* and add it to the list of power-controlled devices. sysfs entries for
* controlling device power management will also be added.
*
- * A different set of lists than the global subsystem list are used to
- * keep track of power info because we use different lists to hold
- * devices based on what stage of the power management process they
- * are in. The power domain dependencies may also differ from the
- * ancestral dependencies that the subsystem list maintains.
+ * A separate list is used for keeping track of power info, because the power
+ * domain dependencies may differ from the ancestral dependencies that the
+ * subsystem list maintains.
*/
#include <linux/device.h>
#include "power.h"
/*
- * The entries in the dpm_active list are in a depth first order, simply
+ * The entries in the dpm_list list are in a depth first order, simply
* because children are guaranteed to be discovered after parents, and
* are inserted at the back of the list on discovery.
*
- * All the other lists are kept in the same order, for consistency.
- * However the lists aren't always traversed in the same order.
- * Semaphores must be acquired from the top (i.e., front) down
- * and released in the opposite order. Devices must be suspended
- * from the bottom (i.e., end) up and resumed in the opposite order.
- * That way no parent will be suspended while it still has an active
- * child.
- *
* Since device_pm_add() may be called with a device semaphore held,
* we must never try to acquire a device semaphore while holding
* dpm_list_mutex.
*/
-LIST_HEAD(dpm_active);
-static LIST_HEAD(dpm_off);
-static LIST_HEAD(dpm_off_irq);
+LIST_HEAD(dpm_list);
static DEFINE_MUTEX(dpm_list_mtx);
-/* 'true' if all devices have been suspended, protected by dpm_list_mtx */
-static bool all_sleeping;
+/*
+ * Set once the preparation of devices for a PM transition has started, reset
+ * before starting to resume devices. Protected by dpm_list_mtx.
+ */
+static bool transition_started;
+
+/**
+ * device_pm_lock - lock the list of active devices used by the PM core
+ */
+void device_pm_lock(void)
+{
+ mutex_lock(&dpm_list_mtx);
+}
+
+/**
+ * device_pm_unlock - unlock the list of active devices used by the PM core
+ */
+void device_pm_unlock(void)
+{
+ mutex_unlock(&dpm_list_mtx);
+}
/**
* device_pm_add - add a device to the list of active devices
dev->bus ? dev->bus->name : "No Bus",
kobject_name(&dev->kobj));
mutex_lock(&dpm_list_mtx);
- if ((dev->parent && dev->parent->power.sleeping) || all_sleeping) {
- if (dev->parent->power.sleeping)
- dev_warn(dev, "parent %s is sleeping\n",
+ if (dev->parent) {
+ if (dev->parent->power.status >= DPM_SUSPENDING) {
+ dev_warn(dev, "parent %s is sleeping, will not add\n",
dev->parent->bus_id);
- else
- dev_warn(dev, "all devices are sleeping\n");
+ WARN_ON(true);
+ }
+ } else if (transition_started) {
+ /*
+ * We refuse to register parentless devices while a PM
+ * transition is in progress in order to avoid leaving them
+ * unhandled down the road
+ */
WARN_ON(true);
}
error = dpm_sysfs_add(dev);
- if (!error)
- list_add_tail(&dev->power.entry, &dpm_active);
+ if (!error) {
+ dev->power.status = DPM_ON;
+ list_add_tail(&dev->power.entry, &dpm_list);
+ }
mutex_unlock(&dpm_list_mtx);
return error;
}
mutex_unlock(&dpm_list_mtx);
}
+/**
+ * pm_op - execute the PM operation appropiate for given PM event
+ * @dev: Device.
+ * @ops: PM operations to choose from.
+ * @state: PM transition of the system being carried out.
+ */
+static int pm_op(struct device *dev, struct pm_ops *ops, pm_message_t state)
+{
+ int error = 0;
+
+ switch (state.event) {
+#ifdef CONFIG_SUSPEND
+ case PM_EVENT_SUSPEND:
+ if (ops->suspend) {
+ error = ops->suspend(dev);
+ suspend_report_result(ops->suspend, error);
+ }
+ break;
+ case PM_EVENT_RESUME:
+ if (ops->resume) {
+ error = ops->resume(dev);
+ suspend_report_result(ops->resume, error);
+ }
+ break;
+#endif /* CONFIG_SUSPEND */
+#ifdef CONFIG_HIBERNATION
+ case PM_EVENT_FREEZE:
+ case PM_EVENT_QUIESCE:
+ if (ops->freeze) {
+ error = ops->freeze(dev);
+ suspend_report_result(ops->freeze, error);
+ }
+ break;
+ case PM_EVENT_HIBERNATE:
+ if (ops->poweroff) {
+ error = ops->poweroff(dev);
+ suspend_report_result(ops->poweroff, error);
+ }
+ break;
+ case PM_EVENT_THAW:
+ case PM_EVENT_RECOVER:
+ if (ops->thaw) {
+ error = ops->thaw(dev);
+ suspend_report_result(ops->thaw, error);
+ }
+ break;
+ case PM_EVENT_RESTORE:
+ if (ops->restore) {
+ error = ops->restore(dev);
+ suspend_report_result(ops->restore, error);
+ }
+ break;
+#endif /* CONFIG_HIBERNATION */
+ default:
+ error = -EINVAL;
+ }
+ return error;
+}
+
+/**
+ * pm_noirq_op - execute the PM operation appropiate for given PM event
+ * @dev: Device.
