summaryrefslogtreecommitdiff
path: root/backend/hp5590_low.c
blob: 51da01ab136f71aadcacb375dc0fd0ef2f84c629 (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
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
/* sane - Scanner Access Now Easy.
   Copyright (C) 2007 Ilia Sotnikov <hostcc@gmail.com>
   This file is part of the SANE package.

   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., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA.

   As a special exception, the authors of SANE give permission for
   additional uses of the libraries contained in this release of SANE.

   The exception is that, if you link a SANE library with other files
   to produce an executable, this does not by itself cause the
   resulting executable to be covered by the GNU General Public
   License.  Your use of that executable is in no way restricted on
   account of linking the SANE library code into it.

   This exception does not, however, invalidate any other reasons why
   the executable file might be covered by the GNU General Public
   License.

   If you submit changes to SANE to the maintainers to be included in
   a subsequent release, you agree by submitting the changes that
   those changes may be distributed with this exception intact.

   If you write modifications of your own for SANE, it is your choice
   whether to permit this exception to apply to your modifications.
   If you do not wish that, delete this exception notice.

   This file is part of a SANE backend for
   HP ScanJet 4500C/4570C/5500C/5550C/5590/7650 Scanners
*/

#include "../include/sane/config.h"

#include <stdio.h>
#include <string.h>
#include <errno.h>
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif /* HAVE_NETINET_IN_H */

#include "byteorder.h"

#include "../include/sane/sanei_debug.h"
#include "../include/sane/sanei_usb.h"
#include "../include/_stdint.h"
#include "hp5590_low.h"

/* Debug levels */
#define DBG_err		0
#define	DBG_proc	10
#define DBG_usb		50

/* Custom assert() macro */
#define hp5590_low_assert(exp) if(!(exp)) { \
  DBG (DBG_err, "Assertion '%s' failed at %s:%u\n", #exp, __FILE__, __LINE__);\
  return SANE_STATUS_INVAL; \
}

/* Structure describing bulk transfer size */
struct bulk_size
{
  uint16_t	size;
  uint8_t 	unused;
} __attribute__ ((packed));

/* Structure describing bulk URB */
/* FIXME: Verify according to USB standard */
struct usb_in_usb_bulk_setup
{
  uint8_t	bRequestType;
  uint8_t	bRequest;
  uint8_t	bEndpoint;
  uint16_t	unknown;
  uint16_t	wLength;	/* MSB first */
  uint8_t 	pad;
} __attribute__ ((packed));

/* Structure describing control URB */
struct usb_in_usb_ctrl_setup {
  uint8_t  bRequestType;
  uint8_t  bRequest;
  uint16_t wValue;		/* MSB first */
  uint16_t wIndex;		/* MSB first */
  uint16_t wLength;		/* LSB first */
} __attribute__ ((packed));

/* CORE status flag - ready or not */
#define CORE_FLAG_NOT_READY		1 << 1

/* Bulk transfers are done in pages, below their respective sizes */
#define BULK_WRITE_PAGE_SIZE		0x0f000
#define BULK_READ_PAGE_SIZE		0x10000
#define ALLOCATE_BULK_READ_PAGES	16	/* 16 * 65536 = 1Mb */

/* Structure describing bulk read state, because bulk reads will be done in
 * pages, but function caller uses its own buffer, whose size is certainly
 * different. Also, each bulk read page is ACK'ed by special command
 * so total pages received should be tracked as well
 */
struct bulk_read_state
{
  unsigned char	*buffer;
  unsigned int	buffer_size;
  unsigned int 	bytes_available;
  unsigned char *buffer_out_ptr;
  unsigned char *buffer_in_ptr;
  unsigned int 	total_pages;
  unsigned char *buffer_end_ptr;
  unsigned int 	initialized;
};

/*******************************************************************************
 * USB-in-USB: get acknowledge for last USB-in-USB operation
 *
 * Parameters
 * dn - sanei_usb device descriptor
 *
 * Returns
 * SANE_STATUS_GOOD - if correct acknowledge was received
 * SANE_STATUS_DEVICE_BUSY - otherwise
 */
static SANE_Status
hp5590_get_ack (SANE_Int dn,
		enum proto_flags proto_flags)
{
  uint8_t 	status;
  SANE_Status	ret;

