aboutsummaryrefslogtreecommitdiffstats
path: root/os/hal/src/usb.c
blob: c4f612d0f1c4ad5ebbb0a66779748a230a55a433 (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
905
/*
    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

/**
 * @file    usb.c
 * @brief   USB Driver code.
 *
 * @addtogroup USB
 * @{
 */

#include <string.h>

#include "hal.h"

#if (HAL_USE_USB == TRUE) || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local variables and types.                                         */
/*===========================================================================*/

static const uint8_t zero_status[] = {0x00, 0x00};
static const uint8_t active_status[] ={0x00, 0x00};
static const uint8_t halted_status[] = {0x01, 0x00};

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

static uint16_t get_hword(uint8_t *p) {
  uint16_t hw;

  hw  = (uint16_t)*p++;
  hw |= (uint16_t)*p << 8U;
  return hw;
}

/**
 * @brief  SET ADDRESS transaction callback.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 */
static void set_address(USBDriver *usbp) {

  usbp->address = usbp->setup[2];
  usb_lld_set_address(usbp);
  _usb_isr_invoke_event_cb(usbp, USB_EVENT_ADDRESS);
  usbp->state = USB_SELECTED;
}

/**
 * @brief   Standard requests handler.
 * @details This is the standard requests default handler, most standard
 *          requests are handled here, the user can override the standard
 *          handling using the @p requests_hook_cb hook in the
 *          @p USBConfig structure.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @return              The request handling exit code.
 * @retval false        Request not recognized by the handler or error.
 * @retval true         Request handled.
 */
static bool default_handler(USBDriver *usbp) {
  const USBDescriptor *dp;

