drivers/rtc/rtc-isl12057.c

   1 /*
   2  * rtc-isl12057 - Driver for Intersil ISL12057 I2C Real Time Clock
   3  *
   4  * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
   5  *
   6  * This work is largely based on Intersil ISL1208 driver developed by
   7  * Hebert Valerio Riedel <hvr@gnu.org>.
   8  *
   9  * Detailed datasheet on which this development is based is available here:
  10  *
  11  *  http://natisbad.org/NAS2/refs/ISL12057.pdf
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/mutex.h>
  26 #include <linux/rtc.h>
  27 #include <linux/i2c.h>
  28 #include <linux/bcd.h>
  29 #include <linux/of.h>
  30 #include <linux/of_device.h>
  31 #include <linux/regmap.h>
  32
  33 #define DRV_NAME "rtc-isl12057"
  34
  35 /* RTC section */
  36 #define ISL12057_REG_RTC_SC     0x00    /* Seconds */
  37 #define ISL12057_REG_RTC_MN     0x01    /* Minutes */
  38 #define ISL12057_REG_RTC_HR     0x02    /* Hours */
  39 #define ISL12057_REG_RTC_HR_PM  BIT(5)  /* AM/PM bit in 12h format */
  40 #define ISL12057_REG_RTC_HR_MIL BIT(6)  /* 24h/12h format */
  41 #define ISL12057_REG_RTC_DW     0x03    /* Day of the Week */
  42 #define ISL12057_REG_RTC_DT     0x04    /* Date */
  43 #define ISL12057_REG_RTC_MO     0x05    /* Month */
  44 #define ISL12057_REG_RTC_MO_CEN BIT(7)  /* Century bit */
  45 #define ISL12057_REG_RTC_YR     0x06    /* Year */
  46 #define ISL12057_RTC_SEC_LEN    7
  47
  48 /* Alarm 1 section */
  49 #define ISL12057_REG_A1_SC      0x07    /* Alarm 1 Seconds */
  50 #define ISL12057_REG_A1_MN      0x08    /* Alarm 1 Minutes */
  51 #define ISL12057_REG_A1_HR      0x09    /* Alarm 1 Hours */
  52 #define ISL12057_REG_A1_HR_PM   BIT(5)  /* AM/PM bit in 12h format */
  53 #define ISL12057_REG_A1_HR_MIL  BIT(6)  /* 24h/12h format */
  54 #define ISL12057_REG_A1_DWDT    0x0A    /* Alarm 1 Date / Day of the week */
  55 #define ISL12057_REG_A1_DWDT_B  BIT(6)  /* DW / DT selection bit */
  56 #define ISL12057_A1_SEC_LEN     4
  57
  58 /* Alarm 2 section */
  59 #define ISL12057_REG_A2_MN      0x0B    /* Alarm 2 Minutes */
  60 #define ISL12057_REG_A2_HR      0x0C    /* Alarm 2 Hours */
  61 #define ISL12057_REG_A2_DWDT    0x0D    /* Alarm 2 Date / Day of the week */
  62 #define ISL12057_A2_SEC_LEN     3
  63
  64 /* Control/Status registers */
  65 #define ISL12057_REG_INT        0x0E
  66 #define ISL12057_REG_INT_A1IE   BIT(0)  /* Alarm 1 interrupt enable bit */
  67 #define ISL12057_REG_INT_A2IE   BIT(1)  /* Alarm 2 interrupt enable bit */
  68 #define ISL12057_REG_INT_INTCN  BIT(2)  /* Interrupt control enable bit */
  69 #define ISL12057_REG_INT_RS1    BIT(3)  /* Freq out control bit 1 */
  70 #define ISL12057_REG_INT_RS2    BIT(4)  /* Freq out control bit 2 */
  71 #define ISL12057_REG_INT_EOSC   BIT(7)  /* Oscillator enable bit */
  72
  73 #define ISL12057_REG_SR         0x0F
  74 #define ISL12057_REG_SR_A1F     BIT(0)  /* Alarm 1 interrupt bit */
  75 #define ISL12057_REG_SR_A2F     BIT(1)  /* Alarm 2 interrupt bit */
  76 #define ISL12057_REG_SR_OSF     BIT(7)  /* Oscillator failure bit */
  77
  78 /* Register memory map length */
  79 #define ISL12057_MEM_MAP_LEN    0x10
  80
  81 struct isl12057_rtc_data {
  82         struct rtc_device *rtc;
  83         struct regmap *regmap;
  84         struct mutex lock;
  85         int irq;
  86 };
  87
  88 static void isl12057_rtc_regs_to_tm(struct rtc_time *tm, u8 *regs)
  89 {
  90         tm->tm_sec = bcd2bin(regs[ISL12057_REG_RTC_SC]);
  91         tm->tm_min = bcd2bin(regs[ISL12057_REG_RTC_MN]);
  92
  93         if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_MIL) { /* AM/PM */
  94                 tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x1f);
  95                 if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_PM)
  96                         tm->tm_hour += 12;
  97         } else {                                            /* 24 hour mode */
  98                 tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x3f);
  99         }
 100
 101         tm->tm_mday = bcd2bin(regs[ISL12057_REG_RTC_DT]);
