linux/drivers/rtc/rtc-rv3029c2.c
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   1/*
   2 * Micro Crystal RV-3029 / RV-3049 rtc class driver
   3 *
   4 * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
   5 *         Michael Buesch <m@bues.ch>
   6 *
   7 * based on previously existing rtc class drivers
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 *
  13 */
  14
  15#include <linux/module.h>
  16#include <linux/i2c.h>
  17#include <linux/spi/spi.h>
  18#include <linux/bcd.h>
  19#include <linux/rtc.h>
  20#include <linux/delay.h>
  21#include <linux/of.h>
  22#include <linux/hwmon.h>
  23#include <linux/hwmon-sysfs.h>
  24#include <linux/regmap.h>
  25
  26/* Register map */
  27/* control section */
  28#define RV3029_ONOFF_CTRL               0x00
  29#define RV3029_ONOFF_CTRL_WE            BIT(0)
  30#define RV3029_ONOFF_CTRL_TE            BIT(1)
  31#define RV3029_ONOFF_CTRL_TAR           BIT(2)
  32#define RV3029_ONOFF_CTRL_EERE          BIT(3)
  33#define RV3029_ONOFF_CTRL_SRON          BIT(4)
  34#define RV3029_ONOFF_CTRL_TD0           BIT(5)
  35#define RV3029_ONOFF_CTRL_TD1           BIT(6)
  36#define RV3029_ONOFF_CTRL_CLKINT        BIT(7)
  37#define RV3029_IRQ_CTRL                 0x01
  38#define RV3029_IRQ_CTRL_AIE             BIT(0)
  39#define RV3029_IRQ_CTRL_TIE             BIT(1)
  40#define RV3029_IRQ_CTRL_V1IE            BIT(2)
  41#define RV3029_IRQ_CTRL_V2IE            BIT(3)
  42#define RV3029_IRQ_CTRL_SRIE            BIT(4)
  43#define RV3029_IRQ_FLAGS                0x02
  44#define RV3029_IRQ_FLAGS_AF             BIT(0)
  45#define RV3029_IRQ_FLAGS_TF             BIT(1)
  46#define RV3029_IRQ_FLAGS_V1IF           BIT(2)
  47#define RV3029_IRQ_FLAGS_V2IF           BIT(3)
  48#define RV3029_IRQ_FLAGS_SRF            BIT(4)
  49#define RV3029_STATUS                   0x03
  50#define RV3029_STATUS_VLOW1             BIT(2)
  51#define RV3029_STATUS_VLOW2             BIT(3)
  52#define RV3029_STATUS_SR                BIT(4)
  53#define RV3029_STATUS_PON               BIT(5)
  54#define RV3029_STATUS_EEBUSY            BIT(7)
  55#define RV3029_RST_CTRL                 0x04
  56#define RV3029_RST_CTRL_SYSR            BIT(4)
  57#define RV3029_CONTROL_SECTION_LEN      0x05
  58
  59/* watch section */
  60#define RV3029_W_SEC                    0x08
  61#define RV3029_W_MINUTES                0x09
  62#define RV3029_W_HOURS                  0x0A
  63#define RV3029_REG_HR_12_24             BIT(6) /* 24h/12h mode */
  64#define RV3029_REG_HR_PM                BIT(5) /* PM/AM bit in 12h mode */
  65#define RV3029_W_DATE                   0x0B
  66#define RV3029_W_DAYS                   0x0C
  67#define RV3029_W_MONTHS                 0x0D
  68#define RV3029_W_YEARS                  0x0E
  69#define RV3029_WATCH_SECTION_LEN        0x07
  70
  71/* alarm section */
  72#define RV3029_A_SC                     0x10
  73#define RV3029_A_MN                     0x11
  74#define RV3029_A_HR                     0x12
  75#define RV3029_A_DT                     0x13
  76#define RV3029_A_DW                     0x14
  77#define RV3029_A_MO                     0x15
  78#define RV3029_A_YR                     0x16
  79#define RV3029_A_AE_X                   BIT(7)
  80#define RV3029_ALARM_SECTION_LEN        0x07
  81
  82/* timer section */
  83#define RV3029_TIMER_LOW                0x18
  84#define RV3029_TIMER_HIGH               0x19
  85
  86/* temperature section */
  87#define RV3029_TEMP_PAGE                0x20
  88
  89/* eeprom data section */
  90#define RV3029_E2P_EEDATA1              0x28
  91#define RV3029_E2P_EEDATA2              0x29
  92#define RV3029_E2PDATA_SECTION_LEN      0x02
  93
  94/* eeprom control section */
  95#define RV3029_CONTROL_E2P_EECTRL       0x30
  96#define RV3029_EECTRL_THP               BIT(0) /* temp scan interval */
  97#define RV3029_EECTRL_THE               BIT(1) /* thermometer enable */
  98#define RV3029_EECTRL_FD0               BIT(2) /* CLKOUT */
  99#define RV3029_EECTRL_FD1               BIT(3) /* CLKOUT */
 100#define RV3029_TRICKLE_1K               BIT(4) /* 1.5K resistance */
 101#define RV3029_TRICKLE_5K               BIT(5) /* 5K   resistance */
 102#define RV3029_TRICKLE_20K              BIT(6) /* 20K  resistance */
 103#define RV3029_TRICKLE_80K              BIT(7) /* 80K  resistance */
 104#define RV3029_TRICKLE_MASK             (RV3029_TRICKLE_1K |\
 105                                         RV3029_TRICKLE_5K |\
 106                                         RV3029_TRICKLE_20K |\
