drm/i915/skl: Adding power domains for AUX controllers

[mirror_ubuntu-bionic-kernel.git] / drivers / gpu / drm / i915 / intel_runtime_pm.c

/*
 * Copyright © 2012-2014 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.
 *
 * Authors:
 *    Eugeni Dodonov <eugeni.dodonov@intel.com>
 *    Daniel Vetter <daniel.vetter@ffwll.ch>
 *
 */

#include <linux/pm_runtime.h>
#include <linux/vgaarb.h>

#include "i915_drv.h"
#include "intel_drv.h"

/**
 * DOC: runtime pm
 *
 * The i915 driver supports dynamic enabling and disabling of entire hardware
 * blocks at runtime. This is especially important on the display side where
 * software is supposed to control many power gates manually on recent hardware,
 * since on the GT side a lot of the power management is done by the hardware.
 * But even there some manual control at the device level is required.
 *
 * Since i915 supports a diverse set of platforms with a unified codebase and
 * hardware engineers just love to shuffle functionality around between power
 * domains there's a sizeable amount of indirection required. This file provides
 * generic functions to the driver for grabbing and releasing references for
 * abstract power domains. It then maps those to the actual power wells
 * present for a given platform.
 */

#define for_each_power_well(i, power_well, domain_mask, power_domains)  \
        for (i = 0;                                                     \
             i < (power_domains)->power_well_count &&                   \
                 ((power_well) = &(power_domains)->power_wells[i]);     \
             i++)                                                       \
                if ((power_well)->domains & (domain_mask))

#define for_each_power_well_rev(i, power_well, domain_mask, power_domains) \
        for (i = (power_domains)->power_well_count - 1;                  \
             i >= 0 && ((power_well) = &(power_domains)->power_wells[i]);\
             i--)                                                        \
                if ((power_well)->domains & (domain_mask))

/*
 * We should only use the power well if we explicitly asked the hardware to
 * enable it, so check if it's enabled and also check if we've requested it to
 * be enabled.
 */
static bool hsw_power_well_enabled(struct drm_i915_private *dev_priv,
                                   struct i915_power_well *power_well)
{
        return I915_READ(HSW_PWR_WELL_DRIVER) ==
                     (HSW_PWR_WELL_ENABLE_REQUEST | HSW_PWR_WELL_STATE_ENABLED);
}

/**
 * __intel_display_power_is_enabled - unlocked check for a power domain
 * @dev_priv: i915 device instance
 * @domain: power domain to check
 *
 * This is the unlocked version of intel_display_power_is_enabled() and should
 * only be used from error capture and recovery code where deadlocks are
 * possible.
 *
 * Returns:
 * True when the power domain is enabled, false otherwise.
 */
bool __intel_display_power_is_enabled(struct drm_i915_private *dev_priv,
                                      enum intel_display_power_domain domain)
{
        struct i915_power_domains *power_domains;
        struct i915_power_well *power_well;
        bool is_enabled;
        int i;

        if (dev_priv->pm.suspended)
                return false;

        power_domains = &dev_priv->power_domains;

        is_enabled = true;

        for_each_power_well_rev(i, power_well, BIT(domain), power_domains) {
                if (power_well->always_on)
                        continue;

                if (!power_well->hw_enabled) {
                        is_enabled = false;
                        break;
                }
        }

        return is_enabled;
}

/**
 * intel_display_power_is_enabled - check for a power domain
 * @dev_priv: i915 device instance
 * @domain: power domain to check
 *
 * This function can be used to check the hw power domain state. It is mostly
 * used in hardware state readout functions. Everywhere else code should rely
 * upon explicit power domain reference counting to ensure that the hardware
 * block is powered up before accessing it.
 *
 * Callers must hold the relevant modesetting locks to ensure that concurrent
 * threads can't disable the power well while the caller tries to read a few
 * registers.
 *
 * Returns:
 * True when the power domain is enabled, false otherwise.
 */
bool intel_display_power_is_enabled(struct drm_i915_private *dev_priv,
                                    enum intel_display_power_domain domain)
{
        struct i915_power_domains *power_domains;
        bool ret;

        power_domains = &dev_priv->power_domains;

        mutex_lock(&power_domains->lock);
        ret = __intel_display_power_is_enabled(dev_priv, domain);
        mutex_unlock(&power_domains->lock);

        return ret;
}

/**
 * intel_display_set_init_power - set the initial power domain state
 * @dev_priv: i915 device instance
 * @enable: whether to enable or disable the initial power domain state
 *
 * For simplicity our driver load/unload and system suspend/resume code assumes
 * that all power domains are always enabled. This functions controls the state
 * of this little hack. While the initial power domain state is enabled runtime
 * pm is effectively disabled.
 */
void intel_display_set_init_power(struct drm_i915_private *dev_priv,
                                  bool enable)
{
        if (dev_priv->power_domains.init_power_on == enable)
                return;

        if (enable)
                intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
        else
                intel_display_power_put(dev_priv, POWER_DOMAIN_INIT);

        dev_priv->power_domains.init_power_on = enable;
}

/*
 * Starting with Haswell, we have a "Power Down Well" that can be turned off
 * when not needed anymore. We have 4 registers that can request the power well
 * to be enabled, and it will only be disabled if none of the registers is
 * requesting it to be enabled.
 */
static void hsw_power_well_post_enable(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;

