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                 {
 108                         .addr = client->addr,
 109                         .flags = I2C_M_RD,
 110                         .len = sizeof(rs5c->buf),
 111                         .buf = rs5c->buf
 112                 },
 113         };
 114
 115         /* This implements the third reading method from the datasheet, using
 116          * an internal address that's reset after each transaction (by STOP)
 117          * to 0x0f ... so we read extra registers, and skip the first one.
 118          *
 119          * The first method doesn't work with the iop3xx adapter driver, on at
 120          * least 80219 chips; this works around that bug.
 121          *
 122          * The third method on the other hand doesn't work for the SMBus-only
 123          * configurations, so we use the the first method there, stripping off
 124          * the extra register in the process.
 125          */
 126         if (rs5c->smbus) {
 127                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
 128                 int size = sizeof(rs5c->buf) - 1;
 129
 130                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
 131                                                   rs5c->buf + 1) != size) {
 132                         dev_warn(&client->dev, "can't read registers\n");
 133                         return -EIO;
 134                 }
 135         } else {
 136                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
 137                         dev_warn(&client->dev, "can't read registers\n");
 138                         return -EIO;
 139                 }
 140         }
 141
 142         dev_dbg(&client->dev,
 143                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
 144                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
 145                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
 146                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
 147                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
 148                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 149
 150         return 0;
 151 }
 152
 153 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 154 {
 155         unsigned        hour;
 156
 157         if (rs5c->time24)
 158                 return bcd2bin(reg & 0x3f);
 159
 160         hour = bcd2bin(reg & 0x1f);
 161         if (hour == 12)
 162                 hour = 0;
 163         if (reg & 0x20)
 164                 hour += 12;
 165         return hour;
 166 }
 167
 168 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 169 {
 170         if (rs5c->time24)
 171                 return bin2bcd(hour);
 172
 173         if (hour > 12)
 174                 return 0x20 | bin2bcd(hour - 12);
 175         if (hour == 12)
 176                 return 0x20 | bin2bcd(12);
 177         if (hour == 0)
 178                 return bin2bcd(12);
 179         return bin2bcd(hour);
 180 }
 181
 182 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 183 {
 184         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 185         int             status = rs5c_get_regs(rs5c);
 186
 187         if (status < 0)
 188                 return status;
 189
 190         tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 191         tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 192         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 193
 194         tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 195         tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 196
 197         /* tm->tm_mon is zero-based */
 198         tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 199
 200         /* year is 1900 + tm->tm_year */
 201         tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 202
 203         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 204                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 205                 __func__,
 206                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 207                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 208
 209         /* rtc might need initialization */
 210         return rtc_valid_tm(tm);
 211 }
 212
 213 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 214 {
 215         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 216         unsigned char   buf[7];
 217         int             addr;
 218
 219         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 220                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 221                 __func__,
 222                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 223                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 224
 225         addr   = RS5C_ADDR(RS5C372_REG_SECS);
 226         buf[0] = bin2bcd(tm->tm_sec);
 227         buf[1] = bin2bcd(tm->tm_min);
 228         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
 229         buf[3] = bin2bcd(tm->tm_wday);
 230         buf[4] = bin2bcd(tm->tm_mday);
 231         buf[5] = bin2bcd(tm->tm_mon + 1);
 232         buf[6] = bin2bcd(tm->tm_year - 100);
 233
 234         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
 235                 dev_err(&client->dev, "%s: write error\n", __func__);
 236                 return -EIO;
 237         }
 238
 239         return 0;
 240 }
 241
 242 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 243 #define NEED_TRIM
 244 #endif
 245
 246 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 247 #define NEED_TRIM
 248 #endif
