/*
* 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>
*
* The DS1621 device is a digital temperature/thermometer with 9-bit
* resolution, a thermal alarm output (Tout), and user-defined minimum
* and maximum temperature thresholds (TH and TL).
*
* The DS1625 and DS1721 are pin compatible with the DS1621 and similar
* in operation, with slight variations as noted in the device
* datasheets (please refer to www.maximintegrated.com for specific
* device information).
*
* Since the DS1621 was the first chipset supported by this driver,
* most comments will refer to this chipset, but are actually general
* and concern all supported chipsets, unless mentioned otherwise.
*
* 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/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/kernel.h>
/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
/* Supported devices */
enum chips { ds1621, ds1625, ds1721 };
/* Insmod parameters */
static int polarity = -1;
module_param(polarity, int, 0);
MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
/*
* The Configuration/Status register
*
* - DS1621:
* 7 6 5 4 3 2 1 0
* |Done|THF |TLF |NVB | X | X |POL |1SHOT|
*
* - DS1625:
* 7 6 5 4 3 2 1 0
* |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT|
*
* - DS1721:
* 7 6 5 4 3 2 1 0
* |Done| X | X | U | R1 | R0 |POL |1SHOT|
*
* Where:
* - 'X' is Reserved
* - 'U' is Undefined
*/
#define DS1621_REG_CONFIG_NVB 0x10
#define DS1621_REG_CONFIG_RESOL 0x0C
#define DS1621_REG_CONFIG_POLARITY 0x02
#define DS1621_REG_CONFIG_1SHOT 0x01
#define DS1621_REG_CONFIG_DONE 0x80
#define DS1621_REG_CONFIG_RESOL_SHIFT 2
/* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */
static const unsigned short ds1721_convrates[] = {
94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */
188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */
375, /* 11-bits (0.125, 375, RES[0..1] = 2 */
750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */
};
#define DS1621_CONVERSION_MAX 750
#define DS1625_CONVERSION_MAX 500
#define DS1621_TEMP_MAX 125000
#define DS1621_TEMP_MIN (-55000)
/* The DS1621 temperature registers */
static const u8 DS1621_REG_TEMP[3] = {
0xAA, /* input, word, RO */
0xA2, /* min, word, RW */
0xA1, /* max, word, RW */
};
#define DS1621_REG_CONF 0xAC /* byte, RW */
#define DS1621_COM_START 0xEE /* no data */
#define DS1721_COM_START 0x51 /* 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 */
#define ALARMS_FROM_REG(val) ((val) & \
(DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
/* Each client has this additional data */
struct ds1621_data {
struct device *hwmon_dev;
struct mutex update_lock;
char valid; /* !=0 if following fields are valid */
unsigned long last_updated; /* In jiffies */
enum chips kind; /* device type */
u16 temp[3]; /* Register values, word */
u8 conf; /* Register encoding, combined */
u16 update_interval; /* Conversion rate in milliseconds */
};
static inline int DS1621_TEMP_FROM_REG(u16 reg)
{
return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10);
}
/*
* TEMP: 0.001C/bit (-55C to +125C)
* REG:
* - 1621, 1625: x = 0.5C
* - 1721: x = 0.0625C
* Assume highest resolution and let the bits fall where they may..
*/
static inline u16 DS1621_TEMP_TO_REG(long temp)
{
int ntemp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX);
ntemp += (ntemp < 0 ? -31 : 31);
ntemp = DIV_ROUND_CLOSEST(ntemp * 10, 625) << 4;
return (u16)ntemp;
}
static void ds1621_init_client(struct i2c_client *client)
{
u8 conf, new_conf, sreg, resol;
struct ds1621_data *data = i2c_get_clientdata(client);
new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
/* switch to continuous conversion mode */
new_conf &= ~DS1621_REG_CONFIG_1SHOT;
/* setup output polarity */
if (polarity == 0)
new_conf &= ~DS1621_REG_CONFIG_POLARITY;
else if (polarity == 1)
new_conf |= DS1621_REG_CONFIG_POLARITY;
if (conf != new_conf)
i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf);
switch (data->kind) {
case ds1625:
data->update_interval = DS1625_CONVERSION_MAX;
sreg = DS1621_COM_START;
break;
case ds1721:
resol = (new_conf & DS1621_REG_CONFIG_RESOL) >>
DS1621_REG_CONFIG_RESOL_SHIFT;
data->update_interval = ds1721_convrates[resol];
sreg = DS1721_COM_START;
break;
default:
data->update_interval = DS1621_CONVERSION_MAX;
sreg = DS1621_COM_START;
break;
}
/* start conversion */
i2c_smbus_write_byte(client, sreg);
}
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;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + data->update_interval) ||
!data->valid) {
int i;
dev_dbg(&client->dev, "Starting ds1621 update\n");
data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
for (i = 0; i < ARRAY_SIZE(data->temp); i++)
data->temp[i] = i2c_smbus_read_word_swapped(client,
DS1621_REG_TEMP[i]);
/* reset alarms if necessary */
new_conf = data->conf;
if (data->temp[0] > data->temp[1]) /* input > min */
new_conf &= ~DS1621_ALARM_TEMP_LOW;
if (data->temp[0] < data->temp[2]) /* input < max */
new_conf &= ~DS1621_ALARM_TEMP_HIGH;
if (data->conf != new_conf)
i2c_smbus_write_byte_data(client, DS1621_REG_CONF,
new_conf);
data->last_updated = jiffies;
data->valid = 1;
}
mutex_unlock(&data->update_lock);
return data;
}
