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

 /*
  * Battery driver for One Laptop Per Child board.
  *
  *	Copyright © 2006-2010  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/kernel.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/err.h>
 #include <linux/device.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	/* int16_t,	*6250/15,    µAh  */
 #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_STAT_TRICKLE	0x80

 #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,
 };

 static char bat_serial[17]; /* Ick */

 static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
 {
 	if (olpc_platform_info.ecver > 0x44) {
 		if (ec_byte & (BAT_STAT_CHARGING | BAT_STAT_TRICKLE))
 			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;
 	}

 	return 0;
 }

 static int olpc_bat_get_health(union power_supply_propval *val)
 {
 	uint8_t ec_byte;
 	int ret;

 	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 */
 		ret = -EIO;
 	}

 	return ret;
 }

 static int olpc_bat_get_mfr(union power_supply_propval *val)
 {
 	uint8_t ec_byte;
 	int ret;

 	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;
 	}

 	return ret;
 }

 static int olpc_bat_get_tech(union power_supply_propval *val)
 {
 	uint8_t ec_byte;
 	int ret;

 	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;
 	}

 	return ret;
 }

 static int olpc_bat_get_charge_full_design(union power_supply_propval *val)
 {
 	uint8_t ec_byte;
 	union power_supply_propval tech;
 	int ret, mfr;

 	ret = olpc_bat_get_tech(&tech);
 	if (ret)
 		return ret;

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

 	mfr = ec_byte >> 4;

 	switch (tech.intval) {
 	case POWER_SUPPLY_TECHNOLOGY_NiMH:
 		switch (mfr) {
 		case 1: /* Gold Peak */
 			val->intval = 3000000*.8;
 			break;
 		default:
 			return -EIO;
 		}
 		break;

 	case POWER_SUPPLY_TECHNOLOGY_LiFe:
 		switch (mfr) {
 		case 1: /* Gold Peak, fall through */
 		case 2: /* BYD */
 			val->intval = 2800000;
 			break;
 		default:
 			return -EIO;
 		}
 		break;

 	default:
 		return -EIO;
 	}

 	return ret;
 }

 static int olpc_bat_get_charge_now(union power_supply_propval *val)
 {
 	uint8_t soc;
 	union power_supply_propval full;
 	int ret;

 	ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &soc, 1);
 	if (ret)
 		return ret;

 	ret = olpc_bat_get_charge_full_design(&full);
 	if (ret)
 		return ret;

 	val->intval = soc * (full.intval / 100);
 	return 0;
 }

 static int olpc_bat_get_voltage_max_design(union power_supply_propval *val)
 {
 	uint8_t ec_byte;
 	union power_supply_propval tech;
 	int mfr;
 	int ret;

 	ret = olpc_bat_get_tech(&tech);
 	if (ret)
 		return ret;

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

 	mfr = ec_byte >> 4;

 	switch (tech.intval) {
 	case POWER_SUPPLY_TECHNOLOGY_NiMH:
 		switch (mfr) {
 		case 1: /* Gold Peak */
 			val->intval = 6000000;
 			break;
 		default:
 			return -EIO;
 		}
 		break;

 	case POWER_SUPPLY_TECHNOLOGY_LiFe:
 		switch (mfr) {
 		case 1: /* Gold Peak */
 			val->intval = 6400000;
 			break;
 		case 2: /* BYD */
 			val->intval = 6500000;
 			break;
 		default:
 			return -EIO;
 		}
 		break;

 	default:
 		return -EIO;
 	}

 	return ret;
 }

 /*********************************************************************
  *		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;
 	__be16 ec_word;
 	uint8_t ec_byte;
 	__be64 ser_buf;

