drivers/rtc/rtc-rv3029c2.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Micro Crystal RV-3029 / RV-3049 rtc class driver
   4  *
   5  * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
   6  *         Michael Buesch <m@bues.ch>
   7  *
   8  * based on previously existing rtc class drivers
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/i2c.h>
  13 #include <linux/spi/spi.h>
  14 #include <linux/bcd.h>
  15 #include <linux/rtc.h>
  16 #include <linux/delay.h>
  17 #include <linux/of.h>
  18 #include <linux/hwmon.h>
  19 #include <linux/hwmon-sysfs.h>
  20 #include <linux/regmap.h>
  21
  22 /* Register map */
  23 /* control section */
  24 #define RV3029_ONOFF_CTRL               0x00
  25 #define RV3029_ONOFF_CTRL_WE            BIT(0)
  26 #define RV3029_ONOFF_CTRL_TE            BIT(1)
  27 #define RV3029_ONOFF_CTRL_TAR           BIT(2)
  28 #define RV3029_ONOFF_CTRL_EERE          BIT(3)
  29 #define RV3029_ONOFF_CTRL_SRON          BIT(4)
  30 #define RV3029_ONOFF_CTRL_TD0           BIT(5)
  31 #define RV3029_ONOFF_CTRL_TD1           BIT(6)
  32 #define RV3029_ONOFF_CTRL_CLKINT        BIT(7)
  33 #define RV3029_IRQ_CTRL                 0x01
  34 #define RV3029_IRQ_CTRL_AIE             BIT(0)
  35 #define RV3029_IRQ_CTRL_TIE             BIT(1)
  36 #define RV3029_IRQ_CTRL_V1IE            BIT(2)
  37 #define RV3029_IRQ_CTRL_V2IE            BIT(3)
  38 #define RV3029_IRQ_CTRL_SRIE            BIT(4)
  39 #define RV3029_IRQ_FLAGS                0x02
  40 #define RV3029_IRQ_FLAGS_AF             BIT(0)
  41 #define RV3029_IRQ_FLAGS_TF             BIT(1)
  42 #define RV3029_IRQ_FLAGS_V1IF           BIT(2)
  43 #define RV3029_IRQ_FLAGS_V2IF           BIT(3)
  44 #define RV3029_IRQ_FLAGS_SRF            BIT(4)
  45 #define RV3029_STATUS                   0x03
  46 #define RV3029_STATUS_VLOW1             BIT(2)
  47 #define RV3029_STATUS_VLOW2             BIT(3)
  48 #define RV3029_STATUS_SR                BIT(4)
  49 #define RV3029_STATUS_PON               BIT(5)
  50 #define RV3029_STATUS_EEBUSY            BIT(7)
  51 #define RV3029_RST_CTRL                 0x04
  52 #define RV3029_RST_CTRL_SYSR            BIT(4)
  53 #define RV3029_CONTROL_SECTION_LEN      0x05
  54
  55 /* watch section */
  56 #define RV3029_W_SEC                    0x08
  57 #define RV3029_W_MINUTES                0x09
  58 #define RV3029_W_HOURS                  0x0A
  59 #define RV3029_REG_HR_12_24             BIT(6) /* 24h/12h mode */
  60 #define RV3029_REG_HR_PM                BIT(5) /* PM/AM bit in 12h mode */
  61 #define RV3029_W_DATE                   0x0B
  62 #define RV3029_W_DAYS                   0x0C
  63 #define RV3029_W_MONTHS                 0x0D
  64 #define RV3029_W_YEARS                  0x0E
  65 #define RV3029_WATCH_SECTION_LEN        0x07
  66
  67 /* alarm section */
  68 #define RV3029_A_SC                     0x10
  69 #define RV3029_A_MN                     0x11
  70 #define RV3029_A_HR                     0x12
  71 #define RV3029_A_DT                     0x13
  72 #define RV3029_A_DW                     0x14
  73 #define RV3029_A_MO                     0x15
  74 #define RV3029_A_YR                     0x16
  75 #define RV3029_A_AE_X                   BIT(7)
  76 #define RV3029_ALARM_SECTION_LEN        0x07
  77
  78 /* timer section */
  79 #define RV3029_TIMER_LOW                0x18
  80 #define RV3029_TIMER_HIGH               0x19
  81
  82 /* temperature section */
  83 #define RV3029_TEMP_PAGE                0x20
