drivers/rtc/rtc-ds1286.c

   1 /*
   2  * DS1286 Real Time Clock interface for Linux
   3  *
   4  * Copyright (C) 1998, 1999, 2000 Ralf Baechle
   5  * Copyright (C) 2008 Thomas Bogendoerfer
   6  *
   7  * Based on code written by Paul Gortmaker.
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the
  11  * Free Software Foundation; either version 2 of the License, or (at your
  12  * option) any later version.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/rtc.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/bcd.h>
  19 #include <linux/ds1286.h>
  20 #include <linux/io.h>
  21
  22 #define DRV_VERSION             "1.0"
  23
  24 struct ds1286_priv {
  25         struct rtc_device *rtc;
  26         u32 __iomem *rtcregs;
  27         size_t size;
  28         unsigned long baseaddr;
  29         spinlock_t lock;
  30 };
  31
  32 static inline u8 ds1286_rtc_read(struct ds1286_priv *priv, int reg)
  33 {
  34         return __raw_readl(&priv->rtcregs[reg]) & 0xff;
  35 }
  36
  37 static inline void ds1286_rtc_write(struct ds1286_priv *priv, u8 data, int reg)
  38 {
  39         __raw_writel(data, &priv->rtcregs[reg]);
  40 }
  41
  42 #ifdef CONFIG_RTC_INTF_DEV
  43
  44 static int ds1286_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
  45 {
  46         struct ds1286_priv *priv = dev_get_drvdata(dev);
  47         unsigned long flags;
  48         unsigned char val;
  49
  50         switch (cmd) {
  51         case RTC_AIE_OFF:
  52                 /* Mask alarm int. enab. bit    */
  53                 spin_lock_irqsave(&priv->lock, flags);
  54                 val = ds1286_rtc_read(priv, RTC_CMD);
  55                 val |=  RTC_TDM;
  56                 ds1286_rtc_write(priv, val, RTC_CMD);
  57                 spin_unlock_irqrestore(&priv->lock, flags);
  58                 break;
  59         case RTC_AIE_ON:
  60                 /* Allow alarm interrupts.      */
  61                 spin_lock_irqsave(&priv->lock, flags);
  62                 val = ds1286_rtc_read(priv, RTC_CMD);
  63                 val &=  ~RTC_TDM;
  64                 ds1286_rtc_write(priv, val, RTC_CMD);
  65                 spin_unlock_irqrestore(&priv->lock, flags);
  66                 break;
  67         case RTC_WIE_OFF:
  68                 /* Mask watchdog int. enab. bit */
  69                 spin_lock_irqsave(&priv->lock, flags);
  70                 val = ds1286_rtc_read(priv, RTC_CMD);
  71                 val |= RTC_WAM;
  72                 ds1286_rtc_write(priv, val, RTC_CMD);
  73                 spin_unlock_irqrestore(&priv->lock, flags);
  74                 break;
  75         case RTC_WIE_ON:
  76                 /* Allow watchdog interrupts.   */
  77                 spin_lock_irqsave(&priv->lock, flags);
  78                 val = ds1286_rtc_read(priv, RTC_CMD);
  79                 val &= ~RTC_WAM;
  80                 ds1286_rtc_write(priv, val, RTC_CMD);
  81                 spin_unlock_irqrestore(&priv->lock, flags);
  82                 break;
  83         default:
  84                 return -ENOIOCTLCMD;
  85         }
  86         return 0;
  87 }
  88
  89 #else
  90 #define ds1286_ioctl    NULL
  91 #endif
  92
  93 #ifdef CONFIG_PROC_FS
  94
  95 static int ds1286_proc(struct device *dev, struct seq_file *seq)
  96 {
  97         struct ds1286_priv *priv = dev_get_drvdata(dev);
  98         unsigned char month, cmd, amode;
  99         const char *s;
