text: /*
   * 1-wire client/driver for the Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC
   *
   * Author: Renata Sayakhova <renata@oktetlabs.ru>
   *
   * Based on ds2780_battery drivers
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   */
  
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/param.h>
  #include <linux/pm.h>
  #include <linux/platform_device.h>
  #include <linux/power_supply.h>
  #include <linux/idr.h>
  
  #include <linux/w1.h>
  #include "../../w1/slaves/w1_ds2781.h"
  
  /* Current unit measurement in uA for a 1 milli-ohm sense resistor */
  #define DS2781_CURRENT_UNITS	1563
  /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
  #define DS2781_CHARGE_UNITS		6250
  /* Number of bytes in user EEPROM space */
  #define DS2781_USER_EEPROM_SIZE		(DS2781_EEPROM_BLOCK0_END - \
  					DS2781_EEPROM_BLOCK0_START + 1)
  /* Number of bytes in parameter EEPROM space */
  #define DS2781_PARAM_EEPROM_SIZE	(DS2781_EEPROM_BLOCK1_END - \
  					DS2781_EEPROM_BLOCK1_START + 1)
  
  struct ds2781_device_info {
  	struct device *dev;
  	struct power_supply *bat;
  	struct power_supply_desc bat_desc;
  	struct device *w1_dev;
  };
  
  enum current_types {
  	CURRENT_NOW,
  	CURRENT_AVG,
  };
  
  static const char model[] = "DS2781";
  static const char manufacturer[] = "Maxim/Dallas";
  
  static inline struct ds2781_device_info *
  to_ds2781_device_info(struct power_supply *psy)
  {
  	return power_supply_get_drvdata(psy);
  }
  
  static inline int ds2781_battery_io(struct ds2781_device_info *dev_info,
  	char *buf, int addr, size_t count, int io)
  {
  	return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
  }
  
  static int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf,
  		int addr, size_t count)
  {
  	return ds2781_battery_io(dev_info, buf, addr, count, 0);
  }
  
  static inline int ds2781_read8(struct ds2781_device_info *dev_info, u8 *val,
  	int addr)
  {
  	return ds2781_battery_io(dev_info, val, addr, sizeof(u8), 0);
  }
  
  static int ds2781_read16(struct ds2781_device_info *dev_info, s16 *val,
  	int addr)
  {
  	int ret;
  	u8 raw[2];
  
  	ret = ds2781_battery_io(dev_info, raw, addr, sizeof(raw), 0);
  	if (ret < 0)
  		return ret;
  
  	*val = (raw[0] << 8) | raw[1];
  
  	return 0;
  }
  
  static inline int ds2781_read_block(struct ds2781_device_info *dev_info,
  	u8 *val, int addr, size_t count)
  {
  	return ds2781_battery_io(dev_info, val, addr, count, 0);
  }
  
  static inline int ds2781_write(struct ds2781_device_info *dev_info, u8 *val,
  	int addr, size_t count)
  {
  	return ds2781_battery_io(dev_info, val, addr, count, 1);
  }
  
  static inline int ds2781_store_eeprom(struct device *dev, int addr)
  {
  	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_COPY_DATA);
  }
  
  static inline int ds2781_recall_eeprom(struct device *dev, int addr)
  {
  	return w1_ds2781_eeprom_cmd(dev, addr, W1_DS2781_RECALL_DATA);
  }
  
  static int ds2781_save_eeprom(struct ds2781_device_info *dev_info, int reg)
  {
  	int ret;
  
  	ret = ds2781_store_eeprom(dev_info->w1_dev, reg);
  	if (ret < 0)
  		return ret;
  
  	ret = ds2781_recall_eeprom(dev_info->w1_dev, reg);
  	if (ret < 0)
  		return ret;
  
  	return 0;
  }
  
  /* Set sense resistor value in mhos */
  static int ds2781_set_sense_register(struct ds2781_device_info *dev_info,
  	u8 conductance)
  {
  	int ret;
  
  	ret = ds2781_write(dev_info, &conductance,
  				DS2781_RSNSP, sizeof(u8));
  	if (ret < 0)
  		return ret;
  
  	return ds2781_save_eeprom(dev_info, DS2781_RSNSP);
  }
  
  /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
  static int ds2781_get_rsgain_register(struct ds2781_device_info *dev_info,
  	u16 *rsgain)
  {
  	return ds2781_read16(dev_info, rsgain, DS2781_RSGAIN_MSB);
  }
  
