1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * u_f.h
 4 *
 5 * Utility definitions for USB functions
 6 *
 7 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
 8 *		http://www.samsung.com
 9 *
10 * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
11 */
12
13#ifndef __U_F_H__
14#define __U_F_H__
15
16#include <linux/usb/gadget.h>
17
18/* Variable Length Array Macros **********************************************/
19#define vla_group(groupname) size_t groupname##__next = 0
20#define vla_group_size(groupname) groupname##__next
21
22#define vla_item(groupname, type, name, n) \
23	size_t groupname##_##name##__offset = ({			       \
24		size_t align_mask = __alignof__(type) - 1;		       \
25		size_t offset = (groupname##__next + align_mask) & ~align_mask;\
26		size_t size = (n) * sizeof(type);			       \
27		groupname##__next = offset + size;			       \
28		offset;							       \
29	})
30
31#define vla_item_with_sz(groupname, type, name, n) \
32	size_t groupname##_##name##__sz = (n) * sizeof(type);		       \
33	size_t groupname##_##name##__offset = ({			       \
34		size_t align_mask = __alignof__(type) - 1;		       \
35		size_t offset = (groupname##__next + align_mask) & ~align_mask;\
36		size_t size = groupname##_##name##__sz;			       \
37		groupname##__next = offset + size;			       \
38		offset;							       \
39	})
40
41#define vla_ptr(ptr, groupname, name) \
42	((void *) ((char *)ptr + groupname##_##name##__offset))
43
44struct usb_ep;
45struct usb_request;
46
47/**
48 * alloc_ep_req - returns a usb_request allocated by the gadget driver and
49 * allocates the request's buffer.
50 *
51 * @ep: the endpoint to allocate a usb_request
52 * @len: usb_requests's buffer suggested size
53 *
54 * In case @ep direction is OUT, the @len will be aligned to ep's
55 * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
56 * usb_requests's length (req->length) to refer to the allocated buffer size.
57 * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
58 */
59struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len);
60
61/* Frees a usb_request previously allocated by alloc_ep_req() */
62static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
63{
64	WARN_ON(req->buf == NULL);
65	kfree(req->buf);
66	req->buf = NULL;
67	usb_ep_free_request(ep, req);
68}
69
70#endif /* __U_F_H__ */