adb.c revision 1.1 1 1.1 briggs /* $NetBSD: adb.c,v 1.1 1994/12/03 23:34:12 briggs Exp $ */
2 1.1 briggs
3 1.1 briggs /*-
4 1.1 briggs * Copyright (C) 1994 Bradley A. Grantham
5 1.1 briggs * All rights reserved.
6 1.1 briggs *
7 1.1 briggs * Redistribution and use in source and binary forms, with or without
8 1.1 briggs * modification, are permitted provided that the following conditions
9 1.1 briggs * are met:
10 1.1 briggs * 1. Redistributions of source code must retain the above copyright
11 1.1 briggs * notice, this list of conditions and the following disclaimer.
12 1.1 briggs * 2. Redistributions in binary form must reproduce the above copyright
13 1.1 briggs * notice, this list of conditions and the following disclaimer in the
14 1.1 briggs * documentation and/or other materials provided with the distribution.
15 1.1 briggs * 3. All advertising materials mentioning features or use of this software
16 1.1 briggs * must display the following acknowledgement:
17 1.1 briggs * This product includes software developed by Bradley A. Grantham.
18 1.1 briggs * 4. The name of the author may not be used to endorse or promote products
19 1.1 briggs * derived from this software without specific prior written permission.
20 1.1 briggs *
21 1.1 briggs * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 1.1 briggs * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 1.1 briggs * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 1.1 briggs * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 1.1 briggs * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 1.1 briggs * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 1.1 briggs * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 1.1 briggs * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 1.1 briggs * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30 1.1 briggs * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 1.1 briggs */
32 1.1 briggs
33 1.1 briggs #include <sys/types.h>
34 1.1 briggs #include <sys/param.h>
35 1.1 briggs #include <machine/param.h>
36 1.1 briggs #include <sys/device.h>
37 1.1 briggs #include <sys/fcntl.h>
38 1.1 briggs #include <sys/select.h>
39 1.1 briggs #include <sys/proc.h>
40 1.1 briggs #include <sys/systm.h>
41 1.1 briggs #include <machine/adbsys.h>
42 1.1 briggs #include "adbvar.h"
43 1.1 briggs #include <machine/keyboard.h>
44 1.1 briggs #include "../mac68k/macrom.h"
45 1.1 briggs
46 1.1 briggs /*
47 1.1 briggs * External keyboard translation matrix
48 1.1 briggs */
49 1.1 briggs extern unsigned char keyboard[128][3];
50 1.1 briggs
51 1.1 briggs
52 1.1 briggs /*
53 1.1 briggs * Event queue definitions
54 1.1 briggs */
55 1.1 briggs #if !defined(ADB_MAX_EVENTS)
56 1.1 briggs #define ADB_MAX_EVENTS 200 /* Maximum events to be kept in queue */
57 1.1 briggs #endif /* !defined(ADB_MAX_EVENTS) */
58 1.1 briggs /* maybe should be higher for slower macs? */
59 1.1 briggs
60 1.1 briggs static adb_event_t adb_evq[ADB_MAX_EVENTS]; /* ADB event queue */
