/*
   * 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.
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   */
  
  #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/regmap.h>
  
  #define THERMAL_PID_REG		0xfd
  #define THERMAL_SMSC_ID_REG	0xfe
  #define THERMAL_REVISION_REG	0xff
  
  enum emc1403_chip { emc1402, emc1403, emc1404 };
  
  struct thermal_data {
  	struct regmap *regmap;
  	struct mutex mutex;
  	const struct attribute_group *groups[4];
  };
  
  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);
  	unsigned int val;
  	int retval;
  
  	retval = regmap_read(data->regmap, sda->index, &val);
  	if (retval < 0)
  		return retval;
  	return sprintf(buf, "%d000
  ", val);
  }
  
  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);
  	unsigned int val;
  	int retval;
  
  	retval = regmap_read(data->regmap, sda->nr, &val);
  	if (retval < 0)
  		return retval;
  	return sprintf(buf, "%d
  ", !!(val & 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 = regmap_write(data->regmap, 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);
  	unsigned long val;
  	int retval;
  
  	if (kstrtoul(buf, 10, &val))
  		return -EINVAL;
  
  	retval = regmap_update_bits(data->regmap, sda->nr, sda->index,
  				    val ? sda->index : 0);
  	if (retval < 0)
  		return retval;
  	return count;
  }
  
  static ssize_t show_hyst_common(struct device *dev,
  				struct device_attribute *attr, char *buf,
  				bool is_min)
  {
  	struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  	struct thermal_data *data = dev_get_drvdata(dev);
  	struct regmap *regmap = data->regmap;
  	unsigned int limit;
  	unsigned int hyst;
  	int retval;
  
  	retval = regmap_read(regmap, sda->index, &limit);
  	if (retval < 0)
  		return retval;
  
  	retval = regmap_read(regmap, 0x21, &hyst);
  	if (retval < 0)
  		return retval;
  
  	return sprintf(buf, "%d000
  ", is_min ? limit + hyst : limit - hyst);
  }
  
  static ssize_t show_hyst(struct device *dev,
  			 struct device_attribute *attr, char *buf)
  {
  	return show_hyst_common(dev, attr, buf, false);
  }
  
  static ssize_t show_min_hyst(struct device *dev,
  			     struct device_attribute *attr, char *buf)
  {
  	return show_hyst_common(dev, attr, buf, true);
  }
  
  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 regmap *regmap = data->regmap;
  	unsigned int limit;
  	int retval;
  	int hyst;
  	unsigned long val;
  
  	if (kstrtoul(buf, 10, &val))
  		return -EINVAL;
  
  	mutex_lock(&data->mutex);
  	retval = regmap_read(regmap, sda->index, &limit);
  	if (retval < 0)
  		goto fail;
  
  	hyst = limit * 1000 - val;
  	hyst = clamp_val(DIV_ROUND_CLOSEST(hyst, 1000), 0, 255);
  	retval = regmap_write(regmap, 0x21, hyst);
  	if (retval == 0)
  		retval = count;
  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_min_hyst, S_IRUGO, show_min_hyst, NULL, 0x06);
  static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_hyst, NULL, 0x05);
  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_fault, S_IRUGO, show_bit, NULL, 0x1b, 0x02);
  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_min_hyst, S_IRUGO, show_min_hyst, NULL, 0x08);
  static SENSOR_DEVICE_ATTR(temp2_max_hyst, S_IRUGO, show_hyst, NULL, 0x07);
  static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_hyst, NULL, 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_fault, S_IRUGO, show_bit, NULL, 0x1b, 0x04);
  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_min_hyst, S_IRUGO, show_min_hyst, NULL, 0x16);
  static SENSOR_DEVICE_ATTR(temp3_max_hyst, S_IRUGO, show_hyst, NULL, 0x15);
  static SENSOR_DEVICE_ATTR(temp3_crit_hyst, S_IRUGO, show_hyst, NULL, 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_fault, S_IRUGO, show_bit, NULL, 0x1b, 0x08);
  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_min_hyst, S_IRUGO, show_min_hyst, NULL, 0x2D);
  static SENSOR_DEVICE_ATTR(temp4_max_hyst, S_IRUGO, show_hyst, NULL, 0x2C);
  static SENSOR_DEVICE_ATTR(temp4_crit_hyst, S_IRUGO, show_hyst, NULL, 0x30);
  
  static SENSOR_DEVICE_ATTR_2(power_state, S_IRUGO | S_IWUSR,
  	show_bit, store_bit, 0x03, 0x40);
  
  static struct attribute *emc1402_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_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp1_max_hyst.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_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
  
