| /* |
| lm77.c - Part of lm_sensors, Linux kernel modules for hardware |
| monitoring |
| |
| Copyright (c) 2004 Andras BALI <drewie@freemail.hu> |
| |
| Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77 |
| is a temperature sensor and thermal window comparator with 0.5 deg |
| resolution made by National Semiconductor. Complete datasheet can be |
| obtained at their site: |
| http://www.national.com/pf/LM/LM77.html |
| |
| 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/i2c-sensor.h> |
| #include <linux/hwmon.h> |
| #include <linux/err.h> |
| |
| /* Addresses to scan */ |
| static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END }; |
| |
| /* Insmod parameters */ |
| SENSORS_INSMOD_1(lm77); |
| |
| /* The LM77 registers */ |
| #define LM77_REG_TEMP 0x00 |
| #define LM77_REG_CONF 0x01 |
| #define LM77_REG_TEMP_HYST 0x02 |
| #define LM77_REG_TEMP_CRIT 0x03 |
| #define LM77_REG_TEMP_MIN 0x04 |
| #define LM77_REG_TEMP_MAX 0x05 |
| |
| /* Each client has this additional data */ |
| struct lm77_data { |
| struct i2c_client client; |
| struct class_device *class_dev; |
| struct semaphore update_lock; |
| char valid; |
| unsigned long last_updated; /* In jiffies */ |
| int temp_input; /* Temperatures */ |
| int temp_crit; |
| int temp_min; |
| int temp_max; |
| int temp_hyst; |
| u8 alarms; |
| }; |
| |
| static int lm77_attach_adapter(struct i2c_adapter *adapter); |
| static int lm77_detect(struct i2c_adapter *adapter, int address, int kind); |
| static void lm77_init_client(struct i2c_client *client); |
| static int lm77_detach_client(struct i2c_client *client); |
| static u16 lm77_read_value(struct i2c_client *client, u8 reg); |
| static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value); |
| |
| static struct lm77_data *lm77_update_device(struct device *dev); |
| |
| |
| /* This is the driver that will be inserted */ |
| static struct i2c_driver lm77_driver = { |
| .owner = THIS_MODULE, |
| .name = "lm77", |
| .flags = I2C_DF_NOTIFY, |
| .attach_adapter = lm77_attach_adapter, |
| .detach_client = lm77_detach_client, |
| }; |
| |
| /* straight from the datasheet */ |
| #define LM77_TEMP_MIN (-55000) |
| #define LM77_TEMP_MAX 125000 |
| |
| /* In the temperature registers, the low 3 bits are not part of the |
| temperature values; they are the status bits. */ |
| static inline u16 LM77_TEMP_TO_REG(int temp) |
| { |
| int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); |
| return (u16)((ntemp / 500) * 8); |
| } |
| |
| static inline int LM77_TEMP_FROM_REG(u16 reg) |
| { |
| return ((int)reg / 8) * 500; |
| } |
| |
| /* sysfs stuff */ |
| |
| /* read routines for temperature limits */ |
| #define show(value) \ |
| static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
| { \ |
| struct lm77_data *data = lm77_update_device(dev); \ |
| return sprintf(buf, "%d\n", data->value); \ |
| } |
| |
| show(temp_input); |
| show(temp_crit); |
| show(temp_min); |
| show(temp_max); |
| show(alarms); |
| |
| /* read routines for hysteresis values */ |
| static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct lm77_data *data = lm77_update_device(dev); |
| return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); |
| } |
| static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct lm77_data *data = lm77_update_device(dev); |
| return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); |
| } |
| static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct lm77_data *data = lm77_update_device(dev); |
| return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); |
| } |
| |
| /* write routines */ |
| #define set(value, reg) \ |
| static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \ |
| { \ |
| struct i2c_client *client = to_i2c_client(dev); \ |
| struct lm77_data *data = i2c_get_clientdata(client); \ |
| long val = simple_strtoul(buf, NULL, 10); \ |
| \ |
| down(&data->update_lock); \ |
| data->value = val; \ |
| lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ |
| up(&data->update_lock); \ |
| return count; \ |
| } |
| |
| set(temp_min, LM77_REG_TEMP_MIN); |
| set(temp_max, LM77_REG_TEMP_MAX); |
| |
