forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathxircom_pgs.S
1192 lines (1081 loc) · 29.1 KB
/
xircom_pgs.S
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
/* $Id: loop.s,v 1.23 2000/03/20 09:49:06 warner Exp $
*
* Firmware for the Keyspan PDA Serial Adapter, a USB serial port based on
* the EzUSB microcontroller.
*
* (C) Copyright 2000 Brian Warner <[email protected]>
*
* 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.
*
* "Keyspan PDA Serial Adapter" is probably a copyright of Keyspan, the
* company.
*
* This serial adapter is basically an EzUSB chip and an RS-232 line driver
* in a little widget that has a DB-9 on one end and a USB plug on the other.
* It uses the EzUSB's internal UART0 (using the pins from Port C) and timer2
* as a baud-rate generator. The wiring is:
* PC0/RxD0 <- rxd (DB9 pin 2) PC4 <- dsr pin 6
* PC1/TxD0 -> txd pin 3 PC5 <- ri pin 9
* PC2 -> rts pin 7 PC6 <- dcd pin 1
* PC3 <- cts pin 8 PC7 -> dtr pin 4
* PB1 -> line driver standby
*
* The EzUSB register constants below come from their excellent documentation
* and sample code (which used to be available at www.anchorchips.com, but
* that has now been absorbed into Cypress' site and the CD-ROM contents
* don't appear to be available online anymore). If we get multiple
* EzUSB-based drivers into the kernel, it might be useful to pull them out
* into a separate .h file.
*
* THEORY OF OPERATION:
*
* There are two 256-byte ring buffers, one for tx, one for rx.
*
* EP2out is pure tx data. When it appears, the data is copied into the tx
* ring and serial transmission is started if it wasn't already running. The
* "tx buffer empty" interrupt may kick off another character if the ring
* still has data. If the host is tx-blocked because the ring filled up,
* it will request a "tx unthrottle" interrupt. If sending a serial character
* empties the ring below the desired threshold, we set a bit that will send
* up the tx unthrottle message as soon as the rx buffer becomes free.
*
* EP2in (interrupt) is used to send both rx chars and rx status messages
* (only "tx unthrottle" at this time) back up to the host. The first byte
* of the rx message indicates data (0) or status msg (1). Status messages
* are sent before any data.
*
* Incoming serial characters are put into the rx ring by the serial
* interrupt, and the EP2in buffer sent if it wasn't already in transit.
* When the EP2in buffer returns, the interrupt prompts us to send more
* rx chars (or status messages) if they are pending.
*
* Device control happens through "vendor specific" control messages on EP0.
* All messages are destined for the "Interface" (with the index always 0,
* so that if their two-port device might someday use similar firmware, we
* can use index=1 to refer to the second port). The messages defined are:
*
* bRequest = 0 : set baud/bits/parity
* 1 : unused
* 2 : reserved for setting HW flow control (CTSRTS)
* 3 : get/set "modem info" (pin states: DTR, RTS, DCD, RI, etc)
* 4 : set break (on/off)
* 5 : reserved for requesting interrupts on pin state change
* 6 : query buffer room or chars in tx buffer
* 7 : request tx unthrottle interrupt
*
* The host-side driver is set to recognize the device ID values stashed in
* serial EEPROM (0x06cd, 0x0103), program this firmware into place, then
* start it running. This firmware will use EzUSB's "renumeration" trick by
* simulating a bus disconnect, then reconnect with a different device ID
* (encoded in the desc_device descriptor below). The host driver then
* recognizes the new device ID and glues it to the real serial driver code.
*
* USEFUL DOCS:
* EzUSB Technical Reference Manual: <http://www.cypress.com/>
* 8051 manuals: everywhere, but try www.dalsemi.com because the EzUSB is
* basically the Dallas enhanced 8051 code. Remember that the EzUSB IO ports
* use totally different registers!