  /* Bypass reading acknowledge if the device doesn't need it */
  if (proto_flags & PF_NO_USB_IN_USB_ACK)
    return SANE_STATUS_GOOD;

  DBG (DBG_proc, "%s\n", __FUNCTION__);

  /* Check if USB-in-USB operation was accepted */
  ret = sanei_usb_control_msg (dn, USB_DIR_IN | USB_TYPE_VENDOR,
			       0x0c, 0x8e, 0x20,
			       sizeof (status), &status);
  if (ret != SANE_STATUS_GOOD)
    {
      DBG (DBG_err, "%s: USB-in-USB: error getting acknowledge\n",
	   __FUNCTION__);
      return ret;
    }

  DBG (DBG_usb, "%s: USB-in-USB: accepted\n", __FUNCTION__);

  /* Check if we received correct acknowledgement */
  if (status != 0x01)
    {
      DBG (DBG_err, "%s: USB-in-USB: not accepted (status %u)\n",
	   __FUNCTION__, status);
      return SANE_STATUS_DEVICE_BUSY;
    }

  return SANE_STATUS_GOOD;
}

/*******************************************************************************
 * USB-in-USB: get device status
 *
 * Parameters
 * dn - sanei_usb device descriptor
 *
 * Returns
 * SANE_STATUS_GOOD - if correct status was received
 * SANE_STATUS_DEVICE_BUSY - otherwise
 */
static SANE_Status
hp5590_get_status (SANE_Int dn,
		   __sane_unused__ enum proto_flags proto_flags)
{
  uint8_t status;
  SANE_Status ret;

  DBG (DBG_proc, "%s\n", __FUNCTION__);

  ret = sanei_usb_control_msg (dn, USB_DIR_IN | USB_TYPE_VENDOR,
			       0x0c, 0x8e, 0x00,
			       sizeof (status), &status);
  if (ret != SANE_STATUS_GOOD)
    {
      DBG (DBG_err, "%s: USB-in-USB: error getting device status\n",
	   __FUNCTION__);
      return ret;
    }

  /* Check if we received correct status */
  if (status != 0x00)
    {
      DBG (DBG_err, "%s: USB-in-USB: got non-zero device status (status %u)\n",
	   __FUNCTION__, status);
      return SANE_STATUS_DEVICE_BUSY;
    }

  return SANE_STATUS_GOOD;
}

/*******************************************************************************
 * USB-in-USB: sends control message for IN or OUT operation
 *
 * Parameters
 * dn - sanei_usb device descriptor
 * requesttype, request, value, index - their meaninings are similar to
 * sanei_control_msg()
 * bytes - pointer to data buffer
 * size - size of data
 * core_flags - 
 *  CORE_NONE - no CORE operation will be performed
 *  CORE_DATA - operation on CORE data will be performed
 *  CORE_BULK_IN - preparation for bulk IN transfer (not used yet)
 *  CORE_BULK_OUT - preparation for bulk OUT trasfer
 *
 * Returns
 * SANE_STATUS_GOOD - control message was sent w/o any errors
 * all other SANE_Status values - otherwise
 */
static SANE_Status
hp5590_control_msg (SANE_Int dn,
		    enum proto_flags proto_flags,
		    int requesttype, int request,
		    int value, int index, unsigned char *bytes,
		    int size, int core_flags)
{
  struct usb_in_usb_ctrl_setup	ctrl;
  SANE_Status 			ret;
  unsigned int 			len;
  unsigned char 		*ptr;
  uint8_t 			ack;
  uint8_t 			response;
  unsigned int 			needed_response;

  DBG (DBG_proc, "%s: USB-in-USB: core data: %s\n",
       __FUNCTION__, core_flags & CORE_DATA ? "yes" : "no");

  hp5590_low_assert (bytes != NULL);

  /* IN (read) operation will be performed */
  if (requesttype & USB_DIR_IN)
    {
      /* Prepare USB-in-USB control message */
      memset (&ctrl, 0, sizeof (ctrl));
      ctrl.bRequestType = 0xc0;
      ctrl.bRequest = request;
      ctrl.wValue = htons (value);
      ctrl.wIndex = htons (index);
      ctrl.wLength = htole16 (size);

