CoCalc -- Huion__Kamvas-Pro-19.bpf.c

GitHub Repository: torvalds/linux
Path: blob/master/drivers/hid/bpf/progs/Huion__Kamvas-Pro-19.bpf.c
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1
// SPDX-License-Identifier: GPL-2.0-only
2
/* Copyright (c) 2024 Benjamin Tissoires
3
 */
4

5
#include "vmlinux.h"
6
#include "hid_bpf.h"
7
#include "hid_bpf_helpers.h"
8
#include <bpf/bpf_tracing.h>
9

10
#define VID_HUION 0x256C
11
#define PID_KAMVAS_PRO_19 0x006B
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#define NAME_KAMVAS_PRO_19 "HUION Huion Tablet_GT1902"
13

14
#define TEST_PREFIX "uhid test "
15

16
HID_BPF_CONFIG(
17
	HID_DEVICE(BUS_USB, HID_GROUP_MULTITOUCH_WIN_8, VID_HUION, PID_KAMVAS_PRO_19),
18
);
19

20
bool prev_was_out_of_range;
21
bool in_eraser_mode;
22

23
/*
24
 * We need to amend the report descriptor for the following:
25
 * - the second button is reported through Secondary Tip Switch instead of Secondary Barrel Switch
26
 * - the third button is reported through Invert, and we need some room to report it.
27
 *
28
 */
29
static const __u8 fixed_rdesc[] = {
30
	0x05, 0x0d,                    // Usage Page (Digitizers)             0
31
	0x09, 0x02,                    // Usage (Pen)                         2
32
	0xa1, 0x01,                    // Collection (Application)            4
33
	0x85, 0x0a,                    //  Report ID (10)                     6
34
	0x09, 0x20,                    //  Usage (Stylus)                     8
35
	0xa1, 0x01,                    //  Collection (Application)           10
36
	0x09, 0x42,                    //   Usage (Tip Switch)                12
37
	0x09, 0x44,                    //   Usage (Barrel Switch)             14
38
	0x09, 0x5a,                    //   Usage (Secondary Barrel Switch)   16 /* changed from Secondary Tip Switch */
39
	0x09, 0x3c,                    //   Usage (Invert)                    18
40
	0x09, 0x45,                    //   Usage (Eraser)                    20
41
	0x15, 0x00,                    //   Logical Minimum (0)               22
42
	0x25, 0x01,                    //   Logical Maximum (1)               24
43
	0x75, 0x01,                    //   Report Size (1)                   26
44
	0x95, 0x05,                    //   Report Count (5)                  28 /* changed (was 6) */
45
	0x81, 0x02,                    //   Input (Data,Var,Abs)              30
46
	0x05, 0x09,                    //   Usage Page (Button)                  /* inserted */
47
	0x09, 0x4a,                    //   Usage (0x4a)                         /* inserted to be translated as input usage 0x149: BTN_STYLUS3 */
48
	0x95, 0x01,                    //   Report Count (1)                     /* inserted */
49
	0x81, 0x02,                    //   Input (Data,Var,Abs)                 /* inserted */
50
	0x05, 0x0d,                    //   Usage Page (Digitizers)              /* inserted */
51
	0x09, 0x32,                    //   Usage (In Range)                  32
52
	0x75, 0x01,                    //   Report Size (1)                   34
53
	0x95, 0x01,                    //   Report Count (1)                  36
54
	0x81, 0x02,                    //   Input (Data,Var,Abs)              38
55
	0x81, 0x03,                    //   Input (Cnst,Var,Abs)              40
56
	0x05, 0x01,                    //   Usage Page (Generic Desktop)      42
57
	0x09, 0x30,                    //   Usage (X)                         44
58
	0x09, 0x31,                    //   Usage (Y)                         46
59
	0x55, 0x0d,                    //   Unit Exponent (-3)                48
60
	0x65, 0x33,                    //   Unit (EnglishLinear: in³)         50
61
	0x26, 0xff, 0x7f,              //   Logical Maximum (32767)           52
62
	0x35, 0x00,                    //   Physical Minimum (0)              55
63
	0x46, 0x00, 0x08,              //   Physical Maximum (2048)           57
64
	0x75, 0x10,                    //   Report Size (16)                  60
65
	0x95, 0x02,                    //   Report Count (2)                  62
66
	0x81, 0x02,                    //   Input (Data,Var,Abs)              64
67
	0x05, 0x0d,                    //   Usage Page (Digitizers)           66
68
	0x09, 0x30,                    //   Usage (Tip Pressure)              68
69
	0x26, 0xff, 0x3f,              //   Logical Maximum (16383)           70
70
	0x75, 0x10,                    //   Report Size (16)                  73
71
	0x95, 0x01,                    //   Report Count (1)                  75
72
	0x81, 0x02,                    //   Input (Data,Var,Abs)              77
73
	0x09, 0x3d,                    //   Usage (X Tilt)                    79
74
	0x09, 0x3e,                    //   Usage (Y Tilt)                    81
75
	0x15, 0xa6,                    //   Logical Minimum (-90)             83
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	0x25, 0x5a,                    //   Logical Maximum (90)              85