 100
 101         month = ds1286_rtc_read(priv, RTC_MONTH);
 102         seq_printf(seq,
 103                    "oscillator\t: %s\n"
 104                    "square_wave\t: %s\n",
 105                    (month & RTC_EOSC) ? "disabled" : "enabled",
 106                    (month & RTC_ESQW) ? "disabled" : "enabled");
 107
 108         amode = ((ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x80) >> 5) |
 109                 ((ds1286_rtc_read(priv, RTC_HOURS_ALARM) & 0x80) >> 6) |
 110                 ((ds1286_rtc_read(priv, RTC_DAY_ALARM) & 0x80) >> 7);
 111         switch (amode) {
 112         case 7:
 113                 s = "each minute";
 114                 break;
 115         case 3:
 116                 s = "minutes match";
 117                 break;
 118         case 1:
 119                 s = "hours and minutes match";
 120                 break;
 121         case 0:
 122                 s = "days, hours and minutes match";
 123                 break;
 124         default:
 125                 s = "invalid";
 126                 break;
 127         }
 128         seq_printf(seq, "alarm_mode\t: %s\n", s);
 129
 130         cmd = ds1286_rtc_read(priv, RTC_CMD);
 131         seq_printf(seq,
 132                    "alarm_enable\t: %s\n"
 133                    "wdog_alarm\t: %s\n"
 134                    "alarm_mask\t: %s\n"
 135                    "wdog_alarm_mask\t: %s\n"
 136                    "interrupt_mode\t: %s\n"
 137                    "INTB_mode\t: %s_active\n"
 138                    "interrupt_pins\t: %s\n",
 139                    (cmd & RTC_TDF) ? "yes" : "no",
 140                    (cmd & RTC_WAF) ? "yes" : "no",
 141                    (cmd & RTC_TDM) ? "disabled" : "enabled",
 142                    (cmd & RTC_WAM) ? "disabled" : "enabled",
 143                    (cmd & RTC_PU_LVL) ? "pulse" : "level",
 144                    (cmd & RTC_IBH_LO) ? "low" : "high",
 145                    (cmd & RTC_IPSW) ? "unswapped" : "swapped");
 146         return 0;
 147 }
 148
 149 #else
 150 #define ds1286_proc     NULL
 151 #endif
 152
 153 static int ds1286_read_time(struct device *dev, struct rtc_time *tm)
 154 {
 155         struct ds1286_priv *priv = dev_get_drvdata(dev);
 156         unsigned char save_control;
 157         unsigned long flags;
 158         unsigned long uip_watchdog = jiffies;
 159
 160         /*
 161          * read RTC once any update in progress is done. The update
 162          * can take just over 2ms. We wait 10 to 20ms. There is no need to
 163          * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
 164          * If you need to know *exactly* when a second has started, enable
 165          * periodic update complete interrupts, (via ioctl) and then
 166          * immediately read /dev/rtc which will block until you get the IRQ.
 167          * Once the read clears, read the RTC time (again via ioctl). Easy.
 168          */
 169
 170         if (ds1286_rtc_read(priv, RTC_CMD) & RTC_TE)
 171                 while (time_before(jiffies, uip_watchdog + 2*HZ/100))
 172                         barrier();
 173
 174         /*
 175          * Only the values that we read from the RTC are set. We leave
 176          * tm_wday, tm_yday and tm_isdst untouched. Even though the
 177          * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
 178          * by the RTC when initially set to a non-zero value.
