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"; |
David Brownell | f1cc0a8 | 2006-08-14 23:11:08 -0700 | [diff] [blame] | 37 | case PM_EVENT_PRETHAW: return "prethaw"; |
David Brownell | fd869db | 2006-05-16 17:03:25 -0700 | [diff] [blame] | 38 | default: return "(unknown suspend event)"; |
| 39 | } |
| 40 | } |
| 41 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | /** |
| 44 | * suspend_device - Save state of one device. |
| 45 | * @dev: Device. |
| 46 | * @state: Power state device is entering. |
| 47 | */ |
| 48 | |
| 49 | int suspend_device(struct device * dev, pm_message_t state) |
| 50 | { |
| 51 | int error = 0; |
| 52 | |
mochel@digitalimplant.org | af70316 | 2005-03-21 10:41:04 -0800 | [diff] [blame] | 53 | down(&dev->sem); |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 54 | if (dev->power.power_state.event) { |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 55 | dev_dbg(dev, "PM: suspend %d-->%d\n", |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 56 | dev->power.power_state.event, state.event); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 57 | } |
Rafael J. Wysocki | 9cddad7 | 2007-06-13 15:53:34 +0200 | [diff] [blame^] | 58 | if (dev->parent && dev->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, |
Rafael J. Wysocki | 9cddad7 | 2007-06-13 15:53:34 +0200 | [diff] [blame^] | 62 | dev->parent->bus_id, |
| 63 | dev->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 | |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 68 | if (dev->class && dev->class->suspend && !dev->power.power_state.event) { |
| 69 | dev_dbg(dev, "class %s%s\n", |
| 70 | suspend_verb(state.event), |
| 71 | ((state.event == PM_EVENT_SUSPEND) |
| 72 | && device_may_wakeup(dev)) |
| 73 | ? ", may wakeup" |
| 74 | : "" |
| 75 | ); |
| 76 | error = dev->class->suspend(dev, state); |
| 77 | suspend_report_result(dev->class->suspend, error); |
| 78 | } |
| 79 | |
Dmitry Torokhov | f89cbc3 | 2007-04-03 01:08:40 -0400 | [diff] [blame] | 80 | if (!error && dev->type && dev->type->suspend && !dev->power.power_state.event) { |
| 81 | dev_dbg(dev, "%s%s\n", |
| 82 | suspend_verb(state.event), |
| 83 | ((state.event == PM_EVENT_SUSPEND) |
| 84 | && device_may_wakeup(dev)) |
| 85 | ? ", may wakeup" |
| 86 | : "" |
| 87 | ); |
| 88 | error = dev->type->suspend(dev, state); |
| 89 | suspend_report_result(dev->type->suspend, error); |
| 90 | } |
| 91 | |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 92 | if (!error && dev->bus && dev->bus->suspend && !dev->power.power_state.event) { |
David Brownell | fd869db | 2006-05-16 17:03:25 -0700 | [diff] [blame] | 93 | dev_dbg(dev, "%s%s\n", |
| 94 | suspend_verb(state.event), |
| 95 | ((state.event == PM_EVENT_SUSPEND) |
| 96 | && device_may_wakeup(dev)) |
| 97 | ? ", may wakeup" |
| 98 | : "" |
| 99 | ); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | error = dev->bus->suspend(dev, state); |
Andrew Morton | 0266949 | 2006-03-23 01:38:34 -0800 | [diff] [blame] | 101 | suspend_report_result(dev->bus->suspend, error); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 102 | } |
mochel@digitalimplant.org | af70316 | 2005-03-21 10:41:04 -0800 | [diff] [blame] | 103 | up(&dev->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | return error; |
| 105 | } |
| 106 | |
Andrew Morton | 760f1fc | 2006-05-30 21:26:03 -0700 | [diff] [blame] | 107 | |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 108 | /* |
| 109 | * This is called with interrupts off, only a single CPU |
Matthias Kaehlcke | 11048dc | 2007-05-23 14:19:41 -0700 | [diff] [blame] | 110 | * running. We can't acquire a mutex or semaphore (and we don't |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 111 | * need the protection) |
| 112 | */ |
| 113 | static int suspend_device_late(struct device *dev, pm_message_t state) |
| 114 | { |
| 115 | int error = 0; |
| 116 | |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 117 | if (dev->bus && dev->bus->suspend_late && !dev->power.power_state.event) { |
| 118 | dev_dbg(dev, "LATE %s%s\n", |
| 119 | suspend_verb(state.event), |
| 120 | ((state.event == PM_EVENT_SUSPEND) |
| 121 | && device_may_wakeup(dev)) |
| 122 | ? ", may wakeup" |
| 123 | : "" |
| 124 | ); |
| 125 | error = dev->bus->suspend_late(dev, state); |
| 126 | suspend_report_result(dev->bus->suspend_late, error); |
| 127 | } |
| 128 | return error; |
| 129 | } |
| 130 | |
| 131 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | * device_suspend - Save state and stop all devices in system. |
| 133 | * @state: Power state to put each device in. |
| 134 | * |
| 135 | * Walk the dpm_active list, call ->suspend() for each device, and move |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 136 | * it to the dpm_off list. |
