isa.c revision 1.15 1 /*-
2 * Copyright (c) 1991 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: @(#)isa.c 7.2 (Berkeley) 5/13/91
37 * $Id: isa.c,v 1.15 1993/06/06 04:16:42 cgd Exp $
38 */
39
40 /*
41 * code to manage AT bus
42 *
43 * 92/08/18 Frank P. MacLachlan (fpm (at) crash.cts.com):
44 * Fixed uninitialized variable problem and added code to deal
45 * with DMA page boundaries in isa_dmarangecheck(). Fixed word
46 * mode DMA count compution and reorganized DMA setup code in
47 * isa_dmastart()
48 */
49
50 #include "param.h"
51 #include "systm.h"
52 #include "conf.h"
53 #include "file.h"
54 #include "buf.h"
55 #include "uio.h"
56 #include "syslog.h"
57 #include "malloc.h"
58 #include "rlist.h"
59 #include "machine/segments.h"
60 #include "vm/vm.h"
61 #include "i386/isa/isa_device.h"
62 #include "i386/isa/isa.h"
63 #include "i386/isa/icu.h"
64 #include "i386/isa/ic/i8237.h"
65 #include "i386/isa/ic/i8042.h"
66
67 /* sorry, has to be here, no place else really suitable */
68 #include "machine/pc/display.h"
69 u_short *Crtat = (u_short *)MONO_BUF;
70
71 /*
72 ** Register definitions for DMA controller 1 (channels 0..3):
73 */
74 #define DMA1_CHN(c) (IO_DMA1 + 1*(2*(c))) /* addr reg for channel c */
75 #define DMA1_SMSK (IO_DMA1 + 1*10) /* single mask register */
76 #define DMA1_MODE (IO_DMA1 + 1*11) /* mode register */
77 #define DMA1_FFC (IO_DMA1 + 1*12) /* clear first/last FF */
78
79 /*
80 ** Register definitions for DMA controller 2 (channels 4..7):
81 */
82 #define DMA2_CHN(c) (IO_DMA1 + 2*(2*(c))) /* addr reg for channel c */
83 #define DMA2_SMSK (IO_DMA2 + 2*10) /* single mask register */
84 #define DMA2_MODE (IO_DMA2 + 2*11) /* mode register */
85 #define DMA2_FFC (IO_DMA2 + 2*12) /* clear first/last FF */
86
87 int config_isadev(struct isa_device *, u_int *);
88 void config_attach(struct isa_driver *, struct isa_device *);
89
90 /*
91 * Configure all ISA devices
92 */
93 isa_configure() {
94 struct isa_device *dvp;
95 struct isa_driver *dp;
96
97 enable_intr();
98 splhigh();
99 INTREN(IRQ_SLAVE);
100 for (dvp = isa_devtab_tty; config_isadev(dvp,&ttymask); dvp++)
101 ;
102 for (dvp = isa_devtab_bio; config_isadev(dvp,&biomask); dvp++)
103 ;
104 for (dvp = isa_devtab_net; config_isadev(dvp,&netmask); dvp++)
105 ;
106 for (dvp = isa_devtab_null; config_isadev(dvp, (u_int *) NULL); dvp++)
107 ;
108 #include "sl.h"
109 #if NSL > 0
110 netmask |= ttymask;
111 ttymask |= netmask;
112 #endif
113
114 /* and the problem is... if netmask == 0, then the loopback
115 * code can do some really ugly things.
116 * workaround for this: if netmask == 0, set it to 0x8000, which
117 * is the value used by splsoftclock. this is nasty, but it
118 * should work until this interrupt system goes away. -- cgd
119 */
120 if (netmask == 0)
121 netmask = 0x8000; /* same as for softclock. XXX */
122
123 /* biomask |= ttymask ; can some tty devices use buffers? */
124 printf("biomask %x ttymask %x netmask %x\n", biomask, ttymask, netmask);
125 splnone();
126 }
127
128 /*
129 * Configure an ISA device.
130 */
131 config_isadev(isdp, mp)
132 struct isa_device *isdp;
133 u_int *mp;
134 {
135 struct isa_driver *dp;
136
137 if (dp = isdp->id_driver) {
138 if (isdp->id_maddr) {
139 extern u_int atdevbase;
140
141 isdp->id_maddr -= 0xa0000; /* XXX should be a define */
142 isdp->id_maddr += atdevbase;
143 }
144 isdp->id_alive = (*dp->probe)(isdp);
145 if (isdp->id_irq == (u_short)-1)
146 isdp->id_alive = 0;
147 /*
148 * Only print the I/O address range if id_alive != -1
149 * Right now this is a temporary fix just for the new
150 * NPX code so that if it finds a 486 that can use trap
151 * 16 it will not report I/O addresses.
152 * Rod Grimes 04/26/94
153 *
154 * XXX -- cgd
155 */
156 if (isdp->id_alive) {
157 printf("%s%d", dp->name, isdp->id_unit);
158 printf(" at 0x%x", isdp->id_iobase);
159 if ((isdp->id_iobase + isdp->id_alive - 1) !=
160 isdp->id_iobase)
161 printf("-0x%x",
162 isdp->id_iobase + isdp->id_alive - 1);
163 if (isdp->id_irq != 0)
164 printf(" irq %d", ffs(isdp->id_irq)-1);
165 if (isdp->id_drq != -1)
166 printf(" drq %d", isdp->id_drq);
167 if (isdp->id_maddr != 0)
168 printf(" maddr 0x%x", kvtop(isdp->id_maddr));
169 if (isdp->id_msize != 0)
170 printf(" msize %d", isdp->id_msize);
171 if (isdp->id_flags != 0)
172 printf(" flags 0x%x", isdp->id_flags);
173 printf(" on isa\n");
174
175 config_attach(dp, isdp);
176
177 if (isdp->id_irq) {
178 int intrno;
179
180 intrno = ffs(isdp->id_irq)-1;
181 setidt(ICU_OFFSET+intrno, isdp->id_intr,
182 SDT_SYS386IGT, SEL_KPL);
183 if(mp)
184 INTRMASK(*mp,isdp->id_irq);
185 INTREN(isdp->id_irq);
186 }
187 }
188 return (1);
189 } else return(0);
190 }
191
192 void
193 config_attach(struct isa_driver *dp, struct isa_device *isdp)
194 {
195 extern struct isa_device isa_subdev[];
196 struct isa_device *dvp;
197
198 if(isdp->id_masunit==-1) {
199 (void)(*dp->attach)(isdp);
200 return;
201 }
202
203 if(isdp->id_masunit==0) {
204 for(dvp = isa_subdev; dvp->id_driver; dvp++) {
205 if (dvp->id_driver != dp)
206 continue;
207 if (dvp->id_masunit != isdp->id_unit)
208 continue;
209 if (dvp->id_physid == -1)
210 continue;
211 dvp->id_alive = (*dp->attach)(dvp);
212 }
213 for(dvp = isa_subdev; dvp->id_driver; dvp++) {
214 if (dvp->id_driver != dp)
215 continue;
216 if (dvp->id_masunit != isdp->id_unit)
217 continue;
218 if (dvp->id_physid != -1)
219 continue;
220 dvp->id_alive = (*dp->attach)(dvp);
221 }
222 return;
223 }
224 printf("id_masunit has weird value\n");
225 }
226
227
228 #define IDTVEC(name) __CONCAT(X,name)
229 /* default interrupt vector table entries */
230 extern IDTVEC(intr0), IDTVEC(intr1), IDTVEC(intr2), IDTVEC(intr3),
231 IDTVEC(intr4), IDTVEC(intr5), IDTVEC(intr6), IDTVEC(intr7),
232 IDTVEC(intr8), IDTVEC(intr9), IDTVEC(intr10), IDTVEC(intr11),
233 IDTVEC(intr12), IDTVEC(intr13), IDTVEC(intr14), IDTVEC(intr15);
234
