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[7];
 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         default:
 303                 return -ENOIOCTLCMD;
 304         }
 305
 306         status = rs5c_get_regs(rs5c);
 307         if (status < 0)
 308                 return status;
 309
 310         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 311         switch (cmd) {
 312         case RTC_UIE_OFF:       /* update off */
 313                 buf &= ~RS5C_CTRL1_CT_MASK;
 314                 break;
 315         case RTC_UIE_ON:        /* update on */
 316                 buf &= ~RS5C_CTRL1_CT_MASK;
 317                 buf |= RS5C_CTRL1_CT4;
 318                 break;
 319         }
 320
 321         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 322                 printk(KERN_WARNING "%s: can't update alarm\n",
 323                         rs5c->rtc->name);
 324                 status = -EIO;
 325         } else
 326                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 327
 328         return status;
 329 }
 330
 331 #else
 332 #define rs5c_rtc_ioctl  NULL
 333 #endif
 334
 335
 336 static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 337 {
 338         struct i2c_client       *client = to_i2c_client(dev);
 339         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 340         unsigned char           buf;
 341         int                     status, addr;
 342
 343         buf = rs5c->regs[RS5C_REG_CTRL1];
 344
 345         if (!rs5c->has_irq)
 346                 return -EINVAL;
 347
 348         status = rs5c_get_regs(rs5c);
 349         if (status < 0)
 350                 return status;
 351
 352         addr = RS5C_ADDR(RS5C_REG_CTRL1);
 353         if (enabled)
 354                 buf |= RS5C_CTRL1_AALE;
 355         else
 356                 buf &= ~RS5C_CTRL1_AALE;
 357
 358         if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
 359                 printk(KERN_WARNING "%s: can't update alarm\n",
 360                         rs5c->rtc->name);
 361                 status = -EIO;
 362         } else
 363                 rs5c->regs[RS5C_REG_CTRL1] = buf;
 364
 365         return status;
 366 }
 367
 368
 369 /* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
 370  * which only exposes a polled programming interface; and since
 371  * these calls map directly to those EFI requests; we don't demand
 372  * we have an IRQ for this chip when we go through this API.
 373  *
 374  * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
 375  * though, managed through RTC_AIE_{ON,OFF} requests.
 376  */
 377
 378 static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 379 {
 380         struct i2c_client       *client = to_i2c_client(dev);
 381         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 382         int                     status;
 383
 384         status = rs5c_get_regs(rs5c);
 385         if (status < 0)
 386                 return status;
 387
 388         /* report alarm time */
 389         t->time.tm_sec = 0;
 390         t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
 391         t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 392         t->time.tm_mday = -1;
 393         t->time.tm_mon = -1;
 394         t->time.tm_year = -1;
 395         t->time.tm_wday = -1;
 396         t->time.tm_yday = -1;
 397         t->time.tm_isdst = -1;
 398
 399         /* ... and status */
 400         t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
 401         t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
 402
 403         return 0;
 404 }
 405
 406 static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 407 {
 408         struct i2c_client       *client = to_i2c_client(dev);
 409         struct rs5c372          *rs5c = i2c_get_clientdata(client);
 410         int                     status, addr, i;
 411         unsigned char           buf[3];
 412
 413         /* only handle up to 24 hours in the future, like RTC_ALM_SET */
 414         if (t->time.tm_mday != -1
 415                         || t->time.tm_mon != -1
 416                         || t->time.tm_year != -1)
 417                 return -EINVAL;
 418
 419         /* REVISIT: round up tm_sec */
 420
 421         /* if needed, disable irq (clears pending status) */
 422         status = rs5c_get_regs(rs5c);
 423         if (status < 0)
 424                 return status;
 425         if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
 426                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 427                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
 428                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
 429                         pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
 430                         return -EIO;
 431                 }
 432                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 433         }
 434
 435         /* set alarm */
 436         buf[0] = bin2bcd(t->time.tm_min);
 437         buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
 438         buf[2] = 0x7f;  /* any/all days */
 439
 440         for (i = 0; i < sizeof(buf); i++) {
 441                 addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
 442                 if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
 443                         pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
 444                         return -EIO;
 445                 }
 446         }
 447
 448         /* ... and maybe enable its irq */
 449         if (t->enabled) {
 450                 addr = RS5C_ADDR(RS5C_REG_CTRL1);
 451                 buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