      DBG (DBG_usb, "%s: USB-in-USB: sending control msg\n", __FUNCTION__);
      /* Send USB-in-USB control message */
      ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				   0x04, 0x8f, 0x00,
				   sizeof (ctrl), (unsigned char *) &ctrl);
      if (ret != SANE_STATUS_GOOD)
	{
	  DBG (DBG_err, "%s: USB-in-USB: error sending control message\n",
	       __FUNCTION__);
	  return ret;
	}

      /* USB-in-USB: checking acknowledge for control message */
      ret = hp5590_get_ack (dn, proto_flags);
      if (ret != SANE_STATUS_GOOD)
	return ret;

      len = size;
      ptr = bytes;
      /* Data is read in 8 byte portions */
      while (len)
	{
	  unsigned int next_packet_size;
	  next_packet_size = 8;
	  if (len < 8)
	    next_packet_size = len;

	  /* Read USB-in-USB data */
	  ret = sanei_usb_control_msg (dn, USB_DIR_IN | USB_TYPE_VENDOR,
				       core_flags & CORE_DATA ? 0x0c : 0x04,
				       0x90, 0x00, next_packet_size, ptr);
	  if (ret != SANE_STATUS_GOOD)
	    {
	      DBG (DBG_err, "%s: USB-in-USB: error reading data\n", __FUNCTION__);
	      return ret;
	    }

	  ptr += next_packet_size;
	  len -= next_packet_size;
	}

      /* Confirm data reception */
      ack = 0;
      ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				   0x0c, 0x8f, 0x00,
				   sizeof (ack), &ack);
      if (ret != SANE_STATUS_GOOD)
	{
	  DBG (DBG_err, "%s: USB-in-USB: error confirming data reception\n",
	       __FUNCTION__);
	  return -1;
	}

      /* USB-in-USB: checking if confirmation was acknowledged */
      ret = hp5590_get_ack (dn, proto_flags);
      if (ret != SANE_STATUS_GOOD)
	return ret;
    }

  /* OUT (write) operation will be performed */
  if (!(requesttype & USB_DIR_IN))
    {
      /* Prepare USB-in-USB control message */
      memset (&ctrl, 0, sizeof (ctrl));
      ctrl.bRequestType = 0x40;
      ctrl.bRequest = request;
      ctrl.wValue = htons (value);
      ctrl.wIndex = htons (index);
      ctrl.wLength = htole16 (size);

      DBG (DBG_usb, "%s: USB-in-USB: sending control msg\n", __FUNCTION__);
      /* Send USB-in-USB control message */
      ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				   0x04, 0x8f, 0x00,
				   sizeof (ctrl), (unsigned char *) &ctrl);
      if (ret != SANE_STATUS_GOOD)
	{
	  DBG (DBG_err, "%s: USB-in-USB: error sending control message\n",
	       __FUNCTION__);
	  return ret;
	}

      /* USB-in-USB: checking acknowledge for control message */
      ret = hp5590_get_ack (dn, proto_flags);
      if (ret != SANE_STATUS_GOOD)
	return ret;

      len = size;
      ptr = bytes;
      /* Data is sent in 8 byte portions */
      while (len)
	{
	  unsigned int next_packet_size;
	  next_packet_size = 8;
	  if (len < 8)
	    next_packet_size = len;

	  /* Send USB-in-USB data */
	  ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				       core_flags & CORE_DATA ? 0x04 : 0x0c,
				       0x8f, 0x00, next_packet_size, ptr);
	  if (ret != SANE_STATUS_GOOD)
	    {
	      DBG (DBG_err, "%s: USB-in-USB: error sending data\n", __FUNCTION__);
	      return ret;
	    }

	  /* CORE data is acknowledged packet by packet */
	  if (core_flags & CORE_DATA)
	    {
	      /* USB-in-USB: checking if data was accepted */
	      ret = hp5590_get_ack (dn, proto_flags);
	      if (ret != SANE_STATUS_GOOD)
		return ret;
	    }

	  ptr += next_packet_size;
	  len -= next_packet_size;
	}

      /* Normal (non-CORE) data is acknowledged after its full transmission */
      if (!(core_flags & CORE_DATA))
	{
	  /* USB-in-USB: checking if data was accepted */
	  ret = hp5590_get_ack (dn, proto_flags);
	  if (ret != SANE_STATUS_GOOD)
	    return ret;
	}

