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 "android_alarm.h"
  26
  27 /* XXX - Hack out wakelocks, while they are out of tree */
  28 struct wake_lock {
  29         int i;
  30 };
  31 #define wake_lock(x)
  32 #define wake_lock_timeout(x, y)
  33 #define wake_unlock(x)
  34 #define WAKE_LOCK_SUSPEND 0
  35 #define wake_lock_init(x, y, z) ((x)->i = 1)
  36 #define wake_lock_destroy(x)
  37
  38 #define ANDROID_ALARM_PRINT_INFO (1U << 0)
  39 #define ANDROID_ALARM_PRINT_IO (1U << 1)
  40 #define ANDROID_ALARM_PRINT_INT (1U << 2)
  41
  42
  43 static int debug_mask = ANDROID_ALARM_PRINT_INFO;
  44 module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
  45
  46 #define pr_alarm(debug_level_mask, args...) \
  47         do { \
  48                 if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
  49                         pr_info(args); \
  50                 } \
  51         } while (0)
  52
  53 #define ANDROID_ALARM_WAKEUP_MASK ( \
  54         ANDROID_ALARM_RTC_WAKEUP_MASK | \
  55         ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
  56
  57 /* support old usespace code */
  58 #define ANDROID_ALARM_SET_OLD               _IOW('a', 2, time_t) /* set alarm */
  59 #define ANDROID_ALARM_SET_AND_WAIT_OLD      _IOW('a', 3, time_t)
  60
  61 static int alarm_opened;
  62 static DEFINE_SPINLOCK(alarm_slock);
  63 static struct wake_lock alarm_wake_lock;
  64 static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
  65 static uint32_t alarm_pending;
  66 static uint32_t alarm_enabled;
  67 static uint32_t wait_pending;
  68
  69 static struct android_alarm alarms[ANDROID_ALARM_TYPE_COUNT];
  70
  71 static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  72 {
  73         int rv = 0;
  74         unsigned long flags;
  75         struct timespec new_alarm_time;
  76         struct timespec new_rtc_time;
  77         struct timespec tmp_time;
  78         enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
  79         uint32_t alarm_type_mask = 1U << alarm_type;
  80
  81         if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
  82                 return -EINVAL;
  83
  84         if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
  85                 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
  86                         return -EPERM;
  87                 if (file->private_data == NULL &&
  88                     cmd != ANDROID_ALARM_SET_RTC) {
  89                         spin_lock_irqsave(&alarm_slock, flags);
  90                         if (alarm_opened) {
  91                                 spin_unlock_irqrestore(&alarm_slock, flags);
  92                                 return -EBUSY;
  93                         }
  94                         alarm_opened = 1;
  95                         file->private_data = (void *)1;
  96                         spin_unlock_irqrestore(&alarm_slock, flags);
  97                 }
  98         }
  99
 100         switch (ANDROID_ALARM_BASE_CMD(cmd)) {
 101         case ANDROID_ALARM_CLEAR(0):
 102                 spin_lock_irqsave(&alarm_slock, flags);
 103                 pr_alarm(IO, "alarm %d clear\n", alarm_type);
 104                 android_alarm_try_to_cancel(&alarms[alarm_type]);
 105                 if (alarm_pending) {
 106                         alarm_pending &= ~alarm_type_mask;
 107                         if (!alarm_pending && !wait_pending)
 108                                 wake_unlock(&alarm_wake_lock);
 109                 }
 110                 alarm_enabled &= ~alarm_type_mask;
 111                 spin_unlock_irqrestore(&alarm_slock, flags);
 112                 break;
 113
 114         case ANDROID_ALARM_SET_OLD:
 115         case ANDROID_ALARM_SET_AND_WAIT_OLD:
 116                 if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
 117                         rv = -EFAULT;
 118                         goto err1;
 119                 }
 120                 new_alarm_time.tv_nsec = 0;
 121                 goto from_old_alarm_set;
 122
 123         case ANDROID_ALARM_SET_AND_WAIT(0):
 124         case ANDROID_ALARM_SET(0):
 125                 if (copy_from_user(&new_alarm_time, (void __user *)arg,
 126                     sizeof(new_alarm_time))) {
 127                         rv = -EFAULT;
 128                         goto err1;
 129                 }
 130 from_old_alarm_set:
 131                 spin_lock_irqsave(&alarm_slock, flags);
 132                 pr_alarm(IO, "alarm %d set %ld.%09ld\n", alarm_type,
 133                         new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
 134                 alarm_enabled |= alarm_type_mask;
 135                 android_alarm_start_range(&alarms[alarm_type],
 136                         timespec_to_ktime(new_alarm_time),
 137                         timespec_to_ktime(new_alarm_time));
 138                 spin_unlock_irqrestore(&alarm_slock, flags);
 139                 if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
 140                     && cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
 141                         break;
 142                 /* fall though */
 143         case ANDROID_ALARM_WAIT:
 144                 spin_lock_irqsave(&alarm_slock, flags);
 145                 pr_alarm(IO, "alarm wait\n");
 146                 if (!alarm_pending && wait_pending) {
 147                         wake_unlock(&alarm_wake_lock);
 148                         wait_pending = 0;
 149                 }
 150                 spin_unlock_irqrestore(&alarm_slock, flags);
 151                 rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
 152                 if (rv)
