[PATCH 01/10] PM: Add wake lock api.

Arve Hjønnevåg
2009-02-11T01:49:06Z

Adds /sys/power/request_state, a non-blocking interface that specifies
which suspend state to enter when no wakelocks are locked. A special
state, "on", stops the process by locking the "main" wakelock.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
---
Documentation/power/wakelocks.txt | 80 +++++
include/linux/wakelock.h | 93 +++++
kernel/power/Kconfig | 17 +
kernel/power/Makefile | 1 +
kernel/power/main.c | 63 ++++
kernel/power/power.h | 7 +
kernel/power/wakelock.c | 664 +++++++++++++++++++++++++++++++++++++
7 files changed, 925 insertions(+), 0 deletions(-)
create mode 100644 Documentation/power/wakelocks.txt
create mode 100755 include/linux/wakelock.h
create mode 100644 kernel/power/wakelock.c

diff --git a/Documentation/power/wakelocks.txt b/Documentation/power/wakelocks.txt
new file mode 100644
index 0000000..893a438
--- /dev/null
+++ b/Documentation/power/wakelocks.txt
@@ -0,0 +1,80 @@
+Wakelocks
+=========
+
+A locked wakelock, depending on its type, prevents the system from entering
+suspend or other low-power states. When creating a wakelock, you can select
+if it prevents suspend or low-power idle states. If the type is set to
+WAKE_LOCK_SUSPEND, the wakelock prevents a full system suspend. If the type
+is WAKE_LOCK_IDLE, low-power states that cause large interrupt latencies, or
+that disable a set of interrupts, will not be entered from idle until the
+wakelocks are released. Unless the type is specified, this document refers
+to wakelocks with the type set to WAKE_LOCK_SUSPEND.
+
+If the suspend operation has already started when locking a wakelock, it will
+abort the suspend operation as long it has not already reached the suspend_late
+stage. This means that locking a wakelock from an interrupt handler or a
+freezeable thread always works, but if you lock a wakelock from a suspend_late
+handler you must also return an error from that handler to abort suspend.
+
+Wakelocks can be used to allow user-space to decide which keys should wake the
+full system up and turn the screen on. Use set_irq_wake or a platform specific
+api to make sure the keypad interrupt wakes up the cpu. Once the keypad driver
+has resumed, the sequence of events can look like this:
+- The Keypad driver gets an interrupt. It then locks the keypad-scan wakelock
+ and starts scanning the keypad matrix.
+- The keypad-scan code detects a key change and reports it to the input-event
+ driver.
+- The input-event driver sees the key change, enqueues an event, and locks
+ the input-event-queue wakelock.
+- The keypad-scan code detects that no keys are held and unlocks the
+ keypad-scan wakelock.
+- The user-space input-event thread returns from select/poll, locks the
+ process-input-events wakelock and then calls read in the input-event device.
+- The input-event driver dequeues the key-event and, since the queue is now
+ empty, it unlocks the input-event-queue wakelock.
+- The user-space input-event thread returns from read. It determines that the
+ key should not wake up the full system, releases the process-input-events
+ wakelock and calls select or poll.
+
+ Key pressed Key released
+ | |
+keypad-scan ++++++++++++++++++
+input-event-queue +++ +++
+process-input-events +++ +++
+
+
+Driver API
+==========
+
+A driver can use the wakelock api by adding a wakelock variable to its state
+and calling wake_lock_init. For instance:
+struct state {
+ struct wakelock wakelock;
+}
+
+init() {
+ wake_lock_init(&state->wakelock, WAKE_LOCK_SUSPEND, "wakelockname");
+}
+
+Before freeing the memory, wake_lock_destroy must be called:
+
+uninit() {
+ wake_lock_destroy(&state->wakelock);
+}
+
+When the driver determines that it needs to run (usually in an interrupt
+handler) it calls wake_lock:
+ wake_lock(&state->wakelock);
+
+When it no longer needs to run it calls wake_unlock:
+ wake_unlock(&state->wakelock);
+
+It can also call wake_lock_timeout to release the wakelock after a delay:
+ wake_lock_timeout(&state->wakelock, HZ);
+
+This works whether the wakelock is already held or not. It is useful if the
+driver woke up other parts of the system that do not use wakelocks but
+still need to run. Avoid this when possible, since it will waste power
+if the timeout is long or may fail to finish needed work if the timeout is
+short.
+
diff --git a/include/linux/wakelock.h b/include/linux/wakelock.h
new file mode 100755
index 0000000..ec878d2
--- /dev/null
+++ b/include/linux/wakelock.h
@@ -0,0 +1,93 @@
+/* include/linux/wakelock.h
+ *
+ * Copyright (C) 2007-2008 Google, Inc.