      /* Getting  response after data transmission */
      DBG (DBG_usb, "%s: USB-in-USB: getting response\n", __FUNCTION__);
      ret = sanei_usb_control_msg (dn, USB_DIR_IN | USB_TYPE_VENDOR,
				   0x0c, 0x90, 0x00,
				   sizeof (response), &response);
      if (ret != SANE_STATUS_GOOD)
	{
	  DBG (DBG_err, "%s: USB-in-USB: error getting response\n", __FUNCTION__);
	  return ret;
	}

      /* Necessary response after normal (non-CORE) data is 0x00,
       * after bulk OUT preparation - 0x24
       */
      needed_response = core_flags & CORE_BULK_OUT ? 0x24 : 0x00;
      if (response == needed_response)
	DBG (DBG_usb, "%s: USB-in-USB: got correct response\n",
	     __FUNCTION__);

      if (response != needed_response)
	{
	  DBG (DBG_err,
	       "%s: USB-in-USB: invalid response received "
	       "(needed %04x, got %04x)\n",
	       __FUNCTION__, needed_response, response);
	  return SANE_STATUS_IO_ERROR;
	}

      /* Send bulk OUT flags is bulk OUT preparation is performed */
      if (core_flags & CORE_BULK_OUT)
	{
	  uint8_t bulk_flags = 0x24;
	  DBG (DBG_usb, "%s: USB-in-USB: sending bulk flags\n",
	       __FUNCTION__);

	  ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				       0x0c, 0x83, 0x00,
				       sizeof (bulk_flags), &bulk_flags);
	  if (ret != SANE_STATUS_GOOD)
	    {
	      DBG (DBG_err, "%s: USB-in-USB: error sending bulk flags\n",
		   __FUNCTION__);
	      return ret;
	    }

	  /* USB-in-USB: checking confirmation for bulk flags */
	  ret = hp5590_get_ack (dn, proto_flags);
	  if (ret != SANE_STATUS_GOOD)
	    return ret;
	}
    }

  return SANE_STATUS_GOOD;
}

/*******************************************************************************
 * USB-in-USB: verifies last command
 *
 * Parameters
 * dn - sanei_usb device descriptor
 * cmd - command to verify
 *
 * Returns
 * SANE_STATUS_GOOD - command verified successfully and CORE is ready
 * SANE_STATUS_IO_ERROR - command verification failed
 * SANE_STATUS_DEVICE_BUSY - command verified successfully but CORE isn't ready
 * all other SANE_Status values - otherwise
 */
static SANE_Status
hp5590_verify_last_cmd (SANE_Int dn,
			enum proto_flags proto_flags,
			unsigned int cmd)
{
  uint16_t	verify_cmd;
  unsigned int	last_cmd;
  unsigned int	core_status;
  SANE_Status 	ret;

  DBG (3, "%s: USB-in-USB: command verification requested\n",
       __FUNCTION__);

  /* Read last command along with CORE status */
  ret = hp5590_control_msg (dn,
  			    proto_flags,
  			    USB_DIR_IN,
			    0x04, 0xc5, 0x00,
			    (unsigned char *) &verify_cmd,
			    sizeof (verify_cmd), CORE_NONE);
  if (ret != SANE_STATUS_GOOD)
    return ret;

  verify_cmd = le16toh (verify_cmd); /* Response is LSB first */

  /* Last command - minor byte */
  last_cmd = verify_cmd & 0xff;
  /* CORE status - major byte */
  core_status = (verify_cmd & 0xff00) >> 8;

  /* Verify last command */
  DBG (DBG_usb, "%s: USB-in-USB: command verification %04x, "
       "last command: %04x, core status: %04x\n",
       __FUNCTION__, verify_cmd, last_cmd, core_status);
  if ((cmd & 0x00ff) != last_cmd)
    {
      DBG (DBG_err, "%s: USB-in-USB: command verification failed: "
	   "expected 0x%04x, got 0x%04x\n",
	   __FUNCTION__, cmd, last_cmd);
      return SANE_STATUS_IO_ERROR;
    }

  DBG (DBG_usb, "%s: USB-in-USB: command verified successfully\n",
       __FUNCTION__);

  /* Return value depends on CORE status */
  return core_status & CORE_FLAG_NOT_READY ?
    SANE_STATUS_DEVICE_BUSY : SANE_STATUS_GOOD;
}

