1 files changed, 341 insertions, 0 deletions

diff --git a/drivers/hwmon/ds1621.c b/drivers/hwmon/ds1621.c
new file mode 100644
index 000000000000..5360d58804f6
--- /dev/null
+++ b/drivers/hwmon/ds1621.c
@@ -0,0 +1,341 @@
+/*
+    ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
+             monitoring
+    Christian W. Zuckschwerdt  <zany@triq.net>  2000-11-23
+    based on lm75.c by Frodo Looijaard <frodol@dds.nl>
+    Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with 
+    the help of Jean Delvare <khali@linux-fr.org>
+
+    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(ds1621);
+static int polarity = -1;
+module_param(polarity, int, 0);
+MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
+
+/* Many DS1621 constants specified below */
+/* Config register used for detection         */
+/*  7    6    5    4    3    2    1    0      */
+/* |Done|THF |TLF |NVB | X  | X  |POL |1SHOT| */
+#define DS1621_REG_CONFIG_NVB           0x10
+#define DS1621_REG_CONFIG_POLARITY      0x02
+#define DS1621_REG_CONFIG_1SHOT         0x01
+#define DS1621_REG_CONFIG_DONE          0x80
+
+/* The DS1621 registers */
+#define DS1621_REG_TEMP                 0xAA /* word, RO */
+#define DS1621_REG_TEMP_MIN             0xA1 /* word, RW */
+#define DS1621_REG_TEMP_MAX             0xA2 /* word, RW */
+#define DS1621_REG_CONF                 0xAC /* byte, RW */
+#define DS1621_COM_START                0xEE /* no data */
+#define DS1621_COM_STOP                 0x22 /* no data */
+
+/* The DS1621 configuration register */
+#define DS1621_ALARM_TEMP_HIGH          0x40
+#define DS1621_ALARM_TEMP_LOW           0x20
+
+/* Conversions. Rounding and limit checking is only done on the TO_REG
+   variants. Note that you should be a bit careful with which arguments
+   these macros are called: arguments may be evaluated more than once.
+   Fixing this is just not worth it. */
+#define ALARMS_FROM_REG(val) ((val) & \
+                              (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
+
+/* Each client has this additional data */
+struct ds1621_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, temp_min, temp_max;   /* Register values, word */
+        u8 conf;                        /* Register encoding, combined */
+};
+
+static int ds1621_attach_adapter(struct i2c_adapter *adapter);
+static int ds1621_detect(struct i2c_adapter *adapter, int address,
+                         int kind);
+static void ds1621_init_client(struct i2c_client *client);
+static int ds1621_detach_client(struct i2c_client *client);
+static struct ds1621_data *ds1621_update_client(struct device *dev);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver ds1621_driver = {
+        .owner          = THIS_MODULE,
+        .name           = "ds1621",
+        .id             = I2C_DRIVERID_DS1621,
+        .flags          = I2C_DF_NOTIFY,
+        .attach_adapter = ds1621_attach_adapter,
+        .detach_client  = ds1621_detach_client,
+};
+
+/* All registers are word-sized, except for the configuration register.
+   DS1621 uses a high-byte first convention, which is exactly opposite to
+   the usual practice. */
+static int ds1621_read_value(struct i2c_client *client, u8 reg)
+{
+        if (reg == DS1621_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.
+   DS1621 uses a high-byte first convention, which is exactly opposite to
+   the usual practice. */
+static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+        if (reg == DS1621_REG_CONF)
+                return i2c_smbus_write_byte_data(client, reg, value);
+        else
+                return i2c_smbus_write_word_data(client, reg, swab16(value));
+}
+
+static void ds1621_init_client(struct i2c_client *client)
+{
+        int reg = ds1621_read_value(client, DS1621_REG_CONF);
+        /* switch to continuous conversion mode */
+        reg &= ~ DS1621_REG_CONFIG_1SHOT;
+
+        /* setup output polarity */
+        if (polarity == 0)
+                reg &= ~DS1621_REG_CONFIG_POLARITY;
+        else if (polarity == 1)
+                reg |= DS1621_REG_CONFIG_POLARITY;
+        
+        ds1621_write_value(client, DS1621_REG_CONF, reg);
+        
+        /* start conversion */
+        i2c_smbus_write_byte(client, DS1621_COM_START);
+}
+
+#define show(value)                                                     \
+static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf)               \
+{                                                                       \
+        struct ds1621_data *data = ds1621_update_client(dev);           \
+        return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value));   \
+}
+
+show(temp);
+show(temp_min);
+show(temp_max);
+
+#define set_temp(suffix, value, reg)                                    \
+static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf,    \
+                                 size_t count)                          \
+{                                                                       \
+        struct i2c_client *client = to_i2c_client(dev);                 \
+        struct ds1621_data *data = ds1621_update_client(dev);           \
+        u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10));      \
+                                                                        \
+        down(&data->update_lock);                                       \
+        data->value = val;                                              \
+        ds1621_write_value(client, reg, data->value);                   \
+        up(&data->update_lock);                                         \
+        return count;                                                   \
+}
+
