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authorRussell King <rmk+kernel@arm.linux.org.uk>2011-09-26 09:36:36 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-09-26 09:36:36 +0100
commitc825dda905bac330c2da7fabdf5c0ac28758b3cd (patch)
tree597fe4f90c49f784a0dbf1596c027880747210ec /kernel
parentb0a37dca72a05b7b579f288d8a67afeed96bffa5 (diff)
parent8fb54284ba6aa1f0d832ec015fde64ecf4bb0f4f (diff)
downloadlinux-linaro-precise-c825dda905bac330c2da7fabdf5c0ac28758b3cd.tar.gz
Merge branch 'for_3_2/for-rmk/arm_cpu_pm' of git://gitorious.org/omap-sw-develoment/linux-omap-dev into devel-stable
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/cpu_pm.c233
-rw-r--r--kernel/power/Kconfig4
3 files changed, 238 insertions, 0 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index eca595e2fd5..988cb3da703 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -101,6 +101,7 @@ obj-$(CONFIG_RING_BUFFER) += trace/
obj-$(CONFIG_TRACEPOINTS) += trace/
obj-$(CONFIG_SMP) += sched_cpupri.o
obj-$(CONFIG_IRQ_WORK) += irq_work.o
+obj-$(CONFIG_CPU_PM) += cpu_pm.o
obj-$(CONFIG_PERF_EVENTS) += events/
diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c
new file mode 100644
index 00000000000..249152e1530
--- /dev/null
+++ b/kernel/cpu_pm.c
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * Author:
+ * Colin Cross <ccross@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpu_pm.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/spinlock.h>
+#include <linux/syscore_ops.h>
+
+static DEFINE_RWLOCK(cpu_pm_notifier_lock);
+static RAW_NOTIFIER_HEAD(cpu_pm_notifier_chain);
+
+static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls)
+{
+ int ret;
+
+ ret = __raw_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL,
+ nr_to_call, nr_calls);
+
+ return notifier_to_errno(ret);
+}
+
+/**
+ * cpu_pm_register_notifier - register a driver with cpu_pm
+ * @nb: notifier block to register
+ *
+ * Add a driver to a list of drivers that are notified about
+ * CPU and CPU cluster low power entry and exit.
+ *
+ * This function may sleep, and has the same return conditions as
+ * raw_notifier_chain_register.
+ */
+int cpu_pm_register_notifier(struct notifier_block *nb)
+{
+ unsigned long flags;
+ int ret;
+
+ write_lock_irqsave(&cpu_pm_notifier_lock, flags);
+ ret = raw_notifier_chain_register(&cpu_pm_notifier_chain, nb);
+ write_unlock_irqrestore(&cpu_pm_notifier_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpu_pm_register_notifier);
+
+/**
+ * cpu_pm_unregister_notifier - unregister a driver with cpu_pm
+ * @nb: notifier block to be unregistered
+ *
+ * Remove a driver from the CPU PM notifier list.
+ *
+ * This function may sleep, and has the same return conditions as
+ * raw_notifier_chain_unregister.
+ */
+int cpu_pm_unregister_notifier(struct notifier_block *nb)
+{
+ unsigned long flags;
+ int ret;
+
+ write_lock_irqsave(&cpu_pm_notifier_lock, flags);
+ ret = raw_notifier_chain_unregister(&cpu_pm_notifier_chain, nb);
+ write_unlock_irqrestore(&cpu_pm_notifier_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpu_pm_unregister_notifier);
+
+/**
+ * cpm_pm_enter - CPU low power entry notifier
+ *
+ * Notifies listeners that a single CPU is entering a low power state that may
+ * cause some blocks in the same power domain as the cpu to reset.
+ *
+ * Must be called on the affected CPU with interrupts disabled. Platform is
+ * responsible for ensuring that cpu_pm_enter is not called twice on the same
+ * CPU before cpu_pm_exit is called. Notified drivers can include VFP
+ * co-processor, interrupt controller and it's PM extensions, local CPU
+ * timers context save/restore which shouldn't be interrupted. Hence it
+ * must be called with interrupts disabled.
+ *
+ * Return conditions are same as __raw_notifier_call_chain.
+ */
+int cpu_pm_enter(void)
+{
+ int nr_calls;
+ int ret = 0;
+
+ read_lock(&cpu_pm_notifier_lock);
+ ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls);
+ if (ret)
+ /*
+ * Inform listeners (nr_calls - 1) about failure of CPU PM
+ * PM entry who are notified earlier to prepare for it.