  /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
  static int ds2781_set_rsgain_register(struct ds2781_device_info *dev_info,
  	u16 rsgain)
  {
  	int ret;
  	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};
  
  	ret = ds2781_write(dev_info, raw,
  				DS2781_RSGAIN_MSB, sizeof(raw));
  	if (ret < 0)
  		return ret;
  
  	return ds2781_save_eeprom(dev_info, DS2781_RSGAIN_MSB);
  }
  
  static int ds2781_get_voltage(struct ds2781_device_info *dev_info,
  	int *voltage_uV)
  {
  	int ret;
  	char val[2];
  	int voltage_raw;
  
  	ret = w1_ds2781_read(dev_info, val, DS2781_VOLT_MSB, 2 * sizeof(u8));
  	if (ret < 0)
  		return ret;
  	/*
  	 * The voltage value is located in 10 bits across the voltage MSB
  	 * and LSB registers in two's compliment form
  	 * Sign bit of the voltage value is in bit 7 of the voltage MSB register
  	 * Bits 9 - 3 of the voltage value are in bits 6 - 0 of the
  	 * voltage MSB register
  	 * Bits 2 - 0 of the voltage value are in bits 7 - 5 of the
  	 * voltage LSB register
  	 */
  	voltage_raw = (val[0] << 3) |
  		(val[1] >> 5);
  
  	/* DS2781 reports voltage in units of 9.76mV, but the battery class
  	 * reports in units of uV, so convert by multiplying by 9760. */
  	*voltage_uV = voltage_raw * 9760;
  
  	return 0;
  }
  
  static int ds2781_get_temperature(struct ds2781_device_info *dev_info,
  	int *temp)
  {
  	int ret;
  	char val[2];
  	int temp_raw;
  
  	ret = w1_ds2781_read(dev_info, val, DS2781_TEMP_MSB, 2 * sizeof(u8));
  	if (ret < 0)
  		return ret;
  	/*
  	 * The temperature value is located in 10 bits across the temperature
  	 * MSB and LSB registers in two's compliment form
  	 * Sign bit of the temperature value is in bit 7 of the temperature
  	 * MSB register
  	 * Bits 9 - 3 of the temperature value are in bits 6 - 0 of the
  	 * temperature MSB register
  	 * Bits 2 - 0 of the temperature value are in bits 7 - 5 of the
  	 * temperature LSB register
  	 */
  	temp_raw = ((val[0]) << 3) |
  		(val[1] >> 5);
  	*temp = temp_raw + (temp_raw / 4);
  
  	return 0;
  }
  
  static int ds2781_get_current(struct ds2781_device_info *dev_info,
  	enum current_types type, int *current_uA)
  {
  	int ret, sense_res;
  	s16 current_raw;
  	u8 sense_res_raw, reg_msb;
  
  	/*
  	 * The units of measurement for current are dependent on the value of
  	 * the sense resistor.
  	 */
  	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
  	if (ret < 0)
  		return ret;
  
  	if (sense_res_raw == 0) {
  		dev_err(dev_info->dev, "sense resistor value is 0\n");
  		return -EINVAL;
  	}
  	sense_res = 1000 / sense_res_raw;
  
  	if (type == CURRENT_NOW)
  		reg_msb = DS2781_CURRENT_MSB;
  	else if (type == CURRENT_AVG)
  		reg_msb = DS2781_IAVG_MSB;
  	else
  		return -EINVAL;
  
  	/*
  	 * The current value is located in 16 bits across the current MSB
  	 * and LSB registers in two's compliment form
  	 * Sign bit of the current value is in bit 7 of the current MSB register
  	 * Bits 14 - 8 of the current value are in bits 6 - 0 of the current
  	 * MSB register
  	 * Bits 7 - 0 of the current value are in bits 7 - 0 of the current
  	 * LSB register
  	 */
  	ret = ds2781_read16(dev_info, &current_raw, reg_msb);
  	if (ret < 0)
  		return ret;
  
  	*current_uA = current_raw * (DS2781_CURRENT_UNITS / sense_res);
  	return 0;
  }
  
  static int ds2781_get_accumulated_current(struct ds2781_device_info *dev_info,
  	int *accumulated_current)
  {
  	int ret, sense_res;
  	s16 current_raw;
  	u8 sense_res_raw;
  