235 static *defvec[16] = {
236 &IDTVEC(intr0), &IDTVEC(intr1), &IDTVEC(intr2), &IDTVEC(intr3),
237 &IDTVEC(intr4), &IDTVEC(intr5), &IDTVEC(intr6), &IDTVEC(intr7),
238 &IDTVEC(intr8), &IDTVEC(intr9), &IDTVEC(intr10), &IDTVEC(intr11),
239 &IDTVEC(intr12), &IDTVEC(intr13), &IDTVEC(intr14), &IDTVEC(intr15) };
240
241 /* out of range default interrupt vector gate entry */
242 extern IDTVEC(intrdefault);
243
244 /*
245 * Fill in default interrupt table (in case of spuruious interrupt
246 * during configuration of kernel, setup interrupt control unit
247 */
248 isa_defaultirq() {
249 int i;
250
251 /* icu vectors */
252 for (i = NRSVIDT ; i < NRSVIDT+ICU_LEN ; i++)
253 setidt(i, defvec[i], SDT_SYS386IGT, SEL_KPL);
254
255 /* out of range vectors */
256 for (i = NRSVIDT; i < NIDT; i++)
257 setidt(i, &IDTVEC(intrdefault), SDT_SYS386IGT, SEL_KPL);
258
259 /* initialize 8259's */
260 outb(IO_ICU1, 0x11); /* reset; program device, four bytes */
261 outb(IO_ICU1+1, NRSVIDT); /* starting at this vector index */
262 outb(IO_ICU1+1, 1<<2); /* slave on line 2 */
263 #ifdef AUTO_EOI_1
264 outb(IO_ICU1+1, 2 | 1); /* auto EOI, 8086 mode */
265 #else
266 outb(IO_ICU1+1, 1); /* 8086 mode */
267 #endif
268 outb(IO_ICU1+1, 0xff); /* leave interrupts masked */
269 outb(IO_ICU1, 0x0a); /* default to IRR on read */
270 outb(IO_ICU1, 0xc0 | (3 - 1)); /* pri order 3-7, 0-2 (com2 first) */
271
272 outb(IO_ICU2, 0x11); /* reset; program device, four bytes */
273 outb(IO_ICU2+1, NRSVIDT+8); /* staring at this vector index */
274 outb(IO_ICU2+1,2); /* my slave id is 2 */
275 #ifdef AUTO_EOI_2
276 outb(IO_ICU2+1, 2 | 1); /* auto EOI, 8086 mode */
277 #else
278 outb(IO_ICU2+1,1); /* 8086 mode */
279 #endif
280 outb(IO_ICU2+1, 0xff); /* leave interrupts masked */
281 outb(IO_ICU2, 0x0a); /* default to IRR on read */
282 }
283
284 /* region of physical memory known to be contiguous */
285 vm_offset_t isaphysmem;
286 static caddr_t dma_bounce[8]; /* XXX */
287 static char bounced[8]; /* XXX */
288 #define MAXDMASZ 512 /* XXX */
289
290 /* high byte of address is stored in this port for i-th dma channel */
291 static short dmapageport[8] =
292 { 0x87, 0x83, 0x81, 0x82, 0x8f, 0x8b, 0x89, 0x8a };
293
294 /*
295 * isa_dmacascade(): program 8237 DMA controller channel to accept
296 * external dma control by a board.
297 */
298 void isa_dmacascade(unsigned chan)
299 {
300 if (chan > 7)
301 panic("isa_dmacascade: impossible request");
302
303 /* set dma channel mode, and set dma channel mode */
304 if ((chan & 4) == 0) {
305 outb(DMA1_MODE, DMA37MD_CASCADE | chan);
306 outb(DMA1_SMSK, chan);
307 } else {
308 outb(DMA2_MODE, DMA37MD_CASCADE | (chan & 3));
309 outb(DMA2_SMSK, chan & 3);
310 }
311 }
312
313 /*
314 * isa_dmastart(): program 8237 DMA controller channel, avoid page alignment
315 * problems by using a bounce buffer.