 	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 | BAT_STAT_TRICKLE)) &&
 			psp != POWER_SUPPLY_PROP_PRESENT)
 		return -ENODEV;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		ret = olpc_bat_get_status(val, ec_byte);
 		if (ret)
 			return ret;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
 		if (ec_byte & BAT_STAT_TRICKLE)
 			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
 		else if (ec_byte & BAT_STAT_CHARGING)
 			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
 		else
 			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
 		break;
 	case POWER_SUPPLY_PROP_PRESENT:
 		val->intval = !!(ec_byte & (BAT_STAT_PRESENT |
 					    BAT_STAT_TRICKLE));
 		break;

 	case POWER_SUPPLY_PROP_HEALTH:
 		if (ec_byte & BAT_STAT_DESTROY)
 			val->intval = POWER_SUPPLY_HEALTH_DEAD;
 		else {
 			ret = olpc_bat_get_health(val);
 			if (ret)
 				return ret;
 		}
 		break;

 	case POWER_SUPPLY_PROP_MANUFACTURER:
 		ret = olpc_bat_get_mfr(val);
 		if (ret)
 			return ret;
 		break;
 	case POWER_SUPPLY_PROP_TECHNOLOGY:
 		ret = olpc_bat_get_tech(val);
 		if (ret)
 			return ret;
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;

 		val->intval = (s16)be16_to_cpu(ec_word) * 9760L / 32;
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_AVG:
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 		ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;

 		val->intval = (s16)be16_to_cpu(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_CAPACITY_LEVEL:
 		if (ec_byte & BAT_STAT_FULL)
 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
 		else if (ec_byte & BAT_STAT_LOW)
 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
 		else
 			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 		ret = olpc_bat_get_charge_full_design(val);
 		if (ret)
 			return ret;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_NOW:
 		ret = olpc_bat_get_charge_now(val);
 		if (ret)
 			return ret;
 		break;
 	case POWER_SUPPLY_PROP_TEMP:
 		ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;

 		val->intval = (s16)be16_to_cpu(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;

 		val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
 		ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
 		if (ret)
 			return ret;

 		val->intval = (s16)be16_to_cpu(ec_word) * 6250 / 15;
 		break;
 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 		ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
 		if (ret)
 			return ret;

 		sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
 		val->strval = bat_serial;
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 		ret = olpc_bat_get_voltage_max_design(val);
 		if (ret)
 			return ret;
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	return ret;
 }

 static enum power_supply_property olpc_xo1_bat_props[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_CHARGE_TYPE,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_HEALTH,
 	POWER_SUPPLY_PROP_TECHNOLOGY,
 	POWER_SUPPLY_PROP_VOLTAGE_AVG,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_CURRENT_AVG,
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_TEMP_AMBIENT,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
 };

 /* XO-1.5 does not have ambient temperature property */
 static enum power_supply_property olpc_xo15_bat_props[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_CHARGE_TYPE,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_HEALTH,
 	POWER_SUPPLY_PROP_TECHNOLOGY,
 	POWER_SUPPLY_PROP_VOLTAGE_AVG,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_CURRENT_AVG,
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
 };

 /* EEPROM reading goes completely around the power_supply API, sadly */

 #define EEPROM_START	0x20
 #define EEPROM_END	0x80
 #define EEPROM_SIZE	(EEPROM_END - EEPROM_START)

 static ssize_t olpc_bat_eeprom_read(struct file *filp, struct kobject *kobj,
 		struct bin_attribute *attr, char *buf, loff_t off, size_t count)
 {
 	uint8_t ec_byte;
 	int ret;
 	int i;

 	if (off >= EEPROM_SIZE)
 		return 0;
 	if (off + count > EEPROM_SIZE)
 		count = EEPROM_SIZE - off;

 	for (i = 0; i < count; i++) {
 		ec_byte = EEPROM_START + off + i;
 		ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
 		if (ret) {
 			pr_err("olpc-battery: "
 			       "EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
 			       ec_byte, ret);
 			return -EIO;
 		}
 	}

 	return count;
 }

 static struct bin_attribute olpc_bat_eeprom = {
 	.attr = {
 		.name = "eeprom",
 		.mode = S_IRUGO,
 	},
 	.size = 0,
 	.read = olpc_bat_eeprom_read,
 };

