/*
      adm1021.c - Part of lm_sensors, Linux kernel modules for hardware

  		monitoring

      Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl> and
      Philip Edelbrock <phil@netroedge.com>
  
      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/hwmon-sysfs.h>

  #include <linux/err.h>

  #include <linux/mutex.h>

  
  
  /* Addresses to scan */

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

  enum chips {
  	adm1021, adm1023, max1617, max1617a, thmc10, lm84, gl523sm, mc1066 };

  
  /* adm1021 constants specified below */
  
  /* The adm1021 registers */
  /* Read-only */

  /* For nr in 0-1 */
  #define ADM1021_REG_TEMP(nr)		(nr)

  #define ADM1021_REG_STATUS		0x02

  /* 0x41 = AD, 0x49 = TI, 0x4D = Maxim, 0x23 = Genesys , 0x54 = Onsemi */
  #define ADM1021_REG_MAN_ID		0xFE
  /* ADM1021 = 0x0X, ADM1023 = 0x3X */
  #define ADM1021_REG_DEV_ID		0xFF

  /* These use different addresses for reading/writing */
  #define ADM1021_REG_CONFIG_R		0x03
  #define ADM1021_REG_CONFIG_W		0x09
  #define ADM1021_REG_CONV_RATE_R		0x04
  #define ADM1021_REG_CONV_RATE_W		0x0A
  /* These are for the ADM1023's additional precision on the remote temp sensor */

  #define ADM1023_REG_REM_TEMP_PREC	0x10
  #define ADM1023_REG_REM_OFFSET		0x11
  #define ADM1023_REG_REM_OFFSET_PREC	0x12
  #define ADM1023_REG_REM_TOS_PREC	0x13
  #define ADM1023_REG_REM_THYST_PREC	0x14

  /* limits */

  /* For nr in 0-1 */
  #define ADM1021_REG_TOS_R(nr)		(0x05 + 2 * (nr))
  #define ADM1021_REG_TOS_W(nr)		(0x0B + 2 * (nr))
  #define ADM1021_REG_THYST_R(nr)		(0x06 + 2 * (nr))
  #define ADM1021_REG_THYST_W(nr)		(0x0C + 2 * (nr))

  /* write-only */
  #define ADM1021_REG_ONESHOT		0x0F

  /* Initial values */

  /* Note: Even though I left the low and high limits named os and hyst,
  they don't quite work like a thermostat the way the LM75 does.  I.e.,
  a lower temp than THYST actually triggers an alarm instead of

  clearing it.  Weird, ey?   --Phil  */
  
  /* Each client has this additional data */
  struct adm1021_data {

  	struct device *hwmon_dev;

  	enum chips type;

  	struct mutex update_lock;

  	char valid;		/* !=0 if following fields are valid */

  	char low_power;		/* !=0 if device in low power mode */

  	unsigned long last_updated;	/* In jiffies */

  	int temp_max[2];		/* Register values */
  	int temp_min[2];
  	int temp[2];

  	u8 alarms;
  	/* Special values for ADM1023 only */

  	u8 remote_temp_offset;
  	u8 remote_temp_offset_prec;

  };

  static int adm1021_probe(struct i2c_client *client,
  			 const struct i2c_device_id *id);

  static int adm1021_detect(struct i2c_client *client,

  			  struct i2c_board_info *info);

  static void adm1021_init_client(struct i2c_client *client);

  static int adm1021_remove(struct i2c_client *client);

  static struct adm1021_data *adm1021_update_device(struct device *dev);
  
  /* (amalysh) read only mode, otherwise any limit's writing confuse BIOS */

  static bool read_only;

  static const struct i2c_device_id adm1021_id[] = {
  	{ "adm1021", adm1021 },
  	{ "adm1023", adm1023 },
  	{ "max1617", max1617 },
  	{ "max1617a", max1617a },
  	{ "thmc10", thmc10 },
  	{ "lm84", lm84 },
  	{ "gl523sm", gl523sm },
  	{ "mc1066", mc1066 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, adm1021_id);

