xref: /openbsd-src/sys/arch/macppc/dev/zs.c (revision f1dd7b858388b4a23f4f67a4957ec5ff656ebbe8)
1 /*	$OpenBSD: zs.c,v 1.31 2021/03/11 11:16:58 jsg Exp $	*/
2 /*	$NetBSD: zs.c,v 1.17 2001/06/19 13:42:15 wiz Exp $	*/
3 
4 /*
5  * Copyright (c) 1996, 1998 Bill Studenmund
6  * Copyright (c) 1995 Gordon W. Ross
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  * 4. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *      This product includes software developed by Gordon Ross
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 /*
36  * Zilog Z8530 Dual UART driver (machine-dependent part)
37  *
38  * Runs two serial lines per chip using slave drivers.
39  * Plain tty/async lines use the zstty slave.
40  * Sun keyboard/mouse uses the zskbd/zsms slaves.
41  * Other ports use their own mice & keyboard slaves.
42  *
43  * Credits & history:
44  *
45  * With NetBSD 1.1, port-mac68k started using a port of the port-sparc
46  * (port-sun3?) zs.c driver (which was in turn based on code in the
47  * Berkeley 4.4 Lite release). Bill Studenmund did the port, with
48  * help from Allen Briggs and Gordon Ross <gwr@netbsd.org>. Noud de
49  * Brouwer field-tested the driver at a local ISP.
50  *
51  * Bill Studenmund and Gordon Ross then ported the machine-independent
52  * z8530 driver to work with port-mac68k. NetBSD 1.2 contained an
53  * intermediate version (mac68k using a local, patched version of
54  * the m.i. drivers), with NetBSD 1.3 containing a full version.
55  */
56 
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/proc.h>
60 #include <sys/device.h>
61 #include <sys/conf.h>
62 #include <sys/ioctl.h>
63 #include <sys/tty.h>
64 #include <sys/time.h>
65 #include <sys/kernel.h>
66 #include <sys/syslog.h>
67 
68 #include <dev/cons.h>
69 #include <dev/ofw/openfirm.h>
70 #include <dev/ic/z8530reg.h>
71 
72 #include <machine/z8530var.h>
73 #include <machine/autoconf.h>
74 #include <machine/cpu.h>
75 
76 #include "zs.h"
77 
78 /*
79  * Some warts needed by z8530tty.c -
80  */
81 int zs_def_cflag = (CREAD | CS8 | HUPCL);
82 int zs_major = 7;
83 
84 struct zsdevice {
85 	/* Yes, they are backwards. */
86 	struct	zschan zs_chan_b;
87 	struct	zschan zs_chan_a;
88 };
89 
90 /* Flags from cninit() */
91 static int zs_hwflags[NZS][2];
92 /* Default speed for each channel */
93 static int zs_defspeed[NZS][2] = {
94 	{ 38400,	/* tty00 */
95 	  38400 },	/* tty01 */
96 };
97 
98 /* console stuff */
99 void	*zs_conschan = 0;
100 #ifdef	ZS_CONSOLE_ABORT
101 int	zs_cons_canabort = 1;
102 #else
103 int	zs_cons_canabort = 0;
104 #endif /* ZS_CONSOLE_ABORT*/
105 
106 /* device to which the console is attached--if serial. */
107 /* Mac stuff */
108 
109 int zs_get_speed(struct zs_chanstate *);
110 
111 /*
112  * Even though zsparam will set up the clock multiples, etc., we
113  * still set them here as: 1) mice & keyboards don't use zsparam,
114  * and 2) the console stuff uses these defaults before device
115  * attach.
116  */
117 
118 static u_char zs_init_reg[16] = {
119 	0,	/* 0: CMD (reset, etc.) */
120 	ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE, 	/* 1: No interrupts yet. ??? */
121 	0,	/* IVECT */
122 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
123 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
124 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
125 	0,	/* 6: TXSYNC/SYNCLO */
126 	0,	/* 7: RXSYNC/SYNCHI */
127 	0,	/* 8: alias for data port */
128 	ZSWR9_MASTER_IE,
129 	0,	/*10: Misc. TX/RX control bits */
130 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
131 	((PCLK/32)/38400)-2,	/*12: BAUDLO (default=38400) */
132 	0,			/*13: BAUDHI (default=38400) */
133 	ZSWR14_BAUD_ENA,
134 	ZSWR15_BREAK_IE,
135 };
136 
137 /****************************************************************
138  * Autoconfig
139  ****************************************************************/
140 
141 struct cfdriver zs_cd = {
142 	NULL, "zs", DV_TTY
143 };
144 
145 /* Definition of the driver for autoconfig. */
146 int	zs_match(struct device *, void *, void *);
147 void	zs_attach(struct device *, struct device *, void *);
148 int	zs_print(void *, const char *name);
149 
150 /* Power management hooks */
151 int  zs_enable (struct zs_chanstate *);
152 void zs_disable (struct zs_chanstate *);
153 
154 struct cfattach zs_ca = {
155 	sizeof(struct zsc_softc), zs_match, zs_attach
156 };
157 
158 int zshard(void *);
159 void zssoft(void *);
160 #ifdef ZS_TXDMA
161 int zs_txdma_int(void *);
162 #endif
163 
164 /*
165  * Is the zs chip present?
