| blob | 05d99dd637766a7fd63a5879a57adb21e4f4eeeb |
1 /* $Id: loop.s,v 1.23 2000/03/20 09:49:06 warner Exp $
2 *
3 * Firmware for the Keyspan PDA Serial Adapter, a USB serial port based on
4 * the EzUSB microcontroller.
5 *
6 * (C) Copyright 2000 Brian Warner <warner@lothar.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * "Keyspan PDA Serial Adapter" is probably a copyright of Keyspan, the
14 * company.
15 *
16 * This serial adapter is basically an EzUSB chip and an RS-232 line driver
17 * in a little widget that has a DB-9 on one end and a USB plug on the other.
18 * It uses the EzUSB's internal UART0 (using the pins from Port C) and timer2
19 * as a baud-rate generator. The wiring is:
20 * PC0/RxD0 <- rxd (DB9 pin 2) PC4 <- dsr pin 6
21 * PC1/TxD0 -> txd pin 3 PC5 <- ri pin 9
22 * PC2 -> rts pin 7 PC6 <- dcd pin 1
23 * PC3 <- cts pin 8 PC7 -> dtr pin 4
24 * PB1 -> line driver standby
25 *
26 * The EzUSB register constants below come from their excellent documentation
27 * and sample code (which used to be available at www.anchorchips.com, but
28 * that has now been absorbed into Cypress' site and the CD-ROM contents
29 * don't appear to be available online anymore). If we get multiple
30 * EzUSB-based drivers into the kernel, it might be useful to pull them out
31 * into a separate .h file.
32 *
33 * THEORY OF OPERATION:
34 *
35 * There are two 256-byte ring buffers, one for tx, one for rx.
36 *
37 * EP2out is pure tx data. When it appears, the data is copied into the tx
38 * ring and serial transmission is started if it wasn't already running. The
39 * "tx buffer empty" interrupt may kick off another character if the ring
40 * still has data. If the host is tx-blocked because the ring filled up,
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
43 * up the tx unthrottle message as soon as the rx buffer becomes free.
44 *
45 * EP2in (interrupt) is used to send both rx chars and rx status messages
46 * (only "tx unthrottle" at this time) back up to the host. The first byte
47 * of the rx message indicates data (0) or status msg (1). Status messages
48 * are sent before any data.
49 *
50 * Incoming serial characters are put into the rx ring by the serial
51 * interrupt, and the EP2in buffer sent if it wasn't already in transit.
52 * When the EP2in buffer returns, the interrupt prompts us to send more
53 * rx chars (or status messages) if they are pending.
54 *
55 * Device control happens through "vendor specific" control messages on EP0.
56 * All messages are destined for the "Interface" (with the index always 0,
57 * so that if their two-port device might someday use similar firmware, we
58 * can use index=1 to refer to the second port). The messages defined are:
59 *
60 * bRequest = 0 : set baud/bits/parity
61 * 1 : unused
62 * 2 : reserved for setting HW flow control (CTSRTS)
63 * 3 : get/set "modem info" (pin states: DTR, RTS, DCD, RI, etc)
64 * 4 : set break (on/off)
65 * 5 : reserved for requesting interrupts on pin state change
66 * 6 : query buffer room or chars in tx buffer
67 * 7 : request tx unthrottle interrupt
68 *
69 * The host-side driver is set to recognize the device ID values stashed in
70 * serial EEPROM (0x06cd, 0x0103), program this firmware into place, then
71 * start it running. This firmware will use EzUSB's "renumeration" trick by
72 * simulating a bus disconnect, then reconnect with a different device ID
73 * (encoded in the desc_device descriptor below). The host driver then
74 * recognizes the new device ID and glues it to the real serial driver code.
75 *
76 * USEFUL DOCS:
77 * EzUSB Technical Reference Manual: <http://www.anchorchips.com>
78 * 8051 manuals: everywhere, but try www.dalsemi.com because the EzUSB is
79 * basically the Dallas enhanced 8051 code. Remember that the EzUSB IO ports
80 * use totally different registers!
81 * USB 1.1 spec: www.usb.org
82 *
83 * HOW TO BUILD:
84 * gcc -x assembler-with-cpp -P -E -o keyspan_pda.asm keyspan_pda.s
85 * as31 -l keyspan_pda.asm
86 * mv keyspan_pda.obj keyspan_pda.hex
87 * perl ezusb_convert.pl keyspan_pda < keyspan_pda.hex > keyspan_pda_fw.h
88 * Get as31 from <http://www.pjrc.com/tech/8051/index.html>, and hack on it
89 * a bit to make it build.
90 *
91 * THANKS:
92 * Greg Kroah-Hartman, for coordinating the whole usb-serial thing.
93 * AnchorChips, for making such an incredibly useful little microcontroller.
94 * KeySpan, for making a handy, cheap ($40) widget that was so easy to take
95 * apart and trace with an ohmmeter.
96 *
97 * TODO:
98 * lots. grep for TODO. Interrupt safety needs stress-testing. Better flow
99 * control. Interrupting host upon change in DCD, etc, counting transitions.
100 * Need to find a safe device id to use (the one used by the Keyspan firmware
101 * under Windows would be ideal.. can anyone figure out what it is?). Parity.
102 * More baud rates. Oh, and the string-descriptor-length silicon bug
103 * workaround should be implemented, but I'm lazy, and the consequence is
104 * that the device name strings that show up in your kernel log will have
105 * lots of trailing binary garbage in them (appears as ????). Device strings
106 * should be made more accurate.
107 *
108 * Questions, bugs, patches to Brian.