+ * @ops: PM operations to choose from.
+ * @state: PM transition of the system being carried out.
+ *
+ * The operation is executed with interrupts disabled by the only remaining
+ * functional CPU in the system.
+ */
+static int pm_noirq_op(struct device *dev, struct pm_ext_ops *ops,
+ pm_message_t state)
+{
+ int error = 0;
+
+ switch (state.event) {
+#ifdef CONFIG_SUSPEND
+ case PM_EVENT_SUSPEND:
+ if (ops->suspend_noirq) {
+ error = ops->suspend_noirq(dev);
+ suspend_report_result(ops->suspend_noirq, error);
+ }
+ break;
+ case PM_EVENT_RESUME:
+ if (ops->resume_noirq) {
+ error = ops->resume_noirq(dev);
+ suspend_report_result(ops->resume_noirq, error);
+ }
+ break;
+#endif /* CONFIG_SUSPEND */
+#ifdef CONFIG_HIBERNATION
+ case PM_EVENT_FREEZE:
+ case PM_EVENT_QUIESCE:
+ if (ops->freeze_noirq) {
+ error = ops->freeze_noirq(dev);
+ suspend_report_result(ops->freeze_noirq, error);
+ }
+ break;
+ case PM_EVENT_HIBERNATE:
+ if (ops->poweroff_noirq) {
+ error = ops->poweroff_noirq(dev);
+ suspend_report_result(ops->poweroff_noirq, error);
+ }
+ break;
+ case PM_EVENT_THAW:
+ case PM_EVENT_RECOVER:
+ if (ops->thaw_noirq) {
+ error = ops->thaw_noirq(dev);
+ suspend_report_result(ops->thaw_noirq, error);
+ }
+ break;
+ case PM_EVENT_RESTORE:
+ if (ops->restore_noirq) {
+ error = ops->restore_noirq(dev);
+ suspend_report_result(ops->restore_noirq, error);
+ }
+ break;
+#endif /* CONFIG_HIBERNATION */
+ default:
+ error = -EINVAL;
+ }
+ return error;
+}
+
+static char *pm_verb(int event)
+{
+ switch (event) {
+ case PM_EVENT_SUSPEND:
+ return "suspend";
+ case PM_EVENT_RESUME:
+ return "resume";
+ case PM_EVENT_FREEZE:
+ return "freeze";
+ case PM_EVENT_QUIESCE:
+ return "quiesce";
+ case PM_EVENT_HIBERNATE:
+ return "hibernate";
+ case PM_EVENT_THAW:
+ return "thaw";
+ case PM_EVENT_RESTORE:
+ return "restore";
+ case PM_EVENT_RECOVER:
+ return "recover";
+ default:
+ return "(unknown PM event)";
+ }
+}
+
+static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
+{
+ dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
+ ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
+ ", may wakeup" : "");
+}
+
+static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
+ int error)
+{
+ printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
+ kobject_name(&dev->kobj), pm_verb(state.event), info, error);
+}
+
/*------------------------- Resume routines -------------------------*/
/**
- * resume_device_early - Power on one device (early resume).
+ * resume_device_noirq - Power on one device (early resume).
* @dev: Device.
+ * @state: PM transition of the system being carried out.
*
* Must be called with interrupts disabled.
*/
-static int resume_device_early(struct device *dev)
+static int resume_device_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
- if (dev->bus && dev->bus->resume_early) {
- dev_dbg(dev, "EARLY resume\n");
+ if (!dev->bus)
+ goto End;
+
+ if (dev->bus->pm) {
+ pm_dev_dbg(dev, state, "EARLY ");
+ error = pm_noirq_op(dev, dev->bus->pm, state);
+ } else if (dev->bus->resume_early) {
+ pm_dev_dbg(dev, state, "legacy EARLY ");
error = dev->bus->resume_early(dev);
}
-
+ End:
TRACE_RESUME(error);
return error;
}
/**
* dpm_power_up - Power on all regular (non-sysdev) devices.
+ * @state: PM transition of the system being carried out.
*
- * Walk the dpm_off_irq list and power each device up. This
- * is used for devices that required they be powered down with
- * interrupts disabled. As devices are powered on, they are moved
- * to the dpm_off list.
+ * Execute the appropriate "noirq resume" callback for all devices marked
+ * as DPM_OFF_IRQ.
*
* Must be called with interrupts disabled and only one CPU running.
*/
-static void dpm_power_up(void)
+static void dpm_power_up(pm_message_t state)
{
+ struct device *dev;
- while (!list_empty(&dpm_off_irq)) {
- struct list_head *entry = dpm_off_irq.next;
- struct device *dev = to_device(entry);
+ list_for_each_entry(dev, &dpm_list, power.entry)
+ if (dev->power.status > DPM_OFF) {
+ int error;
- list_move_tail(entry, &dpm_off);
- resume_device_early(dev);
- }
+ dev->power.status = DPM_OFF;
+ error = resume_device_noirq(dev, state);
+ if (error)
+ pm_dev_err(dev, state, " early", error);
+ }
}
/**
* device_power_up - Turn on all devices that need special attention.
