[BATTERY] One Laptop Per Child power/battery driver

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Anton Vorontsov <cbou@mail.ru>

3 files changed, 359 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index 051724f62fa..ab9c3e5a7c1 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -42,4 +42,10 @@ config BATTERY_PMU
 	  Say Y here to expose battery information on Apple machines
 	  through the generic battery class.
 
+config BATTERY_OLPC
+	tristate "One Laptop Per Child battery"
+	depends on X86_32 && OLPC
+	help
+	  Say Y to enable support for the battery on the OLPC laptop.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index a072b0400cd..6413ded5fe5 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_APM_POWER)		+= apm_power.o
 
 obj-$(CONFIG_BATTERY_DS2760)	+= ds2760_battery.o
 obj-$(CONFIG_BATTERY_PMU)	+= pmu_battery.o
+obj-$(CONFIG_BATTERY_OLPC)	+= olpc_battery.o
diff --git a/drivers/power/olpc_battery.c b/drivers/power/olpc_battery.c
new file mode 100644
index 00000000000..878684df766
--- /dev/null
+++ b/drivers/power/olpc_battery.c
@@ -0,0 +1,352 @@
+/*
+ * 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_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_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_CAPACITY_LEVEL,
+	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);
+	return;
+}
+
+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");