* USB 1.1 spec: www.usb.org
*
* HOW TO BUILD:
* gcc -x assembler-with-cpp -P -E -o keyspan_pda.asm keyspan_pda.s
* as31 -l keyspan_pda.asm
* mv keyspan_pda.obj keyspan_pda.hex
* perl ezusb_convert.pl keyspan_pda < keyspan_pda.hex > keyspan_pda_fw.h
* Get as31 from <http://www.pjrc.com/tech/8051/index.html>, and hack on it
* a bit to make it build.
*
* THANKS:
* Greg Kroah-Hartman, for coordinating the whole usb-serial thing.
* AnchorChips, for making such an incredibly useful little microcontroller.
* KeySpan, for making a handy, cheap ($40) widget that was so easy to take
* apart and trace with an ohmmeter.
*
* TODO:
* lots. grep for TODO. Interrupt safety needs stress-testing. Better flow
* control. Interrupting host upon change in DCD, etc, counting transitions.
* Need to find a safe device id to use (the one used by the Keyspan firmware
* under Windows would be ideal.. can anyone figure out what it is?). Parity.
* More baud rates. Oh, and the string-descriptor-length silicon bug
* workaround should be implemented, but I'm lazy, and the consequence is
* that the device name strings that show up in your kernel log will have
* lots of trailing binary garbage in them (appears as ????). Device strings
* should be made more accurate.
*
* Questions, bugs, patches to Brian.
*
* -Brian Warner <[email protected]>
*
*/
#define HIGH(x) (((x) & 0xff00) / 256)
#define LOW(x) ((x) & 0xff)
#define dpl1 0x84
#define dph1 0x85
#define dps 0x86
;;; our bit assignments
#define TX_RUNNING 0
#define DO_TX_UNTHROTTLE 1
;; stack from 0x60 to 0x7f: should really set SP to 0x60-1, not 0x60
#define STACK #0x60-1
#define EXIF 0x91
#define EIE 0xe8
.flag EUSB, EIE.0
.flag ES0, IE.4
#define EP0CS #0x7fb4
#define EP0STALLbit #0x01
#define IN0BUF #0x7f00
#define IN0BC #0x7fb5
#define OUT0BUF #0x7ec0
#define OUT0BC #0x7fc5
#define IN2BUF #0x7e00
#define IN2BC #0x7fb9
#define IN2CS #0x7fb8
#define OUT2BC #0x7fc9
#define OUT2CS #0x7fc8
#define OUT2BUF #0x7dc0
#define IN4BUF #0x7d00
#define IN4BC #0x7fbd
#define IN4CS #0x7fbc
#define OEB #0x7f9d
#define OUTB #0x7f97
#define OEC #0x7f9e
#define OUTC #0x7f98
#define PINSC #0x7f9b
#define PORTBCFG #0x7f94
#define PORTCCFG #0x7f95
#define OEA #0x7f9c
#define IN07IRQ #0x7fa9
#define OUT07IRQ #0x7faa
#define IN07IEN #0x7fac
#define OUT07IEN #0x7fad
#define USBIRQ #0x7fab
#define USBIEN #0x7fae
#define USBBAV #0x7faf
#define USBCS #0x7fd6
#define SUDPTRH #0x7fd4
#define SUDPTRL #0x7fd5
#define SETUPDAT #0x7fe8
;; usb interrupt : enable is EIE.0 (0xe8), flag is EXIF.4 (0x91)
.org 0
ljmp start
;; interrupt vectors
.org 23H
ljmp serial_int
.byte 0
.org 43H
ljmp USB_Jump_Table
.byte 0 ; filled in by the USB core
;;; local variables. These are not initialized properly: do it by hand.
