1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * RTC driver for the Micro Crystal RV3028 4 * 5 * Copyright (C) 2019 Micro Crystal SA 6 * 7 * Alexandre Belloni <alexandre.belloni@bootlin.com> 8 * 9 */ 10 11 #include <linux/clk-provider.h> 12 #include <linux/bcd.h> 13 #include <linux/bitops.h> 14 #include <linux/i2c.h> 15 #include <linux/interrupt.h> 16 #include <linux/kernel.h> 17 #include <linux/log2.h> 18 #include <linux/module.h> 19 #include <linux/of_device.h> 20 #include <linux/regmap.h> 21 #include <linux/rtc.h> 22 23 #define RV3028_SEC 0x00 24 #define RV3028_MIN 0x01 25 #define RV3028_HOUR 0x02 26 #define RV3028_WDAY 0x03 27 #define RV3028_DAY 0x04 28 #define RV3028_MONTH 0x05 29 #define RV3028_YEAR 0x06 30 #define RV3028_ALARM_MIN 0x07 31 #define RV3028_ALARM_HOUR 0x08 32 #define RV3028_ALARM_DAY 0x09 33 #define RV3028_STATUS 0x0E 34 #define RV3028_CTRL1 0x0F 35 #define RV3028_CTRL2 0x10 36 #define RV3028_EVT_CTRL 0x13 37 #define RV3028_TS_COUNT 0x14 38 #define RV3028_TS_SEC 0x15 39 #define RV3028_RAM1 0x1F 40 #define RV3028_EEPROM_ADDR 0x25 41 #define RV3028_EEPROM_DATA 0x26 42 #define RV3028_EEPROM_CMD 0x27 43 #define RV3028_CLKOUT 0x35 44 #define RV3028_OFFSET 0x36 45 #define RV3028_BACKUP 0x37 46 47 #define RV3028_STATUS_PORF BIT(0) 48 #define RV3028_STATUS_EVF BIT(1) 49 #define RV3028_STATUS_AF BIT(2) 50 #define RV3028_STATUS_TF BIT(3) 51 #define RV3028_STATUS_UF BIT(4) 52 #define RV3028_STATUS_BSF BIT(5) 53 #define RV3028_STATUS_CLKF BIT(6) 54 #define RV3028_STATUS_EEBUSY BIT(7) 55 56 #define RV3028_CLKOUT_FD_MASK GENMASK(2, 0) 57 #define RV3028_CLKOUT_PORIE BIT(3) 58 #define RV3028_CLKOUT_CLKSY BIT(6) 59 #define RV3028_CLKOUT_CLKOE BIT(7) 60 61 #define RV3028_CTRL1_EERD BIT(3) 62 #define RV3028_CTRL1_WADA BIT(5) 63 64 #define RV3028_CTRL2_RESET BIT(0) 65 #define RV3028_CTRL2_12_24 BIT(1) 66 #define RV3028_CTRL2_EIE BIT(2) 67 #define RV3028_CTRL2_AIE BIT(3) 68 #define RV3028_CTRL2_TIE BIT(4) 69 #define RV3028_CTRL2_UIE BIT(5) 70 #define RV3028_CTRL2_TSE BIT(7) 71 72 #define RV3028_EVT_CTRL_TSR BIT(2) 73 74 #define RV3028_EEPROM_CMD_WRITE 0x21 75 #define RV3028_EEPROM_CMD_READ 0x22 76 77 #define RV3028_EEBUSY_POLL 10000 78 #define RV3028_EEBUSY_TIMEOUT 100000 79 80 #define RV3028_BACKUP_TCE BIT(5) 81 #define RV3028_BACKUP_TCR_MASK GENMASK(1,0) 82 83 #define OFFSET_STEP_PPT 953674 84 85 enum rv3028_type { 86 rv_3028, 87 }; 88 89 struct rv3028_data { 90 struct regmap *regmap; 91 struct rtc_device *rtc; 92 enum rv3028_type type; 93 #ifdef CONFIG_COMMON_CLK 94 struct clk_hw clkout_hw; 95 #endif 96 }; 97 98 static u16 rv3028_trickle_resistors[] = {1000, 3000, 6000, 11000}; 99 100 static ssize_t timestamp0_store(struct device *dev, 101 struct device_attribute *attr, 102 const char *buf, size_t count) 103 { 104 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); 105 106 regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR, 107 RV3028_EVT_CTRL_TSR); 108 109 return count; 110 }; 111 112 static ssize_t timestamp0_show(struct device *dev, 113 struct device_attribute *attr, char *buf) 114 { 115 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); 116 struct rtc_time tm; 117 int ret, count; 118 u8 date[6]; 119 120 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count); 121 if (ret) 122 return ret; 123 124 if (!count) 125 return 0; 126 127 ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date, 128 sizeof(date)); 129 if (ret) 130 return ret; 131 132 tm.tm_sec = bcd2bin(date[0]); 133 tm.tm_min = bcd2bin(date[1]); 134 tm.tm_hour = bcd2bin(date[2]); 135 tm.tm_mday = bcd2bin(date[3]); 136 tm.tm_mon = bcd2bin(date[4]) - 1; 137 tm.tm_year = bcd2bin(date[5]) + 100; 138 139 ret = rtc_valid_tm(&tm); 140 if (ret) 141 return ret; 142 143 return sprintf(buf, "%llu\n", 144 (unsigned long long)rtc_tm_to_time64(&tm)); 145 }; 146 147 static DEVICE_ATTR_RW(timestamp0); 