xref: /netbsd-src/sys/dev/hil/hil.c (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 /*	$NetBSD: hil.c,v 1.7 2022/06/25 02:36:27 tsutsui Exp $	*/
2 /*	$OpenBSD: hil.c,v 1.24 2010/11/20 16:45:46 miod Exp $	*/
3 /*
4  * Copyright (c) 2003, 2004, Miodrag Vallat.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  *
28  */
29 
30 /*
31  * Copyright (c) 1988 University of Utah.
32  * Copyright (c) 1990, 1993
33  *	The Regents of the University of California.  All rights reserved.
34  *
35  * This code is derived from software contributed to Berkeley by
36  * the Systems Programming Group of the University of Utah Computer
37  * Science Department.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  * from: Utah $Hdr: hil.c 1.38 92/01/21$
64  *
65  *	@(#)hil.c	8.2 (Berkeley) 1/12/94
66  */
67 
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/conf.h>
71 #include <sys/device.h>
72 #include <sys/file.h>
73 #include <sys/ioctl.h>
74 #include <sys/kernel.h>
75 #include <sys/proc.h>
76 #include <sys/kthread.h>
77 #include <sys/bus.h>
78 #include <sys/cpu.h>
79 
80 #include <machine/autoconf.h>
81 
82 #include <dev/hil/hilreg.h>
83 #include <dev/hil/hilvar.h>
84 #include <dev/hil/hildevs.h>
85 #include <dev/hil/hildevs_data.h>
86 
87 #include "hilkbd.h"
88 
89 static void	hilconfig(struct hil_softc *, u_int);
90 static void	hilempty(struct hil_softc *);
91 static int	hilsubmatch(device_t, cfdata_t, const int *, void *);
92 static void	hil_process_int(struct hil_softc *, uint8_t, uint8_t);
93 static int	hil_process_poll(struct hil_softc *, uint8_t, uint8_t);
94 static void	hil_thread(void *);
95 static int	send_device_cmd(struct hil_softc *sc, u_int device, u_int cmd);
96 static void	polloff(struct hil_softc *);
97 static void	pollon(struct hil_softc *);
98 
99 static int hilwait(struct hil_softc *);
100 static int hildatawait(struct hil_softc *);
101 
102 #define	hil_process_pending(sc)	wakeup(&(sc)->sc_pending)
103 
104 static __inline int
105 hilwait(struct hil_softc *sc)
106 {
107 	int cnt;
108 
109 	for (cnt = 50000; cnt != 0; cnt--) {
110 		DELAY(1);
111 		if ((bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT) &
112 		    HIL_BUSY) == 0)
113 			break;
114 	}
115 
116 	return cnt;
117 }
118 
119 static __inline int
120 hildatawait(struct hil_softc *sc)
121 {
122 	int cnt;
123 
124 	for (cnt = 50000; cnt != 0; cnt--) {
125 		DELAY(1);
126 		if ((bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT) &
127 		    HIL_DATA_RDY) != 0)
128 			break;
129 	}
130 
131 	return cnt;
132 }
133 
134 /*
135  * Common HIL bus attachment
136  */
137 
138 void
139 hil_attach(struct hil_softc *sc, int *hil_is_console)
140 {
141 
142 	rnd_attach_source(&sc->sc_rndsource, device_xname(sc->sc_dev),
143 	    RND_TYPE_TTY, RND_FLAG_DEFAULT);
144 
145 	aprint_normal("\n");
146 
147 	/*
148 	 * Initialize loop information
149 	 */
150 	sc->sc_cmdending = 0;
151 	sc->sc_actdev = sc->sc_cmddev = 0;
152 	sc->sc_cmddone = 0;
153 	sc->sc_cmdbp = sc->sc_cmdbuf;
154 	sc->sc_pollbp = sc->sc_pollbuf;
155 	sc->sc_console = hil_is_console;
156 }
157 
158 /*
