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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 | // SPDX-License-Identifier: GPL-2.0 /* * RTC driver for the Micro Crystal RV8803 * * Copyright (C) 2015 Micro Crystal SA * Alexandre Belloni <alexandre.belloni@bootlin.com> * */ #include <linux/bcd.h> #include <linux/bitops.h> #include <linux/bitfield.h> #include <linux/log2.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/rtc.h> #define RV8803_I2C_TRY_COUNT 4 #define RV8803_SEC 0x00 #define RV8803_MIN 0x01 #define RV8803_HOUR 0x02 #define RV8803_WEEK 0x03 #define RV8803_DAY 0x04 #define RV8803_MONTH 0x05 #define RV8803_YEAR 0x06 #define RV8803_RAM 0x07 #define RV8803_ALARM_MIN 0x08 #define RV8803_ALARM_HOUR 0x09 #define RV8803_ALARM_WEEK_OR_DAY 0x0A #define RV8803_EXT 0x0D #define RV8803_FLAG 0x0E #define RV8803_CTRL 0x0F #define RV8803_OSC_OFFSET 0x2C #define RV8803_EXT_WADA BIT(6) #define RV8803_FLAG_V1F BIT(0) #define RV8803_FLAG_V2F BIT(1) #define RV8803_FLAG_AF BIT(3) #define RV8803_FLAG_TF BIT(4) #define RV8803_FLAG_UF BIT(5) #define RV8803_CTRL_RESET BIT(0) #define RV8803_CTRL_EIE BIT(2) #define RV8803_CTRL_AIE BIT(3) #define RV8803_CTRL_TIE BIT(4) #define RV8803_CTRL_UIE BIT(5) #define RX8803_CTRL_CSEL GENMASK(7, 6) #define RX8900_BACKUP_CTRL 0x18 #define RX8900_FLAG_SWOFF BIT(2) #define RX8900_FLAG_VDETOFF BIT(3) enum rv8803_type { rv_8803, rx_8803, rx_8804, rx_8900 }; struct rv8803_data { struct i2c_client *client; struct rtc_device *rtc; struct mutex flags_lock; u8 ctrl; u8 backup; enum rv8803_type type; }; static int rv8803_read_reg(const struct i2c_client *client, u8 reg) { int try = RV8803_I2C_TRY_COUNT; s32 ret; /* * There is a 61µs window during which the RTC does not acknowledge I2C * transfers. In that case, ensure that there are multiple attempts. */ do ret = i2c_smbus_read_byte_data(client, reg); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret < 0) dev_err(&client->dev, "Unable to read register 0x%02x\n", reg); return ret; } static int rv8803_read_regs(const struct i2c_client *client, u8 reg, u8 count, u8 *values) { int try = RV8803_I2C_TRY_COUNT; s32 ret; do ret = i2c_smbus_read_i2c_block_data(client, reg, count, values); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret != count) { dev_err(&client->dev, "Unable to read registers 0x%02x..0x%02x\n", reg, reg + count - 1); return ret < 0 ? ret : -EIO; } return 0; } static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value) { int try = RV8803_I2C_TRY_COUNT; s32 ret; do ret = i2c_smbus_write_byte_data(client, reg, value); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret) dev_err(&client->dev, "Unable to write register 0x%02x\n", reg); return ret; } static int rv8803_write_regs(const struct i2c_client *client, u8 reg, u8 count, const u8 *values) { int try = RV8803_I2C_TRY_COUNT; s32 ret; do ret = i2c_smbus_write_i2c_block_data(client, reg, count, values); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret) dev_err(&client->dev, "Unable to write registers 0x%02x..0x%02x\n", reg, reg + count - 1); return ret; } static int rv8803_regs_init(struct rv8803_data *rv8803) { int ret; ret = rv8803_write_reg(rv8803->client, RV8803_OSC_OFFSET, 0x00); if (ret) return ret; ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, FIELD_PREP(RX8803_CTRL_CSEL, 1)); /* 2s */ if (ret) return ret; ret = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, (u8[]){ 0, 0, 0 }); if (ret) return ret; return rv8803_write_reg(rv8803->client, RV8803_RAM, 0x00); } static int rv8803_regs_configure(struct rv8803_data *rv8803); static int rv8803_regs_reset(struct rv8803_data *rv8803) { /* * The RV-8803 resets all registers to POR defaults after voltage-loss, * the Epson RTCs don't, so we manually reset the remainder here. */ if (rv8803->type == rx_8803 || rv8803->type == rx_8900) { int ret = rv8803_regs_init(rv8803); if (ret) return ret; } return rv8803_regs_configure(rv8803); } static irqreturn_t rv8803_handle_irq(int irq, void *dev_id) { struct i2c_client *client = dev_id; struct rv8803_data *rv8803 = i2c_get_clientdata(client); unsigned long events = 0; int flags; mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags <= 0) { mutex_unlock(&rv8803->flags_lock); return IRQ_NONE; } if (flags & RV8803_FLAG_V1F) dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); if (flags & RV8803_FLAG_V2F) dev_warn(&client->dev, "Voltage low, data loss detected.\n"); if (flags & RV8803_FLAG_TF) { flags &= ~RV8803_FLAG_TF; rv8803->ctrl &= ~RV8803_CTRL_TIE; events |= RTC_PF; } if (flags & RV8803_FLAG_AF) { flags &= ~RV8803_FLAG_AF; rv8803->ctrl &= ~RV8803_CTRL_AIE; events |= RTC_AF; } if (flags & RV8803_FLAG_UF) { flags &= ~RV8803_FLAG_UF; rv8803->ctrl &= ~RV8803_CTRL_UIE; events |= RTC_UF; } if (events) { rtc_update_irq(rv8803->rtc, 1, events); rv8803_write_reg(client, RV8803_FLAG, flags); rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl); } mutex_unlock(&rv8803->flags_lock); return IRQ_HANDLED; } static int rv8803_get_time(struct device *dev, struct rtc_time *tm) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); u8 date1[7]; u8 date2[7]; u8 *date = date1; int ret, flags; flags = rv8803_read_reg(rv8803->client, RV8803_FLAG); if (flags < 0) return flags; if (flags & RV8803_FLAG_V2F) { dev_warn(dev, "Voltage low, data is invalid.