/*
   * emc1403.c - SMSC Thermal Driver
   *
   * Copyright (C) 2008 Intel Corp
   *
   *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   *
   * 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; version 2 of the License.
   *
   * 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.,
   * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   *
   * TODO
   *	-	cache alarm and critical limit registers
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/i2c.h>
  #include <linux/hwmon.h>
  #include <linux/hwmon-sysfs.h>
  #include <linux/err.h>
  #include <linux/sysfs.h>
  #include <linux/mutex.h>
  #include <linux/jiffies.h>
  
  #define THERMAL_PID_REG		0xfd
  #define THERMAL_SMSC_ID_REG	0xfe
  #define THERMAL_REVISION_REG	0xff
  
  struct thermal_data {
  	struct i2c_client *client;
  	const struct attribute_group *groups[3];
  	struct mutex mutex;
  	/*
  	 * Cache the hyst value so we don't keep re-reading it. In theory
  	 * we could cache it forever as nobody else should be writing it.
  	 */
  	u8 cached_hyst;
  	unsigned long hyst_valid;
  };
  
  static ssize_t show_temp(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  	struct thermal_data *data = dev_get_drvdata(dev);
  	int retval;
  
  	retval = i2c_smbus_read_byte_data(data->client, sda->index);
  	if (retval < 0)
  		return retval;
  	return sprintf(buf, "%d000
  ", retval);
  }
  
  static ssize_t show_bit(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
  	struct thermal_data *data = dev_get_drvdata(dev);
  	int retval;
  
  	retval = i2c_smbus_read_byte_data(data->client, sda->nr);
  	if (retval < 0)
  		return retval;
  	return sprintf(buf, "%d
  ", !!(retval & sda->index));
  }
  
  static ssize_t store_temp(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  	struct thermal_data *data = dev_get_drvdata(dev);
  	unsigned long val;
  	int retval;
  
  	if (kstrtoul(buf, 10, &val))
  		return -EINVAL;
  	retval = i2c_smbus_write_byte_data(data->client, sda->index,
  					DIV_ROUND_CLOSEST(val, 1000));
  	if (retval < 0)
  		return retval;
  	return count;
  }
  
  static ssize_t store_bit(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(attr);
  	struct thermal_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;
  	unsigned long val;
  	int retval;
  
  	if (kstrtoul(buf, 10, &val))
  		return -EINVAL;
  
  	mutex_lock(&data->mutex);
  	retval = i2c_smbus_read_byte_data(client, sda->nr);
  	if (retval < 0)
  		goto fail;
  
  	retval &= ~sda->index;
  	if (val)
  		retval |= sda->index;
  
  	retval = i2c_smbus_write_byte_data(client, sda->index, retval);
  	if (retval == 0)
  		retval = count;
  fail:
  	mutex_unlock(&data->mutex);
  	return retval;
  }
  
  static ssize_t show_hyst(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  	struct thermal_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;
  	int retval;
  	int hyst;
  
  	retval = i2c_smbus_read_byte_data(client, sda->index);
  	if (retval < 0)
  		return retval;
  
  	if (time_after(jiffies, data->hyst_valid)) {
  		hyst = i2c_smbus_read_byte_data(client, 0x21);
  		if (hyst < 0)
  			return retval;
  		data->cached_hyst = hyst;
  		data->hyst_valid = jiffies + HZ;
  	}
  	return sprintf(buf, "%d000
  ", retval - data->cached_hyst);
  }
  
  static ssize_t store_hyst(struct device *dev,
  		struct device_attribute *attr, const char *buf, size_t count)
  {
  	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  	struct thermal_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;
  	int retval;
  	int hyst;
  	unsigned long val;
  
  	if (kstrtoul(buf, 10, &val))
  		return -EINVAL;
  
  	mutex_lock(&data->mutex);
  	retval = i2c_smbus_read_byte_data(client, sda->index);
  	if (retval < 0)
  		goto fail;
  
  	hyst = retval * 1000 - val;
  	hyst = DIV_ROUND_CLOSEST(hyst, 1000);
  	if (hyst < 0 || hyst > 255) {
  		retval = -ERANGE;
  		goto fail;
  	}
  
  	retval = i2c_smbus_write_byte_data(client, 0x21, hyst);
  	if (retval == 0) {
  		retval = count;
  		data->cached_hyst = hyst;
  		data->hyst_valid = jiffies + HZ;
  	}
  fail:
  	mutex_unlock(&data->mutex);
  	return retval;
  }
  
  /*
   *	Sensors. We pass the actual i2c register to the methods.
   */
  
  static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x06);
  static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x05);
  static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x20);
  static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0x00);
  static SENSOR_DEVICE_ATTR_2(temp1_min_alarm, S_IRUGO,
  	show_bit, NULL, 0x36, 0x01);
  static SENSOR_DEVICE_ATTR_2(temp1_max_alarm, S_IRUGO,
  	show_bit, NULL, 0x35, 0x01);
  static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO,
  	show_bit, NULL, 0x37, 0x01);
  static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO | S_IWUSR,
  	show_hyst, store_hyst, 0x20);
  
  static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x08);
  static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x07);
  static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x19);
  static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 0x01);
  static SENSOR_DEVICE_ATTR_2(temp2_min_alarm, S_IRUGO,
  	show_bit, NULL, 0x36, 0x02);
  static SENSOR_DEVICE_ATTR_2(temp2_max_alarm, S_IRUGO,
  	show_bit, NULL, 0x35, 0x02);
  static SENSOR_DEVICE_ATTR_2(temp2_crit_alarm, S_IRUGO,
  	show_bit, NULL, 0x37, 0x02);
  static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO | S_IWUSR,
  	show_hyst, store_hyst, 0x19);
  
  static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x16);
  static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x15);
  static SENSOR_DEVICE_ATTR(temp3_crit, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x1A);
  static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 0x23);
  static SENSOR_DEVICE_ATTR_2(temp3_min_alarm, S_IRUGO,
  	show_bit, NULL, 0x36, 0x04);
  static SENSOR_DEVICE_ATTR_2(temp3_max_alarm, S_IRUGO,
  	show_bit, NULL, 0x35, 0x04);
  static SENSOR_DEVICE_ATTR_2(temp3_crit_alarm, S_IRUGO,
  	show_bit, NULL, 0x37, 0x04);
  static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO | S_IWUSR,
  	show_hyst, store_hyst, 0x1A);
  
  static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x2D);
  static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x2C);
  static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO | S_IWUSR,
  	show_temp, store_temp, 0x30);
  static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 0x2A);
  static SENSOR_DEVICE_ATTR_2(temp4_min_alarm, S_IRUGO,
  	show_bit, NULL, 0x36, 0x08);
  static SENSOR_DEVICE_ATTR_2(temp4_max_alarm, S_IRUGO,
  	show_bit, NULL, 0x35, 0x08);
  static SENSOR_DEVICE_ATTR_2(temp4_crit_alarm, S_IRUGO,
  	show_bit, NULL, 0x37, 0x08);
  static SENSOR_DEVICE_ATTR(temp4_crit_hyst, S_IRUGO | S_IWUSR,
  	show_hyst, store_hyst, 0x30);
  
  static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
  	show_bit, store_bit, 0x03, 0x40);
  
  static struct attribute *emc1403_attrs[] = {
  	&sensor_dev_attr_temp1_min.dev_attr.attr,
  	&sensor_dev_attr_temp1_max.dev_attr.attr,
  	&sensor_dev_attr_temp1_crit.dev_attr.attr,
  	&sensor_dev_attr_temp1_input.dev_attr.attr,
  	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp2_min.dev_attr.attr,
  	&sensor_dev_attr_temp2_max.dev_attr.attr,
  	&sensor_dev_attr_temp2_crit.dev_attr.attr,
  	&sensor_dev_attr_temp2_input.dev_attr.attr,
  	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp3_min.dev_attr.attr,
  	&sensor_dev_attr_temp3_max.dev_attr.attr,
  	&sensor_dev_attr_temp3_crit.dev_attr.attr,
  	&sensor_dev_attr_temp3_input.dev_attr.attr,
  	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
  	&sensor_dev_attr_power_state.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group emc1403_group = {
  	.attrs = emc1403_attrs,
  };
  