/*******************************************************************************
 * USB-in-USB: send command (convenience wrapper around hp5590_control_msg())
 *
 * Parameters
 * dn - sanei_usb device descriptor
 * requesttype, request, value, index - their meaninings are similar to
 * sanei_control_msg()
 * bytes - pointer to data buffer
 * size - size of data
 * core_flags - 
 *  CORE_NONE - no CORE operation will be performed
 *  CORE_DATA - operation on CORE data will be performed
 *  CORE_BULK_IN - preparation for bulk IN transfer (not used yet)
 *  CORE_BULK_OUT - preparation for bulk OUT trasfer
 *
 * Returns
 * SANE_STATUS_GOOD - command was sent (and possible verified) w/o any errors
 * all other SANE_Status values - otherwise
 */
static SANE_Status
hp5590_cmd (SANE_Int dn,
	    enum proto_flags proto_flags,
	    unsigned int flags,
	    unsigned int cmd, unsigned char *data, unsigned int size,
	    unsigned int core_flags)
{
  SANE_Status ret;

  DBG (3, "%s: USB-in-USB: command : %04x\n", __FUNCTION__, cmd);

  ret = hp5590_control_msg (dn,
  			    proto_flags,
			    flags & CMD_IN ? USB_DIR_IN : USB_DIR_OUT,
			    0x04, cmd, 0x00, data, size, core_flags);
  if (ret != SANE_STATUS_GOOD)
    return ret;

  ret = SANE_STATUS_GOOD;
  /* Verify last command if requested */
  if (flags & CMD_VERIFY)
    {
      ret = hp5590_verify_last_cmd (dn, proto_flags, cmd);
    }

  return ret;
}

/*******************************************************************************
 * USB-in-USB: initialized bulk read state
 *
 * Parameters
 * state - pointer to a pointer for initialized state
 *
 * Returns
 * SANE_STATUS_GOOD - if state was initialized successfully
 * SANE_STATUS_NO_MEM - memory allocation failed
 */
static SANE_Status
hp5590_low_init_bulk_read_state (void **state)
{
  struct bulk_read_state *bulk_read_state;

  DBG (3, "%s: USB-in-USB: initializing bulk read state\n", __FUNCTION__);

  hp5590_low_assert (state != NULL);

  bulk_read_state = malloc (sizeof (struct bulk_read_state));
  if (!bulk_read_state)
    return SANE_STATUS_NO_MEM;
  memset (bulk_read_state, 0, sizeof (struct bulk_read_state));

  bulk_read_state->buffer = malloc (ALLOCATE_BULK_READ_PAGES
				    * BULK_READ_PAGE_SIZE);
  if (!bulk_read_state->buffer)
    {
      DBG (DBG_err, "%s: Memory allocation failed for %u bytes\n",
	   __FUNCTION__, ALLOCATE_BULK_READ_PAGES * BULK_READ_PAGE_SIZE);
      return SANE_STATUS_NO_MEM;
    }
  bulk_read_state->buffer_size = ALLOCATE_BULK_READ_PAGES
				 * BULK_READ_PAGE_SIZE;
  bulk_read_state->bytes_available = 0;
  bulk_read_state->buffer_out_ptr = bulk_read_state->buffer;
  bulk_read_state->buffer_in_ptr = bulk_read_state->buffer;
  bulk_read_state->total_pages = 0;
  bulk_read_state->buffer_end_ptr = bulk_read_state->buffer
				    + bulk_read_state->buffer_size;
  bulk_read_state->initialized = 1;

  *state = bulk_read_state;
  return SANE_STATUS_GOOD;
}

/*******************************************************************************
 * USB-in-USB: free bulk read state
 *
 * Parameters
 * state - pointer to a pointer to bulk read state
 *
 * Returns
 * SANE_STATUS_GOOD - bulk read state freed successfully
 */
static SANE_Status
hp5590_low_free_bulk_read_state (void **state)
{
  struct bulk_read_state *bulk_read_state;

  DBG (3, "%s\n", __FUNCTION__);

  hp5590_low_assert (state != NULL);
  /* Just return if NULL bulk read state was given */
  if (*state == NULL)
    return SANE_STATUS_GOOD;

  bulk_read_state = *state;

