drivers/rtc/rtc-rv3029c2.c

   1 /*
   2  * Micro Crystal RV-3029 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/bcd.h>
  18 #include <linux/rtc.h>
  19 #include <linux/delay.h>
  20 #include <linux/of.h>
  21 #include <linux/hwmon.h>
  22 #include <linux/hwmon-sysfs.h>
  23
  24
  25 /* Register map */
  26 /* control section */
  27 #define RV3029_ONOFF_CTRL               0x00
  28 #define RV3029_ONOFF_CTRL_WE            BIT(0)
  29 #define RV3029_ONOFF_CTRL_TE            BIT(1)
  30 #define RV3029_ONOFF_CTRL_TAR           BIT(2)
  31 #define RV3029_ONOFF_CTRL_EERE          BIT(3)
  32 #define RV3029_ONOFF_CTRL_SRON          BIT(4)
  33 #define RV3029_ONOFF_CTRL_TD0           BIT(5)
  34 #define RV3029_ONOFF_CTRL_TD1           BIT(6)
  35 #define RV3029_ONOFF_CTRL_CLKINT        BIT(7)
  36 #define RV3029_IRQ_CTRL                 0x01
  37 #define RV3029_IRQ_CTRL_AIE             BIT(0)
  38 #define RV3029_IRQ_CTRL_TIE             BIT(1)
  39 #define RV3029_IRQ_CTRL_V1IE            BIT(2)
  40 #define RV3029_IRQ_CTRL_V2IE            BIT(3)
  41 #define RV3029_IRQ_CTRL_SRIE            BIT(4)
  42 #define RV3029_IRQ_FLAGS                0x02
  43 #define RV3029_IRQ_FLAGS_AF             BIT(0)
  44 #define RV3029_IRQ_FLAGS_TF             BIT(1)
  45 #define RV3029_IRQ_FLAGS_V1IF           BIT(2)
  46 #define RV3029_IRQ_FLAGS_V2IF           BIT(3)
  47 #define RV3029_IRQ_FLAGS_SRF            BIT(4)
  48 #define RV3029_STATUS                   0x03
  49 #define RV3029_STATUS_VLOW1             BIT(2)
  50 #define RV3029_STATUS_VLOW2             BIT(3)
  51 #define RV3029_STATUS_SR                BIT(4)
  52 #define RV3029_STATUS_PON               BIT(5)
  53 #define RV3029_STATUS_EEBUSY            BIT(7)
  54 #define RV3029_RST_CTRL                 0x04
  55 #define RV3029_RST_CTRL_SYSR            BIT(4)
  56 #define RV3029_CONTROL_SECTION_LEN      0x05
  57
  58 /* watch section */
  59 #define RV3029_W_SEC                    0x08
  60 #define RV3029_W_MINUTES                0x09
  61 #define RV3029_W_HOURS                  0x0A
  62 #define RV3029_REG_HR_12_24             BIT(6) /* 24h/12h mode */
  63 #define RV3029_REG_HR_PM                BIT(5) /* PM/AM bit in 12h mode */
  64 #define RV3029_W_DATE                   0x0B
  65 #define RV3029_W_DAYS                   0x0C
  66 #define RV3029_W_MONTHS                 0x0D
  67 #define RV3029_W_YEARS                  0x0E
  68 #define RV3029_WATCH_SECTION_LEN        0x07
  69
  70 /* alarm section */
  71 #define RV3029_A_SC                     0x10
  72 #define RV3029_A_MN                     0x11
  73 #define RV3029_A_HR                     0x12
  74 #define RV3029_A_DT                     0x13
  75 #define RV3029_A_DW                     0x14
  76 #define RV3029_A_MO                     0x15
  77 #define RV3029_A_YR                     0x16
  78 #define RV3029_ALARM_SECTION_LEN        0x07
  79
  80 /* timer section */
  81 #define RV3029_TIMER_LOW                0x18
  82 #define RV3029_TIMER_HIGH               0x19
  83
  84 /* temperature section */
  85 #define RV3029_TEMP_PAGE                0x20
  86
  87 /* eeprom data section */
  88 #define RV3029_E2P_EEDATA1              0x28
  89 #define RV3029_E2P_EEDATA2              0x29
  90 #define RV3029_E2PDATA_SECTION_LEN      0x02
  91
  92 /* eeprom control section */
  93 #define RV3029_CONTROL_E2P_EECTRL       0x30
  94 #define RV3029_EECTRL_THP               BIT(0) /* temp scan interval */
  95 #define RV3029_EECTRL_THE               BIT(1) /* thermometer enable */
  96 #define RV3029_EECTRL_FD0               BIT(2) /* CLKOUT */
  97 #define RV3029_EECTRL_FD1               BIT(3) /* CLKOUT */
  98 #define RV3029_TRICKLE_1K               BIT(4) /* 1.5K resistance */
  99 #define RV3029_TRICKLE_5K               BIT(5) /* 5K   resistance */
