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_USR1_RAM_PAGE            0x38
 113 #define RV3029_USR1_SECTION_LEN         0x04
 114 #define RV3029_USR2_RAM_PAGE            0x3C
 115 #define RV3029_USR2_SECTION_LEN         0x04
 116
 117 struct rv3029_data {
 118         struct device           *dev;
 119         struct rtc_device       *rtc;
 120         struct regmap           *regmap;
 121         int irq;
 122 };
 123
 124 static int rv3029_read_regs(struct device *dev, u8 reg, u8 *buf,
 125                             unsigned int len)
 126 {
 127         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 128
 129         if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
 130             (reg + len > RV3029_USR1_RAM_PAGE + 8))
 131                 return -EINVAL;
 132
 133         return regmap_bulk_read(rv3029->regmap, reg, buf, len);
 134 }
 135
 136 static int rv3029_write_regs(struct device *dev, u8 reg, u8 const buf[],
 137                              unsigned int len)
 138 {
 139         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 140
 141         if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
 142             (reg + len > RV3029_USR1_RAM_PAGE + 8))
 143                 return -EINVAL;
 144
 145         return regmap_bulk_write(rv3029->regmap, reg, buf, len);
 146 }
 147
 148 static int rv3029_update_bits(struct device *dev, u8 reg, u8 mask, u8 set)
 149 {
 150         u8 buf;
 151         int ret;
 152
 153         ret = rv3029_read_regs(dev, reg, &buf, 1);
 154         if (ret < 0)
 155                 return ret;
 156         buf &= ~mask;
 157         buf |= set & mask;
 158         ret = rv3029_write_regs(dev, reg, &buf, 1);
 159         if (ret < 0)
 160                 return ret;
 161
 162         return 0;
 163 }
 164
 165 static int rv3029_get_sr(struct device *dev, u8 *buf)
 166 {
 167         int ret = rv3029_read_regs(dev, RV3029_STATUS, buf, 1);
 168
 169         if (ret < 0)
 170                 return -EIO;
 171         dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
 172         return 0;
 173 }
 174
 175 static int rv3029_set_sr(struct device *dev, u8 val)
 176 {
 177         u8 buf[1];
 178         int sr;
 179
 180         buf[0] = val;
 181         sr = rv3029_write_regs(dev, RV3029_STATUS, buf, 1);
 182         dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
 183         if (sr < 0)
 184                 return -EIO;
 185         return 0;
 186 }
 187
 188 static int rv3029_eeprom_busywait(struct device *dev)
 189 {
 190         int i, ret;
 191         u8 sr;
 192
 193         for (i = 100; i > 0; i--) {
 194                 ret = rv3029_get_sr(dev, &sr);
 195                 if (ret < 0)
 196                         break;
 197                 if (!(sr & RV3029_STATUS_EEBUSY))
 198                         break;
 199                 usleep_range(1000, 10000);
 200         }
 201         if (i <= 0) {
 202                 dev_err(dev, "EEPROM busy wait timeout.\n");
 203                 return -ETIMEDOUT;
 204         }
 205
 206         return ret;
 207 }
 208
 209 static int rv3029_eeprom_exit(struct device *dev)
 210 {
 211         /* Re-enable eeprom refresh */
 212         return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
 213                                   RV3029_ONOFF_CTRL_EERE,
 214                                   RV3029_ONOFF_CTRL_EERE);
 215 }
 216
 217 static int rv3029_eeprom_enter(struct device *dev)
 218 {
 219         int ret;
 220         u8 sr;
 221
 222         /* Check whether we are in the allowed voltage range. */
 223         ret = rv3029_get_sr(dev, &sr);
 224         if (ret < 0)
 225                 return ret;
 226         if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
 227                 /* We clear the bits and retry once just in case
 228                  * we had a brown out in early startup.
