linux/drivers/rtc/rtc-rs5c372.c
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   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
  68enum 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
  78static 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};
  87MODULE_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 */
  94struct 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
 105static 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
 155static 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
 170static 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
 184static 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
 215static 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
 253static 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
 282static 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
 287static 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
 293static 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
 334static 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
 362static 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
 418static 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
 436static 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
 447static 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}
 458static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
 459
 460static 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}
 471static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
 472
 473static 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
 487static 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
 494static int rs5c_sysfs_register(struct device *dev)
 495{
 496        return 0;
 497}
 498
 499static void rs5c_sysfs_unregister(struct device *dev)
 500{
 501        /* nothing */
 502}
 503#endif  /* SYSFS */
 504
 505static struct i2c_driver rs5c372_driver;
 506
 507static 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
 558static 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
 673exit:
 674        return err;
 675}
 676
 677static int rs5c372_remove(struct i2c_client *client)
 678{
 679        rs5c_sysfs_unregister(&client->dev);
 680        return 0;
 681}
 682
 683static 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
 692module_i2c_driver(rs5c372_driver);
 693
 694MODULE_AUTHOR(
 695                "Pavel Mironchik <pmironchik@optifacio.net>, "
 696                "Alessandro Zummo <a.zummo@towertech.it>, "
 697                "Paul Mundt <lethal@linux-sh.org>");
 698MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
 699MODULE_LICENSE("GPL");
 700MODULE_VERSION(DRV_VERSION);
 701