+ *
+ * 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_WAKELOCK_H
+#define _LINUX_WAKELOCK_H
+
+#include <linux/list.h>
+#include <linux/ktime.h>
+
+/* A wake_lock prevents the system from entering suspend or other low power
+ * states when active. If the type is set to WAKE_LOCK_SUSPEND, the wake_lock
+ * prevents a full system suspend. If the type is WAKE_LOCK_IDLE, low power
+ * states that cause large interrupt latencies or that disable a set of
+ * interrupts will not entered from idle until the wake_locks are released.
+ */
+
+enum {
+ WAKE_LOCK_SUSPEND, /* Prevent suspend */
+ WAKE_LOCK_IDLE, /* Prevent low power idle */
+ WAKE_LOCK_TYPE_COUNT
+};
+
+struct wake_lock {
+#ifdef CONFIG_WAKELOCK
+ struct list_head link;
+ int flags;
+ const char *name;
+ unsigned long expires;
+#ifdef CONFIG_WAKELOCK_STAT
+ struct {
+ int count;
+ int expire_count;
+ int wakeup_count;
+ ktime_t total_time;
+ ktime_t prevent_suspend_time;
+ ktime_t max_time;
+ ktime_t last_time;
+ } stat;
+#endif
+#endif
+};
+
+#ifdef CONFIG_WAKELOCK
+
+void wake_lock_init(struct wake_lock *lock, int type, const char *name);
+void wake_lock_destroy(struct wake_lock *lock);
+void wake_lock(struct wake_lock *lock);
+void wake_lock_timeout(struct wake_lock *lock, long timeout);
+void wake_unlock(struct wake_lock *lock);
+
+/* wake_lock_active returns a non-zero value if the wake_lock is currently
+ * locked. If the wake_lock has a timeout, it does not check the timeout,
+ * but if the timeout had already expired when it was checked elsewhere
+ * this function will return 0.
+ */
+int wake_lock_active(struct wake_lock *lock);
+
+/* has_wake_lock can be used by generic power management code to abort suspend.
+ * has_wake_lock returns 0 if no wake locks of the specified type are active,
+ * and non-zero if one or more wake locks are held. Specifically it returns
+ * -1 if one or more wake locks with no timeout are active or the
+ * number of jiffies until all active wake locks time out.
+ */
+long has_wake_lock(int type);
+
+#else
+
+static inline void wake_lock_init(struct wake_lock *lock, int type,
+ const char *name) {}
+static inline void wake_lock_destroy(struct wake_lock *lock) {}
+static inline void wake_lock(struct wake_lock *lock) {}
+static inline void wake_lock_timeout(struct wake_lock *lock, long timeout) {}
+static inline void wake_unlock(struct wake_lock *lock) {}
+
+static inline int wake_lock_active(struct wake_lock *lock) { return 0; }
+static inline long has_wake_lock(int type) { return 0; }
+
+#endif
+
+#endif
+
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 23bd4da..9abd97e 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -116,6 +116,23 @@ config SUSPEND_FREEZER

Turning OFF this setting is NOT recommended! If in doubt, say Y.

+config WAKELOCK
+ bool "Wake lock"
+ depends on PM
+ select RTC_LIB
+ default n
+ ---help---
+ Enable wakelocks. When user space requests a sleep state through
+ /sys/power/request_state, the requested sleep state will be entered
+ when no wake locks are held.
+
+config WAKELOCK_STAT
+ bool "Wake lock stats"
+ depends on WAKELOCK
+ default y
+ ---help---
+ Report wake lock stats in /proc/wakelocks
+
config HIBERNATION
bool "Hibernation (aka 'suspend to disk')"
depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index d7a1016..8d8672b 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -6,6 +6,7 @@ endif
obj-y := main.o
obj-$(CONFIG_PM_SLEEP) += console.o
obj-$(CONFIG_FREEZER) += process.o
+obj-$(CONFIG_WAKELOCK) += wakelock.o
obj-$(CONFIG_HIBERNATION) += swsusp.o disk.o snapshot.o swap.o user.o

obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 2399888..8bdd15a 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -22,6 +22,7 @@
#include <linux/freezer.h>
#include <linux/vmstat.h>
#include <linux/syscalls.h>
+#include <linux/wakelock.h>

#include "power.h"

@@ -388,6 +389,9 @@ static void suspend_finish(void)

static const char * const pm_states[PM_SUSPEND_MAX] = {
+#ifdef CONFIG_WAKELOCK
+ [PM_SUSPEND_ON] = "on",
+#endif
[PM_SUSPEND_STANDBY] = "standby",
[PM_SUSPEND_MEM] = "mem",
};
@@ -536,6 +540,62 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,

power_attr(state);

+/**
+ * request_state - control system power state.