  /* Decoding the request.*/
  switch ((((uint32_t)usbp->setup[0] & (USB_RTYPE_RECIPIENT_MASK |
                                        USB_RTYPE_TYPE_MASK)) |
           ((uint32_t)usbp->setup[1] << 8U))) {
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_GET_STATUS << 8):
    /* Just returns the current status word.*/
    usbSetupTransfer(usbp, (uint8_t *)&usbp->status, 2, NULL);
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_CLEAR_FEATURE << 8):
    /* Only the DEVICE_REMOTE_WAKEUP is handled here, any other feature
       number is handled as an error.*/
    if (usbp->setup[2] == USB_FEATURE_DEVICE_REMOTE_WAKEUP) {
      usbp->status &= ~2U;
      usbSetupTransfer(usbp, NULL, 0, NULL);
      return true;
    }
    return false;
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_SET_FEATURE << 8):
    /* Only the DEVICE_REMOTE_WAKEUP is handled here, any other feature
       number is handled as an error.*/
    if (usbp->setup[2] == USB_FEATURE_DEVICE_REMOTE_WAKEUP) {
      usbp->status |= 2U;
      usbSetupTransfer(usbp, NULL, 0, NULL);
      return true;
    }
    return false;
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_SET_ADDRESS << 8):
    /* The SET_ADDRESS handling can be performed here or postponed after
       the status packed depending on the USB_SET_ADDRESS_MODE low
       driver setting.*/
#if USB_SET_ADDRESS_MODE == USB_EARLY_SET_ADDRESS
    if ((usbp->setup[0] == USB_RTYPE_RECIPIENT_DEVICE) &&
        (usbp->setup[1] == USB_REQ_SET_ADDRESS)) {
      set_address(usbp);
    }
    usbSetupTransfer(usbp, NULL, 0, NULL);
#else
    usbSetupTransfer(usbp, NULL, 0, set_address);
#endif
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_GET_DESCRIPTOR << 8):
    /* Handling descriptor requests from the host.*/
    dp = usbp->config->get_descriptor_cb(usbp, usbp->setup[3],
                                         usbp->setup[2],
                                         get_hword(&usbp->setup[4]));
    if (dp == NULL) {
      return false;
    }
    /*lint -save -e9005 [11.8] Removing const is fine.*/
    usbSetupTransfer(usbp, (uint8_t *)dp->ud_string, dp->ud_size, NULL);
    /*lint -restore*/
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_GET_CONFIGURATION << 8):
    /* Returning the last selected configuration.*/
    usbSetupTransfer(usbp, &usbp->configuration, 1, NULL);
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_SET_CONFIGURATION << 8):
    /* Handling configuration selection from the host.*/
    usbp->configuration = usbp->setup[2];
    if (usbp->configuration == 0U) {
      usbp->state = USB_SELECTED;
    }
    else {
      usbp->state = USB_ACTIVE;
    }
    _usb_isr_invoke_event_cb(usbp, USB_EVENT_CONFIGURED);
    usbSetupTransfer(usbp, NULL, 0, NULL);
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_INTERFACE | ((uint32_t)USB_REQ_GET_STATUS << 8):
  case (uint32_t)USB_RTYPE_RECIPIENT_ENDPOINT | ((uint32_t)USB_REQ_SYNCH_FRAME << 8):
    /* Just sending two zero bytes, the application can change the behavior
       using a hook..*/
    /*lint -save -e9005 [11.8] Removing const is fine.*/
    usbSetupTransfer(usbp, (uint8_t *)zero_status, 2, NULL);
    /*lint -restore*/
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_ENDPOINT | ((uint32_t)USB_REQ_GET_STATUS << 8):
    /* Sending the EP status.*/
    if ((usbp->setup[4] & 0x80U) != 0U) {
      switch (usb_lld_get_status_in(usbp, usbp->setup[4] & 0x0FU)) {
      case EP_STATUS_STALLED:
        /*lint -save -e9005 [11.8] Removing const is fine.*/
        usbSetupTransfer(usbp, (uint8_t *)halted_status, 2, NULL);
        /*lint -restore*/
        return true;
      case EP_STATUS_ACTIVE:
        /*lint -save -e9005 [11.8] Removing const is fine.*/
        usbSetupTransfer(usbp, (uint8_t *)active_status, 2, NULL);
        /*lint -restore*/
        return true;
      case EP_STATUS_DISABLED:
      default:
        return false;
      }
    }
    else {
      switch (usb_lld_get_status_out(usbp, usbp->setup[4] & 0x0FU)) {
      case EP_STATUS_STALLED:
        /*lint -save -e9005 [11.8] Removing const is fine.*/
        usbSetupTransfer(usbp, (uint8_t *)halted_status, 2, NULL);
        /*lint -restore*/
        return true;
      case EP_STATUS_ACTIVE:
        /*lint -save -e9005 [11.8] Removing const is fine.*/
        usbSetupTransfer(usbp, (uint8_t *)active_status, 2, NULL);
        /*lint -restore*/
        return true;
      case EP_STATUS_DISABLED:
      default:
        return false;
      }
    }
  case (uint32_t)USB_RTYPE_RECIPIENT_ENDPOINT | ((uint32_t)USB_REQ_CLEAR_FEATURE << 8):
    /* Only ENDPOINT_HALT is handled as feature.*/
    if (usbp->setup[2] != USB_FEATURE_ENDPOINT_HALT) {
      return false;
    }
    /* Clearing the EP status, not valid for EP0, it is ignored in that case.*/
    if ((usbp->setup[4] & 0x0FU) != 0U) {
      if ((usbp->setup[4] & 0x80U) != 0U) {
        usb_lld_clear_in(usbp, usbp->setup[4] & 0x0FU);
      }
      else {
        usb_lld_clear_out(usbp, usbp->setup[4] & 0x0FU);
      }
    }
    usbSetupTransfer(usbp, NULL, 0, NULL);
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_ENDPOINT | ((uint32_t)USB_REQ_SET_FEATURE << 8):
    /* Only ENDPOINT_HALT is handled as feature.*/
    if (usbp->setup[2] != USB_FEATURE_ENDPOINT_HALT) {
      return false;
    }
    /* Stalling the EP, not valid for EP0, it is ignored in that case.*/
    if ((usbp->setup[4] & 0x0FU) != 0U) {
      if ((usbp->setup[4] & 0x80U) != 0U) {
        usb_lld_stall_in(usbp, usbp->setup[4] & 0x0FU);
      }
      else {
        usb_lld_stall_out(usbp, usbp->setup[4] & 0x0FU);
      }
    }
    usbSetupTransfer(usbp, NULL, 0, NULL);
    return true;
  case (uint32_t)USB_RTYPE_RECIPIENT_DEVICE | ((uint32_t)USB_REQ_SET_DESCRIPTOR << 8):
  case (uint32_t)USB_RTYPE_RECIPIENT_INTERFACE | ((uint32_t)USB_REQ_CLEAR_FEATURE << 8):
  case (uint32_t)USB_RTYPE_RECIPIENT_INTERFACE | ((uint32_t)USB_REQ_SET_FEATURE << 8):
  case (uint32_t)USB_RTYPE_RECIPIENT_INTERFACE | ((uint32_t)USB_REQ_GET_INTERFACE << 8):
  case (uint32_t)USB_RTYPE_RECIPIENT_INTERFACE | ((uint32_t)USB_REQ_SET_INTERFACE << 8):
    /* All the above requests are not handled here, if you need them then
       use the hook mechanism and provide handling.*/
  default:
    return false;
  }
}

