firmware/keyspan_pda/keyspan_pda.S

3  *  Firmware for the Keyspan PDA Serial Adapter, a USB serial port based on
13  *  "Keyspan PDA Serial Adapter" is probably a copyright of Keyspan, the
17  *  in a little widget that has a DB-9 on one end and a USB plug on the other.
19  *  as a baud-rate generator. The wiring is:
31  *  into a separate .h file.
41  *   it will request a "tx unthrottle" interrupt. If sending a serial character
42  *   empties the ring below the desired threshold, we set a bit that will send
72  *  simulating a bus disconnect, then reconnect with a different device ID
89  * a bit to make it build.
94  *  KeySpan, for making a handy, cheap ($40) widget that was so easy to take
100  *  Need to find a safe device id to use (the one used by the Keyspan firmware
187 	.org 0x100H		; wants to be on a page boundary
219 	clr a
220 	mov tx_ring_in, a
221 	mov tx_ring_out, a
222 	mov rx_ring_in, a
223 	mov rx_ring_out, a
224 	mov tx_unthrottle_threshold, a
230 	mov a, #0xfe
233 	movx @dptr, a
237 	mov a, #0xfd
240 	movx @dptr, a
246 	mov a, #02H
248 	movx @dptr,a
250 	mov a, #00H
252 	movx @dptr,a
254 	mov a, #0x86
256 	movx @dptr,a
259 	mov a, #0x03
260 	movx @dptr, a
264 	movx a,@dptr
266 	movx @dptr, a
268 	mov a,#0x01		; enable SUDAV:	setup data available (for ep0)
270 	movx @dptr, a		; clear SUDAVI
272 	movx @dptr, a
275 	mov a,#0x04		; enable IN2 int
276 	movx @dptr, a
279 	mov a,#0x04		; enable OUT2 int
280 	movx @dptr, a
282 	movx @dptr, a		; arm OUT2
284 	mov a, #0x84		; turn on RTS, DTR
286 	movx @dptr, a
288 	mov a,#01010011		; mode 1, enable rx, clear int
289 	mov SCON, a
309 	mov a, #0x41
311 	mov SBUF, a
312 	inc a
313 	anl a, #0x3F
314 	orl a, #0x40
315 ;	xrl a, #0x02
330 	mov a, #0
331 	mov dps, a
333 	mov a, #0x02		; DISCON=0, DISCOE=0, RENUM=1
334 	movx @dptr, a
345 	mov a, #0x06		; DISCON=0, DISCOE=1, RENUM=1
346 	movx @dptr, a
361 	mov a,EXIF
363 	mov EXIF,a		; clear INT2 first
365 	mov a,#01h
366 	movx @dptr,a
370 	movx a, @dptr
371 	mov r1, a		; r1 = bmRequestType
373 	movx a, @dptr
374 	mov r2, a		; r2 = bRequest
376 	movx a, @dptr
377 	mov r3, a		; r3 = wValueL
379 	movx a, @dptr
380 	mov r4, a		; r4 = wValueH
383 	mov a, r1
384 	anl a, #0x60
385 	cjne a, #0x00, setup_bmreq_type_not_standard
390 	;; a still has bmreq&0x60
391 	cjne a, #0x40, setup_bmreq_type_not_vendor
420 	movx a, @dptr
421 	orl a, #0x02
422 	movx @dptr, a
427 	movx a, @dptr
428 	anl a, #0xfd		; ~0x02
429 	movx @dptr, a
431 	movx a, @dptr
432 	anl a, #0xfd		; ~0x02
433 	movx @dptr, a
444 	mov a, tx_ring_out
446 	subb a, tx_ring_in	; out-1-in = 255 - (in-out)
451 	mov a, tx_ring_in
453 	subb a, tx_ring_out	; in-out
478 	clr a
479 	movx @dptr, a
481 	movx @dptr, a
483 	mov a, #2
484 	movx @dptr, a
503 	;; Clear_Feature(stall). should clear a stall bit. TODO
516 	;; Set_Feature(stall). Should set a stall bit. TODO
531 	mov a, #HIGH(desc_device)
532 	movx @dptr, a
534 	mov a, #LOW(desc_device)
535 	movx @dptr, a
543 	mov a, #HIGH(desc_config1)
544 	movx @dptr, a
546 	mov a, #LOW(desc_config1)
547 	movx @dptr, a
553 	mov a, #((desc_strings_end-desc_strings)/2)
555 	subb a,r3		; a=4, r3 = 0..3 . if a<=0 then stall
558 	mov a, r3
559 	add a, r3		; a = 2*wValueL
561 	add a, dpl
562 	mov dpl, a
563 	mov a, #0
564 	addc a, dph
565 	mov dph, a		; dph = desc_strings[a]. big endian! (handy)