+ *
+ * This is similar to state, but it does not block until the system
+ * resumes, and it will try to re-enter the state until another state is
+ * requsted. Wakelocks are respected and the requested state will only
+ * be entered when no wakelocks are held. Write "on" to cancel.
+ *
+ * If CONFIG_EARLYSUSPEND is set, early_suspend hooks are called when
+ * the requested state changes to or from "on"
+ */
+
+#ifdef CONFIG_WAKELOCK
+static ssize_t request_state_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ char *s = buf;
+ int i;
+
+ for (i = 0; i < PM_SUSPEND_MAX; i++) {
+ if (pm_states[i] && (i == PM_SUSPEND_ON || valid_state(i)))
+ s += sprintf(s,"%s ", pm_states[i]);
+ }
+ if (s != buf)
+ /* convert the last space to a newline */
+ *(s-1) = '\n';
+ return (s - buf);
+}
+
+static ssize_t request_state_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ suspend_state_t state = PM_SUSPEND_ON;
+ const char * const *s;
+ char *p;
+ int len;
+ int error = -EINVAL;
+
+ p = memchr(buf, '\n', n);
+ len = p ? p - buf : n;
+
+ for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
+ if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
+ break;
+ }
+ if (state < PM_SUSPEND_MAX && *s)
+ if (state == PM_SUSPEND_ON || valid_state(state)) {
+ error = 0;
+ request_suspend_state(state);
+ }
+ return error ? error : n;
+}
+
+power_attr(request_state);
+#endif /* CONFIG_WAKELOCK */
+
#ifdef CONFIG_PM_TRACE
int pm_trace_enabled;

@@ -563,6 +623,9 @@ power_attr(pm_trace);

static struct attribute * g[] = {
&state_attr.attr,
+#ifdef CONFIG_WAKELOCK
+ &request_state_attr.attr,
+#endif
#ifdef CONFIG_PM_TRACE
&pm_trace_attr.attr,
#endif
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 46b5ec7..9468679 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -223,3 +223,10 @@ static inline void suspend_thaw_processes(void)
{
}
#endif
+
+#ifdef CONFIG_WAKELOCK
+/* kernel/power/wakelock.c */
+extern struct workqueue_struct *suspend_work_queue;
+extern struct wake_lock main_wake_lock;
+void request_suspend_state(suspend_state_t state);
+#endif
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
new file mode 100644
index 0000000..13f5d03
--- /dev/null
+++ b/kernel/power/wakelock.c
@@ -0,0 +1,664 @@
+/* kernel/power/wakelock.c
+ *
+ * Copyright (C) 2005-2008 Google, Inc.
+ *
+ * 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/suspend.h>
+#include <linux/syscalls.h> /* sys_sync */
+#include <linux/wakelock.h>
+#ifdef CONFIG_WAKELOCK_STAT
+#include <linux/proc_fs.h>
+#endif
+#include "power.h"
+
+enum {
+ DEBUG_EXIT_SUSPEND = 1U << 0,
+ DEBUG_WAKEUP = 1U << 1,
+ DEBUG_USER_STATE = 1U << 2,
+ DEBUG_SUSPEND = 1U << 3,
+ DEBUG_EXPIRE = 1U << 4,
+ DEBUG_WAKE_LOCK = 1U << 5,
+};
+static int debug_mask = DEBUG_EXIT_SUSPEND | DEBUG_WAKEUP | DEBUG_USER_STATE;
+module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+#define WAKE_LOCK_TYPE_MASK (0x0f)
+#define WAKE_LOCK_INITIALIZED (1U << 8)
+#define WAKE_LOCK_ACTIVE (1U << 9)
+#define WAKE_LOCK_AUTO_EXPIRE (1U << 10)
+#define WAKE_LOCK_PREVENTING_SUSPEND (1U << 11)
+
+static DEFINE_SPINLOCK(list_lock);
+static DEFINE_SPINLOCK(state_lock);
+static LIST_HEAD(inactive_locks);
+static struct list_head active_wake_locks[WAKE_LOCK_TYPE_COUNT];
+static int current_event_num;
+struct workqueue_struct *suspend_work_queue;
+struct wake_lock main_wake_lock;
+static suspend_state_t requested_suspend_state = PM_SUSPEND_MEM;
+static struct wake_lock unknown_wakeup;
+
+#ifdef CONFIG_WAKELOCK_STAT
+static struct wake_lock deleted_wake_locks;
+static ktime_t last_sleep_time_update;
