1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
|
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2024 Red Hat, Inc
*/
#include "vmlinux.h"
#include "hid_bpf.h"
#include "hid_bpf_helpers.h"
#include "hid_report_helpers.h"
#include <bpf/bpf_tracing.h>
#define VID_HUION 0x256C
#define PID_KEYDIAL_K20_BLUETOOTH 0x8251
HID_BPF_CONFIG(
HID_DEVICE(BUS_BLUETOOTH, HID_GROUP_GENERIC, VID_HUION, PID_KEYDIAL_K20_BLUETOOTH),
);
/* This is the same device as in 0010-Huion__KeydialK20 but connected via Bluetooth.
* It does not need (to support?) switching to a vendor mode so we just modify the
* existing mode.
*
* By default it exports two hidraw nodes, only the second one sends events.
*
* This is the first hidraw node which we disable:
*
* # Keydial mini-050
* # Report descriptor length: 114 bytes
* # Bytes // Field Name Offset
* # ----------------------------------------------------------------------------------
* # 🮥 0x05, 0x01, // Usage Page (Generic Desktop) 0
* # 🭬 0x09, 0x0e, // Usage (System Multi-Axis Controller) 2
* # 0xa1, 0x01, // Collection (Application) 4
* # ┅ 0x85, 0x03, // Report ID (3) 6
* # 🮥 0x05, 0x0d, // Usage Page (Digitizers) 8
* # 0x75, 0x08, // Report Size (8) 10
* # 0x95, 0x01, // Report Count (1) 12
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 14
* # 🭬 0x09, 0x21, // Usage (Puck) 16
* # 0xa1, 0x02, // Collection (Logical) 18
* # 0x15, 0x00, // Logical Minimum (0) 20
* # 0x25, 0x01, // Logical Maximum (1) 22
* # 0x75, 0x01, // Report Size (1) 24
* # 0x95, 0x01, // Report Count (1) 26
* # 0xa1, 0x00, // Collection (Physical) 28
* # 🮥 0x05, 0x09, // Usage Page (Button) 30
* # 🭬 0x09, 0x01, // Usage (Button 1) 32
* # ┇ 0x81, 0x02, // Input (Data,Var,Abs) 34
* # 🮥 0x05, 0x0d, // Usage Page (Digitizers) 36
* # 🭬 0x09, 0x33, // Usage (Touch) 38
* # ┇ 0x81, 0x02, // Input (Data,Var,Abs) 40
* # 0x95, 0x06, // Report Count (6) 42
* # ┇ 0x81, 0x03, // Input (Cnst,Var,Abs) 44
* # 0xa1, 0x02, // Collection (Logical) 46
* # 🮥 0x05, 0x01, // Usage Page (Generic Desktop) 48
* # 🭬 0x09, 0x37, // Usage (Dial) 50
* # 0x16, 0x00, 0x80, // Logical Minimum (32768) 52
* # 0x26, 0xff, 0x7f, // Logical Maximum (32767) 55
* # 0x75, 0x10, // Report Size (16) 58
* # 0x95, 0x01, // Report Count (1) 60
* # ┇ 0x81, 0x06, // Input (Data,Var,Rel) 62
* # 0x35, 0x00, // Physical Minimum (0) 64
* # 0x46, 0x10, 0x0e, // Physical Maximum (3600) 66
* # 0x15, 0x00, // Logical Minimum (0) 69
* # 0x26, 0x10, 0x0e, // Logical Maximum (3600) 71
* # 🭬 0x09, 0x48, // Usage (Resolution Multiplier) 74
* # ║ 0xb1, 0x02, // Feature (Data,Var,Abs) 76
* # 0x45, 0x00, // Physical Maximum (0) 78
* # 0xc0, // End Collection 80
* # 0x75, 0x08, // Report Size (8) 81
* # 0x95, 0x01, // Report Count (1) 83
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 85
* # 0x75, 0x08, // Report Size (8) 87
* # 0x95, 0x01, // Report Count (1) 89
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 91
* # 0x75, 0x08, // Report Size (8) 93
* # 0x95, 0x01, // Report Count (1) 95
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 97
* # 0x75, 0x08, // Report Size (8) 99
* # 0x95, 0x01, // Report Count (1) 101
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 103
* # 0x75, 0x08, // Report Size (8) 105
* # 0x95, 0x01, // Report Count (1) 107
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 109
* # 0xc0, // End Collection 111
* # 0xc0, // End Collection 112
* # 0xc0, // End Collection 113
* R: 114 05 01 09 0e a1 01 85 03 05 0d 75 08 95 01 81 01 09 21 a1 02 15 00 25 01 75 01 95 01 a1 00 05 09 09 01 81 02 05 0d 09 33 81 02 95 06 81 03 a1 02 05 01 09 37 16 00 80 26 ff 7f 75 10 95 01 81 06 35 00 46 10 0e 15 00 26 10 0e 09 48 b1 02 45 00 c0 75 08 95 01 81 01 75 08 95 01 81 01 75 08 95 01 81 01 75 08 95 01 81 01 75 08 95 01 81 01 c0 c0 c0
* N: Keydial mini-050
* I: 5 256c 8251
*
* The second hidraw node is what sends events:
*
* # Keydial mini-050
* # Report descriptor length: 160 bytes
* # Bytes // Field Name Offset
* # ----------------------------------------------------------------------------------
* # 🮥 0x05, 0x01, // Usage Page (Generic Desktop) 0
* # 🭬 0x09, 0x06, // Usage (Keyboard) 2
* # 0xa1, 0x01, // Collection (Application) 4
* # ┅ 0x85, 0x01, // Report ID (1) 6
* # 🮥 0x05, 0x07, // Usage Page (Keyboard/Keypad) 8
* # 🭬 0x19, 0xe0, // Usage Minimum (224) 10
* # 🭬 0x29, 0xe7, // Usage Maximum (231) 12
* # 0x15, 0x00, // Logical Minimum (0) 14
* # 0x25, 0x01, // Logical Maximum (1) 16
* # 0x75, 0x01, // Report Size (1) 18
* # 0x95, 0x08, // Report Count (8) 20
* # ┇ 0x81, 0x02, // Input (Data,Var,Abs) 22
* # 0x95, 0x01, // Report Count (1) 24
* # 0x75, 0x08, // Report Size (8) 26
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 28
* # 0x95, 0x05, // Report Count (5) 30
* # 0x75, 0x01, // Report Size (1) 32
* # 🮥 0x05, 0x08, // Usage Page (LED) 34
* # 🭬 0x19, 0x01, // Usage Minimum (1) 36
* # 🭬 0x29, 0x05, // Usage Maximum (5) 38
* # ┊ 0x91, 0x02, // Output (Data,Var,Abs) 40
* # 0x95, 0x01, // Report Count (1) 42
* # 0x75, 0x03, // Report Size (3) 44
* # ┊ 0x91, 0x01, // Output (Cnst,Arr,Abs) 46
* # 0x95, 0x06, // Report Count (6) 48
* # 0x75, 0x08, // Report Size (8) 50
* # 0x15, 0x00, // Logical Minimum (0) 52
* # 0x25, 0xf1, // Logical Maximum (241) 54
* # 🮥 0x05, 0x07, // Usage Page (Keyboard/Keypad) 56
* # 🭬 0x19, 0x00, // Usage Minimum (0) 58
* # 🭬 0x29, 0xf1, // Usage Maximum (241) 60
* # ┇ 0x81, 0x00, // Input (Data,Arr,Abs) 62
* # 0xc0, // End Collection 64
* # 🮥 0x05, 0x0c, // Usage Page (Consumer) 65
* # 🭬 0x09, 0x01, // Usage (Consumer Control) 67
* # 0xa1, 0x01, // Collection (Application) 69
