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v6.13.7
   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/bitfield.h>
  14#include <linux/bitops.h>
  15#include <linux/i2c.h>
  16#include <linux/interrupt.h>
  17#include <linux/kernel.h>
  18#include <linux/log2.h>
  19#include <linux/module.h>
  20#include <linux/of.h>
  21#include <linux/regmap.h>
  22#include <linux/rtc.h>
  23
  24#define RV3028_SEC			0x00
  25#define RV3028_MIN			0x01
  26#define RV3028_HOUR			0x02
  27#define RV3028_WDAY			0x03
  28#define RV3028_DAY			0x04
  29#define RV3028_MONTH			0x05
  30#define RV3028_YEAR			0x06
  31#define RV3028_ALARM_MIN		0x07
  32#define RV3028_ALARM_HOUR		0x08
  33#define RV3028_ALARM_DAY		0x09
  34#define RV3028_STATUS			0x0E
  35#define RV3028_CTRL1			0x0F
  36#define RV3028_CTRL2			0x10
  37#define RV3028_EVT_CTRL			0x13
  38#define RV3028_TS_COUNT			0x14
  39#define RV3028_TS_SEC			0x15
  40#define RV3028_RAM1			0x1F
  41#define RV3028_EEPROM_ADDR		0x25
  42#define RV3028_EEPROM_DATA		0x26
  43#define RV3028_EEPROM_CMD		0x27
  44#define RV3028_CLKOUT			0x35
  45#define RV3028_OFFSET			0x36
  46#define RV3028_BACKUP			0x37
  47
  48#define RV3028_STATUS_PORF		BIT(0)
  49#define RV3028_STATUS_EVF		BIT(1)
  50#define RV3028_STATUS_AF		BIT(2)
  51#define RV3028_STATUS_TF		BIT(3)
  52#define RV3028_STATUS_UF		BIT(4)
  53#define RV3028_STATUS_BSF		BIT(5)
  54#define RV3028_STATUS_CLKF		BIT(6)
  55#define RV3028_STATUS_EEBUSY		BIT(7)
  56
  57#define RV3028_CLKOUT_FD_MASK		GENMASK(2, 0)
  58#define RV3028_CLKOUT_PORIE		BIT(3)
  59#define RV3028_CLKOUT_CLKSY		BIT(6)
  60#define RV3028_CLKOUT_CLKOE		BIT(7)
  61
  62#define RV3028_CTRL1_EERD		BIT(3)
  63#define RV3028_CTRL1_WADA		BIT(5)
  64
  65#define RV3028_CTRL2_RESET		BIT(0)
  66#define RV3028_CTRL2_12_24		BIT(1)
  67#define RV3028_CTRL2_EIE		BIT(2)
  68#define RV3028_CTRL2_AIE		BIT(3)
  69#define RV3028_CTRL2_TIE		BIT(4)
  70#define RV3028_CTRL2_UIE		BIT(5)
  71#define RV3028_CTRL2_TSE		BIT(7)
  72
  73#define RV3028_EVT_CTRL_TSR		BIT(2)
  74
  75#define RV3028_EEPROM_CMD_UPDATE	0x11
  76#define RV3028_EEPROM_CMD_WRITE		0x21
  77#define RV3028_EEPROM_CMD_READ		0x22
  78
  79#define RV3028_EEBUSY_POLL		10000
  80#define RV3028_EEBUSY_TIMEOUT		100000
  81
  82#define RV3028_BACKUP_TCE		BIT(5)
  83#define RV3028_BACKUP_TCR_MASK		GENMASK(1,0)
  84#define RV3028_BACKUP_BSM		GENMASK(3,2)
  85
  86#define RV3028_BACKUP_BSM_DSM		0x1
  87#define RV3028_BACKUP_BSM_LSM		0x3
  88
  89#define OFFSET_STEP_PPT			953674
  90
  91enum rv3028_type {
  92	rv_3028,
  93};
  94
  95struct rv3028_data {
  96	struct regmap *regmap;
  97	struct rtc_device *rtc;
  98	enum rv3028_type type;
  99#ifdef CONFIG_COMMON_CLK
 100	struct clk_hw clkout_hw;
 101#endif
 102};
 103
 104static u16 rv3028_trickle_resistors[] = {3000, 5000, 9000, 15000};
 105
 106static ssize_t timestamp0_store(struct device *dev,
 107				struct device_attribute *attr,
 108				const char *buf, size_t count)
 109{
 110	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
 111
 112	regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR,
 113			   RV3028_EVT_CTRL_TSR);
 114
 115	return count;
 116};
 117
 118static ssize_t timestamp0_show(struct device *dev,
 119			       struct device_attribute *attr, char *buf)
 120{
 121	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
 122	struct rtc_time tm;
 123	unsigned int count;
 124	u8 date[6];
 125	int ret;
 126
 127	ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
 128	if (ret)
 129		return ret;
 130
 131	if (!count)
 132		return 0;
 133
 134	ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date,
 135			       sizeof(date));
 136	if (ret)
 137		return ret;
 138
 139	tm.tm_sec = bcd2bin(date[0]);
 140	tm.tm_min = bcd2bin(date[1]);
 141	tm.tm_hour = bcd2bin(date[2]);
 142	tm.tm_mday = bcd2bin(date[3]);
 143	tm.tm_mon = bcd2bin(date[4]) - 1;
 144	tm.tm_year = bcd2bin(date[5]) + 100;
 145
 146	ret = rtc_valid_tm(&tm);
 147	if (ret)
 148		return ret;
 149
 150	return sprintf(buf, "%llu\n",
 151		       (unsigned long long)rtc_tm_to_time64(&tm));
 152};
 153
 154static DEVICE_ATTR_RW(timestamp0);
 155
 156static ssize_t timestamp0_count_show(struct device *dev,
 157				     struct device_attribute *attr, char *buf)
 158{
 159	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
 160	unsigned int count;
 161	int ret;
 162
 163	ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
 164	if (ret)
 165		return ret;
 166
 167	return sprintf(buf, "%u\n", count);
 168};
 169
 170static DEVICE_ATTR_RO(timestamp0_count);
 171
 172static struct attribute *rv3028_attrs[] = {
 173	&dev_attr_timestamp0.attr,
 174	&dev_attr_timestamp0_count.attr,
 175	NULL
 176};
 177
 178static const struct attribute_group rv3028_attr_group = {
 179	.attrs	= rv3028_attrs,
 180};
 181
 182static int rv3028_exit_eerd(struct rv3028_data *rv3028, u32 eerd)
 183{
 184	if (eerd)
 185		return 0;
 186
 187	return regmap_update_bits(rv3028->regmap, RV3028_CTRL1, RV3028_CTRL1_EERD, 0);
 188}
 189
 190static int rv3028_enter_eerd(struct rv3028_data *rv3028, u32 *eerd)
 191{
 192	u32 ctrl1, status;
 193	int ret;
 194
 195	ret = regmap_read(rv3028->regmap, RV3028_CTRL1, &ctrl1);
 196	if (ret)
 197		return ret;
 198
 199	*eerd = ctrl1 & RV3028_CTRL1_EERD;
 200	if (*eerd)
 201		return 0;
 202
 203	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
 204				 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
 205	if (ret)
 206		return ret;
 207
 208	ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 209				       !(status & RV3028_STATUS_EEBUSY),
 210				       RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
 211	if (ret) {
 212		rv3028_exit_eerd(rv3028, *eerd);
 213
 214		return ret;
 215	}
 216
 217	return 0;
 218}
 219
 220static int rv3028_update_eeprom(struct rv3028_data *rv3028, u32 eerd)
 221{
 222	u32 status;
 223	int ret;
 224
 225	ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
 226	if (ret)
 227		goto exit_eerd;
 228
 229	ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, RV3028_EEPROM_CMD_UPDATE);
 230	if (ret)
 231		goto exit_eerd;
 232
 233	usleep_range(63000, RV3028_EEBUSY_TIMEOUT);
 234
 235	ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 236				       !(status & RV3028_STATUS_EEBUSY),
 237				       RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
 238
 239exit_eerd:
 240	rv3028_exit_eerd(rv3028, eerd);
 241
 242	return ret;
 243}
 244
 245static int rv3028_update_cfg(struct rv3028_data *rv3028, unsigned int reg,
 246			     unsigned int mask, unsigned int val)
 247{
 248	u32 eerd;
 249	int ret;
 250
 251	ret = rv3028_enter_eerd(rv3028, &eerd);
 252	if (ret)
 253		return ret;
 254
 255	ret = regmap_update_bits(rv3028->regmap, reg, mask, val);
 256	if (ret) {
 257		rv3028_exit_eerd(rv3028, eerd);
 258		return ret;
 259	}
 260
 261	return rv3028_update_eeprom(rv3028, eerd);
 262}
 263
 264static irqreturn_t rv3028_handle_irq(int irq, void *dev_id)
 265{
 266	struct rv3028_data *rv3028 = dev_id;
 267	unsigned long events = 0;
 268	u32 status = 0, ctrl = 0;
 269
 270	if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 ||
 271	   status == 0) {
 272		return IRQ_NONE;
 273	}
 274
