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
  18 #define DRV_VERSION "0.6"
  19
  20
  21 /*
  22  * Ricoh has a family of I2C based RTCs, which differ only slightly from
  23  * each other.  Differences center on pinout (e.g. how many interrupts,
  24  * output clock, etc) and how the control registers are used.  The '372
  25  * is significant only because that's the one this driver first supported.
  26  */
  27 #define RS5C372_REG_SECS        0
  28 #define RS5C372_REG_MINS        1
  29 #define RS5C372_REG_HOURS       2
  30 #define RS5C372_REG_WDAY        3
  31 #define RS5C372_REG_DAY         4
  32 #define RS5C372_REG_MONTH       5
  33 #define RS5C372_REG_YEAR        6
  34 #define RS5C372_REG_TRIM        7
  35 #       define RS5C372_TRIM_XSL         0x80
  36 #       define RS5C372_TRIM_MASK        0x7F
  37
  38 #define RS5C_REG_ALARM_A_MIN    8                       /* or ALARM_W */
  39 #define RS5C_REG_ALARM_A_HOURS  9
  40 #define RS5C_REG_ALARM_A_WDAY   10
  41
  42 #define RS5C_REG_ALARM_B_MIN    11                      /* or ALARM_D */
  43 #define RS5C_REG_ALARM_B_HOURS  12
  44 #define RS5C_REG_ALARM_B_WDAY   13                      /* (ALARM_B only) */
  45
  46 #define RS5C_REG_CTRL1          14
  47 #       define RS5C_CTRL1_AALE          (1 << 7)        /* or WALE */
  48 #       define RS5C_CTRL1_BALE          (1 << 6)        /* or DALE */
  49 #       define RV5C387_CTRL1_24         (1 << 5)
  50 #       define RS5C372A_CTRL1_SL1       (1 << 5)
  51 #       define RS5C_CTRL1_CT_MASK       (7 << 0)
  52 #       define RS5C_CTRL1_CT0           (0 << 0)        /* no periodic irq */
  53 #       define RS5C_CTRL1_CT4           (4 << 0)        /* 1 Hz level irq */
  54 #define RS5C_REG_CTRL2          15
  55 #       define RS5C372_CTRL2_24         (1 << 5)
  56 #       define R2025_CTRL2_XST          (1 << 5)
  57 #       define RS5C_CTRL2_XSTP          (1 << 4)        /* only if !R2025S/D */
  58 #       define RS5C_CTRL2_CTFG          (1 << 2)
  59 #       define RS5C_CTRL2_AAFG          (1 << 1)        /* or WAFG */
  60 #       define RS5C_CTRL2_BAFG          (1 << 0)        /* or DAFG */
  61
  62
  63 /* to read (style 1) or write registers starting at R */
  64 #define RS5C_ADDR(R)            (((R) << 4) | 0)
  65
  66
  67 enum rtc_type {
  68         rtc_undef = 0,
  69         rtc_r2025sd,
  70         rtc_rs5c372a,
  71         rtc_rs5c372b,
  72         rtc_rv5c386,
  73         rtc_rv5c387a,
  74 };
  75
  76 static const struct i2c_device_id rs5c372_id[] = {
  77         { "r2025sd", rtc_r2025sd },
  78         { "rs5c372a", rtc_rs5c372a },
  79         { "rs5c372b", rtc_rs5c372b },
  80         { "rv5c386", rtc_rv5c386 },
  81         { "rv5c387a", rtc_rv5c387a },
  82         { }
  83 };
  84 MODULE_DEVICE_TABLE(i2c, rs5c372_id);
  85
  86 /* REVISIT:  this assumes that:
  87  *  - we're in the 21st century, so it's safe to ignore the century
  88  *    bit for rv5c38[67] (REG_MONTH bit 7);
  89  *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
  90  */
  91 struct rs5c372 {
  92         struct i2c_client       *client;
  93         struct rtc_device       *rtc;
  94         enum rtc_type           type;
  95         unsigned                time24:1;
  96         unsigned                has_irq:1;
  97         unsigned                smbus:1;
  98         char                    buf[17];
  99         char                    *regs;
 100 };
 101
 102 static int rs5c_get_regs(struct rs5c372 *rs5c)
 103 {
 104         struct i2c_client       *client = rs5c->client;
 105         struct i2c_msg          msgs[] = {
 106                 { client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
 107         };
 108
 109         /* This implements the third reading method from the datasheet, using
 110          * an internal address that's reset after each transaction (by STOP)
 111          * to 0x0f ... so we read extra registers, and skip the first one.
