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

 /*
  * Battery driver for One Laptop Per Child board.
  *
  *	Copyright © 2006  David Woodhouse <dwmw2@infradead.org>
  *
  * 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/err.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/jiffies.h>
 #include <linux/sched.h>
 #include <asm/olpc.h>


 #define EC_BAT_VOLTAGE	0x10	/* uint16_t,	*9.76/32,    mV   */
 #define EC_BAT_CURRENT	0x11	/* int16_t,	*15.625/120, mA   */
 #define EC_BAT_ACR	0x12
 #define EC_BAT_TEMP	0x13	/* uint16_t,	*100/256,   °C  */
 #define EC_AMB_TEMP	0x14	/* uint16_t,	*100/256,   °C  */
 #define EC_BAT_STATUS	0x15	/* uint8_t,	bitmask */
 #define EC_BAT_SOC	0x16	/* uint8_t,	percentage */
 #define EC_BAT_SERIAL	0x17	/* uint8_t[6] */
 #define EC_BAT_EEPROM	0x18	/* uint8_t adr as input, uint8_t output */
 #define EC_BAT_ERRCODE	0x1f	/* uint8_t,	bitmask */

 #define BAT_STAT_PRESENT	0x01
 #define BAT_STAT_FULL		0x02
 #define BAT_STAT_LOW		0x04
 #define BAT_STAT_DESTROY	0x08
 #define BAT_STAT_AC		0x10
 #define BAT_STAT_CHARGING	0x20
 #define BAT_STAT_DISCHARGING	0x40

 #define BAT_ERR_INFOFAIL	0x02
 #define BAT_ERR_OVERVOLTAGE	0x04
 #define BAT_ERR_OVERTEMP	0x05
 #define BAT_ERR_GAUGESTOP	0x06
 #define BAT_ERR_OUT_OF_CONTROL	0x07
 #define BAT_ERR_ID_FAIL		0x09
 #define BAT_ERR_ACR_FAIL	0x10

 #define BAT_ADDR_MFR_TYPE	0x5F

 /*********************************************************************
  *		Power
  *********************************************************************/

 static int olpc_ac_get_prop(struct power_supply *psy,
 			    enum power_supply_property psp,
 			    union power_supply_propval *val)
 {
 	int ret = 0;
 	uint8_t status;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_ONLINE:
 		ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 		if (ret)
 			return ret;

 		val->intval = !!(status & BAT_STAT_AC);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}
 	return ret;
 }

 static enum power_supply_property olpc_ac_props[] = {
 	POWER_SUPPLY_PROP_ONLINE,
 };

 static struct power_supply olpc_ac = {
 	.name = "olpc-ac",
 	.type = POWER_SUPPLY_TYPE_MAINS,
 	.properties = olpc_ac_props,
 	.num_properties = ARRAY_SIZE(olpc_ac_props),
 	.get_property = olpc_ac_get_prop,
 };

 /*********************************************************************
  *		Battery properties
  *********************************************************************/
 static int olpc_bat_get_property(struct power_supply *psy,
 				 enum power_supply_property psp,
 				 union power_supply_propval *val)
 {
 	int ret = 0;
 	int16_t ec_word;
 	uint8_t ec_byte;

 	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
 	if (ret)
 		return ret;