 229                  */
 230                 sr &= ~RV3029_STATUS_VLOW1;
 231                 sr &= ~RV3029_STATUS_VLOW2;
 232                 ret = rv3029_set_sr(dev, sr);
 233                 if (ret < 0)
 234                         return ret;
 235                 usleep_range(1000, 10000);
 236                 ret = rv3029_get_sr(dev, &sr);
 237                 if (ret < 0)
 238                         return ret;
 239                 if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
 240                         dev_err(dev,
 241                                 "Supply voltage is too low to safely access the EEPROM.\n");
 242                         return -ENODEV;
 243                 }
 244         }
 245
 246         /* Disable eeprom refresh. */
 247         ret = rv3029_update_bits(dev, RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE,
 248                                  0);
 249         if (ret < 0)
 250                 return ret;
 251
 252         /* Wait for any previous eeprom accesses to finish. */
 253         ret = rv3029_eeprom_busywait(dev);
 254         if (ret < 0)
 255                 rv3029_eeprom_exit(dev);
 256
 257         return ret;
 258 }
 259
 260 static int rv3029_eeprom_read(struct device *dev, u8 reg,
 261                               u8 buf[], size_t len)
 262 {
 263         int ret, err;
 264
 265         err = rv3029_eeprom_enter(dev);
 266         if (err < 0)
 267                 return err;
 268
 269         ret = rv3029_read_regs(dev, reg, buf, len);
 270
 271         err = rv3029_eeprom_exit(dev);
 272         if (err < 0)
 273                 return err;
 274
 275         return ret;
 276 }
 277
 278 static int rv3029_eeprom_write(struct device *dev, u8 reg,
 279                                u8 const buf[], size_t len)
 280 {
 281         int ret, err;
 282         size_t i;
 283         u8 tmp;
 284
 285         err = rv3029_eeprom_enter(dev);
 286         if (err < 0)
 287                 return err;
 288
 289         for (i = 0; i < len; i++, reg++) {
 290                 ret = rv3029_read_regs(dev, reg, &tmp, 1);
 291                 if (ret < 0)
 292                         break;
 293                 if (tmp != buf[i]) {
 294                         ret = rv3029_write_regs(dev, reg, &buf[i], 1);
 295                         if (ret < 0)
 296                                 break;
 297                 }
 298                 ret = rv3029_eeprom_busywait(dev);
 299                 if (ret < 0)
 300                         break;
 301         }
 302
 303         err = rv3029_eeprom_exit(dev);
 304         if (err < 0)
 305                 return err;
 306
 307         return ret;
 308 }
 309
 310 static int rv3029_eeprom_update_bits(struct device *dev,
 311                                      u8 reg, u8 mask, u8 set)
 312 {
 313         u8 buf;
 314         int ret;
 315
 316         ret = rv3029_eeprom_read(dev, reg, &buf, 1);
 317         if (ret < 0)
 318                 return ret;
 319         buf &= ~mask;
 320         buf |= set & mask;
 321         ret = rv3029_eeprom_write(dev, reg, &buf, 1);
 322         if (ret < 0)
 323                 return ret;
 324
 325         return 0;
 326 }
 327
 328 static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
 329 {
 330         struct device *dev = dev_id;
 331         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 332         struct mutex *lock = &rv3029->rtc->ops_lock;
 333         unsigned long events = 0;
 334         u8 flags, controls;
 335         int ret;
 336
 337         mutex_lock(lock);
 338
 339         ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 340         if (ret) {
 341                 dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
 342                 mutex_unlock(lock);
 343                 return IRQ_NONE;
 344         }
 345
 346         ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
 347         if (ret) {
 348                 dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
 349                 mutex_unlock(lock);
 350                 return IRQ_NONE;
 351         }
 352
 353         if (flags & RV3029_IRQ_FLAGS_AF) {
 354                 flags &= ~RV3029_IRQ_FLAGS_AF;
 355                 controls &= ~RV3029_IRQ_CTRL_AIE;
 356                 events |= RTC_AF;
 357         }
 358
 359         if (events) {
 360                 rtc_update_irq(rv3029->rtc, 1, events);
 361                 rv3029_write_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
 362                 rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 363         }
 364         mutex_unlock(lock);
 365
 366         return IRQ_HANDLED;
 367 }
 368
