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                 local_irq_disable();
 165                 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
 166                 local_irq_enable();
 167         }
 168
 169         if (status & RX8025_BIT_CTRL2_DAFG) {
 170                 /* alarm */
 171                 status &= RX8025_BIT_CTRL2_DAFG;
 172                 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
 173                                      rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
 174                         goto out;
 175                 local_irq_disable();
 176                 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
 177                 local_irq_enable();
 178         }
 179
 180         /* acknowledge IRQ */
 181         rx8025_write_reg(client, RX8025_REG_CTRL2,
 182                          status | RX8025_BIT_CTRL2_XST);
 183
 184 out:
 185         if (!rx8025->exiting)
 186                 enable_irq(client->irq);
 187
 188         mutex_unlock(lock);
 189 }
 190
 191 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
 192 {
 193         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 194         u8 date[7];
 195         int err;
 196
 197         err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 198         if (err)
 199                 return err;
 200
 201         dev_dbg(dev, "%s: read 0x%02x 0x%02x "
 202                 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
 203                 date[0], date[1], date[2], date[3], date[4],
 204                 date[5], date[6]);
 205
 206         dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
 207         dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
 208         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 209                 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
 210         else
 211                 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
 212                         + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
 213
 214         dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
 215         dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
 216         dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
 217
 218         if (dt->tm_year < 70)
 219                 dt->tm_year += 100;
 220
 221         dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
 222                 dt->tm_sec, dt->tm_min, dt->tm_hour,
 223                 dt->tm_mday, dt->tm_mon, dt->tm_year);
 224
 225         return rtc_valid_tm(dt);
 226 }
 227
 228 static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
 229 {
 230         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 231         u8 date[7];
 232
 233         /*
 234          * BUG: The HW assumes every year that is a multiple of 4 to be a leap
 235          * year.  Next time this is wrong is 2100, which will not be a leap
 236          * year.
 237          */
 238
 239         /*
 240          * Here the read-only bits are written as "0".  I'm not sure if that
 241          * is sound.
 242          */
 243         date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
 244         date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
 245         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 246                 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
 247         else
 248                 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
 249                         | bin2bcd((dt->tm_hour + 11) % 12 + 1);
 250
 251         date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
 252         date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
 253         date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
 254         date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
 255
 256         dev_dbg(dev,
 257                 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
 258                 __func__,
 259                 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
 260
 261         return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 262 }
 263
 264 static int rx8025_init_client(struct i2c_client *client, int *need_reset)
 265 {
 266         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 267         u8 ctrl[2], ctrl2;
 268         int need_clear = 0;
 269         int err;
 270
 271         err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
 272         if (err)
 273                 goto out;
 274
 275         /* Keep test bit zero ! */
 276         rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
 277
 278         if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
 279                 dev_warn(&client->dev, "power-on reset was detected, "
 280                          "you may have to readjust the clock\n");
 281                 *need_reset = 1;
 282         }
 283
 284         if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
 285                 dev_warn(&client->dev, "a power voltage drop was detected, "
 286                          "you may have to readjust the clock\n");
 287                 *need_reset = 1;
 288         }
 289
 290         if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
 291                 dev_warn(&client->dev, "Oscillation stop was detected,"
 292                          "you may have to readjust the clock\n");
 293                 *need_reset = 1;
 294         }
 295
 296         if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
 297                 dev_warn(&client->dev, "Alarm was detected\n");
 298                 need_clear = 1;
 299         }
 300
 301         if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
 302                 need_clear = 1;
 303
 304         if (*need_reset || need_clear) {
 305                 ctrl2 = ctrl[0];
 306                 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