166  */
167 int
168 zs_match(struct device *parent, void *match, void *aux)
169 {
170 	struct confargs *ca = aux;
171 	struct cfdata *cf = match;
172 
173 	if (strcmp(ca->ca_name, "escc") != 0)
174 		return 0;
175 
176 	if (ca->ca_nreg < 8)
177 		return 0;
178 
179 	if (cf->cf_unit > 1)
180 		return 0;
181 
182 	return 1;
183 }
184 
185 /*
186  * Attach a found zs.
187  *
188  * Match slave number to zs unit number, so that misconfiguration will
189  * not set up the keyboard as ttya, etc.
190  */
191 void
192 zs_attach(struct device *parent, struct device *self, void *aux)
193 {
194 	struct zsc_softc *zsc = (void *)self;
195 	struct confargs *ca = aux;
196 	struct zsc_attach_args zsc_args;
197 	volatile struct zschan *zc;
198 	struct xzs_chanstate *xcs;
199 	struct zs_chanstate *cs;
200 	struct zsdevice *zsd;
201 	int zs_unit, channel;
202 	int s;
203 	int node, intr[3][3];
204 	u_int regs[16];
205 
206 	zs_unit = zsc->zsc_dev.dv_unit;
207 
208 	zsd = mapiodev(ca->ca_baseaddr + ca->ca_reg[0], ca->ca_reg[1]);
209 	node = OF_child(ca->ca_node);	/* ch-a */
210 
211 	for (channel = 0; channel < 2; channel++) {
212 		if (OF_getprop(node, "AAPL,interrupts",
213 			       intr[channel], sizeof(intr[0])) == -1 &&
214 		    OF_getprop(node, "interrupts",
215 			       intr[channel], sizeof(intr[0])) == -1) {
216 			printf(": cannot find interrupt property\n");
217 			return;
218 		}
219 
220 		if (OF_getprop(node, "reg", regs, sizeof(regs)) < 24) {
221 			printf(": cannot find reg property\n");
222 			return;
223 		}
224 		regs[2] += ca->ca_baseaddr;
225 		regs[4] += ca->ca_baseaddr;
226 #ifdef ZS_TXDMA
227 		zsc->zsc_txdmareg[channel] = mapiodev(regs[2], regs[3]);
228 		zsc->zsc_txdmacmd[channel] =
229 			dbdma_alloc(sizeof(dbdma_command_t) * 3);
230 		memset(zsc->zsc_txdmacmd[channel], 0,
231 			sizeof(dbdma_command_t) * 3);
232 		dbdma_reset(zsc->zsc_txdmareg[channel]);
233 #endif
234 		node = OF_peer(node);	/* ch-b */
235 	}
236 
237 	printf(": irq %d,%d\n", intr[0][0], intr[1][0]);
238 
239 	/*
240 	 * Initialize software state for each channel.
241 	 */
242 	for (channel = 0; channel < 2; channel++) {
243 		zsc_args.channel = channel;
244 		zsc_args.hwflags = zs_hwflags[zs_unit][channel];
245 		xcs = &zsc->xzsc_xcs_store[channel];
246 		cs  = &xcs->xzs_cs;
247 		zsc->zsc_cs[channel] = cs;
248 
249 		cs->cs_channel = channel;
250 		cs->cs_private = NULL;
251 		cs->cs_ops = &zsops_null;
252 
253 		zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
254 
255 		cs->cs_reg_csr  = &zc->zc_csr;
256 		cs->cs_reg_data = &zc->zc_data;
257 
258 		memcpy(cs->cs_creg, zs_init_reg, 16);
259 		memcpy(cs->cs_preg, zs_init_reg, 16);
260 
261 		/* Current BAUD rate generator clock. */
262 		/* RTxC is 230400*16, so use 230400 */
263 		cs->cs_brg_clk = PCLK / 16;
264 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE)
265 			cs->cs_defspeed = zs_get_speed(cs);
266 		else
267 			cs->cs_defspeed =
268 			    zs_defspeed[zs_unit][channel];
269 		cs->cs_defcflag = zs_def_cflag;
270 
271 		/* Make these correspond to cs_defcflag (-crtscts) */
272 		cs->cs_rr0_dcd = ZSRR0_DCD;
273 		cs->cs_rr0_cts = 0;
274 		cs->cs_wr5_dtr = ZSWR5_DTR;
275 		cs->cs_wr5_rts = 0;
276 
277 #ifdef __notyet__
278 		cs->cs_slave_type = ZS_SLAVE_NONE;
279 #endif
280 
281 		/* Define BAUD rate stuff. */
282 		xcs->cs_clocks[0].clk = PCLK;
283 		xcs->cs_clocks[0].flags = ZSC_RTXBRG | ZSC_RTXDIV;
284 		xcs->cs_clocks[1].flags =
285 			ZSC_RTXBRG | ZSC_RTXDIV | ZSC_VARIABLE | ZSC_EXTERN;
286 		xcs->cs_clocks[2].flags = ZSC_TRXDIV | ZSC_VARIABLE;
287 		xcs->cs_clock_count = 3;
288 		if (channel == 0) {
289 			/*xcs->cs_clocks[1].clk = mac68k_machine.modem_dcd_clk;*/
290 			/*xcs->cs_clocks[2].clk = mac68k_machine.modem_cts_clk;*/
291 			xcs->cs_clocks[1].clk = 0;
292 			xcs->cs_clocks[2].clk = 0;
293 		} else {
294 			xcs->cs_clocks[1].flags = ZSC_VARIABLE;
295 			/*
296 			 * Yes, we aren't defining ANY clock source enables for the
297 			 * printer's DCD clock in. The hardware won't let us
298 			 * use it. But a clock will freak out the chip, so we
299 			 * let you set it, telling us to bar interrupts on the line.
