git.oblomov.eu Git - linux-2.6/blob - 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/init.h>
  24 #include <linux/bcd.h>
  25 #include <linux/i2c.h>
  26 #include <linux/list.h>
  27 #include <linux/rtc.h>
  28
  29 /* Register definitions */
  30 #define RX8025_REG_SEC          0x00
  31 #define RX8025_REG_MIN          0x01
  32 #define RX8025_REG_HOUR         0x02
  33 #define RX8025_REG_WDAY         0x03
  34 #define RX8025_REG_MDAY         0x04
  35 #define RX8025_REG_MONTH        0x05
  36 #define RX8025_REG_YEAR         0x06
  37 #define RX8025_REG_DIGOFF       0x07
  38 #define RX8025_REG_ALWMIN       0x08
  39 #define RX8025_REG_ALWHOUR      0x09
  40 #define RX8025_REG_ALWWDAY      0x0a
  41 #define RX8025_REG_ALDMIN       0x0b
  42 #define RX8025_REG_ALDHOUR      0x0c
  43 /* 0x0d is reserved */
  44 #define RX8025_REG_CTRL1        0x0e
  45 #define RX8025_REG_CTRL2        0x0f
  46
  47 #define RX8025_BIT_CTRL1_CT     (7 << 0)
  48 /* 1 Hz periodic level irq */
  49 #define RX8025_BIT_CTRL1_CT_1HZ 4
  50 #define RX8025_BIT_CTRL1_TEST   (1 << 3)
  51 #define RX8025_BIT_CTRL1_1224   (1 << 5)
  52 #define RX8025_BIT_CTRL1_DALE   (1 << 6)
  53 #define RX8025_BIT_CTRL1_WALE   (1 << 7)
  54
  55 #define RX8025_BIT_CTRL2_DAFG   (1 << 0)
  56 #define RX8025_BIT_CTRL2_WAFG   (1 << 1)
  57 #define RX8025_BIT_CTRL2_CTFG   (1 << 2)
  58 #define RX8025_BIT_CTRL2_PON    (1 << 4)
  59 #define RX8025_BIT_CTRL2_XST    (1 << 5)
  60 #define RX8025_BIT_CTRL2_VDET   (1 << 6)
  61
  62 /* Clock precision adjustment */
  63 #define RX8025_ADJ_RESOLUTION   3050 /* in ppb */
  64 #define RX8025_ADJ_DATA_MAX     62
  65 #define RX8025_ADJ_DATA_MIN     -62
  66
  67 static const struct i2c_device_id rx8025_id[] = {
  68         { "rx8025", 0 },
  69         { }
  70 };
  71 MODULE_DEVICE_TABLE(i2c, rx8025_id);
  72
  73 struct rx8025_data {
  74         struct i2c_client *client;
  75         struct rtc_device *rtc;
  76         struct work_struct work;
  77         u8 ctrl1;
  78         unsigned exiting:1;
  79 };
  80
  81 static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)
  82 {
  83         int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);
  84
  85         if (ret < 0) {
  86                 dev_err(&client->dev, "Unable to read register #%d\n", number);
  87                 return ret;
  88         }
  89
  90         *value = ret;
  91         return 0;
  92 }
  93
  94 static int rx8025_read_regs(struct i2c_client *client,
  95                             int number, u8 length, u8 *values)
  96 {
  97         int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,
  98                                                 length, values);
  99
 100         if (ret != length) {
 101                 dev_err(&client->dev, "Unable to read registers #%d..#%d\n",
 102                         number, number + length - 1);
 103                 return ret < 0 ? ret : -EIO;
 104         }
 105
 106         return 0;
 107 }
 108
 109 static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
 110 {
 111         int ret = i2c_smbus_write_byte_data(client, number << 4, value);
 112
 113         if (ret)
 114                 dev_err(&client->dev, "Unable to write register #%d\n",
 115                         number);
 116
 117         return ret;
 118 }
 119
 120 static int rx8025_write_regs(struct i2c_client *client,
 121                              int number, u8 length, u8 *values)
 122 {
 123         int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,
 124                                                  length, values);
 125
 126         if (ret)
 127                 dev_err(&client->dev, "Unable to write registers #%d..#%d\n",
 128                         number, number + length - 1);
 129
 130         return ret;
 131 }
 132
 133 static irqreturn_t rx8025_irq(int irq, void *dev_id)
 134 {
 135         struct i2c_client *client = dev_id;
 136         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 137