61 1.1 briggs static int adb_evq_tail = 0; /* event queue tail */
62 1.1 briggs static int adb_evq_len = 0; /* event queue length */
63 1.1 briggs
64 1.1 briggs
65 1.1 briggs /*
66 1.1 briggs * ADB device state information
67 1.1 briggs */
68 1.1 briggs static int adb_isopen = 0; /* Are we queuing events for adb_read? */
69 1.1 briggs int adb_polling = 0; /* Are we polling? (Debugger mode) */
70 1.1 briggs static struct selinfo adb_selinfo; /* select() info */
71 1.1 briggs static struct proc *adb_ioproc = NULL; /* process to wakeup */
72 1.1 briggs
73 1.1 briggs
74 1.1 briggs /*
75 1.1 briggs * Key repeat parameters
76 1.1 briggs */
77 1.1 briggs static int adb_rptdelay = 20; /* ticks before auto-repeat */
78 1.1 briggs static int adb_rptinterval = 6; /* ticks between auto-repeat */
79 1.1 briggs static int adb_repeating = -1; /* key that is auto-repeating */
80 1.1 briggs static adb_event_t adb_rptevent; /* event to auto-repeat */
81 1.1 briggs
82 1.1 briggs
83 1.1 briggs static void
84 1.1 briggs adbattach(parent, dev, aux)
85 1.1 briggs struct device *parent, *dev;
86 1.1 briggs void *aux;
87 1.1 briggs {
88 1.1 briggs printf(" (ADB event device)\n");
89 1.1 briggs }
90 1.1 briggs
91 1.1 briggs
92 1.1 briggs /*
93 1.1 briggs * Auto-configure parameters
94 1.1 briggs */
95 1.1 briggs extern int matchbyname();
96 1.1 briggs
97 1.1 briggs struct cfdriver adbcd =
98 1.1 briggs { NULL,
99 1.1 briggs "adb",
100 1.1 briggs matchbyname,
101 1.1 briggs adbattach,
102 1.1 briggs DV_DULL,
103 1.1 briggs sizeof(struct device),
104 1.1 briggs NULL,
105 1.1 briggs 0 };
106 1.1 briggs
107 1.1 briggs
108 1.1 briggs void adb_enqevent(
109 1.1 briggs adb_event_t *event)
110 1.1 briggs {
111 1.1 briggs int s;
112 1.1 briggs
113 1.1 briggs if(adb_evq_tail < 0 || adb_evq_tail >= ADB_MAX_EVENTS)
114 1.1 briggs panic("adb: event queue tail is out of bounds");
115 1.1 briggs
116 1.1 briggs if(adb_evq_len < 0 || adb_evq_len > ADB_MAX_EVENTS)
117 1.1 briggs panic("adb: event queue len is out of bounds");
118 1.1 briggs
119 1.1 briggs s = splhigh();
120 1.1 briggs
121 1.1 briggs if(adb_evq_len == ADB_MAX_EVENTS){
122 1.1 briggs splx(s);
123 1.1 briggs return; /* Oh, well... */
124 1.1 briggs }
125 1.1 briggs
126 1.1 briggs adb_evq[(adb_evq_len + adb_evq_tail) % ADB_MAX_EVENTS] =
127 1.1 briggs *event;
128 1.1 briggs adb_evq_len++;
129 1.1 briggs
130 1.1 briggs selwakeup(&adb_selinfo);
131 1.1 briggs if(adb_ioproc)
132 1.1 briggs psignal(adb_ioproc, SIGIO);
133 1.1 briggs
134 1.1 briggs splx(s);
135 1.1 briggs }
136 1.1 briggs
137 1.1 briggs void adb_handoff(
138 1.1 briggs adb_event_t *event)
139 1.1 briggs {
140 1.1 briggs if(adb_isopen && !adb_polling){
141 1.1 briggs adb_enqevent(event);
142 1.1 briggs }else{
143 1.1 briggs if(event->def_addr == 2)
144 1.1 briggs ite_intr(event);
145 1.1 briggs }
146 1.1 briggs }
147 1.1 briggs
148 1.1 briggs
149 1.1 briggs void adb_autorepeat(
150 1.1 briggs void *keyp)
151 1.1 briggs {
152 1.1 briggs int key = (int)keyp;
153 1.1 briggs
154 1.1 briggs adb_rptevent.bytes[0] |= 0x80;
