SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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
  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 R2025_CTRL2_XST          (1 << 5)
  56 #       define RS5C_CTRL2_XSTP          (1 << 4)        /* only if !R2025S/D */
  57 #       define RS5C_CTRL2_CTFG          (1 << 2)
  58 #       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
  59 #       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
  60
  61
  62 /* to read (style 1) or write registers starting at R */
  63 #define RS5C_ADDR(R)            (((R) << 4) | 0)
  64
  65
  66 enum rtc_type {
  67         rtc_undef = 0,
  68         rtc_r2025sd,
  69         rtc_rs5c372a,
  70         rtc_rs5c372b,
  71         rtc_rv5c386,
  72         rtc_rv5c387a,
  73 };
  74
  75 static const struct i2c_device_id rs5c372_id[] = {
  76         { "r2025sd", rtc_r2025sd },
  77         { "rs5c372a", rtc_rs5c372a },
  78         { "rs5c372b", rtc_rs5c372b },
  79         { "rv5c386", rtc_rv5c386 },
  80         { "rv5c387a", rtc_rv5c387a },
  81         { }
  82 };
  83 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
  84
  85 /* REVISIT:  this assumes that:
  86  *  - we're in the 21st century, so it's safe to ignore the century
  87  *    bit for rv5c38[67] (REG_MONTH bit 7);
  88  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
  89  */
  90 struct rs5c372 {
  91         struct i2c_client       *client;
  92         struct rtc_device       *rtc;
  93         enum rtc_type           type;
  94         unsigned                time24:1;
  95         unsigned                has_irq:1;
  96         unsigned                smbus:1;
  97         char                    buf[17];
  98         char                    *regs;
  99 };
 100
 101 static int rs5c_get_regs(struct rs5c372 *rs5c)
 102 {
 103         struct i2c_client       *client = rs5c->client;
 104         struct i2c_msg          msgs[] = {
 105                 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
 106         };
 107
 108         /* This implements the third reading method from the datasheet, using
 109          * an internal address that's reset after each transaction (by STOP)
 110          * to 0x0f ... so we read extra registers, and skip the first one.
 111          *
 112          * The first method doesn't work with the iop3xx adapter driver, on at
 113          * least 80219 chips; this works around that bug.
 114          *
 115          * The third method on the other hand doesn't work for the SMBus-only
 116          * configurations, so we use the the first method there, stripping off
 117          * the extra register in the process.
 118          */
 119         if (rs5c->smbus) {
 120                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
 121                 int size = sizeof(rs5c->buf) - 1;
 122
 123                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
 124                                                   rs5c->buf + 1) != size) {
 125                         dev_warn(&client->dev, "can't read registers\n");
 126                         return -EIO;
 127                 }
 128         } else {
 129                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
 130                         dev_warn(&client->dev, "can't read registers\n");
 131                         return -EIO;
 132                 }
 133         }
 134
 135         dev_dbg(&client->dev,
 136                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
 137                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
 138                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
 139                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
 140                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
 141                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 142
 143         return 0;
 144 }
 145
 146 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 147 {
 148         unsigned        hour;
 149
 150         if (rs5c->time24)
 151                 return bcd2bin(reg & 0x3f);
 152
 153         hour = bcd2bin(reg & 0x1f);
 154         if (hour == 12)
 155                 hour = 0;
 156         if (reg & 0x20)
 157                 hour += 12;
 158         return hour;
 159 }
 160
 161 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 162 {
 163         if (rs5c->time24)
 164                 return bin2bcd(hour);
 165
 166         if (hour > 12)
 167                 return 0x20 | bin2bcd(hour - 12);
 168         if (hour == 12)
 169                 return 0x20 | bin2bcd(12);
 170         if (hour == 0)
 171                 return bin2bcd(12);
 172         return bin2bcd(hour);
 173 }
 174
 175 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 176 {
 177         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 178         int             status = rs5c_get_regs(rs5c);
 179
 180         if (status < 0)
 181                 return status;
 182
 183         tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 184         tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 185         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 186
 187         tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 188         tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 189
 190         /* tm->tm_mon is zero-based */
 191         tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 192
 193         /* year is 1900 + tm->tm_year */
 194         tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 195
 196         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 197                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 198                 __func__,
 199                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 200                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 201
 202         /* rtc might need initialization */
 203         return rtc_valid_tm(tm);
 204 }
 205
 206 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 207 {
 208         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 209         unsigned char   buf[8];
 210         int             addr;
 211
 212         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 213                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 214                 __func__,
 215                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 216                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 217
 218         addr   = RS5C_ADDR(RS5C372_REG_SECS);
 219         buf[0] = bin2bcd(tm->tm_sec);
 220         buf[1] = bin2bcd(tm->tm_min);
 221         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
 222         buf[3] = bin2bcd(tm->tm_wday);
 223         buf[4] = bin2bcd(tm->tm_mday);
 224         buf[5] = bin2bcd(tm->tm_mon + 1);
 225         buf[6] = bin2bcd(tm->tm_year - 100);
 226
 227         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
 228                 dev_err(&client->dev, "%s: write error\n", __func__);
 229                 return -EIO;
 230         }
 231
 232         return 0;
 233 }
 234
 235 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 236 #define NEED_TRIM
 237 #endif
 238
 239 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 240 #define NEED_TRIM
 241 #endif
 242
 243 #ifdef  NEED_TRIM
 244 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 245 {
 246         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 247         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 248
 249         if (osc)
 250                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 251
 252         if (trim) {
 253                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
 254                 tmp &= RS5C372_TRIM_MASK;
 255                 if (tmp & 0x3e) {
 256                         int t = tmp & 0x3f;
 257
 258                         if (tmp & 0x40)
 259                                 t = (~t | (s8)0xc0) + 1;
 260                         else
 261                                 t = t - 1;
 262
 263                         tmp = t * 2;
 264                 } else
 265                         tmp = 0;
 266                 *trim = tmp;
 267         }
 268
 269         return 0;
 270 }
 271 #endif
 272
 273 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 274 {
 275         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 276 }
 277
 278 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 279 {
 280         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 281 }
 282
 283 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
 284
 285 static int
 286 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 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         switch (cmd) {
 295         case RTC_UIE_OFF:
 296         case RTC_UIE_ON:
 297                 /* some 327a modes use a different IRQ pin for 1Hz irqs */
 298                 if (rs5c->type == rtc_rs5c372a
 299                                 && (buf & RS5C372A_CTRL1_SL1))
 300                         return -ENOIOCTLCMD;
 301         case RTC_AIE_OFF:
 302         case RTC_AIE_ON:
 303                 /* these irq management calls only make sense for chips
 304                  * which are wired up to an IRQ.
 305                  */
 306                 if (!rs5c->has_irq)
 307                         return -ENOIOCTLCMD;
 308                 break;
 309         default:
 310                 return -ENOIOCTLCMD;
 311         }
 312
 313         status = rs5c_get_regs(rs5c);
 314         if (status < 0)
 315                 return status;
 316
 317         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 318         switch (cmd) {
 319         case RTC_AIE_OFF:       /* alarm off */
 320                 buf &= ~RS5C_CTRL1_AALE;
 321                 break;
 322         case RTC_AIE_ON:        /* alarm on */
 323                 buf |= RS5C_CTRL1_AALE;
 324                 break;
 325         case RTC_UIE_OFF:       /* update off */
 326                 buf &= ~RS5C_CTRL1_CT_MASK;
 327                 break;
 328         case RTC_UIE_ON:        /* update on */
 329                 buf &= ~RS5C_CTRL1_CT_MASK;
 330                 buf |= RS5C_CTRL1_CT4;
 331                 break;
 332         }
 333
 334         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 335                 printk(KERN_WARNING "%s: can't update alarm\n",
 336                         rs5c->rtc->name);
 337                 status = -EIO;
 338         } else
 339                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 340
 341         return status;
 342 }
 343
 344 #else
 345 #define rs5c_rtc_ioctl  NULL
 346 #endif
 347
 348
 349 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 350  * which only exposes a polled programming interface; and since
 351  * these calls map directly to those EFI requests; we don't demand
 352  * we have an IRQ for this chip when we go through this API.
 353  *
 354  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 355  * though, managed through RTC_AIE_{ON,OFF} requests.
 356  */
 357
 358 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 359 {
 360         struct i2c_client       *client = to_i2c_client(dev);
 361         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 362         int                     status;
 363
 364         status = rs5c_get_regs(rs5c);
 365         if (status < 0)
 366                 return status;
 367
 368         /* report alarm time */
 369         t->time.tm_sec = 0;
 370         t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 371         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 372         t->time.tm_mday = -1;
 373         t->time.tm_mon = -1;
 374         t->time.tm_year = -1;
 375         t->time.tm_wday = -1;
 376         t->time.tm_yday = -1;
 377         t->time.tm_isdst = -1;
 378
 379         /* ... and status */
 380         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 381         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 382
 383         return 0;
 384 }
 385
 386 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 387 {
 388         struct i2c_client       *client = to_i2c_client(dev);
 389         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 390         int                     status, addr, i;
 391         unsigned char           buf[3];
 392
 393         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 394         if (t->time.tm_mday != -1
 395                         || t->time.tm_mon != -1
 396                         || t->time.tm_year != -1)
 397                 return -EINVAL;
 398
 399         /* REVISIT: round up tm_sec */
 400
 401         /* if needed, disable irq (clears pending status) */
 402         status = rs5c_get_regs(rs5c);
 403         if (status < 0)
 404                 return status;
 405         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 406                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 407                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 408                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
 409                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
 410                         return -EIO;
 411                 }
 412                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 413         }
 414
 415         /* set alarm */
 416         buf[0] = bin2bcd(t->time.tm_min);
 417         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 418         buf[2] = 0x7f;  /* any/all days */
 419
 420         for (i = 0; i < sizeof(buf); i++) {
 421                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
 422                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
 423                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
 424                         return -EIO;
 425                 }
 426         }
 427
 428         /* ... and maybe enable its irq */
 429         if (t->enabled) {
 430                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 431                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
 432                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
 433                         printk(KERN_WARNING "%s: can't enable alarm\n",
 434                                 rs5c->rtc->name);
 435                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 436         }
 437
 438         return 0;
 439 }
 440
 441 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 442
 443 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 444 {
 445         int err, osc, trim;
 446
 447         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 448         if (err == 0) {
 449                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 450                                 osc / 1000, osc % 1000);
 451                 seq_printf(seq, "trim\t\t: %d\n", trim);
 452         }
 453
 454         return 0;
 455 }
 456
 457 #else
 458 #define rs5c372_rtc_proc        NULL
 459 #endif
 460
 461 static const struct rtc_class_ops rs5c372_rtc_ops = {
 462         .proc           = rs5c372_rtc_proc,
 463         .ioctl          = rs5c_rtc_ioctl,
 464         .read_time      = rs5c372_rtc_read_time,
 465         .set_time       = rs5c372_rtc_set_time,
 466         .read_alarm     = rs5c_read_alarm,
 467         .set_alarm      = rs5c_set_alarm,
 468 };
 469
 470 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 471
 472 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 473                                 struct device_attribute *attr, char *buf)
 474 {
 475         int err, trim;
 476
 477         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 478         if (err)
 479                 return err;
 480
 481         return sprintf(buf, "%d\n", trim);
 482 }
 483 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 484
 485 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 486                                 struct device_attribute *attr, char *buf)
 487 {
 488         int err, osc;
 489
 490         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 491         if (err)
 492                 return err;
 493
 494         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 495 }
 496 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 497
 498 static int rs5c_sysfs_register(struct device *dev)
 499 {
 500         int err;
 501
 502         err = device_create_file(dev, &dev_attr_trim);
 503         if (err)
 504                 return err;
 505         err = device_create_file(dev, &dev_attr_osc);
 506         if (err)
 507                 device_remove_file(dev, &dev_attr_trim);
 508
 509         return err;
 510 }
 511
 512 static void rs5c_sysfs_unregister(struct device *dev)
 513 {
 514         device_remove_file(dev, &dev_attr_trim);
 515         device_remove_file(dev, &dev_attr_osc);
 516 }
 517
 518 #else
 519 static int rs5c_sysfs_register(struct device *dev)
 520 {
 521         return 0;
 522 }
 523
 524 static void rs5c_sysfs_unregister(struct device *dev)
 525 {
 526         /* nothing */
 527 }
 528 #endif  /* SYSFS */
 529
 530 static struct i2c_driver rs5c372_driver;
 531
 532 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
 533 {
 534         unsigned char buf[2];
 535         int addr, i, ret = 0;
 536
 537         if (rs5c372->type == rtc_r2025sd) {
 538                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
 539                         return ret;
 540                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
 541         } else {
 542                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
 543                         return ret;
 544                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 545         }
 546
 547         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
 548         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
 549         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
 550
 551         /* use 24hr mode */
 552         switch (rs5c372->type) {
 553         case rtc_rs5c372a:
 554         case rtc_rs5c372b:
 555                 buf[1] |= RS5C372_CTRL2_24;
 556                 rs5c372->time24 = 1;
 557                 break;
 558         case rtc_r2025sd:
 559         case rtc_rv5c386:
 560         case rtc_rv5c387a:
 561                 buf[0] |= RV5C387_CTRL1_24;
 562                 rs5c372->time24 = 1;
 563                 break;
 564         default:
 565                 /* impossible */
 566                 break;
 567         }
 568
 569         for (i = 0; i < sizeof(buf); i++) {
 570                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
 571                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
 572                 if (unlikely(ret < 0))
 573                         return ret;
 574         }
 575
 576         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
 577         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
 578
 579         return 0;
 580 }
 581
 582 static int rs5c372_probe(struct i2c_client *client,
 583                          const struct i2c_device_id *id)
 584 {
 585         int err = 0;
 586         int smbus_mode = 0;
 587         struct rs5c372 *rs5c372;
 588         struct rtc_time tm;
 589
 590         dev_dbg(&client->dev, "%s\n", __func__);
 591
 592         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 593                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 594                 /*
 595                  * If we don't have any master mode adapter, try breaking
 596                  * it down in to the barest of capabilities.
 597                  */
 598                 if (i2c_check_functionality(client->adapter,
 599                                 I2C_FUNC_SMBUS_BYTE_DATA |
 600                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 601                         smbus_mode = 1;
 602                 else {
 603                         /* Still no good, give up */
 604                         err = -ENODEV;
 605                         goto exit;
 606                 }
 607         }
 608
 609         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 610                 err = -ENOMEM;
 611                 goto exit;
 612         }
 613
 614         rs5c372->client = client;
 615         i2c_set_clientdata(client, rs5c372);
 616         rs5c372->type = id->driver_data;
 617
 618         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 619         rs5c372->regs = &rs5c372->buf[1];
 620         rs5c372->smbus = smbus_mode;
 621
 622         err = rs5c_get_regs(rs5c372);
 623         if (err < 0)
 624                 goto exit_kfree;
 625
 626         /* clock may be set for am/pm or 24 hr time */
 627         switch (rs5c372->type) {
 628         case rtc_rs5c372a:
 629         case rtc_rs5c372b:
 630                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 631                  * so does periodic irq, except some 327a modes.
 632                  */
 633                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 634                         rs5c372->time24 = 1;
 635                 break;
 636         case rtc_r2025sd:
 637         case rtc_rv5c386:
 638         case rtc_rv5c387a:
 639                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 640                         rs5c372->time24 = 1;
 641                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 642                  * irq, on both 386 and 387
 643                  */
 644                 break;
 645         default:
 646                 dev_err(&client->dev, "unknown RTC type\n");
 647                 goto exit_kfree;
 648         }
 649
 650         /* if the oscillator lost power and no other software (like
 651          * the bootloader) set it up, do it here.
 652          *
 653          * The R2025S/D does this a little differently than the other
 654          * parts, so we special case that..
 655          */
 656         err = rs5c_oscillator_setup(rs5c372);
 657         if (unlikely(err < 0)) {
 658                 dev_err(&client->dev, "setup error\n");
 659                 goto exit_kfree;
 660         }
 661
 662         if (rs5c372_get_datetime(client, &tm) < 0)
 663                 dev_warn(&client->dev, "clock needs to be set\n");
 664
 665         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 666                         ({ char *s; switch (rs5c372->type) {
 667                         case rtc_r2025sd:       s = "r2025sd"; break;
 668                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 669                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 670                         case rtc_rv5c386:       s = "rv5c386"; break;
 671                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 672                         default:                s = "chip"; break;
 673                         }; s;}),
 674                         rs5c372->time24 ? "24hr" : "am/pm"
 675                         );
 676
 677         /* REVISIT use client->irq to register alarm irq ... */
 678
 679         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
 680                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
 681
 682         if (IS_ERR(rs5c372->rtc)) {
 683                 err = PTR_ERR(rs5c372->rtc);
 684                 goto exit_kfree;
 685         }
 686
 687         err = rs5c_sysfs_register(&client->dev);
 688         if (err)
 689                 goto exit_devreg;
 690
 691         return 0;
 692
 693 exit_devreg:
 694         rtc_device_unregister(rs5c372->rtc);
 695
 696 exit_kfree:
 697         kfree(rs5c372);
 698
 699 exit:
 700         return err;
 701 }
 702
 703 static int rs5c372_remove(struct i2c_client *client)
 704 {
 705         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 706
 707         rtc_device_unregister(rs5c372->rtc);
 708         rs5c_sysfs_unregister(&client->dev);
 709         kfree(rs5c372);
 710         return 0;
 711 }
 712
 713 static struct i2c_driver rs5c372_driver = {
 714         .driver         = {
 715                 .name   = "rtc-rs5c372",
 716         },
 717         .probe          = rs5c372_probe,
 718         .remove         = rs5c372_remove,
 719         .id_table       = rs5c372_id,
 720 };
 721
 722 static __init int rs5c372_init(void)
 723 {
 724         return i2c_add_driver(&rs5c372_driver);
 725 }
 726
 727 static __exit void rs5c372_exit(void)
 728 {
 729         i2c_del_driver(&rs5c372_driver);
 730 }
 731
 732 module_init(rs5c372_init);
 733 module_exit(rs5c372_exit);
 734
 735 MODULE_AUTHOR(
 736                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 737                 "Alessandro Zummo <a.zummo@towertech.it>, "
 738                 "Paul Mundt <lethal@linux-sh.org>");
 739 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 740 MODULE_LICENSE("GPL");
 741 MODULE_VERSION(DRV_VERSION);