kernel/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                 "%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
 146                 rs5c->regs + 0, rs5c->regs[3],
 147                 rs5c->regs + 4, rs5c->regs[7],
 148                 rs5c->regs + 8, rs5c->regs + 11,
 149                 rs5c->regs[14], rs5c->regs[15]);
 150
 151         return 0;
 152 }
 153
 154 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 155 {
 156         unsigned        hour;
 157
 158         if (rs5c->time24)
 159                 return bcd2bin(reg & 0x3f);
 160
 161         hour = bcd2bin(reg & 0x1f);
 162         if (hour == 12)
 163                 hour = 0;
 164         if (reg & 0x20)
 165                 hour += 12;
 166         return hour;
 167 }
 168
 169 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 170 {
 171         if (rs5c->time24)
 172                 return bin2bcd(hour);
 173
 174         if (hour > 12)
 175                 return 0x20 | bin2bcd(hour - 12);
 176         if (hour == 12)
 177                 return 0x20 | bin2bcd(12);
 178         if (hour == 0)
 179                 return bin2bcd(12);
 180         return bin2bcd(hour);
 181 }
 182
 183 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 184 {
 185         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 186         int             status = rs5c_get_regs(rs5c);
 187
 188         if (status < 0)
 189                 return status;
 190
 191         tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 192         tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 193         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 194
 195         tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 196         tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 197
 198         /* tm->tm_mon is zero-based */
 199         tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 200
 201         /* year is 1900 + tm->tm_year */
 202         tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 203
 204         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 205                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 206                 __func__,
 207                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 208                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 209
 210         /* rtc might need initialization */
 211         return rtc_valid_tm(tm);
 212 }
 213
 214 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 215 {
 216         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 217         unsigned char   buf[7];
 218         int             addr;
 219
 220         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 221                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 222                 __func__,
 223                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 224                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 225
 226         addr   = RS5C_ADDR(RS5C372_REG_SECS);
 227         buf[0] = bin2bcd(tm->tm_sec);
 228         buf[1] = bin2bcd(tm->tm_min);
 229         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
 230         buf[3] = bin2bcd(tm->tm_wday);
 231         buf[4] = bin2bcd(tm->tm_mday);
 232         buf[5] = bin2bcd(tm->tm_mon + 1);
 233         buf[6] = bin2bcd(tm->tm_year - 100);
 234
 235         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
 236                 dev_err(&client->dev, "%s: write error\n", __func__);
 237                 return -EIO;
 238         }
 239
 240         return 0;
 241 }
 242
 243 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 244 #define NEED_TRIM
 245 #endif
 246
 247 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 248 #define NEED_TRIM
 249 #endif
 250
 251 #ifdef  NEED_TRIM
 252 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 253 {
 254         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 255         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 256
 257         if (osc)
 258                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 259
 260         if (trim) {
 261                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
 262                 tmp &= RS5C372_TRIM_MASK;
 263                 if (tmp & 0x3e) {
 264                         int t = tmp & 0x3f;
 265
 266                         if (tmp & 0x40)
 267                                 t = (~t | (s8)0xc0) + 1;
 268                         else
 269                                 t = t - 1;
 270
 271                         tmp = t * 2;
 272                 } else
 273                         tmp = 0;
 274                 *trim = tmp;
 275         }
 276
 277         return 0;
 278 }
 279 #endif
 280
 281 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 282 {
 283         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 284 }
 285
 286 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 287 {
 288         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 289 }
 290
 291
 292 static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 293 {
 294         struct i2c_client       *client = to_i2c_client(dev);
 295         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 296         unsigned char           buf;
 297         int                     status, addr;
 298
 299         buf = rs5c->regs[RS5C_REG_CTRL1];
 300
 301         if (!rs5c->has_irq)
 302                 return -EINVAL;
 303
 304         status = rs5c_get_regs(rs5c);
 305         if (status < 0)
 306                 return status;
 307
 308         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 309         if (enabled)
 310                 buf |= RS5C_CTRL1_AALE;
 311         else
 312                 buf &= ~RS5C_CTRL1_AALE;
 313
 314         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 315                 dev_warn(dev, "can't update alarm\n");
 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                         dev_dbg(dev, "can't disable alarm\n");
 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                         dev_dbg(dev, "can't set alarm time\n");
 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                         dev_warn(dev, "can't enable alarm\n");
 409                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 410         }
 411
 412         return 0;
 413 }
 414
 415 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 416
 417 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 418 {
 419         int err, osc, trim;
 420
 421         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 422         if (err == 0) {
 423                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 424                                 osc / 1000, osc % 1000);
 425                 seq_printf(seq, "trim\t\t: %d\n", trim);
 426         }
 427
 428         return 0;
 429 }
 430
 431 #else
 432 #define rs5c372_rtc_proc        NULL
 433 #endif
 434
 435 static const struct rtc_class_ops rs5c372_rtc_ops = {
 436         .proc           = rs5c372_rtc_proc,
 437         .read_time      = rs5c372_rtc_read_time,
 438         .set_time       = rs5c372_rtc_set_time,
 439         .read_alarm     = rs5c_read_alarm,
 440         .set_alarm      = rs5c_set_alarm,
 441         .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
 442 };
 443
 444 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 445
