Commit 9e87f22a authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
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HID: multitouch: detect serial protocol 



Microsoft's documentation about multitouch protocols tells that
if a device presents one touch per report, then it should be treated
as a serial protocol.

Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@enac.fr>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 8d179a9e

drivers/hid/hid-multitouch.c

+13 −0
Original line number Diff line number Diff line
@@ -81,6 +81,9 @@ struct mt_device { 
	__u8 num_received;	/* how many contacts we received */

	__u8 num_expected;	/* expected last contact index */

	__u8 maxcontacts;

	__u8 touches_by_report;	/* how many touches are present in one report:

				* 1 means we should use a serial protocol

				* > 1 means hybrid (multitouch) protocol */

	bool curvalid;		/* is the current contact valid? */

	struct mt_slot *slots;

};
@@ -365,6 +368,7 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi, 
			input_mt_init_slots(hi->input, td->maxcontacts);

			td->last_slot_field = usage->hid;

			td->last_field_index = field->index;

			td->touches_by_report++;

			return 1;

		case HID_DG_WIDTH:

			hid_map_usage(hi, usage, bit, max,
@@ -670,6 +674,15 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id) 
	if (ret)

		goto fail;



	if (!id && td->touches_by_report == 1) {

		/* the device has been sent by hid-generic */

		mtclass = &td->mtclass;

		mtclass->quirks |= MT_QUIRK_ALWAYS_VALID;

		mtclass->quirks &= ~MT_QUIRK_NOT_SEEN_MEANS_UP;

		mtclass->quirks &= ~MT_QUIRK_VALID_IS_INRANGE;

		mtclass->quirks &= ~MT_QUIRK_VALID_IS_CONFIDENCE;

	}



	td->slots = kzalloc(td->maxcontacts * sizeof(struct mt_slot),

				GFP_KERNEL);

	if (!td->slots) {