445 lines
13 KiB
C
445 lines
13 KiB
C
/*
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lm77.c - Part of lm_sensors, Linux kernel modules for hardware
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monitoring
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Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
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Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
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is a temperature sensor and thermal window comparator with 0.5 deg
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resolution made by National Semiconductor. Complete datasheet can be
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obtained at their site:
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http://www.national.com/pf/LM/LM77.html
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/jiffies.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/err.h>
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#include <linux/mutex.h>
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/* Addresses to scan */
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static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
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I2C_CLIENT_END };
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/* Insmod parameters */
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I2C_CLIENT_INSMOD_1(lm77);
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/* The LM77 registers */
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#define LM77_REG_TEMP 0x00
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#define LM77_REG_CONF 0x01
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#define LM77_REG_TEMP_HYST 0x02
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#define LM77_REG_TEMP_CRIT 0x03
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#define LM77_REG_TEMP_MIN 0x04
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#define LM77_REG_TEMP_MAX 0x05
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/* Each client has this additional data */
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struct lm77_data {
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struct device *hwmon_dev;
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struct mutex update_lock;
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char valid;
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unsigned long last_updated; /* In jiffies */
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int temp_input; /* Temperatures */
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int temp_crit;
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int temp_min;
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int temp_max;
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int temp_hyst;
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u8 alarms;
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};
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static int lm77_probe(struct i2c_client *client,
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const struct i2c_device_id *id);
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static int lm77_detect(struct i2c_client *client, int kind,
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struct i2c_board_info *info);
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static void lm77_init_client(struct i2c_client *client);
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static int lm77_remove(struct i2c_client *client);
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static u16 lm77_read_value(struct i2c_client *client, u8 reg);
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static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
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static struct lm77_data *lm77_update_device(struct device *dev);
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static const struct i2c_device_id lm77_id[] = {
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{ "lm77", lm77 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, lm77_id);
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/* This is the driver that will be inserted */
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static struct i2c_driver lm77_driver = {
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.class = I2C_CLASS_HWMON,
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.driver = {
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.name = "lm77",
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},
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.probe = lm77_probe,
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.remove = lm77_remove,
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.id_table = lm77_id,
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.detect = lm77_detect,
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.address_data = &addr_data,
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};
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/* straight from the datasheet */
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#define LM77_TEMP_MIN (-55000)
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#define LM77_TEMP_MAX 125000
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/* In the temperature registers, the low 3 bits are not part of the
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temperature values; they are the status bits. */
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static inline s16 LM77_TEMP_TO_REG(int temp)
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{
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int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
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return (ntemp / 500) * 8;
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}
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static inline int LM77_TEMP_FROM_REG(s16 reg)
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{
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return (reg / 8) * 500;
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}
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/* sysfs stuff */
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/* read routines for temperature limits */
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#define show(value) \
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static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
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{ \
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struct lm77_data *data = lm77_update_device(dev); \
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return sprintf(buf, "%d\n", data->value); \
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}
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show(temp_input);
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show(temp_crit);
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show(temp_min);
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show(temp_max);
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/* read routines for hysteresis values */
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static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct lm77_data *data = lm77_update_device(dev);
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return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
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}
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static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct lm77_data *data = lm77_update_device(dev);
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return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
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}
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static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct lm77_data *data = lm77_update_device(dev);
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return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
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}
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/* write routines */
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#define set(value, reg) \
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static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
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{ \
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struct i2c_client *client = to_i2c_client(dev); \
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struct lm77_data *data = i2c_get_clientdata(client); \
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long val = simple_strtol(buf, NULL, 10); \
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\
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mutex_lock(&data->update_lock); \
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data->value = val; \
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lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
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mutex_unlock(&data->update_lock); \
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return count; \
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}
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set(temp_min, LM77_REG_TEMP_MIN);
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set(temp_max, LM77_REG_TEMP_MAX);
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/* hysteresis is stored as a relative value on the chip, so it has to be
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converted first */
