This repository has been archived by the owner on Oct 31, 2024. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 110
/
i2c-hid-core.c
1145 lines (936 loc) · 28.6 KB
/
i2c-hid-core.c
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
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* HID over I2C protocol implementation
*
* Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
* Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
* Copyright (c) 2012 Red Hat, Inc
*
* This code is partly based on "USB HID support for Linux":
*
* Copyright (c) 1999 Andreas Gal
* Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
* Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
* Copyright (c) 2007-2008 Oliver Neukum
* Copyright (c) 2006-2010 Jiri Kosina
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive for
* more details.
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/wait.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/hid.h>
#include <linux/mutex.h>
#include "../hid-ids.h"
#include "i2c-hid.h"
/* quirks to control the device */
#define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV BIT(0)
#define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(1)
#define I2C_HID_QUIRK_BOGUS_IRQ BIT(4)
#define I2C_HID_QUIRK_RESET_ON_RESUME BIT(5)
#define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(6)
#define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(7)
/* flags */
#define I2C_HID_STARTED 0
#define I2C_HID_RESET_PENDING 1
#define I2C_HID_READ_PENDING 2
#define I2C_HID_PWR_ON 0x00
#define I2C_HID_PWR_SLEEP 0x01
/* debug option */
static bool debug;
module_param(debug, bool, 0444);
MODULE_PARM_DESC(debug, "print a lot of debug information");
#define i2c_hid_dbg(ihid, fmt, arg...) \
do { \
if (debug) \
dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
} while (0)
struct i2c_hid_desc {
__le16 wHIDDescLength;
__le16 bcdVersion;
__le16 wReportDescLength;
__le16 wReportDescRegister;
__le16 wInputRegister;
__le16 wMaxInputLength;
__le16 wOutputRegister;
__le16 wMaxOutputLength;
__le16 wCommandRegister;
__le16 wDataRegister;
__le16 wVendorID;
__le16 wProductID;
__le16 wVersionID;
__le32 reserved;
} __packed;
struct i2c_hid_cmd {
unsigned int registerIndex;
__u8 opcode;
unsigned int length;
bool wait;
};
union command {
u8 data[0];
struct cmd {
__le16 reg;
__u8 reportTypeID;
__u8 opcode;
} __packed c;
};
#define I2C_HID_CMD(opcode_) \
.opcode = opcode_, .length = 4, \
.registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
/* fetch HID descriptor */
static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
/* fetch report descriptors */
static const struct i2c_hid_cmd hid_report_descr_cmd = {
.registerIndex = offsetof(struct i2c_hid_desc,
wReportDescRegister),
.opcode = 0x00,
.length = 2 };
/* commands */
static const struct i2c_hid_cmd hid_reset_cmd = { I2C_HID_CMD(0x01),
.wait = true };
static const struct i2c_hid_cmd hid_get_report_cmd = { I2C_HID_CMD(0x02) };
static const struct i2c_hid_cmd hid_set_report_cmd = { I2C_HID_CMD(0x03) };
static const struct i2c_hid_cmd hid_set_power_cmd = { I2C_HID_CMD(0x08) };
static const struct i2c_hid_cmd hid_no_cmd = { .length = 0 };
/*
* These definitions are not used here, but are defined by the spec.
* Keeping them here for documentation purposes.
*
* static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
* static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
* static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
* static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
*/
/* The main device structure */
struct i2c_hid {
struct i2c_client *client; /* i2c client */
struct hid_device *hid; /* pointer to corresponding HID dev */
union {
__u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
struct i2c_hid_desc hdesc; /* the HID Descriptor */
};
__le16 wHIDDescRegister; /* location of the i2c
* register of the HID
* descriptor. */
unsigned int bufsize; /* i2c buffer size */
u8 *inbuf; /* Input buffer */
u8 *rawbuf; /* Raw Input buffer */
u8 *cmdbuf; /* Command buffer */
u8 *argsbuf; /* Command arguments buffer */
unsigned long flags; /* device flags */
unsigned long quirks; /* Various quirks */
wait_queue_head_t wait; /* For waiting the interrupt */
bool irq_wake_enabled;
struct mutex reset_lock;
struct i2chid_ops *ops;
};
static const struct i2c_hid_quirks {
__u16 idVendor;
__u16 idProduct;
__u32 quirks;
} i2c_hid_quirks[] = {
{ USB_VENDOR_ID_WEIDA, HID_ANY_ID,
I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
{ I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
{ I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
{ I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
I2C_HID_QUIRK_BOGUS_IRQ },
{ USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
I2C_HID_QUIRK_RESET_ON_RESUME },
{ I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
I2C_HID_QUIRK_RESET_ON_RESUME },
{ USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
I2C_HID_QUIRK_BAD_INPUT_SIZE },
/*
* Sending the wakeup after reset actually break ELAN touchscreen controller
*/
{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET },
{ 0, 0 }
};
/*
* i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
* @idVendor: the 16-bit vendor ID
* @idProduct: the 16-bit product ID
*
* Returns: a u32 quirks value.