  	&sensor_dev_attr_power_state.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group emc1402_group = {
  		.attrs = emc1402_attrs,
  };
  
  static struct attribute *emc1403_attrs[] = {
  	&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_temp2_fault.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_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_fault.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_min_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp3_crit_hyst.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_fault.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_min_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
  	&sensor_dev_attr_temp4_crit_hyst.dev_attr.attr,
  	NULL
  };
  
  static const struct attribute_group emc1404_group = {
  	.attrs = emc1404_attrs,
  };
  
  /*
   * EMC14x2 uses a different register and different bits to report alarm and
   * fault status. For simplicity, provide a separate attribute group for this
   * chip series.
   * Since we can not re-use the same attribute names, create a separate attribute
   * array.
   */
  static struct sensor_device_attribute_2 emc1402_alarms[] = {
  	SENSOR_ATTR_2(temp1_min_alarm, S_IRUGO, show_bit, NULL, 0x02, 0x20),
  	SENSOR_ATTR_2(temp1_max_alarm, S_IRUGO, show_bit, NULL, 0x02, 0x40),
  	SENSOR_ATTR_2(temp1_crit_alarm, S_IRUGO, show_bit, NULL, 0x02, 0x01),
  
  	SENSOR_ATTR_2(temp2_fault, S_IRUGO, show_bit, NULL, 0x02, 0x04),
  	SENSOR_ATTR_2(temp2_min_alarm, S_IRUGO, show_bit, NULL, 0x02, 0x08),
  	SENSOR_ATTR_2(temp2_max_alarm, S_IRUGO, show_bit, NULL, 0x02, 0x10),
  	SENSOR_ATTR_2(temp2_crit_alarm, S_IRUGO, show_bit, NULL, 0x02, 0x02),
  };
  
  static struct attribute *emc1402_alarm_attrs[] = {
  	&emc1402_alarms[0].dev_attr.attr,
  	&emc1402_alarms[1].dev_attr.attr,
  	&emc1402_alarms[2].dev_attr.attr,
  	&emc1402_alarms[3].dev_attr.attr,
  	&emc1402_alarms[4].dev_attr.attr,
  	&emc1402_alarms[5].dev_attr.attr,
  	&emc1402_alarms[6].dev_attr.attr,
  	NULL,
  };
  
  static const struct attribute_group emc1402_alarm_group = {
  	.attrs = emc1402_alarm_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 0x20:
  		strlcpy(info->type, "emc1402", I2C_NAME_SIZE);
  		break;
  	case 0x21:
  		strlcpy(info->type, "emc1403", I2C_NAME_SIZE);
  		break;
  	case 0x22:
  		strlcpy(info->type, "emc1422", 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 bool emc1403_regmap_is_volatile(struct device *dev, unsigned int reg)
  {
  	switch (reg) {
  	case 0x00:	/* internal diode high byte */
  	case 0x01:	/* external diode 1 high byte */
  	case 0x02:	/* status */
  	case 0x10:	/* external diode 1 low byte */
  	case 0x1b:	/* external diode fault */
  	case 0x23:	/* external diode 2 high byte */
  	case 0x24:	/* external diode 2 low byte */
  	case 0x29:	/* internal diode low byte */
  	case 0x2a:	/* externl diode 3 high byte */
  	case 0x2b:	/* external diode 3 low byte */
  	case 0x35:	/* high limit status */
  	case 0x36:	/* low limit status */
  	case 0x37:	/* therm limit status */
  		return true;
  	default:
  		return false;
  	}
  }
  
  static const struct regmap_config emc1403_regmap_config = {
  	.reg_bits = 8,
  	.val_bits = 8,
  	.cache_type = REGCACHE_RBTREE,
  	.volatile_reg = emc1403_regmap_is_volatile,
  };
  
  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->regmap = devm_regmap_init_i2c(client, &emc1403_regmap_config);
  	if (IS_ERR(data->regmap))
  		return PTR_ERR(data->regmap);
  
  	mutex_init(&data->mutex);
  
  	switch (id->driver_data) {
  	case emc1404:
  		data->groups[2] = &emc1404_group;
  	case emc1403:
  		data->groups[1] = &emc1403_group;
  	case emc1402:
  		data->groups[0] = &emc1402_group;
  	}
  
  	if (id->driver_data == emc1402)
  		data->groups[1] = &emc1402_alarm_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, 0x1c, 0x29, 0x4c, 0x4d, 0x5c, I2C_CLIENT_END
  };
  
  /* Last digit of chip name indicates number of channels */
  static const struct i2c_device_id emc1403_idtable[] = {
  	{ "emc1402", emc1402 },
  	{ "emc1403", emc1403 },
  	{ "emc1404", emc1404 },
  	{ "emc1412", emc1402 },
  	{ "emc1413", emc1403 },
  	{ "emc1414", emc1404 },
  	{ "emc1422", emc1402 },
  	{ "emc1423", emc1403 },
  	{ "emc1424", emc1404 },
  	{ }
  };
  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");