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max1619.c

/*
 * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
 *             monitoring
 * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru>
 *                         Jean Delvare <khali@linux-fr.org>
 *
 * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
 * It reports up to two temperatures (its own plus up to
 * one external one). Complete datasheet can be
 * obtained from Maxim's website at:
 *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
 *
 * 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 <linux/sysfs.h>

static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
                              0x29, 0x2a, 0x2b,
                              0x4c, 0x4d, 0x4e,
                              I2C_CLIENT_END };

/*
 * Insmod parameters
 */

I2C_CLIENT_INSMOD_1(max1619);

/*
 * The MAX1619 registers
 */

#define MAX1619_REG_R_MAN_ID        0xFE
#define MAX1619_REG_R_CHIP_ID       0xFF
#define MAX1619_REG_R_CONFIG        0x03
#define MAX1619_REG_W_CONFIG        0x09
#define MAX1619_REG_R_CONVRATE            0x04
#define MAX1619_REG_W_CONVRATE            0x0A
#define MAX1619_REG_R_STATUS        0x02
#define MAX1619_REG_R_LOCAL_TEMP    0x00
#define MAX1619_REG_R_REMOTE_TEMP   0x01
#define MAX1619_REG_R_REMOTE_HIGH   0x07
#define MAX1619_REG_W_REMOTE_HIGH   0x0D
#define MAX1619_REG_R_REMOTE_LOW    0x08
#define MAX1619_REG_W_REMOTE_LOW    0x0E
#define MAX1619_REG_R_REMOTE_CRIT   0x10
#define MAX1619_REG_W_REMOTE_CRIT   0x12
#define MAX1619_REG_R_TCRIT_HYST    0x11
#define MAX1619_REG_W_TCRIT_HYST    0x13

/*
 * Conversions and various macros
 */

#define TEMP_FROM_REG(val)    ((val & 0x80 ? val-0x100 : val) * 1000)
#define TEMP_TO_REG(val)      ((val < 0 ? val+0x100*1000 : val) / 1000)

/*
 * Functions declaration
 */

static int max1619_attach_adapter(struct i2c_adapter *adapter);
static int max1619_detect(struct i2c_adapter *adapter, int address,
      int kind);
static void max1619_init_client(struct i2c_client *client);
static int max1619_detach_client(struct i2c_client *client);
static struct max1619_data *max1619_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */

static struct i2c_driver max1619_driver = {
      .driver = {
            .name = "max1619",
      },
      .attach_adapter   = max1619_attach_adapter,
      .detach_client    = max1619_detach_client,
};

/*
 * Client data (each client gets its own)
 */

struct max1619_data {
      struct i2c_client client;
      struct device *hwmon_dev;
      struct mutex update_lock;
      char valid; /* zero until following fields are valid */
      unsigned long last_updated; /* in jiffies */

      /* registers values */
      u8 temp_input1; /* local */
      u8 temp_input2, temp_low2, temp_high2; /* remote */
      u8 temp_crit2;
      u8 temp_hyst2;
      u8 alarms; 
};

/*
 * Sysfs stuff
 */

#define show_temp(value) \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
      struct max1619_data *data = max1619_update_device(dev); \
      return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
}
show_temp(temp_input1);
show_temp(temp_input2);
show_temp(temp_low2);
show_temp(temp_high2);
show_temp(temp_crit2);
show_temp(temp_hyst2);

#define set_temp2(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 max1619_data *data = i2c_get_clientdata(client); \
      long val = simple_strtol(buf, NULL, 10); \
 \
      mutex_lock(&data->update_lock); \
      data->value = TEMP_TO_REG(val); \
      i2c_smbus_write_byte_data(client, reg, data->value); \
      mutex_unlock(&data->update_lock); \
      return count; \
}

set_temp2(temp_low2, MAX1619_REG_W_REMOTE_LOW);
set_temp2(temp_high2, MAX1619_REG_W_REMOTE_HIGH);
set_temp2(temp_crit2, MAX1619_REG_W_REMOTE_CRIT);
set_temp2(temp_hyst2, MAX1619_REG_W_TCRIT_HYST);

static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
{
      struct max1619_data *data = max1619_update_device(dev);
      return sprintf(buf, "%d\n", data->alarms);
}

static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
      set_temp_low2);
static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
      set_temp_high2);
static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
      set_temp_crit2);
static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst2,
      set_temp_hyst2);
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static struct attribute *max1619_attributes[] = {
      &dev_attr_temp1_input.attr,
      &dev_attr_temp2_input.attr,
      &dev_attr_temp2_min.attr,
      &dev_attr_temp2_max.attr,
      &dev_attr_temp2_crit.attr,
      &dev_attr_temp2_crit_hyst.attr,

      &dev_attr_alarms.attr,
      NULL
};

static const struct attribute_group max1619_group = {
      .attrs = max1619_attributes,
};

/*
 * Real code
 */

static int max1619_attach_adapter(struct i2c_adapter *adapter)
{
      if (!(adapter->class & I2C_CLASS_HWMON))
            return 0;
      return i2c_probe(adapter, &addr_data, max1619_detect);
}

/*
 * The following function does more than just detection. If detection
 * succeeds, it also registers the new chip.
 */
static int max1619_detect(struct i2c_adapter *adapter, int address, int kind)
{
      struct i2c_client *new_client;
      struct max1619_data *data;
      int err = 0;
      const char *name = "";  
      u8 reg_config=0, reg_convrate=0, reg_status=0;

      if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
            goto exit;

      if (!(data = kzalloc(sizeof(struct max1619_data), GFP_KERNEL))) {
            err = -ENOMEM;
            goto exit;
      }