+static bool wait_for_wakeup;
+
+bool stats_get_expired_time(struct wake_lock *lock, ktime_t *expire_time)
+{
+ struct timespec ts;
+ struct timespec kt;
+ struct timespec tomono;
+ struct timespec delta;
+ unsigned long seq;
+ long timeout;
+
+ if (!(lock->flags & WAKE_LOCK_AUTO_EXPIRE))
+ return false;
+ do {
+ seq = read_seqbegin(&xtime_lock);
+ timeout = lock->expires - jiffies;
+ if (timeout > 0)
+ return false;
+ kt = current_kernel_time();
+ tomono = wall_to_monotonic;
+ } while (read_seqretry(&xtime_lock, seq));
+ jiffies_to_timespec(-timeout, &delta);
+ set_normalized_timespec(&ts, kt.tv_sec + tomono.tv_sec - delta.tv_sec,
+ kt.tv_nsec + tomono.tv_nsec - delta.tv_nsec);
+ *expire_time = timespec_to_ktime(ts);
+ return true;
+}
+
+
+static int print_lock_stat(char *buf, struct wake_lock *lock)
+{
+ int lock_count = lock->stat.count;
+ int expire_count = lock->stat.expire_count;
+ ktime_t active_time = ktime_set(0, 0);
+ ktime_t total_time = lock->stat.total_time;
+ ktime_t max_time = lock->stat.max_time;
+ ktime_t prevent_suspend_time = lock->stat.prevent_suspend_time;
+ if (lock->flags & WAKE_LOCK_ACTIVE) {
+ ktime_t now, add_time;
+ bool expired = stats_get_expired_time(lock, &now);
+ if (!expired)
+ now = ktime_get();
+ add_time = ktime_sub(now, lock->stat.last_time);
+ lock_count++;
+ if (!expired)
+ active_time = add_time;
+ else
+ expire_count++;
+ total_time = ktime_add(total_time, add_time);
+ if (lock->flags & WAKE_LOCK_PREVENTING_SUSPEND)
+ prevent_suspend_time = ktime_add(prevent_suspend_time,
+ ktime_sub(now, last_sleep_time_update));
+ if (add_time.tv64 > max_time.tv64)
+ max_time = add_time;
+ }
+
+ return sprintf(buf, "\"%s\"\t%d\t%d\t%d\t%lld\t%lld\t%lld\t%lld\t"
+ "%lld\n", lock->name, lock_count, expire_count,
+ lock->stat.wakeup_count, ktime_to_ns(active_time),
+ ktime_to_ns(total_time),
+ ktime_to_ns(prevent_suspend_time), ktime_to_ns(max_time),
+ ktime_to_ns(lock->stat.last_time));
+}
+
+
+static int wakelock_stats_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ unsigned long irqflags;
+ struct wake_lock *lock;
+ int len = 0;
+ char *p = page;
+ int type;
+
+ spin_lock_irqsave(&list_lock, irqflags);
+
+ p += sprintf(p, "name\tcount\texpire_count\twake_count\tactive_since"
+ "\ttotal_time\tsleep_time\tmax_time\tlast_change\n");
+ list_for_each_entry(lock, &inactive_locks, link) {
+ p += print_lock_stat(p, lock);
+ }
+ for (type = 0; type < WAKE_LOCK_TYPE_COUNT; type++) {
+ list_for_each_entry(lock, &active_wake_locks[type], link)
+ p += print_lock_stat(p, lock);
+ }
+ spin_unlock_irqrestore(&list_lock, irqflags);
+
+ *start = page + off;
+
+ len = p - page;
+ if (len > off)
+ len -= off;
+ else
+ len = 0;
+
+ return len < count ? len : count;
+}
+
+static void wake_lock_stat_init_locked(struct wake_lock *lock)
+{
+ lock->stat.count = 0;
+ lock->stat.expire_count = 0;
+ lock->stat.wakeup_count = 0;
+ lock->stat.total_time = ktime_set(0, 0);
+ lock->stat.prevent_suspend_time = ktime_set(0, 0);
+ lock->stat.max_time = ktime_set(0, 0);
+ lock->stat.last_time = ktime_set(0, 0);
+}
+
+static void wake_lock_stat_destroy_locked(struct wake_lock *lock)
+{
+ if (lock->stat.count) {
+ deleted_wake_locks.stat.count += lock->stat.count;
+ deleted_wake_locks.stat.expire_count += lock->stat.expire_count;
+ deleted_wake_locks.stat.total_time =
+ ktime_add(deleted_wake_locks.stat.total_time,
+ lock->stat.total_time);
+ deleted_wake_locks.stat.prevent_suspend_time =
+ ktime_add(deleted_wake_locks.stat.prevent_suspend_time,
+ lock->stat.prevent_suspend_time);
+ deleted_wake_locks.stat.max_time =
