xref: /netbsd-src/sys/arch/macppc/dev/zs.c (revision 7fa608457b817eca6e0977b37f758ae064f3c99c)
1 /*	$NetBSD: zs.c,v 1.44 2007/11/09 00:05:05 ad Exp $	*/
2 
3 /*
4  * Copyright (c) 1996, 1998 Bill Studenmund
5  * Copyright (c) 1995 Gordon W. Ross
6  * All rights reserved.
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. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  * 4. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by Gordon Ross
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Zilog Z8530 Dual UART driver (machine-dependent part)
36  *
37  * Runs two serial lines per chip using slave drivers.
38  * Plain tty/async lines use the zs_async slave.
39  * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
40  * Other ports use their own mice & keyboard slaves.
41  *
42  * Credits & history:
43  *
44  * With NetBSD 1.1, port-mac68k started using a port of the port-sparc
45  * (port-sun3?) zs.c driver (which was in turn based on code in the
46  * Berkeley 4.4 Lite release). Bill Studenmund did the port, with
47  * help from Allen Briggs and Gordon Ross <gwr@NetBSD.org>. Noud de
48  * Brouwer field-tested the driver at a local ISP.
49  *
50  * Bill Studenmund and Gordon Ross then ported the machine-independent
51  * z8530 driver to work with port-mac68k. NetBSD 1.2 contained an
52  * intermediate version (mac68k using a local, patched version of
53  * the m.i. drivers), with NetBSD 1.3 containing a full version.
54  */
55 
56 #include <sys/cdefs.h>
57 __KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.44 2007/11/09 00:05:05 ad Exp $");
58 
59 #include "opt_ddb.h"
60 #include "opt_kgdb.h"
61 
62 #include <sys/param.h>
63 #include <sys/systm.h>
64 #include <sys/proc.h>
65 #include <sys/device.h>
66 #include <sys/conf.h>
67 #include <sys/file.h>
68 #include <sys/ioctl.h>
69 #include <sys/tty.h>
70 #include <sys/time.h>
71 #include <sys/kernel.h>
72 #include <sys/syslog.h>
73 #ifdef KGDB
74 #include <sys/kgdb.h>
75 #endif
76 
77 #include <dev/cons.h>
78 #include <dev/ofw/openfirm.h>
79 #include <dev/ic/z8530reg.h>
80 
81 #include <machine/z8530var.h>
82 #include <machine/autoconf.h>
83 #include <machine/cpu.h>
84 #include <machine/pio.h>
85 
86 /* Are these in a header file anywhere? */
87 /* Booter flags interface */
88 #define ZSMAC_RAW	0x01
89 #define ZSMAC_LOCALTALK	0x02
90 
91 /*
92  * Some warts needed by z8530tty.c -
93  */
94 int zs_def_cflag = (CREAD | CS8 | HUPCL);
95 
96 /*
97  * abort detection on console will now timeout after iterating on a loop
98  * the following # of times. Cheep hack. Also, abort detection is turned
99  * off after a timeout (i.e. maybe there's not a terminal hooked up).
100  */
101 #define ZSABORT_DELAY 3000000
102 
103 struct zsdevice {
104 	/* Yes, they are backwards. */
105 	struct	zschan zs_chan_b;
106 	struct	zschan zs_chan_a;
107 };
108 
109 static int zs_defspeed[2] = {
110 	38400,		/* ttyZ0 */
111 	38400,		/* ttyZ1 */
112 };
113 
114 /* console stuff */
115 void	*zs_conschan = 0;
116 int	zs_conschannel = -1;
117 #ifdef	ZS_CONSOLE_ABORT
118 int	zs_cons_canabort = 1;
119 #else
120 int	zs_cons_canabort = 0;
121 #endif /* ZS_CONSOLE_ABORT*/
122 
123 /* device to which the console is attached--if serial. */
124 /* Mac stuff */
125 
126 static int zs_get_speed(struct zs_chanstate *);
127 
128 /*
129  * Even though zsparam will set up the clock multiples, etc., we
130  * still set them here as: 1) mice & keyboards don't use zsparam,
131  * and 2) the console stuff uses these defaults before device
132  * attach.
