| // SPDX-License-Identifier: GPL-2.0 | 
 | /* | 
 |  * RTC driver for the Micro Crystal RV3028 | 
 |  * | 
 |  * Copyright (C) 2019 Micro Crystal SA | 
 |  * | 
 |  * Alexandre Belloni <alexandre.belloni@bootlin.com> | 
 |  * | 
 |  */ | 
 |  | 
 | #include <linux/bcd.h> | 
 | #include <linux/bitops.h> | 
 | #include <linux/i2c.h> | 
 | #include <linux/interrupt.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/log2.h> | 
 | #include <linux/module.h> | 
 | #include <linux/of_device.h> | 
 | #include <linux/regmap.h> | 
 | #include <linux/rtc.h> | 
 |  | 
 | #define RV3028_SEC			0x00 | 
 | #define RV3028_MIN			0x01 | 
 | #define RV3028_HOUR			0x02 | 
 | #define RV3028_WDAY			0x03 | 
 | #define RV3028_DAY			0x04 | 
 | #define RV3028_MONTH			0x05 | 
 | #define RV3028_YEAR			0x06 | 
 | #define RV3028_ALARM_MIN		0x07 | 
 | #define RV3028_ALARM_HOUR		0x08 | 
 | #define RV3028_ALARM_DAY		0x09 | 
 | #define RV3028_STATUS			0x0E | 
 | #define RV3028_CTRL1			0x0F | 
 | #define RV3028_CTRL2			0x10 | 
 | #define RV3028_EVT_CTRL			0x13 | 
 | #define RV3028_TS_COUNT			0x14 | 
 | #define RV3028_TS_SEC			0x15 | 
 | #define RV3028_RAM1			0x1F | 
 | #define RV3028_EEPROM_ADDR		0x25 | 
 | #define RV3028_EEPROM_DATA		0x26 | 
 | #define RV3028_EEPROM_CMD		0x27 | 
 | #define RV3028_CLKOUT			0x35 | 
 | #define RV3028_OFFSET			0x36 | 
 | #define RV3028_BACKUP			0x37 | 
 |  | 
 | #define RV3028_STATUS_PORF		BIT(0) | 
 | #define RV3028_STATUS_EVF		BIT(1) | 
 | #define RV3028_STATUS_AF		BIT(2) | 
 | #define RV3028_STATUS_TF		BIT(3) | 
 | #define RV3028_STATUS_UF		BIT(4) | 
 | #define RV3028_STATUS_BSF		BIT(5) | 
 | #define RV3028_STATUS_CLKF		BIT(6) | 
 | #define RV3028_STATUS_EEBUSY		BIT(7) | 
 |  | 
 | #define RV3028_CTRL1_EERD		BIT(3) | 
 | #define RV3028_CTRL1_WADA		BIT(5) | 
 |  | 
 | #define RV3028_CTRL2_RESET		BIT(0) | 
 | #define RV3028_CTRL2_12_24		BIT(1) | 
 | #define RV3028_CTRL2_EIE		BIT(2) | 
 | #define RV3028_CTRL2_AIE		BIT(3) | 
 | #define RV3028_CTRL2_TIE		BIT(4) | 
 | #define RV3028_CTRL2_UIE		BIT(5) | 
 | #define RV3028_CTRL2_TSE		BIT(7) | 
 |  | 
 | #define RV3028_EVT_CTRL_TSR		BIT(2) | 
 |  | 
 | #define RV3028_EEPROM_CMD_WRITE		0x21 | 
 | #define RV3028_EEPROM_CMD_READ		0x22 | 
 |  | 
 | #define RV3028_EEBUSY_POLL		10000 | 
 | #define RV3028_EEBUSY_TIMEOUT		100000 | 
 |  | 
 | #define RV3028_BACKUP_TCE		BIT(5) | 
 | #define RV3028_BACKUP_TCR_MASK		GENMASK(1,0) | 
 |  | 
 | #define OFFSET_STEP_PPT			953674 | 
 |  | 
 | enum rv3028_type { | 
 | 	rv_3028, | 
 | }; | 
 |  | 
 | struct rv3028_data { | 
 | 	struct regmap *regmap; | 
 | 	struct rtc_device *rtc; | 
 | 	enum rv3028_type type; | 
 | }; | 
 |  | 
 | static u16 rv3028_trickle_resistors[] = {1000, 3000, 6000, 11000}; | 
 |  | 
 | static ssize_t timestamp0_store(struct device *dev, | 
 | 				struct device_attribute *attr, | 
 | 				const char *buf, size_t count) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); | 
 |  | 
 | 	regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR, | 
 | 			   RV3028_EVT_CTRL_TSR); | 
 |  | 
 | 	return count; | 
 | }; | 
 |  | 
 | static ssize_t timestamp0_show(struct device *dev, | 
 | 			       struct device_attribute *attr, char *buf) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); | 
 | 	struct rtc_time tm; | 
