arch/arm/common/rtctime.c

   1 /*
   2  *  linux/arch/arm/common/rtctime.c
   3  *
   4  *  Copyright (C) 2003 Deep Blue Solutions Ltd.
   5  *  Based on sa1100-rtc.c, Nils Faerber, CIH, Nicolas Pitre.
   6  *  Based on rtc.c by Paul Gortmaker
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/time.h>
  15 #include <linux/rtc.h>
  16 #include <linux/poll.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/miscdevice.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/capability.h>
  21 #include <linux/device.h>
  22 #include <linux/mutex.h>
  23
  24 #include <asm/rtc.h>
  25 #include <asm/semaphore.h>
  26
  27 static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
  28 static struct fasync_struct *rtc_async_queue;
  29
  30 /*
  31  * rtc_lock protects rtc_irq_data
  32  */
  33 static DEFINE_SPINLOCK(rtc_lock);
  34 static unsigned long rtc_irq_data;
  35
  36 /*
  37  * rtc_sem protects rtc_inuse and rtc_ops
  38  */
  39 static DEFINE_MUTEX(rtc_mutex);
  40 static unsigned long rtc_inuse;
  41 static struct rtc_ops *rtc_ops;
  42
  43 #define rtc_epoch 1900UL
  44
  45 /*
  46  * Calculate the next alarm time given the requested alarm time mask
  47  * and the current time.
  48  */
  49 void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc_time *alrm)
  50 {
  51         unsigned long next_time;
  52         unsigned long now_time;
  53
  54         next->tm_year = now->tm_year;
  55         next->tm_mon = now->tm_mon;
  56         next->tm_mday = now->tm_mday;
  57         next->tm_hour = alrm->tm_hour;
  58         next->tm_min = alrm->tm_min;
  59         next->tm_sec = alrm->tm_sec;
  60
  61         rtc_tm_to_time(now, &now_time);
  62         rtc_tm_to_time(next, &next_time);
  63
  64         if (next_time < now_time) {
  65                 /* Advance one day */
  66                 next_time += 60 * 60 * 24;
  67                 rtc_time_to_tm(next_time, next);
  68         }
  69 }
  70 EXPORT_SYMBOL(rtc_next_alarm_time);
  71
  72 static inline int rtc_arm_read_time(struct rtc_ops *ops, struct rtc_time *tm)
  73 {
  74         memset(tm, 0, sizeof(struct rtc_time));
  75         return ops->read_time(tm);
  76 }
  77
  78 static inline int rtc_arm_set_time(struct rtc_ops *ops, struct rtc_time *tm)
  79 {
  80         int ret;
  81
  82         ret = rtc_valid_tm(tm);
  83         if (ret == 0)
  84                 ret = ops->set_time(tm);
  85
  86         return ret;
  87 }
  88
  89 static inline int rtc_arm_read_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
  90 {
  91         int ret = -EINVAL;
  92         if (ops->read_alarm) {
  93                 memset(alrm, 0, sizeof(struct rtc_wkalrm));
  94                 ret = ops->read_alarm(alrm);
  95         }
  96         return ret;
  97 }
  98
  99 static inline int rtc_arm_set_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
 100 {
 101         int ret = -EINVAL;
 102         if (ops->set_alarm)
 103                 ret = ops->set_alarm(alrm);
 104         return ret;
 105 }
 106
 107 void rtc_update(unsigned long num, unsigned long events)
 108 {
 109         spin_lock(&rtc_lock);
 110         rtc_irq_data = (rtc_irq_data + (num << 8)) | events;
 111         spin_unlock(&rtc_lock);
 112
 113         wake_up_interruptible(&rtc_wait);
 114         kill_fasync(&rtc_async_queue, SIGIO, POLL_IN);
 115 }
 116 EXPORT_SYMBOL(rtc_update);
 117
 118
 119 static ssize_t
 120 rtc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 121 {
 122         DECLARE_WAITQUEUE(wait, current);
 123         unsigned long data;
 124         ssize_t ret;
 125
 126         if (count < sizeof(unsigned long))
 127                 return -EINVAL;
 128
 129         add_wait_queue(&rtc_wait, &wait);
 130         do {
 131                 __set_current_state(TASK_INTERRUPTIBLE);
 132
 133                 spin_lock_irq(&rtc_lock);
 134                 data = rtc_irq_data;
 135                 rtc_irq_data = 0;
 136                 spin_unlock_irq(&rtc_lock);
 137
 138                 if (data != 0) {
 139                         ret = 0;
 140                         break;
 141                 }
 142                 if (file->f_flags & O_NONBLOCK) {
 143                         ret = -EAGAIN;
 144                         break;
 145                 }
 146                 if (signal_pending(current)) {
 147                         ret = -ERESTARTSYS;
 148                         break;
 149                 }
 150                 schedule();
 151         } while (1);
 152         set_current_state(TASK_RUNNING);
 153         remove_wait_queue(&rtc_wait, &wait);
 154
 155         if (ret == 0) {
 156                 ret = put_user(data, (unsigned long __user *)buf);
 157                 if (ret == 0)
 158                         ret = sizeof(unsigned long);
