drivers/rtc/rtc-rs5c372.c

   1 /*
   2  * An I2C driver for Ricoh RS5C372 and RV5C38[67] RTCs
   3  *
   4  * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
   5  * Copyright (C) 2006 Tower Technologies
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/i2c.h>
  13 #include <linux/rtc.h>
  14 #include <linux/bcd.h>
  15
  16 #define DRV_VERSION "0.4"
  17
  18 /* Addresses to scan */
  19 static unsigned short normal_i2c[] = { /* 0x32,*/ I2C_CLIENT_END };
  20
  21 /* Insmod parameters */
  22 I2C_CLIENT_INSMOD;
  23
  24
  25 /*
  26  * Ricoh has a family of I2C based RTCs, which differ only slightly from
  27  * each other.  Differences center on pinout (e.g. how many interrupts,
  28  * output clock, etc) and how the control registers are used.  The '372
  29  * is significant only because that's the one this driver first supported.
  30  */
  31 #define RS5C372_REG_SECS        0
  32 #define RS5C372_REG_MINS        1
  33 #define RS5C372_REG_HOURS       2
  34 #define RS5C372_REG_WDAY        3
  35 #define RS5C372_REG_DAY         4
  36 #define RS5C372_REG_MONTH       5
  37 #define RS5C372_REG_YEAR        6
  38 #define RS5C372_REG_TRIM        7
  39 #       define RS5C372_TRIM_XSL         0x80
  40 #       define RS5C372_TRIM_MASK        0x7F
  41
  42 #define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
  43 #define RS5C_REG_ALARM_A_HOURS  9
  44 #define RS5C_REG_ALARM_A_WDAY   10
  45
  46 #define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
  47 #define RS5C_REG_ALARM_B_HOURS  12
  48 #define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */
  49
  50 #define RS5C_REG_CTRL1          14
  51 #       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
  52 #       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
  53 #       define RV5C387_CTRL1_24         (1 << 5)
  54 #       define RS5C372A_CTRL1_SL1       (1 << 5)
  55 #       define RS5C_CTRL1_CT_MASK       (7 << 0)
  56 #       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
  57 #       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
  58 #define RS5C_REG_CTRL2          15
  59 #       define RS5C372_CTRL2_24         (1 << 5)
  60 #       define RS5C_CTRL2_XSTP          (1 << 4)
  61 #       define RS5C_CTRL2_CTFG          (1 << 2)
  62 #       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
  63 #       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
  64
  65
  66 /* to read (style 1) or write registers starting at R */
  67 #define RS5C_ADDR(R)            (((R) << 4) | 0)
  68
  69
  70 enum rtc_type {
  71         rtc_undef = 0,
  72         rtc_rs5c372a,
  73         rtc_rs5c372b,
  74         rtc_rv5c386,
  75         rtc_rv5c387a,
  76 };
  77
  78 /* REVISIT:  this assumes that:
  79  *  - we're in the 21st century, so it's safe to ignore the century
  80  *    bit for rv5c38[67] (REG_MONTH bit 7);
  81  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
  82  */
  83 struct rs5c372 {
  84         struct i2c_client       *client;
  85         struct rtc_device       *rtc;
  86         enum rtc_type           type;
  87         unsigned                time24:1;
  88         unsigned                has_irq:1;
  89         char                    buf[17];
  90         char                    *regs;
  91
  92         /* on conversion to a "new style" i2c driver, this vanishes */
  93         struct i2c_client       dev;
  94 };
  95
  96 static int rs5c_get_regs(struct rs5c372 *rs5c)
  97 {
  98         struct i2c_client       *client = rs5c->client;
  99         struct i2c_msg          msgs[] = {
 100                 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
 101         };
 102
 103         /* This implements the third reading method from the datasheet, using
 104          * an internal address that's reset after each transaction (by STOP)
 105          * to 0x0f ... so we read extra registers, and skip the first one.
 106          *
 107          * The first method doesn't work with the iop3xx adapter driver, on at
 108          * least 80219 chips; this works around that bug.