 | 	int ret, count; | 
 | 	u8 date[6]; | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	if (!count) | 
 | 		return 0; | 
 |  | 
 | 	ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date, | 
 | 			       sizeof(date)); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	tm.tm_sec = bcd2bin(date[0]); | 
 | 	tm.tm_min = bcd2bin(date[1]); | 
 | 	tm.tm_hour = bcd2bin(date[2]); | 
 | 	tm.tm_mday = bcd2bin(date[3]); | 
 | 	tm.tm_mon = bcd2bin(date[4]) - 1; | 
 | 	tm.tm_year = bcd2bin(date[5]) + 100; | 
 |  | 
 | 	ret = rtc_valid_tm(&tm); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	return sprintf(buf, "%llu\n", | 
 | 		       (unsigned long long)rtc_tm_to_time64(&tm)); | 
 | }; | 
 |  | 
 | static DEVICE_ATTR_RW(timestamp0); | 
 |  | 
 | static ssize_t timestamp0_count_show(struct device *dev, | 
 | 				     struct device_attribute *attr, char *buf) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); | 
 | 	int ret, count; | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	return sprintf(buf, "%u\n", count); | 
 | }; | 
 |  | 
 | static DEVICE_ATTR_RO(timestamp0_count); | 
 |  | 
 | static struct attribute *rv3028_attrs[] = { | 
 | 	&dev_attr_timestamp0.attr, | 
 | 	&dev_attr_timestamp0_count.attr, | 
 | 	NULL | 
 | }; | 
 |  | 
 | static const struct attribute_group rv3028_attr_group = { | 
 | 	.attrs	= rv3028_attrs, | 
 | }; | 
 |  | 
 | static irqreturn_t rv3028_handle_irq(int irq, void *dev_id) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_id; | 
 | 	unsigned long events = 0; | 
 | 	u32 status = 0, ctrl = 0; | 
 |  | 
 | 	if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 || | 
 | 	   status == 0) { | 
 | 		return IRQ_NONE; | 
 | 	} | 
 |  | 
 | 	if (status & RV3028_STATUS_PORF) | 
 | 		dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n"); | 
 |  | 
 | 	if (status & RV3028_STATUS_TF) { | 
 | 		status |= RV3028_STATUS_TF; | 
 | 		ctrl |= RV3028_CTRL2_TIE; | 
 | 		events |= RTC_PF; | 
 | 	} | 
 |  | 
 | 	if (status & RV3028_STATUS_AF) { | 
 | 		status |= RV3028_STATUS_AF; | 
 | 		ctrl |= RV3028_CTRL2_AIE; | 
 | 		events |= RTC_AF; | 
 | 	} | 
 |  | 
 | 	if (status & RV3028_STATUS_UF) { | 
 | 		status |= RV3028_STATUS_UF; | 
 | 		ctrl |= RV3028_CTRL2_UIE; | 
 | 		events |= RTC_UF; | 
 | 	} | 
 |  | 
 | 	if (events) { | 
 | 		rtc_update_irq(rv3028->rtc, 1, events); | 
 | 		regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0); | 
 | 		regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0); | 
 | 	} | 
 |  | 
 | 	if (status & RV3028_STATUS_EVF) { | 
 | 		sysfs_notify(&rv3028->rtc->dev.kobj, NULL, | 
 | 			     dev_attr_timestamp0.attr.name); | 
 | 		dev_warn(&rv3028->rtc->dev, "event detected"); | 
 | 	} | 
 |  | 
 | 	return IRQ_HANDLED; | 
 | } | 
 |  | 
 | static int rv3028_get_time(struct device *dev, struct rtc_time *tm) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	u8 date[7]; | 
 | 	int ret, status; | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	if (status & RV3028_STATUS_PORF) { | 
 | 		dev_warn(dev, "Voltage low, data is invalid.\n"); | 
 | 		return -EINVAL; | 
 | 	} | 
 |  | 
 | 	ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date)); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	tm->tm_sec  = bcd2bin(date[RV3028_SEC] & 0x7f); | 
