// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * max6639.c - Support for Maxim MAX6639
   *
   * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
   *
   * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
   *
   * based on the initial MAX6639 support from semptian.net
   * by He Changqing <hechangqing@semptian.com>

   */
  
  #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>

  #include <linux/platform_data/max6639.h>

  
  /* Addresses to scan */

  static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };

  
  /* The MAX6639 registers, valid channel numbers: 0, 1 */
  #define MAX6639_REG_TEMP(ch)			(0x00 + (ch))
  #define MAX6639_REG_STATUS			0x02
  #define MAX6639_REG_OUTPUT_MASK			0x03
  #define MAX6639_REG_GCONFIG			0x04
  #define MAX6639_REG_TEMP_EXT(ch)		(0x05 + (ch))
  #define MAX6639_REG_ALERT_LIMIT(ch)		(0x08 + (ch))
  #define MAX6639_REG_OT_LIMIT(ch)		(0x0A + (ch))
  #define MAX6639_REG_THERM_LIMIT(ch)		(0x0C + (ch))
  #define MAX6639_REG_FAN_CONFIG1(ch)		(0x10 + (ch) * 4)
  #define MAX6639_REG_FAN_CONFIG2a(ch)		(0x11 + (ch) * 4)
  #define MAX6639_REG_FAN_CONFIG2b(ch)		(0x12 + (ch) * 4)
  #define MAX6639_REG_FAN_CONFIG3(ch)		(0x13 + (ch) * 4)
  #define MAX6639_REG_FAN_CNT(ch)			(0x20 + (ch))
  #define MAX6639_REG_TARGET_CNT(ch)		(0x22 + (ch))
  #define MAX6639_REG_FAN_PPR(ch)			(0x24 + (ch))
  #define MAX6639_REG_TARGTDUTY(ch)		(0x26 + (ch))
  #define MAX6639_REG_FAN_START_TEMP(ch)		(0x28 + (ch))
  #define MAX6639_REG_DEVID			0x3D
  #define MAX6639_REG_MANUID			0x3E
  #define MAX6639_REG_DEVREV			0x3F
  
  /* Register bits */
  #define MAX6639_GCONFIG_STANDBY			0x80
  #define MAX6639_GCONFIG_POR			0x40
  #define MAX6639_GCONFIG_DISABLE_TIMEOUT		0x20
  #define MAX6639_GCONFIG_CH2_LOCAL		0x10

  #define MAX6639_GCONFIG_PWM_FREQ_HI		0x08

  
  #define MAX6639_FAN_CONFIG1_PWM			0x80

  #define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED	0x40

  static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };

  #define FAN_FROM_REG(val, rpm_range)	((val) == 0 || (val) == 255 ? \
  				0 : (rpm_ranges[rpm_range] * 30) / (val))

  #define TEMP_LIMIT_TO_REG(val)	clamp_val((val) / 1000, 0, 255)

  
  /*
   * Client data (each client gets its own)
   */
  struct max6639_data {

  	struct i2c_client *client;

  	struct mutex update_lock;
  	char valid;		/* !=0 if following fields are valid */
  	unsigned long last_updated;	/* In jiffies */
  
  	/* Register values sampled regularly */
  	u16 temp[2];		/* Temperature, in 1/8 C, 0..255 C */
  	bool temp_fault[2];	/* Detected temperature diode failure */
  	u8 fan[2];		/* Register value: TACH count for fans >=30 */
  	u8 status;		/* Detected channel alarms and fan failures */
  
  	/* Register values only written to */
  	u8 pwm[2];		/* Register value: Duty cycle 0..120 */
  	u8 temp_therm[2];	/* THERM Temperature, 0..255 C (->_max) */
  	u8 temp_alert[2];	/* ALERT Temperature, 0..255 C (->_crit) */
  	u8 temp_ot[2];		/* OT Temperature, 0..255 C (->_emergency) */
  
  	/* Register values initialized only once */
  	u8 ppr;			/* Pulses per rotation 0..3 for 1..4 ppr */
  	u8 rpm_range;		/* Index in above rpm_ranges table */
  };
  
  static struct max6639_data *max6639_update_device(struct device *dev)
  {

  	struct max6639_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	struct max6639_data *ret = data;
  	int i;
  	int status_reg;
  
  	mutex_lock(&data->update_lock);
  
