// SPDX-License-Identifier: GPL-2.0-only/* * Driver for Epson RX8111 RTC. * * Copyright (C) 2023 Axis Communications AB */ #include <linux/bcd.h>#include <linux/bitfield.h>#include <linux/i2c.h>#include <linux/module.h>#include <linux/regmap.h> #include <linux/rtc.h> #define RX8111_REG_SEC			0x10	/* Second counter. */#define RX8111_REG_MIN			0x11	/* Minute counter */#define RX8111_REG_HOUR			0x12	/* Hour counter. */#define RX8111_REG_WEEK			0x13	/* Week day counter. */#define RX8111_REG_DAY			0x14	/* Month day counter. */#define RX8111_REG_MONTH		0x15	/* Month counter. */#define RX8111_REG_YEAR			0x16	/* Year counter. */ #define RX8111_REG_ALARM_MIN		0x17	/* Alarm minute. */#define RX8111_REG_ALARM_HOUR		0x18	/* Alarm hour. */#define RX8111_REG_ALARM_WEEK_DAY	0x19	/* Alarm week or month day. */ #define RX8111_REG_TIMER_COUNTER0	0x1a	/* Timer counter LSB. */#define RX8111_REG_TIMER_COUNTER1	0x1b	/* Timer counter. */#define RX8111_REG_TIMER_COUNTER2	0x1c	/* Timer counter MSB. */ #define RX8111_REG_EXT			0x1d	/* Extension register. */#define RX8111_REG_FLAG			0x1e	/* Flag register. */#define RX8111_REG_CTRL			0x1f	/* Control register. */ #define RX8111_REG_TS_1_1000_SEC	0x20	/* Timestamp 256 or 512 Hz . */#define RX8111_REG_TS_1_100_SEC		0x21	/* Timestamp 1 - 128 Hz. */#define RX8111_REG_TS_SEC		0x22	/* Timestamp second. */#define RX8111_REG_TS_MIN		0x23	/* Timestamp minute. */#define RX8111_REG_TS_HOUR		0x24	/* Timestamp hour. */#define RX8111_REG_TS_WEEK		0x25	/* Timestamp week day. */#define RX8111_REG_TS_DAY		0x26	/* Timestamp month day. */#define RX8111_REG_TS_MONTH		0x27	/* Timestamp month. */#define RX8111_REG_TS_YEAR		0x28	/* Timestamp year. */#define RX8111_REG_TS_STATUS		0x29	/* Timestamp status. */ #define RX8111_REG_EVIN_SETTING		0x2b	/* Timestamp trigger setting. */#define RX8111_REG_ALARM_SEC		0x2c	/* Alarm second. */#define RX8111_REG_TIMER_CTRL		0x2d	/* Timer control. */#define RX8111_REG_TS_CTRL0		0x2e	/* Timestamp control 0. */#define RX8111_REG_CMD_TRIGGER		0x2f	/* Timestamp trigger. */#define RX8111_REG_PWR_SWITCH_CTRL	0x32	/* Power switch control. */#define RX8111_REG_STATUS_MON		0x33	/* Status monitor. */#define RX8111_REG_TS_CTRL1		0x34	/* Timestamp control 1. */#define RX8111_REG_TS_CTRL2		0x35	/* Timestamp control 2. */#define RX8111_REG_TS_CTRL3		0x36	/* Timestamp control 3. */ #define RX8111_FLAG_XST_BIT BIT(0)#define RX8111_FLAG_VLF_BIT BIT(1) #define RX8111_TIME_BUF_SZ (RX8111_REG_YEAR - RX8111_REG_SEC + 1) enum rx8111_regfield {	/* RX8111_REG_EXT. */	RX8111_REGF_TSEL0,	RX8111_REGF_TSEL1,	RX8111_REGF_ETS,	RX8111_REGF_WADA,	RX8111_REGF_TE,	RX8111_REGF_USEL,	RX8111_REGF_FSEL0,	RX8111_REGF_FSEL1, 	/* RX8111_REG_FLAG. */	RX8111_REGF_XST,	RX8111_REGF_VLF,	RX8111_REGF_EVF,	RX8111_REGF_AF,	RX8111_REGF_TF,	RX8111_REGF_UF,	RX8111_REGF_POR, 	/* RX8111_REG_CTRL. */	RX8111_REGF_STOP,	RX8111_REGF_EIE,	RX8111_REGF_AIE,	RX8111_REGF_TIE,	RX8111_REGF_UIE, 	/* RX8111_REG_PWR_SWITCH_CTRL. */	RX8111_REGF_SMPT0,	RX8111_REGF_SMPT1,	RX8111_REGF_SWSEL0,	RX8111_REGF_SWSEL1,	RX8111_REGF_INIEN,	RX8111_REGF_CHGEN, 	/* RX8111_REG_STATUS_MON. */	RX8111_REGF_VLOW, 	/* Sentinel value. */	RX8111_REGF_MAX}; static const struct reg_field rx8111_regfields[] = {	[RX8111_REGF_TSEL0] = REG_FIELD(RX8111_REG_EXT, 0, 0),	[RX8111_REGF_TSEL1] = REG_FIELD(RX8111_REG_EXT, 1, 1),	[RX8111_REGF_ETS]   = REG_FIELD(RX8111_REG_EXT, 2, 2),	[RX8111_REGF_WADA]  = REG_FIELD(RX8111_REG_EXT, 3, 3),	[RX8111_REGF_TE]    = REG_FIELD(RX8111_REG_EXT, 4, 4),	[RX8111_REGF_USEL]  = REG_FIELD(RX8111_REG_EXT, 5, 5),	[RX8111_REGF_FSEL0] = REG_FIELD(RX8111_REG_EXT, 6, 6),	[RX8111_REGF_FSEL1] = REG_FIELD(RX8111_REG_EXT, 7, 7), 	[RX8111_REGF_XST] = REG_FIELD(RX8111_REG_FLAG, 0, 0),	[RX8111_REGF_VLF] = REG_FIELD(RX8111_REG_FLAG, 1, 1),	[RX8111_REGF_EVF] = REG_FIELD(RX8111_REG_FLAG, 2, 2),	[RX8111_REGF_AF]  = REG_FIELD(RX8111_REG_FLAG, 3, 3),	[RX8111_REGF_TF]  = REG_FIELD(RX8111_REG_FLAG, 4, 4),	[RX8111_REGF_UF]  = REG_FIELD(RX8111_REG_FLAG, 5, 5),	[RX8111_REGF_POR] = REG_FIELD(RX8111_REG_FLAG, 7, 7), 	[RX8111_REGF_STOP] = REG_FIELD(RX8111_REG_CTRL, 0, 0),	[RX8111_REGF_EIE]  = REG_FIELD(RX8111_REG_CTRL, 2, 2),	[RX8111_REGF_AIE]  = REG_FIELD(RX8111_REG_CTRL, 3, 3),	[RX8111_REGF_TIE]  = REG_FIELD(RX8111_REG_CTRL, 4, 4),	[RX8111_REGF_UIE]  = REG_FIELD(RX8111_REG_CTRL, 5, 5), 	[RX8111_REGF_SMPT0]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 0, 0),	[RX8111_REGF_SMPT1]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 1, 1),	[RX8111_REGF_SWSEL0] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 2, 2),	[RX8111_REGF_SWSEL1] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 3, 3),	[RX8111_REGF_INIEN]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 6, 6),	[RX8111_REGF_CHGEN]  = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 7, 7), 	[RX8111_REGF_VLOW]  = REG_FIELD(RX8111_REG_STATUS_MON, 1, 1),}; static const struct regmap_config rx8111_regmap_config = {	.reg_bits = 8,	.val_bits = 8,	.max_register = RX8111_REG_TS_CTRL3,}; struct rx8111_data {	struct regmap *regmap;	struct regmap_field *regfields[RX8111_REGF_MAX];	struct device *dev;	struct rtc_device *rtc;}; static int rx8111_read_vl_flag(struct rx8111_data *data, unsigned int *vlval){	int ret; 	ret = regmap_field_read(data->regfields[RX8111_REGF_VLF], vlval);	if (ret)		dev_dbg(data->dev, "Could not read VL flag (%d)", ret); 	return ret;} static int rx8111_read_time(struct device *dev, struct rtc_time *tm){	struct rx8111_data *data = dev_get_drvdata(dev);	u8 buf[RX8111_TIME_BUF_SZ];	unsigned int regval;	int ret; 	/* Check status. */	ret = regmap_read(data->regmap, RX8111_REG_FLAG, &regval);	if (ret) {		dev_dbg(data->dev, "Could not read flag register (%d)\n", ret);		return ret;	} 	if (FIELD_GET(RX8111_FLAG_XST_BIT, regval)) {		dev_dbg(data->dev,			"Crystal oscillation stopped, time is not reliable\n");		return -EINVAL;	} 	if (FIELD_GET(RX8111_FLAG_VLF_BIT, regval)) {		dev_dbg(data->dev,			"Low voltage detected, time is not reliable\n");		return -EINVAL;	} 	ret = regmap_field_read(data->regfields[RX8111_REGF_STOP], &regval);	if (ret) {		dev_dbg(data->dev, "Could not read clock status (%d)\n", ret);		return ret;	} 	if (regval) {		dev_dbg(data->dev, "Clock stopped, time is not reliable\n");		return -EINVAL;	} 	/* Read time. */	ret = regmap_bulk_read(data->regmap, RX8111_REG_SEC, buf,			       ARRAY_SIZE(buf));	if (ret) {		dev_dbg(data->dev, "Could not bulk read time (%d)\n", ret);		return ret;	} 	tm->tm_sec = bcd2bin(buf[0]);	tm->tm_min = bcd2bin(buf[1]);	tm->tm_hour = bcd2bin(buf[2]);	tm->tm_wday = ffs(buf[3]) - 1;	tm->tm_mday = bcd2bin(buf[4]);	tm->tm_mon = bcd2bin(buf[5]) - 1;	tm->tm_year = bcd2bin(buf[6]) + 100; 	return 0;} static int rx8111_set_time(struct device *dev, struct rtc_time *tm){	struct rx8111_data *data = dev_get_drvdata(dev);	