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  * Copyright (C) 2008 Paul Mundt
   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
  13 #include <linux/i2c.h>
  14 #include <linux/rtc.h>
  15 #include <linux/bcd.h>
  16
  17 #define DRV_VERSION "0.6"
  18
  19
  20 /*
  21  * Ricoh has a family of I2C based RTCs, which differ only slightly from
  22  * each other.  Differences center on pinout (e.g. how many interrupts,
  23  * output clock, etc) and how the control registers are used.  The '372
  24  * is significant only because that's the one this driver first supported.
  25  */
  26 #define RS5C372_REG_SECS        0
  27 #define RS5C372_REG_MINS        1
  28 #define RS5C372_REG_HOURS       2
  29 #define RS5C372_REG_WDAY        3
  30 #define RS5C372_REG_DAY         4
  31 #define RS5C372_REG_MONTH       5
  32 #define RS5C372_REG_YEAR        6
  33 #define RS5C372_REG_TRIM        7
  34 #       define RS5C372_TRIM_XSL         0x80
  35 #       define RS5C372_TRIM_MASK        0x7F
  36
  37 #define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
  38 #define RS5C_REG_ALARM_A_HOURS  9
  39 #define RS5C_REG_ALARM_A_WDAY   10
  40
  41 #define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
  42 #define RS5C_REG_ALARM_B_HOURS  12
  43 #define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */
  44
  45 #define RS5C_REG_CTRL1          14
  46 #       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
  47 #       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
  48 #       define RV5C387_CTRL1_24         (1 << 5)
  49 #       define RS5C372A_CTRL1_SL1       (1 << 5)
  50 #       define RS5C_CTRL1_CT_MASK       (7 << 0)
  51 #       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
  52 #       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
  53 #define RS5C_REG_CTRL2          15
  54 #       define RS5C372_CTRL2_24         (1 << 5)
  55 #       define RS5C_CTRL2_XSTP          (1 << 4)
  56 #       define RS5C_CTRL2_CTFG          (1 << 2)
  57 #       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
  58 #       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
  59
  60
  61 /* to read (style 1) or write registers starting at R */
  62 #define RS5C_ADDR(R)            (((R) << 4) | 0)
  63
  64
  65 enum rtc_type {
  66         rtc_undef = 0,
  67         rtc_rs5c372a,
  68         rtc_rs5c372b,
  69         rtc_rv5c386,
  70         rtc_rv5c387a,
  71 };
  72
  73 static const struct i2c_device_id rs5c372_id[] = {
  74         { "rs5c372a", rtc_rs5c372a },
  75         { "rs5c372b", rtc_rs5c372b },
  76         { "rv5c386", rtc_rv5c386 },
  77         { "rv5c387a", rtc_rv5c387a },
  78         { }
  79 };
  80 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
  81
  82 /* REVISIT:  this assumes that:
  83  *  - we're in the 21st century, so it's safe to ignore the century
  84  *    bit for rv5c38[67] (REG_MONTH bit 7);
  85  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
  86  */
  87 struct rs5c372 {
  88         struct i2c_client       *client;
  89         struct rtc_device       *rtc;
  90         enum rtc_type           type;
  91         unsigned                time24:1;
  92         unsigned                has_irq:1;
  93         unsigned                smbus:1;
  94         char                    buf[17];
  95         char                    *regs;
  96 };
  97
  98 static int rs5c_get_regs(struct rs5c372 *rs5c)
  99 {
 100         struct i2c_client       *client = rs5c->client;
 101         struct i2c_msg          msgs[] = {
 102                 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
 103         };
 104
 105         /* This implements the third reading method from the datasheet, using
 106          * an internal address that's reset after each transaction (by STOP)
 107          * to 0x0f ... so we read extra registers, and skip the first one.
 108          *
 109          * The first method doesn't work with the iop3xx adapter driver, on at
 110          * least 80219 chips; this works around that bug.
 111          *
 112          * The third method on the other hand doesn't work for the SMBus-only
 113          * configurations, so we use the the first method there, stripping off
 114          * the extra register in the process.