 107                                         RV3029_TRICKLE_80K)
 108#define RV3029_TRICKLE_SHIFT            4
 109#define RV3029_CONTROL_E2P_XOFFS        0x31 /* XTAL offset */
 110#define RV3029_CONTROL_E2P_XOFFS_SIGN   BIT(7) /* Sign: 1->pos, 0->neg */
 111#define RV3029_CONTROL_E2P_QCOEF        0x32 /* XTAL temp drift coef */
 112#define RV3029_CONTROL_E2P_TURNOVER     0x33 /* XTAL turnover temp (in *C) */
 113#define RV3029_CONTROL_E2P_TOV_MASK     0x3F /* XTAL turnover temp mask */
 114
 115/* user ram section */
 116#define RV3029_USR1_RAM_PAGE            0x38
 117#define RV3029_USR1_SECTION_LEN         0x04
 118#define RV3029_USR2_RAM_PAGE            0x3C
 119#define RV3029_USR2_SECTION_LEN         0x04
 120
 121struct rv3029_data {
 122        struct device           *dev;
 123        struct rtc_device       *rtc;
 124        struct regmap           *regmap;
 125        int irq;
 126};
 127
 128static int rv3029_read_regs(struct device *dev, u8 reg, u8 *buf,
 129                            unsigned int len)
 130{
 131        struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 132
 133        if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
 134            (reg + len > RV3029_USR1_RAM_PAGE + 8))
 135                return -EINVAL;
 136
 137        return regmap_bulk_read(rv3029->regmap, reg, buf, len);
 138}
 139
 140static int rv3029_write_regs(struct device *dev, u8 reg, u8 const buf[],
 141                             unsigned int len)
 142{
 143        struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 144
 145        if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
 146            (reg + len > RV3029_USR1_RAM_PAGE + 8))
 147                return -EINVAL;
 148
 149        return regmap_bulk_write(rv3029->regmap, reg, buf, len);
 150}
 151
 152static int rv3029_update_bits(struct device *dev, u8 reg, u8 mask, u8 set)
 153{
 154        u8 buf;
 155        int ret;
 156
 157        ret = rv3029_read_regs(dev, reg, &buf, 1);
 158        if (ret < 0)
 159                return ret;
 160        buf &= ~mask;
 161        buf |= set & mask;
 162        ret = rv3029_write_regs(dev, reg, &buf, 1);
 163        if (ret < 0)
 164                return ret;
 165
 166        return 0;
 167}
 168
 169static int rv3029_get_sr(struct device *dev, u8 *buf)
 170{
 171        int ret = rv3029_read_regs(dev, RV3029_STATUS, buf, 1);
 172
 173        if (ret < 0)
 174                return -EIO;
 175        dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
 176        return 0;
 177}
 178
 179static int rv3029_set_sr(struct device *dev, u8 val)
 180{
 181        u8 buf[1];
 182        int sr;
 183
 184        buf[0] = val;
 185        sr = rv3029_write_regs(dev, RV3029_STATUS, buf, 1);
 186        dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
 187        if (sr < 0)
 188                return -EIO;
 189        return 0;
 190}
 191
 192static int rv3029_eeprom_busywait(struct device *dev)
 193{
 194        int i, ret;
 195        u8 sr;
 196
 197        for (i = 100; i > 0; i--) {
 198                ret = rv3029_get_sr(dev, &sr);
 199                if (ret < 0)
 200                        break;
 201                if (!(sr & RV3029_STATUS_EEBUSY))
 202                        break;
 203                usleep_range(1000, 10000);
 204        }
 205        if (i <= 0) {
 206                dev_err(dev, "EEPROM busy wait timeout.\n");
 207                return -ETIMEDOUT;
 208        }
 209
 210        return ret;
 211}
 212
 213static int rv3029_eeprom_exit(struct device *dev)
 214{
 215        /* Re-enable eeprom refresh */
 216        return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
 217                                  RV3029_ONOFF_CTRL_EERE,
 218                                  RV3029_ONOFF_CTRL_EERE);
 219}
 220
 221static int rv3029_eeprom_enter(struct device *dev)
 222{
 223        int ret;
 224        u8 sr;
 225
 226        /* Check whether we are in the allowed voltage range. */
 227        ret = rv3029_get_sr(dev, &sr);
 228        if (ret < 0)
 229                return ret;
 230        if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
 231                /* We clear the bits and retry once just in case
 232                 * we had a brown out in early startup.
 233                 */
 234                sr &= ~RV3029_STATUS_VLOW1;
 235                sr &= ~RV3029_STATUS_VLOW2;
 236                ret = rv3029_set_sr(dev, sr);
 237                if (ret < 0)