 | 	tm->tm_min  = bcd2bin(date[RV3028_MIN] & 0x7f); | 
 | 	tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f); | 
 | 	tm->tm_wday = ilog2(date[RV3028_WDAY] & 0x7f); | 
 | 	tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f); | 
 | 	tm->tm_mon  = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1; | 
 | 	tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int rv3028_set_time(struct device *dev, struct rtc_time *tm) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	u8 date[7]; | 
 | 	int ret; | 
 |  | 
 | 	date[RV3028_SEC]   = bin2bcd(tm->tm_sec); | 
 | 	date[RV3028_MIN]   = bin2bcd(tm->tm_min); | 
 | 	date[RV3028_HOUR]  = bin2bcd(tm->tm_hour); | 
 | 	date[RV3028_WDAY]  = 1 << (tm->tm_wday); | 
 | 	date[RV3028_DAY]   = bin2bcd(tm->tm_mday); | 
 | 	date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1); | 
 | 	date[RV3028_YEAR]  = bin2bcd(tm->tm_year - 100); | 
 |  | 
 | 	/* | 
 | 	 * Writing to the Seconds register has the same effect as setting RESET | 
 | 	 * bit to 1 | 
 | 	 */ | 
 | 	ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date, | 
 | 				sizeof(date)); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, | 
 | 				 RV3028_STATUS_PORF, 0); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	u8 alarmvals[3]; | 
 | 	int status, ctrl, ret; | 
 |  | 
 | 	ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals, | 
 | 			       sizeof(alarmvals)); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	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 = !!(ctrl & RV3028_CTRL2_AIE); | 
 | 	alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	u8 alarmvals[3]; | 
 | 	u8 ctrl = 0; | 
 | 	int ret; | 
 |  | 
 | 	/* 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); | 
 | 	} | 
 |  | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, | 
 | 				 RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	alarmvals[0] = bin2bcd(alrm->time.tm_min); | 
 | 	alarmvals[1] = bin2bcd(alrm->time.tm_hour); | 
 | 	alarmvals[2] = bin2bcd(alrm->time.tm_mday); | 
 |  | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, | 
 | 				 RV3028_STATUS_AF, 0); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals, | 
 | 				sizeof(alarmvals)); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	if (alrm->enabled) { | 
 | 		if (rv3028->rtc->uie_rtctimer.enabled) | 
 | 			ctrl |= RV3028_CTRL2_UIE; | 
 | 		if (rv3028->rtc->aie_timer.enabled) | 
 | 			ctrl |= RV3028_CTRL2_AIE; | 
 | 	} | 
 |  | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, | 
 | 				 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	int ctrl = 0, ret; | 
 |  | 
 | 	if (enabled) { | 
 | 		if (rv3028->rtc->uie_rtctimer.enabled) | 
 | 			ctrl |= RV3028_CTRL2_UIE; | 
 | 		if (rv3028->rtc->aie_timer.enabled) | 
 | 			ctrl |= RV3028_CTRL2_AIE; | 
 | 	} | 
 |  | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, | 
 | 				 RV3028_STATUS_AF | RV3028_STATUS_UF, 0); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, | 
 | 				 RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int rv3028_read_offset(struct device *dev, long *offset) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	int ret, value, steps; | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	steps = sign_extend32(value << 1, 8); | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	steps += value >> 7; | 
