input: Implement a HID quirk for 2-wheel A4Tech mice.

drivers/usb/input/hid-core.c

@@ -1351,6 +1351,9 @@ void hid_init_reports(struct hid_device *hid)
 #define USB_VENDOR_ID_ESSENTIAL_REALITY	0x0d7f
 #define USB_DEVICE_ID_ESSENTIAL_REALITY_P5	0x0100
 
+#define USB_VENDOR_ID_A4TECH		0x09DA
+#define USB_DEVICE_ID_A4TECH_WCP32PU	0x0006
+
 struct hid_blacklist {
 	__u16 idVendor;
 	__u16 idProduct;
@@ -1398,6 +1401,7 @@ struct hid_blacklist {
 	{ USB_VENDOR_ID_ONTRAK, USB_DEVICE_ID_ONTRAK_ADU100 + 500, HID_QUIRK_IGNORE },
 	{ USB_VENDOR_ID_TANGTOP, USB_DEVICE_ID_TANGTOP_USBPS2, HID_QUIRK_NOGET },
 	{ USB_VENDOR_ID_ESSENTIAL_REALITY, USB_DEVICE_ID_ESSENTIAL_REALITY_P5, HID_QUIRK_IGNORE },
+	{ USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_WCP32PU, HID_QUIRK_2WHEEL_MOUSE_HACK },
 	{ 0, 0 }
 };
 

drivers/usb/input/hid-input.c

@@ -376,6 +376,11 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 	}
 
 	set_bit(usage->type, input->evbit);
+	if ((usage->type == EV_REL)
+			&& (device->quirks & HID_QUIRK_2WHEEL_MOUSE_HACK)
+			&& (usage->code == REL_WHEEL)) {
+		set_bit(REL_HWHEEL, bit);
+	}
 
 	while (usage->code <= max && test_and_set_bit(usage->code, bit)) {
 		usage->code = find_next_zero_bit(bit, max + 1, usage->code);
@@ -426,6 +431,20 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
 
 	input_regs(input, regs);
 
+	if ((hid->quirks & HID_QUIRK_2WHEEL_MOUSE_HACK)
+			&& (usage->code == BTN_BACK)) {
+		if (value)
+			hid->quirks |= HID_QUIRK_2WHEEL_MOUSE_HACK_ON;
+		else
+			hid->quirks &= ~HID_QUIRK_2WHEEL_MOUSE_HACK_ON;
+		return;
+	}
+	if ((hid->quirks & HID_QUIRK_2WHEEL_MOUSE_HACK_ON)
+			&& (usage->code == REL_WHEEL)) {
+		input_event(input, usage->type, REL_HWHEEL, value);
+		return;
+	}
+
 	if (usage->hat_min != usage->hat_max) {
 		value = (value - usage->hat_min) * 8 / (usage->hat_max - usage->hat_min + 1) + 1;
 		if (value < 0 || value > 8) value = 0;

drivers/usb/input/hid.h

@@ -201,13 +201,15 @@ struct hid_item {
  * HID device quirks.
  */
 
-#define HID_QUIRK_INVERT	0x01
-#define HID_QUIRK_NOTOUCH	0x02
-#define HID_QUIRK_IGNORE	0x04
-#define HID_QUIRK_NOGET		0x08
-#define HID_QUIRK_HIDDEV	0x10
-#define HID_QUIRK_BADPAD        0x20
-#define HID_QUIRK_MULTI_INPUT	0x40
+#define HID_QUIRK_INVERT		0x001
+#define HID_QUIRK_NOTOUCH		0x002
+#define HID_QUIRK_IGNORE		0x004
+#define HID_QUIRK_NOGET			0x008
+#define HID_QUIRK_HIDDEV		0x010
+#define HID_QUIRK_BADPAD		0x020
+#define HID_QUIRK_MULTI_INPUT		0x040
+#define HID_QUIRK_2WHEEL_MOUSE_HACK	0x080
+#define HID_QUIRK_2WHEEL_MOUSE_HACK_ON	0x100
 
 /*
  * This is the global environment of the parser. This information is