 109          */
 110         if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
 111                 pr_debug("%s: can't read registers\n", rs5c->rtc->name);
 112                 return -EIO;
 113         }
 114
 115         dev_dbg(&client->dev,
 116                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
 117                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
 118                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
 119                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
 120                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
 121                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 122
 123         return 0;
 124 }
 125
 126 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 127 {
 128         unsigned        hour;
 129
 130         if (rs5c->time24)
 131                 return BCD2BIN(reg & 0x3f);
 132
 133         hour = BCD2BIN(reg & 0x1f);
 134         if (hour == 12)
 135                 hour = 0;
 136         if (reg & 0x20)
 137                 hour += 12;
 138         return hour;
 139 }
 140
 141 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 142 {
 143         if (rs5c->time24)
 144                 return BIN2BCD(hour);
 145
 146         if (hour > 12)
 147                 return 0x20 | BIN2BCD(hour - 12);
 148         if (hour == 12)
 149                 return 0x20 | BIN2BCD(12);
 150         if (hour == 0)
 151                 return BIN2BCD(12);
 152         return BIN2BCD(hour);
 153 }
 154
 155 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 156 {
 157         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 158         int             status = rs5c_get_regs(rs5c);
 159
 160         if (status < 0)
 161                 return status;
 162
 163         tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 164         tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 165         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 166
 167         tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 168         tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 169
 170         /* tm->tm_mon is zero-based */
 171         tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 172
 173         /* year is 1900 + tm->tm_year */
 174         tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 175
 176         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 177                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 178                 __FUNCTION__,
 179                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 180                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 181
 182         /* rtc might need initialization */
 183         return rtc_valid_tm(tm);
 184 }
 185
 186 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 187 {
 188         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 189         unsigned char   buf[8];
 190
 191         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 192                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 193                 __FUNCTION__,
 194                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 195                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 196
 197         buf[0] = RS5C_ADDR(RS5C372_REG_SECS);
 198         buf[1] = BIN2BCD(tm->tm_sec);
 199         buf[2] = BIN2BCD(tm->tm_min);
 200         buf[3] = rs5c_hr2reg(rs5c, tm->tm_hour);
 201         buf[4] = BIN2BCD(tm->tm_wday);
 202         buf[5] = BIN2BCD(tm->tm_mday);
 203         buf[6] = BIN2BCD(tm->tm_mon + 1);
 204         buf[7] = BIN2BCD(tm->tm_year - 100);
 205
 206         if ((i2c_master_send(client, buf, 8)) != 8) {
 207                 dev_err(&client->dev, "%s: write error\n", __FUNCTION__);
 208                 return -EIO;
 209         }
 210
 211         return 0;
 212 }
 213
 214 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 215 #define NEED_TRIM
 216 #endif
 217
 218 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 219 #define NEED_TRIM
 220 #endif
 221
 222 #ifdef  NEED_TRIM
 223 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 224 {
 225         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 226         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 227
 228         if (osc)
 229                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 230
 231         if (trim) {
 232                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, tmp);
 233                 tmp &= RS5C372_TRIM_MASK;
 234                 if (tmp & 0x3e) {
 235                         int t = tmp & 0x3f;
 236
 237                         if (tmp & 0x40)
 238                                 t = (~t | (s8)0xc0) + 1;
 239                         else
 240                                 t = t - 1;
 241
 242                         tmp = t * 2;
 243                 } else
 244                         tmp = 0;
 245                 *trim = tmp;
 246         }
 247
 248         return 0;
 249 }
 250 #endif
 251
 252 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 253 {
 254         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 255 }
 256
 257 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 258 {
 259         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 260 }
 261
 262 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
 263
 264 static int
 265 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 266 {
 267         struct i2c_client       *client = to_i2c_client(dev);
 268         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 269         unsigned char           buf[2];
 270         int                     status;
 271
 272         buf[1] = rs5c->regs[RS5C_REG_CTRL1];
 273         switch (cmd) {
 274         case RTC_UIE_OFF:
 275         case RTC_UIE_ON:
 276                 /* some 327a modes use a different IRQ pin for 1Hz irqs */
 277                 if (rs5c->type == rtc_rs5c372a
 278                                 && (buf[1] & RS5C372A_CTRL1_SL1))
 279                         return -ENOIOCTLCMD;
 280         case RTC_AIE_OFF:
 281         case RTC_AIE_ON:
 282                 /* these irq management calls only make sense for chips
 283                  * which are wired up to an IRQ.
