xref: /netbsd/sys/dev/tc/zs_ioasic.c (revision c4a72b64)
1 /* $NetBSD: zs_ioasic.c,v 1.19 2002/10/02 16:53:10 thorpej Exp $ */
2 
3 /*-
4  * Copyright (c) 1996, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Gordon W. Ross, Ken Hornstein, and by Jason R. Thorpe of the
9  * Numerical Aerospace Simulation Facility, NASA Ames Research Center.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *        This product includes software developed by the NetBSD
22  *        Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Zilog Z8530 Dual UART driver (machine-dependent part).  This driver
42  * handles Z8530 chips attached to the DECstation/Alpha IOASIC.  Modified
43  * for NetBSD/alpha by Ken Hornstein and Jason R. Thorpe.  NetBSD/pmax
44  * adaption by Mattias Drochner.  Merge work by Tohru Nishimura.
45  *
46  * Runs two serial lines per chip using slave drivers.
47  * Plain tty/async lines use the zstty slave.
48  */
49 
50 #include <sys/cdefs.h>
51 __KERNEL_RCSID(0, "$NetBSD: zs_ioasic.c,v 1.19 2002/10/02 16:53:10 thorpej Exp $");
52 
53 #include "opt_ddb.h"
54 #include "opt_kgdb.h"
55 #include "zskbd.h"
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/conf.h>
60 #include <sys/device.h>
61 #include <sys/malloc.h>
62 #include <sys/file.h>
63 #include <sys/ioctl.h>
64 #include <sys/kernel.h>
65 #include <sys/proc.h>
66 #include <sys/tty.h>
67 #include <sys/time.h>
68 #include <sys/syslog.h>
69 
70 #include <machine/autoconf.h>
71 #include <machine/intr.h>
72 #include <machine/z8530var.h>
73 
74 #include <dev/cons.h>
75 #include <dev/ic/z8530reg.h>
76 
77 #include <dev/tc/tcvar.h>
78 #include <dev/tc/ioasicreg.h>
79 #include <dev/tc/ioasicvar.h>
80 
81 #include <dev/tc/zs_ioasicvar.h>
82 
83 #if defined(__alpha__) || defined(alpha)
84 #include <machine/rpb.h>
85 #endif
86 #if defined(pmax)
87 #include <pmax/pmax/pmaxtype.h>
88 #endif
89 
90 /*
91  * Helpers for console support.
92  */
93 void	zs_ioasic_cninit __P((tc_addr_t, tc_offset_t, int));
94 int	zs_ioasic_cngetc __P((dev_t));
95 void	zs_ioasic_cnputc __P((dev_t, int));
96 void	zs_ioasic_cnpollc __P((dev_t, int));
97 
98 struct consdev zs_ioasic_cons = {
99 	NULL, NULL, zs_ioasic_cngetc, zs_ioasic_cnputc,
100 	zs_ioasic_cnpollc, NULL, NODEV, CN_NORMAL,
101 };
102 
103 tc_offset_t zs_ioasic_console_offset;
104 int zs_ioasic_console_channel;
105 int zs_ioasic_console;
106 struct zs_chanstate zs_ioasic_conschanstate_store;
107 
108 int	zs_ioasic_isconsole __P((tc_offset_t, int));
109 int	zs_getc __P((struct zs_chanstate *));
110 void	zs_putc __P((struct zs_chanstate *, int));
111 
112 /*
113  * Some warts needed by z8530tty.c
114  */
115 int zs_def_cflag = (TTYDEF_CFLAG & ~(CSIZE | PARENB)) | CS8;
116 
117 /*
118  * ZS chips are feeded a 7.372 MHz clock.
