drivers/rtc/alarm-dev.c

   1 /* drivers/rtc/alarm-dev.c
   2  *
   3  * Copyright (C) 2007-2009 Google, Inc.
   4  *
   5  * This software is licensed under the terms of the GNU General Public
   6  * License version 2, as published by the Free Software Foundation, and
   7  * may be copied, distributed, and modified under those terms.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15
  16 #include <asm/mach/time.h>
  17 #include <linux/android_alarm.h>
  18 #include <linux/device.h>
  19 #include <linux/miscdevice.h>
  20 #include <linux/fs.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/sched.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/sysdev.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/wakelock.h>
  27
  28 #define ANDROID_ALARM_PRINT_INFO (1U << 0)
  29 #define ANDROID_ALARM_PRINT_IO (1U << 1)
  30 #define ANDROID_ALARM_PRINT_INT (1U << 2)
  31
  32 static int debug_mask = ANDROID_ALARM_PRINT_INFO;
  33 module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
  34
  35 #define pr_alarm(debug_level_mask, args...) \
  36         do { \
  37                 if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
  38                         pr_info(args); \
  39                 } \
  40         } while (0)
  41
  42 #define ANDROID_ALARM_WAKEUP_MASK ( \
  43         ANDROID_ALARM_RTC_WAKEUP_MASK | \
  44         ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
  45
  46 /* support old usespace code */
  47 #define ANDROID_ALARM_SET_OLD               _IOW('a', 2, time_t) /* set alarm */
  48 #define ANDROID_ALARM_SET_AND_WAIT_OLD      _IOW('a', 3, time_t)
  49
  50 static int alarm_opened;
  51 static DEFINE_SPINLOCK(alarm_slock);
  52 static struct wake_lock alarm_wake_lock;
  53 static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
  54 static uint32_t alarm_pending;
  55 static uint32_t alarm_enabled;
  56 static uint32_t wait_pending;
  57
  58 static struct alarm alarms[ANDROID_ALARM_TYPE_COUNT];
  59
  60 static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  61 {
  62         int rv = 0;
  63         unsigned long flags;
  64         struct timespec new_alarm_time;
  65         struct timespec new_rtc_time;
  66         struct timespec tmp_time;
  67         enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
  68         uint32_t alarm_type_mask = 1U << alarm_type;
  69
  70         if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
  71                 return -EINVAL;
  72
  73         if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
  74                 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
  75                         return -EPERM;
  76                 if (file->private_data == NULL &&
  77                     cmd != ANDROID_ALARM_SET_RTC) {
  78                         spin_lock_irqsave(&alarm_slock, flags);
  79                         if (alarm_opened) {
  80                                 spin_unlock_irqrestore(&alarm_slock, flags);
  81                                 return -EBUSY;
  82                         }
  83                         alarm_opened = 1;
  84                         file->private_data = (void *)1;
  85                         spin_unlock_irqrestore(&alarm_slock, flags);
  86                 }
  87         }
  88
  89         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
  90         case ANDROID_ALARM_CLEAR(0):
  91                 spin_lock_irqsave(&alarm_slock, flags);
  92                 pr_alarm(IO, "alarm %d clear\n", alarm_type);
  93                 alarm_try_to_cancel(&alarms[alarm_type]);
  94                 if (alarm_pending) {
  95                         alarm_pending &= ~alarm_type_mask;
  96                         if (!alarm_pending && !wait_pending)
  97                                 wake_unlock(&alarm_wake_lock);
  98                 }
  99                 alarm_enabled &= ~alarm_type_mask;
 100                 spin_unlock_irqrestore(&alarm_slock, flags);
 101                 break;
 102
 103         case ANDROID_ALARM_SET_OLD:
 104         case ANDROID_ALARM_SET_AND_WAIT_OLD:
 105                 if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
 106                         rv = -EFAULT;
 107                         goto err1;
 108                 }
 109                 new_alarm_time.tv_nsec = 0;
 110                 goto from_old_alarm_set;
 111
 112         case ANDROID_ALARM_SET_AND_WAIT(0):
 113         case ANDROID_ALARM_SET(0):
 114                 if (copy_from_user(&new_alarm_time, (void __user *)arg,
 115                     sizeof(new_alarm_time))) {
 116                         rv = -EFAULT;
 117                         goto err1;
 118                 }
 119 from_old_alarm_set:
 120                 spin_lock_irqsave(&alarm_slock, flags);
 121                 pr_alarm(IO, "alarm %d set %ld.%09ld\n", alarm_type,
 122                         new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
 123                 alarm_enabled |= alarm_type_mask;
 124                 alarm_start_range(&alarms[alarm_type],
 125                         timespec_to_ktime(new_alarm_time),
 126                         timespec_to_ktime(new_alarm_time));
 127                 spin_unlock_irqrestore(&alarm_slock, flags);
 128                 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
 129                     && cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
 130                         break;
 131                 /* fall though */
 132         case ANDROID_ALARM_WAIT:
 133                 spin_lock_irqsave(&alarm_slock, flags);
 134                 pr_alarm(IO, "alarm wait\n");
 135                 if (!alarm_pending && wait_pending) {
 136                         wake_unlock(&alarm_wake_lock);
 137                         wait_pending = 0;
 138                 }
 139                 spin_unlock_irqrestore(&alarm_slock, flags);
 140                 rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
 141                 if (rv)
 142                         goto err1;
 143                 spin_lock_irqsave(&alarm_slock, flags);
 144                 rv = alarm_pending;
 145                 wait_pending = 1;
 146                 alarm_pending = 0;
 147                 spin_unlock_irqrestore(&alarm_slock, flags);
 148                 break;
 149         case ANDROID_ALARM_SET_RTC:
 150                 if (copy_from_user(&new_rtc_time, (void __user *)arg,
 151                     sizeof(new_rtc_time))) {
 152                         rv = -EFAULT;
 153                         goto err1;
 154                 }
 155                 rv = alarm_set_rtc(new_rtc_time);
 156                 spin_lock_irqsave(&alarm_slock, flags);
 157                 alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
 158                 wake_up(&alarm_wait_queue);
 159                 spin_unlock_irqrestore(&alarm_slock, flags);
 160                 if (rv < 0)
 161                         goto err1;
 162                 break;
 163         case ANDROID_ALARM_GET_TIME(0):
 164                 switch (alarm_type) {
 165                 case ANDROID_ALARM_RTC_WAKEUP:
 166                 case ANDROID_ALARM_RTC:
 167                         getnstimeofday(&tmp_time);
 168                         break;
 169                 case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
 170                 case ANDROID_ALARM_ELAPSED_REALTIME:
 171                         tmp_time =
 172                                 ktime_to_timespec(alarm_get_elapsed_realtime());
 173                         break;
 174                 case ANDROID_ALARM_TYPE_COUNT:
 175                 case ANDROID_ALARM_SYSTEMTIME:
 176                         ktime_get_ts(&tmp_time);
 177                         break;
 178                 }
 179                 if (copy_to_user((void __user *)arg, &tmp_time,
 180                     sizeof(tmp_time))) {
 181                         rv = -EFAULT;
 182                         goto err1;
 183                 }
 184                 break;
 185
 186         default:
 187                 rv = -EINVAL;
 188                 goto err1;
 189         }
 190 err1:
 191         return rv;
 192 }
 193
 194 static int alarm_open(struct inode *inode, struct file *file)
 195 {
 196         file->private_data = NULL;
 197         return 0;
 198 }
 199
 200 static int alarm_release(struct inode *inode, struct file *file)
 201 {
 202         int i;
 203         unsigned long flags;
 204
 205         spin_lock_irqsave(&alarm_slock, flags);
 206         if (file->private_data != 0) {
 207                 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
 208                         uint32_t alarm_type_mask = 1U << i;
 209                         if (alarm_enabled & alarm_type_mask) {
 210                                 pr_alarm(INFO, "alarm_release: clear alarm, "
 211                                         "pending %d\n",
 212                                         !!(alarm_pending & alarm_type_mask));
 213                                 alarm_enabled &= ~alarm_type_mask;
 214                         }
 215                         spin_unlock_irqrestore(&alarm_slock, flags);
 216                         alarm_cancel(&alarms[i]);
 217                         spin_lock_irqsave(&alarm_slock, flags);
 218                 }
 219                 if (alarm_pending | wait_pending) {
 220                         if (alarm_pending)
 221                                 pr_alarm(INFO, "alarm_release: clear "
 222                                         "pending alarms %x\n", alarm_pending);
 223                         wake_unlock(&alarm_wake_lock);
 224                         wait_pending = 0;
 225                         alarm_pending = 0;
 226                 }
 227                 alarm_opened = 0;
 228         }
 229         spin_unlock_irqrestore(&alarm_slock, flags);
 230         return 0;
 231 }
 232
 233 static void alarm_triggered(struct alarm *alarm)
 234 {
 235         unsigned long flags;
 236         uint32_t alarm_type_mask = 1U << alarm->type;
 237
 238         pr_alarm(INT, "alarm_triggered type %d\n", alarm->type);
 239         spin_lock_irqsave(&alarm_slock, flags);
 240         if (alarm_enabled & alarm_type_mask) {
 241                 wake_lock_timeout(&alarm_wake_lock, 5 * HZ);
 242                 alarm_enabled &= ~alarm_type_mask;
 243                 alarm_pending |= alarm_type_mask;
 244                 wake_up(&alarm_wait_queue);
 245         }
 246         spin_unlock_irqrestore(&alarm_slock, flags);
 247 }
 248
 249 static const struct file_operations alarm_fops = {
 250         .owner = THIS_MODULE,
 251         .unlocked_ioctl = alarm_ioctl,
 252         .open = alarm_open,
 253         .release = alarm_release,
 254 };
 255
 256 static struct miscdevice alarm_device = {
 257         .minor = MISC_DYNAMIC_MINOR,
 258         .name = "alarm",
 259         .fops = &alarm_fops,
 260 };
 261
 262 static int __init alarm_dev_init(void)
 263 {
 264         int err;
 265         int i;
 266
 267         err = misc_register(&alarm_device);
 268         if (err)
 269                 return err;
 270
 271         for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++)
 272                 alarm_init(&alarms[i], i, alarm_triggered);
 273         wake_lock_init(&alarm_wake_lock, WAKE_LOCK_SUSPEND, "alarm");
 274
 275         return 0;
 276 }
 277
 278 static void  __exit alarm_dev_exit(void)
 279 {
 280         misc_deregister(&alarm_device);
 281         wake_lock_destroy(&alarm_wake_lock);
 282 }
 283
 284 module_init(alarm_dev_init);
 285 module_exit(alarm_dev_exit);
 286