 238                        return ret;
 239                usleep_range(1000, 10000);
 240                ret = rv3029_get_sr(dev, &sr);
 241                if (ret < 0)
 242                        return ret;
 243                if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
 244                        dev_err(dev,
 245                                "Supply voltage is too low to safely access the EEPROM.\n");
 246                        return -ENODEV;
 247                }
 248        }
 249
 250        /* Disable eeprom refresh. */
 251        ret = rv3029_update_bits(dev, RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE,
 252                                 0);
 253        if (ret < 0)
 254                return ret;
 255
 256        /* Wait for any previous eeprom accesses to finish. */
 257        ret = rv3029_eeprom_busywait(dev);
 258        if (ret < 0)
 259                rv3029_eeprom_exit(dev);
 260
 261        return ret;
 262}
 263
 264static int rv3029_eeprom_read(struct device *dev, u8 reg,
 265                              u8 buf[], size_t len)
 266{
 267        int ret, err;
 268
 269        err = rv3029_eeprom_enter(dev);
 270        if (err < 0)
 271                return err;
 272
 273        ret = rv3029_read_regs(dev, reg, buf, len);
 274
 275        err = rv3029_eeprom_exit(dev);
 276        if (err < 0)
 277                return err;
 278
 279        return ret;
 280}
 281
 282static int rv3029_eeprom_write(struct device *dev, u8 reg,
 283                               u8 const buf[], size_t len)
 284{
 285        int ret;
 286        size_t i;
 287        u8 tmp;
 288
 289        ret = rv3029_eeprom_enter(dev);
 290        if (ret < 0)
 291                return ret;
 292
 293        for (i = 0; i < len; i++, reg++) {
 294                ret = rv3029_read_regs(dev, reg, &tmp, 1);
 295                if (ret < 0)
 296                        break;
 297                if (tmp != buf[i]) {
 298                        ret = rv3029_write_regs(dev, reg, &buf[i], 1);
 299                        if (ret < 0)
 300                                break;
 301                }
 302                ret = rv3029_eeprom_busywait(dev);
 303                if (ret < 0)
 304                        break;
 305        }
 306
 307        ret = rv3029_eeprom_exit(dev);
 308        if (ret < 0)
 309                return ret;
 310
 311        return 0;
 312}
 313
 314static int rv3029_eeprom_update_bits(struct device *dev,
 315                                     u8 reg, u8 mask, u8 set)
 316{
 317        u8 buf;
 318        int ret;
 319
 320        ret = rv3029_eeprom_read(dev, reg, &buf, 1);
 321        if (ret < 0)
 322                return ret;
 323        buf &= ~mask;
 324        buf |= set & mask;
 325        ret = rv3029_eeprom_write(dev, reg, &buf, 1);
 326        if (ret < 0)
 327                return ret;
 328
 329        return 0;
 330}
 331
 332static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
 333{
 334        struct device *dev = dev_id;
 335        struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 336        struct mutex *lock = &rv3029->rtc->ops_lock;
 337        unsigned long events = 0;
 338        u8 flags, controls;
 339        int ret;
 340
 341        mutex_lock(lock);
 342
 343        ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 344        if (ret) {
 345                dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
 346                mutex_unlock(lock);
 347                return IRQ_NONE;
 348        }
 349
 350        ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
 351        if (ret) {
 352                dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
 353                mutex_unlock(lock);
 354                return IRQ_NONE;
 355        }
 356
 357        if (flags & RV3029_IRQ_FLAGS_AF) {
 358                flags &= ~RV3029_IRQ_FLAGS_AF;
 359                controls &= ~RV3029_IRQ_CTRL_AIE;
 360                events |= RTC_AF;
 361        }
 362
 363        if (events) {
 364                rtc_update_irq(rv3029->rtc, 1, events);
 365                rv3029_write_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
 366                rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 367        }
 368        mutex_unlock(lock);
 369
 370        return IRQ_HANDLED;
 371}
 372
 373static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
 374{
 375        u8 buf[1];
 376        int ret;