109 *
110 * -Brian Warner <warner@lothar.com>
111 *
112 */
114 #define HIGH(x) (((x) & 0xff00) / 256)
115 #define LOW(x) ((x) & 0xff)
117 #define dpl1 0x84
118 #define dph1 0x85
119 #define dps 0x86
121 ;;; our bit assignments
122 #define TX_RUNNING 0
123 #define DO_TX_UNTHROTTLE 1
125 ;; stack from 0x60 to 0x7f: should really set SP to 0x60-1, not 0x60
126 #define STACK #0x60-1
128 #define EXIF 0x91
129 #define EIE 0xe8
130 .flag EUSB, EIE.0
131 .flag ES0, IE.4
133 #define EP0CS #0x7fb4
134 #define EP0STALLbit #0x01
135 #define IN0BUF #0x7f00
136 #define IN0BC #0x7fb5
137 #define OUT0BUF #0x7ec0
138 #define OUT0BC #0x7fc5
139 #define IN2BUF #0x7e00
140 #define IN2BC #0x7fb9
141 #define IN2CS #0x7fb8
142 #define OUT2BC #0x7fc9
143 #define OUT2CS #0x7fc8
144 #define OUT2BUF #0x7dc0
145 #define IN4BUF #0x7d00
146 #define IN4BC #0x7fbd
147 #define IN4CS #0x7fbc
148 #define OEB #0x7f9d
149 #define OUTB #0x7f97
150 #define OEC #0x7f9e
151 #define OUTC #0x7f98
152 #define PINSC #0x7f9b
153 #define PORTBCFG #0x7f94
154 #define PORTCCFG #0x7f95
155 #define OEA #0x7f9c
156 #define IN07IRQ #0x7fa9
157 #define OUT07IRQ #0x7faa
158 #define IN07IEN #0x7fac
159 #define OUT07IEN #0x7fad
160 #define USBIRQ #0x7fab
161 #define USBIEN #0x7fae
162 #define USBBAV #0x7faf
163 #define USBCS #0x7fd6
164 #define SUDPTRH #0x7fd4
165 #define SUDPTRL #0x7fd5
166 #define SETUPDAT #0x7fe8
168 ;; usb interrupt : enable is EIE.0 (0xe8), flag is EXIF.4 (0x91)
170 .org 0
171 ljmp start
172 ;; interrupt vectors
173 .org 23H
174 ljmp serial_int
175 .byte 0
177 .org 43H
178 ljmp USB_Jump_Table
179 .byte 0 ; filled in by the USB core
181 ;;; local variables. These are not initialized properly: do it by hand.
182 .org 30H
183 rx_ring_in: .byte 0
184 rx_ring_out: .byte 0
185 tx_ring_in: .byte 0
186 tx_ring_out: .byte 0
187 tx_unthrottle_threshold: .byte 0
189 .org 0x100H ; wants to be on a page boundary
190 USB_Jump_Table:
191 ljmp ISR_Sudav ; Setup Data Available
192 .byte 0
193 ljmp 0 ; Start of Frame
194 .byte 0
195 ljmp 0 ; Setup Data Loading
196 .byte 0
197 ljmp 0 ; Global Suspend
198 .byte 0
199 ljmp 0 ; USB Reset
200 .byte 0
201 ljmp 0 ; Reserved
202 .byte 0
203 ljmp 0 ; End Point 0 In
204 .byte 0
205 ljmp 0 ; End Point 0 Out
206 .byte 0
207 ljmp 0 ; End Point 1 In
208 .byte 0
209 ljmp 0 ; End Point 1 Out
210 .byte 0
211 ljmp ISR_Ep2in
212 .byte 0
213 ljmp ISR_Ep2out
214 .byte 0
217 .org 0x200
219 start: mov SP,STACK-1 ; set stack
220 ;; clear local variables
221 clr a
222 mov tx_ring_in, a
223 mov tx_ring_out, a
224 mov rx_ring_in, a
225 mov rx_ring_out, a
226 mov tx_unthrottle_threshold, a
227 clr TX_RUNNING
228 clr DO_TX_UNTHROTTLE
230 ;; clear fifo with "fe"
231 mov r1, 0
232 mov a, #0xfe
233 mov dptr, #tx_ring
234 clear_tx_ring_loop:
235 movx @dptr, a
236 inc dptr
237 djnz r1, clear_tx_ring_loop
239 mov a, #0xfd
240 mov dptr, #rx_ring
241 clear_rx_ring_loop:
242 movx @dptr, a
243 inc dptr
244 djnz r1, clear_rx_ring_loop
246 ;;; turn on the RS-232 driver chip (bring the STANDBY pin low)
247 ;;; on Xircom the STANDBY is wired to PB6 and PC4
248 mov dptr, PORTBCFG
249 mov a, #0xBf
250 movx @dptr, a
251 mov dptr, PORTCCFG
252 mov a, #0xef
253 movx @dptr, a
255 ;; set OEC.4
256 mov a, #0x10
257 mov dptr,OEC
258 movx @dptr,a
260 ;; clear PC4
261 mov a, #0x00
262 mov dptr,OUTC
263 movx @dptr,a
265 ;; set OEB.6
266 mov a, #0x40
267 mov dptr,OEB
268 movx @dptr,a
270 ;; clear PB6
271 mov a, #0x00
272 mov dptr,OUTB
273 movx @dptr,a
275 ;; set OEC.[17]
276 mov a, #0x82
277 mov dptr,OEC
278 movx @dptr,a
281 ;; set PORTCCFG.[01] to route TxD0,RxD0 to serial port
282 mov dptr, PORTCCFG
283 mov a, #0x03
284 movx @dptr, a
286 ;; set up interrupts, autovectoring
287 ;; set BKPT
288 mov dptr, USBBAV
289 movx a,@dptr
290 setb acc.0 ; AVEN bit to 0
291 movx @dptr, a
293 mov a,#0x01 ; enable SUDAV: setup data available (for ep0)
294 mov dptr, USBIRQ
295 movx @dptr, a ; clear SUDAVI
296 mov dptr, USBIEN
297 movx @dptr, a
299 mov dptr, IN07IEN
300 mov a,#0x04 ; enable IN2 int
301 movx @dptr, a
303 mov dptr, OUT07IEN
304 mov a,#0x04 ; enable OUT2 int
305 movx @dptr, a
306 mov dptr, OUT2BC
307 movx @dptr, a ; arm OUT2
309 ;; mov a, #0x84 ; turn on RTS, DTR
310 ;; mov dptr,OUTC
311 ;; movx @dptr, a
313 mov a, #0x7 ; turn on DTR
314 mov dptr,USBBAV
315 movx @dptr, a
317 mov a, #0x20 ; turn on the RED led
318 mov dptr,OEA
319 movx @dptr, a
321 mov a, #0x80 ; turn on RTS
322 mov dptr,OUTC
323 movx @dptr, a
325 ;; setup the serial port. 9600 8N1.
