Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: (51 commits)
  PM: Improve error code of pm_notifier_call_chain()
  PM: Add "RTC" to PM trace time stamps to avoid confusion
  PM / Suspend: Export suspend_set_ops, suspend_valid_only_mem
  PM / Suspend: Add .suspend_again() callback to suspend_ops
  PM / OPP: Introduce function to free cpufreq table
  ARM / shmobile: Return -EBUSY from A4LC power off if A3RV is active
  PM / Domains: Take .power_off() error code into account
  ARM / shmobile: Use genpd_queue_power_off_work()
  ARM / shmobile: Use pm_genpd_poweroff_unused()
  PM / Domains: Introduce function to power off all unused PM domains
  OMAP: PM: disable idle on suspend for GPIO and UART
  OMAP: PM: omap_device: add API to disable idle on suspend
  OMAP: PM: omap_device: add system PM methods for PM domain handling
  OMAP: PM: omap_device: conditionally use PM domain runtime helpers
  PM / Runtime: Add new helper function: pm_runtime_status_suspended()
  PM / Domains: Queue up power off work only if it is not pending
  PM / Domains: Improve handling of wakeup devices during system suspend
  PM / Domains: Do not restore all devices on power off error
  PM / Domains: Allow callbacks to execute all runtime PM helpers
  PM / Domains: Do not execute device callbacks under locks
  ...

1 files changed, 1273 insertions, 0 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
new file mode 100644
index 000000000000..be8714aa9dd6
--- /dev/null
+++ b/drivers/base/power/domain.c
@@ -0,0 +1,1273 @@
+/*
+ * drivers/base/power/domain.c - Common code related to device power domains.
+ *
+ * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/suspend.h>
+
+static LIST_HEAD(gpd_list);
+static DEFINE_MUTEX(gpd_list_lock);
+
+#ifdef CONFIG_PM
+
+static struct generic_pm_domain *dev_to_genpd(struct device *dev)
+{
+        if (IS_ERR_OR_NULL(dev->pm_domain))
+                return ERR_PTR(-EINVAL);
+
+        return pd_to_genpd(dev->pm_domain);
+}
+
+static void genpd_sd_counter_dec(struct generic_pm_domain *genpd)
+{
+        if (!WARN_ON(genpd->sd_count == 0))
+                        genpd->sd_count--;
+}
+
+static void genpd_acquire_lock(struct generic_pm_domain *genpd)
+{
+        DEFINE_WAIT(wait);
+
+        mutex_lock(&genpd->lock);
+        /*
+         * Wait for the domain to transition into either the active,
+         * or the power off state.
+         */
+        for (;;) {
+                prepare_to_wait(&genpd->status_wait_queue, &wait,
+                                TASK_UNINTERRUPTIBLE);
+                if (genpd->status == GPD_STATE_ACTIVE
+                    || genpd->status == GPD_STATE_POWER_OFF)
+                        break;
+                mutex_unlock(&genpd->lock);
+
+                schedule();
+
+                mutex_lock(&genpd->lock);
+        }
+        finish_wait(&genpd->status_wait_queue, &wait);
+}
+
+static void genpd_release_lock(struct generic_pm_domain *genpd)
+{
+        mutex_unlock(&genpd->lock);
+}
+
+static void genpd_set_active(struct generic_pm_domain *genpd)
+{
+        if (genpd->resume_count == 0)
+                genpd->status = GPD_STATE_ACTIVE;
+}
+
+/**
+ * pm_genpd_poweron - Restore power to a given PM domain and its parents.
+ * @genpd: PM domain to power up.
+ *
+ * Restore power to @genpd and all of its parents so that it is possible to
+ * resume a device belonging to it.
+ */
+int pm_genpd_poweron(struct generic_pm_domain *genpd)
+{
+        struct generic_pm_domain *parent = genpd->parent;
+        DEFINE_WAIT(wait);
+        int ret = 0;
+
+ start:
+        if (parent) {
+                genpd_acquire_lock(parent);
+                mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING);
+        } else {
+                mutex_lock(&genpd->lock);
+        }
+
+        if (genpd->status == GPD_STATE_ACTIVE
+            || (genpd->prepared_count > 0 && genpd->suspend_power_off))
+                goto out;
+
+        if (genpd->status != GPD_STATE_POWER_OFF) {
+                genpd_set_active(genpd);
+                goto out;
+        }
+
+        if (parent && parent->status != GPD_STATE_ACTIVE) {
+                mutex_unlock(&genpd->lock);
+                genpd_release_lock(parent);
+
+                ret = pm_genpd_poweron(parent);
+                if (ret)
+                        return ret;
+
+                goto start;
+        }
+
+        if (genpd->power_on) {
+                int ret = genpd->power_on(genpd);
+                if (ret)
+                        goto out;
+        }
+
+        genpd_set_active(genpd);
+        if (parent)
+                parent->sd_count++;
+
+ out:
+        mutex_unlock(&genpd->lock);
+        if (parent)
+                genpd_release_lock(parent);
+
+        return ret;
+}
+
+#endif /* CONFIG_PM */
+
+#ifdef CONFIG_PM_RUNTIME
+
+/**
+ * __pm_genpd_save_device - Save the pre-suspend state of a device.