 377        u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
 378
 379        ret = rv3029_get_sr(dev, buf);
 380        if (ret < 0) {
 381                dev_err(dev, "%s: reading SR failed\n", __func__);
 382                return -EIO;
 383        }
 384
 385        ret = rv3029_read_regs(dev, RV3029_W_SEC, regs,
 386                               RV3029_WATCH_SECTION_LEN);
 387        if (ret < 0) {
 388                dev_err(dev, "%s: reading RTC section failed\n", __func__);
 389                return ret;
 390        }
 391
 392        tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
 393        tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
 394
 395        /* HR field has a more complex interpretation */
 396        {
 397                const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
 398
 399                if (_hr & RV3029_REG_HR_12_24) {
 400                        /* 12h format */
 401                        tm->tm_hour = bcd2bin(_hr & 0x1f);
 402                        if (_hr & RV3029_REG_HR_PM)     /* PM flag set */
 403                                tm->tm_hour += 12;
 404                } else /* 24h format */
 405                        tm->tm_hour = bcd2bin(_hr & 0x3f);
 406        }
 407
 408        tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
 409        tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
 410        tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
 411        tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
 412
 413        return 0;
 414}
 415
 416static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 417{
 418        struct rtc_time *const tm = &alarm->time;
 419        int ret;
 420        u8 regs[8], controls, flags;
 421
 422        ret = rv3029_get_sr(dev, regs);
 423        if (ret < 0) {
 424                dev_err(dev, "%s: reading SR failed\n", __func__);
 425                return -EIO;
 426        }
 427
 428        ret = rv3029_read_regs(dev, RV3029_A_SC, regs,
 429                               RV3029_ALARM_SECTION_LEN);
 430
 431        if (ret < 0) {
 432                dev_err(dev, "%s: reading alarm section failed\n", __func__);
 433                return ret;
 434        }
 435
 436        ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 437        if (ret) {
 438                dev_err(dev, "Read IRQ Control Register error %d\n", ret);
 439                return ret;
 440        }
 441        ret = rv3029_read_regs(dev, RV3029_IRQ_FLAGS, &flags, 1);
 442        if (ret < 0) {
 443                dev_err(dev, "Read IRQ Flags Register error %d\n", ret);
 444                return ret;
 445        }
 446
 447        tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
 448        tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
 449        tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
 450        tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
 451        tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
 452        tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
 453        tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
 454
 455        alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
 456        alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
 457
 458        return 0;
 459}
 460
 461static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
 462{
 463        int ret;
 464        u8 controls;
 465
 466        ret = rv3029_read_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 467        if (ret < 0) {
 468                dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
 469                return ret;
 470        }
 471
 472        /* enable/disable AIE irq */
 473        if (enable)
 474                controls |= RV3029_IRQ_CTRL_AIE;
 475        else
 476                controls &= ~RV3029_IRQ_CTRL_AIE;
 477
 478        ret = rv3029_write_regs(dev, RV3029_IRQ_CTRL, &controls, 1);
 479        if (ret < 0) {
 480                dev_err(dev, "can't update INT reg\n");
 481                return ret;
 482        }
 483
 484        return 0;
 485}
 486
 487static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 488{
 489        struct rtc_time *const tm = &alarm->time;
 490        int ret;
 491        u8 regs[8];
 492
 493        /*
 494         * The clock has an 8 bit wide bcd-coded register (they never learn)
 495         * for the year. tm_year is an offset from 1900 and we are interested
 496         * in the 2000-2099 range, so any value less than 100 is invalid.
