1:
                div = 2;
                break;
        case BXT_CDCLK_CD2X_DIV_SEL_2:
                div = 4;
                break;
        default:
                MISSING_CASE(divider);
                return;
        }

        cdclk_state->cdclk = DIV_ROUND_CLOSEST(cdclk_state->vco, div);

 out:
        /*
         * Can't read this out :( Let's assume it's
         * at least what the CDCLK frequency requires.
         */
        cdclk_state->voltage_level =
                cnl_calc_voltage_level(cdclk_state->cdclk);
}

static void cnl_cdclk_pll_disable(struct drm_i915_private *dev_priv)
{
        u32 val;

        val = I915_READ(BXT_DE_PLL_ENABLE);
        val &= ~BXT_DE_PLL_PLL_ENABLE;
        I915_WRITE(BXT_DE_PLL_ENABLE, val);

        /* Timeout 200us */
        if (wait_for((I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK) == 0, 1))
                DRM_ERROR("timeout waiting for CDCLK PLL unlock\n");

        dev_priv->cdclk.hw.vco = 0;
}

static void cnl_cdclk_pll_enable(struct drm_i915_private *dev_priv, int vco)
{
        int ratio = DIV_ROUND_CLOSEST(vco, dev_priv->cdclk.hw.ref);
        u32 val;

        val = CNL_CDCLK_PLL_RATIO(ratio);
        I915_WRITE(BXT_DE_PLL_ENABLE, val);

        val |= BXT_DE_PLL_PLL_ENABLE;
        I915_WRITE(BXT_DE_PLL_ENABLE, val);

        /* Timeout 200us */
        if (wait_for((I915_READ(BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK) != 0, 1))
                DRM_ERROR("timeout waiting for CDCLK PLL lock\n");

        dev_priv->cdclk.hw.vco = vco;
}

static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_state *cdclk_state)
{
        int cdclk = cdclk_state->cdclk;
        int vco = cdclk_state->vco;
        u32 val, divider;
        int ret;

        mutex_lock(&dev_priv->pcu_lock);
        ret = skl_pcode_request(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                SKL_CDCLK_PREPARE_FOR_CHANGE,
                                SKL_CDCLK_READY_FOR_CHANGE,
                                SKL_CDCLK_READY_FOR_CHANGE, 3);
        mutex_unlock(&dev_priv->pcu_lock);
        if (ret) {
                DRM_ERROR("Failed to inform PCU about cdclk change (%d)\n",
                          ret);
                return;
        }

        /* cdclk = vco / 2 / div{1,2} */
        switch (DIV_ROUND_CLOSEST(vco, cdclk)) {
        default:
                WARN_ON(cdclk != dev_priv->cdclk.hw.bypass);
                WARN_ON(vco != 0);
                /* fall through */
        case 2:
                divider = BXT_CDCLK_CD2X_DIV_SEL_1;
                break;
        case 4:
                divider = BXT_CDCLK_CD2X_DIV_SEL_2;
                break;
        }

        if (dev_priv->cdclk.hw.vco != 0 &&
            dev_priv->cdclk.hw.vco != vco)
                cnl_cdclk_pll_disable(dev_priv);

        if (dev_priv->cdclk.hw.vco != vco)
                cnl_cdclk_pll_enable(dev_priv, vco);

        val = divider | skl_cdclk_decimal(cdclk);
        /*
         * FIXME if only the cd2x divider needs changing, it could be done
         * without shutting off the pipe (if only one pipe is active).
         */
        val |= BXT_CDCLK_CD2X_PIPE_NONE;
        I915_WRITE(CDCLK_CTL, val);

        /* inform PCU of the change */
        mutex_lock(&dev_priv->pcu_lock);
        sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                cdclk_state->voltage_level);
        mutex_unlock(&dev_priv->pcu_lock);

        intel_update_cdclk(dev_priv);

        /*
         * Can't read out the voltage level :(
         * Let's just assume everything is as expected.
         */
        dev_priv->cdclk.hw.voltage_level = cdclk_state->voltage_level;
}

static int cnl_cdclk_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
{
        int ratio;

        if (cdclk == dev_priv->cdclk.hw.bypass)
                return 0;

        switch (cdclk) {
        default:
                MISSING_CASE(cdclk);
                /* fall through */
        case 168000:
        case 336000:
                ratio = dev_priv->cdclk.hw.ref == 19200 ? 35 : 28;
                break;
        case 528000:
                ratio = dev_priv->cdclk.hw.ref == 19200 ? 55 : 44;
                break;
        }

        return dev_priv->cdclk.hw.ref * ratio;
}

static void cnl_sanitize_cdclk(struct drm_i915_private *dev_priv)
{
        u32 cdctl, expected;

        intel_update_cdclk(dev_priv);
        intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");

        if (dev_priv->cdclk.hw.vco == 0 ||
            dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.bypass)
                goto sanitize;

        /* DPLL okay; verify the cdclock
         *
         * Some BIOS versions leave an incorrect decimal frequency value and
         * set reserved MBZ bits in CDCLK_CTL at least during exiting from S4,
         * so sanitize this register.
         */
        cdctl = I915_READ(CDCLK_CTL);
        /*
         * Let's ignore the pipe field, since BIOS could have configured the
         * dividers both synching to an active pipe, or asynchronously
         * (PIPE_NONE).
         */
        cdctl &= ~BXT_CDCLK_CD2X_PIPE_NONE;

        expected = (cdctl & BXT_CDCLK_CD2X_DIV_SEL_MASK) |
                   skl_cdclk_decimal(dev_priv->cdclk.hw.cdclk);

        if (cdctl == expected)
                /* All well; nothing to sanitize */
                return;

sanitize:
        DRM_DEBUG_KMS("Sanitizing cdclk programmed by pre-os\n");

