diff options
Diffstat (limited to 'drivers/base/power/runtime.c')
| -rw-r--r-- | drivers/base/power/runtime.c | 1011 |
1 files changed, 1011 insertions, 0 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c new file mode 100644 index 000000000000..38556f6cc22d --- /dev/null +++ b/drivers/base/power/runtime.c @@ -0,0 +1,1011 @@ +/* + * drivers/base/power/runtime.c - Helper functions for device run-time PM + * + * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. + * + * This file is released under the GPLv2. + */ + +#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); + +/** + * 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; + + dev_dbg(dev, "__pm_runtime_idle()!\n"); + + 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: + dev_dbg(dev, "__pm_runtime_idle() returns %d!\n", retval); + + 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) +{ + 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); + +/** + * pm_request_resume - Submit a resume request for given device. + * @dev: Device to resume. + * + * 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; + } + + 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) +{ + 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_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); + +/** + * __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; + + 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; + + if (status != RPM_ACTIVE && status != RPM_SUSPENDED) + return -EINVAL; + + spin_lock_irqsave(&dev->power.lock, flags); + + 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); + + 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); + +/** + * __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. + * + * 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 __pm_runtime_disable(struct device *dev, bool check_resume) +{ + 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); +} |