// SPDX-License-Identifier: GPL-2.0-only/* * An rtc/i2c driver for the EM Microelectronic EM3027 * Copyright 2011 CompuLab, Ltd. * * Author: Mike Rapoport <mike@compulab.co.il> * * Based on rtc-ds1672.c by Alessandro Zummo <a.zummo@towertech.it> */ #include <linux/i2c.h>#include <linux/rtc.h>#include <linux/bcd.h>#include <linux/module.h>#include <linux/of.h> /* Registers */#define EM3027_REG_ON_OFF_CTRL	0x00#define EM3027_REG_IRQ_CTRL	0x01#define EM3027_REG_IRQ_FLAGS	0x02#define EM3027_REG_STATUS	0x03#define EM3027_REG_RST_CTRL	0x04 #define EM3027_REG_WATCH_SEC	0x08#define EM3027_REG_WATCH_MIN	0x09#define EM3027_REG_WATCH_HOUR	0x0a#define EM3027_REG_WATCH_DATE	0x0b#define EM3027_REG_WATCH_DAY	0x0c#define EM3027_REG_WATCH_MON	0x0d#define EM3027_REG_WATCH_YEAR	0x0e #define EM3027_REG_ALARM_SEC	0x10#define EM3027_REG_ALARM_MIN	0x11#define EM3027_REG_ALARM_HOUR	0x12#define EM3027_REG_ALARM_DATE	0x13#define EM3027_REG_ALARM_DAY	0x14#define EM3027_REG_ALARM_MON	0x15#define EM3027_REG_ALARM_YEAR	0x16 static struct i2c_driver em3027_driver; static int em3027_get_time(struct device *dev, struct rtc_time *tm){	struct i2c_client *client = to_i2c_client(dev); 	unsigned char addr = EM3027_REG_WATCH_SEC;	unsigned char buf[7]; 	struct i2c_msg msgs[] = {		{/* setup read addr */			.addr = client->addr,			.len = 1,			.buf = &addr		},		{/* read time/date */			.addr = client->addr,			.flags = I2C_M_RD,			.len = 7,			.buf = buf		},	}; 	/* read time/date registers */	if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {		dev_err(&client->dev, "%s: read error\n", __func__);		return -EIO;	} 	tm->tm_sec	= bcd2bin(buf[0]);	tm->tm_min	= bcd2bin(buf[1]);	tm->tm_hour	= bcd2bin(buf[2]);	tm->tm_mday	= bcd2bin(buf[3]);	tm->tm_wday	= bcd2bin(buf[4]);	tm->tm_mon	= bcd2bin(buf[5]) - 1;	tm->tm_year	= bcd2bin(buf[6]) + 100; 	return 0;} static int em3027_set_time(struct device *dev, struct rtc_time *tm){	struct i2c_client *client = to_i2c_client(dev);	unsigned char buf[8]; 	struct i2c_msg msg = {		.addr = client->addr,		.len = 8,		.buf = buf,	/* write time/date */	}; 	buf[0] = EM3027_REG_WATCH_SEC;	buf[1] = bin2bcd(tm->tm_sec);	buf[2] = bin2bcd(tm->tm_min);	buf[3] = bin2bcd(tm->tm_hour);	buf[4] = bin2bcd(tm->tm_mday);	buf[5] = bin2bcd(tm->tm_wday);	buf[6] = bin2bcd(tm->tm_mon + 1);	buf[7] = bin2bcd(tm->tm_year % 100); 	/* write time/date registers */	if ((i2c_transfer(client->adapter, &msg, 1)) != 1) {		dev_err(&client->dev, "%s: write error\n", __func__);		return -EIO;	} 	return 0;} static const struct rtc_class_ops em3027_rtc_ops = {	.read_time = em3027_get_time,	.set_time = em3027_set_time,}; static int em3027_probe(struct i2c_client *client){	struct rtc_device *rtc; 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))		return -ENODEV; 	rtc = devm_rtc_device_register(&client->dev, em3027_driver.driver.name,				  &em3027_rtc_ops, THIS_MODULE);	if (IS_ERR(rtc))		return PTR_ERR(rtc); 	i2c_set_clientdata(client, rtc); 	return 0;} static const struct i2c_device_id em3027_id[] = {	{ .name = "em3027" },	{ }};MODULE_DEVICE_TABLE(i2c, em3027_id); #ifdef CONFIG_OFstatic const struct of_device_id em3027_of_match[] = {	{ .compatible = "emmicro,em3027", },	{}};MODULE_DEVICE_TABLE(of, em3027_of_match);#endif static struct i2c_driver em3027_driver = {	.driver = {		   .name = "rtc-em3027",		   .of_match_table = of_match_ptr(em3027_of_match),	},	.probe = em3027_probe,	.id_table = em3027_id,}; module_i2c_driver(em3027_driver); MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver");MODULE_LICENSE("GPL");