  	/*
  	 * The units of measurement for accumulated current are dependent on
  	 * the value of the sense resistor.
  	 */
  	ret = ds2781_read8(dev_info, &sense_res_raw, DS2781_RSNSP);
  	if (ret < 0)
  		return ret;
  
  	if (sense_res_raw == 0) {
  		dev_err(dev_info->dev, "sense resistor value is 0\n");
  		return -EINVAL;
  	}
  	sense_res = 1000 / sense_res_raw;
  
  	/*
  	 * The ACR value is located in 16 bits across the ACR MSB and
  	 * LSB registers
  	 * Bits 15 - 8 of the ACR value are in bits 7 - 0 of the ACR
  	 * MSB register
  	 * Bits 7 - 0 of the ACR value are in bits 7 - 0 of the ACR
  	 * LSB register
  	 */
  	ret = ds2781_read16(dev_info, &current_raw, DS2781_ACR_MSB);
  	if (ret < 0)
  		return ret;
  
  	*accumulated_current = current_raw * (DS2781_CHARGE_UNITS / sense_res);
  	return 0;
  }
  
  static int ds2781_get_capacity(struct ds2781_device_info *dev_info,
  	int *capacity)
  {
  	int ret;
  	u8 raw;
  
  	ret = ds2781_read8(dev_info, &raw, DS2781_RARC);
  	if (ret < 0)
  		return ret;
  
  	*capacity = raw;
  	return 0;
  }
  
  static int ds2781_get_status(struct ds2781_device_info *dev_info, int *status)
  {
  	int ret, current_uA, capacity;
  
  	ret = ds2781_get_current(dev_info, CURRENT_NOW, &current_uA);
  	if (ret < 0)
  		return ret;
  
  	ret = ds2781_get_capacity(dev_info, &capacity);
  	if (ret < 0)
  		return ret;
  
  	if (power_supply_am_i_supplied(dev_info->bat)) {
  		if (capacity == 100)
  			*status = POWER_SUPPLY_STATUS_FULL;
  		else if (current_uA > 50000)
  			*status = POWER_SUPPLY_STATUS_CHARGING;
  		else
  			*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
  	} else {
  		*status = POWER_SUPPLY_STATUS_DISCHARGING;
  	}
  	return 0;
  }
  
  static int ds2781_get_charge_now(struct ds2781_device_info *dev_info,
  	int *charge_now)
  {
  	int ret;
  	u16 charge_raw;
  
  	/*
  	 * The RAAC value is located in 16 bits across the RAAC MSB and
  	 * LSB registers
  	 * Bits 15 - 8 of the RAAC value are in bits 7 - 0 of the RAAC
  	 * MSB register
  	 * Bits 7 - 0 of the RAAC value are in bits 7 - 0 of the RAAC
  	 * LSB register
  	 */
  	ret = ds2781_read16(dev_info, &charge_raw, DS2781_RAAC_MSB);
  	if (ret < 0)
  		return ret;
  
  	*charge_now = charge_raw * 1600;
  	return 0;
  }
  
  static int ds2781_get_control_register(struct ds2781_device_info *dev_info,
  	u8 *control_reg)
  {
  	return ds2781_read8(dev_info, control_reg, DS2781_CONTROL);
  }
  
  static int ds2781_set_control_register(struct ds2781_device_info *dev_info,
  	u8 control_reg)
  {
  	int ret;
  
  	ret = ds2781_write(dev_info, &control_reg,
  				DS2781_CONTROL, sizeof(u8));
  	if (ret < 0)
  		return ret;
  
  	return ds2781_save_eeprom(dev_info, DS2781_CONTROL);
  }
  
  static int ds2781_battery_get_property(struct power_supply *psy,
  	enum power_supply_property psp,
  	union power_supply_propval *val)
  {
  	int ret = 0;
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	switch (psp) {
  	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  		ret = ds2781_get_voltage(dev_info, &val->intval);
  		break;
  
  	case POWER_SUPPLY_PROP_TEMP:
  		ret = ds2781_get_temperature(dev_info, &val->intval);
  		break;
  
  	case POWER_SUPPLY_PROP_MODEL_NAME:
  		val->strval = model;
  		break;
  
  	case POWER_SUPPLY_PROP_MANUFACTURER:
  		val->strval = manufacturer;
  		break;
  
  	case POWER_SUPPLY_PROP_CURRENT_NOW:
  		ret = ds2781_get_current(dev_info, CURRENT_NOW, &val->intval);
  		break;
  
  	case POWER_SUPPLY_PROP_CURRENT_AVG:
  		ret = ds2781_get_current(dev_info, CURRENT_AVG, &val->intval);
  		break;
  
  	case POWER_SUPPLY_PROP_STATUS:
  		ret = ds2781_get_status(dev_info, &val->intval);
  		break;
  
  	case POWER_SUPPLY_PROP_CAPACITY:
  		ret = ds2781_get_capacity(dev_info, &val->intval);
  		break;
  