159  * HIL subdevice attachment
160  */
161 
162 int
163 hildevprint(void *aux, const char *pnp)
164 {
165 	struct hil_attach_args *ha = aux;
166 
167 	if (pnp != NULL) {
168 		aprint_normal("\"%s\" at %s id %x",
169 		    ha->ha_descr, pnp, ha->ha_id);
170 	}
171 	aprint_normal(" code %d", ha->ha_code);
172 	if (pnp == NULL) {
173 		aprint_normal(": %s", ha->ha_descr);
174 	}
175 
176 	return UNCONF;
177 }
178 
179 int
180 hilsubmatch(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
181 {
182 	struct hil_attach_args *ha = aux;
183 
184 	if (cf->cf_loc[0] != -1 &&
185 	    cf->cf_loc[0] != ha->ha_code)
186 		return 0;
187 
188 	return config_match(parent, cf, aux);
189 }
190 
191 void
192 hil_attach_deferred(device_t self)
193 {
194 	struct hil_softc *sc = device_private(self);
195 	int tries;
196 	uint8_t db;
197 
198 	sc->sc_status = HIL_STATUS_BUSY;
199 
200 	/*
201 	 * Initialize the loop: reconfigure, don't report errors,
202 	 * put keyboard in cooked mode, and enable autopolling.
203 	 */
204 	db = LPC_RECONF | LPC_KBDCOOK | LPC_NOERROR | LPC_AUTOPOLL;
205 	send_hil_cmd(sc, HIL_WRITELPCTRL, &db, 1, NULL);
206 
207 	/*
208 	 * Delay one second for reconfiguration and then read the
209 	 * data to clear the interrupt (if the loop reconfigured).
210 	 */
211 	DELAY(1000000);
212 	if (bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT) &
213 	    HIL_DATA_RDY) {
214 		db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
215 		DELAY(1);
216 	}
217 
218 	/*
219 	 * The HIL loop may have reconfigured.  If so we proceed on,
220 	 * if not we loop a few times until a successful reconfiguration
221 	 * is reported back to us. If the HIL loop is still lost after a
222 	 * few seconds, give up.
223 	 */
224 	for (tries = 10; tries != 0; tries--) {
225 		if (send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db) == 0) {
226 			if (db & (LPS_CONFFAIL | LPS_CONFGOOD))
227 				break;
228 		}
229 
230 #ifdef HILDEBUG
231 		aprint_debug(self, "%s: loop not ready, retrying...\n");
232 #endif
233 
234 		DELAY(1000000);
235         }
236 
237 	if (tries == 0 || (db & LPS_CONFFAIL)) {
238 		aprint_normal_dev(self, "no devices\n");
239 		sc->sc_pending = 0;
240 		if (tries == 0)
241 			return;
242 	}
243 
244 	/*
245 	 * Create asynchronous loop event handler thread.
246 	 */
247 	if (kthread_create(PRI_NONE, 0, NULL, hil_thread, sc, &sc->sc_thread,
248 	    "%s", device_xname(sc->sc_dev)) != 0) {
249 		aprint_error_dev(self, "unable to create event thread\n");
250 		return;
251 	}
252 
253 	/*
254 	 * Enable loop interrupts.
255 	 */
256 	send_hil_cmd(sc, HIL_INTON, NULL, 0, NULL);
257 
258 	/*
259 	 * Reconfigure if necessary
260 	 */
261 	sc->sc_status = HIL_STATUS_READY;
262 	hil_process_pending(sc);
263 }
264 
265 /*
266  * Asynchronous event processing
267  */
268 
269 int
270 hil_intr(void *v)
271 {
272 	struct hil_softc *sc = v;
273 	uint8_t c, stat;
274 
275 	if (cold)
276 		return 0;
277 
278 	stat = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT);
279 
280 	/*
281 	 * This should never happen if the interrupt comes from the
282 	 * loop.
