HID: hid-multitouch: Filter collections by application usage.

This change fixes two problems.

First, it ensures that the hid-multitouch driver does not incorrectly
map GenericDesktop usages that are intended for other applications,
such as a Mouse.

Second, it sets the appropriate input properties so that user-space
can distinguish TouchScreen devices (INPUT_PROP_DIRECT) from
TouchPad devices (INPUT_PROP_POINTER) and configure them accordingly.

Signed-off-by: jeffbrown@android.com
Acked-By: Benjamin Tissoires <Benjamin_Tissoires@logitech.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 58d0e7aaf088..4ee21ac8e856 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -213,6 +213,16 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
         struct mt_class *cls = td->mtclass;
         __s32 quirks = cls->quirks;
 
+        /* Only map fields from TouchScreen or TouchPad collections.
+         * We need to ignore fields that belong to other collections
+         * such as Mouse that might have the same GenericDesktop usages. */
+        if (field->application == HID_DG_TOUCHSCREEN)
+                set_bit(INPUT_PROP_DIRECT, hi->input->propbit);
+        else if (field->application == HID_DG_TOUCHPAD)
+                set_bit(INPUT_PROP_POINTER, hi->input->propbit);
+        else
+                return 0;
+
         switch (usage->hid & HID_USAGE_PAGE) {
 
         case HID_UP_GENDESK: