- 根目录:
- drivers
- rtc
- alarm.c
/* drivers/rtc/alarm.c
*
* Copyright (C) 2007-2009 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 <asm/mach/time.h>
#include <linux/android_alarm.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/sysdev.h>
#include <linux/wakelock.h>
#define ANDROID_ALARM_PRINT_ERROR (1U << 0)
#define ANDROID_ALARM_PRINT_INIT_STATUS (1U << 1)
#define ANDROID_ALARM_PRINT_TSET (1U << 2)
#define ANDROID_ALARM_PRINT_CALL (1U << 3)
#define ANDROID_ALARM_PRINT_SUSPEND (1U << 4)
#define ANDROID_ALARM_PRINT_INT (1U << 5)
#define ANDROID_ALARM_PRINT_FLOW (1U << 6)
static int debug_mask = ANDROID_ALARM_PRINT_ERROR | \
ANDROID_ALARM_PRINT_INIT_STATUS;
module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
#define pr_alarm(debug_level_mask, args...) \
do { \
if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
pr_info(args); \
} \
} while (0)
#define ANDROID_ALARM_WAKEUP_MASK ( \
ANDROID_ALARM_RTC_WAKEUP_MASK | \
ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
/* support old usespace code */
#define ANDROID_ALARM_SET_OLD _IOW('a', 2, time_t) /* set alarm */
#define ANDROID_ALARM_SET_AND_WAIT_OLD _IOW('a', 3, time_t)
struct alarm_queue {
struct rb_root alarms;
struct rb_node *first;
struct hrtimer timer;
ktime_t delta;
bool stopped;
ktime_t stopped_time;
};
static struct rtc_device *alarm_rtc_dev;
static DEFINE_SPINLOCK(alarm_slock);
static DEFINE_MUTEX(alarm_setrtc_mutex);
static struct wake_lock alarm_rtc_wake_lock;
static struct platform_device *alarm_platform_dev;
struct alarm_queue alarms[ANDROID_ALARM_TYPE_COUNT];
static bool suspended;
static void update_timer_locked(struct alarm_queue *base, bool head_removed)
{
struct alarm *alarm;
bool is_wakeup = base == &alarms[ANDROID_ALARM_RTC_WAKEUP] ||
base == &alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP];
if (base->stopped) {
pr_alarm(FLOW, "changed alarm while setting the wall time\n");
return;
}
if (is_wakeup && !suspended && head_removed)
wake_unlock(&alarm_rtc_wake_lock);
if (!base->first)
return;
alarm = container_of(base->first, struct alarm, node);
pr_alarm(FLOW, "selected alarm, type %d, func %pF at %lld\n",
alarm->type, alarm->function, ktime_to_ns(alarm->expires));
if (is_wakeup && suspended) {
pr_alarm(FLOW, "changed alarm while suspened\n");
wake_lock_timeout(&alarm_rtc_wake_lock, 1 * HZ);
return;
}
hrtimer_try_to_cancel(&base->timer);
base->timer.node.expires = ktime_add(base->delta, alarm->expires);
base->timer._softexpires = ktime_add(base->delta, alarm->softexpires);
hrtimer_start_expires(&base->timer, HRTIMER_MODE_ABS);
}
static void alarm_enqueue_locked(struct alarm *alarm)
{
struct alarm_queue *base = &alarms[alarm->type];
struct rb_node **link = &base->alarms.rb_node;
struct rb_node *parent = NULL;
struct alarm *entry;
int leftmost = 1;
bool was_first = false;
pr_alarm(FLOW, "added alarm, type %d, func %pF at %lld\n",
alarm->type, alarm->function, ktime_to_ns(alarm->expires));
if (base->first == &alarm->node) {
base->first = rb_next(&alarm->node);
was_first = true;
}
if (!RB_EMPTY_NODE(&alarm->node)) {
rb_erase(&alarm->node, &base->alarms);
RB_CLEAR_NODE(&alarm->node);
}
while (*link) {
parent = *link;
entry = rb_entry(parent, struct alarm, node);
/*
* We dont care about collisions. Nodes with
* the same expiry time stay together.