 |  | 
 | 	*offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int rv3028_set_offset(struct device *dev, long offset) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	int ret; | 
 |  | 
 | 	offset = clamp(offset, -244141L, 243187L) * 1000; | 
 | 	offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT); | 
 |  | 
 | 	ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	return regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7), | 
 | 				  offset << 7); | 
 | } | 
 |  | 
 | static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) | 
 | { | 
 | 	struct rv3028_data *rv3028 = dev_get_drvdata(dev); | 
 | 	int status, ret = 0; | 
 |  | 
 | 	switch (cmd) { | 
 | 	case RTC_VL_READ: | 
 | 		ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); | 
 | 		if (ret < 0) | 
 | 			return ret; | 
 |  | 
 | 		if (status & RV3028_STATUS_PORF) | 
 | 			dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n"); | 
 |  | 
 | 		status &= RV3028_STATUS_PORF; | 
 |  | 
 | 		if (copy_to_user((void __user *)arg, &status, sizeof(int))) | 
 | 			return -EFAULT; | 
 |  | 
 | 		return 0; | 
 |  | 
 | 	case RTC_VL_CLR: | 
 | 		ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, | 
 | 					 RV3028_STATUS_PORF, 0); | 
 |  | 
 | 		return ret; | 
 |  | 
 | 	default: | 
 | 		return -ENOIOCTLCMD; | 
 | 	} | 
 | } | 
 |  | 
 | static int rv3028_nvram_write(void *priv, unsigned int offset, void *val, | 
 | 			      size_t bytes) | 
 | { | 
 | 	return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes); | 
 | } | 
 |  | 
 | static int rv3028_nvram_read(void *priv, unsigned int offset, void *val, | 
 | 			     size_t bytes) | 
 | { | 
 | 	return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes); | 
 | } | 
 |  | 
 | static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val, | 
 | 			       size_t bytes) | 
 | { | 
 | 	u32 status, ctrl1; | 
 | 	int i, ret, err; | 
 | 	u8 *buf = val; | 
 |  | 
 | 	ret = regmap_read(priv, RV3028_CTRL1, &ctrl1); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	if (!(ctrl1 & RV3028_CTRL1_EERD)) { | 
 | 		ret = regmap_update_bits(priv, RV3028_CTRL1, | 
 | 					 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD); | 
 | 		if (ret) | 
 | 			return ret; | 
 |  | 
 | 		ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, | 
 | 					       !(status & RV3028_STATUS_EEBUSY), | 
 | 					       RV3028_EEBUSY_POLL, | 
 | 					       RV3028_EEBUSY_TIMEOUT); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 | 	} | 
 |  | 
 | 	for (i = 0; i < bytes; i++) { | 
 | 		ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		ret = regmap_write(priv, RV3028_EEPROM_DATA, buf[i]); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		ret = regmap_write(priv, RV3028_EEPROM_CMD, | 
 | 				   RV3028_EEPROM_CMD_WRITE); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT); | 
 |  | 
 | 		ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, | 
 | 					       !(status & RV3028_STATUS_EEBUSY), | 
 | 					       RV3028_EEBUSY_POLL, | 
 | 					       RV3028_EEBUSY_TIMEOUT); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 | 	} | 
 |  | 
 | restore_eerd: | 
 | 	if (!(ctrl1 & RV3028_CTRL1_EERD)) | 
 | 	{ | 