 275	status &= ~RV3028_STATUS_PORF;
 276
 277	if (status & RV3028_STATUS_TF) {
 278		status |= RV3028_STATUS_TF;
 279		ctrl |= RV3028_CTRL2_TIE;
 280		events |= RTC_PF;
 281	}
 282
 283	if (status & RV3028_STATUS_AF) {
 284		status |= RV3028_STATUS_AF;
 285		ctrl |= RV3028_CTRL2_AIE;
 286		events |= RTC_AF;
 287	}
 288
 289	if (status & RV3028_STATUS_UF) {
 290		status |= RV3028_STATUS_UF;
 291		ctrl |= RV3028_CTRL2_UIE;
 292		events |= RTC_UF;
 293	}
 294
 295	if (events) {
 296		rtc_update_irq(rv3028->rtc, 1, events);
 297		regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
 298		regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
 299	}
 300
 301	if (status & RV3028_STATUS_EVF) {
 302		sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
 303			     dev_attr_timestamp0.attr.name);
 304		dev_warn(&rv3028->rtc->dev, "event detected");
 305	}
 306
 307	return IRQ_HANDLED;
 308}
 309
 310static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
 311{
 312	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 313	u8 date[7];
 314	int ret, status;
 315
 316	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 317	if (ret < 0)
 318		return ret;
 319
 320	if (status & RV3028_STATUS_PORF)
 321		return -EINVAL;
 322
 323	ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
 324	if (ret)
 325		return ret;
 326
 327	tm->tm_sec  = bcd2bin(date[RV3028_SEC] & 0x7f);
 328	tm->tm_min  = bcd2bin(date[RV3028_MIN] & 0x7f);
 329	tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
 330	tm->tm_wday = date[RV3028_WDAY] & 0x7f;
 331	tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
 332	tm->tm_mon  = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
 333	tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
 334
 335	return 0;
 336}
 337
 338static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
 339{
 340	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 341	u8 date[7];
 342	int ret;
 343
 344	date[RV3028_SEC]   = bin2bcd(tm->tm_sec);
 345	date[RV3028_MIN]   = bin2bcd(tm->tm_min);
 346	date[RV3028_HOUR]  = bin2bcd(tm->tm_hour);
 347	date[RV3028_WDAY]  = tm->tm_wday;
 348	date[RV3028_DAY]   = bin2bcd(tm->tm_mday);
 349	date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
 350	date[RV3028_YEAR]  = bin2bcd(tm->tm_year - 100);
 351
 352	/*
 353	 * Writing to the Seconds register has the same effect as setting RESET
 354	 * bit to 1
 355	 */
 356	ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
 357				sizeof(date));
 358	if (ret)
 359		return ret;
 360
 361	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 362				 RV3028_STATUS_PORF, 0);
 363
 364	return ret;
 365}
 366
 367static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 368{
 369	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 370	u8 alarmvals[3];
 371	int status, ctrl, ret;
 372
 373	ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
 374			       sizeof(alarmvals));
 375	if (ret)
 376		return ret;
 377
 378	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 379	if (ret < 0)
 380		return ret;
 381
 382	ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
 383	if (ret < 0)
 384		return ret;
 385
 386	alrm->time.tm_sec  = 0;
 387	alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
 388	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
 389	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
 390
 391	alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
 392	alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
 393
 394	return 0;
 395}
 396
 397static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 398{
 399	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 400	u8 alarmvals[3];
 401	u8 ctrl = 0;
 402	int ret;
 403
 404	/* The alarm has no seconds, round up to nearest minute */
 405	if (alrm->time.tm_sec) {
 406		time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
 407
 408		alarm_time += 60 - alrm->time.tm_sec;
 409		rtc_time64_to_tm(alarm_time, &alrm->time);
 410	}
 411
 412	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 413				 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
 414	if (ret)
 415		return ret;
 416
 417	alarmvals[0] = bin2bcd(alrm->time.tm_min);
 418	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
 419	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
 420
 421	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 422				 RV3028_STATUS_AF, 0);
 423	if (ret)
 424		return ret;
 425
 426	ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
 427				sizeof(alarmvals));
 428	if (ret)
 429		return ret;
 430
 431	if (alrm->enabled) {
 432		if (rv3028->rtc->uie_rtctimer.enabled)
 433			ctrl |= RV3028_CTRL2_UIE;
 434		if (rv3028->rtc->aie_timer.enabled)
 435			ctrl |= RV3028_CTRL2_AIE;
 436	}
 437
 438	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 439				 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
 440
 441	return ret;
 442}
 443
 444static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
 445{
 446	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 447	int ctrl = 0, ret;
 448
 449	if (enabled) {
 450		if (rv3028->rtc->uie_rtctimer.enabled)
 451			ctrl |= RV3028_CTRL2_UIE;
 452		if (rv3028->rtc->aie_timer.enabled)
 453			ctrl |= RV3028_CTRL2_AIE;
 454	}
 455
 456	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 457				 RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
 458	if (ret)
 459		return ret;
 460
 461	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 462				 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
 463	if (ret)
 464		return ret;
 465
 466	return 0;
 467}
 468
 469static int rv3028_read_offset(struct device *dev, long *offset)
 470{
 471	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 472	int ret, value, steps;
 473
 474	ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
 475	if (ret < 0)
 476		return ret;
 477
 478	steps = sign_extend32(value << 1, 8);
 479
 480	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
 481	if (ret < 0)
 482		return ret;
 483
 484	steps += value >> 7;
 485
 486	*offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
 487
 488	return 0;
 489}
 490
 491static int rv3028_set_offset(struct device *dev, long offset)
 492{
 493	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 494	u32 eerd;
 495	int ret;
 496
 497	offset = clamp(offset, -244141L, 243187L) * 1000;
 498	offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
 499
 500	ret = rv3028_enter_eerd(rv3028, &eerd);
 501	if (ret)
 502		return ret;
 503
 504	ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
 505	if (ret < 0)
 506		goto exit_eerd;
 507
 508	ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
 509				 offset << 7);
 510	if (ret < 0)
 511		goto exit_eerd;
 512
 513	return rv3028_update_eeprom(rv3028, eerd);
 514
 515exit_eerd:
 516	rv3028_exit_eerd(rv3028, eerd);
 517
 518	return ret;
 519
 520}
 521
 522static int rv3028_param_get(struct device *dev, struct rtc_param *param)
 523{
 524	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 525	int ret;
 526	u32 value;
 527
 528	switch(param->param) {
 529	case RTC_PARAM_BACKUP_SWITCH_MODE:
 530		ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
 531		if (ret < 0)
 532			return ret;
