drivers/rtc/rtc-rv8803.c

   1 /*
   2  * RTC driver for the Micro Crystal RV8803
   3  *
   4  * Copyright (C) 2015 Micro Crystal SA
   5  *
   6  * Alexandre Belloni <alexandre.belloni@free-electrons.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  */
  13
  14 #include <linux/bcd.h>
  15 #include <linux/bitops.h>
  16 #include <linux/log2.h>
  17 #include <linux/i2c.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/of_device.h>
  22 #include <linux/rtc.h>
  23
  24 #define RV8803_I2C_TRY_COUNT            4
  25
  26 #define RV8803_SEC                      0x00
  27 #define RV8803_MIN                      0x01
  28 #define RV8803_HOUR                     0x02
  29 #define RV8803_WEEK                     0x03
  30 #define RV8803_DAY                      0x04
  31 #define RV8803_MONTH                    0x05
  32 #define RV8803_YEAR                     0x06
  33 #define RV8803_RAM                      0x07
  34 #define RV8803_ALARM_MIN                0x08
  35 #define RV8803_ALARM_HOUR               0x09
  36 #define RV8803_ALARM_WEEK_OR_DAY        0x0A
  37 #define RV8803_EXT                      0x0D
  38 #define RV8803_FLAG                     0x0E
  39 #define RV8803_CTRL                     0x0F
  40
  41 #define RV8803_EXT_WADA                 BIT(6)
  42
  43 #define RV8803_FLAG_V1F                 BIT(0)
  44 #define RV8803_FLAG_V2F                 BIT(1)
  45 #define RV8803_FLAG_AF                  BIT(3)
  46 #define RV8803_FLAG_TF                  BIT(4)
  47 #define RV8803_FLAG_UF                  BIT(5)
  48
  49 #define RV8803_CTRL_RESET               BIT(0)
  50
  51 #define RV8803_CTRL_EIE                 BIT(2)
  52 #define RV8803_CTRL_AIE                 BIT(3)
  53 #define RV8803_CTRL_TIE                 BIT(4)
  54 #define RV8803_CTRL_UIE                 BIT(5)
  55
  56 #define RX8900_BACKUP_CTRL              0x18
  57 #define RX8900_FLAG_SWOFF               BIT(2)
  58 #define RX8900_FLAG_VDETOFF             BIT(3)
  59
  60 enum rv8803_type {
  61         rv_8803,
  62         rx_8900
  63 };
  64
  65 struct rv8803_data {
  66         struct i2c_client *client;
  67         struct rtc_device *rtc;
  68         struct mutex flags_lock;
  69         u8 ctrl;
  70         enum rv8803_type type;
  71 };
  72
  73 static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
  74 {
  75         int try = RV8803_I2C_TRY_COUNT;
  76         s32 ret;
  77
  78         /*
  79          * There is a 61µs window during which the RTC does not acknowledge I2C
  80          * transfers. In that case, ensure that there are multiple attempts.