*/
static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
{
u32 quirks = 0;
int n;
for (n = 0; i2c_hid_quirks[n].idVendor; n++)
if (i2c_hid_quirks[n].idVendor == idVendor &&
(i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
i2c_hid_quirks[n].idProduct == idProduct))
quirks = i2c_hid_quirks[n].quirks;
return quirks;
}
static int __i2c_hid_command(struct i2c_client *client,
const struct i2c_hid_cmd *command, u8 reportID,
u8 reportType, u8 *args, int args_len,
unsigned char *buf_recv, int data_len)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
union command *cmd = (union command *)ihid->cmdbuf;
int ret;
struct i2c_msg msg[2];
int msg_num = 1;
int length = command->length;
bool wait = command->wait;
unsigned int registerIndex = command->registerIndex;
/* special case for hid_descr_cmd */
if (command == &hid_descr_cmd) {
cmd->c.reg = ihid->wHIDDescRegister;
} else {
cmd->data[0] = ihid->hdesc_buffer[registerIndex];
cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
}
if (length > 2) {
cmd->c.opcode = command->opcode;
cmd->c.reportTypeID = reportID | reportType << 4;
}
memcpy(cmd->data + length, args, args_len);
length += args_len;
i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
msg[0].addr = client->addr;
msg[0].flags = client->flags & I2C_M_TEN;
msg[0].len = length;
msg[0].buf = cmd->data;
if (data_len > 0) {
msg[1].addr = client->addr;
msg[1].flags = client->flags & I2C_M_TEN;
msg[1].flags |= I2C_M_RD;
msg[1].len = data_len;
msg[1].buf = buf_recv;
msg_num = 2;
set_bit(I2C_HID_READ_PENDING, &ihid->flags);
}
if (wait)
set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
ret = i2c_transfer(client->adapter, msg, msg_num);
if (data_len > 0)
clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
if (ret != msg_num)
return ret < 0 ? ret : -EIO;
ret = 0;
if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
msleep(100);
} else if (wait) {
i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
if (!wait_event_timeout(ihid->wait,
!test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
msecs_to_jiffies(5000)))
ret = -ENODATA;
i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
}
return ret;
}
static int i2c_hid_command(struct i2c_client *client,
const struct i2c_hid_cmd *command,
unsigned char *buf_recv, int data_len)
{
return __i2c_hid_command(client, command, 0, 0, NULL, 0,
buf_recv, data_len);
}
static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
u8 reportID, unsigned char *buf_recv, int data_len)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
u8 args[3];
int ret;
int args_len = 0;
u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
i2c_hid_dbg(ihid, "%s\n", __func__);
if (reportID >= 0x0F) {
args[args_len++] = reportID;
reportID = 0x0F;
}
args[args_len++] = readRegister & 0xFF;
args[args_len++] = readRegister >> 8;
ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
reportType, args, args_len, buf_recv, data_len);
if (ret) {
dev_err(&client->dev,
"failed to retrieve report from device.\n");
return ret;
}
return 0;
}
/**
* i2c_hid_set_or_send_report: forward an incoming report to the device
* @client: the i2c_client of the device
* @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
* @reportID: the report ID
* @buf: the actual data to transfer, without the report ID
* @data_len: size of buf
* @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
*/
static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
u8 *args = ihid->argsbuf;
const struct i2c_hid_cmd *hidcmd;
int ret;
u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
u16 size;
int args_len;
int index = 0;
i2c_hid_dbg(ihid, "%s\n", __func__);
if (data_len > ihid->bufsize)
return -EINVAL;
size = 2 /* size */ +
(reportID ? 1 : 0) /* reportID */ +
data_len /* buf */;
args_len = (reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
2 /* dataRegister */ +
size /* args */;
if (!use_data && maxOutputLength == 0)
return -ENOSYS;
if (reportID >= 0x0F) {
args[index++] = reportID;
reportID = 0x0F;
}
/*
* use the data register for feature reports or if the device does not
* support the output register
*/
if (use_data) {
args[index++] = dataRegister & 0xFF;
args[index++] = dataRegister >> 8;
hidcmd = &hid_set_report_cmd;
} else {
args[index++] = outputRegister & 0xFF;
args[index++] = outputRegister >> 8;
hidcmd = &hid_no_cmd;
}
args[index++] = size & 0xFF;
args[index++] = size >> 8;
if (reportID)
args[index++] = reportID;
memcpy(&args[index], buf, data_len);
ret = __i2c_hid_command(client, hidcmd, reportID,
reportType, args, args_len, NULL, 0);
if (ret) {
dev_err(&client->dev, "failed to set a report to device.\n");
return ret;
}
return data_len;
}
static int i2c_hid_set_power(struct i2c_client *client, int power_state)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret;
i2c_hid_dbg(ihid, "%s\n", __func__);
/*
* Some devices require to send a command to wakeup before power on.
