drivers/rtc/rtc-rv3032.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * RTC driver for the Micro Crystal RV3032
   4  *
   5  * Copyright (C) 2020 Micro Crystal SA
   6  *
   7  * Alexandre Belloni <alexandre.belloni@bootlin.com>
   8  *
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/clk-provider.h>
  13 #include <linux/bcd.h>
  14 #include <linux/bitfield.h>
  15 #include <linux/bitops.h>
  16 #include <linux/hwmon.h>
  17 #include <linux/i2c.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/kernel.h>
  20 #include <linux/log2.h>
  21 #include <linux/module.h>
  22 #include <linux/of_device.h>
  23 #include <linux/regmap.h>
  24 #include <linux/rtc.h>
  25
  26 #define RV3032_SEC                      0x01
  27 #define RV3032_MIN                      0x02
  28 #define RV3032_HOUR                     0x03
  29 #define RV3032_WDAY                     0x04
  30 #define RV3032_DAY                      0x05
  31 #define RV3032_MONTH                    0x06
  32 #define RV3032_YEAR                     0x07
  33 #define RV3032_ALARM_MIN                0x08
  34 #define RV3032_ALARM_HOUR               0x09
  35 #define RV3032_ALARM_DAY                0x0A
  36 #define RV3032_STATUS                   0x0D
  37 #define RV3032_TLSB                     0x0E
  38 #define RV3032_TMSB                     0x0F
  39 #define RV3032_CTRL1                    0x10
  40 #define RV3032_CTRL2                    0x11
  41 #define RV3032_CTRL3                    0x12
  42 #define RV3032_TS_CTRL                  0x13
  43 #define RV3032_CLK_IRQ                  0x14
  44 #define RV3032_EEPROM_ADDR              0x3D
  45 #define RV3032_EEPROM_DATA              0x3E
  46 #define RV3032_EEPROM_CMD               0x3F
  47 #define RV3032_RAM1                     0x40
  48 #define RV3032_PMU                      0xC0
  49 #define RV3032_OFFSET                   0xC1
  50 #define RV3032_CLKOUT1                  0xC2
  51 #define RV3032_CLKOUT2                  0xC3
  52 #define RV3032_TREF0                    0xC4
  53 #define RV3032_TREF1                    0xC5
  54
  55 #define RV3032_STATUS_VLF               BIT(0)
  56 #define RV3032_STATUS_PORF              BIT(1)
  57 #define RV3032_STATUS_EVF               BIT(2)
  58 #define RV3032_STATUS_AF                BIT(3)
  59 #define RV3032_STATUS_TF                BIT(4)
  60 #define RV3032_STATUS_UF                BIT(5)
  61 #define RV3032_STATUS_TLF               BIT(6)
  62 #define RV3032_STATUS_THF               BIT(7)
  63
  64 #define RV3032_TLSB_CLKF                BIT(1)
  65 #define RV3032_TLSB_EEBUSY              BIT(2)
  66 #define RV3032_TLSB_TEMP                GENMASK(7, 4)
  67
  68 #define RV3032_CLKOUT2_HFD_MSK          GENMASK(4, 0)
  69 #define RV3032_CLKOUT2_FD_MSK           GENMASK(6, 5)
  70 #define RV3032_CLKOUT2_OS               BIT(7)
  71
  72 #define RV3032_CTRL1_EERD               BIT(3)
  73 #define RV3032_CTRL1_WADA               BIT(5)
  74
  75 #define RV3032_CTRL2_STOP               BIT(0)
  76 #define RV3032_CTRL2_EIE                BIT(2)
  77 #define RV3032_CTRL2_AIE                BIT(3)
  78 #define RV3032_CTRL2_TIE                BIT(4)
  79 #define RV3032_CTRL2_UIE                BIT(5)
  80 #define RV3032_CTRL2_CLKIE              BIT(6)
  81 #define RV3032_CTRL2_TSE                BIT(7)
  82
  83 #define RV3032_PMU_TCM                  GENMASK(1, 0)
  84 #define RV3032_PMU_TCR                  GENMASK(3, 2)
  85 #define RV3032_PMU_BSM                  GENMASK(5, 4)
  86 #define RV3032_PMU_NCLKE                BIT(6)
  87
  88 #define RV3032_PMU_BSM_DSM              1
  89 #define RV3032_PMU_BSM_LSM              2
  90
  91 #define RV3032_OFFSET_MSK               GENMASK(5, 0)
  92
  93 #define RV3032_EVT_CTRL_TSR             BIT(2)
  94
  95 #define RV3032_EEPROM_CMD_UPDATE        0x11
  96 #define RV3032_EEPROM_CMD_WRITE         0x21
  97 #define RV3032_EEPROM_CMD_READ          0x22
  98
  99 #define RV3032_EEPROM_USER              0xCB
 100
 101 #define RV3032_EEBUSY_POLL              10000
 102 #define RV3032_EEBUSY_TIMEOUT           100000
 103
 104 #define OFFSET_STEP_PPT                 238419
 105
 106 struct rv3032_data {
 107         struct regmap *regmap;
 108         struct rtc_device *rtc;
 109         bool trickle_charger_set;
 110 #ifdef CONFIG_COMMON_CLK
 111         struct clk_hw clkout_hw;
 112 #endif
 113 };
 114
 115 static u16 rv3032_trickle_resistors[] = {1000, 2000, 7000, 11000};
 116 static u16 rv3032_trickle_voltages[] = {0, 1750, 3000, 4400};
 117
 118 static int rv3032_exit_eerd(struct rv3032_data *rv3032, u32 eerd)
