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 | |
Rafael J. Wysocki | ff4da2e | 2006-03-23 03:00:07 -0800 | [diff] [blame] | 11 | #include <linux/vt_kern.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/device.h> |
Adrian Bunk | f67d115 | 2006-01-19 17:30:17 +0100 | [diff] [blame] | 13 | #include "../base.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include "power.h" |
| 15 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | /* |
| 17 | * The entries in the dpm_active list are in a depth first order, simply |
| 18 | * because children are guaranteed to be discovered after parents, and |
| 19 | * are inserted at the back of the list on discovery. |
| 20 | * |
| 21 | * All list on the suspend path are done in reverse order, so we operate |
| 22 | * on the leaves of the device tree (or forests, depending on how you want |
| 23 | * to look at it ;) first. As nodes are removed from the back of the list, |
| 24 | * they are inserted into the front of their destintation lists. |
| 25 | * |
| 26 | * Things are the reverse on the resume path - iterations are done in |
| 27 | * forward order, and nodes are inserted at the back of their destination |
| 28 | * lists. This way, the ancestors will be accessed before their descendents. |
| 29 | */ |
| 30 | |
| 31 | |
| 32 | /** |
| 33 | * suspend_device - Save state of one device. |
| 34 | * @dev: Device. |
| 35 | * @state: Power state device is entering. |
| 36 | */ |
| 37 | |
| 38 | int suspend_device(struct device * dev, pm_message_t state) |
| 39 | { |
| 40 | int error = 0; |
| 41 | |
mochel@digitalimplant.org | af70316 | 2005-03-21 10:41:04 -0800 | [diff] [blame] | 42 | down(&dev->sem); |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 43 | if (dev->power.power_state.event) { |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 44 | dev_dbg(dev, "PM: suspend %d-->%d\n", |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 45 | dev->power.power_state.event, state.event); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 46 | } |
| 47 | if (dev->power.pm_parent |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 48 | && dev->power.pm_parent->power.power_state.event) { |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 49 | dev_err(dev, |
| 50 | "PM: suspend %d->%d, parent %s already %d\n", |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 51 | dev->power.power_state.event, state.event, |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 52 | dev->power.pm_parent->bus_id, |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 53 | dev->power.pm_parent->power.power_state.event); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 54 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
| 56 | dev->power.prev_state = dev->power.power_state; |
| 57 | |
Pavel Machek | ca078ba | 2005-09-03 15:56:57 -0700 | [diff] [blame] | 58 | if (dev->bus && dev->bus->suspend && !dev->power.power_state.event) { |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 59 | dev_dbg(dev, "suspending\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | error = dev->bus->suspend(dev, state); |
David Brownell | 82428b6 | 2005-05-09 08:07:00 -0700 | [diff] [blame] | 61 | } |
mochel@digitalimplant.org | af70316 | 2005-03-21 10:41:04 -0800 | [diff] [blame] | 62 | up(&dev->sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | return error; |
| 64 | } |
| 65 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | /** |
| 67 | * device_suspend - Save state and stop all devices in system. |
| 68 | * @state: Power state to put each device in. |
| 69 | * |
| 70 | * Walk the dpm_active list, call ->suspend() for each device, and move |
