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