+ * @dle: Device list entry of the device to save the state of.
+ * @genpd: PM domain the device belongs to.
+ */
+static int __pm_genpd_save_device(struct dev_list_entry *dle,
+                                  struct generic_pm_domain *genpd)
+        __releases(&genpd->lock) __acquires(&genpd->lock)
+{
+        struct device *dev = dle->dev;
+        struct device_driver *drv = dev->driver;
+        int ret = 0;
+
+        if (dle->need_restore)
+                return 0;
+
+        mutex_unlock(&genpd->lock);
+
+        if (drv && drv->pm && drv->pm->runtime_suspend) {
+                if (genpd->start_device)
+                        genpd->start_device(dev);
+
+                ret = drv->pm->runtime_suspend(dev);
+
+                if (genpd->stop_device)
+                        genpd->stop_device(dev);
+        }
+
+        mutex_lock(&genpd->lock);
+
+        if (!ret)
+                dle->need_restore = true;
+
+        return ret;
+}
+
+/**
+ * __pm_genpd_restore_device - Restore the pre-suspend state of a device.
+ * @dle: Device list entry of the device to restore the state of.
+ * @genpd: PM domain the device belongs to.
+ */
+static void __pm_genpd_restore_device(struct dev_list_entry *dle,
+                                      struct generic_pm_domain *genpd)
+        __releases(&genpd->lock) __acquires(&genpd->lock)
+{
+        struct device *dev = dle->dev;
+        struct device_driver *drv = dev->driver;
+
+        if (!dle->need_restore)
+                return;
+
+        mutex_unlock(&genpd->lock);
+
+        if (drv && drv->pm && drv->pm->runtime_resume) {
+                if (genpd->start_device)
+                        genpd->start_device(dev);
+
+                drv->pm->runtime_resume(dev);
+
+                if (genpd->stop_device)
+                        genpd->stop_device(dev);
+        }
+
+        mutex_lock(&genpd->lock);
+
+        dle->need_restore = false;
+}
+
+/**
+ * genpd_abort_poweroff - Check if a PM domain power off should be aborted.
+ * @genpd: PM domain to check.
+ *
+ * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
+ * a "power off" operation, which means that a "power on" has occured in the
+ * meantime, or if its resume_count field is different from zero, which means
+ * that one of its devices has been resumed in the meantime.
+ */
+static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
+{
+        return genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
+}
+
+/**
+ * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
+ * @genpd: PM domait to power off.
+ *
+ * Queue up the execution of pm_genpd_poweroff() unless it's already been done
+ * before.
+ */
+void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
+{
+        if (!work_pending(&genpd->power_off_work))
+                queue_work(pm_wq, &genpd->power_off_work);
+}
+
+/**
+ * pm_genpd_poweroff - Remove power from a given PM domain.
+ * @genpd: PM domain to power down.
+ *
+ * If all of the @genpd's devices have been suspended and all of its subdomains
+ * have been powered down, run the runtime suspend callbacks provided by all of
+ * the @genpd's devices' drivers and remove power from @genpd.
+ */
+static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
+        __releases(&genpd->lock) __acquires(&genpd->lock)
+{
+        struct generic_pm_domain *parent;
+        struct dev_list_entry *dle;
+        unsigned int not_suspended;
+        int ret = 0;
+
+ start:
+        /*
+         * Do not try to power off the domain in the following situations:
+         * (1) The domain is already in the "power off" state.
+         * (2) System suspend is in progress.
+         * (3) One of the domain's devices is being resumed right now.