 533
 534		value = FIELD_GET(RV3028_BACKUP_BSM, value);
 535
 536		switch(value) {
 537		case RV3028_BACKUP_BSM_DSM:
 538			param->uvalue = RTC_BSM_DIRECT;
 539			break;
 540		case RV3028_BACKUP_BSM_LSM:
 541			param->uvalue = RTC_BSM_LEVEL;
 542			break;
 543		default:
 544			param->uvalue = RTC_BSM_DISABLED;
 545		}
 546		break;
 547
 548	default:
 549		return -EINVAL;
 550	}
 551
 552	return 0;
 553}
 554
 555static int rv3028_param_set(struct device *dev, struct rtc_param *param)
 556{
 557	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 558	u8 mode;
 559
 560	switch(param->param) {
 561	case RTC_PARAM_BACKUP_SWITCH_MODE:
 562		switch (param->uvalue) {
 563		case RTC_BSM_DISABLED:
 564			mode = 0;
 565			break;
 566		case RTC_BSM_DIRECT:
 567			mode = RV3028_BACKUP_BSM_DSM;
 568			break;
 569		case RTC_BSM_LEVEL:
 570			mode = RV3028_BACKUP_BSM_LSM;
 571			break;
 572		default:
 573			return -EINVAL;
 574		}
 575
 576		return rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_BSM,
 577					 FIELD_PREP(RV3028_BACKUP_BSM, mode));
 578
 579	default:
 580		return -EINVAL;
 581	}
 582
 583	return 0;
 584}
 585
 586static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 587{
 588	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 589	int status, ret = 0;
 590
 591	switch (cmd) {
 592	case RTC_VL_READ:
 593		ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 594		if (ret < 0)
 595			return ret;
 596
 597		status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0;
 598		return put_user(status, (unsigned int __user *)arg);
 599
 600	default:
 601		return -ENOIOCTLCMD;
 602	}
 603}
 604
 605static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
 606			      size_t bytes)
 607{
 608	return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
 609}
 610
 611static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
 612			     size_t bytes)
 613{
 614	return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
 615}
 616
 617static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
 618			       size_t bytes)
 619{
 620	struct rv3028_data *rv3028 = priv;
 621	u32 status, eerd;
 622	int i, ret;
 623	u8 *buf = val;
 624
 625	ret = rv3028_enter_eerd(rv3028, &eerd);
 626	if (ret)
 627		return ret;
 628
 629	for (i = 0; i < bytes; i++) {
 630		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
 631		if (ret)
 632			goto restore_eerd;
 633
 634		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_DATA, buf[i]);
 635		if (ret)
 636			goto restore_eerd;
 637
 638		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
 639		if (ret)
 640			goto restore_eerd;
 641
 642		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
 643				   RV3028_EEPROM_CMD_WRITE);
 644		if (ret)
 645			goto restore_eerd;
 646
 647		usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
 648
 649		ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 650					       !(status & RV3028_STATUS_EEBUSY),
 651					       RV3028_EEBUSY_POLL,
 652					       RV3028_EEBUSY_TIMEOUT);
 653		if (ret)
 654			goto restore_eerd;
 655	}
 656
 657restore_eerd:
 658	rv3028_exit_eerd(rv3028, eerd);
 659
 660	return ret;
 661}
 662
 663static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
 664			      size_t bytes)
 665{
 666	struct rv3028_data *rv3028 = priv;
 667	u32 status, eerd, data;
 668	int i, ret;
 669	u8 *buf = val;
 670
 671	ret = rv3028_enter_eerd(rv3028, &eerd);
 672	if (ret)
 673		return ret;
 674
 675	for (i = 0; i < bytes; i++) {
 676		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
 677		if (ret)
 678			goto restore_eerd;
 679
 680		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
 681		if (ret)
 682			goto restore_eerd;
 683
 684		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
 685				   RV3028_EEPROM_CMD_READ);
 686		if (ret)
 687			goto restore_eerd;
 688
 689		ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 690					       !(status & RV3028_STATUS_EEBUSY),
 691					       RV3028_EEBUSY_POLL,
 692					       RV3028_EEBUSY_TIMEOUT);
 693		if (ret)
 694			goto restore_eerd;
 695
 696		ret = regmap_read(rv3028->regmap, RV3028_EEPROM_DATA, &data);
 697		if (ret)
 698			goto restore_eerd;
 699		buf[i] = data;
 700	}
 701
 702restore_eerd:
 703	rv3028_exit_eerd(rv3028, eerd);
 704
 705	return ret;
 706}
 707
 708#ifdef CONFIG_COMMON_CLK
 709#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw)
 710
 711static int clkout_rates[] = {
 712	32768,
 713	8192,
 714	1024,
 715	64,
 716	32,
 717	1,
 718};
 719
 720static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw,
 721					       unsigned long parent_rate)
 722{
 723	int clkout, ret;
 724	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 725
 726	ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
 727	if (ret < 0)
 728		return 0;
 729
 730	clkout &= RV3028_CLKOUT_FD_MASK;
 731	return clkout_rates[clkout];
 732}
 733
 734static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 735				     unsigned long *prate)
 736{
 737	int i;
 738
 739	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 740		if (clkout_rates[i] <= rate)
 741			return clkout_rates[i];
 742
 743	return 0;
 744}
 745
 746static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 747				  unsigned long parent_rate)
 748{
 749	int i, ret;
 750	u32 enabled;
 751	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 752
 753	ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &enabled);
 754	if (ret < 0)
 755		return ret;
 756
 757	ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
 758	if (ret < 0)
 759		return ret;
 760
 761	enabled &= RV3028_CLKOUT_CLKOE;
 762
 763	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 764		if (clkout_rates[i] == rate)
 765			return rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff,
 766						 RV3028_CLKOUT_CLKSY | enabled | i);
 767
 768	return -EINVAL;
 769}
 770
 771static int rv3028_clkout_prepare(struct clk_hw *hw)
 772{
 773	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 774
 775	return regmap_write(rv3028->regmap, RV3028_CLKOUT,
 776			    RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
 777}
 778
 779static void rv3028_clkout_unprepare(struct clk_hw *hw)
 780{
 781	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 782
 783	regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
 784	regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 785			   RV3028_STATUS_CLKF, 0);
 786}
 787
 788static int rv3028_clkout_is_prepared(struct clk_hw *hw)
 789{
 790	int clkout, ret;
 791	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 792
 793	ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
 794	if (ret < 0)
 795		return ret;
 796
 797	return !!(clkout & RV3028_CLKOUT_CLKOE);
 798}
 799
 800static const struct clk_ops rv3028_clkout_ops = {
 801	.prepare = rv3028_clkout_prepare,
 802	.unprepare = rv3028_clkout_unprepare,
 803	.is_prepared = rv3028_clkout_is_prepared,
 804	.recalc_rate = rv3028_clkout_recalc_rate,
 805	.round_rate = rv3028_clkout_round_rate,
 806	.set_rate = rv3028_clkout_set_rate,
 807};
 808
 809static int rv3028_clkout_register_clk(struct rv3028_data *rv3028,
 810				      struct i2c_client *client)
 811{
 812	int ret;
