/*
 * Copyright © 2006-2016 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include "intel_drv.h"

/**
 * DOC: Display PLLs
 *
 * Display PLLs used for driving outputs vary by platform. While some have
 * per-pipe or per-encoder dedicated PLLs, others allow the use of any PLL
 * from a pool. In the latter scenario, it is possible that multiple pipes
 * share a PLL if their configurations match.
 *
 * This file provides an abstraction over display PLLs. The function
 * intel_shared_dpll_init() initializes the PLLs for the given platform.  The
 * users of a PLL are tracked and that tracking is integrated with the atomic
 * modest interface. During an atomic operation, a PLL can be requested for a
 * given CRTC and encoder configuration by calling intel_get_shared_dpll() and
 * a previously used PLL can be released with intel_release_shared_dpll().
 * Changes to the users are first staged in the atomic state, and then made
 * effective by calling intel_shared_dpll_swap_state() during the atomic
 * commit phase.
 */

static void
intel_atomic_duplicate_dpll_state(struct drm_i915_private *dev_priv,
                                  struct intel_shared_dpll_state *shared_dpll)
{
        enum intel_dpll_id i;

        /* Copy shared dpll state */
        for (i = 0; i < dev_priv->num_shared_dpll; i++) {
                struct intel_shared_dpll *pll = &dev_priv->shared_dplls[i];

                shared_dpll[i] = pll->state;
        }
}

static struct intel_shared_dpll_state *
intel_atomic_get_shared_dpll_state(struct drm_atomic_state *s)
{
        struct intel_atomic_state *state = to_intel_atomic_state(s);

        WARN_ON(!drm_modeset_is_locked(&s->dev->mode_config.connection_mutex));

        if (!state->dpll_set) {
                state->dpll_set = true;

                intel_atomic_duplicate_dpll_state(to_i915(s->dev),
                                                  state->shared_dpll);
        }

        return state->shared_dpll;
}

/**
 * intel_get_shared_dpll_by_id - get a DPLL given its id
 * @dev_priv: i915 device instance
 * @id: pll id
 *
 * Returns:
 * A pointer to the DPLL with @id
 */
struct intel_shared_dpll *
intel_get_shared_dpll_by_id(struct drm_i915_private *dev_priv,
                            enum intel_dpll_id id)
{
        return &dev_priv->shared_dplls[id];
}

/**
 * intel_get_shared_dpll_id - get the id of a DPLL
 * @dev_priv: i915 device instance
 * @pll: the DPLL
 *
 * Returns:
 * The id of @pll
 */
enum intel_dpll_id
intel_get_shared_dpll_id(struct drm_i915_private *dev_priv,
                         struct intel_shared_dpll *pll)
{
        if (WARN_ON(pll < dev_priv->shared_dplls||
                    pll > &dev_priv->shared_dplls[dev_priv->num_shared_dpll]))
                return -1;

        return (enum intel_dpll_id) (pll - dev_priv->shared_dplls);
}

/* For ILK+ */
void assert_shared_dpll(struct drm_i915_private *dev_priv,
                        struct intel_shared_dpll *pll,
                        bool state)
{
        bool cur_state;
        struct intel_dpll_hw_state hw_state;

        if (WARN(!pll, "asserting DPLL %s with no DPLL\n", onoff(state)))
                return;

        cur_state = pll->funcs.get_hw_state(dev_priv, pll, &hw_state);
        I915_STATE_WARN(cur_state != state,
             "%s assertion failure (expected %s, current %s)\n",
                        pll->name, onoff(state), onoff(cur_state));
}

/**
 * intel_prepare_shared_dpll - call a dpll's prepare hook
 * @crtc: CRTC which has a shared dpll
 *
 * This calls the PLL's prepare hook if it has one and if the PLL is not
 * already enabled. The prepare hook is platform specific.
 */
void intel_prepare_shared_dpll(struct intel_crtc *crtc)
{
        struct drm_device *dev = crtc->base.dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_shared_dpll *pll = crtc->config->shared_dpll;

        if (WARN_ON(pll == NULL))
                return;

        mutex_lock(&dev_priv->dpll_lock);
        WARN_ON(!pll->state.crtc_mask);
        if (!pll->active_mask) {
                DRM_DEBUG_DRIVER("setting up %s\n", pll->name);
                WARN_ON(pll->on);
                assert_shared_dpll_disabled(dev_priv, pll);

                pll->funcs.prepare(dev_priv, pll);
        }
        mutex_unlock(&dev_priv->dpll_lock);
}

/**
 * intel_enable_shared_dpll - enable a CRTC's shared DPLL
 * @crtc: CRTC which has a shared DPLL
 *
 * Enable the shared DPLL used by @crtc.
 */
void intel_enable_shared_dpll(struct intel_crtc *crtc)
{
        struct drm_device *dev = crtc->base.dev;
        struct drm_i915_private *dev_priv = to_i915(dev);
        struct intel_shared_dpll *pll = crtc->config->shared_dpll;
        unsigned crtc_mask = 1 << drm_crtc_index(&crtc->base);
        unsigned old_mask;

        if (WARN_ON(pll == NULL))
                return;

        mutex_lock(&dev_priv->dpll_lock);
        old_mask = pll->active_mask;

        if (WARN_ON(!(pll->state.crtc_mask & crtc_mask)) ||
            WARN_ON(pll->active_mask & crtc_mask))
                goto out;

        pll->active_mask |= crtc_mask;

        DRM_DEBUG_KMS("enable %s (active %x, on? %d) for crtc %d\n",
                      pll->name, pll->active_mask, pll->on,
                      crtc->base.base.id);

        if (old_mask) {
                WARN_ON(!pll->on);
                assert_shared_dpll_enabled(dev_priv, pll);
                goto out;
        }
        WARN_ON(pll->on);

        DRM_DEBUG_KMS("enabling %s\n", pll->name);
        pll->funcs.enable(dev_priv, pll);
        pll->on = true;

out:
        mutex_unlock(&dev_priv->dpll_lock);
}

/**
 * intel_disable_shared_dpll - disable a CRTC's shared DPLL
 * @crtc: CRTC which has a shared DPLL
 *
 * Disable the shared DPLL used by @crtc.
 */
void intel_disable_shared_dpll(struct intel_crtc *crtc)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        struct intel_shared_dpll *pll = crtc->config->shared_dpll;
        unsigned crtc_mask = 1 << drm_crtc_index(&crtc->base);

        /* PCH only available on ILK+ */
        if (INTEL_GEN(dev_priv) < 5)
                return;

        if (pll == NULL)
                return;

        mutex_lock(&dev_priv->dpll_lock);
        if (WARN_ON(!(pll->active_mask & crtc_mask)))
                goto out;

        DRM_DEBUG_KMS("disable %s (active %x, on? %d) for crtc %d\n",
                      pll->name, pll->active_mask, pll->on,
                      crtc->base.base.id);

        assert_shared_dpll_enabled(dev_priv, pll);
        WARN_ON(!pll->on);

        pll->active_mask &= ~crtc_mask;
        if (pll->active_mask)
                goto out;

        DRM_DEBUG_KMS("disabling %s\n", pll->name);
        pll->funcs.disable(dev_priv, pll);
        pll->on = false;

out:
        mutex_unlock(&dev_priv->dpll_lock);
}

static struct intel_shared_dpll *
intel_find_shared_dpll(struct intel_crtc *crtc,
                       struct intel_crtc_state *crtc_state,
                       enum intel_dpll_id range_min,
                       enum intel_dpll_id range_max)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        struct intel_shared_dpll *pll;
        struct intel_shared_dpll_state *shared_dpll;
        enum intel_dpll_id i;

        shared_dpll = intel_atomic_get_shared_dpll_state(crtc_state->base.state);

        for (i = range_min; i <= range_max; i++) {
                pll = &dev_priv->shared_dplls[i];

                /* Only want to check enabled timings first */
                if (shared_dpll[i].crtc_mask == 0)
                        continue;

                if (memcmp(&crtc_state->dpll_hw_state,
                           &shared_dpll[i].hw_state,
                           sizeof(crtc_state->dpll_hw_state)) == 0) {
                        DRM_DEBUG_KMS("[CRTC:%d:%s] sharing existing %s (crtc mask 0x%08x, active %x)\n",
                                      crtc->base.base.id, crtc->base.name, pll->name,
                                      shared_dpll[i].crtc_mask,
                                      pll->active_mask);
                        return pll;
                }
        }

        /* Ok no matching timings, maybe there's a free one? */
        for (i = range_min; i <= range_max; i++) {
                pll = &dev_priv->shared_dplls[i];
                if (shared_dpll[i].crtc_mask == 0) {
                        DRM_DEBUG_KMS("[CRTC:%d:%s] allocated %s\n",
                                      crtc->base.base.id, crtc->base.name, pll->name);
                        return pll;
                }
        }

        return NULL;
}

static void
intel_reference_shared_dpll(struct intel_shared_dpll *pll,
                            struct intel_crtc_state *crtc_state)
{
        struct intel_shared_dpll_state *shared_dpll;
        struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
        enum intel_dpll_id i = pll->id;

        shared_dpll = intel_atomic_get_shared_dpll_state(crtc_state->base.state);

        if (shared_dpll[i].crtc_mask == 0)
                shared_dpll[i].hw_state =
                        crtc_state->dpll_hw_state;

        crtc_state->shared_dpll = pll;
        DRM_DEBUG_DRIVER("using %s for pipe %c\n", pll->name,
                         pipe_name(crtc->pipe));

        shared_dpll[pll->id].crtc_mask |= 1 << crtc->pipe;
}

/**
 * intel_shared_dpll_swap_state - make atomic DPLL configuration effective
 * @state: atomic state
 *
 * This is the dpll version of drm_atomic_helper_swap_state() since the
 * helper does not handle driver-specific global state.
 *
 * For consistency with atomic helpers this function does a complete swap,
 * i.e. it also puts the current state into @state, even though there is no
 * need for that at this moment.
 */
void intel_shared_dpll_swap_state(struct drm_atomic_state *state)
{
        struct drm_i915_private *dev_priv = to_i915(state->dev);
        struct intel_shared_dpll_state *shared_dpll;
        struct intel_shared_dpll *pll;
        enum intel_dpll_id i;

        if (!to_intel_atomic_state(state)->dpll_set)
                return;

        shared_dpll = to_intel_atomic_state(state)->shared_dpll;
        for (i = 0; i < dev_priv->num_shared_dpll; i++) {
                struct intel_shared_dpll_state tmp;

                pll = &dev_priv->shared_dplls[i];

                tmp = pll->state;
                pll->state = shared_dpll[i];
                shared_dpll[i] = tmp;
        }
}

static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,
                                      struct intel_shared_dpll *pll,
                                      struct intel_dpll_hw_state *hw_state)
{
        uint32_t val;

        if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
                return false;

        val = I915_READ(PCH_DPLL(pll->id));
        hw_state->dpll = val;
        hw_state->fp0 = I915_READ(PCH_FP0(pll->id));
        hw_state->fp1 = I915_READ(PCH_FP1(pll->id));

        intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);

        return val & DPLL_VCO_ENABLE;
}

static void ibx_pch_dpll_prepare(struct drm_i915_private *dev_priv,
                                 struct intel_shared_dpll *pll)
{
        I915_WRITE(PCH_FP0(pll->id), pll->state.hw_state.fp0);
        I915_WRITE(PCH_FP1(pll->id), pll->state.hw_state.fp1);
}

static void ibx_assert_pch_refclk_enabled(struct drm_i915_private *dev_priv)
{
        u32 val;
        bool enabled;