 102         tm->tm_wday = bcd2bin(regs[ISL12057_REG_RTC_DW]) - 1; /* starts at 1 */
 103         tm->tm_mon  = bcd2bin(regs[ISL12057_REG_RTC_MO] & 0x1f) - 1; /* ditto */
 104         tm->tm_year = bcd2bin(regs[ISL12057_REG_RTC_YR]) + 100;
 105
 106         /* Check if years register has overflown from 99 to 00 */
 107         if (regs[ISL12057_REG_RTC_MO] & ISL12057_REG_RTC_MO_CEN)
 108                 tm->tm_year += 100;
 109 }
 110
 111 static int isl12057_rtc_tm_to_regs(u8 *regs, struct rtc_time *tm)
 112 {
 113         u8 century_bit;
 114
 115         /*
 116          * The clock has an 8 bit wide bcd-coded register for the year.
 117          * It also has a century bit encoded in MO flag which provides
 118          * information about overflow of year register from 99 to 00.
 119          * tm_year is an offset from 1900 and we are interested in the
 120          * 2000-2199 range, so any value less than 100 or larger than
 121          * 299 is invalid.
 122          */
 123         if (tm->tm_year < 100 || tm->tm_year > 299)
 124                 return -EINVAL;
 125
 126         century_bit = (tm->tm_year > 199) ? ISL12057_REG_RTC_MO_CEN : 0;
 127
 128         regs[ISL12057_REG_RTC_SC] = bin2bcd(tm->tm_sec);
 129         regs[ISL12057_REG_RTC_MN] = bin2bcd(tm->tm_min);
 130         regs[ISL12057_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */
 131         regs[ISL12057_REG_RTC_DT] = bin2bcd(tm->tm_mday);
 132         regs[ISL12057_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1) | century_bit;
 133         regs[ISL12057_REG_RTC_YR] = bin2bcd(tm->tm_year % 100);
 134         regs[ISL12057_REG_RTC_DW] = bin2bcd(tm->tm_wday + 1);
 135
 136         return 0;
 137 }
 138
 139 /*
 140  * Try and match register bits w/ fixed null values to see whether we
 141  * are dealing with an ISL12057. Note: this function is called early
 142  * during init and hence does need mutex protection.
 143  */
 144 static int isl12057_i2c_validate_chip(struct regmap *regmap)
 145 {
 146         u8 regs[ISL12057_MEM_MAP_LEN];
 147         static const u8 mask[ISL12057_MEM_MAP_LEN] = { 0x80, 0x80, 0x80, 0xf8,
 148                                                        0xc0, 0x60, 0x00, 0x00,
 149                                                        0x00, 0x00, 0x00, 0x00,
 150                                                        0x00, 0x00, 0x60, 0x7c };
 151         int ret, i;
 152
 153         ret = regmap_bulk_read(regmap, 0, regs, ISL12057_MEM_MAP_LEN);
 154         if (ret)
 155                 return ret;
 156
 157         for (i = 0; i < ISL12057_MEM_MAP_LEN; ++i) {
 158                 if (regs[i] & mask[i])  /* check if bits are cleared */
 159                         return -ENODEV;
 160         }
 161
 162         return 0;
 163 }
 164
 165 static int _isl12057_rtc_clear_alarm(struct device *dev)
 166 {
 167         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 168         int ret;
 169
 170         ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
 171                                  ISL12057_REG_SR_A1F, 0);
 172         if (ret)
 173                 dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret);
 174
 175         return ret;
 176 }
 177
 178 static int _isl12057_rtc_update_alarm(struct device *dev, int enable)
 179 {
 180         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 181         int ret;
 182
 183         ret = regmap_update_bits(data->regmap, ISL12057_REG_INT,
 184                                  ISL12057_REG_INT_A1IE,
 185                                  enable ? ISL12057_REG_INT_A1IE : 0);
 186         if (ret)
 187                 dev_err(dev, "%s: changing alarm interrupt flag failed (%d)\n",
 188                         __func__, ret);
 189
 190         return ret;
 191 }
 192
 193 /*
 194  * Note: as we only read from device and do not perform any update, there is
 195  * no need for an equivalent function which would try and get driver's main
 196  * lock. Here, it is safe for everyone if we just use regmap internal lock
 197  * on the device when reading.