  DBG (3, "%s: USB-in-USB: freeing bulk read state\n", __FUNCTION__);

  free (bulk_read_state->buffer);
  bulk_read_state->buffer = NULL;
  free (bulk_read_state);
  *state = NULL;

  return SANE_STATUS_GOOD;
}

/* FIXME: perhaps needs to be converted to use hp5590_control_msg() */
/*******************************************************************************
 * USB-in-USB: bulk read
 *
 * Parameters
 * dn - sanei_usb device descriptor
 * bytes - pointer to data buffer
 * size - size of data to read
 * state - pointer to initialized bulk read state structure
 */
static SANE_Status
hp5590_bulk_read (SANE_Int dn,
		  enum proto_flags proto_flags,
		  unsigned char *bytes, unsigned int size,
		  void *state)
{
  struct usb_in_usb_bulk_setup	ctrl;
  SANE_Status 			ret;
  unsigned int 			next_pages;
  uint8_t 			bulk_flags;
  size_t 			next_portion;
  struct bulk_read_state	*bulk_read_state;
  unsigned int 			bytes_until_buffer_end;

  DBG (3, "%s\n", __FUNCTION__);

  hp5590_low_assert (state != NULL);
  hp5590_low_assert (bytes != NULL);

  bulk_read_state = state;
  if (bulk_read_state->initialized == 0)
    {
      DBG (DBG_err, "%s: USB-in-USB: bulk read state not initialized\n",
	   __FUNCTION__);
      return SANE_STATUS_INVAL;
    }

  memset (bytes, 0, size);

  /* Check if requested data would fit into the buffer */
  if (size > bulk_read_state->buffer_size)
    {
      DBG (DBG_err, "Data requested won't fit in the bulk read buffer "
	   "(requested: %u, buffer size: %u\n", size,
	   bulk_read_state->buffer_size);
      return SANE_STATUS_NO_MEM;
    }

  /* Read data until requested size of data will be received */
  while (bulk_read_state->bytes_available < size)
    {
      DBG (DBG_usb, "%s: USB-in-USB: not enough data in buffer available "
	   "(available: %u, requested: %u)\n",
	   __FUNCTION__, bulk_read_state->bytes_available, size);

      /* IMPORTANT! 'next_pages' means 'request and receive next_pages pages in
       * one bulk transfer request '. Windows driver uses 4 pages between each
       * request.  The more pages are received between requests the less the
       * scanner does scan head re-positioning thus improving scanning speed.
       * On the other hand, scanner expects that all of the requested pages
       * will be received immediately after the request. In case when a
       * frontend will have a delay between reads we will get bulk transfer
       * timeout sooner or later.
       * Having next_pages = 1 is the most safe case.
       */
      next_pages = 1;
      /* Count all received pages to calculate when we will need to send
       * another bulk request
       */
      bulk_read_state->total_pages++;
      DBG (DBG_usb, "%s: USB-in-USB: total pages done: %u\n",
	   __FUNCTION__, bulk_read_state->total_pages);

      /* Send another bulk request for 'next_pages' before first
       * page or next necessary one
       */
      if (   bulk_read_state->total_pages == 1
	  || bulk_read_state->total_pages % next_pages == 0)
	{
	  /* Send bulk flags */
	  DBG (DBG_usb, "%s: USB-in-USB: sending USB-in-USB bulk flags\n",
	       __FUNCTION__);
	  bulk_flags = 0x24;
	  ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				       0x0c, 0x83, 0x00,
				       sizeof (bulk_flags), &bulk_flags);
	  if (ret != SANE_STATUS_GOOD)
	    {
	      DBG (DBG_err, "%s: USB-in-USB: error sending bulk flags\n",
		   __FUNCTION__);
	      return ret;
	    }

	  /* USB-in-USB: checking confirmation for bulk flags\n" */
	  ret = hp5590_get_ack (dn, proto_flags);
	  if (ret != SANE_STATUS_GOOD)
	    return ret;

	  /* Prepare bulk read request */
	  memset (&ctrl, 0, sizeof (ctrl));
	  ctrl.bRequestType = 0x00;
	  ctrl.bEndpoint = 0x82;
	  ctrl.wLength = htons (next_pages);

	  /* Send bulk read request */
	  DBG (DBG_usb, "%s: USB-in-USB: sending control msg for bulk\n",
	       __FUNCTION__);
	  ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				       0x04, 0x82, 0x00,
				       sizeof (ctrl),
				       (unsigned char *) &ctrl);
	  if (ret != SANE_STATUS_GOOD)
	    {
	      DBG (DBG_err, "%s: USB-in-USB: error sending control msg\n",
		   __FUNCTION__);
	      return ret;
	    }