        I915_STATE_WARN_ON(!(HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv)));

        val = I915_READ(PCH_DREF_CONTROL);
        enabled = !!(val & (DREF_SSC_SOURCE_MASK | DREF_NONSPREAD_SOURCE_MASK |
                            DREF_SUPERSPREAD_SOURCE_MASK));
        I915_STATE_WARN(!enabled, "PCH refclk assertion failure, should be active but is disabled\n");
}

static void ibx_pch_dpll_enable(struct drm_i915_private *dev_priv,
                                struct intel_shared_dpll *pll)
{
        /* PCH refclock must be enabled first */
        ibx_assert_pch_refclk_enabled(dev_priv);

        I915_WRITE(PCH_DPLL(pll->id), pll->state.hw_state.dpll);

        /* Wait for the clocks to stabilize. */
        POSTING_READ(PCH_DPLL(pll->id));
        udelay(150);

        /* The pixel multiplier can only be updated once the
         * DPLL is enabled and the clocks are stable.
         *
         * So write it again.
         */
        I915_WRITE(PCH_DPLL(pll->id), pll->state.hw_state.dpll);
        POSTING_READ(PCH_DPLL(pll->id));
        udelay(200);
}

static void ibx_pch_dpll_disable(struct drm_i915_private *dev_priv,
                                 struct intel_shared_dpll *pll)
{
        struct drm_device *dev = &dev_priv->drm;
        struct intel_crtc *crtc;

        /* Make sure no transcoder isn't still depending on us. */
        for_each_intel_crtc(dev, crtc) {
                if (crtc->config->shared_dpll == pll)
                        assert_pch_transcoder_disabled(dev_priv, crtc->pipe);
        }

        I915_WRITE(PCH_DPLL(pll->id), 0);
        POSTING_READ(PCH_DPLL(pll->id));
        udelay(200);
}

static struct intel_shared_dpll *
ibx_get_dpll(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state,
             struct intel_encoder *encoder)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        struct intel_shared_dpll *pll;
        enum intel_dpll_id i;

        if (HAS_PCH_IBX(dev_priv)) {
                /* Ironlake PCH has a fixed PLL->PCH pipe mapping. */
                i = (enum intel_dpll_id) crtc->pipe;
                pll = &dev_priv->shared_dplls[i];

                DRM_DEBUG_KMS("[CRTC:%d:%s] using pre-allocated %s\n",
                              crtc->base.base.id, crtc->base.name, pll->name);
        } else {
                pll = intel_find_shared_dpll(crtc, crtc_state,
                                             DPLL_ID_PCH_PLL_A,
                                             DPLL_ID_PCH_PLL_B);
        }

        if (!pll)
                return NULL;

        /* reference the pll */
        intel_reference_shared_dpll(pll, crtc_state);

        return pll;
}

static void ibx_dump_hw_state(struct drm_i915_private *dev_priv,
                              struct intel_dpll_hw_state *hw_state)
{
        DRM_DEBUG_KMS("dpll_hw_state: dpll: 0x%x, dpll_md: 0x%x, "
                      "fp0: 0x%x, fp1: 0x%x\n",
                      hw_state->dpll,
                      hw_state->dpll_md,
                      hw_state->fp0,
                      hw_state->fp1);
}

static const struct intel_shared_dpll_funcs ibx_pch_dpll_funcs = {
        .prepare = ibx_pch_dpll_prepare,
        .enable = ibx_pch_dpll_enable,
        .disable = ibx_pch_dpll_disable,
        .get_hw_state = ibx_pch_dpll_get_hw_state,
};

static void hsw_ddi_wrpll_enable(struct drm_i915_private *dev_priv,
                               struct intel_shared_dpll *pll)
{
        I915_WRITE(WRPLL_CTL(pll->id), pll->state.hw_state.wrpll);
        POSTING_READ(WRPLL_CTL(pll->id));
        udelay(20);
}

static void hsw_ddi_spll_enable(struct drm_i915_private *dev_priv,
                                struct intel_shared_dpll *pll)
{
        I915_WRITE(SPLL_CTL, pll->state.hw_state.spll);
        POSTING_READ(SPLL_CTL);
        udelay(20);
}

static void hsw_ddi_wrpll_disable(struct drm_i915_private *dev_priv,
                                  struct intel_shared_dpll *pll)
{
        uint32_t val;

        val = I915_READ(WRPLL_CTL(pll->id));
        I915_WRITE(WRPLL_CTL(pll->id), val & ~WRPLL_PLL_ENABLE);
        POSTING_READ(WRPLL_CTL(pll->id));
}

static void hsw_ddi_spll_disable(struct drm_i915_private *dev_priv,
                                 struct intel_shared_dpll *pll)
{
        uint32_t val;

        val = I915_READ(SPLL_CTL);
        I915_WRITE(SPLL_CTL, val & ~SPLL_PLL_ENABLE);
        POSTING_READ(SPLL_CTL);
}

static bool hsw_ddi_wrpll_get_hw_state(struct drm_i915_private *dev_priv,
                                       struct intel_shared_dpll *pll,
                                       struct intel_dpll_hw_state *hw_state)
{
        uint32_t val;

        if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
                return false;

        val = I915_READ(WRPLL_CTL(pll->id));
        hw_state->wrpll = val;

        intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);

        return val & WRPLL_PLL_ENABLE;
}

static bool hsw_ddi_spll_get_hw_state(struct drm_i915_private *dev_priv,
                                      struct intel_shared_dpll *pll,
                                      struct intel_dpll_hw_state *hw_state)
{
        uint32_t val;

        if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
                return false;

        val = I915_READ(SPLL_CTL);
        hw_state->spll = val;

        intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);

        return val & SPLL_PLL_ENABLE;
}

#define LC_FREQ 2700
#define LC_FREQ_2K U64_C(LC_FREQ * 2000)

#define P_MIN 2
#define P_MAX 64
#define P_INC 2

/* Constraints for PLL good behavior */
#define REF_MIN 48
#define REF_MAX 400
#define VCO_MIN 2400
#define VCO_MAX 4800

struct hsw_wrpll_rnp {
        unsigned p, n2, r2;
};

static unsigned hsw_wrpll_get_budget_for_freq(int clock)
{
        unsigned budget;

        switch (clock) {
        case 25175000:
        case 25200000:
        case 27000000:
        case 27027000:
        case 37762500:
        case 37800000:
        case 40500000:
        case 40541000:
        case 54000000:
        case 54054000:
        case 59341000:
        case 59400000:
        case 72000000:
        case 74176000:
        case 74250000:
        case 81000000:
        case 81081000:
        case 89012000:
        case 89100000:
        case 108000000:
        case 108108000:
        case 111264000:
        case 111375000:
        case 148352000:
        case 148500000:
        case 162000000:
        case 162162000:
        case 222525000:
        case 222750000:
        case 296703000:
        case 297000000:
                budget = 0;
                break;
        case 233500000:
        case 245250000:
        case 247750000:
        case 253250000:
        case 298000000:
                budget = 1500;
                break;
        case 169128000:
        case 169500000:
        case 179500000:
        case 202000000:
                budget = 2000;
                break;
        case 256250000:
        case 262500000:
        case 270000000:
        case 272500000:
        case 273750000:
        case 280750000:
        case 281250000:
        case 286000000:
        case 291750000:
                budget = 4000;
                break;
        case 267250000:
        case 268500000:
                budget = 5000;
                break;
        default:
                budget = 1000;
                break;
        }

        return budget;
}

static void hsw_wrpll_update_rnp(uint64_t freq2k, unsigned budget,
                                 unsigned r2, unsigned n2, unsigned p,
                                 struct hsw_wrpll_rnp *best)
{
        uint64_t a, b, c, d, diff, diff_best;

        /* No best (r,n,p) yet */
        if (best->p == 0) {
                best->p = p;
                best->n2 = n2;
                best->r2 = r2;
                return;
        }

        /*
         * Output clock is (LC_FREQ_2K / 2000) * N / (P * R), which compares to
         * freq2k.
         *
         * delta = 1e6 *
         *         abs(freq2k - (LC_FREQ_2K * n2/(p * r2))) /
         *         freq2k;
         *
         * and we would like delta <= budget.
         *
         * If the discrepancy is above the PPM-based budget, always prefer to
         * improve upon the previous solution.  However, if you're within the
         * budget, try to maximize Ref * VCO, that is N / (P * R^2).
         */
        a = freq2k * budget * p * r2;
        b = freq2k * budget * best->p * best->r2;
        diff = abs_diff(freq2k * p * r2, LC_FREQ_2K * n2);
        diff_best = abs_diff(freq2k * best->p * best->r2,
                             LC_FREQ_2K * best->n2);
        c = 1000000 * diff;
        d = 1000000 * diff_best;

        if (a < c && b < d) {
                /* If both are above the budget, pick the closer */
                if (best->p * best->r2 * diff < p * r2 * diff_best) {
                        best->p = p;
                        best->n2 = n2;
                        best->r2 = r2;
                }
        } else if (a >= c && b < d) {
                /* If A is below the threshold but B is above it?  Update. */
                best->p = p;
                best->n2 = n2;
                best->r2 = r2;
        } else if (a >= c && b >= d) {
                /* Both are below the limit, so pick the higher n2/(r2*r2) */
                if (n2 * best->r2 * best->r2 > best->n2 * r2 * r2) {
                        best->p = p;
                        best->n2 = n2;
                        best->r2 = r2;
                }
        }
        /* Otherwise a < c && b >= d, do nothing */
}

static void
hsw_ddi_calculate_wrpll(int clock /* in Hz */,
                        unsigned *r2_out, unsigned *n2_out, unsigned *p_out)
{
        uint64_t freq2k;
        unsigned p, n2, r2;
        struct hsw_wrpll_rnp best = { 0, 0, 0 };
        unsigned budget;

        freq2k = clock / 100;

        budget = hsw_wrpll_get_budget_for_freq(clock);

        /* Special case handling for 540 pixel clock: bypass WR PLL entirely
         * and directly pass the LC PLL to it. */
        if (freq2k == 5400000) {
                *n2_out = 2;
                *p_out = 1;
                *r2_out = 2;
                return;
        }

