/*
- * drivers/base/power/runtime.c - Handling dynamic device power management.
+ * drivers/base/power/runtime.c - Helper functions for device run-time PM
*
- * Copyright (c) 2003 Patrick Mochel
- * Copyright (c) 2003 Open Source Development Lab
+ * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
*
+ * This file is released under the GPLv2.
*/
-#include <linux/device.h>
-#include "power.h"
+#include <linux/sched.h>
+#include <linux/pm_runtime.h>
+#include <linux/jiffies.h>
+static int __pm_runtime_resume(struct device *dev, bool from_wq);
+static int __pm_request_idle(struct device *dev);
+static int __pm_request_resume(struct device *dev);
-static void runtime_resume(struct device * dev)
+/**
+ * pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
+ * @dev: Device to handle.
+ */
+static void pm_runtime_deactivate_timer(struct device *dev)
+{
+ if (dev->power.timer_expires > 0) {
+ del_timer(&dev->power.suspend_timer);
+ dev->power.timer_expires = 0;
+ }
+}
+
+/**
+ * pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
+ * @dev: Device to handle.
+ */
+static void pm_runtime_cancel_pending(struct device *dev)
+{
+ pm_runtime_deactivate_timer(dev);
+ /*
+ * In case there's a request pending, make sure its work function will
+ * return without doing anything.
+ */
+ dev->power.request = RPM_REQ_NONE;
+}
+
+/**
+ * __pm_runtime_idle - Notify device bus type if the device can be suspended.
+ * @dev: Device to notify the bus type about.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static int __pm_runtime_idle(struct device *dev)
+ __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+ int retval = 0;
+
+ if (dev->power.runtime_error)
+ retval = -EINVAL;
+ else if (dev->power.idle_notification)
+ retval = -EINPROGRESS;
+ else if (atomic_read(&dev->power.usage_count) > 0
+ || dev->power.disable_depth > 0
+ || dev->power.runtime_status != RPM_ACTIVE)
+ retval = -EAGAIN;
+ else if (!pm_children_suspended(dev))
+ retval = -EBUSY;
+ if (retval)
+ goto out;
+
+ if (dev->power.request_pending) {
+ /*
+ * If an idle notification request is pending, cancel it. Any
+ * other pending request takes precedence over us.
+ */
+ if (dev->power.request == RPM_REQ_IDLE) {
+ dev->power.request = RPM_REQ_NONE;
+ } else if (dev->power.request != RPM_REQ_NONE) {
+ retval = -EAGAIN;
+ goto out;
+ }
+ }
+
+ dev->power.idle_notification = true;
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) {
+ spin_unlock_irq(&dev->power.lock);
+
+ dev->bus->pm->runtime_idle(dev);
+
+ spin_lock_irq(&dev->power.lock);
+ }
+
+ dev->power.idle_notification = false;
+ wake_up_all(&dev->power.wait_queue);
+
+ out:
+ return retval;
+}
+
+/**
+ * pm_runtime_idle - Notify device bus type if the device can be suspended.
+ * @dev: Device to notify the bus type about.
+ */
+int pm_runtime_idle(struct device *dev)
+{
+ int retval;
+
+ spin_lock_irq(&dev->power.lock);
+ retval = __pm_runtime_idle(dev);
+ spin_unlock_irq(&dev->power.lock);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_idle);
+
+/**
+ * __pm_runtime_suspend - Carry out run-time suspend of given device.
+ * @dev: Device to suspend.
+ * @from_wq: If set, the function has been called via pm_wq.