  84
  85 /* eeprom data section */
  86 #define RV3029_E2P_EEDATA1              0x28
  87 #define RV3029_E2P_EEDATA2              0x29
  88 #define RV3029_E2PDATA_SECTION_LEN      0x02
  89
  90 /* eeprom control section */
  91 #define RV3029_CONTROL_E2P_EECTRL       0x30
  92 #define RV3029_EECTRL_THP               BIT(0) /* temp scan interval */
  93 #define RV3029_EECTRL_THE               BIT(1) /* thermometer enable */
  94 #define RV3029_EECTRL_FD0               BIT(2) /* CLKOUT */
  95 #define RV3029_EECTRL_FD1               BIT(3) /* CLKOUT */
  96 #define RV3029_TRICKLE_1K               BIT(4) /* 1.5K resistance */
  97 #define RV3029_TRICKLE_5K               BIT(5) /* 5K   resistance */
  98 #define RV3029_TRICKLE_20K              BIT(6) /* 20K  resistance */
  99 #define RV3029_TRICKLE_80K              BIT(7) /* 80K  resistance */
 100 #define RV3029_TRICKLE_MASK             (RV3029_TRICKLE_1K |\
 101                                          RV3029_TRICKLE_5K |\
 102                                          RV3029_TRICKLE_20K |\
 103                                          RV3029_TRICKLE_80K)
 104 #define RV3029_TRICKLE_SHIFT            4
 105 #define RV3029_CONTROL_E2P_XOFFS        0x31 /* XTAL offset */
 106 #define RV3029_CONTROL_E2P_XOFFS_SIGN   BIT(7) /* Sign: 1->pos, 0->neg */
 107 #define RV3029_CONTROL_E2P_QCOEF        0x32 /* XTAL temp drift coef */
 108 #define RV3029_CONTROL_E2P_TURNOVER     0x33 /* XTAL turnover temp (in *C) */
 109 #define RV3029_CONTROL_E2P_TOV_MASK     0x3F /* XTAL turnover temp mask */
 110
 111 /* user ram section */
 112 #define RV3029_RAM_PAGE                 0x38
 113 #define RV3029_RAM_SECTION_LEN          8
 114
 115 struct rv3029_data {
 116         struct device           *dev;
 117         struct rtc_device       *rtc;
 118         struct regmap           *regmap;
 119         int irq;
 120 };
 121
 122 static int rv3029_eeprom_busywait(struct rv3029_data *rv3029)
 123 {
 124         unsigned int sr;
 125         int i, ret;
 126
 127         for (i = 100; i > 0; i--) {
 128                 ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
 129                 if (ret < 0)
 130                         break;
 131                 if (!(sr & RV3029_STATUS_EEBUSY))
 132                         break;
 133                 usleep_range(1000, 10000);
 134         }
 135         if (i <= 0) {
 136                 dev_err(rv3029->dev, "EEPROM busy wait timeout.\n");
 137                 return -ETIMEDOUT;
 138         }
 139
 140         return ret;
 141 }
 142
 143 static int rv3029_eeprom_exit(struct rv3029_data *rv3029)
 144 {
 145         /* Re-enable eeprom refresh */
 146         return regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
 147                                   RV3029_ONOFF_CTRL_EERE,
 148                                   RV3029_ONOFF_CTRL_EERE);
 149 }
 150
 151 static int rv3029_eeprom_enter(struct rv3029_data *rv3029)
 152 {
 153         unsigned int sr;
 154         int ret;
 155
 156         /* Check whether we are in the allowed voltage range. */
 157         ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
 158         if (ret < 0)
 159                 return ret;
 160         if (sr & RV3029_STATUS_VLOW2)
 161                 return -ENODEV;
 162         if (sr & RV3029_STATUS_VLOW1) {
 163                 /* We clear the bits and retry once just in case
 164                  * we had a brown out in early startup.