 | 		err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD, | 
 | 					 0); | 
 | 		if (err && !ret) | 
 | 			ret = err; | 
 | 	} | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val, | 
 | 			      size_t bytes) | 
 | { | 
 | 	u32 status, ctrl1, data; | 
 | 	int i, ret, err; | 
 | 	u8 *buf = val; | 
 |  | 
 | 	ret = regmap_read(priv, RV3028_CTRL1, &ctrl1); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	if (!(ctrl1 & RV3028_CTRL1_EERD)) { | 
 | 		ret = regmap_update_bits(priv, RV3028_CTRL1, | 
 | 					 RV3028_CTRL1_EERD, RV3028_CTRL1_EERD); | 
 | 		if (ret) | 
 | 			return ret; | 
 |  | 
 | 		ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, | 
 | 					       !(status & RV3028_STATUS_EEBUSY), | 
 | 					       RV3028_EEBUSY_POLL, | 
 | 					       RV3028_EEBUSY_TIMEOUT); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 | 	} | 
 |  | 
 | 	for (i = 0; i < bytes; i++) { | 
 | 		ret = regmap_write(priv, RV3028_EEPROM_ADDR, offset + i); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		ret = regmap_write(priv, RV3028_EEPROM_CMD, 0x0); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		ret = regmap_write(priv, RV3028_EEPROM_CMD, | 
 | 				   RV3028_EEPROM_CMD_READ); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		ret = regmap_read_poll_timeout(priv, RV3028_STATUS, status, | 
 | 					       !(status & RV3028_STATUS_EEBUSY), | 
 | 					       RV3028_EEBUSY_POLL, | 
 | 					       RV3028_EEBUSY_TIMEOUT); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 |  | 
 | 		ret = regmap_read(priv, RV3028_EEPROM_DATA, &data); | 
 | 		if (ret) | 
 | 			goto restore_eerd; | 
 | 		buf[i] = data; | 
 | 	} | 
 |  | 
 | restore_eerd: | 
 | 	if (!(ctrl1 & RV3028_CTRL1_EERD)) | 
 | 	{ | 
 | 		err = regmap_update_bits(priv, RV3028_CTRL1, RV3028_CTRL1_EERD, | 
 | 					 0); | 
 | 		if (err && !ret) | 
 | 			ret = err; | 
 | 	} | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | static struct rtc_class_ops rv3028_rtc_ops = { | 
 | 	.read_time = rv3028_get_time, | 
 | 	.set_time = rv3028_set_time, | 
 | 	.read_offset = rv3028_read_offset, | 
 | 	.set_offset = rv3028_set_offset, | 
 | 	.ioctl = rv3028_ioctl, | 
 | }; | 
 |  | 
 | static const struct regmap_config regmap_config = { | 
 |         .reg_bits = 8, | 
 |         .val_bits = 8, | 
 |         .max_register = 0x37, | 
 | }; | 
 |  | 
 | static int rv3028_probe(struct i2c_client *client) | 
 | { | 
 | 	struct rv3028_data *rv3028; | 
 | 	int ret, status; | 
 | 	u32 ohms; | 
 | 	struct nvmem_config nvmem_cfg = { | 
 | 		.name = "rv3028_nvram", | 
 | 		.word_size = 1, | 
 | 		.stride = 1, | 
 | 		.size = 2, | 
 | 		.type = NVMEM_TYPE_BATTERY_BACKED, | 
 | 		.reg_read = rv3028_nvram_read, | 
 | 		.reg_write = rv3028_nvram_write, | 
 | 	}; | 
 | 	struct nvmem_config eeprom_cfg = { | 
 | 		.name = "rv3028_eeprom", | 
 | 		.word_size = 1, | 
 | 		.stride = 1, | 
 | 		.size = 43, | 
 | 		.type = NVMEM_TYPE_EEPROM, | 
 | 		.reg_read = rv3028_eeprom_read, | 
 | 		.reg_write = rv3028_eeprom_write, | 
 | 	}; | 
 |  | 
 | 	rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data), | 
 | 			      GFP_KERNEL); | 
 | 	if (!rv3028) | 
 | 		return -ENOMEM; | 
 |  | 
 | 	rv3028->regmap = devm_regmap_init_i2c(client, ®map_config); | 
 | 	if (IS_ERR(rv3028->regmap)) | 
