[220/289] ACPI battery: support percentage battery remaining capacity

Greg KH
2010-12-08T01:03:19Z

From: Zhang Rui <rui.zhang@intel.com>

commit 557d58687dcdee6bc00c1a8f1fd4e0eac8fefce9 upstream.

According to the ACPI spec, some kinds of primary battery can
report percentage battery remaining capacity directly to OS.

In this case, it reports the LastFullChargedCapacity == 100,
BatteryPresentRate = 0xFFFFFFFF, and BatteryRemaingCapacity a
percentage value, which actually means RemainingBatteryPercentage.

Now we found some battery follows this rule even if it's a rechargeable.
https://bugzilla.kernel.org/show_bug.cgi?id=15979

Handle these batteries correctly in ACPI battery driver
so that they won't break userspace.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/acpi/battery.c | 38 +++++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)

--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -98,6 +98,7 @@ enum {
* due to bad math.
*/
ACPI_BATTERY_QUIRK_SIGNED16_CURRENT,
+ ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
};

struct acpi_battery {
@@ -412,6 +413,8 @@ static int acpi_battery_get_info(struct
result = extract_package(battery, buffer.pointer,
info_offsets, ARRAY_SIZE(info_offsets));
kfree(buffer.pointer);
+ if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
+ battery->full_charge_capacity = battery->design_capacity;
return result;
}

@@ -448,6 +451,10 @@ static int acpi_battery_get_state(struct
battery->rate_now != -1)
battery->rate_now = abs((s16)battery->rate_now);

+ if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
+ && battery->capacity_now >= 0 && battery->capacity_now <= 100)
+ battery->capacity_now = (battery->capacity_now *
+ battery->full_charge_capacity) / 100;
return result;
}

@@ -561,6 +568,33 @@ static void acpi_battery_quirks(struct a
}
}

+/*
+ * According to the ACPI spec, some kinds of primary batteries can
+ * report percentage battery remaining capacity directly to OS.
+ * In this case, it reports the Last Full Charged Capacity == 100
+ * and BatteryPresentRate == 0xFFFFFFFF.
+ *
+ * Now we found some battery reports percentage remaining capacity
+ * even if it's rechargeable.
+ * https://bugzilla.kernel.org/show_bug.cgi?id=15979
+ *
+ * Handle this correctly so that they won't break userspace.
+ */
+static void acpi_battery_quirks2(struct acpi_battery *battery)
+{
+ if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
+ return ;
+
+ if (battery->full_charge_capacity == 100 &&
+ battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
+ battery->capacity_now >=0 && battery->capacity_now <= 100) {
+ set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
+ battery->full_charge_capacity = battery->design_capacity;
+ battery->capacity_now = (battery->capacity_now *
+ battery->full_charge_capacity) / 100;
+ }
+}
+
static int acpi_battery_update(struct acpi_battery *battery)
{
int result, old_present = acpi_battery_present(battery);
@@ -586,7 +620,9 @@ static int acpi_battery_update(struct ac
if (!battery->bat.dev)
sysfs_add_battery(battery);
#endif
- return acpi_battery_get_state(battery);
+ result = acpi_battery_get_state(battery);
+ acpi_battery_quirks2(battery);
+ return result;
}

/* --------------------------------------------------------------------------