+ ktime_add(deleted_wake_locks.stat.max_time,
+ lock->stat.max_time);
+ }
+}
+
+static void wake_unlock_stat_locked(struct wake_lock *lock, bool expired)
+{
+ ktime_t duration;
+ ktime_t now;
+ if (!(lock->flags & WAKE_LOCK_ACTIVE))
+ return;
+ if (stats_get_expired_time(lock, &now))
+ expired = true;
+ else
+ now = ktime_get();
+ lock->stat.count++;
+ if (expired)
+ lock->stat.expire_count++;
+ duration = ktime_sub(now, lock->stat.last_time);
+ lock->stat.total_time = ktime_add(lock->stat.total_time, duration);
+ if (ktime_to_ns(duration) > ktime_to_ns(lock->stat.max_time))
+ lock->stat.max_time = duration;
+ lock->stat.last_time = ktime_get();
+ if (lock->flags & WAKE_LOCK_PREVENTING_SUSPEND) {
+ duration = ktime_sub(now, last_sleep_time_update);
+ lock->stat.prevent_suspend_time = ktime_add(
+ lock->stat.prevent_suspend_time, duration);
+ lock->flags &= ~WAKE_LOCK_PREVENTING_SUSPEND;
+ }
+}
+
+static void wake_lock_stat_locked(struct wake_lock *lock)
+{
+ int type = lock->flags & WAKE_LOCK_TYPE_MASK;
+ if (type == WAKE_LOCK_SUSPEND && wait_for_wakeup) {
+ if (debug_mask & DEBUG_WAKEUP)
+ pr_info("wakeup wake lock: %s\n", lock->name);
+ wait_for_wakeup = false;
+ lock->stat.wakeup_count++;
+ }
+ if ((lock->flags & WAKE_LOCK_AUTO_EXPIRE) &&
+ time_is_before_eq_jiffies(lock->expires)) {
+ wake_unlock_stat_locked(lock, false);
+ lock->stat.last_time = ktime_get();
+ }
+
+ if (!(lock->flags & WAKE_LOCK_ACTIVE))
+ lock->stat.last_time = ktime_get();
+}
+
+static void update_sleep_wait_stats_locked(bool done)
+{
+ struct wake_lock *lock;
+ ktime_t now, etime, elapsed, add;
+ bool expired;
+
+ now = ktime_get();
+ elapsed = ktime_sub(now, last_sleep_time_update);
+ list_for_each_entry(lock, &active_wake_locks[WAKE_LOCK_SUSPEND], link) {
+ expired = stats_get_expired_time(lock, &etime);
+ if (lock->flags & WAKE_LOCK_PREVENTING_SUSPEND) {
+ if (expired)
+ add = ktime_sub(etime, last_sleep_time_update);
+ else
+ add = elapsed;
+ lock->stat.prevent_suspend_time = ktime_add(
+ lock->stat.prevent_suspend_time, add);
+ }
+ if (done || expired)
+ lock->flags &= ~WAKE_LOCK_PREVENTING_SUSPEND;
+ else
+ lock->flags |= WAKE_LOCK_PREVENTING_SUSPEND;
+ }
+ last_sleep_time_update = now;
+}
+
+#else
+
+static inline void wake_lock_stat_init_locked(struct wake_lock *lock) {}
+static inline void wake_lock_stat_destroy_locked(struct wake_lock *lock) {}
+static inline void wake_lock_stat_locked(struct wake_lock *lock) {}
+static inline void wake_unlock_stat_locked(struct wake_lock *lock,
+ bool expired) {}
+static inline void update_sleep_wait_stats_locked(bool done) {}
+
+#endif
+
+
+static void expire_wake_lock(struct wake_lock *lock)
+{
+ wake_unlock_stat_locked(lock, true);
+ lock->flags &= ~(WAKE_LOCK_ACTIVE | WAKE_LOCK_AUTO_EXPIRE);
+ list_del(&lock->link);
+ list_add(&lock->link, &inactive_locks);
+ if (debug_mask & (DEBUG_WAKE_LOCK | DEBUG_EXPIRE))
+ pr_info("expired wake lock %s\n", lock->name);
+}
+
+static void print_active_locks(int type)
+{
+ unsigned long irqflags;
+ struct wake_lock *lock;
+
+ BUG_ON(type >= WAKE_LOCK_TYPE_COUNT);
+ spin_lock_irqsave(&list_lock, irqflags);
+ list_for_each_entry(lock, &active_wake_locks[type], link) {
+ if (lock->flags & WAKE_LOCK_AUTO_EXPIRE) {
+ long timeout = lock->expires - jiffies;
+ if (timeout <= 0)
+ pr_info("wake lock %s, expired\n", lock->name);
+ else
+ pr_info("active wake lock %s, time left %ld\n",
+ lock->name, timeout);
+ } else
+ pr_info("active wake lock %s\n", lock->name);
+ }
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+
+static long has_wake_lock_locked(int type)
+{
+ struct wake_lock *lock, *n;