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static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct lm77_data *data = i2c_get_clientdata(client);
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unsigned long val = simple_strtoul(buf, NULL, 10);
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mutex_lock(&data->update_lock);
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data->temp_hyst = data->temp_crit - val;
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lm77_write_value(client, LM77_REG_TEMP_HYST,
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LM77_TEMP_TO_REG(data->temp_hyst));
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mutex_unlock(&data->update_lock);
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return count;
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}
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/* preserve hysteresis when setting T_crit */
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static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct lm77_data *data = i2c_get_clientdata(client);
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long val = simple_strtoul(buf, NULL, 10);
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int oldcrithyst;
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mutex_lock(&data->update_lock);
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oldcrithyst = data->temp_crit - data->temp_hyst;
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data->temp_crit = val;
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data->temp_hyst = data->temp_crit - oldcrithyst;
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lm77_write_value(client, LM77_REG_TEMP_CRIT,
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LM77_TEMP_TO_REG(data->temp_crit));
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lm77_write_value(client, LM77_REG_TEMP_HYST,
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LM77_TEMP_TO_REG(data->temp_hyst));
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mutex_unlock(&data->update_lock);
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return count;
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}
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static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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int bitnr = to_sensor_dev_attr(attr)->index;
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struct lm77_data *data = lm77_update_device(dev);
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return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
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}
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static DEVICE_ATTR(temp1_input, S_IRUGO,
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show_temp_input, NULL);
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static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
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show_temp_crit, set_temp_crit);
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static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
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show_temp_min, set_temp_min);
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static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
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show_temp_max, set_temp_max);
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static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
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show_temp_crit_hyst, set_temp_crit_hyst);
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static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
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show_temp_min_hyst, NULL);
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static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
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show_temp_max_hyst, NULL);
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static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
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static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
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static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
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static struct attribute *lm77_attributes[] = {
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&dev_attr_temp1_input.attr,
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&dev_attr_temp1_crit.attr,
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&dev_attr_temp1_min.attr,
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&dev_attr_temp1_max.attr,
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&dev_attr_temp1_crit_hyst.attr,
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&dev_attr_temp1_min_hyst.attr,
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&dev_attr_temp1_max_hyst.attr,
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&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
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&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
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&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
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NULL
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};
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static const struct attribute_group lm77_group = {
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.attrs = lm77_attributes,
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};
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/* Return 0 if detection is successful, -ENODEV otherwise */
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static int lm77_detect(struct i2c_client *new_client, int kind,
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struct i2c_board_info *info)
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{
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struct i2c_adapter *adapter = new_client->adapter;
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_SMBUS_WORD_DATA))
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return -ENODEV;
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/* Here comes the remaining detection. Since the LM77 has no
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register dedicated to identification, we have to rely on the
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following tricks:
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1. the high 4 bits represent the sign and thus they should
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always be the same
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2. the high 3 bits are unused in the configuration register
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3. addresses 0x06 and 0x07 return the last read value
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4. registers cycling over 8-address boundaries
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Word-sized registers are high-byte first. */
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if (kind < 0) {
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int i, cur, conf, hyst, crit, min, max;
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/* addresses cycling */
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cur = i2c_smbus_read_word_data(new_client, 0);
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conf = i2c_smbus_read_byte_data(new_client, 1);
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hyst = i2c_smbus_read_word_data(new_client, 2);
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crit = i2c_smbus_read_word_data(new_client, 3);
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min = i2c_smbus_read_word_data(new_client, 4);
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max = i2c_smbus_read_word_data(new_client, 5);
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for (i = 8; i <= 0xff; i += 8)
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if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
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|| i2c_smbus_read_word_data(new_client, i + 2) != hyst
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|| i2c_smbus_read_word_data(new_client, i + 3) != crit
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|| i2c_smbus_read_word_data(new_client, i + 4) != min
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|| i2c_smbus_read_word_data(new_client, i + 5) != max)
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return -ENODEV;
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/* sign bits */
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if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
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|| ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
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|| ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
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|| ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
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|| ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
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return -ENODEV;
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/* unused bits */
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if (conf & 0xe0)
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return -ENODEV;
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/* 0x06 and 0x07 return the last read value */
