Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * suspend.c - Functions for putting devices to sleep. |
| 3 | * |
| 4 | * Copyright (c) 2003 Patrick Mochel |
| 5 | * Copyright (c) 2003 Open Source Development Labs |
| 6 | * |
| 7 | * This file is released under the GPLv2 |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | #include <linux/device.h> |
Andrew Morton | 0266949 | 2006-03-23 01:38:34 -0800 | [diff] [blame] | 12 | #include <linux/kallsyms.h> |
| 13 | #include <linux/pm.h> |
Adrian Bunk | f67d115 | 2006-01-19 17:30:17 +0100 | [diff] [blame] | 14 | #include "../base.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include "power.h" |
| 16 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | /* |
| 18 | * The entries in the dpm_active list are in a depth first order, simply |
| 19 | * because children are guaranteed to be discovered after parents, and |
| 20 | * are inserted at the back of the list on discovery. |
| 21 | * |
| 22 | * All list on the suspend path are done in reverse order, so we operate |
| 23 | * on the leaves of the device tree (or forests, depending on how you want |
| 24 | * to look at it ;) first. As nodes are removed from the back of the list, |
| 25 | * they are inserted into the front of their destintation lists. |
| 26 | * |
| 27 | * Things are the reverse on the resume path - iterations are done in |
| 28 | * forward order, and nodes are inserted at the back of their destination |
| 29 | * lists. This way, the ancestors will be accessed before their descendents. |
| 30 | */ |
| 31 | |
David Brownell | fd869db | 2006-05-16 17:03:25 -0700 | [diff] [blame] | 32 | static inline char *suspend_verb(u32 event) |
| 33 | { |
| 34 | switch (event) { |
| 35 | case PM_EVENT_SUSPEND: return "suspend"; |
| 36 | case PM_EVENT_FREEZE: return "freeze"; |
| 37 | default: return "(unknown suspend event)"; |
| 38 | } |
| 39 | } |
| 40 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | |
| 42 | /** |
| 43 | * suspend_device - Save state of one device. |
| 44 | * @dev: Device. |
| 45 | * @state: Power state device is entering. |
| 46 | */ |
| 47 | |
| 48 | int suspend_device(struct device * dev, pm_message_t state) |
| 49 | { |
| 50 | int error = 0; |
| 51 | |
mochel@digitalimplant.org | af70316 | 2005-03-21 10:41:04 -0800 | [diff] [blame] | 52 | down(&dev->sem); |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 53 | if (dev->power.power_state.event) { |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 54 | dev_dbg(dev, "PM: suspend %d-->%d\n", |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 55 | dev->power.power_state.event, state.event); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 56 | } |
| 57 | if (dev->power.pm_parent |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 58 | && dev->power.pm_parent->power.power_state.event) { |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 59 | dev_err(dev, |
| 60 | "PM: suspend %d->%d, parent %s already %d\n", |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 61 | dev->power.power_state.event, state.event, |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 62 | dev->power.pm_parent->bus_id, |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 63 | dev->power.pm_parent->power.power_state.event); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 64 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
| 66 | dev->power.prev_state = dev->power.power_state; |
| 67 | |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 68 | if (dev->bus && dev->bus->suspend && !dev->power.power_state.event) { |
David Brownell | fd869db | 2006-05-16 17:03:25 -0700 | [diff] [blame] | 69 | dev_dbg(dev, "%s%s\n", |
| 70 | suspend_verb(state.event), |
| 71 | ((state.event == PM_EVENT_SUSPEND) |
| 72 | && device_may_wakeup(dev)) |
| 73 | ? ", may wakeup" |
| 74 | : "" |
| 75 | ); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | error = dev->bus->suspend(dev, state); |
Andrew Morton | 0266949 | 2006-03-23 01:38:34 -0800 | [diff] [blame] | 77 | suspend_report_result(dev->bus->suspend, error); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 78 | } |
mochel@digitalimplant.org | af70316 | 2005-03-21 10:41:04 -0800 | [diff] [blame] | 79 | up(&dev->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | return error; |