.org 30H
rx_ring_in: .byte 0
rx_ring_out: .byte 0
tx_ring_in: .byte 0
tx_ring_out: .byte 0
tx_unthrottle_threshold: .byte 0
.org 0x100H ; wants to be on a page boundary
USB_Jump_Table:
ljmp ISR_Sudav ; Setup Data Available
.byte 0
ljmp 0 ; Start of Frame
.byte 0
ljmp 0 ; Setup Data Loading
.byte 0
ljmp 0 ; Global Suspend
.byte 0
ljmp 0 ; USB Reset
.byte 0
ljmp 0 ; Reserved
.byte 0
ljmp 0 ; End Point 0 In
.byte 0
ljmp 0 ; End Point 0 Out
.byte 0
ljmp 0 ; End Point 1 In
.byte 0
ljmp 0 ; End Point 1 Out
.byte 0
ljmp ISR_Ep2in
.byte 0
ljmp ISR_Ep2out
.byte 0
.org 0x200
start: mov SP,STACK-1 ; set stack
;; clear local variables
clr a
mov tx_ring_in, a
mov tx_ring_out, a
mov rx_ring_in, a
mov rx_ring_out, a
mov tx_unthrottle_threshold, a
clr TX_RUNNING
clr DO_TX_UNTHROTTLE
;; clear fifo with "fe"
mov r1, 0
mov a, #0xfe
mov dptr, #tx_ring
clear_tx_ring_loop:
movx @dptr, a
inc dptr
djnz r1, clear_tx_ring_loop
mov a, #0xfd
mov dptr, #rx_ring
clear_rx_ring_loop:
movx @dptr, a
inc dptr
djnz r1, clear_rx_ring_loop
;;; turn on the RS-232 driver chip (bring the STANDBY pin low)
;;; on Xircom the STANDBY is wired to PB6 and PC4
mov dptr, PORTBCFG
mov a, #0xBf
movx @dptr, a
mov dptr, PORTCCFG
mov a, #0xef
movx @dptr, a
;; set OEC.4
mov a, #0x10
mov dptr,OEC
movx @dptr,a
;; clear PC4
mov a, #0x00
mov dptr,OUTC
movx @dptr,a
;; set OEB.6
mov a, #0x40
mov dptr,OEB
movx @dptr,a
;; clear PB6
mov a, #0x00
mov dptr,OUTB
movx @dptr,a
;; set OEC.[17]
mov a, #0x82
mov dptr,OEC
movx @dptr,a
;; set PORTCCFG.[01] to route TxD0,RxD0 to serial port
mov dptr, PORTCCFG
mov a, #0x03
movx @dptr, a
;; set up interrupts, autovectoring
;; set BKPT
mov dptr, USBBAV
movx a,@dptr
setb acc.0 ; AVEN bit to 0
movx @dptr, a
mov a,#0x01 ; enable SUDAV: setup data available (for ep0)
mov dptr, USBIRQ
movx @dptr, a ; clear SUDAVI
mov dptr, USBIEN
movx @dptr, a
mov dptr, IN07IEN
mov a,#0x04 ; enable IN2 int
movx @dptr, a
mov dptr, OUT07IEN
mov a,#0x04 ; enable OUT2 int
movx @dptr, a
mov dptr, OUT2BC
movx @dptr, a ; arm OUT2
;; mov a, #0x84 ; turn on RTS, DTR
;; mov dptr,OUTC
;; movx @dptr, a
mov a, #0x7 ; turn on DTR
mov dptr,USBBAV
movx @dptr, a
mov a, #0x20 ; turn on the RED led
mov dptr,OEA
movx @dptr, a
mov a, #0x80 ; turn on RTS
mov dptr,OUTC
movx @dptr, a
;; setup the serial port. 9600 8N1.