 369 static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
 370 {
 371         u8 buf[1];
 372         int ret;
 373         u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
 374
 375         ret = rv3029_get_sr(dev, buf);
 376         if (ret < 0) {
 377                 dev_err(dev, "%s: reading SR failed\n", __func__);
 378                 return -EIO;
 379         }
 380
 381         ret = rv3029_read_regs(dev, RV3029_W_SEC, regs,
 382                                RV3029_WATCH_SECTION_LEN);
 383         if (ret < 0) {
 384                 dev_err(dev, "%s: reading RTC section failed\n", __func__);
 385                 return ret;
 386         }
 387
 388         tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
 389         tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
 390
 391         /* HR field has a more complex interpretation */
 392         {
 393                 const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
 394
 395                 if (_hr & RV3029_REG_HR_12_24) {
 396                         /* 12h format */
 397                         tm->tm_hour = bcd2bin(_hr & 0x1f);
 398                         if (_hr & RV3029_REG_HR_PM)     /* PM flag set */
 399                                 tm->tm_hour += 12;
 400                 } else /* 24h format */
 401                         tm->tm_hour = bcd2bin(_hr & 0x3f);
 402         }
 403
 404         tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
 405         tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
 406         tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
 407         tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
 408
 409         return 0;
 410 }
 411
 412 static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 413 {
 414         struct rtc_time *const tm = &alarm->time;
 415         int ret;
 416         u8 regs[8], controls, flags;
 417
 418         ret = rv3029_get_sr(dev, regs);
 419         if (ret < 0) {
 420                 dev_err(dev, "%s: reading SR failed\n", __func__);
 421                 return -EIO;
 422         }
 423
 424         ret = rv3029_read_regs(dev, RV3029_A_SC, regs,
 425                                RV3029_ALARM_SECTION_LEN);
 426
 427         if (ret < 0) {
 428                 dev_err(dev, "%s: reading alarm section failed\n", __func__);
 429                 return ret;
 430         }
 431
 432         ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 433         if (ret) {
 434                 dev_err(dev, "Read IRQ Control Register error %d\n", ret);
 435                 return ret;
 436         }
 437         ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
 438         if (ret < 0) {
 439                 dev_err(dev, "Read IRQ Flags Register error %d\n", ret);
 440                 return ret;
 441         }
 442
 443         tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
 444         tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
 445         tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
 446         tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
 447         tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
 448         tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
 449         tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
 450
 451         alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
 452         alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
 453
 454         return 0;
 455 }
 456
 457 static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
 458 {
 459         int ret;
 460         u8 controls;
 461
 462         ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 463         if (ret < 0) {
 464                 dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
 465                 return ret;
 466         }
 467
 468         /* enable/disable AIE irq */
 469         if (enable)
 470                 controls |= RV3029_IRQ_CTRL_AIE;
 471         else
 472                 controls &= ~RV3029_IRQ_CTRL_AIE;
 473
 474         ret = rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 475         if (ret < 0) {
 476                 dev_err(dev, "can't update INT reg\n");
 477                 return ret;
 478         }
 479
 480         return 0;
 481 }
 482
 483 static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 484 {
 485         struct rtc_time *const tm = &alarm->time;
 486         int ret;
 487         u8 regs[8];
 488
 489         /*
 490          * The clock has an 8 bit wide bcd-coded register (they never learn)
 491          * for the year. tm_year is an offset from 1900 and we are interested
 492          * in the 2000-2099 range, so any value less than 100 is invalid.