        /*
         * After we re-enable the power well, if we touch VGA register 0x3d5
         * we'll get unclaimed register interrupts. This stops after we write
         * anything to the VGA MSR register. The vgacon module uses this
         * register all the time, so if we unbind our driver and, as a
         * consequence, bind vgacon, we'll get stuck in an infinite loop at
         * console_unlock(). So make here we touch the VGA MSR register, making
         * sure vgacon can keep working normally without triggering interrupts
         * and error messages.
         */
        vga_get_uninterruptible(dev->pdev, VGA_RSRC_LEGACY_IO);
        outb(inb(VGA_MSR_READ), VGA_MSR_WRITE);
        vga_put(dev->pdev, VGA_RSRC_LEGACY_IO);

        if (IS_BROADWELL(dev) || (INTEL_INFO(dev)->gen >= 9))
                gen8_irq_power_well_post_enable(dev_priv);
}

static void hsw_set_power_well(struct drm_i915_private *dev_priv,
                               struct i915_power_well *power_well, bool enable)
{
        bool is_enabled, enable_requested;
        uint32_t tmp;

        tmp = I915_READ(HSW_PWR_WELL_DRIVER);
        is_enabled = tmp & HSW_PWR_WELL_STATE_ENABLED;
        enable_requested = tmp & HSW_PWR_WELL_ENABLE_REQUEST;

        if (enable) {
                if (!enable_requested)
                        I915_WRITE(HSW_PWR_WELL_DRIVER,
                                   HSW_PWR_WELL_ENABLE_REQUEST);

                if (!is_enabled) {
                        DRM_DEBUG_KMS("Enabling power well\n");
                        if (wait_for((I915_READ(HSW_PWR_WELL_DRIVER) &
                                      HSW_PWR_WELL_STATE_ENABLED), 20))
                                DRM_ERROR("Timeout enabling power well\n");
                        hsw_power_well_post_enable(dev_priv);
                }

        } else {
                if (enable_requested) {
                        I915_WRITE(HSW_PWR_WELL_DRIVER, 0);
                        POSTING_READ(HSW_PWR_WELL_DRIVER);
                        DRM_DEBUG_KMS("Requesting to disable the power well\n");
                }
        }
}

static void hsw_power_well_sync_hw(struct drm_i915_private *dev_priv,
                                   struct i915_power_well *power_well)
{
        hsw_set_power_well(dev_priv, power_well, power_well->count > 0);

        /*
         * We're taking over the BIOS, so clear any requests made by it since
         * the driver is in charge now.
         */
        if (I915_READ(HSW_PWR_WELL_BIOS) & HSW_PWR_WELL_ENABLE_REQUEST)
                I915_WRITE(HSW_PWR_WELL_BIOS, 0);
}

static void hsw_power_well_enable(struct drm_i915_private *dev_priv,
                                  struct i915_power_well *power_well)
{
        hsw_set_power_well(dev_priv, power_well, true);
}

static void hsw_power_well_disable(struct drm_i915_private *dev_priv,
                                   struct i915_power_well *power_well)
{
        hsw_set_power_well(dev_priv, power_well, false);
}

static void i9xx_always_on_power_well_noop(struct drm_i915_private *dev_priv,
                                           struct i915_power_well *power_well)
{
}

static bool i9xx_always_on_power_well_enabled(struct drm_i915_private *dev_priv,
                                             struct i915_power_well *power_well)
{
        return true;
}

static void vlv_set_power_well(struct drm_i915_private *dev_priv,
                               struct i915_power_well *power_well, bool enable)
{
        enum punit_power_well power_well_id = power_well->data;
        u32 mask;
        u32 state;
        u32 ctrl;

        mask = PUNIT_PWRGT_MASK(power_well_id);
        state = enable ? PUNIT_PWRGT_PWR_ON(power_well_id) :
                         PUNIT_PWRGT_PWR_GATE(power_well_id);

        mutex_lock(&dev_priv->rps.hw_lock);

#define COND \
        ((vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_STATUS) & mask) == state)

        if (COND)
                goto out;

        ctrl = vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_CTRL);
        ctrl &= ~mask;
        ctrl |= state;
        vlv_punit_write(dev_priv, PUNIT_REG_PWRGT_CTRL, ctrl);

        if (wait_for(COND, 100))
                DRM_ERROR("timout setting power well state %08x (%08x)\n",
                          state,
                          vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_CTRL));

#undef COND

out:
        mutex_unlock(&dev_priv->rps.hw_lock);
}

static void vlv_power_well_sync_hw(struct drm_i915_private *dev_priv,
                                   struct i915_power_well *power_well)
{
        vlv_set_power_well(dev_priv, power_well, power_well->count > 0);
}

static void vlv_power_well_enable(struct drm_i915_private *dev_priv,
                                  struct i915_power_well *power_well)
{
        vlv_set_power_well(dev_priv, power_well, true);
}

static void vlv_power_well_disable(struct drm_i915_private *dev_priv,
                                   struct i915_power_well *power_well)
{
        vlv_set_power_well(dev_priv, power_well, false);
}

static bool vlv_power_well_enabled(struct drm_i915_private *dev_priv,
                                   struct i915_power_well *power_well)
{
        int power_well_id = power_well->data;
        bool enabled = false;
        u32 mask;
        u32 state;
        u32 ctrl;

        mask = PUNIT_PWRGT_MASK(power_well_id);
        ctrl = PUNIT_PWRGT_PWR_ON(power_well_id);

        mutex_lock(&dev_priv->rps.hw_lock);

        state = vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_STATUS) & mask;
        /*
         * We only ever set the power-on and power-gate states, anything
         * else is unexpected.
         */
        WARN_ON(state != PUNIT_PWRGT_PWR_ON(power_well_id) &&
                state != PUNIT_PWRGT_PWR_GATE(power_well_id));
        if (state == ctrl)
                enabled = true;

        /*
         * A transient state at this point would mean some unexpected party
         * is poking at the power controls too.
         */
        ctrl = vlv_punit_read(dev_priv, PUNIT_REG_PWRGT_CTRL) & mask;
        WARN_ON(ctrl != state);

        mutex_unlock(&dev_priv->rps.hw_lock);

        return enabled;
}

static void vlv_display_power_well_enable(struct drm_i915_private *dev_priv,
                                          struct i915_power_well *power_well)
{
        WARN_ON_ONCE(power_well->data != PUNIT_POWER_WELL_DISP2D);

        vlv_set_power_well(dev_priv, power_well, true);

        spin_lock_irq(&dev_priv->irq_lock);
        valleyview_enable_display_irqs(dev_priv);
        spin_unlock_irq(&dev_priv->irq_lock);