 452                 if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
 453                         printk(KERN_WARNING "%s: can't enable alarm\n",
 454                                 rs5c->rtc->name);
 455                 rs5c->regs[RS5C_REG_CTRL1] = buf[0];
 456         }
 457
 458         return 0;
 459 }
 460
 461 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
 462
 463 static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 464 {
 465         int err, osc, trim;
 466
 467         err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
 468         if (err == 0) {
 469                 seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
 470                                 osc / 1000, osc % 1000);
 471                 seq_printf(seq, "trim\t\t: %d\n", trim);
 472         }
 473
 474         return 0;
 475 }
 476
 477 #else
 478 #define rs5c372_rtc_proc        NULL
 479 #endif
 480
 481 static const struct rtc_class_ops rs5c372_rtc_ops = {
 482         .proc           = rs5c372_rtc_proc,
 483         .ioctl          = rs5c_rtc_ioctl,
 484         .read_time      = rs5c372_rtc_read_time,
 485         .set_time       = rs5c372_rtc_set_time,
 486         .read_alarm     = rs5c_read_alarm,
 487         .set_alarm      = rs5c_set_alarm,
 488         .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
 489 };
 490
 491 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
 492
 493 static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
 494                                 struct device_attribute *attr, char *buf)
 495 {
 496         int err, trim;
 497
 498         err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
 499         if (err)
 500                 return err;
 501
 502         return sprintf(buf, "%d\n", trim);
 503 }
 504 static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 505
 506 static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
 507                                 struct device_attribute *attr, char *buf)
 508 {
 509         int err, osc;
 510
 511         err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
 512         if (err)
 513                 return err;
 514
 515         return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
 516 }
 517 static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 518
 519 static int rs5c_sysfs_register(struct device *dev)
 520 {
 521         int err;
 522
 523         err = device_create_file(dev, &dev_attr_trim);
 524         if (err)
 525                 return err;
 526         err = device_create_file(dev, &dev_attr_osc);
 527         if (err)
 528                 device_remove_file(dev, &dev_attr_trim);
 529
 530         return err;
 531 }
 532
 533 static void rs5c_sysfs_unregister(struct device *dev)
 534 {
 535         device_remove_file(dev, &dev_attr_trim);
 536         device_remove_file(dev, &dev_attr_osc);
 537 }
 538
 539 #else
 540 static int rs5c_sysfs_register(struct device *dev)
 541 {
 542         return 0;
 543 }
 544
 545 static void rs5c_sysfs_unregister(struct device *dev)
 546 {
 547         /* nothing */
 548 }
 549 #endif  /* SYSFS */
 550
 551 static struct i2c_driver rs5c372_driver;
 552
 553 static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
 554 {
 555         unsigned char buf[2];
 556         int addr, i, ret = 0;
 557
 558         if (rs5c372->type == rtc_r2025sd) {
 559                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
 560                         return ret;
 561                 rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
 562         } else {
 563                 if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
 564                         return ret;
 565                 rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
 566         }
 567
 568         addr   = RS5C_ADDR(RS5C_REG_CTRL1);
 569         buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
 570         buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
 571
 572         /* use 24hr mode */
 573         switch (rs5c372->type) {
 574         case rtc_rs5c372a:
 575         case rtc_rs5c372b:
 576                 buf[1] |= RS5C372_CTRL2_24;
 577                 rs5c372->time24 = 1;
 578                 break;
 579         case rtc_r2025sd:
 580         case rtc_rv5c386:
 581         case rtc_rv5c387a:
 582                 buf[0] |= RV5C387_CTRL1_24;
 583                 rs5c372->time24 = 1;
 584                 break;
 585         default:
 586                 /* impossible */
 587                 break;
 588         }
 589
 590         for (i = 0; i < sizeof(buf); i++) {
 591                 addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
 592                 ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
 593                 if (unlikely(ret < 0))
 594                         return ret;
 595         }
 596
 597         rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
 598         rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
 599
 600         return 0;
 601 }
 602
 603 static int rs5c372_probe(struct i2c_client *client,
 604                          const struct i2c_device_id *id)
 605 {
 606         int err = 0;
 607         int smbus_mode = 0;
 608         struct rs5c372 *rs5c372;
 609         struct rtc_time tm;
 610
 611         dev_dbg(&client->dev, "%s\n", __func__);
 612
 613         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 614                         I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 615                 /*
 616                  * If we don't have any master mode adapter, try breaking
 617                  * it down in to the barest of capabilities.