 100 #define RV3029_TRICKLE_20K              BIT(6) /* 20K  resistance */
 101 #define RV3029_TRICKLE_80K              BIT(7) /* 80K  resistance */
 102 #define RV3029_TRICKLE_MASK             (RV3029_TRICKLE_1K |\
 103                                          RV3029_TRICKLE_5K |\
 104                                          RV3029_TRICKLE_20K |\
 105                                          RV3029_TRICKLE_80K)
 106 #define RV3029_TRICKLE_SHIFT            4
 107 #define RV3029_CONTROL_E2P_XOFFS        0x31 /* XTAL offset */
 108 #define RV3029_CONTROL_E2P_XOFFS_SIGN   BIT(7) /* Sign: 1->pos, 0->neg */
 109 #define RV3029_CONTROL_E2P_QCOEF        0x32 /* XTAL temp drift coef */
 110 #define RV3029_CONTROL_E2P_TURNOVER     0x33 /* XTAL turnover temp (in *C) */
 111 #define RV3029_CONTROL_E2P_TOV_MASK     0x3F /* XTAL turnover temp mask */
 112
 113 /* user ram section */
 114 #define RV3029_USR1_RAM_PAGE            0x38
 115 #define RV3029_USR1_SECTION_LEN         0x04
 116 #define RV3029_USR2_RAM_PAGE            0x3C
 117 #define RV3029_USR2_SECTION_LEN         0x04
 118
 119 static int
 120 rv3029_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf,
 121                      unsigned len)
 122 {
 123         int ret;
 124
 125         if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
 126                 (reg + len > RV3029_USR1_RAM_PAGE + 8))
 127                 return -EINVAL;
 128
 129         ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
 130         if (ret < 0)
 131                 return ret;
 132         if (ret < len)
 133                 return -EIO;
 134         return 0;
 135 }
 136
 137 static int
 138 rv3029_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[],
 139                       unsigned len)
 140 {
 141         if ((reg > RV3029_USR1_RAM_PAGE + 7) ||
 142                 (reg + len > RV3029_USR1_RAM_PAGE + 8))
 143                 return -EINVAL;
 144
 145         return i2c_smbus_write_i2c_block_data(client, reg, len, buf);
 146 }
 147
 148 static int
 149 rv3029_i2c_update_bits(struct i2c_client *client, u8 reg, u8 mask, u8 set)
 150 {
 151         u8 buf;
 152         int ret;
 153
 154         ret = rv3029_i2c_read_regs(client, reg, &buf, 1);
 155         if (ret < 0)
 156                 return ret;
 157         buf &= ~mask;
 158         buf |= set & mask;
 159         ret = rv3029_i2c_write_regs(client, reg, &buf, 1);
 160         if (ret < 0)
 161                 return ret;
 162
 163         return 0;
 164 }
 165
 166 static int
 167 rv3029_i2c_get_sr(struct i2c_client *client, u8 *buf)
 168 {
 169         int ret = rv3029_i2c_read_regs(client, RV3029_STATUS, buf, 1);
 170
 171         if (ret < 0)
 172                 return -EIO;
 173         dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
 174         return 0;
 175 }
 176
 177 static int
 178 rv3029_i2c_set_sr(struct i2c_client *client, u8 val)
 179 {
 180         u8 buf[1];
 181         int sr;
 182
 183         buf[0] = val;
 184         sr = rv3029_i2c_write_regs(client, RV3029_STATUS, buf, 1);
 185         dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
 186         if (sr < 0)
 187                 return -EIO;
 188         return 0;
 189 }
 190
 191 static int rv3029_eeprom_busywait(struct i2c_client *client)
 192 {
 193         int i, ret;
 194         u8 sr;
 195
 196         for (i = 100; i > 0; i--) {
 197                 ret = rv3029_i2c_get_sr(client, &sr);
 198                 if (ret < 0)
 199                         break;
 200                 if (!(sr & RV3029_STATUS_EEBUSY))
 201                         break;
 202                 usleep_range(1000, 10000);
 203         }
 204         if (i <= 0) {
 205                 dev_err(&client->dev, "EEPROM busy wait timeout.\n");