 165                  */
 166                 ret = regmap_update_bits(rv3029->regmap, RV3029_STATUS,
 167                                          RV3029_STATUS_VLOW1, 0);
 168                 if (ret < 0)
 169                         return ret;
 170                 usleep_range(1000, 10000);
 171                 ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
 172                 if (ret < 0)
 173                         return ret;
 174                 if (sr & RV3029_STATUS_VLOW1) {
 175                         dev_err(rv3029->dev,
 176                                 "Supply voltage is too low to safely access the EEPROM.\n");
 177                         return -ENODEV;
 178                 }
 179         }
 180
 181         /* Disable eeprom refresh. */
 182         ret = regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
 183                                  RV3029_ONOFF_CTRL_EERE, 0);
 184         if (ret < 0)
 185                 return ret;
 186
 187         /* Wait for any previous eeprom accesses to finish. */
 188         ret = rv3029_eeprom_busywait(rv3029);
 189         if (ret < 0)
 190                 rv3029_eeprom_exit(rv3029);
 191
 192         return ret;
 193 }
 194
 195 static int rv3029_eeprom_read(struct rv3029_data *rv3029, u8 reg,
 196                               u8 buf[], size_t len)
 197 {
 198         int ret, err;
 199
 200         err = rv3029_eeprom_enter(rv3029);
 201         if (err < 0)
 202                 return err;
 203
 204         ret = regmap_bulk_read(rv3029->regmap, reg, buf, len);
 205
 206         err = rv3029_eeprom_exit(rv3029);
 207         if (err < 0)
 208                 return err;
 209
 210         return ret;
 211 }
 212
 213 static int rv3029_eeprom_write(struct rv3029_data *rv3029, u8 reg,
 214                                u8 const buf[], size_t len)
 215 {
 216         unsigned int tmp;
 217         int ret, err;
 218         size_t i;
 219
 220         err = rv3029_eeprom_enter(rv3029);
 221         if (err < 0)
 222                 return err;
 223
 224         for (i = 0; i < len; i++, reg++) {
 225                 ret = regmap_read(rv3029->regmap, reg, &tmp);
 226                 if (ret < 0)
 227                         break;
 228                 if (tmp != buf[i]) {
 229                         tmp = buf[i];
 230                         ret = regmap_write(rv3029->regmap, reg, tmp);
 231                         if (ret < 0)
 232                                 break;
 233                 }
 234                 ret = rv3029_eeprom_busywait(rv3029);
 235                 if (ret < 0)
 236                         break;
 237         }
 238
 239         err = rv3029_eeprom_exit(rv3029);
 240         if (err < 0)
 241                 return err;
 242
 243         return ret;
 244 }
 245
 246 static int rv3029_eeprom_update_bits(struct rv3029_data *rv3029,
 247                                      u8 reg, u8 mask, u8 set)
 248 {
 249         u8 buf;
 250         int ret;
 251
 252         ret = rv3029_eeprom_read(rv3029, reg, &buf, 1);
 253         if (ret < 0)
 254                 return ret;
 255         buf &= ~mask;
 256         buf |= set & mask;
 257         ret = rv3029_eeprom_write(rv3029, reg, &buf, 1);
 258         if (ret < 0)
 259                 return ret;
 260
 261         return 0;
 262 }
 263
 264 static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
 265 {
 266         struct device *dev = dev_id;
 267         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 268         unsigned int flags, controls;
 269         unsigned long events = 0;
 270         int ret;
 271
 272         rtc_lock(rv3029->rtc);
 273
 274         ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
 275         if (ret) {
 276                 dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
 277                 rtc_unlock(rv3029->rtc);
 278                 return IRQ_NONE;
 279         }
 280
 281         ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
 282         if (ret) {
 283                 dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
 284                 rtc_unlock(rv3029->rtc);
 285                 return IRQ_NONE;
 286         }
 287
 288         if (flags & RV3029_IRQ_FLAGS_AF) {
 289                 flags &= ~RV3029_IRQ_FLAGS_AF;
 290                 controls &= ~RV3029_IRQ_CTRL_AIE;
 291                 events |= RTC_AF;
 292         }
 293
 294         if (events) {
 295                 rtc_update_irq(rv3029->rtc, 1, events);