 119 {
 120         if (eerd)
 121                 return 0;
 122
 123         return regmap_update_bits(rv3032->regmap, RV3032_CTRL1, RV3032_CTRL1_EERD, 0);
 124 }
 125
 126 static int rv3032_enter_eerd(struct rv3032_data *rv3032, u32 *eerd)
 127 {
 128         u32 ctrl1, status;
 129         int ret;
 130
 131         ret = regmap_read(rv3032->regmap, RV3032_CTRL1, &ctrl1);
 132         if (ret)
 133                 return ret;
 134
 135         *eerd = ctrl1 & RV3032_CTRL1_EERD;
 136         if (*eerd)
 137                 return 0;
 138
 139         ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL1,
 140                                  RV3032_CTRL1_EERD, RV3032_CTRL1_EERD);
 141         if (ret)
 142                 return ret;
 143
 144         ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
 145                                        !(status & RV3032_TLSB_EEBUSY),
 146                                        RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
 147         if (ret) {
 148                 rv3032_exit_eerd(rv3032, *eerd);
 149
 150                 return ret;
 151         }
 152
 153         return 0;
 154 }
 155
 156 static int rv3032_update_cfg(struct rv3032_data *rv3032, unsigned int reg,
 157                              unsigned int mask, unsigned int val)
 158 {
 159         u32 status, eerd;
 160         int ret;
 161
 162         ret = rv3032_enter_eerd(rv3032, &eerd);
 163         if (ret)
 164                 return ret;
 165
 166         ret = regmap_update_bits(rv3032->regmap, reg, mask, val);
 167         if (ret)
 168                 goto exit_eerd;
 169
 170         ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD, RV3032_EEPROM_CMD_UPDATE);
 171         if (ret)
 172                 goto exit_eerd;
 173
 174         usleep_range(46000, RV3032_EEBUSY_TIMEOUT);
 175
 176         ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
 177                                        !(status & RV3032_TLSB_EEBUSY),
 178                                        RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
 179
 180 exit_eerd:
 181         rv3032_exit_eerd(rv3032, eerd);
 182
 183         return ret;
 184 }
 185
 186 static irqreturn_t rv3032_handle_irq(int irq, void *dev_id)
 187 {
 188         struct rv3032_data *rv3032 = dev_id;
 189         unsigned long events = 0;
 190         u32 status = 0, ctrl = 0;
 191
 192         if (regmap_read(rv3032->regmap, RV3032_STATUS, &status) < 0 ||
 193             status == 0) {
 194                 return IRQ_NONE;
 195         }
 196
 197         if (status & RV3032_STATUS_TF) {
 198                 status |= RV3032_STATUS_TF;
 199                 ctrl |= RV3032_CTRL2_TIE;
 200                 events |= RTC_PF;
 201         }
 202
 203         if (status & RV3032_STATUS_AF) {
 204                 status |= RV3032_STATUS_AF;
 205                 ctrl |= RV3032_CTRL2_AIE;
 206                 events |= RTC_AF;
 207         }
 208
 209         if (status & RV3032_STATUS_UF) {
 210                 status |= RV3032_STATUS_UF;
 211                 ctrl |= RV3032_CTRL2_UIE;
 212                 events |= RTC_UF;
 213         }
 214
 215         if (events) {
 216                 rtc_update_irq(rv3032->rtc, 1, events);
 217                 regmap_update_bits(rv3032->regmap, RV3032_STATUS, status, 0);
 218                 regmap_update_bits(rv3032->regmap, RV3032_CTRL2, ctrl, 0);
 219         }
 220
 221         return IRQ_HANDLED;
 222 }
 223
 224 static int rv3032_get_time(struct device *dev, struct rtc_time *tm)
 225 {
 226         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 227         u8 date[7];
 228         int ret, status;
 229
 230         ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
 231         if (ret < 0)
 232                 return ret;
 233
 234         if (status & (RV3032_STATUS_PORF | RV3032_STATUS_VLF))
 235                 return -EINVAL;
 236
 237         ret = regmap_bulk_read(rv3032->regmap, RV3032_SEC, date, sizeof(date));
 238         if (ret)
 239                 return ret;
 240
 241         tm->tm_sec  = bcd2bin(date[0] & 0x7f);
 242         tm->tm_min  = bcd2bin(date[1] & 0x7f);
 243         tm->tm_hour = bcd2bin(date[2] & 0x3f);
 244         tm->tm_wday = date[3] & 0x7;
 245         tm->tm_mday = bcd2bin(date[4] & 0x3f);
 246         tm->tm_mon  = bcd2bin(date[5] & 0x1f) - 1;
 247         tm->tm_year = bcd2bin(date[6]) + 100;
 248
 249         return 0;
 250 }
 251
 252 static int rv3032_set_time(struct device *dev, struct rtc_time *tm)