300 			 */
301 			/*xcs->cs_clocks[1].clk = mac68k_machine.print_dcd_clk;*/
302 			/*xcs->cs_clocks[2].clk = mac68k_machine.print_cts_clk;*/
303 			xcs->cs_clocks[1].clk = 0;
304 			xcs->cs_clocks[2].clk = 0;
305 		}
306 		if (xcs->cs_clocks[1].clk)
307 			zsc_args.hwflags |= ZS_HWFLAG_NO_DCD;
308 		if (xcs->cs_clocks[2].clk)
309 			zsc_args.hwflags |= ZS_HWFLAG_NO_CTS;
310 
311 		/* Set defaults in our "extended" chanstate. */
312 		xcs->cs_csource = 0;
313 		xcs->cs_psource = 0;
314 		xcs->cs_cclk_flag = 0;  /* Nothing fancy by default */
315 		xcs->cs_pclk_flag = 0;
316 
317 		/*
318 		 * We used to disable chip interrupts here, but we now
319 		 * do that in zscnprobe, just in case MacOS left the chip on.
320 		 */
321 
322 		xcs->cs_chip = 0;
323 
324 		/* Stash away a copy of the final H/W flags. */
325 		xcs->cs_hwflags = zsc_args.hwflags;
326 
327 		/*
328 		 * Look for a child driver for this channel.
329 		 * The child attach will setup the hardware.
330 		 */
331 		if (!config_found(self, (void *)&zsc_args, zs_print)) {
332 			/* No sub-driver.  Just reset it. */
333 			u_char reset = (channel == 0) ?
334 				ZSWR9_A_RESET : ZSWR9_B_RESET;
335 			s = splzs();
336 			zs_write_reg(cs, 9, reset);
337 			splx(s);
338 		}
339 	}
340 
341 	/* XXX - Now safe to install interrupt handlers. */
342 	mac_intr_establish(parent, intr[0][0], IST_LEVEL, IPL_TTY,
343 	    zshard, NULL, "zs0");
344 	mac_intr_establish(parent, intr[1][0], IST_LEVEL, IPL_TTY,
345 	    zshard, NULL, "zs1");
346 #ifdef ZS_TXDMA
347 	mac_intr_establish(parent, intr[0][1], IST_LEVEL, IPL_TTY,
348 	    zs_txdma_int, NULL, "zsdma0");
349 	mac_intr_establish(parent, intr[1][1], IST_LEVEL, IPL_TTY,
350 	    zs_txdma_int, (void *)1, "zsdma1");
351 #endif
352 	zsc->zsc_softintr = softintr_establish(IPL_SOFTTTY, zssoft, zsc);
353 	if (zsc->zsc_softintr == NULL)
354 		panic("zsattach: could not establish soft interrupt");
355 
356 	/*
357 	 * Set the master interrupt enable and interrupt vector.
358 	 * (common to both channels, do it on A)
359 	 */
360 	cs = zsc->zsc_cs[0];
361 	s = splzs();
362 	/* interrupt vector */
363 	zs_write_reg(cs, 2, zs_init_reg[2]);
364 	/* master interrupt control (enable) */
365 	zs_write_reg(cs, 9, zs_init_reg[9]);
366 	splx(s);
367 
368 	/* connect power management for port 0 */
369 	cs->enable = zs_enable;
370 	cs->disable = zs_disable;
371 }
372 
373 int
374 zs_print(void *aux, const char *name)
375 {
376 	struct zsc_attach_args *args = aux;
377 
378 	if (name != NULL)
379 		printf("%s: ", name);
380 
381 	if (args->channel != -1)
382 		printf(" channel %d", args->channel);
383 
384 	return UNCONF;
385 }
386 
387 int
388 zsmdioctl(struct zs_chanstate *cs, u_long cmd, caddr_t data)
389 {
390 	switch (cmd) {
391 	default:
392 		return (-1);
393 	}
394 	return (0);
395 }
396 
397 void
398 zsmd_setclock(struct zs_chanstate *cs)
399 {
400 #ifdef NOTYET
401 	struct xzs_chanstate *xcs = (void *)cs;
402 
403 	if (cs->cs_channel != 0)
404 		return;
405 
406 	/*
407 	 * If the new clock has the external bit set, then select the
408 	 * external source.
