summaryrefslogtreecommitdiff
path: root/meta-openbmc-mods/meta-common/recipes-kernel/linux/linux-aspeed/0052-drivers-jtag-Add-JTAG-core-driver.patch
blob: 7ba94a7bcd7e4dbfe295cdc51ed4b9f9987950a9 (plain)
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
From 0b8b93851bb79e70e91159f310afd4b56084977f Mon Sep 17 00:00:00 2001
From: "Corona, Ernesto" <ernesto.corona@intel.com>
Date: Mon, 6 May 2019 10:05:51 -0800
Subject: [PATCH v29 1/6] drivers: jtag: Add JTAG core driver

JTAG class driver provide infrastructure to support hardware/software
JTAG platform drivers. It provide user layer API interface for flashing
and debugging external devices which equipped with JTAG interface
using standard transactions.

Driver exposes set of IOCTL to user space for:
- XFER:
  SIR (Scan Instruction Register, IEEE 1149.1 Data Register scan);
  SDR (Scan Data Register, IEEE 1149.1 Instruction Register scan);
- GIOCSTATUS read the current TAPC state of the JTAG controller
- SIOCSTATE Forces the JTAG TAPC to go into a particular state.
- SIOCFREQ/GIOCFREQ for setting and reading JTAG frequency.
- IOCBITBANG for low level control of JTAG signals.

Driver core provides set of internal APIs for allocation and
registration:
- jtag_register;
- jtag_unregister;
- jtag_alloc;
- jtag_free;

Platform driver on registration with jtag-core creates the next
entry in dev folder:
/dev/jtagX

Signed-off-by: Oleksandr Shamray <oleksandrs@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Corona, Ernesto <ernesto.corona@intel.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Vadim Pasternak <vadimp@mellanox.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven A Filary <steven.a.filary@intel.com>
Cc: Bryan Hunt <bryan.hunt@intel.com>
---
v28->v29
Comments pointed by Steven Filary <steven.a.filary@intel.com>
- Expand bitbang function to accept multiples bitbang operations within a
  single JTAG_IOCBITBANG call. It will receive a buffer with TDI and TMS
  values and it is expected that driver fills TDO fields with its
  corresponding output value for every transaction.
- Always setup JTAG controller to master mode but disable JTAG output when
  the driver is not in use to allow other HW to own the JTAG bus. Remove SCU
  register accesses. This register controls the JTAG controller mode
  (master/slave).

v27->v28
Comments pointed by Steven Filary <steven.a.filary@intel.com>
- Replace JTAG_IOCRUNTEST with JTAG_SIOCSTATE adding support for all TAPC
  end states in SW mode using a lookup table to navigate across states.
- Add support for simultaneous READ/WRITE transfers(JTAG_READ_WRITE_XFER).
- Support for switching JTAG controller mode between slave and master
  mode.
- Setup JTAG controller mode to master only when the driver is opened,
  letting
  other HW to own the JTAG bus when it isn't in use.
- Include JTAG bit bang IOCTL for low level JTAG control usage
  (JTAG_IOCBITBANG).

v24->v25
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- set values to enums in jtag.h

v23->v24
Notifications from kbuild test robot <lkp@intel.com>
- Add include types.h header to jtag.h
- remove unecessary jtag_release

v22->v23
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- remove restriction of allocated JTAG devs-
- add validation fo idle values
- remove unnecessary blank line
- change retcode for xfer
- remove unecessary jtag_release callback
- remove unecessary  defined fron jtag.h
- align in one line define JTAG_IOCRUNTEST

v21->v22
Comments pointed by Andy Shevchenko <andy.shevchenko@gmail.com>
- Fix 0x0f -> 0x0F in ioctl-number.txt
- Add description to #define MAX_JTAG_NAME_LEN
- Remove unnecessary entry *dev from struct jtag
- Remove redundant parens
- Described mandatory callbacks and removed unnecessary
- Set JTAG_MAX_XFER_DATA_LEN to power of 2
- rework driver alloc/register to devm_ variant
- increasing line length up to 84 in order to improve readability.