 249
 250 #ifdef  NEED_TRIM
 251 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 252 {
 253         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 254         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 255
 256         if (osc)
 257                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 258
 259         if (trim) {
 260                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
 261                 tmp &= RS5C372_TRIM_MASK;
 262                 if (tmp & 0x3e) {
 263                         int t = tmp & 0x3f;
 264
 265                         if (tmp & 0x40)
 266                                 t = (~t | (s8)0xc0) + 1;
 267                         else
 268                                 t = t - 1;
 269
 270                         tmp = t * 2;
 271                 } else
 272                         tmp = 0;
 273                 *trim = tmp;
 274         }
 275
 276         return 0;
 277 }
 278 #endif
 279
 280 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 281 {
 282         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 283 }
 284
 285 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 286 {
 287         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 288 }
 289
 290
 291 static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 292 {
 293         struct i2c_client       *client = to_i2c_client(dev);
 294         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 295         unsigned char           buf;
 296         int                     status, addr;
 297
 298         buf = rs5c->regs[RS5C_REG_CTRL1];
 299
 300         if (!rs5c->has_irq)
 301                 return -EINVAL;
 302
 303         status = rs5c_get_regs(rs5c);
 304         if (status < 0)
 305                 return status;
 306
 307         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 308         if (enabled)
 309                 buf |= RS5C_CTRL1_AALE;
 310         else
 311                 buf &= ~RS5C_CTRL1_AALE;
 312
 313         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 314                 printk(KERN_WARNING "%s: can't update alarm\n",
 315                         rs5c->rtc->name);
 316                 status = -EIO;
 317         } else
 318                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 319
 320         return status;
 321 }
 322
 323
 324 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 325  * which only exposes a polled programming interface; and since
 326  * these calls map directly to those EFI requests; we don't demand
 327  * we have an IRQ for this chip when we go through this API.
 328  *
 329  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 330  * though, managed through RTC_AIE_{ON,OFF} requests.
 331  */
 332
 333 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 334 {
 335         struct i2c_client       *client = to_i2c_client(dev);
 336         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 337         int                     status;
 338
 339         status = rs5c_get_regs(rs5c);
 340         if (status < 0)
 341                 return status;
 342
 343         /* report alarm time */
 344         t->time.tm_sec = 0;
 345         t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 346         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 347         t->time.tm_mday = -1;
 348         t->time.tm_mon = -1;
 349         t->time.tm_year = -1;
 350         t->time.tm_wday = -1;
 351         t->time.tm_yday = -1;
 352         t->time.tm_isdst = -1;
 353
 354         /* ... and status */
 355         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 356         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 357
 358         return 0;
 359 }
 360
 361 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 362 {
 363         struct i2c_client       *client = to_i2c_client(dev);
 364         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 365         int                     status, addr, i;
 366         unsigned char           buf[3];
 367
 368         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 369         if (t->time.tm_mday != -1
 370                         || t->time.tm_mon != -1
 371                         || t->time.tm_year != -1)
 372                 return -EINVAL;
 373
 374         /* REVISIT: round up tm_sec */
 375
 376         /* if needed, disable irq (clears pending status) */
 377         status = rs5c_get_regs(rs5c);
 378         if (status < 0)
 379                 return status;
 380         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 381                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 382                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 383                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
 384                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
 385                         return -EIO;
 386                 }
 387                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 388         }
 389
 390         /* set alarm */
 391         buf[0] = bin2bcd(t->time.tm_min);
 392         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 393         buf[2] = 0x7f;  /* any/all days */
 394
 395         for (i = 0; i < sizeof(buf); i++) {
 396                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
 397                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
 398                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
 399                         return -EIO;
 400                 }
 401         }
 402
 403         /* ... and maybe enable its irq */
 404         if (t->enabled) {
 405                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 406                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
 407                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
 408                         printk(KERN_WARNING "%s: can't enable alarm\n",
 409                                 rs5c->rtc->name);
 410                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 411         }
 412
 413         return 0;
 414 }
 415
 416 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 417
 418 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 419 {
 420         int err, osc, trim;
 421
 422         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 423         if (err == 0) {
 424                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 425                                 osc / 1000, osc % 1000);
 426                 seq_printf(seq, "trim\t\t: %d\n", trim);
 427         }
 428
 429         return 0;
 430 }
 431
 432 #else
 433 #define rs5c372_rtc_proc        NULL
 434 #endif
 435
 436 static const struct rtc_class_ops rs5c372_rtc_ops = {
 437         .proc           = rs5c372_rtc_proc,
 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         .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
 443 };
 444
 445 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 446
 447 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 448                                 struct device_attribute *attr, char *buf)
 449 {
 450         int err, trim;
 451
 452         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 453         if (err)
 454                 return err;
 455
 456         return sprintf(buf, "%d\n", trim);
 457 }
 458 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 459
 460 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 461                                 struct device_attribute *attr, char *buf)
 462 {
 463         int err, osc;
 464
 465         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 466         if (err)
 467                 return err;
 468
 469         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 470 }
 471 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 472
 473 static int rs5c_sysfs_register(struct device *dev)
 474 {
 475         int err;
 476
 477         err = device_create_file(dev, &dev_attr_trim);
 478         if (err)
 479                 return err;
 480         err = device_create_file(dev, &dev_attr_osc);
 481         if (err)
 482                 device_remove_file(dev, &dev_attr_trim);
 483
 484         return err;
 485 }
 486
 487 static void rs5c_sysfs_unregister(struct device *dev)
 488 {
 489         device_remove_file(dev, &dev_attr_trim);
 490         device_remove_file(dev, &dev_attr_osc);
 491 }
 492
 493 #else
 494 static int rs5c_sysfs_register(struct device *dev)
 495 {
 496         return 0;
 497 }
 498
 499 static void rs5c_sysfs_unregister(struct device *dev)
 500 {
 501         /* nothing */
 502 }
 503 #endif  /* SYSFS */
 504
 505 static struct i2c_driver rs5c372_driver;
 506
 507 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
 508 {
 509         unsigned char buf[2];
 510         int addr, i, ret = 0;
 511
 512         if (rs5c372->type == rtc_r2025sd) {
 513                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
 514                         return ret;
 515                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
 516         } else {
 517                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
 518                         return ret;
 519                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 520         }
 521
 522         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
 523         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
 524         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
 525
 526         /* use 24hr mode */
 527         switch (rs5c372->type) {
 528         case rtc_rs5c372a:
 529         case rtc_rs5c372b:
 530                 buf[1] |= RS5C372_CTRL2_24;
 531                 rs5c372->time24 = 1;
 532                 break;
 533         case rtc_r2025sd:
 534         case rtc_rv5c386:
 535         case rtc_rv5c387a:
 536                 buf[0] |= RV5C387_CTRL1_24;
 537                 rs5c372->time24 = 1;
 538                 break;
 539         default:
 540                 /* impossible */
 541                 break;
 542         }
 543
 544         for (i = 0; i < sizeof(buf); i++) {
 545                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
 546                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
 547                 if (unlikely(ret < 0))
 548                         return ret;
 549         }
 550
 551         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
 552         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
 553
 554         return 0;
 555 }
 556
 557 static int rs5c372_probe(struct i2c_client *client,
 558                          const struct i2c_device_id *id)
 559 {
 560         int err = 0;
 561         int smbus_mode = 0;
 562         struct rs5c372 *rs5c372;
 563         struct rtc_time tm;
 564
 565         dev_dbg(&client->dev, "%s\n", __func__);
 566
 567         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 568                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 569                 /*
 570                  * If we don't have any master mode adapter, try breaking
 571                  * it down in to the barest of capabilities.
 572                  */
 573                 if (i2c_check_functionality(client->adapter,
 574                                 I2C_FUNC_SMBUS_BYTE_DATA |
 575                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 576                         smbus_mode = 1;
 577                 else {
 578                         /* Still no good, give up */
 579                         err = -ENODEV;
 580                         goto exit;
 581                 }
 582         }
 583
 584         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 585                 err = -ENOMEM;
 586                 goto exit;
 587         }
 588
 589         rs5c372->client = client;
 590         i2c_set_clientdata(client, rs5c372);
 591         rs5c372->type = id->driver_data;
 592
 593         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 594         rs5c372->regs = &rs5c372->buf[1];
 595         rs5c372->smbus = smbus_mode;
 596
 597         err = rs5c_get_regs(rs5c372);
 598         if (err < 0)
 599                 goto exit_kfree;
 600
 601         /* clock may be set for am/pm or 24 hr time */
 602         switch (rs5c372->type) {
 603         case rtc_rs5c372a:
 604         case rtc_rs5c372b:
 605                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 606                  * so does periodic irq, except some 327a modes.
 607                  */
 608                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 609                         rs5c372->time24 = 1;
 610                 break;
 611         case rtc_r2025sd:
 612         case rtc_rv5c386:
 613         case rtc_rv5c387a:
 614                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 615                         rs5c372->time24 = 1;
 616                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 617                  * irq, on both 386 and 387
 618                  */
 619                 break;
 620         default:
 621                 dev_err(&client->dev, "unknown RTC type\n");
 622                 goto exit_kfree;
 623         }
 624
 625         /* if the oscillator lost power and no other software (like
 626          * the bootloader) set it up, do it here.
 627          *
 628          * The R2025S/D does this a little differently than the other
 629          * parts, so we special case that..
 630          */
 631         err = rs5c_oscillator_setup(rs5c372);
 632         if (unlikely(err < 0)) {
 633                 dev_err(&client->dev, "setup error\n");
 634                 goto exit_kfree;
 635         }
 636
 637         if (rs5c372_get_datetime(client, &tm) < 0)
 638                 dev_warn(&client->dev, "clock needs to be set\n");
 639
 640         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 641                         ({ char *s; switch (rs5c372->type) {
 642                         case rtc_r2025sd:       s = "r2025sd"; break;
 643                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 644                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 645                         case rtc_rv5c386:       s = "rv5c386"; break;
 646                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 647                         default:                s = "chip"; break;
 648                         }; s;}),
 649                         rs5c372->time24 ? "24hr" : "am/pm"
 650                         );
 651
 652         /* REVISIT use client->irq to register alarm irq ... */
 653
 654         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
 655                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
 656
 657         if (IS_ERR(rs5c372->rtc)) {
 658                 err = PTR_ERR(rs5c372->rtc);
 659                 goto exit_kfree;
 660         }
 661
 662         err = rs5c_sysfs_register(&client->dev);
 663         if (err)
 664                 goto exit_devreg;
 665
 666         return 0;
 667
 668 exit_devreg:
 669         rtc_device_unregister(rs5c372->rtc);
 670
 671 exit_kfree:
 672         kfree(rs5c372);
 673
 674 exit:
 675         return err;
 676 }
 677
 678 static int rs5c372_remove(struct i2c_client *client)
 679 {
 680         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 681
 682         rtc_device_unregister(rs5c372->rtc);
 683         rs5c_sysfs_unregister(&client->dev);
 684         kfree(rs5c372);
 685         return 0;
 686 }
 687
 688 static struct i2c_driver rs5c372_driver = {
 689         .driver         = {
 690                 .name   = "rtc-rs5c372",
 691         },
 692         .probe          = rs5c372_probe,
 693         .remove         = rs5c372_remove,
 694         .id_table       = rs5c372_id,
 695 };
 696
 697 module_i2c_driver(rs5c372_driver);
 698
 699 MODULE_AUTHOR(
 700                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 701                 "Alessandro Zummo <a.zummo@towertech.it>, "
 702                 "Paul Mundt <lethal@linux-sh.org>");
 703 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 704 MODULE_LICENSE("GPL");
 705 MODULE_VERSION(DRV_VERSION);