| /* hysteresis is stored as a relative value on the chip, so it has to be |
| converted first */ |
| static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct lm77_data *data = i2c_get_clientdata(client); |
| unsigned long val = simple_strtoul(buf, NULL, 10); |
| |
| down(&data->update_lock); |
| data->temp_hyst = data->temp_crit - val; |
| lm77_write_value(client, LM77_REG_TEMP_HYST, |
| LM77_TEMP_TO_REG(data->temp_hyst)); |
| up(&data->update_lock); |
| return count; |
| } |
| |
| /* preserve hysteresis when setting T_crit */ |
| static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct lm77_data *data = i2c_get_clientdata(client); |
| long val = simple_strtoul(buf, NULL, 10); |
| int oldcrithyst; |
| |
| down(&data->update_lock); |
| oldcrithyst = data->temp_crit - data->temp_hyst; |
| data->temp_crit = val; |
| data->temp_hyst = data->temp_crit - oldcrithyst; |
| lm77_write_value(client, LM77_REG_TEMP_CRIT, |
| LM77_TEMP_TO_REG(data->temp_crit)); |
| lm77_write_value(client, LM77_REG_TEMP_HYST, |
| LM77_TEMP_TO_REG(data->temp_hyst)); |
| up(&data->update_lock); |
| return count; |
| } |
| |
| static DEVICE_ATTR(temp1_input, S_IRUGO, |
| show_temp_input, NULL); |
| static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, |
| show_temp_crit, set_temp_crit); |
| 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 DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, |
| show_temp_crit_hyst, set_temp_crit_hyst); |
| static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, |
| show_temp_min_hyst, NULL); |
| static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, |
| show_temp_max_hyst, NULL); |
| |
| static DEVICE_ATTR(alarms, S_IRUGO, |
| show_alarms, NULL); |
| |
| static int lm77_attach_adapter(struct i2c_adapter *adapter) |
| { |
| if (!(adapter->class & I2C_CLASS_HWMON)) |
| return 0; |
| return i2c_detect(adapter, &addr_data, lm77_detect); |
| } |
| |
| /* This function is called by i2c_detect */ |
| static int lm77_detect(struct i2c_adapter *adapter, int address, int kind) |
| { |
| struct i2c_client *new_client; |
| struct lm77_data *data; |
| int err = 0; |
| const char *name = ""; |
| |
| if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
| I2C_FUNC_SMBUS_WORD_DATA)) |
| 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 lm77_{read,write}_value. */ |
| if (!(data = kmalloc(sizeof(struct lm77_data), GFP_KERNEL))) { |
| err = -ENOMEM; |
| goto exit; |
| } |
| memset(data, 0, sizeof(struct lm77_data)); |
| |
| new_client = &data->client; |
| i2c_set_clientdata(new_client, data); |
| new_client->addr = address; |
| new_client->adapter = adapter; |
| new_client->driver = &lm77_driver; |
| new_client->flags = 0; |
| |
| /* Here comes the remaining detection. Since the LM77 has no |
| register dedicated to identification, we have to rely on the |
| following tricks: |
| |
| 1. the high 4 bits represent the sign and thus they should |
| always be the same |
| 2. the high 3 bits are unused in the configuration register |
| 3. addresses 0x06 and 0x07 return the last read value |
| 4. registers cycling over 8-address boundaries |
| |
| Word-sized registers are high-byte first. */ |
| if (kind < 0) { |
| int i, cur, conf, hyst, crit, min, max; |
| |
| /* addresses cycling */ |
| 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); |
| crit = i2c_smbus_read_word_data(new_client, 3); |
| min = i2c_smbus_read_word_data(new_client, 4); |
| max = i2c_smbus_read_word_data(new_client, 5); |
| 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) != crit |
| || i2c_smbus_read_word_data(new_client, i + 4) != min |
| || i2c_smbus_read_word_data(new_client, i + 5) != max) |
| goto exit_free; |
| |
| /* sign bits */ |
| if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) |
| || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) |
| || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) |
| || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) |
| || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) |
| goto exit_free; |
| |
| /* unused bits */ |
| if (conf & 0xe0) |
| goto exit_free; |
| |