Comments pointed by Randy Dunlap <rdunlap@infradead.org>
- fix spell in ABI doccumentation

v20->v21
    Comments pointed by Randy Dunlap <rdunlap@infradead.org>
    - Fix JTAG dirver help in Kconfig

v19->v20
Comments pointed by Randy Dunlap <rdunlap@infradead.org>
- Fix JTAG dirver help in Kconfig

Notifications from kbuild test robot <lkp@intel.com>
- fix incompatible type casts

v18->v19
Comments pointed by Julia Cartwright <juliac@eso.teric.us>
- Fix memory leak on jtag_alloc exit

v17->v18
Comments pointed by Julia Cartwright <juliac@eso.teric.us>
- Change to return -EOPNOTSUPP in case of error in JTAG_GIOCFREQ
- Add ops callbacks check to jtag_alloc
- Add err check for copy_to_user
- Move the kfree() above the if (err) in JTAG_IOCXFER
- remove unnecessary check for error after put_user
- add padding to struct jtag_xfer

v16->v17
Comments pointed by Julia Cartwright <juliac@eso.teric.us>
- Fix memory allocation on jtag alloc
- Move out unnecessary form lock on jtag open
- Rework jtag register behavior

v15->v16
Comments pointed by Florian Fainelli <f.fainelli@gmail.com>
- move check jtag->ops->* in ioctl before get_user()
- change error type -EINVAL --> -EBUSY on open already opened jtag
- remove unnecessary ARCH_DMA_MINALIGN flag from kzalloc
- remove define ARCH_DMA_MINALIGN

v14->v15
v13->v14
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change style of head block comment from /**/ to //

v12->v13
Comments pointed by Philippe Ombredanne <pombredanne@nexb.com>
- Change jtag.c licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description

v11->v12
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change jtag.h licence type to
  SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
  and reorder line with license in description

Comments pointed by Chip Bilbrey <chip@bilbrey.org>
- Remove Apeed reference from uapi jtag.h header
- Remove access mode from xfer and idle transactions
- Add new ioctl JTAG_SIOCMODE for set hw mode
- Add single open per device blocking

v10->v11
Notifications from kbuild test robot <lkp@intel.com>
- Add include types.h header to jtag.h
- fix incompatible type of xfer callback
- remove rdundant class defination
- Fix return order in case of xfer error

V9->v10
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- remove unnecessary alignment for pirv data
- move jtag_copy_to_user and jtag_copy_from_user code just to ioctl
- move int jtag_run_test_idle_op and jtag_xfer_op code
  just to ioctl
- change return error codes to more applicable
- add missing error checks
- fix error check order in ioctl
- remove unnecessary blank lines
- add param validation to ioctl
- remove compat_ioctl
- remove only one open per JTAG port blocking.
  User will care about this.
- Fix idr memory leak on jtag_exit
- change cdev device type to misc

V8->v9
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- use get_user() instead of __get_user().
- change jtag->open type from int to atomic_t
- remove spinlock on jtg_open
- remove mutex on jtag_register
- add unregister_chrdev_region on jtag_init err
- add unregister_chrdev_region on jtag_exit
- remove unnecessary pointer casts
- add *data parameter to xfer function prototype

v7->v8
Comments pointed by Moritz Fischer <moritz.fischer@ettus.com>
- Fix misspelling s/friver/driver

v6->v7
Notifications from kbuild test robot <lkp@intel.com>
- Remove include asm/types.h from jtag.h
- Add include <linux/types.h> to jtag.c

v5->v6
v4->v5

v3->v4
Comments pointed by Arnd Bergmann <arnd@arndb.de>
- change transaction pointer tdio type  to __u64
- change internal status type from enum to __u32
- reorder jtag_xfer members to avoid the implied padding
- add __packed attribute to jtag_xfer and jtag_run_test_idle

v2->v3
Notifications from kbuild test robot <lkp@intel.com>
- Change include path to <linux/types.h> in jtag.h

v1->v2
Comments pointed by Greg KH <gregkh@linuxfoundation.org>
- Change license type from GPLv2/BSD to GPLv2
- Change type of variables which crossed user/kernel to __type
- Remove "default n" from Kconfig