 493         */
 494         if (tm->tm_year < 100)
 495                 return -EINVAL;
 496
 497         ret = rv3029_get_sr(dev, regs);
 498         if (ret < 0) {
 499                 dev_err(dev, "%s: reading SR failed\n", __func__);
 500                 return -EIO;
 501         }
 502
 503         /* Activate all the alarms with AE_x bit */
 504         regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
 505         regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
 506         regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
 507                 | RV3029_A_AE_X;
 508         regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
 509                 | RV3029_A_AE_X;
 510         regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
 511                 | RV3029_A_AE_X;
 512         regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
 513                 | RV3029_A_AE_X;
 514         regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
 515                 | RV3029_A_AE_X;
 516
 517         /* Write the alarm */
 518         ret = rv3029_write_regs(dev, RV3029_A_SC, regs,
 519                                 RV3029_ALARM_SECTION_LEN);
 520         if (ret < 0)
 521                 return ret;
 522
 523         if (alarm->enabled) {
 524                 /* enable AIE irq */
 525                 ret = rv3029_alarm_irq_enable(dev, 1);
 526                 if (ret)
 527                         return ret;
 528         } else {
 529                 /* disable AIE irq */
 530                 ret = rv3029_alarm_irq_enable(dev, 0);
 531                 if (ret)
 532                         return ret;
 533         }
 534
 535         return 0;
 536 }
 537
 538 static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
 539 {
 540         u8 regs[8];
 541         int ret;
 542
 543         /*
 544          * The clock has an 8 bit wide bcd-coded register (they never learn)
 545          * for the year. tm_year is an offset from 1900 and we are interested
 546          * in the 2000-2099 range, so any value less than 100 is invalid.
 547         */
 548         if (tm->tm_year < 100)
 549                 return -EINVAL;
 550
 551         regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
 552         regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
 553         regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
 554         regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
 555         regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
 556         regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
 557         regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
 558
 559         ret = rv3029_write_regs(dev, RV3029_W_SEC, regs,
 560                                 RV3029_WATCH_SECTION_LEN);
 561         if (ret < 0)
 562                 return ret;
 563
 564         ret = rv3029_get_sr(dev, regs);
 565         if (ret < 0) {
 566                 dev_err(dev, "%s: reading SR failed\n", __func__);
 567                 return ret;
 568         }
 569         /* clear PON bit */
 570         ret = rv3029_set_sr(dev, (regs[0] & ~RV3029_STATUS_PON));
 571         if (ret < 0) {
 572                 dev_err(dev, "%s: reading SR failed\n", __func__);
 573                 return ret;
 574         }
 575
 576         return 0;
 577 }
 578
 579 static const struct rv3029_trickle_tab_elem {
 580         u32 r;          /* resistance in ohms */
 581         u8 conf;        /* trickle config bits */
 582 } rv3029_trickle_tab[] = {
 583         {
 584                 .r      = 1076,
 585                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 586                           RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 587         }, {
 588                 .r      = 1091,
 589                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 590                           RV3029_TRICKLE_20K,
 591         }, {
 592                 .r      = 1137,
 593                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 594                           RV3029_TRICKLE_80K,
 595         }, {
 596                 .r      = 1154,
 597                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
 598         }, {
 599                 .r      = 1371,
 600                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
 601                           RV3029_TRICKLE_80K,
 602         }, {