 296                 regmap_write(rv3029->regmap, RV3029_IRQ_FLAGS, flags);
 297                 regmap_write(rv3029->regmap, RV3029_IRQ_CTRL, controls);
 298         }
 299         rtc_unlock(rv3029->rtc);
 300
 301         return IRQ_HANDLED;
 302 }
 303
 304 static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
 305 {
 306         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 307         unsigned int sr;
 308         int ret;
 309         u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
 310
 311         ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
 312         if (ret < 0)
 313                 return ret;
 314
 315         if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
 316                 return -EINVAL;
 317
 318         ret = regmap_bulk_read(rv3029->regmap, RV3029_W_SEC, regs,
 319                                RV3029_WATCH_SECTION_LEN);
 320         if (ret < 0)
 321                 return ret;
 322
 323         tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
 324         tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
 325
 326         /* HR field has a more complex interpretation */
 327         {
 328                 const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
 329
 330                 if (_hr & RV3029_REG_HR_12_24) {
 331                         /* 12h format */
 332                         tm->tm_hour = bcd2bin(_hr & 0x1f);
 333                         if (_hr & RV3029_REG_HR_PM)     /* PM flag set */
 334                                 tm->tm_hour += 12;
 335                 } else /* 24h format */
 336                         tm->tm_hour = bcd2bin(_hr & 0x3f);
 337         }
 338
 339         tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
 340         tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
 341         tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
 342         tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
 343
 344         return 0;
 345 }
 346
 347 static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 348 {
 349         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 350         struct rtc_time *const tm = &alarm->time;
 351         unsigned int controls, flags;
 352         int ret;
 353         u8 regs[8];
 354
 355         ret = regmap_bulk_read(rv3029->regmap, RV3029_A_SC, regs,
 356                                RV3029_ALARM_SECTION_LEN);
 357         if (ret < 0)
 358                 return ret;
 359
 360         ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
 361         if (ret)
 362                 return ret;
 363
 364         ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
 365         if (ret < 0)
 366                 return ret;
 367
 368         tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
 369         tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
 370         tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
 371         tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
 372         tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
 373         tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
 374         tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
 375
 376         alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
 377         alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
 378
 379         return 0;
 380 }
 381
 382 static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
 383 {
 384         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 385
 386         return regmap_update_bits(rv3029->regmap, RV3029_IRQ_CTRL,
 387                                   RV3029_IRQ_CTRL_AIE,
 388                                   enable ? RV3029_IRQ_CTRL_AIE : 0);
 389 }
 390
 391 static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 392 {
 393         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 394         struct rtc_time *const tm = &alarm->time;
 395         int ret;
 396         u8 regs[8];
 397
 398         /* Activate all the alarms with AE_x bit */
 399         regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
 400         regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
 401         regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
 402                 | RV3029_A_AE_X;
 403         regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
 404                 | RV3029_A_AE_X;
 405         regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
 406                 | RV3029_A_AE_X;