 813	struct clk *clk;
 814	struct clk_init_data init;
 815	struct device_node *node = client->dev.of_node;
 816
 817	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 818				 RV3028_STATUS_CLKF, 0);
 819	if (ret < 0)
 820		return ret;
 821
 822	init.name = "rv3028-clkout";
 823	init.ops = &rv3028_clkout_ops;
 824	init.flags = 0;
 825	init.parent_names = NULL;
 826	init.num_parents = 0;
 827	rv3028->clkout_hw.init = &init;
 828
 829	/* optional override of the clockname */
 830	of_property_read_string(node, "clock-output-names", &init.name);
 831
 832	/* register the clock */
 833	clk = devm_clk_register(&client->dev, &rv3028->clkout_hw);
 834	if (!IS_ERR(clk))
 835		of_clk_add_provider(node, of_clk_src_simple_get, clk);
 836
 837	return 0;
 838}
 839#endif
 840
 841static const struct rtc_class_ops rv3028_rtc_ops = {
 842	.read_time = rv3028_get_time,
 843	.set_time = rv3028_set_time,
 844	.read_alarm = rv3028_get_alarm,
 845	.set_alarm = rv3028_set_alarm,
 846	.alarm_irq_enable = rv3028_alarm_irq_enable,
 847	.read_offset = rv3028_read_offset,
 848	.set_offset = rv3028_set_offset,
 849	.ioctl = rv3028_ioctl,
 850	.param_get = rv3028_param_get,
 851	.param_set = rv3028_param_set,
 852};
 853
 854static const struct regmap_config regmap_config = {
 855        .reg_bits = 8,
 856        .val_bits = 8,
 857        .max_register = 0x37,
 858};
 859
 860static u8 rv3028_set_trickle_charger(struct rv3028_data *rv3028,
 861				     struct i2c_client *client)
 862{
 863	int ret, val_old, val;
 864	u32 ohms, chargeable;
 865
 866	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old);
 867	if (ret < 0)
 868		return ret;
 869
 870	/* mask out only trickle charger bits */
 871	val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK);
 872	val = val_old;
 873
 874	/* setup trickle charger */
 875	if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
 876				      &ohms)) {
 877		int i;
 878
 879		for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
 880			if (ohms == rv3028_trickle_resistors[i])
 881				break;
 882
 883		if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
 884			/* enable trickle charger and its resistor */
 885			val = RV3028_BACKUP_TCE | i;
 886		} else {
 887			dev_warn(&client->dev, "invalid trickle resistor value\n");
 888		}
 889	}
 890
 891	if (!device_property_read_u32(&client->dev, "aux-voltage-chargeable",
 892				      &chargeable)) {
 893		switch (chargeable) {
 894		case 0:
 895			val &= ~RV3028_BACKUP_TCE;
 896			break;
 897		case 1:
 898			val |= RV3028_BACKUP_TCE;
 899			break;
 900		default:
 901			dev_warn(&client->dev,
 902				 "unsupported aux-voltage-chargeable value\n");
 903			break;
 904		}
 905	}
 906
 907	/* only update EEPROM if changes are necessary */
 908	if (val_old != val) {
 909		ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
 910						RV3028_BACKUP_TCR_MASK, val);
 911		if (ret)
 912			return ret;
 913	}
 914
 915	return ret;
 916}
 917
 918static int rv3028_probe(struct i2c_client *client)
 919{
 920	struct rv3028_data *rv3028;
 921	int ret, status;
 922	struct nvmem_config nvmem_cfg = {
 923		.name = "rv3028_nvram",
 924		.word_size = 1,
 925		.stride = 1,
 926		.size = 2,
 927		.type = NVMEM_TYPE_BATTERY_BACKED,
 928		.reg_read = rv3028_nvram_read,
 929		.reg_write = rv3028_nvram_write,
 930	};
 931	struct nvmem_config eeprom_cfg = {
 932		.name = "rv3028_eeprom",
 933		.word_size = 1,
 934		.stride = 1,
 935		.size = 43,
 936		.type = NVMEM_TYPE_EEPROM,
 937		.reg_read = rv3028_eeprom_read,
 938		.reg_write = rv3028_eeprom_write,
 939	};
 940
 941	rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data),
 942			      GFP_KERNEL);
 943	if (!rv3028)
 944		return -ENOMEM;
 945
 946	rv3028->regmap = devm_regmap_init_i2c(client, &regmap_config);
 947	if (IS_ERR(rv3028->regmap))
 948		return PTR_ERR(rv3028->regmap);
 949
 950	i2c_set_clientdata(client, rv3028);
 951
 952	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 953	if (ret < 0)
 954		return ret;
 955
 956	if (status & RV3028_STATUS_AF)
 957		dev_warn(&client->dev, "An alarm may have been missed.\n");
 958
 959	rv3028->rtc = devm_rtc_allocate_device(&client->dev);
 960	if (IS_ERR(rv3028->rtc))
 961		return PTR_ERR(rv3028->rtc);
 962
 963	if (client->irq > 0) {
 964		unsigned long flags;
 965
 966		/*
 967		 * If flags = 0, devm_request_threaded_irq() will use IRQ flags
 968		 * obtained from device tree.
 969		 */
 970		if (dev_fwnode(&client->dev))
 971			flags = 0;
 972		else
 973			flags = IRQF_TRIGGER_LOW;
 974
 975		ret = devm_request_threaded_irq(&client->dev, client->irq,
 976						NULL, rv3028_handle_irq,
 977						flags | IRQF_ONESHOT,
 978						"rv3028", rv3028);
 979		if (ret) {
 980			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 981			client->irq = 0;
 982		}
 983	}
 984	if (!client->irq)
 985		clear_bit(RTC_FEATURE_ALARM, rv3028->rtc->features);
 986
 987	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
 988				 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
 989	if (ret)
 990		return ret;
 991
 992	/* setup timestamping */
 993	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 994				 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
 995				 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
 996	if (ret)
 997		return ret;
 998
 999	ret = rv3028_set_trickle_charger(rv3028, client);
1000	if (ret)
1001		return ret;
1002
1003	ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
1004	if (ret)
1005		return ret;
1006
1007	set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3028->rtc->features);
1008
1009	rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
1010	rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
1011	rv3028->rtc->ops = &rv3028_rtc_ops;
1012	ret = devm_rtc_register_device(rv3028->rtc);
1013	if (ret)
1014		return ret;
1015
1016	nvmem_cfg.priv = rv3028->regmap;
1017	devm_rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
1018	eeprom_cfg.priv = rv3028;
1019	devm_rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
1020
1021	rv3028->rtc->max_user_freq = 1;
1022
1023#ifdef CONFIG_COMMON_CLK
1024	rv3028_clkout_register_clk(rv3028, client);
1025#endif
1026	return 0;
1027}
1028
1029static const struct acpi_device_id rv3028_i2c_acpi_match[] = {
1030	{ "MCRY3028" },
1031	{ }
1032};
1033MODULE_DEVICE_TABLE(acpi, rv3028_i2c_acpi_match);
1034
1035static const __maybe_unused struct of_device_id rv3028_of_match[] = {
1036	{ .compatible = "microcrystal,rv3028", },
1037	{ }
1038};
1039MODULE_DEVICE_TABLE(of, rv3028_of_match);
1040
1041static const struct i2c_device_id rv3028_id_table[] = {
1042	{ .name = "rv3028", },
1043	{ }
1044};
1045MODULE_DEVICE_TABLE(i2c, rv3028_id_table);
1046
1047static struct i2c_driver rv3028_driver = {
1048	.driver = {
1049		.name = "rtc-rv3028",
1050		.acpi_match_table = rv3028_i2c_acpi_match,
1051		.of_match_table = of_match_ptr(rv3028_of_match),
1052	},
1053	.id_table	= rv3028_id_table,
1054	.probe		= rv3028_probe,
1055};
1056module_i2c_driver(rv3028_driver);
1057
1058MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1059MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
1060MODULE_LICENSE("GPL v2");
v6.8
