Commits
Blaž Hrastnik committed 65889bba7be
HID: Improve Windows Precision Touchpad detection.
[ Upstream commit 2dbc6f113acd74c66b04bf49fb027efd830b1c5a ]
Per Microsoft spec, usage 0xC5 (page 0xFF) returns a blob containing
data used to verify the touchpad as a Windows Precision Touchpad.
0x85, REPORTID_PTPHQA, // REPORT_ID (PTPHQA)
0x09, 0xC5, // USAGE (Vendor Usage 0xC5)
0x15, 0x00, // LOGICAL_MINIMUM (0)
0x26, 0xff, 0x00, // LOGICAL_MAXIMUM (0xff)
0x75, 0x08, // REPORT_SIZE (8)
0x96, 0x00, 0x01, // REPORT_COUNT (0x100 (256))
0xb1, 0x02, // FEATURE (Data,Var,Abs)
However, some devices, namely Microsoft's Surface line of products
instead implement a "segmented device certification report" (usage 0xC6)
which returns the same report, but in smaller chunks.
0x06, 0x00, 0xff, // USAGE_PAGE (Vendor Defined)
0x85, REPORTID_PTPHQA, // REPORT_ID (PTPHQA)
0x09, 0xC6, // USAGE (Vendor usage for segment #)
0x25, 0x08, // LOGICAL_MAXIMUM (8)
0x75, 0x08, // REPORT_SIZE (8)
0x95, 0x01, // REPORT_COUNT (1)
0xb1, 0x02, // FEATURE (Data,Var,Abs)
0x09, 0xC7, // USAGE (Vendor Usage)
0x26, 0xff, 0x00, // LOGICAL_MAXIMUM (0xff)
0x95, 0x20, // REPORT_COUNT (32)
0xb1, 0x02, // FEATURE (Data,Var,Abs)
By expanding Win8 touchpad detection to also look for the segmented
report, all Surface touchpads are now properly recognized by
hid-multitouch.
Signed-off-by: Blaž Hrastnik <blaz@mxxn.io>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>