X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fbase%2Fpower%2Fmain.c;h=05dc8764e7650170ceabfd9c7f0fc8223afd33ce;hb=9617c3e460bbccb6d9496a1f1e6903eb81f336e9;hp=0d2e101e4f158c60b88f66db966d5047b2dc05ed;hpb=3d5271f9883cba7b54762bc4fe027d4172f06db7;p=linux-2.6-omap-h63xx.git diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 0d2e101e4f1..bdc03f7e842 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -19,61 +19,534 @@ * ancestral dependencies that the subsystem list maintains. */ -#include #include +#include +#include +#include +#include +#include + +#include "../base.h" #include "power.h" +/* + * The entries in the dpm_active list are in a depth first order, simply + * because children are guaranteed to be discovered after parents, and + * are inserted at the back of the list on discovery. + * + * All the other lists are kept in the same order, for consistency. + * However the lists aren't always traversed in the same order. + * Semaphores must be acquired from the top (i.e., front) down + * and released in the opposite order. Devices must be suspended + * from the bottom (i.e., end) up and resumed in the opposite order. + * That way no parent will be suspended while it still has an active + * child. + * + * Since device_pm_add() may be called with a device semaphore held, + * we must never try to acquire a device semaphore while holding + * dpm_list_mutex. + */ + LIST_HEAD(dpm_active); -LIST_HEAD(dpm_off); -LIST_HEAD(dpm_off_irq); +static LIST_HEAD(dpm_locked); +static LIST_HEAD(dpm_off); +static LIST_HEAD(dpm_off_irq); +static LIST_HEAD(dpm_destroy); -DECLARE_MUTEX(dpm_sem); -DECLARE_MUTEX(dpm_list_sem); +static DEFINE_MUTEX(dpm_list_mtx); + +static DECLARE_RWSEM(pm_sleep_rwsem); + +int (*platform_enable_wakeup)(struct device *dev, int is_on); + +/** + * device_pm_add - add a device to the list of active devices + * @dev: Device to be added 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", + kobject_name(&dev->kobj)); + mutex_lock(&dpm_list_mtx); + list_add_tail(&dev->power.entry, &dpm_active); + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_pm_remove - remove a device from the list of active devices + * @dev: Device to be removed from the list + * + * This function also removes the device's PM-related sysfs attributes. + */ +void device_pm_remove(struct device *dev) +{ + /* + * If this function is called during a suspend, it will be blocked, + * because we're holding the device's semaphore at that time, which may + * lead to a deadlock. In that case we want to print a warning. + * However, it may also be called by unregister_dropped_devices() with + * the device's semaphore released, in which case the warning should + * not be printed. + */ + if (down_trylock(&dev->sem)) { + if (down_read_trylock(&pm_sleep_rwsem)) { + /* No suspend in progress, wait on dev->sem */ + down(&dev->sem); + up_read(&pm_sleep_rwsem); + } else { + /* Suspend in progress, we may deadlock */ + dev_warn(dev, "Suspicious %s during suspend\n", + __FUNCTION__); + dump_stack(); + /* The user has been warned ... */ + down(&dev->sem); + } + } + pr_debug("PM: Removing info for %s:%s\n", + dev->bus ? dev->bus->name : "No Bus", + kobject_name(&dev->kobj)); + mutex_lock(&dpm_list_mtx); + dpm_sysfs_remove(dev); + list_del_init(&dev->power.entry); + mutex_unlock(&dpm_list_mtx); + up(&dev->sem); +} /** - * device_pm_set_parent - Specify power dependency. - * @dev: Device who needs power. - * @parent: Device that supplies power. + * device_pm_schedule_removal - schedule the removal of a suspended device + * @dev: Device to destroy * - * This function is used to manually describe a power-dependency - * relationship. It may be used to specify a transversal relationship - * (where the power supplier is not the physical (or electrical) - * ancestor of a specific device. - * The effect of this is that the supplier will