HID: Add suport for the brightness control keys on HP keyboards

The keys are found on the keyboards bundled with HP All-In-One machines
with USB VID/PID of 04ca:004d and 04f2:1061.
Signed-off-by: NKeng-Yu Lin <kengyu@canonical.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/hid/hid-input.c

@@ -834,6 +834,15 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 		}
 		break;
 
+	case HID_UP_HPVENDOR2:
+		set_bit(EV_REP, input->evbit);
+		switch (usage->hid & HID_USAGE) {
+		case 0x003: map_key_clear(KEY_BRIGHTNESSDOWN);	break;
+		case 0x004: map_key_clear(KEY_BRIGHTNESSUP);	break;
+		default:    goto ignore;
+		}
+		break;
+
 	case HID_UP_MSVENDOR:
 		goto ignore;
 

include/linux/hid.h

@@ -200,6 +200,7 @@ struct hid_item {
 #define HID_UP_DIGITIZER	0x000d0000
 #define HID_UP_PID		0x000f0000
 #define HID_UP_HPVENDOR         0xff7f0000
+#define HID_UP_HPVENDOR2        0xff010000
 #define HID_UP_MSVENDOR		0xff000000
 #define HID_UP_CUSTOM		0x00ff0000
 #define HID_UP_LOGIVENDOR	0xffbc0000