 206                 return -ETIMEDOUT;
 207         }
 208
 209         return ret;
 210 }
 211
 212 static int rv3029_eeprom_exit(struct i2c_client *client)
 213 {
 214         /* Re-enable eeprom refresh */
 215         return rv3029_i2c_update_bits(client, RV3029_ONOFF_CTRL,
 216                                       RV3029_ONOFF_CTRL_EERE,
 217                                       RV3029_ONOFF_CTRL_EERE);
 218 }
 219
 220 static int rv3029_eeprom_enter(struct i2c_client *client)
 221 {
 222         int ret;
 223         u8 sr;
 224
 225         /* Check whether we are in the allowed voltage range. */
 226         ret = rv3029_i2c_get_sr(client, &sr);
 227         if (ret < 0)
 228                 return ret;
 229         if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
 230                 /* We clear the bits and retry once just in case
 231                  * we had a brown out in early startup.
 232                  */
 233                 sr &= ~RV3029_STATUS_VLOW1;
 234                 sr &= ~RV3029_STATUS_VLOW2;
 235                 ret = rv3029_i2c_set_sr(client, sr);
 236                 if (ret < 0)
 237                         return ret;
 238                 usleep_range(1000, 10000);
 239                 ret = rv3029_i2c_get_sr(client, &sr);
 240                 if (ret < 0)
 241                         return ret;
 242                 if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
 243                         dev_err(&client->dev,
 244                                 "Supply voltage is too low to safely access the EEPROM.\n");
 245                         return -ENODEV;
 246                 }
 247         }
 248
 249         /* Disable eeprom refresh. */
 250         ret = rv3029_i2c_update_bits(client, RV3029_ONOFF_CTRL,
 251                                      RV3029_ONOFF_CTRL_EERE, 0);
 252         if (ret < 0)
 253                 return ret;
 254
 255         /* Wait for any previous eeprom accesses to finish. */
 256         ret = rv3029_eeprom_busywait(client);
 257         if (ret < 0)
 258                 rv3029_eeprom_exit(client);
 259
 260         return ret;
 261 }
 262
 263 static int rv3029_eeprom_read(struct i2c_client *client, u8 reg,
 264                               u8 buf[], size_t len)
 265 {
 266         int ret, err;
 267
 268         err = rv3029_eeprom_enter(client);
 269         if (err < 0)
 270                 return err;
 271
 272         ret = rv3029_i2c_read_regs(client, reg, buf, len);
 273
 274         err = rv3029_eeprom_exit(client);
 275         if (err < 0)
 276                 return err;
 277
 278         return ret;
 279 }
 280
 281 static int rv3029_eeprom_write(struct i2c_client *client, u8 reg,
 282                                u8 const buf[], size_t len)
 283 {
 284         int ret, err;
 285         size_t i;
 286         u8 tmp;
 287
 288         err = rv3029_eeprom_enter(client);
 289         if (err < 0)
 290                 return err;
 291
 292         for (i = 0; i < len; i++, reg++) {
 293                 ret = rv3029_i2c_read_regs(client, reg, &tmp, 1);
 294                 if (ret < 0)
 295                         break;
 296                 if (tmp != buf[i]) {
 297                         ret = rv3029_i2c_write_regs(client, reg, &buf[i], 1);
 298                         if (ret < 0)
 299                                 break;
 300                 }
 301                 ret = rv3029_eeprom_busywait(client);
 302                 if (ret < 0)
 303                         break;
 304         }
 305
 306         err = rv3029_eeprom_exit(client);
 307         if (err < 0)
 308                 return err;
 309
 310         return ret;
 311 }
 312
 313 static int rv3029_eeprom_update_bits(struct i2c_client *client,
 314                                      u8 reg, u8 mask, u8 set)