  /* This is the driver that will be inserted */
  static struct i2c_driver adm1021_driver = {

  	.class		= I2C_CLASS_HWMON,

  	.driver = {

  		.name	= "adm1021",
  	},

  	.probe		= adm1021_probe,
  	.remove		= adm1021_remove,
  	.id_table	= adm1021_id,
  	.detect		= adm1021_detect,

  	.address_list	= normal_i2c,

  };

  static ssize_t show_temp(struct device *dev,
  			 struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct adm1021_data *data = adm1021_update_device(dev);

  	return sprintf(buf, "%d
  ", data->temp[index]);

  }
  
  static ssize_t show_temp_max(struct device *dev,
  			     struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct adm1021_data *data = adm1021_update_device(dev);

  	return sprintf(buf, "%d
  ", data->temp_max[index]);

  }
  
  static ssize_t show_temp_min(struct device *dev,
  			     struct device_attribute *devattr, char *buf)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct adm1021_data *data = adm1021_update_device(dev);

  	return sprintf(buf, "%d
  ", data->temp_min[index]);

  }

  static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
  			  char *buf)
  {
  	int index = to_sensor_dev_attr(attr)->index;
  	struct adm1021_data *data = adm1021_update_device(dev);
  	return sprintf(buf, "%u
  ", (data->alarms >> index) & 1);
  }

  static ssize_t show_alarms(struct device *dev,
  			   struct device_attribute *attr,
  			   char *buf)
  {
  	struct adm1021_data *data = adm1021_update_device(dev);
  	return sprintf(buf, "%u
  ", data->alarms);

  }

  static ssize_t set_temp_max(struct device *dev,
  			    struct device_attribute *devattr,
  			    const char *buf, size_t count)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct adm1021_data *data = i2c_get_clientdata(client);
  	long temp = simple_strtol(buf, NULL, 10) / 1000;
  
  	mutex_lock(&data->update_lock);
  	data->temp_max[index] = SENSORS_LIMIT(temp, -128, 127);
  	if (!read_only)
  		i2c_smbus_write_byte_data(client, ADM1021_REG_TOS_W(index),
  					  data->temp_max[index]);
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }
  
  static ssize_t set_temp_min(struct device *dev,
  			    struct device_attribute *devattr,
  			    const char *buf, size_t count)
  {
  	int index = to_sensor_dev_attr(devattr)->index;
  	struct i2c_client *client = to_i2c_client(dev);
  	struct adm1021_data *data = i2c_get_clientdata(client);
  	long temp = simple_strtol(buf, NULL, 10) / 1000;
  
  	mutex_lock(&data->update_lock);
  	data->temp_min[index] = SENSORS_LIMIT(temp, -128, 127);
  	if (!read_only)
  		i2c_smbus_write_byte_data(client, ADM1021_REG_THYST_W(index),
  					  data->temp_min[index]);
  	mutex_unlock(&data->update_lock);
  
  	return count;

  }

  static ssize_t show_low_power(struct device *dev,
  			      struct device_attribute *devattr, char *buf)
  {
  	struct adm1021_data *data = adm1021_update_device(dev);
  	return sprintf(buf, "%d
  ", data->low_power);
  }
  
  static ssize_t set_low_power(struct device *dev,
  			     struct device_attribute *devattr,
  			     const char *buf, size_t count)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct adm1021_data *data = i2c_get_clientdata(client);
  	int low_power = simple_strtol(buf, NULL, 10) != 0;
  
  	mutex_lock(&data->update_lock);
  	if (low_power != data->low_power) {
  		int config = i2c_smbus_read_byte_data(
  			client, ADM1021_REG_CONFIG_R);
  		data->low_power = low_power;
  		i2c_smbus_write_byte_data(client, ADM1021_REG_CONFIG_W,
  			(config & 0xBF) | (low_power << 6));
  	}
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }

  static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
  static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
  			  set_temp_max, 0);
  static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp_min,
  			  set_temp_min, 0);
  static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
  static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_max,
  			  set_temp_max, 1);
  static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_min,
  			  set_temp_min, 1);

