diff options
Diffstat (limited to 'kernel/power/pm.c')
| -rw-r--r-- | kernel/power/pm.c | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/kernel/power/pm.c b/kernel/power/pm.c deleted file mode 100644 index 60c73fa670d..00000000000 --- a/kernel/power/pm.c +++ /dev/null @@ -1,205 +0,0 @@ -/* - * pm.c - Power management interface - * - * Copyright (C) 2000 Andrew Henroid - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ -#include <linux/init.h> -#include <linux/module.h> -#include <linux/spinlock.h> -#include <linux/mm.h> -#include <linux/slab.h> -#include <linux/pm.h> -#include <linux/pm_legacy.h> -#include <linux/interrupt.h> -#include <linux/mutex.h> - -/* - * Locking notes: - * pm_devs_lock can be a semaphore providing pm ops are not called - * from an interrupt handler (already a bad idea so no change here). Each - * change must be protected so that an unlink of an entry doesn't clash - * with a pm send - which is permitted to sleep in the current architecture - * - * Module unloads clashing with pm events now work out safely, the module - * unload path will block until the event has been sent. It may well block - * until a resume but that will be fine. - */ - -static DEFINE_MUTEX(pm_devs_lock); -static LIST_HEAD(pm_devs); - -/** - * pm_register - register a device with power management - * @type: device type - * @id: device ID - * @callback: callback function - * - * Add a device to the list of devices that wish to be notified about - * power management events. A &pm_dev structure is returned on success, - * on failure the return is %NULL. - * - * The callback function will be called in process context and - * it may sleep. - */ - -struct pm_dev *pm_register(pm_dev_t type, - unsigned long id, - pm_callback callback) -{ - struct pm_dev *dev = kzalloc(sizeof(struct pm_dev), GFP_KERNEL); - if (dev) { - dev->type = type; - dev->id = id; - dev->callback = callback; - - mutex_lock(&pm_devs_lock); - list_add(&dev->entry, &pm_devs); - mutex_unlock(&pm_devs_lock); - } - return dev; -} - -/** - * pm_send - send request to a single device - * @dev: device to send to - * @rqst: power management request - * @data: data for the callback - * - * Issue a power management request to a given device. The - * %PM_SUSPEND and %PM_RESUME events are handled specially. The - * data field must hold the intended next state. No call is made - * if the state matches. - * - * BUGS: what stops two power management requests occurring in parallel - * and conflicting. - * - * WARNING: Calling pm_send directly is not generally recommended, in - * particular there is no locking against the pm_dev going away. The - * caller must maintain all needed locking or have 'inside knowledge' - * on the safety. Also remember that this function is not locked against - * pm_unregister. This means that you must handle SMP races on callback - * execution and unload yourself. - */ - -static int pm_send(struct pm_dev *dev, pm_request_t rqst, void *data) -{ - int status = 0; - unsigned long prev_state, next_state; - - if (in_interrupt()) - BUG(); - - switch (rqst) { - case PM_SUSPEND: - case PM_RESUME: - prev_state = dev->state; - next_state = (unsigned long) data; - if (prev_state != next_state) { - if (dev->callback) - status = (*dev->callback)(dev, rqst, data); - if (!status) { - dev->state = next_state; - dev->prev_state = prev_state; - } - } - else { - dev->prev_state = prev_state; - } - break; - default: - if (dev->callback) - status = (*dev->callback)(dev, rqst, data); - break; - } - return status; -} - -/* - * Undo incomplete request - */ -static void pm_undo_all(struct pm_dev *last) -{ - struct list_head *entry = last->entry.prev; - while (entry != &pm_devs) { - struct pm_dev *dev = list_entry(entry, struct pm_dev, entry); - if (dev->state != dev->prev_state) { - /* previous state was zero (running) resume or - * previous state was non-zero (suspended) suspend - */ - pm_request_t undo = (dev->prev_state - ? PM_SUSPEND:PM_RESUME); - pm_send(dev, undo, (void*) dev->prev_state); - } - entry = entry->prev; - } -} - -/** - * pm_send_all - send request to all managed devices - * @rqst: power management request - * @data: data for the callback - * - * Issue a power management request to a all devices. The - * %PM_SUSPEND events are handled specially. Any device is - * permitted to fail a suspend by returning a non zero (error) - * value from its callback function. If any device vetoes a - * suspend request then all other devices that have suspended - * during the processing of this request are restored to their - * previous state. - * - * WARNING: This function takes the pm_devs_lock. The lock is not dropped until - * the callbacks have completed. This prevents races against pm locking - * functions, races against module unload pm_unregister code. It does - * mean however that you must not issue pm_ functions within the callback - * or you will deadlock and users will hate you. - * - * Zero is returned on success. If a suspend fails then the status - * from the device that vetoes the suspend is returned. - * - * BUGS: what stops two power management requests occurring in parallel - * and conflicting. - */ - -int pm_send_all(pm_request_t rqst, void *data) -{ - struct list_head *entry; - - mutex_lock(&pm_devs_lock); - entry = pm_devs.next; - while (entry != &pm_devs) { - struct pm_dev *dev = list_entry(entry, struct pm_dev, entry); - if (dev->callback) { - int status = pm_send(dev, rqst, data); - if (status) { - /* return devices to previous state on - * failed suspend request - */ - if (rqst == PM_SUSPEND) - pm_undo_all(dev); - mutex_unlock(&pm_devs_lock); - return status; - } - } - entry = entry->next; - } - mutex_unlock(&pm_devs_lock); - return 0; -} - -EXPORT_SYMBOL(pm_register); -EXPORT_SYMBOL(pm_send_all); - |