* # ┅ 0x85, 0x02, // Report ID (2) 71
* # 🮥 0x05, 0x0c, // Usage Page (Consumer) 73
* # 🭬 0x19, 0x00, // Usage Minimum (0) 75
* # 🭬 0x2a, 0x80, 0x03, // Usage Maximum (896) 77
* # 0x15, 0x00, // Logical Minimum (0) 80
* # 0x26, 0x80, 0x03, // Logical Maximum (896) 82
* # 0x75, 0x10, // Report Size (16) 85
* # 0x95, 0x01, // Report Count (1) 87
* # ┇ 0x81, 0x00, // Input (Data,Arr,Abs) 89
* # 0xc0, // End Collection 91
* # 🮥 0x05, 0x01, // Usage Page (Generic Desktop) 92
* # 🭬 0x09, 0x02, // Usage (Mouse) 94
* # 0xa1, 0x01, // Collection (Application) 96
* # 🭬 0x09, 0x01, // Usage (Pointer) 98
* # ┅ 0x85, 0x05, // Report ID (5) 100
* # 0xa1, 0x00, // Collection (Physical) 102
* # 🮥 0x05, 0x09, // Usage Page (Button) 104
* # 🭬 0x19, 0x01, // Usage Minimum (1) 106
* # 🭬 0x29, 0x05, // Usage Maximum (5) 108
* # 0x15, 0x00, // Logical Minimum (0) 110
* # 0x25, 0x01, // Logical Maximum (1) 112
* # 0x95, 0x05, // Report Count (5) 114
* # 0x75, 0x01, // Report Size (1) 116
* # ┇ 0x81, 0x02, // Input (Data,Var,Abs) 118
* # 0x95, 0x01, // Report Count (1) 120
* # 0x75, 0x03, // Report Size (3) 122
* # ┇ 0x81, 0x01, // Input (Cnst,Arr,Abs) 124
* # 🮥 0x05, 0x01, // Usage Page (Generic Desktop) 126
* # 🭬 0x09, 0x30, // Usage (X) 128
* # 🭬 0x09, 0x31, // Usage (Y) 130
* # 0x16, 0x01, 0x80, // Logical Minimum (32769) 132
* # 0x26, 0xff, 0x7f, // Logical Maximum (32767) 135
* # 0x75, 0x10, // Report Size (16) 138
* # 0x95, 0x02, // Report Count (2) 140
* # ┇ 0x81, 0x06, // Input (Data,Var,Rel) 142
* # 🮥 0x05, 0x01, // Usage Page (Generic Desktop) 144
* # 🭬 0x09, 0x38, // Usage (Wheel) 146
* # 0x15, 0x81, // Logical Minimum (129) 148
* # 0x25, 0x7f, // Logical Maximum (127) 150
* # 0x95, 0x01, // Report Count (1) 152
* # 0x75, 0x08, // Report Size (8) 154
* # ┇ 0x81, 0x06, // Input (Data,Var,Rel) 156
* # 0xc0, // End Collection 158
* # 0xc0, // End Collection 159
* R: 160 05 01 09 06 a1 01 85 01 05 07 19 e0 29 e7 15 00 25 01 75 01 95 08 81 02 95 01 75 08 81 01 95 05 75 01 05 08 19 01 29 05 91 02 95 01 75 03 91 01 95 06 75 08 15 00 25 f1 05 07 19 00 29 f1 81 00 c0 05 0c 09 01 a1 01 85 02 05 0c 19 00 2a 80 03 15 00 26 80 03 75 10 95 01 81 00 c0 05 01 09 02 a1 01 09 01 85 05 a1 00 05 09 19 01 29 05 15 00 25 01 95 05 75 01 81 02 95 01 75 03 81 01 05 01 09 30 09 31 16 01 80 26 ff 7f 75 10 95 02 81 06 05 01 09 38 15 81 25 7f 95 01 75 08 81 06 c0 c0
* N: Keydial mini-050
* I: 5 256c 8251
* # Report descriptor:
* # ------- Input Report -------
* # ░ Report ID: 1
* # ░ | Report size: 72 bits
* # ░ Bit: 8 Usage: 0007/00e0: Keyboard/Keypad / Keyboard LeftControl Logical Range: 0..=1
* # ░ Bit: 9 Usage: 0007/00e1: Keyboard/Keypad / Keyboard LeftShift Logical Range: 0..=1
* # ░ Bit: 10 Usage: 0007/00e2: Keyboard/Keypad / Keyboard LeftAlt Logical Range: 0..=1