Comments pointed by Andrew Lunn <andrew@lunn.ch>
- Change list_add_tail in jtag_unregister to list_del

Comments pointed by Neil Armstrong <narmstrong@baylibre.com>
- Add SPDX-License-Identifier instead of license text

Comments pointed by Arnd Bergmann <arnd@arndb.de>
- Change __copy_to_user to memdup_user
- Change __put_user to put_user
- Change type of variables to __type for compatible 32 and 64-bit systems
- Add check for maximum xfer data size
- Change lookup data mechanism to get jtag data from inode
- Add .compat_ioctl to file ops
- Add mem alignment for jtag priv data

Comments pointed by Tobias Klauser <tklauser@distanz.ch>
- Change function names to avoid match with variable types
- Fix description for jtag_ru_test_idle in uapi jtag.h
- Fix misprints IDEL/IDLE, trough/through
---
 drivers/Kconfig           |   1 +
 drivers/Makefile          |   1 +
 drivers/jtag/Kconfig      |  17 +++
 drivers/jtag/Makefile     |   1 +
 drivers/jtag/jtag.c       | 314 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/jtag.h      |  47 +++++++
 include/uapi/linux/jtag.h | 208 ++++++++++++++++++++++++++++++
 7 files changed, 589 insertions(+)
 create mode 100644 drivers/jtag/Kconfig
 create mode 100644 drivers/jtag/Makefile
 create mode 100644 drivers/jtag/jtag.c
 create mode 100644 include/linux/jtag.h
 create mode 100644 include/uapi/linux/jtag.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 4f9f990..0102bae 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -228,4 +228,5 @@ source "drivers/siox/Kconfig"
 
 source "drivers/slimbus/Kconfig"
 
