[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");