        /*
         * During driver initialization/resume we can avoid restoring the
         * part of the HW/SW state that will be inited anyway explicitly.
         */
        if (dev_priv->power_domains.initializing)
                return;

        intel_hpd_init(dev_priv);

        i915_redisable_vga_power_on(dev_priv->dev);
}

static void vlv_display_power_well_disable(struct drm_i915_private *dev_priv,
                                           struct i915_power_well *power_well)
{
        WARN_ON_ONCE(power_well->data != PUNIT_POWER_WELL_DISP2D);

        spin_lock_irq(&dev_priv->irq_lock);
        valleyview_disable_display_irqs(dev_priv);
        spin_unlock_irq(&dev_priv->irq_lock);

        vlv_set_power_well(dev_priv, power_well, false);

        vlv_power_sequencer_reset(dev_priv);
}

static void vlv_dpio_cmn_power_well_enable(struct drm_i915_private *dev_priv,
                                           struct i915_power_well *power_well)
{
        WARN_ON_ONCE(power_well->data != PUNIT_POWER_WELL_DPIO_CMN_BC);

        /*
         * Enable the CRI clock source so we can get at the
         * display and the reference clock for VGA
         * hotplug / manual detection.
         */
        I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) |
                   DPLL_REFA_CLK_ENABLE_VLV | DPLL_INTEGRATED_CRI_CLK_VLV);
        udelay(1); /* >10ns for cmnreset, >0ns for sidereset */

        vlv_set_power_well(dev_priv, power_well, true);

        /*
         * From VLV2A0_DP_eDP_DPIO_driver_vbios_notes_10.docx -
         *  6.  De-assert cmn_reset/side_reset. Same as VLV X0.
         *   a. GUnit 0x2110 bit[0] set to 1 (def 0)
         *   b. The other bits such as sfr settings / modesel may all
         *      be set to 0.
         *
         * This should only be done on init and resume from S3 with
         * both PLLs disabled, or we risk losing DPIO and PLL
         * synchronization.
         */
        I915_WRITE(DPIO_CTL, I915_READ(DPIO_CTL) | DPIO_CMNRST);
}

static void vlv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,
                                            struct i915_power_well *power_well)
{
        enum pipe pipe;

        WARN_ON_ONCE(power_well->data != PUNIT_POWER_WELL_DPIO_CMN_BC);

        for_each_pipe(dev_priv, pipe)
                assert_pll_disabled(dev_priv, pipe);

        /* Assert common reset */
        I915_WRITE(DPIO_CTL, I915_READ(DPIO_CTL) & ~DPIO_CMNRST);

        vlv_set_power_well(dev_priv, power_well, false);
}

static void chv_dpio_cmn_power_well_enable(struct drm_i915_private *dev_priv,
                                           struct i915_power_well *power_well)
{
        enum dpio_phy phy;

        WARN_ON_ONCE(power_well->data != PUNIT_POWER_WELL_DPIO_CMN_BC &&
                     power_well->data != PUNIT_POWER_WELL_DPIO_CMN_D);

        /*
         * Enable the CRI clock source so we can get at the
         * display and the reference clock for VGA
         * hotplug / manual detection.
         */
        if (power_well->data == PUNIT_POWER_WELL_DPIO_CMN_BC) {
                phy = DPIO_PHY0;
                I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) |
                           DPLL_REFA_CLK_ENABLE_VLV);
                I915_WRITE(DPLL(PIPE_B), I915_READ(DPLL(PIPE_B)) |
                           DPLL_REFA_CLK_ENABLE_VLV | DPLL_INTEGRATED_CRI_CLK_VLV);
        } else {
                phy = DPIO_PHY1;
                I915_WRITE(DPLL(PIPE_C), I915_READ(DPLL(PIPE_C)) |
                           DPLL_REFA_CLK_ENABLE_VLV | DPLL_INTEGRATED_CRI_CLK_VLV);
        }
        udelay(1); /* >10ns for cmnreset, >0ns for sidereset */
        vlv_set_power_well(dev_priv, power_well, true);

        /* Poll for phypwrgood signal */
        if (wait_for(I915_READ(DISPLAY_PHY_STATUS) & PHY_POWERGOOD(phy), 1))
                DRM_ERROR("Display PHY %d is not power up\n", phy);

        I915_WRITE(DISPLAY_PHY_CONTROL, I915_READ(DISPLAY_PHY_CONTROL) |
                   PHY_COM_LANE_RESET_DEASSERT(phy));
}

static void chv_dpio_cmn_power_well_disable(struct drm_i915_private *dev_priv,
                                            struct i915_power_well *power_well)
{
        enum dpio_phy phy;

        WARN_ON_ONCE(power_well->data != PUNIT_POWER_WELL_DPIO_CMN_BC &&
                     power_well->data != PUNIT_POWER_WELL_DPIO_CMN_D);

        if (power_well->data == PUNIT_POWER_WELL_DPIO_CMN_BC) {
                phy = DPIO_PHY0;
                assert_pll_disabled(dev_priv, PIPE_A);
                assert_pll_disabled(dev_priv, PIPE_B);
        } else {
                phy = DPIO_PHY1;
                assert_pll_disabled(dev_priv, PIPE_C);
        }

