forked from MathewKing/mcp2210-linux
-
Notifications
You must be signed in to change notification settings - Fork 33
/
mcp2210-core.c
2061 lines (1732 loc) · 57.5 KB
/
mcp2210-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
/*
* MCP2210 driver
*
* Copyright (c) 2013-2017 Daniel Santos <daniel.santos@pobox.com>
* 2013 Mathew King <mking@trilithic.com> for Trilithic, Inc
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*
* TODO:
* Incomplete list:
* - major number from maintainer?
* - honor cs_gpio and allow SPI where idle_cs == active_cs
* - missing mechanism to notify external entities of changes to gpio and
* the dedicated "interrupt counter" line.
*
* Fix list:
* - While we wont see it on x86 & little-endian arm, the flipping
* ctl_complete_urb() may be broken when processing data from the request
* buffer. -- PROBABLY FIXED
* - Using the packed version of protocol structs is bloating code horribly,
* even worse than I had guessed it would!! So we need to have packed and
* unpacked versions of these structs replace the is_mcp_endianness and
* "flipping" functionality with conversions from packed (protocol-correct)
* little-endian structs to unpacked native-endianness structs.
* - When a command dies and can't be retried, we need to do something more
* than just log it. Re-implement device failure?
* - Change ioctl to netlink.
* - ioctl interface not friendly with ABIs where kernel & user space have
* different sized ptrs (x32, sparc64, etc.) (Maybe fix this when we convert
* to netlink)
* - In struct gpio_chip allocate only the number of gpios for pins that are
* configured for it. This will require a revmap.
* - Now that IRQs are working, we have an issue with threaded/non- because gpio
* get() and set() can currently sleep. We probably need to have a specifier
* in the configuration for threaded or not, so that non-threaded IRQs can
* still be used in situtations where it would be more appripriate -- but not
* for SPI transfers, writing gpios (unless we add some type of async
* functionality) or reading gpios (again, unless we add some type of "last
* known value" functionality).
* - Improve the way that spi_mcp_error() (and the rest of the SPI code) decides
* how much time to wait.
*
* Tweak list:
* - examine locking and possibly (hopefully) refine
* - better prediction of how long SPI transfers will take and appropriate
* scheduling so that we don't unnecessarily request a status (update: this
* has some stuff now, but it may need an audit) Update2: it's likely that
* getting too many 0xf8s slows down the device
* - include/linux/spi/spi.h: extend mode (to u16), spi_device, et. al. to
* accommodate missing features (timing, drop cs between words, etc.) (note
* current work with DUAL and QUAD on linux-spi)
* - update spidev driver & userspace to support
* - update mcp2210 driver to use them.
*
* @file
*
* Product page:
* https://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en556614
* Datasheet:
* https://www.microchip.com/downloads/en/DeviceDoc/22288A.pdf
*
* Background:
*
* The MCP2210 is a USB-to-SPI protocol converter with GPIO by Microchip. It
* uses a basic 64-byte request/response protocol for all operations, advertises
* its self as a generic HID device and can be used via the hid-generic driver
* from userspace using the hidraw /dev node. A more friendly interface is
* available via Kerry Wong's MCP2210-Library
* (https://github.com/kerrydwong/MCP2210-Library) which is built on top of
* Signal 11's hidapi library (http://www.signal11.us/oss/hidapi) which in turn
* uses libusb. All together, it gives you a pretty user-friendly userland
* interface to to the device, but carries the following drawbacks:
*
* - Extensive overhead: hid-core driver -> usbhid driver -> (hid-generic
* driver) -> libusb -> hidapi -> MCP2210-Library means lots of memory & CPU.
* (Note however that hid-generic is virtually non-existent.) Additionally,
* an embedded system will have to enable the input and HID layers that it
* otherwise may not require.
* - No way to use SPI protocol drivers to manage peripherals on the other side
* of the MCP2210.
* - No mechanism for auto-configuration outside of userland.
*
* This driver attempts to solve these shortcomings by eliminating all of these
* layers, including the kernel's input, hid, hid-core, usbhid, etc.,
* communicating with the MCP2210 directly via interrupt URBs and allowing your
* choice of spi protocol driver for each SPI device, with the standard option
* of spidev for interacting with the SPI device from userspace. In addition,
* it supplies an (optional) auto-configuration scheme which utilizes the
* devices 256 bytes of user EEPROM to store the wiring information for the
* board and a fairly complete ioctl interface for userland configuration,
* testing and such.