        /* force cdclk programming */
        dev_priv->cdclk.hw.cdclk = 0;

        /* force full PLL disable + enable */
        dev_priv->cdclk.hw.vco = -1;
}

static int icl_calc_cdclk(int min_cdclk, unsigned int ref)
{
        int ranges_24[] = { 312000, 552000, 648000 };
        int ranges_19_38[] = { 307200, 556800, 652800 };
        int *ranges;

        switch (ref) {
        default:
                MISSING_CASE(ref);
                /* fall through */
        case 24000:
                ranges = ranges_24;
                break;
        case 19200:
        case 38400:
                ranges = ranges_19_38;
                break;
        }

        if (min_cdclk > ranges[1])
                return ranges[2];
        else if (min_cdclk > ranges[0])
                return ranges[1];
        else
                return ranges[0];
}

static int icl_calc_cdclk_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
{
        int ratio;

        if (cdclk == dev_priv->cdclk.hw.bypass)
                return 0;

        switch (cdclk) {
        default:
                MISSING_CASE(cdclk);
                /* fall through */
        case 307200:
        case 556800:
        case 652800:
                WARN_ON(dev_priv->cdclk.hw.ref != 19200 &&
                        dev_priv->cdclk.hw.ref != 38400);
                break;
        case 312000:
        case 552000:
        case 648000:
                WARN_ON(dev_priv->cdclk.hw.ref != 24000);
        }

        ratio = cdclk / (dev_priv->cdclk.hw.ref / 2);

        return dev_priv->cdclk.hw.ref * ratio;
}

static void icl_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_state *cdclk_state)
{
        unsigned int cdclk = cdclk_state->cdclk;
        unsigned int vco = cdclk_state->vco;
        int ret;

        mutex_lock(&dev_priv->pcu_lock);
        ret = skl_pcode_request(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                SKL_CDCLK_PREPARE_FOR_CHANGE,
                                SKL_CDCLK_READY_FOR_CHANGE,
                                SKL_CDCLK_READY_FOR_CHANGE, 3);
        mutex_unlock(&dev_priv->pcu_lock);
        if (ret) {
                DRM_ERROR("Failed to inform PCU about cdclk change (%d)\n",
                          ret);
                return;
        }

        if (dev_priv->cdclk.hw.vco != 0 &&
            dev_priv->cdclk.hw.vco != vco)
                cnl_cdclk_pll_disable(dev_priv);

        if (dev_priv->cdclk.hw.vco != vco)
                cnl_cdclk_pll_enable(dev_priv, vco);

        I915_WRITE(CDCLK_CTL, ICL_CDCLK_CD2X_PIPE_NONE |
                              skl_cdclk_decimal(cdclk));

        mutex_lock(&dev_priv->pcu_lock);
        sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                cdclk_state->voltage_level);
        mutex_unlock(&dev_priv->pcu_lock);

        intel_update_cdclk(dev_priv);

        /*
         * Can't read out the voltage level :(
         * Let's just assume everything is as expected.
         */
        dev_priv->cdclk.hw.voltage_level = cdclk_state->voltage_level;
}

static u8 icl_calc_voltage_level(int cdclk)
{
        switch (cdclk) {
        case 50000:
        case 307200:
        case 312000:
                return 0;
        case 556800:
        case 552000:
                return 1;
        default:
                MISSING_CASE(cdclk);
                /* fall through */
        case 652800:
        case 648000:
                return 2;
        }
}

static void icl_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_state *cdclk_state)
{
        u32 val;

        cdclk_state->bypass = 50000;

        val = I915_READ(SKL_DSSM);
        switch (val & ICL_DSSM_CDCLK_PLL_REFCLK_MASK) {
        default:
                MISSING_CASE(val);
                /* fall through */
        case ICL_DSSM_CDCLK_PLL_REFCLK_24MHz:
                cdclk_state->ref = 24000;
                break;
        case ICL_DSSM_CDCLK_PLL_REFCLK_19_2MHz:
                cdclk_state->ref = 19200;
                break;
        case ICL_DSSM_CDCLK_PLL_REFCLK_38_4MHz:
                cdclk_state->ref = 38400;
                break;
        }

        val = I915_READ(BXT_DE_PLL_ENABLE);
        if ((val & BXT_DE_PLL_PLL_ENABLE) == 0 ||
            (val & BXT_DE_PLL_LOCK) == 0) {
                /*
                 * CDCLK PLL is disabled, the VCO/ratio doesn't matter, but
                 * setting it to zero is a way to signal that.
                 */
                cdclk_state->vco = 0;
                cdclk_state->cdclk = cdclk_state->bypass;
                goto out;
        }

        cdclk_state->vco = (val & BXT_DE_PLL_RATIO_MASK) * cdclk_state->ref;

        val = I915_READ(CDCLK_CTL);
        WARN_ON((val & BXT_CDCLK_CD2X_DIV_SEL_MASK) != 0);

        cdclk_state->cdclk = cdclk_state->vco / 2;

out:
        /*
         * Can't read this out :( Let's assume it's
         * at least what the CDCLK frequency requires.
         */
        cdclk_state->voltage_level =
                icl_calc_voltage_level(cdclk_state->cdclk);
}