+set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
+set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
+
+static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct ds1621_data *data = ds1621_update_client(dev);
+        return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
+}
+
+static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
+static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
+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 int ds1621_attach_adapter(struct i2c_adapter *adapter)
+{
+        return i2c_detect(adapter, &addr_data, ds1621_detect);
+}
+
+/* This function is called by i2c_detect */
+int ds1621_detect(struct i2c_adapter *adapter, int address,
+                  int kind)
+{
+        int conf, temp;
+        struct i2c_client *new_client;
+        struct ds1621_data *data;
+        int err = 0;
+
+        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 
+                                     | I2C_FUNC_SMBUS_WORD_DATA 
+                                     | I2C_FUNC_SMBUS_WRITE_BYTE))
+                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 ds1621_{read,write}_value. */
+        if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
+                err = -ENOMEM;
+                goto exit;
+        }
+        memset(data, 0, sizeof(struct ds1621_data));
+        
+        new_client = &data->client;
+        i2c_set_clientdata(new_client, data);
+        new_client->addr = address;
+        new_client->adapter = adapter;
+        new_client->driver = &ds1621_driver;
+        new_client->flags = 0;
+
+
+        /* Now, we do the remaining detection. It is lousy. */
+        if (kind < 0) {
+                /* The NVB bit should be low if no EEPROM write has been 
+                   requested during the latest 10ms, which is highly 
+                   improbable in our case. */
+                conf = ds1621_read_value(new_client, DS1621_REG_CONF);
+                if (conf & DS1621_REG_CONFIG_NVB)
+                        goto exit_free;
+                /* The 7 lowest bits of a temperature should always be 0. */
+                temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
+                if (temp & 0x007f)
+                        goto exit_free;
+                temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
+                if (temp & 0x007f)
+                        goto exit_free;
+                temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
+                if (temp & 0x007f)
+                        goto exit_free;
+        }
+
+        /* Determine the chip type - only one kind supported! */
+        if (kind <= 0)
+                kind = ds1621;
+
+        /* Fill in remaining client fields and put it into the global list */
+        strlcpy(new_client->name, "ds1621", 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 DS1621 chip */
+        ds1621_init_client(new_client);
+
+        /* Register sysfs hooks */
+        device_create_file(&new_client->dev, &dev_attr_alarms);
+        device_create_file(&new_client->dev, &dev_attr_temp1_input);
+        device_create_file(&new_client->dev, &dev_attr_temp1_min);
+        device_create_file(&new_client->dev, &dev_attr_temp1_max);
+        
+        return 0;
+
+/* OK, this is not exactly good programming practice, usually. But it is
+   very code-efficient in this case. */
+      exit_free:
+        kfree(data);
+      exit:
+        return err;
+}
+
+static int ds1621_detach_client(struct i2c_client *client)
+{
+        int err;
+
+        if ((err = i2c_detach_client(client))) {
+                dev_err(&client->dev, "Client deregistration failed, "
+                        "client not detached.\n");
+                return err;
+        }
+
+        kfree(i2c_get_clientdata(client));
+
+        return 0;
+}
+
+
+static struct ds1621_data *ds1621_update_client(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct ds1621_data *data = i2c_get_clientdata(client);
+        u8 new_conf;
+
+        down(&data->update_lock);
+
+        if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
+            || !data->valid) {
+
+                dev_dbg(&client->dev, "Starting ds1621 update\n");
+
+                data->conf = ds1621_read_value(client, DS1621_REG_CONF);
+
+                data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
+                
+                data->temp_min = ds1621_read_value(client,
+                                                    DS1621_REG_TEMP_MIN);
+                data->temp_max = ds1621_read_value(client,
+                                                    DS1621_REG_TEMP_MAX);
+
+                /* reset alarms if necessary */
+                new_conf = data->conf;
+                if (data->temp < data->temp_min)
+                        new_conf &= ~DS1621_ALARM_TEMP_LOW;
+                if (data->temp > data->temp_max)
+                        new_conf &= ~DS1621_ALARM_TEMP_HIGH;
+                if (data->conf != new_conf)
+                        ds1621_write_value(client, DS1621_REG_CONF,
+                                           new_conf);
+
+                data->last_updated = jiffies;
+                data->valid = 1;
+        }
+
+        up(&data->update_lock);
+
+        return data;
+}
+
+static int __init ds1621_init(void)
+{
+        return i2c_add_driver(&ds1621_driver);
+}
+
+static void __exit ds1621_exit(void)
+{
+        i2c_del_driver(&ds1621_driver);
+}
+
+
+MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
+MODULE_DESCRIPTION("DS1621 driver");
+MODULE_LICENSE("GPL");
+
+module_init(ds1621_init);
+module_exit(ds1621_exit);