*
* Theory of Operation:
* ===================
*
* Commands and The Command Queue
* ------------------------------
* The MCP2210 driver is a queue-driven USB interface driver. All commands are
* executed (or given the opportunity) serially, in FIFO order. Only one
* command may execute at a time. Each command represents a logically atomic
* operation (e.g., send SPI transfer or query settings) and typically exchanges
* at least one message with the device via interrupt URBs.
*
* Commands are objects of either struct mcp2210_cmd or a derived-type using
* pseudo-inheritance -- embedding a struct mcp2210_cmd object as its first
* member and using a type field to specify the command type. There are three
* different types of "normal" commands that interact with the device directly.
* Each populate the cmd->type with a pointer to an appropriate struct
* mcp2210_cmd_type object:
*
* 1. Transfer SPI messages (mcp2210-spi.c)
* 2. Read/write to/from the device's user-EEPROM area (mcp2210-eeprom.c)
* 3. Query and change settings (mcp2210-ctl.c)
*
* General-purpose commands have have a NULL command type, but will populate
* cmd->complete and cmd->context to defer some work, possibly to execute in a
* non-atomic context. Currently, these are only used to probe spi and gpio,
* neither of which can be probed at the time the USB interface is probed
* because the information to do so is not yet available. This occurs either
* when the user-EEPROM area has been read and decoded (when
* CONFIG_MCP2210_CREEK is enabled) or when the configure ioctl command is
* called from userspace.
*
* Delayed & Non-Atomic Commands
* -----------------------------
* Due to the nature of the device, having:
*
* 1. a single USB interface,
* 2. potentially multiple SPI peripherals connected to it,
* 3. the need to poll its gpio values & interrupt counter, and
* 4. late arrival of wiring information to perform a complete probe (with SPI
* & GPIO),
*
* the driver requires a slightly more sophisticated mechanism for processing
* commands than a simple FIFO queue processed by URB completion handlers.
* Polling commands need to be delayed. SPI Transfers (especially on slower
* chips) often need to have delays between URBs to give the device time to
* complete transfers to the chip. Performing the configure (probing spi_master
* and gpio_chip) must occur in a context that can sleep. If a command needs to
* be delayed, its cmd->delayed bit is set and cmd->delay_until will specify a
* time (in jiffies) that the command is to run at. If the command must be able
* to sleep, it's cmd->nonatomic bit will be set.
*
* Note that there is no mechanism (at this time) to assure that a delayed
* command will execute at its requested time, although it is guaranteed not
* to execute prior to it. Delayed commands who's cmd->delay_until time has
* been reached still have to wait their turn in the queue to be eligible for
* execution. If a delayed command is popped from the queue but its
* cmd->delay_until time has not yet arrived, it is moved to the
* dev->delayed_list and an appropriate mechanism (either timer or
* delayed_work) is set to pick it up. If another command is executing when
* the timer expires or delayed_work runs, the delayed command is (effectively)
* moved to the head of the queue and will execute next.
*
* process_commands():
* ------------------
* Messages in the queue are processed via process_commands(). If dev->cur_cmd
* is NULL, it will attempt to retrieve a command from the queue, marking its
* state as new. How it processes commands differs between "normal" commands
* (which interact with the MCP2210) and general-purpose commands (which are
* simply some delayed work)
*
* -- Normal Commands
* If there is a normal command in the new state, submit_urbs() is called and
* its state is set to "submitted". Completion handlers for the in and out URBs
* will eventually be called (if the usb host driver behaves) marking the
* command as "completed" and calling process_commands() to have the completed
* command finalized. Finalization is performed by calling struct mcp2210_cmd's
* complete function (if non-NULL) and freeing it. Then, the next message is
* retrieved, and so forth.
*
* -- General-Purpose Commands
* For general-purpose commands, submit/complete_urbs() is bypassed and it is
* instead immediately marked as completed having its complete() function
* called, allowing any arbitrary work to be performed.
*
* -- Deferred Work
* A command may be deferred because:
* a. it needs to wait before starting,
* c. it needs to run again, but needs to wait before doing so, or
* b. it needs to run in a non-atomic state.