+ */
+ cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL);
+ read_unlock(&cpu_pm_notifier_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpu_pm_enter);
+
+/**
+ * cpm_pm_exit - CPU low power exit notifier
+ *
+ * Notifies listeners that a single CPU is exiting a low power state that may
+ * have caused some blocks in the same power domain as the cpu to reset.
+ *
+ * Notified drivers can include VFP co-processor, interrupt controller
+ * and it's PM extensions, local CPU timers context save/restore which
+ * shouldn't be interrupted. Hence it must be called with interrupts disabled.
+ *
+ * Return conditions are same as __raw_notifier_call_chain.
+ */
+int cpu_pm_exit(void)
+{
+ int ret;
+
+ read_lock(&cpu_pm_notifier_lock);
+ ret = cpu_pm_notify(CPU_PM_EXIT, -1, NULL);
+ read_unlock(&cpu_pm_notifier_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpu_pm_exit);
+
+/**
+ * cpm_cluster_pm_enter - CPU cluster low power entry notifier
+ *
+ * Notifies listeners that all cpus in a power domain are entering a low power
+ * state that may cause some blocks in the same power domain to reset.
+ *
+ * Must be called after cpu_pm_enter has been called on all cpus in the power
+ * domain, and before cpu_pm_exit has been called on any cpu in the power
+ * domain. Notified drivers can include VFP co-processor, interrupt controller
+ * and it's PM extensions, local CPU timers context save/restore which
+ * shouldn't be interrupted. Hence it must be called with interrupts disabled.
+ *
+ * Must be called with interrupts disabled.
+ *
+ * Return conditions are same as __raw_notifier_call_chain.
+ */
+int cpu_cluster_pm_enter(void)
+{
+ int nr_calls;
+ int ret = 0;
+
+ read_lock(&cpu_pm_notifier_lock);
+ ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls);
+ if (ret)
+ /*
+ * Inform listeners (nr_calls - 1) about failure of CPU cluster
+ * PM entry who are notified earlier to prepare for it.
+ */
+ cpu_pm_notify(CPU_CLUSTER_PM_ENTER_FAILED, nr_calls - 1, NULL);
+ read_unlock(&cpu_pm_notifier_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpu_cluster_pm_enter);
+
+/**
+ * cpm_cluster_pm_exit - CPU cluster low power exit notifier
+ *
+ * Notifies listeners that all cpus in a power domain are exiting form a
+ * low power state that may have caused some blocks in the same power domain
+ * to reset.
+ *
+ * Must be called after cpu_pm_exit has been called on all cpus in the power
+ * domain, and before cpu_pm_exit has been called on any cpu in the power
+ * domain. Notified drivers can include VFP co-processor, interrupt controller
+ * and it's PM extensions, local CPU timers context save/restore which
+ * shouldn't be interrupted. Hence it must be called with interrupts disabled.
+ *
+ * Return conditions are same as __raw_notifier_call_chain.
+ */
+int cpu_cluster_pm_exit(void)
+{
+ int ret;
+
+ read_lock(&cpu_pm_notifier_lock);
+ ret = cpu_pm_notify(CPU_CLUSTER_PM_EXIT, -1, NULL);
+ read_unlock(&cpu_pm_notifier_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit);
+
+#ifdef CONFIG_PM
+static int cpu_pm_suspend(void)
+{
+ int ret;
+
+ ret = cpu_pm_enter();
+ if (ret)
+ return ret;
+
+ ret = cpu_cluster_pm_enter();
+ return ret;
+}
+
+static void cpu_pm_resume(void)
+{
+ cpu_cluster_pm_exit();
+ cpu_pm_exit();
+}
+
+static struct syscore_ops cpu_pm_syscore_ops = {
+ .suspend = cpu_pm_suspend,
+ .resume = cpu_pm_resume,
+};
+
+static int cpu_pm_init(void)
+{
+ register_syscore_ops(&cpu_pm_syscore_ops);
+ return 0;
+}
+core_initcall(cpu_pm_init);
+#endif
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 3744c594b19..80a85971cf6 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -235,3 +235,7 @@ config PM_GENERIC_DOMAINS
config PM_GENERIC_DOMAINS_RUNTIME
def_bool y
depends on PM_RUNTIME && PM_GENERIC_DOMAINS
+
+config CPU_PM
+ bool
+ depends on SUSPEND || CPU_IDLE