119  */
120 #define	PCLK	(9600 * 768)	/* PCLK pin input clock rate */
121 
122 /* The layout of this is hardware-dependent (padding, order). */
123 struct zshan {
124 #if defined(__alpha__) || defined(alpha)
125 	volatile u_int	zc_csr;		/* ctrl,status, and indirect access */
126 	u_int		zc_pad0;
127 	volatile u_int	zc_data;	/* data */
128 	u_int		sc_pad1;
129 #endif
130 #if defined(pmax)
131 	volatile u_int16_t zc_csr;	/* ctrl,status, and indirect access */
132 	unsigned : 16;
133 	volatile u_int16_t zc_data;	/* data */
134 	unsigned : 16;
135 #endif
136 };
137 
138 struct zsdevice {
139 	/* Yes, they are backwards. */
140 	struct	zshan zs_chan_b;
141 	struct	zshan zs_chan_a;
142 };
143 
144 static u_char zs_ioasic_init_reg[16] = {
145 	0,	/* 0: CMD (reset, etc.) */
146 	0,	/* 1: No interrupts yet. */
147 	0xf0,	/* 2: IVECT */
148 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
149 	ZSWR4_CLK_X16 | ZSWR4_ONESB,
150 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
151 	0,	/* 6: TXSYNC/SYNCLO */
152 	0,	/* 7: RXSYNC/SYNCHI */
153 	0,	/* 8: alias for data port */
154 	ZSWR9_MASTER_IE | ZSWR9_VECTOR_INCL_STAT,
155 	0,	/*10: Misc. TX/RX control bits */
156 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
157 	22,	/*12: BAUDLO (default=9600) */
158 	0,	/*13: BAUDHI (default=9600) */
159 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
160 	ZSWR15_BREAK_IE,
161 };
162 
163 struct zshan *zs_ioasic_get_chan_addr __P((tc_addr_t, int));
164 
165 struct zshan *
166 zs_ioasic_get_chan_addr(zsaddr, channel)
167 	tc_addr_t zsaddr;
168 	int channel;
169 {
170 	struct zsdevice *addr;
171 	struct zshan *zc;
172 
173 #if defined(__alpha__) || defined(alpha)
174 	addr = (struct zsdevice *)TC_DENSE_TO_SPARSE(zsaddr);
175 #endif
176 #if defined(pmax)
177 	addr = (struct zsdevice *)MIPS_PHYS_TO_KSEG1(zsaddr);
178 #endif
179 
180 	if (channel == 0)
181 		zc = &addr->zs_chan_a;
182 	else
183 		zc = &addr->zs_chan_b;
184 
185 	return (zc);
186 }
187 
188 
189 /****************************************************************
190  * Autoconfig
191  ****************************************************************/
192 
193 /* Definition of the driver for autoconfig. */
194 int	zs_ioasic_match __P((struct device *, struct cfdata *, void *));
195 void	zs_ioasic_attach __P((struct device *, struct device *, void *));
196 int	zs_ioasic_print __P((void *, const char *name));
197 int	zs_ioasic_submatch __P((struct device *, struct cfdata *, void *));
198 
199 CFATTACH_DECL(zsc_ioasic, sizeof(struct zsc_softc),
200     zs_ioasic_match, zs_ioasic_attach, NULL, NULL);
201 
202 /* Interrupt handlers. */
203 int	zs_ioasic_hardintr __P((void *));
204 void	zs_ioasic_softintr __P((void *));
205 
206 /*
207  * Is the zs chip present?
208  */
209 int
210 zs_ioasic_match(parent, cf, aux)
211 	struct device *parent;
212 	struct cfdata *cf;
213 	void *aux;
214 {
215 	struct ioasicdev_attach_args *d = aux;
216 	tc_addr_t zs_addr;
217 
218 	/*
219 	 * Make sure that we're looking for the right kind of device.
220 	 */
221 	if (strncmp(d->iada_modname, "z8530   ", TC_ROM_LLEN) != 0 &&
222 	    strncmp(d->iada_modname, "scc", TC_ROM_LLEN) != 0)
223 		return (0);
224 
225 	/*
226 	 * Check user-specified offset against the ioasic offset.