+ long max_timeout = 0;
+
+ BUG_ON(type >= WAKE_LOCK_TYPE_COUNT);
+ list_for_each_entry_safe(lock, n, &active_wake_locks[type], link) {
+ if (lock->flags & WAKE_LOCK_AUTO_EXPIRE) {
+ long timeout = lock->expires - jiffies;
+ if (timeout <= 0)
+ expire_wake_lock(lock);
+ else if (timeout > max_timeout)
+ max_timeout = timeout;
+ } else
+ return -1;
+ }
+ return max_timeout;
+}
+
+long has_wake_lock(int type)
+{
+ long ret;
+ unsigned long irqflags;
+ spin_lock_irqsave(&list_lock, irqflags);
+ ret = has_wake_lock_locked(type);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+ return ret;
+}
+
+static void suspend_worker(struct work_struct *work)
+{
+ int ret;
+ int entry_event_num;
+
+ if (has_wake_lock(WAKE_LOCK_SUSPEND)) {
+ if (debug_mask & DEBUG_SUSPEND)
+ pr_info("suspend: abort suspend\n");
+ return;
+ }
+
+ entry_event_num = current_event_num;
+ if (debug_mask & DEBUG_SUSPEND)
+ pr_info("suspend: enter suspend\n");
+ ret = pm_suspend(requested_suspend_state);
+ if (debug_mask & DEBUG_EXIT_SUSPEND) {
+ struct timespec ts;
+ struct rtc_time tm;
+ getnstimeofday(&ts);
+ rtc_time_to_tm(ts.tv_sec, &tm);
+ pr_info("suspend: exit suspend, ret = %d "
+ "(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n", ret,
+ tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+ tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
+ }
+ if (current_event_num == entry_event_num) {
+ if (debug_mask & DEBUG_SUSPEND)
+ pr_info("suspend: pm_suspend returned with no event\n");
+ wake_lock_timeout(&unknown_wakeup, HZ / 2);
+ }
+}
+static DECLARE_WORK(suspend_work, suspend_worker);
+
+static void expire_wake_locks(unsigned long data)
+{
+ long has_lock;
+ unsigned long irqflags;
+ if (debug_mask & DEBUG_EXPIRE)
+ pr_info("expire_wake_locks: start\n");
+ if (debug_mask & DEBUG_SUSPEND)
+ print_active_locks(WAKE_LOCK_SUSPEND);
+ spin_lock_irqsave(&list_lock, irqflags);
+ has_lock = has_wake_lock_locked(WAKE_LOCK_SUSPEND);
+ if (debug_mask & DEBUG_EXPIRE)
+ pr_info("expire_wake_locks: done, has_lock %ld\n", has_lock);
+ if (has_lock == 0)
+ queue_work(suspend_work_queue, &suspend_work);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+static DEFINE_TIMER(expire_timer, expire_wake_locks, 0, 0);
+
+static int power_suspend_late(struct platform_device *pdev, pm_message_t state)
+{
+ int ret = has_wake_lock(WAKE_LOCK_SUSPEND) ? -EAGAIN : 0;
+#ifdef CONFIG_WAKELOCK_STAT
+ wait_for_wakeup = true;
+#endif
+ if (debug_mask & DEBUG_SUSPEND)
+ pr_info("power_suspend_late return %d\n", ret);
+ return ret;
+}
+
+static struct platform_driver power_driver = {
+ .driver.name = "power",
+ .suspend_late = power_suspend_late,
+};
+static struct platform_device power_device = {
+ .name = "power",
+};
+
+/**
+ * wake_lock_init() - Initialize a wakelock
+ * @lock: The wakelock to initialize.
+ * @type: Type of wakelock, e.g. WAKE_LOCK_SUSPEND
+ * @name: The name of the wakelock to show in /proc/wakelocks
+ */
+void wake_lock_init(struct wake_lock *lock, int type, const char *name)
+{
+ unsigned long irqflags = 0;
+
+ if (name)
+ lock->name = name;
+ BUG_ON(!lock->name);
+
+ if (debug_mask & DEBUG_WAKE_LOCK)
+ pr_info("wake_lock_init name=%s\n", lock->name);
+
+ lock->flags = (type & WAKE_LOCK_TYPE_MASK) | WAKE_LOCK_INITIALIZED;
+ INIT_LIST_HEAD(&lock->link);
+
+ spin_lock_irqsave(&list_lock, irqflags);
+ wake_lock_stat_init_locked(lock);
+ list_add(&lock->link, &inactive_locks);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(wake_lock_init);
+
+/**
+ * wake_lock_destroy() - Destroy a wakelock
+ * @lock: The wakelock to destroy.
