msm: event_timer: Support to add event timers.
Add support to allow drivers to specify future events
that need to be treated as hard deadlines. Upon event timer
expiry the driver will be notified by callback function
that the driver provides.
The pm code can query the earliest event and modify
the event timer accounting for the back off based on the
latency of the low power mode being entered.
Change-Id: Iec26f77de3b826bff456b12f3230268d9bdc2255
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
diff --git a/arch/arm/mach-msm/include/mach/event_timer.h b/arch/arm/mach-msm/include/mach/event_timer.h
new file mode 100644
index 0000000..7a00b23
--- /dev/null
+++ b/arch/arm/mach-msm/include/mach/event_timer.h
@@ -0,0 +1,77 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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 __ARCH_ARM_MACH_MSM_EVENT_TIMER_H
+#define __ARCH_ARM_MACH_MSM_EVENT_TIMER_H
+
+#include <linux/hrtimer.h>
+
+struct event_timer_info;
+
+#ifdef CONFIG_MSM_EVENT_TIMER
+/**
+ * add_event_timer() : Add a wakeup event. Intended to be called
+ * by clients once. Returns a handle to be used
+ * for future transactions.
+ * @function : The callback function will be called when event
+ * timer expires.
+ * @data : Callback data provided by client.
+ */
+struct event_timer_info *add_event_timer(void (*function)(void *), void *data);
+
+/** activate_event_timer() : Set the expiration time for an event in absolute
+ * ktime. This is a oneshot event timer, clients
+ * should call this again to set another expiration.
+ * @event : Event handle.
+ * @event_time : Event time in absolute ktime.
+ */
+void activate_event_timer(struct event_timer_info *event, ktime_t event_time);
+
+/**
+ * deactivate_event_timer() : Deactivate an event timer.
+ * @event: event handle.
+ */
+void deactivate_event_timer(struct event_timer_info *event);
+
+/**
+ * destroy_event_timer() : Free the event info data structure allocated during
+ * add_event_timer().
+ * @event: event handle.
+ */
+void destroy_event_timer(struct event_timer_info *event);
+
+/**
+ * get_next_event_timer() : Get the next wakeup event.
+ * returns a ktime value of the next
+ * expiring event.
+ */
+ktime_t get_next_event_time(void);
+#else
+static inline void *add_event_timer(void (*function)(void *), void *data)
+{
+ return NULL;
+}
+
+static inline void activate_event_timer(void *event, ktime_t event_time) {}
+
+static inline void deactivate_event_timer(void *event) {}
+
+static inline void destroy_event_timer(void *event) {}
+
+static inline ktime_t get_next_event_time(void)
+{
+ return ns_to_ktime(0);
+}
+
+#endif /* CONFIG_MSM_EVENT_TIMER_MANAGER */
+#endif /* __ARCH_ARM_MACH_MSM_EVENT_TIMER_H */