--- /dev/null
+/*
+ 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/err.h>
+#include <linux/mutex.h>
+#include "lm75.h"
+
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
+ 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(lm75);
+
+/* Many LM75 constants specified below */
+
+/* The LM75 registers */
+#define LM75_REG_TEMP 0x00
+#define LM75_REG_CONF 0x01
+#define LM75_REG_TEMP_HYST 0x02
+#define LM75_REG_TEMP_OS 0x03
+
+/* Each client has this additional data */
+struct lm75_data {
+ struct i2c_client client;
+ struct class_device *class_dev;
+ struct mutex update_lock;
+ char valid; /* !=0 if following fields are valid */
+ unsigned long last_updated; /* In jiffies */
+ u16 temp_input; /* Register values */
+ u16 temp_max;
+ u16 temp_hyst;
+};
+
+static int lm75_attach_adapter(struct i2c_adapter *adapter);
+static int lm75_detect(struct i2c_adapter *adapter, int address, int kind);
+static void lm75_init_client(struct i2c_client *client);
+static int lm75_detach_client(struct i2c_client *client);
+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);
+
+
+/* This is the driver that will be inserted */
+static struct i2c_driver lm75_driver = {
+ .driver = {
+ .name = "lm75",
+ },
+ .id = I2C_DRIVERID_LM75,
+ .attach_adapter = lm75_attach_adapter,
+ .detach_client = lm75_detach_client,
+};
+
+#define show(value) \
+static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
+{ \
+ struct lm75_data *data = lm75_update_device(dev); \
+ return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
+}
+show(temp_max);
+show(temp_hyst);
+show(temp_input);
+
+#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 lm75_data *data = i2c_get_clientdata(client); \
+ int temp = simple_strtoul(buf, NULL, 10); \
+ \
+ mutex_lock(&data->update_lock); \
+ data->value = LM75_TEMP_TO_REG(temp); \
+ lm75_write_value(client, reg, data->value); \
+ mutex_unlock(&data->update_lock); \
+ return count; \
+}
+set(temp_max, LM75_REG_TEMP_OS);
+set(temp_hyst, LM75_REG_TEMP_HYST);
+
+static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
+static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, set_temp_hyst);
+static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL);
+
+static int lm75_attach_adapter(struct i2c_adapter *adapter)
+{
+ if (!(adapter->class & I2C_CLASS_HWMON))
+ return 0;
+ return i2c_probe(adapter, &addr_data, lm75_detect);
+}
+
+/* This function is called by i2c_probe */
+static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
+{
+ int i;
+ struct i2c_client *new_client;
+ struct lm75_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 lm75_{read,write}_value. */
+ if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto exit;
+ }
+
+ new_client = &data->client;
+ i2c_set_clientdata(new_client, data);
+ new_client->addr = address;
+ new_client->adapter = adapter;
+ new_client->driver = &lm75_driver;
+ new_client->flags = 0;
+
+ /* 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. */
+ if (kind < 0) {
+ int cur, conf, hyst, os;
+
+ /* 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)
+ goto exit_free;
+ 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)
+ goto exit_free;
+
+ /* Unused bits */
+ if (conf & 0xe0)
+ goto exit_free;
+
+ /* 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)
+ goto exit_free;
+ }
+
+ /* Determine the chip type - only one kind supported! */
+ if (kind <= 0)
+ kind = lm75;
+
+ if (kind == lm75) {
+ name = "lm75";
+ }
+
+ /* Fill in the remaining client fields and put it into the global list */
+ strlcpy(new_client->name, name, I2C_NAME_SIZE);
+ data->valid = 0;
+ mutex_init(&data->update_lock);
+
+ /* Tell the I2C layer a new client has arrived */
+ if ((err = i2c_attach_client(new_client)))
+ goto exit_free;
+
+ /* Initialize the LM75 chip */
+ lm75_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_max);
+ device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
+ device_create_file(&new_client->dev, &dev_attr_temp1_input);
+
+ return 0;
+
+exit_detach:
+ i2c_detach_client(new_client);
+exit_free:
+ kfree(data);
+exit:
+ return err;
+}
+
+static int lm75_detach_client(struct i2c_client *client)
+{
+ struct lm75_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.
+ LM75 uses a high-byte first convention, which is exactly opposite to
+ the usual practice. */
+static int lm75_read_value(struct i2c_client *client, u8 reg)
+{
+ if (reg == LM75_REG_CONF)
+ return i2c_smbus_read_byte_data(client, reg);
+ else
+ return swab16(i2c_smbus_read_word_data(client, reg));
+}
+
+/* All registers are word-sized, except for the configuration register.
+ LM75 uses a high-byte first convention, which is exactly opposite to
+ the usual practice. */
+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 void lm75_init_client(struct i2c_client *client)
+{
+ int reg;
+
+ /* Enable if in shutdown mode */
+ reg = lm75_read_value(client, LM75_REG_CONF);
+ if (reg >= 0 && (reg & 0x01))
+ lm75_write_value(client, LM75_REG_CONF, reg & 0xfe);
+}
+
+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) {
+ dev_dbg(&client->dev, "Starting lm75 update\n");
+
+ data->temp_input = lm75_read_value(client, LM75_REG_TEMP);
+ data->temp_max = lm75_read_value(client, LM75_REG_TEMP_OS);
+ data->temp_hyst = lm75_read_value(client, LM75_REG_TEMP_HYST);
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+ mutex_unlock(&data->update_lock);
+
+ return data;
+}
+
+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);
git://git.onelab.eu / linux-2.6.git / blobdiff