/*
 * 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 <linux/time.h>

#include "intel_atomic.h"
#include "intel_bw.h"
#include "intel_cdclk.h"
#include "intel_display_types.h"
#include "intel_sideband.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_config *cdclk_config)
{
        cdclk_config->cdclk = 133333;
}

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

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

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

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

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

static void i85x_get_cdclk(struct drm_i915_private *dev_priv,
                           struct intel_cdclk_config *cdclk_config)
{
        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_config->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_config->cdclk = 200000;
                break;
        case GC_CLOCK_166_250:
                cdclk_config->cdclk = 250000;
                break;
        case GC_CLOCK_100_133:
                cdclk_config->cdclk = 133333;
                break;
        case GC_CLOCK_133_266:
        case GC_CLOCK_133_266_2:
        case GC_CLOCK_166_266:
                cdclk_config->cdclk = 266667;
                break;
        }
}

static void i915gm_get_cdclk(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_config *cdclk_config)
{
        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_config->cdclk = 133333;
                return;
        }

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

static void i945gm_get_cdclk(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_config *cdclk_config)
{
        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_config->cdclk = 133333;
                return;
        }

        switch (gcfgc & GC_DISPLAY_CLOCK_MASK) {
        case GC_DISPLAY_CLOCK_333_320_MHZ:
                cdclk_config->cdclk = 320000;
                break;
        default:
        case GC_DISPLAY_CLOCK_190_200_MHZ:
                cdclk_config->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;
        u8 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 = intel_de_read(dev_priv,
                            IS_PINEVIEW(dev_priv) || IS_MOBILE(dev_priv) ? HPLLVCO_MOBILE : HPLLVCO);

        vco = vco_table[tmp & 0x7];
        if (vco == 0)
                drm_err(&dev_priv->drm, "Bad HPLL VCO (HPLLVCO=0x%02x)\n",
                        tmp);
        else
                drm_dbg_kms(&dev_priv->drm, "HPLL VCO %u kHz\n", vco);

        return vco;
}

static void g33_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_config *cdclk_config)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        static const u8 div_3200[] = { 12, 10,  8,  7, 5, 16 };
        static const u8 div_4000[] = { 14, 12, 10,  8, 6, 20 };
        static const u8 div_4800[] = { 20, 14, 12, 10, 8, 24 };
        static const u8 div_5333[] = { 20, 16, 12, 12, 8, 28 };
        const u8 *div_table;
        unsigned int cdclk_sel;
        u16 tmp = 0;

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

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

static void pnv_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_config *cdclk_config)
{
        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_config->cdclk = 266667;
                break;
        case GC_DISPLAY_CLOCK_333_MHZ_PNV:
                cdclk_config->cdclk = 333333;
                break;
        case GC_DISPLAY_CLOCK_444_MHZ_PNV:
                cdclk_config->cdclk = 444444;
                break;
        case GC_DISPLAY_CLOCK_200_MHZ_PNV:
                cdclk_config->cdclk = 200000;
                break;
        default:
                drm_err(&dev_priv->drm,
                        "Unknown pnv display core clock 0x%04x\n", gcfgc);
                fallthrough;
        case GC_DISPLAY_CLOCK_133_MHZ_PNV:
                cdclk_config->cdclk = 133333;
                break;
        case GC_DISPLAY_CLOCK_167_MHZ_PNV:
                cdclk_config->cdclk = 166667;
                break;
        }
}

static void i965gm_get_cdclk(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_config *cdclk_config)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        static const u8 div_3200[] = { 16, 10,  8 };
        static const u8 div_4000[] = { 20, 12, 10 };
        static const u8 div_5333[] = { 24, 16, 14 };
        const u8 *div_table;
        unsigned int cdclk_sel;
        u16 tmp = 0;

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

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

static void gm45_get_cdclk(struct drm_i915_private *dev_priv,
                           struct intel_cdclk_config *cdclk_config)
{
        struct pci_dev *pdev = dev_priv->drm.pdev;
        unsigned int cdclk_sel;
        u16 tmp = 0;

        cdclk_config->vco = intel_hpll_vco(dev_priv);

        pci_read_config_word(pdev, GCFGC, &tmp);

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

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

static void hsw_get_cdclk(struct drm_i915_private *dev_priv,
                          struct intel_cdclk_config *cdclk_config)
{
        u32 lcpll = intel_de_read(dev_priv, LCPLL_CTL);
        u32 freq = lcpll & LCPLL_CLK_FREQ_MASK;

        if (lcpll & LCPLL_CD_SOURCE_FCLK)
                cdclk_config->cdclk = 800000;
        else if (intel_de_read(dev_priv, FUSE_STRAP) & HSW_CDCLK_LIMIT)
                cdclk_config->cdclk = 450000;
        else if (freq == LCPLL_CLK_FREQ_450)
                cdclk_config->cdclk = 450000;
        else if (IS_HSW_ULT(dev_priv))
                cdclk_config->cdclk = 337500;
        else
                cdclk_config->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_config *cdclk_config)
{
        u32 val;

        vlv_iosf_sb_get(dev_priv,
                        BIT(VLV_IOSF_SB_CCK) | BIT(VLV_IOSF_SB_PUNIT));

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

        val = vlv_punit_read(dev_priv, PUNIT_REG_DSPSSPM);

        vlv_iosf_sb_put(dev_priv,
                        BIT(VLV_IOSF_SB_CCK) | BIT(VLV_IOSF_SB_PUNIT));

        if (IS_VALLEYVIEW(dev_priv))
                cdclk_config->voltage_level = (val & DSPFREQGUAR_MASK) >>
                        DSPFREQGUAR_SHIFT;
        else
                cdclk_config->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?
         */
        intel_de_write(dev_priv, GCI_CONTROL,
                       VGA_FAST_MODE_DISABLE | default_credits);

        intel_de_write(dev_priv, GCI_CONTROL,
                       VGA_FAST_MODE_DISABLE | credits | PFI_CREDIT_RESEND);

        /*
         * FIXME is this guaranteed to clear
         * immediately or should we poll for it?
         */
        drm_WARN_ON(&dev_priv->drm,
                    intel_de_read(dev_priv, GCI_CONTROL) & PFI_CREDIT_RESEND);
}

static void vlv_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_config *cdclk_config,
                          enum pipe pipe)
{
        int cdclk = cdclk_config->cdclk;
        u32 val, cmd = cdclk_config->voltage_level;
        intel_wakeref_t wakeref;

        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 display core domain, which covers
         * the HW blocks needed for the following programming.
         */
        wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_DISPLAY_CORE);

        vlv_iosf_sb_get(dev_priv,
                        BIT(VLV_IOSF_SB_CCK) |
                        BIT(VLV_IOSF_SB_BUNIT) |
                        BIT(VLV_IOSF_SB_PUNIT));

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

        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_err(&dev_priv->drm,
                                "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);

        vlv_iosf_sb_put(dev_priv,
                        BIT(VLV_IOSF_SB_CCK) |
                        BIT(VLV_IOSF_SB_BUNIT) |
                        BIT(VLV_IOSF_SB_PUNIT));

        intel_update_cdclk(dev_priv);

        vlv_program_pfi_credits(dev_priv);

        intel_display_power_put(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref);
}

static void chv_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_config *cdclk_config,
                          enum pipe pipe)
{
        int cdclk = cdclk_config->cdclk;
        u32 val, cmd = cdclk_config->voltage_level;
        intel_wakeref_t wakeref;

