1. 根目录:
2. drivers
3. usb
4. gadget
5. u_f.c

/*
 * u_f.c -- USB function utilities for Gadget stack
 *
 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 *
 * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/usb/gadget.h>
#include "u_f.h"

struct usb_request *alloc_ep_req(struct usb_ep *ep, int len, int default_len)
{
	struct usb_request      *req;

	req = usb_ep_alloc_request(ep, GFP_ATOMIC);
	if (req) {
		req->length = len ?: default_len;
		req->buf = kmalloc(req->length, GFP_ATOMIC);
		if (!req->buf) {
			usb_ep_free_request(ep, req);
			req = NULL;
		}
	}
	return req;
}
EXPORT_SYMBOL_GPL(alloc_ep_req);