- 根目录:
- drivers
- base
- power
- main.c
/*
* drivers/base/power/main.c - Where the driver meets power management.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
*
* This file is released under the GPLv2
*
*
* The driver model core calls device_pm_add() when a device is registered.
* This will initialize the embedded device_pm_info object in the device
* and add it to the list of power-controlled devices. sysfs entries for
* controlling device power management will also be added.
*
* 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 <linux/kallsyms.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/resume-trace.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/async.h>
#include <linux/suspend.h>
#include <linux/timer.h>
#include "../base.h"
#include "power.h"
/*
* 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.
*
* Since device_pm_add() may be called with a device lock held,
* we must never try to acquire a device lock while holding
* dpm_list_mutex.
*/
LIST_HEAD(dpm_list);
LIST_HEAD(dpm_prepared_list);
LIST_HEAD(dpm_suspended_list);
LIST_HEAD(dpm_noirq_list);
static DEFINE_MUTEX(dpm_list_mtx);
static pm_message_t pm_transition;
static void dpm_drv_timeout(unsigned long data);
struct dpm_drv_wd_data {
struct device *dev;
struct task_struct *tsk;
};
static int async_error;
/**
* device_pm_init - Initialize the PM-related part of a device object.
* @dev: Device object being initialized.
*/
void device_pm_init(struct device *dev)
{
dev->power.is_prepared = false;
dev->power.is_suspended = false;
init_completion(&dev->power.completion);
complete_all(&dev->power.completion);
dev->power.wakeup = NULL;
spin_lock_init(&dev->power.lock);
pm_runtime_init(dev);
INIT_LIST_HEAD(&dev->power.entry);
}
/**
* 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 PM core's list of active devices.
* @dev: Device to add to the list.
*/
void device_pm_add(struct device *dev)
{
pr_debug("PM: Adding info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
mutex_lock(&dpm_list_mtx);
if (dev->parent && dev->parent->power.is_prepared)
dev_warn(dev, "parent %s should not be sleeping\n",
dev_name(dev->parent));
list_add_tail(&dev->power.entry, &dpm_list);
mutex_unlock(&dpm_list_mtx);
}
/**
* device_pm_remove - Remove a device from the PM core's list of active devices.
* @dev: Device to be removed from the list.
*/
void device_pm_remove(struct device *dev)
{
pr_debug("PM: Removing info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
complete_all(&dev->power.completion);
mutex_lock(&dpm_list_mtx);
list_del_init(&dev->power.entry);
mutex_unlock(&dpm_list_mtx);
device_wakeup_disable(dev);
pm_runtime_remove(dev);
}
/**
* device_pm_move_before - Move device in the PM core's list of active devices.
* @deva: Device to move in dpm_list.
* @devb: Device @deva should come before.
*/
void device_pm_move_before(struct device *deva, struct device *devb)
{
pr_debug("PM: Moving %s:%s before %s:%s\n",
deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
/* Delete deva from dpm_list and reinsert before devb. */
list_move_tail(&deva->power.entry, &devb->power.entry);
}
/**
* device_pm_move_after - Move device in the PM core's list of active devices.
* @deva: Device to move in dpm_list.
* @devb: Device @deva should come after.
*/
void device_pm_move_after(struct device *deva, struct device *devb)
{
pr_debug("PM: Moving %s:%s after %s:%s\n",
deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
/* Delete deva from dpm_list and reinsert after devb. */
list_move(&deva->power.entry, &devb->power.entry);
}
/**
* device_pm_move_last - Move device to end of the PM core's list of devices.
* @dev: Device to move in dpm_list.