 497        */
 498        if (tm->tm_year < 100)
 499                return -EINVAL;
 500
 501        ret = rv3029_get_sr(dev, regs);
 502        if (ret < 0) {
 503                dev_err(dev, "%s: reading SR failed\n", __func__);
 504                return -EIO;
 505        }
 506
 507        /* Activate all the alarms with AE_x bit */
 508        regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
 509        regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
 510        regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
 511                | RV3029_A_AE_X;
 512        regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
 513                | RV3029_A_AE_X;
 514        regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
 515                | RV3029_A_AE_X;
 516        regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
 517                | RV3029_A_AE_X;
 518        regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
 519                | RV3029_A_AE_X;
 520
 521        /* Write the alarm */
 522        ret = rv3029_write_regs(dev, RV3029_A_SC, regs,
 523                                RV3029_ALARM_SECTION_LEN);
 524        if (ret < 0)
 525                return ret;
 526
 527        if (alarm->enabled) {
 528                /* enable AIE irq */
 529                ret = rv3029_alarm_irq_enable(dev, 1);
 530                if (ret)
 531                        return ret;
 532        } else {
 533                /* disable AIE irq */
 534                ret = rv3029_alarm_irq_enable(dev, 0);
 535                if (ret)
 536                        return ret;
 537        }
 538
 539        return 0;
 540}
 541
 542static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
 543{
 544        u8 regs[8];
 545        int ret;
 546
 547        /*
 548         * The clock has an 8 bit wide bcd-coded register (they never learn)
 549         * for the year. tm_year is an offset from 1900 and we are interested
 550         * in the 2000-2099 range, so any value less than 100 is invalid.
 551        */
 552        if (tm->tm_year < 100)
 553                return -EINVAL;
 554
 555        regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
 556        regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
 557        regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
 558        regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
 559        regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
 560        regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
 561        regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
 562
 563        ret = rv3029_write_regs(dev, RV3029_W_SEC, regs,
 564                                RV3029_WATCH_SECTION_LEN);
 565        if (ret < 0)
 566                return ret;
 567
 568        ret = rv3029_get_sr(dev, regs);
 569        if (ret < 0) {
 570                dev_err(dev, "%s: reading SR failed\n", __func__);
 571                return ret;
 572        }
 573        /* clear PON bit */
 574        ret = rv3029_set_sr(dev, (regs[0] & ~RV3029_STATUS_PON));
 575        if (ret < 0) {
 576                dev_err(dev, "%s: reading SR failed\n", __func__);
 577                return ret;
 578        }
 579
 580        return 0;
 581}
 582
 583static const struct rv3029_trickle_tab_elem {
 584        u32 r;          /* resistance in ohms */
 585        u8 conf;        /* trickle config bits */
 586} rv3029_trickle_tab[] = {
 587        {
 588                .r      = 1076,
 589                .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 590                          RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 591        }, {
 592                .r      = 1091,
 593                .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 594                          RV3029_TRICKLE_20K,
 595        }, {
 596                .r      = 1137,
 597                .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 598                          RV3029_TRICKLE_80K,
 599        }, {
 600                .r      = 1154,
 601                .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
 602        }, {
 603                .r      = 1371,
 604                .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
 605                          RV3029_TRICKLE_80K,
 606        }, {