+source "drivers/jtag/Kconfig"
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index e1ce029..6d756c2 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -186,3 +186,4 @@ obj-$(CONFIG_MULTIPLEXER)	+= mux/
 obj-$(CONFIG_SIOX)		+= siox/
 obj-$(CONFIG_GNSS)		+= gnss/
 obj-$(CONFIG_PECI)		+= peci/
+obj-$(CONFIG_JTAG)		+= jtag/
diff --git a/drivers/jtag/Kconfig b/drivers/jtag/Kconfig
new file mode 100644
index 0000000..47771fc
--- /dev/null
+++ b/drivers/jtag/Kconfig
@@ -0,0 +1,17 @@
+menuconfig JTAG
+	tristate "JTAG support"
+	help
+	  This provides basic core functionality support for JTAG class devices.
+	  Hardware that is equipped with a JTAG microcontroller can be
+	  supported by using this driver's interfaces.
+	  This driver exposes a set of IOCTLs to the user space for
+	  the following commands:
+	    SDR: Performs an IEEE 1149.1 Data Register scan
+	    SIR: Performs an IEEE 1149.1 Instruction Register scan.
+	    RUNTEST: Forces the IEEE 1149.1 bus to a run state for a specified
+	    number of clocks or a specified time period.
+
+	  If you want this support, you should say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called jtag.
diff --git a/drivers/jtag/Makefile b/drivers/jtag/Makefile
new file mode 100644
index 0000000..af37493
--- /dev/null
+++ b/drivers/jtag/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_JTAG)		+= jtag.o
diff --git a/drivers/jtag/jtag.c b/drivers/jtag/jtag.c
new file mode 100644
index 0000000..47503a1
--- /dev/null
+++ b/drivers/jtag/jtag.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
+// Copyright (c) 2018 Oleksandr Shamray <oleksandrs@mellanox.com>
+// Copyright (c) 2019 Intel Corporation
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/jtag.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/rtnetlink.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+struct jtag {
+	struct miscdevice miscdev;
+	const struct jtag_ops *ops;
+	int id;
+	unsigned long priv[0];
+};
+
+static DEFINE_IDA(jtag_ida);
+
+void *jtag_priv(struct jtag *jtag)
+{
+	return jtag->priv;
+}
+EXPORT_SYMBOL_GPL(jtag_priv);
+
+static long jtag_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct jtag *jtag = file->private_data;
+	struct jtag_end_tap_state endstate;
+	struct jtag_xfer xfer;
+	struct bitbang_packet bitbang;
+	struct tck_bitbang *bitbang_data;
+	struct jtag_mode mode;
+	u8 *xfer_data;
+	u32 data_size;
+	u32 value;
+	int err;
+
+	if (!arg)
+		return -EINVAL;
+
+	switch (cmd) {
+	case JTAG_GIOCFREQ:
+		if (!jtag->ops->freq_get)
+			return -EOPNOTSUPP;
+
+		err = jtag->ops->freq_get(jtag, &value);
+		if (err)
+			break;
+
+		if (put_user(value, (__u32 __user *)arg))
+			err = -EFAULT;
+		break;
+
+	case JTAG_SIOCFREQ:
+		if (!jtag->ops->freq_set)
+			return -EOPNOTSUPP;
+
+		if (get_user(value, (__u32 __user *)arg))
+			return -EFAULT;
+		if (value == 0)
+			return -EINVAL;
+
+		err = jtag->ops->freq_set(jtag, value);
+		break;
+
+	case JTAG_SIOCSTATE:
+		if (copy_from_user(&endstate, (const void __user *)arg,
+				   sizeof(struct jtag_end_tap_state)))
+			return -EFAULT;
+
+		if (endstate.endstate > JTAG_STATE_UPDATEIR)
+			return -EINVAL;
+
+		if (endstate.reset > JTAG_FORCE_RESET)
+			return -EINVAL;
+
+		err = jtag->ops->status_set(jtag, &endstate);
+		break;
+
+	case JTAG_IOCXFER:
+		if (copy_from_user(&xfer, (const void __user *)arg,
+				   sizeof(struct jtag_xfer)))
+			return -EFAULT;
+
+		if (xfer.length >= JTAG_MAX_XFER_DATA_LEN)
+			return -EINVAL;
+
+		if (xfer.type > JTAG_SDR_XFER)
+			return -EINVAL;
+
+		if (xfer.direction > JTAG_READ_WRITE_XFER)
+			return -EINVAL;
+
+		if (xfer.endstate > JTAG_STATE_UPDATEIR)
+			return -EINVAL;
+
+		data_size = DIV_ROUND_UP(xfer.length, BITS_PER_BYTE);
+		xfer_data = memdup_user(u64_to_user_ptr(xfer.tdio), data_size);
+		if (IS_ERR(xfer_data))
+			return -EFAULT;
+
+		err = jtag->ops->xfer(jtag, &xfer, xfer_data);
+		if (err) {
+			kfree(xfer_data);
+			return err;
+		}
+
+		err = copy_to_user(u64_to_user_ptr(xfer.tdio),
+				   (void *)xfer_data, data_size);
+		kfree(xfer_data);
+		if (err)
+			return -EFAULT;
+
+		if (copy_to_user((void __user *)arg, (void *)&xfer,
+				 sizeof(struct jtag_xfer)))
+			return -EFAULT;
+		break;
+
+	case JTAG_GIOCSTATUS:
+		err = jtag->ops->status_get(jtag, &value);
+		if (err)
+			break;
+
+		err = put_user(value, (__u32 __user *)arg);
+		break;
+	case JTAG_IOCBITBANG:
+		if (copy_from_user(&bitbang, (const void __user *)arg,
+				   sizeof(struct bitbang_packet)))
+			return -EFAULT;
+
+		if (bitbang.length >= JTAG_MAX_XFER_DATA_LEN)
+			return -EINVAL;
+
+		data_size = bitbang.length * sizeof(struct tck_bitbang);
+		bitbang_data = memdup_user((void __user *)bitbang.data,
+					   data_size);
+		if (IS_ERR(bitbang_data))
+			return -EFAULT;
+
+		err = jtag->ops->bitbang(jtag, &bitbang, bitbang_data);
+		if (err) {
+			kfree(bitbang_data);
+			return err;
+		}
+		err = copy_to_user((void __user *)bitbang.data,
+				   (void *)bitbang_data, data_size);
+		kfree(bitbang_data);
+		if (err)
+			return -EFAULT;
+		break;
+	case JTAG_SIOCMODE:
+		if (!jtag->ops->mode_set)
+			return -EOPNOTSUPP;
+
+		if (copy_from_user(&mode, (const void __user *)arg,
+				   sizeof(struct jtag_mode)))
+			return -EFAULT;
+
+		err = jtag->ops->mode_set(jtag, &mode);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return err;
+}
+
+static int jtag_open(struct inode *inode, struct file *file)
+{
+	struct jtag *jtag = container_of(file->private_data,
+					 struct jtag,
+					 miscdev);
+
+	file->private_data = jtag;
+	if (jtag->ops->enable(jtag))
+		return -EBUSY;
+	return nonseekable_open(inode, file);
+}
+
+static int jtag_release(struct inode *inode, struct file *file)
+{
+	struct jtag *jtag = file->private_data;
+
+	if (jtag->ops->disable(jtag))
+		return -EBUSY;
+	return 0;
+}
+
+static const struct file_operations jtag_fops = {
+	.owner		= THIS_MODULE,
+	.open		= jtag_open,
+	.llseek		= noop_llseek,
+	.unlocked_ioctl	= jtag_ioctl,
+	.release	= jtag_release,
+};
+
+struct jtag *jtag_alloc(struct device *host, size_t priv_size,
+			const struct jtag_ops *ops)
+{
+	struct jtag *jtag;
+
+	if (!host)
+		return NULL;
+
+	if (!ops)
+		return NULL;
+
+	if (!ops->status_set || !ops->status_get || !ops->xfer)
+		return NULL;
+
+	jtag = kzalloc(sizeof(*jtag) + priv_size, GFP_KERNEL);
+	if (!jtag)
+		return NULL;
+
+	jtag->ops = ops;
+	jtag->miscdev.parent = host;
+
+	return jtag;
+}
+EXPORT_SYMBOL_GPL(jtag_alloc);
+
+void jtag_free(struct jtag *jtag)
+{
+	kfree(jtag);
+}
+EXPORT_SYMBOL_GPL(jtag_free);
+
+static int jtag_register(struct jtag *jtag)
+{
+	struct device *dev = jtag->miscdev.parent;