 407         regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
 408                 | RV3029_A_AE_X;
 409         regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
 410                 | RV3029_A_AE_X;
 411
 412         /* Write the alarm */
 413         ret = regmap_bulk_write(rv3029->regmap, RV3029_A_SC, regs,
 414                                 RV3029_ALARM_SECTION_LEN);
 415         if (ret < 0)
 416                 return ret;
 417
 418         return rv3029_alarm_irq_enable(dev, alarm->enabled);
 419 }
 420
 421 static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
 422 {
 423         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 424         u8 regs[8];
 425         int ret;
 426
 427         regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
 428         regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
 429         regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
 430         regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
 431         regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
 432         regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
 433         regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
 434
 435         ret = regmap_bulk_write(rv3029->regmap, RV3029_W_SEC, regs,
 436                                 RV3029_WATCH_SECTION_LEN);
 437         if (ret < 0)
 438                 return ret;
 439
 440         /* clear PON and VLOW2 bits */
 441         return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
 442                                   RV3029_STATUS_PON | RV3029_STATUS_VLOW2, 0);
 443 }
 444
 445 static int rv3029_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 446 {
 447         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 448         unsigned long vl = 0;
 449         int sr, ret = 0;
 450
 451         switch (cmd) {
 452         case RTC_VL_READ:
 453                 ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
 454                 if (ret < 0)
 455                         return ret;
 456
 457                 if (sr & RV3029_STATUS_VLOW1)
 458                         vl = RTC_VL_ACCURACY_LOW;
 459
 460                 if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
 461                         vl |= RTC_VL_DATA_INVALID;
 462
 463                 return put_user(vl, (unsigned int __user *)arg);
 464
 465         case RTC_VL_CLR:
 466                 return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
 467                                           RV3029_STATUS_VLOW1, 0);
 468
 469         default:
 470                 return -ENOIOCTLCMD;
 471         }
 472 }
 473
 474 static int rv3029_nvram_write(void *priv, unsigned int offset, void *val,
 475                               size_t bytes)
 476 {
 477         return regmap_bulk_write(priv, RV3029_RAM_PAGE + offset, val, bytes);
 478 }
 479
 480 static int rv3029_nvram_read(void *priv, unsigned int offset, void *val,
 481                              size_t bytes)
 482 {
 483         return regmap_bulk_read(priv, RV3029_RAM_PAGE + offset, val, bytes);
 484 }
 485
 486 static const struct rv3029_trickle_tab_elem {
 487         u32 r;          /* resistance in ohms */
 488         u8 conf;        /* trickle config bits */
 489 } rv3029_trickle_tab[] = {
 490         {
 491                 .r      = 1076,
 492                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 493                           RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 494         }, {
 495                 .r      = 1091,
 496                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 497                           RV3029_TRICKLE_20K,
 498         }, {
 499                 .r      = 1137,
 500                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 501                           RV3029_TRICKLE_80K,
 502         }, {
 503                 .r      = 1154,
 504                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
 505         }, {
 506                 .r      = 1371,
 507                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
 508                           RV3029_TRICKLE_80K,
 509         }, {
 510                 .r      = 1395,
 511                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
 512         }, {
 513                 .r      = 1472,
 514                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
 515         }, {
 516                 .r      = 1500,
 517                 .conf   = RV3029_TRICKLE_1K,
