1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
4 Copyright (C) 2020 Collabora Ltd.
5
6 This software is provided 'as-is', without any express or implied
7 warranty. In no event will the authors be held liable for any damages
8 arising from the use of this software.
9
10 Permission is granted to anyone to use this software for any purpose,
11 including commercial applications, and to alter it and redistribute it
12 freely, subject to the following restrictions:
13
14 1. The origin of this software must not be misrepresented; you must not
15 claim that you wrote the original software. If you use this software
16 in a product, an acknowledgment in the product documentation would be
17 appreciated but is not required.
18 2. Altered source versions must be plainly marked as such, and must not be
19 misrepresented as being the original software.
20 3. This notice may not be removed or altered from any source distribution.
21*/
22
23#include "SDL_evdev_capabilities.h"
24
25#if HAVE_LIBUDEV_H || defined(SDL_JOYSTICK_LINUX)
26
27/* missing defines in older Linux kernel headers */
28#ifndef BTN_TRIGGER_HAPPY
29#define BTN_TRIGGER_HAPPY 0x2c0
30#endif
31#ifndef BTN_DPAD_UP
32#define BTN_DPAD_UP 0x220
33#endif
34#ifndef KEY_ALS_TOGGLE
35#define KEY_ALS_TOGGLE 0x230
36#endif
37
38extern int
39SDL_EVDEV_GuessDeviceClass(unsigned long bitmask_ev[NBITS(EV_MAX)],
40 unsigned long bitmask_abs[NBITS(ABS_MAX)],
41 unsigned long bitmask_key[NBITS(KEY_MAX)],
42 unsigned long bitmask_rel[NBITS(REL_MAX)])
43{
44 struct range {
45 unsigned start;
46 unsigned end;
47 };
48
49 /* key code ranges above BTN_MISC (start is inclusive, stop is exclusive)*/
50 static const struct range high_key_blocks[] = {
51 { KEY_OK, BTN_DPAD_UP },
52 { KEY_ALS_TOGGLE, BTN_TRIGGER_HAPPY }
53 };
54
55 int devclass = 0;
56 unsigned long keyboard_mask;
57
58 /* X, Y, Z axes but no buttons probably means an accelerometer */
59 if (test_bit(EV_ABS, bitmask_ev) &&
60 test_bit(ABS_X, bitmask_abs) &&
61 test_bit(ABS_Y, bitmask_abs) &&
62 test_bit(ABS_Z, bitmask_abs) &&
63 !test_bit(EV_KEY, bitmask_ev)) {
64 return SDL_UDEV_DEVICE_ACCELEROMETER;
65 }
66
67 /* RX, RY, RZ axes but no buttons also probably means an accelerometer */
68 if (test_bit(EV_ABS, bitmask_ev) &&
69 test_bit(ABS_RX, bitmask_abs) &&
70 test_bit(ABS_RY, bitmask_abs) &&
71 test_bit(ABS_RZ, bitmask_abs) &&
72 !test_bit(EV_KEY, bitmask_ev)) {
73 return SDL_UDEV_DEVICE_ACCELEROMETER;
74 }
75
76 if (test_bit(EV_ABS, bitmask_ev) &&
77 test_bit(ABS_X, bitmask_abs) && test_bit(ABS_Y, bitmask_abs)) {
78 if (test_bit(BTN_STYLUS, bitmask_key) || test_bit(BTN_TOOL_PEN, bitmask_key)) {
79 ; /* ID_INPUT_TABLET */
80 } else if (test_bit(BTN_TOOL_FINGER, bitmask_key) && !test_bit(BTN_TOOL_PEN, bitmask_key)) {
81 ; /* ID_INPUT_TOUCHPAD */
82 } else if (test_bit(BTN_MOUSE, bitmask_key)) {
83 devclass |= SDL_UDEV_DEVICE_MOUSE; /* ID_INPUT_MOUSE */
84 } else if (test_bit(BTN_TOUCH, bitmask_key)) {
85 /* TODO: better determining between touchscreen and multitouch touchpad,
86 see https://github.com/systemd/systemd/blob/master/src/udev/udev-builtin-input_id.c */
87 devclass |= SDL_UDEV_DEVICE_TOUCHSCREEN; /* ID_INPUT_TOUCHSCREEN */
88 }
89
90 if (test_bit(BTN_TRIGGER, bitmask_key) ||
91 test_bit(BTN_A, bitmask_key) ||
92 test_bit(BTN_1, bitmask_key) ||
93 test_bit(ABS_RX, bitmask_abs) ||
94 test_bit(ABS_RY, bitmask_abs) ||
95 test_bit(ABS_RZ, bitmask_abs) ||
96 test_bit(ABS_THROTTLE, bitmask_abs) ||
97 test_bit(ABS_RUDDER, bitmask_abs) ||
98 test_bit(ABS_WHEEL, bitmask_abs) ||
99 test_bit(ABS_GAS, bitmask_abs) ||
100 test_bit(ABS_BRAKE, bitmask_abs)) {
101 devclass |= SDL_UDEV_DEVICE_JOYSTICK; /* ID_INPUT_JOYSTICK */
102 }
103 }
104
105 if (test_bit(EV_REL, bitmask_ev) &&
106 test_bit(REL_X, bitmask_rel) && test_bit(REL_Y, bitmask_rel) &&
107 test_bit(BTN_MOUSE, bitmask_key)) {
108 devclass |= SDL_UDEV_DEVICE_MOUSE; /* ID_INPUT_MOUSE */
109 }
110
111 if (test_bit(EV_KEY, bitmask_ev)) {
112 unsigned i;
113 unsigned long found = 0;
114
115 for (i = 0; i < BTN_MISC/BITS_PER_LONG; ++i) {
116 found |= bitmask_key[i];
117 }
118 /* If there are no keys in the lower block, check the higher blocks */
119 if (!found) {
120 unsigned block;
121 for (block = 0; block < (sizeof(high_key_blocks) / sizeof(struct range)); ++block) {
122 for (i = high_key_blocks[block].start; i < high_key_blocks[block].end; ++i) {
123 if (test_bit(i, bitmask_key)) {
124 found = 1;
125 break;
126 }
127 }
128 }
129 }
130
131 if (found > 0) {
132 devclass |= SDL_UDEV_DEVICE_KEYBOARD; /* ID_INPUT_KEY */
133 }
134 }
135
136 /* the first 32 bits are ESC, numbers, and Q to D; if we have any of
137 * those, consider it a keyboard device; do not test KEY_RESERVED, though */
138 keyboard_mask = 0xFFFFFFFE;
139 if ((bitmask_key[0] & keyboard_mask) != 0)
140 devclass |= SDL_UDEV_DEVICE_KEYBOARD; /* ID_INPUT_KEYBOARD */
141
142 return devclass;
143}
144
145#endif
146