/**
 * icl_init_cdclk - Initialize CDCLK on ICL
 * @dev_priv: i915 device
 *
 * Initialize CDCLK for ICL. This consists mainly of initializing
 * dev_priv->cdclk.hw and sanitizing the state of the hardware if needed. This
 * is generally done only during the display core initialization sequence, after
 * which the DMC will take care of turning CDCLK off/on as needed.
 */
void icl_init_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state sanitized_state;
        u32 val;

        /* This sets dev_priv->cdclk.hw. */
        intel_update_cdclk(dev_priv);
        intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");

        /* This means CDCLK disabled. */
        if (dev_priv->cdclk.hw.cdclk == dev_priv->cdclk.hw.bypass)
                goto sanitize;

        val = I915_READ(CDCLK_CTL);

        if ((val & BXT_CDCLK_CD2X_DIV_SEL_MASK) != 0)
                goto sanitize;

        if ((val & CDCLK_FREQ_DECIMAL_MASK) !=
            skl_cdclk_decimal(dev_priv->cdclk.hw.cdclk))
                goto sanitize;

        return;

sanitize:
        DRM_DEBUG_KMS("Sanitizing cdclk programmed by pre-os\n");

        sanitized_state.ref = dev_priv->cdclk.hw.ref;
        sanitized_state.cdclk = icl_calc_cdclk(0, sanitized_state.ref);
        sanitized_state.vco = icl_calc_cdclk_pll_vco(dev_priv,
                                                     sanitized_state.cdclk);
        sanitized_state.voltage_level =
                                icl_calc_voltage_level(sanitized_state.cdclk);

        icl_set_cdclk(dev_priv, &sanitized_state);
}

/**
 * icl_uninit_cdclk - Uninitialize CDCLK on ICL
 * @dev_priv: i915 device
 *
 * Uninitialize CDCLK for ICL. This is done only during the display core
 * uninitialization sequence.
 */
void icl_uninit_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state cdclk_state = dev_priv->cdclk.hw;

        cdclk_state.cdclk = cdclk_state.bypass;
        cdclk_state.vco = 0;
        cdclk_state.voltage_level = icl_calc_voltage_level(cdclk_state.cdclk);

        icl_set_cdclk(dev_priv, &cdclk_state);
}

/**
 * cnl_init_cdclk - Initialize CDCLK on CNL
 * @dev_priv: i915 device
 *
 * Initialize CDCLK for CNL. This is generally
 * done only during the display core initialization sequence,
 * after which the DMC will take care of turning CDCLK off/on
 * as needed.
 */
void cnl_init_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state cdclk_state;

        cnl_sanitize_cdclk(dev_priv);

        if (dev_priv->cdclk.hw.cdclk != 0 &&
            dev_priv->cdclk.hw.vco != 0)
                return;

        cdclk_state = dev_priv->cdclk.hw;

        cdclk_state.cdclk = cnl_calc_cdclk(0);
        cdclk_state.vco = cnl_cdclk_pll_vco(dev_priv, cdclk_state.cdclk);
        cdclk_state.voltage_level = cnl_calc_voltage_level(cdclk_state.cdclk);

        cnl_set_cdclk(dev_priv, &cdclk_state);
}

/**
 * cnl_uninit_cdclk - Uninitialize CDCLK on CNL
 * @dev_priv: i915 device
 *
 * Uninitialize CDCLK for CNL. This is done only
 * during the display core uninitialization sequence.
 */
void cnl_uninit_cdclk(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state cdclk_state = dev_priv->cdclk.hw;

        cdclk_state.cdclk = cdclk_state.bypass;
        cdclk_state.vco = 0;
        cdclk_state.voltage_level = cnl_calc_voltage_level(cdclk_state.cdclk);

        cnl_set_cdclk(dev_priv, &cdclk_state);
}

/**
 * intel_cdclk_needs_modeset - Determine if two CDCLK states require a modeset on all pipes
 * @a: first CDCLK state
 * @b: second CDCLK state
 *
 * Returns:
 * True if the CDCLK states require pipes to be off during reprogramming, false if not.
 */
bool intel_cdclk_needs_modeset(const struct intel_cdclk_state *a,
                               const struct intel_cdclk_state *b)
{
        return a->cdclk != b->cdclk ||
                a->vco != b->vco ||
                a->ref != b->ref;
}

/**
 * intel_cdclk_changed - Determine if two CDCLK states are different
 * @a: first CDCLK state
 * @b: second CDCLK state
 *
 * Returns:
 * True if the CDCLK states don't match, false if they do.
 */
bool intel_cdclk_changed(const struct intel_cdclk_state *a,
                         const struct intel_cdclk_state *b)
{
        return intel_cdclk_needs_modeset(a, b) ||
                a->voltage_level != b->voltage_level;
}

void intel_dump_cdclk_state(const struct intel_cdclk_state *cdclk_state,
                            const char *context)
{
        DRM_DEBUG_DRIVER("%s %d kHz, VCO %d kHz, ref %d kHz, bypass %d kHz, voltage level %d\n",
                         context, cdclk_state->cdclk, cdclk_state->vco,
                         cdclk_state->ref, cdclk_state->bypass,
                         cdclk_state->voltage_level);
}

