drivers/power/ds2780_battery.c - kernel/msm-4.9 - Gitiles

 /*
  * 1-wire client/driver for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC
  *
  * Copyright (C) 2010 Indesign, LLC
  *
  * Author: Clifton Barnes <cabarnes@indesign-llc.com>
  *
  * Based on ds2760_battery and ds2782_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 "../w1/w1.h"
 #include "../w1/slaves/w1_ds2780.h"

 /* Current unit measurement in uA for a 1 milli-ohm sense resistor */
 #define DS2780_CURRENT_UNITS	1563
 /* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
 #define DS2780_CHARGE_UNITS		6250
 /* Number of bytes in user EEPROM space */
 #define DS2780_USER_EEPROM_SIZE		(DS2780_EEPROM_BLOCK0_END - \
 					DS2780_EEPROM_BLOCK0_START + 1)
 /* Number of bytes in parameter EEPROM space */
 #define DS2780_PARAM_EEPROM_SIZE	(DS2780_EEPROM_BLOCK1_END - \
 					DS2780_EEPROM_BLOCK1_START + 1)

 struct ds2780_device_info {
 	struct device *dev;
 	struct power_supply bat;
 	struct device *w1_dev;
 };

 enum current_types {
 	CURRENT_NOW,
 	CURRENT_AVG,
 };

 static const char model[] = "DS2780";
 static const char manufacturer[] = "Maxim/Dallas";

 static inline struct ds2780_device_info *
 to_ds2780_device_info(struct power_supply *psy)
 {
 	return container_of(psy, struct ds2780_device_info, bat);
 }

 static inline struct power_supply *to_power_supply(struct device *dev)
 {
 	return dev_get_drvdata(dev);
 }

 static inline int ds2780_battery_io(struct ds2780_device_info *dev_info,
 	char *buf, int addr, size_t count, int io)
 {
 	return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
 }

 static inline int ds2780_read8(struct ds2780_device_info *dev_info, u8 *val,
 	int addr)
 {
 	return ds2780_battery_io(dev_info, val, addr, sizeof(u8), 0);
 }

 static int ds2780_read16(struct ds2780_device_info *dev_info, s16 *val,
 	int addr)
 {
 	int ret;
 	u8 raw[2];

 	ret = ds2780_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 ds2780_read_block(struct ds2780_device_info *dev_info,
 	u8 *val, int addr, size_t count)
 {
 	return ds2780_battery_io(dev_info, val, addr, count, 0);
 }

 static inline int ds2780_write(struct ds2780_device_info *dev_info, u8 *val,
 	int addr, size_t count)
 {
 	return ds2780_battery_io(dev_info, val, addr, count, 1);
 }

 static inline int ds2780_store_eeprom(struct device *dev, int addr)
 {
 	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_COPY_DATA);
 }

 static inline int ds2780_recall_eeprom(struct device *dev, int addr)
 {
 	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_RECALL_DATA);
 }

 static int ds2780_save_eeprom(struct ds2780_device_info *dev_info, int reg)
 {
 	int ret;

 	ret = ds2780_store_eeprom(dev_info->w1_dev, reg);
 	if (ret < 0)
 		return ret;

 	ret = ds2780_recall_eeprom(dev_info->w1_dev, reg);
 	if (ret < 0)
 		return ret;

 	return 0;
 }

 /* Set sense resistor value in mhos */
 static int ds2780_set_sense_register(struct ds2780_device_info *dev_info,
 	u8 conductance)
 {
 	int ret;

 	ret = ds2780_write(dev_info, &conductance,
 				DS2780_RSNSP_REG, sizeof(u8));
 	if (ret < 0)
 		return ret;

 	return ds2780_save_eeprom(dev_info, DS2780_RSNSP_REG);
 }

 /* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
 static int ds2780_get_rsgain_register(struct ds2780_device_info *dev_info,
 	u16 *rsgain)
 {
 	return ds2780_read16(dev_info, rsgain, DS2780_RSGAIN_MSB_REG);
 }