	  /* USB-in-USB: checking if control msg was accepted */
	  ret = hp5590_get_ack (dn, proto_flags); 
	  if (ret != SANE_STATUS_GOOD)
	    return ret;
	}

      next_portion = BULK_READ_PAGE_SIZE;
      /* Check if next page will fit into the buffer */
      if (bulk_read_state->buffer_size
	  - bulk_read_state->bytes_available < next_portion)
	{
	  DBG (DBG_err, "%s: USB-in-USB: buffer too small\n", __FUNCTION__);
	  return SANE_STATUS_NO_MEM;
	}

      /* Bulk read next page */
      DBG (DBG_usb, "%s: USB-in-USB: bulk reading %lu bytes\n",
	   __FUNCTION__, (u_long) next_portion);
      ret = sanei_usb_read_bulk (dn,
				 bulk_read_state->buffer_in_ptr,
				 &next_portion);
      if (ret != SANE_STATUS_GOOD)
	{
	  if (ret == SANE_STATUS_EOF)
	    return ret;
	  DBG (DBG_err, "%s: USB-in-USB: error during bulk read: %s\n",
	       __FUNCTION__, sane_strstatus (ret));
	  return ret;
	}

      /* Check if we received the same amount of data as requsted */
      if (next_portion != BULK_READ_PAGE_SIZE)
	{
	  DBG (DBG_err, "%s: USB-in-USB: incomplete bulk read "
	       "(requested %u bytes, got %lu bytes)\n",
	       __FUNCTION__, BULK_READ_PAGE_SIZE, (u_long) next_portion);
	  return SANE_STATUS_IO_ERROR;
	}

      /* Move pointers to the next position */
      bulk_read_state->buffer_in_ptr += next_portion;

      /* Check for the end of the buffer */
      if (bulk_read_state->buffer_in_ptr > bulk_read_state->buffer_end_ptr)
	{
	  DBG (DBG_err,
	       "%s: USB-in-USB: attempted to access over the end of buffer "
	       "(in_ptr: %p, end_ptr: %p, ptr: %p, buffer size: %u\n",
	       __FUNCTION__, bulk_read_state->buffer_in_ptr,
	       bulk_read_state->buffer_end_ptr, bulk_read_state->buffer,
	       bulk_read_state->buffer_size);
	  return SANE_STATUS_NO_MEM;
	}

      /* Check for buffer pointer wrapping */
      if (bulk_read_state->buffer_in_ptr == bulk_read_state->buffer_end_ptr)
	{
	  DBG (DBG_usb, "%s: USB-in-USB: buffer wrapped while writing\n",
	       __FUNCTION__);
	  bulk_read_state->buffer_in_ptr = bulk_read_state->buffer;
	}

      /* Count the amount of data we read */
      bulk_read_state->bytes_available += next_portion;
    }

  /* Transfer requested amount of data to the caller */
  DBG (DBG_usb, "%s: USB-in-USB: data in bulk buffer is available "
       "(requested %u bytes, available %u bytes)\n",
       __FUNCTION__, size, bulk_read_state->bytes_available);

  /* Check for buffer pointer wrapping */
  bytes_until_buffer_end = bulk_read_state->buffer_end_ptr
    - bulk_read_state->buffer_out_ptr;
  if (bytes_until_buffer_end <= size)
    {
      /* First buffer part */
      DBG (DBG_usb, "%s: USB-in-USB: reached bulk read buffer end\n", __FUNCTION__);
      memcpy (bytes, bulk_read_state->buffer_out_ptr, bytes_until_buffer_end);
      bulk_read_state->buffer_out_ptr = bulk_read_state->buffer;
      /* And second part (if any) */
      if (bytes_until_buffer_end < size)
	{
	  DBG (DBG_usb, "%s: USB-in-USB: giving 2nd buffer part\n", __FUNCTION__);
	  memcpy (bytes + bytes_until_buffer_end,
		  bulk_read_state->buffer_out_ptr,
		  size - bytes_until_buffer_end);
	  bulk_read_state->buffer_out_ptr += size - bytes_until_buffer_end;
	}
    }
  else
    {
      /* The data is in one buffer part (w/o wrapping) */
      memcpy (bytes, bulk_read_state->buffer_out_ptr, size);
      bulk_read_state->buffer_out_ptr += size;
      if (bulk_read_state->buffer_out_ptr == bulk_read_state->buffer_end_ptr)
	{
	  DBG (DBG_usb, "%s: USB-in-USB: buffer wrapped while reading\n",
	       __FUNCTION__);
	  bulk_read_state->buffer_out_ptr = bulk_read_state->buffer;
	}
    }