 198  */
 199 static int _isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
 200 {
 201         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 202         u8 regs[ISL12057_RTC_SEC_LEN];
 203         unsigned int sr;
 204         int ret;
 205
 206         ret = regmap_read(data->regmap, ISL12057_REG_SR, &sr);
 207         if (ret) {
 208                 dev_err(dev, "%s: unable to read oscillator status flag (%d)\n",
 209                         __func__, ret);
 210                 goto out;
 211         } else {
 212                 if (sr & ISL12057_REG_SR_OSF) {
 213                         ret = -ENODATA;
 214                         goto out;
 215                 }
 216         }
 217
 218         ret = regmap_bulk_read(data->regmap, ISL12057_REG_RTC_SC, regs,
 219                                ISL12057_RTC_SEC_LEN);
 220         if (ret)
 221                 dev_err(dev, "%s: unable to read RTC time section (%d)\n",
 222                         __func__, ret);
 223
 224 out:
 225         if (ret)
 226                 return ret;
 227
 228         isl12057_rtc_regs_to_tm(tm, regs);
 229
 230         return rtc_valid_tm(tm);
 231 }
 232
 233 static int isl12057_rtc_update_alarm(struct device *dev, int enable)
 234 {
 235         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 236         int ret;
 237
 238         mutex_lock(&data->lock);
 239         ret = _isl12057_rtc_update_alarm(dev, enable);
 240         mutex_unlock(&data->lock);
 241
 242         return ret;
 243 }
 244
 245 static int isl12057_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 246 {
 247         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 248         struct rtc_time *alarm_tm = &alarm->time;
 249         u8 regs[ISL12057_A1_SEC_LEN];
 250         unsigned int ir;
 251         int ret;
 252
 253         mutex_lock(&data->lock);
 254         ret = regmap_bulk_read(data->regmap, ISL12057_REG_A1_SC, regs,
 255                                ISL12057_A1_SEC_LEN);
 256         if (ret) {
 257                 dev_err(dev, "%s: reading alarm section failed (%d)\n",
 258                         __func__, ret);
 259                 goto err_unlock;
 260         }
 261
 262         alarm_tm->tm_sec  = bcd2bin(regs[0] & 0x7f);
 263         alarm_tm->tm_min  = bcd2bin(regs[1] & 0x7f);
 264         alarm_tm->tm_hour = bcd2bin(regs[2] & 0x3f);
 265         alarm_tm->tm_mday = bcd2bin(regs[3] & 0x3f);
 266
 267         ret = regmap_read(data->regmap, ISL12057_REG_INT, &ir);
 268         if (ret) {
 269                 dev_err(dev, "%s: reading alarm interrupt flag failed (%d)\n",
 270                         __func__, ret);
 271                 goto err_unlock;
 272         }
 273
 274         alarm->enabled = !!(ir & ISL12057_REG_INT_A1IE);
 275
 276 err_unlock:
 277         mutex_unlock(&data->lock);
 278
 279         return ret;
 280 }
 281
 282 static int isl12057_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 283 {
 284         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 285         struct rtc_time *alarm_tm = &alarm->time;
 286         unsigned long rtc_secs, alarm_secs;
 287         u8 regs[ISL12057_A1_SEC_LEN];
 288         struct rtc_time rtc_tm;
 289         int ret, enable = 1;
 290
 291         mutex_lock(&data->lock);
 292         ret = _isl12057_rtc_read_time(dev, &rtc_tm);
 293         if (ret)
 294                 goto err_unlock;
 295
 296         ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
 297         if (ret)
 298                 goto err_unlock;
 299
 300         ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
 301         if (ret)
 302                 goto err_unlock;
 303
 304         /* If alarm time is before current time, disable the alarm */
 305         if (!alarm->enabled || alarm_secs <= rtc_secs) {
 306                 enable = 0;
 307         } else {
 308                 /*
 309                  * Chip only support alarms up to one month in the future. Let's
 310                  * return an error if we get something after that limit.