 607                .r      = 1395,
 608                .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
 609        }, {
 610                .r      = 1472,
 611                .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
 612        }, {
 613                .r      = 1500,
 614                .conf   = RV3029_TRICKLE_1K,
 615        }, {
 616                .r      = 3810,
 617                .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
 618                          RV3029_TRICKLE_80K,
 619        }, {
 620                .r      = 4000,
 621                .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
 622        }, {
 623                .r      = 4706,
 624                .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
 625        }, {
 626                .r      = 5000,
 627                .conf   = RV3029_TRICKLE_5K,
 628        }, {
 629                .r      = 16000,
 630                .conf   = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 631        }, {
 632                .r      = 20000,
 633                .conf   = RV3029_TRICKLE_20K,
 634        }, {
 635                .r      = 80000,
 636                .conf   = RV3029_TRICKLE_80K,
 637        },
 638};
 639
 640static void rv3029_trickle_config(struct device *dev)
 641{
 642        struct device_node *of_node = dev->of_node;
 643        const struct rv3029_trickle_tab_elem *elem;
 644        int i, err;
 645        u32 ohms;
 646        u8 trickle_set_bits;
 647
 648        if (!of_node)
 649                return;
 650
 651        /* Configure the trickle charger. */
 652        err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
 653        if (err) {
 654                /* Disable trickle charger. */
 655                trickle_set_bits = 0;
 656        } else {
 657                /* Enable trickle charger. */
 658                for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
 659                        elem = &rv3029_trickle_tab[i];
 660                        if (elem->r >= ohms)
 661                                break;
 662                }
 663                trickle_set_bits = elem->conf;
 664                dev_info(dev,
 665                         "Trickle charger enabled at %d ohms resistance.\n",
 666                         elem->r);
 667        }
 668        err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
 669                                        RV3029_TRICKLE_MASK,
 670                                        trickle_set_bits);
 671        if (err < 0)
 672                dev_err(dev, "Failed to update trickle charger config\n");
 673}
 674
 675#ifdef CONFIG_RTC_DRV_RV3029_HWMON
 676
 677static int rv3029_read_temp(struct device *dev, int *temp_mC)
 678{
 679        int ret;
 680        u8 temp;
 681
 682        ret = rv3029_read_regs(dev, RV3029_TEMP_PAGE, &temp, 1);
 683        if (ret < 0)
 684                return ret;
 685
 686        *temp_mC = ((int)temp - 60) * 1000;
 687
 688        return 0;
 689}
 690
 691static ssize_t rv3029_hwmon_show_temp(struct device *dev,
 692                                      struct device_attribute *attr,
 693                                      char *buf)
 694{
 695        int ret, temp_mC;
 696
 697        ret = rv3029_read_temp(dev, &temp_mC);
 698        if (ret < 0)
 699                return ret;
 700
 701        return sprintf(buf, "%d\n", temp_mC);
 702}
 703
 704static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
 705                                                struct device_attribute *attr,
 706                                                const char *buf,
 707                                                size_t count)
 708{
 709        unsigned long interval_ms;
 710        int ret;
 711        u8 th_set_bits = 0;
 712
 713        ret = kstrtoul(buf, 10, &interval_ms);
 714        if (ret < 0)
 715                return ret;
 716
 717        if (interval_ms != 0) {
 718                th_set_bits |= RV3029_EECTRL_THE;
 719                if (interval_ms >= 16000)
 720                        th_set_bits |= RV3029_EECTRL_THP;
 721        }
 722        ret = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
 723                                        RV3029_EECTRL_THE | RV3029_EECTRL_THP,
 724                                        th_set_bits);