+ *
+ * Check if the device can be suspended and run the ->runtime_suspend() callback
+ * provided by its bus type. If another suspend has been started earlier, wait
+ * for it to finish. If an idle notification or suspend request is pending or
+ * scheduled, cancel it.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+int __pm_runtime_suspend(struct device *dev, bool from_wq)
+ __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+ struct device *parent = NULL;
+ bool notify = false;
+ int retval = 0;
+
+ dev_dbg(dev, "__pm_runtime_suspend()%s!\n",
+ from_wq ? " from workqueue" : "");
+
+ repeat:
+ if (dev->power.runtime_error) {
+ retval = -EINVAL;
+ goto out;
+ }
+
+ /* Pending resume requests take precedence over us. */
+ if (dev->power.request_pending
+ && dev->power.request == RPM_REQ_RESUME) {
+ retval = -EAGAIN;
+ goto out;
+ }
+
+ /* Other scheduled or pending requests need to be canceled. */
+ pm_runtime_cancel_pending(dev);
+
+ if (dev->power.runtime_status == RPM_SUSPENDED)
+ retval = 1;
+ else if (dev->power.runtime_status == RPM_RESUMING
+ || dev->power.disable_depth > 0
+ || atomic_read(&dev->power.usage_count) > 0)
+ retval = -EAGAIN;
+ else if (!pm_children_suspended(dev))
+ retval = -EBUSY;
+ if (retval)
+ goto out;
+
+ if (dev->power.runtime_status == RPM_SUSPENDING) {
+ DEFINE_WAIT(wait);
+
+ if (from_wq) {
+ retval = -EINPROGRESS;
+ goto out;
+ }
+
+ /* Wait for the other suspend running in parallel with us. */
+ for (;;) {
+ prepare_to_wait(&dev->power.wait_queue, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (dev->power.runtime_status != RPM_SUSPENDING)
+ break;
+
+ spin_unlock_irq(&dev->power.lock);
+
+ schedule();
+
+ spin_lock_irq(&dev->power.lock);
+ }
+ finish_wait(&dev->power.wait_queue, &wait);
+ goto repeat;
+ }
+
+ dev->power.runtime_status = RPM_SUSPENDING;
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) {
+ spin_unlock_irq(&dev->power.lock);
+
+ retval = dev->bus->pm->runtime_suspend(dev);
+
+ spin_lock_irq(&dev->power.lock);
+ dev->power.runtime_error = retval;
+ } else {
+ retval = -ENOSYS;
+ }
+
+ if (retval) {
+ dev->power.runtime_status = RPM_ACTIVE;
+ pm_runtime_cancel_pending(dev);
+ dev->power.deferred_resume = false;
+
+ if (retval == -EAGAIN || retval == -EBUSY) {
+ notify = true;
+ dev->power.runtime_error = 0;
+ }
+ } else {
+ dev->power.runtime_status = RPM_SUSPENDED;
+
+ if (dev->parent) {
+ parent = dev->parent;
+ atomic_add_unless(&parent->power.child_count, -1, 0);
+ }
+ }
+ wake_up_all(&dev->power.wait_queue);
+
+ if (dev->power.deferred_resume) {
+ dev->power.deferred_resume = false;
+ __pm_runtime_resume(dev, false);
+ retval = -EAGAIN;
+ goto out;
+ }
+
+ if (notify)
+ __pm_runtime_idle(dev);
+
+ if (parent && !parent->power.ignore_children) {
+ spin_unlock_irq(&dev->power.lock);
+
+ pm_request_idle(parent);
+
+ spin_lock_irq(&dev->power.lock);
+ }
+
+ out:
+ dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval);
+
+ return retval;
+}
+
+/**
+ * pm_runtime_suspend - Carry out run-time suspend of given device.
+ * @dev: Device to suspend.
+ */
+int pm_runtime_suspend(struct device *dev)
+{
+ int retval;
+
+ spin_lock_irq(&dev->power.lock);
+ retval = __pm_runtime_suspend(dev, false);
+ spin_unlock_irq(&dev->power.lock);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_suspend);
+
+/**
+ * __pm_runtime_resume - Carry out run-time resume of given device.
+ * @dev: Device to resume.
+ * @from_wq: If set, the function has been called via pm_wq.