   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/bitfield.h>
  14#include <linux/bitops.h>
  15#include <linux/i2c.h>
  16#include <linux/interrupt.h>
  17#include <linux/kernel.h>
  18#include <linux/log2.h>
  19#include <linux/module.h>
  20#include <linux/of.h>
  21#include <linux/regmap.h>
  22#include <linux/rtc.h>
  23
  24#define RV3028_SEC			0x00
  25#define RV3028_MIN			0x01
  26#define RV3028_HOUR			0x02
  27#define RV3028_WDAY			0x03
  28#define RV3028_DAY			0x04
  29#define RV3028_MONTH			0x05
  30#define RV3028_YEAR			0x06
  31#define RV3028_ALARM_MIN		0x07
  32#define RV3028_ALARM_HOUR		0x08
  33#define RV3028_ALARM_DAY		0x09
  34#define RV3028_STATUS			0x0E
  35#define RV3028_CTRL1			0x0F
  36#define RV3028_CTRL2			0x10
  37#define RV3028_EVT_CTRL			0x13
  38#define RV3028_TS_COUNT			0x14
  39#define RV3028_TS_SEC			0x15
  40#define RV3028_RAM1			0x1F
  41#define RV3028_EEPROM_ADDR		0x25
  42#define RV3028_EEPROM_DATA		0x26
  43#define RV3028_EEPROM_CMD		0x27
  44#define RV3028_CLKOUT			0x35
  45#define RV3028_OFFSET			0x36
  46#define RV3028_BACKUP			0x37
  47
  48#define RV3028_STATUS_PORF		BIT(0)
  49#define RV3028_STATUS_EVF		BIT(1)
  50#define RV3028_STATUS_AF		BIT(2)
  51#define RV3028_STATUS_TF		BIT(3)
  52#define RV3028_STATUS_UF		BIT(4)
  53#define RV3028_STATUS_BSF		BIT(5)
  54#define RV3028_STATUS_CLKF		BIT(6)
  55#define RV3028_STATUS_EEBUSY		BIT(7)
  56
  57#define RV3028_CLKOUT_FD_MASK		GENMASK(2, 0)
  58#define RV3028_CLKOUT_PORIE		BIT(3)
  59#define RV3028_CLKOUT_CLKSY		BIT(6)
  60#define RV3028_CLKOUT_CLKOE		BIT(7)
  61
  62#define RV3028_CTRL1_EERD		BIT(3)
  63#define RV3028_CTRL1_WADA		BIT(5)
  64
  65#define RV3028_CTRL2_RESET		BIT(0)
  66#define RV3028_CTRL2_12_24		BIT(1)
  67#define RV3028_CTRL2_EIE		BIT(2)
  68#define RV3028_CTRL2_AIE		BIT(3)
  69#define RV3028_CTRL2_TIE		BIT(4)
  70#define RV3028_CTRL2_UIE		BIT(5)
  71#define RV3028_CTRL2_TSE		BIT(7)
  72
  73#define RV3028_EVT_CTRL_TSR		BIT(2)
  74
  75#define RV3028_EEPROM_CMD_UPDATE	0x11
  76#define RV3028_EEPROM_CMD_WRITE		0x21
  77#define RV3028_EEPROM_CMD_READ		0x22
  78
  79#define RV3028_EEBUSY_POLL		10000
  80#define RV3028_EEBUSY_TIMEOUT		100000
  81
  82#define RV3028_BACKUP_TCE		BIT(5)
  83#define RV3028_BACKUP_TCR_MASK		GENMASK(1,0)
  84#define RV3028_BACKUP_BSM		GENMASK(3,2)
  85
  86#define RV3028_BACKUP_BSM_DSM		0x1
  87#define RV3028_BACKUP_BSM_LSM		0x3
  88
  89#define OFFSET_STEP_PPT			953674
  90
  91enum rv3028_type {
  92	rv_3028,
  93};
  94
  95struct rv3028_data {
  96	struct regmap *regmap;
  97	struct rtc_device *rtc;
  98	enum rv3028_type type;
  99#ifdef CONFIG_COMMON_CLK
 100	struct clk_hw clkout_hw;
 101#endif
 102};
 103
 104static u16 rv3028_trickle_resistors[] = {3000, 5000, 9000, 15000};
 105
 106static ssize_t timestamp0_store(struct device *dev,
 107				struct device_attribute *attr,
 108				const char *buf, size_t count)
 109{
 110	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
 111
 112	regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR,
 113			   RV3028_EVT_CTRL_TSR);
 114
 115	return count;
 116};
 117
 118static ssize_t timestamp0_show(struct device *dev,
 119			       struct device_attribute *attr, char *buf)
 120{
 121	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
 122	struct rtc_time tm;
 123	int ret, count;
 124	u8 date[6];
 
 125
 126	ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
 127	if (ret)
 128		return ret;
 129
 130	if (!count)
 131		return 0;
 132
 133	ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date,
 134			       sizeof(date));
 135	if (ret)
 136		return ret;
 137
 138	tm.tm_sec = bcd2bin(date[0]);
 139	tm.tm_min = bcd2bin(date[1]);
 140	tm.tm_hour = bcd2bin(date[2]);
 141	tm.tm_mday = bcd2bin(date[3]);
 142	tm.tm_mon = bcd2bin(date[4]) - 1;
 143	tm.tm_year = bcd2bin(date[5]) + 100;
 144
 145	ret = rtc_valid_tm(&tm);
 146	if (ret)
 147		return ret;
 148
 149	return sprintf(buf, "%llu\n",
 150		       (unsigned long long)rtc_tm_to_time64(&tm));
 151};
 152
 153static DEVICE_ATTR_RW(timestamp0);
 154
 155static ssize_t timestamp0_count_show(struct device *dev,
 156				     struct device_attribute *attr, char *buf)
 157{
 158	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent);
 159	int ret, count;
 
 160
 161	ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count);
 162	if (ret)
 163		return ret;
 164
 165	return sprintf(buf, "%u\n", count);
 166};
 167
 168static DEVICE_ATTR_RO(timestamp0_count);
 169
 170static struct attribute *rv3028_attrs[] = {
 171	&dev_attr_timestamp0.attr,
 172	&dev_attr_timestamp0_count.attr,
 173	NULL
 174};
 175
 176static const struct attribute_group rv3028_attr_group = {
 177	.attrs	= rv3028_attrs,
 178};
 179
 180static int rv3028_exit_eerd(struct rv3028_data *rv3028, u32 eerd)
 181{
 182	if (eerd)
 183		return 0;
 184
 185	return regmap_update_bits(rv3028->regmap, RV3028_CTRL1, RV3028_CTRL1_EERD, 0);
 186}
 187
 188static int rv3028_enter_eerd(struct rv3028_data *rv3028, u32 *eerd)
 189{
 190	u32 ctrl1, status;
 191	int ret;
 192
 193	ret = regmap_read(rv3028->regmap, RV3028_CTRL1, &ctrl1);
 194	if (ret)
 195		return ret;
 196
 197	*eerd = ctrl1 & RV3028_CTRL1_EERD;
 198	if (*eerd)
 199		return 0;
 200
 201	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
 202				 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD);
 203	if (ret)
 204		return ret;
 205
 206	ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 207				       !(status & RV3028_STATUS_EEBUSY),
 208				       RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
 209	if (ret) {
 210		rv3028_exit_eerd(rv3028, *eerd);
 211
 212		return ret;
 213	}
 214
 215	return 0;
 216}
 217
 218static int rv3028_update_eeprom(struct rv3028_data *rv3028, u32 eerd)
 219{
 220	u32 status;
 221	int ret;
 222
 223	ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
 224	if (ret)
 225		goto exit_eerd;
 226
 227	ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, RV3028_EEPROM_CMD_UPDATE);
 228	if (ret)
 229		goto exit_eerd;
 230
 231	usleep_range(63000, RV3028_EEBUSY_TIMEOUT);
 232
 233	ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 234				       !(status & RV3028_STATUS_EEBUSY),
 235				       RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
 236
 237exit_eerd:
 238	rv3028_exit_eerd(rv3028, eerd);
 239
 240	return ret;
 241}
 242
 243static int rv3028_update_cfg(struct rv3028_data *rv3028, unsigned int reg,
 244			     unsigned int mask, unsigned int val)
 245{
 246	u32 eerd;
 247	int ret;
 248
 249	ret = rv3028_enter_eerd(rv3028, &eerd);
 250	if (ret)
 251		return ret;
 252
 253	ret = regmap_update_bits(rv3028->regmap, reg, mask, val);
 254	if (ret) {
 255		rv3028_exit_eerd(rv3028, eerd);
 256		return ret;
 257	}
 258
 259	return rv3028_update_eeprom(rv3028, eerd);
 260}
 261
 262static irqreturn_t rv3028_handle_irq(int irq, void *dev_id)
 263{
 264	struct rv3028_data *rv3028 = dev_id;
 265	unsigned long events = 0;
 266	u32 status = 0, ctrl = 0;
 267
 268	if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 ||
 269	   status == 0) {
 270		return IRQ_NONE;
 271	}
 272
 273	status &= ~RV3028_STATUS_PORF;
 274
 275	if (status & RV3028_STATUS_TF) {
 276		status |= RV3028_STATUS_TF;