        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 display core domain, which covers
         * the HW blocks needed for the following programming.
         */
        wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_DISPLAY_CORE);

        vlv_punit_get(dev_priv);
        val = vlv_punit_read(dev_priv, PUNIT_REG_DSPSSPM);
        val &= ~DSPFREQGUAR_MASK_CHV;
        val |= (cmd << DSPFREQGUAR_SHIFT_CHV);
        vlv_punit_write(dev_priv, PUNIT_REG_DSPSSPM, val);
        if (wait_for((vlv_punit_read(dev_priv, PUNIT_REG_DSPSSPM) &
                      DSPFREQSTAT_MASK_CHV) == (cmd << DSPFREQSTAT_SHIFT_CHV),
                     50)) {
                drm_err(&dev_priv->drm,
                        "timed out waiting for CDclk change\n");
        }

        vlv_punit_put(dev_priv);

        intel_update_cdclk(dev_priv);

        vlv_program_pfi_credits(dev_priv);

        intel_display_power_put(dev_priv, POWER_DOMAIN_DISPLAY_CORE, wakeref);
}

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_config *cdclk_config)
{
        u32 lcpll = intel_de_read(dev_priv, LCPLL_CTL);
        u32 freq = lcpll & LCPLL_CLK_FREQ_MASK;

        if (lcpll & LCPLL_CD_SOURCE_FCLK)
                cdclk_config->cdclk = 800000;
        else if (intel_de_read(dev_priv, FUSE_STRAP) & HSW_CDCLK_LIMIT)
                cdclk_config->cdclk = 450000;
        else if (freq == LCPLL_CLK_FREQ_450)
                cdclk_config->cdclk = 450000;
        else if (freq == LCPLL_CLK_FREQ_54O_BDW)
                cdclk_config->cdclk = 540000;
        else if (freq == LCPLL_CLK_FREQ_337_5_BDW)
                cdclk_config->cdclk = 337500;
        else
                cdclk_config->cdclk = 675000;

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

static void bdw_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_config *cdclk_config,
                          enum pipe pipe)
{
        int cdclk = cdclk_config->cdclk;
        u32 val;
        int ret;

        if (drm_WARN(&dev_priv->drm,
                     (intel_de_read(dev_priv, 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;

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

        val = intel_de_read(dev_priv, LCPLL_CTL);
        val |= LCPLL_CD_SOURCE_FCLK;
        intel_de_write(dev_priv, 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(intel_de_read(dev_priv, LCPLL_CTL) &
                        LCPLL_CD_SOURCE_FCLK_DONE, 100))
                drm_err(&dev_priv->drm, "Switching to FCLK failed\n");

        val = intel_de_read(dev_priv, LCPLL_CTL);
        val &= ~LCPLL_CLK_FREQ_MASK;

        switch (cdclk) {
        default:
                MISSING_CASE(cdclk);
                fallthrough;
        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;
        }

        intel_de_write(dev_priv, LCPLL_CTL, val);

        val = intel_de_read(dev_priv, LCPLL_CTL);
        val &= ~LCPLL_CD_SOURCE_FCLK;
        intel_de_write(dev_priv, LCPLL_CTL, val);

        if (wait_for_us((intel_de_read(dev_priv, LCPLL_CTL) &
                         LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1))
                drm_err(&dev_priv->drm, "Switching back to LCPLL failed\n");

        sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
                                cdclk_config->voltage_level);

        intel_de_write(dev_priv, 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)
{
        if (cdclk > 540000)
                return 3;
        else if (cdclk > 450000)
                return 2;
        else if (cdclk > 337500)
                return 1;
        else
                return 0;
}

static void skl_dpll0_update(struct drm_i915_private *dev_priv,
                             struct intel_cdclk_config *cdclk_config)
{
        u32 val;

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

        val = intel_de_read(dev_priv, LCPLL1_CTL);
        if ((val & LCPLL_PLL_ENABLE) == 0)
                return;

        if (drm_WARN_ON(&dev_priv->drm, (val & LCPLL_PLL_LOCK) == 0))
                return;

        val = intel_de_read(dev_priv, DPLL_CTRL1);

        if (drm_WARN_ON(&dev_priv->drm,
                        (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_config->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_config->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_config *cdclk_config)
{
        u32 cdctl;

        skl_dpll0_update(dev_priv, cdclk_config);

        cdclk_config->cdclk = cdclk_config->bypass = cdclk_config->ref;

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

        cdctl = intel_de_read(dev_priv, CDCLK_CTL);

        if (cdclk_config->vco == 8640000) {
                switch (cdctl & CDCLK_FREQ_SEL_MASK) {
                case CDCLK_FREQ_450_432:
                        cdclk_config->cdclk = 432000;
                        break;
                case CDCLK_FREQ_337_308:
                        cdclk_config->cdclk = 308571;
                        break;
                case CDCLK_FREQ_540:
                        cdclk_config->cdclk = 540000;
                        break;
                case CDCLK_FREQ_675_617:
                        cdclk_config->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_config->cdclk = 450000;
                        break;
                case CDCLK_FREQ_337_308:
                        cdclk_config->cdclk = 337500;
                        break;
                case CDCLK_FREQ_540:
                        cdclk_config->cdclk = 540000;
                        break;
                case CDCLK_FREQ_675_617:
                        cdclk_config->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_config->voltage_level =
                skl_calc_voltage_level(cdclk_config->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;

        drm_WARN_ON(&dev_priv->drm, 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 = intel_de_read(dev_priv, 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);

        intel_de_write(dev_priv, DPLL_CTRL1, val);
        intel_de_posting_read(dev_priv, DPLL_CTRL1);

        intel_de_write(dev_priv, LCPLL1_CTL,
                       intel_de_read(dev_priv, LCPLL1_CTL) | LCPLL_PLL_ENABLE);

        if (intel_de_wait_for_set(dev_priv, LCPLL1_CTL, LCPLL_PLL_LOCK, 5))
                drm_err(&dev_priv->drm, "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)
{

        intel_de_write(dev_priv, LCPLL1_CTL,
                       intel_de_read(dev_priv, LCPLL1_CTL) & ~LCPLL_PLL_ENABLE);
        if (intel_de_wait_for_clear(dev_priv, LCPLL1_CTL, LCPLL_PLL_LOCK, 1))
                drm_err(&dev_priv->drm, "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_config *cdclk_config,
                          enum pipe pipe)
{
        int cdclk = cdclk_config->cdclk;
        int vco = cdclk_config->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.
         */
        drm_WARN_ON_ONCE(&dev_priv->drm,
                         IS_SKYLAKE(dev_priv) && vco == 8640000);

        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);
        if (ret) {
                drm_err(&dev_priv->drm,
                        "Failed to inform PCU about cdclk change (%d)\n", ret);
                return;
        }

        /* Choose frequency for this cdclk */
        switch (cdclk) {
        default:
                drm_WARN_ON(&dev_priv->drm,
                            cdclk != dev_priv->cdclk.hw.bypass);
                drm_WARN_ON(&dev_priv->drm, vco != 0);
                fallthrough;
        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 = intel_de_read(dev_priv, 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);
                intel_de_write(dev_priv, CDCLK_CTL, cdclk_ctl);
        }

        /* Wa Display #1183: skl,kbl,cfl */
        cdclk_ctl |= CDCLK_DIVMUX_CD_OVERRIDE;
        intel_de_write(dev_priv, CDCLK_CTL, cdclk_ctl);
        intel_de_posting_read(dev_priv, 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);
        intel_de_write(dev_priv, CDCLK_CTL, cdclk_ctl);

        cdclk_ctl |= freq_select | skl_cdclk_decimal(cdclk);
        intel_de_write(dev_priv, CDCLK_CTL, cdclk_ctl);

