/*
* An I2C driver for the Ricoh RS5C372 RTC
*
* Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
* Copyright (C) 2006 Tower Technologies
*
* 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>
#define DRV_VERSION "0.2"
/* Addresses to scan */
static unsigned short normal_i2c[] = { /* 0x32,*/ I2C_CLIENT_END };
/* Insmod parameters */
I2C_CLIENT_INSMOD;
#define RS5C372_REG_SECS 0
#define RS5C372_REG_MINS 1
#define RS5C372_REG_HOURS 2
#define RS5C372_REG_WDAY 3
#define RS5C372_REG_DAY 4
#define RS5C372_REG_MONTH 5
#define RS5C372_REG_YEAR 6
#define RS5C372_REG_TRIM 7
#define RS5C372_TRIM_XSL 0x80
#define RS5C372_TRIM_MASK 0x7F
#define RS5C372_REG_BASE 0
static int rs5c372_attach(struct i2c_adapter *adapter);
static int rs5c372_detach(struct i2c_client *client);
static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind);
static struct i2c_driver rs5c372_driver = {
.driver = {
.name = "rs5c372",
},
.attach_adapter = &rs5c372_attach,
.detach_client = &rs5c372_detach,
};
static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
unsigned char buf[7] = { RS5C372_REG_BASE };
/* this implements the 1st reading method, according
* to the datasheet. buf[0] is initialized with
* address ptr and transmission format register.
*/
struct i2c_msg msgs[] = {
{ client->addr, 0, 1, buf },
{ client->addr, I2C_M_RD, 7, buf },
};
if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
return -EIO;
}
tm->tm_sec = BCD2BIN(buf[RS5C372_REG_SECS] & 0x7f);
tm->tm_min = BCD2BIN(buf[RS5C372_REG_MINS] & 0x7f);
tm->tm_hour = BCD2BIN(buf[RS5C372_REG_HOURS] & 0x3f);
tm->tm_wday = BCD2BIN(buf[RS5C372_REG_WDAY] & 0x07);
tm->tm_mday = BCD2BIN(buf[RS5C372_REG_DAY] & 0x3f);
/* tm->tm_mon is zero-based */
tm->tm_mon = BCD2BIN(buf[RS5C372_REG_MONTH] & 0x1f) - 1;
/* year is 1900 + tm->tm_year */
tm->tm_year = BCD2BIN(buf[RS5C372_REG_YEAR]) + 100;
dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__FUNCTION__,
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 rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
unsigned char buf[8] = { RS5C372_REG_BASE };
dev_dbg(&client->dev,
"%s: secs=%d, mins=%d, hours=%d "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__FUNCTION__, tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
buf[1] = BIN2BCD(tm->tm_sec);
buf[2] = BIN2BCD(tm->tm_min);
buf[3] = BIN2BCD(tm->tm_hour);
buf[4] = BIN2BCD(tm->tm_wday);
buf[5] = BIN2BCD(tm->tm_mday);
buf[6] = BIN2BCD(tm->tm_mon + 1);
buf[7] = BIN2BCD(tm->tm_year - 100);
if ((i2c_master_send(client, buf, 8)) != 8) {
dev_err(&client->dev, "%s: write error\n", __FUNCTION__);
return -EIO;
}
return 0;
}
static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
{
unsigned char buf = RS5C372_REG_TRIM;
struct i2c_msg msgs[] = {
{ client->addr, 0, 1, &buf },
{ client->addr, I2C_M_RD, 1, &buf },
};
if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
return -EIO;
}
dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, *trim);
if (osc)
*osc = (buf & RS5C372_TRIM_XSL) ? 32000 : 32768;
if (trim)
*trim = buf & RS5C372_TRIM_MASK;
return 0;
}
static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return rs5c372_get_datetime(to_i2c_client(dev), tm);
}
static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return rs5c372_set_datetime(to_i2c_client(dev), tm);
}
static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
{
int err, osc, trim;
err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
if (err == 0) {
seq_printf(seq, "%d.%03d KHz\n", osc / 1000, osc % 1000);
seq_printf(seq, "trim\t: %d\n", trim);
}
return 0;
}
static const struct rtc_class_ops rs5c372_rtc_ops = {
.proc = rs5c372_rtc_proc,
.read_time = rs5c372_rtc_read_time,
.set_time = rs5c372_rtc_set_time,
};
static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
struct device_attribute *attr, char *buf)
{
int err, trim;
err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
if (err)
return err;
return sprintf(buf, "0x%2x\n", trim);
}
static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
struct device_attribute *attr, char *buf)
{
int err, osc;
err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
if (err)
return err;
return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
}
static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
static int rs5c372_attach(struct i2c_adapter *adapter)
{
return i2c_probe(adapter, &addr_data, rs5c372_probe);
}
static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind)
{
int err = 0;
struct i2c_client *client;
struct rtc_device *rtc;
dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
err = -ENODEV;
goto exit;
}
if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}
/* I2C client */
client->addr = address;
client->driver = &rs5c372_driver;
client->adapter = adapter;
strlcpy(client->name, rs5c372_driver.driver.name, I2C_NAME_SIZE);
/* Inform the i2c layer */
if ((err = i2c_attach_client(client)))
goto exit_kfree;
dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
rtc = rtc_device_register(rs5c372_driver.driver.name, &client->dev,
&rs5c372_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc)) {
err = PTR_ERR(rtc);
goto exit_detach;
}
i2c_set_clientdata(client, rtc);
device_create_file(&client->dev, &dev_attr_trim);
device_create_file(&client->dev, &dev_attr_osc);
return 0;
exit_detach:
i2c_detach_client(client);
exit_kfree:
kfree(client);
exit:
return err;
}
static int rs5c372_detach(struct i2c_client *client)
{
int err;
struct rtc_device *rtc = i2c_get_clientdata(client);
if (rtc)
rtc_device_unregister(rtc);
if ((err = i2c_detach_client(client)))
return err;
kfree(client);
return 0;
}
static __init int rs5c372_init(void)
{
return i2c_add_driver(&rs5c372_driver);
}
static __exit void rs5c372_exit(void)
{
i2c_del_driver(&rs5c372_driver);
}
module_init(rs5c372_init);
module_exit(rs5c372_exit);
MODULE_AUTHOR(
"Pavel Mironchik <pmironchik@optifacio.net>, "
"Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