 603                 .r      = 1395,
 604                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
 605         }, {
 606                 .r      = 1472,
 607                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
 608         }, {
 609                 .r      = 1500,
 610                 .conf   = RV3029_TRICKLE_1K,
 611         }, {
 612                 .r      = 3810,
 613                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
 614                           RV3029_TRICKLE_80K,
 615         }, {
 616                 .r      = 4000,
 617                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
 618         }, {
 619                 .r      = 4706,
 620                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
 621         }, {
 622                 .r      = 5000,
 623                 .conf   = RV3029_TRICKLE_5K,
 624         }, {
 625                 .r      = 16000,
 626                 .conf   = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 627         }, {
 628                 .r      = 20000,
 629                 .conf   = RV3029_TRICKLE_20K,
 630         }, {
 631                 .r      = 80000,
 632                 .conf   = RV3029_TRICKLE_80K,
 633         },
 634 };
 635
 636 static void rv3029_trickle_config(struct device *dev)
 637 {
 638         struct device_node *of_node = dev->of_node;
 639         const struct rv3029_trickle_tab_elem *elem;
 640         int i, err;
 641         u32 ohms;
 642         u8 trickle_set_bits;
 643
 644         if (!of_node)
 645                 return;
 646
 647         /* Configure the trickle charger. */
 648         err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
 649         if (err) {
 650                 /* Disable trickle charger. */
 651                 trickle_set_bits = 0;
 652         } else {
 653                 /* Enable trickle charger. */
 654                 for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
 655                         elem = &rv3029_trickle_tab[i];
 656                         if (elem->r >= ohms)
 657                                 break;
 658                 }
 659                 trickle_set_bits = elem->conf;
 660                 dev_info(dev,
 661                          "Trickle charger enabled at %d ohms resistance.\n",
 662                          elem->r);
 663         }
 664         err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
 665                                         RV3029_TRICKLE_MASK,
 666                                         trickle_set_bits);
 667         if (err < 0)
 668                 dev_err(dev, "Failed to update trickle charger config\n");
 669 }
 670
 671 #ifdef CONFIG_RTC_DRV_RV3029_HWMON
 672
 673 static int rv3029_read_temp(struct device *dev, int *temp_mC)
 674 {
 675         int ret;
 676         u8 temp;
 677
 678         ret = rv3029_read_regs(dev, RV3029_TEMP_PAGE, &temp, 1);
 679         if (ret < 0)
 680                 return ret;
 681
 682         *temp_mC = ((int)temp - 60) * 1000;
 683
 684         return 0;
 685 }
 686
 687 static ssize_t rv3029_hwmon_show_temp(struct device *dev,
 688                                       struct device_attribute *attr,
 689                                       char *buf)
 690 {
 691         int ret, temp_mC;
 692
 693         ret = rv3029_read_temp(dev, &temp_mC);
 694         if (ret < 0)
 695                 return ret;
 696
 697         return sprintf(buf, "%d\n", temp_mC);
 698 }
 699
 700 static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
 701                                                 struct device_attribute *attr,
 702                                                 const char *buf,
 703                                                 size_t count)
 704 {
 705         unsigned long interval_ms;
 706         int ret;
 707         u8 th_set_bits = 0;
 708
 709         ret = kstrtoul(buf, 10, &interval_ms);
 710         if (ret < 0)
 711                 return ret;
 712
 713         if (interval_ms != 0) {
 714                 th_set_bits |= RV3029_EECTRL_THE;
 715                 if (interval_ms >= 16000)
 716                         th_set_bits |= RV3029_EECTRL_THP;
 717         }
 718         ret = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
 719                                         RV3029_EECTRL_THE | RV3029_EECTRL_THP,
 720                                         th_set_bits);
 721         if (ret < 0)