 	/* Theoretically there's a race here -- the battery could be
 	   removed immediately after we check whether it's present, and
 	   then we query for some other property of the now-absent battery.
 	   It doesn't matter though -- the EC will return the last-known
 	   information, and it's as if we just ran that _little_ bit faster
 	   and managed to read it out before the battery went away. */
 	if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
 		return -ENODEV;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		if (olpc_platform_info.ecver > 0x44) {
 			if (ec_byte & BAT_STAT_CHARGING)
 				val->intval = POWER_SUPPLY_STATUS_CHARGING;
 			else if (ec_byte & BAT_STAT_DISCHARGING)
 				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 			else if (ec_byte & BAT_STAT_FULL)
 				val->intval = POWER_SUPPLY_STATUS_FULL;
 			else /* er,... */
 				val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 		} else {
 			/* Older EC didn't report charge/discharge bits */
 			if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
 				val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
 			else if (ec_byte & BAT_STAT_FULL)
 				val->intval = POWER_SUPPLY_STATUS_FULL;
 			else /* Not _necessarily_ true but EC doesn't tell all yet */
 				val->intval = POWER_SUPPLY_STATUS_CHARGING;
 			break;
 		}
 	case POWER_SUPPLY_PROP_PRESENT:
 		val->intval = !!(ec_byte & BAT_STAT_PRESENT);
 		break;

 	case POWER_SUPPLY_PROP_HEALTH:
 		if (ec_byte & BAT_STAT_DESTROY)
 			val->intval = POWER_SUPPLY_HEALTH_DEAD;
 		else {
 			ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
 			if (ret)
 				return ret;

 			switch (ec_byte) {
 			case 0:
 				val->intval = POWER_SUPPLY_HEALTH_GOOD;
 				break;

 			case BAT_ERR_OVERTEMP:
 				val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
 				break;

 			case BAT_ERR_OVERVOLTAGE:
 				val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 				break;

 			case BAT_ERR_INFOFAIL:
 			case BAT_ERR_OUT_OF_CONTROL:
 			case BAT_ERR_ID_FAIL:
 			case BAT_ERR_ACR_FAIL:
 				val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
 				break;

 			default:
 				/* Eep. We don't know this failure code */
 				return -EIO;
 			}
 		}
 		break;

 	case POWER_SUPPLY_PROP_MANUFACTURER:
 		ec_byte = BAT_ADDR_MFR_TYPE;
 		ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 		if (ret)
 			return ret;

 		switch (ec_byte >> 4) {
 		case 1:
 			val->strval = "Gold Peak";
 			break;
 		case 2:
 			val->strval = "BYD";
 			break;
 		default:
 			val->strval = "Unknown";
 			break;
 		}
 		break;
 	case POWER_SUPPLY_PROP_TECHNOLOGY:
 		ec_byte = BAT_ADDR_MFR_TYPE;
 		ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
 		if (ret)
 			return ret;

 		switch (ec_byte & 0xf) {
 		case 1:
 			val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
 			break;
 		case 2:
 			val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
 			break;
 		default:
 			val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 			break;
 		}
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 		ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;

 		ec_word = be16_to_cpu(ec_word);
 		val->intval = ec_word * 9760L / 32;
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_AVG:
 		ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;

 		ec_word = be16_to_cpu(ec_word);
 		val->intval = ec_word * 15625L / 120;
 		break;
 	case POWER_SUPPLY_PROP_CAPACITY:
 		ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
 		if (ret)
 			return ret;
 		val->intval = ec_byte;
 		break;
 	case POWER_SUPPLY_PROP_TEMP:
 		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;
 		ec_word = be16_to_cpu(ec_word);
 		val->intval = ec_word * 100 / 256;
 		break;
 	case POWER_SUPPLY_PROP_TEMP_AMBIENT:
 		ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;

 		ec_word = be16_to_cpu(ec_word);
 		val->intval = ec_word * 100 / 256;
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	return ret;
 }

 static enum power_supply_property olpc_bat_props[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_HEALTH,
 	POWER_SUPPLY_PROP_TECHNOLOGY,
 	POWER_SUPPLY_PROP_VOLTAGE_AVG,
 	POWER_SUPPLY_PROP_CURRENT_AVG,
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_TEMP_AMBIENT,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 };