  81          */
  82         do
  83                 ret = i2c_smbus_read_byte_data(client, reg);
  84         while ((ret == -ENXIO || ret == -EIO) && --try);
  85         if (ret < 0)
  86                 dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
  87
  88         return ret;
  89 }
  90
  91 static int rv8803_read_regs(const struct i2c_client *client,
  92                             u8 reg, u8 count, u8 *values)
  93 {
  94         int try = RV8803_I2C_TRY_COUNT;
  95         s32 ret;
  96
  97         do
  98                 ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
  99         while ((ret == -ENXIO || ret == -EIO) && --try);
 100         if (ret != count) {
 101                 dev_err(&client->dev,
 102                         "Unable to read registers 0x%02x..0x%02x\n",
 103                         reg, reg + count - 1);
 104                 return ret < 0 ? ret : -EIO;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
 111 {
 112         int try = RV8803_I2C_TRY_COUNT;
 113         s32 ret;
 114
 115         do
 116                 ret = i2c_smbus_write_byte_data(client, reg, value);
 117         while ((ret == -ENXIO || ret == -EIO) && --try);
 118         if (ret)
 119                 dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
 120
 121         return ret;
 122 }
 123
 124 static int rv8803_write_regs(const struct i2c_client *client,
 125                              u8 reg, u8 count, const u8 *values)
 126 {
 127         int try = RV8803_I2C_TRY_COUNT;
 128         s32 ret;
 129
 130         do
 131                 ret = i2c_smbus_write_i2c_block_data(client, reg, count,
 132                                                      values);
 133         while ((ret == -ENXIO || ret == -EIO) && --try);
 134         if (ret)
 135                 dev_err(&client->dev,
 136                         "Unable to write registers 0x%02x..0x%02x\n",
 137                         reg, reg + count - 1);
 138
 139         return ret;
 140 }
 141
 142 static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
 143 {
 144         struct i2c_client *client = dev_id;
 145         struct rv8803_data *rv8803 = i2c_get_clientdata(client);
 146         unsigned long events = 0;
 147         int flags;
 148
 149         mutex_lock(&rv8803->flags_lock);
 150
 151         flags = rv8803_read_reg(client, RV8803_FLAG);
 152         if (flags <= 0) {
 153                 mutex_unlock(&rv8803->flags_lock);
 154                 return IRQ_NONE;
 155         }
 156
 157         if (flags & RV8803_FLAG_V1F)
 158                 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
 159
 160         if (flags & RV8803_FLAG_V2F)
 161                 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
 162
 163         if (flags & RV8803_FLAG_TF) {
 164                 flags &= ~RV8803_FLAG_TF;
 165                 rv8803->ctrl &= ~RV8803_CTRL_TIE;
 166                 events |= RTC_PF;
 167         }
 168
 169         if (flags & RV8803_FLAG_AF) {
 170                 flags &= ~RV8803_FLAG_AF;
 171                 rv8803->ctrl &= ~RV8803_CTRL_AIE;
 172                 events |= RTC_AF;
 173         }
 174
 175         if (flags & RV8803_FLAG_UF) {
 176                 flags &= ~RV8803_FLAG_UF;
 177                 rv8803->ctrl &= ~RV8803_CTRL_UIE;
 178                 events |= RTC_UF;
 179         }
 180
 181         if (events) {
 182                 rtc_update_irq(rv8803->rtc, 1, events);
 183                 rv8803_write_reg(client, RV8803_FLAG, flags);
 184                 rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
 185         }
 186
 187         mutex_unlock(&rv8803->flags_lock);
 188
 189         return IRQ_HANDLED;
 190 }
 191
 192 static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
 193 {
 194         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 195         u8 date1[7];
 196         u8 date2[7];
 197         u8 *date = date1;
 198         int ret, flags;
 199
 200         flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
 201         if (flags < 0)
 202                 return flags;
 203
 204         if (flags & RV8803_FLAG_V2F) {
 205                 dev_warn(dev, "Voltage low, data is invalid.\n");
 206                 return -EINVAL;
 207         }
 208
 209         ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
 210         if (ret)
 211                 return ret;
 212
 213         if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
 214                 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
 215                 if (ret)
 216                         return ret;
 217
 218                 if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
 219                         date = date2;
 220         }
 221
 222         tm->tm_sec  = bcd2bin(date[RV8803_SEC] & 0x7f);
 223         tm->tm_min  = bcd2bin(date[RV8803_MIN] & 0x7f);
 224         tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
 225         tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f);
 226         tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
 227         tm->tm_mon  = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
 228         tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