not be powered down - * before the power dependent. + * Moves the device to the dpm_destroy list for further processing by + * unregister_dropped_devices(). */ +void device_pm_schedule_removal(struct device *dev) +{ + pr_debug("PM: Preparing for removal: %s:%s\n", + dev->bus ? dev->bus->name : "No Bus", + kobject_name(&dev->kobj)); + mutex_lock(&dpm_list_mtx); + list_move_tail(&dev->power.entry, &dpm_destroy); + mutex_unlock(&dpm_list_mtx); +} +EXPORT_SYMBOL_GPL(device_pm_schedule_removal); -void device_pm_set_parent(struct device * dev, struct device * parent) +/** + * pm_sleep_lock - mutual exclusion for registration and suspend + * + * Returns 0 if no suspend is underway and device registration + * may proceed, otherwise -EBUSY. + */ +int pm_sleep_lock(void) { - put_device(dev->power.pm_parent); - dev->power.pm_parent = get_device(parent); + if (down_read_trylock(&pm_sleep_rwsem)) + return 0; + + return -EBUSY; } -EXPORT_SYMBOL_GPL(device_pm_set_parent); -int device_pm_add(struct device * dev) +/** + * pm_sleep_unlock - mutual exclusion for registration and suspend + * + * This routine undoes the effect of device_pm_add_lock + * when a device's registration is complete. + */ +void pm_sleep_unlock(void) { - int error; + up_read(&pm_sleep_rwsem); +} - pr_debug("PM: Adding info for %s:%s\n", - dev->bus ? dev->bus->name : "No Bus", dev->kobj.name); - down(&dpm_list_sem); - list_add_tail(&dev->power.entry, &dpm_active); - device_pm_set_parent(dev, dev->parent); - if ((error = dpm_sysfs_add(dev))) - list_del(&dev->power.entry); - up(&dpm_list_sem); + +/*------------------------- Resume routines -------------------------*/ + +/** + * resume_device_early - Power on one device (early resume). + * @dev: Device. + * + * Must be called with interrupts disabled. + */ +static int resume_device_early(struct device *dev) +{ + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + if (dev->bus && dev->bus->resume_early) { + dev_dbg(dev, "EARLY resume\n"); + error = dev->bus->resume_early(dev); + } + + TRACE_RESUME(error); return error; } -void device_pm_remove(struct device * dev) +/** + * dpm_power_up - Power on all regular (non-sysdev) devices. + * + * Walk the dpm_off_irq list and power each device up. This + * is used for devices that required they be powered down with + * interrupts disabled. As devices are powered on, they are moved + * to the dpm_off list. + * + * Must be called with interrupts disabled and only one CPU running. + */ +static void dpm_power_up(void) { - pr_debug("PM: Removing info for %s:%s\n", - dev->bus ? dev->bus->name : "No Bus", dev->kobj.name); - down(&dpm_list_sem); - dpm_sysfs_remove(dev); - put_device(dev->power.pm_parent); - list_del_init(&dev->power.entry); - up(&dpm_list_sem); + + while (!list_empty(&dpm_off_irq)) { + struct list_head *entry = dpm_off_irq.next; + struct device *dev = to_device(entry); + + list_move_tail(entry, &dpm_off); + resume_device_early(dev); + } +} + +/** + * device_power_up - Turn on all devices that need special attention. + * + * Power on system devices, then devices that required we shut them down + * with interrupts disabled. + * + * Must be called with interrupts disabled. + */ +void device_power_up(void) +{ + sysdev_resume(); + dpm_power_up(); +} +EXPORT_SYMBOL_GPL(device_power_up); + +/** + * resume_device - Restore state for one device. + * @dev: Device. + * + */ +static int resume_device(struct device *dev) +{ + int error = 0; + + TRACE_DEVICE(dev); + TRACE_RESUME(0); + + if (dev->bus && dev->bus->resume) { + dev_dbg(dev,"resuming\n"); + error = dev->bus->resume(dev); + } + + if (!error && dev->type && dev->type->resume) { + dev_dbg(dev,"resuming\n"); + error = dev->type->resume(dev); + } + + if (!error && dev->class && dev->class->resume) { + dev_dbg(dev,"class resume\n"); + error = dev->class->resume(dev); + } + + TRACE_RESUME(error); + return