static ssize_t show_temp(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ds1621_data *data = ds1621_update_client(dev);
return sprintf(buf, "%d\n",
DS1621_TEMP_FROM_REG(data->temp[attr->index]));
}
static ssize_t set_temp(struct device *dev, struct device_attribute *da,
const char *buf, size_t count)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct i2c_client *client = to_i2c_client(dev);
struct ds1621_data *data = i2c_get_clientdata(client);
long val;
int err;
err = kstrtol(buf, 10, &val);
if (err)
return err;
mutex_lock(&data->update_lock);
data->temp[attr->index] = DS1621_TEMP_TO_REG(val);
i2c_smbus_write_word_swapped(client, DS1621_REG_TEMP[attr->index],
data->temp[attr->index]);
mutex_unlock(&data->update_lock);
return count;
}
static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
char *buf)
{
struct ds1621_data *data = ds1621_update_client(dev);
return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
}
static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
struct ds1621_data *data = ds1621_update_client(dev);
return sprintf(buf, "%d\n", !!(data->conf & attr->index));
}
static ssize_t show_convrate(struct device *dev, struct device_attribute *da,
char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1621_data *data = i2c_get_clientdata(client);
return scnprintf(buf, PAGE_SIZE, "%hu\n", data->update_interval);
}
static ssize_t set_convrate(struct device *dev, struct device_attribute *da,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1621_data *data = i2c_get_clientdata(client);
unsigned long convrate;
s32 err;
int resol = 0;
err = kstrtoul(buf, 10, &convrate);
if (err)
return err;
/* Convert rate into resolution bits */
while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) &&
convrate > ds1721_convrates[resol])
resol++;
mutex_lock(&data->update_lock);
data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
data->conf &= ~DS1621_REG_CONFIG_RESOL;
data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT);
i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf);
data->update_interval = ds1721_convrates[resol];
mutex_unlock(&data->update_lock);
return count;
}
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_convrate,
set_convrate);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
DS1621_ALARM_TEMP_LOW);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
DS1621_ALARM_TEMP_HIGH);
static struct attribute *ds1621_attributes[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
&dev_attr_alarms.attr,
&dev_attr_update_interval.attr,
NULL
};
static umode_t ds1621_attribute_visible(struct kobject *kobj,
struct attribute *attr, int index)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct i2c_client *client = to_i2c_client(dev);
struct ds1621_data *data = i2c_get_clientdata(client);
if (attr == &dev_attr_update_interval.attr)
if (data->kind != ds1721)
/* shhh, we're hiding update_interval */
return 0;
return attr->mode;
}
static const struct attribute_group ds1621_group = {
.attrs = ds1621_attributes,
.is_visible = ds1621_attribute_visible
};
/* Return 0 if detection is successful, -ENODEV otherwise */
static int ds1621_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
int conf, temp;
int i;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_WORD_DATA
| I2C_FUNC_SMBUS_WRITE_BYTE))
return -ENODEV;
/*
* Now, we do the remaining detection. It is lousy.
*
* 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 = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
if (conf < 0 || conf & DS1621_REG_CONFIG_NVB)
return -ENODEV;
/* The 7 lowest bits of a temperature should always be 0. */
for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) {
temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]);
if (temp < 0 || (temp & 0x7f00))
return -ENODEV;
}
strlcpy(info->type, "ds1621", I2C_NAME_SIZE);
return 0;
}
static int ds1621_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ds1621_data *data;
int err;
data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
data->kind = id->driver_data;
/* Initialize the DS1621 chip */
ds1621_init_client(client);
/* Register sysfs hooks */
err = sysfs_create_group(&client->dev.kobj, &ds1621_group);
if (err)
return err;
data->hwmon_dev = hwmon_device_register(&client->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove_files;
}
return 0;
exit_remove_files:
sysfs_remove_group(&client->dev.kobj, &ds1621_group);
return err;
}
static int ds1621_remove(struct i2c_client *client)
{
struct ds1621_data *data = i2c_get_clientdata(client);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&client->dev.kobj, &ds1621_group);
return 0;
}
static const struct i2c_device_id ds1621_id[] = {
{ "ds1621", ds1621 },
{ "ds1625", ds1625 },
{ "ds1721", ds1721 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ds1621_id);
/* This is the driver that will be inserted */
static struct i2c_driver ds1621_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "ds1621",
},
.probe = ds1621_probe,
.remove = ds1621_remove,
.id_table = ds1621_id,
.detect = ds1621_detect,
.address_list = normal_i2c,
};
module_i2c_driver(ds1621_driver);
MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
MODULE_DESCRIPTION("DS1621 driver");
MODULE_LICENSE("GPL");