148 149 static ssize_t timestamp0_count_show(struct device *dev, 150 struct device_attribute *attr, char *buf) 151 { 152 struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); 153 int ret, count; 154 155 ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count); 156 if (ret) 157 return ret; 158 159 return sprintf(buf, "%u\n", count); 160 }; 161 162 static DEVICE_ATTR_RO(timestamp0_count); 163 164 static struct attribute *rv3028_attrs[] = { 165 &dev_attr_timestamp0.attr, 166 &dev_attr_timestamp0_count.attr, 167 NULL 168 }; 169 170 static const struct attribute_group rv3028_attr_group = { 171 .attrs = rv3028_attrs, 172 }; 173 174 static irqreturn_t rv3028_handle_irq(int irq, void *dev_id) 175 { 176 struct rv3028_data *rv3028 = dev_id; 177 unsigned long events = 0; 178 u32 status = 0, ctrl = 0; 179 180 if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 || 181 status == 0) { 182 return IRQ_NONE; 183 } 184 185 if (status & RV3028_STATUS_PORF) 186 dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n"); 187 188 if (status & RV3028_STATUS_TF) { 189 status |= RV3028_STATUS_TF; 190 ctrl |= RV3028_CTRL2_TIE; 191 events |= RTC_PF; 192 } 193 194 if (status & RV3028_STATUS_AF) { 195 status |= RV3028_STATUS_AF; 196 ctrl |= RV3028_CTRL2_AIE; 197 events |= RTC_AF; 198 } 199 200 if (status & RV3028_STATUS_UF) { 201 status |= RV3028_STATUS_UF; 202 ctrl |= RV3028_CTRL2_UIE; 203 events |= RTC_UF; 204 } 205 206 if (events) { 207 rtc_update_irq(rv3028->rtc, 1, events); 208 regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0); 209 regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0); 210 } 211 212 if (status & RV3028_STATUS_EVF) { 213 sysfs_notify(&rv3028->rtc->dev.kobj, NULL, 214 dev_attr_timestamp0.attr.name); 215 dev_warn(&rv3028->rtc->dev, "event detected"); 216 } 217 218 return IRQ_HANDLED; 219 } 220 221 static int rv3028_get_time(struct device *dev, struct rtc_time *tm) 222 { 223 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 224 u8 date[7]; 225 int ret, status; 226 227 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); 228 if (ret < 0) 229 return ret; 230 231 if (status & RV3028_STATUS_PORF) { 232 dev_warn(dev, "Voltage low, data is invalid.\n"); 233 return -EINVAL; 234 } 235 236 ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date)); 237 if (ret) 238 return ret; 239 240 tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f); 241 tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f); 242 tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f); 243 tm->tm_wday = ilog2(date[RV3028_WDAY] & 0x7f); 244 tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f); 245 tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1; 246 tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100; 247 248 return 0; 249 } 250 251 static int rv3028_set_time(struct device *dev, struct rtc_time *tm) 252 { 253 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 254 u8 date[7]; 255 int ret; 256 257 date[RV3028_SEC] = bin2bcd(tm->tm_sec); 258 date[RV3028_MIN] = bin2bcd(tm->tm_min); 259 date[RV3028_HOUR] = bin2bcd(tm->tm_hour); 260 date[RV3028_WDAY] = 1 << (tm->tm_wday); 261 date[RV3028_DAY] = bin2bcd(tm->tm_mday); 262 date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1); 263 date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100); 264 265 /* 266 * Writing to the Seconds register has the same effect as setting RESET 267 * bit to 1 268 */ 269 ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date, 270 sizeof(date)); 271 if (ret) 272 return ret; 273 274 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, 275 RV3028_STATUS_PORF, 0); 276 277 return ret; 278 } 279 280 static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) 281 { 282 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 283 u8 alarmvals[3]; 284 int status, ctrl, ret; 285 286 ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals, 287 sizeof(alarmvals)); 288 if (ret) 289 return ret; 290 291 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); 292 if (ret < 0) 293 return ret; 294 295 ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl); 296 if (ret < 0) 297 return ret; 298 299 alrm->time.tm_sec = 0; 300 alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); 301 alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); 302 alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f); 303 304 alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE); 305 alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled; 306 307 return 0; 308 } 309 310 static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 311 { 312 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 313 u8 alarmvals[3]; 314 u8 ctrl = 0; 315 int ret; 316 317 /* The alarm has no seconds, round up to nearest minute */ 318 if (alrm->time.tm_sec) { 319 time64_t alarm_time = rtc_tm_to_time64(&alrm->time); 320 321 alarm_time += 60 - alrm->time.tm_sec; 322 rtc_time64_to_tm(alarm_time, &alrm->time); 323 } 324 325 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, 326 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0); 327 if (ret) 328 return ret; 329 330 alarmvals[0] = bin2bcd(alrm->time.tm_min); 331 alarmvals[1] = bin2bcd(alrm->time.tm_hour); 332 alarmvals[2] = bin2bcd(alrm->time.tm_mday); 333 334 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, 335 RV3028_STATUS_AF, 0); 336 if (ret) 337 return ret; 338 339 ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals, 340 sizeof(alarmvals)); 341 if (ret) 342 return ret; 343 344 if (alrm->enabled) { 345 if (rv3028->rtc->uie_rtctimer.enabled) 346 ctrl |= RV3028_CTRL2_UIE; 347 if (rv3028->rtc->aie_timer.enabled) 348 ctrl |= RV3028_CTRL2_AIE; 349 } 350 351 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, 352 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl); 353 354 return ret; 355 } 356 357 static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled) 358 { 359 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 360 int ctrl = 0, ret; 361 362 if (enabled) { 363 if (rv3028->rtc->uie_rtctimer.enabled) 364 ctrl |= RV3028_CTRL2_UIE; 365 if (rv3028->rtc->aie_timer.enabled) 366 ctrl |= RV3028_CTRL2_AIE; 367 } 368 369 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, 370 RV3028_STATUS_AF | RV3028_STATUS_UF, 0); 371 if (ret) 372 return ret; 373 374 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, 375 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl); 376 if (ret) 377 return ret; 378 379 return 0; 380 } 381 382 static int rv3028_read_offset(struct device *dev, long *offset) 383 { 384 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 385 int ret, value, steps; 386 387 ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value); 388 if (ret < 0) 389 return ret; 390 391 steps = sign_extend32(value << 1, 8); 392 393 ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value); 394 if (ret < 0) 395 return ret; 396 397 steps += value >> 7; 398 399 *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000); 400 401 return 0; 402 } 403 404 static int rv3028_set_offset(struct device *dev, long offset) 405 { 406 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 407 int ret; 408 409 offset = clamp(offset, -244141L, 243187L) * 1000; 410 offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT); 411 412 ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1); 413 if (ret < 0) 414 return ret; 415 416 return regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7), 417 offset << 7); 418 } 419 420 static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 421 { 422 struct rv3028_data *rv3028 = dev_get_drvdata(dev); 423 int status, ret = 0; 424 425 switch (cmd) { 426 case RTC_VL_READ: 427 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); 