blob: 79038e50cb2a6c5ec3df109e8896fc71dbc1a56a [file] [log] [blame]
/*
* drivers/base/power/domain.c - Common code related to device power domains.
*
* Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
*
* This file is released under the GPLv2.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/suspend.h>
static LIST_HEAD(gpd_list);
static DEFINE_MUTEX(gpd_list_lock);
#ifdef CONFIG_PM
static struct generic_pm_domain *dev_to_genpd(struct device *dev)
{
if (IS_ERR_OR_NULL(dev->pm_domain))
return ERR_PTR(-EINVAL);
return pd_to_genpd(dev->pm_domain);
}
static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
{
bool ret = false;
if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
ret = !!atomic_dec_and_test(&genpd->sd_count);
return ret;
}
static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
{
atomic_inc(&genpd->sd_count);
smp_mb__after_atomic_inc();
}
static void genpd_acquire_lock(struct generic_pm_domain *genpd)
{
DEFINE_WAIT(wait);
mutex_lock(&genpd->lock);
/*
* Wait for the domain to transition into either the active,
* or the power off state.
*/
for (;;) {
prepare_to_wait(&genpd->status_wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
if (genpd->status == GPD_STATE_ACTIVE
|| genpd->status == GPD_STATE_POWER_OFF)
break;
mutex_unlock(&genpd->lock);
schedule();
mutex_lock(&genpd->lock);
}
finish_wait(&genpd->status_wait_queue, &wait);
}
static void genpd_release_lock(struct generic_pm_domain *genpd)
{
mutex_unlock(&genpd->lock);
}
static void genpd_set_active(struct generic_pm_domain *genpd)
{
if (genpd->resume_count == 0)
genpd->status = GPD_STATE_ACTIVE;
}
/**
* __pm_genpd_poweron - Restore power to a given PM domain and its masters.
* @genpd: PM domain to power up.
*
* Restore power to @genpd and all of its masters so that it is possible to
* resume a device belonging to it.
*/
int __pm_genpd_poweron(struct generic_pm_domain *genpd)
__releases(&genpd->lock) __acquires(&genpd->lock)
{
struct gpd_link *link;
DEFINE_WAIT(wait);
int ret = 0;
/* If the domain's master is being waited for, we have to wait too. */
for (;;) {
prepare_to_wait(&genpd->status_wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
if (genpd->status != GPD_STATE_WAIT_MASTER)
break;
mutex_unlock(&genpd->lock);
schedule();
mutex_lock(&genpd->lock);
}
finish_wait(&genpd->status_wait_queue, &wait);
if (genpd->status == GPD_STATE_ACTIVE
|| (genpd->prepared_count > 0 && genpd->suspend_power_off))
return 0;
if (genpd->status != GPD_STATE_POWER_OFF) {
genpd_set_active(genpd);
return 0;
}
/*
* The list is guaranteed not to change while the loop below is being
* executed, unless one of the masters' .power_on() callbacks fiddles
* with it.
*/
list_for_each_entry(link, &genpd->slave_links, slave_node) {
genpd_sd_counter_inc(link->master);
genpd->status = GPD_STATE_WAIT_MASTER;
mutex_unlock(&genpd->lock);
ret = pm_genpd_poweron(link->master);
mutex_lock(&genpd->lock);
/*
* The "wait for parent" status is guaranteed not to change
* while the master is powering on.
*/
genpd->status = GPD_STATE_POWER_OFF;
wake_up_all(&genpd->status_wait_queue);
if (ret) {
genpd_sd_counter_dec(link->master);
goto err;
}
}
if (genpd->power_on) {
ret = genpd->power_on(genpd);
if (ret)
goto err;
}
genpd_set_active(genpd);
return 0;
err:
list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node)
genpd_sd_counter_dec(link->master);
return ret;
}
/**
* pm_genpd_poweron - Restore power to a given PM domain and its masters.
* @genpd: PM domain to power up.
*/
int pm_genpd_poweron(struct generic_pm_domain *genpd)
{
int ret;
mutex_lock(&genpd->lock);
ret = __pm_genpd_poweron(genpd);
mutex_unlock(&genpd->lock);
return ret;
}
#endif /* CONFIG_PM */
#ifdef CONFIG_PM_RUNTIME
/**
* __pm_genpd_save_device - Save the pre-suspend state of a device.
* @pdd: Domain data of the device to save the state of.
* @genpd: PM domain the device belongs to.
*/
static int __pm_genpd_save_device(struct pm_domain_data *pdd,
struct generic_pm_domain *genpd)
__releases(&genpd->lock) __acquires(&genpd->lock)
{
struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
struct device *dev = pdd->dev;
struct device_driver *drv = dev->driver;
int ret = 0;
if (gpd_data->need_restore)
return 0;
mutex_unlock(&genpd->lock);
if (drv && drv->pm && drv->pm->runtime_suspend) {
if (genpd->start_device)
genpd->start_device(dev);
ret = drv->pm->runtime_suspend(dev);
if (genpd->stop_device)
genpd->stop_device(dev);
}
mutex_lock(&genpd->lock);
if (!ret)
gpd_data->need_restore = true;
return ret;
}
/**
* __pm_genpd_restore_device - Restore the pre-suspend state of a device.
* @pdd: Domain data of the device to restore the state of.
* @genpd: PM domain the device belongs to.
*/
static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
struct generic_pm_domain *genpd)
__releases(&genpd->lock) __acquires(&genpd->lock)
{
struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
struct device *dev = pdd->dev;
struct device_driver *drv = dev->driver;
if (!gpd_data->need_restore)
return;
mutex_unlock(&genpd->lock);
if (drv && drv->pm && drv->pm->runtime_resume) {
if (genpd->start_device)
genpd->start_device(dev);
drv->pm->runtime_resume(dev);
if (genpd->stop_device)
genpd->stop_device(dev);
}
mutex_lock(&genpd->lock);
gpd_data->need_restore = false;
}
/**
* genpd_abort_poweroff - Check if a PM domain power off should be aborted.
* @genpd: PM domain to check.
*
* Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
* a "power off" operation, which means that a "power on" has occured in the
* meantime, or if its resume_count field is different from zero, which means
* that one of its devices has been resumed in the meantime.
*/
static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
{
return genpd->status == GPD_STATE_WAIT_MASTER
|| genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
}
/**
* genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
* @genpd: PM domait to power off.
*
* Queue up the execution of pm_genpd_poweroff() unless it's already been done
* before.
*/
void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
{
if (!work_pending(&genpd->power_off_work))
queue_work(pm_wq, &genpd->power_off_work);
}
/**
* pm_genpd_poweroff - Remove power from a given PM domain.
* @genpd: PM domain to power down.
*
* If all of the @genpd's devices have been suspended and all of its subdomains
* have been powered down, run the runtime suspend callbacks provided by all of
* the @genpd's devices' drivers and remove power from @genpd.
*/
static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
__releases(&genpd->lock) __acquires(&genpd->lock)
{
struct pm_domain_data *pdd;
struct gpd_link *link;
unsigned int not_suspended;
int ret = 0;
start:
/*
* Do not try to power off the domain in the following situations:
* (1) The domain is already in the "power off" state.
* (2) The domain is waiting for its master to power up.
* (3) One of the domain's devices is being resumed right now.
* (4) System suspend is in progress.
*/
if (genpd->status == GPD_STATE_POWER_OFF
|| genpd->status == GPD_STATE_WAIT_MASTER
|| genpd->resume_count > 0 || genpd->prepared_count > 0)
return 0;
if (atomic_read(&genpd->sd_count) > 0)
return -EBUSY;
not_suspended = 0;
list_for_each_entry(pdd, &genpd->dev_list, list_node)
if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
|| pdd->dev->power.irq_safe))
not_suspended++;
if (not_suspended > genpd->in_progress)
return -EBUSY;
if (genpd->poweroff_task) {
/*
* Another instance of pm_genpd_poweroff() is executing
* callbacks, so tell it to start over and return.
*/
genpd->status = GPD_STATE_REPEAT;
return 0;
}
if (genpd->gov && genpd->gov->power_down_ok) {
if (!genpd->gov->power_down_ok(&genpd->domain))
return -EAGAIN;
}
genpd->status = GPD_STATE_BUSY;
genpd->poweroff_task = current;
list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
ret = atomic_read(&genpd->sd_count) == 0 ?
__pm_genpd_save_device(pdd, genpd) : -EBUSY;
if (genpd_abort_poweroff(genpd))
goto out;
if (ret) {
genpd_set_active(genpd);
goto out;
}
if (genpd->status == GPD_STATE_REPEAT) {
genpd->poweroff_task = NULL;
goto start;
}
}
if (genpd->power_off) {
if (atomic_read(&genpd->sd_count) > 0) {
ret = -EBUSY;
goto out;
}
/*
* If sd_count > 0 at this point, one of the subdomains hasn't
* managed to call pm_genpd_poweron() for the master yet after
* incrementing it. In that case pm_genpd_poweron() will wait
* for us to drop the lock, so we can call .power_off() and let
* the pm_genpd_poweron() restore power for us (this shouldn't
* happen very often).
*/
ret = genpd->power_off(genpd);
if (ret == -EBUSY) {
genpd_set_active(genpd);
goto out;
}
}
genpd->status = GPD_STATE_POWER_OFF;
list_for_each_entry(link, &genpd->slave_links, slave_node) {
genpd_sd_counter_dec(link->master);
genpd_queue_power_off_work(link->master);
}
out:
genpd->poweroff_task = NULL;
wake_up_all(&genpd->status_wait_queue);
return ret;
}
/**
* genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
* @work: Work structure used for scheduling the execution of this function.
*/
static void genpd_power_off_work_fn(struct work_struct *work)
{
struct generic_pm_domain *genpd;
genpd = container_of(work, struct generic_pm_domain, power_off_work);
genpd_acquire_lock(genpd);
pm_genpd_poweroff(genpd);
genpd_release_lock(genpd);
}
/**
* pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
* @dev: Device to suspend.
*
* Carry out a runtime suspend of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a PM domain consisting of I/O devices.
*/
static int pm_genpd_runtime_suspend(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
might_sleep_if(!genpd->dev_irq_safe);
if (genpd->stop_device) {
int ret = genpd->stop_device(dev);
if (ret)
return ret;
}
/*
* If power.irq_safe is set, this routine will be run with interrupts
* off, so it can't use mutexes.
*/
if (dev->power.irq_safe)
return 0;
mutex_lock(&genpd->lock);
genpd->in_progress++;
pm_genpd_poweroff(genpd);
genpd->in_progress--;
mutex_unlock(&genpd->lock);
return 0;
}
/**
* pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
* @dev: Device to resume.
*
* Carry out a runtime resume of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a PM domain consisting of I/O devices.
*/
static int pm_genpd_runtime_resume(struct device *dev)
{
struct generic_pm_domain *genpd;
DEFINE_WAIT(wait);
int ret;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
might_sleep_if(!genpd->dev_irq_safe);
/* If power.irq_safe, the PM domain is never powered off. */
if (dev->power.irq_safe)
goto out;
mutex_lock(&genpd->lock);
ret = __pm_genpd_poweron(genpd);
if (ret) {
mutex_unlock(&genpd->lock);
return ret;
}
genpd->status = GPD_STATE_BUSY;
genpd->resume_count++;
for (;;) {
prepare_to_wait(&genpd->status_wait_queue, &wait,
TASK_UNINTERRUPTIBLE);
/*
* If current is the powering off task, we have been called
* reentrantly from one of the device callbacks, so we should
* not wait.
*/
if (!genpd->poweroff_task || genpd->poweroff_task == current)
break;
mutex_unlock(&genpd->lock);
schedule();
mutex_lock(&genpd->lock);
}
finish_wait(&genpd->status_wait_queue, &wait);
__pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
genpd->resume_count--;
genpd_set_active(genpd);
wake_up_all(&genpd->status_wait_queue);
mutex_unlock(&genpd->lock);
out:
if (genpd->start_device)
genpd->start_device(dev);
return 0;
}
/**
* pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
*/
void pm_genpd_poweroff_unused(void)
{
struct generic_pm_domain *genpd;
mutex_lock(&gpd_list_lock);
list_for_each_entry(genpd, &gpd_list, gpd_list_node)
genpd_queue_power_off_work(genpd);
mutex_unlock(&gpd_list_lock);
}
#else
static inline void genpd_power_off_work_fn(struct work_struct *work) {}
#define pm_genpd_runtime_suspend NULL
#define pm_genpd_runtime_resume NULL
#endif /* CONFIG_PM_RUNTIME */
#ifdef CONFIG_PM_SLEEP
/**
* pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
* @genpd: PM domain to power off, if possible.
*
* Check if the given PM domain can be powered off (during system suspend or
* hibernation) and do that if so. Also, in that case propagate to its masters.
*
* This function is only called in "noirq" stages of system power transitions,
* so it need not acquire locks (all of the "noirq" callbacks are executed
* sequentially, so it is guaranteed that it will never run twice in parallel).
*/
static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
{
struct gpd_link *link;
if (genpd->status == GPD_STATE_POWER_OFF)
return;
if (genpd->suspended_count != genpd->device_count
|| atomic_read(&genpd->sd_count) > 0)
return;
if (genpd->power_off)
genpd->power_off(genpd);
genpd->status = GPD_STATE_POWER_OFF;
list_for_each_entry(link, &genpd->slave_links, slave_node) {
genpd_sd_counter_dec(link->master);
pm_genpd_sync_poweroff(link->master);
}
}
/**
* resume_needed - Check whether to resume a device before system suspend.
* @dev: Device to check.
* @genpd: PM domain the device belongs to.
*
* There are two cases in which a device that can wake up the system from sleep
* states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
* to wake up the system and it has to remain active for this purpose while the
* system is in the sleep state and (2) if the device is not enabled to wake up
* the system from sleep states and it generally doesn't generate wakeup signals
* by itself (those signals are generated on its behalf by other parts of the
* system). In the latter case it may be necessary to reconfigure the device's
* wakeup settings during system suspend, because it may have been set up to
* signal remote wakeup from the system's working state as needed by runtime PM.
* Return 'true' in either of the above cases.
*/
static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
{
bool active_wakeup;
if (!device_can_wakeup(dev))
return false;
active_wakeup = genpd->active_wakeup && genpd->active_wakeup(dev);
return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
}
/**
* pm_genpd_prepare - Start power transition of a device in a PM domain.
* @dev: Device to start the transition of.
*
* Start a power transition of a device (during a system-wide power transition)
* under the assumption that its pm_domain field points to the domain member of
* an object of type struct generic_pm_domain representing a PM domain
* consisting of I/O devices.
*/
static int pm_genpd_prepare(struct device *dev)
{
struct generic_pm_domain *genpd;
int ret;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
/*
* If a wakeup request is pending for the device, it should be woken up
* at this point and a system wakeup event should be reported if it's
* set up to wake up the system from sleep states.
*/
pm_runtime_get_noresume(dev);
if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
pm_wakeup_event(dev, 0);
if (pm_wakeup_pending()) {
pm_runtime_put_sync(dev);
return -EBUSY;
}
if (resume_needed(dev, genpd))
pm_runtime_resume(dev);
genpd_acquire_lock(genpd);
if (genpd->prepared_count++ == 0)
genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
genpd_release_lock(genpd);
if (genpd->suspend_power_off) {
pm_runtime_put_noidle(dev);
return 0;
}
/*
* The PM domain must be in the GPD_STATE_ACTIVE state at this point,
* so pm_genpd_poweron() will return immediately, but if the device
* is suspended (e.g. it's been stopped by .stop_device()), we need
* to make it operational.
*/
pm_runtime_resume(dev);
__pm_runtime_disable(dev, false);
ret = pm_generic_prepare(dev);
if (ret) {
mutex_lock(&genpd->lock);
if (--genpd->prepared_count == 0)
genpd->suspend_power_off = false;
mutex_unlock(&genpd->lock);
pm_runtime_enable(dev);
}
pm_runtime_put_sync(dev);
return ret;
}
/**
* pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
* @dev: Device to suspend.
*
* Suspend a device under the assumption that its pm_domain field points to the
* domain member of an object of type struct generic_pm_domain representing
* a PM domain consisting of I/O devices.
*/
static int pm_genpd_suspend(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev);
}
/**
* pm_genpd_suspend_noirq - Late suspend of a device from an I/O PM domain.
* @dev: Device to suspend.
*
* Carry out a late suspend of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a PM domain consisting of I/O devices.
*/
static int pm_genpd_suspend_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
int ret;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (genpd->suspend_power_off)
return 0;
ret = pm_generic_suspend_noirq(dev);
if (ret)
return ret;
if (dev->power.wakeup_path
&& genpd->active_wakeup && genpd->active_wakeup(dev))
return 0;
if (genpd->stop_device)
genpd->stop_device(dev);
/*
* Since all of the "noirq" callbacks are executed sequentially, it is
* guaranteed that this function will never run twice in parallel for
* the same PM domain, so it is not necessary to use locking here.
*/
genpd->suspended_count++;
pm_genpd_sync_poweroff(genpd);
return 0;
}
/**
* pm_genpd_resume_noirq - Early resume of a device from an I/O power domain.