*
* submit_urbs():
* -------------
* This function will first call the command type's submit_prepare() function,
* which should perform any needed initialization, populate the 64-byte request
* message and return non-zero unless it has an error. However, there are two
* exceptions to this: submit_prepare() may return -ERESTARTSYS to have the
* command deleted w/o further processing or -EAGAIN to have the message
* restarted and submit_urbs() called again). It will then submit the URBS and
* change the command's state to "submitted".
*
* complete_urb():
* This function manages both the in & out URBs.
*
* Once both URBs have completed,
* the command type's complete_urb() function is called and the command's
* state is set to "completed".
*
#if 0
out of date info:
* When the in URB completes, complete_urb_in() performs the following:
* - basic sanity checks & URB status via check_urb_status()
* - sets command status to "sent"
* - calls the command type's complete_tx() function (if it has one)
*
* complete_urb_out():
* Similarly, when the out URB completes, complete_urb_out() performs
* the following:
* - calls check_urb_status() and exits upon error
* - checks for and handles out-of-order responses
* - sets the command status to "done"
* - checks the status field and general validity of the response message via
* check_response().
* - calls complete_rx()
* - if complete_rx() returns -EAGAIN, the command's state is reset to "new" so
* that the next call to process_commands will run it again.
* - calls process_commands() (in GFP_ATOMIC mode) to process the next command.
#endif
*
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/workqueue.h>
#include <linux/uaccess.h>
//#include <linux/completion.h>
#include <linux/compiler.h>
#include "mcp2210.h"
#include "mcp2210-debug.h"
#ifdef CONFIG_MCP2210_CREEK
# include "mcp2210-creek.h"
#endif /* CONFIG_MCP2210_CREEK */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,34)
# define HAVE_USB_ALLOC_COHERENT 1
#endif
static void mcp2210_delete(struct kref *kref);
static int mcp2210_probe(struct usb_interface *intf,
const struct usb_device_id *id);
static void mcp2210_disconnect(struct usb_interface *intf);
static int report_status_error(struct mcp2210_device *dev, u8 status);
static bool reschedule_delayed_work(struct mcp2210_device *dev,
unsigned long _jiffies);
static inline bool reschedule_delayed_work_ms(struct mcp2210_device *dev,
unsigned int ms);
static void delayed_work_callback(struct work_struct *work);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,14,0)
static __maybe_unused void timer_callback(struct timer_list *t);
#else
static __maybe_unused void timer_callback(unsigned long context);
#endif
static int unlink_urbs(struct mcp2210_device *dev);
static void kill_urbs(struct mcp2210_device *dev, unsigned long *irqflags);
static void complete_urb(struct urb *urb);
static int submit_urbs(struct mcp2210_cmd *cmd, gfp_t gfp_flags);
struct mcp2210_cmd_type mcp2210_cmd_types[MCP2210_CMD_TYPE_MAX];
/******************************************************************************
* Module parameters
*/
int debug_level = CONFIG_MCP2210_DEBUG_INITIAL;
int creek_enabled = IS_ENABLED(CONFIG_MCP2210_CREEK);
int dump_urbs = CONFIG_MCP2210_DEBUG_INITIAL >= 7;
int dump_cmds = CONFIG_MCP2210_DEBUG_INITIAL >= 7;
int dump_spi = 0;
uint pending_bytes_wait_threshold = 32;
uint poll_delay_warn_secs = 0;
module_param(debug_level, int, 0664);
module_param(creek_enabled, int, 0664);
module_param(dump_urbs, int, 0664);
module_param(dump_cmds, int, 0664);
module_param(dump_spi, int, 0664);
module_param(pending_bytes_wait_threshold, uint, 0664);
module_param(poll_delay_warn_secs, uint, 0664);
MODULE_PARM_DESC(debug_level, "0-7: Like /proc/sys/kernel/printk, but "
"specific to this driver.");
MODULE_PARM_DESC(creek_enabled, "0-1: Enables Creek plug-n-pray (reads wiring "
"and configuration from mcp2210 EEPROM).");
MODULE_PARM_DESC(dump_urbs, "0-1: Spew all URBS");
MODULE_PARM_DESC(dump_cmds, "0-1: Spew all (internal) commands");
MODULE_PARM_DESC(dump_spi, "0-1: Dump all SPI communications");
MODULE_PARM_DESC(pending_bytes_wait_threshold,
"1-64: Threshold of buffer population before the driver will "
"delay transfer commands. See README for full details.");
MODULE_PARM_DESC(poll_delay_warn_secs,
