// SPDX-License-Identifier: GPL-2.0-only/* * An I2C driver for the Epson RX8581 RTC * * Author: Martyn Welch <martyn.welch@ge.com> * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc. * * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC) * Copyright 2005-06 Tower Technologies */ #include <linux/module.h>#include <linux/i2c.h>#include <linux/bcd.h>#include <linux/of.h>#include <linux/regmap.h>#include <linux/rtc.h>#include <linux/log2.h> #define RX8581_REG_SC		0x00 /* Second in BCD */#define RX8581_REG_MN		0x01 /* Minute in BCD */#define RX8581_REG_HR		0x02 /* Hour in BCD */#define RX8581_REG_DW		0x03 /* Day of Week */#define RX8581_REG_DM		0x04 /* Day of Month in BCD */#define RX8581_REG_MO		0x05 /* Month in BCD */#define RX8581_REG_YR		0x06 /* Year in BCD */#define RX8581_REG_RAM		0x07 /* RAM */#define RX8581_REG_AMN		0x08 /* Alarm Min in BCD*/#define RX8581_REG_AHR		0x09 /* Alarm Hour in BCD */#define RX8581_REG_ADM		0x0A#define RX8581_REG_ADW		0x0A#define RX8581_REG_TMR0		0x0B#define RX8581_REG_TMR1		0x0C#define RX8581_REG_EXT		0x0D /* Extension Register */#define RX8581_REG_FLAG		0x0E /* Flag Register */#define RX8581_REG_CTRL		0x0F /* Control Register */  /* Flag Register bit definitions */#define RX8581_FLAG_UF		0x20 /* Update */#define RX8581_FLAG_TF		0x10 /* Timer */#define RX8581_FLAG_AF		0x08 /* Alarm */#define RX8581_FLAG_VLF		0x02 /* Voltage Low */ /* Control Register bit definitions */#define RX8581_CTRL_UIE		0x20 /* Update Interrupt Enable */#define RX8581_CTRL_TIE		0x10 /* Timer Interrupt Enable */#define RX8581_CTRL_AIE		0x08 /* Alarm Interrupt Enable */#define RX8581_CTRL_STOP	0x02 /* STOP bit */#define RX8581_CTRL_RESET	0x01 /* RESET bit */ #define RX8571_USER_RAM		0x10#define RX8571_NVRAM_SIZE	0x10 struct rx85x1_config {	struct regmap_config regmap;	unsigned int num_nvram;}; /* * In the routines that deal directly with the rx8581 hardware, we use * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch. */static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm){	struct i2c_client *client = to_i2c_client(dev);	unsigned char date[7];	unsigned int data;	int err;	struct regmap *regmap = i2c_get_clientdata(client); 	/* First we ensure that the "update flag" is not set, we read the	 * time and date then re-read the "update flag". If the update flag	 * has been set, we know that the time has changed during the read so	 * we repeat the whole process again.	 */	err = regmap_read(regmap, RX8581_REG_FLAG, &data);	if (err < 0)		return err; 	if (data & RX8581_FLAG_VLF) {		dev_warn(dev,			 "low voltage detected, date/time is not reliable.\n");		return -EINVAL;	} 	do {		/* If update flag set, clear it */		if (data & RX8581_FLAG_UF) {			err = regmap_write(regmap, RX8581_REG_FLAG,					   data & ~RX8581_FLAG_UF);			if (err < 0)				return err;		} 		/* Now read time and date */		err = regmap_bulk_read(regmap, RX8581_REG_SC, date,				       sizeof(date));		if (err < 0)			return err; 		/* Check flag register */		err = regmap_read(regmap, RX8581_REG_FLAG, &data);		if (err < 0)			return err;	} while (data & RX8581_FLAG_UF); 	dev_dbg(dev, "%s: raw data is sec=%02x, min=%02x, hr=%02x, "		"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",		__func__,		date[0], date[1], date[2], date[3], date[4], date[5], date[6]); 	tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);	tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);	tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */	tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);	tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */	tm->tm_year = bcd2bin(date[RX8581_REG_YR]) + 100; 	dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "		"mday=%d, mon=%d, year=%d, wday=%d\n",		__func__,		tm->tm_sec, tm->tm_min, tm->tm_hour,		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 	return 0;} static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm){	struct i2c_client *client = to_i2c_client(dev);	int err;	unsigned char buf[7];	struct regmap *regmap = i2c_get_clientdata(client); 	dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "		"mday=%d, mon=%d, year=%d, wday=%d\n",		__func__,		tm->tm_sec, tm->tm_min, tm->tm_hour,		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); 	