  	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
  		int res;
  
  		dev_dbg(&client->dev, "Starting max6639 update
  ");
  
  		status_reg = i2c_smbus_read_byte_data(client,
  						      MAX6639_REG_STATUS);
  		if (status_reg < 0) {
  			ret = ERR_PTR(status_reg);
  			goto abort;
  		}
  
  		data->status = status_reg;
  
  		for (i = 0; i < 2; i++) {
  			res = i2c_smbus_read_byte_data(client,
  					MAX6639_REG_FAN_CNT(i));
  			if (res < 0) {
  				ret = ERR_PTR(res);
  				goto abort;
  			}
  			data->fan[i] = res;
  
  			res = i2c_smbus_read_byte_data(client,
  					MAX6639_REG_TEMP_EXT(i));
  			if (res < 0) {
  				ret = ERR_PTR(res);
  				goto abort;
  			}
  			data->temp[i] = res >> 5;
  			data->temp_fault[i] = res & 0x01;
  
  			res = i2c_smbus_read_byte_data(client,
  					MAX6639_REG_TEMP(i));
  			if (res < 0) {
  				ret = ERR_PTR(res);
  				goto abort;
  			}
  			data->temp[i] |= res << 3;
  		}
  
  		data->last_updated = jiffies;
  		data->valid = 1;
  	}
  abort:
  	mutex_unlock(&data->update_lock);
  
  	return ret;
  }

  static ssize_t temp_input_show(struct device *dev,

  			       struct device_attribute *dev_attr, char *buf)
  {
  	long temp;
  	struct max6639_data *data = max6639_update_device(dev);
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
  
  	if (IS_ERR(data))
  		return PTR_ERR(data);
  
  	temp = data->temp[attr->index] * 125;
  	return sprintf(buf, "%ld
  ", temp);
  }

  static ssize_t temp_fault_show(struct device *dev,

  			       struct device_attribute *dev_attr, char *buf)
  {
  	struct max6639_data *data = max6639_update_device(dev);
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
  
  	if (IS_ERR(data))
  		return PTR_ERR(data);
  
  	return sprintf(buf, "%d
  ", data->temp_fault[attr->index]);
  }

  static ssize_t temp_max_show(struct device *dev,

  			     struct device_attribute *dev_attr, char *buf)
  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);

  
  	return sprintf(buf, "%d
  ", (data->temp_therm[attr->index] * 1000));
  }

  static ssize_t temp_max_store(struct device *dev,
  			      struct device_attribute *dev_attr,
  			      const char *buf, size_t count)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	unsigned long val;
  	int res;

  	res = kstrtoul(buf, 10, &val);

  	if (res)
  		return res;
  
  	mutex_lock(&data->update_lock);
  	data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
  	i2c_smbus_write_byte_data(client,
  				  MAX6639_REG_THERM_LIMIT(attr->index),
  				  data->temp_therm[attr->index]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }

  static ssize_t temp_crit_show(struct device *dev,

  			      struct device_attribute *dev_attr, char *buf)
  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);

  
  	return sprintf(buf, "%d
  ", (data->temp_alert[attr->index] * 1000));
  }

  static ssize_t temp_crit_store(struct device *dev,
  			       struct device_attribute *dev_attr,
  			       const char *buf, size_t count)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	unsigned long val;
  	int res;

  	res = kstrtoul(buf, 10, &val);

  	if (res)
  		return res;
  
  	mutex_lock(&data->update_lock);
  	data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
  	i2c_smbus_write_byte_data(client,
  				  MAX6639_REG_ALERT_LIMIT(attr->index),
  				  data->temp_alert[attr->index]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }

  static ssize_t temp_emergency_show(struct device *dev,

  				   struct device_attribute *dev_attr,
  				   char *buf)
  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);

  
  	return sprintf(buf, "%d
  ", (data->temp_ot[attr->index] * 1000));
  }

  static ssize_t temp_emergency_store(struct device *dev,
  				    struct device_attribute *dev_attr,
  				    const char *buf, size_t count)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	unsigned long val;
  	int res;

  	res = kstrtoul(buf, 10, &val);

  	if (res)
  		return res;
  
  	mutex_lock(&data->update_lock);
  	data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
  	i2c_smbus_write_byte_data(client,
  				  MAX6639_REG_OT_LIMIT(attr->index),
  				  data->temp_ot[attr->index]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }

  static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
  			char *buf)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);

  
  	return sprintf(buf, "%d
  ", data->pwm[attr->index] * 255 / 120);
  }

  static ssize_t pwm_store(struct device *dev,
  			 struct device_attribute *dev_attr, const char *buf,
  			 size_t count)