  static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
  static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 5);
  static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
  static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
  static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);

  static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

  static DEVICE_ATTR(low_power, S_IWUSR | S_IRUGO, show_low_power, set_low_power);

  static struct attribute *adm1021_attributes[] = {

  	&sensor_dev_attr_temp1_max.dev_attr.attr,
  	&sensor_dev_attr_temp1_min.dev_attr.attr,
  	&sensor_dev_attr_temp1_input.dev_attr.attr,
  	&sensor_dev_attr_temp2_max.dev_attr.attr,
  	&sensor_dev_attr_temp2_min.dev_attr.attr,
  	&sensor_dev_attr_temp2_input.dev_attr.attr,

  	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_fault.dev_attr.attr,

  	&dev_attr_alarms.attr,

  	&dev_attr_low_power.attr,

  	NULL
  };
  
  static const struct attribute_group adm1021_group = {
  	.attrs = adm1021_attributes,
  };

  /* Return 0 if detection is successful, -ENODEV otherwise */

  static int adm1021_detect(struct i2c_client *client,

  			  struct i2c_board_info *info)

  {

  	struct i2c_adapter *adapter = client->adapter;

  	const char *type_name;
  	int conv_rate, status, config, man_id, dev_id;

  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
  		pr_debug("adm1021: detect failed, "
  			 "smbus byte data not supported!
  ");

  		return -ENODEV;

  	}

  	status = i2c_smbus_read_byte_data(client, ADM1021_REG_STATUS);
  	conv_rate = i2c_smbus_read_byte_data(client,
  					     ADM1021_REG_CONV_RATE_R);
  	config = i2c_smbus_read_byte_data(client, ADM1021_REG_CONFIG_R);

  	/* Check unused bits */
  	if ((status & 0x03) || (config & 0x3F) || (conv_rate & 0xF8)) {
  		pr_debug("adm1021: detect failed, chip not detected!
  ");
  		return -ENODEV;

  	}
  
  	/* Determine the chip type. */

  	man_id = i2c_smbus_read_byte_data(client, ADM1021_REG_MAN_ID);
  	dev_id = i2c_smbus_read_byte_data(client, ADM1021_REG_DEV_ID);

  	if (man_id == 0x4d && dev_id == 0x01)

  		type_name = "max1617a";

  	else if (man_id == 0x41) {
  		if ((dev_id & 0xF0) == 0x30)
  			type_name = "adm1023";
  		else
  			type_name = "adm1021";
  	} else if (man_id == 0x49)

  		type_name = "thmc10";

  	else if (man_id == 0x23)

  		type_name = "gl523sm";

  	else if (man_id == 0x54)

  		type_name = "mc1066";

  	/* LM84 Mfr ID in a different place, and it has more unused bits */
  	else if (conv_rate == 0x00
  		 && (config & 0x7F) == 0x00
  		 && (status & 0xAB) == 0x00)
  		type_name = "lm84";
  	else
  		type_name = "max1617";

  	pr_debug("adm1021: Detected chip %s at adapter %d, address 0x%02x.
  ",

  		 type_name, i2c_adapter_id(adapter), client->addr);
  	strlcpy(info->type, type_name, I2C_NAME_SIZE);

  	return 0;
  }

  static int adm1021_probe(struct i2c_client *client,
  			 const struct i2c_device_id *id)
  {
  	struct adm1021_data *data;
  	int err;
  
  	data = kzalloc(sizeof(struct adm1021_data), GFP_KERNEL);
  	if (!data) {
  		pr_debug("adm1021: detect failed, kzalloc failed!
  ");
  		err = -ENOMEM;
  		goto error0;
  	}
  
  	i2c_set_clientdata(client, data);
  	data->type = id->driver_data;
  	mutex_init(&data->update_lock);

  
  	/* Initialize the ADM1021 chip */

  	if (data->type != lm84 && !read_only)

  		adm1021_init_client(client);