326 mov a,#0x53 ; mode 1, enable rx, clear int
327 mov SCON, a
328 ;; using timer2, in 16-bit baud-rate-generator mode
329 ;; (xtal 12MHz, internal fosc 24MHz)
330 ;; RCAP2H,RCAP2L = 65536 - fosc/(32*baud)
331 ;; 57600: 0xFFF2.F, say 0xFFF3
332 ;; 9600: 0xFFB1.E, say 0xFFB2
333 ;; 300: 0xF63C
334 #define BAUD 9600
335 #define BAUD_TIMEOUT(rate) (65536 - (24 * 1000 * 1000) / (32 * rate))
336 #define BAUD_HIGH(rate) HIGH(BAUD_TIMEOUT(rate))
337 #define BAUD_LOW(rate) LOW(BAUD_TIMEOUT(rate))
339 mov T2CON, #030h ; rclk=1,tclk=1,cp=0,tr2=0(enable later)
340 mov r3, #5
341 acall set_baud
342 setb TR2
343 mov SCON, #050h
345 #if 0
346 mov r1, #0x40
347 mov a, #0x41
348 send:
349 mov SBUF, a
350 inc a
351 anl a, #0x3F
352 orl a, #0x40
353 ; xrl a, #0x02
354 wait1:
355 jnb TI, wait1
356 clr TI
357 djnz r1, send
358 ;done: sjmp done
360 #endif
362 setb EUSB
363 setb EA
364 setb ES0
365 ;acall dump_stat
367 ;; hey, what say we RENUMERATE! (TRM p.62)
368 mov a, #0
369 mov dps, a
370 mov dptr, USBCS
371 mov a, #0x02 ; DISCON=0, DISCOE=0, RENUM=1
372 movx @dptr, a
373 ;; now presence pin is floating, simulating disconnect. wait 0.5s
374 mov r1, #46
375 renum_wait1:
376 mov r2, #0
377 renum_wait2:
378 mov r3, #0
379 renum_wait3:
380 djnz r3, renum_wait3
381 djnz r2, renum_wait2
382 djnz r1, renum_wait1 ; wait about n*(256^2) 6MHz clocks
383 mov a, #0x06 ; DISCON=0, DISCOE=1, RENUM=1
384 movx @dptr, a
385 ;; we are back online. the host device will now re-query us
388 main: sjmp main
392 ISR_Sudav:
393 push dps
394 push dpl
395 push dph
396 push dpl1
397 push dph1
398 push acc
399 mov a,EXIF
400 clr acc.4
401 mov EXIF,a ; clear INT2 first
402 mov dptr, USBIRQ ; clear USB int
403 mov a,#01h
404 movx @dptr,a
406 ;; get request type
407 mov dptr, SETUPDAT
408 movx a, @dptr
409 mov r1, a ; r1 = bmRequestType
410 inc dptr
411 movx a, @dptr
412 mov r2, a ; r2 = bRequest
413 inc dptr
414 movx a, @dptr
415 mov r3, a ; r3 = wValueL
416 inc dptr
417 movx a, @dptr
418 mov r4, a ; r4 = wValueH
420 ;; main switch on bmRequest.type: standard or vendor
421 mov a, r1
422 anl a, #0x60
423 cjne a, #0x00, setup_bmreq_type_not_standard
424 ;; standard request: now main switch is on bRequest
425 ljmp setup_bmreq_is_standard
427 setup_bmreq_type_not_standard:
428 ;; a still has bmreq&0x60
429 cjne a, #0x40, setup_bmreq_type_not_vendor
430 ;; Anchor reserves bRequest 0xa0-0xaf, we use small ones
431 ;; switch on bRequest. bmRequest will always be 0x41 or 0xc1
432 cjne r2, #0x00, setup_ctrl_not_00
433 ;; 00 is set baud, wValue[0] has baud rate index
434 lcall set_baud ; index in r3, carry set if error
435 jc setup_bmreq_type_not_standard__do_stall
436 ljmp setup_done_ack
437 setup_bmreq_type_not_standard__do_stall:
438 ljmp setup_stall
439 setup_ctrl_not_00:
440 cjne r2, #0x01, setup_ctrl_not_01
441 ;; 01 is reserved for set bits (parity). TODO
442 ljmp setup_stall
443 setup_ctrl_not_01:
444 cjne r2, #0x02, setup_ctrl_not_02
445 ;; 02 is set HW flow control. TODO
446 ljmp setup_stall
447 setup_ctrl_not_02:
448 cjne r2, #0x03, setup_ctrl_not_03
449 ;; 03 is control pins (RTS, DTR).
