1/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2#ifndef __UHID_H_
3#define __UHID_H_
4
5/*
6 * User-space I/O driver support for HID subsystem
7 * Copyright (c) 2012 David Herrmann
8 */
9
10/*
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the Free
13 * Software Foundation; either version 2 of the License, or (at your option)
14 * any later version.
15 */
16
17/*
18 * Public header for user-space communication. We try to keep every structure
19 * aligned but to be safe we also use __attribute__((__packed__)). Therefore,
20 * the communication should be ABI compatible even between architectures.
21 */
22
23#include <linux/input.h>
24#include <linux/types.h>
25#include <linux/hid.h>
26
27enum uhid_event_type {
28	__UHID_LEGACY_CREATE,
29	UHID_DESTROY,
30	UHID_START,
31	UHID_STOP,
32	UHID_OPEN,
33	UHID_CLOSE,
34	UHID_OUTPUT,
35	__UHID_LEGACY_OUTPUT_EV,
36	__UHID_LEGACY_INPUT,
37	UHID_GET_REPORT,
38	UHID_GET_REPORT_REPLY,
39	UHID_CREATE2,
40	UHID_INPUT2,
41	UHID_SET_REPORT,
42	UHID_SET_REPORT_REPLY,
43};
44
45struct uhid_create2_req {
46	__u8 name[128];
47	__u8 phys[64];
48	__u8 uniq[64];
49	__u16 rd_size;
50	__u16 bus;
51	__u32 vendor;
52	__u32 product;
53	__u32 version;
54	__u32 country;
55	__u8 rd_data[HID_MAX_DESCRIPTOR_SIZE];
56} __attribute__((__packed__));
57
58enum uhid_dev_flag {
59	UHID_DEV_NUMBERED_FEATURE_REPORTS			= (1ULL << 0),
60	UHID_DEV_NUMBERED_OUTPUT_REPORTS			= (1ULL << 1),
61	UHID_DEV_NUMBERED_INPUT_REPORTS				= (1ULL << 2),
62};
63
64struct uhid_start_req {
65	__u64 dev_flags;
66};
67
68#define UHID_DATA_MAX 4096
69
70enum uhid_report_type {
71	UHID_FEATURE_REPORT,
72	UHID_OUTPUT_REPORT,
73	UHID_INPUT_REPORT,
74};
75
76struct uhid_input2_req {
77	__u16 size;
78	__u8 data[UHID_DATA_MAX];
79} __attribute__((__packed__));
80
81struct uhid_output_req {
82	__u8 data[UHID_DATA_MAX];
83	__u16 size;
84	__u8 rtype;
85} __attribute__((__packed__));
86
87struct uhid_get_report_req {
88	__u32 id;
89	__u8 rnum;
90	__u8 rtype;
91} __attribute__((__packed__));
92
93struct uhid_get_report_reply_req {
94	__u32 id;
95	__u16 err;
96	__u16 size;
97	__u8 data[UHID_DATA_MAX];
98} __attribute__((__packed__));
99
100struct uhid_set_report_req {
101	__u32 id;
102	__u8 rnum;
103	__u8 rtype;
104	__u16 size;
105	__u8 data[UHID_DATA_MAX];
106} __attribute__((__packed__));
107
108struct uhid_set_report_reply_req {
109	__u32 id;
110	__u16 err;
111} __attribute__((__packed__));
112
113/*
114 * Compat Layer
115 * All these commands and requests are obsolete. You should avoid using them in
116 * new code. We support them for backwards-compatibility, but you might not get
117 * access to new feature in case you use them.
118 */
119
120enum uhid_legacy_event_type {
121	UHID_CREATE			= __UHID_LEGACY_CREATE,
122	UHID_OUTPUT_EV			= __UHID_LEGACY_OUTPUT_EV,
123	UHID_INPUT			= __UHID_LEGACY_INPUT,
124	UHID_FEATURE			= UHID_GET_REPORT,
125	UHID_FEATURE_ANSWER		= UHID_GET_REPORT_REPLY,
126};
127
128/* Obsolete! Use UHID_CREATE2. */
129struct uhid_create_req {
130	__u8 name[128];
131	__u8 phys[64];
132	__u8 uniq[64];
133	__u8 __user *rd_data;
134	__u16 rd_size;
135
136	__u16 bus;
137	__u32 vendor;
138	__u32 product;
139	__u32 version;
140	__u32 country;
141} __attribute__((__packed__));
142
143/* Obsolete! Use UHID_INPUT2. */
144struct uhid_input_req {
145	__u8 data[UHID_DATA_MAX];
146	__u16 size;
147} __attribute__((__packed__));
148
149/* Obsolete! Kernel uses UHID_OUTPUT exclusively now. */
150struct uhid_output_ev_req {
151	__u16 type;
152	__u16 code;
153	__s32 value;
154} __attribute__((__packed__));
155
156/* Obsolete! Kernel uses ABI compatible UHID_GET_REPORT. */
157struct uhid_feature_req {
158	__u32 id;
159	__u8 rnum;
160	__u8 rtype;
161} __attribute__((__packed__));
162
163/* Obsolete! Use ABI compatible UHID_GET_REPORT_REPLY. */
164struct uhid_feature_answer_req {
165	__u32 id;
166	__u16 err;
167	__u16 size;
168	__u8 data[UHID_DATA_MAX];
169} __attribute__((__packed__));
170
171/*
172 * UHID Events
173 * All UHID events from and to the kernel are encoded as "struct uhid_event".
174 * The "type" field contains a UHID_* type identifier. All payload depends on
175 * that type and can be accessed via ev->u.XYZ accordingly.
176 * If user-space writes short events, they're extended with 0s by the kernel. If
177 * the kernel writes short events, user-space shall extend them with 0s.
178 */
179
180struct uhid_event {
181	__u32 type;
182
183	union {
184		struct uhid_create_req create;
185		struct uhid_input_req input;
186		struct uhid_output_req output;
187		struct uhid_output_ev_req output_ev;
188		struct uhid_feature_req feature;
189		struct uhid_get_report_req get_report;
190		struct uhid_feature_answer_req feature_answer;
191		struct uhid_get_report_reply_req get_report_reply;
192		struct uhid_create2_req create2;
193		struct uhid_input2_req input2;
194		struct uhid_set_report_req set_report;
195		struct uhid_set_report_reply_req set_report_reply;
196		struct uhid_start_req start;
197	} u;
198} __attribute__((__packed__));
199
200#endif /* __UHID_H_ */
201