283 	 */
284 	if ((stat & HIL_DATA_RDY) == 0)
285 		return 0;	/* not for us */
286 
287 	c = bus_space_read_1(sc->sc_bst, sc->sc_bsh,
288 	    HILP_DATA);	/* clears interrupt */
289 	DELAY(1);
290 
291 	hil_process_int(sc, stat, c);
292 
293 	if (sc->sc_status != HIL_STATUS_BUSY)
294 		hil_process_pending(sc);
295 
296 	rnd_add_uint32(&sc->sc_rndsource, (stat << 8) | c);
297 
298 	return 1;
299 }
300 
301 void
302 hil_process_int(struct hil_softc *sc, uint8_t stat, uint8_t c)
303 {
304 	device_t child;
305 	struct hildev_softc *hdsc;
306 
307 	switch ((stat >> HIL_SSHIFT) & HIL_SMASK) {
308 	case HIL_STATUS:
309 		if (c & HIL_ERROR) {
310 		  	sc->sc_cmddone = 1;
311 			switch (c) {
312 			case HIL_RECONFIG:
313 				sc->sc_pending = HIL_PENDING_RECONFIG;
314 				break;
315 			case HIL_UNPLUGGED:
316 				sc->sc_pending = HIL_PENDING_UNPLUGGED;
317 				break;
318 			}
319 			break;
320 		}
321 		if (c & HIL_COMMAND) {
322 		  	if (c & HIL_POLLDATA) {	/* End of data */
323 				child = sc->sc_devices[sc->sc_actdev];
324 				if (child != NULL) {
325 					hdsc = device_private(child);
326 					if (hdsc->sc_fn != NULL)
327 						(*hdsc->sc_fn)(hdsc,
328 						    sc->sc_pollbp
329 						    - sc->sc_pollbuf,
330 						    sc->sc_pollbuf);
331 				}
332 			} else {		/* End of command */
333 			  	sc->sc_cmdending = 1;
334 			}
335 			sc->sc_actdev = 0;
336 		} else {
337 		  	if (c & HIL_POLLDATA) {	/* Start of polled data */
338 				sc->sc_actdev = (c & HIL_DEVMASK);
339 				sc->sc_pollbp = sc->sc_pollbuf;
340 			} else {		/* Start of command */
341 				if (sc->sc_cmddev == (c & HIL_DEVMASK)) {
342 					sc->sc_cmdbp = sc->sc_cmdbuf;
343 					sc->sc_actdev = 0;
344 				}
345 			}
346 		}
347 	        break;
348 	case HIL_DATA:
349 		if (sc->sc_actdev != 0)	/* Collecting poll data */
350 			*sc->sc_pollbp++ = c;
351 		else {
352 			if (sc->sc_cmddev != 0) {  /* Collecting cmd data */
353 				if (sc->sc_cmdending) {
354 					sc->sc_cmddone = 1;
355 					sc->sc_cmdending = 0;
356 				} else
357 					*sc->sc_cmdbp++ = c;
358 		        }
359 		}
360 		break;
361 	}
362 }
363 
364 /*
365  * Same as above, but in polled mode: return data as it gets seen, instead
366  * of buffering it.
367  */
368 int
369 hil_process_poll(struct hil_softc *sc, uint8_t stat, uint8_t c)
370 {
371 	uint8_t db;
372 
373 	switch ((stat >> HIL_SSHIFT) & HIL_SMASK) {
374 	case HIL_STATUS:
375 		if (c & HIL_ERROR) {
376 		  	sc->sc_cmddone = 1;
377 			switch (c) {
378 			case HIL_RECONFIG:
379 				/*
380 				 * Remember that a configuration event
381 				 * occurred; it will be processed upon
382 				 * leaving polled mode...
383 				 */
384 				sc->sc_pending = HIL_PENDING_RECONFIG;
385 				/*
386 				 * However, the keyboard will come back as
387 				 * cooked, and we rely on it being in raw
388 				 * mode. So, put it back in raw mode right
389 				 * now.