mov a,#0x53 ; mode 1, enable rx, clear int
mov SCON, a
;; using timer2, in 16-bit baud-rate-generator mode
;; (xtal 12MHz, internal fosc 24MHz)
;; RCAP2H,RCAP2L = 65536 - fosc/(32*baud)
;; 57600: 0xFFF2.F, say 0xFFF3
;; 9600: 0xFFB1.E, say 0xFFB2
;; 300: 0xF63C
#define BAUD 9600
#define BAUD_TIMEOUT(rate) (65536 - (24 * 1000 * 1000) / (32 * rate))
#define BAUD_HIGH(rate) HIGH(BAUD_TIMEOUT(rate))
#define BAUD_LOW(rate) LOW(BAUD_TIMEOUT(rate))
mov T2CON, #030h ; rclk=1,tclk=1,cp=0,tr2=0(enable later)
mov r3, #5
acall set_baud
setb TR2
mov SCON, #050h
#if 0
mov r1, #0x40
mov a, #0x41
send:
mov SBUF, a
inc a
anl a, #0x3F
orl a, #0x40
; xrl a, #0x02
wait1:
jnb TI, wait1
clr TI
djnz r1, send
;done: sjmp done
#endif
setb EUSB
setb EA
setb ES0
;acall dump_stat
;; hey, what say we RENUMERATE! (TRM p.62)
mov a, #0
mov dps, a
mov dptr, USBCS
mov a, #0x02 ; DISCON=0, DISCOE=0, RENUM=1
movx @dptr, a
;; now presence pin is floating, simulating disconnect. wait 0.5s
mov r1, #46
renum_wait1:
mov r2, #0
renum_wait2:
mov r3, #0
renum_wait3:
djnz r3, renum_wait3
djnz r2, renum_wait2
djnz r1, renum_wait1 ; wait about n*(256^2) 6MHz clocks
mov a, #0x06 ; DISCON=0, DISCOE=1, RENUM=1
movx @dptr, a
;; we are back online. the host device will now re-query us
main: sjmp main
ISR_Sudav:
push dps
push dpl
push dph
push dpl1
push dph1
push acc
mov a,EXIF
clr acc.4
mov EXIF,a ; clear INT2 first
mov dptr, USBIRQ ; clear USB int
mov a,#01h
movx @dptr,a
;; get request type
mov dptr, SETUPDAT
movx a, @dptr
mov r1, a ; r1 = bmRequestType
inc dptr
movx a, @dptr
mov r2, a ; r2 = bRequest
inc dptr
movx a, @dptr
mov r3, a ; r3 = wValueL
inc dptr
movx a, @dptr
mov r4, a ; r4 = wValueH
;; main switch on bmRequest.type: standard or vendor
mov a, r1
anl a, #0x60
cjne a, #0x00, setup_bmreq_type_not_standard
;; standard request: now main switch is on bRequest
ljmp setup_bmreq_is_standard
setup_bmreq_type_not_standard:
;; a still has bmreq&0x60
cjne a, #0x40, setup_bmreq_type_not_vendor
;; Anchor reserves bRequest 0xa0-0xaf, we use small ones
;; switch on bRequest. bmRequest will always be 0x41 or 0xc1
cjne r2, #0x00, setup_ctrl_not_00
;; 00 is set baud, wValue[0] has baud rate index
lcall set_baud ; index in r3, carry set if error
jc setup_bmreq_type_not_standard__do_stall
ljmp setup_done_ack
setup_bmreq_type_not_standard__do_stall:
ljmp setup_stall
setup_ctrl_not_00:
cjne r2, #0x01, setup_ctrl_not_01
;; 01 is reserved for set bits (parity). TODO
ljmp setup_stall
setup_ctrl_not_01:
cjne r2, #0x02, setup_ctrl_not_02
;; 02 is set HW flow control. TODO
ljmp setup_stall
setup_ctrl_not_02:
cjne r2, #0x03, setup_ctrl_not_03
;; 03 is control pins (RTS, DTR).