  static struct attribute *emc1404_attrs[] = {
  	&sensor_dev_attr_temp4_min.dev_attr.attr,
  	&sensor_dev_attr_temp4_max.dev_attr.attr,
  	&sensor_dev_attr_temp4_crit.dev_attr.attr,
  	&sensor_dev_attr_temp4_input.dev_attr.attr,
  	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp4_crit_hyst.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group emc1404_group = {
  	.attrs = emc1404_attrs,
  };
  
  static int emc1403_detect(struct i2c_client *client,
  			struct i2c_board_info *info)
  {
  	int id;
  	/* Check if thermal chip is SMSC and EMC1403 or EMC1423 */
  
  	id = i2c_smbus_read_byte_data(client, THERMAL_SMSC_ID_REG);
  	if (id != 0x5d)
  		return -ENODEV;
  
  	id = i2c_smbus_read_byte_data(client, THERMAL_PID_REG);
  	switch (id) {
  	case 0x21:
  		strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
  		break;
  	case 0x23:
  		strlcpy(info->type, "emc1423", I2C_NAME_SIZE);
  		break;
  	case 0x25:
  		strlcpy(info->type, "emc1404", I2C_NAME_SIZE);
  		break;
  	case 0x27:
  		strlcpy(info->type, "emc1424", I2C_NAME_SIZE);
  		break;
  	default:
  		return -ENODEV;
  	}
  
  	id = i2c_smbus_read_byte_data(client, THERMAL_REVISION_REG);
  	if (id < 0x01 || id > 0x04)
  		return -ENODEV;
  
  	return 0;
  }
  
  static int emc1403_probe(struct i2c_client *client,
  			const struct i2c_device_id *id)
  {
  	struct thermal_data *data;
  	struct device *hwmon_dev;
  
  	data = devm_kzalloc(&client->dev, sizeof(struct thermal_data),
  			    GFP_KERNEL);
  	if (data == NULL)
  		return -ENOMEM;
  
  	data->client = client;
  	mutex_init(&data->mutex);
  	data->hyst_valid = jiffies - 1;		/* Expired */
  
  	data->groups[0] = &emc1403_group;
  	if (id->driver_data)
  		data->groups[1] = &emc1404_group;
  
  	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
  							   client->name, data,
  							   data->groups);
  	if (IS_ERR(hwmon_dev))
  		return PTR_ERR(hwmon_dev);
  
  	dev_info(&client->dev, "%s Thermal chip found
  ", id->name);
  	return 0;
  }
  
  static const unsigned short emc1403_address_list[] = {
  	0x18, 0x29, 0x4c, 0x4d, I2C_CLIENT_END
  };
  
  static const struct i2c_device_id emc1403_idtable[] = {
  	{ "emc1403", 0 },
  	{ "emc1404", 1 },
  	{ "emc1423", 0 },
  	{ "emc1424", 1 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, emc1403_idtable);
  
  static struct i2c_driver sensor_emc1403 = {
  	.class = I2C_CLASS_HWMON,
  	.driver = {
  		.name = "emc1403",
  	},
  	.detect = emc1403_detect,
  	.probe = emc1403_probe,
  	.id_table = emc1403_idtable,
  	.address_list = emc1403_address_list,
  };
  
  module_i2c_driver(sensor_emc1403);
  
  MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
  MODULE_DESCRIPTION("emc1403 Thermal Driver");
  MODULE_LICENSE("GPL v2");