 722                 return ret;
 723
 724         return count;
 725 }
 726
 727 static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
 728                                                  struct device_attribute *attr,
 729                                                  char *buf)
 730 {
 731         int ret, interval_ms;
 732         u8 eectrl;
 733
 734         ret = rv3029_eeprom_read(dev, RV3029_CONTROL_E2P_EECTRL,
 735                                  &eectrl, 1);
 736         if (ret < 0)
 737                 return ret;
 738
 739         if (eectrl & RV3029_EECTRL_THE) {
 740                 if (eectrl & RV3029_EECTRL_THP)
 741                         interval_ms = 16000;
 742                 else
 743                         interval_ms = 1000;
 744         } else {
 745                 interval_ms = 0;
 746         }
 747
 748         return sprintf(buf, "%d\n", interval_ms);
 749 }
 750
 751 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
 752                           NULL, 0);
 753 static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
 754                           rv3029_hwmon_show_update_interval,
 755                           rv3029_hwmon_set_update_interval, 0);
 756
 757 static struct attribute *rv3029_hwmon_attrs[] = {
 758         &sensor_dev_attr_temp1_input.dev_attr.attr,
 759         &sensor_dev_attr_update_interval.dev_attr.attr,
 760         NULL,
 761 };
 762 ATTRIBUTE_GROUPS(rv3029_hwmon);
 763
 764 static void rv3029_hwmon_register(struct device *dev, const char *name)
 765 {
 766         struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 767         struct device *hwmon_dev;
 768
 769         hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
 770                                                            rv3029_hwmon_groups);
 771         if (IS_ERR(hwmon_dev)) {
 772                 dev_warn(dev, "unable to register hwmon device %ld\n",
 773                          PTR_ERR(hwmon_dev));
 774         }
 775 }
 776
 777 #else /* CONFIG_RTC_DRV_RV3029_HWMON */
 778
 779 static void rv3029_hwmon_register(struct device *dev, const char *name)
 780 {
 781 }
 782
 783 #endif /* CONFIG_RTC_DRV_RV3029_HWMON */
 784
 785 static struct rtc_class_ops rv3029_rtc_ops = {
 786         .read_time      = rv3029_read_time,
 787         .set_time       = rv3029_set_time,
 788 };
 789
 790 static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
 791                         const char *name)
 792 {
 793         struct rv3029_data *rv3029;
 794         int rc = 0;
 795         u8 buf[1];
 796
 797         rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
 798         if (!rv3029)
 799                 return -ENOMEM;
 800
 801         rv3029->regmap = regmap;
 802         rv3029->irq = irq;
 803         rv3029->dev = dev;
 804         dev_set_drvdata(dev, rv3029);
 805
 806         rc = rv3029_get_sr(dev, buf);
 807         if (rc < 0) {
 808                 dev_err(dev, "reading status failed\n");
 809                 return rc;
 810         }
 811
 812         rv3029_trickle_config(dev);
 813         rv3029_hwmon_register(dev, name);
 814
 815         rv3029->rtc = devm_rtc_device_register(dev, name, &rv3029_rtc_ops,
 816                                                THIS_MODULE);
 817         if (IS_ERR(rv3029->rtc)) {
 818                 dev_err(dev, "unable to register the class device\n");
 819                 return PTR_ERR(rv3029->rtc);
 820         }
 821
 822         if (rv3029->irq > 0) {
 823                 rc = devm_request_threaded_irq(dev, rv3029->irq,
 824                                                NULL, rv3029_handle_irq,
 825                                                IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 826                                                "rv3029", dev);
 827                 if (rc) {
 828                         dev_warn(dev, "unable to request IRQ, alarms disabled\n");
 829                         rv3029->irq = 0;
 830                 } else {
 831                         rv3029_rtc_ops.read_alarm = rv3029_read_alarm;
 832                         rv3029_rtc_ops.set_alarm = rv3029_set_alarm;
 833                         rv3029_rtc_ops.alarm_irq_enable = rv3029_alarm_irq_enable;
 834                 }
 835         }
 836
 837         return 0;
 838 }
 839
 840 #if IS_ENABLED(CONFIG_I2C)
 841
 842 static int rv3029_i2c_probe(struct i2c_client *client,