 115          */
 116         if (rs5c->smbus) {
 117                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
 118                 int size = sizeof(rs5c->buf) - 1;
 119
 120                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
 121                                                   rs5c->buf + 1) != size) {
 122                         dev_warn(&client->dev, "can't read registers\n");
 123                         return -EIO;
 124                 }
 125         } else {
 126                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
 127                         dev_warn(&client->dev, "can't read registers\n");
 128                         return -EIO;
 129                 }
 130         }
 131
 132         dev_dbg(&client->dev,
 133                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
 134                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
 135                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
 136                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
 137                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
 138                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 139
 140         return 0;
 141 }
 142
 143 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 144 {
 145         unsigned        hour;
 146
 147         if (rs5c->time24)
 148                 return BCD2BIN(reg & 0x3f);
 149
 150         hour = BCD2BIN(reg & 0x1f);
 151         if (hour == 12)
 152                 hour = 0;
 153         if (reg & 0x20)
 154                 hour += 12;
 155         return hour;
 156 }
 157
 158 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 159 {
 160         if (rs5c->time24)
 161                 return BIN2BCD(hour);
 162
 163         if (hour > 12)
 164                 return 0x20 | BIN2BCD(hour - 12);
 165         if (hour == 12)
 166                 return 0x20 | BIN2BCD(12);
 167         if (hour == 0)
 168                 return BIN2BCD(12);
 169         return BIN2BCD(hour);
 170 }
 171
 172 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 173 {
 174         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 175         int             status = rs5c_get_regs(rs5c);
 176
 177         if (status < 0)
 178                 return status;
 179
 180         tm->tm_sec = BCD2BIN(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 181         tm->tm_min = BCD2BIN(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 182         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 183
 184         tm->tm_wday = BCD2BIN(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 185         tm->tm_mday = BCD2BIN(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 186
 187         /* tm->tm_mon is zero-based */
 188         tm->tm_mon = BCD2BIN(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 189
 190         /* year is 1900 + tm->tm_year */
 191         tm->tm_year = BCD2BIN(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 192
 193         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 194                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 195                 __func__,
 196                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 197                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 198
 199         /* rtc might need initialization */
 200         return rtc_valid_tm(tm);
 201 }
 202
 203 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 204 {
 205         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 206         unsigned char   buf[8];
 207         int             addr;
 208
 209         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 210                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 211                 __func__,
 212                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 213                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 214
 215         addr   = RS5C_ADDR(RS5C372_REG_SECS);
 216         buf[0] = BIN2BCD(tm->tm_sec);
 217         buf[1] = BIN2BCD(tm->tm_min);
 218         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
 219         buf[3] = BIN2BCD(tm->tm_wday);
 220         buf[4] = BIN2BCD(tm->tm_mday);
 221         buf[5] = BIN2BCD(tm->tm_mon + 1);
 222         buf[6] = BIN2BCD(tm->tm_year - 100);
 223
 224         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
 225                 dev_err(&client->dev, "%s: write error\n", __func__);
 226                 return -EIO;
 227         }
 228
 229         return 0;
 230 }
 231
 232 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 233 #define NEED_TRIM
 234 #endif
 235
 236 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 237 #define NEED_TRIM
 238 #endif
 239
 240 #ifdef  NEED_TRIM
 241 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 242 {
 243         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 244         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 245
 246         if (osc)
 247                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 248
 249         if (trim) {
 250                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
 251                 tmp &= RS5C372_TRIM_MASK;
 252                 if (tmp & 0x3e) {
 253                         int t = tmp & 0x3f;
 254
 255                         if (tmp & 0x40)
 256                                 t = (~t | (s8)0xc0) + 1;
 257                         else
 258                                 t = t - 1;
 259
 260                         tmp = t * 2;
 261                 } else
 262                         tmp = 0;
 263                 *trim = tmp;
 264         }
 265
 266         return 0;
 267 }
 268 #endif
 269
 270 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 271 {
 272         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 273 }
 274
 275 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 276 {
 277         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 278 }
 279
 280 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
 281
 282 static int
 283 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 284 {
 285         struct i2c_client       *client = to_i2c_client(dev);
 286         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 287         unsigned char           buf;
 288         int                     status, addr;
 289
 290         buf = rs5c->regs[RS5C_REG_CTRL1];
 291         switch (cmd) {
 292         case RTC_UIE_OFF:
 293         case RTC_UIE_ON:
 294                 /* some 327a modes use a different IRQ pin for 1Hz irqs */
 295                 if (rs5c->type == rtc_rs5c372a
 296                                 && (buf & RS5C372A_CTRL1_SL1))
 297                         return -ENOIOCTLCMD;
 298         case RTC_AIE_OFF:
 299         case RTC_AIE_ON:
 300                 /* these irq management calls only make sense for chips
 301                  * which are wired up to an IRQ.