+ * @state: PM transition of the system being carried out.
*
* Power on system devices, then devices that required we shut them down
* with interrupts disabled.
*
* Must be called with interrupts disabled.
*/
-void device_power_up(void)
+void device_power_up(pm_message_t state)
{
sysdev_resume();
- dpm_power_up();
+ dpm_power_up(state);
}
EXPORT_SYMBOL_GPL(device_power_up);
/**
* resume_device - Restore state for one device.
* @dev: Device.
- *
+ * @state: PM transition of the system being carried out.
*/
-static int resume_device(struct device *dev)
+static int resume_device(struct device *dev, pm_message_t state)
{
int error = 0;
down(&dev->sem);
- if (dev->bus && dev->bus->resume) {
- dev_dbg(dev,"resuming\n");
- error = dev->bus->resume(dev);
+ if (dev->bus) {
+ if (dev->bus->pm) {
+ pm_dev_dbg(dev, state, "");
+ error = pm_op(dev, &dev->bus->pm->base, state);
+ } else if (dev->bus->resume) {
+ pm_dev_dbg(dev, state, "legacy ");
+ error = dev->bus->resume(dev);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->type && dev->type->resume) {
- dev_dbg(dev,"resuming\n");
- error = dev->type->resume(dev);
+ if (dev->type) {
+ if (dev->type->pm) {
+ pm_dev_dbg(dev, state, "type ");
+ error = pm_op(dev, dev->type->pm, state);
+ } else if (dev->type->resume) {
+ pm_dev_dbg(dev, state, "legacy type ");
+ error = dev->type->resume(dev);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->class && dev->class->resume) {
- dev_dbg(dev,"class resume\n");
- error = dev->class->resume(dev);
+ if (dev->class) {
+ if (dev->class->pm) {
+ pm_dev_dbg(dev, state, "class ");
+ error = pm_op(dev, dev->class->pm, state);
+ } else if (dev->class->resume) {
+ pm_dev_dbg(dev, state, "legacy class ");
+ error = dev->class->resume(dev);
+ }
}
-
+ End:
up(&dev->sem);
TRACE_RESUME(error);
/**
* dpm_resume - Resume every device.
+ * @state: PM transition of the system being carried out.
*
- * Resume the devices that have either not gone through
- * the late suspend, or that did go through it but also
- * went through the early resume.
+ * Execute the appropriate "resume" callback for all devices the status of
+ * which indicates that they are inactive.
+ */
+static void dpm_resume(pm_message_t state)
+{
+ struct list_head list;
+
+ INIT_LIST_HEAD(&list);
+ mutex_lock(&dpm_list_mtx);
+ transition_started = false;
+ while (!list_empty(&dpm_list)) {
+ struct device *dev = to_device(dpm_list.next);
+
+ get_device(dev);
+ if (dev->power.status >= DPM_OFF) {
+ int error;
+
+ dev->power.status = DPM_RESUMING;
+ mutex_unlock(&dpm_list_mtx);
+
+ error = resume_device(dev, state);
+
+ mutex_lock(&dpm_list_mtx);
+ if (error)
+ pm_dev_err(dev, state, "", error);
+ } else if (dev->power.status == DPM_SUSPENDING) {
+ /* Allow new children of the device to be registered */
+ dev->power.status = DPM_RESUMING;
+ }
+ if (!list_empty(&dev->power.entry))
+ list_move_tail(&dev->power.entry, &list);
+ put_device(dev);
+ }
+ list_splice(&list, &dpm_list);
+ mutex_unlock(&dpm_list_mtx);
+}
+
+/**
+ * complete_device - Complete a PM transition for given device
+ * @dev: Device.
+ * @state: PM transition of the system being carried out.
+ */
+static void complete_device(struct device *dev, pm_message_t state)
+{
+ down(&dev->sem);
+
+ if (dev->class && dev->class->pm && dev->class->pm->complete) {
+ pm_dev_dbg(dev, state, "completing class ");
+ dev->class->pm->complete(dev);
+ }
+
+ if (dev->type && dev->type->pm && dev->type->pm->complete) {
+ pm_dev_dbg(dev, state, "completing type ");
+ dev->type->pm->complete(dev);
+ }
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->base.complete) {
+ pm_dev_dbg(dev, state, "completing ");
+ dev->bus->pm->base.complete(dev);
+ }
+
+ up(&dev->sem);
+}
+
+/**
+ * dpm_complete - Complete a PM transition for all devices.
+ * @state: PM transition of the system being carried out.
*
- * Take devices from the dpm_off_list, resume them,
- * and put them on the dpm_locked list.
+ * Execute the ->complete() callbacks for all devices that are not marked
+ * as DPM_ON.
