drivers/rtc/rtc-rs5c372.c

   1 /*
   2  * An I2C driver for Ricoh RS5C372, R2025S/D 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 #include <linux/slab.h>
  17 #include <linux/module.h>
  18
  19 #define DRV_VERSION "0.6"
  20
  21
  22 /*
  23  * Ricoh has a family of I2C based RTCs, which differ only slightly from
  24  * each other.  Differences center on pinout (e.g. how many interrupts,
  25  * output clock, etc) and how the control registers are used.  The '372
  26  * is significant only because that's the one this driver first supported.
  27  */
  28 #define RS5C372_REG_SECS        0
  29 #define RS5C372_REG_MINS        1
  30 #define RS5C372_REG_HOURS       2
  31 #define RS5C372_REG_WDAY        3
  32 #define RS5C372_REG_DAY         4
  33 #define RS5C372_REG_MONTH       5
  34 #define RS5C372_REG_YEAR        6
  35 #define RS5C372_REG_TRIM        7
  36 #       define RS5C372_TRIM_XSL         0x80
  37 #       define RS5C372_TRIM_MASK        0x7F
  38
  39 #define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
  40 #define RS5C_REG_ALARM_A_HOURS  9
  41 #define RS5C_REG_ALARM_A_WDAY   10
  42
  43 #define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
  44 #define RS5C_REG_ALARM_B_HOURS  12
  45 #define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */
  46
  47 #define RS5C_REG_CTRL1          14
  48 #       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
  49 #       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
  50 #       define RV5C387_CTRL1_24         (1 << 5)
  51 #       define RS5C372A_CTRL1_SL1       (1 << 5)
  52 #       define RS5C_CTRL1_CT_MASK       (7 << 0)
  53 #       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
  54 #       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
  55 #define RS5C_REG_CTRL2          15
  56 #       define RS5C372_CTRL2_24         (1 << 5)
  57 #       define R2025_CTRL2_XST          (1 << 5)
  58 #       define RS5C_CTRL2_XSTP          (1 << 4)        /* only if !R2025S/D */
  59 #       define RS5C_CTRL2_CTFG          (1 << 2)
  60 #       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
  61 #       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
  62
  63
  64 /* to read (style 1) or write registers starting at R */
  65 #define RS5C_ADDR(R)            (((R) << 4) | 0)
  66
  67
  68 enum rtc_type {
  69         rtc_undef = 0,
  70         rtc_r2025sd,
  71         rtc_rs5c372a,
  72         rtc_rs5c372b,
  73         rtc_rv5c386,
  74         rtc_rv5c387a,
  75 };
  76
  77 static const struct i2c_device_id rs5c372_id[] = {
  78         { "r2025sd", rtc_r2025sd },
  79         { "rs5c372a", rtc_rs5c372a },
  80         { "rs5c372b", rtc_rs5c372b },
  81         { "rv5c386", rtc_rv5c386 },
  82         { "rv5c387a", rtc_rv5c387a },
  83         { }
  84 };
  85 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
  86
  87 /* REVISIT:  this assumes that:
  88  *  - we're in the 21st century, so it's safe to ignore the century
  89  *    bit for rv5c38[67] (REG_MONTH bit 7);
  90  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
  91  */
  92 struct rs5c372 {
  93         struct i2c_client       *client;
  94         struct rtc_device       *rtc;
  95         enum rtc_type           type;
  96         unsigned                time24:1;
  97         unsigned                has_irq:1;
  98         unsigned                smbus:1;
  99         char                    buf[17];
 100         char                    *regs;
 101 };
 102
 103 static int rs5c_get_regs(struct rs5c372 *rs5c)
 104 {
 105         struct i2c_client       *client = rs5c->client;
 106         struct i2c_msg          msgs[] = {
 107                 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
 108         };
 109
 110         /* This implements the third reading method from the datasheet, using
 111          * an internal address that's reset after each transaction (by STOP)
 112          * to 0x0f ... so we read extra registers, and skip the first one.
 113          *
 114          * The first method doesn't work with the iop3xx adapter driver, on at
 115          * least 80219 chips; this works around that bug.
 116          *
 117          * The third method on the other hand doesn't work for the SMBus-only
 118          * configurations, so we use the the first method there, stripping off
 119          * the extra register in the process.
 120          */
 121         if (rs5c->smbus) {
 122                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
 123                 int size = sizeof(rs5c->buf) - 1;
 124
 125                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
 126                                                   rs5c->buf + 1) != size) {
 127                         dev_warn(&client->dev, "can't read registers\n");
 128                         return -EIO;
 129                 }
 130         } else {
 131                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
 132                         dev_warn(&client->dev, "can't read registers\n");
 133                         return -EIO;
 134                 }
 135         }
 136
 137         dev_dbg(&client->dev,
 138                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
 139                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
 140                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
 141                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
 142                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
 143                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 144
 145         return 0;
 146 }
 147
 148 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 149 {
 150         unsigned        hour;
 151
 152         if (rs5c->time24)
 153                 return bcd2bin(reg & 0x3f);
 154
 155         hour = bcd2bin(reg & 0x1f);
 156         if (hour == 12)
 157                 hour = 0;
 158         if (reg & 0x20)
 159                 hour += 12;
 160         return hour;
 161 }
 162
 163 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 164 {
 165         if (rs5c->time24)
 166                 return bin2bcd(hour);
 167
 168         if (hour > 12)
 169                 return 0x20 | bin2bcd(hour - 12);
 170         if (hour == 12)
 171                 return 0x20 | bin2bcd(12);
 172         if (hour == 0)
 173                 return bin2bcd(12);
 174         return bin2bcd(hour);
 175 }
 176
 177 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 178 {
 179         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 180         int             status = rs5c_get_regs(rs5c);
 181
 182         if (status < 0)
 183                 return status;
 184
 185         tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 186         tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 187         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 188
 189         tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 190         tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 191
 192         /* tm->tm_mon is zero-based */
 193         tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 194
 195         /* year is 1900 + tm->tm_year */
 196         tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 197
 198         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 199                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 200                 __func__,
 201                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 202                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 203
 204         /* rtc might need initialization */
 205         return rtc_valid_tm(tm);
 206 }
 207
 208 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 209 {
 210         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 211         unsigned char   buf[7];
 212         int             addr;
 213
 214         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 215                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 216                 __func__,
 217                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 218                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 219
 220         addr   = RS5C_ADDR(RS5C372_REG_SECS);
 221         buf[0] = bin2bcd(tm->tm_sec);
 222         buf[1] = bin2bcd(tm->tm_min);
 223         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
 224         buf[3] = bin2bcd(tm->tm_wday);
 225         buf[4] = bin2bcd(tm->tm_mday);
 226         buf[5] = bin2bcd(tm->tm_mon + 1);
 227         buf[6] = bin2bcd(tm->tm_year - 100);
 228
 229         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
 230                 dev_err(&client->dev, "%s: write error\n", __func__);
 231                 return -EIO;
 232         }
 233
 234         return 0;
 235 }
 236
 237 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 238 #define NEED_TRIM
 239 #endif
 240
 241 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 242 #define NEED_TRIM
 243 #endif
 244
 245 #ifdef  NEED_TRIM
 246 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 247 {
 248         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 249         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 250
 251         if (osc)
 252                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 253
 254         if (trim) {
 255                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
 256                 tmp &= RS5C372_TRIM_MASK;
 257                 if (tmp & 0x3e) {
 258                         int t = tmp & 0x3f;
 259
 260                         if (tmp & 0x40)
 261                                 t = (~t | (s8)0xc0) + 1;
 262                         else
 263                                 t = t - 1;
 264
 265                         tmp = t * 2;
 266                 } else
 267                         tmp = 0;
 268                 *trim = tmp;
 269         }
 270
 271         return 0;
 272 }
 273 #endif
 274
 275 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 276 {
 277         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 278 }
 279
 280 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 281 {
 282         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 283 }
 284
 285
 286 static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 287 {
 288         struct i2c_client       *client = to_i2c_client(dev);
 289         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 290         unsigned char           buf;
 291         int                     status, addr;
 292
 293         buf = rs5c->regs[RS5C_REG_CTRL1];
 294
 295         if (!rs5c->has_irq)
 296                 return -EINVAL;
 297
 298         status = rs5c_get_regs(rs5c);
 299         if (status < 0)
 300                 return status;
 301
 302         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 303         if (enabled)
 304                 buf |= RS5C_CTRL1_AALE;
 305         else
 306                 buf &= ~RS5C_CTRL1_AALE;
 307
 308         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 309                 printk(KERN_WARNING "%s: can't update alarm\n",
 310                         rs5c->rtc->name);
 311                 status = -EIO;
 312         } else
 313                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 314
 315         return status;
 316 }
 317
 318
 319 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 320  * which only exposes a polled programming interface; and since
 321  * these calls map directly to those EFI requests; we don't demand
 322  * we have an IRQ for this chip when we go through this API.
 323  *
 324  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 325  * though, managed through RTC_AIE_{ON,OFF} requests.
 326  */
 327
 328 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 329 {
 330         struct i2c_client       *client = to_i2c_client(dev);
 331         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 332         int                     status;
 333
 334         status = rs5c_get_regs(rs5c);
 335         if (status < 0)
 336                 return status;
 337
 338         /* report alarm time */
 339         t->time.tm_sec = 0;
 340         t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 341         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 342         t->time.tm_mday = -1;
 343         t->time.tm_mon = -1;
 344         t->time.tm_year = -1;
 345         t->time.tm_wday = -1;
 346         t->time.tm_yday = -1;
 347         t->time.tm_isdst = -1;
 348
 349         /* ... and status */
 350         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 351         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 352
 353         return 0;
 354 }
 355
 356 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 357 {
 358         struct i2c_client       *client = to_i2c_client(dev);
 359         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 360         int                     status, addr, i;
 361         unsigned char           buf[3];
 362
 363         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 364         if (t->time.tm_mday != -1
 365                         || t->time.tm_mon != -1
 366                         || t->time.tm_year != -1)
 367                 return -EINVAL;
 368
 369         /* REVISIT: round up tm_sec */
 370
 371         /* if needed, disable irq (clears pending status) */
 372         status = rs5c_get_regs(rs5c);
 373         if (status < 0)
 374                 return status;
 375         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 376                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 377                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 378                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
 379                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
 380                         return -EIO;
 381                 }
 382                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 383         }
 384
 385         /* set alarm */
 386         buf[0] = bin2bcd(t->time.tm_min);
 387         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 388         buf[2] = 0x7f;  /* any/all days */
 389
 390         for (i = 0; i < sizeof(buf); i++) {
 391                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
 392                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
 393                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
 394                         return -EIO;
 395                 }
 396         }
 397
 398         /* ... and maybe enable its irq */
 399         if (t->enabled) {
 400                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 401                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
 402                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
 403                         printk(KERN_WARNING "%s: can't enable alarm\n",
 404                                 rs5c->rtc->name);
 405                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 406         }
 407
 408         return 0;
 409 }
 410
 411 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 412
 413 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 414 {
 415         int err, osc, trim;
 416
 417         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 418         if (err == 0) {
 419                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 420                                 osc / 1000, osc % 1000);
 421                 seq_printf(seq, "trim\t\t: %d\n", trim);
 422         }
 423
 424         return 0;
 425 }
 426
 427 #else
 428 #define rs5c372_rtc_proc        NULL
 429 #endif
 430
 431 static const struct rtc_class_ops rs5c372_rtc_ops = {
 432         .proc           = rs5c372_rtc_proc,
 433         .read_time      = rs5c372_rtc_read_time,
 434         .set_time       = rs5c372_rtc_set_time,
 435         .read_alarm     = rs5c_read_alarm,
 436         .set_alarm      = rs5c_set_alarm,
 437         .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
 438 };
 439
 440 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 441
 442 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 443                                 struct device_attribute *attr, char *buf)
 444 {
 445         int err, trim;
 446
 447         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 448         if (err)
 449                 return err;
 450
 451         return sprintf(buf, "%d\n", trim);
 452 }
 453 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 454
 455 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 456                                 struct device_attribute *attr, char *buf)
 457 {
 458         int err, osc;
 459
 460         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 461         if (err)
 462                 return err;
 463
 464         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 465 }
 466 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 467
 468 static int rs5c_sysfs_register(struct device *dev)
 469 {
 470         int err;
 471
 472         err = device_create_file(dev, &dev_attr_trim);
 473         if (err)
 474                 return err;
 475         err = device_create_file(dev, &dev_attr_osc);
 476         if (err)
 477                 device_remove_file(dev, &dev_attr_trim);
 478
 479         return err;
 480 }
 481
 482 static void rs5c_sysfs_unregister(struct device *dev)
 483 {
 484         device_remove_file(dev, &dev_attr_trim);
 485         device_remove_file(dev, &dev_attr_osc);
 486 }
 487
 488 #else
 489 static int rs5c_sysfs_register(struct device *dev)
 490 {
 491         return 0;
 492 }
 493
 494 static void rs5c_sysfs_unregister(struct device *dev)
 495 {
 496         /* nothing */
 497 }
 498 #endif  /* SYSFS */
 499
 500 static struct i2c_driver rs5c372_driver;
 501
 502 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
 503 {
 504         unsigned char buf[2];
 505         int addr, i, ret = 0;
 506
 507         if (rs5c372->type == rtc_r2025sd) {
 508                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
 509                         return ret;
 510                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
 511         } else {
 512                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
 513                         return ret;
 514                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 515         }
 516
 517         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
 518         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
 519         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
 520
 521         /* use 24hr mode */
 522         switch (rs5c372->type) {
 523         case rtc_rs5c372a:
 524         case rtc_rs5c372b:
 525                 buf[1] |= RS5C372_CTRL2_24;
 526                 rs5c372->time24 = 1;
 527                 break;
 528         case rtc_r2025sd:
 529         case rtc_rv5c386:
 530         case rtc_rv5c387a:
 531                 buf[0] |= RV5C387_CTRL1_24;
 532                 rs5c372->time24 = 1;
 533                 break;
 534         default:
 535                 /* impossible */
 536                 break;
 537         }
 538
 539         for (i = 0; i < sizeof(buf); i++) {
 540                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
 541                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
 542                 if (unlikely(ret < 0))
 543                         return ret;
 544         }
 545
 546         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
 547         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
 548
 549         return 0;
 550 }
 551
 552 static int rs5c372_probe(struct i2c_client *client,
 553                          const struct i2c_device_id *id)
 554 {
 555         int err = 0;
 556         int smbus_mode = 0;
 557         struct rs5c372 *rs5c372;
 558         struct rtc_time tm;
 559
 560         dev_dbg(&client->dev, "%s\n", __func__);
 561
 562         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 563                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 564                 /*
 565                  * If we don't have any master mode adapter, try breaking
 566                  * it down in to the barest of capabilities.
 567                  */
 568                 if (i2c_check_functionality(client->adapter,
 569                                 I2C_FUNC_SMBUS_BYTE_DATA |
 570                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 571                         smbus_mode = 1;
 572                 else {
 573                         /* Still no good, give up */
 574                         err = -ENODEV;
 575                         goto exit;
 576                 }
 577         }
 578
 579         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 580                 err = -ENOMEM;
 581                 goto exit;
 582         }
 583
 584         rs5c372->client = client;
 585         i2c_set_clientdata(client, rs5c372);
 586         rs5c372->type = id->driver_data;
 587
 588         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 589         rs5c372->regs = &rs5c372->buf[1];
 590         rs5c372->smbus = smbus_mode;
 591
 592         err = rs5c_get_regs(rs5c372);
 593         if (err < 0)
 594                 goto exit_kfree;
 595
 596         /* clock may be set for am/pm or 24 hr time */
 597         switch (rs5c372->type) {
 598         case rtc_rs5c372a:
 599         case rtc_rs5c372b:
 600                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 601                  * so does periodic irq, except some 327a modes.
 602                  */
 603                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 604                         rs5c372->time24 = 1;
 605                 break;
 606         case rtc_r2025sd:
 607         case rtc_rv5c386:
 608         case rtc_rv5c387a:
 609                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 610                         rs5c372->time24 = 1;
 611                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 612                  * irq, on both 386 and 387
 613                  */
 614                 break;
 615         default:
 616                 dev_err(&client->dev, "unknown RTC type\n");
 617                 goto exit_kfree;
 618         }
 619
 620         /* if the oscillator lost power and no other software (like
 621          * the bootloader) set it up, do it here.
 622          *
 623          * The R2025S/D does this a little differently than the other
 624          * parts, so we special case that..
 625          */
 626         err = rs5c_oscillator_setup(rs5c372);
 627         if (unlikely(err < 0)) {
 628                 dev_err(&client->dev, "setup error\n");
 629                 goto exit_kfree;
 630         }
 631
 632         if (rs5c372_get_datetime(client, &tm) < 0)
 633                 dev_warn(&client->dev, "clock needs to be set\n");
 634
 635         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 636                         ({ char *s; switch (rs5c372->type) {
 637                         case rtc_r2025sd:       s = "r2025sd"; break;
 638                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 639                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 640                         case rtc_rv5c386:       s = "rv5c386"; break;
 641                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 642                         default:                s = "chip"; break;
 643                         }; s;}),
 644                         rs5c372->time24 ? "24hr" : "am/pm"
 645                         );
 646
 647         /* REVISIT use client->irq to register alarm irq ... */
 648
 649         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
 650                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
 651
 652         if (IS_ERR(rs5c372->rtc)) {
 653                 err = PTR_ERR(rs5c372->rtc);
 654                 goto exit_kfree;
 655         }
 656
 657         err = rs5c_sysfs_register(&client->dev);
 658         if (err)
 659                 goto exit_devreg;
 660
 661         return 0;
 662
 663 exit_devreg:
 664         rtc_device_unregister(rs5c372->rtc);
 665
 666 exit_kfree:
 667         kfree(rs5c372);
 668
 669 exit:
 670         return err;
 671 }
 672
 673 static int rs5c372_remove(struct i2c_client *client)
 674 {
 675         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 676
 677         rtc_device_unregister(rs5c372->rtc);
 678         rs5c_sysfs_unregister(&client->dev);
 679         kfree(rs5c372);
 680         return 0;
 681 }
 682
 683 static struct i2c_driver rs5c372_driver = {
 684         .driver         = {
 685                 .name   = "rtc-rs5c372",
 686         },
 687         .probe          = rs5c372_probe,
 688         .remove         = rs5c372_remove,
 689         .id_table       = rs5c372_id,
 690 };
 691
 692 static __init int rs5c372_init(void)
 693 {
 694         return i2c_add_driver(&rs5c372_driver);
 695 }
 696
 697 static __exit void rs5c372_exit(void)
 698 {
 699         i2c_del_driver(&rs5c372_driver);
 700 }
 701
 702 module_init(rs5c372_init);
 703 module_exit(rs5c372_exit);
 704
 705 MODULE_AUTHOR(
 706                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 707                 "Alessandro Zummo <a.zummo@towertech.it>, "
 708                 "Paul Mundt <lethal@linux-sh.org>");
 709 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 710 MODULE_LICENSE("GPL");
 711 MODULE_VERSION(DRV_VERSION);