/* hours, minutes and seconds */	buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);	buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);	buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour); 	buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday); 	/* month, 1 - 12 */	buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1); 	/* year and century */	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year - 100);	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday); 	/* Stop the clock */	err = regmap_update_bits(regmap, RX8581_REG_CTRL,				 RX8581_CTRL_STOP, RX8581_CTRL_STOP);	if (err < 0)		return err; 	/* write register's data */	err = regmap_bulk_write(regmap, RX8581_REG_SC, buf, sizeof(buf));	if (err < 0)		return err; 	/* get VLF and clear it */	err = regmap_update_bits(regmap, RX8581_REG_FLAG, RX8581_FLAG_VLF, 0);	if (err < 0)		return err; 	/* Restart the clock */	return regmap_update_bits(regmap, RX8581_REG_CTRL,				 RX8581_CTRL_STOP, 0);} static const struct rtc_class_ops rx8581_rtc_ops = {	.read_time	= rx8581_rtc_read_time,	.set_time	= rx8581_rtc_set_time,}; static int rx8571_nvram_read(void *priv, unsigned int offset, void *val,			     size_t bytes){	struct regmap *regmap = priv; 	return regmap_bulk_read(regmap, RX8571_USER_RAM + offset, val, bytes);} static int rx8571_nvram_write(void *priv, unsigned int offset, void *val,			      size_t bytes){	struct regmap *regmap = priv; 	return regmap_bulk_write(regmap, RX8571_USER_RAM + offset, val, bytes);} static int rx85x1_nvram_read(void *priv, unsigned int offset, void *val,			     size_t bytes){	struct regmap *regmap = priv;	unsigned int tmp_val;	int ret; 	ret = regmap_read(regmap, RX8581_REG_RAM, &tmp_val);	(*(unsigned char *)val) = (unsigned char) tmp_val; 	return ret;} static int rx85x1_nvram_write(void *priv, unsigned int offset, void *val,			      size_t bytes){	struct regmap *regmap = priv;	unsigned char tmp_val; 	tmp_val = *((unsigned char *)val);	return regmap_write(regmap, RX8581_REG_RAM, (unsigned int)tmp_val);} static const struct rx85x1_config rx8581_config = {	.regmap = {		.reg_bits = 8,		.val_bits = 8,		.max_register = 0xf,	},	.num_nvram = 1}; static const struct rx85x1_config rx8571_config = {	.regmap = {		.reg_bits = 8,		.val_bits = 8,		.max_register = 0x1f,	},	.num_nvram = 2}; static int rx8581_probe(struct i2c_client *client){	struct regmap *regmap;	const struct rx85x1_config *config = &rx8581_config;	const void *data = of_device_get_match_data(&client->dev);	struct rtc_device *rtc;	static struct nvmem_config nvmem_cfg[] = {		{			.name = "rx85x1-",			.word_size = 1,			.stride = 1,			.size = 1,			.reg_read = rx85x1_nvram_read,			.reg_write = rx85x1_nvram_write,		}, {			.name = "rx8571-",			.word_size = 1,			.stride = 1,			.size = RX8571_NVRAM_SIZE,			.reg_read = rx8571_nvram_read,			.reg_write = rx8571_nvram_write,		},	};	int ret, i; 	dev_dbg(&client->dev, "%s\n", __func__); 	if (data)		config = data; 	regmap = devm_regmap_init_i2c(client, &config->regmap);	if (IS_ERR(regmap))		return PTR_ERR(regmap); 	i2c_set_clientdata(client, regmap); 	rtc = devm_rtc_allocate_device(&client->dev);	if (IS_ERR(rtc))		return PTR_ERR(rtc); 	rtc->ops = &rx8581_rtc_ops;	rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;	rtc->range_max = RTC_TIMESTAMP_END_2099;	rtc->start_secs = 0;	rtc->set_start_time = true; 	ret = devm_rtc_register_device(rtc); 	for (i = 0; i < config->num_nvram; i++) {		nvmem_cfg[i].priv = regmap;		devm_rtc_nvmem_register(rtc, &nvmem_cfg[i]);	} 	return ret;} static const struct i2c_device_id rx8581_id[] = {	{ .name = "rx8581" },	{ }};MODULE_DEVICE_TABLE(i2c, rx8581_id); static const __maybe_unused struct of_device_id rx8581_of_match[] = {	{ .compatible = "epson,rx8571", .data = &rx8571_config },	{ .compatible = "epson,rx8581", .data = &rx8581_config },	{ /* sentinel */ }};MODULE_DEVICE_TABLE(of, rx8581_of_match); static struct i2c_driver rx8581_driver = {	.driver		= {		.name	= "rtc-rx8581",		.of_match_table = of_match_ptr(rx8581_of_match),	},	.probe		= rx8581_probe,	.id_table	= rx8581_id,}; module_i2c_driver(rx8581_driver); MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");MODULE_DESCRIPTION("Epson RX-8571/RX-8581 RTC driver");MODULE_LICENSE("GPL");