*/
-static void dpm_resume(void)
+static void dpm_complete(pm_message_t state)
{
+ struct list_head list;
+
+ INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
- all_sleeping = false;
- while(!list_empty(&dpm_off)) {
- struct list_head *entry = dpm_off.next;
- struct device *dev = to_device(entry);
+ while (!list_empty(&dpm_list)) {
+ struct device *dev = to_device(dpm_list.prev);
- list_move_tail(entry, &dpm_active);
- dev->power.sleeping = false;
- mutex_unlock(&dpm_list_mtx);
- resume_device(dev);
- mutex_lock(&dpm_list_mtx);
+ get_device(dev);
+ if (dev->power.status > DPM_ON) {
+ dev->power.status = DPM_ON;
+ mutex_unlock(&dpm_list_mtx);
+
+ complete_device(dev, state);
+
+ mutex_lock(&dpm_list_mtx);
+ }
+ if (!list_empty(&dev->power.entry))
+ list_move(&dev->power.entry, &list);
+ put_device(dev);
}
+ list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
}
/**
* device_resume - Restore state of each device in system.
+ * @state: PM transition of the system being carried out.
*
* Resume all the devices, unlock them all, and allow new
* devices to be registered once again.
*/
-void device_resume(void)
+void device_resume(pm_message_t state)
{
might_sleep();
- dpm_resume();
+ dpm_resume(state);
+ dpm_complete(state);
}
EXPORT_SYMBOL_GPL(device_resume);
/*------------------------- Suspend routines -------------------------*/
-static inline char *suspend_verb(u32 event)
+/**
+ * resume_event - return a PM message representing the resume event
+ * corresponding to given sleep state.
+ * @sleep_state: PM message representing a sleep state.
+ */
+static pm_message_t resume_event(pm_message_t sleep_state)
{
- switch (event) {
- case PM_EVENT_SUSPEND: return "suspend";
- case PM_EVENT_FREEZE: return "freeze";
- case PM_EVENT_PRETHAW: return "prethaw";
- default: return "(unknown suspend event)";
+ switch (sleep_state.event) {
+ case PM_EVENT_SUSPEND:
+ return PMSG_RESUME;
+ case PM_EVENT_FREEZE:
+ case PM_EVENT_QUIESCE:
+ return PMSG_RECOVER;
+ case PM_EVENT_HIBERNATE:
+ return PMSG_RESTORE;
}
-}
-
-static void
-suspend_device_dbg(struct device *dev, pm_message_t state, char *info)
-{
- dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event),
- ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ?
- ", may wakeup" : "");
+ return PMSG_ON;
}
/**
- * suspend_device_late - Shut down one device (late suspend).
+ * suspend_device_noirq - Shut down one device (late suspend).
* @dev: Device.
- * @state: Power state device is entering.
+ * @state: PM transition of the system being carried out.
*
* This is called with interrupts off and only a single CPU running.
*/
-static int suspend_device_late(struct device *dev, pm_message_t state)
+static int suspend_device_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
- if (dev->bus && dev->bus->suspend_late) {
- suspend_device_dbg(dev, state, "LATE ");
+ if (!dev->bus)
+ return 0;
+
+ if (dev->bus->pm) {
+ pm_dev_dbg(dev, state, "LATE ");
+ error = pm_noirq_op(dev, dev->bus->pm, state);
+ } else if (dev->bus->suspend_late) {
+ pm_dev_dbg(dev, state, "legacy LATE ");
error = dev->bus->suspend_late(dev, state);
suspend_report_result(dev->bus->suspend_late, error);
}
/**
* device_power_down - Shut down special devices.
- * @state: Power state to enter.
+ * @state: PM transition of the system being carried out.
*
- * Power down devices that require interrupts to be disabled
- * and move them from the dpm_off list to the dpm_off_irq list.
+ * Power down devices that require interrupts to be disabled.
* Then power down system devices.
*
* Must be called with interrupts disabled and only one CPU running.
*/
int device_power_down(pm_message_t state)
{
+ struct device *dev;
int error = 0;
- while (!list_empty(&dpm_off)) {
- struct list_head *entry = dpm_off.prev;
- struct device *dev = to_device(entry);
-
- error = suspend_device_late(dev, state);
+ list_for_each_entry_reverse(dev, &dpm_list, power.entry) {
+ error = suspend_device_noirq(dev, state);
if (error) {
- printk(KERN_ERR "Could not power down device %s: "
- "error %d\n",
- kobject_name(&dev->kobj), error);
+ pm_dev_err(dev, state, " late", error);
break;
}
- if (!list_empty(&dev->power.entry))
- list_move(&dev->power.entry, &dpm_off_irq);
+ dev->power.status = DPM_OFF_IRQ;
}
-
if (!error)
error = sysdev_suspend(state);
if (error)
- dpm_power_up();
+ dpm_power_up(resume_event(state));
return error;
}
EXPORT_SYMBOL_GPL(device_power_down);
/**
* suspend_device - Save state of one device.
* @dev: Device.
- * @state: Power state device is entering.
+ * @state: PM transition of the system being carried out.