 | 		return PTR_ERR(rv3028->regmap); | 
 |  | 
 | 	i2c_set_clientdata(client, rv3028); | 
 |  | 
 | 	ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	if (status & RV3028_STATUS_PORF) | 
 | 		dev_warn(&client->dev, "Voltage low, data loss detected.\n"); | 
 |  | 
 | 	if (status & RV3028_STATUS_AF) | 
 | 		dev_warn(&client->dev, "An alarm may have been missed.\n"); | 
 |  | 
 | 	rv3028->rtc = devm_rtc_allocate_device(&client->dev); | 
 | 	if (IS_ERR(rv3028->rtc)) | 
 | 		return PTR_ERR(rv3028->rtc); | 
 |  | 
 | 	if (client->irq > 0) { | 
 | 		ret = devm_request_threaded_irq(&client->dev, client->irq, | 
 | 						NULL, rv3028_handle_irq, | 
 | 						IRQF_TRIGGER_LOW | IRQF_ONESHOT, | 
 | 						"rv3028", rv3028); | 
 | 		if (ret) { | 
 | 			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); | 
 | 			client->irq = 0; | 
 | 		} else { | 
 | 			rv3028_rtc_ops.read_alarm = rv3028_get_alarm; | 
 | 			rv3028_rtc_ops.set_alarm = rv3028_set_alarm; | 
 | 			rv3028_rtc_ops.alarm_irq_enable = rv3028_alarm_irq_enable; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1, | 
 | 				 RV3028_CTRL1_WADA, RV3028_CTRL1_WADA); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	/* setup timestamping */ | 
 | 	ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, | 
 | 				 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE, | 
 | 				 RV3028_CTRL2_EIE | RV3028_CTRL2_TSE); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	/* setup trickle charger */ | 
 | 	if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms", | 
 | 				      &ohms)) { | 
 | 		int i; | 
 |  | 
 | 		for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) | 
 | 			if (ohms == rv3028_trickle_resistors[i]) | 
 | 				break; | 
 |  | 
 | 		if (i < ARRAY_SIZE(rv3028_trickle_resistors)) { | 
 | 			ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, | 
 | 						 RV3028_BACKUP_TCE | | 
 | 						 RV3028_BACKUP_TCR_MASK, | 
 | 						 RV3028_BACKUP_TCE | i); | 
 | 			if (ret) | 
 | 				return ret; | 
 | 		} else { | 
 | 			dev_warn(&client->dev, "invalid trickle resistor value\n"); | 
 | 		} | 
 | 	} | 
 |  | 
 | 	ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; | 
 | 	rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099; | 
 | 	rv3028->rtc->ops = &rv3028_rtc_ops; | 
 | 	ret = rtc_register_device(rv3028->rtc); | 
 | 	if (ret) | 
 | 		return ret; | 
 |  | 
 | 	nvmem_cfg.priv = rv3028->regmap; | 
 | 	rtc_nvmem_register(rv3028->rtc, &nvmem_cfg); | 
 | 	eeprom_cfg.priv = rv3028->regmap; | 
 | 	rtc_nvmem_register(rv3028->rtc, &eeprom_cfg); | 
 |  | 
 | 	rv3028->rtc->max_user_freq = 1; | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static const struct of_device_id rv3028_of_match[] = { | 
 | 	{ .compatible = "microcrystal,rv3028", }, | 
 | 	{ } | 
 | }; | 
 | MODULE_DEVICE_TABLE(of, rv3028_of_match); | 
 |  | 
 | static struct i2c_driver rv3028_driver = { | 
 | 	.driver = { | 
 | 		.name = "rtc-rv3028", | 
 | 		.of_match_table = of_match_ptr(rv3028_of_match), | 
 | 	}, | 
 | 	.probe_new	= rv3028_probe, | 
 | }; | 
 | module_i2c_driver(rv3028_driver); | 
 |  | 
 | MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>"); | 
 | MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver"); | 
 | MODULE_LICENSE("GPL v2"); |