390 				 */
391 				db = 0;
392 				send_hil_cmd(sc, HIL_WRITEKBDSADR, &db,
393 				    1, NULL);
394 				break;
395 			case HIL_UNPLUGGED:
396 				/*
397 				 * Remember that an unplugged event
398 				 * occurred; it will be processed upon
399 				 * leaving polled mode...
400 				 */
401 				sc->sc_pending = HIL_PENDING_UNPLUGGED;
402 				break;
403 			}
404 			break;
405 		}
406 		if (c & HIL_COMMAND) {
407 		  	if (!(c & HIL_POLLDATA)) {
408 				/* End of command */
409 			  	sc->sc_cmdending = 1;
410 			}
411 			sc->sc_actdev = 0;
412 		} else {
413 		  	if (c & HIL_POLLDATA) {
414 				/* Start of polled data */
415 				sc->sc_actdev = (c & HIL_DEVMASK);
416 				sc->sc_pollbp = sc->sc_pollbuf;
417 			} else {
418 				/* Start of command - should not happen */
419 				if (sc->sc_cmddev == (c & HIL_DEVMASK)) {
420 					sc->sc_cmdbp = sc->sc_cmdbuf;
421 					sc->sc_actdev = 0;
422 				}
423 			}
424 		}
425 	        break;
426 	case HIL_DATA:
427 		if (sc->sc_actdev != 0)	/* Collecting poll data */
428 			return 1;
429 		else {
430 			if (sc->sc_cmddev != 0) {  /* Discarding cmd data */
431 				if (sc->sc_cmdending) {
432 					sc->sc_cmddone = 1;
433 					sc->sc_cmdending = 0;
434 				}
435 		        }
436 		}
437 		break;
438 	}
439 
440 	return 0;
441 }
442 
443 void
444 hil_thread(void *arg)
445 {
446 	struct hil_softc *sc = arg;
447 	int s;
448 
449 	for (;;) {
450 		s = splhil();
451 		if (sc->sc_pending == 0) {
452 			splx(s);
453 			(void)tsleep(&sc->sc_pending, PWAIT, "hil_event", 0);
454 			continue;
455 		}
456 
457 		switch (sc->sc_pending) {
458 		case HIL_PENDING_RECONFIG:
459 			sc->sc_pending = 0;
460 			hilconfig(sc, sc->sc_maxdev);
461 			break;
462 		case HIL_PENDING_UNPLUGGED:
463 			sc->sc_pending = 0;
464 			hilempty(sc);
465 			break;
466 		}
467 		splx(s);
468 	}
469 }
470 
471 /*
472  * Called after the loop has reconfigured.  Here we need to:
473  *	- determine how many devices are on the loop
474  *	  (some may have been added or removed)
475  *	- make sure all keyboards are in raw mode
476  *
477  * Note that our device state is now potentially invalid as
478  * devices may no longer be where they were.  What we should
479  * do here is either track where the devices went and move
480  * state around accordingly...
481  *
482  * Note that it is necessary that we operate the loop with the keyboards
483  * in raw mode: they won't cause the loop to generate an NMI if the
484  * ``reset'' key combination is pressed, and we do not handle the hil
485  * NMI interrupt...
486  */
487 void
488 hilconfig(struct hil_softc *sc, u_int knowndevs)
489 {
490 	struct hil_attach_args ha;
491 	uint8_t db;
492 	int id, s;
493 
494 	s = splhil();
495 
496 	/*
497 	 * Determine how many devices are on the loop.
498 	 */
499 	db = 0;
500 	send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db);
501 	sc->sc_maxdev = db & LPS_DEVMASK;
502 #ifdef HILDEBUG
503 	printf("%s: %d device(s)\n", device_xname(sc->sc_dev), sc->sc_maxdev);
504 #endif
505 
506 	/*
507 	 * Put all keyboards in raw mode now.