 311                  * Comparison is done by incrementing rtc_tm month field by one
 312                  * and checking alarm value is still below.
 313                  */
 314                 if (rtc_tm.tm_mon == 11) { /* handle year wrapping */
 315                         rtc_tm.tm_mon = 0;
 316                         rtc_tm.tm_year += 1;
 317                 } else {
 318                         rtc_tm.tm_mon += 1;
 319                 }
 320
 321                 ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
 322                 if (ret)
 323                         goto err_unlock;
 324
 325                 if (alarm_secs > rtc_secs) {
 326                         dev_err(dev, "%s: max for alarm is one month (%d)\n",
 327                                 __func__, ret);
 328                         ret = -EINVAL;
 329                         goto err_unlock;
 330                 }
 331         }
 332
 333         /* Disable the alarm before modifying it */
 334         ret = _isl12057_rtc_update_alarm(dev, 0);
 335         if (ret < 0) {
 336                 dev_err(dev, "%s: unable to disable the alarm (%d)\n",
 337                         __func__, ret);
 338                 goto err_unlock;
 339         }
 340
 341         /* Program alarm registers */
 342         regs[0] = bin2bcd(alarm_tm->tm_sec) & 0x7f;
 343         regs[1] = bin2bcd(alarm_tm->tm_min) & 0x7f;
 344         regs[2] = bin2bcd(alarm_tm->tm_hour) & 0x3f;
 345         regs[3] = bin2bcd(alarm_tm->tm_mday) & 0x3f;
 346
 347         ret = regmap_bulk_write(data->regmap, ISL12057_REG_A1_SC, regs,
 348                                 ISL12057_A1_SEC_LEN);
 349         if (ret < 0) {
 350                 dev_err(dev, "%s: writing alarm section failed (%d)\n",
 351                         __func__, ret);
 352                 goto err_unlock;
 353         }
 354
 355         /* Enable or disable alarm */
 356         ret = _isl12057_rtc_update_alarm(dev, enable);
 357
 358 err_unlock:
 359         mutex_unlock(&data->lock);
 360
 361         return ret;
 362 }
 363
 364 static int isl12057_rtc_set_time(struct device *dev, struct rtc_time *tm)
 365 {
 366         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 367         u8 regs[ISL12057_RTC_SEC_LEN];
 368         int ret;
 369
 370         ret = isl12057_rtc_tm_to_regs(regs, tm);
 371         if (ret)
 372                 return ret;
 373
 374         mutex_lock(&data->lock);
 375         ret = regmap_bulk_write(data->regmap, ISL12057_REG_RTC_SC, regs,
 376                                 ISL12057_RTC_SEC_LEN);
 377         if (ret) {
 378                 dev_err(dev, "%s: unable to write RTC time section (%d)\n",
 379                         __func__, ret);
 380                 goto out;
 381         }
 382
 383         /*
 384          * Now that RTC time has been updated, let's clear oscillator
 385          * failure flag, if needed.
 386          */
 387         ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
 388                                  ISL12057_REG_SR_OSF, 0);
 389         if (ret < 0)
 390                 dev_err(dev, "%s: unable to clear osc. failure bit (%d)\n",
 391                         __func__, ret);
 392
 393 out:
 394         mutex_unlock(&data->lock);
 395
 396         return ret;
 397 }
 398
 399 /*
 400  * Check current RTC status and enable/disable what needs to be. Return 0 if
 401  * everything went ok and a negative value upon error. Note: this function
 402  * is called early during init and hence does need mutex protection.