        /*
         * Ref = LC_FREQ / R, where Ref is the actual reference input seen by
         * the WR PLL.
         *
         * We want R so that REF_MIN <= Ref <= REF_MAX.
         * Injecting R2 = 2 * R gives:
         *   REF_MAX * r2 > LC_FREQ * 2 and
         *   REF_MIN * r2 < LC_FREQ * 2
         *
         * Which means the desired boundaries for r2 are:
         *  LC_FREQ * 2 / REF_MAX < r2 < LC_FREQ * 2 / REF_MIN
         *
         */
        for (r2 = LC_FREQ * 2 / REF_MAX + 1;
             r2 <= LC_FREQ * 2 / REF_MIN;
             r2++) {

                /*
                 * VCO = N * Ref, that is: VCO = N * LC_FREQ / R
                 *
                 * Once again we want VCO_MIN <= VCO <= VCO_MAX.
                 * Injecting R2 = 2 * R and N2 = 2 * N, we get:
                 *   VCO_MAX * r2 > n2 * LC_FREQ and
                 *   VCO_MIN * r2 < n2 * LC_FREQ)
                 *
                 * Which means the desired boundaries for n2 are:
                 * VCO_MIN * r2 / LC_FREQ < n2 < VCO_MAX * r2 / LC_FREQ
                 */
                for (n2 = VCO_MIN * r2 / LC_FREQ + 1;
                     n2 <= VCO_MAX * r2 / LC_FREQ;
                     n2++) {

                        for (p = P_MIN; p <= P_MAX; p += P_INC)
                                hsw_wrpll_update_rnp(freq2k, budget,
                                                     r2, n2, p, &best);
                }
        }

        *n2_out = best.n2;
        *p_out = best.p;
        *r2_out = best.r2;
}

static struct intel_shared_dpll *hsw_ddi_hdmi_get_dpll(int clock,
                                                       struct intel_crtc *crtc,
                                                       struct intel_crtc_state *crtc_state)
{
        struct intel_shared_dpll *pll;
        uint32_t val;
        unsigned int p, n2, r2;

        hsw_ddi_calculate_wrpll(clock * 1000, &r2, &n2, &p);

        val = WRPLL_PLL_ENABLE | WRPLL_PLL_LCPLL |
              WRPLL_DIVIDER_REFERENCE(r2) | WRPLL_DIVIDER_FEEDBACK(n2) |
              WRPLL_DIVIDER_POST(p);

        crtc_state->dpll_hw_state.wrpll = val;

        pll = intel_find_shared_dpll(crtc, crtc_state,
                                     DPLL_ID_WRPLL1, DPLL_ID_WRPLL2);

        if (!pll)
                return NULL;

        return pll;
}

static struct intel_shared_dpll *
hsw_ddi_dp_get_dpll(struct intel_encoder *encoder, int clock)
{
        struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
        struct intel_shared_dpll *pll;
        enum intel_dpll_id pll_id;

        switch (clock / 2) {
        case 81000:
                pll_id = DPLL_ID_LCPLL_810;
                break;
        case 135000:
                pll_id = DPLL_ID_LCPLL_1350;
                break;
        case 270000:
                pll_id = DPLL_ID_LCPLL_2700;
                break;
        default:
                DRM_DEBUG_KMS("Invalid clock for DP: %d\n", clock);
                return NULL;
        }

        pll = intel_get_shared_dpll_by_id(dev_priv, pll_id);

        if (!pll)
                return NULL;

        return pll;
}

static struct intel_shared_dpll *
hsw_get_dpll(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state,
             struct intel_encoder *encoder)
{
        struct intel_shared_dpll *pll;
        int clock = crtc_state->port_clock;

        memset(&crtc_state->dpll_hw_state, 0,
               sizeof(crtc_state->dpll_hw_state));

        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
                pll = hsw_ddi_hdmi_get_dpll(clock, crtc, crtc_state);
        } else if (intel_crtc_has_dp_encoder(crtc_state)) {
                pll = hsw_ddi_dp_get_dpll(encoder, clock);
        } else if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_ANALOG)) {
                if (WARN_ON(crtc_state->port_clock / 2 != 135000))
                        return NULL;

                crtc_state->dpll_hw_state.spll =
                        SPLL_PLL_ENABLE | SPLL_PLL_FREQ_1350MHz | SPLL_PLL_SSC;

                pll = intel_find_shared_dpll(crtc, crtc_state,
                                             DPLL_ID_SPLL, DPLL_ID_SPLL);
        } else {
                return NULL;
        }

        if (!pll)
                return NULL;

        intel_reference_shared_dpll(pll, crtc_state);

        return pll;
}

static void hsw_dump_hw_state(struct drm_i915_private *dev_priv,
                              struct intel_dpll_hw_state *hw_state)
{
        DRM_DEBUG_KMS("dpll_hw_state: wrpll: 0x%x spll: 0x%x\n",
                      hw_state->wrpll, hw_state->spll);
}

static const struct intel_shared_dpll_funcs hsw_ddi_wrpll_funcs = {
        .enable = hsw_ddi_wrpll_enable,
        .disable = hsw_ddi_wrpll_disable,
        .get_hw_state = hsw_ddi_wrpll_get_hw_state,
};

static const struct intel_shared_dpll_funcs hsw_ddi_spll_funcs = {
        .enable = hsw_ddi_spll_enable,
        .disable = hsw_ddi_spll_disable,
        .get_hw_state = hsw_ddi_spll_get_hw_state,
};

static void hsw_ddi_lcpll_enable(struct drm_i915_private *dev_priv,
                                 struct intel_shared_dpll *pll)
{
}

static void hsw_ddi_lcpll_disable(struct drm_i915_private *dev_priv,
                                  struct intel_shared_dpll *pll)
{
}

static bool hsw_ddi_lcpll_get_hw_state(struct drm_i915_private *dev_priv,
                                       struct intel_shared_dpll *pll,
                                       struct intel_dpll_hw_state *hw_state)
{
        return true;
}

static const struct intel_shared_dpll_funcs hsw_ddi_lcpll_funcs = {
        .enable = hsw_ddi_lcpll_enable,
        .disable = hsw_ddi_lcpll_disable,
        .get_hw_state = hsw_ddi_lcpll_get_hw_state,
};

struct skl_dpll_regs {
        i915_reg_t ctl, cfgcr1, cfgcr2;
};

/* this array is indexed by the *shared* pll id */
static const struct skl_dpll_regs skl_dpll_regs[4] = {
        {
                /* DPLL 0 */
                .ctl = LCPLL1_CTL,
                /* DPLL 0 doesn't support HDMI mode */
        },
        {
                /* DPLL 1 */
                .ctl = LCPLL2_CTL,
                .cfgcr1 = DPLL_CFGCR1(SKL_DPLL1),
                .cfgcr2 = DPLL_CFGCR2(SKL_DPLL1),
        },
        {
                /* DPLL 2 */
                .ctl = WRPLL_CTL(0),
                .cfgcr1 = DPLL_CFGCR1(SKL_DPLL2),
                .cfgcr2 = DPLL_CFGCR2(SKL_DPLL2),
        },
        {
                /* DPLL 3 */
                .ctl = WRPLL_CTL(1),
                .cfgcr1 = DPLL_CFGCR1(SKL_DPLL3),
                .cfgcr2 = DPLL_CFGCR2(SKL_DPLL3),
        },
};

static void skl_ddi_pll_write_ctrl1(struct drm_i915_private *dev_priv,
                                    struct intel_shared_dpll *pll)
{
        uint32_t val;

        val = I915_READ(DPLL_CTRL1);

        val &= ~(DPLL_CTRL1_HDMI_MODE(pll->id) | DPLL_CTRL1_SSC(pll->id) |
                 DPLL_CTRL1_LINK_RATE_MASK(pll->id));
        val |= pll->state.hw_state.ctrl1 << (pll->id * 6);

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

static void skl_ddi_pll_enable(struct drm_i915_private *dev_priv,
                               struct intel_shared_dpll *pll)
{
        const struct skl_dpll_regs *regs = skl_dpll_regs;

        skl_ddi_pll_write_ctrl1(dev_priv, pll);

        I915_WRITE(regs[pll->id].cfgcr1, pll->state.hw_state.cfgcr1);
        I915_WRITE(regs[pll->id].cfgcr2, pll->state.hw_state.cfgcr2);
        POSTING_READ(regs[pll->id].cfgcr1);
        POSTING_READ(regs[pll->id].cfgcr2);

        /* the enable bit is always bit 31 */
        I915_WRITE(regs[pll->id].ctl,
                   I915_READ(regs[pll->id].ctl) | LCPLL_PLL_ENABLE);

        if (intel_wait_for_register(dev_priv,
                                    DPLL_STATUS,
                                    DPLL_LOCK(pll->id),
                                    DPLL_LOCK(pll->id),
                                    5))
                DRM_ERROR("DPLL %d not locked\n", pll->id);
}

static void skl_ddi_dpll0_enable(struct drm_i915_private *dev_priv,
                                 struct intel_shared_dpll *pll)
{
        skl_ddi_pll_write_ctrl1(dev_priv, pll);
}

static void skl_ddi_pll_disable(struct drm_i915_private *dev_priv,
                                struct intel_shared_dpll *pll)
{
        const struct skl_dpll_regs *regs = skl_dpll_regs;

        /* the enable bit is always bit 31 */
        I915_WRITE(regs[pll->id].ctl,
                   I915_READ(regs[pll->id].ctl) & ~LCPLL_PLL_ENABLE);
        POSTING_READ(regs[pll->id].ctl);
}

static void skl_ddi_dpll0_disable(struct drm_i915_private *dev_priv,
                                  struct intel_shared_dpll *pll)
{
}

static bool skl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
                                     struct intel_shared_dpll *pll,
                                     struct intel_dpll_hw_state *hw_state)
{
        uint32_t val;
        const struct skl_dpll_regs *regs = skl_dpll_regs;
        bool ret;

        if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
                return false;

        ret = false;

        val = I915_READ(regs[pll->id].ctl);
        if (!(val & LCPLL_PLL_ENABLE))
                goto out;

        val = I915_READ(DPLL_CTRL1);
        hw_state->ctrl1 = (val >> (pll->id * 6)) & 0x3f;

        /* avoid reading back stale values if HDMI mode is not enabled */
        if (val & DPLL_CTRL1_HDMI_MODE(pll->id)) {
                hw_state->cfgcr1 = I915_READ(regs[pll->id].cfgcr1);
                hw_state->cfgcr2 = I915_READ(regs[pll->id].cfgcr2);
        }
        ret = true;

out:
        intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);

        return ret;
}

static bool skl_ddi_dpll0_get_hw_state(struct drm_i915_private *dev_priv,
                                       struct intel_shared_dpll *pll,
                                       struct intel_dpll_hw_state *hw_state)
{
        uint32_t val;
        const struct skl_dpll_regs *regs = skl_dpll_regs;
        bool ret;

        if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
                return false;

        ret = false;