155 1.1 briggs microtime(&adb_rptevent.timestamp);
156 1.1 briggs adb_handoff(&adb_rptevent); /* do key up */
157 1.1 briggs
158 1.1 briggs adb_rptevent.bytes[0] &= 0x7f;
159 1.1 briggs microtime(&adb_rptevent.timestamp);
160 1.1 briggs adb_handoff(&adb_rptevent); /* do key down */
161 1.1 briggs
162 1.1 briggs if(adb_repeating == key){
163 1.1 briggs timeout(adb_autorepeat, keyp, adb_rptinterval);
164 1.1 briggs }
165 1.1 briggs }
166 1.1 briggs
167 1.1 briggs
168 1.1 briggs void adb_dokeyupdown(
169 1.1 briggs adb_event_t *event)
170 1.1 briggs {
171 1.1 briggs int adb_key;
172 1.1 briggs
173 1.1 briggs if(event->def_addr == 2){
174 1.1 briggs adb_key = event->u.k.key & 0x7f;
175 1.1 briggs if(!(event->u.k.key & 0x80) &&
176 1.1 briggs keyboard[event->u.k.key & 0x7f][0] != 0)
177 1.1 briggs {
178 1.1 briggs /* ignore shift & control */
179 1.1 briggs if(adb_repeating != -1){
180 1.1 briggs untimeout(adb_autorepeat,
181 1.1 briggs (void *)adb_rptevent.u.k.key);
182 1.1 briggs }
183 1.1 briggs adb_rptevent = *event;
184 1.1 briggs adb_repeating = adb_key;
185 1.1 briggs timeout(adb_autorepeat,
186 1.1 briggs (void *)adb_key, adb_rptdelay);
187 1.1 briggs }else{
188 1.1 briggs if(adb_repeating != -1){
189 1.1 briggs adb_repeating = -1;
190 1.1 briggs untimeout(adb_autorepeat,
191 1.1 briggs (void *)adb_rptevent.u.k.key);
192 1.1 briggs }
193 1.1 briggs adb_rptevent = *event;
194 1.1 briggs }
195 1.1 briggs }
196 1.1 briggs adb_handoff(event);
197 1.1 briggs }
198 1.1 briggs
199 1.1 briggs static adb_ms_buttons = 0;
200 1.1 briggs
201 1.1 briggs void adb_keymaybemouse(
202 1.1 briggs adb_event_t *event)
203 1.1 briggs {
204 1.1 briggs adb_event_t new_event;
205 1.1 briggs static optionkey_down = 0;
206 1.1 briggs
207 1.1 briggs if(event->u.k.key == ADBK_KEYDOWN(ADBK_OPTION)){
208 1.1 briggs optionkey_down = 1;
209 1.1 briggs }else if(event->u.k.key == ADBK_KEYUP(ADBK_OPTION)){ /* keyup */
210 1.1 briggs optionkey_down = 0;
211 1.1 briggs if(adb_ms_buttons & 0xfe){
212 1.1 briggs adb_ms_buttons &= 1;
213 1.1 briggs new_event.def_addr = ADBADDR_MS;
214 1.1 briggs new_event.u.m.buttons = adb_ms_buttons;
215 1.1 briggs new_event.u.m.dx = new_event.u.m.dy = 0;
216 1.1 briggs microtime(&new_event.timestamp);
217 1.1 briggs adb_dokeyupdown(&new_event);
218 1.1 briggs }
219 1.1 briggs }else if(optionkey_down){
220 1.1 briggs if(event->u.k.key == ADBK_KEYDOWN(ADBK_LEFT)){
221 1.1 briggs adb_ms_buttons |= 2; /* middle down */
222 1.1 briggs new_event.def_addr = ADBADDR_MS;
223 1.1 briggs new_event.u.m.buttons = adb_ms_buttons;
224 1.1 briggs new_event.u.m.dx = new_event.u.m.dy = 0;
225 1.1 briggs microtime(&new_event.timestamp);
226 1.1 briggs adb_dokeyupdown(&new_event);
227 1.1 briggs }else if(event->u.k.key == ADBK_KEYUP(ADBK_LEFT)){
228 1.1 briggs adb_ms_buttons &= ~2; /* middle up */
229 1.1 briggs new_event.def_addr = ADBADDR_MS;
230 1.1 briggs new_event.u.m.buttons = adb_ms_buttons;
231 1.1 briggs new_event.u.m.dx = new_event.u.m.dy = 0;
232 1.1 briggs microtime(&new_event.timestamp);
