1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2 /*
3  *  User level driver support for input subsystem
4  *
5  * Heavily based on evdev.c by Vojtech Pavlik
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  *
21  * Author: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
22  *
23  * Changes/Revisions:
24  *	0.5	08/13/2015 (David Herrmann <dh.herrmann@gmail.com> &
25  *			    Benjamin Tissoires <benjamin.tissoires@redhat.com>)
26  *		- add UI_DEV_SETUP ioctl
27  *		- add UI_ABS_SETUP ioctl
28  *		- add UI_GET_VERSION ioctl
29  *	0.4	01/09/2014 (Benjamin Tissoires <benjamin.tissoires@redhat.com>)
30  *		- add UI_GET_SYSNAME ioctl
31  *	0.3	24/05/2006 (Anssi Hannula <anssi.hannulagmail.com>)
32  *		- update ff support for the changes in kernel interface
33  *		- add UINPUT_VERSION
34  *	0.2	16/10/2004 (Micah Dowty <micah@navi.cx>)
35  *		- added force feedback support
36  *             - added UI_SET_PHYS
37  *	0.1	20/06/2002
38  *		- first public version
39  */
40 #ifndef _UAPI__UINPUT_H_
41 #define _UAPI__UINPUT_H_
42 
43 #include <linux/types.h>
44 #include <linux/input.h>
45 
46 #define UINPUT_VERSION		5
47 #define UINPUT_MAX_NAME_SIZE	80
48 
49 struct uinput_ff_upload {
50 	__u32			request_id;
51 	__s32			retval;
52 	struct ff_effect	effect;
53 	struct ff_effect	old;
54 };
55 
56 struct uinput_ff_erase {
57 	__u32			request_id;
58 	__s32			retval;
59 	__u32			effect_id;
60 };
61 
62 /* ioctl */
63 #define UINPUT_IOCTL_BASE	'U'
64 #define UI_DEV_CREATE		_IO(UINPUT_IOCTL_BASE, 1)
65 #define UI_DEV_DESTROY		_IO(UINPUT_IOCTL_BASE, 2)
66 
67 struct uinput_setup {
68 	struct input_id id;
69 	char name[UINPUT_MAX_NAME_SIZE];
70 	__u32 ff_effects_max;
71 };
72 
73 /**
74  * UI_DEV_SETUP - Set device parameters for setup
75  *
76  * This ioctl sets parameters for the input device to be created.  It
77  * supersedes the old "struct uinput_user_dev" method, which wrote this data
78  * via write(). To actually set the absolute axes UI_ABS_SETUP should be
79  * used.
80  *
81  * The ioctl takes a "struct uinput_setup" object as argument. The fields of
82  * this object are as follows:
83  *              id: See the description of "struct input_id". This field is
84  *                  copied unchanged into the new device.
85  *            name: This is used unchanged as name for the new device.
86  *  ff_effects_max: This limits the maximum numbers of force-feedback effects.
87  *                  See below for a description of FF with uinput.
88  *
89  * This ioctl can be called multiple times and will overwrite previous values.
90  * If this ioctl fails with -EINVAL, it is recommended to use the old
91  * "uinput_user_dev" method via write() as a fallback, in case you run on an
92  * old kernel that does not support this ioctl.
93  *
94  * This ioctl may fail with -EINVAL if it is not supported or if you passed
95  * incorrect values, -ENOMEM if the kernel runs out of memory or -EFAULT if the
96  * passed uinput_setup object cannot be read/written.
97  * If this call fails, partial data may have already been applied to the
98  * internal device.
99  */
100 #define UI_DEV_SETUP _IOW(UINPUT_IOCTL_BASE, 3, struct uinput_setup)
101 
102 struct uinput_abs_setup {
103 	__u16  code; /* axis code */
104 	/* __u16 filler; */
105 	struct input_absinfo absinfo;
106 };
107 
108 /**
109  * UI_ABS_SETUP - Set absolute axis information for the device to setup
110  *
111  * This ioctl sets one absolute axis information for the input device to be
112  * created. It supersedes the old "struct uinput_user_dev" method, which wrote
113  * part of this data and the content of UI_DEV_SETUP via write().
114  *
115  * The ioctl takes a "struct uinput_abs_setup" object as argument. The fields
116  * of this object are as follows:
117  *            code: The corresponding input code associated with this axis
118  *                  (ABS_X, ABS_Y, etc...)
119  *         absinfo: See "struct input_absinfo" for a description of this field.
120  *                  This field is copied unchanged into the kernel for the
121  *                  specified axis. If the axis is not enabled via
122  *                  UI_SET_ABSBIT, this ioctl will enable it.
123  *
124  * This ioctl can be called multiple times and will overwrite previous values.
125  * If this ioctl fails with -EINVAL, it is recommended to use the old
126  * "uinput_user_dev" method via write() as a fallback, in case you run on an
127  * old kernel that does not support this ioctl.
128  *
129  * This ioctl may fail with -EINVAL if it is not supported or if you passed
130  * incorrect values, -ENOMEM if the kernel runs out of memory or -EFAULT if the
131  * passed uinput_setup object cannot be read/written.
132  * If this call fails, partial data may have already been applied to the
133  * internal device.
