drivers/rtc/rtc-x1205.c

   1 /*
   2  * An i2c driver for the Xicor/Intersil X1205 RTC
   3  * Copyright 2004 Karen Spearel
   4  * Copyright 2005 Alessandro Zummo
   5  *
   6  * please send all reports to:
   7  *      Karen Spearel <kas111 at gmail dot com>
   8  *      Alessandro Zummo <a.zummo@towertech.it>
   9  *
  10  * based on a lot of other RTC drivers.
  11  *
  12  * Information and datasheet:
  13  * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
  14  *
  15  * This program is free software; you can redistribute it and/or modify
  16  * it under the terms of the GNU General Public License version 2 as
  17  * published by the Free Software Foundation.
  18  */
  19
  20 #include <linux/i2c.h>
  21 #include <linux/bcd.h>
  22 #include <linux/rtc.h>
  23 #include <linux/delay.h>
  24
  25 #define DRV_VERSION "1.0.7"
  26
  27 /* Addresses to scan: none. This chip is located at
  28  * 0x6f and uses a two bytes register addressing.
  29  * Two bytes need to be written to read a single register,
  30  * while most other chips just require one and take the second
  31  * one as the data to be written. To prevent corrupting
  32  * unknown chips, the user must explicitly set the probe parameter.
  33  */
  34
  35 static const unsigned short normal_i2c[] = { I2C_CLIENT_END };
  36
  37 /* Insmod parameters */
  38 I2C_CLIENT_INSMOD;
  39
  40 /* offsets into CCR area */
  41
  42 #define CCR_SEC                 0
  43 #define CCR_MIN                 1
  44 #define CCR_HOUR                2
  45 #define CCR_MDAY                3
  46 #define CCR_MONTH               4
  47 #define CCR_YEAR                5
  48 #define CCR_WDAY                6
  49 #define CCR_Y2K                 7
  50
  51 #define X1205_REG_SR            0x3F    /* status register */
  52 #define X1205_REG_Y2K           0x37
  53 #define X1205_REG_DW            0x36
  54 #define X1205_REG_YR            0x35
  55 #define X1205_REG_MO            0x34
  56 #define X1205_REG_DT            0x33
  57 #define X1205_REG_HR            0x32
  58 #define X1205_REG_MN            0x31
  59 #define X1205_REG_SC            0x30
  60 #define X1205_REG_DTR           0x13
  61 #define X1205_REG_ATR           0x12
  62 #define X1205_REG_INT           0x11
  63 #define X1205_REG_0             0x10
  64 #define X1205_REG_Y2K1          0x0F
  65 #define X1205_REG_DWA1          0x0E
  66 #define X1205_REG_YRA1          0x0D
  67 #define X1205_REG_MOA1          0x0C
  68 #define X1205_REG_DTA1          0x0B
  69 #define X1205_REG_HRA1          0x0A
  70 #define X1205_REG_MNA1          0x09
  71 #define X1205_REG_SCA1          0x08
  72 #define X1205_REG_Y2K0          0x07
  73 #define X1205_REG_DWA0          0x06
  74 #define X1205_REG_YRA0          0x05
  75 #define X1205_REG_MOA0          0x04
  76 #define X1205_REG_DTA0          0x03
  77 #define X1205_REG_HRA0          0x02
  78 #define X1205_REG_MNA0          0x01
  79 #define X1205_REG_SCA0          0x00
  80
  81 #define X1205_CCR_BASE          0x30    /* Base address of CCR */
  82 #define X1205_ALM0_BASE         0x00    /* Base address of ALARM0 */
  83
  84 #define X1205_SR_RTCF           0x01    /* Clock failure */
  85 #define X1205_SR_WEL            0x02    /* Write Enable Latch */
  86 #define X1205_SR_RWEL           0x04    /* Register Write Enable */
  87
  88 #define X1205_DTR_DTR0          0x01
  89 #define X1205_DTR_DTR1          0x02
  90 #define X1205_DTR_DTR2          0x04
  91
  92 #define X1205_HR_MIL            0x80    /* Set in ccr.hour for 24 hr mode */
  93
  94 /* Prototypes */
  95 static int x1205_attach(struct i2c_adapter *adapter);
  96 static int x1205_detach(struct i2c_client *client);
  97 static int x1205_probe(struct i2c_adapter *adapter, int address, int kind);
  98
  99 static struct i2c_driver x1205_driver = {
 100         .driver         = {
 101                 .name   = "x1205",
 102         },
 103         .id             = I2C_DRIVERID_X1205,
 104         .attach_adapter = &x1205_attach,
 105         .detach_client  = &x1205_detach,
 106 };
 107
 108 /*
 109  * In the routines that deal directly with the x1205 hardware, we use
 110  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
 111  * Epoch is initialized as 2000. Time is set to UTC.