 618                  */
 619                 if (i2c_check_functionality(client->adapter,
 620                                 I2C_FUNC_SMBUS_BYTE_DATA |
 621                                 I2C_FUNC_SMBUS_I2C_BLOCK))
 622                         smbus_mode = 1;
 623                 else {
 624                         /* Still no good, give up */
 625                         err = -ENODEV;
 626                         goto exit;
 627                 }
 628         }
 629
 630         if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 631                 err = -ENOMEM;
 632                 goto exit;
 633         }
 634
 635         rs5c372->client = client;
 636         i2c_set_clientdata(client, rs5c372);
 637         rs5c372->type = id->driver_data;
 638
 639         /* we read registers 0x0f then 0x00-0x0f; skip the first one */
 640         rs5c372->regs = &rs5c372->buf[1];
 641         rs5c372->smbus = smbus_mode;
 642
 643         err = rs5c_get_regs(rs5c372);
 644         if (err < 0)
 645                 goto exit_kfree;
 646
 647         /* clock may be set for am/pm or 24 hr time */
 648         switch (rs5c372->type) {
 649         case rtc_rs5c372a:
 650         case rtc_rs5c372b:
 651                 /* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
 652                  * so does periodic irq, except some 327a modes.
 653                  */
 654                 if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
 655                         rs5c372->time24 = 1;
 656                 break;
 657         case rtc_r2025sd:
 658         case rtc_rv5c386:
 659         case rtc_rv5c387a:
 660                 if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
 661                         rs5c372->time24 = 1;
 662                 /* alarm uses ALARM_W; and nINTRB for alarm and periodic
 663                  * irq, on both 386 and 387
 664                  */
 665                 break;
 666         default:
 667                 dev_err(&client->dev, "unknown RTC type\n");
 668                 goto exit_kfree;
 669         }
 670
 671         /* if the oscillator lost power and no other software (like
 672          * the bootloader) set it up, do it here.
 673          *
 674          * The R2025S/D does this a little differently than the other
 675          * parts, so we special case that..
 676          */
 677         err = rs5c_oscillator_setup(rs5c372);
 678         if (unlikely(err < 0)) {
 679                 dev_err(&client->dev, "setup error\n");
 680                 goto exit_kfree;
 681         }
 682
 683         if (rs5c372_get_datetime(client, &tm) < 0)
 684                 dev_warn(&client->dev, "clock needs to be set\n");
 685
 686         dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
 687                         ({ char *s; switch (rs5c372->type) {
 688                         case rtc_r2025sd:       s = "r2025sd"; break;
 689                         case rtc_rs5c372a:      s = "rs5c372a"; break;
 690                         case rtc_rs5c372b:      s = "rs5c372b"; break;
 691                         case rtc_rv5c386:       s = "rv5c386"; break;
 692                         case rtc_rv5c387a:      s = "rv5c387a"; break;
 693                         default:                s = "chip"; break;
 694                         }; s;}),
 695                         rs5c372->time24 ? "24hr" : "am/pm"
 696                         );
 697
 698         /* REVISIT use client->irq to register alarm irq ... */
 699
 700         rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
 701                                 &client->dev, &rs5c372_rtc_ops, THIS_MODULE);
 702
 703         if (IS_ERR(rs5c372->rtc)) {
 704                 err = PTR_ERR(rs5c372->rtc);
 705                 goto exit_kfree;
 706         }
 707
 708         err = rs5c_sysfs_register(&client->dev);
 709         if (err)
 710                 goto exit_devreg;
 711
 712         return 0;
 713
 714 exit_devreg:
 715         rtc_device_unregister(rs5c372->rtc);
 716
 717 exit_kfree:
 718         kfree(rs5c372);
 719
 720 exit:
 721         return err;
 722 }
 723
 724 static int rs5c372_remove(struct i2c_client *client)
 725 {
 726         struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
 727
 728         rtc_device_unregister(rs5c372->rtc);
 729         rs5c_sysfs_unregister(&client->dev);
 730         kfree(rs5c372);
 731         return 0;
 732 }
 733
 734 static struct i2c_driver rs5c372_driver = {
 735         .driver         = {
 736                 .name   = "rtc-rs5c372",
 737         },
 738         .probe          = rs5c372_probe,
 739         .remove         = rs5c372_remove,
 740         .id_table       = rs5c372_id,
 741 };
 742
 743 static __init int rs5c372_init(void)
 744 {
 745         return i2c_add_driver(&rs5c372_driver);
 746 }
 747
 748 static __exit void rs5c372_exit(void)
 749 {
 750         i2c_del_driver(&rs5c372_driver);
 751 }
 752
 753 module_init(rs5c372_init);
 754 module_exit(rs5c372_exit);
 755
 756 MODULE_AUTHOR(
 757                 "Pavel Mironchik <pmironchik@optifacio.net>, "
 758                 "Alessandro Zummo <a.zummo@towertech.it>, "
 759                 "Paul Mundt <lethal@linux-sh.org>");
 760 MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 761 MODULE_LICENSE("GPL");
 762 MODULE_VERSION(DRV_VERSION);