 518         }, {
 519                 .r      = 3810,
 520                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
 521                           RV3029_TRICKLE_80K,
 522         }, {
 523                 .r      = 4000,
 524                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
 525         }, {
 526                 .r      = 4706,
 527                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
 528         }, {
 529                 .r      = 5000,
 530                 .conf   = RV3029_TRICKLE_5K,
 531         }, {
 532                 .r      = 16000,
 533                 .conf   = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 534         }, {
 535                 .r      = 20000,
 536                 .conf   = RV3029_TRICKLE_20K,
 537         }, {
 538                 .r      = 80000,
 539                 .conf   = RV3029_TRICKLE_80K,
 540         },
 541 };
 542
 543 static void rv3029_trickle_config(struct device *dev)
 544 {
 545         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 546         struct device_node *of_node = dev->of_node;
 547         const struct rv3029_trickle_tab_elem *elem;
 548         int i, err;
 549         u32 ohms;
 550         u8 trickle_set_bits;
 551
 552         if (!of_node)
 553                 return;
 554
 555         /* Configure the trickle charger. */
 556         err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
 557         if (err) {
 558                 /* Disable trickle charger. */
 559                 trickle_set_bits = 0;
 560         } else {
 561                 /* Enable trickle charger. */
 562                 for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
 563                         elem = &rv3029_trickle_tab[i];
 564                         if (elem->r >= ohms)
 565                                 break;
 566                 }
 567                 trickle_set_bits = elem->conf;
 568                 dev_info(dev,
 569                          "Trickle charger enabled at %d ohms resistance.\n",
 570                          elem->r);
 571         }
 572         err = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
 573                                         RV3029_TRICKLE_MASK,
 574                                         trickle_set_bits);
 575         if (err < 0)
 576                 dev_err(dev, "Failed to update trickle charger config\n");
 577 }
 578
 579 #ifdef CONFIG_RTC_DRV_RV3029_HWMON
 580
 581 static int rv3029_read_temp(struct rv3029_data *rv3029, int *temp_mC)
 582 {
 583         unsigned int temp;
 584         int ret;
 585
 586         ret = regmap_read(rv3029->regmap, RV3029_TEMP_PAGE, &temp);
 587         if (ret < 0)
 588                 return ret;
 589
 590         *temp_mC = ((int)temp - 60) * 1000;
 591
 592         return 0;
 593 }
 594
 595 static ssize_t rv3029_hwmon_show_temp(struct device *dev,
 596                                       struct device_attribute *attr,
 597                                       char *buf)
 598 {
 599         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 600         int ret, temp_mC;
 601
 602         ret = rv3029_read_temp(rv3029, &temp_mC);
 603         if (ret < 0)
 604                 return ret;
 605
 606         return sprintf(buf, "%d\n", temp_mC);
 607 }
 608
 609 static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
 610                                                 struct device_attribute *attr,
 611                                                 const char *buf,
 612                                                 size_t count)
 613 {
 614         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 615         unsigned int th_set_bits = 0;
 616         unsigned long interval_ms;
 617         int ret;
 618
 619         ret = kstrtoul(buf, 10, &interval_ms);
 620         if (ret < 0)
 621                 return ret;
 622
 623         if (interval_ms != 0) {
 624                 th_set_bits |= RV3029_EECTRL_THE;
 625                 if (interval_ms >= 16000)
 626                         th_set_bits |= RV3029_EECTRL_THP;
 627         }
 628         ret = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
 629                                         RV3029_EECTRL_THE | RV3029_EECTRL_THP,
 630                                         th_set_bits);
 631         if (ret < 0)
 632                 return ret;
 633
 634         return count;
 635 }
 636
 637 static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