 284                  */
 285                 if (!rs5c->has_irq)
 286                         return -ENOIOCTLCMD;
 287                 break;
 288         default:
 289                 return -ENOIOCTLCMD;
 290         }
 291
 292         status = rs5c_get_regs(rs5c);
 293         if (status < 0)
 294                 return status;
 295
 296         buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
 297         switch (cmd) {
 298         case RTC_AIE_OFF:       /* alarm off */
 299                 buf[1] &= ~RS5C_CTRL1_AALE;
 300                 break;
 301         case RTC_AIE_ON:        /* alarm on */
 302                 buf[1] |= RS5C_CTRL1_AALE;
 303                 break;
 304         case RTC_UIE_OFF:       /* update off */
 305                 buf[1] &= ~RS5C_CTRL1_CT_MASK;
 306                 break;
 307         case RTC_UIE_ON:        /* update on */
 308                 buf[1] &= ~RS5C_CTRL1_CT_MASK;
 309                 buf[1] |= RS5C_CTRL1_CT4;
 310                 break;
 311         }
 312         if ((i2c_master_send(client, buf, 2)) != 2) {
 313                 printk(KERN_WARNING "%s: can't update alarm\n",
 314                         rs5c->rtc->name);
 315                 status = -EIO;
 316         } else
 317                 rs5c->regs[RS5C_REG_CTRL1] = buf[1];
 318         return status;
 319 }
 320
 321 #else
 322 #define rs5c_rtc_ioctl  NULL
 323 #endif
 324
 325
 326 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 327  * which only exposes a polled programming interface; and since
 328  * these calls map directly to those EFI requests; we don't demand
 329  * we have an IRQ for this chip when we go through this API.
 330  *
 331  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 332  * though, managed through RTC_AIE_{ON,OFF} requests.
 333  */
 334
 335 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 336 {
 337         struct i2c_client       *client = to_i2c_client(dev);
 338         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 339         int                     status;
 340
 341         status = rs5c_get_regs(rs5c);
 342         if (status < 0)
 343                 return status;
 344
 345         /* report alarm time */
 346         t->time.tm_sec = 0;
 347         t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 348         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 349         t->time.tm_mday = -1;
 350         t->time.tm_mon = -1;
 351         t->time.tm_year = -1;
 352         t->time.tm_wday = -1;
 353         t->time.tm_yday = -1;
 354         t->time.tm_isdst = -1;
 355
 356         /* ... and status */
 357         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 358         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 359
 360         return 0;
 361 }
 362
 363 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 364 {
 365         struct i2c_client       *client = to_i2c_client(dev);
 366         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 367         int                     status;
 368         unsigned char           buf[4];
 369
 370         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 371         if (t->time.tm_mday != -1
 372                         || t->time.tm_mon != -1
 373                         || t->time.tm_year != -1)
 374                 return -EINVAL;
 375
 376         /* REVISIT: round up tm_sec */
 377
 378         /* if needed, disable irq (clears pending status) */
 379         status = rs5c_get_regs(rs5c);
 380         if (status < 0)
 381                 return status;
 382         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 383                 buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
 384                 buf[1] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 385                 if (i2c_master_send(client, buf, 2) != 2) {
 386                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
 387                         return -EIO;
 388                 }
 389                 rs5c->regs[RS5C_REG_CTRL1] = buf[1];
 390         }
 391
 392         /* set alarm */
 393         buf[0] = RS5C_ADDR(RS5C_REG_ALARM_A_MIN);
 394         buf[1] = BIN2BCD(t->time.tm_min);
 395         buf[2] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 396         buf[3] = 0x7f;  /* any/all days */
 397         if ((i2c_master_send(client, buf, 4)) != 4) {
 398                 pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
 399                 return -EIO;
 400         }
 401
 402         /* ... and maybe enable its irq */
 403         if (t->enabled) {
 404                 buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
 405                 buf[1] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
 406                 if ((i2c_master_send(client, buf, 2)) != 2)
 407                         printk(KERN_WARNING "%s: can't enable alarm\n",
 408                                 rs5c->rtc->name);
 409                 rs5c->regs[RS5C_REG_CTRL1] = buf[1];
 410         }
 411
 412         return 0;
 413 }
 414
 415 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 416
 417 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 418 {
 419         int err, osc, trim;
 420