 302                  */
 303                 if (!rs5c->has_irq)
 304                         return -ENOIOCTLCMD;
 305                 break;
 306         default:
 307                 return -ENOIOCTLCMD;
 308         }
 309
 310         status = rs5c_get_regs(rs5c);
 311         if (status < 0)
 312                 return status;
 313
 314         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 315         switch (cmd) {
 316         case RTC_AIE_OFF:       /* alarm off */
 317                 buf &= ~RS5C_CTRL1_AALE;
 318                 break;
 319         case RTC_AIE_ON:        /* alarm on */
 320                 buf |= RS5C_CTRL1_AALE;
 321                 break;
 322         case RTC_UIE_OFF:       /* update off */
 323                 buf &= ~RS5C_CTRL1_CT_MASK;
 324                 break;
 325         case RTC_UIE_ON:        /* update on */
 326                 buf &= ~RS5C_CTRL1_CT_MASK;
 327                 buf |= RS5C_CTRL1_CT4;
 328                 break;
 329         }
 330
 331         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 332                 printk(KERN_WARNING "%s: can't update alarm\n",
 333                         rs5c->rtc->name);
 334                 status = -EIO;
 335         } else
 336                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 337
 338         return status;
 339 }
 340
 341 #else
 342 #define rs5c_rtc_ioctl  NULL
 343 #endif
 344
 345
 346 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 347  * which only exposes a polled programming interface; and since
 348  * these calls map directly to those EFI requests; we don't demand
 349  * we have an IRQ for this chip when we go through this API.
 350  *
 351  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 352  * though, managed through RTC_AIE_{ON,OFF} requests.
 353  */
 354
 355 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 356 {
 357         struct i2c_client       *client = to_i2c_client(dev);
 358         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 359         int                     status;
 360
 361         status = rs5c_get_regs(rs5c);
 362         if (status < 0)
 363                 return status;
 364
 365         /* report alarm time */
 366         t->time.tm_sec = 0;
 367         t->time.tm_min = BCD2BIN(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 368         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 369         t->time.tm_mday = -1;
 370         t->time.tm_mon = -1;
 371         t->time.tm_year = -1;
 372         t->time.tm_wday = -1;
 373         t->time.tm_yday = -1;
 374         t->time.tm_isdst = -1;
 375
 376         /* ... and status */
 377         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 378         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 379
 380         return 0;
 381 }
 382
 383 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 384 {
 385         struct i2c_client       *client = to_i2c_client(dev);
 386         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 387         int                     status, addr, i;
 388         unsigned char           buf[3];
 389
 390         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 391         if (t->time.tm_mday != -1
 392                         || t->time.tm_mon != -1
 393                         || t->time.tm_year != -1)
 394                 return -EINVAL;
 395
 396         /* REVISIT: round up tm_sec */
 397
 398         /* if needed, disable irq (clears pending status) */
 399         status = rs5c_get_regs(rs5c);
 400         if (status < 0)
 401                 return status;
 402         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 403                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 404                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 405                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
 406                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
 407                         return -EIO;
 408                 }
 409                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 410         }
 411
 412         /* set alarm */
 413         buf[0] = BIN2BCD(t->time.tm_min);
 414         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 415         buf[2] = 0x7f;  /* any/all days */
 416
 417         for (i = 0; i < sizeof(buf); i++) {
 418                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
 419                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
 420                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
 421                         return -EIO;
 422                 }
 423         }
 424
 425         /* ... and maybe enable its irq */
 426         if (t->enabled) {
 427                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 428                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
 429                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
 430                         printk(KERN_WARNING "%s: can't enable alarm\n",
 431                                 rs5c->rtc->name);
 432                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 433         }
 434
 435         return 0;
 436 }
 437
 438 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 439
 440 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 441 {
 442         int err, osc, trim;
 443
 444         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 445         if (err == 0) {
 446                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 447                                 osc / 1000, osc % 1000);
 448                 seq_printf(seq, "trim\t\t: %d\n", trim);
 449         }
 450
 451         return 0;
 452 }
 453
 454 #else
 455 #define rs5c372_rtc_proc        NULL
 456 #endif
 457
 458 static const struct rtc_class_ops rs5c372_rtc_ops = {
 459         .proc           = rs5c372_rtc_proc,
 460         .ioctl          = rs5c_rtc_ioctl,
 461         .read_time      = rs5c372_rtc_read_time,
 462         .set_time       = rs5c372_rtc_set_time,
 463         .read_alarm     = rs5c_read_alarm,
 464         .set_alarm      = rs5c_set_alarm,
 465 };
 466
 467 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 468
 469 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 470                                 struct device_attribute *attr, char *buf)
 471 {
 472         int err, trim;
 473
 474         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 475         if (err)
 476                 return err;
 477
 478         return sprintf(buf, "%d\n", trim);
 479 }
 480 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 481
 482 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 483                                 struct device_attribute *attr, char *buf)
 484 {
 485         int err, osc;
 486
 487         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 488         if (err)
 489                 return err;
 490
 491         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 492 }
 493 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 494
 495 static int rs5c_sysfs_register(struct device *dev)
 496 {
 497         int err;
 498
 499         err = device_create_file(dev, &dev_attr_trim);
 500         if (err)
 501                 return err;
 502         err = device_create_file(dev, &dev_attr_osc);
 503         if (err)
 504                 device_remove_file(dev, &dev_attr_trim);
 505
 506         return err;
 507 }
 508
 509 static void rs5c_sysfs_unregister(struct device *dev)
 510 {
 511         device_remove_file(dev, &dev_attr_trim);
 512         device_remove_file(dev, &dev_attr_osc);
 513 }
 514
 515 #else
 516 static int rs5c_sysfs_register(struct device *dev)
 517 {
 518         return 0;
 519 }
 520
 521 static void rs5c_sysfs_unregister(struct device *dev)
 522 {
 523         /* nothing */
 524 }
 525 #endif  /* SYSFS */
 526
 527 static struct i2c_driver rs5c372_driver;
 528
 529 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
 530 {
 531         unsigned char buf[2];
 532         int addr, i, ret = 0;
 533
 534         if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
 535                 return ret;
 536         rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 537
 538         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
 539         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
 540         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
 541
 542         /* use 24hr mode */
 543         switch (rs5c372->type) {
 544         case rtc_rs5c372a:
 545         case rtc_rs5c372b:
 546                 buf[1] |= RS5C372_CTRL2_24;
 547                 rs5c372->time24 = 1;
 548                 break;
 549         case rtc_rv5c386:
 550         case rtc_rv5c387a:
 551                 buf[0] |= RV5C387_CTRL1_24;
 552                 rs5c372->time24 = 1;
 553                 break;
 554         default:
 555                 /* impossible */
 556                 break;
 557         }
 558
 559         for (i = 0; i < sizeof(buf); i++) {
 560                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
 561                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
 562                 if (unlikely(ret < 0))
 563                         return ret;
 564         }
 565
 566         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
 567         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
 568
 569         return 0;
 570 }
 571
 572 static int rs5c372_probe(struct i2c_client *client,
 573                          const struct i2c_device_id *id)
 574 {
 575         int err = 0;
 576         int smbus_mode = 0;
 577         struct rs5c372 *rs5c372;
 578         struct rtc_time tm;
 579
 580         dev_dbg(&client->dev, "%s\n", __func__);
 581
 582         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 583                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 584                 /*
 585                  * If we don't have any master mode adapter, try breaking
 586                  * it down in to the barest of capabilities.