 638                                                  struct device_attribute *attr,
 639                                                  char *buf)
 640 {
 641         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 642         int ret, interval_ms;
 643         u8 eectrl;
 644
 645         ret = rv3029_eeprom_read(rv3029, RV3029_CONTROL_E2P_EECTRL,
 646                                  &eectrl, 1);
 647         if (ret < 0)
 648                 return ret;
 649
 650         if (eectrl & RV3029_EECTRL_THE) {
 651                 if (eectrl & RV3029_EECTRL_THP)
 652                         interval_ms = 16000;
 653                 else
 654                         interval_ms = 1000;
 655         } else {
 656                 interval_ms = 0;
 657         }
 658
 659         return sprintf(buf, "%d\n", interval_ms);
 660 }
 661
 662 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
 663                           NULL, 0);
 664 static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
 665                           rv3029_hwmon_show_update_interval,
 666                           rv3029_hwmon_set_update_interval, 0);
 667
 668 static struct attribute *rv3029_hwmon_attrs[] = {
 669         &sensor_dev_attr_temp1_input.dev_attr.attr,
 670         &sensor_dev_attr_update_interval.dev_attr.attr,
 671         NULL,
 672 };
 673 ATTRIBUTE_GROUPS(rv3029_hwmon);
 674
 675 static void rv3029_hwmon_register(struct device *dev, const char *name)
 676 {
 677         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 678         struct device *hwmon_dev;
 679
 680         hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
 681                                                            rv3029_hwmon_groups);
 682         if (IS_ERR(hwmon_dev)) {
 683                 dev_warn(dev, "unable to register hwmon device %ld\n",
 684                          PTR_ERR(hwmon_dev));
 685         }
 686 }
 687
 688 #else /* CONFIG_RTC_DRV_RV3029_HWMON */
 689
 690 static void rv3029_hwmon_register(struct device *dev, const char *name)
 691 {
 692 }
 693
 694 #endif /* CONFIG_RTC_DRV_RV3029_HWMON */
 695
 696 static const struct rtc_class_ops rv3029_rtc_ops = {
 697         .read_time      = rv3029_read_time,
 698         .set_time       = rv3029_set_time,
 699         .ioctl          = rv3029_ioctl,
 700         .read_alarm     = rv3029_read_alarm,
 701         .set_alarm      = rv3029_set_alarm,
 702         .alarm_irq_enable = rv3029_alarm_irq_enable,
 703 };
 704
 705 static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
 706                         const char *name)
 707 {
 708         struct rv3029_data *rv3029;
 709         struct nvmem_config nvmem_cfg = {
 710                 .name = "rv3029_nvram",
 711                 .word_size = 1,
 712                 .stride = 1,
 713                 .size = RV3029_RAM_SECTION_LEN,
 714                 .type = NVMEM_TYPE_BATTERY_BACKED,
 715                 .reg_read = rv3029_nvram_read,
 716                 .reg_write = rv3029_nvram_write,
 717         };
 718         int rc = 0;
 719
 720         rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
 721         if (!rv3029)
 722                 return -ENOMEM;
 723
 724         rv3029->regmap = regmap;
 725         rv3029->irq = irq;
 726         rv3029->dev = dev;
 727         dev_set_drvdata(dev, rv3029);
 728
 729         rv3029_trickle_config(dev);
 730         rv3029_hwmon_register(dev, name);
 731
 732         rv3029->rtc = devm_rtc_allocate_device(dev);
 733         if (IS_ERR(rv3029->rtc))
 734                 return PTR_ERR(rv3029->rtc);
 735
 736         if (rv3029->irq > 0) {
 737                 rc = devm_request_threaded_irq(dev, rv3029->irq,
 738                                                NULL, rv3029_handle_irq,
 739                                                IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 740                                                "rv3029", dev);
 741                 if (rc) {
 742                         dev_warn(dev, "unable to request IRQ, alarms disabled\n");
 743                         rv3029->irq = 0;
 744                 }
 745         }
 746         if (!rv3029->irq)
 747                 clear_bit(RTC_FEATURE_ALARM, rv3029->rtc->features);
 748
 749         rv3029->rtc->ops = &rv3029_rtc_ops;
 750         rv3029->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 751         rv3029->rtc->range_max = RTC_TIMESTAMP_END_2079;
 752
 753         rc = devm_rtc_register_device(rv3029->rtc);
 754         if (rc)
 755                 return rc;