 112          *
 113          * The first method doesn't work with the iop3xx adapter driver, on at
 114          * least 80219 chips; this works around that bug.
 115          *
 116          * The third method on the other hand doesn't work for the SMBus-only
 117          * configurations, so we use the the first method there, stripping off
 118          * the extra register in the process.
 119          */
 120         if (rs5c->smbus) {
 121                 int addr = RS5C_ADDR(RS5C372_REG_SECS);
 122                 int size = sizeof(rs5c->buf) - 1;
 123
 124                 if (i2c_smbus_read_i2c_block_data(client, addr, size,
 125                                                   rs5c->buf + 1) != size) {
 126                         dev_warn(&client->dev, "can't read registers\n");
 127                         return -EIO;
 128                 }
 129         } else {
 130                 if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
 131                         dev_warn(&client->dev, "can't read registers\n");
 132                         return -EIO;
 133                 }
 134         }
 135
 136         dev_dbg(&client->dev,
 137                 "%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
 138                 "%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
 139                 rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
 140                 rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
 141                 rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
 142                 rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
 143
 144         return 0;
 145 }
 146
 147 static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
 148 {
 149         unsigned        hour;
 150
 151         if (rs5c->time24)
 152                 return bcd2bin(reg & 0x3f);
 153
 154         hour = bcd2bin(reg & 0x1f);
 155         if (hour == 12)
 156                 hour = 0;
 157         if (reg & 0x20)
 158                 hour += 12;
 159         return hour;
 160 }
 161
 162 static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
 163 {
 164         if (rs5c->time24)
 165                 return bin2bcd(hour);
 166
 167         if (hour > 12)
 168                 return 0x20 | bin2bcd(hour - 12);
 169         if (hour == 12)
 170                 return 0x20 | bin2bcd(12);
 171         if (hour == 0)
 172                 return bin2bcd(12);
 173         return bin2bcd(hour);
 174 }
 175
 176 static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 177 {
 178         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 179         int             status = rs5c_get_regs(rs5c);
 180
 181         if (status < 0)
 182                 return status;
 183
 184         tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
 185         tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
 186         tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
 187
 188         tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
 189         tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
 190
 191         /* tm->tm_mon is zero-based */
 192         tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
 193
 194         /* year is 1900 + tm->tm_year */
 195         tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
 196
 197         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 198                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 199                 __func__,
 200                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 201                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 202
 203         /* rtc might need initialization */
 204         return rtc_valid_tm(tm);
 205 }
 206
 207 static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 208 {
 209         struct rs5c372  *rs5c = i2c_get_clientdata(client);
 210         unsigned char   buf[8];
 211         int             addr;
 212
 213         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
 214                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 215                 __func__,
 216                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 217                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 218
 219         addr   = RS5C_ADDR(RS5C372_REG_SECS);
 220         buf[0] = bin2bcd(tm->tm_sec);
 221         buf[1] = bin2bcd(tm->tm_min);
 222         buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
 223         buf[3] = bin2bcd(tm->tm_wday);
 224         buf[4] = bin2bcd(tm->tm_mday);
 225         buf[5] = bin2bcd(tm->tm_mon + 1);
 226         buf[6] = bin2bcd(tm->tm_year - 100);
 227
 228         if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
 229                 dev_err(&client->dev, "%s: write error\n", __func__);
 230                 return -EIO;
 231         }
 232
 233         return 0;
 234 }
 235
 236 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 237 #define NEED_TRIM
 238 #endif
 239
 240 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 241 #define NEED_TRIM
 242 #endif
 243
 244 #ifdef  NEED_TRIM
 245 static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
 246 {
 247         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 248         u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
 249
 250         if (osc)
 251                 *osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
 252
 253         if (trim) {
 254                 dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
 255                 tmp &= RS5C372_TRIM_MASK;
 256                 if (tmp & 0x3e) {
 257                         int t = tmp & 0x3f;
 258
 259                         if (tmp & 0x40)
 260                                 t = (~t | (s8)0xc0) + 1;
 261                         else
 262                                 t = t - 1;
 263
 264                         tmp = t * 2;
 265                 } else
 266                         tmp = 0;
 267                 *trim = tmp;
 268         }
 269
 270         return 0;
 271 }
 272 #endif
 273
 274 static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
 275 {
 276         return rs5c372_get_datetime(to_i2c_client(dev), tm);
 277 }
 278
 279 static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
 280 {
 281         return rs5c372_set_datetime(to_i2c_client(dev), tm);
 282 }
 283
 284 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
 285
 286 static int
 287 rs5c_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 288 {
 289         struct i2c_client       *client = to_i2c_client(dev);
 290         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 291         unsigned char           buf;
 292         int                     status, addr;
 293
 294         buf = rs5c->regs[RS5C_REG_CTRL1];
 295         switch (cmd) {
 296         case RTC_UIE_OFF:
 297         case RTC_UIE_ON:
 298                 /* some 327a modes use a different IRQ pin for 1Hz irqs */
 299                 if (rs5c->type == rtc_rs5c372a
 300                                 && (buf & RS5C372A_CTRL1_SL1))
 301                         return -ENOIOCTLCMD;
 302         case RTC_AIE_OFF:
 303         case RTC_AIE_ON:
 304                 /* these irq management calls only make sense for chips
 305                  * which are wired up to an IRQ.
