1 /* 2 * drivers/base/power/main.c - Where the driver meets power management. 3 * 4 * Copyright (c) 2003 Patrick Mochel 5 * Copyright (c) 2003 Open Source Development Lab 6 * 7 * This file is released under the GPLv2 8 * 9 * 10 * The driver model core calls device_pm_add() when a device is registered. 11 * This will intialize the embedded device_pm_info object in the device 12 * and add it to the list of power-controlled devices. sysfs entries for 13 * controlling device power management will also be added. 14 * 15 * A different set of lists than the global subsystem list are used to 16 * keep track of power info because we use different lists to hold 17 * devices based on what stage of the power management process they 18 * are in. The power domain dependencies may also differ from the 19 * ancestral dependencies that the subsystem list maintains. 20 */ 21 22 #include <linux/device.h> 23 #include "power.h" 24 25 LIST_HEAD(dpm_active); 26 LIST_HEAD(dpm_off); 27 LIST_HEAD(dpm_off_irq); 28 29 DECLARE_MUTEX(dpm_sem); 30 DECLARE_MUTEX(dpm_list_sem); 31 32 int (*platform_enable_wakeup)(struct device *dev, int is_on); 33 34 35 /** 36 * device_pm_set_parent - Specify power dependency. 37 * @dev: Device who needs power. 38 * @parent: Device that supplies power. 39 * 40 * This function is used to manually describe a power-dependency 41 * relationship. It may be used to specify a transversal relationship 42 * (where the power supplier is not the physical (or electrical) 43 * ancestor of a specific device. 44 * The effect of this is that the supplier will not be powered down 45 * before the power dependent. 46 */ 47 48 void device_pm_set_parent(struct device * dev, struct device * parent) 49 { 50 put_device(dev->power.pm_parent); 51 dev->power.pm_parent = get_device(parent); 52 } 53 EXPORT_SYMBOL_GPL(device_pm_set_parent); 54 55 int device_pm_add(struct device * dev) 56 { 57 int error; 58 59 pr_debug("PM: Adding info for %s:%s\n", 60 dev->bus ? dev->bus->name : "No Bus", 61 kobject_name(&dev->kobj)); 62 down(&dpm_list_sem); 63 list_add_tail(&dev->power.entry, &dpm_active); 64 device_pm_set_parent(dev, dev->parent); 65 if ((error = dpm_sysfs_add(dev))) 66 list_del(&dev->power.entry); 67 up(&dpm_list_sem); 68 return error; 69 } 70 71 void device_pm_remove(struct device * dev) 72 { 73 pr_debug("PM: Removing info for %s:%s\n", 74 dev->bus ? dev->bus->name : "No Bus", 75 kobject_name(&dev->kobj)); 76 down(&dpm_list_sem); 77 dpm_sysfs_remove(dev); 78 put_device(dev->power.pm_parent); 79 list_del_init(&dev->power.entry); 80 up(&dpm_list_sem); 81 } 82 83 84