 138         disable_irq_nosync(irq);
 139         schedule_work(&rx8025->work);
 140         return IRQ_HANDLED;
 141 }
 142
 143 static void rx8025_work(struct work_struct *work)
 144 {
 145         struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
 146                                                   work);
 147         struct i2c_client *client = rx8025->client;
 148         struct mutex *lock = &rx8025->rtc->ops_lock;
 149         u8 status;
 150
 151         mutex_lock(lock);
 152
 153         if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
 154                 goto out;
 155
 156         if (!(status & RX8025_BIT_CTRL2_XST))
 157                 dev_warn(&client->dev, "Oscillation stop was detected,"
 158                          "you may have to readjust the clock\n");
 159
 160         if (status & RX8025_BIT_CTRL2_CTFG) {
 161                 /* periodic */
 162                 status &= ~RX8025_BIT_CTRL2_CTFG;
 163                 local_irq_disable();
 164                 rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
 165                 local_irq_enable();
 166         }
 167
 168         if (status & RX8025_BIT_CTRL2_DAFG) {
 169                 /* alarm */
 170                 status &= RX8025_BIT_CTRL2_DAFG;
 171                 if (rx8025_write_reg(client, RX8025_REG_CTRL1,
 172                                      rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
 173                         goto out;
 174                 local_irq_disable();
 175                 rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);
 176                 local_irq_enable();
 177         }
 178
 179         /* acknowledge IRQ */
 180         rx8025_write_reg(client, RX8025_REG_CTRL2,
 181                          status | RX8025_BIT_CTRL2_XST);
 182
 183 out:
 184         if (!rx8025->exiting)
 185                 enable_irq(client->irq);
 186
 187         mutex_unlock(lock);
 188 }
 189
 190 static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
 191 {
 192         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 193         u8 date[7];
 194         int err;
 195
 196         err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 197         if (err)
 198                 return err;
 199
 200         dev_dbg(dev, "%s: read 0x%02x 0x%02x "
 201                 "0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
 202                 date[0], date[1], date[2], date[3], date[4],
 203                 date[5], date[6]);
 204
 205         dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
 206         dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
 207         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 208                 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
 209         else
 210                 dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
 211                         + (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
 212
 213         dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
 214         dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
 215         dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
 216
 217         if (dt->tm_year < 70)
 218                 dt->tm_year += 100;
 219
 220         dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
 221                 dt->tm_sec, dt->tm_min, dt->tm_hour,
 222                 dt->tm_mday, dt->tm_mon, dt->tm_year);
 223
 224         return rtc_valid_tm(dt);
 225 }
 226
 227 static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
 228 {
 229         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 230         u8 date[7];
 231
 232         /*
 233          * BUG: The HW assumes every year that is a multiple of 4 to be a leap
 234          * year.  Next time this is wrong is 2100, which will not be a leap
 235          * year.
 236          */
 237
 238         /*
 239          * Here the read-only bits are written as "0".  I'm not sure if that
 240          * is sound.