 153                         goto err1;
 154                 spin_lock_irqsave(&alarm_slock, flags);
 155                 rv = alarm_pending;
 156                 wait_pending = 1;
 157                 alarm_pending = 0;
 158                 spin_unlock_irqrestore(&alarm_slock, flags);
 159                 break;
 160         case ANDROID_ALARM_SET_RTC:
 161                 if (copy_from_user(&new_rtc_time, (void __user *)arg,
 162                     sizeof(new_rtc_time))) {
 163                         rv = -EFAULT;
 164                         goto err1;
 165                 }
 166                 rv = android_alarm_set_rtc(new_rtc_time);
 167                 spin_lock_irqsave(&alarm_slock, flags);
 168                 alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
 169                 wake_up(&alarm_wait_queue);
 170                 spin_unlock_irqrestore(&alarm_slock, flags);
 171                 if (rv < 0)
 172                         goto err1;
 173                 break;
 174         case ANDROID_ALARM_GET_TIME(0):
 175                 switch (alarm_type) {
 176                 case ANDROID_ALARM_RTC_WAKEUP:
 177                 case ANDROID_ALARM_RTC:
 178                         getnstimeofday(&tmp_time);
 179                         break;
 180                 case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
 181                 case ANDROID_ALARM_ELAPSED_REALTIME:
 182                         tmp_time =
 183                                 ktime_to_timespec(alarm_get_elapsed_realtime());
 184                         break;
 185                 case ANDROID_ALARM_TYPE_COUNT:
 186                 case ANDROID_ALARM_SYSTEMTIME:
 187                         ktime_get_ts(&tmp_time);
 188                         break;
 189                 }
 190                 if (copy_to_user((void __user *)arg, &tmp_time,
 191                     sizeof(tmp_time))) {
 192                         rv = -EFAULT;
 193                         goto err1;
 194                 }
 195                 break;
 196
 197         default:
 198                 rv = -EINVAL;
 199                 goto err1;
 200         }
 201 err1:
 202         return rv;
 203 }
 204
 205 static int alarm_open(struct inode *inode, struct file *file)
 206 {
 207         file->private_data = NULL;
 208         return 0;
 209 }
 210
 211 static int alarm_release(struct inode *inode, struct file *file)
 212 {
 213         int i;
 214         unsigned long flags;
 215
 216         spin_lock_irqsave(&alarm_slock, flags);
 217         if (file->private_data != 0) {
 218                 for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
 219                         uint32_t alarm_type_mask = 1U << i;
 220                         if (alarm_enabled & alarm_type_mask) {
 221                                 pr_alarm(INFO, "alarm_release: clear alarm, "
 222                                         "pending %d\n",
 223                                         !!(alarm_pending & alarm_type_mask));
 224                                 alarm_enabled &= ~alarm_type_mask;
 225                         }
 226                         spin_unlock_irqrestore(&alarm_slock, flags);
 227                         android_alarm_cancel(&alarms[i]);
 228                         spin_lock_irqsave(&alarm_slock, flags);
 229                 }
 230                 if (alarm_pending | wait_pending) {
 231                         if (alarm_pending)
 232                                 pr_alarm(INFO, "alarm_release: clear "
 233                                         "pending alarms %x\n", alarm_pending);
 234                         wake_unlock(&alarm_wake_lock);
 235                         wait_pending = 0;
 236                         alarm_pending = 0;
 237                 }
 238                 alarm_opened = 0;
 239         }
 240         spin_unlock_irqrestore(&alarm_slock, flags);
 241         return 0;
 242 }
 243
 244 static void alarm_triggered(struct android_alarm *alarm)
 245 {
 246         unsigned long flags;
 247         uint32_t alarm_type_mask = 1U << alarm->type;
 248
 249         pr_alarm(INT, "alarm_triggered type %d\n", alarm->type);
 250         spin_lock_irqsave(&alarm_slock, flags);
 251         if (alarm_enabled & alarm_type_mask) {
 252                 wake_lock_timeout(&alarm_wake_lock, 5 * HZ);
 253                 alarm_enabled &= ~alarm_type_mask;
 254                 alarm_pending |= alarm_type_mask;
 255                 wake_up(&alarm_wait_queue);
 256         }
 257         spin_unlock_irqrestore(&alarm_slock, flags);
 258 }
 259
 260 static const struct file_operations alarm_fops = {
 261         .owner = THIS_MODULE,
 262         .unlocked_ioctl = alarm_ioctl,
 263         .open = alarm_open,
 264         .release = alarm_release,
 265 };
 266
 267 static struct miscdevice alarm_device = {
 268         .minor = MISC_DYNAMIC_MINOR,
 269         .name = "alarm",
 270         .fops = &alarm_fops,
 271 };
 272
 273 static int __init alarm_dev_init(void)
 274 {
 275         int err;
 276         int i;
 277
 278         err = misc_register(&alarm_device);
 279         if (err)
 280                 return err;
 281
 282         for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++)
 283                 android_alarm_init(&alarms[i], i, alarm_triggered);
 284         wake_lock_init(&alarm_wake_lock, WAKE_LOCK_SUSPEND, "alarm");
 285
 286         return 0;
 287 }
 288
 289 static void  __exit alarm_dev_exit(void)
 290 {
 291         misc_deregister(&alarm_device);
 292         wake_lock_destroy(&alarm_wake_lock);
 293 }
 294
 295 module_init(alarm_dev_init);
 296 module_exit(alarm_dev_exit);
 297