drivers/rtc/rtc-rv8803.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * RTC driver for the Micro Crystal RV8803
   4  *
   5  * Copyright (C) 2015 Micro Crystal SA
   6  * Alexandre Belloni <alexandre.belloni@bootlin.com>
   7  *
   8  */
   9
  10 #include <linux/bcd.h>
  11 #include <linux/bitops.h>
  12 #include <linux/bitfield.h>
  13 #include <linux/log2.h>
  14 #include <linux/i2c.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/rtc.h>
  20 #include <linux/pm_wakeirq.h>
  21
  22 #define RV8803_I2C_TRY_COUNT            4
  23
  24 #define RV8803_SEC                      0x00
  25 #define RV8803_MIN                      0x01
  26 #define RV8803_HOUR                     0x02
  27 #define RV8803_WEEK                     0x03
  28 #define RV8803_DAY                      0x04
  29 #define RV8803_MONTH                    0x05
  30 #define RV8803_YEAR                     0x06
  31 #define RV8803_RAM                      0x07
  32 #define RV8803_ALARM_MIN                0x08
  33 #define RV8803_ALARM_HOUR               0x09
  34 #define RV8803_ALARM_WEEK_OR_DAY        0x0A
  35 #define RV8803_EXT                      0x0D
  36 #define RV8803_FLAG                     0x0E
  37 #define RV8803_CTRL                     0x0F
  38 #define RV8803_OSC_OFFSET               0x2C
  39
  40 #define RV8803_EXT_WADA                 BIT(6)
  41
  42 #define RV8803_FLAG_V1F                 BIT(0)
  43 #define RV8803_FLAG_V2F                 BIT(1)
  44 #define RV8803_FLAG_AF                  BIT(3)
  45 #define RV8803_FLAG_TF                  BIT(4)
  46 #define RV8803_FLAG_UF                  BIT(5)
  47
  48 #define RV8803_CTRL_RESET               BIT(0)
  49
  50 #define RV8803_CTRL_EIE                 BIT(2)
  51 #define RV8803_CTRL_AIE                 BIT(3)
  52 #define RV8803_CTRL_TIE                 BIT(4)
  53 #define RV8803_CTRL_UIE                 BIT(5)
  54
  55 #define RX8803_CTRL_CSEL                GENMASK(7, 6)
  56
  57 #define RX8900_BACKUP_CTRL              0x18
  58 #define RX8900_FLAG_SWOFF               BIT(2)
  59 #define RX8900_FLAG_VDETOFF             BIT(3)
  60
  61 enum rv8803_type {
  62         rv_8803,
  63         rx_8803,
  64         rx_8804,
  65         rx_8900
  66 };
  67
  68 struct rv8803_data {
  69         struct i2c_client *client;
  70         struct rtc_device *rtc;
  71         struct mutex flags_lock;
  72         u8 ctrl;
  73         u8 backup;
  74         u8 alarm_invalid:1;
  75         enum rv8803_type type;
  76 };
  77
  78 static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
  79 {
  80         int try = RV8803_I2C_TRY_COUNT;
  81         s32 ret;
  82
  83         /*
  84          * There is a 61µs window during which the RTC does not acknowledge I2C
  85          * transfers. In that case, ensure that there are multiple attempts.