 253 {
 254         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 255         u8 date[7];
 256         int ret;
 257
 258         date[0] = bin2bcd(tm->tm_sec);
 259         date[1] = bin2bcd(tm->tm_min);
 260         date[2] = bin2bcd(tm->tm_hour);
 261         date[3] = tm->tm_wday;
 262         date[4] = bin2bcd(tm->tm_mday);
 263         date[5] = bin2bcd(tm->tm_mon + 1);
 264         date[6] = bin2bcd(tm->tm_year - 100);
 265
 266         ret = regmap_bulk_write(rv3032->regmap, RV3032_SEC, date,
 267                                 sizeof(date));
 268         if (ret)
 269                 return ret;
 270
 271         ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
 272                                  RV3032_STATUS_PORF | RV3032_STATUS_VLF, 0);
 273
 274         return ret;
 275 }
 276
 277 static int rv3032_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 278 {
 279         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 280         u8 alarmvals[3];
 281         int status, ctrl, ret;
 282
 283         ret = regmap_bulk_read(rv3032->regmap, RV3032_ALARM_MIN, alarmvals,
 284                                sizeof(alarmvals));
 285         if (ret)
 286                 return ret;
 287
 288         ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
 289         if (ret < 0)
 290                 return ret;
 291
 292         ret = regmap_read(rv3032->regmap, RV3032_CTRL2, &ctrl);
 293         if (ret < 0)
 294                 return ret;
 295
 296         alrm->time.tm_sec  = 0;
 297         alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
 298         alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
 299         alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
 300
 301         alrm->enabled = !!(ctrl & RV3032_CTRL2_AIE);
 302         alrm->pending = (status & RV3032_STATUS_AF) && alrm->enabled;
 303
 304         return 0;
 305 }
 306
 307 static int rv3032_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 308 {
 309         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 310         u8 alarmvals[3];
 311         u8 ctrl = 0;
 312         int ret;
 313
 314         ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
 315                                  RV3032_CTRL2_AIE | RV3032_CTRL2_UIE, 0);
 316         if (ret)
 317                 return ret;
 318
 319         alarmvals[0] = bin2bcd(alrm->time.tm_min);
 320         alarmvals[1] = bin2bcd(alrm->time.tm_hour);
 321         alarmvals[2] = bin2bcd(alrm->time.tm_mday);
 322
 323         ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
 324                                  RV3032_STATUS_AF, 0);
 325         if (ret)
 326                 return ret;
 327
 328         ret = regmap_bulk_write(rv3032->regmap, RV3032_ALARM_MIN, alarmvals,
 329                                 sizeof(alarmvals));
 330         if (ret)
 331                 return ret;
 332
 333         if (alrm->enabled) {
 334                 if (rv3032->rtc->uie_rtctimer.enabled)
 335                         ctrl |= RV3032_CTRL2_UIE;
 336                 if (rv3032->rtc->aie_timer.enabled)
 337                         ctrl |= RV3032_CTRL2_AIE;
 338         }
 339
 340         ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
 341                                  RV3032_CTRL2_UIE | RV3032_CTRL2_AIE, ctrl);
 342
 343         return ret;
 344 }
 345
 346 static int rv3032_alarm_irq_enable(struct device *dev, unsigned int enabled)
 347 {
 348         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 349         int ctrl = 0, ret;
 350
 351         if (enabled) {
 352                 if (rv3032->rtc->uie_rtctimer.enabled)
 353                         ctrl |= RV3032_CTRL2_UIE;
 354                 if (rv3032->rtc->aie_timer.enabled)
 355                         ctrl |= RV3032_CTRL2_AIE;
 356         }
 357
 358         ret = regmap_update_bits(rv3032->regmap, RV3032_STATUS,
 359                                  RV3032_STATUS_AF | RV3032_STATUS_UF, 0);
 360         if (ret)
 361                 return ret;
 362
 363         ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2,
 364                                  RV3032_CTRL2_UIE | RV3032_CTRL2_AIE, ctrl);
 365         if (ret)
 366                 return ret;
 367
 368         return 0;
 369 }
 370
 371 static int rv3032_read_offset(struct device *dev, long *offset)
 372 {
 373         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 374         int ret, value, steps;
 375
 376         ret = regmap_read(rv3032->regmap, RV3032_OFFSET, &value);