ljmp control_pins ; will jump to setup_done_ack,
; or setup_return_one_byte
setup_ctrl_not_03:
cjne r2, #0x04, setup_ctrl_not_04
;; 04 is send break (really "turn break on/off"). TODO
cjne r3, #0x00, setup_ctrl_do_break_on
;; do break off: restore PORTCCFG.1 to reconnect TxD0 to serial port
mov dptr, PORTCCFG
movx a, @dptr
orl a, #0x02
movx @dptr, a
ljmp setup_done_ack
setup_ctrl_do_break_on:
;; do break on: clear PORTCCFG.0, set TxD high(?) (b1 low)
mov dptr, OUTC
movx a, @dptr
anl a, #0xfd ; ~0x02
movx @dptr, a
mov dptr, PORTCCFG
movx a, @dptr
anl a, #0xfd ; ~0x02
movx @dptr, a
ljmp setup_done_ack
setup_ctrl_not_04:
cjne r2, #0x05, setup_ctrl_not_05
;; 05 is set desired interrupt bitmap. TODO
ljmp setup_stall
setup_ctrl_not_05:
cjne r2, #0x06, setup_ctrl_not_06
;; 06 is query room
cjne r3, #0x00, setup_ctrl_06_not_00
;; 06, wValue[0]=0 is query write_room
mov a, tx_ring_out
setb c
subb a, tx_ring_in ; out-1-in = 255 - (in-out)
ljmp setup_return_one_byte
setup_ctrl_06_not_00:
cjne r3, #0x01, setup_ctrl_06_not_01
;; 06, wValue[0]=1 is query chars_in_buffer
mov a, tx_ring_in
clr c
subb a, tx_ring_out ; in-out
ljmp setup_return_one_byte
setup_ctrl_06_not_01:
ljmp setup_stall
setup_ctrl_not_06:
cjne r2, #0x07, setup_ctrl_not_07
;; 07 is request tx unthrottle interrupt
mov tx_unthrottle_threshold, r3; wValue[0] is threshold value
ljmp setup_done_ack
setup_ctrl_not_07:
ljmp setup_stall
setup_bmreq_type_not_vendor:
ljmp setup_stall
setup_bmreq_is_standard:
cjne r2, #0x00, setup_breq_not_00
;; 00: Get_Status (sub-switch on bmRequestType: device, ep, int)
cjne r1, #0x80, setup_Get_Status_not_device
;; Get_Status(device)
;; are we self-powered? no. can we do remote wakeup? no
;; so return two zero bytes. This is reusable
setup_return_two_zero_bytes:
mov dptr, IN0BUF
clr a
movx @dptr, a
inc dptr
movx @dptr, a
mov dptr, IN0BC
mov a, #2
movx @dptr, a
ljmp setup_done_ack
setup_Get_Status_not_device:
cjne r1, #0x82, setup_Get_Status_not_endpoint
;; Get_Status(endpoint)
;; must get stall bit for ep[wIndexL], return two bytes, bit in lsb 0
;; for now: cheat. TODO
sjmp setup_return_two_zero_bytes
setup_Get_Status_not_endpoint:
cjne r1, #0x81, setup_Get_Status_not_interface
;; Get_Status(interface): return two zeros
sjmp setup_return_two_zero_bytes
setup_Get_Status_not_interface:
ljmp setup_stall
setup_breq_not_00:
cjne r2, #0x01, setup_breq_not_01
;; 01: Clear_Feature (sub-switch on wValueL: stall, remote wakeup)
cjne r3, #0x00, setup_Clear_Feature_not_stall
;; Clear_Feature(stall). should clear a stall bit. TODO
ljmp setup_stall
setup_Clear_Feature_not_stall:
cjne r3, #0x01, setup_Clear_Feature_not_rwake
;; Clear_Feature(remote wakeup). ignored.
ljmp setup_done_ack
setup_Clear_Feature_not_rwake:
ljmp setup_stall
setup_breq_not_01:
cjne r2, #0x03, setup_breq_not_03
;; 03: Set_Feature (sub-switch on wValueL: stall, remote wakeup)
cjne r3, #0x00, setup_Set_Feature_not_stall
;; Set_Feature(stall). Should set a stall bit. TODO
ljmp setup_stall
setup_Set_Feature_not_stall:
cjne r3, #0x01, setup_Set_Feature_not_rwake
;; Set_Feature(remote wakeup). ignored.