316 */
317 void isa_dmastart(int flags, caddr_t addr, unsigned nbytes, unsigned chan)
318 { vm_offset_t phys;
319 int waport;
320 caddr_t newaddr;
321
322 if ( chan > 7
323 || (chan < 4 && nbytes > (1<<16))
324 || (chan >= 4 && (nbytes > (1<<17) || (u_int)addr & 1)))
325 panic("isa_dmastart: impossible request");
326
327 if (isa_dmarangecheck(addr, nbytes, chan)) {
328 if (dma_bounce[chan] == 0)
329 dma_bounce[chan] =
330 /*(caddr_t)malloc(MAXDMASZ, M_TEMP, M_WAITOK);*/
331 (caddr_t) isaphysmem + NBPG*chan;
332 bounced[chan] = 1;
333 newaddr = dma_bounce[chan];
334 *(int *) newaddr = 0; /* XXX */
335
336 /* copy bounce buffer on write */
337 if (!(flags & B_READ))
338 bcopy(addr, newaddr, nbytes);
339 addr = newaddr;
340 }
341
342 /* translate to physical */
343 phys = pmap_extract(pmap_kernel(), (vm_offset_t)addr);
344
345 if ((chan & 4) == 0) {
346 /*
347 * Program one of DMA channels 0..3. These are
348 * byte mode channels.
349 */
350 /* set dma channel mode, and reset address ff */
351 if (flags & B_READ)
352 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|chan);
353 else
354 outb(DMA1_MODE, DMA37MD_SINGLE|DMA37MD_READ|chan);
355 outb(DMA1_FFC, 0);
356
357 /* send start address */
358 waport = DMA1_CHN(chan);
359 outb(waport, phys);
360 outb(waport, phys>>8);
361 outb(dmapageport[chan], phys>>16);
362
363 /* send count */
364 outb(waport + 1, --nbytes);
365 outb(waport + 1, nbytes>>8);
366
367 /* unmask channel */
368 outb(DMA1_SMSK, chan);
369 } else {
370 /*
371 * Program one of DMA channels 4..7. These are
372 * word mode channels.
373 */
374 /* set dma channel mode, and reset address ff */
375 if (flags & B_READ)
376 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_WRITE|(chan&3));
377 else
378 outb(DMA2_MODE, DMA37MD_SINGLE|DMA37MD_READ|(chan&3));
379 outb(DMA2_FFC, 0);
380
381 /* send start address */
382 waport = DMA2_CHN(chan - 4);
383 outb(waport, phys>>1);
384 outb(waport, phys>>9);
385 outb(dmapageport[chan], phys>>16);
386
387 /* send count */
388 nbytes >>= 1;
389 outb(waport + 2, --nbytes);
390 outb(waport + 2, nbytes>>8);
391
392 /* unmask channel */
393 outb(DMA2_SMSK, chan & 3);
394 }
395 }
396
397 void isa_dmadone(int flags, caddr_t addr, int nbytes, int chan)
398 {
399
400 /* copy bounce buffer on read */
401 /*if ((flags & (B_PHYS|B_READ)) == (B_PHYS|B_READ))*/
402 if (bounced[chan]) {
403 bcopy(dma_bounce[chan], addr, nbytes);
404 bounced[chan] = 0;
405 }
406 }
407
408 /*
409 * Check for problems with the address range of a DMA transfer
410 * (non-contiguous physical pages, outside of bus address space,
411 * crossing DMA page boundaries).
412 * Return true if special handling needed.
413 */
414
415 isa_dmarangecheck(caddr_t va, unsigned length, unsigned chan) {
416 vm_offset_t phys, priorpage = 0, endva;
417 u_int dma_pgmsk = (chan & 4) ? ~(128*1024-1) : ~(64*1024-1);
418
419 endva = (vm_offset_t)round_page(va + length);
420 for (; va < (caddr_t) endva ; va += NBPG) {
421 phys = trunc_page(pmap_extract(pmap_kernel(), (vm_offset_t)va));
422 #define ISARAM_END RAM_END
423 if (phys == 0)
424 panic("isa_dmacheck: no physical page present");
425 if (phys > ISARAM_END)
426 return (1);
427 if (priorpage) {
428 if (priorpage + NBPG != phys)
429 return (1);
430 /* check if crossing a DMA page boundary */
431 if (((u_int)priorpage ^ (u_int)phys) & dma_pgmsk)
432 return (1);
433 }
434 priorpage = phys;
435 }
436 return (0);
437 }
438
439 /* head of queue waiting for physmem to become available */
440 struct buf isa_physmemq;
441
442 /* blocked waiting for resource to become free for exclusive use */
443 static isaphysmemflag;
444 /* if waited for and call requested when free (B_CALL) */
445 static void (*isaphysmemunblock)(); /* needs to be a list */
446
447 /*
448 * Allocate contiguous physical memory for transfer, returning
449 * a *virtual* address to region. May block waiting for resource.