        I915_WRITE(DISPLAY_PHY_CONTROL, I915_READ(DISPLAY_PHY_CONTROL) &
                   ~PHY_COM_LANE_RESET_DEASSERT(phy));

        vlv_set_power_well(dev_priv, power_well, false);
}

static bool chv_pipe_power_well_enabled(struct drm_i915_private *dev_priv,
                                        struct i915_power_well *power_well)
{
        enum pipe pipe = power_well->data;
        bool enabled;
        u32 state, ctrl;

        mutex_lock(&dev_priv->rps.hw_lock);

        state = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ) & DP_SSS_MASK(pipe);
        /*
         * We only ever set the power-on and power-gate states, anything
         * else is unexpected.
         */
        WARN_ON(state != DP_SSS_PWR_ON(pipe) && state != DP_SSS_PWR_GATE(pipe));
        enabled = state == DP_SSS_PWR_ON(pipe);

        /*
         * A transient state at this point would mean some unexpected party
         * is poking at the power controls too.
         */
        ctrl = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ) & DP_SSC_MASK(pipe);
        WARN_ON(ctrl << 16 != state);

        mutex_unlock(&dev_priv->rps.hw_lock);

        return enabled;
}

static void chv_set_pipe_power_well(struct drm_i915_private *dev_priv,
                                    struct i915_power_well *power_well,
                                    bool enable)
{
        enum pipe pipe = power_well->data;
        u32 state;
        u32 ctrl;

        state = enable ? DP_SSS_PWR_ON(pipe) : DP_SSS_PWR_GATE(pipe);

        mutex_lock(&dev_priv->rps.hw_lock);

#define COND \
        ((vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ) & DP_SSS_MASK(pipe)) == state)

        if (COND)
                goto out;

        ctrl = vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ);
        ctrl &= ~DP_SSC_MASK(pipe);
        ctrl |= enable ? DP_SSC_PWR_ON(pipe) : DP_SSC_PWR_GATE(pipe);
        vlv_punit_write(dev_priv, PUNIT_REG_DSPFREQ, ctrl);

        if (wait_for(COND, 100))
                DRM_ERROR("timout setting power well state %08x (%08x)\n",
                          state,
                          vlv_punit_read(dev_priv, PUNIT_REG_DSPFREQ));

#undef COND

out:
        mutex_unlock(&dev_priv->rps.hw_lock);
}

static void chv_pipe_power_well_sync_hw(struct drm_i915_private *dev_priv,
                                        struct i915_power_well *power_well)
{
        chv_set_pipe_power_well(dev_priv, power_well, power_well->count > 0);
}

static void chv_pipe_power_well_enable(struct drm_i915_private *dev_priv,
                                       struct i915_power_well *power_well)
{
        WARN_ON_ONCE(power_well->data != PIPE_A &&
                     power_well->data != PIPE_B &&
                     power_well->data != PIPE_C);

        chv_set_pipe_power_well(dev_priv, power_well, true);

        if (power_well->data == PIPE_A) {
                spin_lock_irq(&dev_priv->irq_lock);
                valleyview_enable_display_irqs(dev_priv);
                spin_unlock_irq(&dev_priv->irq_lock);

                /*
                 * During driver initialization/resume we can avoid restoring the
                 * part of the HW/SW state that will be inited anyway explicitly.
                 */
                if (dev_priv->power_domains.initializing)
                        return;

                intel_hpd_init(dev_priv);

                i915_redisable_vga_power_on(dev_priv->dev);
        }
}

static void chv_pipe_power_well_disable(struct drm_i915_private *dev_priv,
                                        struct i915_power_well *power_well)
{
        WARN_ON_ONCE(power_well->data != PIPE_A &&
                     power_well->data != PIPE_B &&
                     power_well->data != PIPE_C);

        if (power_well->data == PIPE_A) {
                spin_lock_irq(&dev_priv->irq_lock);
                valleyview_disable_display_irqs(dev_priv);
                spin_unlock_irq(&dev_priv->irq_lock);
        }

        chv_set_pipe_power_well(dev_priv, power_well, false);

        if (power_well->data == PIPE_A)
                vlv_power_sequencer_reset(dev_priv);
}

/**
 * intel_display_power_get - grab a power domain reference
 * @dev_priv: i915 device instance
 * @domain: power domain to reference
 *
 * This function grabs a power domain reference for @domain and ensures that the
 * power domain and all its parents are powered up. Therefore users should only
 * grab a reference to the innermost power domain they need.
 *
 * Any power domain reference obtained by this function must have a symmetric
 * call to intel_display_power_put() to release the reference again.
 */
void intel_display_power_get(struct drm_i915_private *dev_priv,
                             enum intel_display_power_domain domain)
{
        struct i915_power_domains *power_domains;
        struct i915_power_well *power_well;
        int i;

        intel_runtime_pm_get(dev_priv);

        power_domains = &dev_priv->power_domains;

        mutex_lock(&power_domains->lock);

        for_each_power_well(i, power_well, BIT(domain), power_domains) {
                if (!power_well->count++) {
                        DRM_DEBUG_KMS("enabling %s\n", power_well->name);
                        power_well->ops->enable(dev_priv, power_well);
                        power_well->hw_enabled = true;
                }
        }

        power_domains->domain_use_count[domain]++;

        mutex_unlock(&power_domains->lock);
}

/**
 * intel_display_power_put - release a power domain reference
 * @dev_priv: i915 device instance
 * @domain: power domain to reference
 *
 * This function drops the power domain reference obtained by
 * intel_display_power_get() and might power down the corresponding hardware
 * block right away if this is the last reference.
 */
void intel_display_power_put(struct drm_i915_private *dev_priv,
                             enum intel_display_power_domain domain)
{
        struct i915_power_domains *power_domains;
        struct i915_power_well *power_well;
        int i;

        power_domains = &dev_priv->power_domains;

        mutex_lock(&power_domains->lock);

        WARN_ON(!power_domains->domain_use_count[domain]);
        power_domains->domain_use_count[domain]--;

        for_each_power_well_rev(i, power_well, BIT(domain), power_domains) {
                WARN_ON(!power_well->count);

                if (!--power_well->count && i915.disable_power_well) {
                        DRM_DEBUG_KMS("disabling %s\n", power_well->name);
                        power_well->hw_enabled = false;
                        power_well->ops->disable(dev_priv, power_well);
                }
        }

        mutex_unlock(&power_domains->lock);

        intel_runtime_pm_put(dev_priv);
}

#define POWER_DOMAIN_MASK (BIT(POWER_DOMAIN_NUM) - 1)