/**
 * intel_set_cdclk - Push the CDCLK state to the hardware
 * @dev_priv: i915 device
 * @cdclk_state: new CDCLK state
 *
 * Program the hardware based on the passed in CDCLK state,
 * if necessary.
 */
void intel_set_cdclk(struct drm_i915_private *dev_priv,
                     const struct intel_cdclk_state *cdclk_state)
{
        if (!intel_cdclk_changed(&dev_priv->cdclk.hw, cdclk_state))
                return;

        if (WARN_ON_ONCE(!dev_priv->display.set_cdclk))
                return;

        intel_dump_cdclk_state(cdclk_state, "Changing CDCLK to");

        dev_priv->display.set_cdclk(dev_priv, cdclk_state);

        if (WARN(intel_cdclk_changed(&dev_priv->cdclk.hw, cdclk_state),
                 "cdclk state doesn't match!\n")) {
                intel_dump_cdclk_state(&dev_priv->cdclk.hw, "[hw state]");
                intel_dump_cdclk_state(cdclk_state, "[sw state]");
        }
}

static int intel_pixel_rate_to_cdclk(struct drm_i915_private *dev_priv,
                                     int pixel_rate)
{
        if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
                return DIV_ROUND_UP(pixel_rate, 2);
        else if (IS_GEN9(dev_priv) ||
                 IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
                return pixel_rate;
        else if (IS_CHERRYVIEW(dev_priv))
                return DIV_ROUND_UP(pixel_rate * 100, 95);
        else
                return DIV_ROUND_UP(pixel_rate * 100, 90);
}

int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv =
                to_i915(crtc_state->base.crtc->dev);
        int min_cdclk;

        if (!crtc_state->base.enable)
                return 0;

        min_cdclk = intel_pixel_rate_to_cdclk(dev_priv, crtc_state->pixel_rate);

        /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
        if (IS_BROADWELL(dev_priv) && hsw_crtc_state_ips_capable(crtc_state))
                min_cdclk = DIV_ROUND_UP(min_cdclk * 100, 95);

        /* BSpec says "Do not use DisplayPort with CDCLK less than 432 MHz,
         * audio enabled, port width x4, and link rate HBR2 (5.4 GHz), or else
         * there may be audio corruption or screen corruption." This cdclk
         * restriction for GLK is 316.8 MHz.
         */
        if (intel_crtc_has_dp_encoder(crtc_state) &&
            crtc_state->has_audio &&
            crtc_state->port_clock >= 540000 &&
            crtc_state->lane_count == 4) {
                if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
                        /* Display WA #1145: glk,cnl */
                        min_cdclk = max(316800, min_cdclk);
                } else if (IS_GEN9(dev_priv) || IS_BROADWELL(dev_priv)) {
                        /* Display WA #1144: skl,bxt */
                        min_cdclk = max(432000, min_cdclk);
                }
        }

        /*
         * According to BSpec, "The CD clock frequency must be at least twice
         * the frequency of the Azalia BCLK." and BCLK is 96 MHz by default.
         *
         * FIXME: Check the actual, not default, BCLK being used.
         *
         * FIXME: This does not depend on ->has_audio because the higher CDCLK
         * is required for audio probe, also when there are no audio capable
         * displays connected at probe time. This leads to unnecessarily high
         * CDCLK when audio is not required.
         *
         * FIXME: This limit is only applied when there are displays connected
         * at probe time. If we probe without displays, we'll still end up using
         * the platform minimum CDCLK, failing audio probe.
         */
        if (INTEL_GEN(dev_priv) >= 9)
                min_cdclk = max(2 * 96000, min_cdclk);

        /*
         * On Valleyview some DSI panels lose (v|h)sync when the clock is lower
         * than 320000KHz.
         */
        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI) &&
            IS_VALLEYVIEW(dev_priv))
                min_cdclk = max(320000, min_cdclk);

        if (min_cdclk > dev_priv->max_cdclk_freq) {
                DRM_DEBUG_KMS("required cdclk (%d kHz) exceeds max (%d kHz)\n",
                              min_cdclk, dev_priv->max_cdclk_freq);
                return -EINVAL;
        }

        return min_cdclk;
}

static int intel_compute_min_cdclk(struct drm_atomic_state *state)
{
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        struct intel_crtc *crtc;
        struct intel_crtc_state *crtc_state;
        int min_cdclk, i;
        enum i915_pipe pipe;

        memcpy(intel_state->min_cdclk, dev_priv->min_cdclk,
               sizeof(intel_state->min_cdclk));

        for_each_new_intel_crtc_in_state(intel_state, crtc, crtc_state, i) {
                min_cdclk = intel_crtc_compute_min_cdclk(crtc_state);
                if (min_cdclk < 0)
                        return min_cdclk;

                intel_state->min_cdclk[i] = min_cdclk;
        }

        min_cdclk = 0;
        for_each_pipe(dev_priv, pipe)
                min_cdclk = max(intel_state->min_cdclk[pipe], min_cdclk);

        return min_cdclk;
}

/*
 * Note that this functions assumes that 0 is
 * the lowest voltage value, and higher values
 * correspond to increasingly higher voltages.
 *
 * Should that relationship no longer hold on
 * future platforms this code will need to be
 * adjusted.
 */
static u8 cnl_compute_min_voltage_level(struct intel_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        struct intel_crtc *crtc;
        struct intel_crtc_state *crtc_state;
        u8 min_voltage_level;
        int i;
        enum i915_pipe pipe;