 307                            RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
 308                            RX8025_BIT_CTRL2_DAFG);
 309                 ctrl2 |= RX8025_BIT_CTRL2_XST;
 310
 311                 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
 312         }
 313 out:
 314         return err;
 315 }
 316
 317 /* Alarm support */
 318 static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 319 {
 320         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 321         struct i2c_client *client = rx8025->client;
 322         u8 ctrl2, ald[2];
 323         int err;
 324
 325         if (client->irq <= 0)
 326                 return -EINVAL;
 327
 328         err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
 329         if (err)
 330                 return err;
 331
 332         err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
 333         if (err)
 334                 return err;
 335
 336         dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
 337                 __func__, ald[0], ald[1], ctrl2);
 338
 339         /* Hardware alarms precision is 1 minute! */
 340         t->time.tm_sec = 0;
 341         t->time.tm_min = bcd2bin(ald[0] & 0x7f);
 342         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 343                 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
 344         else
 345                 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
 346                         + (ald[1] & 0x20 ? 12 : 0);
 347
 348         t->time.tm_wday = -1;
 349         t->time.tm_mday = -1;
 350         t->time.tm_mon = -1;
 351         t->time.tm_year = -1;
 352
 353         dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
 354                 __func__,
 355                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 356                 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
 357         t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
 358         t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
 359
 360         return err;
 361 }
 362
 363 static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 364 {
 365         struct i2c_client *client = to_i2c_client(dev);
 366         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 367         u8 ald[2];
 368         int err;
 369
 370         if (client->irq <= 0)
 371                 return -EINVAL;
 372
 373         /* Hardware alarm precision is 1 minute! */
 374         ald[0] = bin2bcd(t->time.tm_min);
 375         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 376                 ald[1] = bin2bcd(t->time.tm_hour);
 377         else
 378                 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
 379                         | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
 380
 381         dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
 382
 383         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
 384                 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
 385                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 386                                        rx8025->ctrl1);
 387                 if (err)
 388                         return err;
 389         }
 390         err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
 391         if (err)
 392                 return err;
 393
 394         if (t->enabled) {
 395                 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
 396                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 397                                        rx8025->ctrl1);
 398                 if (err)
 399                         return err;
 400         }
 401
 402         return 0;
 403 }
 404
 405 static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
 406 {
 407         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 408         u8 ctrl1;
 409         int err;
 410
 411         ctrl1 = rx8025->ctrl1;
 412         if (enabled)
 413                 ctrl1 |= RX8025_BIT_CTRL1_DALE;
 414         else
 415                 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
 416
 417         if (ctrl1 != rx8025->ctrl1) {
 418                 rx8025->ctrl1 = ctrl1;
 419                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 420                                        rx8025->ctrl1);
 421                 if (err)
 422                         return err;
 423         }
 424         return 0;
 425 }
 426
 427 static struct rtc_class_ops rx8025_rtc_ops = {
 428         .read_time = rx8025_get_time,
 429         .set_time = rx8025_set_time,
 430         .read_alarm = rx8025_read_alarm,
 431         .set_alarm = rx8025_set_alarm,
 432         .alarm_irq_enable = rx8025_alarm_irq_enable,
 433 };
 434
 435 /*
 436  * Clock precision adjustment support
 437  *
 438  * According to the RX8025 SA/NB application manual the frequency and
 439  * temperature characteristics can be approximated using the following
 440  * equation:
 441  *
 442  *   df = a * (ut - t)**2
 443  *
 444  *   df: Frequency deviation in any temperature
 445  *   a : Coefficient = (-35 +-5) * 10**-9
 446  *   ut: Ultimate temperature in degree = +25 +-5 degree
 447  *   t : Any temperature in degree
 448  *
 449  * Note that the clock adjustment in ppb must be entered (which is
 450  * the negative value of the deviation).
 451  */
 452 static int rx8025_get_clock_adjust(struct device *dev, int *adj)
 453 {
 454         struct i2c_client *client = to_i2c_client(dev);
 455         u8 digoff;
 456         int err;
 457
 458         err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
 459         if (err)
 460                 return err;
 461
 462         *adj = digoff >= 64 ? digoff - 128 : digoff;
 463         if (*adj > 0)
 464                 (*adj)--;
 465         *adj *= -RX8025_ADJ_RESOLUTION;
 466
 467         return 0;
 468 }
 469