 112  */
 113 static int x1205_get_datetime(struct i2c_client *client, struct rtc_time *tm,
 114                                 unsigned char reg_base)
 115 {
 116         unsigned char dt_addr[2] = { 0, reg_base };
 117
 118         unsigned char buf[8];
 119
 120         struct i2c_msg msgs[] = {
 121                 { client->addr, 0, 2, dt_addr },        /* setup read ptr */
 122                 { client->addr, I2C_M_RD, 8, buf },     /* read date */
 123         };
 124
 125         /* read date registers */
 126         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
 127                 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
 128                 return -EIO;
 129         }
 130
 131         dev_dbg(&client->dev,
 132                 "%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
 133                 "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
 134                 __FUNCTION__,
 135                 buf[0], buf[1], buf[2], buf[3],
 136                 buf[4], buf[5], buf[6], buf[7]);
 137
 138         tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
 139         tm->tm_min = BCD2BIN(buf[CCR_MIN]);
 140         tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
 141         tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
 142         tm->tm_mon = BCD2BIN(buf[CCR_MONTH]) - 1; /* mon is 0-11 */
 143         tm->tm_year = BCD2BIN(buf[CCR_YEAR])
 144                         + (BCD2BIN(buf[CCR_Y2K]) * 100) - 1900;
 145         tm->tm_wday = buf[CCR_WDAY];
 146
 147         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
 148                 "mday=%d, mon=%d, year=%d, wday=%d\n",
 149                 __FUNCTION__,
 150                 tm->tm_sec, tm->tm_min, tm->tm_hour,
 151                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 152
 153         return 0;
 154 }
 155
 156 static int x1205_get_status(struct i2c_client *client, unsigned char *sr)
 157 {
 158         static unsigned char sr_addr[2] = { 0, X1205_REG_SR };
 159
 160         struct i2c_msg msgs[] = {
 161                 { client->addr, 0, 2, sr_addr },        /* setup read ptr */
 162                 { client->addr, I2C_M_RD, 1, sr },      /* read status */
 163         };
 164
 165         /* read status register */
 166         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
 167                 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
 168                 return -EIO;
 169         }
 170
 171         return 0;
 172 }
 173
 174 static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
 175                                 int datetoo, u8 reg_base)
 176 {
 177         int i, xfer;
 178         unsigned char buf[8];
 179
 180         static const unsigned char wel[3] = { 0, X1205_REG_SR,
 181                                                 X1205_SR_WEL };
 182
 183         static const unsigned char rwel[3] = { 0, X1205_REG_SR,
 184                                                 X1205_SR_WEL | X1205_SR_RWEL };
 185
 186         static const unsigned char diswe[3] = { 0, X1205_REG_SR, 0 };
 187
 188         dev_dbg(&client->dev,
 189                 "%s: secs=%d, mins=%d, hours=%d\n",
 190                 __FUNCTION__,
 191                 tm->tm_sec, tm->tm_min, tm->tm_hour);
 192
 193         buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
 194         buf[CCR_MIN] = BIN2BCD(tm->tm_min);
 195
 196         /* set hour and 24hr bit */
 197         buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL;
 198
 199         /* should we also set the date? */
 200         if (datetoo) {
 201                 dev_dbg(&client->dev,
 202                         "%s: mday=%d, mon=%d, year=%d, wday=%d\n",
 203                         __FUNCTION__,
 204                         tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 205
 206                 buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);
 207
 208                 /* month, 1 - 12 */