227 	 * Allow it to be wildcarded.
228 	 */
229 	if (cf->cf_loc[IOASICCF_OFFSET] != IOASICCF_OFFSET_DEFAULT &&
230 	    cf->cf_loc[IOASICCF_OFFSET] != d->iada_offset)
231 		return (0);
232 
233 	/*
234 	 * Find out the device address, and check it for validity.
235 	 */
236 	zs_addr = TC_DENSE_TO_SPARSE((tc_addr_t)d->iada_addr);
237 	if (tc_badaddr(zs_addr))
238 		return (0);
239 
240 	return (1);
241 }
242 
243 /*
244  * Attach a found zs.
245  */
246 void
247 zs_ioasic_attach(parent, self, aux)
248 	struct device *parent;
249 	struct device *self;
250 	void *aux;
251 {
252 	struct zsc_softc *zs = (void *) self;
253 	struct zsc_attach_args zs_args;
254 	struct zs_chanstate *cs;
255 	struct ioasicdev_attach_args *d = aux;
256 	struct zshan *zc;
257 	int s, channel;
258 	u_long zflg;
259 
260 	printf("\n");
261 
262 	/*
263 	 * Initialize software state for each channel.
264 	 */
265 	for (channel = 0; channel < 2; channel++) {
266 		zs_args.channel = channel;
267 		zs_args.hwflags = 0;
268 
269 		if (zs_ioasic_isconsole(d->iada_offset, channel)) {
270 			cs = &zs_ioasic_conschanstate_store;
271 			zs_args.hwflags |= ZS_HWFLAG_CONSOLE;
272 		} else {
273 			cs = malloc(sizeof(struct zs_chanstate),
274 					M_DEVBUF, M_NOWAIT|M_ZERO);
275 			zc = zs_ioasic_get_chan_addr(d->iada_addr, channel);
276 			cs->cs_reg_csr = (void *)&zc->zc_csr;
277 
278 			bcopy(zs_ioasic_init_reg, cs->cs_creg, 16);
279 			bcopy(zs_ioasic_init_reg, cs->cs_preg, 16);
280 
281 			cs->cs_defcflag = zs_def_cflag;
282 			cs->cs_defspeed = 9600;		/* XXX */
283 			(void) zs_set_modes(cs, cs->cs_defcflag);
284 		}
285 
286 		zs->zsc_cs[channel] = cs;
287 		zs->zsc_addroffset = d->iada_offset; /* cookie only */
288 		cs->cs_channel = channel;
289 		cs->cs_ops = &zsops_null;
290 		cs->cs_brg_clk = PCLK / 16;
291 
292 		/*
293 		 * DCD and CTS interrupts are only meaningful on
294 		 * SCC 0/B, and RTS and DTR only on B of SCC 0 & 1.
295 		 *
296 		 * XXX This is sorta gross.
297 		 */
298 		if (d->iada_offset == 0x00100000 && channel == 1) {
299 			cs->cs_creg[15] |= ZSWR15_DCD_IE;
300 			cs->cs_preg[15] |= ZSWR15_DCD_IE;
301 			zflg = ZIP_FLAGS_DCDCTS;
302 		} else
303 			zflg = 0;
304 		if (channel == 1)
305 			zflg |= ZIP_FLAGS_DTRRTS;
306 		(u_long)cs->cs_private = zflg;
307 
308 		/*
309 		 * Clear the master interrupt enable.
310 		 * The INTENA is common to both channels,
311 		 * so just do it on the A channel.
312 		 */
313 		if (channel == 0) {
314 			zs_write_reg(cs, 9, 0);
315 		}
316 
317 		/*
318 		 * Set up the flow/modem control channel pointer to
319 		 * deal with the weird wiring on the TC Alpha and
320 		 * DECstation.
321 		 */
322 		if (channel == 1)
323 			cs->cs_ctl_chan = zs->zsc_cs[0];
324 		else
325 			cs->cs_ctl_chan = NULL;
326 
327 		/*
328 		 * Look for a child driver for this channel.