*/
void device_pm_move_last(struct device *dev)
{
pr_debug("PM: Moving %s:%s to end of list\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
list_move_tail(&dev->power.entry, &dpm_list);
}
static ktime_t initcall_debug_start(struct device *dev)
{
ktime_t calltime = ktime_set(0, 0);
if (initcall_debug) {
pr_info("calling %s+ @ %i\n",
dev_name(dev), task_pid_nr(current));
calltime = ktime_get();
}
return calltime;
}
static void initcall_debug_report(struct device *dev, ktime_t calltime,
int error)
{
ktime_t delta, rettime;
if (initcall_debug) {
rettime = ktime_get();
delta = ktime_sub(rettime, calltime);
pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
error, (unsigned long long)ktime_to_ns(delta) >> 10);
}
}
/**
* dpm_wait - Wait for a PM operation to complete.
* @dev: Device to wait for.
* @async: If unset, wait only if the device's power.async_suspend flag is set.
*/
static void dpm_wait(struct device *dev, bool async)
{
if (!dev)
return;
if (async || (pm_async_enabled && dev->power.async_suspend))
wait_for_completion(&dev->power.completion);
}
static int dpm_wait_fn(struct device *dev, void *async_ptr)
{
dpm_wait(dev, *((bool *)async_ptr));
return 0;
}
static void dpm_wait_for_children(struct device *dev, bool async)
{
device_for_each_child(dev, &async, dpm_wait_fn);
}
/**
* pm_op - Execute the PM operation appropriate for given PM event.
* @dev: Device to handle.
* @ops: PM operations to choose from.
* @state: PM transition of the system being carried out.
*/
static int pm_op(struct device *dev,
const struct dev_pm_ops *ops,
pm_message_t state)
{
int error = 0;
ktime_t calltime;
calltime = initcall_debug_start(dev);
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_HIBERNATE_CALLBACKS
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_HIBERNATE_CALLBACKS */
default:
error = -EINVAL;
}
initcall_debug_report(dev, calltime, error);
return error;
}
/**
* pm_noirq_op - Execute the PM operation appropriate for given PM event.
* @dev: Device to handle.
* @ops: PM operations to choose from.
* @state: PM transition of the system being carried out.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int pm_noirq_op(struct device *dev,
const struct dev_pm_ops *ops,
pm_message_t state)
{
int error = 0;
ktime_t calltime = ktime_set(0, 0), delta, rettime;
if (initcall_debug) {
pr_info("calling %s+ @ %i, parent: %s\n",
dev_name(dev), task_pid_nr(current),
dev->parent ? dev_name(dev->parent) : "none");
calltime = ktime_get();
}
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_HIBERNATE_CALLBACKS
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_HIBERNATE_CALLBACKS */
default:
error = -EINVAL;
}
if (initcall_debug) {
rettime = ktime_get();
delta = ktime_sub(rettime, calltime);
printk("initcall %s_i+ returned %d after %Ld usecs\n",
dev_name(dev), error,
(unsigned long long)ktime_to_ns(delta) >> 10);
}
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",
dev_name(dev), pm_verb(state.event), info, error);
}
static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
{
ktime_t calltime;
u64 usecs64;
int usecs;
calltime = ktime_get();
usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
do_div(usecs64, NSEC_PER_USEC);
usecs = usecs64;
if (usecs == 0)
usecs = 1;
pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
info ?: "", info ? " " : "", pm_verb(state.event),
usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
}
/*------------------------- Resume routines -------------------------*/
/**
* device_resume_noirq - Execute an "early resume" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int device_resume_noirq(struct device *dev, pm_message_t state)
{
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
if (dev->pwr_domain) {
pm_dev_dbg(dev, state, "EARLY power domain ");
error = pm_noirq_op(dev, &dev->pwr_domain->ops, state);
} else if (dev->type && dev->type->pm) {
pm_dev_dbg(dev, state, "EARLY type ");
error = pm_noirq_op(dev, dev->type->pm, state);
} else if (dev->class && dev->class->pm) {
pm_dev_dbg(dev, state, "EARLY class ");
error = pm_noirq_op(dev, dev->class->pm, state);
} else if (dev->bus && dev->bus->pm) {
pm_dev_dbg(dev, state, "EARLY ");
error = pm_noirq_op(dev, dev->bus->pm, state);
}
TRACE_RESUME(error);
return error;
}
/**
* dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
* enable device drivers to receive interrupts.
