drivers/rtc/rtc-rx8025.c

   1 /*
   2  * Driver for Epson's RTC module RX-8025 SA/NB
   3  *
   4  * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
   5  *
   6  * Copyright (C) 2005 by Digi International Inc.
   7  * All rights reserved.
   8  *
   9  * Modified by fengjh at rising.com.cn
  10  * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
  11  * 2006.11
  12  *
  13  * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
  14  * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
  15  * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU General Public License
  19  * version 2 as published by the Free Software Foundation.
  20  */
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/slab.h>
  24 #include <linux/init.h>
  25 #include <linux/bcd.h>
  26 #include <linux/i2c.h>
  27 #include <linux/list.h>
  28 #include <linux/rtc.h>
  29
  30 /* Register definitions */
  31 #define RX8025_REG_SEC          0x00
  32 #define RX8025_REG_MIN          0x01
  33 #define RX8025_REG_HOUR         0x02
  34 #define RX8025_REG_WDAY         0x03
  35 #define RX8025_REG_MDAY         0x04
  36 #define RX8025_REG_MONTH        0x05
  37 #define RX8025_REG_YEAR         0x06
  38 #define RX8025_REG_DIGOFF       0x07
  39 #define RX8025_REG_ALWMIN       0x08
  40 #define RX8025_REG_ALWHOUR      0x09
  41 #define RX8025_REG_ALWWDAY      0x0a
  42 #define RX8025_REG_ALDMIN       0x0b
  43 #define RX8025_REG_ALDHOUR      0x0c
  44 /* 0x0d is reserved */
  45 #define RX8025_REG_CTRL1        0x0e
  46 #define RX8025_REG_CTRL2        0x0f
  47
  48 #define RX8025_BIT_CTRL1_CT     (7 << 0)
  49 /* 1 Hz periodic level irq */
  50 #define RX8025_BIT_CTRL1_CT_1HZ 4
  51 #define RX8025_BIT_CTRL1_TEST   (1 << 3)
  52 #define RX8025_BIT_CTRL1_1224   (1 << 5)
  53 #define RX8025_BIT_CTRL1_DALE   (1 << 6)
  54 #define RX8025_BIT_CTRL1_WALE   (1 << 7)
  55
  56 #define RX8025_BIT_CTRL2_DAFG   (1 << 0)
  57 #define RX8025_BIT_CTRL2_WAFG   (1 << 1)
  58 #define RX8025_BIT_CTRL2_CTFG   (1 << 2)
  59 #define RX8025_BIT_CTRL2_PON    (1 << 4)
  60 #define RX8025_BIT_CTRL2_XST    (1 << 5)
  61 #define RX8025_BIT_CTRL2_VDET   (1 << 6)
  62
  63 /* Clock precision adjustment */
  64 #define RX8025_ADJ_RESOLUTION   3050 /* in ppb */
  65 #define RX8025_ADJ_DATA_MAX     62
  66 #define RX8025_ADJ_DATA_MIN     -62
  67
  68 static const struct i2c_device_id rx8025_id[] = {
  69         { "rx8025", 0 },
  70         { }
  71 };
  72 MODULE_DEVICE_TABLE(i2c, rx8025_id);
  73
  74 struct rx8025_data {
  75         struct i2c_client *client;
  76         struct rtc_device *rtc;
  77         struct work_struct work;
  78         u8 ctrl1;
  79         unsigned exiting:1;
  80 };
  81
  82 static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
  83 {
  84         int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);
  85
  86         if (ret < 0) {
  87                 dev_err(&client->dev, "Unable to read register #%d\n", number);
  88                 return ret;
  89         }
  90
  91         *value = ret;
  92         return 0;
  93 }
  94
  95 static int rx8025_read_regs(struct i2c_client *client,
  96                             int number, u8 length, u8 *values)
  97 {
  98         int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,
  99                                                 length, values);
 100
 101         if (ret != length) {
 102                 dev_err(&client->dev, "Unable to read registers #%d..#%d\n",
 103                         number, number + length - 1);
 104                 return ret < 0 ? ret : -EIO;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
 111 {
 112         int ret = i2c_smbus_write_byte_data(client, number << 4, value);
 113
 114         if (ret)
 115                 dev_err(&client->dev, "Unable to write register #%d\n",
 116                         number);
 117
 118         return ret;
 119 }
 120
 121 static int rx8025_write_regs(struct i2c_client *client,
 122                              int number, u8 length, u8 *values)
 123 {
 124         int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,
 125                                                  length, values);
 126
 127         if (ret)
 128                 dev_err(&client->dev, "Unable to write registers #%d..#%d\n",
 129                         number, number + length - 1);
 130
 131         return ret;
 132 }
 133
 134 static irqreturn_t rx8025_irq(int irq, void *dev_id)
 135 {
 136         struct i2c_client *client = dev_id;
 137         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 138
 139         disable_irq_nosync(irq);
 140         schedule_work(&rx8025->work);
 141         return IRQ_HANDLED;
 142 }
 143
 144 static void rx8025_work(struct work_struct *work)
 145 {
 146         struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
 147                                                   work);
 148         struct i2c_client *client = rx8025->client;
 149         struct mutex *lock = &rx8025->rtc->ops_lock;
 150         u8 status;
 151
 152         mutex_lock(lock);
 153
 154         if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
 155                 goto out;
 156
 157         if (!(status & RX8025_BIT_CTRL2_XST))
 158                 dev_warn(&client->dev, "Oscillation stop was detected,"
 159                          "you may have to readjust the clock\n");
 160
 161         if (status & RX8025_BIT_CTRL2_CTFG) {
 162                 /* periodic */
 163                 status &= ~RX8025_BIT_CTRL2_CTFG;