"-1, 0, <n>: Number of seconds to suppress warnings after a "
"poll completes but is already past due, requring "
"rescheduling. Set to zero to always spam (can become "
"perpetuating) and set to -1 to (mostly) suppress the warning "
"all together.");
/******************************************************************************
* USB Driver structs
*/
static const struct usb_device_id mcp2210_devices[] = {
{ USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2210)},
{ }
};
static struct usb_driver mcp2210_driver = {
.name = "mcp2210",
.probe = mcp2210_probe,
.disconnect = mcp2210_disconnect,
.suspend = NULL,
.resume = NULL,
.reset_resume = NULL,
.id_table = mcp2210_devices,
.supports_autosuspend = IS_ENABLED(CONFIG_MCP2210_AUTOPM),
};
/******************************************************************************
* Module functions
*/
static int __init mcp2210_init(void)
{
int ret;
printk(KERN_INFO "%s\n", __func__);
msg_validate_size();
ret = usb_register_driver(&mcp2210_driver, THIS_MODULE, "mcp2210");
if (ret)
printk(KERN_ERR "%s: usb_register_driver() failed with %d\n",
__func__, ret);
return ret;
}
static void __exit mcp2210_exit(void)
{
printk(KERN_INFO "%s\n", __func__);
usb_deregister(&mcp2210_driver);
}
module_init(mcp2210_init);
module_exit(mcp2210_exit);
MODULE_AUTHOR("Daniel Santos <daniel.santos@pobox.com>");
MODULE_DESCRIPTION("Microchip MCP2210 USB-to-SPI protocol converter with GPIO");
MODULE_LICENSE("GPL");
/* TODO: I have no idea what this should say, this shouldn't be a "platform:"
* device if I understand correctly */
MODULE_ALIAS("mcp2210");
/******************************************************************************
* USB Class Driver & file ops
*/
static inline struct mcp2210_device *mcp2210_kref_to_dev(struct kref *kref)
{
return container_of(kref, struct mcp2210_device, kref);
}
#ifdef CONFIG_MCP2210_IOCTL
static int mcp2210_open(struct inode *inode, struct file *file)
{
struct mcp2210_device *dev;
struct usb_interface *intf;
int subminor = iminor(inode);
int ret;
if (!(intf = usb_find_interface(&mcp2210_driver, subminor))) {
pr_err("%s - error, can't find device for minor %d\n",
__func__, subminor);
return -ENODEV;
}
if (!(dev = usb_get_intfdata(intf)))
return -ENODEV;
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM)) {
ret = usb_autopm_get_interface(intf);
if (ret && ret != -EACCES) {
mcp2210_err("usb_autopm_get_interface() failed:%d",
ret);
return ret;
}
}
kref_get(&dev->kref);
file->private_data = dev;
return 0;
}
static int mcp2210_release(struct inode *inode, struct file *file)
{
struct mcp2210_device *dev = file->private_data;
if (!dev)
return -ENODEV;
/* allow the device to be autosuspended */
mutex_lock(&dev->io_mutex);
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM) && dev->intf)
usb_autopm_put_interface(dev->intf);
mutex_unlock(&dev->io_mutex);
/* decrement the count on our device */
kref_put(&dev->kref, mcp2210_delete);
return 0;
}
static int mcp2210_flush (struct file *file, fl_owner_t id)
{
return 0;
}
static loff_t mcp2210_no_llseek (struct file *file, loff_t offset, int i)
{
return -EPERM;
}
static ssize_t mcp2210_no_read_write (struct file *file,
const char __user *data, size_t size,
loff_t *offset)
{
return -EPERM;
}
const struct file_operations mcp2210_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = mcp2210_ioctl,
.compat_ioctl = mcp2210_ioctl,
.llseek = mcp2210_no_llseek,
.read = (void*)mcp2210_no_read_write,
.write = mcp2210_no_read_write,
.open = mcp2210_open,
.flush = mcp2210_flush,
.release = mcp2210_release,
};
static struct usb_class_driver mcp2210_class = {
.name = "usb2spi_bridge%d",
.fops = &mcp2210_fops,
.minor_base = 0, /* FIXME: need a minor base from USB maintainer? */
};
#endif /* CONFIG_MCP2210_IOCTL */
/******************************************************************************
* USB Driver functions
*/
static inline void reset_endpoint(struct mcp2210_endpoint *ep)
{
ep->state = MCP2210_STATE_NEW;
ep->kill = 0;
}
/* init_endpoint - Initialize an endpoint proxy struct
*
* may sleep
*
* This is only called from one place now but the code is cleaner with it
* separated out in another function, so I'm marking inlining it for the
* possible reduction in size. (It's only called in probe, so performance isn't
* a big deal here.)