508 	 */
509 	db = 0;
510 	send_hil_cmd(sc, HIL_WRITEKBDSADR, &db, 1, NULL);
511 
512 	/*
513 	 * If the loop grew, attach new devices.
514 	 */
515 	for (id = knowndevs + 1; id <= sc->sc_maxdev; id++) {
516 		int len;
517 		const struct hildevice *hd;
518 
519 		if (send_device_cmd(sc, id, HIL_IDENTIFY) != 0) {
520 			aprint_normal_dev(sc->sc_dev,
521 			    "no answer from device %d\n", id);
522 			continue;
523 		}
524 
525 		len = sc->sc_cmdbp - sc->sc_cmdbuf;
526 		if (len == 0) {
527 #ifdef HILDEBUG
528 			printf("%s: no device at code %d\n",
529 			    device_xname(sc->sc_dev), id);
530 #endif
531 			continue;
532 		}
533 
534 		/* Identify and attach device */
535 		for (hd = hildevs; hd->minid >= 0; hd++)
536 			if (sc->sc_cmdbuf[0] >= hd->minid &&
537 			    sc->sc_cmdbuf[0] <= hd->maxid) {
538 
539 			ha.ha_console = *sc->sc_console;
540 			ha.ha_code = id;
541 			ha.ha_type = hd->type;
542 			ha.ha_descr = hd->descr;
543 			ha.ha_infolen = len;
544 			memcpy(ha.ha_info, sc->sc_cmdbuf, len);
545 
546 			sc->sc_devices[id] =
547 			    config_found(sc->sc_dev, &ha, hildevprint,
548 					 CFARGS(.submatch = hilsubmatch));
549 
550 #if NHILKBD > 0
551 			/*
552 			 * If we just attached a keyboard as console,
553 			 * console choice is not indeterminate anymore.
554 			 */
555 			if (sc->sc_devices[id] != NULL &&
556 			    ha.ha_type == HIL_DEVICE_KEYBOARD &&
557 			    ha.ha_console != 0)
558 				*sc->sc_console = 1;
559 #endif
560 		}
561 	}
562 
563 	/*
564 	 * Detach remaining devices, if the loop has shrunk.
565 	 */
566 	for (id = sc->sc_maxdev + 1; id < NHILD; id++) {
567 		if (sc->sc_devices[id] != NULL)
568 			config_detach(sc->sc_devices[id],
569 			    DETACH_FORCE);
570 		sc->sc_devices[id] = NULL;
571 	}
572 
573 	sc->sc_cmdbp = sc->sc_cmdbuf;
574 
575 	splx(s);
576 }
577 
578 /*
579  * Called after the loop has been unplugged. We simply force detach of
580  * all our children.
581  */
582 void
583 hilempty(struct hil_softc *sc)
584 {
585 	uint8_t db;
586 	int id, s;
587 	u_int oldmaxdev;
588 
589 	s = splhil();
590 
591 	/*
592 	 * Wait for the loop to be stable.
593 	 */
594 	for (;;) {
595 		if (send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db) == 0) {
596 			if (db & (LPS_CONFFAIL | LPS_CONFGOOD))
597 				break;
598 		} else {
599 			db = LPS_CONFFAIL;
600 			break;
601 		}
602 	}
603 
604 	if (db & LPS_CONFFAIL) {
605 		sc->sc_maxdev = 0;
606 	} else {
607 		db = 0;
608 		send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db);
609 		oldmaxdev = sc->sc_maxdev;
610 		sc->sc_maxdev = db & LPS_DEVMASK;
611 
612 		if (sc->sc_maxdev != 0) {
613 			/*
614 			 * The loop was not unplugged after all, but its
615 			 * configuration has changed.
616 			 */
617 			hilconfig(sc, oldmaxdev);
618 			return;
619 		}
620 	}
621 
622 	/*
623 	 * Now detach all hil devices.