329 		 * The child attach will setup the hardware.
330 		 */
331 		if (config_found_sm(self, (void *)&zs_args,
332 				zs_ioasic_print, zs_ioasic_submatch) == NULL) {
333 			/* No sub-driver.  Just reset it. */
334 			u_char reset = (channel == 0) ?
335 				ZSWR9_A_RESET : ZSWR9_B_RESET;
336 			s = splhigh();
337 			zs_write_reg(cs, 9, reset);
338 			splx(s);
339 		}
340 	}
341 
342 	/*
343 	 * Set up the ioasic interrupt handler.
344 	 */
345 	ioasic_intr_establish(parent, d->iada_cookie, TC_IPL_TTY,
346 	    zs_ioasic_hardintr, zs);
347 	zs->zsc_sih = softintr_establish(IPL_SOFTSERIAL,
348 	    zs_ioasic_softintr, zs);
349 	if (zs->zsc_sih == NULL)
350 		panic("zs_ioasic_attach: unable to register softintr");
351 
352 	/*
353 	 * Set the master interrupt enable and interrupt vector.  The
354 	 * Sun does this only on one channel.  The old Alpha SCC driver
355 	 * did it on both.  We'll do it on both.
356 	 */
357 	s = splhigh();
358 	/* interrupt vector */
359 	zs_write_reg(zs->zsc_cs[0], 2, zs_ioasic_init_reg[2]);
360 	zs_write_reg(zs->zsc_cs[1], 2, zs_ioasic_init_reg[2]);
361 
362 	/* master interrupt control (enable) */
363 	zs_write_reg(zs->zsc_cs[0], 9, zs_ioasic_init_reg[9]);
364 	zs_write_reg(zs->zsc_cs[1], 9, zs_ioasic_init_reg[9]);
365 #if defined(__alpha__) || defined(alpha)
366 	/* ioasic interrupt enable */
367 	*(volatile u_int *)(ioasic_base + IOASIC_IMSK) |=
368 		    IOASIC_INTR_SCC_1 | IOASIC_INTR_SCC_0;
369 	tc_mb();
370 #endif
371 	splx(s);
372 }
373 
374 int
375 zs_ioasic_print(aux, name)
376 	void *aux;
377 	const char *name;
378 {
379 	struct zsc_attach_args *args = aux;
380 
381 	if (name != NULL)
382 		printf("%s:", name);
383 
384 	if (args->channel != -1)
385 		printf(" channel %d", args->channel);
386 
387 	return (UNCONF);
388 }
389 
390 int
391 zs_ioasic_submatch(parent, cf, aux)
392 	struct device *parent;
393 	struct cfdata *cf;
394 	void *aux;
395 {
396 	struct zsc_softc *zs = (void *)parent;
397 	struct zsc_attach_args *pa = aux;
398 	char *defname = "";
399 
400 	if (cf->cf_loc[ZSCCF_CHANNEL] != ZSCCF_CHANNEL_DEFAULT &&
401 	    cf->cf_loc[ZSCCF_CHANNEL] != pa->channel)
402 		return (0);
403 	if (cf->cf_loc[ZSCCF_CHANNEL] == ZSCCF_CHANNEL_DEFAULT) {
404 		if (pa->channel == 0) {
405 #if defined(pmax)
406 			if (systype == DS_MAXINE)
407 				return (0);
408 #endif
409 			if (zs->zsc_addroffset == 0x100000)
410 				defname = "vsms";
411 			else
412 				defname = "lkkbd";
413 		}
414 		else if (zs->zsc_addroffset == 0x100000)
415 			defname = "zstty";
416 #if defined(pmax)
417 		else if (systype == DS_MAXINE)
418 			return (0);
419 #endif
420 #if defined(__alpha__) || defined(alpha)
421 		else if (cputype == ST_DEC_3000_300)
422 			return (0);
423 #endif
424 		else
425 			defname = "zstty"; /* 3min/3max+, DEC3000/500 */
426 
427 		if (strcmp(cf->cf_name, defname))
428 			return (0);
429 	}
430 	return (config_match(parent, cf, aux));
431 }
432 
433 /*
434  * Hardware interrupt handler.