#define HSW_ALWAYS_ON_POWER_DOMAINS (                   \
        BIT(POWER_DOMAIN_PIPE_A) |                      \
        BIT(POWER_DOMAIN_TRANSCODER_EDP) |              \
        BIT(POWER_DOMAIN_PORT_DDI_A_2_LANES) |          \
        BIT(POWER_DOMAIN_PORT_DDI_A_4_LANES) |          \
        BIT(POWER_DOMAIN_PORT_DDI_B_2_LANES) |          \
        BIT(POWER_DOMAIN_PORT_DDI_B_4_LANES) |          \
        BIT(POWER_DOMAIN_PORT_DDI_C_2_LANES) |          \
        BIT(POWER_DOMAIN_PORT_DDI_C_4_LANES) |          \
        BIT(POWER_DOMAIN_PORT_DDI_D_2_LANES) |          \
        BIT(POWER_DOMAIN_PORT_DDI_D_4_LANES) |          \
        BIT(POWER_DOMAIN_PORT_CRT) |                    \
        BIT(POWER_DOMAIN_PLLS) |                        \
        BIT(POWER_DOMAIN_AUX_A) |                       \
        BIT(POWER_DOMAIN_AUX_B) |                       \
        BIT(POWER_DOMAIN_AUX_C) |                       \
        BIT(POWER_DOMAIN_AUX_D) |                       \
        BIT(POWER_DOMAIN_INIT))
#define HSW_DISPLAY_POWER_DOMAINS (                             \
        (POWER_DOMAIN_MASK & ~HSW_ALWAYS_ON_POWER_DOMAINS) |    \
        BIT(POWER_DOMAIN_INIT))

#define BDW_ALWAYS_ON_POWER_DOMAINS (                   \
        HSW_ALWAYS_ON_POWER_DOMAINS |                   \
        BIT(POWER_DOMAIN_PIPE_A_PANEL_FITTER))
#define BDW_DISPLAY_POWER_DOMAINS (                             \
        (POWER_DOMAIN_MASK & ~BDW_ALWAYS_ON_POWER_DOMAINS) |    \
        BIT(POWER_DOMAIN_INIT))

#define VLV_ALWAYS_ON_POWER_DOMAINS     BIT(POWER_DOMAIN_INIT)
#define VLV_DISPLAY_POWER_DOMAINS       POWER_DOMAIN_MASK

#define VLV_DPIO_CMN_BC_POWER_DOMAINS (         \
        BIT(POWER_DOMAIN_PORT_DDI_B_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_B_4_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_C_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_C_4_LANES) |  \
        BIT(POWER_DOMAIN_PORT_CRT) |            \
        BIT(POWER_DOMAIN_AUX_B) |               \
        BIT(POWER_DOMAIN_AUX_C) |               \
        BIT(POWER_DOMAIN_INIT))

#define VLV_DPIO_TX_B_LANES_01_POWER_DOMAINS (  \
        BIT(POWER_DOMAIN_PORT_DDI_B_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_B_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_B) |               \
        BIT(POWER_DOMAIN_INIT))

#define VLV_DPIO_TX_B_LANES_23_POWER_DOMAINS (  \
        BIT(POWER_DOMAIN_PORT_DDI_B_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_B) |               \
        BIT(POWER_DOMAIN_INIT))

#define VLV_DPIO_TX_C_LANES_01_POWER_DOMAINS (  \
        BIT(POWER_DOMAIN_PORT_DDI_C_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_C_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_C) |               \
        BIT(POWER_DOMAIN_INIT))

#define VLV_DPIO_TX_C_LANES_23_POWER_DOMAINS (  \
        BIT(POWER_DOMAIN_PORT_DDI_C_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_C) |               \
        BIT(POWER_DOMAIN_INIT))

#define CHV_PIPE_A_POWER_DOMAINS (      \
        BIT(POWER_DOMAIN_PIPE_A) |      \
        BIT(POWER_DOMAIN_INIT))

#define CHV_PIPE_B_POWER_DOMAINS (      \
        BIT(POWER_DOMAIN_PIPE_B) |      \
        BIT(POWER_DOMAIN_INIT))

#define CHV_PIPE_C_POWER_DOMAINS (      \
        BIT(POWER_DOMAIN_PIPE_C) |      \
        BIT(POWER_DOMAIN_INIT))

#define CHV_DPIO_CMN_BC_POWER_DOMAINS (         \
        BIT(POWER_DOMAIN_PORT_DDI_B_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_B_4_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_C_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_C_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_B) |               \
        BIT(POWER_DOMAIN_AUX_C) |               \
        BIT(POWER_DOMAIN_INIT))

#define CHV_DPIO_CMN_D_POWER_DOMAINS (          \
        BIT(POWER_DOMAIN_PORT_DDI_D_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_D_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_D) |               \
        BIT(POWER_DOMAIN_INIT))

#define CHV_DPIO_TX_D_LANES_01_POWER_DOMAINS (  \
        BIT(POWER_DOMAIN_PORT_DDI_D_2_LANES) |  \
        BIT(POWER_DOMAIN_PORT_DDI_D_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_D) |               \
        BIT(POWER_DOMAIN_INIT))