 /* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
 static int ds2780_set_rsgain_register(struct ds2780_device_info *dev_info,
 	u16 rsgain)
 {
 	int ret;
 	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};

 	ret = ds2780_write(dev_info, raw,
 				DS2780_RSGAIN_MSB_REG, sizeof(raw));
 	if (ret < 0)
 		return ret;

 	return ds2780_save_eeprom(dev_info, DS2780_RSGAIN_MSB_REG);
 }

 static int ds2780_get_voltage(struct ds2780_device_info *dev_info,
 	int *voltage_uV)
 {
 	int ret;
 	s16 voltage_raw;

 	/*
 	 * 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
 	 */
 	ret = ds2780_read16(dev_info, &voltage_raw,
 				DS2780_VOLT_MSB_REG);
 	if (ret < 0)
 		return ret;

 	/*
 	 * DS2780 reports voltage in units of 4.88mV, but the battery class
 	 * reports in units of uV, so convert by multiplying by 4880.
 	 */
 	*voltage_uV = (voltage_raw / 32) * 4880;
 	return 0;
 }

 static int ds2780_get_temperature(struct ds2780_device_info *dev_info,
 	int *temperature)
 {
 	int ret;
 	s16 temperature_raw;

 	/*
 	 * 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
 	 */
 	ret = ds2780_read16(dev_info, &temperature_raw,
 				DS2780_TEMP_MSB_REG);
 	if (ret < 0)
 		return ret;

 	/*
 	 * Temperature is measured in units of 0.125 degrees celcius, the
 	 * power_supply class measures temperature in tenths of degrees
 	 * celsius. The temperature value is stored as a 10 bit number, plus
 	 * sign in the upper bits of a 16 bit register.
 	 */
 	*temperature = ((temperature_raw / 32) * 125) / 100;
 	return 0;
 }

 static int ds2780_get_current(struct ds2780_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 = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
 	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 = DS2780_CURRENT_MSB_REG;
 	else if (type == CURRENT_AVG)
 		reg_msb = DS2780_IAVG_MSB_REG;
 	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 = ds2780_read16(dev_info, &current_raw, reg_msb);
 	if (ret < 0)
 		return ret;

 	*current_uA = current_raw * (DS2780_CURRENT_UNITS / sense_res);
 	return 0;
 }

 static int ds2780_get_accumulated_current(struct ds2780_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 = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
 	if (ret < 0)
 		return ret;

 	if (sense_res_raw == 0) {
 		dev_err(dev_info->dev, "sense resistor value is 0\n");
 		return -ENXIO;
 	}
 	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 = ds2780_read16(dev_info, &current_raw, DS2780_ACR_MSB_REG);
 	if (ret < 0)
 		return ret;

 	*accumulated_current = current_raw * (DS2780_CHARGE_UNITS / sense_res);
 	return 0;
 }

 static int ds2780_get_capacity(struct ds2780_device_info *dev_info,
 	int *capacity)
 {
 	int ret;
 	u8 raw;

 	ret = ds2780_read8(dev_info, &raw, DS2780_RARC_REG);
 	if (ret < 0)
 		return ret;

 	*capacity = raw;
 	return raw;
 }

 static int ds2780_get_status(struct ds2780_device_info *dev_info, int *status)
 {
 	int ret, current_uA, capacity;

 	ret = ds2780_get_current(dev_info, CURRENT_NOW, &current_uA);
 	if (ret < 0)
 		return ret;

 	ret = ds2780_get_capacity(dev_info, &capacity);
 	if (ret < 0)
 		return ret;

 	if (capacity == 100)
 		*status = POWER_SUPPLY_STATUS_FULL;
 	else if (current_uA == 0)
 		*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
 	else if (current_uA < 0)
 		*status = POWER_SUPPLY_STATUS_DISCHARGING;
 	else
 		*status = POWER_SUPPLY_STATUS_CHARGING;

 	return 0;
 }

 static int ds2780_get_charge_now(struct ds2780_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 = ds2780_read16(dev_info, &charge_raw, DS2780_RAAC_MSB_REG);
 	if (ret < 0)
 		return ret;

