06e857251e
During some CPU power modes entered during idle, hotplug and suspend, peripherals located in the CPU power domain, such as the GIC, localtimers, and VFP, may be powered down. Add a notifier chain that allows drivers for those peripherals to be notified before and after they may be reset. Signed-off-by: Colin Cross <ccross <at> android.com> [santosh.shilimkar <at> ti.com: Rebased against 3.1-rc3] Signed-off-by: Santosh Shilimkar <santosh.shilimkar <at> ti.com> Tested-by: Kevin Hilman <khilman <at> ti.com> Change-Id: I6e076344b268869d12033f57321f3e7cf23b05e8 Signed-off-by: Ashwin Chaugule <ashwinc@codeaurora.org>
116 lines
2.7 KiB
C
116 lines
2.7 KiB
C
/*
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* Copyright (C) 2011 Google, Inc.
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*
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* Author:
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* Colin Cross <ccross <at> android.com>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/cpu_pm.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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#include <linux/spinlock.h>
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static DEFINE_RWLOCK(cpu_pm_notifier_lock);
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static RAW_NOTIFIER_HEAD(cpu_pm_notifier_chain);
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int cpu_pm_register_notifier(struct notifier_block *nb)
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{
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unsigned long flags;
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int ret;
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write_lock_irqsave(&cpu_pm_notifier_lock, flags);
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ret = raw_notifier_chain_register(&cpu_pm_notifier_chain, nb);
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write_unlock_irqrestore(&cpu_pm_notifier_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL_GPL(cpu_pm_register_notifier);
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int cpu_pm_unregister_notifier(struct notifier_block *nb)
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{
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unsigned long flags;
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int ret;
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write_lock_irqsave(&cpu_pm_notifier_lock, flags);
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ret = raw_notifier_chain_unregister(&cpu_pm_notifier_chain, nb);
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write_unlock_irqrestore(&cpu_pm_notifier_lock, flags);
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return ret;
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}
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EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier);
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static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls)
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{
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int ret;
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ret = __raw_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL,
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nr_to_call, nr_calls);
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return notifier_to_errno(ret);
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}
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int cpu_pm_enter(void)
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{
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int nr_calls;
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int ret = 0;
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read_lock(&cpu_pm_notifier_lock);
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ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls);
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if (ret)
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cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL);
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read_unlock(&cpu_pm_notifier_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(cpu_pm_enter);
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int cpu_pm_exit(void)
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{
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int ret;
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read_lock(&cpu_pm_notifier_lock);
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ret = cpu_pm_notify(CPU_PM_EXIT, -1, NULL);
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read_unlock(&cpu_pm_notifier_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(cpu_pm_exit);
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int cpu_cluster_pm_enter(void)
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{
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int nr_calls;
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int ret = 0;
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read_lock(&cpu_pm_notifier_lock);
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ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls);
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if (ret)
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cpu_pm_notify(CPU_CLUSTER_PM_ENTER_FAILED, nr_calls - 1, NULL);
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read_unlock(&cpu_pm_notifier_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(cpu_cluster_pm_enter);
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int cpu_cluster_pm_exit(void)
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{
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int ret;
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read_lock(&cpu_pm_notifier_lock);
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ret = cpu_pm_notify(CPU_CLUSTER_PM_EXIT, -1, NULL);
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read_unlock(&cpu_pm_notifier_lock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit);
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