 179          */
 180         spin_lock_irqsave(&priv->lock, flags);
 181         save_control = ds1286_rtc_read(priv, RTC_CMD);
 182         ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
 183
 184         tm->tm_sec = ds1286_rtc_read(priv, RTC_SECONDS);
 185         tm->tm_min = ds1286_rtc_read(priv, RTC_MINUTES);
 186         tm->tm_hour = ds1286_rtc_read(priv, RTC_HOURS) & 0x3f;
 187         tm->tm_mday = ds1286_rtc_read(priv, RTC_DATE);
 188         tm->tm_mon = ds1286_rtc_read(priv, RTC_MONTH) & 0x1f;
 189         tm->tm_year = ds1286_rtc_read(priv, RTC_YEAR);
 190
 191         ds1286_rtc_write(priv, save_control, RTC_CMD);
 192         spin_unlock_irqrestore(&priv->lock, flags);
 193
 194         tm->tm_sec = bcd2bin(tm->tm_sec);
 195         tm->tm_min = bcd2bin(tm->tm_min);
 196         tm->tm_hour = bcd2bin(tm->tm_hour);
 197         tm->tm_mday = bcd2bin(tm->tm_mday);
 198         tm->tm_mon = bcd2bin(tm->tm_mon);
 199         tm->tm_year = bcd2bin(tm->tm_year);
 200
 201         /*
 202          * Account for differences between how the RTC uses the values
 203          * and how they are defined in a struct rtc_time;
 204          */
 205         if (tm->tm_year < 45)
 206                 tm->tm_year += 30;
 207         tm->tm_year += 40;
 208         if (tm->tm_year < 70)
 209                 tm->tm_year += 100;
 210
 211         tm->tm_mon--;
 212
 213         return rtc_valid_tm(tm);
 214 }
 215
 216 static int ds1286_set_time(struct device *dev, struct rtc_time *tm)
 217 {
 218         struct ds1286_priv *priv = dev_get_drvdata(dev);
 219         unsigned char mon, day, hrs, min, sec;
 220         unsigned char save_control;
 221         unsigned int yrs;
 222         unsigned long flags;
 223
 224         yrs = tm->tm_year + 1900;
 225         mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
 226         day = tm->tm_mday;
 227         hrs = tm->tm_hour;
 228         min = tm->tm_min;
 229         sec = tm->tm_sec;
 230
 231         if (yrs < 1970)
 232                 return -EINVAL;
 233
 234         yrs -= 1940;
 235         if (yrs > 255)    /* They are unsigned */
 236                 return -EINVAL;
 237
 238         if (yrs >= 100)
 239                 yrs -= 100;
 240
 241         sec = bin2bcd(sec);
 242         min = bin2bcd(min);
 243         hrs = bin2bcd(hrs);
 244         day = bin2bcd(day);
 245         mon = bin2bcd(mon);
 246         yrs = bin2bcd(yrs);
 247
 248         spin_lock_irqsave(&priv->lock, flags);
 249         save_control = ds1286_rtc_read(priv, RTC_CMD);
 250         ds1286_rtc_write(priv, (save_control|RTC_TE), RTC_CMD);
 251
 252         ds1286_rtc_write(priv, yrs, RTC_YEAR);
 253         ds1286_rtc_write(priv, mon, RTC_MONTH);
 254         ds1286_rtc_write(priv, day, RTC_DATE);
 255         ds1286_rtc_write(priv, hrs, RTC_HOURS);
 256         ds1286_rtc_write(priv, min, RTC_MINUTES);
 257         ds1286_rtc_write(priv, sec, RTC_SECONDS);
 258         ds1286_rtc_write(priv, 0, RTC_HUNDREDTH_SECOND);
 259
 260         ds1286_rtc_write(priv, save_control, RTC_CMD);
 261         spin_unlock_irqrestore(&priv->lock, flags);
 262         return 0;
 263 }
 264
 265 static int ds1286_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 266 {
 267         struct ds1286_priv *priv = dev_get_drvdata(dev);
 268         unsigned char cmd;
 269         unsigned long flags;
 270
 271         /*
 272          * Only the values that we read from the RTC are set. That
 273          * means only tm_wday, tm_hour, tm_min.