*/
if (alarm->expires.tv64 < entry->expires.tv64) {
link = &(*link)->rb_left;
} else {
link = &(*link)->rb_right;
leftmost = 0;
}
}
if (leftmost)
base->first = &alarm->node;
if (leftmost || was_first)
update_timer_locked(base, was_first);
rb_link_node(&alarm->node, parent, link);
rb_insert_color(&alarm->node, &base->alarms);
}
/**
* alarm_init - initialize an alarm
* @alarm: the alarm to be initialized
* @type: the alarm type to be used
* @function: alarm callback function
*/
void alarm_init(struct alarm *alarm,
enum android_alarm_type type, void (*function)(struct alarm *))
{
RB_CLEAR_NODE(&alarm->node);
alarm->type = type;
alarm->function = function;
pr_alarm(FLOW, "created alarm, type %d, func %pF\n", type, function);
}
/**
* alarm_start_range - (re)start an alarm
* @alarm: the alarm to be added
* @start: earliest expiry time
* @end: expiry time
*/
void alarm_start_range(struct alarm *alarm, ktime_t start, ktime_t end)
{
unsigned long flags;
spin_lock_irqsave(&alarm_slock, flags);
alarm->softexpires = start;
alarm->expires = end;
alarm_enqueue_locked(alarm);
spin_unlock_irqrestore(&alarm_slock, flags);
}
/**
* alarm_try_to_cancel - try to deactivate an alarm
* @alarm: alarm to stop
*
* Returns:
* 0 when the alarm was not active
* 1 when the alarm was active
* -1 when the alarm may currently be excuting the callback function and
* cannot be stopped (it may also be inactive)
*/
int alarm_try_to_cancel(struct alarm *alarm)
{
struct alarm_queue *base = &alarms[alarm->type];
unsigned long flags;
bool first = false;
int ret = 0;
spin_lock_irqsave(&alarm_slock, flags);
if (!RB_EMPTY_NODE(&alarm->node)) {
pr_alarm(FLOW, "canceled alarm, type %d, func %pF at %lld\n",
alarm->type, alarm->function,
ktime_to_ns(alarm->expires));
ret = 1;
if (base->first == &alarm->node) {
base->first = rb_next(&alarm->node);
first = true;
}
rb_erase(&alarm->node, &base->alarms);
RB_CLEAR_NODE(&alarm->node);
if (first)
update_timer_locked(base, true);
} else
pr_alarm(FLOW, "tried to cancel alarm, type %d, func %pF\n",
alarm->type, alarm->function);
spin_unlock_irqrestore(&alarm_slock, flags);
if (!ret && hrtimer_callback_running(&base->timer))
ret = -1;
return ret;
}
/**
* alarm_cancel - cancel an alarm and wait for the handler to finish.