ljmp setup_done_ack
setup_Set_Feature_not_rwake:
ljmp setup_stall
setup_breq_not_03:
cjne r2, #0x06, setup_breq_not_06
;; 06: Get_Descriptor (s-switch on wValueH: dev, config[n], string[n])
cjne r4, #0x01, setup_Get_Descriptor_not_device
;; Get_Descriptor(device)
mov dptr, SUDPTRH
mov a, #HIGH(desc_device)
movx @dptr, a
mov dptr, SUDPTRL
mov a, #LOW(desc_device)
movx @dptr, a
ljmp setup_done_ack
setup_Get_Descriptor_not_device:
cjne r4, #0x02, setup_Get_Descriptor_not_config
;; Get_Descriptor(config[n])
cjne r3, #0x00, setup_stall; only handle n==0
;; Get_Descriptor(config[0])
mov dptr, SUDPTRH
mov a, #HIGH(desc_config1)
movx @dptr, a
mov dptr, SUDPTRL
mov a, #LOW(desc_config1)
movx @dptr, a
ljmp setup_done_ack
setup_Get_Descriptor_not_config:
cjne r4, #0x03, setup_Get_Descriptor_not_string
;; Get_Descriptor(string[wValueL])
;; if (wValueL >= maxstrings) stall
mov a, #((desc_strings_end-desc_strings)/2)
clr c
subb a,r3 ; a=4, r3 = 0..3 . if a<=0 then stall
jc setup_stall
jz setup_stall
mov a, r3
add a, r3 ; a = 2*wValueL
mov dptr, #desc_strings
add a, dpl
mov dpl, a
mov a, #0
addc a, dph
mov dph, a ; dph = desc_strings[a]. big endian! (handy)
;; it looks like my adapter uses a revision of the EZUSB that
;; contains "rev D errata number 8", as hinted in the EzUSB example
;; code. I cannot find an actual errata description on the Cypress
;; web site, but from the example code it looks like this bug causes
;; the length of string descriptors to be read incorrectly, possibly
;; sending back more characters than the descriptor has. The workaround
;; is to manually send out all of the data. The consequence of not
;; using the workaround is that the strings gathered by the kernel
;; driver are too long and are filled with trailing garbage (including
;; leftover strings). Writing this out by hand is a nuisance, so for
;; now I will just live with the bug.
movx a, @dptr
mov r1, a
inc dptr
movx a, @dptr
mov r2, a
mov dptr, SUDPTRH
mov a, r1
movx @dptr, a
mov dptr, SUDPTRL
mov a, r2
movx @dptr, a
;; done
ljmp setup_done_ack
setup_Get_Descriptor_not_string:
ljmp setup_stall
setup_breq_not_06:
cjne r2, #0x08, setup_breq_not_08
;; Get_Configuration. always 1. return one byte.
;; this is reusable
mov a, #1
setup_return_one_byte:
mov dptr, IN0BUF
movx @dptr, a
mov a, #1
mov dptr, IN0BC
movx @dptr, a
ljmp setup_done_ack
setup_breq_not_08:
cjne r2, #0x09, setup_breq_not_09
;; 09: Set_Configuration. ignored.
