/* 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 */ }; /* Temperature registers are word-sized. DS1621 uses a high-byte first convention, which is exactly opposite to the SMBus standard. */ static int ds1621_read_temp(struct i2c_client *client, u8 reg) { int ret; ret = i2c_smbus_read_word_data(client, reg); if (ret < 0) return ret; return swab16(ret); } static int ds1621_write_temp(struct i2c_client *client, u8 reg, u16 value) { return i2c_smbus_write_word_data(client, reg, swab16(value)); } static void ds1621_init_client(struct i2c_client *client) { u8 conf, new_conf; 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); /* start conversion */ i2c_smbus_write_byte(client, DS1621_COM_START); } 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 = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); for (i = 0; i < ARRAY_SIZE(data->temp); i++) data->temp[i] = ds1621_read_temp(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", 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 = i2c_get_clientdata(client); u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10)); mutex_lock(&data->update_lock); data->temp[attr->index] = val; ds1621_write_temp(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. */ /* 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 = 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 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, }; 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);