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   USB Driver initialization.
 * @note    This function is implicitly invoked by @p halInit(), there is
 *          no need to explicitly initialize the driver.
 *
 * @init
 */
void usbInit(void) {

  usb_lld_init();
}

/**
 * @brief   Initializes the standard part of a @p USBDriver structure.
 *
 * @param[out] usbp     pointer to the @p USBDriver object
 *
 * @init
 */
void usbObjectInit(USBDriver *usbp) {
  unsigned i;

  usbp->state        = USB_STOP;
  usbp->config       = NULL;
  for (i = 0; i < (unsigned)USB_MAX_ENDPOINTS; i++) {
    usbp->in_params[i]  = NULL;
    usbp->out_params[i] = NULL;
  }
  usbp->transmitting = 0;
  usbp->receiving    = 0;
}

/**
 * @brief   Configures and activates the USB peripheral.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] config    pointer to the @p USBConfig object
 *
 * @api
 */
void usbStart(USBDriver *usbp, const USBConfig *config) {
  unsigned i;

  osalDbgCheck((usbp != NULL) && (config != NULL));

  osalSysLock();
  osalDbgAssert((usbp->state == USB_STOP) || (usbp->state == USB_READY),
                "invalid state");
  usbp->config = config;
  for (i = 0; i <= (unsigned)USB_MAX_ENDPOINTS; i++) {
    usbp->epc[i] = NULL;
  }
  usb_lld_start(usbp);
  usbp->state = USB_READY;
  osalSysUnlock();
}

/**
 * @brief   Deactivates the USB peripheral.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 *
 * @api
 */
void usbStop(USBDriver *usbp) {

  osalDbgCheck(usbp != NULL);

  osalSysLock();
  osalDbgAssert((usbp->state == USB_STOP) || (usbp->state == USB_READY) ||
                (usbp->state == USB_SELECTED) || (usbp->state == USB_ACTIVE) ||
                (usbp->state == USB_SUSPENDED),
                "invalid state");
  usb_lld_stop(usbp);
  usbp->state = USB_STOP;
  osalSysUnlock();
}

/**
 * @brief   Enables an endpoint.
 * @details This function enables an endpoint, both IN and/or OUT directions
 *          depending on the configuration structure.
 * @note    This function must be invoked in response of a SET_CONFIGURATION
 *          or SET_INTERFACE message.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 * @param[in] epcp      the endpoint configuration
 *
 * @iclass
 */
void usbInitEndpointI(USBDriver *usbp, usbep_t ep,
                      const USBEndpointConfig *epcp) {

  osalDbgCheckClassI();
  osalDbgCheck((usbp != NULL) && (epcp != NULL));
  osalDbgAssert(usbp->state == USB_ACTIVE,
                "invalid state");
  osalDbgAssert(usbp->epc[ep] == NULL, "already initialized");

  /* Logically enabling the endpoint in the USBDriver structure.*/
  if (epcp->in_state != NULL) {
    memset(epcp->in_state, 0, sizeof(USBInEndpointState));
  }
  if (epcp->out_state != NULL) {
    memset(epcp->out_state, 0, sizeof(USBOutEndpointState));
  }

  usbp->epc[ep] = epcp;

  /* Low level endpoint activation.*/
  usb_lld_init_endpoint(usbp, ep);
}

/**
 * @brief   Disables all the active endpoints.
 * @details This function disables all the active endpoints except the
 *          endpoint zero.
 * @note    This function must be invoked in response of a SET_CONFIGURATION
 *          message with configuration number zero.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 *
 * @iclass
 */
void usbDisableEndpointsI(USBDriver *usbp) {
  unsigned i;

  osalDbgCheckClassI();
  osalDbgCheck(usbp != NULL);
  osalDbgAssert(usbp->state == USB_SELECTED, "invalid state");

  usbp->transmitting &= ~1U;
  usbp->receiving    &= ~1U;
  for (i = 1; i <= (unsigned)USB_MAX_ENDPOINTS; i++) {
    usbp->epc[i] = NULL;
  }