  86          */
  87         do
  88                 ret = i2c_smbus_read_byte_data(client, reg);
  89         while ((ret == -ENXIO || ret == -EIO) && --try);
  90         if (ret < 0)
  91                 dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
  92
  93         return ret;
  94 }
  95
  96 static int rv8803_read_regs(const struct i2c_client *client,
  97                             u8 reg, u8 count, u8 *values)
  98 {
  99         int try = RV8803_I2C_TRY_COUNT;
 100         s32 ret;
 101
 102         do
 103                 ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
 104         while ((ret == -ENXIO || ret == -EIO) && --try);
 105         if (ret != count) {
 106                 dev_err(&client->dev,
 107                         "Unable to read registers 0x%02x..0x%02x\n",
 108                         reg, reg + count - 1);
 109                 return ret < 0 ? ret : -EIO;
 110         }
 111
 112         return 0;
 113 }
 114
 115 static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
 116 {
 117         int try = RV8803_I2C_TRY_COUNT;
 118         s32 ret;
 119
 120         do
 121                 ret = i2c_smbus_write_byte_data(client, reg, value);
 122         while ((ret == -ENXIO || ret == -EIO) && --try);
 123         if (ret)
 124                 dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
 125
 126         return ret;
 127 }
 128
 129 static int rv8803_write_regs(const struct i2c_client *client,
 130                              u8 reg, u8 count, const u8 *values)
 131 {
 132         int try = RV8803_I2C_TRY_COUNT;
 133         s32 ret;
 134
 135         do
 136                 ret = i2c_smbus_write_i2c_block_data(client, reg, count,
 137                                                      values);
 138         while ((ret == -ENXIO || ret == -EIO) && --try);
 139         if (ret)
 140                 dev_err(&client->dev,
 141                         "Unable to write registers 0x%02x..0x%02x\n",
 142                         reg, reg + count - 1);
 143
 144         return ret;
 145 }
 146
 147 static int rv8803_regs_init(struct rv8803_data *rv8803)
 148 {
 149         int ret;
 150
 151         ret = rv8803_write_reg(rv8803->client, RV8803_OSC_OFFSET, 0x00);
 152         if (ret)
 153                 return ret;
 154
 155         ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 156                                FIELD_PREP(RX8803_CTRL_CSEL, 1)); /* 2s */
 157         if (ret)
 158                 return ret;
 159
 160         ret = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3,
 161                                 (u8[]){ 0, 0, 0 });
 162         if (ret)
 163                 return ret;
 164
 165         return rv8803_write_reg(rv8803->client, RV8803_RAM, 0x00);
 166 }
 167
 168 static int rv8803_regs_configure(struct rv8803_data *rv8803);
 169
 170 static int rv8803_regs_reset(struct rv8803_data *rv8803, bool full)
 171 {
 172         /*
 173          * The RV-8803 resets all registers to POR defaults after voltage-loss,
 174          * the Epson RTCs don't, so we manually reset the remainder here.
 175          */
 176         if (full || rv8803->type == rx_8803 || rv8803->type == rx_8900) {
 177                 int ret = rv8803_regs_init(rv8803);
 178                 if (ret)
 179                         return ret;
 180         }
 181
 182         return rv8803_regs_configure(rv8803);
 183 }
 184
 185 static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
 186 {
 187         struct i2c_client *client = dev_id;
 188         struct rv8803_data *rv8803 = i2c_get_clientdata(client);
 189         unsigned long events = 0;
 190         int flags;
 191
 192         mutex_lock(&rv8803->flags_lock);
 193
 194         flags = rv8803_read_reg(client, RV8803_FLAG);
 195         if (flags <= 0) {
 196                 mutex_unlock(&rv8803->flags_lock);
 197                 return IRQ_NONE;
 198         }
 199
 200         if (flags & RV8803_FLAG_V1F)
 201                 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
 202
 203         if (flags & RV8803_FLAG_V2F)
 204                 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
 205
 206         if (flags & RV8803_FLAG_TF) {
 207                 flags &= ~RV8803_FLAG_TF;
 208                 rv8803->ctrl &= ~RV8803_CTRL_TIE;
 209                 events |= RTC_PF;
 210         }
 211
 212         if (flags & RV8803_FLAG_AF) {
 213                 flags &= ~RV8803_FLAG_AF;
 214                 rv8803->ctrl &= ~RV8803_CTRL_AIE;
 215                 events |= RTC_AF;
 216         }
 217
 218         if (flags & RV8803_FLAG_UF) {
 219                 flags &= ~RV8803_FLAG_UF;
 220                 rv8803->ctrl &= ~RV8803_CTRL_UIE;
 221                 events |= RTC_UF;
 222         }
 223
 224         if (events) {
 225                 rtc_update_irq(rv8803->rtc, 1, events);
 226                 rv8803_write_reg(client, RV8803_FLAG, flags);
 227                 rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