+         */
+        if (genpd->status == GPD_STATE_POWER_OFF || genpd->prepared_count > 0
+            || genpd->resume_count > 0)
+                return 0;
+
+        if (genpd->sd_count > 0)
+                return -EBUSY;
+
+        not_suspended = 0;
+        list_for_each_entry(dle, &genpd->dev_list, node)
+                if (dle->dev->driver && !pm_runtime_suspended(dle->dev))
+                        not_suspended++;
+
+        if (not_suspended > genpd->in_progress)
+                return -EBUSY;
+
+        if (genpd->poweroff_task) {
+                /*
+                 * Another instance of pm_genpd_poweroff() is executing
+                 * callbacks, so tell it to start over and return.
+                 */
+                genpd->status = GPD_STATE_REPEAT;
+                return 0;
+        }
+
+        if (genpd->gov && genpd->gov->power_down_ok) {
+                if (!genpd->gov->power_down_ok(&genpd->domain))
+                        return -EAGAIN;
+        }
+
+        genpd->status = GPD_STATE_BUSY;
+        genpd->poweroff_task = current;
+
+        list_for_each_entry_reverse(dle, &genpd->dev_list, node) {
+                ret = __pm_genpd_save_device(dle, genpd);
+                if (ret) {
+                        genpd_set_active(genpd);
+                        goto out;
+                }
+
+                if (genpd_abort_poweroff(genpd))
+                        goto out;
+
+                if (genpd->status == GPD_STATE_REPEAT) {
+                        genpd->poweroff_task = NULL;
+                        goto start;
+                }
+        }
+
+        parent = genpd->parent;
+        if (parent) {
+                mutex_unlock(&genpd->lock);
+
+                genpd_acquire_lock(parent);
+                mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING);
+
+                if (genpd_abort_poweroff(genpd)) {
+                        genpd_release_lock(parent);
+                        goto out;
+                }
+        }
+
+        if (genpd->power_off) {
+                ret = genpd->power_off(genpd);
+                if (ret == -EBUSY) {
+                        genpd_set_active(genpd);
+                        if (parent)
+                                genpd_release_lock(parent);
+
+                        goto out;
+                }
+        }
+
+        genpd->status = GPD_STATE_POWER_OFF;
+
+        if (parent) {
+                genpd_sd_counter_dec(parent);
+                if (parent->sd_count == 0)
+                        genpd_queue_power_off_work(parent);
+
+                genpd_release_lock(parent);
+        }
+
+ out:
+        genpd->poweroff_task = NULL;
+        wake_up_all(&genpd->status_wait_queue);
+        return ret;
+}
+
+/**
+ * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
+ * @work: Work structure used for scheduling the execution of this function.
+ */
+static void genpd_power_off_work_fn(struct work_struct *work)
+{
+        struct generic_pm_domain *genpd;
+
+        genpd = container_of(work, struct generic_pm_domain, power_off_work);
+
+        genpd_acquire_lock(genpd);
+        pm_genpd_poweroff(genpd);
+        genpd_release_lock(genpd);
+}
+
+/**
+ * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
+ * @dev: Device to suspend.
+ *
+ * Carry out a runtime suspend of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a PM domain consisting of I/O devices.
+ */
+static int pm_genpd_runtime_suspend(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        if (genpd->stop_device) {
+                int ret = genpd->stop_device(dev);
+                if (ret)
+                        return ret;
+        }
+
+        mutex_lock(&genpd->lock);
+        genpd->in_progress++;
+        pm_genpd_poweroff(genpd);
+        genpd->in_progress--;
+        mutex_unlock(&genpd->lock);
+
+        return 0;
+}
+
+/**
+ * __pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
+ * @dev: Device to resume.
+ * @genpd: PM domain the device belongs to.
+ */
+static void __pm_genpd_runtime_resume(struct device *dev,
+                                      struct generic_pm_domain *genpd)
+{
+        struct dev_list_entry *dle;
+
+        list_for_each_entry(dle, &genpd->dev_list, node) {
+                if (dle->dev == dev) {
+                        __pm_genpd_restore_device(dle, genpd);
+                        break;
+                }
+        }
+}
+
+/**
+ * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
+ * @dev: Device to resume.
+ *
+ * Carry out a runtime resume of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a PM domain consisting of I/O devices.
+ */
+static int pm_genpd_runtime_resume(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+        DEFINE_WAIT(wait);
+        int ret;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        ret = pm_genpd_poweron(genpd);
+        if (ret)
+                return ret;
+
+        mutex_lock(&genpd->lock);
+        genpd->status = GPD_STATE_BUSY;
+        genpd->resume_count++;
+        for (;;) {
+                prepare_to_wait(&genpd->status_wait_queue, &wait,
+                                TASK_UNINTERRUPTIBLE);
+                /*
+                 * If current is the powering off task, we have been called
+                 * reentrantly from one of the device callbacks, so we should
+                 * not wait.