 843                             const struct i2c_device_id *id)
 844 {
 845         struct regmap *regmap;
 846         static const struct regmap_config config = {
 847                 .reg_bits = 8,
 848                 .val_bits = 8,
 849         };
 850
 851         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
 852                                      I2C_FUNC_SMBUS_BYTE)) {
 853                 dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
 854                 return -ENODEV;
 855         }
 856
 857         regmap = devm_regmap_init_i2c(client, &config);
 858         if (IS_ERR(regmap)) {
 859                 dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
 860                         __func__, PTR_ERR(regmap));
 861                 return PTR_ERR(regmap);
 862         }
 863
 864         return rv3029_probe(&client->dev, regmap, client->irq, client->name);
 865 }
 866
 867 static const struct i2c_device_id rv3029_id[] = {
 868         { "rv3029", 0 },
 869         { "rv3029c2", 0 },
 870         { }
 871 };
 872 MODULE_DEVICE_TABLE(i2c, rv3029_id);
 873
 874 static const struct of_device_id rv3029_of_match[] = {
 875         { .compatible = "microcrystal,rv3029" },
 876         /* Backward compatibility only, do not use compatibles below: */
 877         { .compatible = "rv3029" },
 878         { .compatible = "rv3029c2" },
 879         { .compatible = "mc,rv3029c2" },
 880         { }
 881 };
 882 MODULE_DEVICE_TABLE(of, rv3029_of_match);
 883
 884 static struct i2c_driver rv3029_driver = {
 885         .driver = {
 886                 .name = "rtc-rv3029c2",
 887                 .of_match_table = of_match_ptr(rv3029_of_match),
 888         },
 889         .probe          = rv3029_i2c_probe,
 890         .id_table       = rv3029_id,
 891 };
 892
 893 static int rv3029_register_driver(void)
 894 {
 895         return i2c_add_driver(&rv3029_driver);
 896 }
 897
 898 static void rv3029_unregister_driver(void)
 899 {
 900         i2c_del_driver(&rv3029_driver);
 901 }
 902
 903 #else
 904
 905 static int rv3029_register_driver(void)
 906 {
 907         return 0;
 908 }
 909
 910 static void rv3029_unregister_driver(void)
 911 {
 912 }
 913
 914 #endif
 915
 916 #if IS_ENABLED(CONFIG_SPI_MASTER)
 917
 918 static int rv3049_probe(struct spi_device *spi)
 919 {
 920         static const struct regmap_config config = {
 921                 .reg_bits = 8,
 922                 .val_bits = 8,
 923         };
 924         struct regmap *regmap;
 925
 926         regmap = devm_regmap_init_spi(spi, &config);
 927         if (IS_ERR(regmap)) {
 928                 dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
 929                         __func__, PTR_ERR(regmap));
 930                 return PTR_ERR(regmap);
 931         }
 932
 933         return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
 934 }
 935
 936 static struct spi_driver rv3049_driver = {
 937         .driver = {
 938                 .name    = "rv3049",
 939         },
 940         .probe   = rv3049_probe,
 941 };
 942
 943 static int rv3049_register_driver(void)
 944 {
 945         return spi_register_driver(&rv3049_driver);
 946 }
 947
 948 static void rv3049_unregister_driver(void)
 949 {
 950         spi_unregister_driver(&rv3049_driver);
 951 }
 952
 953 #else
 954
 955 static int rv3049_register_driver(void)
 956 {
 957         return 0;
 958 }
 959
 960 static void rv3049_unregister_driver(void)
 961 {
 962 }
 963
 964 #endif
 965
 966 static int __init rv30x9_init(void)
 967 {
 968         int ret;
 969
 970         ret = rv3029_register_driver();
 971         if (ret) {
 972                 pr_err("Failed to register rv3029 driver: %d\n", ret);
 973                 return ret;
 974         }
 975
 976         ret = rv3049_register_driver();
 977         if (ret) {
 978                 pr_err("Failed to register rv3049 driver: %d\n", ret);
 979                 rv3029_unregister_driver();
 980         }
 981
 982         return ret;
 983 }
 984 module_init(rv30x9_init)
 985
 986 static void __exit rv30x9_exit(void)
 987 {
 988         rv3049_unregister_driver();
 989         rv3029_unregister_driver();
 990 }
 991 module_exit(rv30x9_exit)
 992
 993 MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
 994 MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
 995 MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
 996 MODULE_LICENSE("GPL");
 997 MODULE_ALIAS("spi:rv3049");