428 if (ret < 0) 429 return ret; 430 431 status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0; 432 return put_user(status, (unsigned int __user *)arg); 433 434 default: 435 return -ENOIOCTLCMD; 436 } 437 } 438 439 static int rv3028_nvram_write(void *priv, unsigned int offset, void *val, 440 size_t bytes) 441 { 442 return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes); 443 } 444 445 static int rv3028_nvram_read(void *priv, unsigned int offset, void *val, 446 size_t bytes) 447 { 448 return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes); 449 } 450 451 static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val, 452 size_t bytes) 453 { 454 u32 status, ctrl1; 455 int i, ret, err; 456 u8 *buf = val; 457 458 ret = regmap_read(priv, RV3028_CTRL1, &ctrl1); 459 if (ret) 460 return ret; 461 462 if (!(ctrl1 & RV3028_CTRL1_EERD)) { 463 ret = regmap_update_bits(priv, RV3028_CTRL1, 464 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD); 465 if (ret) 466 return ret; 467 468 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, 469 !(status & RV3028_STATUS_EEBUSY), 470 RV3028_EEBUSY_POLL, 471 RV3028_EEBUSY_TIMEOUT); 472 if (ret) 473 goto restore_eerd; 474 } 475 476 for (i = 0; i < bytes; i++) { 477 ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i); 478 if (ret) 479 goto restore_eerd; 480 481 ret = regmap_write(priv, RV3028_EEPROM_DATA, buf[i]); 482 if (ret) 483 goto restore_eerd; 484 485 ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0); 486 if (ret) 487 goto restore_eerd; 488 489 ret = regmap_write(priv, RV3028_EEPROM_CMD, 490 RV3028_EEPROM_CMD_WRITE); 491 if (ret) 492 goto restore_eerd; 493 494 usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT); 495 496 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, 497 !(status & RV3028_STATUS_EEBUSY), 498 RV3028_EEBUSY_POLL, 499 RV3028_EEBUSY_TIMEOUT); 500 if (ret) 501 goto restore_eerd; 502 } 503 504 restore_eerd: 505 if (!(ctrl1 & RV3028_CTRL1_EERD)) 506 { 507 err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD, 508 0); 509 if (err && !ret) 510 ret = err; 511 } 512 513 return ret; 514 } 515 516 static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val, 517 size_t bytes) 518 { 519 u32 status, ctrl1, data; 520 int i, ret, err; 521 u8 *buf = val; 522 523 ret = regmap_read(priv, RV3028_CTRL1, &ctrl1); 524 if (ret) 525 return ret; 526 527 if (!(ctrl1 & RV3028_CTRL1_EERD)) { 528 ret = regmap_update_bits(priv, RV3028_CTRL1, 529 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD); 530 if (ret) 531 return ret; 532 533 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, 534 !(status & RV3028_STATUS_EEBUSY), 535 RV3028_EEBUSY_POLL, 536 RV3028_EEBUSY_TIMEOUT); 537 if (ret) 538 goto restore_eerd; 539 } 540 541 for (i = 0; i < bytes; i++) { 542 ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i); 543 if (ret) 544 goto restore_eerd; 545 546 ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0); 547 if (ret) 548 goto restore_eerd; 549 550 ret = regmap_write(priv, RV3028_EEPROM_CMD, 551 RV3028_EEPROM_CMD_READ); 552 if (ret) 553 goto restore_eerd; 554 555 ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, 556 !(status & RV3028_STATUS_EEBUSY), 557 RV3028_EEBUSY_POLL, 558 RV3028_EEBUSY_TIMEOUT); 559 if (ret) 560 goto restore_eerd; 561 562 ret = regmap_read(priv, RV3028_EEPROM_DATA, &data); 563 if (ret) 564 goto restore_eerd; 565 buf[i] = data; 566 } 567 568 restore_eerd: 569 if (!