        memcpy(state->min_voltage_level, dev_priv->min_voltage_level,
               sizeof(state->min_voltage_level));

        for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
                if (crtc_state->base.enable)
                        state->min_voltage_level[i] =
                                crtc_state->min_voltage_level;
                else
                        state->min_voltage_level[i] = 0;
        }

        min_voltage_level = 0;
        for_each_pipe(dev_priv, pipe)
                min_voltage_level = max(state->min_voltage_level[pipe],
                                        min_voltage_level);

        return min_voltage_level;
}

static int vlv_modeset_calc_cdclk(struct drm_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        int min_cdclk, cdclk;

        min_cdclk = intel_compute_min_cdclk(state);
        if (min_cdclk < 0)
                return min_cdclk;

        cdclk = vlv_calc_cdclk(dev_priv, min_cdclk);

        intel_state->cdclk.logical.cdclk = cdclk;
        intel_state->cdclk.logical.voltage_level =
                vlv_calc_voltage_level(dev_priv, cdclk);

        if (!intel_state->active_crtcs) {
                cdclk = vlv_calc_cdclk(dev_priv, 0);

                intel_state->cdclk.actual.cdclk = cdclk;
                intel_state->cdclk.actual.voltage_level =
                        vlv_calc_voltage_level(dev_priv, cdclk);
        } else {
                intel_state->cdclk.actual =
                        intel_state->cdclk.logical;
        }

        return 0;
}

static int bdw_modeset_calc_cdclk(struct drm_atomic_state *state)
{
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        int min_cdclk, cdclk;

        min_cdclk = intel_compute_min_cdclk(state);
        if (min_cdclk < 0)
                return min_cdclk;

        /*
         * FIXME should also account for plane ratio
         * once 64bpp pixel formats are supported.
         */
        cdclk = bdw_calc_cdclk(min_cdclk);

        intel_state->cdclk.logical.cdclk = cdclk;
        intel_state->cdclk.logical.voltage_level =
                bdw_calc_voltage_level(cdclk);

        if (!intel_state->active_crtcs) {
                cdclk = bdw_calc_cdclk(0);

                intel_state->cdclk.actual.cdclk = cdclk;
                intel_state->cdclk.actual.voltage_level =
                        bdw_calc_voltage_level(cdclk);
        } else {
                intel_state->cdclk.actual =
                        intel_state->cdclk.logical;
        }

        return 0;
}

static int skl_dpll0_vco(struct intel_atomic_state *intel_state)
{
        struct drm_i915_private *dev_priv = to_i915(intel_state->base.dev);
        struct intel_crtc *crtc;
        struct intel_crtc_state *crtc_state;
        int vco, i;

        vco = intel_state->cdclk.logical.vco;
        if (!vco)
                vco = dev_priv->skl_preferred_vco_freq;

        for_each_new_intel_crtc_in_state(intel_state, crtc, crtc_state, i) {
                if (!crtc_state->base.enable)
                        continue;

                if (!intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP))
                        continue;

                /*
                 * DPLL0 VCO may need to be adjusted to get the correct
                 * clock for eDP. This will affect cdclk as well.
                 */
                switch (crtc_state->port_clock / 2) {
                case 108000:
                case 216000:
                        vco = 8640000;
                        break;
                default:
                        vco = 8100000;
                        break;
                }
        }

        return vco;
}

static int skl_modeset_calc_cdclk(struct drm_atomic_state *state)
{
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        int min_cdclk, cdclk, vco;

        min_cdclk = intel_compute_min_cdclk(state);
        if (min_cdclk < 0)
                return min_cdclk;

        vco = skl_dpll0_vco(intel_state);

        /*
         * FIXME should also account for plane ratio
         * once 64bpp pixel formats are supported.
         */
        cdclk = skl_calc_cdclk(min_cdclk, vco);

        intel_state->cdclk.logical.vco = vco;
        intel_state->cdclk.logical.cdclk = cdclk;
        intel_state->cdclk.logical.voltage_level =
                skl_calc_voltage_level(cdclk);

        if (!intel_state->active_crtcs) {
                cdclk = skl_calc_cdclk(0, vco);

                intel_state->cdclk.actual.vco = vco;
                intel_state->cdclk.actual.cdclk = cdclk;
                intel_state->cdclk.actual.voltage_level =
                        skl_calc_voltage_level(cdclk);
        } else {
                intel_state->cdclk.actual =
                        intel_state->cdclk.logical;
        }

        return 0;
}

static int bxt_modeset_calc_cdclk(struct drm_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        int min_cdclk, cdclk, vco;

        min_cdclk = intel_compute_min_cdclk(state);
        if (min_cdclk < 0)
                return min_cdclk;

        if (IS_GEMINILAKE(dev_priv)) {
                cdclk = glk_calc_cdclk(min_cdclk);
                vco = glk_de_pll_vco(dev_priv, cdclk);
        } else {
                cdclk = bxt_calc_cdclk(min_cdclk);
                vco = bxt_de_pll_vco(dev_priv, cdclk);
        }

        intel_state->cdclk.logical.vco = vco;
        intel_state->cdclk.logical.cdclk = cdclk;
        intel_state->cdclk.logical.voltage_level =
                bxt_calc_voltage_level(cdclk);