 470 static int rx8025_set_clock_adjust(struct device *dev, int adj)
 471 {
 472         struct i2c_client *client = to_i2c_client(dev);
 473         u8 digoff;
 474         int err;
 475
 476         adj /= -RX8025_ADJ_RESOLUTION;
 477         if (adj > RX8025_ADJ_DATA_MAX)
 478                 adj = RX8025_ADJ_DATA_MAX;
 479         else if (adj < RX8025_ADJ_DATA_MIN)
 480                 adj = RX8025_ADJ_DATA_MIN;
 481         else if (adj > 0)
 482                 adj++;
 483         else if (adj < 0)
 484                 adj += 128;
 485         digoff = adj;
 486
 487         err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
 488         if (err)
 489                 return err;
 490
 491         dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
 492
 493         return 0;
 494 }
 495
 496 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
 497                                               struct device_attribute *attr,
 498                                               char *buf)
 499 {
 500         int err, adj;
 501
 502         err = rx8025_get_clock_adjust(dev, &adj);
 503         if (err)
 504                 return err;
 505
 506         return sprintf(buf, "%d\n", adj);
 507 }
 508
 509 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
 510                                                struct device_attribute *attr,
 511                                                const char *buf, size_t count)
 512 {
 513         int adj, err;
 514
 515         if (sscanf(buf, "%i", &adj) != 1)
 516                 return -EINVAL;
 517
 518         err = rx8025_set_clock_adjust(dev, adj);
 519
 520         return err ? err : count;
 521 }
 522
 523 static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
 524                    rx8025_sysfs_show_clock_adjust,
 525                    rx8025_sysfs_store_clock_adjust);
 526
 527 static int rx8025_sysfs_register(struct device *dev)
 528 {
 529         return device_create_file(dev, &dev_attr_clock_adjust_ppb);
 530 }
 531
 532 static void rx8025_sysfs_unregister(struct device *dev)
 533 {
 534         device_remove_file(dev, &dev_attr_clock_adjust_ppb);
 535 }
 536
 537 static int rx8025_probe(struct i2c_client *client,
 538                         const struct i2c_device_id *id)
 539 {
 540         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 541         struct rx8025_data *rx8025;
 542         int err, need_reset = 0;
 543
 544         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
 545                                      | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 546                 dev_err(&adapter->dev,
 547                         "doesn't support required functionality\n");
 548                 err = -EIO;
 549                 goto errout;
 550         }
 551
 552         rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
 553         if (!rx8025) {
 554                 err = -ENOMEM;
 555                 goto errout;
 556         }
 557
 558         rx8025->client = client;
 559         i2c_set_clientdata(client, rx8025);
 560         INIT_WORK(&rx8025->work, rx8025_work);
 561
 562         err = rx8025_init_client(client, &need_reset);
 563         if (err)
 564                 goto errout;
 565
 566         if (need_reset) {
 567                 struct rtc_time tm;
 568                 dev_info(&client->dev,
 569                          "bad conditions detected, resetting date\n");
 570                 rtc_time_to_tm(0, &tm); /* 1970/1/1 */
 571                 rx8025_set_time(&client->dev, &tm);
 572         }
 573
 574         rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
 575                                           &rx8025_rtc_ops, THIS_MODULE);
 576         if (IS_ERR(rx8025->rtc)) {
 577                 err = PTR_ERR(rx8025->rtc);
 578                 dev_err(&client->dev, "unable to register the class device\n");
 579                 goto errout;
 580         }
 581
 582         if (client->irq > 0) {
 583                 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
 584                 err = request_irq(client->irq, rx8025_irq,
 585                                   0, "rx8025", client);
 586                 if (err) {
 587                         dev_err(&client->dev, "unable to request IRQ\n");
 588                         goto errout;
 589                 }
 590         }
 591
 592         rx8025->rtc->irq_freq = 1;
 593         rx8025->rtc->max_user_freq = 1;
 594
 595         err = rx8025_sysfs_register(&client->dev);
 596         if (err)
 597                 goto errout_irq;
 598
 599         return 0;
 600
 601 errout_irq:
 602         if (client->irq > 0)
 603                 free_irq(client->irq, client);
 604
 605 errout:
 606         dev_err(&adapter->dev, "probing for rx8025 failed\n");
 607         return err;
 608 }
 609
 610 static int rx8025_remove(struct i2c_client *client)
 611 {
 612         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 613         struct mutex *lock = &rx8025->rtc->ops_lock;
 614
 615         if (client->irq > 0) {
 616                 mutex_lock(lock);
 617                 rx8025->exiting = 1;
 618                 mutex_unlock(lock);
 619
 620                 free_irq(client->irq, client);
 621                 cancel_work_sync(&rx8025->work);
 622         }
 623
 624         rx8025_sysfs_unregister(&client->dev);
 625         return 0;
 626 }
 627
 628 static struct i2c_driver rx8025_driver = {
 629         .driver = {
 630                 .name = "rtc-rx8025",
 631                 .owner = THIS_MODULE,
 632         },
 633         .probe          = rx8025_probe,
 634         .remove         = rx8025_remove,
 635         .id_table       = rx8025_id,
 636 };
 637
 638 module_i2c_driver(rx8025_driver);
 639
 640 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 641 MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
 642 MODULE_LICENSE("GPL");