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

        /* inform PCU of the change */
        sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                cdclk_config->voltage_level);

        intel_update_cdclk(dev_priv);
}

static void skl_sanitize_cdclk(struct drm_i915_private *dev_priv)
{
        u32 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 ((intel_de_read(dev_priv, SWF_ILK(0x18)) & 0x00FFFFFF) == 0)
                goto sanitize;

        intel_update_cdclk(dev_priv);
        intel_dump_cdclk_config(&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 = intel_de_read(dev_priv, 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_dbg_kms(&dev_priv->drm, "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 void skl_cdclk_init_hw(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_config cdclk_config;

        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_config = dev_priv->cdclk.hw;

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

        skl_set_cdclk(dev_priv, &cdclk_config, INVALID_PIPE);
}

static void skl_cdclk_uninit_hw(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_config cdclk_config = dev_priv->cdclk.hw;

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

        skl_set_cdclk(dev_priv, &cdclk_config, INVALID_PIPE);
}

static const struct intel_cdclk_vals bxt_cdclk_table[] = {
        { .refclk = 19200, .cdclk = 144000, .divider = 8, .ratio = 60 },
        { .refclk = 19200, .cdclk = 288000, .divider = 4, .ratio = 60 },
        { .refclk = 19200, .cdclk = 384000, .divider = 3, .ratio = 60 },
        { .refclk = 19200, .cdclk = 576000, .divider = 2, .ratio = 60 },
        { .refclk = 19200, .cdclk = 624000, .divider = 2, .ratio = 65 },
        {}
};

static const struct intel_cdclk_vals glk_cdclk_table[] = {
        { .refclk = 19200, .cdclk =  79200, .divider = 8, .ratio = 33 },
        { .refclk = 19200, .cdclk = 158400, .divider = 4, .ratio = 33 },
        { .refclk = 19200, .cdclk = 316800, .divider = 2, .ratio = 33 },
        {}
};

static const struct intel_cdclk_vals cnl_cdclk_table[] = {
        { .refclk = 19200, .cdclk = 168000, .divider = 4, .ratio = 35 },
        { .refclk = 19200, .cdclk = 336000, .divider = 2, .ratio = 35 },
        { .refclk = 19200, .cdclk = 528000, .divider = 2, .ratio = 55 },

        { .refclk = 24000, .cdclk = 168000, .divider = 4, .ratio = 28 },
        { .refclk = 24000, .cdclk = 336000, .divider = 2, .ratio = 28 },
        { .refclk = 24000, .cdclk = 528000, .divider = 2, .ratio = 44 },
        {}
};

static const struct intel_cdclk_vals icl_cdclk_table[] = {
        { .refclk = 19200, .cdclk = 172800, .divider = 2, .ratio = 18 },
        { .refclk = 19200, .cdclk = 192000, .divider = 2, .ratio = 20 },
        { .refclk = 19200, .cdclk = 307200, .divider = 2, .ratio = 32 },
        { .refclk = 19200, .cdclk = 326400, .divider = 4, .ratio = 68 },
        { .refclk = 19200, .cdclk = 556800, .divider = 2, .ratio = 58 },
        { .refclk = 19200, .cdclk = 652800, .divider = 2, .ratio = 68 },

        { .refclk = 24000, .cdclk = 180000, .divider = 2, .ratio = 15 },
        { .refclk = 24000, .cdclk = 192000, .divider = 2, .ratio = 16 },
        { .refclk = 24000, .cdclk = 312000, .divider = 2, .ratio = 26 },
        { .refclk = 24000, .cdclk = 324000, .divider = 4, .ratio = 54 },
        { .refclk = 24000, .cdclk = 552000, .divider = 2, .ratio = 46 },
        { .refclk = 24000, .cdclk = 648000, .divider = 2, .ratio = 54 },

        { .refclk = 38400, .cdclk = 172800, .divider = 2, .ratio =  9 },
        { .refclk = 38400, .cdclk = 192000, .divider = 2, .ratio = 10 },
        { .refclk = 38400, .cdclk = 307200, .divider = 2, .ratio = 16 },
        { .refclk = 38400, .cdclk = 326400, .divider = 4, .ratio = 34 },
        { .refclk = 38400, .cdclk = 556800, .divider = 2, .ratio = 29 },
        { .refclk = 38400, .cdclk = 652800, .divider = 2, .ratio = 34 },
        {}
};

static int bxt_calc_cdclk(struct drm_i915_private *dev_priv, int min_cdclk)
{
        const struct intel_cdclk_vals *table = dev_priv->cdclk.table;
        int i;

        for (i = 0; table[i].refclk; i++)
                if (table[i].refclk == dev_priv->cdclk.hw.ref &&
                    table[i].cdclk >= min_cdclk)
                        return table[i].cdclk;

        drm_WARN(&dev_priv->drm, 1,
                 "Cannot satisfy minimum cdclk %d with refclk %u\n",
                 min_cdclk, dev_priv->cdclk.hw.ref);
        return 0;
}

static int bxt_calc_cdclk_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
{
        const struct intel_cdclk_vals *table = dev_priv->cdclk.table;
        int i;

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

        for (i = 0; table[i].refclk; i++)
                if (table[i].refclk == dev_priv->cdclk.hw.ref &&
                    table[i].cdclk == cdclk)
                        return dev_priv->cdclk.hw.ref * table[i].ratio;

        drm_WARN(&dev_priv->drm, 1, "cdclk %d not valid for refclk %u\n",
                 cdclk, dev_priv->cdclk.hw.ref);
        return 0;
}

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

static u8 cnl_calc_voltage_level(int cdclk)
{
        if (cdclk > 336000)
                return 2;
        else if (cdclk > 168000)
                return 1;
        else
                return 0;
}

static u8 icl_calc_voltage_level(int cdclk)
{
        if (cdclk > 556800)
                return 2;
        else if (cdclk > 312000)
                return 1;
        else
                return 0;
}

static u8 ehl_calc_voltage_level(int cdclk)
{
        if (cdclk > 326400)
                return 3;
        else if (cdclk > 312000)
                return 2;
        else if (cdclk > 180000)
                return 1;
        else
                return 0;
}

static u8 tgl_calc_voltage_level(int cdclk)
{
        if (cdclk > 556800)
                return 3;
        else if (cdclk > 326400)
                return 2;
        else if (cdclk > 312000)
                return 1;
        else
                return 0;
}

static void cnl_readout_refclk(struct drm_i915_private *dev_priv,
                               struct intel_cdclk_config *cdclk_config)
{
        if (intel_de_read(dev_priv, SKL_DSSM) & CNL_DSSM_CDCLK_PLL_REFCLK_24MHz)
                cdclk_config->ref = 24000;
        else
                cdclk_config->ref = 19200;
}

static void icl_readout_refclk(struct drm_i915_private *dev_priv,
                               struct intel_cdclk_config *cdclk_config)
{
        u32 dssm = intel_de_read(dev_priv, SKL_DSSM) & ICL_DSSM_CDCLK_PLL_REFCLK_MASK;

        switch (dssm) {
        default:
                MISSING_CASE(dssm);
                fallthrough;
        case ICL_DSSM_CDCLK_PLL_REFCLK_24MHz:
                cdclk_config->ref = 24000;
                break;
        case ICL_DSSM_CDCLK_PLL_REFCLK_19_2MHz:
                cdclk_config->ref = 19200;
                break;
        case ICL_DSSM_CDCLK_PLL_REFCLK_38_4MHz:
                cdclk_config->ref = 38400;
                break;
        }
}

static void bxt_de_pll_readout(struct drm_i915_private *dev_priv,
                               struct intel_cdclk_config *cdclk_config)
{
        u32 val, ratio;

        if (INTEL_GEN(dev_priv) >= 11)
                icl_readout_refclk(dev_priv, cdclk_config);
        else if (IS_CANNONLAKE(dev_priv))
                cnl_readout_refclk(dev_priv, cdclk_config);
        else
                cdclk_config->ref = 19200;

        val = intel_de_read(dev_priv, 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_config->vco = 0;
                return;
        }