 	*charge_now = charge_raw * 1600;
 	return 0;
 }

 static int ds2780_get_control_register(struct ds2780_device_info *dev_info,
 	u8 *control_reg)
 {
 	return ds2780_read8(dev_info, control_reg, DS2780_CONTROL_REG);
 }

 static int ds2780_set_control_register(struct ds2780_device_info *dev_info,
 	u8 control_reg)
 {
 	int ret;

 	ret = ds2780_write(dev_info, &control_reg,
 				DS2780_CONTROL_REG, sizeof(u8));
 	if (ret < 0)
 		return ret;

 	return ds2780_save_eeprom(dev_info, DS2780_CONTROL_REG);
 }

 static int ds2780_battery_get_property(struct power_supply *psy,
 	enum power_supply_property psp,
 	union power_supply_propval *val)
 {
 	int ret = 0;
 	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	switch (psp) {
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		ret = ds2780_get_voltage(dev_info, &val->intval);
 		break;

 	case POWER_SUPPLY_PROP_TEMP:
 		ret = ds2780_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 = ds2780_get_current(dev_info, CURRENT_NOW, &val->intval);
 		break;

 	case POWER_SUPPLY_PROP_CURRENT_AVG:
 		ret = ds2780_get_current(dev_info, CURRENT_AVG, &val->intval);
 		break;

 	case POWER_SUPPLY_PROP_STATUS:
 		ret = ds2780_get_status(dev_info, &val->intval);
 		break;

 	case POWER_SUPPLY_PROP_CAPACITY:
 		ret = ds2780_get_capacity(dev_info, &val->intval);
 		break;

 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
 		ret = ds2780_get_accumulated_current(dev_info, &val->intval);
 		break;

 	case POWER_SUPPLY_PROP_CHARGE_NOW:
 		ret = ds2780_get_charge_now(dev_info, &val->intval);
 		break;

 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static enum power_supply_property ds2780_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 ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	/* Get power mode */
 	ret = ds2780_get_control_register(dev_info, &control_reg);
 	if (ret < 0)
 		return ret;

 	return sprintf(buf, "%d\n",
 		 !!(control_reg & DS2780_CONTROL_REG_PMOD));
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	/* Set power mode */
 	ret = ds2780_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 |= DS2780_CONTROL_REG_PMOD;
 	else
 		control_reg &= ~DS2780_CONTROL_REG_PMOD;

 	ret = ds2780_set_control_register(dev_info, control_reg);
 	if (ret < 0)
 		return ret;

 	return count;
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	ret = ds2780_read8(dev_info, &sense_resistor, DS2780_RSNSP_REG);
 	if (ret < 0)
 		return ret;

 	ret = sprintf(buf, "%d\n", sense_resistor);
 	return ret;
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	ret = kstrtou8(buf, 0, &new_setting);
 	if (ret < 0)
 		return ret;

 	ret = ds2780_set_sense_register(dev_info, new_setting);
 	if (ret < 0)
 		return ret;

 	return count;
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	ret = ds2780_get_rsgain_register(dev_info, &rsgain);
 	if (ret < 0)
 		return ret;

 	return sprintf(buf, "%d\n", rsgain);
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_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 = ds2780_set_rsgain_register(dev_info, new_setting);
 	if (ret < 0)
 		return ret;

 	return count;
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	ret = ds2780_read8(dev_info, &sfr, DS2780_SFR_REG);
 	if (ret < 0)
 		return ret;

 	ret = sprintf(buf, "%d\n", sfr & DS2780_SFR_REG_PIOSC);
 	return ret;
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_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 = ds2780_write(dev_info, &new_setting,
 				DS2780_SFR_REG, sizeof(u8));
 	if (ret < 0)
 		return ret;

 	return count;
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	count = min_t(loff_t, count,
 		DS2780_EEPROM_BLOCK1_END -
 		DS2780_EEPROM_BLOCK1_START + 1 - off);

 	return ds2780_read_block(dev_info, buf,
 				DS2780_EEPROM_BLOCK1_START + off, count);
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);
 	int ret;

 	count = min_t(loff_t, count,
 		DS2780_EEPROM_BLOCK1_END -
 		DS2780_EEPROM_BLOCK1_START + 1 - off);

 	ret = ds2780_write(dev_info, buf,
 				DS2780_EEPROM_BLOCK1_START + off, count);
 	if (ret < 0)
 		return ret;

 	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK1_START);
 	if (ret < 0)
 		return ret;

 	return count;
 }

 static struct bin_attribute ds2780_param_eeprom_bin_attr = {
 	.attr = {
 		.name = "param_eeprom",
 		.mode = S_IRUGO | S_IWUSR,
 	},
 	.size = DS2780_EEPROM_BLOCK1_END - DS2780_EEPROM_BLOCK1_START + 1,
 	.read = ds2780_read_param_eeprom_bin,
 	.write = ds2780_write_param_eeprom_bin,
 };