 /* Allow userspace to see the specific error value pulled from the EC */

 static ssize_t olpc_bat_error_read(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	uint8_t ec_byte;
 	ssize_t ret;

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

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

 static struct device_attribute olpc_bat_error = {
 	.attr = {
 		.name = "error",
 		.mode = S_IRUGO,
 	},
 	.show = olpc_bat_error_read,
 };

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

 static struct power_supply olpc_bat = {
 	.name = "olpc-battery",
 	.get_property = olpc_bat_get_property,
 	.use_for_apm = 1,
 };

 static int olpc_battery_suspend(struct platform_device *pdev,
 				pm_message_t state)
 {
 	if (device_may_wakeup(olpc_ac.dev))
 		olpc_ec_wakeup_set(EC_SCI_SRC_ACPWR);
 	else
 		olpc_ec_wakeup_clear(EC_SCI_SRC_ACPWR);

 	if (device_may_wakeup(olpc_bat.dev))
 		olpc_ec_wakeup_set(EC_SCI_SRC_BATTERY | EC_SCI_SRC_BATSOC
 				   | EC_SCI_SRC_BATERR);
 	else
 		olpc_ec_wakeup_clear(EC_SCI_SRC_BATTERY | EC_SCI_SRC_BATSOC
 				     | EC_SCI_SRC_BATERR);

 	return 0;
 }

 static int __devinit olpc_battery_probe(struct platform_device *pdev)
 {
 	int ret;
 	uint8_t status;

 	/*
 	 * We've seen a number of EC protocol changes; this driver requires
 	 * the latest EC protocol, supported by 0x44 and above.
 	 */
 	if (olpc_platform_info.ecver < 0x44) {
 		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 */

 	ret = power_supply_register(&pdev->dev, &olpc_ac);
 	if (ret)
 		return ret;

 	if (olpc_board_at_least(olpc_board_pre(0xd0))) { /* XO-1.5 */
 		olpc_bat.properties = olpc_xo15_bat_props;
 		olpc_bat.num_properties = ARRAY_SIZE(olpc_xo15_bat_props);
 	} else { /* XO-1 */
 		olpc_bat.properties = olpc_xo1_bat_props;
 		olpc_bat.num_properties = ARRAY_SIZE(olpc_xo1_bat_props);
 	}

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

 	ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 	if (ret)
 		goto eeprom_failed;

 	ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
 	if (ret)
 		goto error_failed;

 	if (olpc_ec_wakeup_available()) {
 		device_set_wakeup_capable(olpc_ac.dev, true);
 		device_set_wakeup_capable(olpc_bat.dev, true);
 	}

 	return 0;

 error_failed:
 	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 eeprom_failed:
 	power_supply_unregister(&olpc_bat);
 battery_failed:
 	power_supply_unregister(&olpc_ac);
 	return ret;
 }

 static int __devexit olpc_battery_remove(struct platform_device *pdev)
 {
 	device_remove_file(olpc_bat.dev, &olpc_bat_error);
 	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
 	power_supply_unregister(&olpc_bat);
 	power_supply_unregister(&olpc_ac);
 	return 0;
 }

 static const struct of_device_id olpc_battery_ids[] __devinitconst = {
 	{ .compatible = "olpc,xo1-battery" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, olpc_battery_ids);

 static struct platform_driver olpc_battery_driver = {
 	.driver = {
 		.name = "olpc-battery",
 		.owner = THIS_MODULE,
 		.of_match_table = olpc_battery_ids,
 	},
 	.probe = olpc_battery_probe,
 	.remove = __devexit_p(olpc_battery_remove),
 	.suspend = olpc_battery_suspend,
 };

 module_platform_driver(olpc_battery_driver);

 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 © 2006-2010 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/kernel.h>
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/err.h>
	#include <linux/device.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 /* int16_t, 6250/15, µAh /
	#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_STAT_TRICKLE 0x80

