HID: input: map battery capacity (00850065)

This is the capacity in percentage, relative to design capacity.
Specifically, it is present in Apple Magic Mouse 2.

In contrast, usage 00850064 is also the capacity in percentage, but is
relative to full capacity. It is not mapped here because I don't have
such device.

Signed-off-by: John Chen <johnchen902@gmail.com>

drivers/hid/hid-debug.c

@@ -417,6 +417,7 @@ static const struct hid_usage_entry hid_usage_table[] = {
     { 0x85, 0x44, "Charging" },
     { 0x85, 0x45, "Discharging" },
     { 0x85, 0x4b, "NeedReplacement" },
+    { 0x85, 0x65, "AbsoluteStateOfCharge" },
     { 0x85, 0x66, "RemainingCapacity" },
     { 0x85, 0x68, "RunTimeToEmpty" },
     { 0x85, 0x6a, "AverageTimeToFull" },

drivers/hid/hid-input.c

@@ -1074,6 +1074,17 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 		}
 		goto unknown;
 
+	case HID_UP_BATTERY:
+		switch (usage->hid) {
+		case HID_BAT_ABSOLUTESTATEOFCHARGE:
+			hidinput_setup_battery(device, HID_INPUT_REPORT, field);
+			usage->type = EV_PWR;
+			device->battery_min = 0;
+			device->battery_max = 100;
+			return;
+		}
+		goto unknown;
+
 	case HID_UP_HPVENDOR:	/* Reported on a Dutch layout HP5308 */
 		set_bit(EV_REP, input->evbit);
 		switch (usage->hid & HID_USAGE) {

include/linux/hid.h

@@ -153,6 +153,7 @@ struct hid_item {
 #define HID_UP_CONSUMER		0x000c0000
 #define HID_UP_DIGITIZER	0x000d0000
 #define HID_UP_PID		0x000f0000
+#define HID_UP_BATTERY		0x00850000
 #define HID_UP_HPVENDOR         0xff7f0000
 #define HID_UP_HPVENDOR2        0xff010000
 #define HID_UP_MSVENDOR		0xff000000
@@ -299,6 +300,8 @@ struct hid_item {
 #define HID_DG_TOOLSERIALNUMBER	0x000d005b
 #define HID_DG_LATENCYMODE	0x000d0060
 
+#define HID_BAT_ABSOLUTESTATEOFCHARGE	0x00850065
+
 #define HID_VD_ASUS_CUSTOM_MEDIA_KEYS	0xff310076
 /*
  * HID report types --- Ouch! HID spec says 1 2 3!