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

 	count = min_t(loff_t, count,
 		DS2780_EEPROM_BLOCK0_END -
 		DS2780_EEPROM_BLOCK0_START + 1 - off);

 	return ds2780_read_block(dev_info, buf,
 				DS2780_EEPROM_BLOCK0_START + off, count);
 }

 static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);
 	int ret;

 	count = min_t(loff_t, count,
 		DS2780_EEPROM_BLOCK0_END -
 		DS2780_EEPROM_BLOCK0_START + 1 - off);

 	ret = ds2780_write(dev_info, buf,
 				DS2780_EEPROM_BLOCK0_START + off, count);
 	if (ret < 0)
 		return ret;

 	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK0_START);
 	if (ret < 0)
 		return ret;

 	return count;
 }

 static struct bin_attribute ds2780_user_eeprom_bin_attr = {
 	.attr = {
 		.name = "user_eeprom",
 		.mode = S_IRUGO | S_IWUSR,
 	},
 	.size = DS2780_EEPROM_BLOCK0_END - DS2780_EEPROM_BLOCK0_START + 1,
 	.read = ds2780_read_user_eeprom_bin,
 	.write = ds2780_write_user_eeprom_bin,
 };

 static DEVICE_ATTR(pmod_enabled, S_IRUGO | S_IWUSR, ds2780_get_pmod_enabled,
 	ds2780_set_pmod_enabled);
 static DEVICE_ATTR(sense_resistor_value, S_IRUGO | S_IWUSR,
 	ds2780_get_sense_resistor_value, ds2780_set_sense_resistor_value);
 static DEVICE_ATTR(rsgain_setting, S_IRUGO | S_IWUSR, ds2780_get_rsgain_setting,
 	ds2780_set_rsgain_setting);
 static DEVICE_ATTR(pio_pin, S_IRUGO | S_IWUSR, ds2780_get_pio_pin,
 	ds2780_set_pio_pin);


 static struct attribute *ds2780_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 ds2780_attr_group = {
 	.attrs = ds2780_attributes,
 };

 static int __devinit ds2780_battery_probe(struct platform_device *pdev)
 {
 	int ret = 0;
 	struct ds2780_device_info *dev_info;

 	dev_info = kzalloc(sizeof(*dev_info), GFP_KERNEL);
 	if (!dev_info) {
 		ret = -ENOMEM;
 		goto fail;
 	}

 	platform_set_drvdata(pdev, dev_info);

 	dev_info->dev			= &pdev->dev;
 	dev_info->w1_dev		= pdev->dev.parent;
 	dev_info->bat.name		= dev_name(&pdev->dev);
 	dev_info->bat.type		= POWER_SUPPLY_TYPE_BATTERY;
 	dev_info->bat.properties	= ds2780_battery_props;
 	dev_info->bat.num_properties	= ARRAY_SIZE(ds2780_battery_props);
 	dev_info->bat.get_property	= ds2780_battery_get_property;

 	ret = power_supply_register(&pdev->dev, &dev_info->bat);
 	if (ret) {
 		dev_err(dev_info->dev, "failed to register battery\n");
 		goto fail_free_info;
 	}

 	ret = sysfs_create_group(&dev_info->bat.dev->kobj, &ds2780_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,
 					&ds2780_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,
 					&ds2780_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,
 				&ds2780_param_eeprom_bin_attr);
 fail_remove_group:
 	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);
 fail_unregister:
 	power_supply_unregister(&dev_info->bat);
 fail_free_info:
 	kfree(dev_info);
 fail:
 	return ret;
 }

 static int __devexit ds2780_battery_remove(struct platform_device *pdev)
 {
 	struct ds2780_device_info *dev_info = platform_get_drvdata(pdev);