 377         if (ret < 0)
 378                 return ret;
 379
 380         steps = sign_extend32(FIELD_GET(RV3032_OFFSET_MSK, value), 5);
 381
 382         *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
 383
 384         return 0;
 385 }
 386
 387 static int rv3032_set_offset(struct device *dev, long offset)
 388 {
 389         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 390
 391         offset = clamp(offset, -7629L, 7391L) * 1000;
 392         offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
 393
 394         return rv3032_update_cfg(rv3032, RV3032_OFFSET, RV3032_OFFSET_MSK,
 395                                  FIELD_PREP(RV3032_OFFSET_MSK, offset));
 396 }
 397
 398 static int rv3032_param_get(struct device *dev, struct rtc_param *param)
 399 {
 400         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 401         int ret;
 402
 403         switch(param->param) {
 404                 u32 value;
 405
 406         case RTC_PARAM_BACKUP_SWITCH_MODE:
 407                 ret = regmap_read(rv3032->regmap, RV3032_PMU, &value);
 408                 if (ret < 0)
 409                         return ret;
 410
 411                 value = FIELD_GET(RV3032_PMU_BSM, value);
 412
 413                 switch(value) {
 414                 case RV3032_PMU_BSM_DSM:
 415                         param->uvalue = RTC_BSM_DIRECT;
 416                         break;
 417                 case RV3032_PMU_BSM_LSM:
 418                         param->uvalue = RTC_BSM_LEVEL;
 419                         break;
 420                 default:
 421                         param->uvalue = RTC_BSM_DISABLED;
 422                 }
 423
 424                 break;
 425
 426         default:
 427                 return -EINVAL;
 428         }
 429
 430         return 0;
 431 }
 432
 433 static int rv3032_param_set(struct device *dev, struct rtc_param *param)
 434 {
 435         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 436
 437         switch(param->param) {
 438                 u8 mode;
 439         case RTC_PARAM_BACKUP_SWITCH_MODE:
 440                 if (rv3032->trickle_charger_set)
 441                         return -EINVAL;
 442
 443                 switch (param->uvalue) {
 444                 case RTC_BSM_DISABLED:
 445                         mode = 0;
 446                         break;
 447                 case RTC_BSM_DIRECT:
 448                         mode = RV3032_PMU_BSM_DSM;
 449                         break;
 450                 case RTC_BSM_LEVEL:
 451                         mode = RV3032_PMU_BSM_LSM;
 452                         break;
 453                 default:
 454                         return -EINVAL;
 455                 }
 456
 457                 return rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_BSM,
 458                                          FIELD_PREP(RV3032_PMU_BSM, mode));
 459
 460         default:
 461                 return -EINVAL;
 462         }
 463
 464         return 0;
 465 }
 466
 467 static int rv3032_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 468 {
 469         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 470         int status, val = 0, ret = 0;
 471
 472         switch (cmd) {
 473         case RTC_VL_READ:
 474                 ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
 475                 if (ret < 0)
 476                         return ret;
 477
 478                 if (status & (RV3032_STATUS_PORF | RV3032_STATUS_VLF))
 479                         val = RTC_VL_DATA_INVALID;
 480                 return put_user(val, (unsigned int __user *)arg);
 481
 482         default:
 483                 return -ENOIOCTLCMD;
 484         }
 485 }
 486
 487 static int rv3032_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes)
 488 {
 489         return regmap_bulk_write(priv, RV3032_RAM1 + offset, val, bytes);
 490 }
 491
 492 static int rv3032_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes)
 493 {
 494         return regmap_bulk_read(priv, RV3032_RAM1 + offset, val, bytes);
 495 }
 496
 497 static int rv3032_eeprom_write(void *priv, unsigned int offset, void *val, size_t bytes)
 498 {
 499         struct rv3032_data *rv3032 = priv;
 500         u32 status, eerd;
 501         int i, ret;
 502         u8 *buf = val;
 503
 504         ret = rv3032_enter_eerd(rv3032, &eerd);
 505         if (ret)
 506                 return ret;
 507
 508         for (i = 0; i < bytes; i++) {
 509                 ret = regmap_write(rv3032->regmap, RV3032_EEPROM_ADDR,