+	int err;
+	int id;
+
+	if (!dev)
+		return -ENODEV;
+
+	id = ida_simple_get(&jtag_ida, 0, 0, GFP_KERNEL);
+	if (id < 0)
+		return id;
+
+	jtag->id = id;
+
+	jtag->miscdev.fops =  &jtag_fops;
+	jtag->miscdev.minor = MISC_DYNAMIC_MINOR;
+	jtag->miscdev.name = kasprintf(GFP_KERNEL, "jtag%d", id);
+	if (!jtag->miscdev.name) {
+		err = -ENOMEM;
+		goto err_jtag_alloc;
+	}
+
+	err = misc_register(&jtag->miscdev);
+	if (err) {
+		dev_err(jtag->miscdev.parent, "Unable to register device\n");
+		goto err_jtag_name;
+	}
+	return 0;
+
+err_jtag_name:
+	kfree(jtag->miscdev.name);
+err_jtag_alloc:
+	ida_simple_remove(&jtag_ida, id);
+	return err;
+}
+
+static void jtag_unregister(struct jtag *jtag)
+{
+	misc_deregister(&jtag->miscdev);
+	kfree(jtag->miscdev.name);
+	ida_simple_remove(&jtag_ida, jtag->id);
+}
+
+static void devm_jtag_unregister(struct device *dev, void *res)
+{
+	jtag_unregister(*(struct jtag **)res);
+}
+
+int devm_jtag_register(struct device *dev, struct jtag *jtag)
+{
+	struct jtag **ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_jtag_unregister, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = jtag_register(jtag);
+	if (!ret) {
+		*ptr = jtag;
+		devres_add(dev, ptr);
+	} else {
+		devres_free(ptr);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_jtag_register);
+
+static void __exit jtag_exit(void)
+{
+	ida_destroy(&jtag_ida);
+}
+
+module_exit(jtag_exit);
+
+MODULE_AUTHOR("Oleksandr Shamray <oleksandrs@mellanox.com>");
+MODULE_DESCRIPTION("Generic jtag support");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/jtag.h b/include/linux/jtag.h
new file mode 100644
index 0000000..4153c90
--- /dev/null
+++ b/include/linux/jtag.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018 Mellanox Technologies. All rights reserved. */
+/* Copyright (c) 2018 Oleksandr Shamray <oleksandrs@mellanox.com> */
+/* Copyright (c) 2019 Intel Corporation */
+
+#ifndef __LINUX_JTAG_H
+#define __LINUX_JTAG_H
+
+#include <linux/types.h>
+#include <uapi/linux/jtag.h>
+
+#define JTAG_MAX_XFER_DATA_LEN 65535
+
+struct jtag;
+/**
+ * struct jtag_ops - callbacks for JTAG control functions:
+ *
+ * @freq_get: get frequency function. Filled by dev driver
+ * @freq_set: set frequency function. Filled by dev driver
+ * @status_get: get JTAG TAPC state function. Mandatory, Filled by dev driver
+ * @status_set: set JTAG TAPC state function. Mandatory, Filled by dev driver
+ * @xfer: send JTAG xfer function. Mandatory func. Filled by dev driver
+ * @mode_set: set specific work mode for JTAG. Filled by dev driver
+ * @bitbang: set low level bitbang operations. Filled by dev driver
+ * @enable: enables JTAG interface in master mode. Filled by dev driver
+ * @disable: disables JTAG interface master mode. Filled by dev driver
+ */
+struct jtag_ops {
+	int (*freq_get)(struct jtag *jtag, u32 *freq);
+	int (*freq_set)(struct jtag *jtag, u32 freq);
+	int (*status_get)(struct jtag *jtag, u32 *state);
+	int (*status_set)(struct jtag *jtag, struct jtag_end_tap_state *endst);
+	int (*xfer)(struct jtag *jtag, struct jtag_xfer *xfer, u8 *xfer_data);
+	int (*mode_set)(struct jtag *jtag, struct jtag_mode *jtag_mode);
+	int (*bitbang)(struct jtag *jtag, struct bitbang_packet *bitbang,
+		       struct tck_bitbang *bitbang_data);
+	int (*enable)(struct jtag *jtag);
