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lm83.c

/*
 * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 * Copyright (C) 2003-2006  Jean Delvare <khali@linux-fr.org>
 *
 * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
 * a sensor chip made by National Semiconductor. It reports up to four
 * temperatures (its own plus up to three external ones) with a 1 deg
 * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
 * from National's website at:
 *   http://www.national.com/pf/LM/LM83.html
 * Since the datasheet omits to give the chip stepping code, I give it
 * here: 0x03 (at register 0xff).
 *
 * Also supports the LM82 temp sensor, which is basically a stripped down
 * model of the LM83.  Datasheet is here:
 * http://www.national.com/pf/LM/LM82.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/hwmon-sysfs.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>

/*
 * Addresses to scan
 * Address is selected using 2 three-level pins, resulting in 9 possible
 * addresses.
 */

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

/*
 * Insmod parameters
 */

I2C_CLIENT_INSMOD_2(lm83, lm82);

/*
 * The LM83 registers
 * Manufacturer ID is 0x01 for National Semiconductor.
 */

#define LM83_REG_R_MAN_ID           0xFE
#define LM83_REG_R_CHIP_ID          0xFF
#define LM83_REG_R_CONFIG           0x03
#define LM83_REG_W_CONFIG           0x09
#define LM83_REG_R_STATUS1          0x02
#define LM83_REG_R_STATUS2          0x35
#define LM83_REG_R_LOCAL_TEMP       0x00
#define LM83_REG_R_LOCAL_HIGH       0x05
#define LM83_REG_W_LOCAL_HIGH       0x0B
#define LM83_REG_R_REMOTE1_TEMP           0x30
#define LM83_REG_R_REMOTE1_HIGH           0x38
#define LM83_REG_W_REMOTE1_HIGH           0x50
#define LM83_REG_R_REMOTE2_TEMP           0x01
#define LM83_REG_R_REMOTE2_HIGH           0x07
#define LM83_REG_W_REMOTE2_HIGH           0x0D
#define LM83_REG_R_REMOTE3_TEMP           0x31
#define LM83_REG_R_REMOTE3_HIGH           0x3A
#define LM83_REG_W_REMOTE3_HIGH           0x52
#define LM83_REG_R_TCRIT            0x42
#define LM83_REG_W_TCRIT            0x5A

/*
 * Conversions and various macros
 * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
 */

#define TEMP_FROM_REG(val)    ((val) * 1000)
#define TEMP_TO_REG(val)      ((val) <= -128000 ? -128 : \
                         (val) >= 127000 ? 127 : \
                         (val) < 0 ? ((val) - 500) / 1000 : \
                         ((val) + 500) / 1000)

static const u8 LM83_REG_R_TEMP[] = {
      LM83_REG_R_LOCAL_TEMP,
      LM83_REG_R_REMOTE1_TEMP,
      LM83_REG_R_REMOTE2_TEMP,
      LM83_REG_R_REMOTE3_TEMP,
      LM83_REG_R_LOCAL_HIGH,
      LM83_REG_R_REMOTE1_HIGH,
      LM83_REG_R_REMOTE2_HIGH,
      LM83_REG_R_REMOTE3_HIGH,
      LM83_REG_R_TCRIT,
};

static const u8 LM83_REG_W_HIGH[] = {
      LM83_REG_W_LOCAL_HIGH,
      LM83_REG_W_REMOTE1_HIGH,
      LM83_REG_W_REMOTE2_HIGH,
      LM83_REG_W_REMOTE3_HIGH,
      LM83_REG_W_TCRIT,
};

/*
 * Functions declaration
 */

static int lm83_attach_adapter(struct i2c_adapter *adapter);
static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
static int lm83_detach_client(struct i2c_client *client);
static struct lm83_data *lm83_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */
 
static struct i2c_driver lm83_driver = {
      .driver = {
            .name = "lm83",
      },
      .id         = I2C_DRIVERID_LM83,
      .attach_adapter   = lm83_attach_adapter,
      .detach_client    = lm83_detach_client,
};

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

struct lm83_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 */
      s8 temp[9]; /* 0..3: input 1-4,
                     4..7: high limit 1-4,
                     8   : critical limit */
      u16 alarms; /* bitvector, combined */
};

/*
 * Sysfs stuff
 */

static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
                   char *buf)
{
      struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
      struct lm83_data *data = lm83_update_device(dev);
      return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
}

static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
                  const char *buf, size_t count)
{
      struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
      struct i2c_client *client = to_i2c_client(dev);
      struct lm83_data *data = i2c_get_clientdata(client);
      long val = simple_strtol(buf, NULL, 10);
      int nr = attr->index;

      mutex_lock(&data->update_lock);
      data->temp[nr] = TEMP_TO_REG(val);
      i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
                          data->temp[nr]);
      mutex_unlock(&data->update_lock);
      return count;
}

static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
                     char *buf)
{
      struct lm83_data *data = lm83_update_device(dev);
      return sprintf(buf, "%d\n", data->alarms);
}

static ssize_t show_alarm(struct device *dev, struct device_attribute
                    *devattr, char *buf)
{
      struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
      struct lm83_data *data = lm83_update_device(dev);
      int bitnr = attr->index;

      return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
      set_temp, 4);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
      set_temp, 5);
static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
      set_temp, 6);
static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
      set_temp, 7);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
      set_temp, 8);
static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);

