HID: hid-input: add support for HID devices reporting Battery Strength
Some HID devices, such as my Bluetooth mouse, report their battery
strength as an event. Rather than passing it through as a strange
absolute input event, this patch registers it with the power_supply
subsystem as a battery, so that the device's Battery Strength can be
reported to usermode.
The battery appears in sysfs names
/sys/class/power_supply/hid-<UNIQ>-battery, and it is a child of the
battery-containing device, so it should be clear what it's the battery of.
Unfortunately on my current Fedora 16 system, while the battery does
appear in the UI, it is listed as a Laptop Battery with 0% charge (since
it ignores the "capacity" property of the battery and instead computes
it from the "energy*" fields, which we can't supply given the limited
information contained within the HID Report).
Still, this patch is the first step.
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/linux/hid.h b/include/linux/hid.h
index deed5f9..7f344c3 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -72,6 +72,7 @@
#include <linux/workqueue.h>
#include <linux/input.h>
#include <linux/semaphore.h>
+#include <linux/power_supply.h>
/*
* We parse each description item into this structure. Short items data
@@ -190,6 +191,7 @@
#define HID_UP_UNDEFINED 0x00000000
#define HID_UP_GENDESK 0x00010000
#define HID_UP_SIMULATION 0x00020000
+#define HID_UP_GENDEVCTRLS 0x00060000
#define HID_UP_KEYBOARD 0x00070000
#define HID_UP_LED 0x00080000
#define HID_UP_BUTTON 0x00090000
@@ -239,6 +241,8 @@
#define HID_GD_RIGHT 0x00010092
#define HID_GD_LEFT 0x00010093
+#define HID_DC_BATTERYSTRENGTH 0x00060020
+
#define HID_DG_DIGITIZER 0x000d0001
#define HID_DG_PEN 0x000d0002
#define HID_DG_LIGHTPEN 0x000d0003
@@ -482,6 +486,18 @@
struct hid_driver *driver;
struct hid_ll_driver *ll_driver;
+#ifdef CONFIG_HID_BATTERY_STRENGTH
+ /*
+ * Power supply information for HID devices which report
+ * battery strength. power_supply is registered iff
+ * battery.name is non-NULL.
+ */
+ struct power_supply battery;
+ __s32 battery_min;
+ __s32 battery_max;
+ __s32 battery_val;
+#endif
+
unsigned int status; /* see STAT flags above */
unsigned claimed; /* Claimed by hidinput, hiddev? */
unsigned quirks; /* Various quirks the device can pull on us */