*/
static __always_inline int init_endpoint(struct mcp2210_device *dev,
const struct usb_host_endpoint *ep)
{
int is_dir_in = !!usb_endpoint_dir_in(&ep->desc);
struct mcp2210_endpoint *dest = &dev->eps[is_dir_in];
unsigned int pipe;
struct urb *urb;
if (is_dir_in)
pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
else
pipe = usb_sndintpipe(dev->udev, ep->desc.bEndpointAddress);
/* just another struct size sanity check */
BUILD_BUG_ON(sizeof(*dest->buffer) != 64);
if (unlikely(dest->ep)) {
mcp2210_warn("Unexpected: more than one interrupt %s endpoint "
"discovered, ingoring them\n",
urb_dir_str[is_dir_in]);
return 0;
}
dest->is_dir_in = is_dir_in;
dest->ep = ep;
reset_endpoint(dest);
//= ATOMIC_INIT(0);
atomic_set(&dest->unlink_in_process, 1);
urb = usb_alloc_urb(0, GFP_KERNEL);
if (unlikely(!urb)) {
mcp2210_err("Failed to alloc %s URB\n", urb_dir_str[is_dir_in]);
return -ENOMEM;
}
/* If we have usb_alloc_coherent, we'll use that. Otherwise, we'll let
* the usb host controller driver allocate a DMA buffer if it needs one
*/
#ifdef HAVE_USB_ALLOC_COHERENT
dest->buffer = usb_alloc_coherent(dev->udev, 64, GFP_KERNEL,
&urb->transfer_dma);
urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
#else
dest->buffer = kzalloc(64, GFP_KERNEL);
#endif
if (unlikely(!dest->buffer)) {
usb_free_urb(urb);
mcp2210_err("Failed to alloc %s URB DMA buffer\n",
urb_dir_str[is_dir_in]);
return -ENOMEM;
}
dest->urb = urb;
usb_fill_int_urb(urb,
dev->udev,
pipe,
dest->buffer,
64,
complete_urb,
dev,
ep->desc.bInterval);
/* well, this isn't really helpful, but usb_host_endpoint ptr will
* eventually replace pipe and usb_submit_urb() will have to
* populate this later anyway */
urb->ep = (struct usb_host_endpoint*)ep;
#if 0
/* apparently, this isn't reliable on all host controllers, so we'll
* just check acutal_length ourselves */
if (is_dir_in)
urb->transfer_flags |= URB_SHORT_NOT_OK;
#endif
return 0;
}
static void mcp2210_delete(struct kref *kref)
{
struct mcp2210_device *dev = mcp2210_kref_to_dev(kref);
struct mcp2210_endpoint *ep;
for (ep = dev->eps; ep < &dev->eps[2]; ++ep) {
if (ep->urb) {
if (ep->buffer)
#ifdef HAVE_USB_ALLOC_COHERENT
usb_free_coherent(dev->udev, 64, ep->buffer,
ep->urb->transfer_dma);
#else
kfree(ep->buffer);
#endif
usb_free_urb(ep->urb);
}
}
if (dev->config)
kfree(dev->config);
kfree(dev);
}
#ifdef CONFIG_MCP2210_CREEK
static int creek_configure(struct mcp2210_cmd *cmd, void *context) {
struct mcp2210_device *dev = cmd->dev;
struct mcp2210_board_config *board_config;
int ret;
board_config = mcp2210_creek_probe(dev, GFP_KERNEL);
BUG_ON(dev->config);
if (IS_ERR(board_config)) {
mcp2210_err("Failed to decode board config from MCP2210's "
"user-EEPROM: %d", (int)PTR_ERR(board_config));
return 0;
}
ret = mcp2210_configure(dev, board_config);
if (ret) {
mcp2210_err("mcp2210_configure failed: %d", ret);
kfree(board_config);
}
/*
spin_lock_irqsave(&dev->eeprom_spinlock, irqflags);