409 	 */
410 	via_set_modem((xcs->cs_pclk_flag & ZSC_EXTERN) ? 1 : 0);
411 #endif
412 }
413 
414 static int zssoftpending;
415 
416 /*
417  * Our ZS chips all share a common, autovectored interrupt,
418  * so we have to look at all of them on each interrupt.
419  */
420 int
421 zshard(void *arg)
422 {
423 	struct zsc_softc *zsc;
424 	int unit, rval;
425 
426 	rval = 0;
427 	for (unit = 0; unit < zs_cd.cd_ndevs; unit++) {
428 		zsc = zs_cd.cd_devs[unit];
429 		if (zsc == NULL)
430 			continue;
431 		rval |= zsc_intr_hard(zsc);
432 		if (zsc->zsc_cs[0]->cs_softreq)
433 		{
434 			/* zs_req_softint(zsc); */
435 			/* We are at splzs here, so no need to lock. */
436 			if (zssoftpending == 0) {
437 				zssoftpending = 1;
438 				softintr_schedule(zsc->zsc_softintr);
439 			}
440 		}
441 	}
442 	return (rval);
443 }
444 
445 /*
446  * Similar scheme as for zshard (look at all of them)
447  */
448 void
449 zssoft(void *arg)
450 {
451 	struct zsc_softc *zsc;
452 	int unit;
453 
454 	/* This is not the only ISR on this IPL. */
455 	if (zssoftpending == 0)
456 		return;
457 
458 	/*
459 	 * The soft intr. bit will be set by zshard only if
460 	 * the variable zssoftpending is zero.
461 	 */
462 	zssoftpending = 0;
463 
464 	for (unit = 0; unit < zs_cd.cd_ndevs; ++unit) {
465 		zsc = zs_cd.cd_devs[unit];
466 		if (zsc == NULL)
467 			continue;
468 		(void) zsc_intr_soft(zsc);
469 	}
470 }
471 
472 #ifdef ZS_TXDMA
473 int
474 zs_txdma_int(void *arg)
475 {
476 	int ch = (int)arg;
477 	struct zsc_softc *zsc;
478 	struct zs_chanstate *cs;
479 	int unit = 0;			/* XXX */
480 	extern int zstty_txdma_int();
481 
482 	zsc = zs_cd.cd_devs[unit];
483 	if (zsc == NULL)
484 		panic("zs_txdma_int");
485 
486 	cs = zsc->zsc_cs[ch];
487 	zstty_txdma_int(cs);
488 
489 	if (cs->cs_softreq) {
490 		if (zssoftpending == 0) {
491 			zssoftpending = 1;
492 			softintr_schedule(zsc->zsc_softintr);
493 		}
494 	}
495 	return 1;
496 }
497 
498 void
499 zs_dma_setup(struct zs_chanstate *cs, caddr_t pa, int len)
500 {
501 	struct zsc_softc *zsc;
502 	dbdma_command_t *cmdp;
503 	int ch = cs->cs_channel;
504 
505 	zsc = zs_cd.cd_devs[ch];
506 	cmdp = zsc->zsc_txdmacmd[ch];
507 
508 	DBDMA_BUILD(cmdp, DBDMA_CMD_OUT_LAST, 0, len, kvtop(pa),
509 		DBDMA_INT_ALWAYS, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
510 	cmdp++;
511 	DBDMA_BUILD(cmdp, DBDMA_CMD_STOP, 0, 0, 0,
512 		DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
513 
514 	__asm volatile("eieio");
515 
516 	dbdma_start(zsc->zsc_txdmareg[ch], zsc->zsc_txdmacmd[ch]);
517 }
518 #endif
519 
520 /*
521  * Compute the current baud rate given a ZS channel.
522  * XXX Assume internal BRG.
523  */
524 int
525 zs_get_speed(struct zs_chanstate *cs)
526 {
527 	int tconst;
528 
529 	tconst = zs_read_reg(cs, 12);
530 	tconst |= zs_read_reg(cs, 13) << 8;
531 	return TCONST_TO_BPS(cs->cs_brg_clk, tconst);
532 }
533 
534 #ifndef ZS_TOLERANCE
535 #define ZS_TOLERANCE 51
536 /* 5% in tenths of a %, plus 1 so that exactly 5% will be ok. */
537 #endif
538 
539 /*
540  * Search through the signal sources in the channel, and
541  * pick the best one for the baud rate requested. Return
542  * a -1 if not achievable in tolerance. Otherwise return 0
543  * and fill in the values.