 274          */
 275         spin_lock_irqsave(&priv->lock, flags);
 276         alm->time.tm_min = ds1286_rtc_read(priv, RTC_MINUTES_ALARM) & 0x7f;
 277         alm->time.tm_hour = ds1286_rtc_read(priv, RTC_HOURS_ALARM)  & 0x1f;
 278         alm->time.tm_wday = ds1286_rtc_read(priv, RTC_DAY_ALARM)    & 0x07;
 279         cmd = ds1286_rtc_read(priv, RTC_CMD);
 280         spin_unlock_irqrestore(&priv->lock, flags);
 281
 282         alm->time.tm_min = bcd2bin(alm->time.tm_min);
 283         alm->time.tm_hour = bcd2bin(alm->time.tm_hour);
 284         alm->time.tm_sec = 0;
 285         return 0;
 286 }
 287
 288 static int ds1286_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 289 {
 290         struct ds1286_priv *priv = dev_get_drvdata(dev);
 291         unsigned char hrs, min, sec;
 292
 293         hrs = alm->time.tm_hour;
 294         min = alm->time.tm_min;
 295         sec = alm->time.tm_sec;
 296
 297         if (hrs >= 24)
 298                 hrs = 0xff;
 299
 300         if (min >= 60)
 301                 min = 0xff;
 302
 303         if (sec != 0)
 304                 return -EINVAL;
 305
 306         min = bin2bcd(min);
 307         hrs = bin2bcd(hrs);
 308
 309         spin_lock(&priv->lock);
 310         ds1286_rtc_write(priv, hrs, RTC_HOURS_ALARM);
 311         ds1286_rtc_write(priv, min, RTC_MINUTES_ALARM);
 312         spin_unlock(&priv->lock);
 313
 314         return 0;
 315 }
 316
 317 static const struct rtc_class_ops ds1286_ops = {
 318         .ioctl          = ds1286_ioctl,
 319         .proc           = ds1286_proc,
 320         .read_time      = ds1286_read_time,
 321         .set_time       = ds1286_set_time,
 322         .read_alarm     = ds1286_read_alarm,
 323         .set_alarm      = ds1286_set_alarm,
 324 };
 325
 326 static int __devinit ds1286_probe(struct platform_device *pdev)
 327 {
 328         struct rtc_device *rtc;
 329         struct resource *res;
 330         struct ds1286_priv *priv;
 331         int ret = 0;
 332
 333         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 334         if (!res)
 335                 return -ENODEV;
 336         priv = kzalloc(sizeof(struct ds1286_priv), GFP_KERNEL);
 337         if (!priv)
 338                 return -ENOMEM;
 339
 340         priv->size = res->end - res->start + 1;
 341         if (!request_mem_region(res->start, priv->size, pdev->name)) {
 342                 ret = -EBUSY;
 343                 goto out;
 344         }
 345         priv->baseaddr = res->start;
 346         priv->rtcregs = ioremap(priv->baseaddr, priv->size);
 347         if (!priv->rtcregs) {
 348                 ret = -ENOMEM;
 349                 goto out;
 350         }
 351         spin_lock_init(&priv->lock);
 352         rtc = rtc_device_register("ds1286", &pdev->dev,
 353                                   &ds1286_ops, THIS_MODULE);
 354         if (IS_ERR(rtc)) {
 355                 ret = PTR_ERR(rtc);
 356                 goto out;
 357         }
 358         priv->rtc = rtc;
 359         platform_set_drvdata(pdev, priv);
 360         return 0;
 361
 362 out:
 363         if (priv->rtc)
 364                 rtc_device_unregister(priv->rtc);
 365         if (priv->rtcregs)
 366                 iounmap(priv->rtcregs);
 367         if (priv->baseaddr)
 368                 release_mem_region(priv->baseaddr, priv->size);
 369         kfree(priv);
 370         return ret;
 371 }
 372
 373 static int __devexit ds1286_remove(struct platform_device *pdev)
 374 {
 375         struct ds1286_priv *priv = platform_get_drvdata(pdev);
 376
 377         rtc_device_unregister(priv->rtc);
 378         iounmap(priv->rtcregs);
 379         release_mem_region(priv->baseaddr, priv->size);
 380         kfree(priv);
 381         return 0;
 382 }
 383
 384 static struct platform_driver ds1286_platform_driver = {
 385         .driver         = {
 386                 .name   = "rtc-ds1286",
 387                 .owner  = THIS_MODULE,
 388         },
 389         .probe          = ds1286_probe,
 390         .remove         = __devexit_p(ds1286_remove),
 391 };
 392
 393 static int __init ds1286_init(void)
 394 {
 395         return platform_driver_register(&ds1286_platform_driver);
 396 }
 397
 398 static void __exit ds1286_exit(void)
 399 {
 400         platform_driver_unregister(&ds1286_platform_driver);
 401 }
 402
 403 MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
 404 MODULE_DESCRIPTION("DS1286 RTC driver");
 405 MODULE_LICENSE("GPL");
 406 MODULE_VERSION(DRV_VERSION);
 407 MODULE_ALIAS("platform:rtc-ds1286");
 408
 409 module_init(ds1286_init);
 410 module_exit(ds1286_exit);