*/
void dpm_resume_noirq(pm_message_t state)
{
ktime_t starttime = ktime_get();
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_noirq_list)) {
struct device *dev = to_device(dpm_noirq_list.next);
int error;
get_device(dev);
list_move_tail(&dev->power.entry, &dpm_suspended_list);
mutex_unlock(&dpm_list_mtx);
error = device_resume_noirq(dev, state);
if (error)
pm_dev_err(dev, state, " early", error);
mutex_lock(&dpm_list_mtx);
put_device(dev);
}
mutex_unlock(&dpm_list_mtx);
dpm_show_time(starttime, state, "early");
resume_device_irqs();
}
EXPORT_SYMBOL_GPL(dpm_resume_noirq);
/**
* legacy_resume - Execute a legacy (bus or class) resume callback for device.
* @dev: Device to resume.
* @cb: Resume callback to execute.
*/
static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
{
int error;
ktime_t calltime;
calltime = initcall_debug_start(dev);
error = cb(dev);
suspend_report_result(cb, error);
initcall_debug_report(dev, calltime, error);
return error;
}
/**
* device_resume - Execute "resume" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being resumed asynchronously.
*/
static int device_resume(struct device *dev, pm_message_t state, bool async)
{
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
dpm_wait(dev->parent, async);
device_lock(dev);
/*
* This is a fib. But we'll allow new children to be added below
* a resumed device, even if the device hasn't been completed yet.
*/
dev->power.is_prepared = false;
if (!dev->power.is_suspended)
goto Unlock;
if (dev->pwr_domain) {
pm_dev_dbg(dev, state, "power domain ");
error = pm_op(dev, &dev->pwr_domain->ops, state);
goto End;
}
if (dev->type && dev->type->pm) {
pm_dev_dbg(dev, state, "type ");
error = pm_op(dev, dev->type->pm, state);
goto End;
}
if (dev->class) {
if (dev->class->pm) {
pm_dev_dbg(dev, state, "class ");
error = pm_op(dev, dev->class->pm, state);
goto End;
} else if (dev->class->resume) {
pm_dev_dbg(dev, state, "legacy class ");
error = legacy_resume(dev, dev->class->resume);
goto End;
}
}
if (dev->bus) {
if (dev->bus->pm) {
pm_dev_dbg(dev, state, "");
error = pm_op(dev, dev->bus->pm, state);
} else if (dev->bus->resume) {
pm_dev_dbg(dev, state, "legacy ");
error = legacy_resume(dev, dev->bus->resume);
}
}
End:
dev->power.is_suspended = false;
Unlock:
device_unlock(dev);
complete_all(&dev->power.completion);
TRACE_RESUME(error);
return error;
}
static void async_resume(void *data, async_cookie_t cookie)
{
struct device *dev = (struct device *)data;
int error;
error = device_resume(dev, pm_transition, true);
if (error)
pm_dev_err(dev, pm_transition, " async", error);
put_device(dev);
}
static bool is_async(struct device *dev)
{
return dev->power.async_suspend && pm_async_enabled
&& !pm_trace_is_enabled();
}
/**
* dpm_drv_timeout - Driver suspend / resume watchdog handler
* @data: struct device which timed out
*
* Called when a driver has timed out suspending or resuming.
* There's not much we can do here to recover so
* BUG() out for a crash-dump
*
*/
static void dpm_drv_timeout(unsigned long data)
{
struct dpm_drv_wd_data *wd_data = (void *)data;
struct device *dev = wd_data->dev;
struct task_struct *tsk = wd_data->tsk;
printk(KERN_EMERG "**** DPM device timeout: %s (%s)\n", dev_name(dev),
(dev->driver ? dev->driver->name : "no driver"));
printk(KERN_EMERG "dpm suspend stack:\n");
show_stack(tsk, NULL);
BUG();
}
/**
* dpm_resume - Execute "resume" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Execute the appropriate "resume" callback for all devices whose status
* indicates that they are suspended.
