diff options
Diffstat (limited to 'drivers/hwmon/ds1621.c')
| -rw-r--r-- | drivers/hwmon/ds1621.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/hwmon/ds1621.c b/drivers/hwmon/ds1621.c new file mode 100644 index 0000000..7415381 --- /dev/null +++ b/drivers/hwmon/ds1621.c @@ -0,0 +1,353 @@ +/* + 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/hwmon-sysfs.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/sysfs.h> +#include "lm75.h" + +/* Addresses to scan */ +static const 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 */ +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 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 */ + + u16 temp[3]; /* Register values, word */ + u8 conf; /* Register encoding, combined */ +}; + +static int ds1621_probe(struct i2c_client *client, + const struct i2c_device_id *id); +static int ds1621_detect(struct i2c_client *client, int kind, + struct i2c_board_info *info); +static void ds1621_init_client(struct i2c_client *client); +static int ds1621_remove(struct i2c_client *client); +static struct ds1621_data *ds1621_update_client(struct device *dev); + +static const struct i2c_device_id ds1621_id[] = { + { "ds1621", ds1621 }, + { "ds1625", ds1621 }, + { } +}; +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_data = &addr_data, +}; + +/* All registers are word-sized, except for the configuration register. + DS1621 uses a high-byte first convention, which is exactly opposite to + the SMBus standard. */ +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)); +} + +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); +} + +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", + LM75_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 = ds1621_update_client(dev); + u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10)); + + mutex_lock(&data->update_lock); + data->temp[attr->index] = val; + ds1621_write_value(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 DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); +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, + NULL +}; + +static const struct attribute_group ds1621_group = { + .attrs = ds1621_attributes, +}; + + +/* Return 0 if detection is successful, -ENODEV otherwise */ +static int ds1621_detect(struct i2c_client *client, int kind, + 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. */ + 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(client, DS1621_REG_CONF); + if (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 = ds1621_read_value(client, DS1621_REG_TEMP[i]); + if (temp & 0x007f) + 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 = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL); + if (!data) { + err = -ENOMEM; + goto exit; + } + + i2c_set_clientdata(client, data); + mutex_init(&data->update_lock); + + /* Initialize the DS1621 chip */ + ds1621_init_client(client); + + /* Register sysfs hooks */ + if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group))) + goto exit_free; + + 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); + exit_free: + kfree(data); + exit: + 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); + + 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; + + mutex_lock(&data->update_lock); + + if (time_after(jiffies, data->last_updated + HZ + HZ / 2) + || !data->valid) { + int i; + + dev_dbg(&client->dev, "Starting ds1621 update\n"); + + data->conf = ds1621_read_value(client, DS1621_REG_CONF); + + for (i = 0; i < ARRAY_SIZE(data->temp); i++) + data->temp[i] = ds1621_read_value(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) + ds1621_write_value(client, DS1621_REG_CONF, + new_conf); + + data->last_updated = jiffies; + data->valid = 1; + } + + mutex_unlock(&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); |
