/*
* 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");