 /*********************************************************************
  *		Initialisation
  *********************************************************************/

 static struct platform_device *bat_pdev;

 static struct power_supply olpc_bat = {
 	.properties = olpc_bat_props,
 	.num_properties = ARRAY_SIZE(olpc_bat_props),
 	.get_property = olpc_bat_get_property,
 	.use_for_apm = 1,
 };

 void olpc_battery_trigger_uevent(unsigned long cause)
 {
 	if (cause & EC_SCI_SRC_ACPWR)
 		kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
 	if (cause & (EC_SCI_SRC_BATERR|EC_SCI_SRC_BATSOC|EC_SCI_SRC_BATTERY))
 		kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
 }

 static int __init olpc_bat_init(void)
 {
 	int ret = 0;
 	uint8_t status;

 	if (!olpc_platform_info.ecver)
 		return -ENXIO;
 	if (olpc_platform_info.ecver < 0x43) {
 		printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver);
 		return -ENXIO;
 	}

 	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
 	if (ret)
 		return ret;

 	/* Ignore the status. It doesn't actually matter */

 	bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
 	if (IS_ERR(bat_pdev))
 		return PTR_ERR(bat_pdev);

 	ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
 	if (ret)
 		goto ac_failed;

 	olpc_bat.name = bat_pdev->name;

 	ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
 	if (ret)
 		goto battery_failed;

 	olpc_register_battery_callback(&olpc_battery_trigger_uevent);
 	goto success;

 battery_failed:
 	power_supply_unregister(&olpc_ac);
 ac_failed:
 	platform_device_unregister(bat_pdev);
 success:
 	return ret;
 }

 static void __exit olpc_bat_exit(void)
 {
 	olpc_deregister_battery_callback();
 	power_supply_unregister(&olpc_bat);
 	power_supply_unregister(&olpc_ac);
 	platform_device_unregister(bat_pdev);
 }

 module_init(olpc_bat_init);
 module_exit(olpc_bat_exit);

 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");
	/*
	* Battery driver for One Laptop Per Child board.
	*
	* Copyright © 2006 David Woodhouse <dwmw2@infradead.org>
	*
	* 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/err.h>
	#include <linux/platform_device.h>
	#include <linux/power_supply.h>
	#include <linux/jiffies.h>
	#include <linux/sched.h>
	#include <asm/olpc.h>


	#define EC_BAT_VOLTAGE 0x10 /* uint16_t, 9.76/32, mV /
	#define EC_BAT_CURRENT 0x11 /* int16_t, 15.625/120, mA /
	#define EC_BAT_ACR 0x12
	#define EC_BAT_TEMP 0x13 /* uint16_t, 100/256, °C /
	#define EC_AMB_TEMP 0x14 /* uint16_t, 100/256, °C /
	#define EC_BAT_STATUS 0x15 /* uint8_t, bitmask */
	#define EC_BAT_SOC 0x16 /* uint8_t, percentage */
	#define EC_BAT_SERIAL 0x17 /* uint8_t[6] */
	#define EC_BAT_EEPROM 0x18 /* uint8_t adr as input, uint8_t output */
	#define EC_BAT_ERRCODE 0x1f /* uint8_t, bitmask */

	#define BAT_STAT_PRESENT 0x01
	#define BAT_STAT_FULL 0x02
	#define BAT_STAT_LOW 0x04
	#define BAT_STAT_DESTROY 0x08
	#define BAT_STAT_AC 0x10
	#define BAT_STAT_CHARGING 0x20
	#define BAT_STAT_DISCHARGING 0x40

	#define BAT_ERR_INFOFAIL 0x02
	#define BAT_ERR_OVERVOLTAGE 0x04
	#define BAT_ERR_OVERTEMP 0x05
	#define BAT_ERR_GAUGESTOP 0x06
	#define BAT_ERR_OUT_OF_CONTROL 0x07
	#define BAT_ERR_ID_FAIL 0x09
	#define BAT_ERR_ACR_FAIL 0x10

	#define BAT_ADDR_MFR_TYPE 0x5F

	/*********************************************************************
	* Power
	*********************************************************************/

	static int olpc_ac_get_prop(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	int ret = 0;
	uint8_t status;