  /* Low level endpoints deactivation.*/
  usb_lld_disable_endpoints(usbp);
}

/**
 * @brief   Prepares for a receive transaction on an OUT endpoint.
 * @post    The endpoint is ready for @p usbStartReceiveI().
 * @note    This function can be called both in ISR and thread context.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 * @param[out] buf      buffer where to copy the received data
 * @param[in] n         transaction size
 *
 * @special
 */
void usbPrepareReceive(USBDriver *usbp, usbep_t ep, uint8_t *buf, size_t n) {
  USBOutEndpointState *osp = usbp->epc[ep]->out_state;

  osp->rxqueued           = false;
  osp->mode.linear.rxbuf  = buf;
  osp->rxsize             = n;
  osp->rxcnt              = 0;

  usb_lld_prepare_receive(usbp, ep);
}

/**
 * @brief   Prepares for a transmit transaction on an IN endpoint.
 * @post    The endpoint is ready for @p usbStartTransmitI().
 * @note    This function can be called both in ISR and thread context.
 * @note    The queue must contain at least the amount of data specified
 *          as transaction size.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 * @param[in] buf       buffer where to fetch the data to be transmitted
 * @param[in] n         transaction size
 *
 * @special
 */
void usbPrepareTransmit(USBDriver *usbp, usbep_t ep,
                        const uint8_t *buf, size_t n) {
  USBInEndpointState *isp = usbp->epc[ep]->in_state;

  isp->txqueued           = false;
  isp->mode.linear.txbuf  = buf;
  isp->txsize             = n;
  isp->txcnt              = 0;

  usb_lld_prepare_transmit(usbp, ep);
}

/**
 * @brief   Prepares for a receive transaction on an OUT endpoint.
 * @post    The endpoint is ready for @p usbStartReceiveI().
 * @note    This function can be called both in ISR and thread context.
 * @note    The queue must have enough free space to accommodate the
 *          specified transaction size rounded to the next packet size
 *          boundary. For example if the transaction size is 1 and the
 *          packet size is 64 then the queue must have space for at least
 *          64 bytes.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 * @param[in] iqp       input queue to be filled with incoming data
 * @param[in] n         transaction size
 *
 * @special
 */
void usbPrepareQueuedReceive(USBDriver *usbp, usbep_t ep,
                             input_queue_t *iqp, size_t n) {
  USBOutEndpointState *osp = usbp->epc[ep]->out_state;

  osp->rxqueued           = true;
  osp->mode.queue.rxqueue = iqp;
  osp->rxsize             = n;
  osp->rxcnt              = 0;

  usb_lld_prepare_receive(usbp, ep);
}

/**
 * @brief   Prepares for a transmit transaction on an IN endpoint.
 * @post    The endpoint is ready for @p usbStartTransmitI().
 * @note    This function can be called both in ISR and thread context.
 * @note    The transmit transaction size is equal to the data contained
 *          in the queue.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 * @param[in] oqp       output queue to be fetched for outgoing data
 * @param[in] n         transaction size
 *
 * @special
 */
void usbPrepareQueuedTransmit(USBDriver *usbp, usbep_t ep,
                              output_queue_t *oqp, size_t n) {
  USBInEndpointState *isp = usbp->epc[ep]->in_state;

  isp->txqueued           = true;
  isp->mode.queue.txqueue = oqp;
  isp->txsize             = n;
  isp->txcnt              = 0;

  usb_lld_prepare_transmit(usbp, ep);
}

/**
 * @brief   Starts a receive transaction on an OUT endpoint.
 * @post    The endpoint callback is invoked when the transfer has been
 *          completed.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 *
 * @return              The operation status.
 * @retval false        Operation started successfully.
 * @retval true         Endpoint busy, operation not started.
 *
 * @iclass
 */
bool usbStartReceiveI(USBDriver *usbp, usbep_t ep) {

  osalDbgCheckClassI();
  osalDbgCheck(usbp != NULL);

  if (usbGetReceiveStatusI(usbp, ep)) {
    return true;
  }

  usbp->receiving |= (uint16_t)((unsigned)1U << (unsigned)ep);
  usb_lld_start_out(usbp, ep);
  return false;
}