 	/* remove attributes */
 	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);

 	power_supply_unregister(&dev_info->bat);

 	kfree(dev_info);
 	return 0;
 }

 static struct platform_driver ds2780_battery_driver = {
 	.driver = {
 		.name = "ds2780-battery",
 	},
 	.probe	  = ds2780_battery_probe,
 	.remove   = __devexit_p(ds2780_battery_remove),
 };

 module_platform_driver(ds2780_battery_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
 MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauage IC driver");
 MODULE_ALIAS("platform:ds2780-battery");
	/*
	* 1-wire client/driver for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC
	*
	* Copyright (C) 2010 Indesign, LLC
	*
	* Author: Clifton Barnes <cabarnes@indesign-llc.com>
	*
	* Based on ds2760_battery and ds2782_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 "../w1/w1.h"
	#include "../w1/slaves/w1_ds2780.h"

	/* Current unit measurement in uA for a 1 milli-ohm sense resistor */
	#define DS2780_CURRENT_UNITS 1563
	/* Charge unit measurement in uAh for a 1 milli-ohm sense resistor */
	#define DS2780_CHARGE_UNITS 6250
	/* Number of bytes in user EEPROM space */
	#define DS2780_USER_EEPROM_SIZE (DS2780_EEPROM_BLOCK0_END - \
	DS2780_EEPROM_BLOCK0_START + 1)
	/* Number of bytes in parameter EEPROM space */
	#define DS2780_PARAM_EEPROM_SIZE (DS2780_EEPROM_BLOCK1_END - \
	DS2780_EEPROM_BLOCK1_START + 1)

	struct ds2780_device_info {
	struct device *dev;
	struct power_supply bat;
	struct device *w1_dev;
	};

	enum current_types {
	CURRENT_NOW,
	CURRENT_AVG,
	};

	static const char model[] = "DS2780";
	static const char manufacturer[] = "Maxim/Dallas";

	static inline struct ds2780_device_info *
	to_ds2780_device_info(struct power_supply *psy)
	{
	return container_of(psy, struct ds2780_device_info, bat);
	}

	static inline struct power_supply to_power_supply(struct device dev)
	{
	return dev_get_drvdata(dev);
	}

	static inline int ds2780_battery_io(struct ds2780_device_info *dev_info,
	char *buf, int addr, size_t count, int io)
	{
	return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
	}

	static inline int ds2780_read8(struct ds2780_device_info dev_info, u8 val,
	int addr)
	{
	return ds2780_battery_io(dev_info, val, addr, sizeof(u8), 0);
	}

	static int ds2780_read16(struct ds2780_device_info dev_info, s16 val,
	int addr)
	{
	int ret;
	u8 raw[2];

	ret = ds2780_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 ds2780_read_block(struct ds2780_device_info *dev_info,
	u8 *val, int addr, size_t count)
	{
	return ds2780_battery_io(dev_info, val, addr, count, 0);
	}

	static inline int ds2780_write(struct ds2780_device_info dev_info, u8 val,
	int addr, size_t count)
	{
	return ds2780_battery_io(dev_info, val, addr, count, 1);
	}

	static inline int ds2780_store_eeprom(struct device *dev, int addr)
	{
	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_COPY_DATA);
	}

	static inline int ds2780_recall_eeprom(struct device *dev, int addr)
	{
	return w1_ds2780_eeprom_cmd(dev, addr, W1_DS2780_RECALL_DATA);
	}

	static int ds2780_save_eeprom(struct ds2780_device_info *dev_info, int reg)
	{
	int ret;

	ret = ds2780_store_eeprom(dev_info->w1_dev, reg);
	if (ret < 0)
	return ret;

	ret = ds2780_recall_eeprom(dev_info->w1_dev, reg);
	if (ret < 0)
	return ret;

	return 0;
	}

	/* Set sense resistor value in mhos */
	static int ds2780_set_sense_register(struct ds2780_device_info *dev_info,
	u8 conductance)
	{
	int ret;

	ret = ds2780_write(dev_info, &conductance,
	DS2780_RSNSP_REG, sizeof(u8));
	if (ret < 0)
	return ret;

	return ds2780_save_eeprom(dev_info, DS2780_RSNSP_REG);
	}

	/* Get RSGAIN value from 0 to 1.999 in steps of 0.001 */
	static int ds2780_get_rsgain_register(struct ds2780_device_info *dev_info,
	u16 *rsgain)
	{
	return ds2780_read16(dev_info, rsgain, DS2780_RSGAIN_MSB_REG);
	}