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
	if (ret)
	return ret;

	val->intval = !!(status & BAT_STAT_AC);
	break;
	default:
	ret = -EINVAL;
	break;
	}
	return ret;
	}

	static enum power_supply_property olpc_ac_props[] = {
	POWER_SUPPLY_PROP_ONLINE,
	};

	static struct power_supply olpc_ac = {
	.name = "olpc-ac",
	.type = POWER_SUPPLY_TYPE_MAINS,
	.properties = olpc_ac_props,
	.num_properties = ARRAY_SIZE(olpc_ac_props),
	.get_property = olpc_ac_get_prop,
	};

	/*********************************************************************
	* Battery properties
	*********************************************************************/
	static int olpc_bat_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	int ret = 0;
	int16_t ec_word;
	uint8_t ec_byte;

	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &ec_byte, 1);
	if (ret)
	return ret;

	/* Theoretically there's a race here -- the battery could be
	removed immediately after we check whether it's present, and
	then we query for some other property of the now-absent battery.
	It doesn't matter though -- the EC will return the last-known
	information, and it's as if we just ran that _little_ bit faster
	and managed to read it out before the battery went away. */
	if (!(ec_byte & BAT_STAT_PRESENT) && psp != POWER_SUPPLY_PROP_PRESENT)
	return -ENODEV;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	if (olpc_platform_info.ecver > 0x44) {
	if (ec_byte & BAT_STAT_CHARGING)
	val->intval = POWER_SUPPLY_STATUS_CHARGING;
	else if (ec_byte & BAT_STAT_DISCHARGING)
	val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
	else if (ec_byte & BAT_STAT_FULL)
	val->intval = POWER_SUPPLY_STATUS_FULL;
	else /* er,... */
	val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
	} else {
	/* Older EC didn't report charge/discharge bits */
	if (!(ec_byte & BAT_STAT_AC)) /* No AC means discharging */
	val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
	else if (ec_byte & BAT_STAT_FULL)
	val->intval = POWER_SUPPLY_STATUS_FULL;
	else /* Not _necessarily_ true but EC doesn't tell all yet */
	val->intval = POWER_SUPPLY_STATUS_CHARGING;
	break;
	}
	case POWER_SUPPLY_PROP_PRESENT:
	val->intval = !!(ec_byte & BAT_STAT_PRESENT);
	break;

	case POWER_SUPPLY_PROP_HEALTH:
	if (ec_byte & BAT_STAT_DESTROY)
	val->intval = POWER_SUPPLY_HEALTH_DEAD;
	else {
	ret = olpc_ec_cmd(EC_BAT_ERRCODE, NULL, 0, &ec_byte, 1);
	if (ret)
	return ret;

	switch (ec_byte) {
	case 0:
	val->intval = POWER_SUPPLY_HEALTH_GOOD;
	break;

	case BAT_ERR_OVERTEMP:
	val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
	break;

	case BAT_ERR_OVERVOLTAGE:
	val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
	break;

	case BAT_ERR_INFOFAIL:
	case BAT_ERR_OUT_OF_CONTROL:
	case BAT_ERR_ID_FAIL:
	case BAT_ERR_ACR_FAIL:
	val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
	break;

	default:
	/* Eep. We don't know this failure code */
	return -EIO;
	}
	}
	break;

	case POWER_SUPPLY_PROP_MANUFACTURER:
	ec_byte = BAT_ADDR_MFR_TYPE;
	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
	if (ret)
	return ret;

	switch (ec_byte >> 4) {
	case 1:
	val->strval = "Gold Peak";
	break;
	case 2:
	val->strval = "BYD";
	break;
	default:
	val->strval = "Unknown";
	break;
	}
	break;
	case POWER_SUPPLY_PROP_TECHNOLOGY:
	ec_byte = BAT_ADDR_MFR_TYPE;
	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &ec_byte, 1);
	if (ret)
	return ret;