 315 {
 316         u8 buf;
 317         int ret;
 318
 319         ret = rv3029_eeprom_read(client, reg, &buf, 1);
 320         if (ret < 0)
 321                 return ret;
 322         buf &= ~mask;
 323         buf |= set & mask;
 324         ret = rv3029_eeprom_write(client, reg, &buf, 1);
 325         if (ret < 0)
 326                 return ret;
 327
 328         return 0;
 329 }
 330
 331 static int
 332 rv3029_i2c_read_time(struct i2c_client *client, struct rtc_time *tm)
 333 {
 334         u8 buf[1];
 335         int ret;
 336         u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
 337
 338         ret = rv3029_i2c_get_sr(client, buf);
 339         if (ret < 0) {
 340                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 341                 return -EIO;
 342         }
 343
 344         ret = rv3029_i2c_read_regs(client, RV3029_W_SEC, regs,
 345                                    RV3029_WATCH_SECTION_LEN);
 346         if (ret < 0) {
 347                 dev_err(&client->dev, "%s: reading RTC section failed\n",
 348                         __func__);
 349                 return ret;
 350         }
 351
 352         tm->tm_sec = bcd2bin(regs[RV3029_W_SEC-RV3029_W_SEC]);
 353         tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES-RV3029_W_SEC]);
 354
 355         /* HR field has a more complex interpretation */
 356         {
 357                 const u8 _hr = regs[RV3029_W_HOURS-RV3029_W_SEC];
 358
 359                 if (_hr & RV3029_REG_HR_12_24) {
 360                         /* 12h format */
 361                         tm->tm_hour = bcd2bin(_hr & 0x1f);
 362                         if (_hr & RV3029_REG_HR_PM)     /* PM flag set */
 363                                 tm->tm_hour += 12;
 364                 } else /* 24h format */
 365                         tm->tm_hour = bcd2bin(_hr & 0x3f);
 366         }
 367
 368         tm->tm_mday = bcd2bin(regs[RV3029_W_DATE-RV3029_W_SEC]);
 369         tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS-RV3029_W_SEC]) - 1;
 370         tm->tm_year = bcd2bin(regs[RV3029_W_YEARS-RV3029_W_SEC]) + 100;
 371         tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS-RV3029_W_SEC]) - 1;
 372
 373         return 0;
 374 }
 375
 376 static int rv3029_rtc_read_time(struct device *dev, struct rtc_time *tm)
 377 {
 378         return rv3029_i2c_read_time(to_i2c_client(dev), tm);
 379 }
 380
 381 static int
 382 rv3029_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm)
 383 {
 384         struct rtc_time *const tm = &alarm->time;
 385         int ret;
 386         u8 regs[8];
 387
 388         ret = rv3029_i2c_get_sr(client, regs);
 389         if (ret < 0) {
 390                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 391                 return -EIO;
 392         }
 393
 394         ret = rv3029_i2c_read_regs(client, RV3029_A_SC, regs,
 395                                    RV3029_ALARM_SECTION_LEN);
 396
 397         if (ret < 0) {
 398                 dev_err(&client->dev, "%s: reading alarm section failed\n",
 399                         __func__);
 400                 return ret;
 401         }
 402
 403         tm->tm_sec = bcd2bin(regs[RV3029_A_SC-RV3029_A_SC] & 0x7f);
 404         tm->tm_min = bcd2bin(regs[RV3029_A_MN-RV3029_A_SC] & 0x7f);
 405         tm->tm_hour = bcd2bin(regs[RV3029_A_HR-RV3029_A_SC] & 0x3f);
 406         tm->tm_mday = bcd2bin(regs[RV3029_A_DT-RV3029_A_SC] & 0x3f);
 407         tm->tm_mon = bcd2bin(regs[RV3029_A_MO-RV3029_A_SC] & 0x1f) - 1;
 408         tm->tm_year = bcd2bin(regs[RV3029_A_YR-RV3029_A_SC] & 0x7f) + 100;
 409         tm->tm_wday = bcd2bin(regs[RV3029_A_DW-RV3029_A_SC] & 0x07) - 1;
 410
 411         return 0;
 412 }
 413
 414 static int
 415 rv3029_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 416 {
