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 /* support old userspace code */
  46 #define ANDROID_ALARM_SET_OLD               _IOW('a', 2, time_t) /* set alarm */
  47 #define ANDROID_ALARM_SET_AND_WAIT_OLD      _IOW('a', 3, time_t)
  48
  49 static int alarm_opened;
  50 static DEFINE_SPINLOCK(alarm_slock);
  51 static struct wakeup_source alarm_wake_lock;
  52 static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
  53 static uint32_t alarm_pending;
  54 static uint32_t alarm_enabled;
  55 static uint32_t wait_pending;
  56
  57 struct devalarm {
  58         union {
  59                 struct hrtimer hrt;
  60                 struct alarm alrm;
  61         } u;
  62         enum android_alarm_type type;
  63 };
  64
  65 static struct devalarm alarms[ANDROID_ALARM_TYPE_COUNT];
  66
  67
  68 static int is_wakeup(enum android_alarm_type type)
  69 {
  70         return (type == ANDROID_ALARM_RTC_WAKEUP ||
  71                 type == ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP);
  72 }
  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
  84 static int devalarm_try_to_cancel(struct devalarm *alrm)
  85 {
  86         if (is_wakeup(alrm->type))
  87                 return alarm_try_to_cancel(&alrm->u.alrm);
  88         return hrtimer_try_to_cancel(&alrm->u.hrt);
  89 }
  90
  91 static void devalarm_cancel(struct devalarm *alrm)
  92 {
  93         if (is_wakeup(alrm->type))
  94                 alarm_cancel(&alrm->u.alrm);
  95         else
  96                 hrtimer_cancel(&alrm->u.hrt);
  97 }
  98
  99
 100 static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 101 {
 102         int rv = 0;
 103         unsigned long flags;
 104         struct timespec new_alarm_time;
 105         struct timespec new_rtc_time;
 106         struct timespec tmp_time;
 107         struct rtc_time new_rtc_tm;
 108         struct rtc_device *rtc_dev;
 109         enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
 110         uint32_t alarm_type_mask = 1U << alarm_type;
 111
 112         if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
 113                 return -EINVAL;
 114
 115         if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
 116                 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
 117                         return -EPERM;
 118                 if (file->private_data == NULL &&
 119                     cmd != ANDROID_ALARM_SET_RTC) {
 120                         spin_lock_irqsave(&alarm_slock, flags);
 121                         if (alarm_opened) {
 122                                 spin_unlock_irqrestore(&alarm_slock, flags);
 123                                 return -EBUSY;
 124                         }
 125                         alarm_opened = 1;
 126                         file->private_data = (void *)1;
 127                         spin_unlock_irqrestore(&alarm_slock, flags);
 128                 }
 129         }
 130
 131         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
 132         case ANDROID_ALARM_CLEAR(0):
 133                 spin_lock_irqsave(&alarm_slock, flags);
 134                 alarm_dbg(IO, "alarm %d clear\n", alarm_type);
 135                 devalarm_try_to_cancel(&alarms[alarm_type]);
 136                 if (alarm_pending) {
 137                         alarm_pending &= ~alarm_type_mask;
 138                         if (!alarm_pending && !wait_pending)
 139                                 __pm_relax(&alarm_wake_lock);
 140                 }
 141                 alarm_enabled &= ~alarm_type_mask;
 142                 spin_unlock_irqrestore(&alarm_slock, flags);
 143                 break;
 144
 145         case ANDROID_ALARM_SET_OLD:
 146         case ANDROID_ALARM_SET_AND_WAIT_OLD:
 147                 if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
 148                         rv = -EFAULT;
 149                         goto err1;
 150                 }
 151                 new_alarm_time.tv_nsec = 0;
 152                 goto from_old_alarm_set;
 153
 154         case ANDROID_ALARM_SET_AND_WAIT(0):
 155         case ANDROID_ALARM_SET(0):
 156                 if (copy_from_user(&new_alarm_time, (void __user *)arg,
 157                     sizeof(new_alarm_time))) {
 158                         rv = -EFAULT;
 159                         goto err1;