134  */
135 #define UI_ABS_SETUP _IOW(UINPUT_IOCTL_BASE, 4, struct uinput_abs_setup)
136 
137 #define UI_SET_EVBIT		_IOW(UINPUT_IOCTL_BASE, 100, int)
138 #define UI_SET_KEYBIT		_IOW(UINPUT_IOCTL_BASE, 101, int)
139 #define UI_SET_RELBIT		_IOW(UINPUT_IOCTL_BASE, 102, int)
140 #define UI_SET_ABSBIT		_IOW(UINPUT_IOCTL_BASE, 103, int)
141 #define UI_SET_MSCBIT		_IOW(UINPUT_IOCTL_BASE, 104, int)
142 #define UI_SET_LEDBIT		_IOW(UINPUT_IOCTL_BASE, 105, int)
143 #define UI_SET_SNDBIT		_IOW(UINPUT_IOCTL_BASE, 106, int)
144 #define UI_SET_FFBIT		_IOW(UINPUT_IOCTL_BASE, 107, int)
145 #define UI_SET_PHYS		_IOW(UINPUT_IOCTL_BASE, 108, char*)
146 #define UI_SET_SWBIT		_IOW(UINPUT_IOCTL_BASE, 109, int)
147 #define UI_SET_PROPBIT		_IOW(UINPUT_IOCTL_BASE, 110, int)
148 
149 #define UI_BEGIN_FF_UPLOAD	_IOWR(UINPUT_IOCTL_BASE, 200, struct uinput_ff_upload)
150 #define UI_END_FF_UPLOAD	_IOW(UINPUT_IOCTL_BASE, 201, struct uinput_ff_upload)
151 #define UI_BEGIN_FF_ERASE	_IOWR(UINPUT_IOCTL_BASE, 202, struct uinput_ff_erase)
152 #define UI_END_FF_ERASE		_IOW(UINPUT_IOCTL_BASE, 203, struct uinput_ff_erase)
153 
154 /**
155  * UI_GET_SYSNAME - get the sysfs name of the created uinput device
156  *
157  * @return the sysfs name of the created virtual input device.
158  * The complete sysfs path is then /sys/devices/virtual/input/--NAME--
159  * Usually, it is in the form "inputN"
160  */
161 #define UI_GET_SYSNAME(len)	_IOC(_IOC_READ, UINPUT_IOCTL_BASE, 44, len)
162 
163 /**
164  * UI_GET_VERSION - Return version of uinput protocol
165  *
166  * This writes uinput protocol version implemented by the kernel into
167  * the integer pointed to by the ioctl argument. The protocol version
168  * is hard-coded in the kernel and is independent of the uinput device.
169  */
170 #define UI_GET_VERSION		_IOR(UINPUT_IOCTL_BASE, 45, unsigned int)
171 
172 /*
173  * To write a force-feedback-capable driver, the upload_effect
174  * and erase_effect callbacks in input_dev must be implemented.
175  * The uinput driver will generate a fake input event when one of
176  * these callbacks are invoked. The userspace code then uses
177  * ioctls to retrieve additional parameters and send the return code.
178  * The callback blocks until this return code is sent.
179  *
180  * The described callback mechanism is only used if ff_effects_max
181  * is set.
182  *
183  * To implement upload_effect():
184  *   1. Wait for an event with type == EV_UINPUT and code == UI_FF_UPLOAD.
185  *      A request ID will be given in 'value'.
186  *   2. Allocate a uinput_ff_upload struct, fill in request_id with
187  *      the 'value' from the EV_UINPUT event.
188  *   3. Issue a UI_BEGIN_FF_UPLOAD ioctl, giving it the
189  *      uinput_ff_upload struct. It will be filled in with the
190  *      ff_effects passed to upload_effect().
191  *   4. Perform the effect upload, and place a return code back into
192         the uinput_ff_upload struct.
193  *   5. Issue a UI_END_FF_UPLOAD ioctl, also giving it the
194  *      uinput_ff_upload_effect struct. This will complete execution
195  *      of our upload_effect() handler.
196  *
197  * To implement erase_effect():
198  *   1. Wait for an event with type == EV_UINPUT and code == UI_FF_ERASE.
199  *      A request ID will be given in 'value'.
200  *   2. Allocate a uinput_ff_erase struct, fill in request_id with
201  *      the 'value' from the EV_UINPUT event.
202  *   3. Issue a UI_BEGIN_FF_ERASE ioctl, giving it the
203  *      uinput_ff_erase struct. It will be filled in with the
204  *      effect ID passed to erase_effect().
205  *   4. Perform the effect erasure, and place a return code back
206  *      into the uinput_ff_erase struct.
207  *   5. Issue a UI_END_FF_ERASE ioctl, also giving it the
208  *      uinput_ff_erase_effect struct. This will complete execution
209  *      of our erase_effect() handler.
210  */
211 
212 /*
213  * This is the new event type, used only by uinput.
214  * 'code' is UI_FF_UPLOAD or UI_FF_ERASE, and 'value'
215  * is the unique request ID. This number was picked
216  * arbitrarily, above EV_MAX (since the input system
217  * never sees it) but in the range of a 16-bit int.
218  */
219 #define EV_UINPUT		0x0101
220 #define UI_FF_UPLOAD		1
221 #define UI_FF_ERASE		2
222 
223 struct uinput_user_dev {
224 	char name[UINPUT_MAX_NAME_SIZE];
225 	struct input_id id;
226 	__u32 ff_effects_max;
227 	__s32 absmax[ABS_CNT];
228 	__s32 absmin[ABS_CNT];
229 	__s32 absfuzz[ABS_CNT];
230 	__s32 absflat[ABS_CNT];
231 };
232 #endif /* _UAPI__UINPUT_H_ */
233