77
	0x75, 0x08,                    //   Report Size (8)                   87
78
	0x95, 0x02,                    //   Report Count (2)                  89
79
	0x81, 0x02,                    //   Input (Data,Var,Abs)              91
80
	0xc0,                          //  End Collection                     93
81
	0xc0,                          // End Collection                      94
82
	0x05, 0x0d,                    // Usage Page (Digitizers)             95
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	0x09, 0x04,                    // Usage (Touch Screen)                97
84
	0xa1, 0x01,                    // Collection (Application)            99
85
	0x85, 0x04,                    //  Report ID (4)                      101
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	0x09, 0x22,                    //  Usage (Finger)                     103
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	0xa1, 0x02,                    //  Collection (Logical)               105
88
	0x05, 0x0d,                    //   Usage Page (Digitizers)           107
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	0x95, 0x01,                    //   Report Count (1)                  109
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	0x75, 0x06,                    //   Report Size (6)                   111
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	0x09, 0x51,                    //   Usage (Contact Id)                113
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	0x15, 0x00,                    //   Logical Minimum (0)               115
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	0x25, 0x3f,                    //   Logical Maximum (63)              117
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	0x81, 0x02,                    //   Input (Data,Var,Abs)              119
95
	0x09, 0x42,                    //   Usage (Tip Switch)                121
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	0x25, 0x01,                    //   Logical Maximum (1)               123
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	0x75, 0x01,                    //   Report Size (1)                   125
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	0x95, 0x01,                    //   Report Count (1)                  127
99
	0x81, 0x02,                    //   Input (Data,Var,Abs)              129
100
	0x75, 0x01,                    //   Report Size (1)                   131
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	0x95, 0x01,                    //   Report Count (1)                  133
102
	0x81, 0x03,                    //   Input (Cnst,Var,Abs)              135
103
	0x05, 0x01,                    //   Usage Page (Generic Desktop)      137
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	0x75, 0x10,                    //   Report Size (16)                  139
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	0x55, 0x0e,                    //   Unit Exponent (-2)                141
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	0x65, 0x11,                    //   Unit (SILinear: cm)               143
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	0x09, 0x30,                    //   Usage (X)                         145
108
	0x26, 0xff, 0x7f,              //   Logical Maximum (32767)           147
109
	0x35, 0x00,                    //   Physical Minimum (0)              150
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	0x46, 0x15, 0x0c,              //   Physical Maximum (3093)           152
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	0x81, 0x42,                    //   Input (Data,Var,Abs,Null)         155
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	0x09, 0x31,                    //   Usage (Y)                         157
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	0x26, 0xff, 0x7f,              //   Logical Maximum (32767)           159
114
	0x46, 0xcb, 0x06,              //   Physical Maximum (1739)           162
115
	0x81, 0x42,                    //   Input (Data,Var,Abs,Null)         165
116
	0x05, 0x0d,                    //   Usage Page (Digitizers)           167
117
	0x09, 0x30,                    //   Usage (Tip Pressure)              169
118
	0x26, 0xff, 0x1f,              //   Logical Maximum (8191)            171
119
	0x75, 0x10,                    //   Report Size (16)                  174
120
	0x95, 0x01,                    //   Report Count (1)                  176
121
	0x81, 0x02,                    //   Input (Data,Var,Abs)              178
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	0xc0,                          //  End Collection                     180
123
	0x05, 0x0d,                    //  Usage Page (Digitizers)            181
124
	0x09, 0x22,                    //  Usage (Finger)                     183
125