* @alarm: the alarm to be cancelled
*
* Returns:
* 0 when the alarm was not active
* 1 when the alarm was active
*/
int alarm_cancel(struct alarm *alarm)
{
for (;;) {
int ret = alarm_try_to_cancel(alarm);
if (ret >= 0)
return ret;
cpu_relax();
}
}
/**
* alarm_set_rtc - set the kernel and rtc walltime
* @new_time: timespec value containing the new time
*/
int alarm_set_rtc(struct timespec new_time)
{
int i;
int ret;
unsigned long flags;
struct rtc_time rtc_new_rtc_time;
struct timespec tmp_time;
rtc_time_to_tm(new_time.tv_sec, &rtc_new_rtc_time);
pr_alarm(TSET, "set rtc %ld %ld - rtc %02d:%02d:%02d %02d/%02d/%04d\n",
new_time.tv_sec, new_time.tv_nsec,
rtc_new_rtc_time.tm_hour, rtc_new_rtc_time.tm_min,
rtc_new_rtc_time.tm_sec, rtc_new_rtc_time.tm_mon + 1,
rtc_new_rtc_time.tm_mday,
rtc_new_rtc_time.tm_year + 1900);
mutex_lock(&alarm_setrtc_mutex);
spin_lock_irqsave(&alarm_slock, flags);
wake_lock(&alarm_rtc_wake_lock);
getnstimeofday(&tmp_time);
for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
hrtimer_try_to_cancel(&alarms[i].timer);
alarms[i].stopped = true;
alarms[i].stopped_time = timespec_to_ktime(tmp_time);
}
alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
ktime_sub(alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta,
timespec_to_ktime(timespec_sub(tmp_time, new_time)));
spin_unlock_irqrestore(&alarm_slock, flags);
ret = do_settimeofday(&new_time);
spin_lock_irqsave(&alarm_slock, flags);
for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
alarms[i].stopped = false;
update_timer_locked(&alarms[i], false);
}
spin_unlock_irqrestore(&alarm_slock, flags);
if (ret < 0) {
pr_alarm(ERROR, "alarm_set_rtc: Failed to set time\n");
goto err;
}
if (!alarm_rtc_dev) {
pr_alarm(ERROR,
"alarm_set_rtc: no RTC, time will be lost on reboot\n");
goto err;
}
ret = rtc_set_time(alarm_rtc_dev, &rtc_new_rtc_time);
if (ret < 0)
pr_alarm(ERROR, "alarm_set_rtc: "
"Failed to set RTC, time will be lost on reboot\n");
err:
wake_unlock(&alarm_rtc_wake_lock);
mutex_unlock(&alarm_setrtc_mutex);
return ret;
}
/**
* alarm_get_elapsed_realtime - get the elapsed real time in ktime_t format
*
* returns the time in ktime_t format
*/
ktime_t alarm_get_elapsed_realtime(void)
{
ktime_t now;
unsigned long flags;
struct alarm_queue *base = &alarms[ANDROID_ALARM_ELAPSED_REALTIME];
spin_lock_irqsave(&alarm_slock, flags);
now = base->stopped ? base->stopped_time : ktime_get_real();
now = ktime_sub(now, base->delta);
spin_unlock_irqrestore(&alarm_slock, flags);
return now;
}
static enum hrtimer_restart alarm_timer_triggered(struct hrtimer *timer)
{
struct alarm_queue *base;
struct alarm *alarm;
unsigned long flags;
ktime_t now;
spin_lock_irqsave(&alarm_slock, flags);
base = container_of(timer, struct alarm_queue, timer);
now = base->stopped ? base->stopped_time : hrtimer_cb_get_time(timer);
now = ktime_sub(now, base->delta);
pr_alarm(INT, "alarm_timer_triggered type %d at %lld\n",
base - alarms, ktime_to_ns(now));
while (base->first) {
alarm = container_of(base->first, struct alarm, node);
if (alarm->softexpires.tv64 > now.tv64) {
pr_alarm(FLOW, "don't call alarm, %pF, %lld (s %lld)\n",
alarm->function, ktime_to_ns(alarm->expires),
ktime_to_ns(alarm->softexpires));
break;
}
base->first = rb_next(&alarm->node);