* # ░ Bit: 11 Usage: 0007/00e3: Keyboard/Keypad / Keyboard Left GUI Logical Range: 0..=1
* # ░ Bit: 12 Usage: 0007/00e4: Keyboard/Keypad / Keyboard RightControl Logical Range: 0..=1
* # ░ Bit: 13 Usage: 0007/00e5: Keyboard/Keypad / Keyboard RightShift Logical Range: 0..=1
* # ░ Bit: 14 Usage: 0007/00e6: Keyboard/Keypad / Keyboard RightAlt Logical Range: 0..=1
* # ░ Bit: 15 Usage: 0007/00e7: Keyboard/Keypad / Keyboard Right GUI Logical Range: 0..=1
* # ░ Bits: 16..=23 ######### Padding
* # ░ Bits: 24..=71 Usages: Logical Range: 0..=241
* # ░ 0007/0000: <unknown>
* # ░ 0007/0001: Keyboard/Keypad / ErrorRollOver
* # ░ 0007/0002: Keyboard/Keypad / POSTFail
* # ░ 0007/0003: Keyboard/Keypad / ErrorUndefined
* # ░ 0007/0004: Keyboard/Keypad / Keyboard A
* # ░ ... use --full to see all usages
* # ------- Input Report -------
* # ▒ Report ID: 2
* # ▒ | Report size: 24 bits
* # ▒ Bits: 8..=23 Usages: Logical Range: 0..=896
* # ▒ 000c/0000: <unknown>
* # ▒ 000c/0001: Consumer / Consumer Control
* # ▒ 000c/0002: Consumer / Numeric Key Pad
* # ▒ 000c/0003: Consumer / Programmable Buttons
* # ▒ 000c/0004: Consumer / Microphone
* # ▒ ... use --full to see all usages
* # ------- Input Report -------
* # ▞ Report ID: 5
* # ▞ | Report size: 56 bits
* # ▞ Bit: 8 Usage: 0009/0001: Button / Button 1 Logical Range: 0..=1
* # ▞ Bit: 9 Usage: 0009/0002: Button / Button 2 Logical Range: 0..=1
* # ▞ Bit: 10 Usage: 0009/0003: Button / Button 3 Logical Range: 0..=1
* # ▞ Bit: 11 Usage: 0009/0004: Button / Button 4 Logical Range: 0..=1
* # ▞ Bit: 12 Usage: 0009/0005: Button / Button 5 Logical Range: 0..=1
* # ▞ Bits: 13..=15 ######### Padding
* # ▞ Bits: 16..=31 Usage: 0001/0030: Generic Desktop / X Logical Range: 32769..=32767
* # ▞ Bits: 32..=47 Usage: 0001/0031: Generic Desktop / Y Logical Range: 32769..=32767
* # ▞ Bits: 48..=55 Usage: 0001/0038: Generic Desktop / Wheel Logical Range: 129..=127
* # ------- Output Report -------
* # ░ Report ID: 1
* # ░ | Report size: 16 bits
* # ░ Bit: 8 Usage: 0008/0001: LED / Num Lock Logical Range: 0..=1
* # ░ Bit: 9 Usage: 0008/0002: LED / Caps Lock Logical Range: 0..=1
* # ░ Bit: 10 Usage: 0008/0003: LED / Scroll Lock Logical Range: 0..=1
* # ░ Bit: 11 Usage: 0008/0004: LED / Compose Logical Range: 0..=1
* # ░ Bit: 12 Usage: 0008/0005: LED / Kana Logical Range: 0..=1
* # ░ Bits: 13..=15 ######### Padding
* ##############################################################################
* # Event nodes:
* # - /dev/input/event12: "Keydial mini-050 Keyboard"
* # - /dev/input/event14: "Keydial mini-050 Mouse"
* ##############################################################################
* # Recorded events below in format:
* # E: <seconds>.<microseconds> <length-in-bytes> [bytes ...]
* #
*
* - Report ID 1 sends keyboard shortcuts when pressing the buttons, e.g.