 241          */
 242         date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
 243         date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
 244         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 245                 date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
 246         else
 247                 date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
 248                         | bin2bcd((dt->tm_hour + 11) % 12 + 1);
 249
 250         date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
 251         date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
 252         date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
 253         date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
 254
 255         dev_dbg(dev,
 256                 "%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
 257                 __func__,
 258                 date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
 259
 260         return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
 261 }
 262
 263 static int rx8025_init_client(struct i2c_client *client, int *need_reset)
 264 {
 265         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 266         u8 ctrl[2], ctrl2;
 267         int need_clear = 0;
 268         int err;
 269
 270         err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
 271         if (err)
 272                 goto out;
 273
 274         /* Keep test bit zero ! */
 275         rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
 276
 277         if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
 278                 dev_warn(&client->dev, "power-on reset was detected, "
 279                          "you may have to readjust the clock\n");
 280                 *need_reset = 1;
 281         }
 282
 283         if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
 284                 dev_warn(&client->dev, "a power voltage drop was detected, "
 285                          "you may have to readjust the clock\n");
 286                 *need_reset = 1;
 287         }
 288
 289         if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
 290                 dev_warn(&client->dev, "Oscillation stop was detected,"
 291                          "you may have to readjust the clock\n");
 292                 *need_reset = 1;
 293         }
 294
 295         if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
 296                 dev_warn(&client->dev, "Alarm was detected\n");
 297                 need_clear = 1;
 298         }
 299
 300         if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
 301                 need_clear = 1;
 302
 303         if (*need_reset || need_clear) {
 304                 ctrl2 = ctrl[0];
 305                 ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |
 306                            RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
 307                            RX8025_BIT_CTRL2_DAFG);
 308                 ctrl2 |= RX8025_BIT_CTRL2_XST;
 309
 310                 err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
 311         }
 312 out:
 313         return err;
 314 }
 315
 316 /* Alarm support */
 317 static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 318 {
 319         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 320         struct i2c_client *client = rx8025->client;
 321         u8 ctrl2, ald[2];
 322         int err;
 323
 324         if (client->irq <= 0)
 325                 return -EINVAL;
 326
 327         err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
 328         if (err)
 329                 return err;
 330
 331         err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
 332         if (err)
 333                 return err;
 334
 335         dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
 336                 __func__, ald[0], ald[1], ctrl2);
 337
 338         /* Hardware alarms precision is 1 minute! */
 339         t->time.tm_sec = 0;
 340         t->time.tm_min = bcd2bin(ald[0] & 0x7f);
 341         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 342                 t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
 343         else
 344                 t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
 345                         + (ald[1] & 0x20 ? 12 : 0);
 346
 347         t->time.tm_wday = -1;
 348         t->time.tm_mday = -1;
 349         t->time.tm_mon = -1;
 350         t->time.tm_year = -1;
 351
 352         dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
 353                 __func__,
 354                 t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 355                 t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
 356         t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
 357         t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
 358
 359         return err;
 360 }
 361
 362 static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 363 {
 364         struct i2c_client *client = to_i2c_client(dev);
 365         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 366         u8 ald[2];
 367         int err;
 368
 369         if (client->irq <= 0)
 370                 return -EINVAL;
 371
 372         /* Hardware alarm precision is 1 minute! */
 373         ald[0] = bin2bcd(t->time.tm_min);
 374         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
 375                 ald[1] = bin2bcd(t->time.tm_hour);
 376         else
 377                 ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
 378                         | bin2bcd((t->time.tm_hour + 11) % 12 + 1);
 379
 380         dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
 381
 382         if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
 383                 rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
 384                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 385                                        rx8025->ctrl1);
 386                 if (err)
 387                         return err;
 388         }
 389         err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
 390         if (err)
 391                 return err;
 392
 393         if (t->enabled) {
 394                 rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
 395                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 396                                        rx8025->ctrl1);
 397                 if (err)
 398                         return err;
 399         }
 400
 401         return 0;
 402 }
 403
 404 static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
 405 {
 406         struct rx8025_data *rx8025 = dev_get_drvdata(dev);
 407         u8 ctrl1;
 408         int err;
 409
 410         ctrl1 = rx8025->ctrl1;
 411         if (enabled)
 412                 ctrl1 |= RX8025_BIT_CTRL1_DALE;
 413         else
 414                 ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
 415
 416         if (ctrl1 != rx8025->ctrl1) {
 417                 rx8025->ctrl1 = ctrl1;
 418                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 419                                        rx8025->ctrl1);
 420                 if (err)
 421                         return err;
 422         }
 423         return 0;
 424 }
 425
 426 static int rx8025_irq_set_state(struct device *dev, int enabled)
 427 {
 428         struct i2c_client *client = to_i2c_client(dev);
 429         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 430         int ctrl1;
 431         int err;
 432
 433         if (client->irq <= 0)
 434                 return -ENXIO;
 435
 436         ctrl1 = rx8025->ctrl1 & ~RX8025_BIT_CTRL1_CT;
 437         if (enabled)
 438                 ctrl1 |= RX8025_BIT_CTRL1_CT_1HZ;
 439         if (ctrl1 != rx8025->ctrl1) {
 440                 rx8025->ctrl1 = ctrl1;
 441                 err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
 442                                        rx8025->ctrl1);
 443                 if (err)
 444                         return err;
 445         }
 446
 447         return 0;
 448 }
 449
 450 static struct rtc_class_ops rx8025_rtc_ops = {
 451         .read_time = rx8025_get_time,
 452         .set_time = rx8025_set_time,
 453         .read_alarm = rx8025_read_alarm,
 454         .set_alarm = rx8025_set_alarm,
 455         .alarm_irq_enable = rx8025_alarm_irq_enable,
 456         .irq_set_state  = rx8025_irq_set_state,
 457 };
 458
 459 /*
 460  * Clock precision adjustment support
 461  *
 462  * According to the RX8025 SA/NB application manual the frequency and
 463  * temperature charateristics can be approximated using the following
 464  * equation:
 465  *
 466  *   df = a * (ut - t)**2
 467  *
 468  *   df: Frequency deviation in any temperature
 469  *   a : Coefficient = (-35 +-5) * 10**-9
 470  *   ut: Ultimate temperature in degree = +25 +-5 degree
 471  *   t : Any temperature in degree
 472  *
 473  * Note that the clock adjustment in ppb must be entered (which is
 474  * the negative value of the deviation).
 475  */
 476 static int rx8025_get_clock_adjust(struct device *dev, int *adj)
 477 {
 478         struct i2c_client *client = to_i2c_client(dev);
 479         u8 digoff;
 480         int err;
 481
 482         err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
 483         if (err)
 484                 return err;
 485
 486         *adj = digoff >= 64 ? digoff - 128 : digoff;
 487         if (*adj > 0)
 488                 (*adj)--;
 489         *adj *= -RX8025_ADJ_RESOLUTION;
 490
 491         return 0;
 492 }
 493
 494 static int rx8025_set_clock_adjust(struct device *dev, int adj)
 495 {
 496         struct i2c_client *client = to_i2c_client(dev);
 497         u8 digoff;
 498         int err;
 499
 500         adj /= -RX8025_ADJ_RESOLUTION;
 501         if (adj > RX8025_ADJ_DATA_MAX)
 502                 adj = RX8025_ADJ_DATA_MAX;
 503         else if (adj < RX8025_ADJ_DATA_MIN)
 504                 adj = RX8025_ADJ_DATA_MIN;
 505         else if (adj > 0)
 506                 adj++;
 507         else if (adj < 0)
 508                 adj += 128;
 509         digoff = adj;
 510
 511         err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
 512         if (err)
 513                 return err;
 514
 515         dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
 516
 517         return 0;
 518 }
 519
 520 static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
 521                                               struct device_attribute *attr,
 522                                               char *buf)
 523 {
 524         int err, adj;
 525
 526         err = rx8025_get_clock_adjust(dev, &adj);
 527         if (err)
 528                 return err;
 529