 510                                    RV3032_EEPROM_USER + offset + i);
 511                 if (ret)
 512                         goto exit_eerd;
 513
 514                 ret = regmap_write(rv3032->regmap, RV3032_EEPROM_DATA, buf[i]);
 515                 if (ret)
 516                         goto exit_eerd;
 517
 518                 ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD,
 519                                    RV3032_EEPROM_CMD_WRITE);
 520                 if (ret)
 521                         goto exit_eerd;
 522
 523                 usleep_range(RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
 524
 525                 ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
 526                                                !(status & RV3032_TLSB_EEBUSY),
 527                                                RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
 528                 if (ret)
 529                         goto exit_eerd;
 530         }
 531
 532 exit_eerd:
 533         rv3032_exit_eerd(rv3032, eerd);
 534
 535         return ret;
 536 }
 537
 538 static int rv3032_eeprom_read(void *priv, unsigned int offset, void *val, size_t bytes)
 539 {
 540         struct rv3032_data *rv3032 = priv;
 541         u32 status, eerd, data;
 542         int i, ret;
 543         u8 *buf = val;
 544
 545         ret = rv3032_enter_eerd(rv3032, &eerd);
 546         if (ret)
 547                 return ret;
 548
 549         for (i = 0; i < bytes; i++) {
 550                 ret = regmap_write(rv3032->regmap, RV3032_EEPROM_ADDR,
 551                                    RV3032_EEPROM_USER + offset + i);
 552                 if (ret)
 553                         goto exit_eerd;
 554
 555                 ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD,
 556                                    RV3032_EEPROM_CMD_READ);
 557                 if (ret)
 558                         goto exit_eerd;
 559
 560                 ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
 561                                                !(status & RV3032_TLSB_EEBUSY),
 562                                                RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
 563                 if (ret)
 564                         goto exit_eerd;
 565
 566                 ret = regmap_read(rv3032->regmap, RV3032_EEPROM_DATA, &data);
 567                 if (ret)
 568                         goto exit_eerd;
 569                 buf[i] = data;
 570         }
 571
 572 exit_eerd:
 573         rv3032_exit_eerd(rv3032, eerd);
 574
 575         return ret;
 576 }
 577
 578 static int rv3032_trickle_charger_setup(struct device *dev, struct rv3032_data *rv3032)
 579 {
 580         u32 val, ohms, voltage;
 581         int i;
 582
 583         val = FIELD_PREP(RV3032_PMU_TCM, 1) | FIELD_PREP(RV3032_PMU_BSM, RV3032_PMU_BSM_DSM);
 584         if (!device_property_read_u32(dev, "trickle-voltage-millivolt", &voltage)) {
 585                 for (i = 0; i < ARRAY_SIZE(rv3032_trickle_voltages); i++)
 586                         if (voltage == rv3032_trickle_voltages[i])
 587                                 break;
 588                 if (i < ARRAY_SIZE(rv3032_trickle_voltages))
 589                         val = FIELD_PREP(RV3032_PMU_TCM, i) |
 590                               FIELD_PREP(RV3032_PMU_BSM, RV3032_PMU_BSM_LSM);
 591         }
 592
 593         if (device_property_read_u32(dev, "trickle-resistor-ohms", &ohms))
 594                 return 0;
 595
 596         for (i = 0; i < ARRAY_SIZE(rv3032_trickle_resistors); i++)
 597                 if (ohms == rv3032_trickle_resistors[i])
 598                         break;
 599
 600         if (i >= ARRAY_SIZE(rv3032_trickle_resistors)) {
 601                 dev_warn(dev, "invalid trickle resistor value\n");
 602
 603                 return 0;
 604         }
 605
 606         rv3032->trickle_charger_set = true;
 607
 608         return rv3032_update_cfg(rv3032, RV3032_PMU,
 609                                  RV3032_PMU_TCR | RV3032_PMU_TCM | RV3032_PMU_BSM,
 610                                  val | FIELD_PREP(RV3032_PMU_TCR, i));
 611 }
 612
 613 #ifdef CONFIG_COMMON_CLK
 614 #define clkout_hw_to_rv3032(hw) container_of(hw, struct rv3032_data, clkout_hw)
 615
 616 static int clkout_xtal_rates[] = {
 617         32768,
 618         1024,
 619         64,
 620         1,
 621 };
 622
 623 #define RV3032_HFD_STEP 8192
 624
 625 static unsigned long rv3032_clkout_recalc_rate(struct clk_hw *hw,
 626                                                unsigned long parent_rate)