 209                 buf[CCR_MONTH] = BIN2BCD(tm->tm_mon + 1);
 210
 211                 /* year, since the rtc epoch*/
 212                 buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100);
 213                 buf[CCR_WDAY] = tm->tm_wday & 0x07;
 214                 buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
 215         }
 216
 217         /* this sequence is required to unlock the chip */
 218         if ((xfer = i2c_master_send(client, wel, 3)) != 3) {
 219                 dev_err(&client->dev, "%s: wel - %d\n", __FUNCTION__, xfer);
 220                 return -EIO;
 221         }
 222
 223         if ((xfer = i2c_master_send(client, rwel, 3)) != 3) {
 224                 dev_err(&client->dev, "%s: rwel - %d\n", __FUNCTION__, xfer);
 225                 return -EIO;
 226         }
 227
 228         /* write register's data */
 229         for (i = 0; i < (datetoo ? 8 : 3); i++) {
 230                 unsigned char rdata[3] = { 0, reg_base + i, buf[i] };
 231
 232                 xfer = i2c_master_send(client, rdata, 3);
 233                 if (xfer != 3) {
 234                         dev_err(&client->dev,
 235                                 "%s: xfer=%d addr=%02x, data=%02x\n",
 236                                 __FUNCTION__,
 237                                  xfer, rdata[1], rdata[2]);
 238                         return -EIO;
 239                 }
 240         };
 241
 242         /* disable further writes */
 243         if ((xfer = i2c_master_send(client, diswe, 3)) != 3) {
 244                 dev_err(&client->dev, "%s: diswe - %d\n", __FUNCTION__, xfer);
 245                 return -EIO;
 246         }
 247
 248         return 0;
 249 }
 250
 251 static int x1205_fix_osc(struct i2c_client *client)
 252 {
 253         int err;
 254         struct rtc_time tm;
 255
 256         tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
 257
 258         if ((err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE)) < 0)
 259                 dev_err(&client->dev,
 260                         "unable to restart the oscillator\n");
 261
 262         return err;
 263 }
 264
 265 static int x1205_get_dtrim(struct i2c_client *client, int *trim)
 266 {
 267         unsigned char dtr;
 268         static unsigned char dtr_addr[2] = { 0, X1205_REG_DTR };
 269
 270         struct i2c_msg msgs[] = {
 271                 { client->addr, 0, 2, dtr_addr },       /* setup read ptr */
 272                 { client->addr, I2C_M_RD, 1, &dtr },    /* read dtr */
 273         };
 274
 275         /* read dtr register */
 276         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
 277                 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
 278                 return -EIO;
 279         }
 280
 281         dev_dbg(&client->dev, "%s: raw dtr=%x\n", __FUNCTION__, dtr);
 282
 283         *trim = 0;
 284
 285         if (dtr & X1205_DTR_DTR0)
 286                 *trim += 20;
 287
 288         if (dtr & X1205_DTR_DTR1)
 289                 *trim += 10;
 290
 291         if (dtr & X1205_DTR_DTR2)
 292                 *trim = -*trim;
 293
 294         return 0;
 295 }
 296
 297 static int x1205_get_atrim(struct i2c_client *client, int *trim)
 298 {
 299         s8 atr;
 300         static unsigned char atr_addr[2] = { 0, X1205_REG_ATR };
 301
 302         struct i2c_msg msgs[] = {
 303                 { client->addr, 0, 2, atr_addr },       /* setup read ptr */
 304                 { client->addr, I2C_M_RD, 1, &atr },    /* read atr */
 305         };
 306
 307         /* read atr register */
 308         if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
 309                 dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
 310                 return -EIO;
 311         }
 312
 313         dev_dbg(&client->dev, "%s: raw atr=%x\n", __FUNCTION__, atr);
 314
 315         /* atr is a two's complement value on 6 bits,
 316          * perform sign extension. The formula is
 317          * Catr = (atr * 0.25pF) + 11.00pF.