 229
 230         return 0;
 231 }
 232
 233 static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
 234 {
 235         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 236         u8 date[7];
 237         int ctrl, flags, ret;
 238
 239         if ((tm->tm_year < 100) || (tm->tm_year > 199))
 240                 return -EINVAL;
 241
 242         ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
 243         if (ctrl < 0)
 244                 return ctrl;
 245
 246         /* Stop the clock */
 247         ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 248                                ctrl | RV8803_CTRL_RESET);
 249         if (ret)
 250                 return ret;
 251
 252         date[RV8803_SEC]   = bin2bcd(tm->tm_sec);
 253         date[RV8803_MIN]   = bin2bcd(tm->tm_min);
 254         date[RV8803_HOUR]  = bin2bcd(tm->tm_hour);
 255         date[RV8803_WEEK]  = 1 << (tm->tm_wday);
 256         date[RV8803_DAY]   = bin2bcd(tm->tm_mday);
 257         date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
 258         date[RV8803_YEAR]  = bin2bcd(tm->tm_year - 100);
 259
 260         ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
 261         if (ret)
 262                 return ret;
 263
 264         /* Restart the clock */
 265         ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 266                                ctrl & ~RV8803_CTRL_RESET);
 267         if (ret)
 268                 return ret;
 269
 270         mutex_lock(&rv8803->flags_lock);
 271
 272         flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
 273         if (flags < 0) {
 274                 mutex_unlock(&rv8803->flags_lock);
 275                 return flags;
 276         }
 277
 278         ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
 279                                flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
 280
 281         mutex_unlock(&rv8803->flags_lock);
 282
 283         return ret;
 284 }
 285
 286 static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 287 {
 288         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 289         struct i2c_client *client = rv8803->client;
 290         u8 alarmvals[3];
 291         int flags, ret;
 292
 293         ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
 294         if (ret)
 295                 return ret;
 296
 297         flags = rv8803_read_reg(client, RV8803_FLAG);
 298         if (flags < 0)
 299                 return flags;
 300
 301         alrm->time.tm_sec  = 0;
 302         alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
 303         alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
 304         alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
 305
 306         alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
 307         alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
 308
 309         return 0;
 310 }
 311
 312 static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 313 {
 314         struct i2c_client *client = to_i2c_client(dev);
 315         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 316         u8 alarmvals[3];
 317         u8 ctrl[2];
 318         int ret, err;
 319
 320         /* The alarm has no seconds, round up to nearest minute */
 321         if (alrm->time.tm_sec) {
 322                 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
 323
 324                 alarm_time += 60 - alrm->time.tm_sec;
 325                 rtc_time64_to_tm(alarm_time, &alrm->time);
 326         }
 327
 328         mutex_lock(&rv8803->flags_lock);
 329
 330         ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
 331         if (ret) {
 332                 mutex_unlock(&rv8803->flags_lock);
 333                 return ret;
 334         }
 335
 336         alarmvals[0] = bin2bcd(alrm->time.tm_min);
 337         alarmvals[1] = bin2bcd(alrm->time.tm_hour);
 338         alarmvals[2] = bin2bcd(alrm->time.tm_mday);
 339
 340         if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
 341                 rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
 342                 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 343                                        rv8803->ctrl);
 344                 if (err) {
 345                         mutex_unlock(&rv8803->flags_lock);
 346                         return err;
 347                 }
 348         }
 349
 350         ctrl[1] &= ~RV8803_FLAG_AF;
 351         err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
 352         mutex_unlock(&rv8803->flags_lock);
 353         if (err)
 354                 return err;
 355
 356         err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
 357         if (err)
 358                 return err;
 359
 360         if (alrm->enabled) {
 361                 if (rv8803->rtc->uie_rtctimer.enabled)
 362                         rv8803->ctrl |= RV8803_CTRL_UIE;
 363                 if (rv8803->rtc->aie_timer.enabled)
 364                         rv8803->ctrl |= RV8803_CTRL_AIE;
 365
 366                 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 367                                        rv8803->ctrl);
 368                 if (err)
 369                         return err;