624 	 */
625 	for (id = sc->sc_maxdev + 1; id < NHILD; id++) {
626 		if (sc->sc_devices[id] != NULL)
627 			config_detach(sc->sc_devices[id],
628 			    DETACH_FORCE);
629 		sc->sc_devices[id] = NULL;
630 	}
631 
632 	sc->sc_cmdbp = sc->sc_cmdbuf;
633 
634 	splx(s);
635 }
636 
637 /*
638  * Low level routines which actually talk to the 8042 chip.
639  */
640 
641 /*
642  * Send a command to the 8042 with zero or more bytes of data.
643  * If rdata is non-null, wait for and return a byte of data.
644  */
645 int
646 send_hil_cmd(struct hil_softc *sc, u_int cmd, uint8_t *data, u_int dlen,
647     uint8_t *rdata)
648 {
649 	uint8_t status;
650 	int s;
651 
652 	s = splhil();
653 
654 	if (hilwait(sc) == 0) {
655 #ifdef HILDEBUG
656 		printf("%s: no answer from the loop\n",
657 		    device_xname(sc->sc_dev));
658 #endif
659 		splx(s);
660 		return EBUSY;
661 	}
662 
663 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, cmd);
664 	while (dlen--) {
665 	  	hilwait(sc);
666 		bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, *data++);
667 		DELAY(1);
668 	}
669 	if (rdata) {
670 		do {
671 			if (hildatawait(sc) == 0) {
672 #ifdef HILDEBUG
673 				printf("%s: no answer from the loop\n",
674 				    device_xname(sc->sc_dev));
675 #endif
676 				break;
677 			}
678 			status = bus_space_read_1(sc->sc_bst, sc->sc_bsh,
679 			    HILP_STAT);
680 			*rdata = bus_space_read_1(sc->sc_bst, sc->sc_bsh,
681 			    HILP_DATA);
682 			DELAY(1);
683 		} while (((status >> HIL_SSHIFT) & HIL_SMASK) != HIL_68K);
684 	}
685 	splx(s);
686 	return 0;
687 }
688 
689 /*
690  * Send a command to a device on the loop.
691  * Since only one command can be active on the loop at any time,
692  * we must ensure that we are not interrupted during this process.
693  * Hence we mask interrupts to prevent potential access from most
694  * interrupt routines and turn off auto-polling to disable the
695  * internally generated poll commands.
696  * Needs to be called at splhil().
697  */
698 int
699 send_device_cmd(struct hil_softc *sc, u_int device, u_int cmd)
700 {
701 	uint8_t status, c;
702 	int rc = 0;
703 
704 	polloff(sc);
705 
706 	sc->sc_cmdbp = sc->sc_cmdbuf;
707 	sc->sc_cmddev = device;
708 
709 	if (hilwait(sc) == 0) {
710 #ifdef HILDEBUG
711 		printf("%s: no answer from device %d\n",
712 		    device_xname(sc->sc_dev), device);
713 #endif
714 		rc = EBUSY;
715 		goto out;
716 	}
717 
718 	/*
719 	 * Transfer the command and device info to the chip
720 	 */
721 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_STARTCMD);
722   	hilwait(sc);
723 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, 8 + device);
724   	hilwait(sc);
725 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, cmd);
726   	hilwait(sc);
727 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, HIL_TIMEOUT);
728 
729 	/*
730 	 * Trigger the command and wait for completion
731 	 */
732 	hilwait(sc);
733 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_TRIGGER);
734 	sc->sc_cmddone = 0;
735 	do {
736 		if (hildatawait(sc) == 0) {
737 #ifdef HILDEBUG
738 			printf("%s: no answer from device %d\n",
739 			    device_xname(sc->sc_dev), device);
740 #endif
741 			rc = EBUSY;
742 			break;
743 		}
744 		status = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT);
745 		c = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
746 		DELAY(1);
747 		hil_process_int(sc, status, c);
748 	} while (sc->sc_cmddone == 0);
749 out:
750 	sc->sc_cmddev = 0;
751 
752 	pollon(sc);
753 	return rc;
754 }
755 
756 int
757 send_hildev_cmd(struct hildev_softc *hdsc, u_int cmd,
758     uint8_t *outbuf, u_int *outlen)
759 {
760 	struct hil_softc *sc = device_private(device_parent(hdsc->sc_dev));
761 	int s, rc;
762 
763 	s = splhil();
764 
765 	if ((rc = send_device_cmd(sc, hdsc->sc_code, cmd)) == 0) {
766 		/*
767 		 * Return the command response in the buffer if necessary
768 	 	*/
769 		if (outbuf != NULL && outlen != NULL) {
770 			*outlen = uimin(*outlen, sc->sc_cmdbp - sc->sc_cmdbuf);
771 			memcpy(outbuf, sc->sc_cmdbuf, *outlen);
772 		}
773 	}
774 
775 	splx(s);
776 	return rc;
777 }
778 
779 /*
780  * Turn auto-polling off and on.