 627 {
 628         int clkout, ret;
 629         struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
 630
 631         ret = regmap_read(rv3032->regmap, RV3032_CLKOUT2, &clkout);
 632         if (ret < 0)
 633                 return 0;
 634
 635         if (clkout & RV3032_CLKOUT2_OS) {
 636                 unsigned long rate = FIELD_GET(RV3032_CLKOUT2_HFD_MSK, clkout) << 8;
 637
 638                 ret = regmap_read(rv3032->regmap, RV3032_CLKOUT1, &clkout);
 639                 if (ret < 0)
 640                         return 0;
 641
 642                 rate += clkout + 1;
 643
 644                 return rate * RV3032_HFD_STEP;
 645         }
 646
 647         return clkout_xtal_rates[FIELD_GET(RV3032_CLKOUT2_FD_MSK, clkout)];
 648 }
 649
 650 static long rv3032_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 651                                      unsigned long *prate)
 652 {
 653         int i, hfd;
 654
 655         if (rate < RV3032_HFD_STEP)
 656                 for (i = 0; i < ARRAY_SIZE(clkout_xtal_rates); i++)
 657                         if (clkout_xtal_rates[i] <= rate)
 658                                 return clkout_xtal_rates[i];
 659
 660         hfd = DIV_ROUND_CLOSEST(rate, RV3032_HFD_STEP);
 661
 662         return RV3032_HFD_STEP * clamp(hfd, 0, 8192);
 663 }
 664
 665 static int rv3032_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 666                                   unsigned long parent_rate)
 667 {
 668         struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
 669         u32 status, eerd;
 670         int i, hfd, ret;
 671
 672         for (i = 0; i < ARRAY_SIZE(clkout_xtal_rates); i++) {
 673                 if (clkout_xtal_rates[i] == rate) {
 674                         return rv3032_update_cfg(rv3032, RV3032_CLKOUT2, 0xff,
 675                                                  FIELD_PREP(RV3032_CLKOUT2_FD_MSK, i));
 676                 }
 677         }
 678
 679         hfd = DIV_ROUND_CLOSEST(rate, RV3032_HFD_STEP);
 680         hfd = clamp(hfd, 1, 8192) - 1;
 681
 682         ret = rv3032_enter_eerd(rv3032, &eerd);
 683         if (ret)
 684                 return ret;
 685
 686         ret = regmap_write(rv3032->regmap, RV3032_CLKOUT1, hfd & 0xff);
 687         if (ret)
 688                 goto exit_eerd;
 689
 690         ret = regmap_write(rv3032->regmap, RV3032_CLKOUT2, RV3032_CLKOUT2_OS |
 691                             FIELD_PREP(RV3032_CLKOUT2_HFD_MSK, hfd >> 8));
 692         if (ret)
 693                 goto exit_eerd;
 694
 695         ret = regmap_write(rv3032->regmap, RV3032_EEPROM_CMD, RV3032_EEPROM_CMD_UPDATE);
 696         if (ret)
 697                 goto exit_eerd;
 698
 699         usleep_range(46000, RV3032_EEBUSY_TIMEOUT);
 700
 701         ret = regmap_read_poll_timeout(rv3032->regmap, RV3032_TLSB, status,
 702                                        !(status & RV3032_TLSB_EEBUSY),
 703                                        RV3032_EEBUSY_POLL, RV3032_EEBUSY_TIMEOUT);
 704
 705 exit_eerd:
 706         rv3032_exit_eerd(rv3032, eerd);
 707
 708         return ret;
 709 }
 710
 711 static int rv3032_clkout_prepare(struct clk_hw *hw)
 712 {
 713         struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
 714
 715         return rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_NCLKE, 0);
 716 }
 717
 718 static void rv3032_clkout_unprepare(struct clk_hw *hw)
 719 {
 720         struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
 721
 722         rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_NCLKE, RV3032_PMU_NCLKE);
 723 }
 724
 725 static int rv3032_clkout_is_prepared(struct clk_hw *hw)
 726 {
 727         int val, ret;
 728         struct rv3032_data *rv3032 = clkout_hw_to_rv3032(hw);
 729
 730         ret = regmap_read(rv3032->regmap, RV3032_PMU, &val);
 731         if (ret < 0)
 732                 return ret;
 733
 734         return !(val & RV3032_PMU_NCLKE);
 735 }
 736
 737 static const struct clk_ops rv3032_clkout_ops = {
 738         .prepare = rv3032_clkout_prepare,
 739         .unprepare = rv3032_clkout_unprepare,
 740         .is_prepared = rv3032_clkout_is_prepared,
 741         .recalc_rate = rv3032_clkout_recalc_rate,
 742         .round_rate = rv3032_clkout_round_rate,
 743         .set_rate = rv3032_clkout_set_rate,
 744 };
 745
 746 static int rv3032_clkout_register_clk(struct rv3032_data *rv3032,
 747                                       struct i2c_client *client)
 748 {
 749         int ret;
 750         struct clk *clk;