\n"); return -EINVAL; } ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date); if (ret) return ret; if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) { ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2); if (ret) return ret; if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59)) date = date2; } tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f); tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f); tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f); tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f); tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f); tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1; tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100; return 0; } static int rv8803_set_time(struct device *dev, struct rtc_time *tm) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); u8 date[7]; int ctrl, flags, ret; ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL); if (ctrl < 0) return ctrl; /* Stop the clock */ ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, ctrl | RV8803_CTRL_RESET); if (ret) return ret; date[RV8803_SEC] = bin2bcd(tm->tm_sec); date[RV8803_MIN] = bin2bcd(tm->tm_min); date[RV8803_HOUR] = bin2bcd(tm->tm_hour); date[RV8803_WEEK] = 1 << (tm->tm_wday); date[RV8803_DAY] = bin2bcd(tm->tm_mday); date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1); date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100); ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date); if (ret) return ret; /* Restart the clock */ ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, ctrl & ~RV8803_CTRL_RESET); if (ret) return ret; mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(rv8803->client, RV8803_FLAG); if (flags < 0) { mutex_unlock(&rv8803->flags_lock); return flags; } if (flags & RV8803_FLAG_V2F) { ret = rv8803_regs_reset(rv8803); if (ret) { mutex_unlock(&rv8803->flags_lock); return ret; } } ret = rv8803_write_reg(rv8803->client, RV8803_FLAG, flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F)); mutex_unlock(&rv8803->flags_lock); return ret; } static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); struct i2c_client *client = rv8803->client; u8 alarmvals[3]; int flags, ret; ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals); if (ret) return ret; flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) return flags; alrm->time.tm_sec = 0; alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f); alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE); alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled; return 0; } static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); u8 alarmvals[3]; u8 ctrl[2]; int ret, err; /* The alarm has no seconds, round up to nearest minute */ if (alrm->time.tm_sec) { time64_t alarm_time = rtc_tm_to_time64(&alrm->time); alarm_time += 60 - alrm->time.tm_sec; rtc_time64_to_tm(alarm_time, &alrm->time); } mutex_lock(&rv8803->flags_lock); ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl); if (ret) { mutex_unlock(&rv8803->flags_lock); return ret; } alarmvals[0] = bin2bcd(alrm->time.tm_min); alarmvals[1] = bin2bcd(alrm->time.tm_hour); alarmvals[2] = bin2bcd(alrm->time.tm_mday); if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) { rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE); err = rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl); if (err) { mutex_unlock(&rv8803->flags_lock); return err; } } ctrl[0] &= ~RV8803_FLAG_AF; err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]); mutex_unlock(&rv8803->flags_lock); if (err) return err; err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals); if (err) return err; if (alrm->enabled) { if (rv8803->rtc->uie_rtctimer.enabled) rv8803->ctrl |= RV8803_CTRL_UIE; if (rv8803->rtc->aie_timer.enabled) rv8803->ctrl |= RV8803_CTRL_AIE; err = rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl); if (err) return err; } return 0; } static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); int ctrl, flags, err; ctrl = rv8803->ctrl; if (enabled) { if (rv8803->rtc->uie_rtctimer.enabled) ctrl |= RV8803_CTRL_UIE; if (rv8803->rtc->aie_timer.enabled) ctrl |= RV8803_CTRL_AIE; } else { if (!rv8803->rtc->uie_rtctimer.enabled) ctrl &= ~RV8803_CTRL_UIE; if (!rv8803->rtc->aie_timer.enabled) ctrl &= ~RV8803_CTRL_AIE; } mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) { mutex_unlock(&rv8803->flags_lock); return flags; } flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF); err = rv8803_write_reg(client, RV8803_FLAG, flags); mutex_unlock(&rv8803->flags_lock); if (err) return err; if (ctrl != rv8803->ctrl) { rv8803->ctrl = ctrl; err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl); if (err) return err; } return 0; } static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); unsigned int vl = 0; int flags, ret = 