magic = le32_to_cpu(*((u32*)dev->eeprom_cache));
spin_unlock_irqrestore(&dev->eeprom_spinlock, irqflags);
*/
return 0;
}
static int eeprom_read_complete(struct mcp2210_cmd *cmd_head, void *context)
{
struct mcp2210_device *dev = context;
struct mcp2210_cmd_eeprom *cmd = (void *)cmd_head;
unsigned long irqflags;
int ret;
mcp2210_debug();
BUG_ON(!cmd);
BUG_ON(!dev);
BUG_ON(!cmd_head->type);
BUG_ON(cmd_head->type->id != MCP2210_CMD_TYPE_EEPROM);
/* deal with fuck-ups */
if (cmd->head.status) {
if (dev->eeprom_retry_count == 32) {
mcp2210_err("Failed %d EEPROM reads, giving up.",
dev->eeprom_retry_count);
return 0;
}
mcp2210_err("EEPROM read failed, retry %d..",
++dev->eeprom_retry_count);
ret = mcp2210_eeprom_read(dev, NULL, 0, cmd->size,
eeprom_read_complete, dev,
GFP_ATOMIC);
if (ret && ret != -EINPROGRESS)
mcp2210_err("Adding eeprom command failed with %d, "
"giving up", ret);
return 0;
}
/* We can get 0xfa (write failure) for writing to EEPROM, but we
* supposedly can't get a failure for reading, so we pretty much should
* always have a zero for the mcpstatus
*/
if (cmd->head.mcp_status) {
mcp2210_err("Unexpected failure of EEPROM read: 0x%02x",
cmd->head.mcp_status);
return 0;
}
if (cmd->size == 4) {
u8 magic[4];
spin_lock_irqsave(&dev->eeprom_spinlock, irqflags);
memcpy(magic, dev->eeprom_cache, 4);
//magic = le32_to_cpu(*((u32*)dev->eeprom_cache));
spin_unlock_irqrestore(&dev->eeprom_spinlock, irqflags);
if (memcmp(magic, CREEK_CONFIG_MAGIC, 4)) {
mcp2210_notice("creek magic not detected: 0x%08x != "
"0x%08x", *(u32*)magic,
*(u32*)CREEK_CONFIG_MAGIC);
return 0;
}
mcp2210_notice("creek magic detected, reading config from "
"EEPROM");
ret = mcp2210_eeprom_read(dev, NULL, 0, 0x100,
eeprom_read_complete, dev,
GFP_ATOMIC);
if (ret && ret != -EINPROGRESS)
mcp2210_err("Adding eeprom command failed with %d",
ret);
return 0;
} else if (cmd->size == 0x100) {
struct mcp2210_cmd *cmd;
if (!dev->s.have_power_up_chip_settings) {
mcp2210_err("Don't have power up chip settings, "
"aborting probe... :(");
return 0;
}
cmd = mcp2210_alloc_cmd(dev, NULL, sizeof(struct mcp2210_cmd),
GFP_ATOMIC);
if (!cmd) {
mcp2210_err("mcp2210_alloc_cmd failed (ENOMEM)");
return 0;
}
cmd->complete = creek_configure;
cmd->nonatomic = 1;
ret = mcp2210_add_cmd(cmd, true);
if (ret)
return 0;
}
#if 0
if (ret && ret != -EINPROGRESS) {
mcp2210_err("Adding eeprom command failed with %d", ret);
goto error2;
}
CREEK_CONFIG_MAGIC
le32_to_cpu(creek_get_bits(&bs, 32));
/* HACK: This is a hack for when URBs fail on the rpi, since we're not
* really even using these yet */
dev->have_power_up_chip_settings = 1;
dev->have_power_up_spi_settings = 1;
dev->do_spi_probe = 1;
#endif
return 0;
}
#else
static inline int eeprom_read_complete(struct mcp2210_cmd *cmd_head,
void *context)
{
return 0;
}
#endif /* CONFIG_MCP2210_CREEK */
/* mcp2210_probe
* can sleep, but keep it minimal as the USB core uses a single thread to probe
* & remove all USB devices.