*/
static int suspend_device(struct device *dev, pm_message_t state)
{
down(&dev->sem);
- if (dev->class && dev->class->suspend) {
- suspend_device_dbg(dev, state, "class ");
- error = dev->class->suspend(dev, state);
- suspend_report_result(dev->class->suspend, error);
+ if (dev->class) {
+ if (dev->class->pm) {
+ pm_dev_dbg(dev, state, "class ");
+ error = pm_op(dev, dev->class->pm, state);
+ } else if (dev->class->suspend) {
+ pm_dev_dbg(dev, state, "legacy class ");
+ error = dev->class->suspend(dev, state);
+ suspend_report_result(dev->class->suspend, error);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->type && dev->type->suspend) {
- suspend_device_dbg(dev, state, "type ");
- error = dev->type->suspend(dev, state);
- suspend_report_result(dev->type->suspend, error);
+ if (dev->type) {
+ if (dev->type->pm) {
+ pm_dev_dbg(dev, state, "type ");
+ error = pm_op(dev, dev->type->pm, state);
+ } else if (dev->type->suspend) {
+ pm_dev_dbg(dev, state, "legacy type ");
+ error = dev->type->suspend(dev, state);
+ suspend_report_result(dev->type->suspend, error);
+ }
+ if (error)
+ goto End;
}
- if (!error && dev->bus && dev->bus->suspend) {
- suspend_device_dbg(dev, state, "");
- error = dev->bus->suspend(dev, state);
- suspend_report_result(dev->bus->suspend, error);
+ if (dev->bus) {
+ if (dev->bus->pm) {
+ pm_dev_dbg(dev, state, "");
+ error = pm_op(dev, &dev->bus->pm->base, state);
+ } else if (dev->bus->suspend) {
+ pm_dev_dbg(dev, state, "legacy ");
+ error = dev->bus->suspend(dev, state);
+ suspend_report_result(dev->bus->suspend, error);
+ }
}
-
+ End:
up(&dev->sem);
return error;
/**
* dpm_suspend - Suspend every device.
- * @state: Power state to put each device in.
+ * @state: PM transition of the system being carried out.
*
- * Walk the dpm_locked list. Suspend each device and move it
- * to the dpm_off list.
- *
- * (For historical reasons, if it returns -EAGAIN, that used to mean
- * that the device would be called again with interrupts disabled.
- * These days, we use the "suspend_late()" callback for that, so we
- * print a warning and consider it an error).
+ * Execute the appropriate "suspend" callbacks for all devices.
*/
static int dpm_suspend(pm_message_t state)
{
+ struct list_head list;
int error = 0;
+ INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
- while (!list_empty(&dpm_active)) {
- struct list_head *entry = dpm_active.prev;
- struct device *dev = to_device(entry);
-
- WARN_ON(dev->parent && dev->parent->power.sleeping);
+ while (!list_empty(&dpm_list)) {
+ struct device *dev = to_device(dpm_list.prev);
- dev->power.sleeping = true;
+ get_device(dev);
mutex_unlock(&dpm_list_mtx);
+
error = suspend_device(dev, state);
+
mutex_lock(&dpm_list_mtx);
if (error) {
- printk(KERN_ERR "Could not suspend device %s: "
- "error %d%s\n",
- kobject_name(&dev->kobj),
- error,
- (error == -EAGAIN ?
- " (please convert to suspend_late)" :
- ""));
- dev->power.sleeping = false;
+ pm_dev_err(dev, state, "", error);
+ put_device(dev);
break;
}
+ dev->power.status = DPM_OFF;
if (!list_empty(&dev->power.entry))
- list_move(&dev->power.entry, &dpm_off);
+ list_move(&dev->power.entry, &list);
+ put_device(dev);
}
- if (!error)
- all_sleeping = true;
+ list_splice(&list, dpm_list.prev);
mutex_unlock(&dpm_list_mtx);
+ return error;
+}
+
+/**
+ * prepare_device - Execute the ->prepare() callback(s) for given device.
+ * @dev: Device.
+ * @state: PM transition of the system being carried out.
+ */
+static int prepare_device(struct device *dev, pm_message_t state)
+{
+ int error = 0;
+
+ down(&dev->sem);
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->base.prepare) {
+ pm_dev_dbg(dev, state, "preparing ");
+ error = dev->bus->pm->base.prepare(dev);
+ suspend_report_result(dev->bus->pm->base.prepare, error);
+ if (error)
+ goto End;
+ }
+
+ if (dev->type && dev->type->pm && dev->type->pm->prepare) {
+ pm_dev_dbg(dev, state, "preparing type ");
+ error = dev->type->pm->prepare(dev);
+ suspend_report_result(dev->type->pm->prepare, error);
+ if (error)
+ goto End;
+ }
+
+ if (dev->class && dev->class->pm && dev->class->pm->prepare) {
+ pm_dev_dbg(dev, state, "preparing class ");
+ error = dev->class->pm->prepare(dev);
+ suspend_report_result(dev->class->pm->prepare, error);
+ }
+ End:
+ up(&dev->sem);
+
+ return error;
+}
+/**
+ * dpm_prepare - Prepare all devices for a PM transition.
+ * @state: PM transition of the system being carried out.
+ *
+ * Execute the ->prepare() callback for all devices.