*/
void dpm_resume(pm_message_t state)
{
struct device *dev;
ktime_t starttime = ktime_get();
might_sleep();
mutex_lock(&dpm_list_mtx);
pm_transition = state;
async_error = 0;
list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
INIT_COMPLETION(dev->power.completion);
if (is_async(dev)) {
get_device(dev);
async_schedule(async_resume, dev);
}
}
while (!list_empty(&dpm_suspended_list)) {
dev = to_device(dpm_suspended_list.next);
get_device(dev);
if (!is_async(dev)) {
int error;
mutex_unlock(&dpm_list_mtx);
error = device_resume(dev, state, false);
if (error)
pm_dev_err(dev, state, "", error);
mutex_lock(&dpm_list_mtx);
}
if (!list_empty(&dev->power.entry))
list_move_tail(&dev->power.entry, &dpm_prepared_list);
put_device(dev);
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
dpm_show_time(starttime, state, NULL);
}
/**
* device_complete - Complete a PM transition for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*/
static void device_complete(struct device *dev, pm_message_t state)
{
device_lock(dev);
if (dev->pwr_domain) {
pm_dev_dbg(dev, state, "completing power domain ");
if (dev->pwr_domain->ops.complete)
dev->pwr_domain->ops.complete(dev);
} else if (dev->type && dev->type->pm) {
pm_dev_dbg(dev, state, "completing type ");
if (dev->type->pm->complete)
dev->type->pm->complete(dev);
} else if (dev->class && dev->class->pm) {
pm_dev_dbg(dev, state, "completing class ");
if (dev->class->pm->complete)
dev->class->pm->complete(dev);
} else if (dev->bus && dev->bus->pm) {
pm_dev_dbg(dev, state, "completing ");
if (dev->bus->pm->complete)
dev->bus->pm->complete(dev);
}
device_unlock(dev);
}
/**
* dpm_complete - Complete a PM transition for all non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Execute the ->complete() callbacks for all devices whose PM status is not
* DPM_ON (this allows new devices to be registered).
*/
void dpm_complete(pm_message_t state)
{
struct list_head list;
might_sleep();
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_prepared_list)) {
struct device *dev = to_device(dpm_prepared_list.prev);
get_device(dev);
dev->power.is_prepared = false;
list_move(&dev->power.entry, &list);
mutex_unlock(&dpm_list_mtx);
device_complete(dev, state);
mutex_lock(&dpm_list_mtx);
put_device(dev);
}
list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
}
/**
* dpm_resume_end - Execute "resume" callbacks and complete system transition.
* @state: PM transition of the system being carried out.
*
* Execute "resume" callbacks for all devices and complete the PM transition of
* the system.
*/
void dpm_resume_end(pm_message_t state)
{
dpm_resume(state);
dpm_complete(state);
}
EXPORT_SYMBOL_GPL(dpm_resume_end);
/*------------------------- Suspend routines -------------------------*/
/**
* resume_event - Return a "resume" message for given "suspend" sleep state.
* @sleep_state: PM message representing a sleep state.
*
* Return a PM message representing the resume event corresponding to given
* sleep state.
*/
static pm_message_t resume_event(pm_message_t sleep_state)
{
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;
}
return PMSG_ON;
}
/**
* device_suspend_noirq - Execute a "late suspend" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int device_suspend_noirq(struct device *dev, pm_message_t state)
{
int error;
if (dev->pwr_domain) {
pm_dev_dbg(dev, state, "LATE power domain ");
error = pm_noirq_op(dev, &dev->pwr_domain->ops, state);
if (error)
return error;
} else if (dev->type && dev->type->pm) {
pm_dev_dbg(dev, state, "LATE type ");
error = pm_noirq_op(dev, dev->type->pm, state);
if (error)
return error;
} else if (dev->class && dev->class->pm) {
pm_dev_dbg(dev, state, "LATE class ");
error = pm_noirq_op(dev, dev->class->pm, state);
if (error)
return error;
} else if (dev->bus && dev->bus->pm) {
pm_dev_dbg(dev, state, "LATE ");
error = pm_noirq_op(dev, dev->bus->pm, state);
if (error)
return error;
}
return 0;
}
/**
* dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Prevent device drivers from receiving interrupts and call the "noirq" suspend
* handlers for all non-sysdev devices.