  
  	/* Register sysfs hooks */

  	if ((err = sysfs_create_group(&client->dev.kobj, &adm1021_group)))

  		goto error1;

  	data->hwmon_dev = hwmon_device_register(&client->dev);
  	if (IS_ERR(data->hwmon_dev)) {
  		err = PTR_ERR(data->hwmon_dev);

  		goto error3;

  	}

  	return 0;

  error3:

  	sysfs_remove_group(&client->dev.kobj, &adm1021_group);

  error1:
  	kfree(data);
  error0:
  	return err;
  }
  
  static void adm1021_init_client(struct i2c_client *client)
  {
  	/* Enable ADC and disable suspend mode */

  	i2c_smbus_write_byte_data(client, ADM1021_REG_CONFIG_W,
  		i2c_smbus_read_byte_data(client, ADM1021_REG_CONFIG_R) & 0xBF);

  	/* Set Conversion rate to 1/sec (this can be tinkered with) */

  	i2c_smbus_write_byte_data(client, ADM1021_REG_CONV_RATE_W, 0x04);

  }

  static int adm1021_remove(struct i2c_client *client)

  {

  	struct adm1021_data *data = i2c_get_clientdata(client);

  	hwmon_device_unregister(data->hwmon_dev);

  	sysfs_remove_group(&client->dev.kobj, &adm1021_group);

  	kfree(data);

  	return 0;
  }

  static struct adm1021_data *adm1021_update_device(struct device *dev)
  {
  	struct i2c_client *client = to_i2c_client(dev);
  	struct adm1021_data *data = i2c_get_clientdata(client);

  	mutex_lock(&data->update_lock);

  
  	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
  	    || !data->valid) {

  		int i;

  		dev_dbg(&client->dev, "Starting adm1021 update
  ");

  		for (i = 0; i < 2; i++) {

  			data->temp[i] = 1000 *
  				(s8) i2c_smbus_read_byte_data(
  					client, ADM1021_REG_TEMP(i));
  			data->temp_max[i] = 1000 *
  				(s8) i2c_smbus_read_byte_data(
  					client, ADM1021_REG_TOS_R(i));
  			data->temp_min[i] = 1000 *
  				(s8) i2c_smbus_read_byte_data(
  					client, ADM1021_REG_THYST_R(i));

  		}

  		data->alarms = i2c_smbus_read_byte_data(client,
  						ADM1021_REG_STATUS) & 0x7c;

  		if (data->type == adm1023) {

  			/* The ADM1023 provides 3 extra bits of precision for
  			 * the remote sensor in extra registers. */
  			data->temp[1] += 125 * (i2c_smbus_read_byte_data(
  				client, ADM1023_REG_REM_TEMP_PREC) >> 5);
  			data->temp_max[1] += 125 * (i2c_smbus_read_byte_data(
  				client, ADM1023_REG_REM_TOS_PREC) >> 5);
  			data->temp_min[1] += 125 * (i2c_smbus_read_byte_data(
  				client, ADM1023_REG_REM_THYST_PREC) >> 5);

  			data->remote_temp_offset =
  				i2c_smbus_read_byte_data(client,
  						ADM1023_REG_REM_OFFSET);
  			data->remote_temp_offset_prec =
  				i2c_smbus_read_byte_data(client,
  						ADM1023_REG_REM_OFFSET_PREC);

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

  	mutex_unlock(&data->update_lock);

  
  	return data;
  }
  
  static int __init sensors_adm1021_init(void)
  {
  	return i2c_add_driver(&adm1021_driver);
  }
  
  static void __exit sensors_adm1021_exit(void)
  {
  	i2c_del_driver(&adm1021_driver);
  }
  
  MODULE_AUTHOR ("Frodo Looijaard <frodol@dds.nl> and "
  		"Philip Edelbrock <phil@netroedge.com>");
  MODULE_DESCRIPTION("adm1021 driver");
  MODULE_LICENSE("GPL");
  
  module_param(read_only, bool, 0);
  MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");
  
  module_init(sensors_adm1021_init)
  module_exit(sensors_adm1021_exit)