435  */
436 int
437 zs_ioasic_hardintr(arg)
438 	void *arg;
439 {
440 	struct zsc_softc *zsc = arg;
441 
442 	/*
443 	 * Call the upper-level MI hardware interrupt handler.
444 	 */
445 	zsc_intr_hard(zsc);
446 
447 	/*
448 	 * Check to see if we need to schedule any software-level
449 	 * processing interrupts.
450 	 */
451 	if (zsc->zsc_cs[0]->cs_softreq | zsc->zsc_cs[1]->cs_softreq)
452 		softintr_schedule(zsc->zsc_sih);
453 
454 	return (1);
455 }
456 
457 /*
458  * Software-level interrupt (character processing, lower priority).
459  */
460 void
461 zs_ioasic_softintr(arg)
462 	void *arg;
463 {
464 	struct zsc_softc *zsc = arg;
465 	int s;
466 
467 	s = spltty();
468 	(void) zsc_intr_soft(zsc);
469 	splx(s);
470 }
471 
472 /*
473  * MD functions for setting the baud rate and control modes.
474  */
475 int
476 zs_set_speed(cs, bps)
477 	struct zs_chanstate *cs;
478 	int bps;	/* bits per second */
479 {
480 	int tconst, real_bps;
481 
482 	if (bps == 0)
483 		return (0);
484 
485 #ifdef DIAGNOSTIC
486 	if (cs->cs_brg_clk == 0)
487 		panic("zs_set_speed");
488 #endif
489 
490 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
491 	if (tconst < 0)
492 		return (EINVAL);
493 
494 	/* Convert back to make sure we can do it. */
495 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
496 
497 	/* XXX - Allow some tolerance here? */
498 	if (real_bps != bps)
499 		return (EINVAL);
500 
501 	cs->cs_preg[12] = tconst;
502 	cs->cs_preg[13] = tconst >> 8;
503 
504 	/* Caller will stuff the pending registers. */
505 	return (0);
506 }
507 
508 int
509 zs_set_modes(cs, cflag)
510 	struct zs_chanstate *cs;
511 	int cflag;	/* bits per second */
512 {
513 	u_long privflags = (u_long)cs->cs_private;
514 	int s;
515 
516 	/*
517 	 * Output hardware flow control on the chip is horrendous:
518 	 * if carrier detect drops, the receiver is disabled, and if
519 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
520 	 * Therefore, NEVER set the HFC bit, and instead use the
521 	 * status interrupt to detect CTS changes.
522 	 */
523 	s = splzs();
524 	if ((cflag & (CLOCAL | MDMBUF)) != 0)
525 		cs->cs_rr0_dcd = 0;
526 	else
527 		cs->cs_rr0_dcd = ZSRR0_DCD;
528 	if ((cflag & CRTSCTS) != 0) {
529 		cs->cs_wr5_dtr = ZSWR5_DTR;
530 		cs->cs_wr5_rts = ZSWR5_RTS;
531 		cs->cs_rr0_cts = ZSRR0_CTS;
532 	} else if ((cflag & CDTRCTS) != 0) {
533 		cs->cs_wr5_dtr = 0;
534 		cs->cs_wr5_rts = ZSWR5_DTR;
535 		cs->cs_rr0_cts = ZSRR0_CTS;
536 	} else if ((cflag & MDMBUF) != 0) {
537 		cs->cs_wr5_dtr = 0;
538 		cs->cs_wr5_rts = ZSWR5_DTR;
539 		cs->cs_rr0_cts = ZSRR0_DCD;
540 	} else {
541 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
542 		cs->cs_wr5_rts = 0;
543 		cs->cs_rr0_cts = 0;
544 	}
545 
546 	if ((privflags & ZIP_FLAGS_DCDCTS) == 0) {
547 		cs->cs_rr0_dcd &= ~(ZSRR0_CTS|ZSRR0_DCD);
548 		cs->cs_rr0_cts &= ~(ZSRR0_CTS|ZSRR0_DCD);
549 	}
550 	if ((privflags & ZIP_FLAGS_DTRRTS) == 0) {
551 		cs->cs_wr5_dtr &= ~(ZSWR5_RTS|ZSWR5_DTR);
552 		cs->cs_wr5_rts &= ~(ZSWR5_RTS|ZSWR5_DTR);
553 	}
554 	splx(s);
555 
556 	/* Caller will stuff the pending registers. */
557 	return (0);
558 }
559 
560 /*
561  * Functions to read and write individual registers in a channel.