error; +} + +/** + * dpm_resume - Resume every device. + * + * Resume the devices that have either not gone through + * the late suspend, or that did go through it but also + * went through the early resume. + * + * Take devices from the dpm_off_list, resume them, + * and put them on the dpm_locked list. + */ +static void dpm_resume(void) +{ + mutex_lock(&dpm_list_mtx); + while(!list_empty(&dpm_off)) { + struct list_head *entry = dpm_off.next; + struct device *dev = to_device(entry); + + list_move_tail(entry, &dpm_locked); + mutex_unlock(&dpm_list_mtx); + resume_device(dev); + mutex_lock(&dpm_list_mtx); + } + mutex_unlock(&dpm_list_mtx); +} + +/** + * unlock_all_devices - Release each device's semaphore + * + * Go through the dpm_off list. Put each device on the dpm_active + * list and unlock it. + */ +static void unlock_all_devices(void) +{ + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_locked)) { + struct list_head *entry = dpm_locked.prev; + struct device *dev = to_device(entry); + + list_move(entry, &dpm_active); + up(&dev->sem); + } + mutex_unlock(&dpm_list_mtx); +} + +/** + * unregister_dropped_devices - Unregister devices scheduled for removal + * + * Unregister all devices on the dpm_destroy list. + */ +static void unregister_dropped_devices(void) +{ + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_destroy)) { + struct list_head *entry = dpm_destroy.next; + struct device *dev = to_device(entry); + + up(&dev->sem); + mutex_unlock(&dpm_list_mtx); + /* This also removes the device from the list */ + device_unregister(dev); + mutex_lock(&dpm_list_mtx); + } + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_resume - Restore state of each device in system. + * + * Resume all the devices, unlock them all, and allow new + * devices to be registered once again. + */ +void device_resume(void) +{ + might_sleep(); + dpm_resume(); + unlock_all_devices(); + unregister_dropped_devices(); + up_write(&pm_sleep_rwsem); +} +EXPORT_SYMBOL_GPL(device_resume); + + +/*------------------------- Suspend routines -------------------------*/ + +static inline char *suspend_verb(u32 event) +{ + switch (event) { + case PM_EVENT_SUSPEND: return "suspend"; + case PM_EVENT_FREEZE: return "freeze"; + case PM_EVENT_PRETHAW: return "prethaw"; + default: return "(unknown suspend event)"; + } +} + +static void +suspend_device_dbg(struct device *dev, pm_message_t state, char *info) +{ + dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event), + ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ? + ", may wakeup" : ""); +} + +/** + * suspend_device_late - Shut down one device (late suspend). + * @dev: Device. + * @state: Power state device is entering. + * + * This is called with interrupts off and only a single CPU running. + */ +static int suspend_device_late(struct device *dev, pm_message_t state) +{ + int error = 0; + + if (dev->bus && dev->bus->suspend_late) { + suspend_device_dbg(dev, state, "LATE "); + error = dev->bus->suspend_late(dev, state); + suspend_report_result(dev->bus->suspend_late, error); + } + return error; +} + +/** + * device_power_down - Shut down special devices. + * @state: Power state to enter. + * + * Power down devices that require interrupts to be disabled + * and move them from the dpm_off list to the dpm_off_irq list. + * Then power down system devices. + * + * Must be called with interrupts disabled and only one CPU running. + */ +int device_power_down(pm_message_t state) +{ + int error = 0; + + while (!list_empty(&dpm_off)) { + struct list_head *entry = dpm_off.prev; + struct device *dev = to_device(entry); + + list_del_init(&dev->power.entry); + error = suspend_device_late(dev, state); + if (error) { + printk(KERN_ERR "Could not power down device %s: " + "error %d\n", + kobject_name(&dev->kobj), error); + if (list_empty(&dev->power.entry)) + list_add(&dev->power.entry, &dpm_off); + break; + } + if (list_empty(&dev->power.entry)) + list_add(&dev->power.entry, &dpm_off_irq); + } + + if (!error) + error = sysdev_suspend(state); + if (error) + dpm_power_up(); + return error; +} +EXPORT_SYMBOL_GPL(device_power_down); + +/** + * suspend_device - Save state of one device. + * @dev: Device. + * @state: Power state device is entering. + */ +int suspend_device(struct device *dev, pm_message_t state) +{ + int error = 0; + + if (dev->power.power_state.event) { + dev_dbg(dev, "PM: suspend %d-->%d\n", + dev->power.power_state.event, state.event); + } + + if (dev->class && dev->class->suspend) { + suspend_device_dbg(dev, state, "class "); + error = dev->class->suspend(dev, state); + suspend_report_result(dev->class->suspend, error); + } + + if (!error && dev->type && dev->type->suspend) { + suspend_device_dbg(dev, state, "type "); + error = dev->type->suspend(dev, state); + suspend_report_result(dev->type->suspend, error); + } + + if (!error && dev->bus && dev->bus->suspend) { + suspend_device_dbg(dev, state, ""); + error = dev->bus->suspend(dev, state); + suspend_report_result(dev->bus->suspend, error); + } + return error; +} + +/** + * dpm_suspend - Suspend every device. + * @state: Power state to put each device in. + * + * Walk the dpm_locked list. Suspend each device and move it + * to the dpm_off list. + * + * (For historical reasons, if it returns -EAGAIN, that used to mean + * that the device would be called again with interrupts disabled. + * These days, we use the "suspend_late()" callback for that, so we + * print a warning and consider it an error). + */ +static int dpm_suspend(pm_message_t state) +{ + int error = 0; + + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_locked)) { + struct list_head *entry = dpm_locked.prev; + struct device *dev = to_device(entry); + + list_del_init(&dev->power.entry); + mutex_unlock(&dpm_list_mtx); + error = suspend_device(dev, state); + if (error) { + printk(KERN_ERR "Could not suspend device %s: " + "error %d%s\n", + kobject_name(&dev->kobj), + error, + (error == -EAGAIN ? + " (please convert to suspend_late)" : + "")); + mutex_lock(&dpm_list_mtx); + if (list_empty(&dev->power.entry)) + list_add(&dev->power.entry, &dpm_locked); + mutex_unlock(&dpm_list_mtx); + break; + } + mutex_lock(&dpm_list_mtx); + if (list_empty(&dev->power.entry)) + list_add(&dev->power.entry, &dpm_off); + } + mutex_unlock(&dpm_list_mtx); + + return error; } +/** + * lock_all_devices - Acquire every device's semaphore + * + * Go through the dpm_active list. Carefully lock each device's + * semaphore and put it in on the dpm_locked list. + */ +static void lock_all_devices(void) +{ + mutex_lock(&dpm_list_mtx); + while (!list_empty(&dpm_active)) { + struct list_head *entry = dpm_active.next; + struct device *dev = to_device(entry); + + /* Required locking order is dev->sem first, + * then dpm_list_mutex. Hence this awkward code. + */ + get_device(dev); + mutex_unlock(&dpm_list_mtx); + down(&dev->sem); + mutex_lock(&dpm_list_mtx); + if (list_empty(entry)) + up(&dev->sem); /* Device was removed */ + else + list_move_tail(entry, &dpm_locked); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); +} + +/** + * device_suspend - Save state and stop all devices in system. + * + * Prevent new devices from being registered, then lock all devices + * and suspend them. + */ +int device_suspend(pm_message_t state) +{ + int error; + + might_sleep(); + down_write(&pm_sleep_rwsem); + lock_all_devices(); + error = dpm_suspend(state); + if (error) + device_resume(); + return error; +} +EXPORT_SYMBOL_GPL(device_suspend); + +void __suspend_report_result(const char *function, void *fn, int ret) +{ + if (ret) { + printk(KERN_ERR "%s(): ", function); + print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn); + printk("%d\n", ret); + } +} +EXPORT_SYMBOL_GPL(__suspend_report_result);