drivers/staging/android/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 <linux/time.h>
  17 #include <linux/module.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/uaccess.h>
  25 #include <linux/alarmtimer.h>
  26 #include "android_alarm.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 alarm_dbg(debug_level_mask, fmt, ...)                           \
  36 do {                                                                    \
  37         if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask)        \
  38                 pr_info(fmt, ##__VA_ARGS__);                            \
  39 } while (0)
  40
  41 #define ANDROID_ALARM_WAKEUP_MASK ( \
  42         ANDROID_ALARM_RTC_WAKEUP_MASK | \
  43         ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
  44
  45 static int alarm_opened;
  46 static DEFINE_SPINLOCK(alarm_slock);
  47 static struct wakeup_source alarm_wake_lock;
  48 static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
  49 static uint32_t alarm_pending;
  50 static uint32_t alarm_enabled;
  51 static uint32_t wait_pending;
  52
  53 struct devalarm {
  54         union {
  55                 struct hrtimer hrt;
  56                 struct alarm alrm;
  57         } u;
  58         enum android_alarm_type type;
  59 };
  60
  61 static struct devalarm alarms[ANDROID_ALARM_TYPE_COUNT];
  62
  63 /**
  64  * is_wakeup() - Checks to see if this alarm can wake the device
  65  * @type:        The type of alarm being checked
  66  *
  67  * Return: 1 if this is a wakeup alarm, otherwise 0
  68  */
  69 static int is_wakeup(enum android_alarm_type type)
  70 {
  71         return type == ANDROID_ALARM_RTC_WAKEUP ||
  72                 type == ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP;
  73 }
  74
  75 static void devalarm_start(struct devalarm *alrm, ktime_t exp)
  76 {
  77         if (is_wakeup(alrm->type))
  78                 alarm_start(&alrm->u.alrm, exp);
  79         else
  80                 hrtimer_start(&alrm->u.hrt, exp, HRTIMER_MODE_ABS);
  81 }
  82
  83 static int devalarm_try_to_cancel(struct devalarm *alrm)
  84 {
  85         if (is_wakeup(alrm->type))
  86                 return alarm_try_to_cancel(&alrm->u.alrm);
  87         return hrtimer_try_to_cancel(&alrm->u.hrt);
  88 }
  89
  90 static void devalarm_cancel(struct devalarm *alrm)
  91 {
  92         if (is_wakeup(alrm->type))
  93                 alarm_cancel(&alrm->u.alrm);
  94         else
  95                 hrtimer_cancel(&alrm->u.hrt);
  96 }
  97
  98 static void alarm_clear(enum android_alarm_type alarm_type)
  99 {
 100         uint32_t alarm_type_mask = 1U << alarm_type;
 101         unsigned long flags;
 102
 103         spin_lock_irqsave(&alarm_slock, flags);
 104         alarm_dbg(IO, "alarm %d clear\n", alarm_type);
 105         devalarm_try_to_cancel(&alarms[alarm_type]);
 106         if (alarm_pending) {
 107                 alarm_pending &= ~alarm_type_mask;
 108                 if (!alarm_pending && !wait_pending)
 109                         __pm_relax(&alarm_wake_lock);
 110         }
 111         alarm_enabled &= ~alarm_type_mask;
 112         spin_unlock_irqrestore(&alarm_slock, flags);
 113 }
 114
 115 static void alarm_set(enum android_alarm_type alarm_type,
 116                                                         struct timespec *ts)
 117 {
 118         uint32_t alarm_type_mask = 1U << alarm_type;
 119         unsigned long flags;
 120
 121         spin_lock_irqsave(&alarm_slock, flags);
 122         alarm_dbg(IO, "alarm %d set %ld.%09ld\n",
 123                         alarm_type, ts->tv_sec, ts->tv_nsec);
 124         alarm_enabled |= alarm_type_mask;
 125         devalarm_start(&alarms[alarm_type], timespec_to_ktime(*ts));
 126         spin_unlock_irqrestore(&alarm_slock, flags);
 127 }
 128
 129 static int alarm_wait(void)
 130 {
 131         unsigned long flags;
 132         int rv = 0;
 133
 134         spin_lock_irqsave(&alarm_slock, flags);
 135         alarm_dbg(IO, "alarm wait\n");
 136         if (!alarm_pending && wait_pending) {
 137                 __pm_relax(&alarm_wake_lock);
 138                 wait_pending = 0;
 139         }
 140         spin_unlock_irqrestore(&alarm_slock, flags);
 141
 142         rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
 143         if (rv)
 144                 return rv;
 145
 146         spin_lock_irqsave(&alarm_slock, flags);
 147         rv = alarm_pending;
 148         wait_pending = 1;
 149         alarm_pending = 0;
 150         spin_unlock_irqrestore(&alarm_slock, flags);
 151
 152         return rv;
 153 }
 154
 155 static int alarm_set_rtc(struct timespec *ts)
 156 {
 157         struct rtc_time new_rtc_tm;
 158         struct rtc_device *rtc_dev;
 159         unsigned long flags;
 160         int rv = 0;
 161
 162         rtc_time_to_tm(ts->tv_sec, &new_rtc_tm);
 163         rtc_dev = alarmtimer_get_rtcdev();
 164         rv = do_settimeofday(ts);
 165         if (rv < 0)
 166                 return rv;
 167         if (rtc_dev)
 168                 rv = rtc_set_time(rtc_dev, &new_rtc_tm);
 169
 170         spin_lock_irqsave(&alarm_slock, flags);