 160                 }
 161 from_old_alarm_set:
 162                 spin_lock_irqsave(&alarm_slock, flags);
 163                 alarm_dbg(IO, "alarm %d set %ld.%09ld\n",
 164                           alarm_type,
 165                           new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
 166                 alarm_enabled |= alarm_type_mask;
 167                 devalarm_start(&alarms[alarm_type],
 168                         timespec_to_ktime(new_alarm_time));
 169                 spin_unlock_irqrestore(&alarm_slock, flags);
 170                 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
 171                     && cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
 172                         break;
 173                 /* fall though */
 174         case ANDROID_ALARM_WAIT:
 175                 spin_lock_irqsave(&alarm_slock, flags);
 176                 alarm_dbg(IO, "alarm wait\n");
 177                 if (!alarm_pending && wait_pending) {
 178                         __pm_relax(&alarm_wake_lock);
 179                         wait_pending = 0;
 180                 }
 181                 spin_unlock_irqrestore(&alarm_slock, flags);
 182                 rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
 183                 if (rv)
 184                         goto err1;
 185                 spin_lock_irqsave(&alarm_slock, flags);
 186                 rv = alarm_pending;
 187                 wait_pending = 1;
 188                 alarm_pending = 0;
 189                 spin_unlock_irqrestore(&alarm_slock, flags);
 190                 break;
 191         case ANDROID_ALARM_SET_RTC:
 192                 if (copy_from_user(&new_rtc_time, (void __user *)arg,
 193                     sizeof(new_rtc_time))) {
 194                         rv = -EFAULT;
 195                         goto err1;
 196                 }
 197                 rtc_time_to_tm(new_rtc_time.tv_sec, &new_rtc_tm);
 198                 rtc_dev = alarmtimer_get_rtcdev();
 199                 rv = do_settimeofday(&new_rtc_time);
 200                 if (rv < 0)
 201                         goto err1;
 202                 if (rtc_dev)
 203                         rv = rtc_set_time(rtc_dev, &new_rtc_tm);
 204                 spin_lock_irqsave(&alarm_slock, flags);
 205                 alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
 206                 wake_up(&alarm_wait_queue);
 207                 spin_unlock_irqrestore(&alarm_slock, flags);
 208                 if (rv < 0)
 209                         goto err1;
 210                 break;
 211         case ANDROID_ALARM_GET_TIME(0):
 212                 switch (alarm_type) {
 213                 case ANDROID_ALARM_RTC_WAKEUP:
 214                 case ANDROID_ALARM_RTC:
 215                         getnstimeofday(&tmp_time);
 216                         break;
 217                 case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
 218                 case ANDROID_ALARM_ELAPSED_REALTIME:
 219                         get_monotonic_boottime(&tmp_time);
 220                         break;
 221                 case ANDROID_ALARM_SYSTEMTIME:
 222                         ktime_get_ts(&tmp_time);
 223                         break;
 224                 default:
 225                         rv = -EINVAL;
 226                         goto err1;
 227                 }
 228                 if (copy_to_user((void __user *)arg, &tmp_time,
 229                     sizeof(tmp_time))) {
 230                         rv = -EFAULT;
 231                         goto err1;
 232                 }
 233                 break;
 234
 235         default:
 236                 rv = -EINVAL;
 237         }
 238 err1:
 239         return rv;
 240 }
 241
 242 static int alarm_open(struct inode *inode, struct file *file)
 243 {
 244         file->private_data = NULL;
 245         return 0;
 246 }
 247
 248 static int alarm_release(struct inode *inode, struct file *file)
 249 {
 250         int i;
 251         unsigned long flags;
 252
 253         spin_lock_irqsave(&alarm_slock, flags);
 254         if (file->private_data) {
 255                 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
 256                         uint32_t alarm_type_mask = 1U << i;
 257                         if (alarm_enabled & alarm_type_mask) {