        /* DPLL0 is always enabled since it drives CDCLK */
        val = I915_READ(regs[pll->id].ctl);
        if (WARN_ON(!(val & LCPLL_PLL_ENABLE)))
                goto out;

        val = I915_READ(DPLL_CTRL1);
        hw_state->ctrl1 = (val >> (pll->id * 6)) & 0x3f;

        ret = true;

out:
        intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);

        return ret;
}

struct skl_wrpll_context {
        uint64_t min_deviation;         /* current minimal deviation */
        uint64_t central_freq;          /* chosen central freq */
        uint64_t dco_freq;              /* chosen dco freq */
        unsigned int p;                 /* chosen divider */
};

static void skl_wrpll_context_init(struct skl_wrpll_context *ctx)
{
        memset(ctx, 0, sizeof(*ctx));

        ctx->min_deviation = U64_MAX;
}

/* DCO freq must be within +1%/-6%  of the DCO central freq */
#define SKL_DCO_MAX_PDEVIATION  100
#define SKL_DCO_MAX_NDEVIATION  600

static void skl_wrpll_try_divider(struct skl_wrpll_context *ctx,
                                  uint64_t central_freq,
                                  uint64_t dco_freq,
                                  unsigned int divider)
{
        uint64_t deviation;

        deviation = div64_u64(10000 * abs_diff(dco_freq, central_freq),
                              central_freq);

        /* positive deviation */
        if (dco_freq >= central_freq) {
                if (deviation < SKL_DCO_MAX_PDEVIATION &&
                    deviation < ctx->min_deviation) {
                        ctx->min_deviation = deviation;
                        ctx->central_freq = central_freq;
                        ctx->dco_freq = dco_freq;
                        ctx->p = divider;
                }
        /* negative deviation */
        } else if (deviation < SKL_DCO_MAX_NDEVIATION &&
                   deviation < ctx->min_deviation) {
                ctx->min_deviation = deviation;
                ctx->central_freq = central_freq;
                ctx->dco_freq = dco_freq;
                ctx->p = divider;
        }
}

static void skl_wrpll_get_multipliers(unsigned int p,
                                      unsigned int *p0 /* out */,
                                      unsigned int *p1 /* out */,
                                      unsigned int *p2 /* out */)
{
        /* even dividers */
        if (p % 2 == 0) {
                unsigned int half = p / 2;

                if (half == 1 || half == 2 || half == 3 || half == 5) {
                        *p0 = 2;
                        *p1 = 1;
                        *p2 = half;
                } else if (half % 2 == 0) {
                        *p0 = 2;
                        *p1 = half / 2;
                        *p2 = 2;
                } else if (half % 3 == 0) {
                        *p0 = 3;
                        *p1 = half / 3;
                        *p2 = 2;
                } else if (half % 7 == 0) {
                        *p0 = 7;
                        *p1 = half / 7;
                        *p2 = 2;
                }
        } else if (p == 3 || p == 9) {  /* 3, 5, 7, 9, 15, 21, 35 */
                *p0 = 3;
                *p1 = 1;
                *p2 = p / 3;
        } else if (p == 5 || p == 7) {
                *p0 = p;
                *p1 = 1;
                *p2 = 1;
        } else if (p == 15) {
                *p0 = 3;
                *p1 = 1;
                *p2 = 5;
        } else if (p == 21) {
                *p0 = 7;
                *p1 = 1;
                *p2 = 3;
        } else if (p == 35) {
                *p0 = 7;
                *p1 = 1;
                *p2 = 5;
        }
}

struct skl_wrpll_params {
        uint32_t        dco_fraction;
        uint32_t        dco_integer;
        uint32_t        qdiv_ratio;
        uint32_t        qdiv_mode;
        uint32_t        kdiv;
        uint32_t        pdiv;
        uint32_t        central_freq;
};

static void skl_wrpll_params_populate(struct skl_wrpll_params *params,
                                      uint64_t afe_clock,
                                      uint64_t central_freq,
                                      uint32_t p0, uint32_t p1, uint32_t p2)
{
        uint64_t dco_freq;

        switch (central_freq) {
        case 9600000000ULL:
                params->central_freq = 0;
                break;
        case 9000000000ULL:
                params->central_freq = 1;
                break;
        case 8400000000ULL:
                params->central_freq = 3;
        }

        switch (p0) {
        case 1:
                params->pdiv = 0;
                break;
        case 2:
                params->pdiv = 1;
                break;
        case 3:
                params->pdiv = 2;
                break;
        case 7:
                params->pdiv = 4;
                break;
        default:
                WARN(1, "Incorrect PDiv\n");
        }

        switch (p2) {
        case 5:
                params->kdiv = 0;
                break;
        case 2:
                params->kdiv = 1;
                break;
        case 3:
                params->kdiv = 2;
                break;
        case 1:
                params->kdiv = 3;
                break;
        default:
                WARN(1, "Incorrect KDiv\n");
        }

        params->qdiv_ratio = p1;
        params->qdiv_mode = (params->qdiv_ratio == 1) ? 0 : 1;

        dco_freq = p0 * p1 * p2 * afe_clock;

        /*
         * Intermediate values are in Hz.
         * Divide by MHz to match bsepc
         */
        params->dco_integer = div_u64(dco_freq, 24 * MHz(1));
        params->dco_fraction =
                div_u64((div_u64(dco_freq, 24) -
                         params->dco_integer * MHz(1)) * 0x8000, MHz(1));
}

static bool
skl_ddi_calculate_wrpll(int clock /* in Hz */,
                        struct skl_wrpll_params *wrpll_params)
{
        uint64_t afe_clock = clock * 5; /* AFE Clock is 5x Pixel clock */
        uint64_t dco_central_freq[3] = {8400000000ULL,
                                        9000000000ULL,
                                        9600000000ULL};
        static const int even_dividers[] = {  4,  6,  8, 10, 12, 14, 16, 18, 20,
                                             24, 28, 30, 32, 36, 40, 42, 44,
                                             48, 52, 54, 56, 60, 64, 66, 68,
                                             70, 72, 76, 78, 80, 84, 88, 90,
                                             92, 96, 98 };
        static const int odd_dividers[] = { 3, 5, 7, 9, 15, 21, 35 };
        static const struct {
                const int *list;
                int n_dividers;
        } dividers[] = {
                { even_dividers, ARRAY_SIZE(even_dividers) },
                { odd_dividers, ARRAY_SIZE(odd_dividers) },
        };
        struct skl_wrpll_context ctx;
        unsigned int dco, d, i;
        unsigned int p0, p1, p2;

        skl_wrpll_context_init(&ctx);

        for (d = 0; d < ARRAY_SIZE(dividers); d++) {
                for (dco = 0; dco < ARRAY_SIZE(dco_central_freq); dco++) {
                        for (i = 0; i < dividers[d].n_dividers; i++) {
                                unsigned int p = dividers[d].list[i];
                                uint64_t dco_freq = p * afe_clock;

                                skl_wrpll_try_divider(&ctx,
                                                      dco_central_freq[dco],
                                                      dco_freq,
                                                      p);
                                /*
                                 * Skip the remaining dividers if we're sure to
                                 * have found the definitive divider, we can't
                                 * improve a 0 deviation.
                                 */
                                if (ctx.min_deviation == 0)
                                        goto skip_remaining_dividers;
                        }
                }

skip_remaining_dividers:
                /*
                 * If a solution is found with an even divider, prefer
                 * this one.
                 */
                if (d == 0 && ctx.p)
                        break;
        }

        if (!ctx.p) {
                DRM_DEBUG_DRIVER("No valid divider found for %dHz\n", clock);
                return false;
        }

        /*
         * gcc incorrectly analyses that these can be used without being
         * initialized. To be fair, it's hard to guess.
         */
        p0 = p1 = p2 = 0;
        skl_wrpll_get_multipliers(ctx.p, &p0, &p1, &p2);
        skl_wrpll_params_populate(wrpll_params, afe_clock, ctx.central_freq,
                                  p0, p1, p2);

        return true;
}

static bool skl_ddi_hdmi_pll_dividers(struct intel_crtc *crtc,
                                      struct intel_crtc_state *crtc_state,
                                      int clock)
{
        uint32_t ctrl1, cfgcr1, cfgcr2;
        struct skl_wrpll_params wrpll_params = { 0, };

        /*
         * See comment in intel_dpll_hw_state to understand why we always use 0
         * as the DPLL id in this function.
         */
        ctrl1 = DPLL_CTRL1_OVERRIDE(0);

        ctrl1 |= DPLL_CTRL1_HDMI_MODE(0);

        if (!skl_ddi_calculate_wrpll(clock * 1000, &wrpll_params))
                return false;

        cfgcr1 = DPLL_CFGCR1_FREQ_ENABLE |
                DPLL_CFGCR1_DCO_FRACTION(wrpll_params.dco_fraction) |
                wrpll_params.dco_integer;

        cfgcr2 = DPLL_CFGCR2_QDIV_RATIO(wrpll_params.qdiv_ratio) |
                DPLL_CFGCR2_QDIV_MODE(wrpll_params.qdiv_mode) |
                DPLL_CFGCR2_KDIV(wrpll_params.kdiv) |
                DPLL_CFGCR2_PDIV(wrpll_params.pdiv) |
                wrpll_params.central_freq;

        memset(&crtc_state->dpll_hw_state, 0,
               sizeof(crtc_state->dpll_hw_state));

        crtc_state->dpll_hw_state.ctrl1 = ctrl1;
        crtc_state->dpll_hw_state.cfgcr1 = cfgcr1;
        crtc_state->dpll_hw_state.cfgcr2 = cfgcr2;
        return true;
}

static bool
skl_ddi_dp_set_dpll_hw_state(int clock,
                             struct intel_dpll_hw_state *dpll_hw_state)
{
        uint32_t ctrl1;

        /*
         * See comment in intel_dpll_hw_state to understand why we always use 0
         * as the DPLL id in this function.
         */
        ctrl1 = DPLL_CTRL1_OVERRIDE(0);
        switch (clock / 2) {
        case 81000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_810, 0);
                break;
        case 135000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1350, 0);
                break;
        case 270000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2700, 0);
                break;
                /* eDP 1.4 rates */
        case 162000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1620, 0);
                break;
        case 108000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_1080, 0);
                break;
        case 216000:
                ctrl1 |= DPLL_CTRL1_LINK_RATE(DPLL_CTRL1_LINK_RATE_2160, 0);
                break;
        }

        dpll_hw_state->ctrl1 = ctrl1;
        return true;
}

static struct intel_shared_dpll *
skl_get_dpll(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state,
             struct intel_encoder *encoder)
{
        struct intel_shared_dpll *pll;
        int clock = crtc_state->port_clock;
        bool bret;
        struct intel_dpll_hw_state dpll_hw_state;

        memset(&dpll_hw_state, 0, sizeof(dpll_hw_state));

        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
                bret = skl_ddi_hdmi_pll_dividers(crtc, crtc_state, clock);
                if (!bret) {
                        DRM_DEBUG_KMS("Could not get HDMI pll dividers.\n");
                        return NULL;
                }
        } else if (intel_crtc_has_dp_encoder(crtc_state)) {
                bret = skl_ddi_dp_set_dpll_hw_state(clock, &dpll_hw_state);
                if (!bret) {
                        DRM_DEBUG_KMS("Could not set DP dpll HW state.\n");
                        return NULL;
                }
                crtc_state->dpll_hw_state = dpll_hw_state;
        } else {
                return NULL;
        }

