diff options
Diffstat (limited to 'drivers/i2c/chips/lm77.c')
| -rw-r--r-- | drivers/i2c/chips/lm77.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/drivers/i2c/chips/lm77.c b/drivers/i2c/chips/lm77.c new file mode 100644 index 000000000000..f56b7a37de75 --- /dev/null +++ b/drivers/i2c/chips/lm77.c @@ -0,0 +1,421 @@ +/* + 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/config.h> +#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> + + +/* Addresses to scan */ +static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END }; +static unsigned int normal_isa[] = { I2C_CLIENT_ISA_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 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, 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, 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, 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, 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, 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, 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, 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 */ + 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_free: + kfree(data); +exit: + return err; +} + +static int lm77_detach_client(struct i2c_client *client) +{ + i2c_detach_client(client); + kfree(i2c_get_clientdata(client)); + 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); |