 417         return rv3029_i2c_read_alarm(to_i2c_client(dev), alarm);
 418 }
 419
 420 static int rv3029_rtc_i2c_alarm_set_irq(struct i2c_client *client,
 421                                         int enable)
 422 {
 423         int ret;
 424
 425         /* enable/disable AIE irq */
 426         ret = rv3029_i2c_update_bits(client, RV3029_IRQ_CTRL,
 427                                      RV3029_IRQ_CTRL_AIE,
 428                                      (enable ? RV3029_IRQ_CTRL_AIE : 0));
 429         if (ret < 0) {
 430                 dev_err(&client->dev, "can't update INT reg\n");
 431                 return ret;
 432         }
 433
 434         return 0;
 435 }
 436
 437 static int rv3029_rtc_i2c_set_alarm(struct i2c_client *client,
 438                                     struct rtc_wkalrm *alarm)
 439 {
 440         struct rtc_time *const tm = &alarm->time;
 441         int ret;
 442         u8 regs[8];
 443
 444         /*
 445          * The clock has an 8 bit wide bcd-coded register (they never learn)
 446          * for the year. tm_year is an offset from 1900 and we are interested
 447          * in the 2000-2099 range, so any value less than 100 is invalid.
 448         */
 449         if (tm->tm_year < 100)
 450                 return -EINVAL;
 451
 452         ret = rv3029_i2c_get_sr(client, regs);
 453         if (ret < 0) {
 454                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 455                 return -EIO;
 456         }
 457         regs[RV3029_A_SC-RV3029_A_SC] = bin2bcd(tm->tm_sec & 0x7f);
 458         regs[RV3029_A_MN-RV3029_A_SC] = bin2bcd(tm->tm_min & 0x7f);
 459         regs[RV3029_A_HR-RV3029_A_SC] = bin2bcd(tm->tm_hour & 0x3f);
 460         regs[RV3029_A_DT-RV3029_A_SC] = bin2bcd(tm->tm_mday & 0x3f);
 461         regs[RV3029_A_MO-RV3029_A_SC] = bin2bcd((tm->tm_mon & 0x1f) - 1);
 462         regs[RV3029_A_DW-RV3029_A_SC] = bin2bcd((tm->tm_wday & 7) - 1);
 463         regs[RV3029_A_YR-RV3029_A_SC] = bin2bcd((tm->tm_year & 0x7f) - 100);
 464
 465         ret = rv3029_i2c_write_regs(client, RV3029_A_SC, regs,
 466                                     RV3029_ALARM_SECTION_LEN);
 467         if (ret < 0)
 468                 return ret;
 469
 470         if (alarm->enabled) {
 471                 /* clear AF flag */
 472                 ret = rv3029_i2c_update_bits(client, RV3029_IRQ_FLAGS,
 473                                              RV3029_IRQ_FLAGS_AF, 0);
 474                 if (ret < 0) {
 475                         dev_err(&client->dev, "can't clear alarm flag\n");
 476                         return ret;
 477                 }
 478                 /* enable AIE irq */
 479                 ret = rv3029_rtc_i2c_alarm_set_irq(client, 1);
 480                 if (ret)
 481                         return ret;
 482
 483                 dev_dbg(&client->dev, "alarm IRQ armed\n");
 484         } else {
 485                 /* disable AIE irq */
 486                 ret = rv3029_rtc_i2c_alarm_set_irq(client, 0);
 487                 if (ret)
 488                         return ret;
 489
 490                 dev_dbg(&client->dev, "alarm IRQ disabled\n");
 491         }
 492
 493         return 0;
 494 }
 495
 496 static int rv3029_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 497 {
 498         return rv3029_rtc_i2c_set_alarm(to_i2c_client(dev), alarm);
 499 }
 500
 501 static int
 502 rv3029_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm)
 503 {
 504         u8 regs[8];
 505         int ret;
 506
 507         /*
 508          * The clock has an 8 bit wide bcd-coded register (they never learn)
 509          * for the year. tm_year is an offset from 1900 and we are interested
 510          * in the 2000-2099 range, so any value less than 100 is invalid.