*
* # ░ Report ID: 1 /
* # ░ Keyboard LeftControl: 0 |Keyboard LeftShift: 0 |Keyboard LeftAlt: 0 |Keyboard Left GUI: 0 |Keyboard RightControl: 0 |Keyboard RightShift: 0 |Keyboard RightAlt: 0 |Keyboard Right GUI: 0 |<8 bits padding> |0007/0000: 0| Keyboard K: 14| 0007/0000: 0| 0007/0000: 0| 0007/0000: 0| 0007/0000: 0
* E: 000000.000292 9 01 00 00 00 0e 00 00 00 00
*
* - Report ID 2 sends the button inside the wheel/dial thing
* # ▒ Report ID: 2 /
* # ▒ Play/Pause: 205
* E: 000134.347845 3 02 cd 00
* # ▒ Report ID: 2 /
* # ▒ 000c/0000: 0
* E: 000134.444965 3 02 00 00
*
* - Report ID 5 sends the wheel relative events (always a double-event with the second as zero)
* # ▞ Report ID: 5 /
* # ▞ Button 1: 0 |Button 2: 0 |Button 3: 0 |Button 4: 0 |Button 5: 0 |<3 bits padding> |X: 0 |Y: 0 |Wheel: 255
* E: 000064.859915 7 05 00 00 00 00 00 ff
* # ▞ Report ID: 5 /
* # ▞ Button 1: 0 |Button 2: 0 |Button 3: 0 |Button 4: 0 |Button 5: 0 |<3 bits padding> |X: 0 |Y: 0 |Wheel: 0
* E: 000064.882009 7 05 00 00 00 00 00 00
*/
#define BT_PAD_REPORT_DESCRIPTOR_LENGTH 160
#define BT_PUCK_REPORT_DESCRIPTOR_LENGTH 114 // This one doesn't send events
#define BT_PAD_KBD_REPORT_ID 1
#define BT_PAD_CC_REPORT_ID 2
#define BT_PAD_MOUSE_REPORT_ID 5
#define BT_PAD_KBD_REPORT_LENGTH 9
#define BT_PAD_CC_REPORT_LENGTH 3
#define BT_PAD_MOUSE_REPORT_LENGTH 7
#define OUR_REPORT_ID 11 /* "randomly" picked report ID for our reports */
__u32 last_button_state = 0;
static const __u8 disabled_rdesc_puck[] = {
FixedSizeVendorReport(BT_PUCK_REPORT_DESCRIPTOR_LENGTH)
};
static const __u8 fixed_rdesc_pad[] = {
UsagePage_GenericDesktop
Usage_GD_Keypad
CollectionApplication(
// Byte 0
ReportId(OUR_REPORT_ID)
UsagePage_Digitizers
Usage_Dig_TabletFunctionKeys
CollectionPhysical(
// Byte 1 is a button so we look like a tablet
Usage_Dig_BarrelSwitch // BTN_STYLUS, needed so we get to be a tablet pad
ReportCount(1)
ReportSize(1)
Input(Var|Abs)
ReportCount(7) // Padding
Input(Const)
// Bytes 2/3 - x/y just exist so we get to be a tablet pad
UsagePage_GenericDesktop
Usage_GD_X
Usage_GD_Y
LogicalMinimum_i8(0x0)
LogicalMaximum_i8(0x1)
ReportCount(2)
ReportSize(8)
Input(Var|Abs)
// Bytes 4-7 are the button state for 19 buttons + pad out to u32
// We send the first 10 buttons as buttons 1-10 which is BTN_0 -> BTN_9
UsagePage_Button
UsageMinimum_i8(1)
UsageMaximum_i8(10)
LogicalMinimum_i8(0x0)
LogicalMaximum_i8(0x1)
ReportCount(10)
ReportSize(1)
Input(Var|Abs)
// We send the other 9 buttons as buttons 0x31 and above -> BTN_A - BTN_TL2
UsageMinimum_i8(0x31)
UsageMaximum_i8(0x3a)
ReportCount(9)
ReportSize(1)
Input(Var|Abs)
ReportCount(13)
ReportSize(1)
Input(Const) // padding
// Byte 8 is the wheel
UsagePage_GenericDesktop
Usage_GD_Wheel
LogicalMinimum_i8(-1)
LogicalMaximum_i8(1)
ReportCount(1)
ReportSize(8)
Input(Var|Rel)
)
// Make sure we match our original report length
FixedSizeVendorReport(BT_PAD_KBD_REPORT_LENGTH)
)
};
SEC(HID_BPF_RDESC_FIXUP)
int BPF_PROG(k20_bt_fix_rdesc, struct hid_bpf_ctx *hctx)
{
__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, HID_MAX_DESCRIPTOR_SIZE /* size */);
__s32 rdesc_size = hctx->size;
if (!data)
return 0; /* EPERM check */
if (rdesc_size == BT_PAD_REPORT_DESCRIPTOR_LENGTH) {