 277		ctrl |= RV3028_CTRL2_TIE;
 278		events |= RTC_PF;
 279	}
 280
 281	if (status & RV3028_STATUS_AF) {
 282		status |= RV3028_STATUS_AF;
 283		ctrl |= RV3028_CTRL2_AIE;
 284		events |= RTC_AF;
 285	}
 286
 287	if (status & RV3028_STATUS_UF) {
 288		status |= RV3028_STATUS_UF;
 289		ctrl |= RV3028_CTRL2_UIE;
 290		events |= RTC_UF;
 291	}
 292
 293	if (events) {
 294		rtc_update_irq(rv3028->rtc, 1, events);
 295		regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0);
 296		regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0);
 297	}
 298
 299	if (status & RV3028_STATUS_EVF) {
 300		sysfs_notify(&rv3028->rtc->dev.kobj, NULL,
 301			     dev_attr_timestamp0.attr.name);
 302		dev_warn(&rv3028->rtc->dev, "event detected");
 303	}
 304
 305	return IRQ_HANDLED;
 306}
 307
 308static int rv3028_get_time(struct device *dev, struct rtc_time *tm)
 309{
 310	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 311	u8 date[7];
 312	int ret, status;
 313
 314	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 315	if (ret < 0)
 316		return ret;
 317
 318	if (status & RV3028_STATUS_PORF)
 319		return -EINVAL;
 320
 321	ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date));
 322	if (ret)
 323		return ret;
 324
 325	tm->tm_sec  = bcd2bin(date[RV3028_SEC] & 0x7f);
 326	tm->tm_min  = bcd2bin(date[RV3028_MIN] & 0x7f);
 327	tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f);
 328	tm->tm_wday = date[RV3028_WDAY] & 0x7f;
 329	tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f);
 330	tm->tm_mon  = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1;
 331	tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100;
 332
 333	return 0;
 334}
 335
 336static int rv3028_set_time(struct device *dev, struct rtc_time *tm)
 337{
 338	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 339	u8 date[7];
 340	int ret;
 341
 342	date[RV3028_SEC]   = bin2bcd(tm->tm_sec);
 343	date[RV3028_MIN]   = bin2bcd(tm->tm_min);
 344	date[RV3028_HOUR]  = bin2bcd(tm->tm_hour);
 345	date[RV3028_WDAY]  = tm->tm_wday;
 346	date[RV3028_DAY]   = bin2bcd(tm->tm_mday);
 347	date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1);
 348	date[RV3028_YEAR]  = bin2bcd(tm->tm_year - 100);
 349
 350	/*
 351	 * Writing to the Seconds register has the same effect as setting RESET
 352	 * bit to 1
 353	 */
 354	ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date,
 355				sizeof(date));
 356	if (ret)
 357		return ret;
 358
 359	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 360				 RV3028_STATUS_PORF, 0);
 361
 362	return ret;
 363}
 364
 365static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 366{
 367	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 368	u8 alarmvals[3];
 369	int status, ctrl, ret;
 370
 371	ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
 372			       sizeof(alarmvals));
 373	if (ret)
 374		return ret;
 375
 376	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 377	if (ret < 0)
 378		return ret;
 379
 380	ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl);
 381	if (ret < 0)
 382		return ret;
 383
 384	alrm->time.tm_sec  = 0;
 385	alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
 386	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
 387	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
 388
 389	alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE);
 390	alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled;
 391
 392	return 0;
 393}
 394
 395static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 396{
 397	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 398	u8 alarmvals[3];
 399	u8 ctrl = 0;
 400	int ret;
 401
 402	/* The alarm has no seconds, round up to nearest minute */
 403	if (alrm->time.tm_sec) {
 404		time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
 405
 406		alarm_time += 60 - alrm->time.tm_sec;
 407		rtc_time64_to_tm(alarm_time, &alrm->time);
 408	}
 409
 410	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 411				 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0);
 412	if (ret)
 413		return ret;
 414
 415	alarmvals[0] = bin2bcd(alrm->time.tm_min);
 416	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
 417	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
 418
 419	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 420				 RV3028_STATUS_AF, 0);
 421	if (ret)
 422		return ret;
 423
 424	ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals,
 425				sizeof(alarmvals));
 426	if (ret)
 427		return ret;
 428
 429	if (alrm->enabled) {
 430		if (rv3028->rtc->uie_rtctimer.enabled)
 431			ctrl |= RV3028_CTRL2_UIE;
 432		if (rv3028->rtc->aie_timer.enabled)
 433			ctrl |= RV3028_CTRL2_AIE;
 434	}
 435
 436	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 437				 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
 438
 439	return ret;
 440}
 441
 442static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled)
 443{
 444	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 445	int ctrl = 0, ret;
 446
 447	if (enabled) {
 448		if (rv3028->rtc->uie_rtctimer.enabled)
 449			ctrl |= RV3028_CTRL2_UIE;
 450		if (rv3028->rtc->aie_timer.enabled)
 451			ctrl |= RV3028_CTRL2_AIE;
 452	}
 453
 454	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 455				 RV3028_STATUS_AF | RV3028_STATUS_UF, 0);
 456	if (ret)
 457		return ret;
 458
 459	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 460				 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl);
 461	if (ret)
 462		return ret;
 463
 464	return 0;
 465}
 466
 467static int rv3028_read_offset(struct device *dev, long *offset)
 468{
 469	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 470	int ret, value, steps;
 471
 472	ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value);
 473	if (ret < 0)
 474		return ret;
 475
 476	steps = sign_extend32(value << 1, 8);
 477
 478	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
 479	if (ret < 0)
 480		return ret;
 481
 482	steps += value >> 7;
 483
 484	*offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000);
 485
 486	return 0;
 487}
 488
 489static int rv3028_set_offset(struct device *dev, long offset)
 490{
 491	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 492	u32 eerd;
 493	int ret;
 494
 495	offset = clamp(offset, -244141L, 243187L) * 1000;
 496	offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT);
 497
 498	ret = rv3028_enter_eerd(rv3028, &eerd);
 499	if (ret)
 500		return ret;
 501
 502	ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1);
 503	if (ret < 0)
 504		goto exit_eerd;
 505
 506	ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7),
 507				 offset << 7);
 508	if (ret < 0)
 509		goto exit_eerd;
 510
 511	return rv3028_update_eeprom(rv3028, eerd);
 512
 513exit_eerd:
 514	rv3028_exit_eerd(rv3028, eerd);
 515
 516	return ret;
 517
 518}
 519
 520static int rv3028_param_get(struct device *dev, struct rtc_param *param)
 521{
 522	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 523	int ret;
 524	u32 value;
 525
 526	switch(param->param) {
 527	case RTC_PARAM_BACKUP_SWITCH_MODE:
 528		ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value);
 529		if (ret < 0)
 530			return ret;
 531