+                 */
+                if (!genpd->poweroff_task || genpd->poweroff_task == current)
+                        break;
+                mutex_unlock(&genpd->lock);
+
+                schedule();
+
+                mutex_lock(&genpd->lock);
+        }
+        finish_wait(&genpd->status_wait_queue, &wait);
+        __pm_genpd_runtime_resume(dev, genpd);
+        genpd->resume_count--;
+        genpd_set_active(genpd);
+        wake_up_all(&genpd->status_wait_queue);
+        mutex_unlock(&genpd->lock);
+
+        if (genpd->start_device)
+                genpd->start_device(dev);
+
+        return 0;
+}
+
+#else
+
+static inline void genpd_power_off_work_fn(struct work_struct *work) {}
+static inline void __pm_genpd_runtime_resume(struct device *dev,
+                                             struct generic_pm_domain *genpd) {}
+
+#define pm_genpd_runtime_suspend        NULL
+#define pm_genpd_runtime_resume         NULL
+
+#endif /* CONFIG_PM_RUNTIME */
+
+#ifdef CONFIG_PM_SLEEP
+
+/**
+ * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its parents.
+ * @genpd: PM domain to power off, if possible.
+ *
+ * Check if the given PM domain can be powered off (during system suspend or
+ * hibernation) and do that if so.  Also, in that case propagate to its parent.
+ *
+ * This function is only called in "noirq" stages of system power transitions,
+ * so it need not acquire locks (all of the "noirq" callbacks are executed
+ * sequentially, so it is guaranteed that it will never run twice in parallel).
+ */
+static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
+{
+        struct generic_pm_domain *parent = genpd->parent;
+
+        if (genpd->status == GPD_STATE_POWER_OFF)
+                return;
+
+        if (genpd->suspended_count != genpd->device_count || genpd->sd_count > 0)
+                return;
+
+        if (genpd->power_off)
+                genpd->power_off(genpd);
+
+        genpd->status = GPD_STATE_POWER_OFF;
+        if (parent) {
+                genpd_sd_counter_dec(parent);
+                pm_genpd_sync_poweroff(parent);
+        }
+}
+
+/**
+ * resume_needed - Check whether to resume a device before system suspend.
+ * @dev: Device to check.
+ * @genpd: PM domain the device belongs to.
+ *
+ * There are two cases in which a device that can wake up the system from sleep
+ * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
+ * to wake up the system and it has to remain active for this purpose while the
+ * system is in the sleep state and (2) if the device is not enabled to wake up
+ * the system from sleep states and it generally doesn't generate wakeup signals
+ * by itself (those signals are generated on its behalf by other parts of the
+ * system).  In the latter case it may be necessary to reconfigure the device's
+ * wakeup settings during system suspend, because it may have been set up to
+ * signal remote wakeup from the system's working state as needed by runtime PM.
+ * Return 'true' in either of the above cases.
+ */
+static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
+{
+        bool active_wakeup;
+
+        if (!device_can_wakeup(dev))
+                return false;
+
+        active_wakeup = genpd->active_wakeup && genpd->active_wakeup(dev);
+        return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
+}
+
+/**
+ * pm_genpd_prepare - Start power transition of a device in a PM domain.
+ * @dev: Device to start the transition of.
+ *
+ * Start a power transition of a device (during a system-wide power transition)
+ * under the assumption that its pm_domain field points to the domain member of
+ * an object of type struct generic_pm_domain representing a PM domain
+ * consisting of I/O devices.
+ */
+static int pm_genpd_prepare(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+        int ret;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        /*
+         * If a wakeup request is pending for the device, it should be woken up
+         * at this point and a system wakeup event should be reported if it's
+         * set up to wake up the system from sleep states.
+         */
+        pm_runtime_get_noresume(dev);
+        if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
+                pm_wakeup_event(dev, 0);
+
+        if (pm_wakeup_pending()) {
+                pm_runtime_put_sync(dev);
+                return -EBUSY;
+        }
+
+        if (resume_needed(dev, genpd))
+                pm_runtime_resume(dev);
+
+        genpd_acquire_lock(genpd);
+
+        if (genpd->prepared_count++ == 0)
+                genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
+
+        genpd_release_lock(genpd);
+
+        if (genpd->suspend_power_off) {
+                pm_runtime_put_noidle(dev);
+                return 0;
+        }
+
+        /*
+         * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
+         * so pm_genpd_poweron() will return immediately, but if the device
+         * is suspended (e.g. it's been stopped by .stop_device()), we need
+         * to make it operational.