450 * (assumed to be called at splbio())
451 */
452 caddr_t
453 isa_allocphysmem(caddr_t va, unsigned length, void (*func)()) {
454
455 isaphysmemunblock = func;
456 while (isaphysmemflag & B_BUSY) {
457 isaphysmemflag |= B_WANTED;
458 sleep(&isaphysmemflag, PRIBIO);
459 }
460 isaphysmemflag |= B_BUSY;
461
462 return((caddr_t)isaphysmem);
463 }
464
465 /*
466 * Free contiguous physical memory used for transfer.
467 * (assumed to be called at splbio())
468 */
469 void
470 isa_freephysmem(caddr_t va, unsigned length) {
471
472 isaphysmemflag &= ~B_BUSY;
473 if (isaphysmemflag & B_WANTED) {
474 isaphysmemflag &= B_WANTED;
475 wakeup(&isaphysmemflag);
476 if (isaphysmemunblock)
477 (*isaphysmemunblock)();
478 }
479 }
480
481 /*
482 * Handle a NMI, possibly a machine check.
483 * return true to panic system, false to ignore.
484 */
485 isa_nmi(cd) {
486
487 log(LOG_CRIT, "\nNMI port 61 %x, port 70 %x\n", inb(0x61), inb(0x70));
488 return(0);
489 }
490
491 /*
492 * Caught a stray interrupt, notify
493 */
494 isa_strayintr(d) {
495
496 /* DON'T BOTHER FOR NOW! */
497 /* for some reason, we get bursts of intr #7, even if not enabled! */
498 /*
499 * Well the reason you got bursts of intr #7 is because someone
500 * raised an interrupt line and dropped it before the 8259 could
501 * prioritize it. This is documented in the intel data book. This
502 * means you have BAD hardware! I have changed this so that only
503 * the first 5 get logged, then it quits logging them, and puts
504 * out a special message. rgrimes 3/25/1993
505 */
506 extern u_long intrcnt_stray;
507
508 intrcnt_stray++;
509 if (intrcnt_stray <= 5)
510 log(LOG_ERR,"ISA strayintr %x\n", d);
511 if (intrcnt_stray == 5)
512 log(LOG_CRIT,"Too many ISA strayintr not logging any more\n");
513 }
514
515 /*
516 * Wait "n" microseconds.
517 * Relies on timer 1 counting down from (TIMER_FREQ / hz) at
518 * (2 * TIMER_FREQ) Hz.
519 * Note: timer had better have been programmed before this is first used!
520 * (The standard programming causes the timer to generate a square wave and
521 * the counter is decremented twice every cycle.)
522 */
523 #define CF (2 * TIMER_FREQ)
524 #define TIMER_FREQ 1193182 /* XXX - should be elsewhere */
525
526 extern int hz; /* XXX - should be elsewhere */
527
528 int DELAY(n)
529 int n;
530 {
531 int counter_limit;
532 int prev_tick;
533 int tick;
534 int ticks_left;
535 int sec;
536 int usec;
537
538 #ifdef DELAYDEBUG
539 int getit_calls = 1;
540 int n1;
541 static int state = 0;
542
543 if (state == 0) {
544 state = 1;
545 for (n1 = 1; n1 <= 10000000; n1 *= 10)
546 DELAY(n1);
547 state = 2;
548 }
549 if (state == 1)
550 printf("DELAY(%d)...", n);
551 #endif
552
553 /*
554 * Read the counter first, so that the rest of the setup overhead is
555 * counted. Guess the initial overhead is 20 usec (on most systems it
556 * takes about 1.5 usec for each of the i/o's in getit(). The loop
557 * takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
558 * multiplications and divisions to scale the count take a while).
