| /* |
| lm75.c - Part of lm_sensors, Linux kernel modules for hardware |
| monitoring |
| Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl> |
| |
| 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 "lm75.h" |
| |
| |
| /* |
| * This driver handles the LM75 and compatible digital temperature sensors. |
| * Only types which are _not_ listed in I2C_CLIENT_INSMOD_*() need to be |
| * listed here. We start at 9 since I2C_CLIENT_INSMOD_*() currently allow |
| * definition of up to 8 chip types (plus zero). |
| */ |
| |
| enum lm75_type { /* keep sorted in alphabetical order */ |
| ds1775 = 9, |
| ds75, |
| /* lm75 -- in I2C_CLIENT_INSMOD_1() */ |
| lm75a, |
| max6625, |
| max6626, |
| mcp980x, |
| stds75, |
| tcn75, |
| tmp100, |
| tmp101, |
| tmp175, |
| tmp275, |
| tmp75, |
| }; |
| |
| /* Addresses scanned */ |
| static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, |
| 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; |
| |
| /* Insmod parameters */ |
| I2C_CLIENT_INSMOD_1(lm75); |
| |
| |
| /* The LM75 registers */ |
| #define LM75_REG_CONF 0x01 |
| static const u8 LM75_REG_TEMP[3] = { |
| 0x00, /* input */ |
| 0x03, /* max */ |
| 0x02, /* hyst */ |
| }; |
| |
| /* Each client has this additional data */ |
| struct lm75_data { |
| struct device *hwmon_dev; |
| struct mutex update_lock; |
| u8 orig_conf; |
| char valid; /* !=0 if registers are valid */ |
| unsigned long last_updated; /* In jiffies */ |
| u16 temp[3]; /* Register values, |
| 0 = input |
| 1 = max |
| 2 = hyst */ |
| }; |
| |
| static int lm75_read_value(struct i2c_client *client, u8 reg); |
| static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); |
| static struct lm75_data *lm75_update_device(struct device *dev); |
| |
| |
| /*-----------------------------------------------------------------------*/ |
| |
| /* sysfs attributes for hwmon */ |
| |
| 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 lm75_data *data = lm75_update_device(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 lm75_data *data = i2c_get_clientdata(client); |
| int nr = attr->index; |
| long temp = simple_strtol(buf, NULL, 10); |
| |
| mutex_lock(&data->update_lock); |
| data->temp[nr] = LM75_TEMP_TO_REG(temp); |
| lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]); |
| mutex_unlock(&data->update_lock); |
| return count; |
| } |
| |
| static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, |
| show_temp, set_temp, 1); |
| static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, |
| show_temp, set_temp, 2); |
| static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); |
| |
| static struct attribute *lm75_attributes[] = { |
| &sensor_dev_attr_temp1_input.dev_attr.attr, |
| &sensor_dev_attr_temp1_max.dev_attr.attr, |
| &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, |
| |
| NULL |
| }; |
| |
| static const struct attribute_group lm75_group = { |
| .attrs = lm75_attributes, |
| }; |
| |
| /*-----------------------------------------------------------------------*/ |
| |
| /* device probe and removal */ |
| |
| static int |
| lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) |
| { |
| struct lm75_data *data; |
| int status; |
| u8 set_mask, clr_mask; |
| int new; |
| |
| if (!i2c_check_functionality(client->adapter, |
| I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) |
| return -EIO; |
| |
| data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| i2c_set_clientdata(client, data); |
| mutex_init(&data->update_lock); |
| |
| /* Set to LM75 resolution (9 bits, 1/2 degree C) and range. |
| * Then tweak to be more precise when appropriate. |
| */ |
| set_mask = 0; |
| clr_mask = (1 << 0) /* continuous conversions */ |
| | (1 << 6) | (1 << 5); /* 9-bit mode */ |
| |
| /* configure as specified */ |
| status = lm75_read_value(client, LM75_REG_CONF); |
| if (status < 0) { |
| dev_dbg(&client->dev, "Can't read config? %d\n", status); |
| goto exit_free; |
| } |
| data->orig_conf = status; |
| new = status & ~clr_mask; |
| new |= set_mask; |
| if (status != new) |
| lm75_write_value(client, LM75_REG_CONF, new); |
| dev_dbg(&client->dev, "Config %02x\n", new); |
| |
| /* Register sysfs hooks */ |
| status = sysfs_create_group(&client->dev.kobj, &lm75_group); |
| if (status) |
| goto exit_free; |
| |
| data->hwmon_dev = hwmon_device_register(&client->dev); |
| if (IS_ERR(data->hwmon_dev)) { |
| status = PTR_ERR(data->hwmon_dev); |
| goto exit_remove; |
| } |
| |
| dev_info(&client->dev, "%s: sensor '%s'\n", |
| dev_name(data->hwmon_dev), client->name); |
| |
| return 0; |
| |
| exit_remove: |
| sysfs_remove_group(&client->dev.kobj, &lm75_group); |
| exit_free: |
| i2c_set_clientdata(client, NULL); |
| kfree(data); |
| return status; |
| } |
| |
| static int lm75_remove(struct i2c_client *client) |
| { |
| struct lm75_data *data = i2c_get_clientdata(client); |
| |
| hwmon_device_unregister(data->hwmon_dev); |