/* Individual alarm files */
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
/* Raw alarm file for compatibility */
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static struct attribute *lm83_attributes[] = {
      &sensor_dev_attr_temp1_input.dev_attr.attr,
      &sensor_dev_attr_temp3_input.dev_attr.attr,
      &sensor_dev_attr_temp1_max.dev_attr.attr,
      &sensor_dev_attr_temp3_max.dev_attr.attr,
      &sensor_dev_attr_temp1_crit.dev_attr.attr,
      &sensor_dev_attr_temp3_crit.dev_attr.attr,

      &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
      &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
      &sensor_dev_attr_temp3_fault.dev_attr.attr,
      &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
      &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
      &dev_attr_alarms.attr,
      NULL
};

static const struct attribute_group lm83_group = {
      .attrs = lm83_attributes,
};

static struct attribute *lm83_attributes_opt[] = {
      &sensor_dev_attr_temp2_input.dev_attr.attr,
      &sensor_dev_attr_temp4_input.dev_attr.attr,
      &sensor_dev_attr_temp2_max.dev_attr.attr,
      &sensor_dev_attr_temp4_max.dev_attr.attr,
      &sensor_dev_attr_temp2_crit.dev_attr.attr,
      &sensor_dev_attr_temp4_crit.dev_attr.attr,

      &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
      &sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
      &sensor_dev_attr_temp4_fault.dev_attr.attr,
      &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
      &sensor_dev_attr_temp2_fault.dev_attr.attr,
      &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
      NULL
};

static const struct attribute_group lm83_group_opt = {
      .attrs = lm83_attributes_opt,
};

/*
 * Real code
 */

static int lm83_attach_adapter(struct i2c_adapter *adapter)
{
      if (!(adapter->class & I2C_CLASS_HWMON))
            return 0;
      return i2c_probe(adapter, &addr_data, lm83_detect);
}

/*
 * The following function does more than just detection. If detection
 * succeeds, it also registers the new chip.
 */
static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
{
      struct i2c_client *new_client;
      struct lm83_data *data;
      int err = 0;
      const char *name = "";

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

      if (!(data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
            err = -ENOMEM;
            goto exit;
      }

      /* The common I2C client data is placed right after the
       * LM83-specific data. */
      new_client = &data->client;
      i2c_set_clientdata(new_client, data);
      new_client->addr = address;
      new_client->adapter = adapter;
      new_client->driver = &lm83_driver;
      new_client->flags = 0;

      /* Now we do the detection and identification. A negative kind
       * means that the driver was loaded with no force parameter
       * (default), so we must both detect and identify the chip
       * (actually there is only one possible kind of chip for now, LM83).
       * 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. */

      /* Default to an LM83 if forced */
      if (kind == 0)
            kind = lm83;

      if (kind < 0) { /* detection */
            if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
                & 0xA8) != 0x00) ||
                ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
                & 0x48) != 0x00) ||
                ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
                & 0x41) != 0x00)) {
                  dev_dbg(&adapter->dev,
                      "LM83 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,
                LM83_REG_R_MAN_ID);
            chip_id = i2c_smbus_read_byte_data(new_client,
                LM83_REG_R_CHIP_ID);

            if (man_id == 0x01) { /* National Semiconductor */
                  if (chip_id == 0x03) {
                        kind = lm83;
                  } else
                  if (chip_id == 0x01) {
                        kind = lm82;
                  }
            }

            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 == lm83) {
            name = "lm83";
      } else
      if (kind == lm82) {
            name = "lm82";
      }

      /* 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;

      /*
       * Register sysfs hooks
       * The LM82 can only monitor one external diode which is
       * at the same register as the LM83 temp3 entry - so we
       * declare 1 and 3 common, and then 2 and 4 only for the LM83.
       */

      if ((err = sysfs_create_group(&new_client->dev.kobj, &lm83_group)))
            goto exit_detach;

      if (kind == lm83) {
            if ((err = sysfs_create_group(&new_client->dev.kobj,
                                    &lm83_group_opt)))
                  goto exit_remove_files;
      }

      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, &lm83_group);
      sysfs_remove_group(&new_client->dev.kobj, &lm83_group_opt);
exit_detach:
      i2c_detach_client(new_client);
exit_free:
      kfree(data);
exit:
      return err;
}

static int lm83_detach_client(struct i2c_client *client)
{
      struct lm83_data *data = i2c_get_clientdata(client);
      int err;

      hwmon_device_unregister(data->hwmon_dev);
      sysfs_remove_group(&client->dev.kobj, &lm83_group);
      sysfs_remove_group(&client->dev.kobj, &lm83_group_opt);

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

      kfree(data);
      return 0;
}

static struct lm83_data *lm83_update_device(struct device *dev)
{
      struct i2c_client *client = to_i2c_client(dev);
      struct lm83_data *data = i2c_get_clientdata(client);

      mutex_lock(&data->update_lock);

      if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
            int nr;

            dev_dbg(&client->dev, "Updating lm83 data.\n");
            for (nr = 0; nr < 9; nr++) {
                  data->temp[nr] =
                      i2c_smbus_read_byte_data(client,
                      LM83_REG_R_TEMP[nr]);
            }
            data->alarms =
                i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
                + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
                << 8);

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

      mutex_unlock(&data->update_lock);

      return data;
}

static int __init sensors_lm83_init(void)
{
      return i2c_add_driver(&lm83_driver);
}

static void __exit sensors_lm83_exit(void)
{
      i2c_del_driver(&lm83_driver);
}

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("LM83 driver");
MODULE_LICENSE("GPL");

module_init(sensors_lm83_init);
module_exit(sensors_lm83_exit);

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