        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP))
                pll = intel_find_shared_dpll(crtc, crtc_state,
                                             DPLL_ID_SKL_DPLL0,
                                             DPLL_ID_SKL_DPLL0);
        else
                pll = intel_find_shared_dpll(crtc, crtc_state,
                                             DPLL_ID_SKL_DPLL1,
                                             DPLL_ID_SKL_DPLL3);
        if (!pll)
                return NULL;

        intel_reference_shared_dpll(pll, crtc_state);

        return pll;
}

static void skl_dump_hw_state(struct drm_i915_private *dev_priv,
                              struct intel_dpll_hw_state *hw_state)
{
        DRM_DEBUG_KMS("dpll_hw_state: "
                      "ctrl1: 0x%x, cfgcr1: 0x%x, cfgcr2: 0x%x\n",
                      hw_state->ctrl1,
                      hw_state->cfgcr1,
                      hw_state->cfgcr2);
}

static const struct intel_shared_dpll_funcs skl_ddi_pll_funcs = {
        .enable = skl_ddi_pll_enable,
        .disable = skl_ddi_pll_disable,
        .get_hw_state = skl_ddi_pll_get_hw_state,
};

static const struct intel_shared_dpll_funcs skl_ddi_dpll0_funcs = {
        .enable = skl_ddi_dpll0_enable,
        .disable = skl_ddi_dpll0_disable,
        .get_hw_state = skl_ddi_dpll0_get_hw_state,
};

static void bxt_ddi_pll_enable(struct drm_i915_private *dev_priv,
                                struct intel_shared_dpll *pll)
{
        uint32_t temp;
        enum port port = (enum port)pll->id;    /* 1:1 port->PLL mapping */
        enum dpio_phy phy;
        enum dpio_channel ch;

        bxt_port_to_phy_channel(dev_priv, port, &phy, &ch);

        /* Non-SSC reference */
        temp = I915_READ(BXT_PORT_PLL_ENABLE(port));
        temp |= PORT_PLL_REF_SEL;
        I915_WRITE(BXT_PORT_PLL_ENABLE(port), temp);

        if (IS_GEMINILAKE(dev_priv)) {
                temp = I915_READ(BXT_PORT_PLL_ENABLE(port));
                temp |= PORT_PLL_POWER_ENABLE;
                I915_WRITE(BXT_PORT_PLL_ENABLE(port), temp);

                if (wait_for_us((I915_READ(BXT_PORT_PLL_ENABLE(port)) &
                                 PORT_PLL_POWER_STATE), 200))
                        DRM_ERROR("Power state not set for PLL:%d\n", port);
        }

        /* Disable 10 bit clock */
        temp = I915_READ(BXT_PORT_PLL_EBB_4(phy, ch));
        temp &= ~PORT_PLL_10BIT_CLK_ENABLE;
        I915_WRITE(BXT_PORT_PLL_EBB_4(phy, ch), temp);

        /* Write P1 & P2 */
        temp = I915_READ(BXT_PORT_PLL_EBB_0(phy, ch));
        temp &= ~(PORT_PLL_P1_MASK | PORT_PLL_P2_MASK);
        temp |= pll->state.hw_state.ebb0;
        I915_WRITE(BXT_PORT_PLL_EBB_0(phy, ch), temp);

        /* Write M2 integer */
        temp = I915_READ(BXT_PORT_PLL(phy, ch, 0));
        temp &= ~PORT_PLL_M2_MASK;
        temp |= pll->state.hw_state.pll0;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 0), temp);

        /* Write N */
        temp = I915_READ(BXT_PORT_PLL(phy, ch, 1));
        temp &= ~PORT_PLL_N_MASK;
        temp |= pll->state.hw_state.pll1;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 1), temp);

        /* Write M2 fraction */
        temp = I915_READ(BXT_PORT_PLL(phy, ch, 2));
        temp &= ~PORT_PLL_M2_FRAC_MASK;
        temp |= pll->state.hw_state.pll2;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 2), temp);

        /* Write M2 fraction enable */
        temp = I915_READ(BXT_PORT_PLL(phy, ch, 3));
        temp &= ~PORT_PLL_M2_FRAC_ENABLE;
        temp |= pll->state.hw_state.pll3;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 3), temp);

        /* Write coeff */
        temp = I915_READ(BXT_PORT_PLL(phy, ch, 6));
        temp &= ~PORT_PLL_PROP_COEFF_MASK;
        temp &= ~PORT_PLL_INT_COEFF_MASK;
        temp &= ~PORT_PLL_GAIN_CTL_MASK;
        temp |= pll->state.hw_state.pll6;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 6), temp);

        /* Write calibration val */
        temp = I915_READ(BXT_PORT_PLL(phy, ch, 8));
        temp &= ~PORT_PLL_TARGET_CNT_MASK;
        temp |= pll->state.hw_state.pll8;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 8), temp);

        temp = I915_READ(BXT_PORT_PLL(phy, ch, 9));
        temp &= ~PORT_PLL_LOCK_THRESHOLD_MASK;
        temp |= pll->state.hw_state.pll9;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 9), temp);

        temp = I915_READ(BXT_PORT_PLL(phy, ch, 10));
        temp &= ~PORT_PLL_DCO_AMP_OVR_EN_H;
        temp &= ~PORT_PLL_DCO_AMP_MASK;
        temp |= pll->state.hw_state.pll10;
        I915_WRITE(BXT_PORT_PLL(phy, ch, 10), temp);

        /* Recalibrate with new settings */
        temp = I915_READ(BXT_PORT_PLL_EBB_4(phy, ch));
        temp |= PORT_PLL_RECALIBRATE;
        I915_WRITE(BXT_PORT_PLL_EBB_4(phy, ch), temp);
        temp &= ~PORT_PLL_10BIT_CLK_ENABLE;
        temp |= pll->state.hw_state.ebb4;
        I915_WRITE(BXT_PORT_PLL_EBB_4(phy, ch), temp);

        /* Enable PLL */
        temp = I915_READ(BXT_PORT_PLL_ENABLE(port));
        temp |= PORT_PLL_ENABLE;
        I915_WRITE(BXT_PORT_PLL_ENABLE(port), temp);
        POSTING_READ(BXT_PORT_PLL_ENABLE(port));

        if (wait_for_us((I915_READ(BXT_PORT_PLL_ENABLE(port)) & PORT_PLL_LOCK),
                        200))
                DRM_ERROR("PLL %d not locked\n", port);

        if (IS_GEMINILAKE(dev_priv)) {
                temp = I915_READ(BXT_PORT_TX_DW5_LN0(phy, ch));
                temp |= DCC_DELAY_RANGE_2;
                I915_WRITE(BXT_PORT_TX_DW5_GRP(phy, ch), temp);
        }

        /*
         * While we write to the group register to program all lanes at once we
         * can read only lane registers and we pick lanes 0/1 for that.
         */
        temp = I915_READ(BXT_PORT_PCS_DW12_LN01(phy, ch));
        temp &= ~LANE_STAGGER_MASK;
        temp &= ~LANESTAGGER_STRAP_OVRD;
        temp |= pll->state.hw_state.pcsdw12;
        I915_WRITE(BXT_PORT_PCS_DW12_GRP(phy, ch), temp);
}

static void bxt_ddi_pll_disable(struct drm_i915_private *dev_priv,
                                        struct intel_shared_dpll *pll)
{
        enum port port = (enum port)pll->id;    /* 1:1 port->PLL mapping */
        uint32_t temp;

        temp = I915_READ(BXT_PORT_PLL_ENABLE(port));
        temp &= ~PORT_PLL_ENABLE;
        I915_WRITE(BXT_PORT_PLL_ENABLE(port), temp);
        POSTING_READ(BXT_PORT_PLL_ENABLE(port));

        if (IS_GEMINILAKE(dev_priv)) {
                temp = I915_READ(BXT_PORT_PLL_ENABLE(port));
                temp &= ~PORT_PLL_POWER_ENABLE;
                I915_WRITE(BXT_PORT_PLL_ENABLE(port), temp);

                if (wait_for_us(!(I915_READ(BXT_PORT_PLL_ENABLE(port)) &
                                PORT_PLL_POWER_STATE), 200))
                        DRM_ERROR("Power state not reset for PLL:%d\n", port);
        }
}

static bool bxt_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
                                        struct intel_shared_dpll *pll,
                                        struct intel_dpll_hw_state *hw_state)
{
        enum port port = (enum port)pll->id;    /* 1:1 port->PLL mapping */
        uint32_t val;
        bool ret;
        enum dpio_phy phy;
        enum dpio_channel ch;

        bxt_port_to_phy_channel(dev_priv, port, &phy, &ch);

        if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
                return false;

        ret = false;

        val = I915_READ(BXT_PORT_PLL_ENABLE(port));
        if (!(val & PORT_PLL_ENABLE))
                goto out;

        hw_state->ebb0 = I915_READ(BXT_PORT_PLL_EBB_0(phy, ch));
        hw_state->ebb0 &= PORT_PLL_P1_MASK | PORT_PLL_P2_MASK;

        hw_state->ebb4 = I915_READ(BXT_PORT_PLL_EBB_4(phy, ch));
        hw_state->ebb4 &= PORT_PLL_10BIT_CLK_ENABLE;

        hw_state->pll0 = I915_READ(BXT_PORT_PLL(phy, ch, 0));
        hw_state->pll0 &= PORT_PLL_M2_MASK;

        hw_state->pll1 = I915_READ(BXT_PORT_PLL(phy, ch, 1));
        hw_state->pll1 &= PORT_PLL_N_MASK;

        hw_state->pll2 = I915_READ(BXT_PORT_PLL(phy, ch, 2));
        hw_state->pll2 &= PORT_PLL_M2_FRAC_MASK;

        hw_state->pll3 = I915_READ(BXT_PORT_PLL(phy, ch, 3));
        hw_state->pll3 &= PORT_PLL_M2_FRAC_ENABLE;

        hw_state->pll6 = I915_READ(BXT_PORT_PLL(phy, ch, 6));
        hw_state->pll6 &= PORT_PLL_PROP_COEFF_MASK |
                          PORT_PLL_INT_COEFF_MASK |
                          PORT_PLL_GAIN_CTL_MASK;

        hw_state->pll8 = I915_READ(BXT_PORT_PLL(phy, ch, 8));
        hw_state->pll8 &= PORT_PLL_TARGET_CNT_MASK;

        hw_state->pll9 = I915_READ(BXT_PORT_PLL(phy, ch, 9));
        hw_state->pll9 &= PORT_PLL_LOCK_THRESHOLD_MASK;

        hw_state->pll10 = I915_READ(BXT_PORT_PLL(phy, ch, 10));
        hw_state->pll10 &= PORT_PLL_DCO_AMP_OVR_EN_H |
                           PORT_PLL_DCO_AMP_MASK;