 403  */
 404 static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap)
 405 {
 406         int ret;
 407
 408         /* Enable oscillator if not already running */
 409         ret = regmap_update_bits(regmap, ISL12057_REG_INT,
 410                                  ISL12057_REG_INT_EOSC, 0);
 411         if (ret < 0) {
 412                 dev_err(dev, "%s: unable to enable oscillator (%d)\n",
 413                         __func__, ret);
 414                 return ret;
 415         }
 416
 417         /* Clear alarm bit if needed */
 418         ret = regmap_update_bits(regmap, ISL12057_REG_SR,
 419                                  ISL12057_REG_SR_A1F, 0);
 420         if (ret < 0) {
 421                 dev_err(dev, "%s: unable to clear alarm bit (%d)\n",
 422                         __func__, ret);
 423                 return ret;
 424         }
 425
 426         return 0;
 427 }
 428
 429 #ifdef CONFIG_OF
 430 /*
 431  * One would expect the device to be marked as a wakeup source only
 432  * when an IRQ pin of the RTC is routed to an interrupt line of the
 433  * CPU. In practice, such an IRQ pin can be connected to a PMIC and
 434  * this allows the device to be powered up when RTC alarm rings. This
 435  * is for instance the case on ReadyNAS 102, 104 and 2120. On those
 436  * devices with no IRQ driectly connected to the SoC, the RTC chip
 437  * can be forced as a wakeup source by stating that explicitly in
 438  * the device's .dts file using the "wakeup-source" boolean property.
 439  * This will guarantee 'wakealarm' sysfs entry is available on the device.
 440  *
 441  * The function below returns 1, i.e. the capability of the chip to
 442  * wakeup the device, based on IRQ availability or if the boolean
 443  * property has been set in the .dts file. Otherwise, it returns 0.
 444  */
 445
 446 static bool isl12057_can_wakeup_machine(struct device *dev)
 447 {
 448         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 449
 450         return data->irq || of_property_read_bool(dev->of_node, "wakeup-source")
 451                 || of_property_read_bool(dev->of_node, /* legacy */
 452                                          "isil,irq2-can-wakeup-machine");
 453 }
 454 #else
 455 static bool isl12057_can_wakeup_machine(struct device *dev)
 456 {
 457         struct isl12057_rtc_data *data = dev_get_drvdata(dev);
 458
 459         return !!data->irq;
 460 }
 461 #endif
 462
 463 static int isl12057_rtc_alarm_irq_enable(struct device *dev,
 464                                          unsigned int enable)
 465 {
 466         struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
 467         int ret = -ENOTTY;
 468
 469         if (rtc_data->irq)
 470                 ret = isl12057_rtc_update_alarm(dev, enable);
 471
 472         return ret;
 473 }
 474
 475 static irqreturn_t isl12057_rtc_interrupt(int irq, void *data)
 476 {
 477         struct i2c_client *client = data;
 478         struct isl12057_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
 479         struct rtc_device *rtc = rtc_data->rtc;
 480         int ret, handled = IRQ_NONE;
 481         unsigned int sr;
 482
 483         ret = regmap_read(rtc_data->regmap, ISL12057_REG_SR, &sr);
 484         if (!ret && (sr & ISL12057_REG_SR_A1F)) {
 485                 dev_dbg(&client->dev, "RTC alarm!\n");
 486
 487                 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
 488
 489                 /* Acknowledge and disable the alarm */
 490                 _isl12057_rtc_clear_alarm(&client->dev);
 491                 _isl12057_rtc_update_alarm(&client->dev, 0);
 492
 493                 handled = IRQ_HANDLED;
 494         }
 495
 496         return handled;
 497 }
 498
 499 static const struct rtc_class_ops rtc_ops = {
 500         .read_time = _isl12057_rtc_read_time,
 501         .set_time = isl12057_rtc_set_time,
 502         .read_alarm = isl12057_rtc_read_alarm,
 503         .set_alarm = isl12057_rtc_set_alarm,
 504         .alarm_irq_enable = isl12057_rtc_alarm_irq_enable,
 505 };
 506
 507 static const struct regmap_config isl12057_rtc_regmap_config = {
 508         .reg_bits = 8,
 509         .val_bits = 8,
 510 };
 511
 512 static int isl12057_probe(struct i2c_client *client,
 513                           const struct i2c_device_id *id)
 514 {
 515         struct device *dev = &client->dev;
 516         struct isl12057_rtc_data *data;
 517         struct regmap *regmap;