ljmp setup_done_ack
setup_breq_not_09:
cjne r2, #0x0a, setup_breq_not_0a
;; 0a: Get_Interface. get the current altsetting for int[wIndexL]
;; since we only have one interface, ignore wIndexL, return a 0
mov a, #0
ljmp setup_return_one_byte
setup_breq_not_0a:
cjne r2, #0x0b, setup_breq_not_0b
;; 0b: Set_Interface. set altsetting for interface[wIndexL]. ignored
ljmp setup_done_ack
setup_breq_not_0b:
ljmp setup_stall
setup_done_ack:
;; now clear HSNAK
mov dptr, EP0CS
mov a, #0x02
movx @dptr, a
sjmp setup_done
setup_stall:
;; unhandled. STALL
;EP0CS |= bmEPSTALL
mov dptr, EP0CS
movx a, @dptr
orl a, EP0STALLbit
movx @dptr, a
sjmp setup_done
setup_done:
pop acc
pop dph1
pop dpl1
pop dph
pop dpl
pop dps
reti
;;; ==============================================================
set_baud: ; baud index in r3
;; verify a < 10
mov a, r3
jb ACC.7, set_baud__badbaud
clr c
subb a, #10
jnc set_baud__badbaud
mov a, r3
rl a ; a = index*2
add a, #LOW(baud_table)
mov dpl, a
mov a, #HIGH(baud_table)
addc a, #0
mov dph, a
;; TODO: shut down xmit/receive
;; TODO: wait for current xmit char to leave
;; TODO: shut down timer to avoid partial-char glitch
movx a,@dptr ; BAUD_HIGH
mov RCAP2H, a
mov TH2, a
inc dptr
movx a,@dptr ; BAUD_LOW
mov RCAP2L, a
mov TL2, a
;; TODO: restart xmit/receive
;; TODO: reenable interrupts, resume tx if pending
clr c ; c=0: success
ret
set_baud__badbaud:
setb c ; c=1: failure
ret
;;; ==================================================
control_pins:
cjne r1, #0x41, control_pins_in
control_pins_out:
;TODO BKPT is DTR
mov a, r3 ; wValue[0] holds new bits: b7 is new RTS
xrl a, #0xff ; 1 means active, 0V, +12V ?
anl a, #0x80
mov r3, a
mov dptr, OUTC
movx a, @dptr ; only change bit 7
anl a, #0x7F ; ~0x84
orl a, r3
movx @dptr, a ; other pins are inputs, bits ignored
ljmp setup_done_ack
control_pins_in:
mov dptr, PINSC
movx a, @dptr
xrl a, #0xff
ljmp setup_return_one_byte
;;; ========================================
ISR_Ep2in:
push dps
push dpl
push dph
push dpl1
push dph1
push acc
mov a,EXIF
clr acc.4
mov EXIF,a ; clear INT2 first
mov dptr, IN07IRQ ; clear USB int
mov a,#04h
movx @dptr,a
mov a, #0x20 ; Turn off the green LED
mov dptr,OEA
movx @dptr, a
;; do stuff
lcall start_in
mov a, #0x20 ; Turn off the green LED
mov dptr,OEA
movx @dptr, a
pop acc
pop dph1
pop dpl1
pop dph
pop dpl
pop dps
reti
ISR_Ep2out:
push dps
push dpl
push dph
push dpl1
push dph1
push acc
mov a, #0x10 ; Turn the green LED
mov dptr,OEA
movx @dptr, a
mov a,EXIF
clr acc.4
mov EXIF,a ; clear INT2 first
mov dptr, OUT07IRQ ; clear USB int
mov a,#04h
movx @dptr,a
;; do stuff
;; copy data into buffer. for now, assume we will have enough space
mov dptr, OUT2BC ; get byte count
movx a,@dptr
mov r1, a
clr a
mov dps, a
mov dptr, OUT2BUF ; load DPTR0 with source
mov dph1, #HIGH(tx_ring) ; load DPTR1 with target
mov dpl1, tx_ring_in
OUT_loop:
movx a,@dptr ; read
inc dps ; switch to DPTR1: target
inc dpl1 ; target = tx_ring_in+1
movx @dptr,a ; store
mov a,dpl1
cjne a, tx_ring_out, OUT_no_overflow
sjmp OUT_overflow
OUT_no_overflow:
inc tx_ring_in ; tx_ring_in++
inc dps ; switch to DPTR0: source
