| Rafael J. Wysocki | ec2cd81 | 2012-11-02 01:40:09 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * drivers/acpi/device_pm.c - ACPI device power management routines. |
| 3 | * |
| 4 | * Copyright (C) 2012, Intel Corp. |
| 5 | * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| 6 | * |
| 7 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as published |
| 11 | * by the Free Software Foundation. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, but |
| 14 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License along |
| 19 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 20 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. |
| 21 | * |
| 22 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 23 | */ |
| 24 | |
| 25 | #include <linux/device.h> |
| 26 | #include <linux/mutex.h> |
| 27 | |
| 28 | #include <acpi/acpi.h> |
| 29 | #include <acpi/acpi_bus.h> |
| 30 | |
| 31 | static DEFINE_MUTEX(acpi_pm_notifier_lock); |
| 32 | |
| 33 | /** |
| 34 | * acpi_add_pm_notifier - Register PM notifier for given ACPI device. |
| 35 | * @adev: ACPI device to add the notifier for. |
| 36 | * @context: Context information to pass to the notifier routine. |
| 37 | * |
| 38 | * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of |
| 39 | * PM wakeup events. For example, wakeup events may be generated for bridges |
| 40 | * if one of the devices below the bridge is signaling wakeup, even if the |
| 41 | * bridge itself doesn't have a wakeup GPE associated with it. |
| 42 | */ |
| 43 | acpi_status acpi_add_pm_notifier(struct acpi_device *adev, |
| 44 | acpi_notify_handler handler, void *context) |
| 45 | { |
| 46 | acpi_status status = AE_ALREADY_EXISTS; |
| 47 | |
| 48 | mutex_lock(&acpi_pm_notifier_lock); |
| 49 | |
| 50 | if (adev->wakeup.flags.notifier_present) |
| 51 | goto out; |
| 52 | |
| 53 | status = acpi_install_notify_handler(adev->handle, |
| 54 | ACPI_SYSTEM_NOTIFY, |
| 55 | handler, context); |
| 56 | if (ACPI_FAILURE(status)) |
| 57 | goto out; |
| 58 | |
| 59 | adev->wakeup.flags.notifier_present = true; |
| 60 | |
| 61 | out: |
| 62 | mutex_unlock(&acpi_pm_notifier_lock); |
| 63 | return status; |
| 64 | } |
| 65 | |
| 66 | /** |
| 67 | * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device. |
| 68 | * @adev: ACPI device to remove the notifier from. |
| 69 | */ |
| 70 | acpi_status acpi_remove_pm_notifier(struct acpi_device *adev, |
| 71 | acpi_notify_handler handler) |
| 72 | { |
| 73 | acpi_status status = AE_BAD_PARAMETER; |
| 74 | |
| 75 | mutex_lock(&acpi_pm_notifier_lock); |
| 76 | |
| 77 | if (!adev->wakeup.flags.notifier_present) |
| 78 | goto out; |
| 79 | |
| 80 | status = acpi_remove_notify_handler(adev->handle, |
| 81 | ACPI_SYSTEM_NOTIFY, |
| 82 | handler); |
| 83 | if (ACPI_FAILURE(status)) |
| 84 | goto out; |
| 85 | |
| 86 | adev->wakeup.flags.notifier_present = false; |
| 87 | |
| 88 | out: |
| 89 | mutex_unlock(&acpi_pm_notifier_lock); |
| 90 | return status; |
| 91 | } |