0; switch (cmd) { case RTC_VL_READ: flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) return flags; if (flags & RV8803_FLAG_V1F) { dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); vl = RTC_VL_ACCURACY_LOW; } if (flags & RV8803_FLAG_V2F) vl |= RTC_VL_DATA_INVALID; return put_user(vl, (unsigned int __user *)arg); case RTC_VL_CLR: mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) { mutex_unlock(&rv8803->flags_lock); return flags; } flags &= ~RV8803_FLAG_V1F; ret = rv8803_write_reg(client, RV8803_FLAG, flags); mutex_unlock(&rv8803->flags_lock); if (ret) return ret; return 0; default: return -ENOIOCTLCMD; } } static int rv8803_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes) { return rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val); } static int rv8803_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes) { int ret; ret = rv8803_read_reg(priv, RV8803_RAM); if (ret < 0) return ret; *(u8 *)val = ret; return 0; } static const struct rtc_class_ops rv8803_rtc_ops = { .read_time = rv8803_get_time, .set_time = rv8803_set_time, .ioctl = rv8803_ioctl, .read_alarm = rv8803_get_alarm, .set_alarm = rv8803_set_alarm, .alarm_irq_enable = rv8803_alarm_irq_enable, }; static int rx8900_trickle_charger_init(struct rv8803_data *rv8803) { struct i2c_client *client = rv8803->client; struct device_node *node = client->dev.of_node; int err; u8 flags; if (!node) return 0; if (rv8803->type != rx_8900) return 0; err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL); if (err < 0) return err; flags = (u8)err; flags &= ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF); flags |= rv8803->backup; return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL, flags); } /* configure registers with values different than the Power-On reset defaults */ static int rv8803_regs_configure(struct rv8803_data *rv8803) { int err; err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA); if (err) return err; err = rx8900_trickle_charger_init(rv8803); if (err) { dev_err(&rv8803->client->dev, "failed to init charger\n"); return err; } return 0; } static int rv8803_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = client->adapter; struct rv8803_data *rv8803; int err, flags; struct nvmem_config nvmem_cfg = { .name = "rv8803_nvram", .word_size = 1, .stride = 1, .size = 1, .reg_read = rv8803_nvram_read, .reg_write = rv8803_nvram_write, .priv = client, }; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) { dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n"); return -EIO; } rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data), GFP_KERNEL); if (!rv8803) return -ENOMEM; mutex_init(&rv8803->flags_lock); rv8803->client = client; if (client->dev.of_node) rv8803->type = (enum rv8803_type) of_device_get_match_data(&client->dev); else rv8803->type = id->driver_data; i2c_set_clientdata(client, rv8803); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) return flags; if (flags & RV8803_FLAG_V1F) dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); if (flags & RV8803_FLAG_V2F) dev_warn(&client->dev, "Voltage low, data loss detected.\n"); if (flags & RV8803_FLAG_AF) dev_warn(&client->dev, "An alarm maybe have been missed.\n"); rv8803->rtc = devm_rtc_allocate_device(&client->dev); if (IS_ERR(rv8803->rtc)) return PTR_ERR(rv8803->rtc); if (client->irq > 0) { err = devm_request_threaded_irq(&client->dev, client->irq, NULL, rv8803_handle_irq, IRQF_TRIGGER_LOW | IRQF_ONESHOT, "rv8803", client); if (err) { dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); client->irq = 0; } } if (!client->irq) clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features); if (of_property_read_bool(client->dev.of_node, "epson,vdet-disable")) rv8803->backup |= RX8900_FLAG_VDETOFF; if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable")) rv8803->backup |= RX8900_FLAG_SWOFF; err = rv8803_regs_configure(rv8803); if (err) return err; rv8803->rtc->ops = &rv8803_rtc_ops; rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099; err = devm_rtc_register_device(rv8803->rtc); if (err) return err; devm_rtc_nvmem_register(rv8803->rtc, &nvmem_cfg); rv8803->rtc->max_user_freq = 1; return 0; } static const struct i2c_device_id rv8803_id[] = { { "rv8803", rv_8803 }, { "rv8804", rx_8804 }, { "rx8803", rx_8803 }, { "rx8900", rx_8900 }, { } }; MODULE_DEVICE_TABLE(i2c, rv8803_id); static const __maybe_unused struct of_device_id rv8803_of_match[] = { { .compatible = "microcrystal,rv8803", .data = (void *)rv_8803 }, { .compatible = "epson,rx8803", .data = (void *)rx_8803 }, { .compatible = "epson,rx8804", .data = (void *)rx_8804 }, { .compatible = "epson,rx8900", .data = (void *)rx_8900 }, { } }; MODULE_DEVICE_TABLE(of, rv8803_of_match); static struct i2c_driver rv8803_driver = { .driver = { .name = "rtc-rv8803", .of_match_table = of_match_ptr(rv8803_of_match), }, .probe = rv8803_probe, .id_table = rv8803_id, }; module_i2c_driver(rv8803_driver); MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>"); MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver"); MODULE_LICENSE("GPL v2"); |