	/* Set RSGAIN value from 0 to 1.999 in steps of 0.001 */
	static int ds2780_set_rsgain_register(struct ds2780_device_info *dev_info,
	u16 rsgain)
	{
	int ret;
	u8 raw[] = {rsgain >> 8, rsgain & 0xFF};

	ret = ds2780_write(dev_info, raw,
	DS2780_RSGAIN_MSB_REG, sizeof(raw));
	if (ret < 0)
	return ret;

	return ds2780_save_eeprom(dev_info, DS2780_RSGAIN_MSB_REG);
	}

	static int ds2780_get_voltage(struct ds2780_device_info *dev_info,
	int *voltage_uV)
	{
	int ret;
	s16 voltage_raw;

	/*
	* 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
	*/
	ret = ds2780_read16(dev_info, &voltage_raw,
	DS2780_VOLT_MSB_REG);
	if (ret < 0)
	return ret;

	/*
	* DS2780 reports voltage in units of 4.88mV, but the battery class
	* reports in units of uV, so convert by multiplying by 4880.
	*/
	voltage_uV = (voltage_raw / 32) 4880;
	return 0;
	}

	static int ds2780_get_temperature(struct ds2780_device_info *dev_info,
	int *temperature)
	{
	int ret;
	s16 temperature_raw;

	/*
	* 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
	*/
	ret = ds2780_read16(dev_info, &temperature_raw,
	DS2780_TEMP_MSB_REG);
	if (ret < 0)
	return ret;

	/*
	* Temperature is measured in units of 0.125 degrees celcius, the
	* power_supply class measures temperature in tenths of degrees
	* celsius. The temperature value is stored as a 10 bit number, plus
	* sign in the upper bits of a 16 bit register.
	*/
	temperature = ((temperature_raw / 32) 125) / 100;
	return 0;
	}

	static int ds2780_get_current(struct ds2780_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 = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
	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 = DS2780_CURRENT_MSB_REG;
	else if (type == CURRENT_AVG)
	reg_msb = DS2780_IAVG_MSB_REG;
	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 = ds2780_read16(dev_info, &current_raw, reg_msb);
	if (ret < 0)
	return ret;

	current_uA = current_raw (DS2780_CURRENT_UNITS / sense_res);
	return 0;
	}

	static int ds2780_get_accumulated_current(struct ds2780_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 = ds2780_read8(dev_info, &sense_res_raw, DS2780_RSNSP_REG);
	if (ret < 0)
	return ret;

	if (sense_res_raw == 0) {
	dev_err(dev_info->dev, "sense resistor value is 0\n");
	return -ENXIO;
	}
	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 = ds2780_read16(dev_info, &current_raw, DS2780_ACR_MSB_REG);
	if (ret < 0)
	return ret;

	accumulated_current = current_raw (DS2780_CHARGE_UNITS / sense_res);
	return 0;
	}

	static int ds2780_get_capacity(struct ds2780_device_info *dev_info,
	int *capacity)
	{
	int ret;
	u8 raw;

	ret = ds2780_read8(dev_info, &raw, DS2780_RARC_REG);
	if (ret < 0)
	return ret;

	*capacity = raw;
	return raw;
	}

	static int ds2780_get_status(struct ds2780_device_info dev_info, int status)
	{
	int ret, current_uA, capacity;

	ret = ds2780_get_current(dev_info, CURRENT_NOW, &current_uA);
	if (ret < 0)
	return ret;

	ret = ds2780_get_capacity(dev_info, &capacity);
	if (ret < 0)
	return ret;

	if (capacity == 100)
	*status = POWER_SUPPLY_STATUS_FULL;
	else if (current_uA == 0)
	*status = POWER_SUPPLY_STATUS_NOT_CHARGING;
	else if (current_uA < 0)
	*status = POWER_SUPPLY_STATUS_DISCHARGING;
	else
	*status = POWER_SUPPLY_STATUS_CHARGING;

	return 0;
	}

	static int ds2780_get_charge_now(struct ds2780_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 = ds2780_read16(dev_info, &charge_raw, DS2780_RAAC_MSB_REG);
	if (ret < 0)
	return ret;

	charge_now = charge_raw 1600;
	return 0;
	}

	static int ds2780_get_control_register(struct ds2780_device_info *dev_info,
	u8 *control_reg)
	{
	return ds2780_read8(dev_info, control_reg, DS2780_CONTROL_REG);
	}

	static int ds2780_set_control_register(struct ds2780_device_info *dev_info,
	u8 control_reg)
	{
	int ret;

