/*
ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
monitoring
Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23
based on lm75.c by Frodo Looijaard <frodol@dds.nl>
Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
the help of Jean Delvare <khali@linux-fr.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include "lm75.h"
/* Addresses to scan */
static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
/* Insmod parameters */
I2C_CLIENT_INSMOD_1(ds1621);
static int polarity = -1;
module_param(polarity, int, 0);
MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
/* Many DS1621 constants specified below */
/* Config register used for detection */
/* 7 6 5 4 3 2 1 0 */
/* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */
#define DS1621_REG_CONFIG_NVB 0x10
#define DS1621_REG_CONFIG_POLARITY 0x02
#define DS1621_REG_CONFIG_1SHOT 0x01
#define DS1621_REG_CONFIG_DONE 0x80
/* The DS1621 registers */
#define DS1621_REG_TEMP 0xAA /* word, RO */
#define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */
#define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */
#define DS1621_REG_CONF 0xAC /* byte, RW */
#define DS1621_COM_START 0xEE /* no data */
#define DS1621_COM_STOP 0x22 /* no data */
/* The DS1621 configuration register */
#define DS1621_ALARM_TEMP_HIGH 0x40
#define DS1621_ALARM_TEMP_LOW 0x20
/* Conversions. Rounding and limit checking is only done on the TO_REG
variants. Note that you should be a bit careful with which arguments
these macros are called: arguments may be evaluated more than once.
Fixing this is just not worth it. */
#define ALARMS_FROM_REG(val) ((val) & \
(DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
/* Each client has this additional data */
struct ds1621_data {
struct i2c_client client;
struct class_device *class_dev;
struct semaphore update_lock;
char valid; /* !=0 if following fields are valid */
unsigned long last_updated; /* In jiffies */
u16 temp, temp_min, temp_max; /* Register values, word */
u8 conf; /* Register encoding, combined */
};
static int ds1621_attach_adapter(struct i2c_adapter *adapter);
static int ds1621_detect(struct i2c_adapter *adapter, int address,
int kind);
static void ds1621_init_client(struct i2c_client *client);
static int ds1621_detach_client(struct i2c_client *client);
static struct ds1621_data *ds1621_update_client(struct device *dev);
/* This is the driver that will be inserted */
static struct i2c_driver ds1621_driver = {
.owner = THIS_MODULE,
.name = "ds1621",
.id = I2C_DRIVERID_DS1621,
.attach_adapter = ds1621_attach_adapter,
.detach_client = ds1621_detach_client,
};
/* All registers are word-sized, except for the configuration register.
DS1621 uses a high-byte first convention, which is exactly opposite to
the usual practice. */
static int ds1621_read_value(struct i2c_client *client, u8 reg)
{
if (reg == DS1621_REG_CONF)
return i2c_smbus_read_byte_data(client, reg);
else
return swab16(i2c_smbus_read_word_data(client, reg));
}
/* All registers are word-sized, except for the configuration register.
DS1621 uses a high-byte first convention, which is exactly opposite to
the usual practice. */
static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
{
if (reg == DS1621_REG_CONF)
return i2c_smbus_write_byte_data(client, reg, value);
else
return i2c_smbus_write_word_data(client, reg, swab16(value));
}
static void ds1621_init_client(struct i2c_client *client)
{
int reg = ds1621_read_value(client, DS1621_REG_CONF);
/* switch to continuous conversion mode */
reg &= ~ DS1621_REG_CONFIG_1SHOT;
/* setup output polarity */
if (polarity == 0)
reg &= ~DS1621_REG_CONFIG_POLARITY;
else if (polarity == 1)
reg |= DS1621_REG_CONFIG_POLARITY;
ds1621_write_value(client, DS1621_REG_CONF, reg);
/* start conversion */
i2c_smbus_write_byte(client, DS1621_COM_START);
}
#define show(value) \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
struct ds1621_data *data = ds1621_update_client(dev); \
return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
}
show(temp);
show(temp_min);
show(temp_max);
#define set_temp(suffix, value, reg) \
static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
size_t count) \
{ \
struct i2c_client *client = to_i2c_client(dev); \
struct ds1621_data *data = ds1621_update_client(dev); \
u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
\
down(&data->update_lock); \
data->value = val; \
ds1621_write_value(client, reg, data->value); \
up(&data->update_lock); \
return count; \
}
set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
struct ds1621_data *data = ds1621_update_client(dev);
return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
}
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min);
static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
static int ds1621_attach_adapter(struct i2c_adapter *adapter)
{
if (!(adapter->class & I2C_CLASS_HWMON))
return 0;
return i2c_probe(adapter, &addr_data, ds1621_detect);
}
/* This function is called by i2c_probe */
static int ds1621_detect(struct i2c_adapter *adapter, int address,
int kind)
{
int conf, temp;
struct i2c_client *new_client;
struct ds1621_data *data;
int err = 0;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_WORD_DATA
| I2C_FUNC_SMBUS_WRITE_BYTE))
goto exit;
/* OK. For now, we presume we have a valid client. We now create the
client structure, even though we cannot fill it completely yet.
