278 lines
6.4 KiB
C
278 lines
6.4 KiB
C
/*
|
|
* An rtc/i2c driver for the Dallas DS1672
|
|
* Copyright 2005-06 Tower Technologies
|
|
*
|
|
* Author: 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/module.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/rtc.h>
|
|
|
|
#define DRV_VERSION "0.3"
|
|
|
|
/* Addresses to scan: none. This chip cannot be detected. */
|
|
static unsigned short normal_i2c[] = { I2C_CLIENT_END };
|
|
|
|
/* Insmod parameters */
|
|
I2C_CLIENT_INSMOD;
|
|
|
|
/* Registers */
|
|
|
|
#define DS1672_REG_CNT_BASE 0
|
|
#define DS1672_REG_CONTROL 4
|
|
#define DS1672_REG_TRICKLE 5
|
|
|
|
#define DS1672_REG_CONTROL_EOSC 0x80
|
|
|
|
/* Prototypes */
|
|
static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind);
|
|
|
|
/*
|
|
* In the routines that deal directly with the ds1672 hardware, we use
|
|
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
|
|
* Epoch is initialized as 2000. Time is set to UTC.
|
|
*/
|
|
static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm)
|
|
{
|
|
unsigned long time;
|
|
unsigned char addr = DS1672_REG_CNT_BASE;
|
|
unsigned char buf[4];
|
|
|
|
struct i2c_msg msgs[] = {
|
|
{ client->addr, 0, 1, &addr }, /* setup read ptr */
|
|
{ client->addr, I2C_M_RD, 4, buf }, /* read date */
|
|
};
|
|
|
|
/* read date registers */
|
|
if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
|
|
dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
|
|
return -EIO;
|
|
}
|
|
|
|
dev_dbg(&client->dev,
|
|
"%s: raw read data - counters=%02x,%02x,%02x,%02x\n",
|
|
__FUNCTION__, buf[0], buf[1], buf[2], buf[3]);
|
|
|
|
time = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
|
|
|
|
rtc_time_to_tm(time, tm);
|
|
|
|
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 ds1672_set_mmss(struct i2c_client *client, unsigned long secs)
|
|
{
|
|
int xfer;
|
|
unsigned char buf[6];
|
|
|
|
buf[0] = DS1672_REG_CNT_BASE;
|
|
buf[1] = secs & 0x000000FF;
|
|
buf[2] = (secs & 0x0000FF00) >> 8;
|
|
buf[3] = (secs & 0x00FF0000) >> 16;
|
|
buf[4] = (secs & 0xFF000000) >> 24;
|
|
buf[5] = 0; /* set control reg to enable counting */
|
|
|
|
xfer = i2c_master_send(client, buf, 6);
|
|
if (xfer != 6) {
|
|
dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer);
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ds1672_set_datetime(struct i2c_client *client, struct rtc_time *tm)
|
|
{
|
|
unsigned long secs;
|
|
|
|
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);
|
|
|
|
rtc_tm_to_time(tm, &secs);
|
|
|
|
return ds1672_set_mmss(client, secs);
|
|
}
|
|
|
|
static int ds1672_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
return ds1672_get_datetime(to_i2c_client(dev), tm);
|
|
}
|
|
|
|
static int ds1672_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
return ds1672_set_datetime(to_i2c_client(dev), tm);
|
|
}
|
|
|
|
static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs)
|
|
{
|
|
return ds1672_set_mmss(to_i2c_client(dev), secs);
|
|
}
|
|
|
|
static int ds1672_get_control(struct i2c_client *client, u8 *status)
|
|
{
|
|
unsigned char addr = DS1672_REG_CONTROL;
|
|
|
|
struct i2c_msg msgs[] = {
|
|
{ client->addr, 0, 1, &addr }, /* setup read ptr */
|
|
{ client->addr, I2C_M_RD, 1, status }, /* read control */
|
|
};
|
|
|
|
/* read control register */
|
|
if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
|
|
dev_err(&client->dev, "%s: read error\n", __FUNCTION__);
|
|
return -EIO;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* following are the sysfs callback functions */
|
|
static ssize_t show_control(struct device *dev, struct device_attribute *attr, char *buf)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
u8 control;
|
|
int err;
|
|
|
|
err = ds1672_get_control(client, &control);
|
|
if (err)
|
|
return err;
|
|
|
|
return sprintf(buf, "%s\n", (control & DS1672_REG_CONTROL_EOSC)
|
|
? "disabled" : "enabled");
|
|
}
|
|
static DEVICE_ATTR(control, S_IRUGO, show_control, NULL);
|
|
|
|
static const struct rtc_class_ops ds1672_rtc_ops = {
|
|
.read_time = ds1672_rtc_read_time,
|
|
.set_time = ds1672_rtc_set_time,
|
|
.set_mmss = ds1672_rtc_set_mmss,
|
|
};
|
|
|
|
static int ds1672_attach(struct i2c_adapter *adapter)
|
|
{
|
|
return i2c_probe(adapter, &addr_data, ds1672_probe);
|
|
}
|
|
|
|
static int ds1672_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 struct i2c_driver ds1672_driver = {
|
|
.driver = {
|
|
.name = "ds1672",
|
|
},
|
|
.id = I2C_DRIVERID_DS1672,
|
|
.attach_adapter = &ds1672_attach,
|
|
.detach_client = &ds1672_detach,
|
|
};
|
|
|
|
static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind)
|
|
{
|
|
int err = 0;
|
|
u8 control;
|
|
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 = &ds1672_driver;
|
|
client->adapter = adapter;
|
|
|
|
strlcpy(client->name, ds1672_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(ds1672_driver.driver.name, &client->dev,
|
|
&ds1672_rtc_ops, THIS_MODULE);
|
|
|
|
if (IS_ERR(rtc)) {
|
|
err = PTR_ERR(rtc);
|
|
goto exit_detach;
|
|
}
|
|
|
|
i2c_set_clientdata(client, rtc);
|
|
|
|
/* read control register */
|
|
err = ds1672_get_control(client, &control);
|
|
if (err)
|
|
goto exit_detach;
|
|
|
|
if (control & DS1672_REG_CONTROL_EOSC)
|
|
dev_warn(&client->dev, "Oscillator not enabled. "
|
|
"Set time to enable.\n");
|
|
|
|
/* Register sysfs hooks */
|
|
device_create_file(&client->dev, &dev_attr_control);
|
|
|
|
return 0;
|
|
|
|
exit_detach:
|
|
i2c_detach_client(client);
|
|
|
|
exit_kfree:
|
|
kfree(client);
|
|
|
|
exit:
|
|
return err;
|
|
}
|
|
|
|
static int __init ds1672_init(void)
|
|
{
|
|
return i2c_add_driver(&ds1672_driver);
|
|
}
|
|
|
|
static void __exit ds1672_exit(void)
|
|
{
|
|
i2c_del_driver(&ds1672_driver);
|
|
}
|
|
|
|
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
|
|
MODULE_DESCRIPTION("Dallas/Maxim DS1672 timekeeper driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_VERSION(DRV_VERSION);
|
|
|
|
module_init(ds1672_init);
|
|
module_exit(ds1672_exit);
|