 228         }
 229
 230         mutex_unlock(&rv8803->flags_lock);
 231
 232         return IRQ_HANDLED;
 233 }
 234
 235 static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
 236 {
 237         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 238         u8 date1[7];
 239         u8 date2[7];
 240         u8 *date = date1;
 241         int ret, flags;
 242
 243         if (rv8803->alarm_invalid) {
 244                 dev_warn(dev, "Corruption detected, data may be invalid.\n");
 245                 return -EINVAL;
 246         }
 247
 248         flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
 249         if (flags < 0)
 250                 return flags;
 251
 252         if (flags & RV8803_FLAG_V2F) {
 253                 dev_warn(dev, "Voltage low, data is invalid.\n");
 254                 return -EINVAL;
 255         }
 256
 257         ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
 258         if (ret)
 259                 return ret;
 260
 261         if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
 262                 ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
 263                 if (ret)
 264                         return ret;
 265
 266                 if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
 267                         date = date2;
 268         }
 269
 270         tm->tm_sec  = bcd2bin(date[RV8803_SEC] & 0x7f);
 271         tm->tm_min  = bcd2bin(date[RV8803_MIN] & 0x7f);
 272         tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
 273         tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f);
 274         tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
 275         tm->tm_mon  = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
 276         tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
 277
 278         return 0;
 279 }
 280
 281 static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
 282 {
 283         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 284         u8 date[7];
 285         int ctrl, flags, ret;
 286
 287         ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
 288         if (ctrl < 0)
 289                 return ctrl;
 290
 291         /* Stop the clock */
 292         ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 293                                ctrl | RV8803_CTRL_RESET);
 294         if (ret)
 295                 return ret;
 296
 297         date[RV8803_SEC]   = bin2bcd(tm->tm_sec);
 298         date[RV8803_MIN]   = bin2bcd(tm->tm_min);
 299         date[RV8803_HOUR]  = bin2bcd(tm->tm_hour);
 300         date[RV8803_WEEK]  = 1 << (tm->tm_wday);
 301         date[RV8803_DAY]   = bin2bcd(tm->tm_mday);
 302         date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
 303         date[RV8803_YEAR]  = bin2bcd(tm->tm_year - 100);
 304
 305         ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
 306         if (ret)
 307                 return ret;
 308
 309         /* Restart the clock */
 310         ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 311                                ctrl & ~RV8803_CTRL_RESET);
 312         if (ret)
 313                 return ret;
 314
 315         mutex_lock(&rv8803->flags_lock);
 316
 317         flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
 318         if (flags < 0) {
 319                 mutex_unlock(&rv8803->flags_lock);
 320                 return flags;
 321         }
 322
 323         if ((flags & RV8803_FLAG_V2F) || rv8803->alarm_invalid) {
 324                 /*
 325                  * If we sense corruption in the alarm registers, but see no
 326                  * voltage loss flag, we can't rely on other registers having
 327                  * sensible values. Reset them fully.
 328                  */
 329                 ret = rv8803_regs_reset(rv8803, rv8803->alarm_invalid);
 330                 if (ret) {
 331                         mutex_unlock(&rv8803->flags_lock);
 332                         return ret;
 333                 }
 334
 335                 rv8803->alarm_invalid = false;
 336         }
 337
 338         ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
 339                                flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F));
 340
 341         mutex_unlock(&rv8803->flags_lock);
 342
 343         return ret;
 344 }
 345
 346 static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 347 {
 348         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 349         struct i2c_client *client = rv8803->client;
 350         u8 alarmvals[3];
 351         int flags, ret;
 352
 353         ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
 354         if (ret)
 355                 return ret;
 356
 357         flags = rv8803_read_reg(client, RV8803_FLAG);
 358         if (flags < 0)
 359                 return flags;
 360
 361         alarmvals[0] &= 0x7f;
 362         alarmvals[1] &= 0x3f;
 363         alarmvals[2] &= 0x3f;
 364
 365         if (!bcd_is_valid(alarmvals[0]) ||