 725        if (ret < 0)
 726                return ret;
 727
 728        return count;
 729}
 730
 731static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
 732                                                 struct device_attribute *attr,
 733                                                 char *buf)
 734{
 735        int ret, interval_ms;
 736        u8 eectrl;
 737
 738        ret = rv3029_eeprom_read(dev, RV3029_CONTROL_E2P_EECTRL,
 739                                 &eectrl, 1);
 740        if (ret < 0)
 741                return ret;
 742
 743        if (eectrl & RV3029_EECTRL_THE) {
 744                if (eectrl & RV3029_EECTRL_THP)
 745                        interval_ms = 16000;
 746                else
 747                        interval_ms = 1000;
 748        } else {
 749                interval_ms = 0;
 750        }
 751
 752        return sprintf(buf, "%d\n", interval_ms);
 753}
 754
 755static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
 756                          NULL, 0);
 757static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
 758                          rv3029_hwmon_show_update_interval,
 759                          rv3029_hwmon_set_update_interval, 0);
 760
 761static struct attribute *rv3029_hwmon_attrs[] = {
 762        &sensor_dev_attr_temp1_input.dev_attr.attr,
 763        &sensor_dev_attr_update_interval.dev_attr.attr,
 764        NULL,
 765};
 766ATTRIBUTE_GROUPS(rv3029_hwmon);
 767
 768static void rv3029_hwmon_register(struct device *dev, const char *name)
 769{
 770        struct rv3029_data *rv3029 = dev_get_drvdata(dev);
 771        struct device *hwmon_dev;
 772
 773        hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
 774                                                           rv3029_hwmon_groups);
 775        if (IS_ERR(hwmon_dev)) {
 776                dev_warn(dev, "unable to register hwmon device %ld\n",
 777                         PTR_ERR(hwmon_dev));
 778        }
 779}
 780
 781#else /* CONFIG_RTC_DRV_RV3029_HWMON */
 782
 783static void rv3029_hwmon_register(struct device *dev, const char *name)
 784{
 785}
 786
 787#endif /* CONFIG_RTC_DRV_RV3029_HWMON */
 788
 789static struct rtc_class_ops rv3029_rtc_ops = {
 790        .read_time      = rv3029_read_time,
 791        .set_time       = rv3029_set_time,
 792};
 793
 794static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
 795                        const char *name)
 796{
 797        struct rv3029_data *rv3029;
 798        int rc = 0;
 799        u8 buf[1];
 800
 801        rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
 802        if (!rv3029)
 803                return -ENOMEM;
 804
 805        rv3029->regmap = regmap;
 806        rv3029->irq = irq;
 807        rv3029->dev = dev;
 808        dev_set_drvdata(dev, rv3029);
 809
 810        rc = rv3029_get_sr(dev, buf);
 811        if (rc < 0) {
 812                dev_err(dev, "reading status failed\n");
 813                return rc;
 814        }
 815
 816        rv3029_trickle_config(dev);
 817        rv3029_hwmon_register(dev, name);
 818
 819        rv3029->rtc = devm_rtc_device_register(dev, name, &rv3029_rtc_ops,
 820                                               THIS_MODULE);
 821        if (IS_ERR(rv3029->rtc)) {
 822                dev_err(dev, "unable to register the class device\n");
 823                return PTR_ERR(rv3029->rtc);
 824        }
 825
 826        if (rv3029->irq > 0) {
 827                rc = devm_request_threaded_irq(dev, rv3029->irq,
 828                                               NULL, rv3029_handle_irq,
 829                                               IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 830                                               "rv3029", dev);
 831                if (rc) {
 832                        dev_warn(dev, "unable to request IRQ, alarms disabled\n");
 833                        rv3029->irq = 0;
 834                } else {
 835                        rv3029_rtc_ops.read_alarm = rv3029_read_alarm;
 836                        rv3029_rtc_ops.set_alarm = rv3029_set_alarm;
 837                        rv3029_rtc_ops.alarm_irq_enable = rv3029_alarm_irq_enable;
 838                }
 839        }
 840
 841        return 0;
 842}
 843
 844#if IS_ENABLED(CONFIG_I2C)
 845
 846static int rv3029_i2c_probe(struct i2c_client *client,