/**
 * @brief   Starts a transmit transaction on an IN endpoint.
 * @post    The endpoint callback is invoked when the transfer has been
 *          completed.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 *
 * @return              The operation status.
 * @retval false        Operation started successfully.
 * @retval true         Endpoint busy, operation not started.
 *
 * @iclass
 */
bool usbStartTransmitI(USBDriver *usbp, usbep_t ep) {

  osalDbgCheckClassI();
  osalDbgCheck(usbp != NULL);

  if (usbGetTransmitStatusI(usbp, ep)) {
    return true;
  }

  usbp->transmitting |= (uint16_t)((unsigned)1U << (unsigned)ep);
  usb_lld_start_in(usbp, ep);
  return false;
}

/**
 * @brief   Stalls an OUT endpoint.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 *
 * @return              The operation status.
 * @retval false        Endpoint stalled.
 * @retval true         Endpoint busy, not stalled.
 *
 * @iclass
 */
bool usbStallReceiveI(USBDriver *usbp, usbep_t ep) {

  osalDbgCheckClassI();
  osalDbgCheck(usbp != NULL);

  if (usbGetReceiveStatusI(usbp, ep)) {
    return true;
  }

  usb_lld_stall_out(usbp, ep);
  return false;
}

/**
 * @brief   Stalls an IN endpoint.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number
 *
 * @return              The operation status.
 * @retval false        Endpoint stalled.
 * @retval true         Endpoint busy, not stalled.
 *
 * @iclass
 */
bool usbStallTransmitI(USBDriver *usbp, usbep_t ep) {

  osalDbgCheckClassI();
  osalDbgCheck(usbp != NULL);

  if (usbGetTransmitStatusI(usbp, ep)) {
    return true;
  }

  usb_lld_stall_in(usbp, ep);
  return false;
}

/**
 * @brief   USB reset routine.
 * @details This function must be invoked when an USB bus reset condition is
 *          detected.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 *
 * @notapi
 */
void _usb_reset(USBDriver *usbp) {
  unsigned i;

  /* State transition.*/
  usbp->state         = USB_READY;

  /* Resetting internal state.*/
  usbp->status        = 0;
  usbp->address       = 0;
  usbp->configuration = 0;
  usbp->transmitting  = 0;
  usbp->receiving     = 0;

  /* Invalidates all endpoints into the USBDriver structure.*/
  for (i = 0; i <= (unsigned)USB_MAX_ENDPOINTS; i++) {
    usbp->epc[i] = NULL;
  }

  /* EP0 state machine initialization.*/
  usbp->ep0state = USB_EP0_WAITING_SETUP;

  /* Low level reset.*/
  usb_lld_reset(usbp);

  /* Notification of reset event.*/
  _usb_isr_invoke_event_cb(usbp, USB_EVENT_RESET);
}

/**
 * @brief   USB suspend routine.
 * @details This function must be invoked when an USB bus suspend condition is
 *          detected.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 *
 * @notapi
 */
void _usb_suspend(USBDriver *usbp) {

  /* State transition.*/
  usbp->state         = USB_SUSPENDED;

  /* Notification of suspend event.*/
  _usb_isr_invoke_event_cb(usbp, USB_EVENT_SUSPEND);
}

/**
 * @brief   USB wake-up routine.
 * @details This function must be invoked when an USB bus wake-up condition is
 *          detected.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 *
 * @notapi
 */
void _usb_wakeup(USBDriver *usbp) {

  /* State transition.*/
  usbp->state         = USB_ACTIVE;

  /* Notification of suspend event.*/
  _usb_isr_invoke_event_cb(usbp, USB_EVENT_WAKEUP);
}

/**
 * @brief   Default EP0 SETUP callback.
 * @details This function is used by the low level driver as default handler
 *          for EP0 SETUP events.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number, always zero
 *
 * @notapi
 */
void _usb_ep0setup(USBDriver *usbp, usbep_t ep) {
  size_t max;

  usbp->ep0state = USB_EP0_WAITING_SETUP;
  usbReadSetup(usbp, ep, usbp->setup);