	#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,
	};

	static char bat_serial[17]; /* Ick */

	static int olpc_bat_get_status(union power_supply_propval *val, uint8_t ec_byte)
	{
	if (olpc_platform_info.ecver > 0x44) {
	if (ec_byte & (BAT_STAT_CHARGING \| BAT_STAT_TRICKLE))
	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;
	}

	return 0;
	}

	static int olpc_bat_get_health(union power_supply_propval *val)
	{
	uint8_t ec_byte;
	int ret;

	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 */
	ret = -EIO;
	}

	return ret;
	}

	static int olpc_bat_get_mfr(union power_supply_propval *val)
	{
	uint8_t ec_byte;
	int ret;

	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;
	}

	return ret;
	}

	static int olpc_bat_get_tech(union power_supply_propval *val)
	{
	uint8_t ec_byte;
	int ret;

	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;
	}

	return ret;
	}

	static int olpc_bat_get_charge_full_design(union power_supply_propval *val)
	{
	uint8_t ec_byte;
	union power_supply_propval tech;
	int ret, mfr;

	ret = olpc_bat_get_tech(&tech);
	if (ret)
	return ret;

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

	mfr = ec_byte >> 4;

	switch (tech.intval) {
	case POWER_SUPPLY_TECHNOLOGY_NiMH:
	switch (mfr) {
	case 1: /* Gold Peak */
	val->intval = 3000000*.8;
	break;
	default:
	return -EIO;
	}
	break;

	case POWER_SUPPLY_TECHNOLOGY_LiFe:
	switch (mfr) {
	case 1: /* Gold Peak, fall through */
	case 2: /* BYD */
	val->intval = 2800000;
	break;
	default:
	return -EIO;
	}
	break;

	default:
	return -EIO;
	}

	return ret;
	}

	static int olpc_bat_get_charge_now(union power_supply_propval *val)
	{
	uint8_t soc;
	union power_supply_propval full;
	int ret;

	ret = olpc_ec_cmd(EC_BAT_SOC, NULL, 0, &soc, 1);
	if (ret)
	return ret;

	ret = olpc_bat_get_charge_full_design(&full);
	if (ret)
	return ret;

	val->intval = soc * (full.intval / 100);
	return 0;
	}

	static int olpc_bat_get_voltage_max_design(union power_supply_propval *val)
	{
	uint8_t ec_byte;
	union power_supply_propval tech;
	int mfr;
	int ret;

	ret = olpc_bat_get_tech(&tech);
	if (ret)
	return ret;

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

	mfr = ec_byte >> 4;

	switch (tech.intval) {
	case POWER_SUPPLY_TECHNOLOGY_NiMH:
	switch (mfr) {
	case 1: /* Gold Peak */
	val->intval = 6000000;
	break;
	default:
	return -EIO;
	}
	break;

	case POWER_SUPPLY_TECHNOLOGY_LiFe:
	switch (mfr) {
	case 1: /* Gold Peak */
	val->intval = 6400000;
	break;
	case 2: /* BYD */
	val->intval = 6500000;
	break;
	default:
	return -EIO;
	}
	break;

	default:
	return -EIO;
	}

	return ret;
	}

	/*********************************************************************
	* 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;
	__be16 ec_word;
	uint8_t ec_byte;
	__be64 ser_buf;

	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 \| BAT_STAT_TRICKLE)) &&
	psp != POWER_SUPPLY_PROP_PRESENT)
	return -ENODEV;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	ret = olpc_bat_get_status(val, ec_byte);
	if (ret)
	return ret;
	break;
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
	if (ec_byte & BAT_STAT_TRICKLE)
	val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
	else if (ec_byte & BAT_STAT_CHARGING)
	val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
	else
	val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
	break;
	case POWER_SUPPLY_PROP_PRESENT:
	val->intval = !!(ec_byte & (BAT_STAT_PRESENT \|
	BAT_STAT_TRICKLE));
	break;

	case POWER_SUPPLY_PROP_HEALTH:
	if (ec_byte & BAT_STAT_DESTROY)
	val->intval = POWER_SUPPLY_HEALTH_DEAD;
	else {
	ret = olpc_bat_get_health(val);
	if (ret)
	return ret;
	}
	break;