233 1.1 briggs adb_dokeyupdown(&new_event);
234 1.1 briggs }else if(event->u.k.key == ADBK_KEYDOWN(ADBK_RIGHT)){
235 1.1 briggs adb_ms_buttons |= 4; /* right down */
236 1.1 briggs new_event.def_addr = ADBADDR_MS;
237 1.1 briggs new_event.u.m.buttons = adb_ms_buttons;
238 1.1 briggs new_event.u.m.dx = new_event.u.m.dy = 0;
239 1.1 briggs microtime(&new_event.timestamp);
240 1.1 briggs adb_dokeyupdown(&new_event);
241 1.1 briggs }else if(event->u.k.key == ADBK_KEYUP(ADBK_RIGHT)){
242 1.1 briggs adb_ms_buttons &= ~4; /* right up */
243 1.1 briggs new_event.def_addr = ADBADDR_MS;
244 1.1 briggs new_event.u.m.buttons = adb_ms_buttons;
245 1.1 briggs new_event.u.m.dx = new_event.u.m.dy = 0;
246 1.1 briggs microtime(&new_event.timestamp);
247 1.1 briggs adb_dokeyupdown(&new_event);
248 1.1 briggs }else if(ADBK_MODIFIER(event->u.k.key)){ /* ctrl, shift, cmd */
249 1.1 briggs adb_dokeyupdown(event);
250 1.1 briggs }else if(event->u.k.key & 0x80){ /* key down */
251 1.1 briggs new_event = *event;
252 1.1 briggs
253 1.1 briggs new_event.u.k.key = ADBK_KEYDOWN(ADBK_OPTION); /* send option-down */
254 1.1 briggs new_event.bytes[0] = new_event.u.k.key;
255 1.1 briggs microtime(&new_event.timestamp);
256 1.1 briggs adb_dokeyupdown(&new_event);
257 1.1 briggs
258 1.1 briggs new_event.u.k.key = event->bytes[0]; /* send key-down */
259 1.1 briggs new_event.bytes[0] = new_event.u.k.key;
260 1.1 briggs microtime(&new_event.timestamp);
261 1.1 briggs adb_dokeyupdown(&new_event);
262 1.1 briggs
263 1.1 briggs new_event.u.k.key = ADBK_KEYVAL(event->bytes[0]); /* send key-up */
264 1.1 briggs adb_dokeyupdown(&new_event);
265 1.1 briggs microtime(&new_event.timestamp);
266 1.1 briggs new_event.bytes[0] = new_event.u.k.key;
267 1.1 briggs
268 1.1 briggs new_event.u.k.key = ADBK_OPTION; /* send option-up */
269 1.1 briggs new_event.bytes[0] = new_event.u.k.key;
270 1.1 briggs microtime(&new_event.timestamp);
271 1.1 briggs adb_dokeyupdown(&new_event);
272 1.1 briggs
273 1.1 briggs }else{
274 1.1 briggs /* option-keyup -- do nothing */
275 1.1 briggs }
276 1.1 briggs }else{
277 1.1 briggs adb_dokeyupdown(event);
278 1.1 briggs }
279 1.1 briggs }
280 1.1 briggs
281 1.1 briggs
282 1.1 briggs void adb_processevent(
283 1.1 briggs adb_event_t *event)
284 1.1 briggs {
285 1.1 briggs adb_event_t new_event;
286 1.1 briggs
287 1.1 briggs new_event = *event;
288 1.1 briggs
289 1.1 briggs switch(event->def_addr){
290 1.1 briggs case ADBADDR_KBD:
291 1.1 briggs new_event.u.k.key = event->bytes[0];
292 1.1 briggs new_event.bytes[1] = 0xff;
293 1.1 briggs adb_keymaybemouse(&new_event);
294 1.1 briggs if(event->bytes[1] != 0xff){
295 1.1 briggs new_event.u.k.key = event->bytes[1];
296 1.1 briggs new_event.bytes[0] = event->bytes[1];
297 1.1 briggs new_event.bytes[1] = 0xff;
298 1.1 briggs adb_keymaybemouse(&new_event);
299 1.1 briggs }
300 1.1 briggs break;
301 1.1 briggs
302 1.1 briggs case ADBADDR_MS:
303 1.1 briggs if(! (event->bytes[0] & 0x80)) /* 0 is button down */