562  * The ZS chip requires a 1.6 uSec. recovery time between accesses,
563  * and the Alpha TC hardware does NOT take care of this for you.
564  * The delay is now handled inside the chip access functions.
565  * These could be inlines, but with the delay, speed is moot.
566  */
567 #if defined(pmax)
568 #undef	DELAY
569 #define	DELAY(x)
570 #endif
571 
572 u_int
573 zs_read_reg(cs, reg)
574 	struct zs_chanstate *cs;
575 	u_int reg;
576 {
577 	struct zshan *zc = (void *)cs->cs_reg_csr;
578 	unsigned val;
579 
580 	zc->zc_csr = reg << 8;
581 	tc_wmb();
582 	DELAY(5);
583 	val = (zc->zc_csr >> 8) & 0xff;
584 	/* tc_mb(); */
585 	DELAY(5);
586 	return (val);
587 }
588 
589 void
590 zs_write_reg(cs, reg, val)
591 	struct zs_chanstate *cs;
592 	u_int reg, val;
593 {
594 	struct zshan *zc = (void *)cs->cs_reg_csr;
595 
596 	zc->zc_csr = reg << 8;
597 	tc_wmb();
598 	DELAY(5);
599 	zc->zc_csr = val << 8;
600 	tc_wmb();
601 	DELAY(5);
602 }
603 
604 u_int
605 zs_read_csr(cs)
606 	struct zs_chanstate *cs;
607 {
608 	struct zshan *zc = (void *)cs->cs_reg_csr;
609 	unsigned val;
610 
611 	val = (zc->zc_csr >> 8) & 0xff;
612 	/* tc_mb(); */
613 	DELAY(5);
614 	return (val);
615 }
616 
617 void
618 zs_write_csr(cs, val)
619 	struct zs_chanstate *cs;
620 	u_int val;
621 {
622 	struct zshan *zc = (void *)cs->cs_reg_csr;
623 
624 	zc->zc_csr = val << 8;
625 	tc_wmb();
626 	DELAY(5);
627 }
628 
629 u_int
630 zs_read_data(cs)
631 	struct zs_chanstate *cs;
632 {
633 	struct zshan *zc = (void *)cs->cs_reg_csr;
634 	unsigned val;
635 
636 	val = (zc->zc_data) >> 8 & 0xff;
637 	/* tc_mb(); */
638 	DELAY(5);
639 	return (val);
640 }
641 
642 void
643 zs_write_data(cs, val)
644 	struct zs_chanstate *cs;
645 	u_int val;
646 {
647 	struct zshan *zc = (void *)cs->cs_reg_csr;
648 
649 	zc->zc_data = val << 8;
650 	tc_wmb();
651 	DELAY(5);
652 }
653 
654 /****************************************************************
655  * Console support functions
656  ****************************************************************/
657 
658 /*
659  * Handle user request to enter kernel debugger.