	0xa1, 0x02,                    //  Collection (Logical)               185
126
	0x05, 0x0d,                    //   Usage Page (Digitizers)           187
127
	0x95, 0x01,                    //   Report Count (1)                  189
128
	0x75, 0x06,                    //   Report Size (6)                   191
129
	0x09, 0x51,                    //   Usage (Contact Id)                193
130
	0x15, 0x00,                    //   Logical Minimum (0)               195
131
	0x25, 0x3f,                    //   Logical Maximum (63)              197
132
	0x81, 0x02,                    //   Input (Data,Var,Abs)              199
133
	0x09, 0x42,                    //   Usage (Tip Switch)                201
134
	0x25, 0x01,                    //   Logical Maximum (1)               203
135
	0x75, 0x01,                    //   Report Size (1)                   205
136
	0x95, 0x01,                    //   Report Count (1)                  207
137
	0x81, 0x02,                    //   Input (Data,Var,Abs)              209
138
	0x75, 0x01,                    //   Report Size (1)                   211
139
	0x95, 0x01,                    //   Report Count (1)                  213
140
	0x81, 0x03,                    //   Input (Cnst,Var,Abs)              215
141
	0x05, 0x01,                    //   Usage Page (Generic Desktop)      217
142
	0x75, 0x10,                    //   Report Size (16)                  219
143
	0x55, 0x0e,                    //   Unit Exponent (-2)                221
144
	0x65, 0x11,                    //   Unit (SILinear: cm)               223
145
	0x09, 0x30,                    //   Usage (X)                         225
146
	0x26, 0xff, 0x7f,              //   Logical Maximum (32767)           227
147
	0x35, 0x00,                    //   Physical Minimum (0)              230
148
	0x46, 0x15, 0x0c,              //   Physical Maximum (3093)           232
149
	0x81, 0x42,                    //   Input (Data,Var,Abs,Null)         235
150
	0x09, 0x31,                    //   Usage (Y)                         237
151
	0x26, 0xff, 0x7f,              //   Logical Maximum (32767)           239
152
	0x46, 0xcb, 0x06,              //   Physical Maximum (1739)           242
153
	0x81, 0x42,                    //   Input (Data,Var,Abs,Null)         245
154
	0x05, 0x0d,                    //   Usage Page (Digitizers)           247
155
	0x09, 0x30,                    //   Usage (Tip Pressure)              249
156
	0x26, 0xff, 0x1f,              //   Logical Maximum (8191)            251
157
	0x75, 0x10,                    //   Report Size (16)                  254
158
	0x95, 0x01,                    //   Report Count (1)                  256
159
	0x81, 0x02,                    //   Input (Data,Var,Abs)              258
160
	0xc0,                          //  End Collection                     260
161
	0x05, 0x0d,                    //  Usage Page (Digitizers)            261
162
	0x09, 0x56,                    //  Usage (Scan Time)                  263
163
	0x55, 0x00,                    //  Unit Exponent (0)                  265
164
	0x65, 0x00,                    //  Unit (None)                        267
165
	0x27, 0xff, 0xff, 0xff, 0x7f,  //  Logical Maximum (2147483647)       269
166
	0x95, 0x01,                    //  Report Count (1)                   274
167
	0x75, 0x20,                    //  Report Size (32)                   276
168
	0x81, 0x02,                    //  Input (Data,Var,Abs)               278
169
	0x09, 0x54,                    //  Usage (Contact Count)              280
170
	0x25, 0x7f,                    //  Logical Maximum (127)              282
171
	0x95, 0x01,                    //  Report Count (1)                   284
172
	0x75, 0x08,                    //  Report Size (8)                    286
173
	0x81, 0x02,                    //  Input (Data,Var,Abs)               288
174
	0x75, 0x08,                    //  Report Size (8)                    290
175
	0x95, 0x08,                    //  Report Count (8)                   292
176
	0x81, 0x03,                    //  Input (Cnst,Var,Abs)               294
177
	0x85, 0x05,                    //  Report ID (5)                      296
178
	0x09, 0x55,                    //  Usage (Contact Max)                298
179
	0x25, 0x0a,                    //  Logical Maximum (10)               300
180
	0x75, 0x08,                    //  Report Size (8)                    302
181
	0x95, 0x01,                    //  Report Count (1)                   304
182
	0xb1, 0x02,                    //  Feature (Data,Var,Abs)             306
183
	0x06, 0x00, 0xff,              //  Usage Page (Vendor Defined Page 1) 308
184
	0x09, 0xc5,                    //  Usage (Vendor Usage 0xc5)          311
185
	0x85, 0x06,                    //  Report ID (6)                      313
186
	0x15, 0x00,                    //  Logical Minimum (0)                315
187