+ *
+ * Check if the device can be woken up and run the ->runtime_resume() callback
+ * provided by its bus type. If another resume has been started earlier, wait
+ * for it to finish. If there's a suspend running in parallel with this
+ * function, wait for it to finish and resume the device. Cancel any scheduled
+ * or pending requests.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+int __pm_runtime_resume(struct device *dev, bool from_wq)
+ __releases(&dev->power.lock) __acquires(&dev->power.lock)
+{
+ struct device *parent = NULL;
+ int retval = 0;
+
+ dev_dbg(dev, "__pm_runtime_resume()%s!\n",
+ from_wq ? " from workqueue" : "");
+
+ repeat:
+ if (dev->power.runtime_error) {
+ retval = -EINVAL;
+ goto out;
+ }
+
+ pm_runtime_cancel_pending(dev);
+
+ if (dev->power.runtime_status == RPM_ACTIVE)
+ retval = 1;
+ else if (dev->power.disable_depth > 0)
+ retval = -EAGAIN;
+ if (retval)
+ goto out;
+
+ if (dev->power.runtime_status == RPM_RESUMING
+ || dev->power.runtime_status == RPM_SUSPENDING) {
+ DEFINE_WAIT(wait);
+
+ if (from_wq) {
+ if (dev->power.runtime_status == RPM_SUSPENDING)
+ dev->power.deferred_resume = true;
+ retval = -EINPROGRESS;
+ goto out;
+ }
+
+ /* Wait for the operation carried out in parallel with us. */
+ for (;;) {
+ prepare_to_wait(&dev->power.wait_queue, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (dev->power.runtime_status != RPM_RESUMING
+ && dev->power.runtime_status != RPM_SUSPENDING)
+ break;
+
+ spin_unlock_irq(&dev->power.lock);
+
+ schedule();
+
+ spin_lock_irq(&dev->power.lock);
+ }
+ finish_wait(&dev->power.wait_queue, &wait);
+ goto repeat;
+ }
+
+ if (!parent && dev->parent) {
+ /*
+ * Increment the parent's resume counter and resume it if
+ * necessary.
+ */
+ parent = dev->parent;
+ spin_unlock_irq(&dev->power.lock);
+
+ pm_runtime_get_noresume(parent);
+
+ spin_lock_irq(&parent->power.lock);
+ /*
+ * We can resume if the parent's run-time PM is disabled or it
+ * is set to ignore children.
+ */
+ if (!parent->power.disable_depth
+ && !parent->power.ignore_children) {
+ __pm_runtime_resume(parent, false);
+ if (parent->power.runtime_status != RPM_ACTIVE)
+ retval = -EBUSY;
+ }
+ spin_unlock_irq(&parent->power.lock);
+
+ spin_lock_irq(&dev->power.lock);
+ if (retval)
+ goto out;
+ goto repeat;
+ }
+
+ dev->power.runtime_status = RPM_RESUMING;
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) {
+ spin_unlock_irq(&dev->power.lock);
+
+ retval = dev->bus->pm->runtime_resume(dev);
+
+ spin_lock_irq(&dev->power.lock);
+ dev->power.runtime_error = retval;
+ } else {
+ retval = -ENOSYS;
+ }
+
+ if (retval) {
+ dev->power.runtime_status = RPM_SUSPENDED;
+ pm_runtime_cancel_pending(dev);
+ } else {
+ dev->power.runtime_status = RPM_ACTIVE;
+ if (parent)
+ atomic_inc(&parent->power.child_count);
+ }
+ wake_up_all(&dev->power.wait_queue);
+
+ if (!retval)
+ __pm_request_idle(dev);
+
+ out:
+ if (parent) {
+ spin_unlock_irq(&dev->power.lock);
+
+ pm_runtime_put(parent);
+
+ spin_lock_irq(&dev->power.lock);
+ }
+
+ dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval);
+
+ return retval;
+}
+
+/**
+ * pm_runtime_resume - Carry out run-time resume of given device.
+ * @dev: Device to suspend.
