[PATCH] HID: multitouch: Add required quirk for Synaptics 0xce4b device

[chenshuyang.cn@outlook.com]

From: chenshuyang <chenshuyang.cn@outlook.com>

The Synaptics 0xce4b is a touchpad + Accupoint pointing stick combo
found in the Dynabook Portege X40-J. The kernel enumerates it as two
input nodes ("06CB:CE4B Touchpad" and "06CB:CE4B Mouse"), but the
stick node never receives events: pushing the stick makes the device
generate a steady stream of I2C interrupts, so the firmware is
reporting data - the reports are just never forwarded to the stick
input node.

The device currently falls back to the default Win8 class, which
keeps HID_QUIRK_INPUT_PER_APP. That report routing does not work for
this hardware. The 0xcddc sibling found in some Toshiba/dynabook
Portege X30 and X40 models had the exact same problem, fixed by commit
1741a8269e1c ("HID: multitouch: Add required quirk for Synaptics 0xcddc device")
by switching to HID_QUIRK_MULTI_INPUT.

Add the same MT_CLS_WIN_8_FORCE_MULTI_INPUT quirk for 0xce4b.

Tested on a Dynabook Portege X40-J (PPH11A-09J002) with kernel v7.1.9:
with the quirk applied, the Accupoint moves the pointer, its three
buttons work, and touchpad movement and gestures behave as before.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=205817
Signed-off-by: chenshuyang <chenshuyang.cn@outlook.com>
---
 drivers/hid/hid-multitouch.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 2c41bac..57e37e7 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -2620,6 +2620,10 @@ static const struct hid_device_id mt_devices[] = {
 		HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
 			USB_VENDOR_ID_SYNAPTICS, 0xce09) },
 
+	{ .driver_data = MT_CLS_WIN_8_FORCE_MULTI_INPUT,
+		HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
+			USB_VENDOR_ID_SYNAPTICS, 0xce4b) },
+
 	/* TopSeed panels */
 	{ .driver_data = MT_CLS_TOPSEED,
 		MT_USB_DEVICE(USB_VENDOR_ID_TOPSEED2,
-- 
2.55.0