* @dev: Device to resume.
*
* Carry out an early resume of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a power domain consisting of I/O
* devices.
*/
static int pm_genpd_resume_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (genpd->suspend_power_off
|| (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
return 0;
/*
* Since all of the "noirq" callbacks are executed sequentially, it is
* guaranteed that this function will never run twice in parallel for
* the same PM domain, so it is not necessary to use locking here.
*/
pm_genpd_poweron(genpd);
genpd->suspended_count--;
if (genpd->start_device)
genpd->start_device(dev);
return pm_generic_resume_noirq(dev);
}
/**
* pm_genpd_resume - Resume a device belonging to an I/O power domain.
* @dev: Device to resume.
*
* Resume a device under the assumption that its pm_domain field points to the
* domain member of an object of type struct generic_pm_domain representing
* a power domain consisting of I/O devices.
*/
static int pm_genpd_resume(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
return genpd->suspend_power_off ? 0 : pm_generic_resume(dev);
}
/**
* pm_genpd_freeze - Freeze a device belonging to an I/O power domain.
* @dev: Device to freeze.
*
* Freeze a device under the assumption that its pm_domain field points to the
* domain member of an object of type struct generic_pm_domain representing
* a power domain consisting of I/O devices.
*/
static int pm_genpd_freeze(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev);
}
/**
* pm_genpd_freeze_noirq - Late freeze of a device from an I/O power domain.
* @dev: Device to freeze.
*
* Carry out a late freeze of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a power domain consisting of I/O
* devices.
*/
static int pm_genpd_freeze_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
int ret;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (genpd->suspend_power_off)
return 0;
ret = pm_generic_freeze_noirq(dev);
if (ret)
return ret;
if (genpd->stop_device)
genpd->stop_device(dev);
return 0;
}
/**
* pm_genpd_thaw_noirq - Early thaw of a device from an I/O power domain.
* @dev: Device to thaw.
*
* Carry out an early thaw of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a power domain consisting of I/O
* devices.
*/
static int pm_genpd_thaw_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (genpd->suspend_power_off)
return 0;
if (genpd->start_device)
genpd->start_device(dev);
return pm_generic_thaw_noirq(dev);
}
/**
* pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
* @dev: Device to thaw.
*
* Thaw a device under the assumption that its pm_domain field points to the
* domain member of an object of type struct generic_pm_domain representing
* a power domain consisting of I/O devices.
*/
static int pm_genpd_thaw(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev);
}
/**
* pm_genpd_dev_poweroff - Power off a device belonging to an I/O PM domain.
* @dev: Device to suspend.
*
* Power off a device under the assumption that its pm_domain field points to
* the domain member of an object of type struct generic_pm_domain representing
* a PM domain consisting of I/O devices.
*/
static int pm_genpd_dev_poweroff(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
return genpd->suspend_power_off ? 0 : pm_generic_poweroff(dev);
}
/**
* pm_genpd_dev_poweroff_noirq - Late power off of a device from a PM domain.
* @dev: Device to suspend.
*
* Carry out a late powering off of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a PM domain consisting of I/O devices.
*/
static int pm_genpd_dev_poweroff_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
int ret;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
if (genpd->suspend_power_off)
return 0;
ret = pm_generic_poweroff_noirq(dev);
if (ret)
return ret;
if (dev->power.wakeup_path
&& genpd->active_wakeup && genpd->active_wakeup(dev))
return 0;
if (genpd->stop_device)
genpd->stop_device(dev);
/*
* Since all of the "noirq" callbacks are executed sequentially, it is
* guaranteed that this function will never run twice in parallel for
* the same PM domain, so it is not necessary to use locking here.
*/
genpd->suspended_count++;
pm_genpd_sync_poweroff(genpd);
return 0;
}
/**
* pm_genpd_restore_noirq - Early restore of a device from an I/O power domain.
* @dev: Device to resume.
*
* Carry out an early restore of a device under the assumption that its
* pm_domain field points to the domain member of an object of type
* struct generic_pm_domain representing a power domain consisting of I/O
* devices.
*/
static int pm_genpd_restore_noirq(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
/*
* Since all of the "noirq" callbacks are executed sequentially, it is
* guaranteed that this function will never run twice in parallel for
* the same PM domain, so it is not necessary to use locking here.