  /* First verify if the application has an handler installed for this
     request.*/
  /*lint -save -e9007 [13.5] No side effects, it is intentional.*/
  if ((usbp->config->requests_hook_cb == NULL) ||
      !(usbp->config->requests_hook_cb(usbp))) {
  /*lint -restore*/
    /* Invoking the default handler, if this fails then stalls the
       endpoint zero as error.*/
    /*lint -save -e9007 [13.5] No side effects, it is intentional.*/
    if (((usbp->setup[0] & USB_RTYPE_TYPE_MASK) != USB_RTYPE_TYPE_STD) ||
        !default_handler(usbp)) {
    /*lint -restore*/
      /* Error response, the state machine goes into an error state, the low
         level layer will have to reset it to USB_EP0_WAITING_SETUP after
         receiving a SETUP packet.*/
      usb_lld_stall_in(usbp, 0);
      usb_lld_stall_out(usbp, 0);
      _usb_isr_invoke_event_cb(usbp, USB_EVENT_STALLED);
      usbp->ep0state = USB_EP0_ERROR;
      return;
    }
  }
#if (USB_SET_ADDRESS_ACK_HANDLING == USB_SET_ADDRESS_ACK_HW)
  if (usbp->setup[1] == USB_REQ_SET_ADDRESS) {
    /* Zero-length packet sent by hardware */
    return;
  }
#endif
  /* Transfer preparation. The request handler must have populated
     correctly the fields ep0next, ep0n and ep0endcb using the macro
     usbSetupTransfer().*/
  max = (size_t)get_hword(&usbp->setup[6]);
  /* The transfer size cannot exceed the specified amount.*/
  if (usbp->ep0n > max) {
    usbp->ep0n = max;
  }
  if ((usbp->setup[0] & USB_RTYPE_DIR_MASK) == USB_RTYPE_DIR_DEV2HOST) {
    /* IN phase.*/
    if (usbp->ep0n != 0U) {
      /* Starts the transmit phase.*/
      usbp->ep0state = USB_EP0_TX;
      usbPrepareTransmit(usbp, 0, usbp->ep0next, usbp->ep0n);
      osalSysLockFromISR();
      (void) usbStartTransmitI(usbp, 0);
      osalSysUnlockFromISR();
    }
    else {
      /* No transmission phase, directly receiving the zero sized status
         packet.*/
      usbp->ep0state = USB_EP0_WAITING_STS;
#if (USB_EP0_STATUS_STAGE == USB_EP0_STATUS_STAGE_SW)
      usbPrepareReceive(usbp, 0, NULL, 0);
      osalSysLockFromISR();
      (void) usbStartReceiveI(usbp, 0);
      osalSysUnlockFromISR();
#else
      usb_lld_end_setup(usbp, ep);
#endif
    }
  }
  else {
    /* OUT phase.*/
    if (usbp->ep0n != 0U) {
      /* Starts the receive phase.*/
      usbp->ep0state = USB_EP0_RX;
      usbPrepareReceive(usbp, 0, usbp->ep0next, usbp->ep0n);
      osalSysLockFromISR();
      (void) usbStartReceiveI(usbp, 0);
      osalSysUnlockFromISR();
    }
    else {
      /* No receive phase, directly sending the zero sized status
         packet.*/
      usbp->ep0state = USB_EP0_SENDING_STS;
#if (USB_EP0_STATUS_STAGE == USB_EP0_STATUS_STAGE_SW)
      usbPrepareTransmit(usbp, 0, NULL, 0);
      osalSysLockFromISR();
      (void) usbStartTransmitI(usbp, 0);
      osalSysUnlockFromISR();
#else
      usb_lld_end_setup(usbp, ep);
#endif
    }
  }
}

/**
 * @brief   Default EP0 IN callback.
 * @details This function is used by the low level driver as default handler
 *          for EP0 IN events.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number, always zero
 *
 * @notapi
 */
void _usb_ep0in(USBDriver *usbp, usbep_t ep) {
  size_t max;