	0x26, 0xff, 0x00,              //  Logical Maximum (255)              317
188
	0x75, 0x08,                    //  Report Size (8)                    320
189
	0x96, 0x00, 0x01,              //  Report Count (256)                 322
190
	0xb1, 0x02,                    //  Feature (Data,Var,Abs)             325
191
	0xc0,                          // End Collection                      327
192
	/* New in Firmware Version: HUION_M220_240524 */
193
	0x05, 0x01,                    // Usage Page (Generic Desktop)            328
194
	0x09, 0x01,                    // Usage (Pointer)                         330
195
	0xa1, 0x01,                    // Collection (Application)                332
196
	0x09, 0x01,                    //   Usage (Pointer)                       334
197
	0xa1, 0x00,                    //   Collection (Physical)                 336
198
	0x05, 0x09,                    //     Usage Page (Button)                 338
199
	0x19, 0x01,                    //     UsageMinimum (1)                    340
200
	0x29, 0x03,                    //     UsageMaximum (3)                    342
201
	0x15, 0x00,                    //     Logical Minimum (0)                 344
202
	0x25, 0x01,                    //     Logical Maximum (1)                 346
203
	0x85, 0x02,                    //     Report ID (2)                       348
204
	0x95, 0x03,                    //     Report Count (3)                    350
205
	0x75, 0x01,                    //     Report Size (1)                     352
206
	0x81, 0x02,                    //     Input (Data,Var,Abs)                354
207
	0x95, 0x01,                    //     Report Count (1)                    356
208
	0x75, 0x05,                    //     Report Size (5)                     358
209
	0x81, 0x01,                    //     Input (Cnst,Arr,Abs)                360
210
	0x05, 0x01,                    //     Usage Page (Generic Desktop)        362
211
	0x09, 0x30,                    //     Usage (X)                           364
212
	0x09, 0x31,                    //     Usage (Y)                           366
213
	0x15, 0x81,                    //     Logical Minimum (-127)              368
214
	0x25, 0x7f,                    //     Logical Maximum (127)               370
215
	0x75, 0x08,                    //     Report Size (8)                     372
216
	0x95, 0x02,                    //     Report Count (2)                    374
217
	0x81, 0x06,                    //     Input (Data,Var,Rel)                376
218
	0x95, 0x04,                    //     Report Count (4)                    378
219
	0x75, 0x08,                    //     Report Size (8)                     380
220
	0x81, 0x01,                    //     Input (Cnst,Arr,Abs)                382
221
	0xc0,                          //   End Collection                        384
222
	0xc0,                          // End Collection                          385
223
	0x05, 0x0d,                    // Usage Page (Digitizers)                 386
224
	0x09, 0x05,                    // Usage (Touch Pad)                       388
225
	0xa1, 0x01,                    // Collection (Application)                390
226
	0x06, 0x00, 0xff,              //   Usage Page (Vendor Defined Page FF00) 392
227
	0x09, 0x0c,                    //   Usage (Vendor Usage 0x0c)             395
228
	0x15, 0x00,                    //   Logical Minimum (0)                   397
229
	0x26, 0xff, 0x00,              //   Logical Maximum (255)                 399
230
	0x75, 0x08,                    //   Report Size (8)                       402
231
	0x95, 0x10,                    //   Report Count (16)                     404
232
	0x85, 0x3f,                    //   Report ID (63)                        406
233
	0x81, 0x22,                    //   Input (Data,Var,Abs,NoPref)           408
234
	0xc0,                          // End Collection                          410
235
	0x06, 0x00, 0xff,              // Usage Page (Vendor Defined Page FF00)   411
236
	0x09, 0x0c,                    // Usage (Vendor Usage 0x0c)               414
237
	0xa1, 0x01,                    // Collection (Application)                416
238
	0x06, 0x00, 0xff,              //   Usage Page (Vendor Defined Page FF00) 418
239
	0x09, 0x0c,                    //   Usage (Vendor Usage 0x0c)             421
240
	0x15, 0x00,                    //   Logical Minimum (0)                   423
241
	0x26, 0xff, 0x00,              //   Logical Maximum (255)                 425
242
	0x85, 0x44,                    //   Report ID (68)                        428
243
	0x75, 0x08,                    //   Report Size (8)                       430
244
	0x96, 0x6b, 0x05,              //   Report Count (1387)                   432
245
	0x81, 0x00,                    //   Input (Data,Arr,Abs)                  435
246
	0xc0,                          // End Collection                          437
247
};
248