450 ljmp control_pins ; will jump to setup_done_ack,
451 ; or setup_return_one_byte
452 setup_ctrl_not_03:
453 cjne r2, #0x04, setup_ctrl_not_04
454 ;; 04 is send break (really "turn break on/off"). TODO
455 cjne r3, #0x00, setup_ctrl_do_break_on
456 ;; do break off: restore PORTCCFG.1 to reconnect TxD0 to serial port
457 mov dptr, PORTCCFG
458 movx a, @dptr
459 orl a, #0x02
460 movx @dptr, a
461 ljmp setup_done_ack
462 setup_ctrl_do_break_on:
463 ;; do break on: clear PORTCCFG.0, set TxD high(?) (b1 low)
464 mov dptr, OUTC
465 movx a, @dptr
466 anl a, #0xfd ; ~0x02
467 movx @dptr, a
468 mov dptr, PORTCCFG
469 movx a, @dptr
470 anl a, #0xfd ; ~0x02
471 movx @dptr, a
472 ljmp setup_done_ack
473 setup_ctrl_not_04:
474 cjne r2, #0x05, setup_ctrl_not_05
475 ;; 05 is set desired interrupt bitmap. TODO
476 ljmp setup_stall
477 setup_ctrl_not_05:
478 cjne r2, #0x06, setup_ctrl_not_06
479 ;; 06 is query room
480 cjne r3, #0x00, setup_ctrl_06_not_00
481 ;; 06, wValue[0]=0 is query write_room
482 mov a, tx_ring_out
483 setb c
484 subb a, tx_ring_in ; out-1-in = 255 - (in-out)
485 ljmp setup_return_one_byte
486 setup_ctrl_06_not_00:
487 cjne r3, #0x01, setup_ctrl_06_not_01
488 ;; 06, wValue[0]=1 is query chars_in_buffer
489 mov a, tx_ring_in
490 clr c
491 subb a, tx_ring_out ; in-out
492 ljmp setup_return_one_byte
493 setup_ctrl_06_not_01:
494 ljmp setup_stall
495 setup_ctrl_not_06:
496 cjne r2, #0x07, setup_ctrl_not_07
497 ;; 07 is request tx unthrottle interrupt
498 mov tx_unthrottle_threshold, r3; wValue[0] is threshold value
499 ljmp setup_done_ack
500 setup_ctrl_not_07:
501 ljmp setup_stall
503 setup_bmreq_type_not_vendor:
504 ljmp setup_stall
507 setup_bmreq_is_standard:
508 cjne r2, #0x00, setup_breq_not_00
509 ;; 00: Get_Status (sub-switch on bmRequestType: device, ep, int)
510 cjne r1, #0x80, setup_Get_Status_not_device
511 ;; Get_Status(device)
512 ;; are we self-powered? no. can we do remote wakeup? no
513 ;; so return two zero bytes. This is reusable
514 setup_return_two_zero_bytes:
515 mov dptr, IN0BUF
516 clr a
517 movx @dptr, a
518 inc dptr
519 movx @dptr, a
520 mov dptr, IN0BC
521 mov a, #2
522 movx @dptr, a
523 ljmp setup_done_ack
524 setup_Get_Status_not_device:
525 cjne r1, #0x82, setup_Get_Status_not_endpoint
526 ;; Get_Status(endpoint)
527 ;; must get stall bit for ep[wIndexL], return two bytes, bit in lsb 0
528 ;; for now: cheat. TODO
529 sjmp setup_return_two_zero_bytes
530 setup_Get_Status_not_endpoint:
531 cjne r1, #0x81, setup_Get_Status_not_interface
532 ;; Get_Status(interface): return two zeros
533 sjmp setup_return_two_zero_bytes
534 setup_Get_Status_not_interface:
535 ljmp setup_stall
537 setup_breq_not_00:
538 cjne r2, #0x01, setup_breq_not_01
539 ;; 01: Clear_Feature (sub-switch on wValueL: stall, remote wakeup)
540 cjne r3, #0x00, setup_Clear_Feature_not_stall
541 ;; Clear_Feature(stall). should clear a stall bit. TODO
542 ljmp setup_stall
543 setup_Clear_Feature_not_stall:
544 cjne r3, #0x01, setup_Clear_Feature_not_rwake
545 ;; Clear_Feature(remote wakeup). ignored.
546 ljmp setup_done_ack
547 setup_Clear_Feature_not_rwake:
548 ljmp setup_stall
550 setup_breq_not_01:
551 cjne r2, #0x03, setup_breq_not_03
552 ;; 03: Set_Feature (sub-switch on wValueL: stall, remote wakeup)
553 cjne r3, #0x00, setup_Set_Feature_not_stall
554 ;; Set_Feature(stall). Should set a stall bit. TODO
555 ljmp setup_stall
556 setup_Set_Feature_not_stall:
557 cjne r3, #0x01, setup_Set_Feature_not_rwake
558 ;; Set_Feature(remote wakeup). ignored.