        /*
         * While we write to the group register to program all lanes at once we
         * can read only lane registers. We configure all lanes the same way, so
         * here just read out lanes 0/1 and output a note if lanes 2/3 differ.
         */
        hw_state->pcsdw12 = I915_READ(BXT_PORT_PCS_DW12_LN01(phy, ch));
        if (I915_READ(BXT_PORT_PCS_DW12_LN23(phy, ch)) != hw_state->pcsdw12)
                DRM_DEBUG_DRIVER("lane stagger config different for lane 01 (%08x) and 23 (%08x)\n",
                                 hw_state->pcsdw12,
                                 I915_READ(BXT_PORT_PCS_DW12_LN23(phy, ch)));
        hw_state->pcsdw12 &= LANE_STAGGER_MASK | LANESTAGGER_STRAP_OVRD;

        ret = true;

out:
        intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);

        return ret;
}

/* bxt clock parameters */
struct bxt_clk_div {
        int clock;
        uint32_t p1;
        uint32_t p2;
        uint32_t m2_int;
        uint32_t m2_frac;
        bool m2_frac_en;
        uint32_t n;

        int vco;
};

/* pre-calculated values for DP linkrates */
static const struct bxt_clk_div bxt_dp_clk_val[] = {
        {162000, 4, 2, 32, 1677722, 1, 1},
        {270000, 4, 1, 27,       0, 0, 1},
        {540000, 2, 1, 27,       0, 0, 1},
        {216000, 3, 2, 32, 1677722, 1, 1},
        {243000, 4, 1, 24, 1258291, 1, 1},
        {324000, 4, 1, 32, 1677722, 1, 1},
        {432000, 3, 1, 32, 1677722, 1, 1}
};

static bool
bxt_ddi_hdmi_pll_dividers(struct intel_crtc *intel_crtc,
                          struct intel_crtc_state *crtc_state, int clock,
                          struct bxt_clk_div *clk_div)
{
        struct dpll best_clock;

        /* Calculate HDMI div */
        /*
         * FIXME: tie the following calculation into
         * i9xx_crtc_compute_clock
         */
        if (!bxt_find_best_dpll(crtc_state, clock, &best_clock)) {
                DRM_DEBUG_DRIVER("no PLL dividers found for clock %d pipe %c\n",
                                 clock, pipe_name(intel_crtc->pipe));
                return false;
        }

        clk_div->p1 = best_clock.p1;
        clk_div->p2 = best_clock.p2;
        WARN_ON(best_clock.m1 != 2);
        clk_div->n = best_clock.n;
        clk_div->m2_int = best_clock.m2 >> 22;
        clk_div->m2_frac = best_clock.m2 & ((1 << 22) - 1);
        clk_div->m2_frac_en = clk_div->m2_frac != 0;

        clk_div->vco = best_clock.vco;

        return true;
}

static void bxt_ddi_dp_pll_dividers(int clock, struct bxt_clk_div *clk_div)
{
        int i;

        *clk_div = bxt_dp_clk_val[0];
        for (i = 0; i < ARRAY_SIZE(bxt_dp_clk_val); ++i) {
                if (bxt_dp_clk_val[i].clock == clock) {
                        *clk_div = bxt_dp_clk_val[i];
                        break;
                }
        }

        clk_div->vco = clock * 10 / 2 * clk_div->p1 * clk_div->p2;
}

static bool bxt_ddi_set_dpll_hw_state(int clock,
                          struct bxt_clk_div *clk_div,
                          struct intel_dpll_hw_state *dpll_hw_state)
{
        int vco = clk_div->vco;
        uint32_t prop_coef, int_coef, gain_ctl, targ_cnt;
        uint32_t lanestagger;

        if (vco >= 6200000 && vco <= 6700000) {
                prop_coef = 4;
                int_coef = 9;
                gain_ctl = 3;
                targ_cnt = 8;
        } else if ((vco > 5400000 && vco < 6200000) ||
                        (vco >= 4800000 && vco < 5400000)) {
                prop_coef = 5;
                int_coef = 11;
                gain_ctl = 3;
                targ_cnt = 9;
        } else if (vco == 5400000) {
                prop_coef = 3;
                int_coef = 8;
                gain_ctl = 1;
                targ_cnt = 9;
        } else {
                DRM_ERROR("Invalid VCO\n");
                return false;
        }

        if (clock > 270000)
                lanestagger = 0x18;
        else if (clock > 135000)
                lanestagger = 0x0d;
        else if (clock > 67000)
                lanestagger = 0x07;
        else if (clock > 33000)
                lanestagger = 0x04;
        else
                lanestagger = 0x02;

        dpll_hw_state->ebb0 = PORT_PLL_P1(clk_div->p1) | PORT_PLL_P2(clk_div->p2);
        dpll_hw_state->pll0 = clk_div->m2_int;
        dpll_hw_state->pll1 = PORT_PLL_N(clk_div->n);
        dpll_hw_state->pll2 = clk_div->m2_frac;

        if (clk_div->m2_frac_en)
                dpll_hw_state->pll3 = PORT_PLL_M2_FRAC_ENABLE;

        dpll_hw_state->pll6 = prop_coef | PORT_PLL_INT_COEFF(int_coef);
        dpll_hw_state->pll6 |= PORT_PLL_GAIN_CTL(gain_ctl);

        dpll_hw_state->pll8 = targ_cnt;

        dpll_hw_state->pll9 = 5 << PORT_PLL_LOCK_THRESHOLD_SHIFT;

        dpll_hw_state->pll10 =
                PORT_PLL_DCO_AMP(PORT_PLL_DCO_AMP_DEFAULT)
                | PORT_PLL_DCO_AMP_OVR_EN_H;

        dpll_hw_state->ebb4 = PORT_PLL_10BIT_CLK_ENABLE;

        dpll_hw_state->pcsdw12 = LANESTAGGER_STRAP_OVRD | lanestagger;

        return true;
}

static bool
bxt_ddi_dp_set_dpll_hw_state(int clock,
                             struct intel_dpll_hw_state *dpll_hw_state)
{
        struct bxt_clk_div clk_div = {0};

        bxt_ddi_dp_pll_dividers(clock, &clk_div);

        return bxt_ddi_set_dpll_hw_state(clock, &clk_div, dpll_hw_state);
}

static bool
bxt_ddi_hdmi_set_dpll_hw_state(struct intel_crtc *intel_crtc,
                               struct intel_crtc_state *crtc_state, int clock,
                               struct intel_dpll_hw_state *dpll_hw_state)
{
        struct bxt_clk_div clk_div = { };

        bxt_ddi_hdmi_pll_dividers(intel_crtc, crtc_state, clock, &clk_div);

        return bxt_ddi_set_dpll_hw_state(clock, &clk_div, dpll_hw_state);
}

static struct intel_shared_dpll *
bxt_get_dpll(struct intel_crtc *crtc,
                struct intel_crtc_state *crtc_state,
                struct intel_encoder *encoder)
{
        struct intel_dpll_hw_state dpll_hw_state = { };
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        struct intel_shared_dpll *pll;
        int i, clock = crtc_state->port_clock;

        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI) &&
            !bxt_ddi_hdmi_set_dpll_hw_state(crtc, crtc_state, clock,
                                            &dpll_hw_state))
                return NULL;

        if (intel_crtc_has_dp_encoder(crtc_state) &&
            !bxt_ddi_dp_set_dpll_hw_state(clock, &dpll_hw_state))
                return NULL;

        memset(&crtc_state->dpll_hw_state, 0,
               sizeof(crtc_state->dpll_hw_state));

        crtc_state->dpll_hw_state = dpll_hw_state;

        /* 1:1 mapping between ports and PLLs */
        i = (enum intel_dpll_id) encoder->port;
        pll = intel_get_shared_dpll_by_id(dev_priv, i);

        DRM_DEBUG_KMS("[CRTC:%d:%s] using pre-allocated %s\n",
                      crtc->base.base.id, crtc->base.name, pll->name);

        intel_reference_shared_dpll(pll, crtc_state);

        return pll;
}

static void bxt_dump_hw_state(struct drm_i915_private *dev_priv,
                              struct intel_dpll_hw_state *hw_state)
{
        DRM_DEBUG_KMS("dpll_hw_state: ebb0: 0x%x, ebb4: 0x%x,"
                      "pll0: 0x%x, pll1: 0x%x, pll2: 0x%x, pll3: 0x%x, "
                      "pll6: 0x%x, pll8: 0x%x, pll9: 0x%x, pll10: 0x%x, pcsdw12: 0x%x\n",
                      hw_state->ebb0,
                      hw_state->ebb4,
                      hw_state->pll0,
                      hw_state->pll1,
                      hw_state->pll2,
                      hw_state->pll3,
                      hw_state->pll6,
                      hw_state->pll8,
                      hw_state->pll9,
                      hw_state->pll10,
                      hw_state->pcsdw12);
}

static const struct intel_shared_dpll_funcs bxt_ddi_pll_funcs = {
        .enable = bxt_ddi_pll_enable,
        .disable = bxt_ddi_pll_disable,
        .get_hw_state = bxt_ddi_pll_get_hw_state,
};

static void intel_ddi_pll_init(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);

        if (INTEL_GEN(dev_priv) < 9) {
                uint32_t val = I915_READ(LCPLL_CTL);

                /*
                 * The LCPLL register should be turned on by the BIOS. For now
                 * let's just check its state and print errors in case
                 * something is wrong.  Don't even try to turn it on.
                 */

                if (val & LCPLL_CD_SOURCE_FCLK)
                        DRM_ERROR("CDCLK source is not LCPLL\n");

                if (val & LCPLL_PLL_DISABLE)
                        DRM_ERROR("LCPLL is disabled\n");
        }
}

struct dpll_info {
        const char *name;
        const int id;
        const struct intel_shared_dpll_funcs *funcs;
        uint32_t flags;
};

struct intel_dpll_mgr {
        const struct dpll_info *dpll_info;

        struct intel_shared_dpll *(*get_dpll)(struct intel_crtc *crtc,
                                              struct intel_crtc_state *crtc_state,
                                              struct intel_encoder *encoder);

        void (*dump_hw_state)(struct drm_i915_private *dev_priv,
                              struct intel_dpll_hw_state *hw_state);
};

static const struct dpll_info pch_plls[] = {
        { "PCH DPLL A", DPLL_ID_PCH_PLL_A, &ibx_pch_dpll_funcs, 0 },
        { "PCH DPLL B", DPLL_ID_PCH_PLL_B, &ibx_pch_dpll_funcs, 0 },
        { NULL, -1, NULL, 0 },
};

static const struct intel_dpll_mgr pch_pll_mgr = {
        .dpll_info = pch_plls,
        .get_dpll = ibx_get_dpll,
        .dump_hw_state = ibx_dump_hw_state,
};

