diff options
Diffstat (limited to 'drivers/base/power/domain.c')
| -rw-r--r-- | drivers/base/power/domain.c | 1273 |
1 files changed, 1273 insertions, 0 deletions
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c new file mode 100644 index 000000000000..be8714aa9dd6 --- /dev/null +++ b/drivers/base/power/domain.c @@ -0,0 +1,1273 @@ +/* + * 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 void genpd_sd_counter_dec(struct generic_pm_domain *genpd) +{ + if (!WARN_ON(genpd->sd_count == 0)) + genpd->sd_count--; +} + +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 parents. + * @genpd: PM domain to power up. + * + * Restore power to @genpd and all of its parents so that it is possible to + * resume a device belonging to it. + */ +int pm_genpd_poweron(struct generic_pm_domain *genpd) +{ + struct generic_pm_domain *parent = genpd->parent; + DEFINE_WAIT(wait); + int ret = 0; + + start: + if (parent) { + genpd_acquire_lock(parent); + mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); + } else { + mutex_lock(&genpd->lock); + } + + if (genpd->status == GPD_STATE_ACTIVE + || (genpd->prepared_count > 0 && genpd->suspend_power_off)) + goto out; + + if (genpd->status != GPD_STATE_POWER_OFF) { + genpd_set_active(genpd); + goto out; + } + + if (parent && parent->status != GPD_STATE_ACTIVE) { + mutex_unlock(&genpd->lock); + genpd_release_lock(parent); + + ret = pm_genpd_poweron(parent); + if (ret) + return ret; + + goto start; + } + + if (genpd->power_on) { + int ret = genpd->power_on(genpd); + if (ret) + goto out; + } + + genpd_set_active(genpd); + if (parent) + parent->sd_count++; + + out: + mutex_unlock(&genpd->lock); + if (parent) + genpd_release_lock(parent); + + return ret; +} + +#endif /* CONFIG_PM */ + +#ifdef CONFIG_PM_RUNTIME + +/** + * __pm_genpd_save_device - Save the pre-suspend state of a device. + * @dle: Device list entry of the device to save the state of. + * @genpd: PM domain the device belongs to. + */ +static int __pm_genpd_save_device(struct dev_list_entry *dle, + struct generic_pm_domain *genpd) + __releases(&genpd->lock) __acquires(&genpd->lock) +{ + struct device *dev = dle->dev; + struct device_driver *drv = dev->driver; + int ret = 0; + + if (dle->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) + dle->need_restore = true; + + return ret; +} + +/** + * __pm_genpd_restore_device - Restore the pre-suspend state of a device. + * @dle: Device list entry of the device to restore the state of. + * @genpd: PM domain the device belongs to. + */ +static void __pm_genpd_restore_device(struct dev_list_entry *dle, + struct generic_pm_domain *genpd) + __releases(&genpd->lock) __acquires(&genpd->lock) +{ + struct device *dev = dle->dev; + struct device_driver *drv = dev->driver; + + if (!dle->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); + + dle->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_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 generic_pm_domain *parent; + struct dev_list_entry *dle; + 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) System suspend is in progress. + * (3) One of the domain's devices is being resumed right now. + */ + if (genpd->status == GPD_STATE_POWER_OFF || genpd->prepared_count > 0 + || genpd->resume_count > 0) + return 0; + + if (genpd->sd_count > 0) + return -EBUSY; + + not_suspended = 0; + list_for_each_entry(dle, &genpd->dev_list, node) + if (dle->dev->driver && !pm_runtime_suspended(dle->dev)) + 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(dle, &genpd->dev_list, node) { + ret = __pm_genpd_save_device(dle, genpd); + if (ret) { + genpd_set_active(genpd); + goto out; + } + + if (genpd_abort_poweroff(genpd)) + goto out; + + if (genpd->status == GPD_STATE_REPEAT) { + genpd->poweroff_task = NULL; + goto start; + } + } + + parent = genpd->parent; + if (parent) { + mutex_unlock(&genpd->lock); + + genpd_acquire_lock(parent); + mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); + + if (genpd_abort_poweroff(genpd)) { + genpd_release_lock(parent); + goto out; + } + } + + if (genpd->power_off) { + ret = genpd->power_off(genpd); + if (ret == -EBUSY) { + genpd_set_active(genpd); + if (parent) + genpd_release_lock(parent); + + goto out; + } + } + + genpd->status = GPD_STATE_POWER_OFF; + + if (parent) { + genpd_sd_counter_dec(parent); + if (parent->sd_count == 0) + genpd_queue_power_off_work(parent); + + genpd_release_lock(parent); + } + + 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; + + if (genpd->stop_device) { + int ret = genpd->stop_device(dev); + if (ret) + return ret; + } + + 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. + * @genpd: PM domain the device belongs to. + */ +static void __pm_genpd_runtime_resume(struct device *dev, + struct generic_pm_domain *genpd) +{ + struct dev_list_entry *dle; + + list_for_each_entry(dle, &genpd->dev_list, node) { + if (dle->dev == dev) { + __pm_genpd_restore_device(dle, genpd); + break; + } + } +} + +/** + * 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; + + ret = pm_genpd_poweron(genpd); + if (ret) + return ret; + + mutex_lock(&genpd->lock); + 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_runtime_resume(dev, genpd); + genpd->resume_count--; + genpd_set_active(genpd); + wake_up_all(&genpd->status_wait_queue); + mutex_unlock(&genpd->lock); + + if (genpd->start_device) + genpd->start_device(dev); + + return 0; +} + +#else + +static inline void genpd_power_off_work_fn(struct work_struct *work) {} +static inline void __pm_genpd_runtime_resume(struct device *dev, + struct generic_pm_domain *genpd) {} + +#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 parents. + * @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 parent. + * + * 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 generic_pm_domain *parent = genpd->parent; + + if (genpd->status == GPD_STATE_POWER_OFF) + return; + + if (genpd->suspended_count != genpd->device_count || genpd->sd_count > 0) + return; + + if (genpd->power_off) + genpd->power_off(genpd); + + genpd->status = GPD_STATE_POWER_OFF; + if (parent) { + genpd_sd_counter_dec(parent); + pm_genpd_sync_poweroff(parent); + } +} + +/** + * 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 (device_may_wakeup(dev) + && 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) + 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 (device_may_wakeup(dev) + && 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 dev_list_entry *dle; + 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(dle, &genpd->dev_list, node) + if (dle->dev == dev) { + ret = -EINVAL; + goto out; + } + + dle = kzalloc(sizeof(*dle), GFP_KERNEL); + if (!dle) { + ret = -ENOMEM; + goto out; + } + + dle->dev = dev; + dle->need_restore = false; + list_add_tail(&dle->node, &genpd->dev_list); + genpd->device_count++; + + spin_lock_irq(&dev->power.lock); + dev->pm_domain = &genpd->domain; + spin_unlock_irq(&dev->power.lock); + + 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 dev_list_entry *dle; + 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(dle, &genpd->dev_list, node) { + if (dle->dev != dev) + continue; + + spin_lock_irq(&dev->power.lock); + dev->pm_domain = NULL; + spin_unlock_irq(&dev->power.lock); + + genpd->device_count--; + list_del(&dle->node); + kfree(dle); + + 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. + * @new_subdomain: Subdomain to be added. + */ +int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, + struct generic_pm_domain *new_subdomain) +{ + struct generic_pm_domain *subdomain; + int ret = 0; + + if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(new_subdomain)) + return -EINVAL; + + start: + genpd_acquire_lock(genpd); + mutex_lock_nested(&new_subdomain->lock, SINGLE_DEPTH_NESTING); + + if (new_subdomain->status != GPD_STATE_POWER_OFF + && new_subdomain->status != GPD_STATE_ACTIVE) { + mutex_unlock(&new_subdomain->lock); + genpd_release_lock(genpd); + goto start; + } + + if (genpd->status == GPD_STATE_POWER_OFF + && new_subdomain->status != GPD_STATE_POWER_OFF) { + ret = -EINVAL; + goto out; + } + + list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { + if (subdomain == new_subdomain) { + ret = -EINVAL; + goto out; + } + } + + list_add_tail(&new_subdomain->sd_node, &genpd->sd_list); + new_subdomain->parent = genpd; + if (subdomain->status != GPD_STATE_POWER_OFF) + genpd->sd_count++; + + out: + mutex_unlock(&new_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. + * @target: Subdomain to be removed. + */ +int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, + struct generic_pm_domain *target) +{ + struct generic_pm_domain *subdomain; + int ret = -EINVAL; + + if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(target)) + return -EINVAL; + + start: + genpd_acquire_lock(genpd); + + list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { + if (subdomain != target) + 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(&subdomain->sd_node); + subdomain->parent = NULL; + 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->sd_node); + genpd->parent = NULL; + INIT_LIST_HEAD(&genpd->dev_list); + INIT_LIST_HEAD(&genpd->sd_list); + mutex_init(&genpd->lock); + genpd->gov = gov; + INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn); + genpd->in_progress = 0; + 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); +} + +/** + * 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); +} |