inc dptr
djnz r1, OUT_loop
sjmp OUT_done
OUT_overflow:
;; signal overflow
;; fall through
OUT_done:
;; ack
mov dptr,OUT2BC
movx @dptr,a
;; start tx
acall maybe_start_tx
;acall dump_stat
mov a, #0x20 ; Turn off the green LED
mov dptr,OEA
movx @dptr, a
pop acc
pop dph1
pop dpl1
pop dph
pop dpl
pop dps
reti
dump_stat:
;; fill in EP4in with a debugging message:
;; tx_ring_in, tx_ring_out, rx_ring_in, rx_ring_out
;; tx_active
;; tx_ring[0..15]
;; 0xfc
;; rx_ring[0..15]
clr a
mov dps, a
mov dptr, IN4CS
movx a, @dptr
jb acc.1, dump_stat__done; busy: cannot dump, old one still pending
mov dptr, IN4BUF
mov a, tx_ring_in
movx @dptr, a
inc dptr
mov a, tx_ring_out
movx @dptr, a
inc dptr
mov a, rx_ring_in
movx @dptr, a
inc dptr
mov a, rx_ring_out
movx @dptr, a
inc dptr
clr a
jnb TX_RUNNING, dump_stat__no_tx_running
inc a
dump_stat__no_tx_running:
movx @dptr, a
inc dptr
;; tx_ring[0..15]
inc dps
mov dptr, #tx_ring ; DPTR1: source
mov r1, #16
dump_stat__tx_ring_loop:
movx a, @dptr
inc dptr
inc dps
movx @dptr, a
inc dptr
inc dps
djnz r1, dump_stat__tx_ring_loop
inc dps
mov a, #0xfc
movx @dptr, a
inc dptr
;; rx_ring[0..15]
inc dps
mov dptr, #rx_ring ; DPTR1: source
mov r1, #16
dump_stat__rx_ring_loop:
movx a, @dptr
inc dptr
inc dps
movx @dptr, a
inc dptr
inc dps
djnz r1, dump_stat__rx_ring_loop
;; now send it
clr a
mov dps, a
mov dptr, IN4BC
mov a, #38
movx @dptr, a
dump_stat__done:
ret
;;; ============================================================
maybe_start_tx:
;; make sure the tx process is running.
jb TX_RUNNING, start_tx_done
start_tx:
;; is there work to be done?
mov a, tx_ring_in
cjne a,tx_ring_out, start_tx__work
ret ; no work
start_tx__work:
;; tx was not running. send the first character, setup the TI int
inc tx_ring_out ; [++tx_ring_out]
mov dph, #HIGH(tx_ring)
mov dpl, tx_ring_out
movx a, @dptr
mov sbuf, a
setb TX_RUNNING
start_tx_done:
;; can we unthrottle the host tx process?
;; step 1: do we care?
mov a, #0
cjne a, tx_unthrottle_threshold, start_tx__maybe_unthrottle_tx
;; nope
start_tx_really_done:
ret
start_tx__maybe_unthrottle_tx:
;; step 2: is there now room?
mov a, tx_ring_out
setb c
subb a, tx_ring_in
;; a is now write_room. If thresh >= a, we can unthrottle
clr c
subb a, tx_unthrottle_threshold
jc start_tx_really_done ; nope
;; yes, we can unthrottle. remove the threshold and mark a request
mov tx_unthrottle_threshold, #0
setb DO_TX_UNTHROTTLE
;; prod rx, which will actually send the message when in2 becomes free
ljmp start_in
serial_int:
push dps
push dpl
push dph
push dpl1
push dph1
push acc
jnb TI, serial_int__not_tx
;; tx finished. send another character if we have one
clr TI ; clear int
clr TX_RUNNING
lcall start_tx
serial_int__not_tx:
jnb RI, serial_int__not_rx
lcall get_rx_char
clr RI ; clear int
serial_int__not_rx:
;; return
pop acc
pop dph1
pop dpl1
pop dph
pop dpl
pop dps
reti
get_rx_char:
mov dph, #HIGH(rx_ring)
mov dpl, rx_ring_in
inc dpl ; target = rx_ring_in+1
mov a, sbuf
movx @dptr, a
;; check for overflow before incrementing rx_ring_in
mov a, dpl
cjne a, rx_ring_out, get_rx_char__no_overflow