+	int (*disable)(struct jtag *jtag);
+};
+
+void *jtag_priv(struct jtag *jtag);
+int devm_jtag_register(struct device *dev, struct jtag *jtag);
+struct jtag *jtag_alloc(struct device *host, size_t priv_size,
+			const struct jtag_ops *ops);
+void jtag_free(struct jtag *jtag);
+
+#endif /* __LINUX_JTAG_H */
diff --git a/include/uapi/linux/jtag.h b/include/uapi/linux/jtag.h
new file mode 100644
index 0000000..3f9e195
--- /dev/null
+++ b/include/uapi/linux/jtag.h
@@ -0,0 +1,208 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018 Mellanox Technologies. All rights reserved. */
+/* Copyright (c) 2018 Oleksandr Shamray <oleksandrs@mellanox.com> */
+/* Copyright (c) 2019 Intel Corporation */
+
+#ifndef __UAPI_LINUX_JTAG_H
+#define __UAPI_LINUX_JTAG_H
+
+/*
+ * JTAG_XFER_MODE: JTAG transfer mode. Used to set JTAG controller transfer mode
+ * This is bitmask for feature param in jtag_mode for ioctl JTAG_SIOCMODE
+ */
+#define  JTAG_XFER_MODE 0
+/*
+ * JTAG_CONTROL_MODE: JTAG controller mode. Used to set JTAG controller mode
+ * This is bitmask for feature param in jtag_mode for ioctl JTAG_SIOCMODE
+ */
+#define  JTAG_CONTROL_MODE 1
+/*
+ * JTAG_MASTER_OUTPUT_DISABLE: JTAG master mode output disable, it is used to
+ * enable other devices to own the JTAG bus.
+ * This is bitmask for mode param in jtag_mode for ioctl JTAG_SIOCMODE
+ */
+#define  JTAG_MASTER_OUTPUT_DISABLE 0
+/*
+ * JTAG_MASTER_MODE: JTAG master mode. Used to set JTAG controller master mode
+ * This is bitmask for mode param in jtag_mode for ioctl JTAG_SIOCMODE
+ */
+#define  JTAG_MASTER_MODE 1
+/*
+ * JTAG_XFER_HW_MODE: JTAG hardware mode. Used to set HW drived or bitbang
+ * mode. This is bitmask for mode param in jtag_mode for ioctl JTAG_SIOCMODE
+ */
+#define  JTAG_XFER_HW_MODE 1
+/*
+ * JTAG_XFER_SW_MODE: JTAG software mode. Used to set SW drived or bitbang
+ * mode. This is bitmask for mode param in jtag_mode for ioctl JTAG_SIOCMODE
+ */
+#define  JTAG_XFER_SW_MODE 0
+
+/**
+ * enum jtag_endstate:
+ *
+ * @JTAG_STATE_TLRESET: JTAG state machine Test Logic Reset state
+ * @JTAG_STATE_IDLE: JTAG state machine IDLE state
+ * @JTAG_STATE_SELECTDR: JTAG state machine SELECT_DR state
+ * @JTAG_STATE_CAPTUREDR: JTAG state machine CAPTURE_DR state
+ * @JTAG_STATE_SHIFTDR: JTAG state machine SHIFT_DR state
+ * @JTAG_STATE_EXIT1DR: JTAG state machine EXIT-1 DR state
+ * @JTAG_STATE_PAUSEDR: JTAG state machine PAUSE_DR state
+ * @JTAG_STATE_EXIT2DR: JTAG state machine EXIT-2 DR state
+ * @JTAG_STATE_UPDATEDR: JTAG state machine UPDATE DR state
+ * @JTAG_STATE_SELECTIR: JTAG state machine SELECT_IR state
+ * @JTAG_STATE_CAPTUREIR: JTAG state machine CAPTURE_IR state
+ * @JTAG_STATE_SHIFTIR: JTAG state machine SHIFT_IR state
+ * @JTAG_STATE_EXIT1IR: JTAG state machine EXIT-1 IR state
+ * @JTAG_STATE_PAUSEIR: JTAG state machine PAUSE_IR state
+ * @JTAG_STATE_EXIT2IR: JTAG state machine EXIT-2 IR state
+ * @JTAG_STATE_UPDATEIR: JTAG state machine UPDATE IR state
+ */
+enum jtag_endstate {
+	JTAG_STATE_TLRESET,
+	JTAG_STATE_IDLE,
+	JTAG_STATE_SELECTDR,
+	JTAG_STATE_CAPTUREDR,
+	JTAG_STATE_SHIFTDR,
+	JTAG_STATE_EXIT1DR,
+	JTAG_STATE_PAUSEDR,
+	JTAG_STATE_EXIT2DR,
+	JTAG_STATE_UPDATEDR,
+	JTAG_STATE_SELECTIR,
+	JTAG_STATE_CAPTUREIR,
+	JTAG_STATE_SHIFTIR,
+	JTAG_STATE_EXIT1IR,
+	JTAG_STATE_PAUSEIR,
+	JTAG_STATE_EXIT2IR,