#define CHV_DPIO_TX_D_LANES_23_POWER_DOMAINS (  \
        BIT(POWER_DOMAIN_PORT_DDI_D_4_LANES) |  \
        BIT(POWER_DOMAIN_AUX_D) |               \
        BIT(POWER_DOMAIN_INIT))

static const struct i915_power_well_ops i9xx_always_on_power_well_ops = {
        .sync_hw = i9xx_always_on_power_well_noop,
        .enable = i9xx_always_on_power_well_noop,
        .disable = i9xx_always_on_power_well_noop,
        .is_enabled = i9xx_always_on_power_well_enabled,
};

static const struct i915_power_well_ops chv_pipe_power_well_ops = {
        .sync_hw = chv_pipe_power_well_sync_hw,
        .enable = chv_pipe_power_well_enable,
        .disable = chv_pipe_power_well_disable,
        .is_enabled = chv_pipe_power_well_enabled,
};

static const struct i915_power_well_ops chv_dpio_cmn_power_well_ops = {
        .sync_hw = vlv_power_well_sync_hw,
        .enable = chv_dpio_cmn_power_well_enable,
        .disable = chv_dpio_cmn_power_well_disable,
        .is_enabled = vlv_power_well_enabled,
};

static struct i915_power_well i9xx_always_on_power_well[] = {
        {
                .name = "always-on",
                .always_on = 1,
                .domains = POWER_DOMAIN_MASK,
                .ops = &i9xx_always_on_power_well_ops,
        },
};

static const struct i915_power_well_ops hsw_power_well_ops = {
        .sync_hw = hsw_power_well_sync_hw,
        .enable = hsw_power_well_enable,
        .disable = hsw_power_well_disable,
        .is_enabled = hsw_power_well_enabled,
};

static struct i915_power_well hsw_power_wells[] = {
        {
                .name = "always-on",
                .always_on = 1,
                .domains = HSW_ALWAYS_ON_POWER_DOMAINS,
                .ops = &i9xx_always_on_power_well_ops,
        },
        {
                .name = "display",
                .domains = HSW_DISPLAY_POWER_DOMAINS,
                .ops = &hsw_power_well_ops,
        },
};

static struct i915_power_well bdw_power_wells[] = {
        {
                .name = "always-on",
                .always_on = 1,
                .domains = BDW_ALWAYS_ON_POWER_DOMAINS,
                .ops = &i9xx_always_on_power_well_ops,
        },
        {
                .name = "display",
                .domains = BDW_DISPLAY_POWER_DOMAINS,
                .ops = &hsw_power_well_ops,
        },
};

static const struct i915_power_well_ops vlv_display_power_well_ops = {
        .sync_hw = vlv_power_well_sync_hw,
        .enable = vlv_display_power_well_enable,
        .disable = vlv_display_power_well_disable,
        .is_enabled = vlv_power_well_enabled,
};

static const struct i915_power_well_ops vlv_dpio_cmn_power_well_ops = {
        .sync_hw = vlv_power_well_sync_hw,
        .enable = vlv_dpio_cmn_power_well_enable,
        .disable = vlv_dpio_cmn_power_well_disable,
        .is_enabled = vlv_power_well_enabled,
};

static const struct i915_power_well_ops vlv_dpio_power_well_ops = {
        .sync_hw = vlv_power_well_sync_hw,
        .enable = vlv_power_well_enable,
        .disable = vlv_power_well_disable,
        .is_enabled = vlv_power_well_enabled,
};

static struct i915_power_well vlv_power_wells[] = {
        {
                .name = "always-on",
                .always_on = 1,
                .domains = VLV_ALWAYS_ON_POWER_DOMAINS,
                .ops = &i9xx_always_on_power_well_ops,
        },
        {
                .name = "display",
                .domains = VLV_DISPLAY_POWER_DOMAINS,
                .data = PUNIT_POWER_WELL_DISP2D,
                .ops = &vlv_display_power_well_ops,
        },
        {
                .name = "dpio-tx-b-01",
                .domains = VLV_DPIO_TX_B_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_B_LANES_23_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_B_LANES_01,
        },
        {
                .name = "dpio-tx-b-23",
                .domains = VLV_DPIO_TX_B_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_B_LANES_23_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_B_LANES_23,
        },
        {
                .name = "dpio-tx-c-01",
                .domains = VLV_DPIO_TX_B_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_B_LANES_23_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_C_LANES_01,
        },
        {
                .name = "dpio-tx-c-23",
                .domains = VLV_DPIO_TX_B_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_B_LANES_23_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_C_LANES_23,
        },
        {
                .name = "dpio-common",
                .domains = VLV_DPIO_CMN_BC_POWER_DOMAINS,
                .data = PUNIT_POWER_WELL_DPIO_CMN_BC,
                .ops = &vlv_dpio_cmn_power_well_ops,
        },
};