* The call will get a return value (EREMOTEIO) but device will be
* triggered and activated. After that, it goes like a normal device.
*/
if (power_state == I2C_HID_PWR_ON &&
ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
/* Device was already activated */
if (!ret)
goto set_pwr_exit;
}
ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
0, NULL, 0, NULL, 0);
if (ret)
dev_err(&client->dev, "failed to change power setting.\n");
set_pwr_exit:
/*
* The HID over I2C specification states that if a DEVICE needs time
* after the PWR_ON request, it should utilise CLOCK stretching.
* However, it has been observered that the Windows driver provides a
* 1ms sleep between the PWR_ON and RESET requests.
* According to Goodix Windows even waits 60 ms after (other?)
* PWR_ON requests. Testing has confirmed that several devices
* will not work properly without a delay after a PWR_ON request.
*/
if (!ret && power_state == I2C_HID_PWR_ON)
msleep(60);
return ret;
}
static int i2c_hid_hwreset(struct i2c_client *client)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret;
i2c_hid_dbg(ihid, "%s\n", __func__);
/*
* This prevents sending feature reports while the device is
* being reset. Otherwise we may lose the reset complete
* interrupt.
*/
mutex_lock(&ihid->reset_lock);
ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
if (ret)
goto out_unlock;
i2c_hid_dbg(ihid, "resetting...\n");
ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
if (ret) {
dev_err(&client->dev, "failed to reset device.\n");
i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
goto out_unlock;
}
/* At least some SIS devices need this after reset */
if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
out_unlock:
mutex_unlock(&ihid->reset_lock);
return ret;
}
static void i2c_hid_get_input(struct i2c_hid *ihid)
{
int ret;
u32 ret_size;
int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
if (size > ihid->bufsize)
size = ihid->bufsize;
ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
if (ret != size) {
if (ret < 0)
return;
dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
__func__, ret, size);
return;
}
ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
if (!ret_size) {
/* host or device initiated RESET completed */
if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
wake_up(&ihid->wait);
return;
}
if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
"there's no data\n", __func__);
return;
}
if ((ret_size > size) || (ret_size < 2)) {
if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
ihid->inbuf[0] = size & 0xff;
ihid->inbuf[1] = size >> 8;
ret_size = size;
} else {
dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
__func__, size, ret_size);
return;
}
}
i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
if (test_bit(I2C_HID_STARTED, &ihid->flags))
hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
ret_size - 2, 1);
return;
}
static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
{
struct i2c_hid *ihid = dev_id;
if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
return IRQ_HANDLED;
i2c_hid_get_input(ihid);
return IRQ_HANDLED;
}
static int i2c_hid_get_report_length(struct hid_report *report)
{
return ((report->size - 1) >> 3) + 1 +
report->device->report_enum[report->type].numbered + 2;
}
/*
* Traverse the supplied list of reports and find the longest
*/
static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
unsigned int *max)
{
struct hid_report *report;
unsigned int size;
/* We should not rely on wMaxInputLength, as some devices may set it to
* a wrong length. */
list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
size = i2c_hid_get_report_length(report);
if (*max < size)
*max = size;
}
}
static void i2c_hid_free_buffers(struct i2c_hid *ihid)
{
kfree(ihid->inbuf);
kfree(ihid->rawbuf);
kfree(ihid->argsbuf);
kfree(ihid->cmdbuf);
ihid->inbuf = NULL;
ihid->rawbuf = NULL;
ihid->cmdbuf = NULL;
ihid->argsbuf = NULL;
ihid->bufsize = 0;
}
static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
{
/* the worst case is computed from the set_report command with a
* reportID > 15 and the maximum report length */
int args_len = sizeof(__u8) + /* ReportID */
sizeof(__u8) + /* optional ReportID byte */
sizeof(__u16) + /* data register */