304 1.1 briggs adb_ms_buttons |= 1;
305 1.1 briggs else
306 1.1 briggs adb_ms_buttons &= 0xfe;
307 1.1 briggs new_event.u.m.buttons = adb_ms_buttons;
308 1.1 briggs new_event.u.m.dx = ((signed int)(event->bytes[1] &
309 1.1 briggs 0x3f)) - ((event->bytes[1] &
310 1.1 briggs 0x40) ? 64 : 0);
311 1.1 briggs new_event.u.m.dy = ((signed int)(event->bytes[0] &
312 1.1 briggs 0x3f)) - ((event->bytes[0] &
313 1.1 briggs 0x40) ? 64 : 0);
314 1.1 briggs adb_dokeyupdown(&new_event);
315 1.1 briggs break;
316 1.1 briggs
317 1.1 briggs default: /* God only knows. */
318 1.1 briggs adb_dokeyupdown(event);
319 1.1 briggs }
320 1.1 briggs
321 1.1 briggs }
322 1.1 briggs
323 1.1 briggs
324 1.1 briggs int adbopen(
325 1.1 briggs dev_t dev,
326 1.1 briggs int flag,
327 1.1 briggs int mode,
328 1.1 briggs struct proc *p)
329 1.1 briggs {
330 1.1 briggs register int unit;
331 1.1 briggs int error = 0;
332 1.1 briggs int s;
333 1.1 briggs
334 1.1 briggs unit = minor(dev);
335 1.1 briggs if(unit != 0)
336 1.1 briggs return(ENXIO);
337 1.1 briggs
338 1.1 briggs s = splhigh();
339 1.1 briggs if (adb_isopen)
340 1.1 briggs {
341 1.1 briggs splx(s);
342 1.1 briggs return(EBUSY);
343 1.1 briggs }
344 1.1 briggs splx(s);
345 1.1 briggs adb_evq_tail = 0;
346 1.1 briggs adb_evq_len = 0;
347 1.1 briggs adb_isopen = 1;
348 1.1 briggs adb_ioproc = p;
349 1.1 briggs
350 1.1 briggs return (error);
351 1.1 briggs }
352 1.1 briggs
353 1.1 briggs
354 1.1 briggs int adbclose(
355 1.1 briggs dev_t dev,
356 1.1 briggs int flag,
357 1.1 briggs int mode,
358 1.1 briggs struct proc *p)
359 1.1 briggs {
360 1.1 briggs adb_isopen = 0;
361 1.1 briggs adb_ioproc = NULL;
362 1.1 briggs return (0);
363 1.1 briggs }
364 1.1 briggs
365 1.1 briggs
366 1.1 briggs int adbread(
367 1.1 briggs dev_t dev,
368 1.1 briggs struct uio *uio,
369 1.1 briggs int flag)
370 1.1 briggs {
371 1.1 briggs int s, error;
372 1.1 briggs int willfit;
373 1.1 briggs int total;
374 1.1 briggs int firstmove;
375 1.1 briggs int moremove;
376 1.1 briggs
377 1.1 briggs if (uio->uio_resid < sizeof(adb_event_t))
378 1.1 briggs return (EMSGSIZE); /* close enough. */
379 1.1 briggs
380 1.1 briggs s = splhigh();
381 1.1 briggs if(adb_evq_len == 0){
382 1.1 briggs splx(s);
383 1.1 briggs return(0);
384 1.1 briggs }
385 1.1 briggs
386 1.1 briggs willfit = howmany(uio->uio_resid, sizeof(adb_event_t));
387 1.1 briggs total = (adb_evq_len < willfit) ? adb_evq_len : willfit;
388 1.1 briggs
389 1.1 briggs firstmove = (adb_evq_tail + total > ADB_MAX_EVENTS)
390 1.1 briggs ? (ADB_MAX_EVENTS - adb_evq_tail) : total;
391 1.1 briggs
392 1.1 briggs error = uiomove((caddr_t)&adb_evq[adb_evq_tail],
393 1.1 briggs firstmove * sizeof(adb_event_t), uio);
394 1.1 briggs if(error) {
395 1.1 briggs splx(s);
396 1.1 briggs return(error);
397 1.1 briggs }
398 1.1 briggs moremove = total - firstmove;
399 1.1 briggs
400 1.1 briggs if (moremove > 0){
401 1.1 briggs error = uiomove((caddr_t)&adb_evq[0],
402 1.1 briggs moremove * sizeof(adb_event_t), uio);
403 1.1 briggs if(error) {