        if (!intel_state->active_crtcs) {
                if (IS_GEMINILAKE(dev_priv)) {
                        cdclk = glk_calc_cdclk(0);
                        vco = glk_de_pll_vco(dev_priv, cdclk);
                } else {
                        cdclk = bxt_calc_cdclk(0);
                        vco = bxt_de_pll_vco(dev_priv, cdclk);
                }

                intel_state->cdclk.actual.vco = vco;
                intel_state->cdclk.actual.cdclk = cdclk;
                intel_state->cdclk.actual.voltage_level =
                        bxt_calc_voltage_level(cdclk);
        } else {
                intel_state->cdclk.actual =
                        intel_state->cdclk.logical;
        }

        return 0;
}

static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        int min_cdclk, cdclk, vco;

        min_cdclk = intel_compute_min_cdclk(state);
        if (min_cdclk < 0)
                return min_cdclk;

        cdclk = cnl_calc_cdclk(min_cdclk);
        vco = cnl_cdclk_pll_vco(dev_priv, cdclk);

        intel_state->cdclk.logical.vco = vco;
        intel_state->cdclk.logical.cdclk = cdclk;
        intel_state->cdclk.logical.voltage_level =
                max(cnl_calc_voltage_level(cdclk),
                    cnl_compute_min_voltage_level(intel_state));

        if (!intel_state->active_crtcs) {
                cdclk = cnl_calc_cdclk(0);
                vco = cnl_cdclk_pll_vco(dev_priv, cdclk);

                intel_state->cdclk.actual.vco = vco;
                intel_state->cdclk.actual.cdclk = cdclk;
                intel_state->cdclk.actual.voltage_level =
                        cnl_calc_voltage_level(cdclk);
        } else {
                intel_state->cdclk.actual =
                        intel_state->cdclk.logical;
        }

        return 0;
}

static int icl_modeset_calc_cdclk(struct drm_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        struct intel_atomic_state *intel_state = to_intel_atomic_state(state);
        unsigned int ref = intel_state->cdclk.logical.ref;
        int min_cdclk, cdclk, vco;

        min_cdclk = intel_compute_min_cdclk(state);
        if (min_cdclk < 0)
                return min_cdclk;

        cdclk = icl_calc_cdclk(min_cdclk, ref);
        vco = icl_calc_cdclk_pll_vco(dev_priv, cdclk);

        intel_state->cdclk.logical.vco = vco;
        intel_state->cdclk.logical.cdclk = cdclk;
        intel_state->cdclk.logical.voltage_level =
                max(icl_calc_voltage_level(cdclk),
                    cnl_compute_min_voltage_level(intel_state));

        if (!intel_state->active_crtcs) {
                cdclk = icl_calc_cdclk(0, ref);
                vco = icl_calc_cdclk_pll_vco(dev_priv, cdclk);

                intel_state->cdclk.actual.vco = vco;
                intel_state->cdclk.actual.cdclk = cdclk;
                intel_state->cdclk.actual.voltage_level =
                        icl_calc_voltage_level(cdclk);
        } else {
                intel_state->cdclk.actual = intel_state->cdclk.logical;
        }

        return 0;
}

static int intel_compute_max_dotclk(struct drm_i915_private *dev_priv)
{
        int max_cdclk_freq = dev_priv->max_cdclk_freq;

        if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
                return 2 * max_cdclk_freq;
        else if (IS_GEN9(dev_priv) ||
                 IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
                return max_cdclk_freq;
        else if (IS_CHERRYVIEW(dev_priv))
                return max_cdclk_freq*95/100;
        else if (INTEL_GEN(dev_priv) < 4)
                return 2*max_cdclk_freq*90/100;
        else
                return max_cdclk_freq*90/100;
}

/**
 * intel_update_max_cdclk - Determine the maximum support CDCLK frequency
 * @dev_priv: i915 device
 *
 * Determine the maximum CDCLK frequency the platform supports, and also
 * derive the maximum dot clock frequency the maximum CDCLK frequency
 * allows.
 */
void intel_update_max_cdclk(struct drm_i915_private *dev_priv)
{
        if (IS_ICELAKE(dev_priv)) {
                if (dev_priv->cdclk.hw.ref == 24000)
                        dev_priv->max_cdclk_freq = 648000;
                else
                        dev_priv->max_cdclk_freq = 652800;
        } else if (IS_CANNONLAKE(dev_priv)) {
                dev_priv->max_cdclk_freq = 528000;
        } else if (IS_GEN9_BC(dev_priv)) {
                u32 limit = I915_READ(SKL_DFSM) & SKL_DFSM_CDCLK_LIMIT_MASK;
                int max_cdclk, vco;

                vco = dev_priv->skl_preferred_vco_freq;
                WARN_ON(vco != 8100000 && vco != 8640000);