544  *
545  * This routine draws inspiration from the Atari port's zs.c
546  * driver in NetBSD 1.1 which did the same type of source switching.
547  * Tolerance code inspired by comspeed routine in isa/com.c.
548  *
549  * By Bill Studenmund, 1996-05-12
550  */
551 int
552 zs_set_speed(struct zs_chanstate *cs, int bps)
553 {
554 	struct xzs_chanstate *xcs = (void *)cs;
555 	int i, tc, tc0 = 0, tc1, s, sf = 0;
556 	int src, rate0, rate1, err, tol;
557 
558 	if (bps == 0)
559 		return (0);
560 
561 	src = -1;		/* no valid source yet */
562 	tol = ZS_TOLERANCE;
563 
564 	/*
565 	 * Step through all the sources and see which one matches
566 	 * the best. A source has to match BETTER than tol to be chosen.
567 	 * Thus if two sources give the same error, the first one will be
568 	 * chosen. Also, allow for the possibility that one source might run
569 	 * both the BRG and the direct divider (i.e. RTxC).
570 	 */
571 	for (i = 0; i < xcs->cs_clock_count; i++) {
572 		if (xcs->cs_clocks[i].clk <= 0)
573 			continue;	/* skip non-existent or bad clocks */
574 		if (xcs->cs_clocks[i].flags & ZSC_BRG) {
575 			/* check out BRG at /16 */
576 			tc1 = BPS_TO_TCONST(xcs->cs_clocks[i].clk >> 4, bps);
577 			if (tc1 >= 0) {
578 				rate1 = TCONST_TO_BPS(xcs->cs_clocks[i].clk >> 4, tc1);
579 				err = abs(((rate1 - bps)*1000)/bps);
580 				if (err < tol) {
581 					tol = err;
582 					src = i;
583 					sf = xcs->cs_clocks[i].flags & ~ZSC_DIV;
584 					tc0 = tc1;
585 					rate0 = rate1;
586 				}
587 			}
588 		}
589 		if (xcs->cs_clocks[i].flags & ZSC_DIV) {
590 			/*
591 			 * Check out either /1, /16, /32, or /64
592 			 * Note: for /1, you'd better be using a synchronized
593 			 * clock!
594 			 */
595 			int b0 = xcs->cs_clocks[i].clk, e0 = abs(b0-bps);
596 			int b1 = b0 >> 4, e1 = abs(b1-bps);
597 			int b2 = b1 >> 1, e2 = abs(b2-bps);
598 			int b3 = b2 >> 1, e3 = abs(b3-bps);
599 
600 			if (e0 < e1 && e0 < e2 && e0 < e3) {
601 				err = e0;
602 				rate1 = b0;
603 				tc1 = ZSWR4_CLK_X1;
604 			} else if (e0 > e1 && e1 < e2  && e1 < e3) {
605 				err = e1;
606 				rate1 = b1;
607 				tc1 = ZSWR4_CLK_X16;
608 			} else if (e0 > e2 && e1 > e2 && e2 < e3) {
609 				err = e2;
610 				rate1 = b2;
611 				tc1 = ZSWR4_CLK_X32;
612 			} else {
613 				err = e3;
614 				rate1 = b3;
615 				tc1 = ZSWR4_CLK_X64;
616 			}
617 
618 			err = (err * 1000)/bps;
619 			if (err < tol) {
620 				tol = err;
621 				src = i;
622 				sf = xcs->cs_clocks[i].flags & ~ZSC_BRG;
623 				tc0 = tc1;
624 				rate0 = rate1;
625 			}
626 		}
627 	}
628 #ifdef ZSMACDEBUG
629 	printf("Checking for rate %d. Found source #%d.\n",bps, src);
630 #endif
631 	if (src == -1)
632 		return (EINVAL); /* no can do */
633 
634 	/*
635 	 * The M.I. layer likes to keep cs_brg_clk current, even though
636 	 * we are the only ones who should be touching the BRG's rate.
637 	 *
638 	 * Note: we are assuming that any ZSC_EXTERN signal source comes in
639 	 * on the RTxC pin. Correct for the mac68k obio zsc.
640 	 */
641 	if (sf & ZSC_EXTERN)
642 		cs->cs_brg_clk = xcs->cs_clocks[i].clk >> 4;
643 	else
644 		cs->cs_brg_clk = PCLK / 16;
645 
646 	/*
647 	 * Now we have a source, so set it up.