133  */
134 
135 static u_char zs_init_reg[16] = {
136 	0,	/* 0: CMD (reset, etc.) */
137 	0,	/* 1: No interrupts yet. */
138 	0,	/* IVECT */
139 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
140 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
141 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
142 	0,	/* 6: TXSYNC/SYNCLO */
143 	0,	/* 7: RXSYNC/SYNCHI */
144 	0,	/* 8: alias for data port */
145 	ZSWR9_MASTER_IE,
146 	0,	/*10: Misc. TX/RX control bits */
147 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
148 	((PCLK/32)/38400)-2,	/*12: BAUDLO (default=38400) */
149 	0,			/*13: BAUDHI (default=38400) */
150 	ZSWR14_BAUD_ENA,
151 	ZSWR15_BREAK_IE,
152 };
153 
154 /****************************************************************
155  * Autoconfig
156  ****************************************************************/
157 
158 /* Definition of the driver for autoconfig. */
159 static int	zsc_match(struct device *, struct cfdata *, void *);
160 static void	zsc_attach(struct device *, struct device *, void *);
161 static int	zsc_print(void *, const char *);
162 
163 CFATTACH_DECL(zsc, sizeof(struct zsc_softc),
164     zsc_match, zsc_attach, NULL, NULL);
165 
166 extern struct cfdriver zsc_cd;
167 
168 int zsc_attached;
169 
170 int zshard(void *);
171 #ifdef ZS_TXDMA
172 static int zs_txdma_int(void *);
173 #endif
174 
175 void zscnprobe(struct consdev *);
176 void zscninit(struct consdev *);
177 int  zscngetc(dev_t);
178 void zscnputc(dev_t, int);
179 void zscnpollc(dev_t, int);
180 
181 /*
182  * Is the zs chip present?
183  */
184 static int
185 zsc_match(struct device *parent, struct cfdata *cf, void *aux)
186 {
187 	struct confargs *ca = aux;
188 
189 	if (strcmp(ca->ca_name, "escc") != 0)
190 		return 0;
191 
192 	if (zsc_attached)
193 		return 0;
194 
195 	return 1;
196 }
197 
198 /*
199  * Attach a found zs.
200  *
201  * Match slave number to zs unit number, so that misconfiguration will
202  * not set up the keyboard as ttya, etc.
203  */
204 static void
205 zsc_attach(struct device *parent, struct device *self, void *aux)
206 {
207 	struct zsc_softc *zsc = (void *)self;
208 	struct confargs *ca = aux;
209 	struct zsc_attach_args zsc_args;
210 	volatile struct zschan *zc;
211 	struct xzs_chanstate *xcs;
212 	struct zs_chanstate *cs;
213 	struct zsdevice *zsd;
214 	int channel;
215 	int s, chip, theflags;
216 	int node, intr[2][3];
217 	u_int regs[6];
218 
219 	zsc_attached = 1;
220 
221 	chip = 0;
222 	ca->ca_reg[0] += ca->ca_baseaddr;
223 	zsd = mapiodev(ca->ca_reg[0], ca->ca_reg[1]);
224 
225 	node = OF_child(ca->ca_node);	/* ch-a */
226 
227 	for (channel = 0; channel < 2; channel++) {
228 		if (OF_getprop(node, "AAPL,interrupts",
229 			       intr[channel], sizeof(intr[0])) == -1 &&
230 		    OF_getprop(node, "interrupts",
231 			       intr[channel], sizeof(intr[0])) == -1) {
232 			printf(": cannot find interrupt property\n");
233 			return;
234 		}
235 
236 		if (OF_getprop(node, "reg", regs, sizeof(regs)) < 24) {
237 			printf(": cannot find reg property\n");
238 			return;
239 		}
240 		regs[2] += ca->ca_baseaddr;
241 		regs[4] += ca->ca_baseaddr;
242 #ifdef ZS_TXDMA
243 		zsc->zsc_txdmareg[channel] = mapiodev(regs[2], regs[3]);
244 		zsc->zsc_txdmacmd[channel] =
245 			dbdma_alloc(sizeof(dbdma_command_t) * 3);
246 		memset(zsc->zsc_txdmacmd[channel], 0,
247 			sizeof(dbdma_command_t) * 3);
248 		dbdma_reset(zsc->zsc_txdmareg[channel]);
249 #endif
250 		node = OF_peer(node);	/* ch-b */
251 	}
252 
253 	printf(": irq %d,%d\n", intr[0][0], intr[1][0]);
254 
255 	/*
256 	 * Initialize software state for each channel.