 258                                 alarm_dbg(INFO,
 259                                           "%s: clear alarm, pending %d\n",
 260                                           __func__,
 261                                           !!(alarm_pending & alarm_type_mask));
 262                                 alarm_enabled &= ~alarm_type_mask;
 263                         }
 264                         spin_unlock_irqrestore(&alarm_slock, flags);
 265                         devalarm_cancel(&alarms[i]);
 266                         spin_lock_irqsave(&alarm_slock, flags);
 267                 }
 268                 if (alarm_pending | wait_pending) {
 269                         if (alarm_pending)
 270                                 alarm_dbg(INFO, "%s: clear pending alarms %x\n",
 271                                           __func__, alarm_pending);
 272                         __pm_relax(&alarm_wake_lock);
 273                         wait_pending = 0;
 274                         alarm_pending = 0;
 275                 }
 276                 alarm_opened = 0;
 277         }
 278         spin_unlock_irqrestore(&alarm_slock, flags);
 279         return 0;
 280 }
 281
 282 static void devalarm_triggered(struct devalarm *alarm)
 283 {
 284         unsigned long flags;
 285         uint32_t alarm_type_mask = 1U << alarm->type;
 286
 287         alarm_dbg(INT, "%s: type %d\n", __func__, alarm->type);
 288         spin_lock_irqsave(&alarm_slock, flags);
 289         if (alarm_enabled & alarm_type_mask) {
 290                 __pm_wakeup_event(&alarm_wake_lock, 5000); /* 5secs */
 291                 alarm_enabled &= ~alarm_type_mask;
 292                 alarm_pending |= alarm_type_mask;
 293                 wake_up(&alarm_wait_queue);
 294         }
 295         spin_unlock_irqrestore(&alarm_slock, flags);
 296 }
 297
 298
 299 static enum hrtimer_restart devalarm_hrthandler(struct hrtimer *hrt)
 300 {
 301         struct devalarm *devalrm = container_of(hrt, struct devalarm, u.hrt);
 302
 303         devalarm_triggered(devalrm);
 304         return HRTIMER_NORESTART;
 305 }
 306
 307 static enum alarmtimer_restart devalarm_alarmhandler(struct alarm *alrm,
 308                                                         ktime_t now)
 309 {
 310         struct devalarm *devalrm = container_of(alrm, struct devalarm, u.alrm);
 311
 312         devalarm_triggered(devalrm);
 313         return ALARMTIMER_NORESTART;
 314 }
 315
 316
 317 static const struct file_operations alarm_fops = {
 318         .owner = THIS_MODULE,
 319         .unlocked_ioctl = alarm_ioctl,
 320         .open = alarm_open,
 321         .release = alarm_release,
 322 };
 323
 324 static struct miscdevice alarm_device = {
 325         .minor = MISC_DYNAMIC_MINOR,
 326         .name = "alarm",
 327         .fops = &alarm_fops,
 328 };
 329
 330 static int __init alarm_dev_init(void)
 331 {
 332         int err;
 333         int i;
 334
 335         err = misc_register(&alarm_device);
 336         if (err)
 337                 return err;
 338
 339         alarm_init(&alarms[ANDROID_ALARM_RTC_WAKEUP].u.alrm,
 340                         ALARM_REALTIME, devalarm_alarmhandler);
 341         hrtimer_init(&alarms[ANDROID_ALARM_RTC].u.hrt,
 342                         CLOCK_REALTIME, HRTIMER_MODE_ABS);
 343         alarm_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].u.alrm,
 344                         ALARM_BOOTTIME, devalarm_alarmhandler);
 345         hrtimer_init(&alarms[ANDROID_ALARM_ELAPSED_REALTIME].u.hrt,
 346                         CLOCK_BOOTTIME, HRTIMER_MODE_ABS);
 347         hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].u.hrt,
 348                         CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 349
 350         for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
 351                 alarms[i].type = i;
 352                 if (!is_wakeup(i))
 353                         alarms[i].u.hrt.function = devalarm_hrthandler;
 354         }
 355
 356         wakeup_source_init(&alarm_wake_lock, "alarm");
 357         return 0;
 358 }
 359
 360 static void  __exit alarm_dev_exit(void)
 361 {
 362         misc_deregister(&alarm_device);
 363         wakeup_source_trash(&alarm_wake_lock);
 364 }
 365
 366 module_init(alarm_dev_init);
 367 module_exit(alarm_dev_exit);
 368