static struct i915_power_well chv_power_wells[] = {
        {
                .name = "always-on",
                .always_on = 1,
                .domains = VLV_ALWAYS_ON_POWER_DOMAINS,
                .ops = &i9xx_always_on_power_well_ops,
        },
#if 0
        {
                .name = "display",
                .domains = VLV_DISPLAY_POWER_DOMAINS,
                .data = PUNIT_POWER_WELL_DISP2D,
                .ops = &vlv_display_power_well_ops,
        },
#endif
        {
                .name = "pipe-a",
                /*
                 * FIXME: pipe A power well seems to be the new disp2d well.
                 * At least all registers seem to be housed there. Figure
                 * out if this a a temporary situation in pre-production
                 * hardware or a permanent state of affairs.
                 */
                .domains = CHV_PIPE_A_POWER_DOMAINS | VLV_DISPLAY_POWER_DOMAINS,
                .data = PIPE_A,
                .ops = &chv_pipe_power_well_ops,
        },
#if 0
        {
                .name = "pipe-b",
                .domains = CHV_PIPE_B_POWER_DOMAINS,
                .data = PIPE_B,
                .ops = &chv_pipe_power_well_ops,
        },
        {
                .name = "pipe-c",
                .domains = CHV_PIPE_C_POWER_DOMAINS,
                .data = PIPE_C,
                .ops = &chv_pipe_power_well_ops,
        },
#endif
        {
                .name = "dpio-common-bc",
                /*
                 * XXX: cmnreset for one PHY seems to disturb the other.
                 * As a workaround keep both powered on at the same
                 * time for now.
                 */
                .domains = CHV_DPIO_CMN_BC_POWER_DOMAINS | CHV_DPIO_CMN_D_POWER_DOMAINS,
                .data = PUNIT_POWER_WELL_DPIO_CMN_BC,
                .ops = &chv_dpio_cmn_power_well_ops,
        },
        {
                .name = "dpio-common-d",
                /*
                 * XXX: cmnreset for one PHY seems to disturb the other.
                 * As a workaround keep both powered on at the same
                 * time for now.
                 */
                .domains = CHV_DPIO_CMN_BC_POWER_DOMAINS | CHV_DPIO_CMN_D_POWER_DOMAINS,
                .data = PUNIT_POWER_WELL_DPIO_CMN_D,
                .ops = &chv_dpio_cmn_power_well_ops,
        },
#if 0
        {
                .name = "dpio-tx-b-01",
                .domains = VLV_DPIO_TX_B_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_B_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_B_LANES_01,
        },
        {
                .name = "dpio-tx-b-23",
                .domains = VLV_DPIO_TX_B_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_B_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_B_LANES_23,
        },
        {
                .name = "dpio-tx-c-01",
                .domains = VLV_DPIO_TX_C_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_C_LANES_01,
        },
        {
                .name = "dpio-tx-c-23",
                .domains = VLV_DPIO_TX_C_LANES_01_POWER_DOMAINS |
                           VLV_DPIO_TX_C_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_C_LANES_23,
        },
        {
                .name = "dpio-tx-d-01",
                .domains = CHV_DPIO_TX_D_LANES_01_POWER_DOMAINS |
                           CHV_DPIO_TX_D_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_D_LANES_01,
        },
        {
                .name = "dpio-tx-d-23",
                .domains = CHV_DPIO_TX_D_LANES_01_POWER_DOMAINS |
                           CHV_DPIO_TX_D_LANES_23_POWER_DOMAINS,
                .ops = &vlv_dpio_power_well_ops,
                .data = PUNIT_POWER_WELL_DPIO_TX_D_LANES_23,
        },
#endif
};

static struct i915_power_well *lookup_power_well(struct drm_i915_private *dev_priv,
                                                 enum punit_power_well power_well_id)
{
        struct i915_power_domains *power_domains = &dev_priv->power_domains;
        struct i915_power_well *power_well;
        int i;

        for_each_power_well(i, power_well, POWER_DOMAIN_MASK, power_domains) {
                if (power_well->data == power_well_id)
                        return power_well;
        }

        return NULL;
}

#define set_power_wells(power_domains, __power_wells) ({                \
        (power_domains)->power_wells = (__power_wells);                 \
        (power_domains)->power_well_count = ARRAY_SIZE(__power_wells);  \
})

/**
 * intel_power_domains_init - initializes the power domain structures
 * @dev_priv: i915 device instance
 *
 * Initializes the power domain structures for @dev_priv depending upon the
 * supported platform.
 */
int intel_power_domains_init(struct drm_i915_private *dev_priv)
{
        struct i915_power_domains *power_domains = &dev_priv->power_domains;

        mutex_init(&power_domains->lock);

        /*
         * The enabling order will be from lower to higher indexed wells,
         * the disabling order is reversed.
         */
        if (IS_HASWELL(dev_priv->dev)) {
                set_power_wells(power_domains, hsw_power_wells);
        } else if (IS_BROADWELL(dev_priv->dev)) {
                set_power_wells(power_domains, bdw_power_wells);
        } else if (IS_CHERRYVIEW(dev_priv->dev)) {
                set_power_wells(power_domains, chv_power_wells);
        } else if (IS_VALLEYVIEW(dev_priv->dev)) {
                set_power_wells(power_domains, vlv_power_wells);
        } else {
                set_power_wells(power_domains, i9xx_always_on_power_well);
        }

        return 0;
}

static void intel_runtime_pm_disable(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        struct device *device = &dev->pdev->dev;

        if (!HAS_RUNTIME_PM(dev))
                return;

        if (!intel_enable_rc6(dev))
                return;

        /* Make sure we're not suspended first. */
        pm_runtime_get_sync(device);
        pm_runtime_disable(device);
}

/**
 * intel_power_domains_fini - finalizes the power domain structures
 * @dev_priv: i915 device instance
 *
 * Finalizes the power domain structures for @dev_priv depending upon the
 * supported platform. This function also disables runtime pm and ensures that
 * the device stays powered up so that the driver can be reloaded.
 */
void intel_power_domains_fini(struct drm_i915_private *dev_priv)
{
        intel_runtime_pm_disable(dev_priv);

        /* The i915.ko module is still not prepared to be loaded when
         * the power well is not enabled, so just enable it in case
         * we're going to unload/reload. */
        intel_display_set_init_power(dev_priv, true);
}

static void intel_power_domains_resume(struct drm_i915_private *dev_priv)
{
        struct i915_power_domains *power_domains = &dev_priv->power_domains;
        struct i915_power_well *power_well;
        int i;

        mutex_lock(&power_domains->lock);
        for_each_power_well(i, power_well, POWER_DOMAIN_MASK, power_domains) {
                power_well->ops->sync_hw(dev_priv, power_well);
                power_well->hw_enabled = power_well->ops->is_enabled(dev_priv,
                                                                     power_well);
        }
        mutex_unlock(&power_domains->lock);
}

static void vlv_cmnlane_wa(struct drm_i915_private *dev_priv)
{
        struct i915_power_well *cmn =
                lookup_power_well(dev_priv, PUNIT_POWER_WELL_DPIO_CMN_BC);
        struct i915_power_well *disp2d =
                lookup_power_well(dev_priv, PUNIT_POWER_WELL_DISP2D);