u8 buf[RX8111_TIME_BUF_SZ];	int ret; 	buf[0] = bin2bcd(tm->tm_sec);	buf[1] = bin2bcd(tm->tm_min);	buf[2] = bin2bcd(tm->tm_hour);	buf[3] = BIT(tm->tm_wday);	buf[4] = bin2bcd(tm->tm_mday);	buf[5] = bin2bcd(tm->tm_mon + 1);	buf[6] = bin2bcd(tm->tm_year - 100); 	ret = regmap_clear_bits(data->regmap, RX8111_REG_FLAG,				RX8111_FLAG_XST_BIT | RX8111_FLAG_VLF_BIT);	if (ret)		return ret; 	/* Stop the clock. */	ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 1);	if (ret) {		dev_dbg(data->dev, "Could not stop the clock (%d)\n", ret);		return ret;	} 	/* Set the time. */	ret = regmap_bulk_write(data->regmap, RX8111_REG_SEC, buf,				ARRAY_SIZE(buf));	if (ret) {		dev_dbg(data->dev, "Could not bulk write time (%d)\n", ret); 		/*		 * We don't bother with trying to start the clock again. We		 * check for this in rx8111_read_time() (and thus force user to		 * call rx8111_set_time() to try again).		 */		return ret;	} 	/* Start the clock. */	ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 0);	if (ret) {		dev_dbg(data->dev, "Could not start the clock (%d)\n", ret);		return ret;	} 	return 0;} static int rx8111_ioctl(struct device *dev, unsigned int cmd, unsigned long arg){	struct rx8111_data *data = dev_get_drvdata(dev);	unsigned int regval;	unsigned int vlval;	int ret; 	switch (cmd) {	case RTC_VL_READ:		ret = rx8111_read_vl_flag(data, &regval);		if (ret)			return ret; 		vlval = regval ? RTC_VL_DATA_INVALID : 0; 		ret = regmap_field_read(data->regfields[RX8111_REGF_VLOW],					&regval);		if (ret)			return ret; 		vlval |= regval ? RTC_VL_BACKUP_LOW : 0; 		return put_user(vlval, (typeof(vlval) __user *)arg);	default:		return -ENOIOCTLCMD;	}} static const struct rtc_class_ops rx8111_rtc_ops = {	.read_time = rx8111_read_time,	.set_time = rx8111_set_time,	.ioctl = rx8111_ioctl,}; static int rx8111_probe(struct i2c_client *client){	struct rx8111_data *data;	struct rtc_device *rtc;	size_t i; 	data = devm_kmalloc(&client->dev, sizeof(*data), GFP_KERNEL);	if (!data) {		dev_dbg(&client->dev, "Could not allocate device data\n");		return -ENOMEM;	} 	data->dev = &client->dev;	dev_set_drvdata(data->dev, data); 	data->regmap = devm_regmap_init_i2c(client, &rx8111_regmap_config);	if (IS_ERR(data->regmap)) {		dev_dbg(data->dev, "Could not initialize regmap\n");		return PTR_ERR(data->regmap);	} 	for (i = 0; i < RX8111_REGF_MAX; ++i) {		data->regfields[i] = devm_regmap_field_alloc(			data->dev, data->regmap, rx8111_regfields[i]);		if (IS_ERR(data->regfields[i])) {			dev_dbg(data->dev,				"Could not allocate register field %zu\n", i);			return PTR_ERR(data->regfields[i]);		}	} 	rtc = devm_rtc_allocate_device(data->dev);	if (IS_ERR(rtc)) {		dev_dbg(data->dev, "Could not allocate rtc device\n");		return PTR_ERR(rtc);	} 	rtc->ops = &rx8111_rtc_ops;	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;	rtc->range_max = RTC_TIMESTAMP_END_2099; 	clear_bit(RTC_FEATURE_ALARM, rtc->features); 	return devm_rtc_register_device(rtc);} static const struct of_device_id rx8111_of_match[] = {	{		.compatible = "epson,rx8111",	},	{}};MODULE_DEVICE_TABLE(of, rx8111_of_match); static struct i2c_driver rx8111_driver = {	.driver = {		.name = "rtc-rx8111",		.of_match_table = rx8111_of_match,	},	.probe = rx8111_probe,};module_i2c_driver(rx8111_driver); MODULE_AUTHOR("Waqar Hameed <waqar.hameed@axis.com>");MODULE_DESCRIPTION("Epson RX8111 RTC driver");MODULE_LICENSE("GPL");