                /*
                 * Use the lower (vco 8640) cdclk values as a
                 * first guess. skl_calc_cdclk() will correct it
                 * if the preferred vco is 8100 instead.
                 */
                if (limit == SKL_DFSM_CDCLK_LIMIT_675)
                        max_cdclk = 617143;
                else if (limit == SKL_DFSM_CDCLK_LIMIT_540)
                        max_cdclk = 540000;
                else if (limit == SKL_DFSM_CDCLK_LIMIT_450)
                        max_cdclk = 432000;
                else
                        max_cdclk = 308571;

                dev_priv->max_cdclk_freq = skl_calc_cdclk(max_cdclk, vco);
        } else if (IS_GEMINILAKE(dev_priv)) {
                dev_priv->max_cdclk_freq = 316800;
        } else if (IS_BROXTON(dev_priv)) {
                dev_priv->max_cdclk_freq = 624000;
        } else if (IS_BROADWELL(dev_priv))  {
                /*
                 * FIXME with extra cooling we can allow
                 * 540 MHz for ULX and 675 Mhz for ULT.
                 * How can we know if extra cooling is
                 * available? PCI ID, VTB, something else?
                 */
                if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
                        dev_priv->max_cdclk_freq = 450000;
                else if (IS_BDW_ULX(dev_priv))
                        dev_priv->max_cdclk_freq = 450000;
                else if (IS_BDW_ULT(dev_priv))
                        dev_priv->max_cdclk_freq = 540000;
                else
                        dev_priv->max_cdclk_freq = 675000;
        } else if (IS_CHERRYVIEW(dev_priv)) {
                dev_priv->max_cdclk_freq = 320000;
        } else if (IS_VALLEYVIEW(dev_priv)) {
                dev_priv->max_cdclk_freq = 400000;
        } else {
                /* otherwise assume cdclk is fixed */
                dev_priv->max_cdclk_freq = dev_priv->cdclk.hw.cdclk;
        }

        dev_priv->max_dotclk_freq = intel_compute_max_dotclk(dev_priv);

        DRM_DEBUG_DRIVER("Max CD clock rate: %d kHz\n",
                         dev_priv->max_cdclk_freq);

        DRM_DEBUG_DRIVER("Max dotclock rate: %d kHz\n",
                         dev_priv->max_dotclk_freq);
}

/**
 * intel_update_cdclk - Determine the current CDCLK frequency
 * @dev_priv: i915 device
 *
 * Determine the current CDCLK frequency.
 */
void intel_update_cdclk(struct drm_i915_private *dev_priv)
{
        dev_priv->display.get_cdclk(dev_priv, &dev_priv->cdclk.hw);

        /*
         * 9:0 CMBUS [sic] CDCLK frequency (cdfreq):
         * Programmng [sic] note: bit[9:2] should be programmed to the number
         * of cdclk that generates 4MHz reference clock freq which is used to
         * generate GMBus clock. This will vary with the cdclk freq.
         */
        if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                I915_WRITE(GMBUSFREQ_VLV,
                           DIV_ROUND_UP(dev_priv->cdclk.hw.cdclk, 1000));
}

static int cnp_rawclk(struct drm_i915_private *dev_priv)
{
        u32 rawclk;
        int divider, fraction;

        if (I915_READ(SFUSE_STRAP) & SFUSE_STRAP_RAW_FREQUENCY) {
                /* 24 MHz */
                divider = 24000;
                fraction = 0;
        } else {
                /* 19.2 MHz */
                divider = 19000;
                fraction = 200;
        }

        rawclk = CNP_RAWCLK_DIV((divider / 1000) - 1);
        if (fraction)
                rawclk |= CNP_RAWCLK_FRAC(DIV_ROUND_CLOSEST(1000,
                                                            fraction) - 1);

        I915_WRITE(PCH_RAWCLK_FREQ, rawclk);
        return divider + fraction;
}

static int icp_rawclk(struct drm_i915_private *dev_priv)
{
        u32 rawclk;
        int divider, numerator, denominator, frequency;

        if (I915_READ(SFUSE_STRAP) & SFUSE_STRAP_RAW_FREQUENCY) {
                frequency = 24000;
                divider = 23;
                numerator = 0;
                denominator = 0;
        } else {
                frequency = 19200;
                divider = 18;
                numerator = 1;
                denominator = 4;
        }

        rawclk = CNP_RAWCLK_DIV(divider) | ICP_RAWCLK_NUM(numerator) |
                 ICP_RAWCLK_DEN(denominator);

        I915_WRITE(PCH_RAWCLK_FREQ, rawclk);
        return frequency;
}

static int pch_rawclk(struct drm_i915_private *dev_priv)
{
        return (I915_READ(PCH_RAWCLK_FREQ) & RAWCLK_FREQ_MASK) * 1000;
}

static int vlv_hrawclk(struct drm_i915_private *dev_priv)
{
        /* RAWCLK_FREQ_VLV register updated from power well code */
        return vlv_get_cck_clock_hpll(dev_priv, "hrawclk",
                                      CCK_DISPLAY_REF_CLOCK_CONTROL);
}

static int g4x_hrawclk(struct drm_i915_private *dev_priv)
{
        uint32_t clkcfg;

        /* hrawclock is 1/4 the FSB frequency */
        clkcfg = I915_READ(CLKCFG);
        switch (clkcfg & CLKCFG_FSB_MASK) {
        case CLKCFG_FSB_400:
                return 100000;
        case CLKCFG_FSB_533:
                return 133333;
        case CLKCFG_FSB_667:
                return 166667;
        case CLKCFG_FSB_800:
                return 200000;
        case CLKCFG_FSB_1067:
        case CLKCFG_FSB_1067_ALT:
                return 266667;
        case CLKCFG_FSB_1333:
        case CLKCFG_FSB_1333_ALT:
                return 333333;
        default:
                return 133333;
        }
}