566 	;; it looks like my adapter uses a revision of the EZUSB that
575 	;; leftover strings). Writing this out by hand is a nuisance, so for
577 	movx a, @dptr
578 	mov r1, a
580 	movx a, @dptr
581 	mov r2, a
583 	mov a, r1
584 	movx @dptr, a
586 	mov a, r2
587 	movx @dptr, a
598 	mov a, #1
601 	movx @dptr, a
602 	mov a, #1
604 	movx @dptr, a
612 	;; 0a: Get_Interface. get the current altsetting for int[wIndexL]
613 	;;  since we only have one interface, ignore wIndexL, return a 0
614 	mov a, #0
627 	mov a, #0x02
628 	movx @dptr, a
634 	movx a, @dptr
635 	orl a, EP0STALLbit
636 	movx @dptr, a
651 	;; verify a < 10
652 	mov a, r3
655 	subb a, #10
657 	mov a, r3
658 	rl a			; a = index*2
659 	add a, #LOW(baud_table)
660 	mov dpl, a
661 	mov a, #HIGH(baud_table)
662 	addc a, #0
663 	mov dph, a
667 	movx a,@dptr		; BAUD_HIGH
668 	mov RCAP2H, a
669 	mov TH2, a
671 	movx a,@dptr		; BAUD_LOW
672 	mov RCAP2L, a
673 	mov TL2, a
686 	mov a, r3 ; wValue[0] holds new bits:	b7 is new DTR, b2 is new RTS
687 	xrl a, #0xff		; 1 means active, 0V, +12V ?
688 	anl a, #0x84
689 	mov r3, a
691 	movx a, @dptr		; only change bits 7 and 2
692 	anl a, #0x7b		; ~0x84
693 	orl a, r3
694 	movx @dptr, a		; other pins are inputs, bits ignored
698 	movx a, @dptr
699 	xrl a, #0xff
711 	mov a,EXIF
713 	mov EXIF,a		; clear INT2 first
715 	mov a,#04h
716 	movx @dptr,a
736 	mov a,EXIF
738 	mov EXIF,a		; clear INT2 first
740 	mov a,#04h
741 	movx @dptr,a
747 	movx a,@dptr
748 	mov r1, a
749 	clr a
750 	mov dps, a
755 	movx a,@dptr		; read
758 	movx @dptr,a		; store
759 	mov a,dpl1
760 	cjne a, tx_ring_out, OUT_no_overflow
774 	movx @dptr,a
789 	;; fill in EP4in with a debugging message:
795 	clr a
796 	mov dps, a
799 	movx a, @dptr
803 	mov a, tx_ring_in
804 	movx @dptr, a
806 	mov a, tx_ring_out
807 	movx @dptr, a
810 	mov a, rx_ring_in
811 	movx @dptr, a
813 	mov a, rx_ring_out
814 	movx @dptr, a
817 	clr a
819 	inc a
821 	movx @dptr, a
828 	movx a, @dptr
831 	movx @dptr, a
837 	mov a, #0xfc
838 	movx @dptr, a
846 	movx a, @dptr
849 	movx @dptr, a
855 	clr a
856 	mov dps, a
858 	mov a, #38
859 	movx @dptr, a
870 	mov a, tx_ring_in
871 	cjne a,tx_ring_out, start_tx__work
878 	movx a, @dptr
879 	mov sbuf, a
884 	mov a, #0
885 	cjne a, tx_unthrottle_threshold, start_tx__maybe_unthrottle_tx
891 	mov a, tx_ring_out
893 	subb a, tx_ring_in
894 	;; a is now write_room. If thresh >= a, we can unthrottle
896 	subb a, tx_unthrottle_threshold
898 	;; yes, we can unthrottle. remove the threshold and mark a request
935 	mov a, sbuf
936 	movx @dptr, a
938 	mov a, dpl
939 	cjne a, rx_ring_out, get_rx_char__no_overflow
951 	movx a, @dptr
954 	;; see if there is any work to do. a serial interrupt might occur
956 	mov a, rx_ring_in
957 	cjne a, rx_ring_out, start_in__have_work
961 	clr a
962 	mov dps, a
966 	movx @dptr, a		; in[0] signals that rest of IN is rx data
972 	mov a, rx_ring_in
973 	cjne a, rx_ring_out, start_inlocal_irq_enablell_copying
978 	movx a, @dptr
980 	movx @dptr, a		; write into IN buffer
989 	mov a, r1
991 	movx @dptr, a
997 	;; special sequence: send a tx unthrottle message
999 	clr a
1000 	mov dps, a
1002 	mov a, #1
1003 	movx @dptr, a
1005 	mov a, #2
1006 	movx @dptr, a
1008 	movx @dptr, a
1013 	mov SBUF, a
1074 	;; *that* is a pain in the ass to encode. And they are little-endian