*/
int mcp2210_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_host_interface *intf_desc = intf->cur_altsetting;
struct mcp2210_device *dev;
struct usb_host_endpoint *ep, *ep_end;
int ret = -ENODEV;
dev_printk(KERN_NOTICE, &udev->dev, "%s\n", __func__);
if (!udev)
return -ENODEV;
dev = kzalloc(sizeof(struct mcp2210_device), GFP_KERNEL);
if (unlikely(!dev)) {
mcp2210_err("failed to allocate struct usb_device (%u bytes)",
(unsigned)sizeof(struct mcp2210_device));
return -ENOMEM;
}
dev->intf = intf;
dev->udev = udev;
kref_init(&dev->kref);
INIT_LIST_HEAD(&dev->cmd_queue);
INIT_LIST_HEAD(&dev->delayed_list);
spin_lock_init(&dev->dev_spinlock);
spin_lock_init(&dev->queue_spinlock);
#ifdef CONFIG_MCP2210_EEPROM
spin_lock_init(&dev->eeprom_spinlock);
#endif
mutex_init(&dev->io_mutex);
ctl_cmd_init(dev, &dev->ctl_cmd, 0, 0, NULL, 0, false);
INIT_DELAYED_WORK(&dev->delayed_work, delayed_work_callback);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,14,0)
timer_setup(&dev->timer, timer_callback, 0);
#else
init_timer(&dev->timer);
dev->timer.function = timer_callback;
dev->timer.data = (unsigned long)dev;
#endif
#ifdef CONFIG_MCP2210_DEBUG
atomic_set(&dev->manager_running, 0);
#endif
#ifdef CONFIG_MCP2210_GPIO
#endif
#ifdef CONFIG_MCP2210_SPI
/* mark current spi config as uninitialized */
dev->s.cur_spi_config = -1;
#endif
/* Set up interrupt endpoint information. */
ep_end = &intf_desc->endpoint[intf_desc->desc.bNumEndpoints];
for (ep = intf_desc->endpoint; ep != ep_end; ++ep) {
if (!usb_endpoint_xfer_int(&ep->desc))
continue;
if ((ret = init_endpoint(dev, ep)))
goto error_kref_put;
}
if (unlikely(!dev->eps[EP_OUT].ep || !dev->eps[EP_IN].ep)) {
mcp2210_err("could not find in and/or out interrupt endpoints");
goto error_kref_put;
}
usb_set_intfdata(intf, dev);
/* no sleeping until we're done with all of our probing */
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM))
usb_autopm_get_interface_no_resume(intf);
#ifdef CONFIG_MCP2210_IOCTL
/* TODO: Do I need a "major number" from maintainer?
* https://www.kernel.org/doc/htmldocs/usb/API-usb-register-dev.html
*/
ret = usb_register_dev(intf, &mcp2210_class);
if (unlikely(ret)) {
mcp2210_err("failed to register device %d\n", ret);
goto error_autopm_put;
}
#endif /* CONFIG_MCP2210_IOCTL */
/* TODO: set USB power to max until we know how much we need? */
dump_dev(KERN_INFO, 0, "This is the initial device state: ", dev);
/* Submit initial commands & queries. First, we have to cancel any SPI
* messages that were started (and not finished) prior the host machine
* rebooting since the chip fails to do this upon USB reset. */
if ((ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_SPI_CANCEL, 0,
NULL, 0, false, GFP_KERNEL))
/* current chip configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_CHIP_CONFIG, 0,
NULL, 0, false, GFP_KERNEL))
/* current SPI configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_SPI_CONFIG, 0,
NULL, 0, false, GFP_KERNEL))
/* power-up chip configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_NVRAM,
MCP2210_NVRAM_SPI,
NULL, 0, false, GFP_KERNEL))
/* power-up SPI configuration */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_NVRAM,
MCP2210_NVRAM_CHIP,
NULL, 0, false, GFP_KERNEL))
/* user key parameters */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_NVRAM,
MCP2210_NVRAM_KEY_PARAMS,
NULL, 0, false, GFP_KERNEL))
/* need gpio pin values now so we don't trigger an irq after we probe it */
|| (ret = mcp2210_add_ctl_cmd(dev, MCP2210_CMD_GET_PIN_VALUE, 0,
