--- /dev/null
+/*
+ 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/i2c.h>
+#include <linux/i2c-sensor.h>
+
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { I2C_CLIENT_END };
+static unsigned short normal_i2c_range[] = { 0x48, 0x4b, I2C_CLIENT_END };
+static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
+static unsigned int normal_isa_range[] = { 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,
+};
+
+static int lm77_id = 0;
+
+/* 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); \
+ data->value = simple_strtoul(buf, NULL, 10); \
+ lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
+ 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);
+ data->temp_hyst = data->temp_crit - simple_strtoul(buf, NULL, 10);
+ lm77_write_value(client, LM77_REG_TEMP_HYST,
+ LM77_TEMP_TO_REG(data->temp_hyst));
+ 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);
+ int oldcrithyst = data->temp_crit - data->temp_hyst;
+ data->temp_crit = simple_strtoul(buf, NULL, 10);
+ 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));
+ 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);
+
+ new_client->id = lm77_id++;
+ 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 ((jiffies - data->last_updated > HZ + HZ / 2) ||
+ (jiffies < data->last_updated) || !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);
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