*/
int dpm_suspend_noirq(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error = 0;
suspend_device_irqs();
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_suspended_list)) {
struct device *dev = to_device(dpm_suspended_list.prev);
get_device(dev);
mutex_unlock(&dpm_list_mtx);
error = device_suspend_noirq(dev, state);
mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, " late", error);
put_device(dev);
break;
}
if (!list_empty(&dev->power.entry))
list_move(&dev->power.entry, &dpm_noirq_list);
put_device(dev);
}
mutex_unlock(&dpm_list_mtx);
if (error)
dpm_resume_noirq(resume_event(state));
else
dpm_show_time(starttime, state, "late");
return error;
}
EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
/**
* legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
* @dev: Device to suspend.
* @state: PM transition of the system being carried out.
* @cb: Suspend callback to execute.
*/
static int legacy_suspend(struct device *dev, pm_message_t state,
int (*cb)(struct device *dev, pm_message_t state))
{
int error;
ktime_t calltime;
calltime = initcall_debug_start(dev);
error = cb(dev, state);
suspend_report_result(cb, error);
initcall_debug_report(dev, calltime, error);
return error;
}
/**
* device_suspend - Execute "suspend" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being suspended asynchronously.
*/
static int __device_suspend(struct device *dev, pm_message_t state, bool async)
{
int error = 0;
struct timer_list timer;
struct dpm_drv_wd_data data;
dpm_wait_for_children(dev, async);
data.dev = dev;
data.tsk = get_current();
init_timer_on_stack(&timer);
timer.expires = jiffies + HZ * 12;
timer.function = dpm_drv_timeout;
timer.data = (unsigned long)&data;
add_timer(&timer);
device_lock(dev);
if (async_error)
goto Unlock;
if (pm_wakeup_pending()) {
async_error = -EBUSY;
goto Unlock;
}
if (dev->pwr_domain) {
pm_dev_dbg(dev, state, "power domain ");
error = pm_op(dev, &dev->pwr_domain->ops, state);
goto End;
}
if (dev->type && dev->type->pm) {
pm_dev_dbg(dev, state, "type ");
error = pm_op(dev, dev->type->pm, state);
goto End;
}
if (dev->class) {
if (dev->class->pm) {
pm_dev_dbg(dev, state, "class ");
error = pm_op(dev, dev->class->pm, state);
goto End;
} else if (dev->class->suspend) {
pm_dev_dbg(dev, state, "legacy class ");
error = legacy_suspend(dev, state, dev->class->suspend);
goto End;
}
}
if (dev->bus) {
if (dev->bus->pm) {
pm_dev_dbg(dev, state, "");
error = pm_op(dev, dev->bus->pm, state);
} else if (dev->bus->suspend) {
pm_dev_dbg(dev, state, "legacy ");
error = legacy_suspend(dev, state, dev->bus->suspend);
}
}
End:
dev->power.is_suspended = !error;
Unlock:
device_unlock(dev);
del_timer_sync(&timer);
destroy_timer_on_stack(&timer);
complete_all(&dev->power.completion);
if (error)
async_error = error;
return error;
}
static void async_suspend(void *data, async_cookie_t cookie)
{
struct device *dev = (struct device *)data;
int error;
error = __device_suspend(dev, pm_transition, true);
if (error)
pm_dev_err(dev, pm_transition, " async", error);
put_device(dev);
}
static int device_suspend(struct device *dev)
{
INIT_COMPLETION(dev->power.completion);
if (pm_async_enabled && dev->power.async_suspend) {
get_device(dev);
async_schedule(async_suspend, dev);
return 0;
}
return __device_suspend(dev, pm_transition, false);
}
/**
* dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
* @state: PM transition of the system being carried out.
