[BATTERY] One Laptop Per Child power/battery driver
authorDavid Woodhouse <dwmw2@infradead.org>
Thu, 3 May 2007 20:51:18 +0000 (00:51 +0400)
committerDavid Woodhouse <dwmw2@infradead.org>
Tue, 10 Jul 2007 10:28:22 +0000 (11:28 +0100)
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Anton Vorontsov <cbou@mail.ru>
drivers/power/Kconfig
drivers/power/Makefile
drivers/power/olpc_battery.c [new file with mode: 0644]

index 051724f62fa388054ba4f501be87c90661ed888e..ab9c3e5a7c1dae99e905a54de131d28736d42e24 100644 (file)
@@ -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
index a072b0400cdaa636e911efe446fac3979e4ea42e..6413ded5fe5f26d3912af3ff75b324950e2ce12c 100644 (file)
@@ -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 (file)
index 0000000..878684d
--- /dev/null
@@ -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");