 171         alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
 172         wake_up(&alarm_wait_queue);
 173         spin_unlock_irqrestore(&alarm_slock, flags);
 174
 175         return rv;
 176 }
 177
 178 static int alarm_get_time(enum android_alarm_type alarm_type,
 179                                                         struct timespec *ts)
 180 {
 181         int rv = 0;
 182
 183         switch (alarm_type) {
 184         case ANDROID_ALARM_RTC_WAKEUP:
 185         case ANDROID_ALARM_RTC:
 186                 getnstimeofday(ts);
 187                 break;
 188         case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
 189         case ANDROID_ALARM_ELAPSED_REALTIME:
 190                 get_monotonic_boottime(ts);
 191                 break;
 192         case ANDROID_ALARM_SYSTEMTIME:
 193                 ktime_get_ts(ts);
 194                 break;
 195         default:
 196                 rv = -EINVAL;
 197         }
 198         return rv;
 199 }
 200
 201 static long alarm_do_ioctl(struct file *file, unsigned int cmd,
 202                                                         struct timespec *ts)
 203 {
 204         int rv = 0;
 205         unsigned long flags;
 206         enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
 207
 208         if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
 209                 return -EINVAL;
 210
 211         if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
 212                 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
 213                         return -EPERM;
 214                 if (file->private_data == NULL &&
 215                     cmd != ANDROID_ALARM_SET_RTC) {
 216                         spin_lock_irqsave(&alarm_slock, flags);
 217                         if (alarm_opened) {
 218                                 spin_unlock_irqrestore(&alarm_slock, flags);
 219                                 return -EBUSY;
 220                         }
 221                         alarm_opened = 1;
 222                         file->private_data = (void *)1;
 223                         spin_unlock_irqrestore(&alarm_slock, flags);
 224                 }
 225         }
 226
 227         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
 228         case ANDROID_ALARM_CLEAR(0):
 229                 alarm_clear(alarm_type);
 230                 break;
 231         case ANDROID_ALARM_SET(0):
 232                 alarm_set(alarm_type, ts);
 233                 break;
 234         case ANDROID_ALARM_SET_AND_WAIT(0):
 235                 alarm_set(alarm_type, ts);
 236                 /* fall though */
 237         case ANDROID_ALARM_WAIT:
 238                 rv = alarm_wait();
 239                 break;
 240         case ANDROID_ALARM_SET_RTC:
 241                 rv = alarm_set_rtc(ts);
 242                 break;
 243         case ANDROID_ALARM_GET_TIME(0):
 244                 rv = alarm_get_time(alarm_type, ts);
 245                 break;
 246
 247         default:
 248                 rv = -EINVAL;
 249         }
 250         return rv;
 251 }
 252
 253 static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 254 {
 255
 256         struct timespec ts;
 257         int rv;
 258
 259         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
 260         case ANDROID_ALARM_SET_AND_WAIT(0):
 261         case ANDROID_ALARM_SET(0):
 262         case ANDROID_ALARM_SET_RTC:
 263                 if (copy_from_user(&ts, (void __user *)arg, sizeof(ts)))
 264                         return -EFAULT;
 265                 break;
 266         }
 267
 268         rv = alarm_do_ioctl(file, cmd, &ts);
 269         if (rv)
 270                 return rv;
 271
 272         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
 273         case ANDROID_ALARM_GET_TIME(0):
 274                 if (copy_to_user((void __user *)arg, &ts, sizeof(ts)))
 275                         return -EFAULT;
 276                 break;
 277         }
 278
 279         return 0;
 280 }
 281
 282 #ifdef CONFIG_COMPAT
 283 static long alarm_compat_ioctl(struct file *file, unsigned int cmd,
 284                                                         unsigned long arg)
 285 {
 286
 287         struct timespec ts;
 288         int rv;
 289
 290         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
 291         case ANDROID_ALARM_SET_AND_WAIT_COMPAT(0):
 292         case ANDROID_ALARM_SET_COMPAT(0):
 293         case ANDROID_ALARM_SET_RTC_COMPAT:
 294                 if (compat_get_timespec(&ts, (void __user *)arg))
 295                         return -EFAULT;
 296                 /* fall through */
 297         case ANDROID_ALARM_GET_TIME_COMPAT(0):
 298                 cmd = ANDROID_ALARM_COMPAT_TO_NORM(cmd);
 299                 break;
 300         }
 301
 302         rv = alarm_do_ioctl(file, cmd, &ts);
 303         if (rv)
 304                 return rv;
 305
 306         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
 307         case ANDROID_ALARM_GET_TIME(0): /* NOTE: we modified cmd above */
 308                 if (compat_put_timespec(&ts, (void __user *)arg))
 309                         return -EFAULT;