+         */
+        pm_runtime_resume(dev);
+        __pm_runtime_disable(dev, false);
+
+        ret = pm_generic_prepare(dev);
+        if (ret) {
+                mutex_lock(&genpd->lock);
+
+                if (--genpd->prepared_count == 0)
+                        genpd->suspend_power_off = false;
+
+                mutex_unlock(&genpd->lock);
+                pm_runtime_enable(dev);
+        }
+
+        pm_runtime_put_sync(dev);
+        return ret;
+}
+
+/**
+ * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
+ * @dev: Device to suspend.
+ *
+ * Suspend a device under the assumption that its pm_domain field points to the
+ * domain member of an object of type struct generic_pm_domain representing
+ * a PM domain consisting of I/O devices.
+ */
+static int pm_genpd_suspend(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev);
+}
+
+/**
+ * pm_genpd_suspend_noirq - Late suspend of a device from an I/O PM domain.
+ * @dev: Device to suspend.
+ *
+ * Carry out a late suspend of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a PM domain consisting of I/O devices.
+ */
+static int pm_genpd_suspend_noirq(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+        int ret;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        if (genpd->suspend_power_off)
+                return 0;
+
+        ret = pm_generic_suspend_noirq(dev);
+        if (ret)
+                return ret;
+
+        if (device_may_wakeup(dev)
+            && genpd->active_wakeup && genpd->active_wakeup(dev))
+                return 0;
+
+        if (genpd->stop_device)
+                genpd->stop_device(dev);
+
+        /*
+         * Since all of the "noirq" callbacks are executed sequentially, it is
+         * guaranteed that this function will never run twice in parallel for
+         * the same PM domain, so it is not necessary to use locking here.
+         */
+        genpd->suspended_count++;
+        pm_genpd_sync_poweroff(genpd);
+
+        return 0;
+}
+
+/**
+ * pm_genpd_resume_noirq - Early resume of a device from an I/O power domain.
+ * @dev: Device to resume.
+ *
+ * Carry out an early resume of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a power domain consisting of I/O
+ * devices.
+ */
+static int pm_genpd_resume_noirq(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        if (genpd->suspend_power_off)
+                return 0;
+
+        /*
+         * Since all of the "noirq" callbacks are executed sequentially, it is
+         * guaranteed that this function will never run twice in parallel for
+         * the same PM domain, so it is not necessary to use locking here.
+         */
+        pm_genpd_poweron(genpd);
+        genpd->suspended_count--;
+        if (genpd->start_device)
+                genpd->start_device(dev);
+
+        return pm_generic_resume_noirq(dev);
+}
+
+/**
+ * pm_genpd_resume - Resume a device belonging to an I/O power domain.
+ * @dev: Device to resume.
+ *
+ * Resume a device under the assumption that its pm_domain field points to the
+ * domain member of an object of type struct generic_pm_domain representing
+ * a power domain consisting of I/O devices.
+ */
+static int pm_genpd_resume(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        return genpd->suspend_power_off ? 0 : pm_generic_resume(dev);
+}
+
+/**
+ * pm_genpd_freeze - Freeze a device belonging to an I/O power domain.
+ * @dev: Device to freeze.
+ *
+ * Freeze a device under the assumption that its pm_domain field points to the
+ * domain member of an object of type struct generic_pm_domain representing
+ * a power domain consisting of I/O devices.
+ */
+static int pm_genpd_freeze(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev);
+}
+
+/**
+ * pm_genpd_freeze_noirq - Late freeze of a device from an I/O power domain.
+ * @dev: Device to freeze.
+ *
+ * Carry out a late freeze of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a power domain consisting of I/O
+ * devices.
+ */
+static int pm_genpd_freeze_noirq(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+        int ret;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        if (genpd->suspend_power_off)
+                return 0;
+
+        ret = pm_generic_freeze_noirq(dev);
+        if (ret)
+                return ret;
+
+        if (genpd->stop_device)
+                genpd->stop_device(dev);
+
+        return 0;
+}
+
+/**
+ * pm_genpd_thaw_noirq - Early thaw of a device from an I/O power domain.
+ * @dev: Device to thaw.