	case POWER_SUPPLY_PROP_MANUFACTURER:
	ret = olpc_bat_get_mfr(val);
	if (ret)
	return ret;
	break;
	case POWER_SUPPLY_PROP_TECHNOLOGY:
	ret = olpc_bat_get_tech(val);
	if (ret)
	return ret;
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	ret = olpc_ec_cmd(EC_BAT_VOLTAGE, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;

	val->intval = (s16)be16_to_cpu(ec_word) * 9760L / 32;
	break;
	case POWER_SUPPLY_PROP_CURRENT_AVG:
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	ret = olpc_ec_cmd(EC_BAT_CURRENT, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;

	val->intval = (s16)be16_to_cpu(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_CAPACITY_LEVEL:
	if (ec_byte & BAT_STAT_FULL)
	val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
	else if (ec_byte & BAT_STAT_LOW)
	val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
	else
	val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
	break;
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
	ret = olpc_bat_get_charge_full_design(val);
	if (ret)
	return ret;
	break;
	case POWER_SUPPLY_PROP_CHARGE_NOW:
	ret = olpc_bat_get_charge_now(val);
	if (ret)
	return ret;
	break;
	case POWER_SUPPLY_PROP_TEMP:
	ret = olpc_ec_cmd(EC_BAT_TEMP, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;

	val->intval = (s16)be16_to_cpu(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;

	val->intval = (int)be16_to_cpu(ec_word) * 100 / 256;
	break;
	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
	ret = olpc_ec_cmd(EC_BAT_ACR, NULL, 0, (void *)&ec_word, 2);
	if (ret)
	return ret;

	val->intval = (s16)be16_to_cpu(ec_word) * 6250 / 15;
	break;
	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
	ret = olpc_ec_cmd(EC_BAT_SERIAL, NULL, 0, (void *)&ser_buf, 8);
	if (ret)
	return ret;

	sprintf(bat_serial, "%016llx", (long long)be64_to_cpu(ser_buf));
	val->strval = bat_serial;
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
	ret = olpc_bat_get_voltage_max_design(val);
	if (ret)
	return ret;
	break;
	default:
	ret = -EINVAL;
	break;
	}

	return ret;
	}

	static enum power_supply_property olpc_xo1_bat_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_VOLTAGE_AVG,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_CURRENT_AVG,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
	POWER_SUPPLY_PROP_CHARGE_NOW,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_TEMP_AMBIENT,
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	POWER_SUPPLY_PROP_CHARGE_COUNTER,
	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
	};

	/* XO-1.5 does not have ambient temperature property */
	static enum power_supply_property olpc_xo15_bat_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_VOLTAGE_AVG,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_CURRENT_AVG,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
	POWER_SUPPLY_PROP_CHARGE_NOW,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	POWER_SUPPLY_PROP_CHARGE_COUNTER,
	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
	};

	/* EEPROM reading goes completely around the power_supply API, sadly */

	#define EEPROM_START 0x20
	#define EEPROM_END 0x80
	#define EEPROM_SIZE (EEPROM_END - EEPROM_START)

	static ssize_t olpc_bat_eeprom_read(struct file filp, struct kobject kobj,
	struct bin_attribute attr, char buf, loff_t off, size_t count)
	{
	uint8_t ec_byte;
	int ret;
	int i;

	if (off >= EEPROM_SIZE)
	return 0;
	if (off + count > EEPROM_SIZE)
	count = EEPROM_SIZE - off;

	for (i = 0; i < count; i++) {
	ec_byte = EEPROM_START + off + i;
	ret = olpc_ec_cmd(EC_BAT_EEPROM, &ec_byte, 1, &buf[i], 1);
	if (ret) {
	pr_err("olpc-battery: "
	"EC_BAT_EEPROM cmd @ 0x%x failed - %d!\n",
	ec_byte, ret);
	return -EIO;
	}
	}

	return count;
	}

	static struct bin_attribute olpc_bat_eeprom = {
	.attr = {
	.name = "eeprom",
	.mode = S_IRUGO,
	},
	.size = 0,
	.read = olpc_bat_eeprom_read,
	};