  (void)ep;
  switch (usbp->ep0state) {
  case USB_EP0_TX:
    max = (size_t)get_hword(&usbp->setup[6]);
    /* If the transmitted size is less than the requested size and it is a
       multiple of the maximum packet size then a zero size packet must be
       transmitted.*/
    if ((usbp->ep0n < max) &&
        ((usbp->ep0n % usbp->epc[0]->in_maxsize) == 0U)) {
      usbPrepareTransmit(usbp, 0, NULL, 0);
      osalSysLockFromISR();
      (void) usbStartTransmitI(usbp, 0);
      osalSysUnlockFromISR();
      usbp->ep0state = USB_EP0_WAITING_TX0;
      return;
    }
    /* Falls into, it is intentional.*/
  case USB_EP0_WAITING_TX0:
    /* Transmit phase over, receiving the zero sized status packet.*/
    usbp->ep0state = USB_EP0_WAITING_STS;
#if (USB_EP0_STATUS_STAGE == USB_EP0_STATUS_STAGE_SW)
    usbPrepareReceive(usbp, 0, NULL, 0);
    osalSysLockFromISR();
    (void) usbStartReceiveI(usbp, 0);
    osalSysUnlockFromISR();
#else
    usb_lld_end_setup(usbp, ep);
#endif
    return;
  case USB_EP0_SENDING_STS:
    /* Status packet sent, invoking the callback if defined.*/
    if (usbp->ep0endcb != NULL) {
      usbp->ep0endcb(usbp);
    }
    usbp->ep0state = USB_EP0_WAITING_SETUP;
    return;
  case USB_EP0_WAITING_SETUP:
  case USB_EP0_WAITING_STS:
  case USB_EP0_RX:
    /* All the above are invalid states in the IN phase.*/
    osalDbgAssert(false, "EP0 state machine error");
    /* Falling through is intentional.*/
  case USB_EP0_ERROR:
    /* Error response, the state machine goes into an error state, the low
       level layer will have to reset it to USB_EP0_WAITING_SETUP after
       receiving a SETUP packet.*/
    usb_lld_stall_in(usbp, 0);
    usb_lld_stall_out(usbp, 0);
    _usb_isr_invoke_event_cb(usbp, USB_EVENT_STALLED);
    usbp->ep0state = USB_EP0_ERROR;
    return;
  default:
    osalDbgAssert(false, "EP0 state machine invalid state");
  }
}

/**
 * @brief   Default EP0 OUT callback.
 * @details This function is used by the low level driver as default handler
 *          for EP0 OUT events.
 *
 * @param[in] usbp      pointer to the @p USBDriver object
 * @param[in] ep        endpoint number, always zero
 *
 * @notapi
 */
void _usb_ep0out(USBDriver *usbp, usbep_t ep) {

  (void)ep;
  switch (usbp->ep0state) {
  case USB_EP0_RX:
    /* Receive phase over, sending the zero sized status packet.*/
    usbp->ep0state = USB_EP0_SENDING_STS;
#if (USB_EP0_STATUS_STAGE == USB_EP0_STATUS_STAGE_SW)
    usbPrepareTransmit(usbp, 0, NULL, 0);
    osalSysLockFromISR();
    (void) usbStartTransmitI(usbp, 0);
    osalSysUnlockFromISR();
#else
    usb_lld_end_setup(usbp, ep);
#endif
    return;
  case USB_EP0_WAITING_STS:
    /* Status packet received, it must be zero sized, invoking the callback
       if defined.*/
#if (USB_EP0_STATUS_STAGE == USB_EP0_STATUS_STAGE_SW)
    if (usbGetReceiveTransactionSizeI(usbp, 0) != 0U) {
      break;
    }
#endif
    if (usbp->ep0endcb != NULL) {
      usbp->ep0endcb(usbp);
    }
    usbp->ep0state = USB_EP0_WAITING_SETUP;
    return;
  case USB_EP0_WAITING_SETUP:
  case USB_EP0_TX:
  case USB_EP0_WAITING_TX0:
  case USB_EP0_SENDING_STS:
    /* All the above are invalid states in the IN phase.*/
    osalDbgAssert(false, "EP0 state machine error");
    /* Falling through is intentional.*/
  case USB_EP0_ERROR:
    /* Error response, the state machine goes into an error state, the low
       level layer will have to reset it to USB_EP0_WAITING_SETUP after
       receiving a SETUP packet.*/
    usb_lld_stall_in(usbp, 0);
    usb_lld_stall_out(usbp, 0);
    _usb_isr_invoke_event_cb(usbp, USB_EVENT_STALLED);
    usbp->ep0state = USB_EP0_ERROR;
    return;
  default:
    osalDbgAssert(false, "EP0 state machine invalid state");
  }
}

#endif /* HAL_USE_USB == TRUE */

/** @} */