        /*
         * CNL+ have the ratio directly in the PLL enable register, gen9lp had
         * it in a separate PLL control register.
         */
        if (INTEL_GEN(dev_priv) >= 10)
                ratio = val & CNL_CDCLK_PLL_RATIO_MASK;
        else
                ratio = intel_de_read(dev_priv, BXT_DE_PLL_CTL) & BXT_DE_PLL_RATIO_MASK;

        cdclk_config->vco = ratio * cdclk_config->ref;
}

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

        bxt_de_pll_readout(dev_priv, cdclk_config);

        if (INTEL_GEN(dev_priv) >= 12)
                cdclk_config->bypass = cdclk_config->ref / 2;
        else if (INTEL_GEN(dev_priv) >= 11)
                cdclk_config->bypass = 50000;
        else
                cdclk_config->bypass = cdclk_config->ref;

        if (cdclk_config->vco == 0) {
                cdclk_config->cdclk = cdclk_config->bypass;
                goto out;
        }

        divider = intel_de_read(dev_priv, 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:
                drm_WARN(&dev_priv->drm,
                         IS_GEMINILAKE(dev_priv) || INTEL_GEN(dev_priv) >= 10,
                         "Unsupported divider\n");
                div = 3;
                break;
        case BXT_CDCLK_CD2X_DIV_SEL_2:
                div = 4;
                break;
        case BXT_CDCLK_CD2X_DIV_SEL_4:
                drm_WARN(&dev_priv->drm, INTEL_GEN(dev_priv) >= 10,
                         "Unsupported divider\n");
                div = 8;
                break;
        default:
                MISSING_CASE(divider);
                return;
        }

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

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

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

        /* Timeout 200us */
        if (intel_de_wait_for_clear(dev_priv,
                                    BXT_DE_PLL_ENABLE, BXT_DE_PLL_LOCK, 1))
                drm_err(&dev_priv->drm, "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 = intel_de_read(dev_priv, BXT_DE_PLL_CTL);
        val &= ~BXT_DE_PLL_RATIO_MASK;
        val |= BXT_DE_PLL_RATIO(ratio);
        intel_de_write(dev_priv, BXT_DE_PLL_CTL, val);

        intel_de_write(dev_priv, BXT_DE_PLL_ENABLE, BXT_DE_PLL_PLL_ENABLE);

        /* Timeout 200us */
        if (intel_de_wait_for_set(dev_priv,
                                  BXT_DE_PLL_ENABLE, BXT_DE_PLL_LOCK, 1))
                drm_err(&dev_priv->drm, "timeout waiting for DE PLL lock\n");

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

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

        val = intel_de_read(dev_priv, BXT_DE_PLL_ENABLE);
        val &= ~BXT_DE_PLL_PLL_ENABLE;
        intel_de_write(dev_priv, BXT_DE_PLL_ENABLE, val);

        /* Timeout 200us */
        if (wait_for((intel_de_read(dev_priv, BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK) == 0, 1))
                drm_err(&dev_priv->drm,
                        "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);
        intel_de_write(dev_priv, BXT_DE_PLL_ENABLE, val);

        val |= BXT_DE_PLL_PLL_ENABLE;
        intel_de_write(dev_priv, BXT_DE_PLL_ENABLE, val);

        /* Timeout 200us */
        if (wait_for((intel_de_read(dev_priv, BXT_DE_PLL_ENABLE) & BXT_DE_PLL_LOCK) != 0, 1))
                drm_err(&dev_priv->drm,
                        "timeout waiting for CDCLK PLL lock\n");

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

static u32 bxt_cdclk_cd2x_pipe(struct drm_i915_private *dev_priv, enum pipe pipe)
{
        if (INTEL_GEN(dev_priv) >= 12) {
                if (pipe == INVALID_PIPE)
                        return TGL_CDCLK_CD2X_PIPE_NONE;
                else
                        return TGL_CDCLK_CD2X_PIPE(pipe);
        } else if (INTEL_GEN(dev_priv) >= 11) {
                if (pipe == INVALID_PIPE)
                        return ICL_CDCLK_CD2X_PIPE_NONE;
                else
                        return ICL_CDCLK_CD2X_PIPE(pipe);
        } else {
                if (pipe == INVALID_PIPE)
                        return BXT_CDCLK_CD2X_PIPE_NONE;
                else
                        return BXT_CDCLK_CD2X_PIPE(pipe);
        }
}

static void bxt_set_cdclk(struct drm_i915_private *dev_priv,
                          const struct intel_cdclk_config *cdclk_config,
                          enum pipe pipe)
{
        int cdclk = cdclk_config->cdclk;
        int vco = cdclk_config->vco;
        u32 val, divider;
        int ret;

        /* Inform power controller of upcoming frequency change. */
        if (INTEL_GEN(dev_priv) >= 10)
                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);
        else
                /*
                 * BSpec requires us to wait up to 150usec, but that leads to
                 * timeouts; the 2ms used here is based on experiment.
                 */
                ret = sandybridge_pcode_write_timeout(dev_priv,
                                                      HSW_PCODE_DE_WRITE_FREQ_REQ,
                                                      0x80000000, 150, 2);

        if (ret) {
                drm_err(&dev_priv->drm,
                        "Failed to inform PCU about cdclk change (err %d, freq %d)\n",
                        ret, cdclk);
                return;
        }

        /* cdclk = vco / 2 / div{1,1.5,2,4} */
        switch (DIV_ROUND_CLOSEST(vco, cdclk)) {
        default:
                drm_WARN_ON(&dev_priv->drm,
                            cdclk != dev_priv->cdclk.hw.bypass);
                drm_WARN_ON(&dev_priv->drm, vco != 0);
                fallthrough;
        case 2:
                divider = BXT_CDCLK_CD2X_DIV_SEL_1;
                break;
        case 3:
                drm_WARN(&dev_priv->drm,
                         IS_GEMINILAKE(dev_priv) || INTEL_GEN(dev_priv) >= 10,
                         "Unsupported divider\n");
                divider = BXT_CDCLK_CD2X_DIV_SEL_1_5;
                break;
        case 4:
                divider = BXT_CDCLK_CD2X_DIV_SEL_2;
                break;
        case 8:
                drm_WARN(&dev_priv->drm, INTEL_GEN(dev_priv) >= 10,
                         "Unsupported divider\n");
                divider = BXT_CDCLK_CD2X_DIV_SEL_4;
                break;
        }

        if (INTEL_GEN(dev_priv) >= 10) {
                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);

        } else {
                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) |
                bxt_cdclk_cd2x_pipe(dev_priv, pipe);

        /*
         * Disable SSA Precharge when CD clock frequency < 500 MHz,
         * enable otherwise.
         */
        if (IS_GEN9_LP(dev_priv) && cdclk >= 500000)
                val |= BXT_CDCLK_SSA_PRECHARGE_ENABLE;
        intel_de_write(dev_priv, CDCLK_CTL, val);

        if (pipe != INVALID_PIPE)
                intel_wait_for_vblank(dev_priv, pipe);

        if (INTEL_GEN(dev_priv) >= 10) {
                ret = sandybridge_pcode_write(dev_priv, SKL_PCODE_CDCLK_CONTROL,
                                              cdclk_config->voltage_level);
        } else {
                /*
                 * 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_config->voltage_level,
                                                      150, 2);
        }

        if (ret) {
                drm_err(&dev_priv->drm,
                        "PCode CDCLK freq set failed, (err %d, freq %d)\n",
                        ret, cdclk);
                return;
        }

        intel_update_cdclk(dev_priv);

        if (INTEL_GEN(dev_priv) >= 10)
                /*
                 * Can't read out the voltage level :(
                 * Let's just assume everything is as expected.
                 */
                dev_priv->cdclk.hw.voltage_level = cdclk_config->voltage_level;
}

