1 /*
2 * u_f.h
3 *
4 * Utility definitions for USB functions
5 *
6 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
7 * http://www.samsung.com
8 *
9 * Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16 #ifndef __U_F_H__
17 #define __U_F_H__
18
19 #include <linux/usb/gadget.h>
20
21 /* Variable Length Array Macros **********************************************/
22 #define vla_group(groupname) size_t groupname##__next = 0
23 #define vla_group_size(groupname) groupname##__next
24
25 #define vla_item(groupname, type, name, n) \
26 size_t groupname##_##name##__offset = ({ \
27 size_t align_mask = __alignof__(type) - 1; \
28 size_t offset = (groupname##__next + align_mask) & ~align_mask;\
29 size_t size = (n) * sizeof(type); \
30 groupname##__next = offset + size; \
31 offset; \
32 })
33
34 #define vla_item_with_sz(groupname, type, name, n) \
35 size_t groupname##_##name##__sz = (n) * sizeof(type); \
36 size_t groupname##_##name##__offset = ({ \
37 size_t align_mask = __alignof__(type) - 1; \
38 size_t offset = (groupname##__next + align_mask) & ~align_mask;\
39 size_t size = groupname##_##name##__sz; \
40 groupname##__next = offset + size; \
41 offset; \
42 })
43
44 #define vla_ptr(ptr, groupname, name) \
45 ((void *) ((char *)ptr + groupname##_##name##__offset))
46
47 struct usb_ep;
48 struct usb_request;
49
50 /**
51 * alloc_ep_req - returns a usb_request allocated by the gadget driver and
52 * allocates the request's buffer.
53 *
54 * @ep: the endpoint to allocate a usb_request
55 * @len: usb_requests's buffer suggested size
56 * @default_len: used if @len is not provided, ie, is 0
57 *
58 * In case @ep direction is OUT, the @len will be aligned to ep's
59 * wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
60 * usb_requests's length (req->length) to refer to the allocated buffer size.
61 * Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
62 */
63 struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len, int default_len);
64
65 /* Frees a usb_request previously allocated by alloc_ep_req() */
free_ep_req(struct usb_ep * ep,struct usb_request * req)66 static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
67 {
68 WARN_ON(req->buf == NULL);
69 kfree(req->buf);
70 req->buf = NULL;
71 usb_ep_free_request(ep, req);
72 }
73
74 #endif /* __U_F_H__ */
75