 756
 757         nvmem_cfg.priv = rv3029->regmap;
 758         devm_rtc_nvmem_register(rv3029->rtc, &nvmem_cfg);
 759
 760         return 0;
 761 }
 762
 763 static const struct regmap_range rv3029_holes_range[] = {
 764         regmap_reg_range(0x05, 0x07),
 765         regmap_reg_range(0x0f, 0x0f),
 766         regmap_reg_range(0x17, 0x17),
 767         regmap_reg_range(0x1a, 0x1f),
 768         regmap_reg_range(0x21, 0x27),
 769         regmap_reg_range(0x34, 0x37),
 770 };
 771
 772 static const struct regmap_access_table rv3029_regs = {
 773         .no_ranges =    rv3029_holes_range,
 774         .n_no_ranges =  ARRAY_SIZE(rv3029_holes_range),
 775 };
 776
 777 static const struct regmap_config config = {
 778         .reg_bits = 8,
 779         .val_bits = 8,
 780         .rd_table = &rv3029_regs,
 781         .wr_table = &rv3029_regs,
 782         .max_register = 0x3f,
 783 };
 784
 785 #if IS_ENABLED(CONFIG_I2C)
 786
 787 static int rv3029_i2c_probe(struct i2c_client *client,
 788                             const struct i2c_device_id *id)
 789 {
 790         struct regmap *regmap;
 791         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
 792                                      I2C_FUNC_SMBUS_BYTE)) {
 793                 dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
 794                 return -ENODEV;
 795         }
 796
 797         regmap = devm_regmap_init_i2c(client, &config);
 798         if (IS_ERR(regmap))
 799                 return PTR_ERR(regmap);
 800
 801         return rv3029_probe(&client->dev, regmap, client->irq, client->name);
 802 }
 803
 804 static const struct i2c_device_id rv3029_id[] = {
 805         { "rv3029", 0 },
 806         { "rv3029c2", 0 },
 807         { }
 808 };
 809 MODULE_DEVICE_TABLE(i2c, rv3029_id);
 810
 811 static const __maybe_unused struct of_device_id rv3029_of_match[] = {
 812         { .compatible = "microcrystal,rv3029" },
 813         { }
 814 };
 815 MODULE_DEVICE_TABLE(of, rv3029_of_match);
 816
 817 static struct i2c_driver rv3029_driver = {
 818         .driver = {
 819                 .name = "rv3029",
 820                 .of_match_table = of_match_ptr(rv3029_of_match),
 821         },
 822         .probe          = rv3029_i2c_probe,
 823         .id_table       = rv3029_id,
 824 };
 825
 826 static int __init rv3029_register_driver(void)
 827 {
 828         return i2c_add_driver(&rv3029_driver);
 829 }
 830
 831 static void rv3029_unregister_driver(void)
 832 {
 833         i2c_del_driver(&rv3029_driver);
 834 }
 835
 836 #else
 837
 838 static int __init rv3029_register_driver(void)
 839 {
 840         return 0;
 841 }
 842
 843 static void rv3029_unregister_driver(void)
 844 {
 845 }
 846
 847 #endif
 848
 849 #if IS_ENABLED(CONFIG_SPI_MASTER)
 850
 851 static int rv3049_probe(struct spi_device *spi)
 852 {
 853         struct regmap *regmap;
 854
 855         regmap = devm_regmap_init_spi(spi, &config);
 856         if (IS_ERR(regmap))
 857                 return PTR_ERR(regmap);
 858
 859         return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
 860 }
 861
 862 static struct spi_driver rv3049_driver = {
 863         .driver = {
 864                 .name    = "rv3049",
 865         },
 866         .probe   = rv3049_probe,
 867 };
 868
 869 static int __init rv3049_register_driver(void)
 870 {
 871         return spi_register_driver(&rv3049_driver);
 872 }
 873
 874 static void __exit rv3049_unregister_driver(void)
 875 {
 876         spi_unregister_driver(&rv3049_driver);
 877 }
 878
 879 #else
 880
 881 static int __init rv3049_register_driver(void)
 882 {
 883         return 0;
 884 }
 885
 886 static void __exit rv3049_unregister_driver(void)
 887 {
 888 }
 889
 890 #endif
 891
 892 static int __init rv30x9_init(void)
 893 {
 894         int ret;
 895
 896         ret = rv3029_register_driver();
 897         if (ret)
 898                 return ret;
 899
 900         ret = rv3049_register_driver();
 901         if (ret)
 902                 rv3029_unregister_driver();
 903
 904         return ret;
 905 }
 906 module_init(rv30x9_init)
 907
 908 static void __exit rv30x9_exit(void)
 909 {
 910         rv3049_unregister_driver();
 911         rv3029_unregister_driver();
 912 }
 913 module_exit(rv30x9_exit)
 914
 915 MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
 916 MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
 917 MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
 918 MODULE_LICENSE("GPL");
 919 MODULE_ALIAS("spi:rv3049");