sizeof(__u16) + /* size of the report */
report_size; /* report */
ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
i2c_hid_free_buffers(ihid);
return -ENOMEM;
}
ihid->bufsize = report_size;
return 0;
}
static int i2c_hid_get_raw_report(struct hid_device *hid,
unsigned char report_number, __u8 *buf, size_t count,
unsigned char report_type)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
size_t ret_count, ask_count;
int ret;
if (report_type == HID_OUTPUT_REPORT)
return -EINVAL;
/* +2 bytes to include the size of the reply in the query buffer */
ask_count = min(count + 2, (size_t)ihid->bufsize);
ret = i2c_hid_get_report(client,
report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
report_number, ihid->rawbuf, ask_count);
if (ret < 0)
return ret;
ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
if (ret_count <= 2)
return 0;
ret_count = min(ret_count, ask_count);
/* The query buffer contains the size, dropping it in the reply */
count = min(count, ret_count - 2);
memcpy(buf, ihid->rawbuf + 2, count);
return count;
}
static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
size_t count, unsigned char report_type, bool use_data)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
int report_id = buf[0];
int ret;
if (report_type == HID_INPUT_REPORT)
return -EINVAL;
mutex_lock(&ihid->reset_lock);
if (report_id) {
buf++;
count--;
}
ret = i2c_hid_set_or_send_report(client,
report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
report_id, buf, count, use_data);
if (report_id && ret >= 0)
ret++; /* add report_id to the number of transfered bytes */
mutex_unlock(&ihid->reset_lock);
return ret;
}
static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
size_t count)
{
return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
false);
}
static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
__u8 *buf, size_t len, unsigned char rtype,
int reqtype)
{
switch (reqtype) {
case HID_REQ_GET_REPORT:
return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
case HID_REQ_SET_REPORT:
if (buf[0] != reportnum)
return -EINVAL;
return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
default:
return -EIO;
}
}
static int i2c_hid_parse(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
struct i2c_hid_desc *hdesc = &ihid->hdesc;
unsigned int rsize;
char *rdesc;
int ret;
int tries = 3;
char *use_override;
i2c_hid_dbg(ihid, "entering %s\n", __func__);
rsize = le16_to_cpu(hdesc->wReportDescLength);
if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
dbg_hid("weird size of report descriptor (%u)\n", rsize);
return -EINVAL;
}
do {
ret = i2c_hid_hwreset(client);
if (ret)
msleep(1000);
} while (tries-- > 0 && ret);
if (ret)
return ret;
use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
&rsize);
if (use_override) {
rdesc = use_override;
i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
} else {
rdesc = kzalloc(rsize, GFP_KERNEL);
if (!rdesc) {
dbg_hid("couldn't allocate rdesc memory\n");
return -ENOMEM;
}
i2c_hid_dbg(ihid, "asking HID report descriptor\n");
ret = i2c_hid_command(client, &hid_report_descr_cmd,
rdesc, rsize);
if (ret) {
hid_err(hid, "reading report descriptor failed\n");
kfree(rdesc);
return -EIO;
}
}
i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
ret = hid_parse_report(hid, rdesc, rsize);
if (!use_override)
kfree(rdesc);
if (ret) {
dbg_hid("parsing report descriptor failed\n");
return ret;
}
return 0;
}
static int i2c_hid_start(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret;
unsigned int bufsize = HID_MIN_BUFFER_SIZE;
i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
if (bufsize > ihid->bufsize) {
disable_irq(client->irq);
i2c_hid_free_buffers(ihid);
ret = i2c_hid_alloc_buffers(ihid, bufsize);
enable_irq(client->irq);
if (ret)
return ret;
}
return 0;
}
static void i2c_hid_stop(struct hid_device *hid)
{
hid->claimed = 0;
}
static int i2c_hid_open(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
set_bit(I2C_HID_STARTED, &ihid->flags);
return 0;
}
static void i2c_hid_close(struct hid_device *hid)
{
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
clear_bit(I2C_HID_STARTED, &ihid->flags);
}
struct hid_ll_driver i2c_hid_ll_driver = {
.parse = i2c_hid_parse,
.start = i2c_hid_start,