+ */
+int pm_runtime_resume(struct device *dev)
+{
+ int retval;
+
+ spin_lock_irq(&dev->power.lock);
+ retval = __pm_runtime_resume(dev, false);
+ spin_unlock_irq(&dev->power.lock);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_resume);
+
+/**
+ * pm_runtime_work - Universal run-time PM work function.
+ * @work: Work structure used for scheduling the execution of this function.
+ *
+ * Use @work to get the device object the work is to be done for, determine what
+ * is to be done and execute the appropriate run-time PM function.
+ */
+static void pm_runtime_work(struct work_struct *work)
+{
+ struct device *dev = container_of(work, struct device, power.work);
+ enum rpm_request req;
+
+ spin_lock_irq(&dev->power.lock);
+
+ if (!dev->power.request_pending)
+ goto out;
+
+ req = dev->power.request;
+ dev->power.request = RPM_REQ_NONE;
+ dev->power.request_pending = false;
+
+ switch (req) {
+ case RPM_REQ_NONE:
+ break;
+ case RPM_REQ_IDLE:
+ __pm_runtime_idle(dev);
+ break;
+ case RPM_REQ_SUSPEND:
+ __pm_runtime_suspend(dev, true);
+ break;
+ case RPM_REQ_RESUME:
+ __pm_runtime_resume(dev, true);
+ break;
+ }
+
+ out:
+ spin_unlock_irq(&dev->power.lock);
+}
+
+/**
+ * __pm_request_idle - Submit an idle notification request for given device.
+ * @dev: Device to handle.
+ *
+ * Check if the device's run-time PM status is correct for suspending the device
+ * and queue up a request to run __pm_runtime_idle() for it.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static int __pm_request_idle(struct device *dev)
+{
+ int retval = 0;
+
+ if (dev->power.runtime_error)
+ retval = -EINVAL;
+ else if (atomic_read(&dev->power.usage_count) > 0
+ || dev->power.disable_depth > 0
+ || dev->power.runtime_status == RPM_SUSPENDED
+ || dev->power.runtime_status == RPM_SUSPENDING)
+ retval = -EAGAIN;
+ else if (!pm_children_suspended(dev))
+ retval = -EBUSY;
+ if (retval)
+ return retval;
+
+ if (dev->power.request_pending) {
+ /* Any requests other then RPM_REQ_IDLE take precedence. */
+ if (dev->power.request == RPM_REQ_NONE)
+ dev->power.request = RPM_REQ_IDLE;
+ else if (dev->power.request != RPM_REQ_IDLE)
+ retval = -EAGAIN;
+ return retval;
+ }
+
+ dev->power.request = RPM_REQ_IDLE;
+ dev->power.request_pending = true;
+ queue_work(pm_wq, &dev->power.work);
+
+ return retval;
+}
+
+/**
+ * pm_request_idle - Submit an idle notification request for given device.
+ * @dev: Device to handle.
+ */
+int pm_request_idle(struct device *dev)
{
- dev_dbg(dev, "resuming\n");
- if (!dev->power.power_state.event)
- return;
- if (!resume_device(dev))
- dev->power.power_state = PMSG_ON;
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = __pm_request_idle(dev);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ return retval;
}
+EXPORT_SYMBOL_GPL(pm_request_idle);
+
+/**
+ * __pm_request_suspend - Submit a suspend request for given device.
+ * @dev: Device to suspend.
+ *
+ * This function must be called under dev->power.lock with interrupts disabled.
+ */
+static int __pm_request_suspend(struct device *dev)
+{
+ int retval = 0;
+
+ if (dev->power.runtime_error)
+ return -EINVAL;
+
+ if (dev->power.runtime_status == RPM_SUSPENDED)
+ retval = 1;
+ else if (atomic_read(&dev->power.usage_count) > 0
+ || dev->power.disable_depth > 0)
+ retval = -EAGAIN;
+ else if (dev->power.runtime_status == RPM_SUSPENDING)
+ retval = -EINPROGRESS;
+ else if (!pm_children_suspended(dev))
+ retval = -EBUSY;
+ if (retval < 0)
+ return retval;
+
+ pm_runtime_deactivate_timer(dev);
+
+ if (dev->power.request_pending) {
+ /*
+ * Pending resume requests take precedence over us, but we can
+ * overtake any other pending request.
