/* * 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> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/i2c.h> #include <linux/rtc.h> #include <linux/bcd.h> #include <linux/module.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]); 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); 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, const struct i2c_device_id *id) { 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 int em3027_remove(struct i2c_client *client) { return 0; } static struct i2c_device_id em3027_id[] = { { "em3027", 0 }, { } }; static struct i2c_driver em3027_driver = { .driver = { .name = "rtc-em3027", }, .probe = &em3027_probe, .remove = &em3027_remove, .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");