1 files changed, 420 insertions, 0 deletions

diff --git a/drivers/hwmon/lm77.c b/drivers/hwmon/lm77.c
new file mode 100644
index 000000000000..b98f44952997
--- /dev/null
+++ b/drivers/hwmon/lm77.c
@@ -0,0 +1,420 @@
+/*
+    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/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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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, struct device_attribute *attr, 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);