+ */
+ if (dev->power.request == RPM_REQ_RESUME)
+ retval = -EAGAIN;
+ else if (dev->power.request != RPM_REQ_SUSPEND)
+ dev->power.request = retval ?
+ RPM_REQ_NONE : RPM_REQ_SUSPEND;
+ return retval;
+ } else if (retval) {
+ return retval;
+ }
+
+ dev->power.request = RPM_REQ_SUSPEND;
+ dev->power.request_pending = true;
+ queue_work(pm_wq, &dev->power.work);
+
+ return 0;
+}
+
+/**
+ * pm_suspend_timer_fn - Timer function for pm_schedule_suspend().
+ * @data: Device pointer passed by pm_schedule_suspend().
+ *
+ * Check if the time is right and execute __pm_request_suspend() in that case.
+ */
+static void pm_suspend_timer_fn(unsigned long data)
+{
+ struct device *dev = (struct device *)data;
+ unsigned long flags;
+ unsigned long expires;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ expires = dev->power.timer_expires;
+ /* If 'expire' is after 'jiffies' we've been called too early. */
+ if (expires > 0 && !time_after(expires, jiffies)) {
+ dev->power.timer_expires = 0;
+ __pm_request_suspend(dev);
+ }
+
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+
+/**
+ * pm_schedule_suspend - Set up a timer to submit a suspend request in future.
+ * @dev: Device to suspend.
+ * @delay: Time to wait before submitting a suspend request, in milliseconds.
+ */
+int pm_schedule_suspend(struct device *dev, unsigned int delay)
+{
+ unsigned long flags;
+ int retval = 0;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ if (dev->power.runtime_error) {
+ retval = -EINVAL;
+ goto out;
+ }
+
+ if (!delay) {
+ retval = __pm_request_suspend(dev);
+ goto out;
+ }
+
+ pm_runtime_deactivate_timer(dev);
+
+ if (dev->power.request_pending) {
+ /*
+ * Pending resume requests take precedence over us, but any
+ * other pending requests have to be canceled.
+ */
+ if (dev->power.request == RPM_REQ_RESUME) {
+ retval = -EAGAIN;
+ goto out;
+ }
+ dev->power.request = RPM_REQ_NONE;
+ }
+ if (dev->power.runtime_status == RPM_SUSPENDED)
+ retval = 1;
+ else if (dev->power.runtime_status == RPM_SUSPENDING)
+ retval = -EINPROGRESS;
+ else if (atomic_read(&dev->power.usage_count) > 0
+ || dev->power.disable_depth > 0)
+ retval = -EAGAIN;
+ else if (!pm_children_suspended(dev))
+ retval = -EBUSY;
+ if (retval)
+ goto out;
+
+ dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
+ mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
+
+ out:
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_schedule_suspend);
/**
- * dpm_runtime_resume - Power one device back on.
- * @dev: Device.
+ * pm_request_resume - Submit a resume request for given device.
+ * @dev: Device to resume.
*
- * Bring one device back to the on state by first powering it
- * on, then restoring state. We only operate on devices that aren't
- * already on.
- * FIXME: We need to handle devices that are in an unknown state.
+ * This function must be called under dev->power.lock with interrupts disabled.