+ */
+void wake_lock_destroy(struct wake_lock *lock)
+{
+ unsigned long irqflags;
+ if (debug_mask & DEBUG_WAKE_LOCK)
+ pr_info("wake_lock_destroy name=%s\n", lock->name);
+ spin_lock_irqsave(&list_lock, irqflags);
+ wake_lock_stat_destroy_locked(lock);
+ lock->flags &= ~WAKE_LOCK_INITIALIZED;
+ list_del(&lock->link);
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(wake_lock_destroy);
+
+static void __wake_lock(struct wake_lock *lock, long timeout, bool has_timeout)
+{
+ int type;
+ unsigned long irqflags;
+ long expire_in;
+
+ spin_lock_irqsave(&list_lock, irqflags);
+ type = lock->flags & WAKE_LOCK_TYPE_MASK;
+ BUG_ON(type >= WAKE_LOCK_TYPE_COUNT);
+ BUG_ON(!(lock->flags & WAKE_LOCK_INITIALIZED));
+
+ wake_lock_stat_locked(lock);
+ lock->flags |= WAKE_LOCK_ACTIVE;
+ list_del(&lock->link);
+ if (has_timeout) {
+ if (debug_mask & DEBUG_WAKE_LOCK)
+ pr_info("wake_lock: %s, type %d, timeout %ld.%03lu\n",
+ lock->name, type, timeout / HZ,
+ (timeout % HZ) * MSEC_PER_SEC / HZ);
+ lock->expires = jiffies + timeout;
+ lock->flags |= WAKE_LOCK_AUTO_EXPIRE;
+ list_add_tail(&lock->link, &active_wake_locks[type]);
+ } else {
+ if (debug_mask & DEBUG_WAKE_LOCK)
+ pr_info("wake_lock: %s, type %d\n", lock->name, type);
+ lock->expires = LONG_MAX;
+ lock->flags &= ~WAKE_LOCK_AUTO_EXPIRE;
+ /* Add to head so has_wake_lock only has to examine one entry */
+ list_add(&lock->link, &active_wake_locks[type]);
+ }
+ if (type == WAKE_LOCK_SUSPEND) {
+ current_event_num++;
+ if (lock == &main_wake_lock)
+ update_sleep_wait_stats_locked(true);
+ else if (!wake_lock_active(&main_wake_lock))
+ update_sleep_wait_stats_locked(false);
+ expire_in = has_timeout ? has_wake_lock_locked(type) : -1;
+ if (expire_in > 0) {
+ if (debug_mask & DEBUG_EXPIRE)
+ pr_info("wake_lock: %s, start expire timer, "
+ "%ld\n", lock->name, expire_in);
+ mod_timer(&expire_timer, jiffies + expire_in);
+ } else {
+ if (del_timer(&expire_timer))
+ if (debug_mask & DEBUG_EXPIRE)
+ pr_info("wake_lock: %s, stop expire "
+ "timer\n", lock->name);
+ if (expire_in == 0)
+ queue_work(suspend_work_queue, &suspend_work);
+ }
+ }
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+
+/**
+ * wake_lock() - Lock a wakelock
+ * @lock: The wakelock to lock.
+ */
+void wake_lock(struct wake_lock *lock)
+{
+ __wake_lock(lock, 0, false);
+}
+EXPORT_SYMBOL(wake_lock);
+
+/**
+ * wake_lock_timeout() - Lock a wakelock with auto-unlock timeout
+ * @lock: The wakelock to lock.
+ * @timeout: Timeout in jiffies before the lock auto-unlock
+ */
+void wake_lock_timeout(struct wake_lock *lock, long timeout)
+{
+ __wake_lock(lock, timeout, true);
+}
+EXPORT_SYMBOL(wake_lock_timeout);
+
+/**
+ * wake_lock() - Unlock a wakelock
+ * @lock: The wakelock to unlock.