 306                  */
 307                 if (!rs5c->has_irq)
 308                         return -ENOIOCTLCMD;
 309                 break;
 310         default:
 311                 return -ENOIOCTLCMD;
 312         }
 313
 314         status = rs5c_get_regs(rs5c);
 315         if (status < 0)
 316                 return status;
 317
 318         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 319         switch (cmd) {
 320         case RTC_AIE_OFF:       /* alarm off */
 321                 buf &= ~RS5C_CTRL1_AALE;
 322                 break;
 323         case RTC_AIE_ON:        /* alarm on */
 324                 buf |= RS5C_CTRL1_AALE;
 325                 break;
 326         case RTC_UIE_OFF:       /* update off */
 327                 buf &= ~RS5C_CTRL1_CT_MASK;
 328                 break;
 329         case RTC_UIE_ON:        /* update on */
 330                 buf &= ~RS5C_CTRL1_CT_MASK;
 331                 buf |= RS5C_CTRL1_CT4;
 332                 break;
 333         }
 334
 335         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 336                 printk(KERN_WARNING "%s: can't update alarm\n",
 337                         rs5c->rtc->name);
 338                 status = -EIO;
 339         } else
 340                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 341
 342         return status;
 343 }
 344
 345 #else
 346 #define rs5c_rtc_ioctl  NULL
 347 #endif
 348
 349
 350 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 351  * which only exposes a polled programming interface; and since
 352  * these calls map directly to those EFI requests; we don't demand
 353  * we have an IRQ for this chip when we go through this API.
 354  *
 355  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 356  * though, managed through RTC_AIE_{ON,OFF} requests.
 357  */
 358
 359 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 360 {
 361         struct i2c_client       *client = to_i2c_client(dev);
 362         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 363         int                     status;
 364
 365         status = rs5c_get_regs(rs5c);
 366         if (status < 0)
 367                 return status;
 368
 369         /* report alarm time */
 370         t->time.tm_sec = 0;
 371         t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 372         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 373         t->time.tm_mday = -1;
 374         t->time.tm_mon = -1;
 375         t->time.tm_year = -1;
 376         t->time.tm_wday = -1;
 377         t->time.tm_yday = -1;
 378         t->time.tm_isdst = -1;
 379
 380         /* ... and status */
 381         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 382         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 383
 384         return 0;
 385 }
 386
 387 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 388 {
 389         struct i2c_client       *client = to_i2c_client(dev);
 390         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 391         int                     status, addr, i;
 392         unsigned char           buf[3];
 393
 394         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 395         if (t->time.tm_mday != -1
 396                         || t->time.tm_mon != -1
 397                         || t->time.tm_year != -1)
 398                 return -EINVAL;
 399
 400         /* REVISIT: round up tm_sec */
 401
 402         /* if needed, disable irq (clears pending status) */
 403         status = rs5c_get_regs(rs5c);
 404         if (status < 0)
 405                 return status;
 406         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 407                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 408                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 409                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
 410                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
 411                         return -EIO;
 412                 }
 413                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 414         }
 415
 416         /* set alarm */
 417         buf[0] = bin2bcd(t->time.tm_min);
 418         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 419         buf[2] = 0x7f;  /* any/all days */
 420
 421         for (i = 0; i < sizeof(buf); i++) {
 422                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
 423                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
 424                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
 425                         return -EIO;
 426                 }
 427         }
 428
 429         /* ... and maybe enable its irq */
 430         if (t->enabled) {
 431                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 432                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
 433                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
 434                         printk(KERN_WARNING "%s: can't enable alarm\n",
 435                                 rs5c->rtc->name);
 436                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 437         }
 438
 439         return 0;
 440 }
 441