257 	 */
258 	for (channel = 0; channel < 2; channel++) {
259 		zsc_args.channel = channel;
260 		zsc_args.hwflags = (channel == zs_conschannel ?
261 				    ZS_HWFLAG_CONSOLE : 0);
262 		xcs = &zsc->xzsc_xcs_store[channel];
263 		cs  = &xcs->xzs_cs;
264 		zsc->zsc_cs[channel] = cs;
265 
266 		zs_lock_init(cs);
267 		cs->cs_channel = channel;
268 		cs->cs_private = NULL;
269 		cs->cs_ops = &zsops_null;
270 
271 		zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
272 
273 		cs->cs_reg_csr  = &zc->zc_csr;
274 		cs->cs_reg_data = &zc->zc_data;
275 
276 		memcpy(cs->cs_creg, zs_init_reg, 16);
277 		memcpy(cs->cs_preg, zs_init_reg, 16);
278 
279 		/* Current BAUD rate generator clock. */
280 		cs->cs_brg_clk = PCLK / 16;	/* RTxC is 230400*16, so use 230400 */
281 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE)
282 			cs->cs_defspeed = zs_get_speed(cs);
283 		else
284 			cs->cs_defspeed = zs_defspeed[channel];
285 		cs->cs_defcflag = zs_def_cflag;
286 
287 		/* Make these correspond to cs_defcflag (-crtscts) */
288 		cs->cs_rr0_dcd = ZSRR0_DCD;
289 		cs->cs_rr0_cts = 0;
290 		cs->cs_wr5_dtr = ZSWR5_DTR;
291 		cs->cs_wr5_rts = 0;
292 
293 #ifdef __notyet__
294 		cs->cs_slave_type = ZS_SLAVE_NONE;
295 #endif
296 
297 		/* Define BAUD rate stuff. */
298 		xcs->cs_clocks[0].clk = PCLK;
299 		xcs->cs_clocks[0].flags = ZSC_RTXBRG | ZSC_RTXDIV;
300 		xcs->cs_clocks[1].flags =
301 			ZSC_RTXBRG | ZSC_RTXDIV | ZSC_VARIABLE | ZSC_EXTERN;
302 		xcs->cs_clocks[2].flags = ZSC_TRXDIV | ZSC_VARIABLE;
303 		xcs->cs_clock_count = 3;
304 		if (channel == 0) {
305 			theflags = 0; /*mac68k_machine.modem_flags;*/
306 			/*xcs->cs_clocks[1].clk = mac68k_machine.modem_dcd_clk;*/
307 			/*xcs->cs_clocks[2].clk = mac68k_machine.modem_cts_clk;*/
308 			xcs->cs_clocks[1].clk = 0;
309 			xcs->cs_clocks[2].clk = 0;
310 		} else {
311 			theflags = 0; /*mac68k_machine.print_flags;*/
312 			xcs->cs_clocks[1].flags = ZSC_VARIABLE;
313 			/*
314 			 * Yes, we aren't defining ANY clock source enables for the
315 			 * printer's DCD clock in. The hardware won't let us
316 			 * use it. But a clock will freak out the chip, so we
317 			 * let you set it, telling us to bar interrupts on the line.
