[PATCH v3 3/9] HID: multitouch: support getting the contact ID from HID_DG_TRANSDUCER_INDEX fields

Aditya Garg
2024-08-08T13:52:19Z

This is needed to support Apple Touch Bars, where the contact ID is
contained in fields with the HID_DG_TRANSDUCER_INDEX usage.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
drivers/hid/hid-multitouch.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 56fc78841..3e92789ed 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -635,7 +635,9 @@ static struct mt_report_data *mt_allocate_report_data(struct mt_device *td,

if (field->logical == HID_DG_FINGER || td->hdev->group != HID_GROUP_MULTITOUCH_WIN_8) {
for (n = 0; n < field->report_count; n++) {
- if (field->usage[n].hid == HID_DG_CONTACTID) {
+ unsigned int hid = field->usage[n].hid;
+
+ if (hid == HID_DG_CONTACTID || hid == HID_DG_TRANSDUCER_INDEX) {
rdata->is_mt_collection = true;
break;
}
@@ -814,6 +816,7 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
MT_STORE_FIELD(tip_state);
return 1;
case HID_DG_CONTACTID:
+ case HID_DG_TRANSDUCER_INDEX:
MT_STORE_FIELD(contactid);
app->touches_by_report++;
return 1;
--
2.43.0