648 	 */
649 	s = splzs();
650 	xcs->cs_psource = src;
651 	xcs->cs_pclk_flag = sf;
652 	bps = rate0;
653 	if (sf & ZSC_BRG) {
654 		cs->cs_preg[4] = ZSWR4_CLK_X16;
655 		cs->cs_preg[11]= ZSWR11_RXCLK_BAUD | ZSWR11_TXCLK_BAUD;
656 		if (sf & ZSC_PCLK) {
657 			cs->cs_preg[14] = ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK;
658 		} else {
659 			cs->cs_preg[14] = ZSWR14_BAUD_ENA;
660 		}
661 		tc = tc0;
662 	} else {
663 		cs->cs_preg[4] = tc0;
664 		if (sf & ZSC_RTXDIV) {
665 			cs->cs_preg[11] = ZSWR11_RXCLK_RTXC | ZSWR11_TXCLK_RTXC;
666 		} else {
667 			cs->cs_preg[11] = ZSWR11_RXCLK_TRXC | ZSWR11_TXCLK_TRXC;
668 		}
669 		cs->cs_preg[14]= 0;
670 		tc = 0xffff;
671 	}
672 	/* Set the BAUD rate divisor. */
673 	cs->cs_preg[12] = tc;
674 	cs->cs_preg[13] = tc >> 8;
675 	splx(s);
676 
677 #ifdef ZSMACDEBUG
678 	printf("Rate is %7d, tc is %7d, source no. %2d, flags %4x\n", \
679 	    bps, tc, src, sf);
680 	printf("Registers are: 4 %x, 11 %x, 14 %x\n\n",
681 		cs->cs_preg[4], cs->cs_preg[11], cs->cs_preg[14]);
682 #endif
683 
684 	cs->cs_preg[5] |= ZSWR5_RTS;	/* Make sure the drivers are on! */
685 
686 	/* Caller will stuff the pending registers. */
687 	return (0);
688 }
689 
690 int
691 zs_set_modes(struct zs_chanstate *cs, int cflag)
692 {
693 	struct xzs_chanstate *xcs = (void*)cs;
694 	int s;
695 
696 	/*
697 	 * Make sure we don't enable hfc on a signal line we're ignoring.
698 	 * As we enable CTS interrupts only if we have CRTSCTS or CDTRCTS,
699 	 * this code also effectivly turns off ZSWR15_CTS_IE.
700 	 *
701 	 * Also, disable DCD interrupts if we've been told to ignore
702 	 * the DCD pin. Happens on mac68k because the input line for
703 	 * DCD can also be used as a clock input.  (Just set CLOCAL.)
704 	 *
705 	 * If someone tries to turn an invalid flow mode on, Just Say No
706 	 * (Suggested by gwr)
707 	 */
708 	if (xcs->cs_hwflags & ZS_HWFLAG_NO_DCD) {
709 		if (cflag & MDMBUF)
710 			return (EINVAL);
711 		cflag |= CLOCAL;
712 	}
713 #if 0
714 	if ((xcs->cs_hwflags & ZS_HWFLAG_NO_CTS) && (cflag & CRTSCTS))
715 		return (EINVAL);
716 #endif
717 
718 	/*
719 	 * Output hardware flow control on the chip is horrendous:
720 	 * if carrier detect drops, the receiver is disabled, and if
721 	 * CTS drops, the transmitter is stopped IN MID CHARACTER!
722 	 * Therefore, NEVER set the HFC bit, and instead use the
723 	 * status interrupt to detect CTS changes.
724 	 */
725 	s = splzs();
726 	if ((cflag & (CLOCAL | MDMBUF)) != 0)
727 		cs->cs_rr0_dcd = 0;
728 	else
729 		cs->cs_rr0_dcd = ZSRR0_DCD;
730 	/*
731 	 * The mac hardware only has one output, DTR (HSKo in Mac
732 	 * parlance). In HFC mode, we use it for the functions
733 	 * typically served by RTS and DTR on other ports, so we
734 	 * have to fake the upper layer out some.
735 	 *
736 	 * CRTSCTS we use CTS as an input which tells us when to shut up.
737 	 * We make no effort to shut up the other side of the connection.
738 	 * DTR is used to hang up the modem.
739 	 *
740 	 * In CDTRCTS, we use CTS to tell us to stop, but we use DTR to
741 	 * shut up the other side.
742 	 */
743 	if ((cflag & CRTSCTS) != 0) {
744 		cs->cs_wr5_dtr = ZSWR5_DTR;
745 		cs->cs_wr5_rts = 0;
746 		cs->cs_rr0_cts = ZSRR0_CTS;
747 #if 0
748 	} else if ((cflag & CDTRCTS) != 0) {
749 		cs->cs_wr5_dtr = 0;
750 		cs->cs_wr5_rts = ZSWR5_DTR;
751 		cs->cs_rr0_cts = ZSRR0_CTS;
752 #endif
753 	} else if ((cflag & MDMBUF) != 0) {
754 		cs->cs_wr5_dtr = 0;
755 		cs->cs_wr5_rts = ZSWR5_DTR;
756 		cs->cs_rr0_cts = ZSRR0_DCD;
757 	} else {
758 		cs->cs_wr5_dtr = ZSWR5_DTR;
759 		cs->cs_wr5_rts = 0;
760 		cs->cs_rr0_cts = 0;
761 	}
762 	splx(s);
763 
764 	/* Caller will stuff the pending registers. */
765 	return (0);
766 }
767 
768 
769 /*
770  * Read or write the chip with suitable delays.
