HID: core: implement generic .request()

.request() can be emulated through .raw_request()
we can implement this emulation in hid-core, and make .request
not mandatory for transport layer drivers.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/linux/hid.h b/include/linux/hid.h
index a837ede..09fbbd7f 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -753,6 +753,7 @@
 unsigned int hidinput_count_leds(struct hid_device *hid);
 __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code);
 void hid_output_report(struct hid_report *report, __u8 *data);
+void __hid_request(struct hid_device *hid, struct hid_report *rep, int reqtype);
 u8 *hid_alloc_report_buf(struct hid_report *report, gfp_t flags);
 struct hid_device *hid_allocate_device(void);
 struct hid_report *hid_register_report(struct hid_device *device, unsigned type, unsigned id);
@@ -965,7 +966,9 @@
 				  struct hid_report *report, int reqtype)
 {
 	if (hdev->ll_driver->request)
-		hdev->ll_driver->request(hdev, report, reqtype);
+		return hdev->ll_driver->request(hdev, report, reqtype);
+
+	__hid_request(hdev, report, reqtype);
 }
 
 /**