  {

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);

  	struct max6639_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	unsigned long val;
  	int res;

  	res = kstrtoul(buf, 10, &val);

  	if (res)
  		return res;

  	val = clamp_val(val, 0, 255);

  
  	mutex_lock(&data->update_lock);
  	data->pwm[attr->index] = (u8)(val * 120 / 255);
  	i2c_smbus_write_byte_data(client,
  				  MAX6639_REG_TARGTDUTY(attr->index),
  				  data->pwm[attr->index]);
  	mutex_unlock(&data->update_lock);
  	return count;
  }

  static ssize_t fan_input_show(struct device *dev,

  			      struct device_attribute *dev_attr, char *buf)
  {
  	struct max6639_data *data = max6639_update_device(dev);
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
  
  	if (IS_ERR(data))
  		return PTR_ERR(data);
  
  	return sprintf(buf, "%d
  ", FAN_FROM_REG(data->fan[attr->index],

  		       data->rpm_range));

  }

  static ssize_t alarm_show(struct device *dev,

  			  struct device_attribute *dev_attr, char *buf)
  {
  	struct max6639_data *data = max6639_update_device(dev);
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
  
  	if (IS_ERR(data))
  		return PTR_ERR(data);
  
  	return sprintf(buf, "%d
  ", !!(data->status & (1 << attr->index)));
  }

  static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
  static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_input, 1);
  static SENSOR_DEVICE_ATTR_RO(temp1_fault, temp_fault, 0);
  static SENSOR_DEVICE_ATTR_RO(temp2_fault, temp_fault, 1);
  static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
  static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
  static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp_crit, 0);
  static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp_crit, 1);
  static SENSOR_DEVICE_ATTR_RW(temp1_emergency, temp_emergency, 0);
  static SENSOR_DEVICE_ATTR_RW(temp2_emergency, temp_emergency, 1);
  static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
  static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, 1);
  static SENSOR_DEVICE_ATTR_RO(fan1_input, fan_input, 0);
  static SENSOR_DEVICE_ATTR_RO(fan2_input, fan_input, 1);
  static SENSOR_DEVICE_ATTR_RO(fan1_fault, alarm, 1);
  static SENSOR_DEVICE_ATTR_RO(fan2_fault, alarm, 0);
  static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 3);
  static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 2);
  static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 7);
  static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 6);
  static SENSOR_DEVICE_ATTR_RO(temp1_emergency_alarm, alarm, 5);
  static SENSOR_DEVICE_ATTR_RO(temp2_emergency_alarm, alarm, 4);

  static struct attribute *max6639_attrs[] = {

  	&sensor_dev_attr_temp1_input.dev_attr.attr,
  	&sensor_dev_attr_temp2_input.dev_attr.attr,
  	&sensor_dev_attr_temp1_fault.dev_attr.attr,
  	&sensor_dev_attr_temp2_fault.dev_attr.attr,
  	&sensor_dev_attr_temp1_max.dev_attr.attr,
  	&sensor_dev_attr_temp2_max.dev_attr.attr,
  	&sensor_dev_attr_temp1_crit.dev_attr.attr,
  	&sensor_dev_attr_temp2_crit.dev_attr.attr,
  	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
  	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
  	&sensor_dev_attr_pwm1.dev_attr.attr,
  	&sensor_dev_attr_pwm2.dev_attr.attr,
  	&sensor_dev_attr_fan1_input.dev_attr.attr,
  	&sensor_dev_attr_fan2_input.dev_attr.attr,
  	&sensor_dev_attr_fan1_fault.dev_attr.attr,
  	&sensor_dev_attr_fan2_fault.dev_attr.attr,
  	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
  	NULL
  };

  ATTRIBUTE_GROUPS(max6639);

  
  /*
   *  returns respective index in rpm_ranges table
   *  1 by default on invalid range
   */
  static int rpm_range_to_reg(int range)
  {
  	int i;
  
  	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
  		if (rpm_ranges[i] == range)
  			return i;
  	}
  
  	return 1; /* default: 4000 RPM */
  }

  static int max6639_init_client(struct i2c_client *client,
  			       struct max6639_data *data)

  {

  	struct max6639_platform_data *max6639_info =

  		dev_get_platdata(&client->dev);

  	int i;

  	int rpm_range = 1; /* default: 4000 RPM */

  	int err;

  	/* Reset chip to default values, see below for GCONFIG setup */

  	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
  				  MAX6639_GCONFIG_POR);
  	if (err)
  		goto exit;
  
  	/* Fans pulse per revolution is 2 by default */
  	if (max6639_info && max6639_info->ppr > 0 &&
  			max6639_info->ppr < 5)
  		data->ppr = max6639_info->ppr;
  	else
  		data->ppr = 2;
  	data->ppr -= 1;

  
  	if (max6639_info)
  		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
  	data->rpm_range = rpm_range;
  
  	for (i = 0; i < 2; i++) {

  		/* Set Fan pulse per revolution */
  		err = i2c_smbus_write_byte_data(client,
  				MAX6639_REG_FAN_PPR(i),
  				data->ppr << 6);
  		if (err)
  			goto exit;