404 1.1 briggs splx(s);
405 1.1 briggs return(error);
406 1.1 briggs }
407 1.1 briggs }
408 1.1 briggs
409 1.1 briggs adb_evq_tail = (adb_evq_tail + total) % ADB_MAX_EVENTS;
410 1.1 briggs adb_evq_len -= total;
411 1.1 briggs splx(s);
412 1.1 briggs return (0);
413 1.1 briggs }
414 1.1 briggs
415 1.1 briggs
416 1.1 briggs int adbwrite(
417 1.1 briggs dev_t dev,
418 1.1 briggs struct uio *uio,
419 1.1 briggs int flag)
420 1.1 briggs {
421 1.1 briggs return 0;
422 1.1 briggs }
423 1.1 briggs
424 1.1 briggs
425 1.1 briggs int adbioctl(
426 1.1 briggs dev_t dev,
427 1.1 briggs int cmd,
428 1.1 briggs caddr_t data,
429 1.1 briggs int flag,
430 1.1 briggs struct proc *p)
431 1.1 briggs {
432 1.1 briggs switch(cmd){
433 1.1 briggs case ADBIOC_DEVSINFO: {
434 1.1 briggs adb_devinfo_t *di = (void *)data;
435 1.1 briggs int totaldevs;
436 1.1 briggs ADBDataBlock adbdata;
437 1.1 briggs int adbaddr;
438 1.1 briggs int i;
439 1.1 briggs
440 1.1 briggs /* Initialize to no devices */
441 1.1 briggs for(i = 0; i < 16; i++)
442 1.1 briggs di->dev[i].addr = -1;
443 1.1 briggs
444 1.1 briggs totaldevs = CountADBs();
445 1.1 briggs for(i = 1; i <= totaldevs; i++){
446 1.1 briggs adbaddr = GetIndADB(&adbdata, i);
447 1.1 briggs di->dev[adbaddr].addr = adbaddr;
448 1.1 briggs di->dev[adbaddr].default_addr =
449 1.1 briggs adbdata.origADBAddr;
450 1.1 briggs di->dev[adbaddr].handler_id =
451 1.1 briggs adbdata.devType;
452 1.1 briggs }
453 1.1 briggs
454 1.1 briggs /* Must call ADB Manager to get devices now */
455 1.1 briggs break;
456 1.1 briggs }
457 1.1 briggs
458 1.1 briggs case ADBIOC_GETREPEAT:{
459 1.1 briggs adb_rptinfo_t *ri = (void *)data;
460 1.1 briggs
461 1.1 briggs ri->delay_ticks = adb_rptdelay;
462 1.1 briggs ri->interval_ticks = adb_rptinterval;
463 1.1 briggs break;
464 1.1 briggs }
465 1.1 briggs
466 1.1 briggs case ADBIOC_SETREPEAT:{
467 1.1 briggs adb_rptinfo_t *ri = (void *)data;
468 1.1 briggs
469 1.1 briggs adb_rptdelay = ri->delay_ticks;
470 1.1 briggs adb_rptinterval = ri->interval_ticks;
471 1.1 briggs break;
472 1.1 briggs }
473 1.1 briggs
474 1.1 briggs case ADBIOC_RESET:
475 1.1 briggs adb_init();
476 1.1 briggs break;
477 1.1 briggs
478 1.1 briggs case ADBIOC_LISTENCMD:{
479 1.1 briggs adb_listencmd_t *lc = (void *)data;
480 1.1 briggs }
481 1.1 briggs
482 1.1 briggs default:
483 1.1 briggs return(EINVAL);
484 1.1 briggs }
485 1.1 briggs return(0);
486 1.1 briggs }
487 1.1 briggs
488 1.1 briggs
489 1.1 briggs int adbselect(
490 1.1 briggs dev_t dev,
491 1.1 briggs int rw,
492 1.1 briggs struct proc *p)
493 1.1 briggs {
494 1.1 briggs switch (rw) {
495 1.1 briggs case FREAD:
496 1.1 briggs /* succeed if there is something to read */
497 1.1 briggs if (adb_evq_len > 0)
498 1.1 briggs return (1);
499 1.1 briggs selrecord(p, &adb_selinfo);
500 1.1 briggs break;
501 1.1 briggs
502 1.1 briggs case FWRITE:
503 1.1 briggs return (1); /* always fails => never blocks */
504 1.1 briggs break;
505 1.1 briggs }
506 1.1 briggs
507 1.1 briggs return (0);
508 1.1 briggs }
509