 370         }
 371
 372         return 0;
 373 }
 374
 375 static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
 376 {
 377         struct i2c_client *client = to_i2c_client(dev);
 378         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 379         int ctrl, flags, err;
 380
 381         ctrl = rv8803->ctrl;
 382
 383         if (enabled) {
 384                 if (rv8803->rtc->uie_rtctimer.enabled)
 385                         ctrl |= RV8803_CTRL_UIE;
 386                 if (rv8803->rtc->aie_timer.enabled)
 387                         ctrl |= RV8803_CTRL_AIE;
 388         } else {
 389                 if (!rv8803->rtc->uie_rtctimer.enabled)
 390                         ctrl &= ~RV8803_CTRL_UIE;
 391                 if (!rv8803->rtc->aie_timer.enabled)
 392                         ctrl &= ~RV8803_CTRL_AIE;
 393         }
 394
 395         mutex_lock(&rv8803->flags_lock);
 396         flags = rv8803_read_reg(client, RV8803_FLAG);
 397         if (flags < 0) {
 398                 mutex_unlock(&rv8803->flags_lock);
 399                 return flags;
 400         }
 401         flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
 402         err = rv8803_write_reg(client, RV8803_FLAG, flags);
 403         mutex_unlock(&rv8803->flags_lock);
 404         if (err)
 405                 return err;
 406
 407         if (ctrl != rv8803->ctrl) {
 408                 rv8803->ctrl = ctrl;
 409                 err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
 410                 if (err)
 411                         return err;
 412         }
 413
 414         return 0;
 415 }
 416
 417 static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 418 {
 419         struct i2c_client *client = to_i2c_client(dev);
 420         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 421         int flags, ret = 0;
 422
 423         switch (cmd) {
 424         case RTC_VL_READ:
 425                 flags = rv8803_read_reg(client, RV8803_FLAG);
 426                 if (flags < 0)
 427                         return flags;
 428
 429                 if (flags & RV8803_FLAG_V1F)
 430                         dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
 431
 432                 if (flags & RV8803_FLAG_V2F)
 433                         dev_warn(&client->dev, "Voltage low, data loss detected.\n");
 434
 435                 flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F;
 436
 437                 if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
 438                         return -EFAULT;
 439
 440                 return 0;
 441
 442         case RTC_VL_CLR:
 443                 mutex_lock(&rv8803->flags_lock);
 444                 flags = rv8803_read_reg(client, RV8803_FLAG);
 445                 if (flags < 0) {
 446                         mutex_unlock(&rv8803->flags_lock);
 447                         return flags;
 448                 }
 449
 450                 flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
 451                 ret = rv8803_write_reg(client, RV8803_FLAG, flags);
 452                 mutex_unlock(&rv8803->flags_lock);
 453                 if (ret)
 454                         return ret;
 455
 456                 return 0;
 457
 458         default:
 459                 return -ENOIOCTLCMD;
 460         }
 461 }
 462
 463 static ssize_t rv8803_nvram_write(struct file *filp, struct kobject *kobj,
 464                                   struct bin_attribute *attr,
 465                                   char *buf, loff_t off, size_t count)
 466 {
 467         struct device *dev = kobj_to_dev(kobj);
 468         struct i2c_client *client = to_i2c_client(dev);
 469         int ret;
 470
 471         ret = rv8803_write_reg(client, RV8803_RAM, buf[0]);
 472         if (ret)
 473                 return ret;
 474
 475         return 1;
 476 }
 477
 478 static ssize_t rv8803_nvram_read(struct file *filp, struct kobject *kobj,
 479                                  struct bin_attribute *attr,
 480                                  char *buf, loff_t off, size_t count)
 481 {
 482         struct device *dev = kobj_to_dev(kobj);
 483         struct i2c_client *client = to_i2c_client(dev);
 484         int ret;
 485
 486         ret = rv8803_read_reg(client, RV8803_RAM);
 487         if (ret < 0)
 488                 return ret;
 489
 490         buf[0] = ret;
 491
 492         return 1;
 493 }
 494
 495 static struct bin_attribute rv8803_nvram_attr = {
 496         .attr = {
 497                 .name = "nvram",
 498                 .mode = S_IRUGO | S_IWUSR,
 499         },
 500         .size = 1,
 501         .read = rv8803_nvram_read,
 502         .write = rv8803_nvram_write,
 503 };
 504
 505 static struct rtc_class_ops rv8803_rtc_ops = {
 506         .read_time = rv8803_get_time,
 507         .set_time = rv8803_set_time,
 508         .ioctl = rv8803_ioctl,
 509 };
 510
 511 static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
 512 {
 513         struct i2c_client *client = rv8803->client;
 514         struct device_node *node = client->dev.of_node;
 515         int err;
 516         u8 flags;
 517
 518         if (!node)
 519                 return 0;
 520
 521         if (rv8803->type != rx_8900)
 522                 return 0;
 523
 524         err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
 525         if (err < 0)
 526                 return err;
 527
 528         flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
 529
 530         if (of_property_read_bool(node, "epson,vdet-disable"))
 531                 flags |= RX8900_FLAG_VDETOFF;
 532
 533         if (of_property_read_bool(node, "trickle-diode-disable"))
 534                 flags |= RX8900_FLAG_SWOFF;
 535
 536         return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
 537                                          flags);
 538 }
 539
 540 static int rv8803_probe(struct i2c_client *client,
 541                         const struct i2c_device_id *id)
 542 {
 543         struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 544         struct rv8803_data *rv8803;
 545         int err, flags;
 546
 547         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 548                                      I2C_FUNC_SMBUS_I2C_BLOCK)) {
 549                 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
 550                 return -EIO;
 551         }
 552
 553         rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
 554                               GFP_KERNEL);
 555         if (!rv8803)
 556                 return -ENOMEM;
 557
 558         mutex_init(&rv8803->flags_lock);
 559         rv8803->client = client;
 560         if (client->dev.of_node)
 561                 rv8803->type = (enum rv8803_type)
 562                         of_device_get_match_data(&client->dev);
 563         else
 564                 rv8803->type = id->driver_data;
 565         i2c_set_clientdata(client, rv8803);
 566
 567         flags = rv8803_read_reg(client, RV8803_FLAG);
 568         if (flags < 0)
 569                 return flags;
 570
 571         if (flags & RV8803_FLAG_V1F)
 572                 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
 573
 574         if (flags & RV8803_FLAG_V2F)
 575                 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
 576
 577         if (flags & RV8803_FLAG_AF)
 578                 dev_warn(&client->dev, "An alarm maybe have been missed.\n");
 579
 580         if (client->irq > 0) {
 581                 err = devm_request_threaded_irq(&client->dev, client->irq,
 582                                                 NULL, rv8803_handle_irq,
 583                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 584                                                 "rv8803", client);
 585                 if (err) {
 586                         dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 587                         client->irq = 0;
 588                 } else {
 589                         rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
 590                         rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
 591                         rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
 592                 }
 593         }
 594
 595         rv8803->rtc = devm_rtc_device_register(&client->dev, client->name,
 596                                                &rv8803_rtc_ops, THIS_MODULE);
 597         if (IS_ERR(rv8803->rtc)) {
 598                 dev_err(&client->dev, "unable to register the class device\n");
 599                 return PTR_ERR(rv8803->rtc);
 600         }
 601
 602         err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
 603         if (err)
 604                 return err;
 605
 606         err = rx8900_trickle_charger_init(rv8803);
 607         if (err) {
 608                 dev_err(&client->dev, "failed to init charger\n");
 609                 return err;
 610         }
 611
 612         err = device_create_bin_file(&client->dev, &rv8803_nvram_attr);
 613         if (err)
 614                 return err;
 615
 616         rv8803->rtc->max_user_freq = 1;
 617
 618         return 0;
 619 }
 620
 621 static int rv8803_remove(struct i2c_client *client)
 622 {
 623         device_remove_bin_file(&client->dev, &rv8803_nvram_attr);
 624
 625         return 0;
 626 }
 627
 628 static const struct i2c_device_id rv8803_id[] = {
 629         { "rv8803", rv_8803 },
 630         { "rx8900", rx_8900 },
 631         { }
 632 };
 633 MODULE_DEVICE_TABLE(i2c, rv8803_id);
 634
 635 static const struct of_device_id rv8803_of_match[] = {
 636         {
 637                 .compatible = "microcrystal,rv8803",
 638                 .data = (void *)rx_8900
 639         },
 640         {
 641                 .compatible = "epson,rx8900",
 642                 .data = (void *)rx_8900
 643         },
 644         { }
 645 };
 646 MODULE_DEVICE_TABLE(of, rv8803_of_match);
 647
 648 static struct i2c_driver rv8803_driver = {
 649         .driver = {
 650                 .name = "rtc-rv8803",
 651                 .of_match_table = of_match_ptr(rv8803_of_match),
 652         },
 653         .probe          = rv8803_probe,
 654         .remove         = rv8803_remove,
 655         .id_table       = rv8803_id,
 656 };
 657 module_i2c_driver(rv8803_driver);
 658
 659 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
 660 MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
 661 MODULE_LICENSE("GPL v2");