	switch (ec_byte & 0xf) {
	case 1:
	val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
	break;
	case 2:
	val->intval = POWER_SUPPLY_TECHNOLOGY_LiFe;
	break;
	default:
	val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
	break;
	}
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
	ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;

	ec_word = be16_to_cpu(ec_word);
	val->intval = ec_word * 9760L / 32;
	break;
	case POWER_SUPPLY_PROP_CURRENT_AVG:
	ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;

	ec_word = be16_to_cpu(ec_word);
	val->intval = ec_word * 15625L / 120;
	break;
	case POWER_SUPPLY_PROP_CAPACITY:
	ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &ec_byte, 1);
	if (ret)
	return ret;
	val->intval = ec_byte;
	break;
	case POWER_SUPPLY_PROP_TEMP:
	ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;
	ec_word = be16_to_cpu(ec_word);
	val->intval = ec_word * 100 / 256;
	break;
	case POWER_SUPPLY_PROP_TEMP_AMBIENT:
	ret = olpc_ec_cmd(EC_AMB_TEMP, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;

	ec_word = be16_to_cpu(ec_word);
	val->intval = ec_word * 100 / 256;
	break;
	default:
	ret = -EINVAL;
	break;
	}

	return ret;
	}

	static enum power_supply_property olpc_bat_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_VOLTAGE_AVG,
	POWER_SUPPLY_PROP_CURRENT_AVG,
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_TEMP_AMBIENT,
	POWER_SUPPLY_PROP_MANUFACTURER,
	};

	/*********************************************************************
	* Initialisation
	*********************************************************************/

	static struct platform_device *bat_pdev;

	static struct power_supply olpc_bat = {
	.properties = olpc_bat_props,
	.num_properties = ARRAY_SIZE(olpc_bat_props),
	.get_property = olpc_bat_get_property,
	.use_for_apm = 1,
	};

	void olpc_battery_trigger_uevent(unsigned long cause)
	{
	if (cause & EC_SCI_SRC_ACPWR)
	kobject_uevent(&olpc_ac.dev->kobj, KOBJ_CHANGE);
	if (cause & (EC_SCI_SRC_BATERR\|EC_SCI_SRC_BATSOC\|EC_SCI_SRC_BATTERY))
	kobject_uevent(&olpc_bat.dev->kobj, KOBJ_CHANGE);
	}

	static int __init olpc_bat_init(void)
	{
	int ret = 0;
	uint8_t status;

	if (!olpc_platform_info.ecver)
	return -ENXIO;
	if (olpc_platform_info.ecver < 0x43) {
	printk(KERN_NOTICE "OLPC EC version 0x%02x too old for battery driver.\n", olpc_platform_info.ecver);
	return -ENXIO;
	}

	ret = olpc_ec_cmd(EC_BAT_STATUS, NULL, 0, &status, 1);
	if (ret)
	return ret;

	/* Ignore the status. It doesn't actually matter */

	bat_pdev = platform_device_register_simple("olpc-battery", 0, NULL, 0);
	if (IS_ERR(bat_pdev))
	return PTR_ERR(bat_pdev);

	ret = power_supply_register(&bat_pdev->dev, &olpc_ac);
	if (ret)
	goto ac_failed;

	olpc_bat.name = bat_pdev->name;

	ret = power_supply_register(&bat_pdev->dev, &olpc_bat);
	if (ret)
	goto battery_failed;

	olpc_register_battery_callback(&olpc_battery_trigger_uevent);
	goto success;

	battery_failed:
	power_supply_unregister(&olpc_ac);
	ac_failed:
	platform_device_unregister(bat_pdev);
	success:
	return ret;
	}

	static void __exit olpc_bat_exit(void)
	{
	olpc_deregister_battery_callback();
	power_supply_unregister(&olpc_bat);
	power_supply_unregister(&olpc_ac);
	platform_device_unregister(bat_pdev);
	}

	module_init(olpc_bat_init);
	module_exit(olpc_bat_exit);

	MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Battery driver for One Laptop Per Child 'XO' machine");