+ *
+ * Carry out an early thaw of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a power domain consisting of I/O
+ * devices.
+ */
+static int pm_genpd_thaw_noirq(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        if (genpd->suspend_power_off)
+                return 0;
+
+        if (genpd->start_device)
+                genpd->start_device(dev);
+
+        return pm_generic_thaw_noirq(dev);
+}
+
+/**
+ * pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
+ * @dev: Device to thaw.
+ *
+ * Thaw a device under the assumption that its pm_domain field points to the
+ * domain member of an object of type struct generic_pm_domain representing
+ * a power domain consisting of I/O devices.
+ */
+static int pm_genpd_thaw(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev);
+}
+
+/**
+ * pm_genpd_dev_poweroff - Power off a device belonging to an I/O PM domain.
+ * @dev: Device to suspend.
+ *
+ * Power off a device under the assumption that its pm_domain field points to
+ * the domain member of an object of type struct generic_pm_domain representing
+ * a PM domain consisting of I/O devices.
+ */
+static int pm_genpd_dev_poweroff(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        return genpd->suspend_power_off ? 0 : pm_generic_poweroff(dev);
+}
+
+/**
+ * pm_genpd_dev_poweroff_noirq - Late power off of a device from a PM domain.
+ * @dev: Device to suspend.
+ *
+ * Carry out a late powering off of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a PM domain consisting of I/O devices.
+ */
+static int pm_genpd_dev_poweroff_noirq(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+        int ret;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        if (genpd->suspend_power_off)
+                return 0;
+
+        ret = pm_generic_poweroff_noirq(dev);
+        if (ret)
+                return ret;
+
+        if (device_may_wakeup(dev)
+            && genpd->active_wakeup && genpd->active_wakeup(dev))
+                return 0;
+
+        if (genpd->stop_device)
+                genpd->stop_device(dev);
+
+        /*
+         * Since all of the "noirq" callbacks are executed sequentially, it is
+         * guaranteed that this function will never run twice in parallel for
+         * the same PM domain, so it is not necessary to use locking here.
+         */
+        genpd->suspended_count++;
+        pm_genpd_sync_poweroff(genpd);
+
+        return 0;
+}
+
+/**
+ * pm_genpd_restore_noirq - Early restore of a device from an I/O power domain.
+ * @dev: Device to resume.
+ *
+ * Carry out an early restore of a device under the assumption that its
+ * pm_domain field points to the domain member of an object of type
+ * struct generic_pm_domain representing a power domain consisting of I/O
+ * devices.
+ */
+static int pm_genpd_restore_noirq(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        /*
+         * Since all of the "noirq" callbacks are executed sequentially, it is
+         * guaranteed that this function will never run twice in parallel for
+         * the same PM domain, so it is not necessary to use locking here.
+         */
+        genpd->status = GPD_STATE_POWER_OFF;
+        if (genpd->suspend_power_off) {
+                /*
+                 * The boot kernel might put the domain into the power on state,
+                 * so make sure it really is powered off.
+                 */
+                if (genpd->power_off)
+                        genpd->power_off(genpd);
+                return 0;
+        }
+
+        pm_genpd_poweron(genpd);
+        genpd->suspended_count--;
+        if (genpd->start_device)
+                genpd->start_device(dev);
+
+        return pm_generic_restore_noirq(dev);
+}
+
+/**
+ * pm_genpd_restore - Restore a device belonging to an I/O power domain.
+ * @dev: Device to resume.
+ *
+ * Restore a device under the assumption that its pm_domain field points to the
+ * domain member of an object of type struct generic_pm_domain representing
+ * a power domain consisting of I/O devices.
+ */
+static int pm_genpd_restore(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return -EINVAL;
+
+        return genpd->suspend_power_off ? 0 : pm_generic_restore(dev);
+}
+
+/**
+ * pm_genpd_complete - Complete power transition of a device in a power domain.
+ * @dev: Device to complete the transition of.
+ *
+ * Complete a power transition of a device (during a system-wide power
+ * transition) under the assumption that its pm_domain field points to the
+ * domain member of an object of type struct generic_pm_domain representing
+ * a power domain consisting of I/O devices.