660  */
661 void
662 zs_abort(cs)
663 	struct zs_chanstate *cs;
664 {
665 	int rr0;
666 
667 	/* Wait for end of break. */
668 	/* XXX - Limit the wait? */
669 	do {
670 		rr0 = zs_read_csr(cs);
671 	} while (rr0 & ZSRR0_BREAK);
672 
673 #if defined(KGDB)
674 	zskgdb(cs);
675 #elif defined(DDB)
676 	Debugger();
677 #else
678 	printf("zs_abort: ignoring break on console\n");
679 #endif
680 }
681 
682 /*
683  * Polled input char.
684  */
685 int
686 zs_getc(cs)
687 	struct zs_chanstate *cs;
688 {
689 	int s, c, rr0;
690 
691 	s = splhigh();
692 	/* Wait for a character to arrive. */
693 	do {
694 		rr0 = zs_read_csr(cs);
695 	} while ((rr0 & ZSRR0_RX_READY) == 0);
696 
697 	c = zs_read_data(cs);
698 	splx(s);
699 
700 	/*
701 	 * This is used by the kd driver to read scan codes,
702 	 * so don't translate '\r' ==> '\n' here...
703 	 */
704 	return (c);
705 }
706 
707 /*
708  * Polled output char.
709  */
710 void
711 zs_putc(cs, c)
712 	struct zs_chanstate *cs;
713 	int c;
714 {
715 	register int s, rr0;
716 
717 	s = splhigh();
718 	/* Wait for transmitter to become ready. */
719 	do {
720 		rr0 = zs_read_csr(cs);
721 	} while ((rr0 & ZSRR0_TX_READY) == 0);
722 
723 	zs_write_data(cs, c);
724 
725 	/* Wait for the character to be transmitted. */
726 	do {
727 		rr0 = zs_read_csr(cs);
728 	} while ((rr0 & ZSRR0_TX_READY) == 0);
729 	splx(s);
730 }
731 
732 /*****************************************************************/
733 
734 /*
735  * zs_ioasic_cninit --
736  *	Initialize the serial channel for either a keyboard or
737  *	a serial console.
738  */
739 void
740 zs_ioasic_cninit(ioasic_addr, zs_offset, channel)
741 	tc_addr_t ioasic_addr;
742 	tc_offset_t zs_offset;
743 	int channel;
744 {
745 	struct zs_chanstate *cs;
746 	tc_addr_t zs_addr;
747 	struct zshan *zc;
748 	u_long zflg;
749 
750 	/*
751 	 * Initialize the console finder helpers.
752 	 */
753 	zs_ioasic_console_offset = zs_offset;
754 	zs_ioasic_console_channel = channel;
755 	zs_ioasic_console = 1;
756 
757 	/*
758 	 * Pointer to channel state.
759 	 */
760 	cs = &zs_ioasic_conschanstate_store;
761 
762 	/*
763 	 * Compute the physical address of the chip, "map" it via
764 	 * K0SEG, and then get the address of the actual channel.
765 	 */
766 #if defined(__alpha__) || defined(alpha)
767 	zs_addr = ALPHA_PHYS_TO_K0SEG(ioasic_addr + zs_offset);
768 #endif
769 #if defined(pmax)
770 	zs_addr = MIPS_PHYS_TO_KSEG1(ioasic_addr + zs_offset);
771 #endif
772 	zc = zs_ioasic_get_chan_addr(zs_addr, channel);
773 
774 	/* Setup temporary chanstate. */
775 	cs->cs_reg_csr = (void *)&zc->zc_csr;
776 
777 	cs->cs_channel = channel;
778 	cs->cs_ops = &zsops_null;
779 	cs->cs_brg_clk = PCLK / 16;
780 
781 	/* Initialize the pending registers. */
782 	bcopy(zs_ioasic_init_reg, cs->cs_preg, 16);
783 	/* cs->cs_preg[5] |= (ZSWR5_DTR | ZSWR5_RTS); */
784 
785 	/*
786 	 * DCD and CTS interrupts are only meaningful on
787 	 * SCC 0/B, and RTS and DTR only on B of SCC 0 & 1.
