Staging
v0.6.0
v0.6.0
https://github.com/torvalds/linux
Tip revision: 949db153b6466c6f7cad5a427ecea94985927311 authored by Linus Torvalds on 25 January 2013, 19:57:28 UTC
Linux 3.8-rc5
Linux 3.8-rc5
Tip revision: 949db15
alarm-dev.c
/* drivers/rtc/alarm-dev.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 <linux/time.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/alarmtimer.h>
#include "android_alarm.h"
#define ANDROID_ALARM_PRINT_INFO (1U << 0)
#define ANDROID_ALARM_PRINT_IO (1U << 1)
#define ANDROID_ALARM_PRINT_INT (1U << 2)
static int debug_mask = ANDROID_ALARM_PRINT_INFO;
module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
#define alarm_dbg(debug_level_mask, fmt, ...) \
do { \
if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) \
pr_info(fmt, ##__VA_ARGS__); \
} while (0)
#define ANDROID_ALARM_WAKEUP_MASK ( \
ANDROID_ALARM_RTC_WAKEUP_MASK | \
ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
/* support old userspace 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)
static int alarm_opened;
static DEFINE_SPINLOCK(alarm_slock);
static struct wakeup_source alarm_wake_lock;
static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
static uint32_t alarm_pending;
static uint32_t alarm_enabled;
static uint32_t wait_pending;
struct devalarm {
union {
struct hrtimer hrt;
struct alarm alrm;
} u;
enum android_alarm_type type;
};
static struct devalarm alarms[ANDROID_ALARM_TYPE_COUNT];
static int is_wakeup(enum android_alarm_type type)
{
return (type == ANDROID_ALARM_RTC_WAKEUP ||
type == ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP);
}
static void devalarm_start(struct devalarm *alrm, ktime_t exp)
{
if (is_wakeup(alrm->type))
alarm_start(&alrm->u.alrm, exp);
else
hrtimer_start(&alrm->u.hrt, exp, HRTIMER_MODE_ABS);
}
static int devalarm_try_to_cancel(struct devalarm *alrm)
{
if (is_wakeup(alrm->type))
return alarm_try_to_cancel(&alrm->u.alrm);
return hrtimer_try_to_cancel(&alrm->u.hrt);
}
static void devalarm_cancel(struct devalarm *alrm)
{
if (is_wakeup(alrm->type))
alarm_cancel(&alrm->u.alrm);
else
hrtimer_cancel(&alrm->u.hrt);
}
static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int rv = 0;
unsigned long flags;
struct timespec new_alarm_time;
struct timespec new_rtc_time;
struct timespec tmp_time;
struct rtc_time new_rtc_tm;
struct rtc_device *rtc_dev;
enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
uint32_t alarm_type_mask = 1U << alarm_type;
if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
return -EINVAL;
if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
if ((file->f_flags & O_ACCMODE) == O_RDONLY)
return -EPERM;
if (file->private_data == NULL &&
cmd != ANDROID_ALARM_SET_RTC) {
spin_lock_irqsave(&alarm_slock, flags);
if (alarm_opened) {
spin_unlock_irqrestore(&alarm_slock, flags);
return -EBUSY;
}
alarm_opened = 1;
file->private_data = (void *)1;
spin_unlock_irqrestore(&alarm_slock, flags);
}
}
switch (ANDROID_ALARM_BASE_CMD(cmd)) {
case ANDROID_ALARM_CLEAR(0):
spin_lock_irqsave(&alarm_slock, flags);
alarm_dbg(IO, "alarm %d clear\n", alarm_type);
devalarm_try_to_cancel(&alarms[alarm_type]);
if (alarm_pending) {
alarm_pending &= ~alarm_type_mask;
if (!alarm_pending && !wait_pending)
__pm_relax(&alarm_wake_lock);
}
alarm_enabled &= ~alarm_type_mask;
spin_unlock_irqrestore(&alarm_slock, flags);
break;
case ANDROID_ALARM_SET_OLD:
case ANDROID_ALARM_SET_AND_WAIT_OLD:
if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
rv = -EFAULT;
goto err1;
}
new_alarm_time.tv_nsec = 0;
goto from_old_alarm_set;
case ANDROID_ALARM_SET_AND_WAIT(0):
case ANDROID_ALARM_SET(0):
if (copy_from_user(&new_alarm_time, (void __user *)arg,
sizeof(new_alarm_time))) {
rv = -EFAULT;
goto err1;
}
from_old_alarm_set:
spin_lock_irqsave(&alarm_slock, flags);
alarm_dbg(IO, "alarm %d set %ld.%09ld\n",
alarm_type,
new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
alarm_enabled |= alarm_type_mask;
devalarm_start(&alarms[alarm_type],
timespec_to_ktime(new_alarm_time));
spin_unlock_irqrestore(&alarm_slock, flags);
if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
&& cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
break;
/* fall though */
case ANDROID_ALARM_WAIT:
spin_lock_irqsave(&alarm_slock, flags);
alarm_dbg(IO, "alarm wait\n");
if (!alarm_pending && wait_pending) {
__pm_relax(&alarm_wake_lock);
wait_pending = 0;