 511         */
 512         if (tm->tm_year < 100)
 513                 return -EINVAL;
 514
 515         regs[RV3029_W_SEC-RV3029_W_SEC] = bin2bcd(tm->tm_sec);
 516         regs[RV3029_W_MINUTES-RV3029_W_SEC] = bin2bcd(tm->tm_min);
 517         regs[RV3029_W_HOURS-RV3029_W_SEC] = bin2bcd(tm->tm_hour);
 518         regs[RV3029_W_DATE-RV3029_W_SEC] = bin2bcd(tm->tm_mday);
 519         regs[RV3029_W_MONTHS-RV3029_W_SEC] = bin2bcd(tm->tm_mon+1);
 520         regs[RV3029_W_DAYS-RV3029_W_SEC] = bin2bcd((tm->tm_wday & 7)+1);
 521         regs[RV3029_W_YEARS-RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
 522
 523         ret = rv3029_i2c_write_regs(client, RV3029_W_SEC, regs,
 524                                     RV3029_WATCH_SECTION_LEN);
 525         if (ret < 0)
 526                 return ret;
 527
 528         ret = rv3029_i2c_get_sr(client, regs);
 529         if (ret < 0) {
 530                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 531                 return ret;
 532         }
 533         /* clear PON bit */
 534         ret = rv3029_i2c_set_sr(client, (regs[0] & ~RV3029_STATUS_PON));
 535         if (ret < 0) {
 536                 dev_err(&client->dev, "%s: reading SR failed\n", __func__);
 537                 return ret;
 538         }
 539
 540         return 0;
 541 }
 542
 543 static int rv3029_rtc_set_time(struct device *dev, struct rtc_time *tm)
 544 {
 545         return rv3029_i2c_set_time(to_i2c_client(dev), tm);
 546 }
 547
 548 static const struct rv3029_trickle_tab_elem {
 549         u32 r;          /* resistance in ohms */
 550         u8 conf;        /* trickle config bits */
 551 } rv3029_trickle_tab[] = {
 552         {
 553                 .r      = 1076,
 554                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 555                           RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 556         }, {
 557                 .r      = 1091,
 558                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 559                           RV3029_TRICKLE_20K,
 560         }, {
 561                 .r      = 1137,
 562                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
 563                           RV3029_TRICKLE_80K,
 564         }, {
 565                 .r      = 1154,
 566                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
 567         }, {
 568                 .r      = 1371,
 569                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
 570                           RV3029_TRICKLE_80K,
 571         }, {
 572                 .r      = 1395,
 573                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
 574         }, {
 575                 .r      = 1472,
 576                 .conf   = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
 577         }, {
 578                 .r      = 1500,
 579                 .conf   = RV3029_TRICKLE_1K,
 580         }, {
 581                 .r      = 3810,
 582                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
 583                           RV3029_TRICKLE_80K,
 584         }, {
 585                 .r      = 4000,
 586                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
 587         }, {
 588                 .r      = 4706,
 589                 .conf   = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
 590         }, {
 591                 .r      = 5000,
 592                 .conf   = RV3029_TRICKLE_5K,
 593         }, {
 594                 .r      = 16000,
 595                 .conf   = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
 596         }, {
 597                 .r      = 20000,
 598                 .conf   = RV3029_TRICKLE_20K,
 599         }, {
 600                 .r      = 80000,