 164                 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
 165         }
 166
 167         if (status & RX8025_BIT_CTRL2_DAFG) {
 168                 /* alarm */
 169                 status &= RX8025_BIT_CTRL2_DAFG;
 170                 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
 171                                      rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
 172                         goto out;
 173                 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
 174         }
 175
 176         /* acknowledge IRQ */
 177         rx8025_write_reg(client, RX8025_REG_CTRL2,
 178                          status | RX8025_BIT_CTRL2_XST);
 179
 180 out:
 181         if (!rx8025->exiting)
 182                 enable_irq(client->irq);
 183
 184         mutex_unlock(lock);
 185 }
 186
 187 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
 188 {
 189         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 190         u8 date[7];
 191         int err;
 192
 193         err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 194         if (err)
 195                 return err;
 196
 197         dev_dbg(dev, "%s: read 0x%02x 0x%02x "
 198                 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
 199                 date[0], date[1], date[2], date[3], date[4],
 200                 date[5], date[6]);
 201
 202         dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
 203         dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
 204         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 205                 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
 206         else
 207                 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
 208                         + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
 209
 210         dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
 211         dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
 212         dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
 213
 214         if (dt->tm_year < 70)
 215                 dt->tm_year += 100;
 216
 217         dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
 218                 dt->tm_sec, dt->tm_min, dt->tm_hour,
 219                 dt->tm_mday, dt->tm_mon, dt->tm_year);
 220
 221         return rtc_valid_tm(dt);
 222 }
 223
 224 static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
 225 {
 226         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 227         u8 date[7];
 228
 229         /*
 230          * BUG: The HW assumes every year that is a multiple of 4 to be a leap
 231          * year.  Next time this is wrong is 2100, which will not be a leap
 232          * year.
 233          */
 234
 235         /*
 236          * Here the read-only bits are written as "0".  I'm not sure if that
 237          * is sound.
 238          */
 239         date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
 240         date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
 241         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 242                 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
 243         else
 244                 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
 245                         | bin2bcd((dt->tm_hour + 11) % 12 + 1);
 246
 247         date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
 248         date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
 249         date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
 250         date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
 251
 252         dev_dbg(dev,
 253                 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
 254                 __func__,
 255                 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
 256
 257         return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 258 }
 259
 260 static int rx8025_init_client(struct i2c_client *client, int *need_reset)
 261 {
 262         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 263         u8 ctrl[2], ctrl2;
 264         int need_clear = 0;
 265         int err;
 266
 267         err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
 268         if (err)
 269                 goto out;
 270
 271         /* Keep test bit zero ! */
 272         rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
 273
 274         if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
 275                 dev_warn(&client->dev, "power-on reset was detected, "
 276                          "you may have to readjust the clock\n");
 277                 *need_reset = 1;
 278         }
 279
 280         if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
 281                 dev_warn(&client->dev, "a power voltage drop was detected, "
 282                          "you may have to readjust the clock\n");
 283                 *need_reset = 1;
 284         }
 285
 286         if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
 287                 dev_warn(&client->dev, "Oscillation stop was detected,"
 288                          "you may have to readjust the clock\n");
 289                 *need_reset = 1;
 290         }
 291
 292         if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
 293                 dev_warn(&client->dev, "Alarm was detected\n");
 294                 need_clear = 1;
 295         }
 296
 297         if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
 298                 need_clear = 1;
 299