 159         }
 160         return ret;
 161 }
 162
 163 static unsigned int rtc_poll(struct file *file, poll_table *wait)
 164 {
 165         unsigned long data;
 166
 167         poll_wait(file, &rtc_wait, wait);
 168
 169         spin_lock_irq(&rtc_lock);
 170         data = rtc_irq_data;
 171         spin_unlock_irq(&rtc_lock);
 172
 173         return data != 0 ? POLLIN | POLLRDNORM : 0;
 174 }
 175
 176 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 177                      unsigned long arg)
 178 {
 179         struct rtc_ops *ops = file->private_data;
 180         struct rtc_time tm;
 181         struct rtc_wkalrm alrm;
 182         void __user *uarg = (void __user *)arg;
 183         int ret = -EINVAL;
 184
 185         switch (cmd) {
 186         case RTC_ALM_READ:
 187                 ret = rtc_arm_read_alarm(ops, &alrm);
 188                 if (ret)
 189                         break;
 190                 ret = copy_to_user(uarg, &alrm.time, sizeof(tm));
 191                 if (ret)
 192                         ret = -EFAULT;
 193                 break;
 194
 195         case RTC_ALM_SET:
 196                 ret = copy_from_user(&alrm.time, uarg, sizeof(tm));
 197                 if (ret) {
 198                         ret = -EFAULT;
 199                         break;
 200                 }
 201                 alrm.enabled = 0;
 202                 alrm.pending = 0;
 203                 alrm.time.tm_mday = -1;
 204                 alrm.time.tm_mon = -1;
 205                 alrm.time.tm_year = -1;
 206                 alrm.time.tm_wday = -1;
 207                 alrm.time.tm_yday = -1;
 208                 alrm.time.tm_isdst = -1;
 209                 ret = rtc_arm_set_alarm(ops, &alrm);
 210                 break;
 211
 212         case RTC_RD_TIME:
 213                 ret = rtc_arm_read_time(ops, &tm);
 214                 if (ret)
 215                         break;
 216                 ret = copy_to_user(uarg, &tm, sizeof(tm));
 217                 if (ret)
 218                         ret = -EFAULT;
 219                 break;
 220
 221         case RTC_SET_TIME:
 222                 if (!capable(CAP_SYS_TIME)) {
 223                         ret = -EACCES;
 224                         break;
 225                 }
 226                 ret = copy_from_user(&tm, uarg, sizeof(tm));
 227                 if (ret) {
 228                         ret = -EFAULT;
 229                         break;
 230                 }
 231                 ret = rtc_arm_set_time(ops, &tm);
 232                 break;
 233
 234         case RTC_EPOCH_SET:
 235 #ifndef rtc_epoch
 236                 /*
 237                  * There were no RTC clocks before 1900.
 238                  */
 239                 if (arg < 1900) {
 240                         ret = -EINVAL;
 241                         break;
 242                 }
 243                 if (!capable(CAP_SYS_TIME)) {
 244                         ret = -EACCES;
 245                         break;
 246                 }
 247                 rtc_epoch = arg;
 248                 ret = 0;
 249 #endif
 250                 break;
 251
 252         case RTC_EPOCH_READ:
 253                 ret = put_user(rtc_epoch, (unsigned long __user *)uarg);
 254                 break;
 255
 256         case RTC_WKALM_SET:
 257                 ret = copy_from_user(&alrm, uarg, sizeof(alrm));
 258                 if (ret) {
 259                         ret = -EFAULT;
 260                         break;
 261                 }
 262                 ret = rtc_arm_set_alarm(ops, &alrm);
 263                 break;
 264
 265         case RTC_WKALM_RD:
 266                 ret = rtc_arm_read_alarm(ops, &alrm);
 267                 if (ret)
 268                         break;
 269                 ret = copy_to_user(uarg, &alrm, sizeof(alrm));
 270                 if (ret)
 271                         ret = -EFAULT;
 272                 break;
 273
 274         default:
 275                 if (ops->ioctl)
 276                         ret = ops->ioctl(cmd, arg);
 277                 break;
 278         }
 279         return ret;
 280 }
 281
 282 static int rtc_open(struct inode *inode, struct file *file)
 283 {
 284         int ret;
 285
 286         mutex_lock(&rtc_mutex);
 287
 288         if (rtc_inuse) {
 289                 ret = -EBUSY;
 290         } else if (!rtc_ops || !try_module_get(rtc_ops->owner)) {
 291                 ret = -ENODEV;
 292         } else {
 293                 file->private_data = rtc_ops;
 294
 295                 ret = rtc_ops->open ? rtc_ops->open() : 0;
 296                 if (ret == 0) {
 297                         spin_lock_irq(&rtc_lock);
 298                         rtc_irq_data = 0;
 299                         spin_unlock_irq(&rtc_lock);
 300