 601                 .conf   = RV3029_TRICKLE_80K,
 602         },
 603 };
 604
 605 static void rv3029_trickle_config(struct i2c_client *client)
 606 {
 607         struct device_node *of_node = client->dev.of_node;
 608         const struct rv3029_trickle_tab_elem *elem;
 609         int i, err;
 610         u32 ohms;
 611         u8 trickle_set_bits;
 612
 613         if (!of_node)
 614                 return;
 615
 616         /* Configure the trickle charger. */
 617         err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
 618         if (err) {
 619                 /* Disable trickle charger. */
 620                 trickle_set_bits = 0;
 621         } else {
 622                 /* Enable trickle charger. */
 623                 for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
 624                         elem = &rv3029_trickle_tab[i];
 625                         if (elem->r >= ohms)
 626                                 break;
 627                 }
 628                 trickle_set_bits = elem->conf;
 629                 dev_info(&client->dev,
 630                          "Trickle charger enabled at %d ohms resistance.\n",
 631                          elem->r);
 632         }
 633         err = rv3029_eeprom_update_bits(client, RV3029_CONTROL_E2P_EECTRL,
 634                                         RV3029_TRICKLE_MASK,
 635                                         trickle_set_bits);
 636         if (err < 0) {
 637                 dev_err(&client->dev,
 638                         "Failed to update trickle charger config\n");
 639         }
 640 }
 641
 642 #ifdef CONFIG_RTC_DRV_RV3029_HWMON
 643
 644 static int rv3029_read_temp(struct i2c_client *client, int *temp_mC)
 645 {
 646         int ret;
 647         u8 temp;
 648
 649         ret = rv3029_i2c_read_regs(client, RV3029_TEMP_PAGE, &temp, 1);
 650         if (ret < 0)
 651                 return ret;
 652
 653         *temp_mC = ((int)temp - 60) * 1000;
 654
 655         return 0;
 656 }
 657
 658 static ssize_t rv3029_hwmon_show_temp(struct device *dev,
 659                                       struct device_attribute *attr,
 660                                       char *buf)
 661 {
 662         struct i2c_client *client = dev_get_drvdata(dev);
 663         int ret, temp_mC;
 664
 665         ret = rv3029_read_temp(client, &temp_mC);
 666         if (ret < 0)
 667                 return ret;
 668
 669         return sprintf(buf, "%d\n", temp_mC);
 670 }
 671
 672 static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
 673                                                 struct device_attribute *attr,
 674                                                 const char *buf,
 675                                                 size_t count)
 676 {
 677         struct i2c_client *client = dev_get_drvdata(dev);
 678         unsigned long interval_ms;
 679         int ret;
 680         u8 th_set_bits = 0;
 681
 682         ret = kstrtoul(buf, 10, &interval_ms);
 683         if (ret < 0)
 684                 return ret;
 685
 686         if (interval_ms != 0) {
 687                 th_set_bits |= RV3029_EECTRL_THE;
 688                 if (interval_ms >= 16000)
 689                         th_set_bits |= RV3029_EECTRL_THP;
 690         }
 691         ret = rv3029_eeprom_update_bits(client, RV3029_CONTROL_E2P_EECTRL,
 692                                         RV3029_EECTRL_THE | RV3029_EECTRL_THP,
 693                                         th_set_bits);
 694         if (ret < 0)
 695                 return ret;
 696
 697         return count;
 698 }
 699
 700 static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
 701                                                  struct device_attribute *attr,
 702                                                  char *buf)