But it allows us to access ds1621_{read,write}_value. */
if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}
new_client = &data->client;
i2c_set_clientdata(new_client, data);
new_client->addr = address;
new_client->adapter = adapter;
new_client->driver = &ds1621_driver;
new_client->flags = 0;
/* Now, we do the remaining detection. It is lousy. */
if (kind < 0) {
/* The NVB bit should be low if no EEPROM write has been
requested during the latest 10ms, which is highly
improbable in our case. */
conf = ds1621_read_value(new_client, DS1621_REG_CONF);
if (conf & DS1621_REG_CONFIG_NVB)
goto exit_free;
/* The 7 lowest bits of a temperature should always be 0. */
temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
if (temp & 0x007f)
goto exit_free;
temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
if (temp & 0x007f)
goto exit_free;
temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
if (temp & 0x007f)
goto exit_free;
}
/* Determine the chip type - only one kind supported! */
if (kind <= 0)
kind = ds1621;
/* Fill in remaining client fields and put it into the global list */
strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE);
data->valid = 0;
init_MUTEX(&data->update_lock);
/* Tell the I2C layer a new client has arrived */
if ((err = i2c_attach_client(new_client)))
goto exit_free;
/* Initialize the DS1621 chip */
ds1621_init_client(new_client);
/* Register sysfs hooks */
data->class_dev = hwmon_device_register(&new_client->dev);
if (IS_ERR(data->class_dev)) {
err = PTR_ERR(data->class_dev);
goto exit_detach;
}
device_create_file(&new_client->dev, &dev_attr_alarms);
device_create_file(&new_client->dev, &dev_attr_temp1_input);
device_create_file(&new_client->dev, &dev_attr_temp1_min);
device_create_file(&new_client->dev, &dev_attr_temp1_max);
return 0;
/* OK, this is not exactly good programming practice, usually. But it is
very code-efficient in this case. */
exit_detach:
i2c_detach_client(new_client);
exit_free:
kfree(data);
exit:
return err;
}
static int ds1621_detach_client(struct i2c_client *client)
{
struct ds1621_data *data = i2c_get_clientdata(client);
int err;
hwmon_device_unregister(data->class_dev);
if ((err = i2c_detach_client(client)))
return err;
kfree(data);
return 0;
}
static struct ds1621_data *ds1621_update_client(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1621_data *data = i2c_get_clientdata(client);
u8 new_conf;
down(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
|| !data->valid) {
dev_dbg(&client->dev, "Starting ds1621 update\n");
data->conf = ds1621_read_value(client, DS1621_REG_CONF);
data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
data->temp_min = ds1621_read_value(client,
DS1621_REG_TEMP_MIN);
data->temp_max = ds1621_read_value(client,
DS1621_REG_TEMP_MAX);
/* reset alarms if necessary */
new_conf = data->conf;
if (data->temp < data->temp_min)
new_conf &= ~DS1621_ALARM_TEMP_LOW;
if (data->temp > data->temp_max)
new_conf &= ~DS1621_ALARM_TEMP_HIGH;
if (data->conf != new_conf)
ds1621_write_value(client, DS1621_REG_CONF,
new_conf);
data->last_updated = jiffies;
data->valid = 1;
}
up(&data->update_lock);
return data;
}
static int __init ds1621_init(void)
{
return i2c_add_driver(&ds1621_driver);
}
static void __exit ds1621_exit(void)
{
i2c_del_driver(&ds1621_driver);
}
MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
MODULE_DESCRIPTION("DS1621 driver");
MODULE_LICENSE("GPL");
module_init(ds1621_init);
module_exit(ds1621_exit);