559 ljmp setup_done_ack
560 setup_Set_Feature_not_rwake:
561 ljmp setup_stall
563 setup_breq_not_03:
564 cjne r2, #0x06, setup_breq_not_06
565 ;; 06: Get_Descriptor (s-switch on wValueH: dev, config[n], string[n])
566 cjne r4, #0x01, setup_Get_Descriptor_not_device
567 ;; Get_Descriptor(device)
568 mov dptr, SUDPTRH
569 mov a, #HIGH(desc_device)
570 movx @dptr, a
571 mov dptr, SUDPTRL
572 mov a, #LOW(desc_device)
573 movx @dptr, a
574 ljmp setup_done_ack
575 setup_Get_Descriptor_not_device:
576 cjne r4, #0x02, setup_Get_Descriptor_not_config
577 ;; Get_Descriptor(config[n])
578 cjne r3, #0x00, setup_stall; only handle n==0
579 ;; Get_Descriptor(config[0])
580 mov dptr, SUDPTRH
581 mov a, #HIGH(desc_config1)
582 movx @dptr, a
583 mov dptr, SUDPTRL
584 mov a, #LOW(desc_config1)
585 movx @dptr, a
586 ljmp setup_done_ack
587 setup_Get_Descriptor_not_config:
588 cjne r4, #0x03, setup_Get_Descriptor_not_string
589 ;; Get_Descriptor(string[wValueL])
590 ;; if (wValueL >= maxstrings) stall
591 mov a, #((desc_strings_end-desc_strings)/2)
592 clr c
593 subb a,r3 ; a=4, r3 = 0..3 . if a<=0 then stall
594 jc setup_stall
595 jz setup_stall
596 mov a, r3
597 add a, r3 ; a = 2*wValueL
598 mov dptr, #desc_strings
599 add a, dpl
600 mov dpl, a
601 mov a, #0
602 addc a, dph
603 mov dph, a ; dph = desc_strings[a]. big endian! (handy)
604 ;; it looks like my adapter uses a revision of the EZUSB that
605 ;; contains "rev D errata number 8", as hinted in the EzUSB example
606 ;; code. I cannot find an actual errata description on the Cypress
607 ;; web site, but from the example code it looks like this bug causes
608 ;; the length of string descriptors to be read incorrectly, possibly
609 ;; sending back more characters than the descriptor has. The workaround
610 ;; is to manually send out all of the data. The consequence of not
611 ;; using the workaround is that the strings gathered by the kernel
612 ;; driver are too long and are filled with trailing garbage (including
613 ;; leftover strings). Writing this out by hand is a nuisance, so for
614 ;; now I will just live with the bug.
615 movx a, @dptr
616 mov r1, a
617 inc dptr
618 movx a, @dptr
619 mov r2, a
620 mov dptr, SUDPTRH
621 mov a, r1
622 movx @dptr, a
623 mov dptr, SUDPTRL
624 mov a, r2
625 movx @dptr, a
626 ;; done
627 ljmp setup_done_ack
629 setup_Get_Descriptor_not_string:
630 ljmp setup_stall
632 setup_breq_not_06:
633 cjne r2, #0x08, setup_breq_not_08
634 ;; Get_Configuration. always 1. return one byte.
635 ;; this is reusable
636 mov a, #1
637 setup_return_one_byte:
638 mov dptr, IN0BUF
639 movx @dptr, a
640 mov a, #1
641 mov dptr, IN0BC
642 movx @dptr, a
643 ljmp setup_done_ack
644 setup_breq_not_08:
645 cjne r2, #0x09, setup_breq_not_09
646 ;; 09: Set_Configuration. ignored.
647 ljmp setup_done_ack
648 setup_breq_not_09:
649 cjne r2, #0x0a, setup_breq_not_0a
650 ;; 0a: Get_Interface. get the current altsetting for int[wIndexL]
651 ;; since we only have one interface, ignore wIndexL, return a 0
652 mov a, #0
653 ljmp setup_return_one_byte
654 setup_breq_not_0a:
655 cjne r2, #0x0b, setup_breq_not_0b
656 ;; 0b: Set_Interface. set altsetting for interface[wIndexL]. ignored
657 ljmp setup_done_ack
658 setup_breq_not_0b:
659 ljmp setup_stall
662 setup_done_ack:
663 ;; now clear HSNAK
664 mov dptr, EP0CS
665 mov a, #0x02
666 movx @dptr, a
667 sjmp setup_done
668 setup_stall:
669 ;; unhandled. STALL
670 ;EP0CS |= bmEPSTALL
671 mov dptr, EP0CS
672 movx a, @dptr
673 orl a, EP0STALLbit
674 movx @dptr, a
675 sjmp setup_done
677 setup_done:
678 pop acc
679 pop dph1
680 pop dpl1
681 pop dph
682 pop dpl
683 pop dps
684 reti
686 ;;; ==============================================================
688 set_baud: ; baud index in r3
689 ;; verify a < 10
690 mov a, r3
691 jb ACC.7, set_baud__badbaud
692 clr c
693 subb a, #10
694 jnc set_baud__badbaud
695 mov a, r3
696 rl a ; a = index*2
697 add a, #LOW(baud_table)
698 mov dpl, a
699 mov a, #HIGH(baud_table)
700 addc a, #0
701 mov dph, a
702 ;; TODO: shut down xmit/receive
703 ;; TODO: wait for current xmit char to leave
704 ;; TODO: shut down timer to avoid partial-char glitch
705 movx a,@dptr ; BAUD_HIGH
706 mov RCAP2H, a
707 mov TH2, a
708 inc dptr
709 movx a,@dptr ; BAUD_LOW
710 mov RCAP2L, a
711 mov TL2, a
712 ;; TODO: restart xmit/receive
713 ;; TODO: reenable interrupts, resume tx if pending
714 clr c ; c=0: success
715 ret
716 set_baud__badbaud:
717 setb c ; c=1: failure
718 ret
720 ;;; ==================================================
721 control_pins:
722 cjne r1, #0x41, control_pins_in
723 control_pins_out:
724 ;TODO BKPT is DTR
725 mov a, r3 ; wValue[0] holds new bits: b7 is new RTS
726 xrl a, #0xff ; 1 means active, 0V, +12V ?