 318          */
 319         if (atr & 0x20)
 320                 atr |= 0xC0;
 321
 322         dev_dbg(&client->dev, "%s: raw atr=%x (%d)\n", __FUNCTION__, atr, atr);
 323
 324         *trim = (atr * 250) + 11000;
 325
 326         dev_dbg(&client->dev, "%s: real=%d\n", __FUNCTION__, *trim);
 327
 328         return 0;
 329 }
 330
 331 struct x1205_limit
 332 {
 333         unsigned char reg, mask, min, max;
 334 };
 335
 336 static int x1205_validate_client(struct i2c_client *client)
 337 {
 338         int i, xfer;
 339
 340         /* Probe array. We will read the register at the specified
 341          * address and check if the given bits are zero.
 342          */
 343         static const unsigned char probe_zero_pattern[] = {
 344                 /* register, mask */
 345                 X1205_REG_SR,   0x18,
 346                 X1205_REG_DTR,  0xF8,
 347                 X1205_REG_ATR,  0xC0,
 348                 X1205_REG_INT,  0x18,
 349                 X1205_REG_0,    0xFF,
 350         };
 351
 352         static const struct x1205_limit probe_limits_pattern[] = {
 353                 /* register, mask, min, max */
 354                 { X1205_REG_Y2K,        0xFF,   19,     20      },
 355                 { X1205_REG_DW,         0xFF,   0,      6       },
 356                 { X1205_REG_YR,         0xFF,   0,      99      },
 357                 { X1205_REG_MO,         0xFF,   0,      12      },
 358                 { X1205_REG_DT,         0xFF,   0,      31      },
 359                 { X1205_REG_HR,         0x7F,   0,      23      },
 360                 { X1205_REG_MN,         0xFF,   0,      59      },
 361                 { X1205_REG_SC,         0xFF,   0,      59      },
 362                 { X1205_REG_Y2K1,       0xFF,   19,     20      },
 363                 { X1205_REG_Y2K0,       0xFF,   19,     20      },
 364         };
 365
 366         /* check that registers have bits a 0 where expected */
 367         for (i = 0; i < ARRAY_SIZE(probe_zero_pattern); i += 2) {
 368                 unsigned char buf;
 369
 370                 unsigned char addr[2] = { 0, probe_zero_pattern[i] };
 371
 372                 struct i2c_msg msgs[2] = {
 373                         { client->addr, 0, 2, addr },
 374                         { client->addr, I2C_M_RD, 1, &buf },
 375                 };
 376
 377                 if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
 378                         dev_err(&client->dev,
 379                                 "%s: could not read register %x\n",
 380                                 __FUNCTION__, probe_zero_pattern[i]);
 381
 382                         return -EIO;
 383                 }
 384
 385                 if ((buf & probe_zero_pattern[i+1]) != 0) {
 386                         dev_err(&client->dev,
 387                                 "%s: register=%02x, zero pattern=%d, value=%x\n",
 388                                 __FUNCTION__, probe_zero_pattern[i], i, buf);
 389
 390                         return -ENODEV;
 391                 }
 392         }
 393
 394         /* check limits (only registers with bcd values) */
 395         for (i = 0; i < ARRAY_SIZE(probe_limits_pattern); i++) {
 396                 unsigned char reg, value;
 397
 398                 unsigned char addr[2] = { 0, probe_limits_pattern[i].reg };
 399
 400                 struct i2c_msg msgs[2] = {
 401                         { client->addr, 0, 2, addr },
 402                         { client->addr, I2C_M_RD, 1, &reg },
 403                 };
 404
 405                 if ((xfer = i2c_transfer(client->adapter, msgs, 2)) != 2) {
 406                         dev_err(&client->dev,
 407                                 "%s: could not read register %x\n",
 408                                 __FUNCTION__, probe_limits_pattern[i].reg);
 409
 410                         return -EIO;
 411                 }
 412
 413                 value = BCD2BIN(reg & probe_limits_pattern[i].mask);
 414
 415                 if (value > probe_limits_pattern[i].max ||
 416                         value < probe_limits_pattern[i].min) {
 417                         dev_dbg(&client->dev,
 418                                 "%s: register=%x, lim pattern=%d, value=%d\n",
 419                                 __FUNCTION__, probe_limits_pattern[i].reg,
 420                                 i, value);
 421
 422                         return -ENODEV;
 423                 }
 424         }
 425
 426         return 0;
 427 }
 428
 429 static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 430 {
 431         return x1205_get_datetime(to_i2c_client(dev),
 432                 &alrm->time, X1205_ALM0_BASE);
 433 }
 434
 435 static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 436 {
 437         return x1205_set_datetime(to_i2c_client(dev),
 438                 &alrm->time, 1, X1205_ALM0_BASE);
 439 }
 440
 441 static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm)
 442 {
 443         return x1205_get_datetime(to_i2c_client(dev),
 444                 tm, X1205_CCR_BASE);
 445 }
 446
 447 static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm)
 448 {
 449         return x1205_set_datetime(to_i2c_client(dev),
 450                 tm, 1, X1205_CCR_BASE);
 451 }
 452
 453 static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
 454 {
 455         int err, dtrim, atrim;
 456
 457         if ((err = x1205_get_dtrim(to_i2c_client(dev), &dtrim)) == 0)
 458                 seq_printf(seq, "digital_trim\t: %d ppm\n", dtrim);
 459
 460         if ((err = x1205_get_atrim(to_i2c_client(dev), &atrim)) == 0)
 461                 seq_printf(seq, "analog_trim\t: %d.%02d pF\n",
 462                         atrim / 1000, atrim % 1000);
 463         return 0;
 464 }
 465
 466 static const struct rtc_class_ops x1205_rtc_ops = {
 467         .proc           = x1205_rtc_proc,
 468         .read_time      = x1205_rtc_read_time,
 469         .set_time       = x1205_rtc_set_time,
 470         .read_alarm     = x1205_rtc_read_alarm,
 471         .set_alarm      = x1205_rtc_set_alarm,
 472 };
 473
 474 static ssize_t x1205_sysfs_show_atrim(struct device *dev,
 475                                 struct device_attribute *attr, char *buf)
 476 {
 477         int err, atrim;
 478
 479         err = x1205_get_atrim(to_i2c_client(dev), &atrim);
 480         if (err)
 481                 return err;
 482
 483         return sprintf(buf, "%d.%02d pF\n", atrim / 1000, atrim % 1000);
 484 }
 485 static DEVICE_ATTR(atrim, S_IRUGO, x1205_sysfs_show_atrim, NULL);
 486
 487 static ssize_t x1205_sysfs_show_dtrim(struct device *dev,
 488                                 struct device_attribute *attr, char *buf)
 489 {
 490         int err, dtrim;
 491
 492         err = x1205_get_dtrim(to_i2c_client(dev), &dtrim);
 493         if (err)
 494                 return err;
 495
 496         return sprintf(buf, "%d ppm\n", dtrim);
 497 }
 498 static DEVICE_ATTR(dtrim, S_IRUGO, x1205_sysfs_show_dtrim, NULL);
 499
 500 static int x1205_attach(struct i2c_adapter *adapter)
 501 {
 502         return i2c_probe(adapter, &addr_data, x1205_probe);
 503 }
 504
 505 static int x1205_probe(struct i2c_adapter *adapter, int address, int kind)
 506 {
 507         int err = 0;