788 	 *
789 	 * XXX This is sorta gross.
790 	 */
791 	if (zs_offset == 0x00100000 && channel == 1)
792 		zflg = ZIP_FLAGS_DCDCTS;
793 	else
794 		zflg = 0;
795 	if (channel == 1)
796 		zflg |= ZIP_FLAGS_DTRRTS;
797 	(u_long)cs->cs_private = zflg;
798 
799 	/* Clear the master interrupt enable. */
800 	zs_write_reg(cs, 9, 0);
801 
802 	/* Reset the whole SCC chip. */
803 	zs_write_reg(cs, 9, ZSWR9_HARD_RESET);
804 
805 	/* Copy "pending" to "current" and H/W. */
806 	zs_loadchannelregs(cs);
807 }
808 
809 /*
810  * zs_ioasic_cnattach --
811  *	Initialize and attach a serial console.
812  */
813 void
814 zs_ioasic_cnattach(ioasic_addr, zs_offset, channel)
815 	tc_addr_t ioasic_addr;
816 	tc_offset_t zs_offset;
817 	int channel;
818 {
819 	struct zs_chanstate *cs = &zs_ioasic_conschanstate_store;
820 	extern const struct cdevsw zstty_cdevsw;
821 
822 	zs_ioasic_cninit(ioasic_addr, zs_offset, channel);
823 	cs->cs_defspeed = 9600;
824 	cs->cs_defcflag = (TTYDEF_CFLAG & ~(CSIZE | PARENB)) | CS8;
825 
826 	/* Point the console at the SCC. */
827 	cn_tab = &zs_ioasic_cons;
828 	cn_tab->cn_pri = CN_REMOTE;
829 	cn_tab->cn_dev = makedev(cdevsw_lookup_major(&zstty_cdevsw),
830 				 (zs_offset == 0x100000) ? 0 : 1);
831 }
832 
833 /*
834  * zs_ioasic_lk201_cnattach --
835  *	Initialize and attach a keyboard.
836  */
837 int
838 zs_ioasic_lk201_cnattach(ioasic_addr, zs_offset, channel)
839 	tc_addr_t ioasic_addr;
840 	tc_offset_t zs_offset;
841 	int channel;
842 {
843 #if (NZSKBD > 0)
844 	struct zs_chanstate *cs = &zs_ioasic_conschanstate_store;
845 
846 	zs_ioasic_cninit(ioasic_addr, zs_offset, channel);
847 	cs->cs_defspeed = 4800;
848 	cs->cs_defcflag = (TTYDEF_CFLAG & ~(CSIZE | PARENB)) | CS8;
849 	return (zskbd_cnattach(cs));
850 #else
851 	return (ENXIO);
852 #endif
853 }
854 
855 int
856 zs_ioasic_isconsole(offset, channel)
857 	tc_offset_t offset;
858 	int channel;
859 {
860 
861 	if (zs_ioasic_console &&
862 	    offset == zs_ioasic_console_offset &&
863 	    channel == zs_ioasic_console_channel)
864 		return (1);
865 
866 	return (0);
867 }
868 
869 /*
870  * Polled console input putchar.
871  */
872 int
873 zs_ioasic_cngetc(dev)
874 	dev_t dev;
875 {
876 
877 	return (zs_getc(&zs_ioasic_conschanstate_store));
878 }
879 
880 /*
881  * Polled console output putchar.
882  */
883 void
884 zs_ioasic_cnputc(dev, c)
885 	dev_t dev;
886 	int c;
887 {
888 
889 	zs_putc(&zs_ioasic_conschanstate_store, c);
890 }
891 
892 /*
893  * Set polling/no polling on console.
894  */
895 void
896 zs_ioasic_cnpollc(dev, onoff)
897 	dev_t dev;
898 	int onoff;
899 {
900 
901 	/* XXX ??? */
902 }
903