1 files changed, 296 insertions, 0 deletions

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
new file mode 100644
index 000000000000..5be164ed278e
--- /dev/null
+++ b/drivers/hwmon/lm75.c
@@ -0,0 +1,296 @@
+/*
+    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/i2c-sensor.h>
+#include "lm75.h"
+
+
+/* Addresses to scan */
+static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
+                                        0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
+static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
+
+/* Insmod parameters */
+SENSORS_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 semaphore        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 = {
+        .owner          = THIS_MODULE,
+        .name           = "lm75",
+        .id             = I2C_DRIVERID_LM75,
+        .flags          = I2C_DF_NOTIFY,
+        .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);               \
+                                                                \
+        down(&data->update_lock);                               \
+        data->value = LM75_TEMP_TO_REG(temp);                   \
+        lm75_write_value(client, reg, data->value);             \
+        up(&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_detect(adapter, &addr_data, lm75_detect);
+}
+
+/* This function is called by i2c_detect */
+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 = "";
+
+        /* Make sure we aren't probing the ISA bus!! This is just a safety check
+           at this moment; i2c_detect really won't call us. */
+#ifdef DEBUG
+        if (i2c_is_isa_adapter(adapter)) {
+                dev_dbg(&adapter->dev,
+                        "lm75_detect called for an ISA bus adapter?!?\n");
+                goto exit;
+        }
+#endif
+
+        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 = kmalloc(sizeof(struct lm75_data), GFP_KERNEL))) {
+                err = -ENOMEM;
+                goto exit;
+        }
+        memset(data, 0, sizeof(struct lm75_data));
+
+        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;
+        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 LM75 chip */
+        lm75_init_client(new_client);
+        
+        /* Register sysfs hooks */
+        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_free:
+        kfree(data);
+exit:
+        return err;
+}
+
+static int lm75_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.
+   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)
+{
+        /* Initialize the LM75 chip */
+        lm75_write_value(client, LM75_REG_CONF, 0);
+}
+
+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);
+
+        down(&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;
+        }
+
+        up(&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);