 518         int ret;
 519
 520         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
 521                                      I2C_FUNC_SMBUS_BYTE_DATA |
 522                                      I2C_FUNC_SMBUS_I2C_BLOCK))
 523                 return -ENODEV;
 524
 525         regmap = devm_regmap_init_i2c(client, &isl12057_rtc_regmap_config);
 526         if (IS_ERR(regmap)) {
 527                 ret = PTR_ERR(regmap);
 528                 dev_err(dev, "%s: regmap allocation failed (%d)\n",
 529                         __func__, ret);
 530                 return ret;
 531         }
 532
 533         ret = isl12057_i2c_validate_chip(regmap);
 534         if (ret)
 535                 return ret;
 536
 537         ret = isl12057_check_rtc_status(dev, regmap);
 538         if (ret)
 539                 return ret;
 540
 541         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 542         if (!data)
 543                 return -ENOMEM;
 544
 545         mutex_init(&data->lock);
 546         data->regmap = regmap;
 547         dev_set_drvdata(dev, data);
 548
 549         if (client->irq > 0) {
 550                 ret = devm_request_threaded_irq(dev, client->irq, NULL,
 551                                                 isl12057_rtc_interrupt,
 552                                                 IRQF_SHARED|IRQF_ONESHOT,
 553                                                 DRV_NAME, client);
 554                 if (!ret)
 555                         data->irq = client->irq;
 556                 else
 557                         dev_err(dev, "%s: irq %d unavailable (%d)\n", __func__,
 558                                 client->irq, ret);
 559         }
 560
 561         if (isl12057_can_wakeup_machine(dev))
 562                 device_init_wakeup(dev, true);
 563
 564         data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops,
 565                                              THIS_MODULE);
 566         ret = PTR_ERR_OR_ZERO(data->rtc);
 567         if (ret) {
 568                 dev_err(dev, "%s: unable to register RTC device (%d)\n",
 569                         __func__, ret);
 570                 goto err;
 571         }
 572
 573         /* We cannot support UIE mode if we do not have an IRQ line */
 574         if (!data->irq)
 575                 data->rtc->uie_unsupported = 1;
 576
 577 err:
 578         return ret;
 579 }
 580
 581 static int isl12057_remove(struct i2c_client *client)
 582 {
 583         if (isl12057_can_wakeup_machine(&client->dev))
 584                 device_init_wakeup(&client->dev, false);
 585
 586         return 0;
 587 }
 588
 589 #ifdef CONFIG_PM_SLEEP
 590 static int isl12057_rtc_suspend(struct device *dev)
 591 {
 592         struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
 593
 594         if (rtc_data->irq && device_may_wakeup(dev))
 595                 return enable_irq_wake(rtc_data->irq);
 596
 597         return 0;
 598 }
 599
 600 static int isl12057_rtc_resume(struct device *dev)
 601 {
 602         struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
 603
 604         if (rtc_data->irq && device_may_wakeup(dev))
 605                 return disable_irq_wake(rtc_data->irq);
 606
 607         return 0;
 608 }
 609 #endif
 610
 611 static SIMPLE_DEV_PM_OPS(isl12057_rtc_pm_ops, isl12057_rtc_suspend,
 612                          isl12057_rtc_resume);
 613
 614 #ifdef CONFIG_OF
 615 static const struct of_device_id isl12057_dt_match[] = {
 616         { .compatible = "isl,isl12057" }, /* for backward compat., don't use */
 617         { .compatible = "isil,isl12057" },
 618         { },
 619 };
 620 MODULE_DEVICE_TABLE(of, isl12057_dt_match);
 621 #endif
 622
 623 static const struct i2c_device_id isl12057_id[] = {
 624         { "isl12057", 0 },
 625         { }
 626 };
 627 MODULE_DEVICE_TABLE(i2c, isl12057_id);
 628
 629 static struct i2c_driver isl12057_driver = {
 630         .driver = {
 631                 .name = DRV_NAME,
 632                 .pm = &isl12057_rtc_pm_ops,
 633                 .of_match_table = of_match_ptr(isl12057_dt_match),
 634         },
 635         .probe    = isl12057_probe,
 636         .remove   = isl12057_remove,
 637         .id_table = isl12057_id,
 638 };
 639 module_i2c_driver(isl12057_driver);
 640
 641 MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
 642 MODULE_DESCRIPTION("Intersil ISL12057 RTC driver");
 643 MODULE_LICENSE("GPL");