| 71 | * it to dpm_off. |
| 72 | * Check the return value for each. If it returns 0, then we move the |
| 73 | * the device to the dpm_off list. If it returns -EAGAIN, we move it to |
| 74 | * the dpm_off_irq list. If we get a different error, try and back out. |
| 75 | * |
| 76 | * If we hit a failure with any of the devices, call device_resume() |
| 77 | * above to bring the suspended devices back to life. |
| 78 | * |
| 79 | */ |
| 80 | |
| 81 | int device_suspend(pm_message_t state) |
| 82 | { |
| 83 | int error = 0; |
| 84 | |
Rafael J. Wysocki | ff4da2e | 2006-03-23 03:00:07 -0800 | [diff] [blame] | 85 | if (!is_console_suspend_safe()) |
| 86 | return -EINVAL; |
| 87 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | down(&dpm_sem); |
| 89 | down(&dpm_list_sem); |
| 90 | while (!list_empty(&dpm_active) && error == 0) { |
| 91 | struct list_head * entry = dpm_active.prev; |
| 92 | struct device * dev = to_device(entry); |
| 93 | |
| 94 | get_device(dev); |
| 95 | up(&dpm_list_sem); |
| 96 | |
| 97 | error = suspend_device(dev, state); |
| 98 | |
| 99 | down(&dpm_list_sem); |
| 100 | |
| 101 | /* Check if the device got removed */ |
| 102 | if (!list_empty(&dev->power.entry)) { |
| 103 | /* Move it to the dpm_off or dpm_off_irq list */ |
| 104 | if (!error) { |
| 105 | list_del(&dev->power.entry); |
| 106 | list_add(&dev->power.entry, &dpm_off); |
| 107 | } else if (error == -EAGAIN) { |
| 108 | list_del(&dev->power.entry); |
| 109 | list_add(&dev->power.entry, &dpm_off_irq); |
| 110 | error = 0; |
| 111 | } |
| 112 | } |
| 113 | if (error) |
| 114 | printk(KERN_ERR "Could not suspend device %s: " |
| 115 | "error %d\n", kobject_name(&dev->kobj), error); |
| 116 | put_device(dev); |
| 117 | } |
| 118 | up(&dpm_list_sem); |
Benjamin Herrenschmidt | 42b16c05 | 2005-05-31 17:08:49 +1000 | [diff] [blame] | 119 | if (error) { |
| 120 | /* we failed... before resuming, bring back devices from |
| 121 | * dpm_off_irq list back to main dpm_off list, we do want |
| 122 | * to call resume() on them, in case they partially suspended |
| 123 | * despite returning -EAGAIN |
| 124 | */ |
| 125 | while (!list_empty(&dpm_off_irq)) { |
| 126 | struct list_head * entry = dpm_off_irq.next; |
| 127 | list_del(entry); |
| 128 | list_add(entry, &dpm_off); |
| 129 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | dpm_resume(); |
Benjamin Herrenschmidt | 42b16c05 | 2005-05-31 17:08:49 +1000 | [diff] [blame] | 131 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | up(&dpm_sem); |
| 133 | return error; |
| 134 | } |
| 135 | |
| 136 | EXPORT_SYMBOL_GPL(device_suspend); |
| 137 | |
| 138 | |
| 139 | /** |
| 140 | * device_power_down - Shut down special devices. |
| 141 | * @state: Power state to enter. |
| 142 | * |
| 143 | * Walk the dpm_off_irq list, calling ->power_down() for each device that |
| 144 | * couldn't power down the device with interrupts enabled. When we're |
| 145 | * done, power down system devices. |
| 146 | */ |
| 147 | |
| 148 | int device_power_down(pm_message_t state) |
| 149 | { |
| 150 | int error = 0; |
| 151 | struct device * dev; |
| 152 | |
| 153 | list_for_each_entry_reverse(dev, &dpm_off_irq, power.entry) { |
| 154 | if ((error = suspend_device(dev, state))) |
| 155 | break; |
| 156 | } |
| 157 | if (error) |
| 158 | goto Error; |
| 159 | if ((error = sysdev_suspend(state))) |
| 160 | goto Error; |
| 161 | Done: |
| 162 | return error; |
| 163 | Error: |
| 164 | printk(KERN_ERR "Could not power down device %s: " |
| 165 | "error %d\n", kobject_name(&dev->kobj), error); |
| 166 | dpm_power_up(); |
| 167 | goto Done; |
| 168 | } |
| 169 | |
| 170 | EXPORT_SYMBOL_GPL(device_power_down); |
| 171 | |