781  */
782 void
783 polloff(struct hil_softc *sc)
784 {
785 	uint8_t db;
786 
787 	if (hilwait(sc) == 0)
788 		return;
789 
790 	/*
791 	 * Turn off auto repeat
792 	 */
793 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_SETARR);
794 	hilwait(sc);
795 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, 0);
796 
797 	/*
798 	 * Turn off auto-polling
799 	 */
800 	hilwait(sc);
801 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_READLPCTRL);
802 	hildatawait(sc);
803 	db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
804 	db &= ~LPC_AUTOPOLL;
805 	hilwait(sc);
806 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_WRITELPCTRL);
807 	hilwait(sc);
808 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, db);
809 
810 	/*
811 	 * Must wait until polling is really stopped
812 	 */
813 	do {
814 		hilwait(sc);
815 		bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_READBUSY);
816 		hildatawait(sc);
817 		db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
818 	} while (db & BSY_LOOPBUSY);
819 
820 	sc->sc_cmddone = 0;
821 	sc->sc_cmddev = 0;
822 }
823 
824 void
825 pollon(struct hil_softc *sc)
826 {
827 	uint8_t db;
828 
829 	if (hilwait(sc) == 0)
830 		return;
831 
832 	/*
833 	 * Turn on auto polling
834 	 */
835 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_READLPCTRL);
836 	hildatawait(sc);
837 	db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
838 	db |= LPC_AUTOPOLL;
839 	hilwait(sc);
840 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_WRITELPCTRL);
841 	hilwait(sc);
842 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, db);
843 
844 	/*
845 	 * Turn off auto repeat - we emulate this through wscons
846 	 */
847 	hilwait(sc);
848 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_SETARR);
849 	hilwait(sc);
850 	bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, 0);
851 	DELAY(1);
852 }
853 
854 void
855 hil_set_poll(struct hil_softc *sc, int on)
856 {
857 	if (on) {
858 		pollon(sc);
859 	} else {
860 		hil_process_pending(sc);
861 		send_hil_cmd(sc, HIL_INTON, NULL, 0, NULL);
862 	}
863 }
864 
865 int
866 hil_poll_data(struct hildev_softc *hdsc, uint8_t *stat, uint8_t *data)
867 {
868 	struct hil_softc *sc = device_private(device_parent(hdsc->sc_dev));
869 	uint8_t s, c;
870 
871 	s = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT);
872 	if ((s & HIL_DATA_RDY) == 0)
873 		return -1;
874 
875 	c = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
876 	DELAY(1);
877 
878 	if (hil_process_poll(sc, s, c)) {
879 		/* Discard any data not for us */
880 		if (sc->sc_actdev == hdsc->sc_code) {
881 			*stat = s;
882 			*data = c;
883 			return 0;
884 		}
885 	}
886 
887 	return -1;
888 }
889