	/* Allow userspace to see the specific error value pulled from the EC */

	static ssize_t olpc_bat_error_read(struct device *dev,
	struct device_attribute attr, char buf)
	{
	uint8_t ec_byte;
	ssize_t ret;

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

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

	static struct device_attribute olpc_bat_error = {
	.attr = {
	.name = "error",
	.mode = S_IRUGO,
	},
	.show = olpc_bat_error_read,
	};

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

	static struct power_supply olpc_bat = {
	.name = "olpc-battery",
	.get_property = olpc_bat_get_property,
	.use_for_apm = 1,
	};

	static int olpc_battery_suspend(struct platform_device *pdev,
	pm_message_t state)
	{
	if (device_may_wakeup(olpc_ac.dev))
	olpc_ec_wakeup_set(EC_SCI_SRC_ACPWR);
	else
	olpc_ec_wakeup_clear(EC_SCI_SRC_ACPWR);

	if (device_may_wakeup(olpc_bat.dev))
	olpc_ec_wakeup_set(EC_SCI_SRC_BATTERY \| EC_SCI_SRC_BATSOC
	\| EC_SCI_SRC_BATERR);
	else
	olpc_ec_wakeup_clear(EC_SCI_SRC_BATTERY \| EC_SCI_SRC_BATSOC
	\| EC_SCI_SRC_BATERR);

	return 0;
	}

	static int __devinit olpc_battery_probe(struct platform_device *pdev)
	{
	int ret;
	uint8_t status;

	/*
	* We've seen a number of EC protocol changes; this driver requires
	* the latest EC protocol, supported by 0x44 and above.
	*/
	if (olpc_platform_info.ecver < 0x44) {
	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 */

	ret = power_supply_register(&pdev->dev, &olpc_ac);
	if (ret)
	return ret;

	if (olpc_board_at_least(olpc_board_pre(0xd0))) { /* XO-1.5 */
	olpc_bat.properties = olpc_xo15_bat_props;
	olpc_bat.num_properties = ARRAY_SIZE(olpc_xo15_bat_props);
	} else { /* XO-1 */
	olpc_bat.properties = olpc_xo1_bat_props;
	olpc_bat.num_properties = ARRAY_SIZE(olpc_xo1_bat_props);
	}

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

	ret = device_create_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
	if (ret)
	goto eeprom_failed;

	ret = device_create_file(olpc_bat.dev, &olpc_bat_error);
	if (ret)
	goto error_failed;

	if (olpc_ec_wakeup_available()) {
	device_set_wakeup_capable(olpc_ac.dev, true);
	device_set_wakeup_capable(olpc_bat.dev, true);
	}

	return 0;

	error_failed:
	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
	eeprom_failed:
	power_supply_unregister(&olpc_bat);
	battery_failed:
	power_supply_unregister(&olpc_ac);
	return ret;
	}

	static int __devexit olpc_battery_remove(struct platform_device *pdev)
	{
	device_remove_file(olpc_bat.dev, &olpc_bat_error);
	device_remove_bin_file(olpc_bat.dev, &olpc_bat_eeprom);
	power_supply_unregister(&olpc_bat);
	power_supply_unregister(&olpc_ac);
	return 0;
	}

	static const struct of_device_id olpc_battery_ids[] __devinitconst = {
	{ .compatible = "olpc,xo1-battery" },
	{}
	};
	MODULE_DEVICE_TABLE(of, olpc_battery_ids);

	static struct platform_driver olpc_battery_driver = {
	.driver = {
	.name = "olpc-battery",
	.owner = THIS_MODULE,
	.of_match_table = olpc_battery_ids,
	},
	.probe = olpc_battery_probe,
	.remove = __devexit_p(olpc_battery_remove),
	.suspend = olpc_battery_suspend,
	};

	module_platform_driver(olpc_battery_driver);

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