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

        intel_update_cdclk(dev_priv);
        intel_dump_cdclk_config(&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 = intel_de_read(dev_priv, 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(dev_priv, INVALID_PIPE);

        /* Make sure this is a legal cdclk value for the platform */
        cdclk = bxt_calc_cdclk(dev_priv, dev_priv->cdclk.hw.cdclk);
        if (cdclk != dev_priv->cdclk.hw.cdclk)
                goto sanitize;

        /* Make sure the VCO is correct for the cdclk */
        vco = bxt_calc_cdclk_pll_vco(dev_priv, cdclk);
        if (vco != dev_priv->cdclk.hw.vco)
                goto sanitize;

        expected = skl_cdclk_decimal(cdclk);

        /* Figure out what CD2X divider we should be using for this cdclk */
        switch (DIV_ROUND_CLOSEST(dev_priv->cdclk.hw.vco,
                                  dev_priv->cdclk.hw.cdclk)) {
        case 2:
                expected |= BXT_CDCLK_CD2X_DIV_SEL_1;
                break;
        case 3:
                expected |= BXT_CDCLK_CD2X_DIV_SEL_1_5;
                break;
        case 4:
                expected |= BXT_CDCLK_CD2X_DIV_SEL_2;
                break;
        case 8:
                expected |= BXT_CDCLK_CD2X_DIV_SEL_4;
                break;
        default:
                goto sanitize;
        }

        /*
         * Disable SSA Precharge when CD clock frequency < 500 MHz,
         * enable otherwise.
         */
        if (IS_GEN9_LP(dev_priv) && dev_priv->cdclk.hw.cdclk >= 500000)
                expected |= BXT_CDCLK_SSA_PRECHARGE_ENABLE;

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

sanitize:
        drm_dbg_kms(&dev_priv->drm, "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 void bxt_cdclk_init_hw(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_config cdclk_config;

        bxt_sanitize_cdclk(dev_priv);

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

        cdclk_config = 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.
         */
        cdclk_config.cdclk = bxt_calc_cdclk(dev_priv, 0);
        cdclk_config.vco = bxt_calc_cdclk_pll_vco(dev_priv, cdclk_config.cdclk);
        cdclk_config.voltage_level =
                dev_priv->display.calc_voltage_level(cdclk_config.cdclk);

        bxt_set_cdclk(dev_priv, &cdclk_config, INVALID_PIPE);
}

static void bxt_cdclk_uninit_hw(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_config cdclk_config = dev_priv->cdclk.hw;

        cdclk_config.cdclk = cdclk_config.bypass;
        cdclk_config.vco = 0;
        cdclk_config.voltage_level =
                dev_priv->display.calc_voltage_level(cdclk_config.cdclk);

        bxt_set_cdclk(dev_priv, &cdclk_config, INVALID_PIPE);
}

/**
 * intel_cdclk_init_hw - Initialize CDCLK hardware
 * @i915: i915 device
 *
 * Initialize CDCLK. 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 intel_cdclk_init_hw(struct drm_i915_private *i915)
{
        if (IS_GEN9_LP(i915) || INTEL_GEN(i915) >= 10)
                bxt_cdclk_init_hw(i915);
        else if (IS_GEN9_BC(i915))
                skl_cdclk_init_hw(i915);
}

/**
 * intel_cdclk_uninit_hw - Uninitialize CDCLK hardware
 * @i915: i915 device
 *
 * Uninitialize CDCLK. This is done only during the display core
 * uninitialization sequence.
 */
void intel_cdclk_uninit_hw(struct drm_i915_private *i915)
{
        if (INTEL_GEN(i915) >= 10 || IS_GEN9_LP(i915))
                bxt_cdclk_uninit_hw(i915);
        else if (IS_GEN9_BC(i915))
                skl_cdclk_uninit_hw(i915);
}

/**
 * intel_cdclk_needs_modeset - Determine if changong between the CDCLK
 *                             configurations requires a modeset on all pipes
 * @a: first CDCLK configuration
 * @b: second CDCLK configuration
 *
 * Returns:
 * True if changing between the two CDCLK configurations
 * requires all pipes to be off, false if not.
 */
bool intel_cdclk_needs_modeset(const struct intel_cdclk_config *a,
                               const struct intel_cdclk_config *b)
{
        return a->cdclk != b->cdclk ||
                a->vco != b->vco ||
                a->ref != b->ref;
}

/**
 * intel_cdclk_can_cd2x_update - Determine if changing between the two CDCLK
 *                               configurations requires only a cd2x divider update
 * @dev_priv: i915 device
 * @a: first CDCLK configuration
 * @b: second CDCLK configuration
 *
 * Returns:
 * True if changing between the two CDCLK configurations
 * can be done with just a cd2x divider update, false if not.
 */
static bool intel_cdclk_can_cd2x_update(struct drm_i915_private *dev_priv,
                                        const struct intel_cdclk_config *a,
                                        const struct intel_cdclk_config *b)
{
        /* Older hw doesn't have the capability */
        if (INTEL_GEN(dev_priv) < 10 && !IS_GEN9_LP(dev_priv))
                return false;

        return a->cdclk != b->cdclk &&
                a->vco == b->vco &&
                a->ref == b->ref;
}

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

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

/**
 * intel_set_cdclk - Push the CDCLK configuration to the hardware
 * @dev_priv: i915 device
 * @cdclk_config: new CDCLK configuration
 * @pipe: pipe with which to synchronize the update
 *
 * Program the hardware based on the passed in CDCLK state,
 * if necessary.
 */
static void intel_set_cdclk(struct drm_i915_private *dev_priv,
                            const struct intel_cdclk_config *cdclk_config,
                            enum pipe pipe)
{
        struct intel_encoder *encoder;

        if (!intel_cdclk_changed(&dev_priv->cdclk.hw, cdclk_config))
                return;

        if (drm_WARN_ON_ONCE(&dev_priv->drm, !dev_priv->display.set_cdclk))
                return;

        intel_dump_cdclk_config(cdclk_config, "Changing CDCLK to");

        /*
         * Lock aux/gmbus while we change cdclk in case those
         * functions use cdclk. Not all platforms/ports do,
         * but we'll lock them all for simplicity.
         */
        mutex_lock(&dev_priv->gmbus_mutex);
        for_each_intel_dp(&dev_priv->drm, encoder) {
                struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

                mutex_lock_nest_lock(&intel_dp->aux.hw_mutex,
                                     &dev_priv->gmbus_mutex);
        }

        dev_priv->display.set_cdclk(dev_priv, cdclk_config, pipe);

        for_each_intel_dp(&dev_priv->drm, encoder) {
                struct intel_dp *intel_dp = enc_to_intel_dp(encoder);

                mutex_unlock(&intel_dp->aux.hw_mutex);
        }
        mutex_unlock(&dev_priv->gmbus_mutex);

        if (drm_WARN(&dev_priv->drm,
                     intel_cdclk_changed(&dev_priv->cdclk.hw, cdclk_config),
                     "cdclk state doesn't match!\n")) {
                intel_dump_cdclk_config(&dev_priv->cdclk.hw, "[hw state]");
                intel_dump_cdclk_config(cdclk_config, "[sw state]");
        }
}