727 anl a, #0x80
728 mov r3, a
729 mov dptr, OUTC
730 movx a, @dptr ; only change bit 7
731 anl a, #0x7F ; ~0x84
732 orl a, r3
733 movx @dptr, a ; other pins are inputs, bits ignored
734 ljmp setup_done_ack
735 control_pins_in:
736 mov dptr, PINSC
737 movx a, @dptr
738 xrl a, #0xff
739 ljmp setup_return_one_byte
741 ;;; ========================================
743 ISR_Ep2in:
744 push dps
745 push dpl
746 push dph
747 push dpl1
748 push dph1
749 push acc
750 mov a,EXIF
751 clr acc.4
752 mov EXIF,a ; clear INT2 first
753 mov dptr, IN07IRQ ; clear USB int
754 mov a,#04h
755 movx @dptr,a
757 mov a, #0x20 ; Turn off the green LED
758 mov dptr,OEA
759 movx @dptr, a
762 ;; do stuff
763 lcall start_in
765 mov a, #0x20 ; Turn off the green LED
766 mov dptr,OEA
767 movx @dptr, a
771 pop acc
772 pop dph1
773 pop dpl1
774 pop dph
775 pop dpl
776 pop dps
777 reti
779 ISR_Ep2out:
780 push dps
781 push dpl
782 push dph
783 push dpl1
784 push dph1
785 push acc
787 mov a, #0x10 ; Turn the green LED
788 mov dptr,OEA
789 movx @dptr, a
793 mov a,EXIF
794 clr acc.4
795 mov EXIF,a ; clear INT2 first
796 mov dptr, OUT07IRQ ; clear USB int
797 mov a,#04h
798 movx @dptr,a
800 ;; do stuff
802 ;; copy data into buffer. for now, assume we will have enough space
803 mov dptr, OUT2BC ; get byte count
804 movx a,@dptr
805 mov r1, a
806 clr a
807 mov dps, a
808 mov dptr, OUT2BUF ; load DPTR0 with source
809 mov dph1, #HIGH(tx_ring) ; load DPTR1 with target
810 mov dpl1, tx_ring_in
811 OUT_loop:
812 movx a,@dptr ; read
813 inc dps ; switch to DPTR1: target
814 inc dpl1 ; target = tx_ring_in+1
815 movx @dptr,a ; store
816 mov a,dpl1
817 cjne a, tx_ring_out, OUT_no_overflow
818 sjmp OUT_overflow
819 OUT_no_overflow:
820 inc tx_ring_in ; tx_ring_in++
821 inc dps ; switch to DPTR0: source
822 inc dptr
823 djnz r1, OUT_loop
824 sjmp OUT_done
825 OUT_overflow:
826 ;; signal overflow
827 ;; fall through
828 OUT_done:
829 ;; ack
830 mov dptr,OUT2BC
831 movx @dptr,a
833 ;; start tx
834 acall maybe_start_tx
835 ;acall dump_stat
837 mov a, #0x20 ; Turn off the green LED
838 mov dptr,OEA
839 movx @dptr, a
841 pop acc
842 pop dph1
843 pop dpl1
844 pop dph
845 pop dpl
846 pop dps
847 reti
849 dump_stat:
850 ;; fill in EP4in with a debugging message:
851 ;; tx_ring_in, tx_ring_out, rx_ring_in, rx_ring_out
852 ;; tx_active
853 ;; tx_ring[0..15]
854 ;; 0xfc
855 ;; rx_ring[0..15]
856 clr a
857 mov dps, a
859 mov dptr, IN4CS
860 movx a, @dptr
861 jb acc.1, dump_stat__done; busy: cannot dump, old one still pending
862 mov dptr, IN4BUF
864 mov a, tx_ring_in
865 movx @dptr, a
866 inc dptr
867 mov a, tx_ring_out
868 movx @dptr, a
869 inc dptr
871 mov a, rx_ring_in
872 movx @dptr, a
873 inc dptr
874 mov a, rx_ring_out
875 movx @dptr, a
876 inc dptr
878 clr a
879 jnb TX_RUNNING, dump_stat__no_tx_running
880 inc a
881 dump_stat__no_tx_running:
882 movx @dptr, a
883 inc dptr
884 ;; tx_ring[0..15]
885 inc dps
886 mov dptr, #tx_ring ; DPTR1: source
887 mov r1, #16
888 dump_stat__tx_ring_loop:
889 movx a, @dptr
890 inc dptr
891 inc dps
892 movx @dptr, a
893 inc dptr
894 inc dps
895 djnz r1, dump_stat__tx_ring_loop
896 inc dps
898 mov a, #0xfc
899 movx @dptr, a
900 inc dptr
902 ;; rx_ring[0..15]
903 inc dps
904 mov dptr, #rx_ring ; DPTR1: source
905 mov r1, #16
906 dump_stat__rx_ring_loop:
907 movx a, @dptr
908 inc dptr
909 inc dps
910 movx @dptr, a
911 inc dptr
912 inc dps
913 djnz r1, dump_stat__rx_ring_loop
915 ;; now send it
916 clr a
917 mov dps, a
918 mov dptr, IN4BC
919 mov a, #38
920 movx @dptr, a
921 dump_stat__done:
922 ret
924 ;;; ============================================================
926 maybe_start_tx:
927 ;; make sure the tx process is running.