 300         if (*need_reset || need_clear) {
 301                 ctrl2 = ctrl[0];
 302                 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
 303                            RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
 304                            RX8025_BIT_CTRL2_DAFG);
 305                 ctrl2 |= RX8025_BIT_CTRL2_XST;
 306
 307                 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
 308         }
 309 out:
 310         return err;
 311 }
 312
 313 /* Alarm support */
 314 static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 315 {
 316         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 317         struct i2c_client *client = rx8025->client;
 318         u8 ctrl2, ald[2];
 319         int err;
 320
 321         if (client->irq <= 0)
 322                 return -EINVAL;
 323
 324         err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
 325         if (err)
 326                 return err;
 327
 328         err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
 329         if (err)
 330                 return err;
 331
 332         dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
 333                 __func__, ald[0], ald[1], ctrl2);
 334
 335         /* Hardware alarms precision is 1 minute! */
 336         t->time.tm_sec = 0;
 337         t->time.tm_min = bcd2bin(ald[0] & 0x7f);
 338         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 339                 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
 340         else
 341                 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
 342                         + (ald[1] & 0x20 ? 12 : 0);
 343
 344         t->time.tm_wday = -1;
 345         t->time.tm_mday = -1;
 346         t->time.tm_mon = -1;
 347         t->time.tm_year = -1;
 348
 349         dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
 350                 __func__,
 351                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 352                 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
 353         t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
 354         t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
 355
 356         return err;
 357 }
 358
 359 static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 360 {
 361         struct i2c_client *client = to_i2c_client(dev);
 362         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 363         u8 ald[2];
 364         int err;
 365
 366         if (client->irq <= 0)
 367                 return -EINVAL;
 368
 369         /* Hardware alarm precision is 1 minute! */
 370         ald[0] = bin2bcd(t->time.tm_min);
 371         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 372                 ald[1] = bin2bcd(t->time.tm_hour);
 373         else
 374                 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
 375                         | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
 376
 377         dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
 378
 379         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
 380                 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
 381                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 382                                        rx8025->ctrl1);
 383                 if (err)
 384                         return err;
 385         }
 386         err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
 387         if (err)
 388                 return err;
 389
 390         if (t->enabled) {
 391                 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
 392                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 393                                        rx8025->ctrl1);
 394                 if (err)
 395                         return err;
 396         }
 397
 398         return 0;
 399 }
 400
 401 static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
 402 {
 403         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 404         u8 ctrl1;
 405         int err;
 406
 407         ctrl1 = rx8025->ctrl1;
 408         if (enabled)
 409                 ctrl1 |= RX8025_BIT_CTRL1_DALE;
 410         else
 411                 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
 412
 413         if (ctrl1 != rx8025->ctrl1) {
 414                 rx8025->ctrl1 = ctrl1;
 415                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 416                                        rx8025->ctrl1);
 417                 if (err)
 418                         return err;
 419         }
 420         return 0;
 421 }
 422
 423 static struct rtc_class_ops rx8025_rtc_ops = {
 424         .read_time = rx8025_get_time,
 425         .set_time = rx8025_set_time,
 426         .read_alarm = rx8025_read_alarm,
 427         .set_alarm = rx8025_set_alarm,
 428         .alarm_irq_enable = rx8025_alarm_irq_enable,
 429 };
 430
 431 /*
 432  * Clock precision adjustment support
 433  *
 434  * According to the RX8025 SA/NB application manual the frequency and
 435  * temperature characteristics can be approximated using the following
 436  * equation:
 437  *
 438  *   df = a * (ut - t)**2
 439  *
 440  *   df: Frequency deviation in any temperature
 441  *   a : Coefficient = (-35 +-5) * 10**-9
 442  *   ut: Ultimate temperature in degree = +25 +-5 degree
 443  *   t : Any temperature in degree
 444  *
 445  * Note that the clock adjustment in ppb must be entered (which is
 446  * the negative value of the deviation).