+	JTAG_STATE_UPDATEIR
+};
+
+/**
+ * enum jtag_reset:
+ *
+ * @JTAG_NO_RESET: JTAG run TAP from current state
+ * @JTAG_FORCE_RESET: JTAG force TAP to reset state
+ */
+enum jtag_reset {
+	JTAG_NO_RESET = 0,
+	JTAG_FORCE_RESET = 1,
+};
+
+/**
+ * enum jtag_xfer_type:
+ *
+ * @JTAG_SIR_XFER: SIR transfer
+ * @JTAG_SDR_XFER: SDR transfer
+ */
+enum jtag_xfer_type {
+	JTAG_SIR_XFER = 0,
+	JTAG_SDR_XFER = 1,
+};
+
+/**
+ * enum jtag_xfer_direction:
+ *
+ * @JTAG_READ_XFER: read transfer
+ * @JTAG_WRITE_XFER: write transfer
+ * @JTAG_READ_WRITE_XFER: read & write transfer
+ */
+enum jtag_xfer_direction {
+	JTAG_READ_XFER = 1,
+	JTAG_WRITE_XFER = 2,
+	JTAG_READ_WRITE_XFER = 3,
+};
+
+/**
+ * struct jtag_end_tap_state - forces JTAG state machine to go into a TAPC
+ * state
+ *
+ * @reset: 0 - run IDLE/PAUSE from current state
+ *         1 - go through TEST_LOGIC/RESET state before  IDLE/PAUSE
+ * @end: completion flag
+ * @tck: clock counter
+ *
+ * Structure provide interface to JTAG device for JTAG set state execution.
+ */
+struct jtag_end_tap_state {
+	__u8	reset;
+	__u8	endstate;
+	__u8	tck;
+};
+
+/**
+ * struct jtag_xfer - jtag xfer:
+ *
+ * @type: transfer type
+ * @direction: xfer direction
+ * @length: xfer bits len
+ * @tdio : xfer data array
+ * @endir: xfer end state
+ *
+ * Structure provide interface to JTAG device for JTAG SDR/SIR xfer execution.
+ */
+struct jtag_xfer {
+	__u8	type;
+	__u8	direction;
+	__u8	endstate;
+	__u8	padding;
+	__u32	length;
+	__u64	tdio;
+};
+
+/**
+ * struct bitbang_packet - jtag bitbang array packet:
+ *
+ * @data:   JTAG Bitbang struct array pointer(input/output)
+ * @length: array size (input)
+ *
+ * Structure provide interface to JTAG device for JTAG bitbang bundle execution
+ */
+struct bitbang_packet {
+	struct tck_bitbang *data;
+	__u32	length;
+} __attribute__((__packed__));
+
+/**
+ * struct jtag_bitbang - jtag bitbang:
+ *
+ * @tms: JTAG TMS
+ * @tdi: JTAG TDI (input)
+ * @tdo: JTAG TDO (output)
+ *
+ * Structure provide interface to JTAG device for JTAG bitbang execution.
+ */
+struct tck_bitbang {
+	__u8	tms;
+	__u8	tdi;
+	__u8	tdo;
+} __attribute__((__packed__));
+
+/**
+ * struct jtag_mode - jtag mode:
+ *
+ * @feature: 0 - JTAG feature setting selector for JTAG controller HW/SW
+ *           1 - JTAG feature setting selector for controller bus master
+ *               mode output (enable / disable).
+ * @mode:    (0 - SW / 1 - HW) for JTAG_XFER_MODE feature(0)
+ *           (0 - output disable / 1 - output enable) for JTAG_CONTROL_MODE
+ *                                                    feature(1)
+ *
+ * Structure provide configuration modes to JTAG device.
+ */
+struct jtag_mode {
+	__u32	feature;
+	__u32	mode;
+};
+
+/* ioctl interface */
+#define __JTAG_IOCTL_MAGIC	0xb2
+
+#define JTAG_SIOCSTATE	_IOW(__JTAG_IOCTL_MAGIC, 0, struct jtag_end_tap_state)
+#define JTAG_SIOCFREQ	_IOW(__JTAG_IOCTL_MAGIC, 1, unsigned int)
+#define JTAG_GIOCFREQ	_IOR(__JTAG_IOCTL_MAGIC, 2, unsigned int)
+#define JTAG_IOCXFER	_IOWR(__JTAG_IOCTL_MAGIC, 3, struct jtag_xfer)
+#define JTAG_GIOCSTATUS _IOWR(__JTAG_IOCTL_MAGIC, 4, enum jtag_endstate)
+#define JTAG_SIOCMODE	_IOW(__JTAG_IOCTL_MAGIC, 5, unsigned int)
+#define JTAG_IOCBITBANG	_IOW(__JTAG_IOCTL_MAGIC, 6, unsigned int)
+
+#endif /* __UAPI_LINUX_JTAG_H */
-- 
2.7.4