/**
 * intel_set_cdclk_pre_plane_update - Push the CDCLK state to the hardware
 * @state: intel atomic state
 *
 * Program the hardware before updating the HW plane state based on the
 * new CDCLK state, if necessary.
 */
void
intel_set_cdclk_pre_plane_update(struct intel_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        const struct intel_cdclk_state *old_cdclk_state =
                intel_atomic_get_old_cdclk_state(state);
        const struct intel_cdclk_state *new_cdclk_state =
                intel_atomic_get_new_cdclk_state(state);
        enum pipe pipe = new_cdclk_state->pipe;

        if (!intel_cdclk_changed(&old_cdclk_state->actual,
                                 &new_cdclk_state->actual))
                return;

        if (pipe == INVALID_PIPE ||
            old_cdclk_state->actual.cdclk <= new_cdclk_state->actual.cdclk) {
                drm_WARN_ON(&dev_priv->drm, !new_cdclk_state->base.changed);

                intel_set_cdclk(dev_priv, &new_cdclk_state->actual, pipe);
        }
}

/**
 * intel_set_cdclk_post_plane_update - Push the CDCLK state to the hardware
 * @state: intel atomic state
 *
 * Program the hardware after updating the HW plane state based on the
 * new CDCLK state, if necessary.
 */
void
intel_set_cdclk_post_plane_update(struct intel_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        const struct intel_cdclk_state *old_cdclk_state =
                intel_atomic_get_old_cdclk_state(state);
        const struct intel_cdclk_state *new_cdclk_state =
                intel_atomic_get_new_cdclk_state(state);
        enum pipe pipe = new_cdclk_state->pipe;

        if (!intel_cdclk_changed(&old_cdclk_state->actual,
                                 &new_cdclk_state->actual))
                return;

        if (pipe != INVALID_PIPE &&
            old_cdclk_state->actual.cdclk > new_cdclk_state->actual.cdclk) {
                drm_WARN_ON(&dev_priv->drm, !new_cdclk_state->base.changed);

                intel_set_cdclk(dev_priv, &new_cdclk_state->actual, pipe);
        }
}

static int intel_pixel_rate_to_cdclk(const struct intel_crtc_state *crtc_state)
{
        struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
        int pixel_rate = crtc_state->pixel_rate;

        if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
                return DIV_ROUND_UP(pixel_rate, 2);
        else if (IS_GEN(dev_priv, 9) ||
                 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 if (crtc_state->double_wide)
                return DIV_ROUND_UP(pixel_rate * 100, 90 * 2);
        else
                return DIV_ROUND_UP(pixel_rate * 100, 90);
}

static int intel_planes_min_cdclk(const struct intel_crtc_state *crtc_state)
{
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        struct intel_plane *plane;
        int min_cdclk = 0;

        for_each_intel_plane_on_crtc(&dev_priv->drm, crtc, plane)
                min_cdclk = max(crtc_state->min_cdclk[plane->id], min_cdclk);

        return min_cdclk;

}

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

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

        min_cdclk = intel_pixel_rate_to_cdclk(crtc_state);

        /* 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_GEN(dev_priv, 9) || 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.
         */
        if (crtc_state->has_audio && INTEL_GEN(dev_priv) >= 9)
                min_cdclk = max(2 * 96000, min_cdclk);

        /*
         * "For DP audio configuration, cdclk frequency shall be set to
         *  meet the following requirements:
         *  DP Link Frequency(MHz) | Cdclk frequency(MHz)
         *  270                    | 320 or higher
         *  162                    | 200 or higher"
         */
        if ((IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) &&
            intel_crtc_has_dp_encoder(crtc_state) && crtc_state->has_audio)
                min_cdclk = max(crtc_state->port_clock, 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);

        /*
         * On Geminilake once the CDCLK gets as low as 79200
         * picture gets unstable, despite that values are
         * correct for DSI PLL and DE PLL.
         */
        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI) &&
            IS_GEMINILAKE(dev_priv))
                min_cdclk = max(158400, min_cdclk);

        /* Account for additional needs from the planes */
        min_cdclk = max(intel_planes_min_cdclk(crtc_state), min_cdclk);

        /*
         * HACK. Currently for TGL platforms we calculate
         * min_cdclk initially based on pixel_rate divided
         * by 2, accounting for also plane requirements,
         * however in some cases the lowest possible CDCLK
         * doesn't work and causing the underruns.
         * Explicitly stating here that this seems to be currently
         * rather a Hack, than final solution.
         */
        if (IS_TIGERLAKE(dev_priv)) {
                /*
                 * Clamp to max_cdclk_freq in case pixel rate is higher,
                 * in order not to break an 8K, but still leave W/A at place.
                 */
                min_cdclk = max_t(int, min_cdclk,
                                  min_t(int, crtc_state->pixel_rate,
                                        dev_priv->max_cdclk_freq));
        }

        if (min_cdclk > dev_priv->max_cdclk_freq) {
                drm_dbg_kms(&dev_priv->drm,
                            "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 intel_cdclk_state *cdclk_state)
{
        struct intel_atomic_state *state = cdclk_state->base.state;
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        struct intel_bw_state *bw_state = NULL;
        struct intel_crtc *crtc;
        struct intel_crtc_state *crtc_state;
        int min_cdclk, i;
        enum pipe pipe;

        for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
                int ret;

                min_cdclk = intel_crtc_compute_min_cdclk(crtc_state);
                if (min_cdclk < 0)
                        return min_cdclk;

                bw_state = intel_atomic_get_bw_state(state);
                if (IS_ERR(bw_state))
                        return PTR_ERR(bw_state);

                if (cdclk_state->min_cdclk[i] == min_cdclk)
                        continue;

                cdclk_state->min_cdclk[i] = min_cdclk;

                ret = intel_atomic_lock_global_state(&cdclk_state->base);
                if (ret)
                        return ret;
        }

        min_cdclk = cdclk_state->force_min_cdclk;
        for_each_pipe(dev_priv, pipe) {
                min_cdclk = max(cdclk_state->min_cdclk[pipe], min_cdclk);

                if (!bw_state)
                        continue;

                min_cdclk = max(bw_state->min_cdclk, min_cdclk);
        }

        return min_cdclk;
}

/*
 * Account for port clock min voltage level requirements.
 * This only really does something on CNL+ but can be
 * called on earlier platforms as well.
 *
 * 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 int bxt_compute_min_voltage_level(struct intel_cdclk_state *cdclk_state)
{
        struct intel_atomic_state *state = cdclk_state->base.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 pipe pipe;

        for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
                int ret;

                if (crtc_state->hw.enable)
                        min_voltage_level = crtc_state->min_voltage_level;
                else
                        min_voltage_level = 0;

                if (cdclk_state->min_voltage_level[i] == min_voltage_level)
                        continue;

                cdclk_state->min_voltage_level[i] = min_voltage_level;

                ret = intel_atomic_lock_global_state(&cdclk_state->base);
                if (ret)
                        return ret;
        }

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

        return min_voltage_level;
}

static int vlv_modeset_calc_cdclk(struct intel_cdclk_state *cdclk_state)
{
        struct intel_atomic_state *state = cdclk_state->base.state;
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        int min_cdclk, cdclk;

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

        cdclk = vlv_calc_cdclk(dev_priv, min_cdclk);

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

        if (!cdclk_state->active_pipes) {
                cdclk = vlv_calc_cdclk(dev_priv, cdclk_state->force_min_cdclk);

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

        return 0;
}

static int bdw_modeset_calc_cdclk(struct intel_cdclk_state *cdclk_state)
{
        int min_cdclk, cdclk;

        min_cdclk = intel_compute_min_cdclk(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);