| sysfs_remove_group(&client->dev.kobj, &lm75_group); |
| lm75_write_value(client, LM75_REG_CONF, data->orig_conf); |
| i2c_set_clientdata(client, NULL); |
| kfree(data); |
| return 0; |
| } |
| |
| static const struct i2c_device_id lm75_ids[] = { |
| { "ds1775", ds1775, }, |
| { "ds75", ds75, }, |
| { "lm75", lm75, }, |
| { "lm75a", lm75a, }, |
| { "max6625", max6625, }, |
| { "max6626", max6626, }, |
| { "mcp980x", mcp980x, }, |
| { "stds75", stds75, }, |
| { "tcn75", tcn75, }, |
| { "tmp100", tmp100, }, |
| { "tmp101", tmp101, }, |
| { "tmp175", tmp175, }, |
| { "tmp275", tmp275, }, |
| { "tmp75", tmp75, }, |
| { /* LIST END */ } |
| }; |
| MODULE_DEVICE_TABLE(i2c, lm75_ids); |
| |
| /* Return 0 if detection is successful, -ENODEV otherwise */ |
| static int lm75_detect(struct i2c_client *new_client, |
| struct i2c_board_info *info) |
| { |
| struct i2c_adapter *adapter = new_client->adapter; |
| int i; |
| int cur, conf, hyst, os; |
| |
| if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
| I2C_FUNC_SMBUS_WORD_DATA)) |
| return -ENODEV; |
| |
| /* Now, we do the remaining detection. There is no identification- |
| dedicated register so we have to rely on several tricks: |
| unused bits, registers cycling over 8-address boundaries, |
| addresses 0x04-0x07 returning the last read value. |
| The cycling+unused addresses combination is not tested, |
| since it would significantly slow the detection down and would |
| hardly add any value. */ |
| |
| /* Unused addresses */ |
| cur = i2c_smbus_read_word_data(new_client, 0); |
| conf = i2c_smbus_read_byte_data(new_client, 1); |
| hyst = i2c_smbus_read_word_data(new_client, 2); |
| if (i2c_smbus_read_word_data(new_client, 4) != hyst |
| || i2c_smbus_read_word_data(new_client, 5) != hyst |
| || i2c_smbus_read_word_data(new_client, 6) != hyst |
| || i2c_smbus_read_word_data(new_client, 7) != hyst) |
| return -ENODEV; |
| os = i2c_smbus_read_word_data(new_client, 3); |
| if (i2c_smbus_read_word_data(new_client, 4) != os |
| || i2c_smbus_read_word_data(new_client, 5) != os |
| || i2c_smbus_read_word_data(new_client, 6) != os |
| || i2c_smbus_read_word_data(new_client, 7) != os) |
| return -ENODEV; |
| |
| /* Unused bits */ |
| if (conf & 0xe0) |
| return -ENODEV; |
| |
| /* Addresses cycling */ |
| for (i = 8; i < 0xff; i += 8) { |
| if (i2c_smbus_read_byte_data(new_client, i + 1) != conf |
| || i2c_smbus_read_word_data(new_client, i + 2) != hyst |
| || i2c_smbus_read_word_data(new_client, i + 3) != os) |
| return -ENODEV; |
| } |
| |
| strlcpy(info->type, "lm75", I2C_NAME_SIZE); |
| |
| return 0; |
| } |
| |
| static struct i2c_driver lm75_driver = { |
| .class = I2C_CLASS_HWMON, |
| .driver = { |
| .name = "lm75", |
| }, |
| .probe = lm75_probe, |
| .remove = lm75_remove, |
| .id_table = lm75_ids, |
| .detect = lm75_detect, |
| .address_data = &addr_data, |
| }; |
| |
| /*-----------------------------------------------------------------------*/ |
| |
| /* register access */ |
| |
| /* All registers are word-sized, except for the configuration register. |
| LM75 uses a high-byte first convention, which is exactly opposite to |
| the SMBus standard. */ |
| static int lm75_read_value(struct i2c_client *client, u8 reg) |
| { |
| int value; |
| |
| if (reg == LM75_REG_CONF) |
| return i2c_smbus_read_byte_data(client, reg); |
| |
| value = i2c_smbus_read_word_data(client, reg); |
| return (value < 0) ? value : swab16(value); |
| } |
| |
| static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) |
| { |
| if (reg == LM75_REG_CONF) |
| return i2c_smbus_write_byte_data(client, reg, value); |
| else |
| return i2c_smbus_write_word_data(client, reg, swab16(value)); |
| } |
| |
| static struct lm75_data *lm75_update_device(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct lm75_data *data = i2c_get_clientdata(client); |
| |
| mutex_lock(&data->update_lock); |
| |
| if (time_after(jiffies, data->last_updated + HZ + HZ / 2) |
| || !data->valid) { |
| int i; |
| dev_dbg(&client->dev, "Starting lm75 update\n"); |
| |
| for (i = 0; i < ARRAY_SIZE(data->temp); i++) { |
| int status; |
| |
| status = lm75_read_value(client, LM75_REG_TEMP[i]); |
| if (status < 0) |
| dev_dbg(&client->dev, "reg %d, err %d\n", |
| LM75_REG_TEMP[i], status); |
| else |
| data->temp[i] = status; |
| } |
| data->last_updated = jiffies; |
| data->valid = 1; |
| } |
| |
| mutex_unlock(&data->update_lock); |
| |
| return data; |
| } |
| |
| /*-----------------------------------------------------------------------*/ |
| |
| /* module glue */ |
| |
| static int __init sensors_lm75_init(void) |
| { |
| return i2c_add_driver(&lm75_driver); |
| } |
| |
| static void __exit sensors_lm75_exit(void) |
| { |
| i2c_del_driver(&lm75_driver); |
| } |
| |
| MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); |
| MODULE_DESCRIPTION("LM75 driver"); |
| MODULE_LICENSE("GPL"); |
| |
| module_init(sensors_lm75_init); |
| module_exit(sensors_lm75_exit); |