 587                  */
 588                 if (i2c_check_functionality(client->adapter,
 589                                 I2C_FUNC_SMBUS_BYTE_DATA |
 590                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 591                         smbus_mode = 1;
 592                 else {
 593                         /* Still no good, give up */
 594                         err = -ENODEV;
 595                         goto exit;
 596                 }
 597         }
 598
 599         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 600                 err = -ENOMEM;
 601                 goto exit;
 602         }
 603
 604         rs5c372->client = client;
 605         i2c_set_clientdata(client, rs5c372);
 606         rs5c372->type = id->driver_data;
 607
 608         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 609         rs5c372->regs = &rs5c372->buf[1];
 610         rs5c372->smbus = smbus_mode;
 611
 612         err = rs5c_get_regs(rs5c372);
 613         if (err < 0)
 614                 goto exit_kfree;
 615
 616         /* clock may be set for am/pm or 24 hr time */
 617         switch (rs5c372->type) {
 618         case rtc_rs5c372a:
 619         case rtc_rs5c372b:
 620                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 621                  * so does periodic irq, except some 327a modes.
 622                  */
 623                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 624                         rs5c372->time24 = 1;
 625                 break;
 626         case rtc_rv5c386:
 627         case rtc_rv5c387a:
 628                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 629                         rs5c372->time24 = 1;
 630                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 631                  * irq, on both 386 and 387
 632                  */
 633                 break;
 634         default:
 635                 dev_err(&client->dev, "unknown RTC type\n");
 636                 goto exit_kfree;
 637         }
 638
 639         /* if the oscillator lost power and no other software (like
 640          * the bootloader) set it up, do it here.
 641          */
 642         err = rs5c_oscillator_setup(rs5c372);
 643         if (unlikely(err < 0)) {
 644                 dev_err(&client->dev, "setup error\n");
 645                 goto exit_kfree;
 646         }
 647
 648         if (rs5c372_get_datetime(client, &tm) < 0)
 649                 dev_warn(&client->dev, "clock needs to be set\n");
 650
 651         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 652                         ({ char *s; switch (rs5c372->type) {
 653                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 654                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 655                         case rtc_rv5c386:       s = "rv5c386"; break;
 656                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 657                         default:                s = "chip"; break;
 658                         }; s;}),
 659                         rs5c372->time24 ? "24hr" : "am/pm"
 660                         );
 661
 662         /* REVISIT use client->irq to register alarm irq ... */
 663
 664         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
 665                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
 666
 667         if (IS_ERR(rs5c372->rtc)) {
 668                 err = PTR_ERR(rs5c372->rtc);
 669                 goto exit_kfree;
 670         }
 671
 672         err = rs5c_sysfs_register(&client->dev);
 673         if (err)
 674                 goto exit_devreg;
 675
 676         return 0;
 677
 678 exit_devreg:
 679         rtc_device_unregister(rs5c372->rtc);
 680
 681 exit_kfree:
 682         kfree(rs5c372);
 683
 684 exit:
 685         return err;
 686 }
 687
 688 static int rs5c372_remove(struct i2c_client *client)
 689 {
 690         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 691
 692         rtc_device_unregister(rs5c372->rtc);
 693         rs5c_sysfs_unregister(&client->dev);
 694         kfree(rs5c372);
 695         return 0;
 696 }
 697
 698 static struct i2c_driver rs5c372_driver = {
 699         .driver         = {
 700                 .name   = "rtc-rs5c372",
 701         },
 702         .probe          = rs5c372_probe,
 703         .remove         = rs5c372_remove,
 704         .id_table       = rs5c372_id,
 705 };
 706
 707 static __init int rs5c372_init(void)
 708 {
 709         return i2c_add_driver(&rs5c372_driver);
 710 }
 711
 712 static __exit void rs5c372_exit(void)
 713 {
 714         i2c_del_driver(&rs5c372_driver);
 715 }
 716
 717 module_init(rs5c372_init);
 718 module_exit(rs5c372_exit);
 719
 720 MODULE_AUTHOR(
 721                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 722                 "Alessandro Zummo <a.zummo@towertech.it>, "
 723                 "Paul Mundt <lethal@linux-sh.org>");
 724 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 725 MODULE_LICENSE("GPL");
 726 MODULE_VERSION(DRV_VERSION);