 532		value = FIELD_GET(RV3028_BACKUP_BSM, value);
 533
 534		switch(value) {
 535		case RV3028_BACKUP_BSM_DSM:
 536			param->uvalue = RTC_BSM_DIRECT;
 537			break;
 538		case RV3028_BACKUP_BSM_LSM:
 539			param->uvalue = RTC_BSM_LEVEL;
 540			break;
 541		default:
 542			param->uvalue = RTC_BSM_DISABLED;
 543		}
 544		break;
 545
 546	default:
 547		return -EINVAL;
 548	}
 549
 550	return 0;
 551}
 552
 553static int rv3028_param_set(struct device *dev, struct rtc_param *param)
 554{
 555	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 556	u8 mode;
 557
 558	switch(param->param) {
 559	case RTC_PARAM_BACKUP_SWITCH_MODE:
 560		switch (param->uvalue) {
 561		case RTC_BSM_DISABLED:
 562			mode = 0;
 563			break;
 564		case RTC_BSM_DIRECT:
 565			mode = RV3028_BACKUP_BSM_DSM;
 566			break;
 567		case RTC_BSM_LEVEL:
 568			mode = RV3028_BACKUP_BSM_LSM;
 569			break;
 570		default:
 571			return -EINVAL;
 572		}
 573
 574		return rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_BSM,
 575					 FIELD_PREP(RV3028_BACKUP_BSM, mode));
 576
 577	default:
 578		return -EINVAL;
 579	}
 580
 581	return 0;
 582}
 583
 584static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 585{
 586	struct rv3028_data *rv3028 = dev_get_drvdata(dev);
 587	int status, ret = 0;
 588
 589	switch (cmd) {
 590	case RTC_VL_READ:
 591		ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 592		if (ret < 0)
 593			return ret;
 594
 595		status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0;
 596		return put_user(status, (unsigned int __user *)arg);
 597
 598	default:
 599		return -ENOIOCTLCMD;
 600	}
 601}
 602
 603static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
 604			      size_t bytes)
 605{
 606	return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
 607}
 608
 609static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
 610			     size_t bytes)
 611{
 612	return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
 613}
 614
 615static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
 616			       size_t bytes)
 617{
 618	struct rv3028_data *rv3028 = priv;
 619	u32 status, eerd;
 620	int i, ret;
 621	u8 *buf = val;
 622
 623	ret = rv3028_enter_eerd(rv3028, &eerd);
 624	if (ret)
 625		return ret;
 626
 627	for (i = 0; i < bytes; i++) {
 628		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
 629		if (ret)
 630			goto restore_eerd;
 631
 632		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_DATA, buf[i]);
 633		if (ret)
 634			goto restore_eerd;
 635
 636		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
 637		if (ret)
 638			goto restore_eerd;
 639
 640		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
 641				   RV3028_EEPROM_CMD_WRITE);
 642		if (ret)
 643			goto restore_eerd;
 644
 645		usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT);
 646
 647		ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 648					       !(status & RV3028_STATUS_EEBUSY),
 649					       RV3028_EEBUSY_POLL,
 650					       RV3028_EEBUSY_TIMEOUT);
 651		if (ret)
 652			goto restore_eerd;
 653	}
 654
 655restore_eerd:
 656	rv3028_exit_eerd(rv3028, eerd);
 657
 658	return ret;
 659}
 660
 661static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val,
 662			      size_t bytes)
 663{
 664	struct rv3028_data *rv3028 = priv;
 665	u32 status, eerd, data;
 666	int i, ret;
 667	u8 *buf = val;
 668
 669	ret = rv3028_enter_eerd(rv3028, &eerd);
 670	if (ret)
 671		return ret;
 672
 673	for (i = 0; i < bytes; i++) {
 674		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i);
 675		if (ret)
 676			goto restore_eerd;
 677
 678		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0);
 679		if (ret)
 680			goto restore_eerd;
 681
 682		ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD,
 683				   RV3028_EEPROM_CMD_READ);
 684		if (ret)
 685			goto restore_eerd;
 686
 687		ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status,
 688					       !(status & RV3028_STATUS_EEBUSY),
 689					       RV3028_EEBUSY_POLL,
 690					       RV3028_EEBUSY_TIMEOUT);
 691		if (ret)
 692			goto restore_eerd;
 693
 694		ret = regmap_read(rv3028->regmap, RV3028_EEPROM_DATA, &data);
 695		if (ret)
 696			goto restore_eerd;
 697		buf[i] = data;
 698	}
 699
 700restore_eerd:
 701	rv3028_exit_eerd(rv3028, eerd);
 702
 703	return ret;
 704}
 705
 706#ifdef CONFIG_COMMON_CLK
 707#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw)
 708
 709static int clkout_rates[] = {
 710	32768,
 711	8192,
 712	1024,
 713	64,
 714	32,
 715	1,
 716};
 717
 718static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw,
 719					       unsigned long parent_rate)
 720{
 721	int clkout, ret;
 722	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 723
 724	ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
 725	if (ret < 0)
 726		return 0;
 727
 728	clkout &= RV3028_CLKOUT_FD_MASK;
 729	return clkout_rates[clkout];
 730}
 731
 732static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
 733				     unsigned long *prate)
 734{
 735	int i;
 736
 737	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 738		if (clkout_rates[i] <= rate)
 739			return clkout_rates[i];
 740
 741	return 0;
 742}
 743
 744static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
 745				  unsigned long parent_rate)
 746{
 747	int i, ret;
 748	u32 enabled;
 749	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 750
 751	ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &enabled);
 752	if (ret < 0)
 753		return ret;
 754
 755	ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
 756	if (ret < 0)
 757		return ret;
 758
 759	enabled &= RV3028_CLKOUT_CLKOE;
 760
 761	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
 762		if (clkout_rates[i] == rate)
 763			return rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff,
 764						 RV3028_CLKOUT_CLKSY | enabled | i);
 765
 766	return -EINVAL;
 767}
 768
 769static int rv3028_clkout_prepare(struct clk_hw *hw)
 770{
 771	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 772
 773	return regmap_write(rv3028->regmap, RV3028_CLKOUT,
 774			    RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE);
 775}
 776
 777static void rv3028_clkout_unprepare(struct clk_hw *hw)
 778{
 779	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 780
 781	regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0);
 782	regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 783			   RV3028_STATUS_CLKF, 0);
 784}
 785
 786static int rv3028_clkout_is_prepared(struct clk_hw *hw)
 787{
 788	int clkout, ret;
 789	struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw);
 790
 791	ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout);
 792	if (ret < 0)
 793		return ret;
 794
 795	return !!(clkout & RV3028_CLKOUT_CLKOE);
 796}
 797
 798static const struct clk_ops rv3028_clkout_ops = {
 799	.prepare = rv3028_clkout_prepare,
 800	.unprepare = rv3028_clkout_unprepare,
 801	.is_prepared = rv3028_clkout_is_prepared,
 802	.recalc_rate = rv3028_clkout_recalc_rate,
 803	.round_rate = rv3028_clkout_round_rate,
 804	.set_rate = rv3028_clkout_set_rate,
 805};
 806
 807static int rv3028_clkout_register_clk(struct rv3028_data *rv3028,
 808				      struct i2c_client *client)
 809{