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cur = i2c_smbus_read_word_data(new_client, 0);
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if (i2c_smbus_read_word_data(new_client, 6) != cur
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|| i2c_smbus_read_word_data(new_client, 7) != cur)
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return -ENODEV;
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hyst = i2c_smbus_read_word_data(new_client, 2);
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if (i2c_smbus_read_word_data(new_client, 6) != hyst
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|| i2c_smbus_read_word_data(new_client, 7) != hyst)
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return -ENODEV;
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min = i2c_smbus_read_word_data(new_client, 4);
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if (i2c_smbus_read_word_data(new_client, 6) != min
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|| i2c_smbus_read_word_data(new_client, 7) != min)
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return -ENODEV;
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}
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strlcpy(info->type, "lm77", I2C_NAME_SIZE);
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return 0;
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}
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static int lm77_probe(struct i2c_client *new_client,
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const struct i2c_device_id *id)
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{
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struct lm77_data *data;
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int err;
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data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL);
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if (!data) {
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err = -ENOMEM;
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goto exit;
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}
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i2c_set_clientdata(new_client, data);
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data->valid = 0;
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mutex_init(&data->update_lock);
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/* Initialize the LM77 chip */
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lm77_init_client(new_client);
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/* Register sysfs hooks */
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if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group)))
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goto exit_free;
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data->hwmon_dev = hwmon_device_register(&new_client->dev);
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if (IS_ERR(data->hwmon_dev)) {
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err = PTR_ERR(data->hwmon_dev);
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goto exit_remove;
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}
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return 0;
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exit_remove:
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sysfs_remove_group(&new_client->dev.kobj, &lm77_group);
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exit_free:
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kfree(data);
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exit:
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return err;
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}
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static int lm77_remove(struct i2c_client *client)
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{
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struct lm77_data *data = i2c_get_clientdata(client);
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hwmon_device_unregister(data->hwmon_dev);
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sysfs_remove_group(&client->dev.kobj, &lm77_group);
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kfree(data);
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return 0;
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}
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/* All registers are word-sized, except for the configuration register.
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The LM77 uses the high-byte first convention. */
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static u16 lm77_read_value(struct i2c_client *client, u8 reg)
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{
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if (reg == LM77_REG_CONF)
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return i2c_smbus_read_byte_data(client, reg);
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else
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return swab16(i2c_smbus_read_word_data(client, reg));
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}
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static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
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{
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if (reg == LM77_REG_CONF)
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return i2c_smbus_write_byte_data(client, reg, value);
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else
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return i2c_smbus_write_word_data(client, reg, swab16(value));
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}
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static void lm77_init_client(struct i2c_client *client)
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{
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/* Initialize the LM77 chip - turn off shutdown mode */
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int conf = lm77_read_value(client, LM77_REG_CONF);
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if (conf & 1)
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lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
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}
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static struct lm77_data *lm77_update_device(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct lm77_data *data = i2c_get_clientdata(client);
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mutex_lock(&data->update_lock);
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if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
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|| !data->valid) {
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dev_dbg(&client->dev, "Starting lm77 update\n");
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data->temp_input =
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LM77_TEMP_FROM_REG(lm77_read_value(client,
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LM77_REG_TEMP));
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data->temp_hyst =
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LM77_TEMP_FROM_REG(lm77_read_value(client,
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LM77_REG_TEMP_HYST));
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data->temp_crit =
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LM77_TEMP_FROM_REG(lm77_read_value(client,
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LM77_REG_TEMP_CRIT));
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data->temp_min =
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LM77_TEMP_FROM_REG(lm77_read_value(client,
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LM77_REG_TEMP_MIN));
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data->temp_max =
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LM77_TEMP_FROM_REG(lm77_read_value(client,
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LM77_REG_TEMP_MAX));
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data->alarms =
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lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
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data->last_updated = jiffies;
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data->valid = 1;
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}
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mutex_unlock(&data->update_lock);
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return data;
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}
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static int __init sensors_lm77_init(void)
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{
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return i2c_add_driver(&lm77_driver);
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}
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static void __exit sensors_lm77_exit(void)
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{
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i2c_del_driver(&lm77_driver);
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}
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MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
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MODULE_DESCRIPTION("LM77 driver");
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MODULE_LICENSE("GPL");
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module_init(sensors_lm77_init);
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module_exit(sensors_lm77_exit);
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