| /* 0x06 and 0x07 return the last read value */ |
| cur = i2c_smbus_read_word_data(new_client, 0); |
| if (i2c_smbus_read_word_data(new_client, 6) != cur |
| || i2c_smbus_read_word_data(new_client, 7) != cur) |
| goto exit_free; |
| hyst = i2c_smbus_read_word_data(new_client, 2); |
| if (i2c_smbus_read_word_data(new_client, 6) != hyst |
| || i2c_smbus_read_word_data(new_client, 7) != hyst) |
| goto exit_free; |
| min = i2c_smbus_read_word_data(new_client, 4); |
| if (i2c_smbus_read_word_data(new_client, 6) != min |
| || i2c_smbus_read_word_data(new_client, 7) != min) |
| goto exit_free; |
| |
| } |
| |
| /* Determine the chip type - only one kind supported! */ |
| if (kind <= 0) |
| kind = lm77; |
| |
| if (kind == lm77) { |
| name = "lm77"; |
| } |
| |
| /* Fill in the remaining client fields and put it into the global list */ |
| strlcpy(new_client->name, name, 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 LM77 chip */ |
| lm77_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_temp1_input); |
| device_create_file(&new_client->dev, &dev_attr_temp1_crit); |
| device_create_file(&new_client->dev, &dev_attr_temp1_min); |
| device_create_file(&new_client->dev, &dev_attr_temp1_max); |
| device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst); |
| device_create_file(&new_client->dev, &dev_attr_temp1_min_hyst); |
| device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst); |
| device_create_file(&new_client->dev, &dev_attr_alarms); |
| return 0; |
| |
| exit_detach: |
| i2c_detach_client(new_client); |
| exit_free: |
| kfree(data); |
| exit: |
| return err; |
| } |
| |
| static int lm77_detach_client(struct i2c_client *client) |
| { |
| struct lm77_data *data = i2c_get_clientdata(client); |
| hwmon_device_unregister(data->class_dev); |
| i2c_detach_client(client); |
| kfree(data); |
| return 0; |
| } |
| |
| /* All registers are word-sized, except for the configuration register. |
| The LM77 uses the high-byte first convention. */ |
| static u16 lm77_read_value(struct i2c_client *client, u8 reg) |
| { |
| if (reg == LM77_REG_CONF) |
| return i2c_smbus_read_byte_data(client, reg); |
| else |
| return swab16(i2c_smbus_read_word_data(client, reg)); |
| } |
| |
| static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) |
| { |
| if (reg == LM77_REG_CONF) |
| return i2c_smbus_write_byte_data(client, reg, value); |
| else |
| return i2c_smbus_write_word_data(client, reg, swab16(value)); |
| } |
| |
| static void lm77_init_client(struct i2c_client *client) |
| { |
| /* Initialize the LM77 chip - turn off shutdown mode */ |
| int conf = lm77_read_value(client, LM77_REG_CONF); |
| if (conf & 1) |
| lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); |
| } |
| |
| static struct lm77_data *lm77_update_device(struct device *dev) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct lm77_data *data = i2c_get_clientdata(client); |
| |
| down(&data->update_lock); |
| |
| if (time_after(jiffies, data->last_updated + HZ + HZ / 2) |
| || !data->valid) { |
| dev_dbg(&client->dev, "Starting lm77 update\n"); |
| data->temp_input = |
| LM77_TEMP_FROM_REG(lm77_read_value(client, |
| LM77_REG_TEMP)); |
| data->temp_hyst = |
| LM77_TEMP_FROM_REG(lm77_read_value(client, |
| LM77_REG_TEMP_HYST)); |
| data->temp_crit = |
| LM77_TEMP_FROM_REG(lm77_read_value(client, |
| LM77_REG_TEMP_CRIT)); |
| data->temp_min = |
| LM77_TEMP_FROM_REG(lm77_read_value(client, |
| LM77_REG_TEMP_MIN)); |
| data->temp_max = |
| LM77_TEMP_FROM_REG(lm77_read_value(client, |
| LM77_REG_TEMP_MAX)); |
| data->alarms = |
| lm77_read_value(client, LM77_REG_TEMP) & 0x0007; |
| data->last_updated = jiffies; |
| data->valid = 1; |
| } |
| |
| up(&data->update_lock); |
| |
| return data; |
| } |
| |
| static int __init sensors_lm77_init(void) |
| { |
| return i2c_add_driver(&lm77_driver); |
| } |
| |
| static void __exit sensors_lm77_exit(void) |
| { |
| i2c_del_driver(&lm77_driver); |
| } |
| |
| MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); |
| MODULE_DESCRIPTION("LM77 driver"); |
| MODULE_LICENSE("GPL"); |
| |
| module_init(sensors_lm77_init); |
| module_exit(sensors_lm77_exit); |