  	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
  		ret = ds2781_get_accumulated_current(dev_info, &val->intval);
  		break;
  
  	case POWER_SUPPLY_PROP_CHARGE_NOW:
  		ret = ds2781_get_charge_now(dev_info, &val->intval);
  		break;
  
  	default:
  		ret = -EINVAL;
  	}
  
  	return ret;
  }
  
  static enum power_supply_property ds2781_battery_props[] = {
  	POWER_SUPPLY_PROP_STATUS,
  	POWER_SUPPLY_PROP_VOLTAGE_NOW,
  	POWER_SUPPLY_PROP_TEMP,
  	POWER_SUPPLY_PROP_MODEL_NAME,
  	POWER_SUPPLY_PROP_MANUFACTURER,
  	POWER_SUPPLY_PROP_CURRENT_NOW,
  	POWER_SUPPLY_PROP_CURRENT_AVG,
  	POWER_SUPPLY_PROP_CAPACITY,
  	POWER_SUPPLY_PROP_CHARGE_COUNTER,
  	POWER_SUPPLY_PROP_CHARGE_NOW,
  };
  
  static ssize_t ds2781_get_pmod_enabled(struct device *dev,
  	struct device_attribute *attr,
  	char *buf)
  {
  	int ret;
  	u8 control_reg;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	/* Get power mode */
  	ret = ds2781_get_control_register(dev_info, &control_reg);
  	if (ret < 0)
  		return ret;
  
  	return sprintf(buf, "%d\n",
  		 !!(control_reg & DS2781_CONTROL_PMOD));
  }
  
  static ssize_t ds2781_set_pmod_enabled(struct device *dev,
  	struct device_attribute *attr,
  	const char *buf,
  	size_t count)
  {
  	int ret;
  	u8 control_reg, new_setting;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	/* Set power mode */
  	ret = ds2781_get_control_register(dev_info, &control_reg);
  	if (ret < 0)
  		return ret;
  
  	ret = kstrtou8(buf, 0, &new_setting);
  	if (ret < 0)
  		return ret;
  
  	if ((new_setting != 0) && (new_setting != 1)) {
  		dev_err(dev_info->dev, "Invalid pmod setting (0 or 1)\n");
  		return -EINVAL;
  	}
  
  	if (new_setting)
  		control_reg |= DS2781_CONTROL_PMOD;
  	else
  		control_reg &= ~DS2781_CONTROL_PMOD;
  
  	ret = ds2781_set_control_register(dev_info, control_reg);
  	if (ret < 0)
  		return ret;
  
  	return count;
  }
  
  static ssize_t ds2781_get_sense_resistor_value(struct device *dev,
  	struct device_attribute *attr,
  	char *buf)
  {
  	int ret;
  	u8 sense_resistor;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	ret = ds2781_read8(dev_info, &sense_resistor, DS2781_RSNSP);
  	if (ret < 0)
  		return ret;
  
  	ret = sprintf(buf, "%d\n", sense_resistor);
  	return ret;
  }
  
  static ssize_t ds2781_set_sense_resistor_value(struct device *dev,
  	struct device_attribute *attr,
  	const char *buf,
  	size_t count)
  {
  	int ret;
  	u8 new_setting;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	ret = kstrtou8(buf, 0, &new_setting);
  	if (ret < 0)
  		return ret;
  
  	ret = ds2781_set_sense_register(dev_info, new_setting);
  	if (ret < 0)
  		return ret;
  
  	return count;
  }
  
  static ssize_t ds2781_get_rsgain_setting(struct device *dev,
  	struct device_attribute *attr,
  	char *buf)
  {
  	int ret;
  	u16 rsgain;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	ret = ds2781_get_rsgain_register(dev_info, &rsgain);
  	if (ret < 0)
  		return ret;
  
  	return sprintf(buf, "%d\n", rsgain);
  }
  
  static ssize_t ds2781_set_rsgain_setting(struct device *dev,
  	struct device_attribute *attr,
  	const char *buf,
  	size_t count)
  {
  	int ret;
  	u16 new_setting;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	ret = kstrtou16(buf, 0, &new_setting);
  	if (ret < 0)
  		return ret;
  
