163 lines
3.8 KiB
C
163 lines
3.8 KiB
C
/*
|
|
* 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[] = {
|
|
{client->addr, 0, 1, &addr}, /* setup read addr */
|
|
{client->addr, I2C_M_RD, 7, buf}, /* read time/date */
|
|
};
|
|
|
|
/* 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 = {
|
|
client->addr, 0, 8, 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 = rtc_device_register(em3027_driver.driver.name, &client->dev,
|
|
&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)
|
|
{
|
|
struct rtc_device *rtc = i2c_get_clientdata(client);
|
|
|
|
if (rtc)
|
|
rtc_device_unregister(rtc);
|
|
|
|
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,
|
|
};
|
|
|
|
static int __init em3027_init(void)
|
|
{
|
|
return i2c_add_driver(&em3027_driver);
|
|
}
|
|
|
|
static void __exit em3027_exit(void)
|
|
{
|
|
i2c_del_driver(&em3027_driver);
|
|
}
|
|
|
|
MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
|
|
MODULE_DESCRIPTION("EM Microelectronic EM3027 RTC driver");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(em3027_init);
|
|
module_exit(em3027_exit);
|