*/
genpd->status = GPD_STATE_POWER_OFF;
if (genpd->suspend_power_off) {
/*
* The boot kernel might put the domain into the power on state,
* so make sure it really is powered off.
*/
if (genpd->power_off)
genpd->power_off(genpd);
return 0;
}
pm_genpd_poweron(genpd);
genpd->suspended_count--;
if (genpd->start_device)
genpd->start_device(dev);
return pm_generic_restore_noirq(dev);
}
/**
* pm_genpd_restore - Restore a device belonging to an I/O power domain.
* @dev: Device to resume.
*
* Restore a device under the assumption that its pm_domain field points to the
* domain member of an object of type struct generic_pm_domain representing
* a power domain consisting of I/O devices.
*/
static int pm_genpd_restore(struct device *dev)
{
struct generic_pm_domain *genpd;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return -EINVAL;
return genpd->suspend_power_off ? 0 : pm_generic_restore(dev);
}
/**
* pm_genpd_complete - Complete power transition of a device in a power domain.
* @dev: Device to complete the transition of.
*
* Complete a power transition of a device (during a system-wide power
* transition) under the assumption that its pm_domain field points to the
* domain member of an object of type struct generic_pm_domain representing
* a power domain consisting of I/O devices.
*/
static void pm_genpd_complete(struct device *dev)
{
struct generic_pm_domain *genpd;
bool run_complete;
dev_dbg(dev, "%s()\n", __func__);
genpd = dev_to_genpd(dev);
if (IS_ERR(genpd))
return;
mutex_lock(&genpd->lock);
run_complete = !genpd->suspend_power_off;
if (--genpd->prepared_count == 0)
genpd->suspend_power_off = false;
mutex_unlock(&genpd->lock);
if (run_complete) {
pm_generic_complete(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
pm_runtime_idle(dev);
}
}
#else
#define pm_genpd_prepare NULL
#define pm_genpd_suspend NULL
#define pm_genpd_suspend_noirq NULL
#define pm_genpd_resume_noirq NULL
#define pm_genpd_resume NULL
#define pm_genpd_freeze NULL
#define pm_genpd_freeze_noirq NULL
#define pm_genpd_thaw_noirq NULL
#define pm_genpd_thaw NULL
#define pm_genpd_dev_poweroff_noirq NULL
#define pm_genpd_dev_poweroff NULL
#define pm_genpd_restore_noirq NULL
#define pm_genpd_restore NULL
#define pm_genpd_complete NULL
#endif /* CONFIG_PM_SLEEP */
/**
* pm_genpd_add_device - Add a device to an I/O PM domain.
* @genpd: PM domain to add the device to.
* @dev: Device to be added.
*/
int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev)
{
struct generic_pm_domain_data *gpd_data;
struct pm_domain_data *pdd;
int ret = 0;
dev_dbg(dev, "%s()\n", __func__);
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
return -EINVAL;
genpd_acquire_lock(genpd);
if (genpd->status == GPD_STATE_POWER_OFF) {
ret = -EINVAL;
goto out;
}
if (genpd->prepared_count > 0) {
ret = -EAGAIN;
goto out;
}
list_for_each_entry(pdd, &genpd->dev_list, list_node)
if (pdd->dev == dev) {
ret = -EINVAL;
goto out;
}
gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
if (!gpd_data) {
ret = -ENOMEM;
goto out;
}
genpd->device_count++;
dev->pm_domain = &genpd->domain;
dev_pm_get_subsys_data(dev);
dev->power.subsys_data->domain_data = &gpd_data->base;
gpd_data->base.dev = dev;
gpd_data->need_restore = false;
list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
out:
genpd_release_lock(genpd);
return ret;
}
/**
* pm_genpd_remove_device - Remove a device from an I/O PM domain.
* @genpd: PM domain to remove the device from.
* @dev: Device to be removed.
*/
int pm_genpd_remove_device(struct generic_pm_domain *genpd,
struct device *dev)
{
struct pm_domain_data *pdd;
int ret = -EINVAL;
dev_dbg(dev, "%s()\n", __func__);
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
return -EINVAL;
genpd_acquire_lock(genpd);
if (genpd->prepared_count > 0) {
ret = -EAGAIN;
goto out;
}
list_for_each_entry(pdd, &genpd->dev_list, list_node) {
if (pdd->dev != dev)
continue;
list_del_init(&pdd->list_node);
pdd->dev = NULL;
dev_pm_put_subsys_data(dev);
dev->pm_domain = NULL;
kfree(to_gpd_data(pdd));
genpd->device_count--;
ret = 0;
break;
}
out:
genpd_release_lock(genpd);
return ret;
}
/**
* pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
* @genpd: Master PM domain to add the subdomain to.