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

        if (!cdclk_state->active_pipes) {
                cdclk = bdw_calc_cdclk(cdclk_state->force_min_cdclk);

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

        return 0;
}

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

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

        for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
                if (!crtc_state->hw.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 intel_cdclk_state *cdclk_state)
{
        int min_cdclk, cdclk, vco;

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

        vco = skl_dpll0_vco(cdclk_state);

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

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

        if (!cdclk_state->active_pipes) {
                cdclk = skl_calc_cdclk(cdclk_state->force_min_cdclk, vco);

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

        return 0;
}

static int bxt_modeset_calc_cdclk(struct intel_cdclk_state *cdclk_state)
{
        struct intel_atomic_state *state = cdclk_state->base.state;
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        int min_cdclk, min_voltage_level, cdclk, vco;

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

        min_voltage_level = bxt_compute_min_voltage_level(cdclk_state);
        if (min_voltage_level < 0)
                return min_voltage_level;

        cdclk = bxt_calc_cdclk(dev_priv, min_cdclk);
        vco = bxt_calc_cdclk_pll_vco(dev_priv, cdclk);

        cdclk_state->logical.vco = vco;
        cdclk_state->logical.cdclk = cdclk;
        cdclk_state->logical.voltage_level =
                max_t(int, min_voltage_level,
                      dev_priv->display.calc_voltage_level(cdclk));

        if (!cdclk_state->active_pipes) {
                cdclk = bxt_calc_cdclk(dev_priv, cdclk_state->force_min_cdclk);
                vco = bxt_calc_cdclk_pll_vco(dev_priv, cdclk);

                cdclk_state->actual.vco = vco;
                cdclk_state->actual.cdclk = cdclk;
                cdclk_state->actual.voltage_level =
                        dev_priv->display.calc_voltage_level(cdclk);
        } else {
                cdclk_state->actual = cdclk_state->logical;
        }

        return 0;
}

static int intel_modeset_all_pipes(struct intel_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        struct intel_crtc *crtc;

        /*
         * Add all pipes to the state, and force
         * a modeset on all the active ones.
         */
        for_each_intel_crtc(&dev_priv->drm, crtc) {
                struct intel_crtc_state *crtc_state;
                int ret;

                crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
                if (IS_ERR(crtc_state))
                        return PTR_ERR(crtc_state);

                if (!crtc_state->hw.active ||
                    drm_atomic_crtc_needs_modeset(&crtc_state->uapi))
                        continue;

                crtc_state->uapi.mode_changed = true;

                ret = drm_atomic_add_affected_connectors(&state->base,
                                                         &crtc->base);
                if (ret)
                        return ret;

                ret = drm_atomic_add_affected_planes(&state->base,
                                                     &crtc->base);
                if (ret)
                        return ret;

                crtc_state->update_planes |= crtc_state->active_planes;
        }

        return 0;
}

static int fixed_modeset_calc_cdclk(struct intel_cdclk_state *cdclk_state)
{
        int min_cdclk;

        /*
         * We can't change the cdclk frequency, but we still want to
         * check that the required minimum frequency doesn't exceed
         * the actual cdclk frequency.
         */
        min_cdclk = intel_compute_min_cdclk(cdclk_state);
        if (min_cdclk < 0)
                return min_cdclk;

        return 0;
}

static struct intel_global_state *intel_cdclk_duplicate_state(struct intel_global_obj *obj)
{
        struct intel_cdclk_state *cdclk_state;

        cdclk_state = kmemdup(obj->state, sizeof(*cdclk_state), GFP_KERNEL);
        if (!cdclk_state)
                return NULL;

        cdclk_state->force_min_cdclk_changed = false;
        cdclk_state->pipe = INVALID_PIPE;

        return &cdclk_state->base;
}

static void intel_cdclk_destroy_state(struct intel_global_obj *obj,
                                      struct intel_global_state *state)
{
        kfree(state);
}

static const struct intel_global_state_funcs intel_cdclk_funcs = {
        .atomic_duplicate_state = intel_cdclk_duplicate_state,
        .atomic_destroy_state = intel_cdclk_destroy_state,
};

struct intel_cdclk_state *
intel_atomic_get_cdclk_state(struct intel_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        struct intel_global_state *cdclk_state;

        cdclk_state = intel_atomic_get_global_obj_state(state, &dev_priv->cdclk.obj);
        if (IS_ERR(cdclk_state))
                return ERR_CAST(cdclk_state);

        return to_intel_cdclk_state(cdclk_state);
}

int intel_cdclk_init(struct drm_i915_private *dev_priv)
{
        struct intel_cdclk_state *cdclk_state;

        cdclk_state = kzalloc(sizeof(*cdclk_state), GFP_KERNEL);
        if (!cdclk_state)
                return -ENOMEM;

        intel_atomic_global_obj_init(dev_priv, &dev_priv->cdclk.obj,
                                     &cdclk_state->base, &intel_cdclk_funcs);

        return 0;
}

int intel_modeset_calc_cdclk(struct intel_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->base.dev);
        const struct intel_cdclk_state *old_cdclk_state;
        struct intel_cdclk_state *new_cdclk_state;
        enum pipe pipe;
        int ret;

        new_cdclk_state = intel_atomic_get_cdclk_state(state);
        if (IS_ERR(new_cdclk_state))
                return PTR_ERR(new_cdclk_state);

        old_cdclk_state = intel_atomic_get_old_cdclk_state(state);

        new_cdclk_state->active_pipes =
                intel_calc_active_pipes(state, old_cdclk_state->active_pipes);

        ret = dev_priv->display.modeset_calc_cdclk(new_cdclk_state);
        if (ret)
                return ret;

        if (intel_cdclk_changed(&old_cdclk_state->actual,
                                &new_cdclk_state->actual)) {
                /*
                 * Also serialize commits across all crtcs
                 * if the actual hw needs to be poked.
                 */
                ret = intel_atomic_serialize_global_state(&new_cdclk_state->base);
                if (ret)
                        return ret;
        } else if (old_cdclk_state->active_pipes != new_cdclk_state->active_pipes ||
                   intel_cdclk_changed(&old_cdclk_state->logical,
                                       &new_cdclk_state->logical)) {
                ret = intel_atomic_lock_global_state(&new_cdclk_state->base);
                if (ret)
                        return ret;
        } else {
                return 0;
        }

        if (is_power_of_2(new_cdclk_state->active_pipes) &&
            intel_cdclk_can_cd2x_update(dev_priv,
                                        &old_cdclk_state->actual,
                                        &new_cdclk_state->actual)) {
                struct intel_crtc *crtc;
                struct intel_crtc_state *crtc_state;

                pipe = ilog2(new_cdclk_state->active_pipes);
                crtc = intel_get_crtc_for_pipe(dev_priv, pipe);

                crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
                if (IS_ERR(crtc_state))
                        return PTR_ERR(crtc_state);

                if (drm_atomic_crtc_needs_modeset(&crtc_state->uapi))
                        pipe = INVALID_PIPE;
        } else {
                pipe = INVALID_PIPE;
        }

        if (pipe != INVALID_PIPE) {
                new_cdclk_state->pipe = pipe;

                drm_dbg_kms(&dev_priv->drm,
                            "Can change cdclk with pipe %c active\n",
                            pipe_name(pipe));
        } else if (intel_cdclk_needs_modeset(&old_cdclk_state->actual,
                                             &new_cdclk_state->actual)) {
                /* All pipes must be switched off while we change the cdclk. */
                ret = intel_modeset_all_pipes(state);
                if (ret)
                        return ret;

                new_cdclk_state->pipe = INVALID_PIPE;

                drm_dbg_kms(&dev_priv->drm,
                            "Modeset required for cdclk change\n");
        }

        drm_dbg_kms(&dev_priv->drm,
                    "New cdclk calculated to be logical %u kHz, actual %u kHz\n",
                    new_cdclk_state->logical.cdclk,
                    new_cdclk_state->actual.cdclk);
        drm_dbg_kms(&dev_priv->drm,
                    "New voltage level calculated to be logical %u, actual %u\n",
                    new_cdclk_state->logical.voltage_level,
                    new_cdclk_state->actual.voltage_level);