static const struct dpll_info hsw_plls[] = {
        { "WRPLL 1",    DPLL_ID_WRPLL1,     &hsw_ddi_wrpll_funcs, 0 },
        { "WRPLL 2",    DPLL_ID_WRPLL2,     &hsw_ddi_wrpll_funcs, 0 },
        { "SPLL",       DPLL_ID_SPLL,       &hsw_ddi_spll_funcs,  0 },
        { "LCPLL 810",  DPLL_ID_LCPLL_810,  &hsw_ddi_lcpll_funcs, INTEL_DPLL_ALWAYS_ON },
        { "LCPLL 1350", DPLL_ID_LCPLL_1350, &hsw_ddi_lcpll_funcs, INTEL_DPLL_ALWAYS_ON },
        { "LCPLL 2700", DPLL_ID_LCPLL_2700, &hsw_ddi_lcpll_funcs, INTEL_DPLL_ALWAYS_ON },
        { NULL, -1, NULL, },
};

static const struct intel_dpll_mgr hsw_pll_mgr = {
        .dpll_info = hsw_plls,
        .get_dpll = hsw_get_dpll,
        .dump_hw_state = hsw_dump_hw_state,
};

static const struct dpll_info skl_plls[] = {
        { "DPLL 0", DPLL_ID_SKL_DPLL0, &skl_ddi_dpll0_funcs, INTEL_DPLL_ALWAYS_ON },
        { "DPLL 1", DPLL_ID_SKL_DPLL1, &skl_ddi_pll_funcs,   0 },
        { "DPLL 2", DPLL_ID_SKL_DPLL2, &skl_ddi_pll_funcs,   0 },
        { "DPLL 3", DPLL_ID_SKL_DPLL3, &skl_ddi_pll_funcs,   0 },
        { NULL, -1, NULL, },
};

static const struct intel_dpll_mgr skl_pll_mgr = {
        .dpll_info = skl_plls,
        .get_dpll = skl_get_dpll,
        .dump_hw_state = skl_dump_hw_state,
};

static const struct dpll_info bxt_plls[] = {
        { "PORT PLL A", DPLL_ID_SKL_DPLL0, &bxt_ddi_pll_funcs, 0 },
        { "PORT PLL B", DPLL_ID_SKL_DPLL1, &bxt_ddi_pll_funcs, 0 },
        { "PORT PLL C", DPLL_ID_SKL_DPLL2, &bxt_ddi_pll_funcs, 0 },
        { NULL, -1, NULL, },
};

static const struct intel_dpll_mgr bxt_pll_mgr = {
        .dpll_info = bxt_plls,
        .get_dpll = bxt_get_dpll,
        .dump_hw_state = bxt_dump_hw_state,
};

static void cnl_ddi_pll_enable(struct drm_i915_private *dev_priv,
                               struct intel_shared_dpll *pll)
{
        uint32_t val;

        /* 1. Enable DPLL power in DPLL_ENABLE. */
        val = I915_READ(CNL_DPLL_ENABLE(pll->id));
        val |= PLL_POWER_ENABLE;
        I915_WRITE(CNL_DPLL_ENABLE(pll->id), val);

        /* 2. Wait for DPLL power state enabled in DPLL_ENABLE. */
        if (intel_wait_for_register(dev_priv,
                                    CNL_DPLL_ENABLE(pll->id),
                                    PLL_POWER_STATE,
                                    PLL_POWER_STATE,
                                    5))
                DRM_ERROR("PLL %d Power not enabled\n", pll->id);

        /*
         * 3. Configure DPLL_CFGCR0 to set SSC enable/disable,
         * select DP mode, and set DP link rate.
         */
        val = pll->state.hw_state.cfgcr0;
        I915_WRITE(CNL_DPLL_CFGCR0(pll->id), val);

        /* 4. Reab back to ensure writes completed */
        POSTING_READ(CNL_DPLL_CFGCR0(pll->id));

        /* 3. Configure DPLL_CFGCR0 */
        /* Avoid touch CFGCR1 if HDMI mode is not enabled */
        if (pll->state.hw_state.cfgcr0 & DPLL_CFGCR0_HDMI_MODE) {
                val = pll->state.hw_state.cfgcr1;
                I915_WRITE(CNL_DPLL_CFGCR1(pll->id), val);
                /* 4. Reab back to ensure writes completed */
                POSTING_READ(CNL_DPLL_CFGCR1(pll->id));
        }

        /*
         * 5. If the frequency will result in a change to the voltage
         * requirement, follow the Display Voltage Frequency Switching
         * Sequence Before Frequency Change
         *
         * Note: DVFS is actually handled via the cdclk code paths,
         * hence we do nothing here.
         */

        /* 6. Enable DPLL in DPLL_ENABLE. */
        val = I915_READ(CNL_DPLL_ENABLE(pll->id));

        val |= PLL_ENABLE;
        I915_WRITE(CNL_DPLL_ENABLE(pll->id), val);

        /* 7. Wait for PLL lock status in DPLL_ENABLE. */
        if (intel_wait_for_register(dev_priv,
                                    CNL_DPLL_ENABLE(pll->id),
                                    PLL_LOCK,
                                    PLL_LOCK,
                                    5))
                DRM_ERROR("PLL %d not locked\n", pll->id);

        /*
         * 8. If the frequency will result in a change to the voltage
         * requirement, follow the Display Voltage Frequency Switching
         * Sequence After Frequency Change
         *
         * Note: DVFS is actually handled via the cdclk code paths,
         * hence we do nothing here.
         */

        /*
         * 9. turn on the clock for the DDI and map the DPLL to the DDI
         * Done at intel_ddi_clk_select
         */
}

static void cnl_ddi_pll_disable(struct drm_i915_private *dev_priv,
                                struct intel_shared_dpll *pll)
{
        uint32_t val;

        /*
         * 1. Configure DPCLKA_CFGCR0 to turn off the clock for the DDI.
         * Done at intel_ddi_post_disable
         */

        /*
         * 2. If the frequency will result in a change to the voltage
         * requirement, follow the Display Voltage Frequency Switching
         * Sequence Before Frequency Change
         *
         * Note: DVFS is actually handled via the cdclk code paths,
         * hence we do nothing here.
         */

        /* 3. Disable DPLL through DPLL_ENABLE. */
        val = I915_READ(CNL_DPLL_ENABLE(pll->id));
        val &= ~PLL_ENABLE;
        I915_WRITE(CNL_DPLL_ENABLE(pll->id), val);

        /* 4. Wait for PLL not locked status in DPLL_ENABLE. */
        if (intel_wait_for_register(dev_priv,
                                    CNL_DPLL_ENABLE(pll->id),
                                    PLL_LOCK,
                                    0,
                                    5))
                DRM_ERROR("PLL %d locked\n", pll->id);

        /*
         * 5. If the frequency will result in a change to the voltage
         * requirement, follow the Display Voltage Frequency Switching
         * Sequence After Frequency Change
         *
         * Note: DVFS is actually handled via the cdclk code paths,
         * hence we do nothing here.
         */

        /* 6. Disable DPLL power in DPLL_ENABLE. */
        val = I915_READ(CNL_DPLL_ENABLE(pll->id));
        val &= ~PLL_POWER_ENABLE;
        I915_WRITE(CNL_DPLL_ENABLE(pll->id), val);

        /* 7. Wait for DPLL power state disabled in DPLL_ENABLE. */
        if (intel_wait_for_register(dev_priv,
                                    CNL_DPLL_ENABLE(pll->id),
                                    PLL_POWER_STATE,
                                    0,
                                    5))
                DRM_ERROR("PLL %d Power not disabled\n", pll->id);
}

static bool cnl_ddi_pll_get_hw_state(struct drm_i915_private *dev_priv,
                                     struct intel_shared_dpll *pll,
                                     struct intel_dpll_hw_state *hw_state)
{
        uint32_t val;
        bool ret;

        if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
                return false;

        ret = false;

        val = I915_READ(CNL_DPLL_ENABLE(pll->id));
        if (!(val & PLL_ENABLE))
                goto out;

        val = I915_READ(CNL_DPLL_CFGCR0(pll->id));
        hw_state->cfgcr0 = val;

        /* avoid reading back stale values if HDMI mode is not enabled */
        if (val & DPLL_CFGCR0_HDMI_MODE) {
                hw_state->cfgcr1 = I915_READ(CNL_DPLL_CFGCR1(pll->id));
        }
        ret = true;

out:
        intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);

        return ret;
}

static void cnl_wrpll_get_multipliers(int bestdiv, int *pdiv,
                                      int *qdiv, int *kdiv)
{
        /* even dividers */
        if (bestdiv % 2 == 0) {
                if (bestdiv == 2) {
                        *pdiv = 2;
                        *qdiv = 1;
                        *kdiv = 1;
                } else if (bestdiv % 4 == 0) {
                        *pdiv = 2;
                        *qdiv = bestdiv / 4;
                        *kdiv = 2;
                } else if (bestdiv % 6 == 0) {
                        *pdiv = 3;
                        *qdiv = bestdiv / 6;
                        *kdiv = 2;
                } else if (bestdiv % 5 == 0) {
                        *pdiv = 5;
                        *qdiv = bestdiv / 10;
                        *kdiv = 2;
                } else if (bestdiv % 14 == 0) {
                        *pdiv = 7;
                        *qdiv = bestdiv / 14;
                        *kdiv = 2;
                }
        } else {
                if (bestdiv == 3 || bestdiv == 5 || bestdiv == 7) {
                        *pdiv = bestdiv;
                        *qdiv = 1;
                        *kdiv = 1;
                } else { /* 9, 15, 21 */
                        *pdiv = bestdiv / 3;
                        *qdiv = 1;
                        *kdiv = 3;
                }
        }
}

static void cnl_wrpll_params_populate(struct skl_wrpll_params *params,
                                      u32 dco_freq, u32 ref_freq,
                                      int pdiv, int qdiv, int kdiv)
{
        u32 dco;

        switch (kdiv) {
        case 1:
                params->kdiv = 1;
                break;
        case 2:
                params->kdiv = 2;
                break;
        case 3:
                params->kdiv = 4;
                break;
        default:
                WARN(1, "Incorrect KDiv\n");
        }

        switch (pdiv) {
        case 2:
                params->pdiv = 1;
                break;
        case 3:
                params->pdiv = 2;
                break;
        case 5:
                params->pdiv = 4;
                break;
        case 7:
                params->pdiv = 8;
                break;
        default:
                WARN(1, "Incorrect PDiv\n");
        }