  		/* Fans config PWM, RPM */
  		err = i2c_smbus_write_byte_data(client,
  			MAX6639_REG_FAN_CONFIG1(i),
  			MAX6639_FAN_CONFIG1_PWM | rpm_range);
  		if (err)
  			goto exit;
  
  		/* Fans PWM polarity high by default */
  		if (max6639_info && max6639_info->pwm_polarity == 0)
  			err = i2c_smbus_write_byte_data(client,
  				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
  		else
  			err = i2c_smbus_write_byte_data(client,
  				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
  		if (err)
  			goto exit;

  		/*
  		 * /THERM full speed enable,
  		 * PWM frequency 25kHz, see also GCONFIG below
  		 */
  		err = i2c_smbus_write_byte_data(client,
  			MAX6639_REG_FAN_CONFIG3(i),
  			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
  		if (err)
  			goto exit;

  		/* Max. temp. 80C/90C/100C */
  		data->temp_therm[i] = 80;
  		data->temp_alert[i] = 90;
  		data->temp_ot[i] = 100;
  		err = i2c_smbus_write_byte_data(client,
  				MAX6639_REG_THERM_LIMIT(i),
  				data->temp_therm[i]);
  		if (err)
  			goto exit;
  		err = i2c_smbus_write_byte_data(client,
  				MAX6639_REG_ALERT_LIMIT(i),
  				data->temp_alert[i]);
  		if (err)
  			goto exit;
  		err = i2c_smbus_write_byte_data(client,
  				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
  		if (err)
  			goto exit;
  
  		/* PWM 120/120 (i.e. 100%) */
  		data->pwm[i] = 120;
  		err = i2c_smbus_write_byte_data(client,
  				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
  		if (err)
  			goto exit;
  	}
  	/* Start monitoring */
  	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,

  		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
  		MAX6639_GCONFIG_PWM_FREQ_HI);

  exit:
  	return err;
  }
  
  /* Return 0 if detection is successful, -ENODEV otherwise */
  static int max6639_detect(struct i2c_client *client,
  			  struct i2c_board_info *info)
  {
  	struct i2c_adapter *adapter = client->adapter;
  	int dev_id, manu_id;
  
  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
  		return -ENODEV;
  
  	/* Actual detection via device and manufacturer ID */
  	dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
  	manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
  	if (dev_id != 0x58 || manu_id != 0x4D)
  		return -ENODEV;
  
  	strlcpy(info->type, "max6639", I2C_NAME_SIZE);
  
  	return 0;
  }

  static int max6639_probe(struct i2c_client *client)

  {

  	struct device *dev = &client->dev;

  	struct max6639_data *data;

  	struct device *hwmon_dev;

  	int err;

  	data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);

  	if (!data)
  		return -ENOMEM;

  	data->client = client;

  	mutex_init(&data->update_lock);
  
  	/* Initialize the max6639 chip */

  	err = max6639_init_client(client, data);

  	if (err < 0)

  		return err;

  	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
  							   data,
  							   max6639_groups);
  	return PTR_ERR_OR_ZERO(hwmon_dev);

  }

  #ifdef CONFIG_PM_SLEEP
  static int max6639_suspend(struct device *dev)

  {

  	struct i2c_client *client = to_i2c_client(dev);

  	int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
  	if (data < 0)
  		return data;
  
  	return i2c_smbus_write_byte_data(client,
  			MAX6639_REG_GCONFIG, data | MAX6639_GCONFIG_STANDBY);
  }

  static int max6639_resume(struct device *dev)

  {

  	struct i2c_client *client = to_i2c_client(dev);

  	int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
  	if (data < 0)
  		return data;
  
  	return i2c_smbus_write_byte_data(client,
  			MAX6639_REG_GCONFIG, data & ~MAX6639_GCONFIG_STANDBY);
  }

  #endif /* CONFIG_PM_SLEEP */

  
  static const struct i2c_device_id max6639_id[] = {
  	{"max6639", 0},
  	{ }
  };
  
  MODULE_DEVICE_TABLE(i2c, max6639_id);

  static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);

  static struct i2c_driver max6639_driver = {
  	.class = I2C_CLASS_HWMON,
  	.driver = {
  		   .name = "max6639",

  		   .pm = &max6639_pm_ops,

  		   },

  	.probe_new = max6639_probe,

  	.id_table = max6639_id,
  	.detect = max6639_detect,
  	.address_list = normal_i2c,
  };

  module_i2c_driver(max6639_driver);

  
  MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
  MODULE_DESCRIPTION("max6639 driver");
  MODULE_LICENSE("GPL");