+ */
+static int dpm_prepare(pm_message_t state)
+{
+ struct list_head list;
+ int error = 0;
+
+ INIT_LIST_HEAD(&list);
+ mutex_lock(&dpm_list_mtx);
+ transition_started = true;
+ while (!list_empty(&dpm_list)) {
+ struct device *dev = to_device(dpm_list.next);
+
+ get_device(dev);
+ dev->power.status = DPM_PREPARING;
+ mutex_unlock(&dpm_list_mtx);
+
+ error = prepare_device(dev, state);
+
+ mutex_lock(&dpm_list_mtx);
+ if (error) {
+ dev->power.status = DPM_ON;
+ if (error == -EAGAIN) {
+ put_device(dev);
+ continue;
+ }
+ printk(KERN_ERR "PM: Failed to prepare device %s "
+ "for power transition: error %d\n",
+ kobject_name(&dev->kobj), error);
+ put_device(dev);
+ break;
+ }
+ dev->power.status = DPM_SUSPENDING;
+ if (!list_empty(&dev->power.entry))
+ list_move_tail(&dev->power.entry, &list);
+ put_device(dev);
+ }
+ list_splice(&list, &dpm_list);
+ mutex_unlock(&dpm_list_mtx);
return error;
}
/**
* device_suspend - Save state and stop all devices in system.
- * @state: new power management state
+ * @state: PM transition of the system being carried out.
*
- * Prevent new devices from being registered, then lock all devices
- * and suspend them.
+ * Prepare and suspend all devices.
*/
int device_suspend(pm_message_t state)
{
int error;
might_sleep();
- error = dpm_suspend(state);
+ error = dpm_prepare(state);
+ if (!error)
+ error = dpm_suspend(state);
if (error)
- device_resume();
+ device_resume(resume_event(state));
return error;
}
EXPORT_SYMBOL_GPL(device_suspend);
int event;
} pm_message_t;
-/*
+/**
+ * struct pm_ops - device PM callbacks
+ *
* Several driver power state transitions are externally visible, affecting
* the state of pending I/O queues and (for drivers that touch hardware)
* interrupts, wakeups, DMA, and other hardware state. There may also be
* to the rest of the driver stack (such as a driver that's ON gating off
* clocks which are not in active use).
*
+ * The externally visible transitions are handled with the help of the following
+ * callbacks included in this structure:
+ *
+ * @prepare: Prepare the device for the upcoming transition, but do NOT change
+ * its hardware state. Prevent new children of the device from being
+ * registered after @prepare() returns (the driver's subsystem and
+ * generally the rest of the kernel is supposed to prevent new calls to the
+ * probe method from being made too once @prepare() has succeeded). If
+ * @prepare() detects a situation it cannot handle (e.g. registration of a
+ * child already in progress), it may return -EAGAIN, so that the PM core
+ * can execute it once again (e.g. after the new child has been registered)
+ * to recover from the race condition. This method is executed for all
+ * kinds of suspend transitions and is followed by one of the suspend
+ * callbacks: @suspend(), @freeze(), or @poweroff().
+ * The PM core executes @prepare() for all devices before starting to
+ * execute suspend callbacks for any of them, so drivers may assume all of
+ * the other devices to be present and functional while @prepare() is being
+ * executed. In particular, it is safe to make GFP_KERNEL memory
+ * allocations from within @prepare(). However, drivers may NOT assume
+ * anything about the availability of the user space at that time and it
+ * is not correct to request firmware from within @prepare() (it's too
+ * late to do that). [To work around this limitation, drivers may
+ * register suspend and hibernation notifiers that are executed before the
+ * freezing of tasks.]
+ *
+ * @complete: Undo the changes made by @prepare(). This method is executed for
+ * all kinds of resume transitions, following one of the resume callbacks:
+ * @resume(), @thaw(), @restore(). Also called if the state transition
+ * fails before the driver's suspend callback (@suspend(), @freeze(),
+ * @poweroff()) can be executed (e.g. if the suspend callback fails for one
+ * of the other devices that the PM core has unsuccessfully attempted to
+ * suspend earlier).
+ * The PM core executes @complete() after it has executed the appropriate
+ * resume callback for all devices.
+ *
+ * @suspend: Executed before putting the system into a sleep state in which the
+ * contents of main memory are preserved. Quiesce the device, put it into
+ * a low power state appropriate for the upcoming system state (such as
+ * PCI_D3hot), and enable wakeup events as appropriate.
+ *
+ * @resume: Executed after waking the system up from a sleep state in which the
+ * contents of main memory were preserved. Put the device into the
+ * appropriate state, according to the information saved in memory by the
+ * preceding @suspend(). The driver starts working again, responding to
+ * hardware events and software requests. The hardware may have gone
+ * through a power-off reset, or it may have maintained state from the
+ * previous suspend() which the driver may rely on while resuming. On most
+ * platforms, there are no restrictions on availability of resources like
+ * clocks during @resume().
+ *
+ * @freeze: Hibernation-specific, executed before creating a hibernation image.
+ * Quiesce operations so that a consistent image can be created, but do NOT
+ * otherwise put the device into a low power device state and do NOT emit
+ * system wakeup events. Save in main memory the device settings to be
+ * used by @restore() during the subsequent resume from hibernation or by
+ * the subsequent @thaw(), if the creation of the image or the restoration
+ * of main memory contents from it fails.
+ *
+ * @thaw: Hibernation-specific, executed after creating a hibernation image OR
+ * if the creation of the image fails. Also executed after a failing
+ * attempt to restore the contents of main memory from such an image.
+ * Undo the changes made by the preceding @freeze(), so the device can be
+ * operated in the same way as immediately before the call to @freeze().
+ *
+ * @poweroff: Hibernation-specific, executed after saving a hibernation image.