/**
 * intel_update_rawclk - Determine the current RAWCLK frequency
 * @dev_priv: i915 device
 *
 * Determine the current RAWCLK frequency. RAWCLK is a fixed
 * frequency clock so this needs to done only once.
 */
void intel_update_rawclk(struct drm_i915_private *dev_priv)
{
        if (HAS_PCH_ICP(dev_priv))
                dev_priv->rawclk_freq = icp_rawclk(dev_priv);
        else if (HAS_PCH_CNP(dev_priv))
                dev_priv->rawclk_freq = cnp_rawclk(dev_priv);
        else if (HAS_PCH_SPLIT(dev_priv))
                dev_priv->rawclk_freq = pch_rawclk(dev_priv);
        else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                dev_priv->rawclk_freq = vlv_hrawclk(dev_priv);
        else if (IS_G4X(dev_priv) || IS_PINEVIEW(dev_priv))
                dev_priv->rawclk_freq = g4x_hrawclk(dev_priv);
        else
                /* no rawclk on other platforms, or no need to know it */
                return;

        DRM_DEBUG_DRIVER("rawclk rate: %d kHz\n", dev_priv->rawclk_freq);
}

/**
 * intel_init_cdclk_hooks - Initialize CDCLK related modesetting hooks
 * @dev_priv: i915 device
 */
void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv)
{
        if (IS_CHERRYVIEW(dev_priv)) {
                dev_priv->display.set_cdclk = chv_set_cdclk;
                dev_priv->display.modeset_calc_cdclk =
                        vlv_modeset_calc_cdclk;
        } else if (IS_VALLEYVIEW(dev_priv)) {
                dev_priv->display.set_cdclk = vlv_set_cdclk;
                dev_priv->display.modeset_calc_cdclk =
                        vlv_modeset_calc_cdclk;
        } else if (IS_BROADWELL(dev_priv)) {
                dev_priv->display.set_cdclk = bdw_set_cdclk;
                dev_priv->display.modeset_calc_cdclk =
                        bdw_modeset_calc_cdclk;
        } else if (IS_GEN9_LP(dev_priv)) {
                dev_priv->display.set_cdclk = bxt_set_cdclk;
                dev_priv->display.modeset_calc_cdclk =
                        bxt_modeset_calc_cdclk;
        } else if (IS_GEN9_BC(dev_priv)) {
                dev_priv->display.set_cdclk = skl_set_cdclk;
                dev_priv->display.modeset_calc_cdclk =
                        skl_modeset_calc_cdclk;
        } else if (IS_CANNONLAKE(dev_priv)) {
                dev_priv->display.set_cdclk = cnl_set_cdclk;
                dev_priv->display.modeset_calc_cdclk =
                        cnl_modeset_calc_cdclk;
        } else if (IS_ICELAKE(dev_priv)) {
                dev_priv->display.set_cdclk = icl_set_cdclk;
                dev_priv->display.modeset_calc_cdclk = icl_modeset_calc_cdclk;
        }

        if (IS_ICELAKE(dev_priv))
                dev_priv->display.get_cdclk = icl_get_cdclk;
        else if (IS_CANNONLAKE(dev_priv))
                dev_priv->display.get_cdclk = cnl_get_cdclk;
        else if (IS_GEN9_BC(dev_priv))
                dev_priv->display.get_cdclk = skl_get_cdclk;
        else if (IS_GEN9_LP(dev_priv))
                dev_priv->display.get_cdclk = bxt_get_cdclk;
        else if (IS_BROADWELL(dev_priv))
                dev_priv->display.get_cdclk = bdw_get_cdclk;
        else if (IS_HASWELL(dev_priv))
                dev_priv->display.get_cdclk = hsw_get_cdclk;
        else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                dev_priv->display.get_cdclk = vlv_get_cdclk;
        else if (IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv))
                dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
        else if (IS_GEN5(dev_priv))
                dev_priv->display.get_cdclk = fixed_450mhz_get_cdclk;
        else if (IS_GM45(dev_priv))
                dev_priv->display.get_cdclk = gm45_get_cdclk;
        else if (IS_G45(dev_priv))
                dev_priv->display.get_cdclk = g33_get_cdclk;
        else if (IS_I965GM(dev_priv))
                dev_priv->display.get_cdclk = i965gm_get_cdclk;
        else if (IS_I965G(dev_priv))
                dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
        else if (IS_PINEVIEW(dev_priv))
                dev_priv->display.get_cdclk = pnv_get_cdclk;
        else if (IS_G33(dev_priv))
                dev_priv->display.get_cdclk = g33_get_cdclk;
        else if (IS_I945GM(dev_priv))
                dev_priv->display.get_cdclk = i945gm_get_cdclk;
        else if (IS_I945G(dev_priv))
                dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
        else if (IS_I915GM(dev_priv))
                dev_priv->display.get_cdclk = i915gm_get_cdclk;
        else if (IS_I915G(dev_priv))
                dev_priv->display.get_cdclk = fixed_333mhz_get_cdclk;
        else if (IS_I865G(dev_priv))
                dev_priv->display.get_cdclk = fixed_266mhz_get_cdclk;
        else if (IS_I85X(dev_priv))
                dev_priv->display.get_cdclk = i85x_get_cdclk;
        else if (IS_I845G(dev_priv))
                dev_priv->display.get_cdclk = fixed_200mhz_get_cdclk;
        else { /* 830 */
                WARN(!IS_I830(dev_priv),
                     "Unknown platform. Assuming 133 MHz CDCLK\n");
                dev_priv->display.get_cdclk = fixed_133mhz_get_cdclk;
        }
}