| 137 | * |
| 138 | * (For historical reasons, if it returns -EAGAIN, that used to mean |
| 139 | * that the device would be called again with interrupts disabled. |
| 140 | * These days, we use the "suspend_late()" callback for that, so we |
| 141 | * print a warning and consider it an error). |
| 142 | * |
| 143 | * If we get a different error, try and back out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | * |
| 145 | * If we hit a failure with any of the devices, call device_resume() |
| 146 | * above to bring the suspended devices back to life. |
| 147 | * |
| 148 | */ |
| 149 | |
| 150 | int device_suspend(pm_message_t state) |
| 151 | { |
| 152 | int error = 0; |
| 153 | |
Pavel Machek | bb84c89 | 2006-08-31 22:02:11 -0700 | [diff] [blame] | 154 | might_sleep(); |
Matthias Kaehlcke | 11048dc | 2007-05-23 14:19:41 -0700 | [diff] [blame] | 155 | mutex_lock(&dpm_mtx); |
| 156 | mutex_lock(&dpm_list_mtx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | while (!list_empty(&dpm_active) && error == 0) { |
| 158 | struct list_head * entry = dpm_active.prev; |
| 159 | struct device * dev = to_device(entry); |
| 160 | |
| 161 | get_device(dev); |
Matthias Kaehlcke | 11048dc | 2007-05-23 14:19:41 -0700 | [diff] [blame] | 162 | mutex_unlock(&dpm_list_mtx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | |
| 164 | error = suspend_device(dev, state); |
| 165 | |
Matthias Kaehlcke | 11048dc | 2007-05-23 14:19:41 -0700 | [diff] [blame] | 166 | mutex_lock(&dpm_list_mtx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | |
| 168 | /* Check if the device got removed */ |
| 169 | if (!list_empty(&dev->power.entry)) { |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 170 | /* Move it to the dpm_off list */ |
Akinobu Mita | 1bfba4e | 2006-06-26 00:24:40 -0700 | [diff] [blame] | 171 | if (!error) |
| 172 | list_move(&dev->power.entry, &dpm_off); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | } |
| 174 | if (error) |
| 175 | printk(KERN_ERR "Could not suspend device %s: " |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 176 | "error %d%s\n", |
| 177 | kobject_name(&dev->kobj), error, |
| 178 | error == -EAGAIN ? " (please convert to suspend_late)" : ""); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | put_device(dev); |
| 180 | } |
Matthias Kaehlcke | 11048dc | 2007-05-23 14:19:41 -0700 | [diff] [blame] | 181 | mutex_unlock(&dpm_list_mtx); |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 182 | if (error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | dpm_resume(); |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 184 | |
Matthias Kaehlcke | 11048dc | 2007-05-23 14:19:41 -0700 | [diff] [blame] | 185 | mutex_unlock(&dpm_mtx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | return error; |
| 187 | } |
| 188 | |
| 189 | EXPORT_SYMBOL_GPL(device_suspend); |
| 190 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | /** |
| 192 | * device_power_down - Shut down special devices. |
| 193 | * @state: Power state to enter. |
| 194 | * |
| 195 | * Walk the dpm_off_irq list, calling ->power_down() for each device that |
| 196 | * couldn't power down the device with interrupts enabled. When we're |
| 197 | * done, power down system devices. |
| 198 | */ |
| 199 | |
| 200 | int device_power_down(pm_message_t state) |
| 201 | { |
| 202 | int error = 0; |
| 203 | struct device * dev; |
| 204 | |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 205 | while (!list_empty(&dpm_off)) { |
| 206 | struct list_head * entry = dpm_off.prev; |
| 207 | |
| 208 | dev = to_device(entry); |
| 209 | error = suspend_device_late(dev, state); |
| 210 | if (error) |
| 211 | goto Error; |
| 212 | list_move(&dev->power.entry, &dpm_off_irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | } |
Linus Torvalds | 7c8265f | 2006-06-24 14:50:29 -0700 | [diff] [blame] | 214 | |
| 215 | error = sysdev_suspend(state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | Done: |
| 217 | return error; |
| 218 | Error: |
| 219 | printk(KERN_ERR "Could not power down device %s: " |
| 220 | "error %d\n", kobject_name(&dev->kobj), error); |
| 221 | dpm_power_up(); |
| 222 | goto Done; |
| 223 | } |
| 224 | |
| 225 | EXPORT_SYMBOL_GPL(device_power_down); |
| 226 | |
Andrew Morton | 0266949 | 2006-03-23 01:38:34 -0800 | [diff] [blame] | 227 | void __suspend_report_result(const char *function, void *fn, int ret) |
| 228 | { |
| 229 | if (ret) { |
| 230 | printk(KERN_ERR "%s(): ", function); |
| 231 | print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn); |
| 232 | printk("%d\n", ret); |
| 233 | } |
| 234 | } |
| 235 | EXPORT_SYMBOL_GPL(__suspend_report_result); |