        WARN_ON(kdiv != 2 && qdiv != 1);

        params->qdiv_ratio = qdiv;
        params->qdiv_mode = (qdiv == 1) ? 0 : 1;

        dco = div_u64((u64)dco_freq << 15, ref_freq);

        params->dco_integer = dco >> 15;
        params->dco_fraction = dco & 0x7fff;
}

static bool
cnl_ddi_calculate_wrpll(int clock,
                        struct drm_i915_private *dev_priv,
                        struct skl_wrpll_params *wrpll_params)
{
        u32 afe_clock = clock * 5;
        u32 dco_min = 7998000;
        u32 dco_max = 10000000;
        u32 dco_mid = (dco_min + dco_max) / 2;
        static const int dividers[] = {  2,  4,  6,  8, 10, 12,  14,  16,
                                         18, 20, 24, 28, 30, 32,  36,  40,
                                         42, 44, 48, 50, 52, 54,  56,  60,
                                         64, 66, 68, 70, 72, 76,  78,  80,
                                         84, 88, 90, 92, 96, 98, 100, 102,
                                          3,  5,  7,  9, 15, 21 };
        u32 dco, best_dco = 0, dco_centrality = 0;
        u32 best_dco_centrality = U32_MAX; /* Spec meaning of 999999 MHz */
        int d, best_div = 0, pdiv = 0, qdiv = 0, kdiv = 0;

        for (d = 0; d < ARRAY_SIZE(dividers); d++) {
                dco = afe_clock * dividers[d];

                if ((dco <= dco_max) && (dco >= dco_min)) {
                        dco_centrality = abs(dco - dco_mid);

                        if (dco_centrality < best_dco_centrality) {
                                best_dco_centrality = dco_centrality;
                                best_div = dividers[d];
                                best_dco = dco;
                        }
                }
        }

        if (best_div == 0)
                return false;

        cnl_wrpll_get_multipliers(best_div, &pdiv, &qdiv, &kdiv);

        cnl_wrpll_params_populate(wrpll_params, best_dco,
                                  dev_priv->cdclk.hw.ref, pdiv, qdiv, kdiv);

        return true;
}

static bool cnl_ddi_hdmi_pll_dividers(struct intel_crtc *crtc,
                                      struct intel_crtc_state *crtc_state,
                                      int clock)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        uint32_t cfgcr0, cfgcr1;
        struct skl_wrpll_params wrpll_params = { 0, };

        cfgcr0 = DPLL_CFGCR0_HDMI_MODE;

        if (!cnl_ddi_calculate_wrpll(clock, dev_priv, &wrpll_params))
                return false;

        cfgcr0 |= DPLL_CFGCR0_DCO_FRACTION(wrpll_params.dco_fraction) |
                wrpll_params.dco_integer;

        cfgcr1 = DPLL_CFGCR1_QDIV_RATIO(wrpll_params.qdiv_ratio) |
                DPLL_CFGCR1_QDIV_MODE(wrpll_params.qdiv_mode) |
                DPLL_CFGCR1_KDIV(wrpll_params.kdiv) |
                DPLL_CFGCR1_PDIV(wrpll_params.pdiv) |
                DPLL_CFGCR1_CENTRAL_FREQ;

        memset(&crtc_state->dpll_hw_state, 0,
               sizeof(crtc_state->dpll_hw_state));

        crtc_state->dpll_hw_state.cfgcr0 = cfgcr0;
        crtc_state->dpll_hw_state.cfgcr1 = cfgcr1;
        return true;
}

static bool
cnl_ddi_dp_set_dpll_hw_state(int clock,
                             struct intel_dpll_hw_state *dpll_hw_state)
{
        uint32_t cfgcr0;

        cfgcr0 = DPLL_CFGCR0_SSC_ENABLE;

        switch (clock / 2) {
        case 81000:
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_810;
                break;
        case 135000:
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_1350;
                break;
        case 270000:
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_2700;
                break;
                /* eDP 1.4 rates */
        case 162000:
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_1620;
                break;
        case 108000:
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_1080;
                break;
        case 216000:
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_2160;
                break;
        case 324000:
                /* Some SKUs may require elevated I/O voltage to support this */
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_3240;
                break;
        case 405000:
                /* Some SKUs may require elevated I/O voltage to support this */
                cfgcr0 |= DPLL_CFGCR0_LINK_RATE_4050;
                break;
        }

        dpll_hw_state->cfgcr0 = cfgcr0;
        return true;
}

static struct intel_shared_dpll *
cnl_get_dpll(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state,
             struct intel_encoder *encoder)
{
        struct intel_shared_dpll *pll;
        int clock = crtc_state->port_clock;
        bool bret;
        struct intel_dpll_hw_state dpll_hw_state;

        memset(&dpll_hw_state, 0, sizeof(dpll_hw_state));

        if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
                bret = cnl_ddi_hdmi_pll_dividers(crtc, crtc_state, clock);
                if (!bret) {
                        DRM_DEBUG_KMS("Could not get HDMI pll dividers.\n");
                        return NULL;
                }
        } else if (intel_crtc_has_dp_encoder(crtc_state)) {
                bret = cnl_ddi_dp_set_dpll_hw_state(clock, &dpll_hw_state);
                if (!bret) {
                        DRM_DEBUG_KMS("Could not set DP dpll HW state.\n");
                        return NULL;
                }
                crtc_state->dpll_hw_state = dpll_hw_state;
        } else {
                DRM_DEBUG_KMS("Skip DPLL setup for output_types 0x%x\n",
                              crtc_state->output_types);
                return NULL;
        }

        pll = intel_find_shared_dpll(crtc, crtc_state,
                                     DPLL_ID_SKL_DPLL0,
                                     DPLL_ID_SKL_DPLL2);
        if (!pll) {
                DRM_DEBUG_KMS("No PLL selected\n");
                return NULL;
        }

        intel_reference_shared_dpll(pll, crtc_state);

        return pll;
}

static void cnl_dump_hw_state(struct drm_i915_private *dev_priv,
                              struct intel_dpll_hw_state *hw_state)
{
        DRM_DEBUG_KMS("dpll_hw_state: "
                      "cfgcr0: 0x%x, cfgcr1: 0x%x\n",
                      hw_state->cfgcr0,
                      hw_state->cfgcr1);
}

static const struct intel_shared_dpll_funcs cnl_ddi_pll_funcs = {
        .enable = cnl_ddi_pll_enable,
        .disable = cnl_ddi_pll_disable,
        .get_hw_state = cnl_ddi_pll_get_hw_state,
};

static const struct dpll_info cnl_plls[] = {
        { "DPLL 0", DPLL_ID_SKL_DPLL0, &cnl_ddi_pll_funcs, 0 },
        { "DPLL 1", DPLL_ID_SKL_DPLL1, &cnl_ddi_pll_funcs, 0 },
        { "DPLL 2", DPLL_ID_SKL_DPLL2, &cnl_ddi_pll_funcs, 0 },
        { NULL, -1, NULL, },
};

static const struct intel_dpll_mgr cnl_pll_mgr = {
        .dpll_info = cnl_plls,
        .get_dpll = cnl_get_dpll,
        .dump_hw_state = cnl_dump_hw_state,
};

/**
 * intel_shared_dpll_init - Initialize shared DPLLs
 * @dev: drm device
 *
 * Initialize shared DPLLs for @dev.
 */
void intel_shared_dpll_init(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = to_i915(dev);
        const struct intel_dpll_mgr *dpll_mgr = NULL;
        const struct dpll_info *dpll_info;
        int i;

        if (IS_CANNONLAKE(dev_priv))
                dpll_mgr = &cnl_pll_mgr;
        else if (IS_GEN9_BC(dev_priv))
                dpll_mgr = &skl_pll_mgr;
        else if (IS_GEN9_LP(dev_priv))
                dpll_mgr = &bxt_pll_mgr;
        else if (HAS_DDI(dev_priv))
                dpll_mgr = &hsw_pll_mgr;
        else if (HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv))
                dpll_mgr = &pch_pll_mgr;

        if (!dpll_mgr) {
                dev_priv->num_shared_dpll = 0;
                return;
        }

        dpll_info = dpll_mgr->dpll_info;

        for (i = 0; dpll_info[i].id >= 0; i++) {
                WARN_ON(i != dpll_info[i].id);

                dev_priv->shared_dplls[i].id = dpll_info[i].id;
                dev_priv->shared_dplls[i].name = dpll_info[i].name;
                dev_priv->shared_dplls[i].funcs = *dpll_info[i].funcs;
                dev_priv->shared_dplls[i].flags = dpll_info[i].flags;
        }

        dev_priv->dpll_mgr = dpll_mgr;
        dev_priv->num_shared_dpll = i;
        mutex_init(&dev_priv->dpll_lock);

        BUG_ON(dev_priv->num_shared_dpll > I915_NUM_PLLS);

        /* FIXME: Move this to a more suitable place */
        if (HAS_DDI(dev_priv))
                intel_ddi_pll_init(dev);
}

/**
 * intel_get_shared_dpll - get a shared DPLL for CRTC and encoder combination
 * @crtc: CRTC
 * @crtc_state: atomic state for @crtc
 * @encoder: encoder
 *
 * Find an appropriate DPLL for the given CRTC and encoder combination. A
 * reference from the @crtc to the returned pll is registered in the atomic
 * state. That configuration is made effective by calling
 * intel_shared_dpll_swap_state(). The reference should be released by calling
 * intel_release_shared_dpll().
 *
 * Returns:
 * A shared DPLL to be used by @crtc and @encoder with the given @crtc_state.
 */
struct intel_shared_dpll *
intel_get_shared_dpll(struct intel_crtc *crtc,
                      struct intel_crtc_state *crtc_state,
                      struct intel_encoder *encoder)
{
        struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
        const struct intel_dpll_mgr *dpll_mgr = dev_priv->dpll_mgr;

        if (WARN_ON(!dpll_mgr))
                return NULL;

        return dpll_mgr->get_dpll(crtc, crtc_state, encoder);
}

/**
 * intel_release_shared_dpll - end use of DPLL by CRTC in atomic state
 * @dpll: dpll in use by @crtc
 * @crtc: crtc
 * @state: atomic state
 *
 * This function releases the reference from @crtc to @dpll from the
 * atomic @state. The new configuration is made effective by calling
 * intel_shared_dpll_swap_state().
 */
void intel_release_shared_dpll(struct intel_shared_dpll *dpll,
                               struct intel_crtc *crtc,
                               struct drm_atomic_state *state)
{
        struct intel_shared_dpll_state *shared_dpll_state;

        shared_dpll_state = intel_atomic_get_shared_dpll_state(state);
        shared_dpll_state[dpll->id].crtc_mask &= ~(1 << crtc->pipe);
}

/**
 * intel_shared_dpll_dump_hw_state - write hw_state to dmesg
 * @dev_priv: i915 drm device
 * @hw_state: hw state to be written to the log
 *
 * Write the relevant values in @hw_state to dmesg using DRM_DEBUG_KMS.
 */
void intel_dpll_dump_hw_state(struct drm_i915_private *dev_priv,
                              struct intel_dpll_hw_state *hw_state)
{
        if (dev_priv->dpll_mgr) {
                dev_priv->dpll_mgr->dump_hw_state(dev_priv, hw_state);
        } else {
                /* fallback for platforms that don't use the shared dpll
                 * infrastructure
                 */
                DRM_DEBUG_KMS("dpll_hw_state: dpll: 0x%x, dpll_md: 0x%x, "
                              "fp0: 0x%x, fp1: 0x%x\n",
                              hw_state->dpll,
                              hw_state->dpll_md,
                              hw_state->fp0,
                              hw_state->fp1);
        }
}