  /* Count the amount of data transferred to the caller */
  bulk_read_state->bytes_available -= size;

  return SANE_STATUS_GOOD;
}

/*******************************************************************************
 * USB-in-USB: bulk write
 *
 * Parameters
 * dn - sanei_usb device descriptor
 * cmd - command for bulk write operation
 * bytes - pointer to data buffer
 * size - size of data
 *
 * Returns
 * SANE_STATUS_GOOD - all data transferred successfully
 * all other SANE_Status value - otherwise 
 */
static SANE_Status
hp5590_bulk_write (SANE_Int dn,
		   enum proto_flags proto_flags,
		   int cmd, unsigned char *bytes,
		   unsigned int size)
{
  struct usb_in_usb_bulk_setup	ctrl;
  SANE_Status 			ret;
  struct bulk_size		bulk_size;

  unsigned int len;
  unsigned char *ptr;
  size_t next_portion;

  DBG (3, "%s: USB-in-USB: command: %04x, size %u\n", __FUNCTION__, cmd,
       size);

  hp5590_low_assert (bytes != NULL);

  /* Prepare bulk write request */ 
  memset (&bulk_size, 0, sizeof (bulk_size));
  /* Counted in page size */
  bulk_size.size = size / BULK_WRITE_PAGE_SIZE;

  /* Send bulk write request */
  DBG (3, "%s: USB-in-USB: total %u pages (each of %u bytes)\n",
       __FUNCTION__, bulk_size.size, BULK_WRITE_PAGE_SIZE);
  ret = hp5590_control_msg (dn,
  			    proto_flags,
  			    USB_DIR_OUT,
			    0x04, cmd, 0,
			    (unsigned char *) &bulk_size, sizeof (bulk_size),
			    CORE_DATA | CORE_BULK_OUT);
  if (ret != SANE_STATUS_GOOD)
    return ret;

  len = size;
  ptr = bytes;

  /* Send all data in pages */
  while (len)
    {
      next_portion = BULK_WRITE_PAGE_SIZE;
      if (len < next_portion)
	next_portion = len;

      DBG (3, "%s: USB-in-USB: next portion %lu bytes\n",
	   __FUNCTION__, (u_long) next_portion);

      /* Prepare bulk write request */
      memset (&ctrl, 0, sizeof (ctrl));
      ctrl.bRequestType = 0x01;
      ctrl.bEndpoint = 0x82;
      ctrl.wLength = htons (next_portion);

      /* Send bulk write request */
      ret = sanei_usb_control_msg (dn, USB_DIR_OUT | USB_TYPE_VENDOR,
				   0x04, 0x82, 0,
				   sizeof (ctrl), (unsigned char *) &ctrl);
      if (ret != SANE_STATUS_GOOD)
	return ret;

      /* USB-in-USB: checking if command was accepted */
      ret = hp5590_get_ack (dn, proto_flags);
      if (ret != SANE_STATUS_GOOD)
	return ret;

      /* Write bulk data */
      DBG (3, "%s: USB-in-USB: bulk writing %lu bytes\n",
	   __FUNCTION__, (u_long) next_portion);
      ret = sanei_usb_write_bulk (dn, ptr, &next_portion);
      if (ret != SANE_STATUS_GOOD)
	{
	  /* Treast EOF as successful result */
	  if (ret == SANE_STATUS_EOF)
	    break;
	  DBG (DBG_err, "%s: USB-in-USB: error during bulk write: %s\n",
	       __FUNCTION__, sane_strstatus (ret));
	  return ret;
	}

      /* Move to the next page */
      len -= next_portion;
      ptr += next_portion;
    }

  /* Verify bulk command */
  return hp5590_verify_last_cmd (dn, proto_flags, cmd);
}
/* vim: sw=2 ts=8
 */