	ret = ds2780_write(dev_info, &control_reg,
	DS2780_CONTROL_REG, sizeof(u8));
	if (ret < 0)
	return ret;

	return ds2780_save_eeprom(dev_info, DS2780_CONTROL_REG);
	}

	static int ds2780_battery_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	int ret = 0;
	struct ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	switch (psp) {
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	ret = ds2780_get_voltage(dev_info, &val->intval);
	break;

	case POWER_SUPPLY_PROP_TEMP:
	ret = ds2780_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 = ds2780_get_current(dev_info, CURRENT_NOW, &val->intval);
	break;

	case POWER_SUPPLY_PROP_CURRENT_AVG:
	ret = ds2780_get_current(dev_info, CURRENT_AVG, &val->intval);
	break;

	case POWER_SUPPLY_PROP_STATUS:
	ret = ds2780_get_status(dev_info, &val->intval);
	break;

	case POWER_SUPPLY_PROP_CAPACITY:
	ret = ds2780_get_capacity(dev_info, &val->intval);
	break;

	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
	ret = ds2780_get_accumulated_current(dev_info, &val->intval);
	break;

	case POWER_SUPPLY_PROP_CHARGE_NOW:
	ret = ds2780_get_charge_now(dev_info, &val->intval);
	break;

	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static enum power_supply_property ds2780_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 ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	/* Get power mode */
	ret = ds2780_get_control_register(dev_info, &control_reg);
	if (ret < 0)
	return ret;

	return sprintf(buf, "%d\n",
	!!(control_reg & DS2780_CONTROL_REG_PMOD));
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	/* Set power mode */
	ret = ds2780_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 \|= DS2780_CONTROL_REG_PMOD;
	else
	control_reg &= ~DS2780_CONTROL_REG_PMOD;

	ret = ds2780_set_control_register(dev_info, control_reg);
	if (ret < 0)
	return ret;

	return count;
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	ret = ds2780_read8(dev_info, &sense_resistor, DS2780_RSNSP_REG);
	if (ret < 0)
	return ret;

	ret = sprintf(buf, "%d\n", sense_resistor);
	return ret;
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	ret = kstrtou8(buf, 0, &new_setting);
	if (ret < 0)
	return ret;

	ret = ds2780_set_sense_register(dev_info, new_setting);
	if (ret < 0)
	return ret;

	return count;
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	ret = ds2780_get_rsgain_register(dev_info, &rsgain);
	if (ret < 0)
	return ret;

	return sprintf(buf, "%d\n", rsgain);
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_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 = ds2780_set_rsgain_register(dev_info, new_setting);
	if (ret < 0)
	return ret;

	return count;
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	ret = ds2780_read8(dev_info, &sfr, DS2780_SFR_REG);
	if (ret < 0)
	return ret;

	ret = sprintf(buf, "%d\n", sfr & DS2780_SFR_REG_PIOSC);
	return ret;
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_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 = ds2780_write(dev_info, &new_setting,
	DS2780_SFR_REG, sizeof(u8));
	if (ret < 0)
	return ret;

	return count;
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	count = min_t(loff_t, count,
	DS2780_EEPROM_BLOCK1_END -
	DS2780_EEPROM_BLOCK1_START + 1 - off);

	return ds2780_read_block(dev_info, buf,
	DS2780_EEPROM_BLOCK1_START + off, count);
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);
	int ret;

	count = min_t(loff_t, count,
	DS2780_EEPROM_BLOCK1_END -
	DS2780_EEPROM_BLOCK1_START + 1 - off);

	ret = ds2780_write(dev_info, buf,
	DS2780_EEPROM_BLOCK1_START + off, count);
	if (ret < 0)
	return ret;

	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK1_START);
	if (ret < 0)
	return ret;

	return count;
	}

	static struct bin_attribute ds2780_param_eeprom_bin_attr = {
	.attr = {
	.name = "param_eeprom",
	.mode = S_IRUGO \| S_IWUSR,
	},
	.size = DS2780_EEPROM_BLOCK1_END - DS2780_EEPROM_BLOCK1_START + 1,
	.read = ds2780_read_param_eeprom_bin,
	.write = ds2780_write_param_eeprom_bin,
	};