+ */
+static void pm_genpd_complete(struct device *dev)
+{
+        struct generic_pm_domain *genpd;
+        bool run_complete;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        genpd = dev_to_genpd(dev);
+        if (IS_ERR(genpd))
+                return;
+
+        mutex_lock(&genpd->lock);
+
+        run_complete = !genpd->suspend_power_off;
+        if (--genpd->prepared_count == 0)
+                genpd->suspend_power_off = false;
+
+        mutex_unlock(&genpd->lock);
+
+        if (run_complete) {
+                pm_generic_complete(dev);
+                pm_runtime_set_active(dev);
+                pm_runtime_enable(dev);
+                pm_runtime_idle(dev);
+        }
+}
+
+#else
+
+#define pm_genpd_prepare                NULL
+#define pm_genpd_suspend                NULL
+#define pm_genpd_suspend_noirq          NULL
+#define pm_genpd_resume_noirq           NULL
+#define pm_genpd_resume                 NULL
+#define pm_genpd_freeze                 NULL
+#define pm_genpd_freeze_noirq           NULL
+#define pm_genpd_thaw_noirq             NULL
+#define pm_genpd_thaw                   NULL
+#define pm_genpd_dev_poweroff_noirq     NULL
+#define pm_genpd_dev_poweroff           NULL
+#define pm_genpd_restore_noirq          NULL
+#define pm_genpd_restore                NULL
+#define pm_genpd_complete               NULL
+
+#endif /* CONFIG_PM_SLEEP */
+
+/**
+ * pm_genpd_add_device - Add a device to an I/O PM domain.
+ * @genpd: PM domain to add the device to.
+ * @dev: Device to be added.
+ */
+int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
+{
+        struct dev_list_entry *dle;
+        int ret = 0;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
+                return -EINVAL;
+
+        genpd_acquire_lock(genpd);
+
+        if (genpd->status == GPD_STATE_POWER_OFF) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        if (genpd->prepared_count > 0) {
+                ret = -EAGAIN;
+                goto out;
+        }
+
+        list_for_each_entry(dle, &genpd->dev_list, node)
+                if (dle->dev == dev) {
+                        ret = -EINVAL;
+                        goto out;
+                }
+
+        dle = kzalloc(sizeof(*dle), GFP_KERNEL);
+        if (!dle) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        dle->dev = dev;
+        dle->need_restore = false;
+        list_add_tail(&dle->node, &genpd->dev_list);
+        genpd->device_count++;
+
+        spin_lock_irq(&dev->power.lock);
+        dev->pm_domain = &genpd->domain;
+        spin_unlock_irq(&dev->power.lock);
+
+ out:
+        genpd_release_lock(genpd);
+
+        return ret;
+}
+
+/**
+ * pm_genpd_remove_device - Remove a device from an I/O PM domain.
+ * @genpd: PM domain to remove the device from.
+ * @dev: Device to be removed.
+ */
+int pm_genpd_remove_device(struct generic_pm_domain *genpd,
+                           struct device *dev)
+{
+        struct dev_list_entry *dle;
+        int ret = -EINVAL;
+
+        dev_dbg(dev, "%s()\n", __func__);
+
+        if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
+                return -EINVAL;
+
+        genpd_acquire_lock(genpd);
+
+        if (genpd->prepared_count > 0) {
+                ret = -EAGAIN;
+                goto out;
+        }
+
+        list_for_each_entry(dle, &genpd->dev_list, node) {
+                if (dle->dev != dev)
+                        continue;
+
+                spin_lock_irq(&dev->power.lock);
+                dev->pm_domain = NULL;
+                spin_unlock_irq(&dev->power.lock);
+
+                genpd->device_count--;
+                list_del(&dle->node);
+                kfree(dle);
+
+                ret = 0;
+                break;
+        }
+
+ out:
+        genpd_release_lock(genpd);
+
+        return ret;
+}
+
+/**
+ * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
+ * @genpd: Master PM domain to add the subdomain to.
+ * @new_subdomain: Subdomain to be added.