}
spin_unlock_irqrestore(&alarm_slock, flags);
rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
if (rv)
goto err1;
spin_lock_irqsave(&alarm_slock, flags);
rv = alarm_pending;
wait_pending = 1;
alarm_pending = 0;
spin_unlock_irqrestore(&alarm_slock, flags);
break;
case ANDROID_ALARM_SET_RTC:
if (copy_from_user(&new_rtc_time, (void __user *)arg,
sizeof(new_rtc_time))) {
rv = -EFAULT;
goto err1;
}
rtc_time_to_tm(new_rtc_time.tv_sec, &new_rtc_tm);
rtc_dev = alarmtimer_get_rtcdev();
rv = do_settimeofday(&new_rtc_time);
if (rv < 0)
goto err1;
if (rtc_dev)
rv = rtc_set_time(rtc_dev, &new_rtc_tm);
spin_lock_irqsave(&alarm_slock, flags);
alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
wake_up(&alarm_wait_queue);
spin_unlock_irqrestore(&alarm_slock, flags);
if (rv < 0)
goto err1;
break;
case ANDROID_ALARM_GET_TIME(0):
switch (alarm_type) {
case ANDROID_ALARM_RTC_WAKEUP:
case ANDROID_ALARM_RTC:
getnstimeofday(&tmp_time);
break;
case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
case ANDROID_ALARM_ELAPSED_REALTIME:
get_monotonic_boottime(&tmp_time);
break;
case ANDROID_ALARM_SYSTEMTIME:
ktime_get_ts(&tmp_time);
break;
default:
rv = -EINVAL;
goto err1;
}
if (copy_to_user((void __user *)arg, &tmp_time,
sizeof(tmp_time))) {
rv = -EFAULT;
goto err1;
}
break;
default:
rv = -EINVAL;
}
err1:
return rv;
}
static int alarm_open(struct inode *inode, struct file *file)
{
file->private_data = NULL;
return 0;
}
static int alarm_release(struct inode *inode, struct file *file)
{
int i;
unsigned long flags;
spin_lock_irqsave(&alarm_slock, flags);
if (file->private_data) {
for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
uint32_t alarm_type_mask = 1U << i;
if (alarm_enabled & alarm_type_mask) {
alarm_dbg(INFO,
"%s: clear alarm, pending %d\n",
__func__,
!!(alarm_pending & alarm_type_mask));
alarm_enabled &= ~alarm_type_mask;
}
spin_unlock_irqrestore(&alarm_slock, flags);
devalarm_cancel(&alarms[i]);
spin_lock_irqsave(&alarm_slock, flags);
}
if (alarm_pending | wait_pending) {
if (alarm_pending)
alarm_dbg(INFO, "%s: clear pending alarms %x\n",
__func__, alarm_pending);
__pm_relax(&alarm_wake_lock);
wait_pending = 0;
alarm_pending = 0;
}
alarm_opened = 0;
}
spin_unlock_irqrestore(&alarm_slock, flags);
return 0;
}
static void devalarm_triggered(struct devalarm *alarm)
{
unsigned long flags;
uint32_t alarm_type_mask = 1U << alarm->type;
alarm_dbg(INT, "%s: type %d\n", __func__, alarm->type);
spin_lock_irqsave(&alarm_slock, flags);
if (alarm_enabled & alarm_type_mask) {
__pm_wakeup_event(&alarm_wake_lock, 5000); /* 5secs */
alarm_enabled &= ~alarm_type_mask;
alarm_pending |= alarm_type_mask;
wake_up(&alarm_wait_queue);
}
spin_unlock_irqrestore(&alarm_slock, flags);
}
static enum hrtimer_restart devalarm_hrthandler(struct hrtimer *hrt)
{
struct devalarm *devalrm = container_of(hrt, struct devalarm, u.hrt);
devalarm_triggered(devalrm);
return HRTIMER_NORESTART;
}
static enum alarmtimer_restart devalarm_alarmhandler(struct alarm *alrm,
ktime_t now)
{
struct devalarm *devalrm = container_of(alrm, struct devalarm, u.alrm);
devalarm_triggered(devalrm);
return ALARMTIMER_NORESTART;
}
static const struct file_operations alarm_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = alarm_ioctl,
.open = alarm_open,
.release = alarm_release,
};
static struct miscdevice alarm_device = {
.minor = MISC_DYNAMIC_MINOR,
.name = "alarm",
.fops = &alarm_fops,
};
static int __init alarm_dev_init(void)
{
int err;
int i;
err = misc_register(&alarm_device);
if (err)
return err;
alarm_init(&alarms[ANDROID_ALARM_RTC_WAKEUP].u.alrm,
ALARM_REALTIME, devalarm_alarmhandler);
hrtimer_init(&alarms[ANDROID_ALARM_RTC].u.hrt,
CLOCK_REALTIME, HRTIMER_MODE_ABS);
alarm_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].u.alrm,
ALARM_BOOTTIME, devalarm_alarmhandler);
hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME].u.hrt,
CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].u.hrt,
CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
alarms[i].type = i;
if (!is_wakeup(i))
alarms[i].u.hrt.function = devalarm_hrthandler;
}
wakeup_source_init(&alarm_wake_lock, "alarm");
return 0;
}
static void __exit alarm_dev_exit(void)
{
misc_deregister(&alarm_device);
wakeup_source_trash(&alarm_wake_lock);
}
module_init(alarm_dev_init);
module_exit(alarm_dev_exit);