 447  */
 448 static int rx8025_get_clock_adjust(struct device *dev, int *adj)
 449 {
 450         struct i2c_client *client = to_i2c_client(dev);
 451         u8 digoff;
 452         int err;
 453
 454         err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
 455         if (err)
 456                 return err;
 457
 458         *adj = digoff >= 64 ? digoff - 128 : digoff;
 459         if (*adj > 0)
 460                 (*adj)--;
 461         *adj *= -RX8025_ADJ_RESOLUTION;
 462
 463         return 0;
 464 }
 465
 466 static int rx8025_set_clock_adjust(struct device *dev, int adj)
 467 {
 468         struct i2c_client *client = to_i2c_client(dev);
 469         u8 digoff;
 470         int err;
 471
 472         adj /= -RX8025_ADJ_RESOLUTION;
 473         if (adj > RX8025_ADJ_DATA_MAX)
 474                 adj = RX8025_ADJ_DATA_MAX;
 475         else if (adj < RX8025_ADJ_DATA_MIN)
 476                 adj = RX8025_ADJ_DATA_MIN;
 477         else if (adj > 0)
 478                 adj++;
 479         else if (adj < 0)
 480                 adj += 128;
 481         digoff = adj;
 482
 483         err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
 484         if (err)
 485                 return err;
 486
 487         dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
 488
 489         return 0;
 490 }
 491
 492 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
 493                                               struct device_attribute *attr,
 494                                               char *buf)
 495 {
 496         int err, adj;
 497
 498         err = rx8025_get_clock_adjust(dev, &adj);
 499         if (err)
 500                 return err;
 501
 502         return sprintf(buf, "%d\n", adj);
 503 }
 504
 505 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
 506                                                struct device_attribute *attr,
 507                                                const char *buf, size_t count)
 508 {
 509         int adj, err;
 510
 511         if (sscanf(buf, "%i", &adj) != 1)
 512                 return -EINVAL;
 513
 514         err = rx8025_set_clock_adjust(dev, adj);
 515
 516         return err ? err : count;
 517 }
 518
 519 static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
 520                    rx8025_sysfs_show_clock_adjust,
 521                    rx8025_sysfs_store_clock_adjust);
 522
 523 static int rx8025_sysfs_register(struct device *dev)
 524 {
 525         return device_create_file(dev, &dev_attr_clock_adjust_ppb);
 526 }
 527
 528 static void rx8025_sysfs_unregister(struct device *dev)
 529 {
 530         device_remove_file(dev, &dev_attr_clock_adjust_ppb);
 531 }
 532
 533 static int rx8025_probe(struct i2c_client *client,
 534                         const struct i2c_device_id *id)
 535 {
 536         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 537         struct rx8025_data *rx8025;
 538         int err, need_reset = 0;
 539
 540         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
 541                                      | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 542                 dev_err(&adapter->dev,
 543                         "doesn't support required functionality\n");
 544                 err = -EIO;
 545                 goto errout;
 546         }
 547
 548         rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
 549         if (!rx8025) {
 550                 err = -ENOMEM;
 551                 goto errout;
 552         }
 553
 554         rx8025->client = client;
 555         i2c_set_clientdata(client, rx8025);
 556         INIT_WORK(&rx8025->work, rx8025_work);
 557
 558         err = rx8025_init_client(client, &need_reset);
 559         if (err)
 560                 goto errout;
 561
 562         if (need_reset) {
 563                 struct rtc_time tm;
 564                 dev_info(&client->dev,
 565                          "bad conditions detected, resetting date\n");
 566                 rtc_time_to_tm(0, &tm); /* 1970/1/1 */
 567                 rx8025_set_time(&client->dev, &tm);
 568         }
 569
 570         rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
 571                                           &rx8025_rtc_ops, THIS_MODULE);
 572         if (IS_ERR(rx8025->rtc)) {
 573                 err = PTR_ERR(rx8025->rtc);
 574                 dev_err(&client->dev, "unable to register the class device\n");
 575                 goto errout;
 576         }
 577
 578         if (client->irq > 0) {
 579                 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
 580                 err = request_irq(client->irq, rx8025_irq,
 581                                   0, "rx8025", client);
 582                 if (err) {
 583                         dev_err(&client->dev, "unable to request IRQ\n");
 584                         goto errout;
 585                 }
 586         }
 587
 588         rx8025->rtc->irq_freq = 1;
 589         rx8025->rtc->max_user_freq = 1;
 590
 591         err = rx8025_sysfs_register(&client->dev);
 592         if (err)
 593                 goto errout_irq;
 594
 595         return 0;
 596
 597 errout_irq:
 598         if (client->irq > 0)
 599                 free_irq(client->irq, client);
 600
 601 errout:
 602         dev_err(&adapter->dev, "probing for rx8025 failed\n");
 603         return err;
 604 }
 605
 606 static int rx8025_remove(struct i2c_client *client)
 607 {
 608         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 609         struct mutex *lock = &rx8025->rtc->ops_lock;
 610
 611         if (client->irq > 0) {
 612                 mutex_lock(lock);
 613                 rx8025->exiting = 1;
 614                 mutex_unlock(lock);
 615
 616                 free_irq(client->irq, client);
 617                 cancel_work_sync(&rx8025->work);
 618         }
 619
 620         rx8025_sysfs_unregister(&client->dev);
 621         return 0;
 622 }
 623
 624 static struct i2c_driver rx8025_driver = {
 625         .driver = {
 626                 .name = "rtc-rx8025",
 627         },
 628         .probe          = rx8025_probe,
 629         .remove         = rx8025_remove,
 630         .id_table       = rx8025_id,
 631 };
 632
 633 module_i2c_driver(rx8025_driver);
 634
 635 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 636 MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
 637 MODULE_LICENSE("GPL");