 530         return sprintf(buf, "%d\n", adj);
 531 }
 532
 533 static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
 534                                                struct device_attribute *attr,
 535                                                const char *buf, size_t count)
 536 {
 537         int adj, err;
 538
 539         if (sscanf(buf, "%i", &adj) != 1)
 540                 return -EINVAL;
 541
 542         err = rx8025_set_clock_adjust(dev, adj);
 543
 544         return err ? err : count;
 545 }
 546
 547 static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,
 548                    rx8025_sysfs_show_clock_adjust,
 549                    rx8025_sysfs_store_clock_adjust);
 550
 551 static int rx8025_sysfs_register(struct device *dev)
 552 {
 553         return device_create_file(dev, &dev_attr_clock_adjust_ppb);
 554 }
 555
 556 static void rx8025_sysfs_unregister(struct device *dev)
 557 {
 558         device_remove_file(dev, &dev_attr_clock_adjust_ppb);
 559 }
 560
 561 static int __devinit rx8025_probe(struct i2c_client *client,
 562                                   const struct i2c_device_id *id)
 563 {
 564         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 565         struct rx8025_data *rx8025;
 566         int err, need_reset = 0;
 567
 568         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
 569                                      | I2C_FUNC_SMBUS_I2C_BLOCK)) {
 570                 dev_err(&adapter->dev,
 571                         "doesn't support required functionality\n");
 572                 err = -EIO;
 573                 goto errout;
 574         }
 575
 576         rx8025 = kzalloc(sizeof(*rx8025), GFP_KERNEL);
 577         if (!rx8025) {
 578                 dev_err(&adapter->dev, "failed to alloc memory\n");
 579                 err = -ENOMEM;
 580                 goto errout;
 581         }
 582
 583         rx8025->client = client;
 584         i2c_set_clientdata(client, rx8025);
 585         INIT_WORK(&rx8025->work, rx8025_work);
 586
 587         err = rx8025_init_client(client, &need_reset);
 588         if (err)
 589                 goto errout_free;
 590
 591         if (need_reset) {
 592                 struct rtc_time tm;
 593                 dev_info(&client->dev,
 594                          "bad conditions detected, resetting date\n");
 595                 rtc_time_to_tm(0, &tm); /* 1970/1/1 */
 596                 rx8025_set_time(&client->dev, &tm);
 597         }
 598
 599         rx8025->rtc = rtc_device_register(client->name, &client->dev,
 600                                           &rx8025_rtc_ops, THIS_MODULE);
 601         if (IS_ERR(rx8025->rtc)) {
 602                 err = PTR_ERR(rx8025->rtc);
 603                 dev_err(&client->dev, "unable to register the class device\n");
 604                 goto errout_free;
 605         }
 606
 607         if (client->irq > 0) {
 608                 dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
 609                 err = request_irq(client->irq, rx8025_irq,
 610                                   0, "rx8025", client);
 611                 if (err) {
 612                         dev_err(&client->dev, "unable to request IRQ\n");
 613                         goto errout_reg;
 614                 }
 615         }
 616
 617         rx8025->rtc->irq_freq = 1;
 618         rx8025->rtc->max_user_freq = 1;
 619
 620         err = rx8025_sysfs_register(&client->dev);
 621         if (err)
 622                 goto errout_irq;
 623
 624         return 0;
 625
 626 errout_irq:
 627         if (client->irq > 0)
 628                 free_irq(client->irq, client);
 629
 630 errout_reg:
 631         rtc_device_unregister(rx8025->rtc);
 632
 633 errout_free:
 634         i2c_set_clientdata(client, NULL);
 635         kfree(rx8025);
 636
 637 errout:
 638         dev_err(&adapter->dev, "probing for rx8025 failed\n");
 639         return err;
 640 }
 641
 642 static int __devexit rx8025_remove(struct i2c_client *client)
 643 {
 644         struct rx8025_data *rx8025 = i2c_get_clientdata(client);
 645         struct mutex *lock = &rx8025->rtc->ops_lock;
 646
 647         if (client->irq > 0) {
 648                 mutex_lock(lock);
 649                 rx8025->exiting = 1;
 650                 mutex_unlock(lock);
 651
 652                 free_irq(client->irq, client);
 653                 flush_scheduled_work();
 654         }
 655
 656         rx8025_sysfs_unregister(&client->dev);
 657         rtc_device_unregister(rx8025->rtc);
 658         i2c_set_clientdata(client, NULL);
 659         kfree(rx8025);
 660         return 0;
 661 }
 662
 663 static struct i2c_driver rx8025_driver = {
 664         .driver = {
 665                 .name = "rtc-rx8025",
 666                 .owner = THIS_MODULE,
 667         },
 668         .probe          = rx8025_probe,
 669         .remove         = __devexit_p(rx8025_remove),
 670         .id_table       = rx8025_id,
 671 };
 672
 673 static int __init rx8025_init(void)
 674 {
 675         return i2c_add_driver(&rx8025_driver);
 676 }
 677
 678 static void __exit rx8025_exit(void)
 679 {
 680         i2c_del_driver(&rx8025_driver);
 681 }
 682
 683 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 684 MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
 685 MODULE_LICENSE("GPL");
 686
 687 module_init(rx8025_init);
 688 module_exit(rx8025_exit);