(ctrl1 & RV3028_CTRL1_EERD)) 570 { 571 err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD, 572 0); 573 if (err && !ret) 574 ret = err; 575 } 576 577 return ret; 578 } 579 580 #ifdef CONFIG_COMMON_CLK 581 #define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw) 582 583 static int clkout_rates[] = { 584 32768, 585 8192, 586 1024, 587 64, 588 32, 589 1, 590 }; 591 592 static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw, 593 unsigned long parent_rate) 594 { 595 int clkout, ret; 596 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); 597 598 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout); 599 if (ret < 0) 600 return 0; 601 602 clkout &= RV3028_CLKOUT_FD_MASK; 603 return clkout_rates[clkout]; 604 } 605 606 static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate, 607 unsigned long *prate) 608 { 609 int i; 610 611 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) 612 if (clkout_rates[i] <= rate) 613 return clkout_rates[i]; 614 615 return 0; 616 } 617 618 static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate, 619 unsigned long parent_rate) 620 { 621 int i, ret; 622 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); 623 624 ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0); 625 if (ret < 0) 626 return ret; 627 628 for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) { 629 if (clkout_rates[i] == rate) { 630 ret = regmap_update_bits(rv3028->regmap, 631 RV3028_CLKOUT, 632 RV3028_CLKOUT_FD_MASK, i); 633 if (ret < 0) 634 return ret; 635 636 return regmap_write(rv3028->regmap, RV3028_CLKOUT, 637 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE); 638 } 639 } 640 641 return -EINVAL; 642 } 643 644 static int rv3028_clkout_prepare(struct clk_hw *hw) 645 { 646 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); 647 648 return regmap_write(rv3028->regmap, RV3028_CLKOUT, 649 RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE); 650 } 651 652 static void rv3028_clkout_unprepare(struct clk_hw *hw) 653 { 654 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); 655 656 regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0); 657 regmap_update_bits(rv3028->regmap, RV3028_STATUS, 658 RV3028_STATUS_CLKF, 0); 659 } 660 661 static int rv3028_clkout_is_prepared(struct clk_hw *hw) 662 { 663 int clkout, ret; 664 struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); 665 666 ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout); 667 if (ret < 0) 668 return ret; 669 670 return !!(clkout & RV3028_CLKOUT_CLKOE); 671 } 672 673 static const struct clk_ops rv3028_clkout_ops = { 674 .prepare = rv3028_clkout_prepare, 675 .unprepare = rv3028_clkout_unprepare, 676 .is_prepared = rv3028_clkout_is_prepared, 677 .recalc_rate = rv3028_clkout_recalc_rate, 678 .round_rate = rv3028_clkout_round_rate, 679 .set_rate = rv3028_clkout_set_rate, 680 }; 681 682 static int rv3028_clkout_register_clk(struct rv3028_data *rv3028, 683 struct i2c_client *client) 684 { 685 int ret; 686 struct clk *clk; 687 struct clk_init_data init; 688 struct device_node *node = client->dev.of_node; 689 690 ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, 691 RV3028_STATUS_CLKF, 0); 692 if (ret < 0) 693 return ret; 694 695 init.name = "rv3028-clkout"; 696 init.ops = &rv3028_clkout_ops; 697 init.flags = 0; 698 init.parent_names = NULL; 699 init.num_parents = 0; 700 rv3028->clkout_hw.init = &init; 701 702 /* optional override of the clockname */ 703 of_property_read_string(node, "clock-output-names", &init.name); 704 705 /* register the clock */ 706 clk = devm_clk_register(&client->dev, &rv3028->clkout_hw); 707 if (!IS_ERR(clk)) 708 of_clk_add_provider(node, of_clk_src_simple_get, clk); 709 710 return 0; 711 } 712 #endif 713 714 static struct rtc_class_ops rv3028_rtc_ops = { 715 .read_time = rv3028_get_time, 716 .set_time = rv3028_set_time, 717 .read_offset = rv3028_read_offset, 718 .set_offset = rv3028_set_offset, 719 .ioctl = rv3028_ioctl, 720 }; 721 722 static const struct regmap_config regmap_config = { 723 .reg_bits = 8, 724 .val_bits = 8, 725 .max_register = 0x37, 726 }; 727 728 static int rv3028_probe(struct i2c_client *client) 729 { 730 struct rv3028_data *rv3028; 731 int ret, status; 732 u32 ohms; 733 struct nvmem_config nvmem_cfg = { 734 .name = "rv3028_nvram", 735 .word_size = 1, 736 .stride = 1, 737 .size = 2, 738 .type = NVMEM_TYPE_BATTERY_BACKED, 739 .reg_read = rv3028_nvram_read, 740 .reg_write = rv3028_nvram_write, 741 }; 742 struct nvmem_config eeprom_cfg = { 743 .name = "rv3028_eeprom", 744 .word_size = 1, 745 .stride = 1, 746 .size = 43, 747 .type = NVMEM_TYPE_EEPROM, 748 .reg_read = rv3028_eeprom_read, 749 .reg_write = rv3028_eeprom_write, 750 }; 751 752 rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data), 753 GFP_KERNEL); 754 if (!rv3028) 755 return -ENOMEM; 756 757 rv3028->regmap = devm_regmap_init_i2c(client, ®map_config); 758 if (IS_ERR(rv3028->regmap)) 759 return PTR_ERR(rv3028->regmap); 760 761 i2c_set_clientdata(client, rv3028); 762 763 ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); 764 if (ret < 0) 765 return ret; 766 767 if (status & RV3028_STATUS_PORF) 768 dev_warn(&client->dev, "Voltage low, data loss detected.\n"); 769 770 if (status & RV3028_STATUS_AF) 771 dev_warn(&client->dev, "An alarm may have been missed.\n"); 772 773 rv3028->rtc = devm_rtc_allocate_device(&client->dev); 774 if (IS_ERR(rv3028->rtc)) 775 return PTR_ERR(rv3028->rtc); 776 777 if (client->irq > 0) { 778 ret = devm_request_threaded_irq(&client->dev, client->irq, 779 NULL, rv3028_handle_irq, 780 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 781 "rv3028", rv3028); 782 if (ret) { 783 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); 784 client->irq = 0; 785 } else { 786 rv3028_rtc_ops.read_alarm = rv3028_get_alarm; 787 rv3028_rtc_ops.set_alarm = rv3028_set_alarm; 788 rv3028_rtc_ops.alarm_irq_enable = rv3028_alarm_irq_enable; 789 } 790 } 791 792 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1, 793 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA); 794 if (ret) 795 return ret; 796 797 /* setup timestamping */ 798 ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, 799 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE, 800 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE); 801 if (ret) 802 return ret; 803 804 /* setup trickle charger */ 805 if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms", 806 &ohms)) { 807 int i; 808 809 for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) 810 if (ohms == rv3028_trickle_resistors[i]) 811 break; 812 813 if (i < ARRAY_SIZE(rv3028_trickle_resistors)) { 814 ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, 815 RV3028_BACKUP_TCE | 816 RV3028_BACKUP_TCR_MASK, 817 RV3028_BACKUP_TCE | i); 818 if (ret) 819 return ret; 820 } else { 821 dev_warn(&client->dev, "invalid trickle resistor value\n"); 822 } 823 } 824 825 ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group); 826 if (ret) 827 return ret; 828 829 rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; 830 rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099; 831 rv3028->rtc->ops = &rv3028_rtc_ops; 832 ret = rtc_register_device(rv3028->rtc); 833 if (ret) 834 return ret; 835 836 nvmem_cfg.priv = rv3028->regmap; 837 rtc_nvmem_register(rv3028->rtc, &nvmem_cfg); 838 eeprom_cfg.priv = rv3028->regmap; 839 rtc_nvmem_register(rv3028->rtc, &eeprom_cfg); 840 841 rv3028->rtc->max_user_freq = 1; 842 843 #ifdef CONFIG_COMMON_CLK 844 rv3028_clkout_register_clk(rv3028, client); 845 #endif 846 return 0; 847 } 848 849 static const struct of_device_id rv3028_of_match[] = { 850 { .compatible = "microcrystal,rv3028", }, 851 { } 852 }; 853 MODULE_DEVICE_TABLE(of, rv3028_of_match); 854 855 static struct i2c_driver rv3028_driver = { 856 .driver = { 857 .name = "rtc-rv3028", 858 .of_match_table = of_match_ptr(rv3028_of_match), 859 }, 860 .probe_new = rv3028_probe, 861 }; 862 module_i2c_driver(rv3028_driver); 863 864 MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>"); 865 MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver"); 866 MODULE_LICENSE("GPL v2"); 867