+ * Quiesce the device, put it into a low power state appropriate for the
+ * upcoming system state (such as PCI_D3hot), and enable wakeup events as
+ * appropriate.
+ *
+ * @restore: Hibernation-specific, executed after restoring the contents of main
+ * memory from a hibernation image. Driver starts working again,
+ * responding to hardware events and software requests. Drivers may NOT
+ * make ANY assumptions about the hardware state right prior to @restore().
+ * On most platforms, there are no restrictions on availability of
+ * resources like clocks during @restore().
+ *
+ * All of the above callbacks, except for @complete(), return error codes.
+ * However, the error codes returned by the resume operations, @resume(),
+ * @thaw(), and @restore(), do not cause the PM core to abort the resume
+ * transition during which they are returned. The error codes returned in
+ * that cases are only printed by the PM core to the system logs for debugging
+ * purposes. Still, it is recommended that drivers only return error codes
+ * from their resume methods in case of an unrecoverable failure (i.e. when the
+ * device being handled refuses to resume and becomes unusable) to allow us to
+ * modify the PM core in the future, so that it can avoid attempting to handle
+ * devices that failed to resume and their children.
+ *
+ * It is allowed to unregister devices while the above callbacks are being
+ * executed. However, it is not allowed to unregister a device from within any
+ * of its own callbacks.
+ */
+
+struct pm_ops {
+ int (*prepare)(struct device *dev);
+ void (*complete)(struct device *dev);
+ int (*suspend)(struct device *dev);
+ int (*resume)(struct device *dev);
+ int (*freeze)(struct device *dev);
+ int (*thaw)(struct device *dev);
+ int (*poweroff)(struct device *dev);
+ int (*restore)(struct device *dev);
+};
+
+/**
+ * struct pm_ext_ops - extended device PM callbacks
+ *
+ * Some devices require certain operations related to suspend and hibernation
+ * to be carried out with interrupts disabled. Thus, 'struct pm_ext_ops' below
+ * is defined, adding callbacks to be executed with interrupts disabled to
+ * 'struct pm_ops'.
+ *
+ * The following callbacks included in 'struct pm_ext_ops' are executed with
+ * the nonboot CPUs switched off and with interrupts disabled on the only
+ * functional CPU. They also are executed with the PM core list of devices
+ * locked, so they must NOT unregister any devices.
+ *
+ * @suspend_noirq: Complete the operations of ->suspend() by carrying out any
+ * actions required for suspending the device that need interrupts to be
+ * disabled
+ *
+ * @resume_noirq: Prepare for the execution of ->resume() by carrying out any
+ * actions required for resuming the device that need interrupts to be
+ * disabled
+ *
+ * @freeze_noirq: Complete the operations of ->freeze() by carrying out any
+ * actions required for freezing the device that need interrupts to be
+ * disabled
+ *
+ * @thaw_noirq: Prepare for the execution of ->thaw() by carrying out any
+ * actions required for thawing the device that need interrupts to be
+ * disabled
+ *
+ * @poweroff_noirq: Complete the operations of ->poweroff() by carrying out any
+ * actions required for handling the device that need interrupts to be
+ * disabled
+ *
+ * @restore_noirq: Prepare for the execution of ->restore() by carrying out any
+ * actions required for restoring the operations of the device that need
+ * interrupts to be disabled
+ *
+ * All of the above callbacks return error codes, but the error codes returned
+ * by the resume operations, @resume_noirq(), @thaw_noirq(), and
+ * @restore_noirq(), do not cause the PM core to abort the resume transition
+ * during which they are returned. The error codes returned in that cases are
+ * only printed by the PM core to the system logs for debugging purposes.
+ * Still, as stated above, it is recommended that drivers only return error
+ * codes from their resume methods if the device being handled fails to resume
+ * and is not usable any more.
+ */
+
+struct pm_ext_ops {
+ struct pm_ops base;
+ int (*suspend_noirq)(struct device *dev);
+ int (*resume_noirq)(struct device *dev);
+ int (*freeze_noirq)(struct device *dev);
+ int (*thaw_noirq)(struct device *dev);
+ int (*poweroff_noirq)(struct device *dev);
+ int (*restore_noirq)(struct device *dev);
+};
+
+/**
+ * PM_EVENT_ messages
+ *
+ * The following PM_EVENT_ messages are defined for the internal use of the PM
+ * core, in order to provide a mechanism allowing the high level suspend and
+ * hibernation code to convey the necessary information to the device PM core
+ * code:
+ *
+ * ON No transition.
+ *
+ * FREEZE System is going to hibernate, call ->prepare() and ->freeze()
+ * for all devices.
+ *
+ * SUSPEND System is going to suspend, call ->prepare() and ->suspend()
+ * for all devices.
+ *
+ * HIBERNATE Hibernation image has been saved, call ->prepare() and
+ * ->poweroff() for all devices.
+ *
+ * QUIESCE Contents of main memory are going to be restored from a (loaded)
+ * hibernation image, call ->prepare() and ->freeze() for all
+ * devices.
+ *
+ * RESUME System is resuming, call ->resume() and ->complete() for all
+ * devices.
+ *
+ * THAW Hibernation image has been created, call ->thaw() and
+ * ->complete() for all devices.
