| Colin Cross | 06e8572 | 2011-11-09 16:39:19 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 Google, Inc. |
| 3 | * |
| 4 | * Author: |
| 5 | * Colin Cross <ccross <at> android.com> |
| 6 | * |
| 7 | * This software is licensed under the terms of the GNU General Public |
| 8 | * License version 2, as published by the Free Software Foundation, and |
| 9 | * may be copied, distributed, and modified under those terms. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | */ |
| 17 | |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/cpu_pm.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/notifier.h> |
| 22 | #include <linux/spinlock.h> |
| 23 | |
| 24 | static DEFINE_RWLOCK(cpu_pm_notifier_lock); |
| 25 | static RAW_NOTIFIER_HEAD(cpu_pm_notifier_chain); |
| 26 | |
| 27 | int cpu_pm_register_notifier(struct notifier_block *nb) |
| 28 | { |
| 29 | unsigned long flags; |
| 30 | int ret; |
| 31 | |
| 32 | write_lock_irqsave(&cpu_pm_notifier_lock, flags); |
| 33 | ret = raw_notifier_chain_register(&cpu_pm_notifier_chain, nb); |
| 34 | write_unlock_irqrestore(&cpu_pm_notifier_lock, flags); |
| 35 | |
| 36 | return ret; |
| 37 | } |
| 38 | EXPORT_SYMBOL_GPL(cpu_pm_register_notifier); |
| 39 | |
| 40 | int cpu_pm_unregister_notifier(struct notifier_block *nb) |
| 41 | { |
| 42 | unsigned long flags; |
| 43 | int ret; |
| 44 | |
| 45 | write_lock_irqsave(&cpu_pm_notifier_lock, flags); |
| 46 | ret = raw_notifier_chain_unregister(&cpu_pm_notifier_chain, nb); |
| 47 | write_unlock_irqrestore(&cpu_pm_notifier_lock, flags); |
| 48 | |
| 49 | return ret; |
| 50 | } |
| 51 | EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier); |
| 52 | |
| 53 | static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls) |
| 54 | { |
| 55 | int ret; |
| 56 | |
| 57 | ret = __raw_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL, |
| 58 | nr_to_call, nr_calls); |
| 59 | |
| 60 | return notifier_to_errno(ret); |
| 61 | } |
| 62 | |
| 63 | int cpu_pm_enter(void) |
| 64 | { |
| 65 | int nr_calls; |
| 66 | int ret = 0; |
| 67 | |
| 68 | read_lock(&cpu_pm_notifier_lock); |
| 69 | ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls); |
| 70 | if (ret) |
| 71 | cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL); |
| 72 | read_unlock(&cpu_pm_notifier_lock); |
| 73 | |
| 74 | return ret; |
| 75 | } |
| 76 | EXPORT_SYMBOL_GPL(cpu_pm_enter); |
| 77 | |
| 78 | int cpu_pm_exit(void) |
| 79 | { |
| 80 | int ret; |
| 81 | |
| 82 | read_lock(&cpu_pm_notifier_lock); |
| 83 | ret = cpu_pm_notify(CPU_PM_EXIT, -1, NULL); |
| 84 | read_unlock(&cpu_pm_notifier_lock); |
| 85 | |
| 86 | return ret; |
| 87 | } |
| 88 | EXPORT_SYMBOL_GPL(cpu_pm_exit); |
| 89 | |
| 90 | int cpu_cluster_pm_enter(void) |
| 91 | { |
| 92 | int nr_calls; |
| 93 | int ret = 0; |
| 94 | |
| 95 | read_lock(&cpu_pm_notifier_lock); |
| 96 | ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls); |
| 97 | if (ret) |
| 98 | cpu_pm_notify(CPU_CLUSTER_PM_ENTER_FAILED, nr_calls - 1, NULL); |
| 99 | read_unlock(&cpu_pm_notifier_lock); |
| 100 | |
| 101 | return ret; |
| 102 | } |
| 103 | EXPORT_SYMBOL_GPL(cpu_cluster_pm_enter); |
| 104 | |
| 105 | int cpu_cluster_pm_exit(void) |
| 106 | { |
| 107 | int ret; |
| 108 | |
| 109 | read_lock(&cpu_pm_notifier_lock); |
| 110 | ret = cpu_pm_notify(CPU_CLUSTER_PM_EXIT, -1, NULL); |
| 111 | read_unlock(&cpu_pm_notifier_lock); |
| 112 | |
| 113 | return ret; |
| 114 | } |
| 115 | EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit); |