*/
+static int __pm_request_resume(struct device *dev)
+{
+ int retval = 0;
+
+ if (dev->power.runtime_error)
+ return -EINVAL;
+
+ if (dev->power.runtime_status == RPM_ACTIVE)
+ retval = 1;
+ else if (dev->power.runtime_status == RPM_RESUMING)
+ retval = -EINPROGRESS;
+ else if (dev->power.disable_depth > 0)
+ retval = -EAGAIN;
+ if (retval < 0)
+ return retval;
+
+ pm_runtime_deactivate_timer(dev);
+
+ if (dev->power.request_pending) {
+ /* If non-resume request is pending, we can overtake it. */
+ dev->power.request = retval ? RPM_REQ_NONE : RPM_REQ_RESUME;
+ return retval;
+ } else if (retval) {
+ return retval;
+ }
-void dpm_runtime_resume(struct device * dev)
+ dev->power.request = RPM_REQ_RESUME;
+ dev->power.request_pending = true;
+ queue_work(pm_wq, &dev->power.work);
+
+ return retval;
+}
+
+/**
+ * pm_request_resume - Submit a resume request for given device.
+ * @dev: Device to resume.
+ */
+int pm_request_resume(struct device *dev)
{
- down(&dpm_sem);
- runtime_resume(dev);
- up(&dpm_sem);
+ unsigned long flags;
+ int retval;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+ retval = __pm_request_resume(dev);
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ return retval;
}
-EXPORT_SYMBOL(dpm_runtime_resume);
+EXPORT_SYMBOL_GPL(pm_request_resume);
+/**
+ * __pm_runtime_get - Reference count a device and wake it up, if necessary.
+ * @dev: Device to handle.
+ * @sync: If set and the device is suspended, resume it synchronously.
+ *
+ * Increment the usage count of the device and if it was zero previously,
+ * resume it or submit a resume request for it, depending on the value of @sync.
+ */
+int __pm_runtime_get(struct device *dev, bool sync)
+{
+ int retval = 1;
+
+ if (atomic_add_return(1, &dev->power.usage_count) == 1)
+ retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_get);
/**
- * dpm_runtime_suspend - Put one device in low-power state.
- * @dev: Device.
- * @state: State to enter.
+ * __pm_runtime_put - Decrement the device's usage counter and notify its bus.
+ * @dev: Device to handle.
+ * @sync: If the device's bus type is to be notified, do that synchronously.
+ *
+ * Decrement the usage count of the device and if it reaches zero, carry out a
+ * synchronous idle notification or submit an idle notification request for it,
+ * depending on the value of @sync.
*/
+int __pm_runtime_put(struct device *dev, bool sync)
+{
+ int retval = 0;
-int dpm_runtime_suspend(struct device * dev, pm_message_t state)
+ if (atomic_dec_and_test(&dev->power.usage_count))
+ retval = sync ? pm_runtime_idle(dev) : pm_request_idle(dev);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_put);
+
+/**
+ * __pm_runtime_set_status - Set run-time PM status of a device.
+ * @dev: Device to handle.
+ * @status: New run-time PM status of the device.
+ *
+ * If run-time PM of the device is disabled or its power.runtime_error field is
+ * different from zero, the status may be changed either to RPM_ACTIVE, or to
+ * RPM_SUSPENDED, as long as that reflects the actual state of the device.
+ * However, if the device has a parent and the parent is not active, and the
+ * parent's power.ignore_children flag is unset, the device's status cannot be
+ * set to RPM_ACTIVE, so -EBUSY is returned in that case.
+ *
+ * If successful, __pm_runtime_set_status() clears the power.runtime_error field
+ * and the device parent's counter of unsuspended children is modified to
+ * reflect the new status. If the new status is RPM_SUSPENDED, an idle
+ * notification request for the parent is submitted.
+ */
+int __pm_runtime_set_status(struct device *dev, unsigned int status)
{
+ struct device *parent = dev->parent;
+ unsigned long flags;
+ bool notify_parent = false;
int error = 0;
- down(&dpm_sem);
- if (dev->power.power_state.event == state.event)
- goto Done;
+ if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
+ return -EINVAL;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
- if (dev->power.power_state.event)
- runtime_resume(dev);
+ if (!dev->power.runtime_error && !dev->power.disable_depth) {
+ error = -EAGAIN;
+ goto out;
+ }
+
+ if (dev->power.runtime_status == status)
+ goto out_set;
+
+ if (status == RPM_SUSPENDED) {
+ /* It always is possible to set the status to 'suspended'. */
+ if (parent) {
+ atomic_add_unless(&parent->power.child_count, -1, 0);
+ notify_parent = !parent->power.ignore_children;
+ }
+ goto out_set;
+ }
+
+ if (parent) {
+ spin_lock_irq(&parent->power.lock);
+
+ /*
+ * It is invalid to put an active child under a parent that is
+ * not active, has run-time PM enabled and the
+ * 'power.ignore_children' flag unset.