* @subdomain: Subdomain to be added.
*/
int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *subdomain)
{
struct gpd_link *link;
int ret = 0;
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
return -EINVAL;
start:
genpd_acquire_lock(genpd);
mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
if (subdomain->status != GPD_STATE_POWER_OFF
&& subdomain->status != GPD_STATE_ACTIVE) {
mutex_unlock(&subdomain->lock);
genpd_release_lock(genpd);
goto start;
}
if (genpd->status == GPD_STATE_POWER_OFF
&& subdomain->status != GPD_STATE_POWER_OFF) {
ret = -EINVAL;
goto out;
}
list_for_each_entry(link, &genpd->slave_links, slave_node) {
if (link->slave == subdomain && link->master == genpd) {
ret = -EINVAL;
goto out;
}
}
link = kzalloc(sizeof(*link), GFP_KERNEL);
if (!link) {
ret = -ENOMEM;
goto out;
}
link->master = genpd;
list_add_tail(&link->master_node, &genpd->master_links);
link->slave = subdomain;
list_add_tail(&link->slave_node, &subdomain->slave_links);
if (subdomain->status != GPD_STATE_POWER_OFF)
genpd_sd_counter_inc(genpd);
out:
mutex_unlock(&subdomain->lock);
genpd_release_lock(genpd);
return ret;
}
/**
* pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
* @genpd: Master PM domain to remove the subdomain from.
* @subdomain: Subdomain to be removed.
*/
int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
struct generic_pm_domain *subdomain)
{
struct gpd_link *link;
int ret = -EINVAL;
if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
return -EINVAL;
start:
genpd_acquire_lock(genpd);
list_for_each_entry(link, &genpd->master_links, master_node) {
if (link->slave != subdomain)
continue;
mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
if (subdomain->status != GPD_STATE_POWER_OFF
&& subdomain->status != GPD_STATE_ACTIVE) {
mutex_unlock(&subdomain->lock);
genpd_release_lock(genpd);
goto start;
}
list_del(&link->master_node);
list_del(&link->slave_node);
kfree(link);
if (subdomain->status != GPD_STATE_POWER_OFF)
genpd_sd_counter_dec(genpd);
mutex_unlock(&subdomain->lock);
ret = 0;
break;
}
genpd_release_lock(genpd);
return ret;
}
/**
* pm_genpd_init - Initialize a generic I/O PM domain object.
* @genpd: PM domain object to initialize.
* @gov: PM domain governor to associate with the domain (may be NULL).
* @is_off: Initial value of the domain's power_is_off field.
*/
void pm_genpd_init(struct generic_pm_domain *genpd,
struct dev_power_governor *gov, bool is_off)
{
if (IS_ERR_OR_NULL(genpd))
return;
INIT_LIST_HEAD(&genpd->master_links);
INIT_LIST_HEAD(&genpd->slave_links);
INIT_LIST_HEAD(&genpd->dev_list);
mutex_init(&genpd->lock);
genpd->gov = gov;
INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
genpd->in_progress = 0;
atomic_set(&genpd->sd_count, 0);
genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
init_waitqueue_head(&genpd->status_wait_queue);
genpd->poweroff_task = NULL;
genpd->resume_count = 0;
genpd->device_count = 0;
genpd->suspended_count = 0;
genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
genpd->domain.ops.runtime_idle = pm_generic_runtime_idle;
genpd->domain.ops.prepare = pm_genpd_prepare;
genpd->domain.ops.suspend = pm_genpd_suspend;
genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
genpd->domain.ops.resume = pm_genpd_resume;
genpd->domain.ops.freeze = pm_genpd_freeze;
genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
genpd->domain.ops.thaw = pm_genpd_thaw;
genpd->domain.ops.poweroff = pm_genpd_dev_poweroff;
genpd->domain.ops.poweroff_noirq = pm_genpd_dev_poweroff_noirq;
genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
genpd->domain.ops.restore = pm_genpd_restore;
genpd->domain.ops.complete = pm_genpd_complete;
mutex_lock(&gpd_list_lock);
list_add(&genpd->gpd_list_node, &gpd_list);
mutex_unlock(&gpd_list_lock);
}