928 jb TX_RUNNING, start_tx_done
929 start_tx:
930 ;; is there work to be done?
931 mov a, tx_ring_in
932 cjne a,tx_ring_out, start_tx__work
933 ret ; no work
934 start_tx__work:
935 ;; tx was not running. send the first character, setup the TI int
936 inc tx_ring_out ; [++tx_ring_out]
937 mov dph, #HIGH(tx_ring)
938 mov dpl, tx_ring_out
939 movx a, @dptr
940 mov sbuf, a
941 setb TX_RUNNING
942 start_tx_done:
943 ;; can we unthrottle the host tx process?
944 ;; step 1: do we care?
945 mov a, #0
946 cjne a, tx_unthrottle_threshold, start_tx__maybe_unthrottle_tx
947 ;; nope
948 start_tx_really_done:
949 ret
950 start_tx__maybe_unthrottle_tx:
951 ;; step 2: is there now room?
952 mov a, tx_ring_out
953 setb c
954 subb a, tx_ring_in
955 ;; a is now write_room. If thresh >= a, we can unthrottle
956 clr c
957 subb a, tx_unthrottle_threshold
958 jc start_tx_really_done ; nope
959 ;; yes, we can unthrottle. remove the threshold and mark a request
960 mov tx_unthrottle_threshold, #0
961 setb DO_TX_UNTHROTTLE
962 ;; prod rx, which will actually send the message when in2 becomes free
963 ljmp start_in
966 serial_int:
967 push dps
968 push dpl
969 push dph
970 push dpl1
971 push dph1
972 push acc
973 jnb TI, serial_int__not_tx
974 ;; tx finished. send another character if we have one
975 clr TI ; clear int
976 clr TX_RUNNING
977 lcall start_tx
978 serial_int__not_tx:
979 jnb RI, serial_int__not_rx
980 lcall get_rx_char
981 clr RI ; clear int
982 serial_int__not_rx:
983 ;; return
984 pop acc
985 pop dph1
986 pop dpl1
987 pop dph
988 pop dpl
989 pop dps
990 reti
992 get_rx_char:
993 mov dph, #HIGH(rx_ring)
994 mov dpl, rx_ring_in
995 inc dpl ; target = rx_ring_in+1
996 mov a, sbuf
997 movx @dptr, a
998 ;; check for overflow before incrementing rx_ring_in
999 mov a, dpl
1000 cjne a, rx_ring_out, get_rx_char__no_overflow
1001 ;; signal overflow
1002 ret
1003 get_rx_char__no_overflow:
1004 inc rx_ring_in
1005 ;; kick off USB INpipe
1006 acall start_in
1007 ret
1009 start_in:
1010 ;; check if the inpipe is already running.
1011 mov a,#0x10
1012 mov dptr, OEA
1013 movx @dptr,a
1015 mov dptr, IN2CS
1016 movx a, @dptr
1017 jb acc.1, start_in__done; int will handle it
1018 jb DO_TX_UNTHROTTLE, start_in__do_tx_unthrottle
1019 ;; see if there is any work to do. a serial interrupt might occur
1020 ;; during this sequence?
1021 mov a, rx_ring_in
1022 cjne a, rx_ring_out, start_in__have_work
1023 ret ; nope
1024 start_in__have_work:
1025 ;; now copy as much data as possible into the pipe. 63 bytes max.
1026 clr a
1027 mov dps, a
1028 mov dph, #HIGH(rx_ring) ; load DPTR0 with source
1029 inc dps
1030 mov dptr, IN2BUF ; load DPTR1 with target
1031 movx @dptr, a ; in[0] signals that rest of IN is rx data
1032 inc dptr
1033 inc dps
1034 ;; loop until we run out of data, or we have copied 64 bytes
1035 mov r1, #1 ; INbuf size counter
1036 start_in__loop:
1037 mov a, rx_ring_in
1038 cjne a, rx_ring_out, start_inlocal_irq_enablell_copying
1039 sjmp start_in__kick
1040 start_inlocal_irq_enablell_copying:
1041 inc rx_ring_out
1042 mov dpl, rx_ring_out
1043 movx a, @dptr
1044 inc dps
1045 movx @dptr, a ; write into IN buffer
1046 inc dptr
1047 inc dps
1048 inc r1
1049 cjne r1, #64, start_in__loop; loop
1050 start_in__kick:
1051 ;; either we ran out of data, or we copied 64 bytes. r1 has byte count
1052 ;; kick off IN
1053 mov a, #0x10 ; Turn the green LED
1054 mov dptr,OEA
1055 movx @dptr, a
1056 mov dptr, IN2BC
1057 mov a, r1
1058 jz start_in__done
1059 movx @dptr, a
1060 ;; done
1061 start_in__done:
1062 ;acall dump_stat
1063 ret
1064 start_in__do_tx_unthrottle:
1065 ;; special sequence: send a tx unthrottle message
1066 clr DO_TX_UNTHROTTLE
1067 clr a