771  * MacII hardware has the delay built in.
772  * No need for extra delay. :-) However, some clock-chirped
773  * macs, or zsc's on serial add-on boards might need it.
774  */
775 #define	ZS_DELAY()
776 
777 u_char
778 zs_read_reg(struct zs_chanstate *cs, u_char reg)
779 {
780 	u_char val;
781 
782 	out8(cs->cs_reg_csr, reg);
783 	ZS_DELAY();
784 	val = in8(cs->cs_reg_csr);
785 	ZS_DELAY();
786 	return val;
787 }
788 
789 void
790 zs_write_reg(struct zs_chanstate *cs, u_char reg, u_char val)
791 {
792 	out8(cs->cs_reg_csr, reg);
793 	ZS_DELAY();
794 	out8(cs->cs_reg_csr, val);
795 	ZS_DELAY();
796 }
797 
798 u_char
799 zs_read_csr(struct zs_chanstate *cs)
800 {
801 	u_char val;
802 
803 	val = in8(cs->cs_reg_csr);
804 	ZS_DELAY();
805 	/* make up for the fact CTS is wired backwards */
806 	val ^= ZSRR0_CTS;
807 	return val;
808 }
809 
810 void
811 zs_write_csr(struct zs_chanstate *cs, u_char val)
812 {
813 	/* Note, the csr does not write CTS... */
814 	out8(cs->cs_reg_csr, val);
815 	ZS_DELAY();
816 }
817 
818 u_char
819 zs_read_data(struct zs_chanstate *cs)
820 {
821 	u_char val;
822 
823 	val = in8(cs->cs_reg_data);
824 	ZS_DELAY();
825 	return val;
826 }
827 
828 void
829 zs_write_data(struct zs_chanstate *cs, u_char val)
830 {
831 	out8(cs->cs_reg_data, val);
832 	ZS_DELAY();
833 }
834 
835 /*
836  * Power management hooks for zsopen() and zsclose().
837  * We use them to power on/off the ports, if necessary.
838  * This should be modified to turn on/off modem in PBG4, etc.
839  */
840 void macobio_modem_power(int enable);
841 
842 int
843 zs_enable(struct zs_chanstate *cs)
844 {
845 	macobio_modem_power(1); /* Whee */
846 	cs->enabled = 1;
847 	return(0);
848 }
849 
850 void
851 zs_disable(struct zs_chanstate *cs)
852 {
853 	macobio_modem_power(0); /* Whee */
854 	cs->enabled = 0;
855 }
856 
857 
858 /****************************************************************
859  * Console support functions (powermac specific!)
860  * Note: this code is allowed to know about the layout of
861  * the chip registers, and uses that to keep things simple.
862  * XXX - I think I like the mvme167 code better. -gwr
863  * XXX - Well :-P  :-)  -wrs
864  ****************************************************************/
865 
866 cons_decl(zs);
867 
868 void	zs_putc(volatile struct zschan *, int);
869 int	zs_getc(volatile struct zschan *);
870 extern int	zsopen( dev_t dev, int flags, int mode, struct proc *p);
871 
872 static int stdin, stdout;
873 
874 /*
875  * Console functions.
876  */
877 
878 /*
879  * zscnprobe is the routine which gets called as the kernel is trying to
880  * figure out where the console should be. Each io driver which might
881  * be the console (as defined in mac68k/conf.c) gets probed. The probe
882  * fills in the consdev structure. Important parts are the device #,
883  * and the console priority. Values are CN_DEAD (don't touch me),
884  * CN_LOWPRI (I'm here, but elsewhere might be better), CN_MIDPRI
885  * (the video, better than CN_LOWPRI), and CN_HIGHPRI (pick me!)
886  *
887  * As the mac's a bit different, we do extra work here. We mainly check
888  * to see if we have serial echo going on. Also chould check for default
889  * speeds.
890  */
891 
892 /*
893  * Polled input char.
894  */
895 int
896 zs_getc(volatile struct zschan *zc)
897 {
898 	register int s, c, rr0;
899 
900 	s = splhigh();
901 	/* Wait for a character to arrive. */
902 	do {
903 		rr0 = in8(&zc->zc_csr);
904 		ZS_DELAY();
905 	} while ((rr0 & ZSRR0_RX_READY) == 0);
906 
907 	c = in8(&zc->zc_data);
908 	ZS_DELAY();
909 	splx(s);
910 
911 	return (c);
912 }
913 
914 /*
915  * Polled output char.
916  */
917 void
918 zs_putc(volatile struct zschan *zc, int c)
919 {
920 	register int s, rr0;
921 	register long wait = 0;
922 
923 	s = splhigh();
924 	/* Wait for transmitter to become ready. */
925 	do {
926 		rr0 = in8(&zc->zc_csr);
927 		ZS_DELAY();
928 	} while (((rr0 & ZSRR0_TX_READY) == 0) && (wait++ < 1000000));
929 
930 	if ((rr0 & ZSRR0_TX_READY) != 0) {
931 		out8(&zc->zc_data, c);
932 		ZS_DELAY();
933 	}
934 	splx(s);
935 }
936 
937 
938 /*
939  * Polled console input putchar.