 703 {
 704         struct i2c_client *client = dev_get_drvdata(dev);
 705         int ret, interval_ms;
 706         u8 eectrl;
 707
 708         ret = rv3029_eeprom_read(client, RV3029_CONTROL_E2P_EECTRL,
 709                                  &eectrl, 1);
 710         if (ret < 0)
 711                 return ret;
 712
 713         if (eectrl & RV3029_EECTRL_THE) {
 714                 if (eectrl & RV3029_EECTRL_THP)
 715                         interval_ms = 16000;
 716                 else
 717                         interval_ms = 1000;
 718         } else {
 719                 interval_ms = 0;
 720         }
 721
 722         return sprintf(buf, "%d\n", interval_ms);
 723 }
 724
 725 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
 726                           NULL, 0);
 727 static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
 728                           rv3029_hwmon_show_update_interval,
 729                           rv3029_hwmon_set_update_interval, 0);
 730
 731 static struct attribute *rv3029_hwmon_attrs[] = {
 732         &sensor_dev_attr_temp1_input.dev_attr.attr,
 733         &sensor_dev_attr_update_interval.dev_attr.attr,
 734         NULL,
 735 };
 736 ATTRIBUTE_GROUPS(rv3029_hwmon);
 737
 738 static void rv3029_hwmon_register(struct i2c_client *client)
 739 {
 740         struct device *hwmon_dev;
 741
 742         hwmon_dev = devm_hwmon_device_register_with_groups(
 743                 &client->dev, client->name, client, rv3029_hwmon_groups);
 744         if (IS_ERR(hwmon_dev)) {
 745                 dev_warn(&client->dev,
 746                         "unable to register hwmon device %ld\n",
 747                         PTR_ERR(hwmon_dev));
 748         }
 749 }
 750
 751 #else /* CONFIG_RTC_DRV_RV3029_HWMON */
 752
 753 static void rv3029_hwmon_register(struct i2c_client *client)
 754 {
 755 }
 756
 757 #endif /* CONFIG_RTC_DRV_RV3029_HWMON */
 758
 759 static const struct rtc_class_ops rv3029_rtc_ops = {
 760         .read_time      = rv3029_rtc_read_time,
 761         .set_time       = rv3029_rtc_set_time,
 762         .read_alarm     = rv3029_rtc_read_alarm,
 763         .set_alarm      = rv3029_rtc_set_alarm,
 764 };
 765
 766 static struct i2c_device_id rv3029_id[] = {
 767         { "rv3029", 0 },
 768         { "rv3029c2", 0 },
 769         { }
 770 };
 771 MODULE_DEVICE_TABLE(i2c, rv3029_id);
 772
 773 static int rv3029_probe(struct i2c_client *client,
 774                         const struct i2c_device_id *id)
 775 {
 776         struct rtc_device *rtc;
 777         int rc = 0;
 778         u8 buf[1];
 779
 780         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_EMUL))
 781                 return -ENODEV;
 782
 783         rc = rv3029_i2c_get_sr(client, buf);
 784         if (rc < 0) {
 785                 dev_err(&client->dev, "reading status failed\n");
 786                 return rc;
 787         }
 788
 789         rv3029_trickle_config(client);
 790         rv3029_hwmon_register(client);
 791
 792         rtc = devm_rtc_device_register(&client->dev, client->name,
 793                                        &rv3029_rtc_ops, THIS_MODULE);
 794
 795         if (IS_ERR(rtc))
 796                 return PTR_ERR(rtc);
 797
 798         i2c_set_clientdata(client, rtc);
 799
 800         return 0;
 801 }
 802
 803 static struct i2c_driver rv3029_driver = {
 804         .driver = {
 805                 .name = "rtc-rv3029c2",
 806         },
 807         .probe          = rv3029_probe,
 808         .id_table       = rv3029_id,
 809 };
 810
 811 module_i2c_driver(rv3029_driver);
 812
 813 MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
 814 MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
 815 MODULE_DESCRIPTION("Micro Crystal RV3029 RTC driver");
 816 MODULE_LICENSE("GPL");