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

  /*
   *  ds620.c - Support for temperature sensor and thermostat DS620
   *
   *  Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
   *
   *  based on ds1621.c by Christian W. Zuckschwerdt  <zany@triq.net>

   */
  
  #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/sysfs.h>

  #include <linux/platform_data/ds620.h>

  
  /*
   * Many DS620 constants specified below
   *  15   14   13   12   11   10   09    08
   * |Done|NVB |THF |TLF |R1  |R0  |AUTOC|1SHOT|
   *
   *  07   06   05   04   03   02   01    00
   * |PO2 |PO1 |A2  |A1  |A0  |    |     |     |
   */
  #define DS620_REG_CONFIG_DONE		0x8000
  #define DS620_REG_CONFIG_NVB		0x4000
  #define DS620_REG_CONFIG_THF		0x2000
  #define DS620_REG_CONFIG_TLF		0x1000
  #define DS620_REG_CONFIG_R1		0x0800
  #define DS620_REG_CONFIG_R0		0x0400
  #define DS620_REG_CONFIG_AUTOC		0x0200
  #define DS620_REG_CONFIG_1SHOT		0x0100
  #define DS620_REG_CONFIG_PO2		0x0080
  #define DS620_REG_CONFIG_PO1		0x0040
  #define DS620_REG_CONFIG_A2		0x0020
  #define DS620_REG_CONFIG_A1		0x0010
  #define DS620_REG_CONFIG_A0		0x0008
  
  /* The DS620 registers */
  static const u8 DS620_REG_TEMP[3] = {
  	0xAA,			/* input, word, RO */
  	0xA2,			/* min, word, RW */
  	0xA0,			/* max, word, RW */
  };
  
  #define DS620_REG_CONF		0xAC	/* word, RW */
  #define DS620_COM_START		0x51	/* no data */
  #define DS620_COM_STOP		0x22	/* no data */
  
  /* Each client has this additional data */
  struct ds620_data {

  	struct i2c_client *client;

  	struct mutex update_lock;
  	char valid;		/* !=0 if following fields are valid */
  	unsigned long last_updated;	/* In jiffies */

  	s16 temp[3];		/* Register values, word */

  };

  static void ds620_init_client(struct i2c_client *client)
  {

  	struct ds620_platform_data *ds620_info = dev_get_platdata(&client->dev);

  	u16 conf, new_conf;
  
  	new_conf = conf =

  	    i2c_smbus_read_word_swapped(client, DS620_REG_CONF);

  
  	/* switch to continuous conversion mode */
  	new_conf &= ~DS620_REG_CONFIG_1SHOT;
  	/* already high at power-on, but don't trust the BIOS! */
  	new_conf |= DS620_REG_CONFIG_PO2;
  	/* thermostat mode according to platform data */
  	if (ds620_info && ds620_info->pomode == 1)
  		new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */
  	else if (ds620_info && ds620_info->pomode == 2)
  		new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */
  	else
  		new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */
  	/* with highest precision */
  	new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0;
  
  	if (conf != new_conf)

  		i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf);

  
  	/* start conversion */
  	i2c_smbus_write_byte(client, DS620_COM_START);
  }
  
  static struct ds620_data *ds620_update_client(struct device *dev)
  {

  	struct ds620_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	struct ds620_data *ret = data;
  
  	mutex_lock(&data->update_lock);
  
  	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
  	    || !data->valid) {
  		int i;
  		int res;
  
  		dev_dbg(&client->dev, "Starting ds620 update
  ");
  
  		for (i = 0; i < ARRAY_SIZE(data->temp); i++) {

  			res = i2c_smbus_read_word_swapped(client,
  							  DS620_REG_TEMP[i]);

  			if (res < 0) {
  				ret = ERR_PTR(res);
  				goto abort;
  			}
  
  			data->temp[i] = res;
  		}
  
  		data->last_updated = jiffies;
  		data->valid = 1;
  	}
  abort:
  	mutex_unlock(&data->update_lock);
  
  	return ret;
  }

  static ssize_t temp_show(struct device *dev, struct device_attribute *da,

  			 char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  	struct ds620_data *data = ds620_update_client(dev);
  
  	if (IS_ERR(data))
  		return PTR_ERR(data);
  
  	return sprintf(buf, "%d
  ", ((data->temp[attr->index] / 8) * 625) / 10);
  }

  static ssize_t temp_store(struct device *dev, struct device_attribute *da,
  			  const char *buf, size_t count)

  {
  	int res;
  	long val;
  
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);

  	struct ds620_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

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

  
  	if (res)
  		return res;

  	val = (clamp_val(val, -128000, 128000) * 10 / 625) * 8;

  
  	mutex_lock(&data->update_lock);
  	data->temp[attr->index] = val;

  	i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index],
  				     data->temp[attr->index]);

  	mutex_unlock(&data->update_lock);
  	return count;
  }

  static ssize_t alarm_show(struct device *dev, struct device_attribute *da,

  			  char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
  	struct ds620_data *data = ds620_update_client(dev);

  	struct i2c_client *client;

  	u16 conf, new_conf;
  	int res;
  
  	if (IS_ERR(data))
  		return PTR_ERR(data);

  	client = data->client;

  	/* reset alarms if necessary */

  	res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF);

  	if (res < 0)
  		return res;

  	new_conf = conf = res;

  	new_conf &= ~attr->index;
  	if (conf != new_conf) {

  		res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF,
  						   new_conf);

  		if (res < 0)
  			return res;
  	}
  
  	return sprintf(buf, "%d
  ", !!(conf & attr->index));
  }

  static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
  static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1);
  static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);
  static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS620_REG_CONFIG_TLF);
  static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS620_REG_CONFIG_THF);

  static struct attribute *ds620_attrs[] = {

  	&sensor_dev_attr_temp1_input.dev_attr.attr,
  	&sensor_dev_attr_temp1_min.dev_attr.attr,
  	&sensor_dev_attr_temp1_max.dev_attr.attr,
  	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
  	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
  	NULL
  };

  ATTRIBUTE_GROUPS(ds620);

  static int ds620_probe(struct i2c_client *client)

  {

  	struct device *dev = &client->dev;
  	struct device *hwmon_dev;

  	struct ds620_data *data;

  	data = devm_kzalloc(dev, sizeof(struct ds620_data), GFP_KERNEL);

  	if (!data)
  		return -ENOMEM;

  	data->client = client;

  	mutex_init(&data->update_lock);
  
  	/* Initialize the DS620 chip */
  	ds620_init_client(client);

  	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
  							   data, ds620_groups);
  	return PTR_ERR_OR_ZERO(hwmon_dev);

  }
  
  static const struct i2c_device_id ds620_id[] = {
  	{"ds620", 0},
  	{}
  };
  
  MODULE_DEVICE_TABLE(i2c, ds620_id);
  
  /* This is the driver that will be inserted */
  static struct i2c_driver ds620_driver = {
  	.class = I2C_CLASS_HWMON,
  	.driver = {
  		   .name = "ds620",
  	},

  	.probe_new = ds620_probe,

  	.id_table = ds620_id,
  };

  module_i2c_driver(ds620_driver);

  
  MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
  MODULE_DESCRIPTION("DS620 driver");
  MODULE_LICENSE("GPL");