 810	int ret;
 811	struct clk *clk;
 812	struct clk_init_data init;
 813	struct device_node *node = client->dev.of_node;
 814
 815	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS,
 816				 RV3028_STATUS_CLKF, 0);
 817	if (ret < 0)
 818		return ret;
 819
 820	init.name = "rv3028-clkout";
 821	init.ops = &rv3028_clkout_ops;
 822	init.flags = 0;
 823	init.parent_names = NULL;
 824	init.num_parents = 0;
 825	rv3028->clkout_hw.init = &init;
 826
 827	/* optional override of the clockname */
 828	of_property_read_string(node, "clock-output-names", &init.name);
 829
 830	/* register the clock */
 831	clk = devm_clk_register(&client->dev, &rv3028->clkout_hw);
 832	if (!IS_ERR(clk))
 833		of_clk_add_provider(node, of_clk_src_simple_get, clk);
 834
 835	return 0;
 836}
 837#endif
 838
 839static const struct rtc_class_ops rv3028_rtc_ops = {
 840	.read_time = rv3028_get_time,
 841	.set_time = rv3028_set_time,
 842	.read_alarm = rv3028_get_alarm,
 843	.set_alarm = rv3028_set_alarm,
 844	.alarm_irq_enable = rv3028_alarm_irq_enable,
 845	.read_offset = rv3028_read_offset,
 846	.set_offset = rv3028_set_offset,
 847	.ioctl = rv3028_ioctl,
 848	.param_get = rv3028_param_get,
 849	.param_set = rv3028_param_set,
 850};
 851
 852static const struct regmap_config regmap_config = {
 853        .reg_bits = 8,
 854        .val_bits = 8,
 855        .max_register = 0x37,
 856};
 857
 858static u8 rv3028_set_trickle_charger(struct rv3028_data *rv3028,
 859				     struct i2c_client *client)
 860{
 861	int ret, val_old, val;
 862	u32 ohms, chargeable;
 863
 864	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old);
 865	if (ret < 0)
 866		return ret;
 867
 868	/* mask out only trickle charger bits */
 869	val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK);
 870	val = val_old;
 871
 872	/* setup trickle charger */
 873	if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms",
 874				      &ohms)) {
 875		int i;
 876
 877		for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++)
 878			if (ohms == rv3028_trickle_resistors[i])
 879				break;
 880
 881		if (i < ARRAY_SIZE(rv3028_trickle_resistors)) {
 882			/* enable trickle charger and its resistor */
 883			val = RV3028_BACKUP_TCE | i;
 884		} else {
 885			dev_warn(&client->dev, "invalid trickle resistor value\n");
 886		}
 887	}
 888
 889	if (!device_property_read_u32(&client->dev, "aux-voltage-chargeable",
 890				      &chargeable)) {
 891		switch (chargeable) {
 892		case 0:
 893			val &= ~RV3028_BACKUP_TCE;
 894			break;
 895		case 1:
 896			val |= RV3028_BACKUP_TCE;
 897			break;
 898		default:
 899			dev_warn(&client->dev,
 900				 "unsupported aux-voltage-chargeable value\n");
 901			break;
 902		}
 903	}
 904
 905	/* only update EEPROM if changes are necessary */
 906	if (val_old != val) {
 907		ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE |
 908						RV3028_BACKUP_TCR_MASK, val);
 909		if (ret)
 910			return ret;
 911	}
 912
 913	return ret;
 914}
 915
 916static int rv3028_probe(struct i2c_client *client)
 917{
 918	struct rv3028_data *rv3028;
 919	int ret, status;
 920	struct nvmem_config nvmem_cfg = {
 921		.name = "rv3028_nvram",
 922		.word_size = 1,
 923		.stride = 1,
 924		.size = 2,
 925		.type = NVMEM_TYPE_BATTERY_BACKED,
 926		.reg_read = rv3028_nvram_read,
 927		.reg_write = rv3028_nvram_write,
 928	};
 929	struct nvmem_config eeprom_cfg = {
 930		.name = "rv3028_eeprom",
 931		.word_size = 1,
 932		.stride = 1,
 933		.size = 43,
 934		.type = NVMEM_TYPE_EEPROM,
 935		.reg_read = rv3028_eeprom_read,
 936		.reg_write = rv3028_eeprom_write,
 937	};
 938
 939	rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data),
 940			      GFP_KERNEL);
 941	if (!rv3028)
 942		return -ENOMEM;
 943
 944	rv3028->regmap = devm_regmap_init_i2c(client, &regmap_config);
 945	if (IS_ERR(rv3028->regmap))
 946		return PTR_ERR(rv3028->regmap);
 947
 948	i2c_set_clientdata(client, rv3028);
 949
 950	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status);
 951	if (ret < 0)
 952		return ret;
 953
 954	if (status & RV3028_STATUS_AF)
 955		dev_warn(&client->dev, "An alarm may have been missed.\n");
 956
 957	rv3028->rtc = devm_rtc_allocate_device(&client->dev);
 958	if (IS_ERR(rv3028->rtc))
 959		return PTR_ERR(rv3028->rtc);
 960
 961	if (client->irq > 0) {
 962		unsigned long flags;
 963
 964		/*
 965		 * If flags = 0, devm_request_threaded_irq() will use IRQ flags
 966		 * obtained from device tree.
 967		 */
 968		if (dev_fwnode(&client->dev))
 969			flags = 0;
 970		else
 971			flags = IRQF_TRIGGER_LOW;
 972
 973		ret = devm_request_threaded_irq(&client->dev, client->irq,
 974						NULL, rv3028_handle_irq,
 975						flags | IRQF_ONESHOT,
 976						"rv3028", rv3028);
 977		if (ret) {
 978			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
 979			client->irq = 0;
 980		}
 981	}
 982	if (!client->irq)
 983		clear_bit(RTC_FEATURE_ALARM, rv3028->rtc->features);
 984
 985	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1,
 986				 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA);
 987	if (ret)
 988		return ret;
 989
 990	/* setup timestamping */
 991	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2,
 992				 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE,
 993				 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE);
 994	if (ret)
 995		return ret;
 996
 997	ret = rv3028_set_trickle_charger(rv3028, client);
 998	if (ret)
 999		return ret;
1000
1001	ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group);
1002	if (ret)
1003		return ret;
1004
1005	set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3028->rtc->features);
1006
1007	rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
1008	rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099;
1009	rv3028->rtc->ops = &rv3028_rtc_ops;
1010	ret = devm_rtc_register_device(rv3028->rtc);
1011	if (ret)
1012		return ret;
1013
1014	nvmem_cfg.priv = rv3028->regmap;
1015	devm_rtc_nvmem_register(rv3028->rtc, &nvmem_cfg);
1016	eeprom_cfg.priv = rv3028;
1017	devm_rtc_nvmem_register(rv3028->rtc, &eeprom_cfg);
1018
1019	rv3028->rtc->max_user_freq = 1;
1020
1021#ifdef CONFIG_COMMON_CLK
1022	rv3028_clkout_register_clk(rv3028, client);
1023#endif
1024	return 0;
1025}
1026
1027static const struct acpi_device_id rv3028_i2c_acpi_match[] = {
1028	{ "MCRY3028" },
1029	{ }
1030};
1031MODULE_DEVICE_TABLE(acpi, rv3028_i2c_acpi_match);
1032
1033static const __maybe_unused struct of_device_id rv3028_of_match[] = {
1034	{ .compatible = "microcrystal,rv3028", },
1035	{ }
1036};
1037MODULE_DEVICE_TABLE(of, rv3028_of_match);
1038
1039static const struct i2c_device_id rv3028_id_table[] = {
1040	{ .name = "rv3028", },
1041	{ }
1042};
1043MODULE_DEVICE_TABLE(i2c, rv3028_id_table);
1044
1045static struct i2c_driver rv3028_driver = {
1046	.driver = {
1047		.name = "rtc-rv3028",
1048		.acpi_match_table = rv3028_i2c_acpi_match,
1049		.of_match_table = of_match_ptr(rv3028_of_match),
1050	},
1051	.id_table	= rv3028_id_table,
1052	.probe		= rv3028_probe,
1053};
1054module_i2c_driver(rv3028_driver);
1055
1056MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1057MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver");
1058MODULE_LICENSE("GPL v2");