559 */
560 prev_tick = getit(0, 0);
561 n -= 20;
562
563 /*
564 * Calculate (n * (CF / 1e6)) without using floating point and without
565 * any avoidable overflows.
566 */
567 sec = n / 1000000;
568 usec = n - sec * 1000000;
569 ticks_left = sec * CF
570 + usec * (CF / 1000000)
571 + usec * ((CF % 1000000) / 1000) / 1000
572 + usec * (CF % 1000) / 1000000;
573
574 counter_limit = TIMER_FREQ / hz;
575 while (ticks_left > 0) {
576 tick = getit(0, 0);
577 #ifdef DELAYDEBUG
578 ++getit_calls;
579 #endif
580 if (tick > prev_tick)
581 ticks_left -= prev_tick - (tick - counter_limit);
582 else
583 ticks_left -= prev_tick - tick;
584 prev_tick = tick;
585 }
586 #ifdef DELAYDEBUG
587 if (state == 1)
588 printf(" %d calls to getit() at %d usec each\n",
589 getit_calls, (n + 5) / getit_calls);
590 #endif
591 }
592
593 getit(unit, timer) {
594 int high;
595 int low;
596
597 /*
598 * XXX - isa.h defines bogus timers. There's no such timer as
599 * IO_TIMER_2 = 0x48. There's a timer in the CMOS RAM chip but
600 * its interface is quite different. Neither timer is an 8252.
601 * We actually only call this with unit = 0 and timer = 0. It
602 * could be static...
603 */
604 /*
605 * Protect ourself against interrupts.
606 * XXX - sysbeep() and sysbeepstop() need protection.
607 */
608 disable_intr();
609 /*
610 * Latch the count for 'timer' (cc00xxxx, c = counter, x = any).
611 */
612 outb(IO_TIMER1 + 3, timer << 6);
613
614 low = inb(IO_TIMER1 + timer);
615 high = inb(IO_TIMER1 + timer);
616 enable_intr();
617 return ((high << 8) | low);
618 }
619
620 static beeping;
621 static
622 sysbeepstop(f)
623 {
624 /* disable counter 2 */
625 outb(0x61, inb(0x61) & 0xFC);
626 if (f)
627 timeout(sysbeepstop, 0, f);
628 else
629 beeping = 0;
630 }
631
632 void sysbeep(int pitch, int period)
633 {
634
635 outb(0x61, inb(0x61) | 3); /* enable counter 2 */
636 /*
637 * XXX - move timer stuff to clock.c.
638 * Program counter 2:
639 * ccaammmb, c counter, a = access, m = mode, b = BCD
640 * 1011x110, 11 for aa = LSB then MSB, x11 for mmm = square wave.
641 */
642 outb(0x43, 0xb6); /* set command for counter 2, 2 byte write */
643
644 outb(0x42, pitch);
645 outb(0x42, (pitch>>8));
646
647 if (!beeping) {
648 beeping = period;
649 timeout(sysbeepstop, period/2, period);
650 }
651 }
652
653 /*
654 * Pass command to keyboard controller (8042)
655 */
656 unsigned kbc_8042cmd(val) {
657
658 while (inb(KBSTATP)&KBS_IBF);
659 if (val) outb(KBCMDP, val);
660 while (inb(KBSTATP)&KBS_IBF);
661 return (inb(KBDATAP));
662 }
663
664 /*
665 * Return nonzero if a (masked) irq is pending for a given device.
666 */
667 int
668 isa_irq_pending(dvp)
669 struct isa_device *dvp;
670 {
671 unsigned id_irq;
672
673 id_irq = (unsigned short) dvp->id_irq; /* XXX silly type in struct */
674 if (id_irq & 0xff)
675 return (inb(IO_ICU1) & id_irq);
676 return (inb(IO_ICU2) & (id_irq >> 8));
677 }
678