249
#define PRE_240524_RDESC_SIZE 328
250
#define PRE_240524_RDESC_FIXED_SIZE 338 /* The original bits of the descriptor */
251
#define FW_240524_RDESC_SIZE 438
252
#define FW_240524_RDESC_FIXED_SIZE sizeof(fixed_rdesc)
253

254
SEC(HID_BPF_RDESC_FIXUP)
255
int BPF_PROG(hid_fix_rdesc_huion_kamvas_pro_19, struct hid_bpf_ctx *hctx)
256
{
257
	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, HID_MAX_DESCRIPTOR_SIZE /* size */);
258

259
	if (!data)
260
		return 0; /* EPERM check */
261

262
	if (hctx->size == FW_240524_RDESC_SIZE) {
263
		__builtin_memcpy(data, fixed_rdesc, FW_240524_RDESC_FIXED_SIZE);
264
		return sizeof(fixed_rdesc);
265
	}
266

267
	__builtin_memcpy(data, fixed_rdesc, PRE_240524_RDESC_FIXED_SIZE);
268

269
	return PRE_240524_RDESC_FIXED_SIZE;
270
}
271

272
/*
273
 * This tablet reports the 3rd button through invert, but this conflict
274
 * with the normal eraser mode.
275
 * Fortunately, before entering eraser mode, (so Invert = 1),
276
 * the tablet always sends an out-of-proximity event.
277
 * So we can detect that single event and:
278
 * - if there was none but the invert bit was toggled: this is the
279
 *   third button
280
 * - if there was this out-of-proximity event, we are entering
281
 *   eraser mode, and we will until the next out-of-proximity.
282
 */
283
SEC(HID_BPF_DEVICE_EVENT)
284
int BPF_PROG(kamvas_pro_19_fix_3rd_button, struct hid_bpf_ctx *hctx)
285
{
286
	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 10 /* size */);
287

288
	if (!data)
289
		return 0; /* EPERM check */
290

291
	if (data[0] != 0x0a) /* not the pen report ID */
292
		return 0;
293

294
	/* stylus is out of range */
295
	if (!(data[1] & 0x40)) {
296
		prev_was_out_of_range = true;
297
		in_eraser_mode = false;
298
		return 0;
299
	}
300

301
	/* going into eraser mode (Invert = 1) only happens after an
302
	 * out of range event
303
	 */
304
	if (prev_was_out_of_range && (data[1] & 0x18))
305
		in_eraser_mode = true;
306

307
	/* eraser mode works fine */
308
	if (in_eraser_mode)
309
		return 0;
310

311
	/* copy the Invert bit reported for the 3rd button in bit 7 */
312
	if (data[1] & 0x08)
313
		data[1] |= 0x20;
314

315
	/* clear Invert bit now that it was copied */
316
	data[1] &= 0xf7;
317

318
	prev_was_out_of_range = false;
319

320
	return 0;
321
}
322

323
HID_BPF_OPS(huion_Kamvas_pro_19) = {
324
	.hid_rdesc_fixup = (void *)hid_fix_rdesc_huion_kamvas_pro_19,
325
	.hid_device_event = (void *)kamvas_pro_19_fix_3rd_button,
326
};
327

328
SEC("syscall")
329
int probe(struct hid_bpf_probe_args *ctx)
330
{
331

332
	ctx->retval = !((ctx->rdesc_size == PRE_240524_RDESC_SIZE) ||
333
			(ctx->rdesc_size == FW_240524_RDESC_SIZE));
334
	if (ctx->retval)
335
		ctx->retval = -EINVAL;
336

337
	/* ensure the kernel isn't fixed already */
338
	if (ctx->rdesc[17] != 0x43) /* Secondary Tip Switch */
339
		ctx->retval = -EINVAL;
340

341
	struct hid_bpf_ctx *hctx = hid_bpf_allocate_context(ctx->hid);
342

343
	if (!hctx) {
344
		return ctx->retval = -EINVAL;
345
		return 0;
346
	}
347

348
	const char *name = hctx->hid->name;
349

350
	/* strip out TEST_PREFIX */
351
	if (!__builtin_memcmp(name, TEST_PREFIX, sizeof(TEST_PREFIX) - 1))
352
		name += sizeof(TEST_PREFIX) - 1;
353

354
	if (__builtin_memcmp(name, NAME_KAMVAS_PRO_19, sizeof(NAME_KAMVAS_PRO_19)))
355
		ctx->retval = -EINVAL;
356

357
	hid_bpf_release_context(hctx);
358

359
	return 0;
360
}
361

362
char _license[] SEC("license") = "GPL";
363

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