  	/* Gain can only be from 0 to 1.999 in steps of .001 */
  	if (new_setting > 1999) {
  		dev_err(dev_info->dev, "Invalid rsgain setting (0 - 1999)\n");
  		return -EINVAL;
  	}
  
  	ret = ds2781_set_rsgain_register(dev_info, new_setting);
  	if (ret < 0)
  		return ret;
  
  	return count;
  }
  
  static ssize_t ds2781_get_pio_pin(struct device *dev,
  	struct device_attribute *attr,
  	char *buf)
  {
  	int ret;
  	u8 sfr;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	ret = ds2781_read8(dev_info, &sfr, DS2781_SFR);
  	if (ret < 0)
  		return ret;
  
  	ret = sprintf(buf, "%d\n", sfr & DS2781_SFR_PIOSC);
  	return ret;
  }
  
  static ssize_t ds2781_set_pio_pin(struct device *dev,
  	struct device_attribute *attr,
  	const char *buf,
  	size_t count)
  {
  	int ret;
  	u8 new_setting;
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	ret = kstrtou8(buf, 0, &new_setting);
  	if (ret < 0)
  		return ret;
  
  	if ((new_setting != 0) && (new_setting != 1)) {
  		dev_err(dev_info->dev, "Invalid pio_pin setting (0 or 1)\n");
  		return -EINVAL;
  	}
  
  	ret = ds2781_write(dev_info, &new_setting,
  				DS2781_SFR, sizeof(u8));
  	if (ret < 0)
  		return ret;
  
  	return count;
  }
  
  static ssize_t ds2781_read_param_eeprom_bin(struct file *filp,
  				struct kobject *kobj,
  				struct bin_attribute *bin_attr,
  				char *buf, loff_t off, size_t count)
  {
  	struct device *dev = container_of(kobj, struct device, kobj);
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	return ds2781_read_block(dev_info, buf,
  				DS2781_EEPROM_BLOCK1_START + off, count);
  }
  
  static ssize_t ds2781_write_param_eeprom_bin(struct file *filp,
  				struct kobject *kobj,
  				struct bin_attribute *bin_attr,
  				char *buf, loff_t off, size_t count)
  {
  	struct device *dev = container_of(kobj, struct device, kobj);
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  	int ret;
  
  	ret = ds2781_write(dev_info, buf,
  				DS2781_EEPROM_BLOCK1_START + off, count);
  	if (ret < 0)
  		return ret;
  
  	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK1_START);
  	if (ret < 0)
  		return ret;
  
  	return count;
  }
  
  static const struct bin_attribute ds2781_param_eeprom_bin_attr = {
  	.attr = {
  		.name = "param_eeprom",
  		.mode = S_IRUGO | S_IWUSR,
  	},
  	.size = DS2781_PARAM_EEPROM_SIZE,
  	.read = ds2781_read_param_eeprom_bin,
  	.write = ds2781_write_param_eeprom_bin,
  };
  
  static ssize_t ds2781_read_user_eeprom_bin(struct file *filp,
  				struct kobject *kobj,
  				struct bin_attribute *bin_attr,
  				char *buf, loff_t off, size_t count)
  {
  	struct device *dev = container_of(kobj, struct device, kobj);
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  
  	return ds2781_read_block(dev_info, buf,
  				DS2781_EEPROM_BLOCK0_START + off, count);
  
  }
  
  static ssize_t ds2781_write_user_eeprom_bin(struct file *filp,
  				struct kobject *kobj,
  				struct bin_attribute *bin_attr,
  				char *buf, loff_t off, size_t count)
  {
  	struct device *dev = container_of(kobj, struct device, kobj);
  	struct power_supply *psy = to_power_supply(dev);
  	struct ds2781_device_info *dev_info = to_ds2781_device_info(psy);
  	int ret;
  
  	ret = ds2781_write(dev_info, buf,
  				DS2781_EEPROM_BLOCK0_START + off, count);
  	if (ret < 0)
  		return ret;
  
  	ret = ds2781_save_eeprom(dev_info, DS2781_EEPROM_BLOCK0_START);
  	if (ret < 0)
  		return ret;
  