+ */
+ if (!parent->power.disable_depth
+ && !parent->power.ignore_children
+ && parent->power.runtime_status != RPM_ACTIVE) {
+ error = -EBUSY;
+ } else {
+ if (dev->power.runtime_status == RPM_SUSPENDED)
+ atomic_inc(&parent->power.child_count);
+ }
+
+ spin_unlock_irq(&parent->power.lock);
+
+ if (error)
+ goto out;
+ }
+
+ out_set:
+ dev->power.runtime_status = status;
+ dev->power.runtime_error = 0;
+ out:
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+
+ if (notify_parent)
+ pm_request_idle(parent);
- if (!(error = suspend_device(dev, state)))
- dev->power.power_state = state;
- Done:
- up(&dpm_sem);
return error;
}
+EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
+
+/**
+ * __pm_runtime_barrier - Cancel pending requests and wait for completions.
+ * @dev: Device to handle.
+ *
+ * Flush all pending requests for the device from pm_wq and wait for all
+ * run-time PM operations involving the device in progress to complete.
+ *
+ * Should be called under dev->power.lock with interrupts disabled.
+ */
+static void __pm_runtime_barrier(struct device *dev)
+{
+ pm_runtime_deactivate_timer(dev);
+
+ if (dev->power.request_pending) {
+ dev->power.request = RPM_REQ_NONE;
+ spin_unlock_irq(&dev->power.lock);
+
+ cancel_work_sync(&dev->power.work);
+
+ spin_lock_irq(&dev->power.lock);
+ dev->power.request_pending = false;
+ }
+ if (dev->power.runtime_status == RPM_SUSPENDING
+ || dev->power.runtime_status == RPM_RESUMING
+ || dev->power.idle_notification) {
+ DEFINE_WAIT(wait);
+
+ /* Suspend, wake-up or idle notification in progress. */
+ for (;;) {
+ prepare_to_wait(&dev->power.wait_queue, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (dev->power.runtime_status != RPM_SUSPENDING
+ && dev->power.runtime_status != RPM_RESUMING
+ && !dev->power.idle_notification)
+ break;
+ spin_unlock_irq(&dev->power.lock);
+
+ schedule();
+
+ spin_lock_irq(&dev->power.lock);
+ }
+ finish_wait(&dev->power.wait_queue, &wait);
+ }
+}
+
+/**
+ * pm_runtime_barrier - Flush pending requests and wait for completions.
+ * @dev: Device to handle.
+ *
+ * Prevent the device from being suspended by incrementing its usage counter and
+ * if there's a pending resume request for the device, wake the device up.
+ * Next, make sure that all pending requests for the device have been flushed
+ * from pm_wq and wait for all run-time PM operations involving the device in
+ * progress to complete.
+ *
+ * Return value:
+ * 1, if there was a resume request pending and the device had to be woken up,
+ * 0, otherwise
+ */
+int pm_runtime_barrier(struct device *dev)
+{
+ int retval = 0;
+
+ pm_runtime_get_noresume(dev);
+ spin_lock_irq(&dev->power.lock);
+
+ if (dev->power.request_pending
+ && dev->power.request == RPM_REQ_RESUME) {
+ __pm_runtime_resume(dev, false);
+ retval = 1;
+ }
+
+ __pm_runtime_barrier(dev);
+
+ spin_unlock_irq(&dev->power.lock);
+ pm_runtime_put_noidle(dev);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(pm_runtime_barrier);
-#if 0
/**
- * dpm_set_power_state - Update power_state field.
- * @dev: Device.