 508         unsigned char sr;
 509         struct i2c_client *client;
 510         struct rtc_device *rtc;
 511
 512         dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
 513
 514         if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
 515                 err = -ENODEV;
 516                 goto exit;
 517         }
 518
 519         if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
 520                 err = -ENOMEM;
 521                 goto exit;
 522         }
 523
 524         /* I2C client */
 525         client->addr = address;
 526         client->driver = &x1205_driver;
 527         client->adapter = adapter;
 528
 529         strlcpy(client->name, x1205_driver.driver.name, I2C_NAME_SIZE);
 530
 531         /* Verify the chip is really an X1205 */
 532         if (kind < 0) {
 533                 if (x1205_validate_client(client) < 0) {
 534                         err = -ENODEV;
 535                         goto exit_kfree;
 536                 }
 537         }
 538
 539         /* Inform the i2c layer */
 540         if ((err = i2c_attach_client(client)))
 541                 goto exit_kfree;
 542
 543         dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
 544
 545         rtc = rtc_device_register(x1205_driver.driver.name, &client->dev,
 546                                 &x1205_rtc_ops, THIS_MODULE);
 547
 548         if (IS_ERR(rtc)) {
 549                 err = PTR_ERR(rtc);
 550                 goto exit_detach;
 551         }
 552
 553         i2c_set_clientdata(client, rtc);
 554
 555         /* Check for power failures and eventualy enable the osc */
 556         if ((err = x1205_get_status(client, &sr)) == 0) {
 557                 if (sr & X1205_SR_RTCF) {
 558                         dev_err(&client->dev,
 559                                 "power failure detected, "
 560                                 "please set the clock\n");
 561                         udelay(50);
 562                         x1205_fix_osc(client);
 563                 }
 564         }
 565         else
 566                 dev_err(&client->dev, "couldn't read status\n");
 567
 568         err = device_create_file(&client->dev, &dev_attr_atrim);
 569         if (err) goto exit_devreg;
 570         err = device_create_file(&client->dev, &dev_attr_dtrim);
 571         if (err) goto exit_atrim;
 572
 573         return 0;
 574
 575 exit_atrim:
 576         device_remove_file(&client->dev, &dev_attr_atrim);
 577
 578 exit_devreg:
 579         rtc_device_unregister(rtc);
 580
 581 exit_detach:
 582         i2c_detach_client(client);
 583
 584 exit_kfree:
 585         kfree(client);
 586
 587 exit:
 588         return err;
 589 }
 590
 591 static int x1205_detach(struct i2c_client *client)
 592 {
 593         int err;
 594         struct rtc_device *rtc = i2c_get_clientdata(client);
 595
 596         if (rtc)
 597                 rtc_device_unregister(rtc);
 598
 599         if ((err = i2c_detach_client(client)))
 600                 return err;
 601
 602         kfree(client);
 603
 604         return 0;
 605 }
 606
 607 static int __init x1205_init(void)
 608 {
 609         return i2c_add_driver(&x1205_driver);
 610 }
 611
 612 static void __exit x1205_exit(void)
 613 {
 614         i2c_del_driver(&x1205_driver);
 615 }
 616
 617 MODULE_AUTHOR(
 618         "Karen Spearel <kas111 at gmail dot com>, "
 619         "Alessandro Zummo <a.zummo@towertech.it>");
 620 MODULE_DESCRIPTION("Xicor/Intersil X1205 RTC driver");
 621 MODULE_LICENSE("GPL");
 622 MODULE_VERSION(DRV_VERSION);
 623
 624 module_init(x1205_init);
 625 module_exit(x1205_exit);