[PATCH v4] HID: multitouch: add support for Goodix GXTP7863 touchpad

The Goodix GXTP7863 touchpad controller (VID: 0x27c6, PID: 0x01e0)
found on Honor MagicBook laptops (e.g. FMI-76 / X14 Plus)
was missing from the mt_devices[] table.

As a result, it was claimed by hid-generic, which erroneously mapped
the vendor telemetry collection (0xFF01) to an input node, translating
the 1-Hz heartbeat timestamp into an endless loop of phantom
KEY_BRIGHTNESSUP autorepeat events.

Fix this by:
 1. Adding I2C_DEVICE_ID_GOODIX_01E0 to hid-ids.h.
 2. Adding the device to mt_devices[] with MT_CLS_WIN_8 so hid-multitouch
    claims the touchpad and retains full Win8 PTP quirks.
 3. Filtering out the 0xFF01 vendor collection in mt_input_mapping()
    so the telemetry report is ignored and no phantom input node is
    created.

Tested on Honor MagicBook X14 Plus (FMI-76, AMD Ryzen 8845HS).

Signed-off-by: Ruzal Daminov <[email protected]>
---
v3 -> v4:
 - Retain MT_CLS_WIN_8 to preserve Win8 PTP quirks, while explicitly
   filtering out field->application == 0xff010001 in mt_input_mapping()
   to ignore the vendor telemetry collection.
v2 -> v3:
 - Use MT_CLS_DEFAULT to keep export_all_inputs false.
v1 -> v2:
 - Move entry to alphabetical order in the Goodix section.
 - Declare I2C_DEVICE_ID_GOODIX_01E0 in hid-ids.h.

 drivers/hid/hid-ids.h        |  1 +
 drivers/hid/hid-multitouch.c | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 1059922baaacd2..60d9d524cd2e15 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -562,6 +562,7 @@
 #define USB_DEVICE_ID_GENERAL_TOUCH_WIN8_PIT_E100 0xe100
 
 #define I2C_VENDOR_ID_GOODIX		0x27c6
+#define I2C_DEVICE_ID_GOODIX_01E0	0x01e0
 #define I2C_DEVICE_ID_GOODIX_01E8	0x01e8
 #define I2C_DEVICE_ID_GOODIX_01E9	0x01e9
 #define I2C_DEVICE_ID_GOODIX_01F0	0x01f0
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index edb37b4c867e4b..d2ada08a6b01bf 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -1543,6 +1543,12 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 	if (ret != 0)
 		return ret;
 
+	/* Ignore Goodix FreeTouch vendor telemetry collection */
+	if (hdev->vendor == I2C_VENDOR_ID_GOODIX &&
+	    hdev->product == I2C_DEVICE_ID_GOODIX_01E0 &&
+	    field->application == 0xff010001)
+		return -1;
+
 	/* let hid-core decide for the others */
 	return 0;
 }
@@ -2460,6 +2466,11 @@ static const struct hid_device_id mt_devices[] = {
 		MT_BT_DEVICE(USB_VENDOR_ID_FRUCTEL,
 			USB_DEVICE_ID_GAMETEL_MT_MODE) },
 
+	/* Goodix GXTP7863 Touchpad */
+	{ .driver_data = MT_CLS_WIN_8,
+	  HID_DEVICE(BUS_I2C, HID_GROUP_ANY, I2C_VENDOR_ID_GOODIX,
+		     I2C_DEVICE_ID_GOODIX_01E0) },
+
 	/* Goodix GT7868Q devices */
 	{ .driver_data = MT_CLS_WIN_8_FORCE_MULTI_INPUT_NSMU,
 	  HID_DEVICE(BUS_I2C, HID_GROUP_ANY, I2C_VENDOR_ID_GOODIX,
-- 
2.45.2