rb_erase(&alarm->node, &base->alarms);
RB_CLEAR_NODE(&alarm->node);
pr_alarm(CALL, "call alarm, type %d, func %pF, %lld (s %lld)\n",
alarm->type, alarm->function,
ktime_to_ns(alarm->expires),
ktime_to_ns(alarm->softexpires));
spin_unlock_irqrestore(&alarm_slock, flags);
alarm->function(alarm);
spin_lock_irqsave(&alarm_slock, flags);
}
if (!base->first)
pr_alarm(FLOW, "no more alarms of type %d\n", base - alarms);
update_timer_locked(base, true);
spin_unlock_irqrestore(&alarm_slock, flags);
return HRTIMER_NORESTART;
}
static void alarm_triggered_func(void *p)
{
struct rtc_device *rtc = alarm_rtc_dev;
if (!(rtc->irq_data & RTC_AF))
return;
pr_alarm(INT, "rtc alarm triggered\n");
wake_lock_timeout(&alarm_rtc_wake_lock, 1 * HZ);
}
static int alarm_suspend(struct platform_device *pdev, pm_message_t state)
{
int err = 0;
unsigned long flags;
struct rtc_wkalrm rtc_alarm;
struct rtc_time rtc_current_rtc_time;
unsigned long rtc_current_time;
unsigned long rtc_alarm_time;
struct timespec rtc_delta;
struct timespec wall_time;
struct alarm_queue *wakeup_queue = NULL;
struct alarm_queue *tmp_queue = NULL;
pr_alarm(SUSPEND, "alarm_suspend(%p, %d)\n", pdev, state.event);
spin_lock_irqsave(&alarm_slock, flags);
suspended = true;
spin_unlock_irqrestore(&alarm_slock, flags);
hrtimer_cancel(&alarms[ANDROID_ALARM_RTC_WAKEUP].timer);
hrtimer_cancel(&alarms[
ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].timer);
tmp_queue = &alarms[ANDROID_ALARM_RTC_WAKEUP];
if (tmp_queue->first)
wakeup_queue = tmp_queue;
tmp_queue = &alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP];
if (tmp_queue->first && (!wakeup_queue ||
hrtimer_get_expires(&tmp_queue->timer).tv64 <
hrtimer_get_expires(&wakeup_queue->timer).tv64))
wakeup_queue = tmp_queue;
if (wakeup_queue) {
rtc_read_time(alarm_rtc_dev, &rtc_current_rtc_time);
getnstimeofday(&wall_time);
rtc_tm_to_time(&rtc_current_rtc_time, &rtc_current_time);
set_normalized_timespec(&rtc_delta,
wall_time.tv_sec - rtc_current_time,
wall_time.tv_nsec);
rtc_alarm_time = timespec_sub(ktime_to_timespec(
hrtimer_get_expires(&wakeup_queue->timer)),
rtc_delta).tv_sec;
rtc_time_to_tm(rtc_alarm_time, &rtc_alarm.time);
rtc_alarm.enabled = 1;
rtc_set_alarm(alarm_rtc_dev, &rtc_alarm);
rtc_read_time(alarm_rtc_dev, &rtc_current_rtc_time);
rtc_tm_to_time(&rtc_current_rtc_time, &rtc_current_time);
pr_alarm(SUSPEND,
"rtc alarm set at %ld, now %ld, rtc delta %ld.%09ld\n",
rtc_alarm_time, rtc_current_time,
rtc_delta.tv_sec, rtc_delta.tv_nsec);
if (rtc_current_time + 1 >= rtc_alarm_time) {
pr_alarm(SUSPEND, "alarm about to go off\n");
memset(&rtc_alarm, 0, sizeof(rtc_alarm));
rtc_alarm.enabled = 0;
rtc_set_alarm(alarm_rtc_dev, &rtc_alarm);
spin_lock_irqsave(&alarm_slock, flags);
suspended = false;
wake_lock_timeout(&alarm_rtc_wake_lock, 2 * HZ);
update_timer_locked(&alarms[ANDROID_ALARM_RTC_WAKEUP],
false);
update_timer_locked(&alarms[
ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP], false);
err = -EBUSY;
spin_unlock_irqrestore(&alarm_slock, flags);
}
}
return err;
}
static int alarm_resume(struct platform_device *pdev)
{
struct rtc_wkalrm alarm;
unsigned long flags;
pr_alarm(SUSPEND, "alarm_resume(%p)\n", pdev);
memset(&alarm, 0, sizeof(alarm));
alarm.enabled = 0;
rtc_set_alarm(alarm_rtc_dev, &alarm);
spin_lock_irqsave(&alarm_slock, flags);
suspended = false;
update_timer_locked(&alarms[ANDROID_ALARM_RTC_WAKEUP], false);
update_timer_locked(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP],
false);
spin_unlock_irqrestore(&alarm_slock, flags);
return 0;
}
static struct rtc_task alarm_rtc_task = {
.func = alarm_triggered_func
};
static int rtc_alarm_add_device(struct device *dev,
struct class_interface *class_intf)
{
int err;
struct rtc_device *rtc = to_rtc_device(dev);
mutex_lock(&alarm_setrtc_mutex);
if (alarm_rtc_dev) {
err = -EBUSY;
goto err1;
}
alarm_platform_dev =
platform_device_register_simple("alarm", -1, NULL, 0);
if (IS_ERR(alarm_platform_dev)) {
err = PTR_ERR(alarm_platform_dev);
goto err2;
}
err = rtc_irq_register(rtc, &alarm_rtc_task);
if (err)
goto err3;
alarm_rtc_dev = rtc;
pr_alarm(INIT_STATUS, "using rtc device, %s, for alarms", rtc->name);
mutex_unlock(&alarm_setrtc_mutex);
return 0;
err3:
platform_device_unregister(alarm_platform_dev);
err2:
err1:
mutex_unlock(&alarm_setrtc_mutex);
return err;
}
static void rtc_alarm_remove_device(struct device *dev,
struct class_interface *class_intf)
{
if (dev == &alarm_rtc_dev->dev) {
pr_alarm(INIT_STATUS, "lost rtc device for alarms");
rtc_irq_unregister(alarm_rtc_dev, &alarm_rtc_task);
platform_device_unregister(alarm_platform_dev);
alarm_rtc_dev = NULL;
}
}
static struct class_interface rtc_alarm_interface = {
.add_dev = &rtc_alarm_add_device,
.remove_dev = &rtc_alarm_remove_device,
};
static struct platform_driver alarm_driver = {
.suspend = alarm_suspend,
.resume = alarm_resume,
.driver = {
.name = "alarm"
}
};
static int __init alarm_late_init(void)
{
unsigned long flags;
struct timespec tmp_time, system_time;
/* this needs to run after the rtc is read at boot */
spin_lock_irqsave(&alarm_slock, flags);
/* We read the current rtc and system time so we can later calulate
* elasped realtime to be (boot_systemtime + rtc - boot_rtc) ==
* (rtc - (boot_rtc - boot_systemtime))
*/
getnstimeofday(&tmp_time);
ktime_get_ts(&system_time);
alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
timespec_to_ktime(timespec_sub(tmp_time, system_time));
spin_unlock_irqrestore(&alarm_slock, flags);
return 0;
}
static int __init alarm_driver_init(void)
{
int err;
int i;
for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
hrtimer_init(&alarms[i].timer,
CLOCK_REALTIME, HRTIMER_MODE_ABS);
alarms[i].timer.function = alarm_timer_triggered;
}
hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].timer,
CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
alarms[ANDROID_ALARM_SYSTEMTIME].timer.function = alarm_timer_triggered;
err = platform_driver_register(&alarm_driver);
if (err < 0)
goto err1;
wake_lock_init(&alarm_rtc_wake_lock, WAKE_LOCK_SUSPEND, "alarm_rtc");
rtc_alarm_interface.class = rtc_class;
err = class_interface_register(&rtc_alarm_interface);
if (err < 0)
goto err2;
return 0;
err2:
wake_lock_destroy(&alarm_rtc_wake_lock);
platform_driver_unregister(&alarm_driver);
err1:
return err;
}
static void __exit alarm_exit(void)
{
class_interface_unregister(&rtc_alarm_interface);
wake_lock_destroy(&alarm_rtc_wake_lock);
platform_driver_unregister(&alarm_driver);
}
late_initcall(alarm_late_init);
module_init(alarm_driver_init);
module_exit(alarm_exit);