 421         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 422         if (err == 0) {
 423                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 424                                 osc / 1000, osc % 1000);
 425                 seq_printf(seq, "trim\t\t: %d\n", trim);
 426         }
 427
 428         return 0;
 429 }
 430
 431 #else
 432 #define rs5c372_rtc_proc        NULL
 433 #endif
 434
 435 static const struct rtc_class_ops rs5c372_rtc_ops = {
 436         .proc           = rs5c372_rtc_proc,
 437         .ioctl          = rs5c_rtc_ioctl,
 438         .read_time      = rs5c372_rtc_read_time,
 439         .set_time       = rs5c372_rtc_set_time,
 440         .read_alarm     = rs5c_read_alarm,
 441         .set_alarm      = rs5c_set_alarm,
 442 };
 443
 444 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 445
 446 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 447                                 struct device_attribute *attr, char *buf)
 448 {
 449         int err, trim;
 450
 451         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 452         if (err)
 453                 return err;
 454
 455         return sprintf(buf, "%d\n", trim);
 456 }
 457 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 458
 459 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 460                                 struct device_attribute *attr, char *buf)
 461 {
 462         int err, osc;
 463
 464         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 465         if (err)
 466                 return err;
 467
 468         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 469 }
 470 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 471
 472 static int rs5c_sysfs_register(struct device *dev)
 473 {
 474         int err;
 475
 476         err = device_create_file(dev, &dev_attr_trim);
 477         if (err)
 478                 return err;
 479         err = device_create_file(dev, &dev_attr_osc);
 480         if (err)
 481                 device_remove_file(dev, &dev_attr_trim);
 482
 483         return err;
 484 }
 485
 486 #else
 487 static int rs5c_sysfs_register(struct device *dev)
 488 {
 489         return 0;
 490 }
 491 #endif  /* SYSFS */
 492
 493 static struct i2c_driver rs5c372_driver;
 494
 495 static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind)
 496 {
 497         int err = 0;
 498         struct i2c_client *client;
 499         struct rs5c372 *rs5c372;
 500         struct rtc_time tm;
 501
 502         dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
 503
 504         if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
 505                 err = -ENODEV;
 506                 goto exit;
 507         }
 508
 509         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 510                 err = -ENOMEM;
 511                 goto exit;
 512         }
 513
 514         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 515         rs5c372->regs=&rs5c372->buf[1];
 516
 517         /* On conversion to a "new style" i2c driver, we'll be handed
 518          * the i2c_client (we won't create it)
 519          */
 520         client = &rs5c372->dev;
 521         rs5c372->client = client;
 522
 523         /* I2C client */
 524         client->addr = address;
 525         client->driver = &rs5c372_driver;
 526         client->adapter = adapter;
 527
 528         strlcpy(client->name, rs5c372_driver.driver.name, I2C_NAME_SIZE);
 529
 530         i2c_set_clientdata(client, rs5c372);
 531
 532         /* Inform the i2c layer */
 533         if ((err = i2c_attach_client(client)))
 534                 goto exit_kfree;
 535
 536         err = rs5c_get_regs(rs5c372);
 537         if (err < 0)
 538                 goto exit_detach;
 539
 540         /* For "new style" drivers, irq is in i2c_client and chip type
 541          * info comes from i2c_client.dev.platform_data.  Meanwhile:
 542          *
 543          * STICK BOARD-SPECIFIC SETUP CODE RIGHT HERE
 544          */
 545         if (rs5c372->type == rtc_undef) {
 546                 rs5c372->type = rtc_rs5c372b;
 547                 dev_warn(&client->dev, "assuming rs5c372b\n");
 548         }
 549
 550         /* clock may be set for am/pm or 24 hr time */
 551         switch (rs5c372->type) {
 552         case rtc_rs5c372a:
 553         case rtc_rs5c372b:
 554                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 555                  * so does periodic irq, except some 327a modes.
 556                  */
 557                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 558                         rs5c372->time24 = 1;
 559                 break;
 560         case rtc_rv5c386:
 561         case rtc_rv5c387a:
 562                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 563                         rs5c372->time24 = 1;
 564                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 565                  * irq, on both 386 and 387
 566                  */
 567                 break;
 568         default:
 569                 dev_err(&client->dev, "unknown RTC type\n");
 570                 goto exit_detach;
 571         }
 572
 573         /* if the oscillator lost power and no other software (like
 574          * the bootloader) set it up, do it here.