        /* If the display might be already active skip this */
        if (cmn->ops->is_enabled(dev_priv, cmn) &&
            disp2d->ops->is_enabled(dev_priv, disp2d) &&
            I915_READ(DPIO_CTL) & DPIO_CMNRST)
                return;

        DRM_DEBUG_KMS("toggling display PHY side reset\n");

        /* cmnlane needs DPLL registers */
        disp2d->ops->enable(dev_priv, disp2d);

        /*
         * From VLV2A0_DP_eDP_HDMI_DPIO_driver_vbios_notes_11.docx:
         * Need to assert and de-assert PHY SB reset by gating the
         * common lane power, then un-gating it.
         * Simply ungating isn't enough to reset the PHY enough to get
         * ports and lanes running.
         */
        cmn->ops->disable(dev_priv, cmn);
}

/**
 * intel_power_domains_init_hw - initialize hardware power domain state
 * @dev_priv: i915 device instance
 *
 * This function initializes the hardware power domain state and enables all
 * power domains using intel_display_set_init_power().
 */
void intel_power_domains_init_hw(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        struct i915_power_domains *power_domains = &dev_priv->power_domains;

        power_domains->initializing = true;

        if (IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev)) {
                mutex_lock(&power_domains->lock);
                vlv_cmnlane_wa(dev_priv);
                mutex_unlock(&power_domains->lock);
        }

        /* For now, we need the power well to be always enabled. */
        intel_display_set_init_power(dev_priv, true);
        intel_power_domains_resume(dev_priv);
        power_domains->initializing = false;
}

/**
 * intel_aux_display_runtime_get - grab an auxilliary power domain reference
 * @dev_priv: i915 device instance
 *
 * This function grabs a power domain reference for the auxiliary power domain
 * (for access to the GMBUS and DP AUX blocks) and ensures that it and all its
 * parents are powered up. Therefore users should only grab a reference to the
 * innermost power domain they need.
 *
 * Any power domain reference obtained by this function must have a symmetric
 * call to intel_aux_display_runtime_put() to release the reference again.
 */
void intel_aux_display_runtime_get(struct drm_i915_private *dev_priv)
{
        intel_runtime_pm_get(dev_priv);
}

/**
 * intel_aux_display_runtime_put - release an auxilliary power domain reference
 * @dev_priv: i915 device instance
 *
 * This function drops the auxilliary power domain reference obtained by
 * intel_aux_display_runtime_get() and might power down the corresponding
 * hardware block right away if this is the last reference.
 */
void intel_aux_display_runtime_put(struct drm_i915_private *dev_priv)
{
        intel_runtime_pm_put(dev_priv);
}

/**
 * intel_runtime_pm_get - grab a runtime pm reference
 * @dev_priv: i915 device instance
 *
 * This function grabs a device-level runtime pm reference (mostly used for GEM
 * code to ensure the GTT or GT is on) and ensures that it is powered up.
 *
 * Any runtime pm reference obtained by this function must have a symmetric
 * call to intel_runtime_pm_put() to release the reference again.
 */
void intel_runtime_pm_get(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        struct device *device = &dev->pdev->dev;

        if (!HAS_RUNTIME_PM(dev))
                return;

        pm_runtime_get_sync(device);
        WARN(dev_priv->pm.suspended, "Device still suspended.\n");
}

/**
 * intel_runtime_pm_get_noresume - grab a runtime pm reference
 * @dev_priv: i915 device instance
 *
 * This function grabs a device-level runtime pm reference (mostly used for GEM
 * code to ensure the GTT or GT is on).
 *
 * It will _not_ power up the device but instead only check that it's powered
 * on.  Therefore it is only valid to call this functions from contexts where
 * the device is known to be powered up and where trying to power it up would
 * result in hilarity and deadlocks. That pretty much means only the system
 * suspend/resume code where this is used to grab runtime pm references for
 * delayed setup down in work items.
 *
 * Any runtime pm reference obtained by this function must have a symmetric
 * call to intel_runtime_pm_put() to release the reference again.
 */
void intel_runtime_pm_get_noresume(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        struct device *device = &dev->pdev->dev;

        if (!HAS_RUNTIME_PM(dev))
                return;

        WARN(dev_priv->pm.suspended, "Getting nosync-ref while suspended.\n");
        pm_runtime_get_noresume(device);
}

/**
 * intel_runtime_pm_put - release a runtime pm reference
 * @dev_priv: i915 device instance
 *
 * This function drops the device-level runtime pm reference obtained by
 * intel_runtime_pm_get() and might power down the corresponding
 * hardware block right away if this is the last reference.
 */
void intel_runtime_pm_put(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        struct device *device = &dev->pdev->dev;

        if (!HAS_RUNTIME_PM(dev))
                return;

        pm_runtime_mark_last_busy(device);
        pm_runtime_put_autosuspend(device);
}

/**
 * intel_runtime_pm_enable - enable runtime pm
 * @dev_priv: i915 device instance
 *
 * This function enables runtime pm at the end of the driver load sequence.
 *
 * Note that this function does currently not enable runtime pm for the
 * subordinate display power domains. That is only done on the first modeset
 * using intel_display_set_init_power().
 */
void intel_runtime_pm_enable(struct drm_i915_private *dev_priv)
{
        struct drm_device *dev = dev_priv->dev;
        struct device *device = &dev->pdev->dev;

        if (!HAS_RUNTIME_PM(dev))
                return;

        pm_runtime_set_active(device);

        /*
         * RPM depends on RC6 to save restore the GT HW context, so make RC6 a
         * requirement.
         */
        if (!intel_enable_rc6(dev)) {
                DRM_INFO("RC6 disabled, disabling runtime PM support\n");
                return;
        }

        pm_runtime_set_autosuspend_delay(device, 10000); /* 10s */
        pm_runtime_mark_last_busy(device);
        pm_runtime_use_autosuspend(device);

        pm_runtime_put_autosuspend(device);
}