*/
int dpm_suspend(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error = 0;
might_sleep();
mutex_lock(&dpm_list_mtx);
pm_transition = state;
async_error = 0;
while (!list_empty(&dpm_prepared_list)) {
struct device *dev = to_device(dpm_prepared_list.prev);
get_device(dev);
mutex_unlock(&dpm_list_mtx);
error = device_suspend(dev);
mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, "", error);
put_device(dev);
break;
}
if (!list_empty(&dev->power.entry))
list_move(&dev->power.entry, &dpm_suspended_list);
put_device(dev);
if (async_error)
break;
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
if (!error)
error = async_error;
if (!error)
dpm_show_time(starttime, state, NULL);
return error;
}
/**
* device_prepare - Prepare a device for system power transition.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*
* Execute the ->prepare() callback(s) for given device. No new children of the
* device may be registered after this function has returned.
*/
static int device_prepare(struct device *dev, pm_message_t state)
{
int error = 0;
device_lock(dev);
if (dev->pwr_domain) {
pm_dev_dbg(dev, state, "preparing power domain ");
if (dev->pwr_domain->ops.prepare)
error = dev->pwr_domain->ops.prepare(dev);
suspend_report_result(dev->pwr_domain->ops.prepare, error);
if (error)
goto End;
} else if (dev->type && dev->type->pm) {
pm_dev_dbg(dev, state, "preparing type ");
if (dev->type->pm->prepare)
error = dev->type->pm->prepare(dev);
suspend_report_result(dev->type->pm->prepare, error);
if (error)
goto End;
} else if (dev->class && dev->class->pm) {
pm_dev_dbg(dev, state, "preparing class ");
if (dev->class->pm->prepare)
error = dev->class->pm->prepare(dev);
suspend_report_result(dev->class->pm->prepare, error);
if (error)
goto End;
} else if (dev->bus && dev->bus->pm) {
pm_dev_dbg(dev, state, "preparing ");
if (dev->bus->pm->prepare)
error = dev->bus->pm->prepare(dev);
suspend_report_result(dev->bus->pm->prepare, error);
}
End:
device_unlock(dev);
return error;
}
/**
* dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
* @state: PM transition of the system being carried out.
*
* Execute the ->prepare() callback(s) for all devices.
*/
int dpm_prepare(pm_message_t state)
{
int error = 0;
might_sleep();
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.next);
get_device(dev);
mutex_unlock(&dpm_list_mtx);
pm_runtime_get_noresume(dev);
if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
pm_wakeup_event(dev, 0);
pm_runtime_put_sync(dev);
error = pm_wakeup_pending() ?
-EBUSY : device_prepare(dev, state);
mutex_lock(&dpm_list_mtx);
if (error) {
if (error == -EAGAIN) {
put_device(dev);
error = 0;
continue;
}
printk(KERN_INFO "PM: Device %s not prepared "
"for power transition: code %d\n",
dev_name(dev), error);
put_device(dev);
break;
}
dev->power.is_prepared = true;
if (!list_empty(&dev->power.entry))
list_move_tail(&dev->power.entry, &dpm_prepared_list);
put_device(dev);
}
mutex_unlock(&dpm_list_mtx);
return error;
}
/**
* dpm_suspend_start - Prepare devices for PM transition and suspend them.
* @state: PM transition of the system being carried out.
*
* Prepare all non-sysdev devices for system PM transition and execute "suspend"
* callbacks for them.
*/
int dpm_suspend_start(pm_message_t state)
{
int error;
error = dpm_prepare(state);
if (!error)
error = dpm_suspend(state);
return error;
}
EXPORT_SYMBOL_GPL(dpm_suspend_start);
void __suspend_report_result(const char *function, void *fn, int ret)
{
if (ret)
printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
}
EXPORT_SYMBOL_GPL(__suspend_report_result);
/**
* device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
* @dev: Device to wait for.
* @subordinate: Device that needs to wait for @dev.
*/
int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
{
dpm_wait(dev, subordinate->power.async_suspend);
return async_error;
}
EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);