 442 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 443
 444 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 445 {
 446         int err, osc, trim;
 447
 448         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 449         if (err == 0) {
 450                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 451                                 osc / 1000, osc % 1000);
 452                 seq_printf(seq, "trim\t\t: %d\n", trim);
 453         }
 454
 455         return 0;
 456 }
 457
 458 #else
 459 #define rs5c372_rtc_proc        NULL
 460 #endif
 461
 462 static const struct rtc_class_ops rs5c372_rtc_ops = {
 463         .proc           = rs5c372_rtc_proc,
 464         .ioctl          = rs5c_rtc_ioctl,
 465         .read_time      = rs5c372_rtc_read_time,
 466         .set_time       = rs5c372_rtc_set_time,
 467         .read_alarm     = rs5c_read_alarm,
 468         .set_alarm      = rs5c_set_alarm,
 469 };
 470
 471 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 472
 473 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 474                                 struct device_attribute *attr, char *buf)
 475 {
 476         int err, trim;
 477
 478         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 479         if (err)
 480                 return err;
 481
 482         return sprintf(buf, "%d\n", trim);
 483 }
 484 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 485
 486 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 487                                 struct device_attribute *attr, char *buf)
 488 {
 489         int err, osc;
 490
 491         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 492         if (err)
 493                 return err;
 494
 495         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 496 }
 497 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 498
 499 static int rs5c_sysfs_register(struct device *dev)
 500 {
 501         int err;
 502
 503         err = device_create_file(dev, &dev_attr_trim);
 504         if (err)
 505                 return err;
 506         err = device_create_file(dev, &dev_attr_osc);
 507         if (err)
 508                 device_remove_file(dev, &dev_attr_trim);
 509
 510         return err;
 511 }
 512
 513 static void rs5c_sysfs_unregister(struct device *dev)
 514 {
 515         device_remove_file(dev, &dev_attr_trim);
 516         device_remove_file(dev, &dev_attr_osc);
 517 }
 518
 519 #else
 520 static int rs5c_sysfs_register(struct device *dev)
 521 {
 522         return 0;
 523 }
 524
 525 static void rs5c_sysfs_unregister(struct device *dev)
 526 {
 527         /* nothing */
 528 }
 529 #endif  /* SYSFS */
 530
 531 static struct i2c_driver rs5c372_driver;
 532
 533 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
 534 {
 535         unsigned char buf[2];
 536         int addr, i, ret = 0;
 537
 538         if (rs5c372->type == rtc_r2025sd) {
 539                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
 540                         return ret;
 541                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
 542         } else {
 543                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
 544                         return ret;
 545                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 546         }
 547
 548         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
 549         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
 550         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
 551
 552         /* use 24hr mode */
 553         switch (rs5c372->type) {
 554         case rtc_rs5c372a:
 555         case rtc_rs5c372b:
 556                 buf[1] |= RS5C372_CTRL2_24;
 557                 rs5c372->time24 = 1;
 558                 break;
 559         case rtc_r2025sd:
 560         case rtc_rv5c386:
 561         case rtc_rv5c387a:
 562                 buf[0] |= RV5C387_CTRL1_24;
 563                 rs5c372->time24 = 1;
 564                 break;
 565         default:
 566                 /* impossible */
 567                 break;
 568         }
 569
 570         for (i = 0; i < sizeof(buf); i++) {
 571                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
 572                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
 573                 if (unlikely(ret < 0))
 574                         return ret;
 575         }
 576
 577         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
 578         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
 579
 580         return 0;
 581 }
 582
 583 static int rs5c372_probe(struct i2c_client *client,
 584                          const struct i2c_device_id *id)
 585 {
 586         int err = 0;
 587         int smbus_mode = 0;
 588         struct rs5c372 *rs5c372;
 589         struct rtc_time tm;
 590
 591         dev_dbg(&client->dev, "%s\n", __func__);
 592
 593         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 594                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 595                 /*
 596                  * If we don't have any master mode adapter, try breaking
 597                  * it down in to the barest of capabilities.