 366             !bcd_is_valid(alarmvals[1]) ||
 367             !bcd_is_valid(alarmvals[2]))
 368                 goto err_invalid;
 369
 370         alrm->time.tm_sec  = 0;
 371         alrm->time.tm_min  = bcd2bin(alarmvals[0]);
 372         alrm->time.tm_hour = bcd2bin(alarmvals[1]);
 373         alrm->time.tm_mday = bcd2bin(alarmvals[2]);
 374
 375         alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
 376         alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
 377
 378         if ((unsigned int)alrm->time.tm_mday > 31 ||
 379             (unsigned int)alrm->time.tm_hour >= 24 ||
 380             (unsigned int)alrm->time.tm_min >= 60)
 381                 goto err_invalid;
 382
 383         return 0;
 384
 385 err_invalid:
 386         rv8803->alarm_invalid = true;
 387         return -EINVAL;
 388 }
 389
 390 static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 391 {
 392         struct i2c_client *client = to_i2c_client(dev);
 393         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 394         u8 alarmvals[3];
 395         u8 ctrl[2];
 396         int ret, err;
 397
 398         /* The alarm has no seconds, round up to nearest minute */
 399         if (alrm->time.tm_sec) {
 400                 time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
 401
 402                 alarm_time += 60 - alrm->time.tm_sec;
 403                 rtc_time64_to_tm(alarm_time, &alrm->time);
 404         }
 405
 406         mutex_lock(&rv8803->flags_lock);
 407
 408         ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
 409         if (ret) {
 410                 mutex_unlock(&rv8803->flags_lock);
 411                 return ret;
 412         }
 413
 414         alarmvals[0] = bin2bcd(alrm->time.tm_min);
 415         alarmvals[1] = bin2bcd(alrm->time.tm_hour);
 416         alarmvals[2] = bin2bcd(alrm->time.tm_mday);
 417
 418         if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
 419                 rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
 420                 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 421                                        rv8803->ctrl);
 422                 if (err) {
 423                         mutex_unlock(&rv8803->flags_lock);
 424                         return err;
 425                 }
 426         }
 427
 428         ctrl[0] &= ~RV8803_FLAG_AF;
 429         err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]);
 430         mutex_unlock(&rv8803->flags_lock);
 431         if (err)
 432                 return err;
 433
 434         err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
 435         if (err)
 436                 return err;
 437
 438         if (alrm->enabled) {
 439                 if (rv8803->rtc->uie_rtctimer.enabled)
 440                         rv8803->ctrl |= RV8803_CTRL_UIE;
 441                 if (rv8803->rtc->aie_timer.enabled)
 442                         rv8803->ctrl |= RV8803_CTRL_AIE;
 443
 444                 err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
 445                                        rv8803->ctrl);
 446                 if (err)
 447                         return err;
 448         }
 449
 450         return 0;
 451 }
 452
 453 static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
 454 {
 455         struct i2c_client *client = to_i2c_client(dev);
 456         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 457         int ctrl, flags, err;
 458
 459         ctrl = rv8803->ctrl;
 460
 461         if (enabled) {
 462                 if (rv8803->rtc->uie_rtctimer.enabled)
 463                         ctrl |= RV8803_CTRL_UIE;
 464                 if (rv8803->rtc->aie_timer.enabled)
 465                         ctrl |= RV8803_CTRL_AIE;
 466         } else {
 467                 if (!rv8803->rtc->uie_rtctimer.enabled)
 468                         ctrl &= ~RV8803_CTRL_UIE;
 469                 if (!rv8803->rtc->aie_timer.enabled)
 470                         ctrl &= ~RV8803_CTRL_AIE;
 471         }
 472
 473         mutex_lock(&rv8803->flags_lock);
 474         flags = rv8803_read_reg(client, RV8803_FLAG);
 475         if (flags < 0) {
 476                 mutex_unlock(&rv8803->flags_lock);
 477                 return flags;
 478         }
 479         flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
 480         err = rv8803_write_reg(client, RV8803_FLAG, flags);
 481         mutex_unlock(&rv8803->flags_lock);
 482         if (err)
 483                 return err;
 484
 485         if (ctrl != rv8803->ctrl) {
 486                 rv8803->ctrl = ctrl;
 487                 err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
 488                 if (err)
 489                         return err;
 490         }
 491
 492         return 0;
 493 }
 494
 495 static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 496 {
 497         struct i2c_client *client = to_i2c_client(dev);
 498         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 499         unsigned int vl = 0;