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);

	count = min_t(loff_t, count,
	DS2780_EEPROM_BLOCK0_END -
	DS2780_EEPROM_BLOCK0_START + 1 - off);

	return ds2780_read_block(dev_info, buf,
	DS2780_EEPROM_BLOCK0_START + off, count);
	}

	static ssize_t ds2780_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 ds2780_device_info *dev_info = to_ds2780_device_info(psy);
	int ret;

	count = min_t(loff_t, count,
	DS2780_EEPROM_BLOCK0_END -
	DS2780_EEPROM_BLOCK0_START + 1 - off);

	ret = ds2780_write(dev_info, buf,
	DS2780_EEPROM_BLOCK0_START + off, count);
	if (ret < 0)
	return ret;

	ret = ds2780_save_eeprom(dev_info, DS2780_EEPROM_BLOCK0_START);
	if (ret < 0)
	return ret;

	return count;
	}

	static struct bin_attribute ds2780_user_eeprom_bin_attr = {
	.attr = {
	.name = "user_eeprom",
	.mode = S_IRUGO \| S_IWUSR,
	},
	.size = DS2780_EEPROM_BLOCK0_END - DS2780_EEPROM_BLOCK0_START + 1,
	.read = ds2780_read_user_eeprom_bin,
	.write = ds2780_write_user_eeprom_bin,
	};

	static DEVICE_ATTR(pmod_enabled, S_IRUGO \| S_IWUSR, ds2780_get_pmod_enabled,
	ds2780_set_pmod_enabled);
	static DEVICE_ATTR(sense_resistor_value, S_IRUGO \| S_IWUSR,
	ds2780_get_sense_resistor_value, ds2780_set_sense_resistor_value);
	static DEVICE_ATTR(rsgain_setting, S_IRUGO \| S_IWUSR, ds2780_get_rsgain_setting,
	ds2780_set_rsgain_setting);
	static DEVICE_ATTR(pio_pin, S_IRUGO \| S_IWUSR, ds2780_get_pio_pin,
	ds2780_set_pio_pin);


	static struct attribute *ds2780_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 ds2780_attr_group = {
	.attrs = ds2780_attributes,
	};

	static int __devinit ds2780_battery_probe(struct platform_device *pdev)
	{
	int ret = 0;
	struct ds2780_device_info *dev_info;

	dev_info = kzalloc(sizeof(*dev_info), GFP_KERNEL);
	if (!dev_info) {
	ret = -ENOMEM;
	goto fail;
	}

	platform_set_drvdata(pdev, dev_info);

	dev_info->dev = &pdev->dev;
	dev_info->w1_dev = pdev->dev.parent;
	dev_info->bat.name = dev_name(&pdev->dev);
	dev_info->bat.type = POWER_SUPPLY_TYPE_BATTERY;
	dev_info->bat.properties = ds2780_battery_props;
	dev_info->bat.num_properties = ARRAY_SIZE(ds2780_battery_props);
	dev_info->bat.get_property = ds2780_battery_get_property;

	ret = power_supply_register(&pdev->dev, &dev_info->bat);
	if (ret) {
	dev_err(dev_info->dev, "failed to register battery\n");
	goto fail_free_info;
	}

	ret = sysfs_create_group(&dev_info->bat.dev->kobj, &ds2780_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,
	&ds2780_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,
	&ds2780_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,
	&ds2780_param_eeprom_bin_attr);
	fail_remove_group:
	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);
	fail_unregister:
	power_supply_unregister(&dev_info->bat);
	fail_free_info:
	kfree(dev_info);
	fail:
	return ret;
	}

	static int __devexit ds2780_battery_remove(struct platform_device *pdev)
	{
	struct ds2780_device_info *dev_info = platform_get_drvdata(pdev);

	/* remove attributes */
	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);

	power_supply_unregister(&dev_info->bat);

	kfree(dev_info);
	return 0;
	}

	static struct platform_driver ds2780_battery_driver = {
	.driver = {
	.name = "ds2780-battery",
	},
	.probe = ds2780_battery_probe,
	.remove = __devexit_p(ds2780_battery_remove),
	};

	module_platform_driver(ds2780_battery_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
	MODULE_DESCRIPTION("Maxim/Dallas DS2780 Stand-Alone Fuel Gauage IC driver");
	MODULE_ALIAS("platform:ds2780-battery");