 598                  */
 599                 if (i2c_check_functionality(client->adapter,
 600                                 I2C_FUNC_SMBUS_BYTE_DATA |
 601                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 602                         smbus_mode = 1;
 603                 else {
 604                         /* Still no good, give up */
 605                         err = -ENODEV;
 606                         goto exit;
 607                 }
 608         }
 609
 610         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 611                 err = -ENOMEM;
 612                 goto exit;
 613         }
 614
 615         rs5c372->client = client;
 616         i2c_set_clientdata(client, rs5c372);
 617         rs5c372->type = id->driver_data;
 618
 619         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 620         rs5c372->regs = &rs5c372->buf[1];
 621         rs5c372->smbus = smbus_mode;
 622
 623         err = rs5c_get_regs(rs5c372);
 624         if (err < 0)
 625                 goto exit_kfree;
 626
 627         /* clock may be set for am/pm or 24 hr time */
 628         switch (rs5c372->type) {
 629         case rtc_rs5c372a:
 630         case rtc_rs5c372b:
 631                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 632                  * so does periodic irq, except some 327a modes.
 633                  */
 634                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 635                         rs5c372->time24 = 1;
 636                 break;
 637         case rtc_r2025sd:
 638         case rtc_rv5c386:
 639         case rtc_rv5c387a:
 640                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 641                         rs5c372->time24 = 1;
 642                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 643                  * irq, on both 386 and 387
 644                  */
 645                 break;
 646         default:
 647                 dev_err(&client->dev, "unknown RTC type\n");
 648                 goto exit_kfree;
 649         }
 650
 651         /* if the oscillator lost power and no other software (like
 652          * the bootloader) set it up, do it here.
 653          *
 654          * The R2025S/D does this a little differently than the other
 655          * parts, so we special case that..
 656          */
 657         err = rs5c_oscillator_setup(rs5c372);
 658         if (unlikely(err < 0)) {
 659                 dev_err(&client->dev, "setup error\n");
 660                 goto exit_kfree;
 661         }
 662
 663         if (rs5c372_get_datetime(client, &tm) < 0)
 664                 dev_warn(&client->dev, "clock needs to be set\n");
 665
 666         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 667                         ({ char *s; switch (rs5c372->type) {
 668                         case rtc_r2025sd:       s = "r2025sd"; break;
 669                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 670                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 671                         case rtc_rv5c386:       s = "rv5c386"; break;
 672                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 673                         default:                s = "chip"; break;
 674                         }; s;}),
 675                         rs5c372->time24 ? "24hr" : "am/pm"
 676                         );
 677
 678         /* REVISIT use client->irq to register alarm irq ... */
 679
 680         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
 681                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
 682
 683         if (IS_ERR(rs5c372->rtc)) {
 684                 err = PTR_ERR(rs5c372->rtc);
 685                 goto exit_kfree;
 686         }
 687
 688         err = rs5c_sysfs_register(&client->dev);
 689         if (err)
 690                 goto exit_devreg;
 691
 692         return 0;
 693
 694 exit_devreg:
 695         rtc_device_unregister(rs5c372->rtc);
 696
 697 exit_kfree:
 698         kfree(rs5c372);
 699
 700 exit:
 701         return err;
 702 }
 703
 704 static int rs5c372_remove(struct i2c_client *client)
 705 {
 706         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 707
 708         rtc_device_unregister(rs5c372->rtc);
 709         rs5c_sysfs_unregister(&client->dev);
 710         kfree(rs5c372);
 711         return 0;
 712 }
 713
 714 static struct i2c_driver rs5c372_driver = {
 715         .driver         = {
 716                 .name   = "rtc-rs5c372",
 717         },
 718         .probe          = rs5c372_probe,
 719         .remove         = rs5c372_remove,
 720         .id_table       = rs5c372_id,
 721 };
 722
 723 static __init int rs5c372_init(void)
 724 {
 725         return i2c_add_driver(&rs5c372_driver);
 726 }
 727
 728 static __exit void rs5c372_exit(void)
 729 {
 730         i2c_del_driver(&rs5c372_driver);
 731 }
 732
 733 module_init(rs5c372_init);
 734 module_exit(rs5c372_exit);
 735
 736 MODULE_AUTHOR(
 737                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 738                 "Alessandro Zummo <a.zummo@towertech.it>, "
 739                 "Paul Mundt <lethal@linux-sh.org>");
 740 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 741 MODULE_LICENSE("GPL");
 742 MODULE_VERSION(DRV_VERSION);