linux/drivers/rtc/rtc-rv3029c2.c
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   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
 117struct rv3029_data {
 118        struct device           *dev;
 119        struct rtc_device       *rtc;
 120        struct regmap           *regmap;
 121        int irq;
 122};
 123
 124static 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
 136static 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
 148static 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
 165static 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
 175static 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
 188static 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
 209static 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
 217static 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
 260static 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
 278static 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
 310static 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
 328static 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
 369static 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
 412static 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
 457static 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
 483static 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
 538static 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
 579static 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
 636static 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
 673static 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
 687static 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
 700static 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
 727static 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
 751static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
 752                          NULL, 0);
 753static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
 754                          rv3029_hwmon_show_update_interval,
 755                          rv3029_hwmon_set_update_interval, 0);
 756
 757static 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};
 762ATTRIBUTE_GROUPS(rv3029_hwmon);
 763
 764static 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
 779static void rv3029_hwmon_register(struct device *dev, const char *name)
 780{
 781}
 782
 783#endif /* CONFIG_RTC_DRV_RV3029_HWMON */
 784
 785static struct rtc_class_ops rv3029_rtc_ops = {
 786        .read_time      = rv3029_read_time,
 787        .set_time       = rv3029_set_time,
 788};
 789
 790static 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
 842static 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
 867static const struct i2c_device_id rv3029_id[] = {
 868        { "rv3029", 0 },
 869        { "rv3029c2", 0 },
 870        { }
 871};
 872MODULE_DEVICE_TABLE(i2c, rv3029_id);
 873
 874static 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};
 882MODULE_DEVICE_TABLE(of, rv3029_of_match);
 883
 884static 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
 893static int rv3029_register_driver(void)
 894{
 895        return i2c_add_driver(&rv3029_driver);
 896}
 897
 898static void rv3029_unregister_driver(void)
 899{
 900        i2c_del_driver(&rv3029_driver);
 901}
 902
 903#else
 904
 905static int rv3029_register_driver(void)
 906{
 907        return 0;
 908}
 909
 910static void rv3029_unregister_driver(void)
 911{
 912}
 913
 914#endif
 915
 916#if IS_ENABLED(CONFIG_SPI_MASTER)
 917
 918static 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
 936static struct spi_driver rv3049_driver = {
 937        .driver = {
 938                .name    = "rv3049",
 939        },
 940        .probe   = rv3049_probe,
 941};
 942
 943static int rv3049_register_driver(void)
 944{
 945        return spi_register_driver(&rv3049_driver);
 946}
 947
 948static void rv3049_unregister_driver(void)
 949{
 950        spi_unregister_driver(&rv3049_driver);
 951}
 952
 953#else
 954
 955static int rv3049_register_driver(void)
 956{
 957        return 0;
 958}
 959
 960static void rv3049_unregister_driver(void)
 961{
 962}
 963
 964#endif
 965
 966static 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}
 984module_init(rv30x9_init)
 985
 986static void __exit rv30x9_exit(void)
 987{
 988        rv3049_unregister_driver();
 989        rv3029_unregister_driver();
 990}
 991module_exit(rv30x9_exit)
 992
 993MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
 994MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
 995MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
 996MODULE_LICENSE("GPL");
 997MODULE_ALIAS("spi:rv3049");
 998