940  */
941 int
942 zscngetc(dev_t dev)
943 {
944 	register volatile struct zschan *zc = zs_conschan;
945 	register int c;
946 
947 	if (zc) {
948 		c = zs_getc(zc);
949 	} else {
950 		char ch = 0;
951 		OF_read(stdin, &ch, 1);
952 		c = ch;
953 	}
954 	return c;
955 }
956 
957 /*
958  * Polled console output putchar.
959  */
960 void
961 zscnputc(dev_t dev, int c)
962 {
963 	register volatile struct zschan *zc = zs_conschan;
964 
965 	if (zc) {
966 		zs_putc(zc, c);
967 	} else {
968 		char ch = c;
969 		OF_write(stdout, &ch, 1);
970 	}
971 }
972 
973 void
974 zscnprobe(struct consdev *cp)
975 {
976 	int chosen, pkg;
977 	int unit = 0;
978 	int maj;
979 	char name[16];
980 
981 	if ((chosen = OF_finddevice("/chosen")) == -1)
982 		return;
983 
984 	if (OF_getprop(chosen, "stdin", &stdin, sizeof(stdin)) == -1)
985 		return;
986 	if (OF_getprop(chosen, "stdout", &stdout, sizeof(stdout)) == -1)
987 		return;
988 
989 	if ((pkg = OF_instance_to_package(stdin)) == -1)
990 		return;
991 
992 	bzero(name, sizeof(name));
993 	if (OF_getprop(pkg, "device_type", name, sizeof(name)) == -1)
994 		return;
995 
996 	if (strcmp(name, "serial") != 0)
997 		return;
998 
999 	bzero(name, sizeof(name));
1000 	if (OF_getprop(pkg, "name", name, sizeof(name)) == -1)
1001 		return;
1002 
1003 	if (strcmp(name, "ch-b") == 0)
1004 		unit = 1;
1005 
1006 	/* locate the major number */
1007 	for (maj = 0; maj < nchrdev; maj++)
1008 		if (cdevsw[maj].d_open == zsopen)
1009 			break;
1010 
1011 	cp->cn_dev = makedev(maj, unit);
1012 	cp->cn_pri = CN_HIGHPRI;
1013 }
1014 
1015 
1016 void
1017 zscninit(struct consdev *cp)
1018 {
1019 	int escc, escc_ch, obio;
1020 	unsigned int zs_offset, zs_size;
1021 	int ch = 0;
1022 	u_int32_t reg[5];
1023 	char name[16];
1024 
1025 	if ((escc_ch = OF_instance_to_package(stdin)) == -1)
1026 		return;
1027 
1028 	bzero(name, sizeof(name));
1029 	if (OF_getprop(escc_ch, "name", name, sizeof(name)) == -1)
1030 		return;
1031 
1032 	if (strcmp(name, "ch-b") == 0)
1033 		ch = 1;
1034 
1035 	if (OF_getprop(escc_ch, "reg", reg, sizeof(reg)) < 8)
1036 		return;
1037 	zs_offset = reg[0];
1038 	zs_size   = reg[1];
1039 
1040 	escc = OF_parent(escc_ch);
1041 	obio = OF_parent(escc);
1042 
1043 	if (OF_getprop(obio, "assigned-addresses", reg, sizeof(reg)) < 12)
1044 		return;
1045 	zs_conschan = mapiodev(reg[2] + zs_offset, zs_size);
1046 
1047 	zs_hwflags[0][ch] = ZS_HWFLAG_CONSOLE;
1048 }
1049 
1050 void
1051 zs_abort(struct zs_chanstate *channel)
1052 {
1053 	volatile struct zschan *zc = zs_conschan;
1054 	int rr0;
1055 
1056 	/* Wait for end of break to avoid PROM abort. */
1057 	/* XXX - Limit the wait? */
1058 	do {
1059 		rr0 = zc->zc_csr;
1060 		ZS_DELAY();
1061 	} while (rr0 & ZSRR0_BREAK);
1062 
1063 #if defined(DDB)
1064 	if (!db_active)
1065 		db_enter();
1066 #endif
1067 }
1068 
1069 /* copied from sparc - XXX? */
1070 void
1071 zscnpollc(dev_t dev, int on)
1072 {
1073 	/*
1074 	 * Need to tell zs driver to acknowledge all interrupts or we get
1075 	 * annoying spurious interrupt messages.  This is because mucking
1076 	 * with spl() levels during polling does not prevent interrupts from
1077 	 * being generated.
1078 	 */
1079 
1080 #if 0
1081 	if (on)
1082 		swallow_zsintrs++;
1083 	else
1084 		swallow_zsintrs--;
1085 #endif
1086 }
1087