 847                            const struct i2c_device_id *id)
 848{
 849        struct regmap *regmap;
 850        static const struct regmap_config config = {
 851                .reg_bits = 8,
 852                .val_bits = 8,
 853        };
 854
 855        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
 856                                     I2C_FUNC_SMBUS_BYTE)) {
 857                dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
 858                return -ENODEV;
 859        }
 860
 861        regmap = devm_regmap_init_i2c(client, &config);
 862        if (IS_ERR(regmap)) {
 863                dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
 864                        __func__, PTR_ERR(regmap));
 865                return PTR_ERR(regmap);
 866        }
 867
 868        return rv3029_probe(&client->dev, regmap, client->irq, client->name);
 869}
 870
 871static const struct i2c_device_id rv3029_id[] = {
 872        { "rv3029", 0 },
 873        { "rv3029c2", 0 },
 874        { }
 875};
 876MODULE_DEVICE_TABLE(i2c, rv3029_id);
 877
 878static const struct of_device_id rv3029_of_match[] = {
 879        { .compatible = "microcrystal,rv3029" },
 880        /* Backward compatibility only, do not use compatibles below: */
 881        { .compatible = "rv3029" },
 882        { .compatible = "rv3029c2" },
 883        { .compatible = "mc,rv3029c2" },
 884        { }
 885};
 886MODULE_DEVICE_TABLE(of, rv3029_of_match);
 887
 888static struct i2c_driver rv3029_driver = {
 889        .driver = {
 890                .name = "rtc-rv3029c2",
 891                .of_match_table = of_match_ptr(rv3029_of_match),
 892        },
 893        .probe          = rv3029_i2c_probe,
 894        .id_table       = rv3029_id,
 895};
 896
 897static int rv3029_register_driver(void)
 898{
 899        return i2c_add_driver(&rv3029_driver);
 900}
 901
 902static void rv3029_unregister_driver(void)
 903{
 904        i2c_del_driver(&rv3029_driver);
 905}
 906
 907#else
 908
 909static int rv3029_register_driver(void)
 910{
 911        return 0;
 912}
 913
 914static void rv3029_unregister_driver(void)
 915{
 916}
 917
 918#endif
 919
 920#if IS_ENABLED(CONFIG_SPI_MASTER)
 921
 922static int rv3049_probe(struct spi_device *spi)
 923{
 924        static const struct regmap_config config = {
 925                .reg_bits = 8,
 926                .val_bits = 8,
 927        };
 928        struct regmap *regmap;
 929
 930        regmap = devm_regmap_init_spi(spi, &config);
 931        if (IS_ERR(regmap)) {
 932                dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
 933                        __func__, PTR_ERR(regmap));
 934                return PTR_ERR(regmap);
 935        }
 936
 937        return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
 938}
 939
 940static struct spi_driver rv3049_driver = {
 941        .driver = {
 942                .name    = "rv3049",
 943        },
 944        .probe   = rv3049_probe,
 945};
 946
 947static int rv3049_register_driver(void)
 948{
 949        return spi_register_driver(&rv3049_driver);
 950}
 951
 952static void rv3049_unregister_driver(void)
 953{
 954        spi_unregister_driver(&rv3049_driver);
 955}
 956
 957#else
 958
 959static int rv3049_register_driver(void)
 960{
 961        return 0;
 962}
 963
 964static void rv3049_unregister_driver(void)
 965{
 966}
 967
 968#endif
 969
 970static int __init rv30x9_init(void)
 971{
 972        int ret;
 973
 974        ret = rv3029_register_driver();
 975        if (ret) {
 976                pr_err("Failed to register rv3029 driver: %d\n", ret);
 977                return ret;
 978        }
 979
 980        ret = rv3049_register_driver();
 981        if (ret) {
 982                pr_err("Failed to register rv3049 driver: %d\n", ret);
 983                rv3029_unregister_driver();
 984        }
 985
 986        return ret;
 987}
 988module_init(rv30x9_init)
 989
 990static void __exit rv30x9_exit(void)
 991{
 992        rv3049_unregister_driver();
 993        rv3029_unregister_driver();
 994}
 995module_exit(rv30x9_exit)
 996
 997MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
 998MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
 999MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
1000MODULE_LICENSE("GPL");
1001MODULE_ALIAS("spi:rv3049");
1002