 301                         rtc_inuse = 1;
 302                 }
 303         }
 304         mutex_unlock(&rtc_mutex);
 305
 306         return ret;
 307 }
 308
 309 static int rtc_release(struct inode *inode, struct file *file)
 310 {
 311         struct rtc_ops *ops = file->private_data;
 312
 313         if (ops->release)
 314                 ops->release();
 315
 316         spin_lock_irq(&rtc_lock);
 317         rtc_irq_data = 0;
 318         spin_unlock_irq(&rtc_lock);
 319
 320         module_put(rtc_ops->owner);
 321         rtc_inuse = 0;
 322
 323         return 0;
 324 }
 325
 326 static int rtc_fasync(int fd, struct file *file, int on)
 327 {
 328         return fasync_helper(fd, file, on, &rtc_async_queue);
 329 }
 330
 331 static const struct file_operations rtc_fops = {
 332         .owner          = THIS_MODULE,
 333         .llseek         = no_llseek,
 334         .read           = rtc_read,
 335         .poll           = rtc_poll,
 336         .ioctl          = rtc_ioctl,
 337         .open           = rtc_open,
 338         .release        = rtc_release,
 339         .fasync         = rtc_fasync,
 340 };
 341
 342 static struct miscdevice rtc_miscdev = {
 343         .minor          = RTC_MINOR,
 344         .name           = "rtc",
 345         .fops           = &rtc_fops,
 346 };
 347
 348
 349 static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data)
 350 {
 351         struct rtc_ops *ops = data;
 352         struct rtc_wkalrm alrm;
 353         struct rtc_time tm;
 354         char *p = page;
 355
 356         if (rtc_arm_read_time(ops, &tm) == 0) {
 357                 p += sprintf(p,
 358                         "rtc_time\t: %02d:%02d:%02d\n"
 359                         "rtc_date\t: %04d-%02d-%02d\n"
 360                         "rtc_epoch\t: %04lu\n",
 361                         tm.tm_hour, tm.tm_min, tm.tm_sec,
 362                         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 363                         rtc_epoch);
 364         }
 365
 366         if (rtc_arm_read_alarm(ops, &alrm) == 0) {
 367                 p += sprintf(p, "alrm_time\t: ");
 368                 if ((unsigned int)alrm.time.tm_hour <= 24)
 369                         p += sprintf(p, "%02d:", alrm.time.tm_hour);
 370                 else
 371                         p += sprintf(p, "**:");
 372                 if ((unsigned int)alrm.time.tm_min <= 59)
 373                         p += sprintf(p, "%02d:", alrm.time.tm_min);
 374                 else
 375                         p += sprintf(p, "**:");
 376                 if ((unsigned int)alrm.time.tm_sec <= 59)
 377                         p += sprintf(p, "%02d\n", alrm.time.tm_sec);
 378                 else
 379                         p += sprintf(p, "**\n");
 380
 381                 p += sprintf(p, "alrm_date\t: ");
 382                 if ((unsigned int)alrm.time.tm_year <= 200)
 383                         p += sprintf(p, "%04d-", alrm.time.tm_year + 1900);
 384                 else
 385                         p += sprintf(p, "****-");
 386                 if ((unsigned int)alrm.time.tm_mon <= 11)
 387                         p += sprintf(p, "%02d-", alrm.time.tm_mon + 1);
 388                 else
 389                         p += sprintf(p, "**-");
 390                 if ((unsigned int)alrm.time.tm_mday <= 31)
 391                         p += sprintf(p, "%02d\n", alrm.time.tm_mday);
 392                 else
 393                         p += sprintf(p, "**\n");
 394                 p += sprintf(p, "alrm_wakeup\t: %s\n",
 395                              alrm.enabled ? "yes" : "no");
 396                 p += sprintf(p, "alrm_pending\t: %s\n",
 397                              alrm.pending ? "yes" : "no");
 398         }
 399
 400         if (ops->proc)
 401                 p += ops->proc(p);
 402
 403         return p - page;
 404 }
 405
 406 int register_rtc(struct rtc_ops *ops)
 407 {
 408         int ret = -EBUSY;
 409
 410         mutex_lock(&rtc_mutex);
 411         if (rtc_ops == NULL) {
 412                 rtc_ops = ops;
 413
 414                 ret = misc_register(&rtc_miscdev);
 415                 if (ret == 0)
 416                         create_proc_read_entry("driver/rtc", 0, NULL,
 417                                                rtc_read_proc, ops);
 418         }
 419         mutex_unlock(&rtc_mutex);
 420
 421         return ret;
 422 }
 423 EXPORT_SYMBOL(register_rtc);
 424
 425 void unregister_rtc(struct rtc_ops *rtc)
 426 {
 427         mutex_lock(&rtc_mutex);
 428         if (rtc == rtc_ops) {
 429                 remove_proc_entry("driver/rtc", NULL);
 430                 misc_deregister(&rtc_miscdev);
 431                 rtc_ops = NULL;
 432         }
 433         mutex_unlock(&rtc_mutex);
 434 }
 435 EXPORT_SYMBOL(unregister_rtc);