+ *
+ * RESTORE Contents of main memory have been restored from a hibernation
+ * image, call ->restore() and ->complete() for all devices.
+ *
+ * RECOVER Creation of a hibernation image or restoration of the main
+ * memory contents from a hibernation image has failed, call
+ * ->thaw() and ->complete() for all devices.
+ */
+
+#define PM_EVENT_ON 0x0000
+#define PM_EVENT_FREEZE 0x0001
+#define PM_EVENT_SUSPEND 0x0002
+#define PM_EVENT_HIBERNATE 0x0004
+#define PM_EVENT_QUIESCE 0x0008
+#define PM_EVENT_RESUME 0x0010
+#define PM_EVENT_THAW 0x0020
+#define PM_EVENT_RESTORE 0x0040
+#define PM_EVENT_RECOVER 0x0080
+
+#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
+
+#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
+#define PMSG_QUIESCE ((struct pm_message){ .event = PM_EVENT_QUIESCE, })
+#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
+#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
+#define PMSG_RESUME ((struct pm_message){ .event = PM_EVENT_RESUME, })
+#define PMSG_THAW ((struct pm_message){ .event = PM_EVENT_THAW, })
+#define PMSG_RESTORE ((struct pm_message){ .event = PM_EVENT_RESTORE, })
+#define PMSG_RECOVER ((struct pm_message){ .event = PM_EVENT_RECOVER, })
+#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
+
+/**
+ * Device power management states
+ *
+ * These state labels are used internally by the PM core to indicate the current
+ * status of a device with respect to the PM core operations.
+ *
+ * DPM_ON Device is regarded as operational. Set this way
+ * initially and when ->complete() is about to be called.
+ * Also set when ->prepare() fails.
+ *
+ * DPM_PREPARING Device is going to be prepared for a PM transition. Set
+ * when ->prepare() is about to be called.
+ *
+ * DPM_RESUMING Device is going to be resumed. Set when ->resume(),
+ * ->thaw(), or ->restore() is about to be called.
+ *
+ * DPM_SUSPENDING Device has been prepared for a power transition. Set
+ * when ->prepare() has just succeeded.
+ *
+ * DPM_OFF Device is regarded as inactive. Set immediately after
+ * ->suspend(), ->freeze(), or ->poweroff() has succeeded.
+ * Also set when ->resume()_noirq, ->thaw_noirq(), or
+ * ->restore_noirq() is about to be called.
+ *
+ * DPM_OFF_IRQ Device is in a "deep sleep". Set immediately after
+ * ->suspend_noirq(), ->freeze_noirq(), or
+ * ->poweroff_noirq() has just succeeded.
+ */
+
+enum dpm_state {
+ DPM_INVALID,
+ DPM_ON,
+ DPM_PREPARING,
+ DPM_RESUMING,
+ DPM_SUSPENDING,
+ DPM_OFF,
+ DPM_OFF_IRQ,
+};
+
+struct dev_pm_info {
+ pm_message_t power_state;
+ unsigned can_wakeup:1;
+ unsigned should_wakeup:1;
+ enum dpm_state status; /* Owned by the PM core */
+#ifdef CONFIG_PM_SLEEP
+ struct list_head entry;
+#endif
+};
+
+/*
+ * The PM_EVENT_ messages are also used by drivers implementing the legacy
+ * suspend framework, based on the ->suspend() and ->resume() callbacks common
+ * for suspend and hibernation transitions, according to the rules below.
+ */
+
+/* Necessary, because several drivers use PM_EVENT_PRETHAW */
+#define PM_EVENT_PRETHAW PM_EVENT_QUIESCE
+
+/*
* One transition is triggered by resume(), after a suspend() call; the
* message is implicit:
*
* or from system low-power states such as standby or suspend-to-RAM.
*/
-#define PM_EVENT_ON 0
-#define PM_EVENT_FREEZE 1
-#define PM_EVENT_SUSPEND 2
-#define PM_EVENT_HIBERNATE 4
-#define PM_EVENT_PRETHAW 8
-
-#define PM_EVENT_SLEEP (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
-
-#define PMSG_FREEZE ((struct pm_message){ .event = PM_EVENT_FREEZE, })
-#define PMSG_PRETHAW ((struct pm_message){ .event = PM_EVENT_PRETHAW, })
-#define PMSG_SUSPEND ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
-#define PMSG_HIBERNATE ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
-#define PMSG_ON ((struct pm_message){ .event = PM_EVENT_ON, })
-
-struct dev_pm_info {
- pm_message_t power_state;
- unsigned can_wakeup:1;
- unsigned should_wakeup:1;
- bool sleeping:1; /* Owned by the PM core */
-#ifdef CONFIG_PM_SLEEP
- struct list_head entry;
-#endif
-};
+#ifdef CONFIG_PM_SLEEP
+extern void device_pm_lock(void);
+extern void device_power_up(pm_message_t state);
+extern void device_resume(pm_message_t state);
+extern void device_pm_unlock(void);
extern int device_power_down(pm_message_t state);
-extern void device_power_up(void);
-extern void device_resume(void);
-
-#ifdef CONFIG_PM_SLEEP
extern int device_suspend(pm_message_t state);
extern int device_prepare_suspend(pm_message_t state);
projects / linux.git / commitdiff