        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_GEN(dev_priv, 9) ||
                 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_ELKHARTLAKE(dev_priv)) {
                if (dev_priv->cdclk.hw.ref == 24000)
                        dev_priv->max_cdclk_freq = 552000;
                else
                        dev_priv->max_cdclk_freq = 556800;
        } else if (INTEL_GEN(dev_priv) >= 11) {
                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 = intel_de_read(dev_priv, SKL_DFSM) & SKL_DFSM_CDCLK_LIMIT_MASK;
                int max_cdclk, vco;

                vco = dev_priv->skl_preferred_vco_freq;
                drm_WARN_ON(&dev_priv->drm, 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 (intel_de_read(dev_priv, 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_dbg(&dev_priv->drm, "Max CD clock rate: %d kHz\n",
                dev_priv->max_cdclk_freq);

        drm_dbg(&dev_priv->drm, "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))
                intel_de_write(dev_priv, 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 (intel_de_read(dev_priv, 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);
        if (fraction) {
                int numerator = 1;

                rawclk |= CNP_RAWCLK_DEN(DIV_ROUND_CLOSEST(numerator * 1000,
                                                           fraction) - 1);
                if (INTEL_PCH_TYPE(dev_priv) >= PCH_ICP)
                        rawclk |= ICP_RAWCLK_NUM(numerator);
        }

        intel_de_write(dev_priv, PCH_RAWCLK_FREQ, rawclk);
        return divider + fraction;
}

static int pch_rawclk(struct drm_i915_private *dev_priv)
{
        return (intel_de_read(dev_priv, 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 i9xx_hrawclk(struct drm_i915_private *dev_priv)
{
        u32 clkcfg;

        /*
         * hrawclock is 1/4 the FSB frequency
         *
         * Note that this only reads the state of the FSB
         * straps, not the actual FSB frequency. Some BIOSen
         * let you configure each independently. Ideally we'd
         * read out the actual FSB frequency but sadly we
         * don't know which registers have that information,
         * and all the relevant docs have gone to bit heaven :(
         */
        clkcfg = intel_de_read(dev_priv, CLKCFG) & CLKCFG_FSB_MASK;

        if (IS_MOBILE(dev_priv)) {
                switch (clkcfg) {
                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:
                        return 266667;
                case CLKCFG_FSB_1333:
                        return 333333;
                default:
                        MISSING_CASE(clkcfg);
                        return 133333;
                }
        } else {
                switch (clkcfg) {
                case CLKCFG_FSB_400_ALT:
                        return 100000;
                case CLKCFG_FSB_533:
                        return 133333;
                case CLKCFG_FSB_667:
                        return 166667;
                case CLKCFG_FSB_800:
                        return 200000;
                case CLKCFG_FSB_1067_ALT:
                        return 266667;
                case CLKCFG_FSB_1333_ALT:
                        return 333333;
                case CLKCFG_FSB_1600_ALT:
                        return 400000;
                default:
                        return 133333;
                }
        }
}

/**
 * intel_read_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.
 */
u32 intel_read_rawclk(struct drm_i915_private *dev_priv)
{
        u32 freq;

        if (INTEL_PCH_TYPE(dev_priv) >= PCH_CNP)
                freq = cnp_rawclk(dev_priv);
        else if (HAS_PCH_SPLIT(dev_priv))
                freq = pch_rawclk(dev_priv);
        else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
                freq = vlv_hrawclk(dev_priv);
        else if (INTEL_GEN(dev_priv) >= 3)
                freq = i9xx_hrawclk(dev_priv);
        else
                /* no rawclk on other platforms, or no need to know it */
                return 0;

        return 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 (INTEL_GEN(dev_priv) >= 12) {
                dev_priv->display.set_cdclk = bxt_set_cdclk;
                dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
                dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
                dev_priv->display.calc_voltage_level = tgl_calc_voltage_level;
                dev_priv->cdclk.table = icl_cdclk_table;
        } else if (IS_ELKHARTLAKE(dev_priv)) {
                dev_priv->display.set_cdclk = bxt_set_cdclk;
                dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
                dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
                dev_priv->display.calc_voltage_level = ehl_calc_voltage_level;
                dev_priv->cdclk.table = icl_cdclk_table;
        } else if (INTEL_GEN(dev_priv) >= 11) {
                dev_priv->display.set_cdclk = bxt_set_cdclk;
                dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
                dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
                dev_priv->display.calc_voltage_level = icl_calc_voltage_level;
                dev_priv->cdclk.table = icl_cdclk_table;
        } else if (IS_CANNONLAKE(dev_priv)) {
                dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
                dev_priv->display.set_cdclk = bxt_set_cdclk;
                dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
                dev_priv->display.calc_voltage_level = cnl_calc_voltage_level;
                dev_priv->cdclk.table = cnl_cdclk_table;
        } else if (IS_GEN9_LP(dev_priv)) {
                dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
                dev_priv->display.set_cdclk = bxt_set_cdclk;
                dev_priv->display.modeset_calc_cdclk = bxt_modeset_calc_cdclk;
                dev_priv->display.calc_voltage_level = bxt_calc_voltage_level;
                if (IS_GEMINILAKE(dev_priv))
                        dev_priv->cdclk.table = glk_cdclk_table;
                else
                        dev_priv->cdclk.table = bxt_cdclk_table;
        } else if (IS_GEN9_BC(dev_priv)) {
                dev_priv->display.bw_calc_min_cdclk = skl_bw_calc_min_cdclk;
                dev_priv->display.set_cdclk = skl_set_cdclk;
                dev_priv->display.modeset_calc_cdclk = skl_modeset_calc_cdclk;
        } else if (IS_BROADWELL(dev_priv)) {
                dev_priv->display.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
                dev_priv->display.set_cdclk = bdw_set_cdclk;
                dev_priv->display.modeset_calc_cdclk = bdw_modeset_calc_cdclk;
        } else if (IS_CHERRYVIEW(dev_priv)) {
                dev_priv->display.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
                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.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
                dev_priv->display.set_cdclk = vlv_set_cdclk;
                dev_priv->display.modeset_calc_cdclk = vlv_modeset_calc_cdclk;
        } else {
                dev_priv->display.bw_calc_min_cdclk = intel_bw_calc_min_cdclk;
                dev_priv->display.modeset_calc_cdclk = fixed_modeset_calc_cdclk;
        }

        if (INTEL_GEN(dev_priv) >= 10 || IS_GEN9_LP(dev_priv))
                dev_priv->display.get_cdclk = bxt_get_cdclk;
        else if (IS_GEN9_BC(dev_priv))
                dev_priv->display.get_cdclk = skl_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_GEN(dev_priv, 6) || IS_IVYBRIDGE(dev_priv))
                dev_priv->display.get_cdclk = fixed_400mhz_get_cdclk;
        else if (IS_GEN(dev_priv, 5))
                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 */
                drm_WARN(&dev_priv->drm, !IS_I830(dev_priv),
                         "Unknown platform. Assuming 133 MHz CDCLK\n");
                dev_priv->display.get_cdclk = fixed_133mhz_get_cdclk;
        }
}