[PATCH] HID: input: Finish TransducerSerialNumber implementation

[Jason Gerecke <killertofu@gmail.com>]

The commit which introduced TransducerSerialNumber (368c966) is missing
two crucial implementation details. Firstly, the commit does not set the
type/code/bit/max fields as expected later down the code which can cause
the driver to crash when a tablet with this usage is connected. Secondly,
the code to send a MSC_SERIAL event to userspace when this usage is seen
in a report is nowhere to be found. This commit addresses both issues.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
---
 drivers/hid/hid-input.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 2619f7f..abed624 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -690,6 +690,10 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 
 		case 0x5b: /* TransducerSerialNumber */
 			set_bit(MSC_SERIAL, input->mscbit);
+			usage->type = EV_MSC;
+			usage->code = MSC_SERIAL;
+			bit = input->mscbit;
+			max = MSC_MAX;
 			break;
 
 		default:  goto unknown;
@@ -1041,6 +1045,11 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
 		input_event(input, EV_KEY, BTN_TOUCH, value > a + ((b - a) >> 3));
 	}
 
+	if (usage->hid == (HID_UP_DIGITIZER | 0x005b)) { /* TransducerSerialNumber */
+		input_event(input, EV_MSC, MSC_SERIAL, value);
+		return;
+	}
+
 	if (usage->hid == (HID_UP_PID | 0x83UL)) { /* Simultaneous Effects Max */
 		dbg_hid("Maximum Effects - %d\n",value);
 		return;
-- 
2.1.0