      /* The common I2C client data is placed right before the
         MAX1619-specific data. */
      new_client = &data->client;
      i2c_set_clientdata(new_client, data);
      new_client->addr = address;
      new_client->adapter = adapter;
      new_client->driver = &max1619_driver;
      new_client->flags = 0;

      /*
       * Now we do the remaining detection. A negative kind means that
       * the driver was loaded with no force parameter (default), so we
       * must both detect and identify the chip. A zero kind means that
       * the driver was loaded with the force parameter, the detection
       * step shall be skipped. A positive kind means that the driver
       * was loaded with the force parameter and a given kind of chip is
       * requested, so both the detection and the identification steps
       * are skipped.
       */
      if (kind < 0) { /* detection */
            reg_config = i2c_smbus_read_byte_data(new_client,
                        MAX1619_REG_R_CONFIG);
            reg_convrate = i2c_smbus_read_byte_data(new_client,
                         MAX1619_REG_R_CONVRATE);
            reg_status = i2c_smbus_read_byte_data(new_client,
                        MAX1619_REG_R_STATUS);
            if ((reg_config & 0x03) != 0x00
             || reg_convrate > 0x07 || (reg_status & 0x61 ) !=0x00) {
                  dev_dbg(&adapter->dev,
                        "MAX1619 detection failed at 0x%02x.\n",
                        address);
                  goto exit_free;
            }
      }

      if (kind <= 0) { /* identification */
            u8 man_id, chip_id;
      
            man_id = i2c_smbus_read_byte_data(new_client,
                   MAX1619_REG_R_MAN_ID);
            chip_id = i2c_smbus_read_byte_data(new_client,
                    MAX1619_REG_R_CHIP_ID);
            
            if ((man_id == 0x4D) && (chip_id == 0x04))
                  kind = max1619;

            if (kind <= 0) { /* identification failed */
                  dev_info(&adapter->dev,
                      "Unsupported chip (man_id=0x%02X, "
                      "chip_id=0x%02X).\n", man_id, chip_id);
                  goto exit_free;
            }
      }

      if (kind == max1619)
            name = "max1619";

      /* We can fill in the remaining client fields */
      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 MAX1619 chip */
      max1619_init_client(new_client);

      /* Register sysfs hooks */
      if ((err = sysfs_create_group(&new_client->dev.kobj, &max1619_group)))
            goto exit_detach;

      data->hwmon_dev = hwmon_device_register(&new_client->dev);
      if (IS_ERR(data->hwmon_dev)) {
            err = PTR_ERR(data->hwmon_dev);
            goto exit_remove_files;
      }

      return 0;

exit_remove_files:
      sysfs_remove_group(&new_client->dev.kobj, &max1619_group);
exit_detach:
      i2c_detach_client(new_client);
exit_free:
      kfree(data);
exit:
      return err;
}

static void max1619_init_client(struct i2c_client *client)
{
      u8 config;

      /*
       * Start the conversions.
       */
      i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
                          5); /* 2 Hz */
      config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
      if (config & 0x40)
            i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
                                config & 0xBF); /* run */
}

static int max1619_detach_client(struct i2c_client *client)
{
      struct max1619_data *data = i2c_get_clientdata(client);
      int err;

      hwmon_device_unregister(data->hwmon_dev);
      sysfs_remove_group(&client->dev.kobj, &max1619_group);

      if ((err = i2c_detach_client(client)))
            return err;

      kfree(data);
      return 0;
}

static struct max1619_data *max1619_update_device(struct device *dev)
{
      struct i2c_client *client = to_i2c_client(dev);
      struct max1619_data *data = i2c_get_clientdata(client);

      mutex_lock(&data->update_lock);

      if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
            dev_dbg(&client->dev, "Updating max1619 data.\n");
            data->temp_input1 = i2c_smbus_read_byte_data(client,
                              MAX1619_REG_R_LOCAL_TEMP);
            data->temp_input2 = i2c_smbus_read_byte_data(client,
                              MAX1619_REG_R_REMOTE_TEMP);
            data->temp_high2 = i2c_smbus_read_byte_data(client,
                              MAX1619_REG_R_REMOTE_HIGH);
            data->temp_low2 = i2c_smbus_read_byte_data(client,
                              MAX1619_REG_R_REMOTE_LOW);
            data->temp_crit2 = i2c_smbus_read_byte_data(client,
                              MAX1619_REG_R_REMOTE_CRIT);
            data->temp_hyst2 = i2c_smbus_read_byte_data(client,
                              MAX1619_REG_R_TCRIT_HYST);
            data->alarms = i2c_smbus_read_byte_data(client,
                              MAX1619_REG_R_STATUS);

            data->last_updated = jiffies;
            data->valid = 1;
      }

      mutex_unlock(&data->update_lock);

      return data;
}

static int __init sensors_max1619_init(void)
{
      return i2c_add_driver(&max1619_driver);
}

static void __exit sensors_max1619_exit(void)
{
      i2c_del_driver(&max1619_driver);
}

MODULE_AUTHOR("Alexey Fisher <fishor@mail.ru> and "
      "Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("MAX1619 sensor driver");
MODULE_LICENSE("GPL");

module_init(sensors_max1619_init);
module_exit(sensors_max1619_exit);

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