1 files changed, 109 insertions, 0 deletions

diff --git a/include/linux/cpu_pm.h b/include/linux/cpu_pm.h
new file mode 100644
index 000000000000..455b233dd3b1
--- /dev/null
+++ b/include/linux/cpu_pm.h
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ *
+ */
+
+#ifndef _LINUX_CPU_PM_H
+#define _LINUX_CPU_PM_H
+
+#include <linux/kernel.h>
+#include <linux/notifier.h>
+
+/*
+ * When a CPU goes to a low power state that turns off power to the CPU's
+ * power domain, the contents of some blocks (floating point coprocessors,
+ * interrupt controllers, caches, timers) in the same power domain can
+ * be lost.  The cpm_pm notifiers provide a method for platform idle, suspend,
+ * and hotplug implementations to notify the drivers for these blocks that
+ * they may be reset.
+ *
+ * All cpu_pm notifications must be called with interrupts disabled.
+ *
+ * The notifications are split into two classes: CPU notifications and CPU
+ * cluster notifications.
+ *
+ * CPU notifications apply to a single CPU and must be called on the affected
+ * CPU.  They are used to save per-cpu context for affected blocks.
+ *
+ * CPU cluster notifications apply to all CPUs in a single power domain. They
+ * are used to save any global context for affected blocks, and must be called
+ * after all the CPUs in the power domain have been notified of the low power
+ * state.
+ */
+
+/*
+ * Event codes passed as unsigned long val to notifier calls
+ */
+enum cpu_pm_event {
+        /* A single cpu is entering a low power state */
+        CPU_PM_ENTER,
+
+        /* A single cpu failed to enter a low power state */
+        CPU_PM_ENTER_FAILED,
+
+        /* A single cpu is exiting a low power state */
+        CPU_PM_EXIT,
+
+        /* A cpu power domain is entering a low power state */
+        CPU_CLUSTER_PM_ENTER,
+
+        /* A cpu power domain failed to enter a low power state */
+        CPU_CLUSTER_PM_ENTER_FAILED,
+
+        /* A cpu power domain is exiting a low power state */
+        CPU_CLUSTER_PM_EXIT,
+};
+
+#ifdef CONFIG_CPU_PM
+int cpu_pm_register_notifier(struct notifier_block *nb);
+int cpu_pm_unregister_notifier(struct notifier_block *nb);
+int cpu_pm_enter(void);
+int cpu_pm_exit(void);
+int cpu_cluster_pm_enter(void);
+int cpu_cluster_pm_exit(void);
+
+#else
+
+static inline int cpu_pm_register_notifier(struct notifier_block *nb)
+{
+        return 0;
+}
+
+static inline int cpu_pm_unregister_notifier(struct notifier_block *nb)
+{
+        return 0;
+}
+
+static inline int cpu_pm_enter(void)
+{
+        return 0;
+}
+
+static inline int cpu_pm_exit(void)
+{
+        return 0;
+}
+
+static inline int cpu_cluster_pm_enter(void)
+{
+        return 0;
+}
+
+static inline int cpu_cluster_pm_exit(void)
+{
+        return 0;
+}
+#endif
+#endif