- * @state: Power state device is in.
+ * __pm_runtime_disable - Disable run-time PM of a device.
+ * @dev: Device to handle.
+ * @check_resume: If set, check if there's a resume request for the device.
*
- * This is an update mechanism for drivers to notify the core
- * what power state a device is in. Device probing code may not
- * always be able to tell, but we need accurate information to
- * work reliably.
+ * Increment power.disable_depth for the device and if was zero previously,
+ * cancel all pending run-time PM requests for the device and wait for all
+ * operations in progress to complete. The device can be either active or
+ * suspended after its run-time PM has been disabled.
+ *
+ * If @check_resume is set and there's a resume request pending when
+ * __pm_runtime_disable() is called and power.disable_depth is zero, the
+ * function will wake up the device before disabling its run-time PM.
*/
-void dpm_set_power_state(struct device * dev, pm_message_t state)
+void __pm_runtime_disable(struct device *dev, bool check_resume)
{
- down(&dpm_sem);
- dev->power.power_state = state;
- up(&dpm_sem);
+ spin_lock_irq(&dev->power.lock);
+
+ if (dev->power.disable_depth > 0) {
+ dev->power.disable_depth++;
+ goto out;
+ }
+
+ /*
+ * Wake up the device if there's a resume request pending, because that
+ * means there probably is some I/O to process and disabling run-time PM
+ * shouldn't prevent the device from processing the I/O.
+ */
+ if (check_resume && dev->power.request_pending
+ && dev->power.request == RPM_REQ_RESUME) {
+ /*
+ * Prevent suspends and idle notifications from being carried
+ * out after we have woken up the device.
+ */
+ pm_runtime_get_noresume(dev);
+
+ __pm_runtime_resume(dev, false);
+
+ pm_runtime_put_noidle(dev);
+ }
+
+ if (!dev->power.disable_depth++)
+ __pm_runtime_barrier(dev);
+
+ out:
+ spin_unlock_irq(&dev->power.lock);
+}
+EXPORT_SYMBOL_GPL(__pm_runtime_disable);
+
+/**
+ * pm_runtime_enable - Enable run-time PM of a device.
+ * @dev: Device to handle.
+ */
+void pm_runtime_enable(struct device *dev)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ if (dev->power.disable_depth > 0)
+ dev->power.disable_depth--;
+ else
+ dev_warn(dev, "Unbalanced %s!\n", __func__);
+
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+EXPORT_SYMBOL_GPL(pm_runtime_enable);
+
+/**
+ * pm_runtime_init - Initialize run-time PM fields in given device object.
+ * @dev: Device object to initialize.
+ */
+void pm_runtime_init(struct device *dev)
+{
+ spin_lock_init(&dev->power.lock);
+
+ dev->power.runtime_status = RPM_SUSPENDED;
+ dev->power.idle_notification = false;
+
+ dev->power.disable_depth = 1;
+ atomic_set(&dev->power.usage_count, 0);
+
+ dev->power.runtime_error = 0;
+
+ atomic_set(&dev->power.child_count, 0);
+ pm_suspend_ignore_children(dev, false);
+
+ dev->power.request_pending = false;
+ dev->power.request = RPM_REQ_NONE;
+ dev->power.deferred_resume = false;
+ INIT_WORK(&dev->power.work, pm_runtime_work);
+
+ dev->power.timer_expires = 0;
+ setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
+ (unsigned long)dev);
+
+ init_waitqueue_head(&dev->power.wait_queue);
+}
+
+/**
+ * pm_runtime_remove - Prepare for removing a device from device hierarchy.
+ * @dev: Device object being removed from device hierarchy.
+ */
+void pm_runtime_remove(struct device *dev)
+{
+ __pm_runtime_disable(dev, false);
+
+ /* Change the status back to 'suspended' to match the initial status. */
+ if (dev->power.runtime_status == RPM_ACTIVE)
+ pm_runtime_set_suspended(dev);
}
-#endif /* 0 */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff