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_r2221tl,
  72         rtc_rs5c372a,
  73         rtc_rs5c372b,
  74         rtc_rv5c386,
  75         rtc_rv5c387a,
  76 };
  77
  78 static const struct i2c_device_id rs5c372_id[] = {
  79         { "r2025sd", rtc_r2025sd },
  80         { "r2221tl", rtc_r2221tl },
  81         { "rs5c372a", rtc_rs5c372a },
  82         { "rs5c372b", rtc_rs5c372b },
  83         { "rv5c386", rtc_rv5c386 },
  84         { "rv5c387a", rtc_rv5c387a },
  85         { }
  86 };
  87 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
  88
  89 /* REVISIT:  this assumes that:
  90  *  - we're in the 21st century, so it's safe to ignore the century
  91  *    bit for rv5c38[67] (REG_MONTH bit 7);
  92  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
  93  */
  94 struct rs5c372 {
  95         struct i2c_client       *client;
  96         struct rtc_device       *rtc;
  97         enum rtc_type           type;
  98         unsigned                time24:1;
  99         unsigned                has_irq:1;
 100         unsigned                smbus:1;
 101         char                    buf[17];
 102         char                    *regs;
 103 };
 104
 105 static int rs5c_get_regs(struct rs5c372 *rs5c)
 106 {
 107         struct i2c_client       *client = rs5c->client;
 108         struct i2c_msg          msgs[] = {
 109                 {
 110                         .addr = client->addr,
 111                         .flags = I2C_M_RD,
 112                         .len = sizeof(rs5c->buf),
 113                         .buf = rs5c->buf
 114                 },
 115         };
 116
 117         /* This implements the third reading method from the datasheet, using
 118          * an internal address that's reset after each transaction (by STOP)
 119          * to 0x0f ... so we read extra registers, and skip the first one.
 120          *
 121          * The first method doesn't work with the iop3xx adapter driver, on at
 122          * least 80219 chips; this works around that bug.
 123          *
 124          * The third method on the other hand doesn't work for the SMBus-only
 125          * configurations, so we use the the first method there, stripping off
 126          * the extra register in the process.
 127          */
 128         if (rs5c->smbus) {
 129                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
 130                 int size = sizeof(rs5c->buf) - 1;
 131
 132                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
 133                                                   rs5c->buf + 1) != size) {
 134                         dev_warn(&client->dev, "can't read registers\n");
 135                         return -EIO;
 136                 }
 137         } else {
 138                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
 139                         dev_warn(&client->dev, "can't read registers\n");
 140                         return -EIO;
 141                 }
 142         }
 143
 144         dev_dbg(&client->dev,
 145                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
 146                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
 147                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
 148                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
 149                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
 150                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 151
 152         return 0;
 153 }
 154
 155 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 156 {
 157         unsigned        hour;
 158
 159         if (rs5c->time24)
 160                 return bcd2bin(reg & 0x3f);
 161
 162         hour = bcd2bin(reg & 0x1f);
 163         if (hour == 12)
 164                 hour = 0;
 165         if (reg & 0x20)
 166                 hour += 12;
 167         return hour;
 168 }
 169
 170 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 171 {
 172         if (rs5c->time24)
 173                 return bin2bcd(hour);
 174
 175         if (hour > 12)
 176                 return 0x20 | bin2bcd(hour - 12);
 177         if (hour == 12)
 178                 return 0x20 | bin2bcd(12);
 179         if (hour == 0)
 180                 return bin2bcd(12);
 181         return bin2bcd(hour);
 182 }
 183
 184 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 185 {
 186         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 187         int             status = rs5c_get_regs(rs5c);
 188
 189         if (status < 0)
 190                 return status;
 191
 192         tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 193         tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 194         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 195
 196         tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 197         tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 198
 199         /* tm->tm_mon is zero-based */
 200         tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 201
 202         /* year is 1900 + tm->tm_year */
 203         tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 204
 205         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 206                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 207                 __func__,
 208                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 209                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 210
 211         /* rtc might need initialization */
 212         return rtc_valid_tm(tm);
 213 }
 214
 215 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 216 {
 217         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 218         unsigned char   buf[7];
 219         int             addr;
 220
 221         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 222                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 223                 __func__,
 224                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 225                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 226
 227         addr   = RS5C_ADDR(RS5C372_REG_SECS);
 228         buf[0] = bin2bcd(tm->tm_sec);
 229         buf[1] = bin2bcd(tm->tm_min);
 230         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
 231         buf[3] = bin2bcd(tm->tm_wday);
 232         buf[4] = bin2bcd(tm->tm_mday);
 233         buf[5] = bin2bcd(tm->tm_mon + 1);
 234         buf[6] = bin2bcd(tm->tm_year - 100);
 235
 236         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
 237                 dev_err(&client->dev, "%s: write error\n", __func__);
 238                 return -EIO;
 239         }
 240
 241         return 0;
 242 }
 243
 244 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 245 #define NEED_TRIM
 246 #endif
 247
 248 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 249 #define NEED_TRIM
 250 #endif
 251
 252 #ifdef  NEED_TRIM
 253 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 254 {
 255         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 256         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 257
 258         if (osc)
 259                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 260
 261         if (trim) {
 262                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
 263                 tmp &= RS5C372_TRIM_MASK;
 264                 if (tmp & 0x3e) {
 265                         int t = tmp & 0x3f;
 266
 267                         if (tmp & 0x40)
 268                                 t = (~t | (s8)0xc0) + 1;
 269                         else
 270                                 t = t - 1;
 271
 272                         tmp = t * 2;
 273                 } else
 274                         tmp = 0;
 275                 *trim = tmp;
 276         }
 277
 278         return 0;
 279 }
 280 #endif
 281
 282 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 283 {
 284         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 285 }
 286
 287 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 288 {
 289         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 290 }
 291
 292
 293 static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 294 {
 295         struct i2c_client       *client = to_i2c_client(dev);
 296         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 297         unsigned char           buf;
 298         int                     status, addr;
 299
 300         buf = rs5c->regs[RS5C_REG_CTRL1];
 301
 302         if (!rs5c->has_irq)
 303                 return -EINVAL;
 304
 305         status = rs5c_get_regs(rs5c);
 306         if (status < 0)
 307                 return status;
 308
 309         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 310         if (enabled)
 311                 buf |= RS5C_CTRL1_AALE;
 312         else
 313                 buf &= ~RS5C_CTRL1_AALE;
 314
 315         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 316                 dev_warn(dev, "can't update alarm\n");
 317                 status = -EIO;
 318         } else
 319                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 320
 321         return status;
 322 }
 323
 324
 325 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 326  * which only exposes a polled programming interface; and since
 327  * these calls map directly to those EFI requests; we don't demand
 328  * we have an IRQ for this chip when we go through this API.
 329  *
 330  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 331  * though, managed through RTC_AIE_{ON,OFF} requests.
 332  */
 333
 334 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 335 {
 336         struct i2c_client       *client = to_i2c_client(dev);
 337         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 338         int                     status;
 339
 340         status = rs5c_get_regs(rs5c);
 341         if (status < 0)
 342                 return status;
 343
 344         /* report alarm time */
 345         t->time.tm_sec = 0;
 346         t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 347         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 348         t->time.tm_mday = -1;
 349         t->time.tm_mon = -1;
 350         t->time.tm_year = -1;
 351         t->time.tm_wday = -1;
 352         t->time.tm_yday = -1;
 353         t->time.tm_isdst = -1;
 354
 355         /* ... and status */
 356         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 357         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 358
 359         return 0;
 360 }
 361
 362 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 363 {
 364         struct i2c_client       *client = to_i2c_client(dev);
 365         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 366         int                     status, addr, i;
 367         unsigned char           buf[3];
 368
 369         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 370         if (t->time.tm_mday != -1
 371                         || t->time.tm_mon != -1
 372                         || t->time.tm_year != -1)
 373                 return -EINVAL;
 374
 375         /* REVISIT: round up tm_sec */
 376
 377         /* if needed, disable irq (clears pending status) */
 378         status = rs5c_get_regs(rs5c);
 379         if (status < 0)
 380                 return status;
 381         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 382                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 383                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 384                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
 385                         dev_dbg(dev, "can't disable alarm\n");
 386                         return -EIO;
 387                 }
 388                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 389         }
 390
 391         /* set alarm */
 392         buf[0] = bin2bcd(t->time.tm_min);
 393         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 394         buf[2] = 0x7f;  /* any/all days */
 395
 396         for (i = 0; i < sizeof(buf); i++) {
 397                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
 398                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
 399                         dev_dbg(dev, "can't set alarm time\n");
 400                         return -EIO;
 401                 }
 402         }
 403
 404         /* ... and maybe enable its irq */
 405         if (t->enabled) {
 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                         dev_warn(dev, "can't enable alarm\n");
 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_r2221tl:
 535         case rtc_rv5c386:
 536         case rtc_rv5c387a:
 537                 buf[0] |= RV5C387_CTRL1_24;
 538                 rs5c372->time24 = 1;
 539                 break;
 540         default:
 541                 /* impossible */
 542                 break;
 543         }
 544
 545         for (i = 0; i < sizeof(buf); i++) {
 546                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
 547                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
 548                 if (unlikely(ret < 0))
 549                         return ret;
 550         }
 551
 552         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
 553         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
 554
 555         return 0;
 556 }
 557
 558 static int rs5c372_probe(struct i2c_client *client,
 559                          const struct i2c_device_id *id)
 560 {
 561         int err = 0;
 562         int smbus_mode = 0;
 563         struct rs5c372 *rs5c372;
 564         struct rtc_time tm;
 565
 566         dev_dbg(&client->dev, "%s\n", __func__);
 567
 568         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 569                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 570                 /*
 571                  * If we don't have any master mode adapter, try breaking
 572                  * it down in to the barest of capabilities.
 573                  */
 574                 if (i2c_check_functionality(client->adapter,
 575                                 I2C_FUNC_SMBUS_BYTE_DATA |
 576                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 577                         smbus_mode = 1;
 578                 else {
 579                         /* Still no good, give up */
 580                         err = -ENODEV;
 581                         goto exit;
 582                 }
 583         }
 584
 585         rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
 586                                 GFP_KERNEL);
 587         if (!rs5c372) {
 588                 err = -ENOMEM;
 589                 goto exit;
 590         }
 591
 592         rs5c372->client = client;
 593         i2c_set_clientdata(client, rs5c372);
 594         rs5c372->type = id->driver_data;
 595
 596         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 597         rs5c372->regs = &rs5c372->buf[1];
 598         rs5c372->smbus = smbus_mode;
 599
 600         err = rs5c_get_regs(rs5c372);
 601         if (err < 0)
 602                 goto exit;
 603
 604         /* clock may be set for am/pm or 24 hr time */
 605         switch (rs5c372->type) {
 606         case rtc_rs5c372a:
 607         case rtc_rs5c372b:
 608                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 609                  * so does periodic irq, except some 327a modes.
 610                  */
 611                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 612                         rs5c372->time24 = 1;
 613                 break;
 614         case rtc_r2025sd:
 615         case rtc_r2221tl:
 616         case rtc_rv5c386:
 617         case rtc_rv5c387a:
 618                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 619                         rs5c372->time24 = 1;
 620                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 621                  * irq, on both 386 and 387
 622                  */
 623                 break;
 624         default:
 625                 dev_err(&client->dev, "unknown RTC type\n");
 626                 goto exit;
 627         }
 628
 629         /* if the oscillator lost power and no other software (like
 630          * the bootloader) set it up, do it here.
 631          *
 632          * The R2025S/D does this a little differently than the other
 633          * parts, so we special case that..
 634          */
 635         err = rs5c_oscillator_setup(rs5c372);
 636         if (unlikely(err < 0)) {
 637                 dev_err(&client->dev, "setup error\n");
 638                 goto exit;
 639         }
 640
 641         if (rs5c372_get_datetime(client, &tm) < 0)
 642                 dev_warn(&client->dev, "clock needs to be set\n");
 643
 644         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 645                         ({ char *s; switch (rs5c372->type) {
 646                         case rtc_r2025sd:       s = "r2025sd"; break;
 647                         case rtc_r2221tl:       s = "r2221tl"; break;
 648                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 649                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 650                         case rtc_rv5c386:       s = "rv5c386"; break;
 651                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 652                         default:                s = "chip"; break;
 653                         }; s;}),
 654                         rs5c372->time24 ? "24hr" : "am/pm"
 655                         );
 656
 657         /* REVISIT use client->irq to register alarm irq ... */
 658         rs5c372->rtc = devm_rtc_device_register(&client->dev,
 659                                         rs5c372_driver.driver.name,
 660                                         &rs5c372_rtc_ops, THIS_MODULE);
 661
 662         if (IS_ERR(rs5c372->rtc)) {
 663                 err = PTR_ERR(rs5c372->rtc);
 664                 goto exit;
 665         }
 666
 667         err = rs5c_sysfs_register(&client->dev);
 668         if (err)
 669                 goto exit;
 670
 671         return 0;
 672
 673 exit:
 674         return err;
 675 }
 676
 677 static int rs5c372_remove(struct i2c_client *client)
 678 {
 679         rs5c_sysfs_unregister(&client->dev);
 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 module_i2c_driver(rs5c372_driver);
 693
 694 MODULE_AUTHOR(
 695                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 696                 "Alessandro Zummo <a.zummo@towertech.it>, "
 697                 "Paul Mundt <lethal@linux-sh.org>");
 698 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 699 MODULE_LICENSE("GPL");
 700 MODULE_VERSION(DRV_VERSION);