+ */
+void wake_unlock(struct wake_lock *lock)
+{
+ int type;
+ unsigned long irqflags;
+
+ spin_lock_irqsave(&list_lock, irqflags);
+
+ wake_unlock_stat_locked(lock, false);
+
+ if (debug_mask & DEBUG_WAKE_LOCK)
+ pr_info("wake_unlock: %s\n", lock->name);
+ lock->flags &= ~(WAKE_LOCK_ACTIVE | WAKE_LOCK_AUTO_EXPIRE);
+ list_del(&lock->link);
+ list_add(&lock->link, &inactive_locks);
+
+ type = lock->flags & WAKE_LOCK_TYPE_MASK;
+ if (type == WAKE_LOCK_SUSPEND) {
+ long has_lock = has_wake_lock_locked(type);
+ if (has_lock > 0) {
+ if (debug_mask & DEBUG_EXPIRE)
+ pr_info("wake_unlock: %s, start expire timer, "
+ "%ld\n", lock->name, has_lock);
+ mod_timer(&expire_timer, jiffies + has_lock);
+ } else {
+ if (del_timer(&expire_timer))
+ if (debug_mask & DEBUG_EXPIRE)
+ pr_info("wake_unlock: %s, stop expire "
+ "timer\n", lock->name);
+ if (has_lock == 0)
+ queue_work(suspend_work_queue, &suspend_work);
+ }
+ if (lock == &main_wake_lock) {
+ if (debug_mask & DEBUG_SUSPEND)
+ print_active_locks(WAKE_LOCK_SUSPEND);
+ update_sleep_wait_stats_locked(false);
+ }
+ }
+ spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(wake_unlock);
+
+/**
+ * wake_lock_active() - Test if a wakelock is locked
+ * @lock: The wakelock to check.
+ */
+int wake_lock_active(struct wake_lock *lock)
+{
+ return !!(lock->flags & WAKE_LOCK_ACTIVE);
+}
+EXPORT_SYMBOL(wake_lock_active);
+
+void request_suspend_state(suspend_state_t state)
+{
+ unsigned long irqflags;
+ spin_lock_irqsave(&state_lock, irqflags);
+ if (debug_mask & DEBUG_USER_STATE) {
+ struct timespec ts;
+ struct rtc_time tm;
+ getnstimeofday(&ts);
+ rtc_time_to_tm(ts.tv_sec, &tm);
+ pr_info("request_suspend_state: %s (%d->%d) at %lld "
+ "(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n",
+ state != PM_SUSPEND_ON ? "sleep" : "wakeup",
+ requested_suspend_state, state,
+ ktime_to_ns(ktime_get()),
+ tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+ tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
+ }
+ requested_suspend_state = state;
+ if (state == PM_SUSPEND_ON)
+ wake_lock(&main_wake_lock);
+ else
+ wake_unlock(&main_wake_lock);
+ spin_unlock_irqrestore(&state_lock, irqflags);
+}
+
+static int __init wakelocks_init(void)
+{
+ int ret;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(active_wake_locks); i++)
+ INIT_LIST_HEAD(&active_wake_locks[i]);
+
+#ifdef CONFIG_WAKELOCK_STAT
+ wake_lock_init(&deleted_wake_locks, WAKE_LOCK_SUSPEND,
+ "deleted_wake_locks");
+#endif
+ wake_lock_init(&main_wake_lock, WAKE_LOCK_SUSPEND, "main");
+ wake_lock(&main_wake_lock);
+ wake_lock_init(&unknown_wakeup, WAKE_LOCK_SUSPEND, "unknown_wakeups");
+
+ ret = platform_device_register(&power_device);
+ if (ret) {
+ pr_err("wakelocks_init: platform_device_register failed\n");
+ goto err_platform_device_register;
+ }
+ ret = platform_driver_register(&power_driver);
+ if (ret) {
+ pr_err("wakelocks_init: platform_driver_register failed\n");
+ goto err_platform_driver_register;
+ }
+
+ suspend_work_queue = create_singlethread_workqueue("suspend");
+ if (suspend_work_queue == NULL) {
+ ret = -ENOMEM;
+ goto err_suspend_work_queue;
+ }
+
+#ifdef CONFIG_WAKELOCK_STAT
+ create_proc_read_entry("wakelocks", S_IRUGO, NULL,
+ wakelock_stats_read_proc, NULL);
+#endif
+
+ return 0;
+
+err_suspend_work_queue:
+ platform_driver_unregister(&power_driver);
+err_platform_driver_register:
+ platform_device_unregister(&power_device);
+err_platform_device_register:
+ wake_lock_destroy(&unknown_wakeup);
+ wake_lock_destroy(&main_wake_lock);
+#ifdef CONFIG_WAKELOCK_STAT
+ wake_lock_destroy(&deleted_wake_locks);
+#endif
+ return ret;
+}
+
+static void __exit wakelocks_exit(void)
+{
+#ifdef CONFIG_WAKELOCK_STAT
+ remove_proc_entry("wakelocks", NULL);
+#endif
+ destroy_workqueue(suspend_work_queue);
+ platform_driver_unregister(&power_driver);
+ platform_device_unregister(&power_device);
+ wake_lock_destroy(&unknown_wakeup);
+ wake_lock_destroy(&main_wake_lock);
+#ifdef CONFIG_WAKELOCK_STAT
+ wake_lock_destroy(&deleted_wake_locks);
+#endif
+}
+
+core_initcall(wakelocks_init);
+module_exit(wakelocks_exit);
--
1.6.1

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