HID: add autodetection of multitouch devices

As mentioned by http://www.microsoft.com/whdc/device/input/DigitizerDrvs_touch.mspx
multitouch devices are those that have the input report HID_CONTACTID.

This patch detects this and unloads the generic-usb driver.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 6559e2e3364..f333139d1a4 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -474,6 +474,10 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
                         map_key_clear(BTN_STYLUS2);
                         break;
 
+                case 0x51: /* ContactID */
+                        device->quirks |= HID_QUIRK_MULTITOUCH;
+                        goto unknown;
+
                 default:  goto unknown;
                 }
                 break;
@@ -978,6 +982,13 @@ int hidinput_connect(struct hid_device *hid, unsigned int force)
                 }
         }
 
+        if (hid->quirks & HID_QUIRK_MULTITOUCH) {
+                /* generic hid does not know how to handle multitouch devices */
+                if (hidinput)
+                        goto out_cleanup;
+                goto out_unwind;
+        }
+
         if (hidinput && input_register_device(hidinput->input))
                 goto out_cleanup;