 751         struct clk_init_data init;
 752         struct device_node *node = client->dev.of_node;
 753
 754         ret = regmap_update_bits(rv3032->regmap, RV3032_TLSB, RV3032_TLSB_CLKF, 0);
 755         if (ret < 0)
 756                 return ret;
 757
 758         ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL2, RV3032_CTRL2_CLKIE, 0);
 759         if (ret < 0)
 760                 return ret;
 761
 762         ret = regmap_write(rv3032->regmap, RV3032_CLK_IRQ, 0);
 763         if (ret < 0)
 764                 return ret;
 765
 766         init.name = "rv3032-clkout";
 767         init.ops = &rv3032_clkout_ops;
 768         init.flags = 0;
 769         init.parent_names = NULL;
 770         init.num_parents = 0;
 771         rv3032->clkout_hw.init = &init;
 772
 773         of_property_read_string(node, "clock-output-names", &init.name);
 774
 775         clk = devm_clk_register(&client->dev, &rv3032->clkout_hw);
 776         if (!IS_ERR(clk))
 777                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 778
 779         return 0;
 780 }
 781 #endif
 782
 783 static int rv3032_hwmon_read_temp(struct device *dev, long *mC)
 784 {
 785         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 786         u8 buf[2];
 787         int temp, prev = 0;
 788         int ret;
 789
 790         ret = regmap_bulk_read(rv3032->regmap, RV3032_TLSB, buf, sizeof(buf));
 791         if (ret)
 792                 return ret;
 793
 794         temp = sign_extend32(buf[1], 7) << 4;
 795         temp |= FIELD_GET(RV3032_TLSB_TEMP, buf[0]);
 796
 797         /* No blocking or shadowing on RV3032_TLSB and RV3032_TMSB */
 798         do {
 799                 prev = temp;
 800
 801                 ret = regmap_bulk_read(rv3032->regmap, RV3032_TLSB, buf, sizeof(buf));
 802                 if (ret)
 803                         return ret;
 804
 805                 temp = sign_extend32(buf[1], 7) << 4;
 806                 temp |= FIELD_GET(RV3032_TLSB_TEMP, buf[0]);
 807         } while (temp != prev);
 808
 809         *mC = (temp * 1000) / 16;
 810
 811         return 0;
 812 }
 813
 814 static umode_t rv3032_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
 815                                        u32 attr, int channel)
 816 {
 817         if (type != hwmon_temp)
 818                 return 0;
 819
 820         switch (attr) {
 821         case hwmon_temp_input:
 822                 return 0444;
 823         default:
 824                 return 0;
 825         }
 826 }
 827
 828 static int rv3032_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
 829                              u32 attr, int channel, long *temp)
 830 {
 831         int err;
 832
 833         switch (attr) {
 834         case hwmon_temp_input:
 835                 err = rv3032_hwmon_read_temp(dev, temp);
 836                 break;
 837         default:
 838                 err = -EOPNOTSUPP;
 839                 break;
 840         }
 841
 842         return err;
 843 }
 844
 845 static const struct hwmon_channel_info * const rv3032_hwmon_info[] = {
 846         HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
 847         HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
 848         NULL
 849 };
 850
 851 static const struct hwmon_ops rv3032_hwmon_hwmon_ops = {
 852         .is_visible = rv3032_hwmon_is_visible,
 853         .read = rv3032_hwmon_read,
 854 };
 855
 856 static const struct hwmon_chip_info rv3032_hwmon_chip_info = {
 857         .ops = &rv3032_hwmon_hwmon_ops,
 858         .info = rv3032_hwmon_info,
 859 };
 860
 861 static void rv3032_hwmon_register(struct device *dev)
 862 {
 863         struct rv3032_data *rv3032 = dev_get_drvdata(dev);
 864
 865         if (!IS_REACHABLE(CONFIG_HWMON))
 866                 return;
 867
 868         devm_hwmon_device_register_with_info(dev, "rv3032", rv3032, &rv3032_hwmon_chip_info, NULL);
 869 }
 870
 871 static const struct rtc_class_ops rv3032_rtc_ops = {
 872         .read_time = rv3032_get_time,
 873         .set_time = rv3032_set_time,
 874         .read_offset = rv3032_read_offset,
 875         .set_offset = rv3032_set_offset,
 876         .ioctl = rv3032_ioctl,
 877         .read_alarm = rv3032_get_alarm,
 878         .set_alarm = rv3032_set_alarm,
 879         .alarm_irq_enable = rv3032_alarm_irq_enable,
 880         .param_get = rv3032_param_get,
 881         .param_set = rv3032_param_set,
 882 };
 883
 884 static const struct regmap_config regmap_config = {
 885         .reg_bits = 8,
 886         .val_bits = 8,
 887         .max_register = 0xCA,