__builtin_memcpy(data, fixed_rdesc_pad, sizeof(fixed_rdesc_pad));
return sizeof(fixed_rdesc_pad);
}
if (rdesc_size == BT_PUCK_REPORT_DESCRIPTOR_LENGTH) {
// This hidraw node doesn't send anything and can be ignored
__builtin_memcpy(data, disabled_rdesc_puck, sizeof(disabled_rdesc_puck));
return sizeof(disabled_rdesc_puck);
}
return 0;
}
SEC(HID_BPF_DEVICE_EVENT)
int BPF_PROG(k20_bt_fix_events, struct hid_bpf_ctx *hctx)
{
__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 12 /* size */);
struct pad_report {
__u8 report_id;
__u8 btn_stylus:1;
__u8 pad:7;
__u8 x;
__u8 y;
__u32 buttons;
__u8 wheel;
} __packed * pad_report = (struct pad_report *)data;
if (!data)
return 0; /* EPERM check */
/* Report ID 1 - Keyboard events (button presses) */
if (data[0] == BT_PAD_KBD_REPORT_ID) {
const __u8 button_mapping[] = {
0x0e, /* Button 1: K */
0x0a, /* Button 2: G */
0x0f, /* Button 3: L */
0x4c, /* Button 4: Delete */
0x0c, /* Button 5: I */
0x07, /* Button 6: D */
0x05, /* Button 7: B */
0x08, /* Button 8: E */
0x16, /* Button 9: S */
0x1d, /* Button 10: Z */
0x06, /* Button 11: C */
0x19, /* Button 12: V */
0xff, /* Button 13: LeftControl */
0xff, /* Button 14: LeftAlt */
0xff, /* Button 15: LeftShift */
0x28, /* Button 16: Return Enter */
0x2c, /* Button 17: Spacebar */
0x11, /* Button 18: N */
};
__u8 modifiers = data[1];
__u32 buttons = 0;
if (modifiers & 0x01) { /* Control */
buttons |= BIT(12);
}
if (modifiers & 0x02) { /* Shift */
buttons |= BIT(14);
}
if (modifiers & 0x04) { /* Alt */
buttons |= BIT(13);
}
for (int i = 4; i < BT_PAD_KBD_REPORT_LENGTH; i++) {
if (!data[i])
break;
for (size_t b = 0; b < ARRAY_SIZE(button_mapping); b++) {
if (data[i] != 0xff && data[i] == button_mapping[b]) {
buttons |= BIT(b);
break;
}
}
}
last_button_state = buttons;
pad_report->report_id = OUR_REPORT_ID;
pad_report->btn_stylus = 0;
pad_report->x = 0;
pad_report->y = 0;
pad_report->buttons = buttons;
pad_report->wheel = 0;
return sizeof(struct pad_report);
}
/* Report ID 2 - Consumer control events (the button inside the wheel) */
if (data[0] == BT_PAD_CC_REPORT_ID) {
const __u8 PlayPause = 0xcd;
if (data[1] == PlayPause)
last_button_state |= BIT(18);
else
last_button_state &= ~BIT(18);
pad_report->report_id = OUR_REPORT_ID;
pad_report->btn_stylus = 0;
pad_report->x = 0;
pad_report->y = 0;
pad_report->buttons = last_button_state;
pad_report->wheel = 0;
return sizeof(struct pad_report);
}
/* Report ID 5 - Mouse events (wheel rotation) */
if (data[0] == BT_PAD_MOUSE_REPORT_ID) {
__u8 wheel_delta = data[6];
pad_report->report_id = OUR_REPORT_ID;
pad_report->btn_stylus = 0;
pad_report->x = 0;
pad_report->y = 0;
pad_report->buttons = last_button_state;
pad_report->wheel = wheel_delta;
return sizeof(struct pad_report);
}
return 0;
}
HID_BPF_OPS(keydial_k20_bluetooth) = {
.hid_device_event = (void *)k20_bt_fix_events,
.hid_rdesc_fixup = (void *)k20_bt_fix_rdesc,
};
SEC("syscall")
int probe(struct hid_bpf_probe_args *ctx)
{
switch (ctx->rdesc_size) {
case BT_PAD_REPORT_DESCRIPTOR_LENGTH:
case BT_PUCK_REPORT_DESCRIPTOR_LENGTH:
ctx->retval = 0;
break;
default:
ctx->retval = -EINVAL;
}
return 0;
}
char _license[] SEC("license") = "GPL";
|