 500         int flags, ret = 0;
 501
 502         switch (cmd) {
 503         case RTC_VL_READ:
 504                 flags = rv8803_read_reg(client, RV8803_FLAG);
 505                 if (flags < 0)
 506                         return flags;
 507
 508                 if (flags & RV8803_FLAG_V1F) {
 509                         dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
 510                         vl = RTC_VL_ACCURACY_LOW;
 511                 }
 512
 513                 if (flags & RV8803_FLAG_V2F)
 514                         vl |= RTC_VL_DATA_INVALID;
 515
 516                 return put_user(vl, (unsigned int __user *)arg);
 517
 518         case RTC_VL_CLR:
 519                 mutex_lock(&rv8803->flags_lock);
 520                 flags = rv8803_read_reg(client, RV8803_FLAG);
 521                 if (flags < 0) {
 522                         mutex_unlock(&rv8803->flags_lock);
 523                         return flags;
 524                 }
 525
 526                 flags &= ~RV8803_FLAG_V1F;
 527                 ret = rv8803_write_reg(client, RV8803_FLAG, flags);
 528                 mutex_unlock(&rv8803->flags_lock);
 529                 if (ret)
 530                         return ret;
 531
 532                 return 0;
 533
 534         default:
 535                 return -ENOIOCTLCMD;
 536         }
 537 }
 538
 539 static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
 540                               size_t bytes)
 541 {
 542         return rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
 543 }
 544
 545 static int rv8803_nvram_read(void *priv, unsigned int offset,
 546                              void *val, size_t bytes)
 547 {
 548         int ret;
 549
 550         ret = rv8803_read_reg(priv, RV8803_RAM);
 551         if (ret < 0)
 552                 return ret;
 553
 554         *(u8 *)val = ret;
 555
 556         return 0;
 557 }
 558
 559 static const struct rtc_class_ops rv8803_rtc_ops = {
 560         .read_time = rv8803_get_time,
 561         .set_time = rv8803_set_time,
 562         .ioctl = rv8803_ioctl,
 563         .read_alarm = rv8803_get_alarm,
 564         .set_alarm = rv8803_set_alarm,
 565         .alarm_irq_enable = rv8803_alarm_irq_enable,
 566 };
 567
 568 static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
 569 {
 570         struct i2c_client *client = rv8803->client;
 571         struct device_node *node = client->dev.of_node;
 572         int err;
 573         u8 flags;
 574
 575         if (!node)
 576                 return 0;
 577
 578         if (rv8803->type != rx_8900)
 579                 return 0;
 580
 581         err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
 582         if (err < 0)
 583                 return err;
 584
 585         flags = (u8)err;
 586         flags &= ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF);
 587         flags |= rv8803->backup;
 588
 589         return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
 590                                          flags);
 591 }
 592
 593 /* configure registers with values different than the Power-On reset defaults */
 594 static int rv8803_regs_configure(struct rv8803_data *rv8803)
 595 {
 596         int err;
 597
 598         err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
 599         if (err)
 600                 return err;
 601
 602         err = rx8900_trickle_charger_init(rv8803);
 603         if (err) {
 604                 dev_err(&rv8803->client->dev, "failed to init charger\n");
 605                 return err;
 606         }
 607
 608         return 0;
 609 }
 610
 611 static int rv8803_resume(struct device *dev)
 612 {
 613         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 614
 615         if (rv8803->client->irq > 0 && device_may_wakeup(dev))
 616                 disable_irq_wake(rv8803->client->irq);
 617
 618         return 0;
 619 }
 620
 621 static int rv8803_suspend(struct device *dev)
 622 {
 623         struct rv8803_data *rv8803 = dev_get_drvdata(dev);
 624
 625         if (rv8803->client->irq > 0 && device_may_wakeup(dev))
 626                 enable_irq_wake(rv8803->client->irq);
 627
 628         return 0;
 629 }
 630
 631 static DEFINE_SIMPLE_DEV_PM_OPS(rv8803_pm_ops, rv8803_suspend, rv8803_resume);
 632
 633 static const struct i2c_device_id rv8803_id[] = {
 634         { "rv8803", rv_8803 },
 635         { "rv8804", rx_8804 },
 636         { "rx8803", rx_8803 },
 637         { "rx8900", rx_8900 },
 638         { }
 639 };
 640 MODULE_DEVICE_TABLE(i2c, rv8803_id);
 641
 642 static int rv8803_probe(struct i2c_client *client)
 643 {
 644         struct i2c_adapter *adapter = client->adapter;
 645         struct rv8803_data *rv8803;
 646         int err, flags;
 647         struct nvmem_config nvmem_cfg = {
 648                 .name = "rv8803_nvram",
 649                 .word_size = 1,
 650                 .stride = 1,
 651                 .size = 1,
 652                 .reg_read = rv8803_nvram_read,