 575          */
 576         if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP) {
 577                 unsigned char buf[3];
 578
 579                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 580
 581                 buf[0] = RS5C_ADDR(RS5C_REG_CTRL1);
 582                 buf[1] = rs5c372->regs[RS5C_REG_CTRL1];
 583                 buf[2] = rs5c372->regs[RS5C_REG_CTRL2];
 584
 585                 /* use 24hr mode */
 586                 switch (rs5c372->type) {
 587                 case rtc_rs5c372a:
 588                 case rtc_rs5c372b:
 589                         buf[2] |= RS5C372_CTRL2_24;
 590                         rs5c372->time24 = 1;
 591                         break;
 592                 case rtc_rv5c386:
 593                 case rtc_rv5c387a:
 594                         buf[1] |= RV5C387_CTRL1_24;
 595                         rs5c372->time24 = 1;
 596                         break;
 597                 default:
 598                         /* impossible */
 599                         break;
 600                 }
 601
 602                 if ((i2c_master_send(client, buf, 3)) != 3) {
 603                         dev_err(&client->dev, "setup error\n");
 604                         goto exit_detach;
 605                 }
 606                 rs5c372->regs[RS5C_REG_CTRL1] = buf[1];
 607                 rs5c372->regs[RS5C_REG_CTRL2] = buf[2];
 608         }
 609
 610         if (rs5c372_get_datetime(client, &tm) < 0)
 611                 dev_warn(&client->dev, "clock needs to be set\n");
 612
 613         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 614                         ({ char *s; switch (rs5c372->type) {
 615                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 616                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 617                         case rtc_rv5c386:       s = "rv5c386"; break;
 618                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 619                         default:                s = "chip"; break;
 620                         }; s;}),
 621                         rs5c372->time24 ? "24hr" : "am/pm"
 622                         );
 623
 624         /* FIXME when client->irq exists, use it to register alarm irq */
 625
 626         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
 627                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
 628
 629         if (IS_ERR(rs5c372->rtc)) {
 630                 err = PTR_ERR(rs5c372->rtc);
 631                 goto exit_detach;
 632         }
 633
 634         err = rs5c_sysfs_register(&client->dev);
 635         if (err)
 636                 goto exit_devreg;
 637
 638         return 0;
 639
 640 exit_devreg:
 641         rtc_device_unregister(rs5c372->rtc);
 642
 643 exit_detach:
 644         i2c_detach_client(client);
 645
 646 exit_kfree:
 647         kfree(rs5c372);
 648
 649 exit:
 650         return err;
 651 }
 652
 653 static int rs5c372_attach(struct i2c_adapter *adapter)
 654 {
 655         return i2c_probe(adapter, &addr_data, rs5c372_probe);
 656 }
 657
 658 static int rs5c372_detach(struct i2c_client *client)
 659 {
 660         int err;
 661         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 662
 663         if (rs5c372->rtc)
 664                 rtc_device_unregister(rs5c372->rtc);
 665
 666         /* REVISIT properly destroy the sysfs files ... */
 667
 668         if ((err = i2c_detach_client(client)))
 669                 return err;
 670
 671         kfree(rs5c372);
 672         return 0;
 673 }
 674
 675 static struct i2c_driver rs5c372_driver = {
 676         .driver         = {
 677                 .name   = "rtc-rs5c372",
 678         },
 679         .attach_adapter = &rs5c372_attach,
 680         .detach_client  = &rs5c372_detach,
 681 };
 682
 683 static __init int rs5c372_init(void)
 684 {
 685         return i2c_add_driver(&rs5c372_driver);
 686 }
 687
 688 static __exit void rs5c372_exit(void)
 689 {
 690         i2c_del_driver(&rs5c372_driver);
 691 }
 692
 693 module_init(rs5c372_init);
 694 module_exit(rs5c372_exit);
 695
 696 MODULE_AUTHOR(
 697                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 698                 "Alessandro Zummo <a.zummo@towertech.it>");
 699 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 700 MODULE_LICENSE("GPL");
 701 MODULE_VERSION(DRV_VERSION);