.stop = i2c_hid_stop,
.open = i2c_hid_open,
.close = i2c_hid_close,
.output_report = i2c_hid_output_report,
.raw_request = i2c_hid_raw_request,
};
EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
static int i2c_hid_init_irq(struct i2c_client *client)
{
struct i2c_hid *ihid = i2c_get_clientdata(client);
unsigned long irqflags = 0;
int ret;
dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
if (!irq_get_trigger_type(client->irq))
irqflags = IRQF_TRIGGER_LOW;
ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
irqflags | IRQF_ONESHOT, client->name, ihid);
if (ret < 0) {
dev_warn(&client->dev,
"Could not register for %s interrupt, irq = %d,"
" ret = %d\n",
client->name, client->irq, ret);
return ret;
}
return 0;
}
static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
{
struct i2c_client *client = ihid->client;
struct i2c_hid_desc *hdesc = &ihid->hdesc;
unsigned int dsize;
int ret;
/* i2c hid fetch using a fixed descriptor size (30 bytes) */
if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
ihid->hdesc =
*i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
} else {
i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
ret = i2c_hid_command(client, &hid_descr_cmd,
ihid->hdesc_buffer,
sizeof(struct i2c_hid_desc));
if (ret) {
dev_err(&client->dev, "hid_descr_cmd failed\n");
return -ENODEV;
}
}
/* Validate the length of HID descriptor, the 4 first bytes:
* bytes 0-1 -> length
* bytes 2-3 -> bcdVersion (has to be 1.00) */
/* check bcdVersion == 1.0 */
if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
dev_err(&client->dev,
"unexpected HID descriptor bcdVersion (0x%04hx)\n",
le16_to_cpu(hdesc->bcdVersion));
return -ENODEV;
}
/* Descriptor length should be 30 bytes as per the specification */
dsize = le16_to_cpu(hdesc->wHIDDescLength);
if (dsize != sizeof(struct i2c_hid_desc)) {
dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
dsize);
return -ENODEV;
}
i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
return 0;
}
static int i2c_hid_core_power_up(struct i2c_hid *ihid)
{
if (!ihid->ops->power_up)
return 0;
return ihid->ops->power_up(ihid->ops);
}
static void i2c_hid_core_power_down(struct i2c_hid *ihid)
{
if (!ihid->ops->power_down)
return;
ihid->ops->power_down(ihid->ops);
}
static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
{
if (!ihid->ops->shutdown_tail)
return;
ihid->ops->shutdown_tail(ihid->ops);
}
int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
u16 hid_descriptor_address)
{
int ret;
struct i2c_hid *ihid;
struct hid_device *hid;
dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
if (!client->irq) {
dev_err(&client->dev,
"HID over i2c has not been provided an Int IRQ\n");
return -EINVAL;
}
if (client->irq < 0) {
if (client->irq != -EPROBE_DEFER)
dev_err(&client->dev,
"HID over i2c doesn't have a valid IRQ\n");
return client->irq;
}
ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
if (!ihid)
return -ENOMEM;
ihid->ops = ops;
ret = i2c_hid_core_power_up(ihid);
if (ret)
return ret;
i2c_set_clientdata(client, ihid);
ihid->client = client;
ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
init_waitqueue_head(&ihid->wait);
mutex_init(&ihid->reset_lock);
/* we need to allocate the command buffer without knowing the maximum
* size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
* real computation later. */
ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
if (ret < 0)
goto err_powered;
device_enable_async_suspend(&client->dev);
/* Make sure there is something at this address */
ret = i2c_smbus_read_byte(client);
if (ret < 0) {
dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
ret = -ENXIO;
goto err_powered;
}
ret = i2c_hid_fetch_hid_descriptor(ihid);
if (ret < 0) {
dev_err(&client->dev,
"Failed to fetch the HID Descriptor\n");
goto err_powered;
}
ret = i2c_hid_init_irq(client);
if (ret < 0)
goto err_powered;
hid = hid_allocate_device();
if (IS_ERR(hid)) {
ret = PTR_ERR(hid);
goto err_irq;
}
ihid->hid = hid;
hid->driver_data = client;
hid->ll_driver = &i2c_hid_ll_driver;
hid->dev.parent = &client->dev;
hid->bus = BUS_I2C;
hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
hid->product = le16_to_cpu(ihid->hdesc.wProductID);
snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",