  	return count;
  }
  
  static const struct bin_attribute ds2781_user_eeprom_bin_attr = {
  	.attr = {
  		.name = "user_eeprom",
  		.mode = S_IRUGO | S_IWUSR,
  	},
  	.size = DS2781_USER_EEPROM_SIZE,
  	.read = ds2781_read_user_eeprom_bin,
  	.write = ds2781_write_user_eeprom_bin,
  };
  
  static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2781_get_pmod_enabled,
  	ds2781_set_pmod_enabled);
  static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
  	ds2781_get_sense_resistor_value, ds2781_set_sense_resistor_value);
  static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2781_get_rsgain_setting,
  	ds2781_set_rsgain_setting);
  static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2781_get_pio_pin,
  	ds2781_set_pio_pin);
  
  
  static struct attribute *ds2781_attributes[] = {
  	&dev_attr_pmod_enabled.attr,
  	&dev_attr_sense_resistor_value.attr,
  	&dev_attr_rsgain_setting.attr,
  	&dev_attr_pio_pin.attr,
  	NULL
  };
  
  static const struct attribute_group ds2781_attr_group = {
  	.attrs = ds2781_attributes,
  };
  
  static int ds2781_battery_probe(struct platform_device *pdev)
  {
  	struct power_supply_config psy_cfg = {};
  	int ret = 0;
  	struct ds2781_device_info *dev_info;
  
  	dev_info = devm_kzalloc(&pdev->dev, sizeof(*dev_info), GFP_KERNEL);
  	if (!dev_info)
  		return -ENOMEM;
  
  	platform_set_drvdata(pdev, dev_info);
  
  	dev_info->dev			= &pdev->dev;
  	dev_info->w1_dev		= pdev->dev.parent;
  	dev_info->bat_desc.name		= dev_name(&pdev->dev);
  	dev_info->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
  	dev_info->bat_desc.properties	= ds2781_battery_props;
  	dev_info->bat_desc.num_properties = ARRAY_SIZE(ds2781_battery_props);
  	dev_info->bat_desc.get_property	= ds2781_battery_get_property;
  
  	psy_cfg.drv_data		= dev_info;
  
  	dev_info->bat = power_supply_register(&pdev->dev, &dev_info->bat_desc,
  						&psy_cfg);
  	if (IS_ERR(dev_info->bat)) {
  		dev_err(dev_info->dev, "failed to register battery\n");
  		ret = PTR_ERR(dev_info->bat);
  		goto fail;
  	}
  
  	ret = sysfs_create_group(&dev_info->bat->dev.kobj, &ds2781_attr_group);
  	if (ret) {
  		dev_err(dev_info->dev, "failed to create sysfs group\n");
  		goto fail_unregister;
  	}
  
  	ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj,
  					&ds2781_param_eeprom_bin_attr);
  	if (ret) {
  		dev_err(dev_info->dev,
  				"failed to create param eeprom bin file");
  		goto fail_remove_group;
  	}
  
  	ret = sysfs_create_bin_file(&dev_info->bat->dev.kobj,
  					&ds2781_user_eeprom_bin_attr);
  	if (ret) {
  		dev_err(dev_info->dev,
  				"failed to create user eeprom bin file");
  		goto fail_remove_bin_file;
  	}
  
  	return 0;
  
  fail_remove_bin_file:
  	sysfs_remove_bin_file(&dev_info->bat->dev.kobj,
  				&ds2781_param_eeprom_bin_attr);
  fail_remove_group:
  	sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2781_attr_group);
  fail_unregister:
  	power_supply_unregister(dev_info->bat);
  fail:
  	return ret;
  }
  
  static int ds2781_battery_remove(struct platform_device *pdev)
  {
  	struct ds2781_device_info *dev_info = platform_get_drvdata(pdev);
  
  	/*
  	 * Remove attributes before unregistering power supply
  	 * because 'bat' will be freed on power_supply_unregister() call.
  	 */
  	sysfs_remove_group(&dev_info->bat->dev.kobj, &ds2781_attr_group);
  
  	power_supply_unregister(dev_info->bat);
  
  	return 0;
  }
  
  static struct platform_driver ds2781_battery_driver = {
  	.driver = {
  		.name = "ds2781-battery",
  	},
  	.probe	  = ds2781_battery_probe,
  	.remove   = ds2781_battery_remove,
  };
  module_platform_driver(ds2781_battery_driver);
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
  MODULE_DESCRIPTION("Maxim/Dallas DS2781 Stand-Alone Fuel Gauage IC driver");
  MODULE_ALIAS("platform:ds2781-battery");
  
  