 446 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 447                                 struct device_attribute *attr, char *buf)
 448 {
 449         int err, trim;
 450
 451         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 452         if (err)
 453                 return err;
 454
 455         return sprintf(buf, "%d\n", trim);
 456 }
 457 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 458
 459 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 460                                 struct device_attribute *attr, char *buf)
 461 {
 462         int err, osc;
 463
 464         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 465         if (err)
 466                 return err;
 467
 468         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 469 }
 470 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 471
 472 static int rs5c_sysfs_register(struct device *dev)
 473 {
 474         int err;
 475
 476         err = device_create_file(dev, &dev_attr_trim);
 477         if (err)
 478                 return err;
 479         err = device_create_file(dev, &dev_attr_osc);
 480         if (err)
 481                 device_remove_file(dev, &dev_attr_trim);
 482
 483         return err;
 484 }
 485
 486 static void rs5c_sysfs_unregister(struct device *dev)
 487 {
 488         device_remove_file(dev, &dev_attr_trim);
 489         device_remove_file(dev, &dev_attr_osc);
 490 }
 491
 492 #else
 493 static int rs5c_sysfs_register(struct device *dev)
 494 {
 495         return 0;
 496 }
 497
 498 static void rs5c_sysfs_unregister(struct device *dev)
 499 {
 500         /* nothing */
 501 }
 502 #endif  /* SYSFS */
 503
 504 static struct i2c_driver rs5c372_driver;
 505
 506 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
 507 {
 508         unsigned char buf[2];
 509         int addr, i, ret = 0;
 510
 511         if (rs5c372->type == rtc_r2025sd) {
 512                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
 513                         return ret;
 514                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
 515         } else {
 516                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
 517                         return ret;
 518                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 519         }
 520
 521         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
 522         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
 523         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
 524
 525         /* use 24hr mode */
 526         switch (rs5c372->type) {
 527         case rtc_rs5c372a:
 528         case rtc_rs5c372b:
 529                 buf[1] |= RS5C372_CTRL2_24;
 530                 rs5c372->time24 = 1;
 531                 break;
 532         case rtc_r2025sd:
 533         case rtc_r2221tl:
 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         rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
 585                                 GFP_KERNEL);
 586         if (!rs5c372) {
 587                 err = -ENOMEM;
 588                 goto exit;
 589         }
 590
 591         rs5c372->client = client;
 592         i2c_set_clientdata(client, rs5c372);
 593         rs5c372->type = id->driver_data;
 594
 595         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 596         rs5c372->regs = &rs5c372->buf[1];
 597         rs5c372->smbus = smbus_mode;
 598
 599         err = rs5c_get_regs(rs5c372);
 600         if (err < 0)
 601                 goto exit;
 602
 603         /* clock may be set for am/pm or 24 hr time */
 604         switch (rs5c372->type) {
 605         case rtc_rs5c372a:
 606         case rtc_rs5c372b:
 607                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 608                  * so does periodic irq, except some 327a modes.
 609                  */
 610                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 611                         rs5c372->time24 = 1;
 612                 break;
 613         case rtc_r2025sd:
 614         case rtc_r2221tl:
 615         case rtc_rv5c386:
 616         case rtc_rv5c387a:
 617                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 618                         rs5c372->time24 = 1;
 619                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 620                  * irq, on both 386 and 387
 621                  */
 622                 break;
 623         default:
 624                 dev_err(&client->dev, "unknown RTC type\n");
 625                 goto exit;
 626         }
 627
 628         /* if the oscillator lost power and no other software (like
 629          * the bootloader) set it up, do it here.
 630          *
 631          * The R2025S/D does this a little differently than the other
 632          * parts, so we special case that..
 633          */
 634         err = rs5c_oscillator_setup(rs5c372);
 635         if (unlikely(err < 0)) {
 636                 dev_err(&client->dev, "setup error\n");
 637                 goto exit;
 638         }
 639
 640         if (rs5c372_get_datetime(client, &tm) < 0)
 641                 dev_warn(&client->dev, "clock needs to be set\n");
 642
 643         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 644                         ({ char *s; switch (rs5c372->type) {
 645                         case rtc_r2025sd:       s = "r2025sd"; break;
 646                         case rtc_r2221tl:       s = "r2221tl"; break;
 647                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 648                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 649                         case rtc_rv5c386:       s = "rv5c386"; break;
 650                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 651                         default:                s = "chip"; break;
 652                         }; s;}),
 653                         rs5c372->time24 ? "24hr" : "am/pm"
 654                         );
 655
 656         /* REVISIT use client->irq to register alarm irq ... */
 657         rs5c372->rtc = devm_rtc_device_register(&client->dev,
 658                                         rs5c372_driver.driver.name,
 659                                         &rs5c372_rtc_ops, THIS_MODULE);
 660
 661         if (IS_ERR(rs5c372->rtc)) {
 662                 err = PTR_ERR(rs5c372->rtc);
 663                 goto exit;
 664         }
 665
 666         err = rs5c_sysfs_register(&client->dev);
 667         if (err)
 668                 goto exit;
 669
 670         return 0;
 671
 672 exit:
 673         return err;
 674 }
 675
 676 static int rs5c372_remove(struct i2c_client *client)
 677 {
 678         rs5c_sysfs_unregister(&client->dev);
 679         return 0;
 680 }
 681
 682 static struct i2c_driver rs5c372_driver = {
 683         .driver         = {
 684                 .name   = "rtc-rs5c372",
 685         },
 686         .probe          = rs5c372_probe,
 687         .remove         = rs5c372_remove,
 688         .id_table       = rs5c372_id,
 689 };
 690
 691 module_i2c_driver(rs5c372_driver);
 692
 693 MODULE_AUTHOR(
 694                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 695                 "Alessandro Zummo <a.zummo@towertech.it>, "
 696                 "Paul Mundt <lethal@linux-sh.org>");
 697 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 698 MODULE_LICENSE("GPL");
 699 MODULE_VERSION(DRV_VERSION);