 310                 break;
 311         }
 312
 313         return 0;
 314 }
 315 #endif
 316
 317 static int alarm_open(struct inode *inode, struct file *file)
 318 {
 319         file->private_data = NULL;
 320         return 0;
 321 }
 322
 323 static int alarm_release(struct inode *inode, struct file *file)
 324 {
 325         int i;
 326         unsigned long flags;
 327
 328         spin_lock_irqsave(&alarm_slock, flags);
 329         if (file->private_data) {
 330                 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
 331                         uint32_t alarm_type_mask = 1U << i;
 332
 333                         if (alarm_enabled & alarm_type_mask) {
 334                                 alarm_dbg(INFO,
 335                                           "%s: clear alarm, pending %d\n",
 336                                           __func__,
 337                                           !!(alarm_pending & alarm_type_mask));
 338                                 alarm_enabled &= ~alarm_type_mask;
 339                         }
 340                         spin_unlock_irqrestore(&alarm_slock, flags);
 341                         devalarm_cancel(&alarms[i]);
 342                         spin_lock_irqsave(&alarm_slock, flags);
 343                 }
 344                 if (alarm_pending | wait_pending) {
 345                         if (alarm_pending)
 346                                 alarm_dbg(INFO, "%s: clear pending alarms %x\n",
 347                                           __func__, alarm_pending);
 348                         __pm_relax(&alarm_wake_lock);
 349                         wait_pending = 0;
 350                         alarm_pending = 0;
 351                 }
 352                 alarm_opened = 0;
 353         }
 354         spin_unlock_irqrestore(&alarm_slock, flags);
 355         return 0;
 356 }
 357
 358 static void devalarm_triggered(struct devalarm *alarm)
 359 {
 360         unsigned long flags;
 361         uint32_t alarm_type_mask = 1U << alarm->type;
 362
 363         alarm_dbg(INT, "%s: type %d\n", __func__, alarm->type);
 364         spin_lock_irqsave(&alarm_slock, flags);
 365         if (alarm_enabled & alarm_type_mask) {
 366                 __pm_wakeup_event(&alarm_wake_lock, 5000); /* 5secs */
 367                 alarm_enabled &= ~alarm_type_mask;
 368                 alarm_pending |= alarm_type_mask;
 369                 wake_up(&alarm_wait_queue);
 370         }
 371         spin_unlock_irqrestore(&alarm_slock, flags);
 372 }
 373
 374 static enum hrtimer_restart devalarm_hrthandler(struct hrtimer *hrt)
 375 {
 376         struct devalarm *devalrm = container_of(hrt, struct devalarm, u.hrt);
 377
 378         devalarm_triggered(devalrm);
 379         return HRTIMER_NORESTART;
 380 }
 381
 382 static enum alarmtimer_restart devalarm_alarmhandler(struct alarm *alrm,
 383                                                         ktime_t now)
 384 {
 385         struct devalarm *devalrm = container_of(alrm, struct devalarm, u.alrm);
 386
 387         devalarm_triggered(devalrm);
 388         return ALARMTIMER_NORESTART;
 389 }
 390
 391
 392 static const struct file_operations alarm_fops = {
 393         .owner = THIS_MODULE,
 394         .unlocked_ioctl = alarm_ioctl,
 395         .open = alarm_open,
 396         .release = alarm_release,
 397 #ifdef CONFIG_COMPAT
 398         .compat_ioctl = alarm_compat_ioctl,
 399 #endif
 400 };
 401
 402 static struct miscdevice alarm_device = {
 403         .minor = MISC_DYNAMIC_MINOR,
 404         .name = "alarm",
 405         .fops = &alarm_fops,
 406 };
 407
 408 static int __init alarm_dev_init(void)
 409 {
 410         int err;
 411         int i;
 412
 413         err = misc_register(&alarm_device);
 414         if (err)
 415                 return err;
 416
 417         alarm_init(&alarms[ANDROID_ALARM_RTC_WAKEUP].u.alrm,
 418                         ALARM_REALTIME, devalarm_alarmhandler);
 419         hrtimer_init(&alarms[ANDROID_ALARM_RTC].u.hrt,
 420                         CLOCK_REALTIME, HRTIMER_MODE_ABS);
 421         alarm_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].u.alrm,
 422                         ALARM_BOOTTIME, devalarm_alarmhandler);
 423         hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME].u.hrt,
 424                         CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
 425         hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].u.hrt,
 426                         CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 427
 428         for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
 429                 alarms[i].type = i;
 430                 if (!is_wakeup(i))
 431                         alarms[i].u.hrt.function = devalarm_hrthandler;
 432         }
 433
 434         wakeup_source_init(&alarm_wake_lock, "alarm");
 435         return 0;
 436 }
 437
 438 static void  __exit alarm_dev_exit(void)
 439 {
 440         misc_deregister(&alarm_device);
 441         wakeup_source_trash(&alarm_wake_lock);
 442 }
 443
 444 module_init(alarm_dev_init);
 445 module_exit(alarm_dev_exit);
 446 MODULE_LICENSE("GPL");