 888 };
 889
 890 static int rv3032_probe(struct i2c_client *client)
 891 {
 892         struct rv3032_data *rv3032;
 893         int ret, status;
 894         struct nvmem_config nvmem_cfg = {
 895                 .name = "rv3032_nvram",
 896                 .word_size = 1,
 897                 .stride = 1,
 898                 .size = 16,
 899                 .type = NVMEM_TYPE_BATTERY_BACKED,
 900                 .reg_read = rv3032_nvram_read,
 901                 .reg_write = rv3032_nvram_write,
 902         };
 903         struct nvmem_config eeprom_cfg = {
 904                 .name = "rv3032_eeprom",
 905                 .word_size = 1,
 906                 .stride = 1,
 907                 .size = 32,
 908                 .type = NVMEM_TYPE_EEPROM,
 909                 .reg_read = rv3032_eeprom_read,
 910                 .reg_write = rv3032_eeprom_write,
 911         };
 912
 913         rv3032 = devm_kzalloc(&client->dev, sizeof(struct rv3032_data),
 914                               GFP_KERNEL);
 915         if (!rv3032)
 916                 return -ENOMEM;
 917
 918         rv3032->regmap = devm_regmap_init_i2c(client, &regmap_config);
 919         if (IS_ERR(rv3032->regmap))
 920                 return PTR_ERR(rv3032->regmap);
 921
 922         i2c_set_clientdata(client, rv3032);
 923
 924         ret = regmap_read(rv3032->regmap, RV3032_STATUS, &status);
 925         if (ret < 0)
 926                 return ret;
 927
 928         rv3032->rtc = devm_rtc_allocate_device(&client->dev);
 929         if (IS_ERR(rv3032->rtc))
 930                 return PTR_ERR(rv3032->rtc);
 931
 932         if (client->irq > 0) {
 933                 unsigned long irqflags = IRQF_TRIGGER_LOW;
 934
 935                 if (dev_fwnode(&client->dev))
 936                         irqflags = 0;
 937
 938                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 939                                                 NULL, rv3032_handle_irq,
 940                                                 irqflags | IRQF_ONESHOT,
 941                                                 "rv3032", rv3032);
 942                 if (ret) {
 943                         dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 944                         client->irq = 0;
 945                 }
 946         }
 947         if (!client->irq)
 948                 clear_bit(RTC_FEATURE_ALARM, rv3032->rtc->features);
 949
 950         ret = regmap_update_bits(rv3032->regmap, RV3032_CTRL1,
 951                                  RV3032_CTRL1_WADA, RV3032_CTRL1_WADA);
 952         if (ret)
 953                 return ret;
 954
 955         rv3032_trickle_charger_setup(&client->dev, rv3032);
 956
 957         set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3032->rtc->features);
 958         set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rv3032->rtc->features);
 959
 960         rv3032->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 961         rv3032->rtc->range_max = RTC_TIMESTAMP_END_2099;
 962         rv3032->rtc->ops = &rv3032_rtc_ops;
 963         ret = devm_rtc_register_device(rv3032->rtc);
 964         if (ret)
 965                 return ret;
 966
 967         nvmem_cfg.priv = rv3032->regmap;
 968         devm_rtc_nvmem_register(rv3032->rtc, &nvmem_cfg);
 969         eeprom_cfg.priv = rv3032;
 970         devm_rtc_nvmem_register(rv3032->rtc, &eeprom_cfg);
 971
 972         rv3032->rtc->max_user_freq = 1;
 973
 974 #ifdef CONFIG_COMMON_CLK
 975         rv3032_clkout_register_clk(rv3032, client);
 976 #endif
 977
 978         rv3032_hwmon_register(&client->dev);
 979
 980         return 0;
 981 }
 982
 983 static const struct acpi_device_id rv3032_i2c_acpi_match[] = {
 984         { "MCRY3032" },
 985         { }
 986 };
 987 MODULE_DEVICE_TABLE(acpi, rv3032_i2c_acpi_match);
 988
 989 static const __maybe_unused struct of_device_id rv3032_of_match[] = {
 990         { .compatible = "microcrystal,rv3032", },
 991         { }
 992 };
 993 MODULE_DEVICE_TABLE(of, rv3032_of_match);
 994
 995 static struct i2c_driver rv3032_driver = {
 996         .driver = {
 997                 .name = "rtc-rv3032",
 998                 .acpi_match_table = rv3032_i2c_acpi_match,
 999                 .of_match_table = of_match_ptr(rv3032_of_match),
1000         },
1001         .probe          = rv3032_probe,
1002 };
1003 module_i2c_driver(rv3032_driver);
1004
1005 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1006 MODULE_DESCRIPTION("Micro Crystal RV3032 RTC driver");
1007 MODULE_LICENSE("GPL v2");