NULL, 0, false, GFP_KERNEL))) {
mcp2210_err("Adding some command failed with %d", ret);
goto error_deregister_dev;
}
if (IS_ENABLED(CONFIG_MCP2210_CREEK) && creek_enabled) {
/* read the first 4 bytes to see if we have our magic number */
ret = mcp2210_eeprom_read(dev, NULL, 0, 4, eeprom_read_complete,
dev, GFP_KERNEL);
if (ret && ret != -EINPROGRESS) {
mcp2210_err("Adding eeprom command failed with %d",
ret);
goto error_deregister_dev;
}
}
/* start up background cleanup thread */
schedule_delayed_work(&dev->delayed_work, msecs_to_jiffies(1000));
/* Submit the first command's URB */
ret = process_commands(dev, false, true);
if (ret < 0)
goto error_deregister_dev;
return 0;
error_deregister_dev:
if (IS_ENABLED(CONFIG_MCP2210_IOCTL))
usb_deregister_dev(intf, &mcp2210_class);
error_autopm_put:
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM))
usb_autopm_put_interface(intf);
usb_set_intfdata(intf, NULL);
error_kref_put:
kref_put(&dev->kref, mcp2210_delete);
return ret;
}
static void fail_device(struct mcp2210_device *dev, int error)
{
mcp2210_err("failing mcp2210 with error %d", error);
*((volatile int *)&dev->dead) = error;
unlink_urbs(dev);
cancel_delayed_work(&dev->delayed_work);
dev->cur_cmd->status = error;
}
/**
* claims new_config (so don't free it)
*/
int mcp2210_configure(struct mcp2210_device *dev,
struct mcp2210_board_config *new_config)
{
unsigned i;
struct mcp2210_chip_settings chip_settings;
int ret;
might_sleep();
mcp2210_info();
if (IS_ENABLED(CONFIG_MCP2210_DEBUG)) {
BUG_ON(dev->spi_master);
BUG_ON(dev->is_gpio_probed);
BUG_ON(dev->config);
BUG_ON(!dev->s.have_chip_settings);
}
if (dev->config)
mcp2210_err("ERROR: already have dev->config!");
if (dev->spi_master)
mcp2210_err("ERROR: already have dev->spi_master!");
if (dev->is_gpio_probed)
mcp2210_err("ERROR: gpio already probed");
if (!dev->s.have_chip_settings)
mcp2210_err("ERROR: don't have dev->s.have_chip_settings!");
if (dev->config || dev->spi_master || dev->is_gpio_probed
|| !dev->s.have_chip_settings)
return -EPERM;
ret = validate_board_config(new_config, &dev->s.chip_settings);
if (ret) {
mcp2210_err("error in board configuration");
return ret;
}
dev->s.cur_spi_config = -1;
dev->have_config = 1;
dev->config = new_config;
memcpy(&chip_settings, &dev->s.chip_settings, sizeof(chip_settings));
for (i = 0; i < MCP2210_NUM_PINS; ++i) {
u8 mode = dev->config->pins[i].mode;
chip_settings.pin_mode[i] = mode;
dev->names[i] = dev->config->pins[i].name;
}
mcp2210_add_ctl_cmd(dev, MCP2210_CMD_SET_CHIP_CONFIG, 0, &chip_settings,
sizeof(chip_settings), false, GFP_KERNEL);
if (IS_ENABLED(CONFIG_MCP2210_GPIO)) {
mcp2210_info("----------probing GPIO----------\n");
ret = mcp2210_gpio_probe(dev);
if (ret) {
mcp2210_err("gpio probe failed: %d", ret);
return 0;
}
}
if (IS_ENABLED(CONFIG_MCP2210_IRQ)) {
mcp2210_info("----------probing IRQ controller----------\n");
ret = mcp2210_irq_probe(dev);
if (ret) {
mcp2210_err("IRQ probe failed: %d", ret);
return 0;
}
}
if (IS_ENABLED(CONFIG_MCP2210_SPI)) {
mcp2210_info("----------probing SPI----------\n");
ret = mcp2210_spi_probe(dev);
if (ret) {
mcp2210_err("spi probe failed: %d", ret);
return 0;
}
}
if (!dev->cur_cmd)
process_commands(dev, false, true);
/* Allow the device to auto-sleep now */
if (IS_ENABLED(CONFIG_MCP2210_AUTOPM))
usb_autopm_put_interface(dev->intf);
if (IS_ENABLED(CONFIG_MCP2210_DEBUG_VERBOSE)) {
mcp2210_notice("Device sucessfully configured. New settings:\n");
dump_dev(KERN_NOTICE, 0, "", dev);
} else
mcp2210_notice("Device sucessfully configured\n");