| 81 | } |
| 82 | |
Andrew Morton | 760f1fc | 2006-05-30 21:26:03 -0700 | [diff] [blame] | 83 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | /** |
| 85 | * device_suspend - Save state and stop all devices in system. |
| 86 | * @state: Power state to put each device in. |
| 87 | * |
| 88 | * Walk the dpm_active list, call ->suspend() for each device, and move |
| 89 | * it to dpm_off. |
| 90 | * Check the return value for each. If it returns 0, then we move the |
| 91 | * the device to the dpm_off list. If it returns -EAGAIN, we move it to |
| 92 | * the dpm_off_irq list. If we get a different error, try and back out. |
| 93 | * |
| 94 | * If we hit a failure with any of the devices, call device_resume() |
| 95 | * above to bring the suspended devices back to life. |
| 96 | * |
| 97 | */ |
| 98 | |
| 99 | int device_suspend(pm_message_t state) |
| 100 | { |
| 101 | int error = 0; |
| 102 | |
| 103 | down(&dpm_sem); |
| 104 | down(&dpm_list_sem); |
| 105 | while (!list_empty(&dpm_active) && error == 0) { |
| 106 | struct list_head * entry = dpm_active.prev; |
| 107 | struct device * dev = to_device(entry); |
| 108 | |
| 109 | get_device(dev); |
| 110 | up(&dpm_list_sem); |
| 111 | |
| 112 | error = suspend_device(dev, state); |
| 113 | |
| 114 | down(&dpm_list_sem); |
| 115 | |
| 116 | /* Check if the device got removed */ |
| 117 | if (!list_empty(&dev->power.entry)) { |
| 118 | /* Move it to the dpm_off or dpm_off_irq list */ |
| 119 | if (!error) { |
| 120 | list_del(&dev->power.entry); |
| 121 | list_add(&dev->power.entry, &dpm_off); |
| 122 | } else if (error == -EAGAIN) { |
| 123 | list_del(&dev->power.entry); |
| 124 | list_add(&dev->power.entry, &dpm_off_irq); |
| 125 | error = 0; |
| 126 | } |
| 127 | } |
| 128 | if (error) |
| 129 | printk(KERN_ERR "Could not suspend device %s: " |
| 130 | "error %d\n", kobject_name(&dev->kobj), error); |
| 131 | put_device(dev); |
| 132 | } |
| 133 | up(&dpm_list_sem); |
Benjamin Herrenschmidt | 42b16c0 | 2005-05-31 17:08:49 +1000 | [diff] [blame] | 134 | if (error) { |
| 135 | /* we failed... before resuming, bring back devices from |
| 136 | * dpm_off_irq list back to main dpm_off list, we do want |
| 137 | * to call resume() on them, in case they partially suspended |
| 138 | * despite returning -EAGAIN |
| 139 | */ |
| 140 | while (!list_empty(&dpm_off_irq)) { |
| 141 | struct list_head * entry = dpm_off_irq.next; |
| 142 | list_del(entry); |
| 143 | list_add(entry, &dpm_off); |
| 144 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | dpm_resume(); |
Benjamin Herrenschmidt | 42b16c0 | 2005-05-31 17:08:49 +1000 | [diff] [blame] | 146 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | up(&dpm_sem); |
| 148 | return error; |
| 149 | } |
| 150 | |
| 151 | EXPORT_SYMBOL_GPL(device_suspend); |
| 152 | |
| 153 | |
| 154 | /** |
| 155 | * device_power_down - Shut down special devices. |
| 156 | * @state: Power state to enter. |
| 157 | * |
| 158 | * Walk the dpm_off_irq list, calling ->power_down() for each device that |
| 159 | * couldn't power down the device with interrupts enabled. When we're |
| 160 | * done, power down system devices. |
| 161 | */ |
| 162 | |
| 163 | int device_power_down(pm_message_t state) |
| 164 | { |
| 165 | int error = 0; |
| 166 | struct device * dev; |
| 167 | |
| 168 | list_for_each_entry_reverse(dev, &dpm_off_irq, power.entry) { |
| 169 | if ((error = suspend_device(dev, state))) |
| 170 | break; |
| 171 | } |
| 172 | if (error) |
| 173 | goto Error; |
| 174 | if ((error = sysdev_suspend(state))) |
| 175 | goto Error; |
| 176 | Done: |
| 177 | return error; |
| 178 | Error: |
| 179 | printk(KERN_ERR "Could not power down device %s: " |
| 180 | "error %d\n", kobject_name(&dev->kobj), error); |
| 181 | dpm_power_up(); |
| 182 | goto Done; |
| 183 | } |
| 184 | |
| 185 | EXPORT_SYMBOL_GPL(device_power_down); |
| 186 | |
Andrew Morton | 0266949 | 2006-03-23 01:38:34 -0800 | [diff] [blame] | 187 | void __suspend_report_result(const char *function, void *fn, int ret) |
| 188 | { |
| 189 | if (ret) { |
| 190 | printk(KERN_ERR "%s(): ", function); |
| 191 | print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn); |
| 192 | printk("%d\n", ret); |
| 193 | } |
| 194 | } |
| 195 | EXPORT_SYMBOL_GPL(__suspend_report_result); |