1068 mov dps, a
1069 mov dptr, IN2BUF
1070 mov a, #1
1071 movx @dptr, a
1072 inc dptr
1073 mov a, #2
1074 movx @dptr, a
1075 mov dptr, IN2BC
1076 movx @dptr, a
1077 ret
1079 putchar:
1080 clr TI
1081 mov SBUF, a
1082 putchar_wait:
1083 jnb TI, putchar_wait
1084 clr TI
1085 ret
1088 baud_table: ; baud_high, then baud_low
1089 ;; baud[0]: 110
1090 .byte BAUD_HIGH(110)
1091 .byte BAUD_LOW(110)
1092 ;; baud[1]: 300
1093 .byte BAUD_HIGH(300)
1094 .byte BAUD_LOW(300)
1095 ;; baud[2]: 1200
1096 .byte BAUD_HIGH(1200)
1097 .byte BAUD_LOW(1200)
1098 ;; baud[3]: 2400
1099 .byte BAUD_HIGH(2400)
1100 .byte BAUD_LOW(2400)
1101 ;; baud[4]: 4800
1102 .byte BAUD_HIGH(4800)
1103 .byte BAUD_LOW(4800)
1104 ;; baud[5]: 9600
1105 .byte BAUD_HIGH(9600)
1106 .byte BAUD_LOW(9600)
1107 ;; baud[6]: 19200
1108 .byte BAUD_HIGH(19200)
1109 .byte BAUD_LOW(19200)
1110 ;; baud[7]: 38400
1111 .byte BAUD_HIGH(38400)
1112 .byte BAUD_LOW(38400)
1113 ;; baud[8]: 57600
1114 .byte BAUD_HIGH(57600)
1115 .byte BAUD_LOW(57600)
1116 ;; baud[9]: 115200
1117 .byte BAUD_HIGH(115200)
1118 .byte BAUD_LOW(115200)
1120 desc_device:
1121 .byte 0x12, 0x01, 0x00, 0x01, 0xff, 0xff, 0xff, 0x40
1122 .byte 0xcd, 0x06, 0x04, 0x01, 0x89, 0xab, 1, 2, 3, 0x01
1123 ;;; The "real" device id, which must match the host driver, is that
1124 ;;; "0xcd 0x06 0x04 0x01" sequence, which is 0x06cd, 0x0104
1126 desc_config1:
1127 .byte 0x09, 0x02, 0x20, 0x00, 0x01, 0x01, 0x00, 0x80, 0x32
1128 .byte 0x09, 0x04, 0x00, 0x00, 0x02, 0xff, 0xff, 0xff, 0x00
1129 .byte 0x07, 0x05, 0x82, 0x03, 0x40, 0x00, 0x01
1130 .byte 0x07, 0x05, 0x02, 0x02, 0x40, 0x00, 0x00
1132 desc_strings:
1133 .word string_langids, string_mfg, string_product, string_serial
1134 desc_strings_end:
1136 string_langids: .byte string_langids_end-string_langids
1137 .byte 3
1138 .word 0
1139 string_langids_end:
1141 ;; sigh. These strings are Unicode, meaning UTF16? 2 bytes each. Now
1142 ;; *that* is a pain in the ass to encode. And they are little-endian
1143 ;; too. Use this perl snippet to get the bytecodes:
1144 /* while (<>) {
1145 @c = split(//);
1146 foreach $c (@c) {
1147 printf("0x%02x, 0x00, ", ord($c));
1148 }
1149 }
1150 */
1152 string_mfg: .byte string_mfg_end-string_mfg
1153 .byte 3
1154 ; .byte "ACME usb widgets"
1155 .byte 0x41, 0x00, 0x43, 0x00, 0x4d, 0x00, 0x45, 0x00, 0x20, 0x00, 0x75, 0x00, 0x73, 0x00, 0x62, 0x00, 0x20, 0x00, 0x77, 0x00, 0x69, 0x00, 0x64, 0x00, 0x67, 0x00, 0x65, 0x00, 0x74, 0x00, 0x73, 0x00
1156 string_mfg_end:
1158 string_product: .byte string_product_end-string_product
1159 .byte 3
1160 ; .byte "ACME USB serial widget"
1161 .byte 0x41, 0x00, 0x43, 0x00, 0x4d, 0x00, 0x45, 0x00, 0x20, 0x00, 0x55, 0x00, 0x53, 0x00, 0x42, 0x00, 0x20, 0x00, 0x73, 0x00, 0x65, 0x00, 0x72, 0x00, 0x69, 0x00, 0x61, 0x00, 0x6c, 0x00, 0x20, 0x00, 0x77, 0x00, 0x69, 0x00, 0x64, 0x00, 0x67, 0x00, 0x65, 0x00, 0x74, 0x00
1162 string_product_end:
1164 string_serial: .byte string_serial_end-string_serial
1165 .byte 3
1166 ; .byte "47"
1167 .byte 0x34, 0x00, 0x37, 0x00
1168 string_serial_end:
1170 ;;; ring buffer memory
1171 ;; tx_ring_in+1 is where the next input byte will go
1172 ;; [tx_ring_out] has been sent
1173 ;; if tx_ring_in == tx_ring_out, theres no work to do
1174 ;; there are (tx_ring_in - tx_ring_out) chars to be written
1175 ;; dont let _in lap _out
1176 ;; cannot inc if tx_ring_in+1 == tx_ring_out
1177 ;; write [tx_ring_in+1] then tx_ring_in++
1178 ;; if (tx_ring_in+1 == tx_ring_out), overflow
1179 ;; else tx_ring_in++
1180 ;; read/send [tx_ring_out+1], then tx_ring_out++
1182 ;; rx_ring_in works the same way
1184 .org 0x1000
1185 tx_ring:
1186 .skip 0x100 ; 256 bytes
1187 rx_ring:
1188 .skip 0x100 ; 256 bytes
1191 .END