hid: quirk for multi-input devices with unneeded output reports

Add new quirk HID_QUIRK_SKIP_OUTPUT_REPORTS to skip output reports
when enumerating reports on a hid-input device. Add this quirk and
HID_QUIRK_MULTI_INPUT to 0810:0001.

PantherLord Twin USB Joystick, 0810:0001 has separate input reports
for 2 distinct game controllers in the same interface, so it needs
HID_QUIRK_MULTI_INPUT. However, the device also contains one output
report per controller which is used to control the force feedback
function, and we do not want those to appear as separate input
devices as well. The simplest approach seems to be to add a quirk to
skip output reports on 0810:0001, and allow the force feedback
driver to handle those.

Signed-off-by: Anssi Hannula <[e-mail]>
Signed-off-by: Jiri Kosina <[e-mail]>

drivers/hid/hid-input.c

···
 	struct hid_input *hidinput = NULL;
 	struct input_dev *input_dev;
 	int i, j, k;
+	int max_report_type = HID_OUTPUT_REPORT;
 
 	INIT_LIST_HEAD(&hid->inputs);
 
···
 	if (i == hid->maxcollection)
 		return -1;
 
-	for (k = HID_INPUT_REPORT; k <= HID_OUTPUT_REPORT; k++)
+	if (hid->quirks & HID_QUIRK_SKIP_OUTPUT_REPORTS)
+		max_report_type = HID_INPUT_REPORT;
+
+	for (k = HID_INPUT_REPORT; k <= max_report_type; k++)
 		list_for_each_entry(report, &hid->report_enum[k].report_list, list) {
 
 			if (!report->maxfield)

drivers/usb/input/hid-core.c

···
 #define USB_VENDOR_ID_IMATION		0x0718
 #define USB_DEVICE_ID_DISC_STAKKA	0xd000
 
+#define USB_VENDOR_ID_PANTHERLORD	0x0810
+#define USB_DEVICE_ID_PANTHERLORD_TWIN_USB_JOYSTICK	0x0001
+
 /*
  * Alphabetically sorted blacklist by quirk type.
  */
···
 	{ USB_VENDOR_ID_TURBOX, USB_DEVICE_ID_TURBOX_KEYBOARD, HID_QUIRK_NOGET },
 
 	{ USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_USB_RECEIVER, HID_QUIRK_BAD_RELATIVE_KEYS },
+
+	{ USB_VENDOR_ID_PANTHERLORD, USB_DEVICE_ID_PANTHERLORD_TWIN_USB_JOYSTICK, HID_QUIRK_MULTI_INPUT | HID_QUIRK_SKIP_OUTPUT_REPORTS },
 
 	{ 0, 0 }
 };

include/linux/hid.h

···
 #define HID_QUIRK_INVERT_HWHEEL			0x00004000
 #define HID_QUIRK_POWERBOOK_ISO_KEYBOARD        0x00008000
 #define HID_QUIRK_BAD_RELATIVE_KEYS		0x00010000
+#define HID_QUIRK_SKIP_OUTPUT_REPORTS		0x00020000
 
 /*
  * This is the global environment of the parser. This information is