 653                 .reg_write = rv8803_nvram_write,
 654                 .priv = client,
 655         };
 656
 657         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 658                                      I2C_FUNC_SMBUS_I2C_BLOCK)) {
 659                 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n");
 660                 return -EIO;
 661         }
 662
 663         rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
 664                               GFP_KERNEL);
 665         if (!rv8803)
 666                 return -ENOMEM;
 667
 668         mutex_init(&rv8803->flags_lock);
 669         rv8803->client = client;
 670         if (client->dev.of_node) {
 671                 rv8803->type = (uintptr_t)of_device_get_match_data(&client->dev);
 672         } else {
 673                 const struct i2c_device_id *id = i2c_match_id(rv8803_id, client);
 674
 675                 rv8803->type = id->driver_data;
 676         }
 677         i2c_set_clientdata(client, rv8803);
 678
 679         flags = rv8803_read_reg(client, RV8803_FLAG);
 680         if (flags < 0)
 681                 return flags;
 682
 683         if (flags & RV8803_FLAG_V1F)
 684                 dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
 685
 686         if (flags & RV8803_FLAG_V2F)
 687                 dev_warn(&client->dev, "Voltage low, data loss detected.\n");
 688
 689         if (flags & RV8803_FLAG_AF)
 690                 dev_warn(&client->dev, "An alarm maybe have been missed.\n");
 691
 692         rv8803->rtc = devm_rtc_allocate_device(&client->dev);
 693         if (IS_ERR(rv8803->rtc))
 694                 return PTR_ERR(rv8803->rtc);
 695
 696         if (client->irq > 0) {
 697                 unsigned long irqflags = IRQF_TRIGGER_LOW;
 698
 699                 if (dev_fwnode(&client->dev))
 700                         irqflags = 0;
 701
 702                 err = devm_request_threaded_irq(&client->dev, client->irq,
 703                                                 NULL, rv8803_handle_irq,
 704                                                 irqflags | IRQF_ONESHOT,
 705                                                 "rv8803", client);
 706                 if (err) {
 707                         dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 708                         client->irq = 0;
 709                 } else {
 710                         device_init_wakeup(&client->dev, true);
 711                         err = dev_pm_set_wake_irq(&client->dev, client->irq);
 712                         if (err)
 713                                 dev_err(&client->dev, "failed to set wake IRQ\n");
 714                 }
 715         } else {
 716                 if (device_property_read_bool(&client->dev, "wakeup-source"))
 717                         device_init_wakeup(&client->dev, true);
 718                 else
 719                         clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features);
 720         }
 721
 722         if (of_property_read_bool(client->dev.of_node, "epson,vdet-disable"))
 723                 rv8803->backup |= RX8900_FLAG_VDETOFF;
 724
 725         if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
 726                 rv8803->backup |= RX8900_FLAG_SWOFF;
 727
 728         err = rv8803_regs_configure(rv8803);
 729         if (err)
 730                 return err;
 731
 732         rv8803->rtc->ops = &rv8803_rtc_ops;
 733         rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 734         rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
 735         err = devm_rtc_register_device(rv8803->rtc);
 736         if (err)
 737                 return err;
 738
 739         devm_rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
 740
 741         rv8803->rtc->max_user_freq = 1;
 742
 743         return 0;
 744 }
 745
 746 static const __maybe_unused struct of_device_id rv8803_of_match[] = {
 747         {
 748                 .compatible = "microcrystal,rv8803",
 749                 .data = (void *)rv_8803
 750         },
 751         {
 752                 .compatible = "epson,rx8803",
 753                 .data = (void *)rx_8803
 754         },
 755         {
 756                 .compatible = "epson,rx8804",
 757                 .data = (void *)rx_8804
 758         },
 759         {
 760                 .compatible = "epson,rx8900",
 761                 .data = (void *)rx_8900
 762         },
 763         { }
 764 };
 765 MODULE_DEVICE_TABLE(of, rv8803_of_match);
 766
 767 static struct i2c_driver rv8803_driver = {
 768         .driver = {
 769                 .name = "rtc-rv8803",
 770                 .of_match_table = of_match_ptr(rv8803_of_match),
 771                 .pm = &rv8803_pm_ops,
 772         },
 773         .probe          = rv8803_probe,
 774         .id_table       = rv8803_id,
 775 };
 776 module_i2c_driver(rv8803_driver);
 777
 778 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
 779 MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
 780 MODULE_LICENSE("GPL v2");