+ */
+int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
+                           struct generic_pm_domain *new_subdomain)
+{
+        struct generic_pm_domain *subdomain;
+        int ret = 0;
+
+        if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(new_subdomain))
+                return -EINVAL;
+
+ start:
+        genpd_acquire_lock(genpd);
+        mutex_lock_nested(&new_subdomain->lock, SINGLE_DEPTH_NESTING);
+
+        if (new_subdomain->status != GPD_STATE_POWER_OFF
+            && new_subdomain->status != GPD_STATE_ACTIVE) {
+                mutex_unlock(&new_subdomain->lock);
+                genpd_release_lock(genpd);
+                goto start;
+        }
+
+        if (genpd->status == GPD_STATE_POWER_OFF
+            &&  new_subdomain->status != GPD_STATE_POWER_OFF) {
+                ret = -EINVAL;
+                goto out;
+        }
+
+        list_for_each_entry(subdomain, &genpd->sd_list, sd_node) {
+                if (subdomain == new_subdomain) {
+                        ret = -EINVAL;
+                        goto out;
+                }
+        }
+
+        list_add_tail(&new_subdomain->sd_node, &genpd->sd_list);
+        new_subdomain->parent = genpd;
+        if (subdomain->status != GPD_STATE_POWER_OFF)
+                genpd->sd_count++;
+
+ out:
+        mutex_unlock(&new_subdomain->lock);
+        genpd_release_lock(genpd);
+
+        return ret;
+}
+
+/**
+ * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
+ * @genpd: Master PM domain to remove the subdomain from.
+ * @target: Subdomain to be removed.
+ */
+int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
+                              struct generic_pm_domain *target)
+{
+        struct generic_pm_domain *subdomain;
+        int ret = -EINVAL;
+
+        if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(target))
+                return -EINVAL;
+
+ start:
+        genpd_acquire_lock(genpd);
+
+        list_for_each_entry(subdomain, &genpd->sd_list, sd_node) {
+                if (subdomain != target)
+                        continue;
+
+                mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
+
+                if (subdomain->status != GPD_STATE_POWER_OFF
+                    && subdomain->status != GPD_STATE_ACTIVE) {
+                        mutex_unlock(&subdomain->lock);
+                        genpd_release_lock(genpd);
+                        goto start;
+                }
+
+                list_del(&subdomain->sd_node);
+                subdomain->parent = NULL;
+                if (subdomain->status != GPD_STATE_POWER_OFF)
+                        genpd_sd_counter_dec(genpd);
+
+                mutex_unlock(&subdomain->lock);
+
+                ret = 0;
+                break;
+        }
+
+        genpd_release_lock(genpd);
+
+        return ret;
+}
+
+/**
+ * pm_genpd_init - Initialize a generic I/O PM domain object.
+ * @genpd: PM domain object to initialize.
+ * @gov: PM domain governor to associate with the domain (may be NULL).
+ * @is_off: Initial value of the domain's power_is_off field.
+ */
+void pm_genpd_init(struct generic_pm_domain *genpd,
+                   struct dev_power_governor *gov, bool is_off)
+{
+        if (IS_ERR_OR_NULL(genpd))
+                return;
+
+        INIT_LIST_HEAD(&genpd->sd_node);
+        genpd->parent = NULL;
+        INIT_LIST_HEAD(&genpd->dev_list);
+        INIT_LIST_HEAD(&genpd->sd_list);
+        mutex_init(&genpd->lock);
+        genpd->gov = gov;
+        INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
+        genpd->in_progress = 0;
+        genpd->sd_count = 0;
+        genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
+        init_waitqueue_head(&genpd->status_wait_queue);
+        genpd->poweroff_task = NULL;
+        genpd->resume_count = 0;
+        genpd->device_count = 0;
+        genpd->suspended_count = 0;
+        genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
+        genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
+        genpd->domain.ops.runtime_idle = pm_generic_runtime_idle;
+        genpd->domain.ops.prepare = pm_genpd_prepare;
+        genpd->domain.ops.suspend = pm_genpd_suspend;
+        genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
+        genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
+        genpd->domain.ops.resume = pm_genpd_resume;
+        genpd->domain.ops.freeze = pm_genpd_freeze;
+        genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
+        genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
+        genpd->domain.ops.thaw = pm_genpd_thaw;
+        genpd->domain.ops.poweroff = pm_genpd_dev_poweroff;
+        genpd->domain.ops.poweroff_noirq = pm_genpd_dev_poweroff_noirq;
+        genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
+        genpd->domain.ops.restore = pm_genpd_restore;
+        genpd->domain.ops.complete = pm_genpd_complete;
+        mutex_lock(&gpd_list_lock);
+        list_add(&genpd->gpd_list_node, &gpd_list);
+        mutex_unlock(&gpd_list_lock);
+}
+
+/**
+ * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
+ */
+void pm_genpd_poweroff_unused(void)
+{
+        struct generic_pm_domain *genpd;
+
+        mutex_lock(&gpd_list_lock);
+
+        list_for_each_entry(genpd, &gpd_list, gpd_list_node)
+                genpd_queue_power_off_work(genpd);
+
+        mutex_unlock(&gpd_list_lock);
+}