318 			 */
319 			/*xcs->cs_clocks[1].clk = mac68k_machine.print_dcd_clk;*/
320 			/*xcs->cs_clocks[2].clk = mac68k_machine.print_cts_clk;*/
321 			xcs->cs_clocks[1].clk = 0;
322 			xcs->cs_clocks[2].clk = 0;
323 		}
324 		if (xcs->cs_clocks[1].clk)
325 			zsc_args.hwflags |= ZS_HWFLAG_NO_DCD;
326 		if (xcs->cs_clocks[2].clk)
327 			zsc_args.hwflags |= ZS_HWFLAG_NO_CTS;
328 
329 		/* Set defaults in our "extended" chanstate. */
330 		xcs->cs_csource = 0;
331 		xcs->cs_psource = 0;
332 		xcs->cs_cclk_flag = 0;  /* Nothing fancy by default */
333 		xcs->cs_pclk_flag = 0;
334 
335 		if (theflags & ZSMAC_RAW) {
336 			zsc_args.hwflags |= ZS_HWFLAG_RAW;
337 			printf(" (raw defaults)");
338 		}
339 
340 		/*
341 		 * XXX - This might be better done with a "stub" driver
342 		 * (to replace zstty) that ignores LocalTalk for now.
343 		 */
344 		if (theflags & ZSMAC_LOCALTALK) {
345 			printf(" shielding from LocalTalk");
346 			cs->cs_defspeed = 1;
347 			cs->cs_creg[ZSRR_BAUDLO] = cs->cs_preg[ZSRR_BAUDLO] = 0xff;
348 			cs->cs_creg[ZSRR_BAUDHI] = cs->cs_preg[ZSRR_BAUDHI] = 0xff;
349 			zs_write_reg(cs, ZSRR_BAUDLO, 0xff);
350 			zs_write_reg(cs, ZSRR_BAUDHI, 0xff);
351 			/*
352 			 * If we might have LocalTalk, then make sure we have the
353 			 * Baud rate low-enough to not do any damage.
354 			 */
355 		}
356 
357 		/*
358 		 * We used to disable chip interrupts here, but we now
359 		 * do that in zscnprobe, just in case MacOS left the chip on.
360 		 */
361 
362 		xcs->cs_chip = chip;
363 
364 		/* Stash away a copy of the final H/W flags. */
365 		xcs->cs_hwflags = zsc_args.hwflags;
366 
367 		/*
368 		 * Look for a child driver for this channel.
369 		 * The child attach will setup the hardware.
370 		 */
371 		if (!config_found(self, (void *)&zsc_args, zsc_print)) {
372 			/* No sub-driver.  Just reset it. */
373 			u_char reset = (channel == 0) ?
374 				ZSWR9_A_RESET : ZSWR9_B_RESET;
375 			s = splzs();
376 			zs_write_reg(cs, 9, reset);
377 			splx(s);
378 		}
379 	}
380 
381 	/* XXX - Now safe to install interrupt handlers. */
382 	intr_establish(intr[0][0], IST_EDGE, IPL_TTY, zshard, zsc);
383 	intr_establish(intr[1][0], IST_EDGE, IPL_TTY, zshard, zsc);
384 #ifdef ZS_TXDMA
385 	intr_establish(intr[0][1], IST_EDGE, IPL_TTY, zs_txdma_int, (void *)0);
386 	intr_establish(intr[1][1], IST_EDGE, IPL_TTY, zs_txdma_int, (void *)1);
387 #endif
388 
389 	zsc->zsc_si = softintr_establish(IPL_SOFTSERIAL,
390 		(void (*)(void *)) zsc_intr_soft, zsc);
391 
392 	/*
393 	 * Set the master interrupt enable and interrupt vector.
394 	 * (common to both channels, do it on A)
395 	 */
396 	cs = zsc->zsc_cs[0];
397 	s = splzs();
398 	/* interrupt vector */
399 	zs_write_reg(cs, 2, zs_init_reg[2]);
400 	/* master interrupt control (enable) */
401 	zs_write_reg(cs, 9, zs_init_reg[9]);
402 	splx(s);
403 }
404 
405 static int
406 zsc_print(void *aux, const char *name)
407 {
408 	struct zsc_attach_args *args = aux;
409 
410 	if (name != NULL)
411 		aprint_normal("%s: ", name);
412 
413 	if (args->channel != -1)
414 		aprint_normal(" channel %d", args->channel);
415 
416 	return UNCONF;
417 }
418 
419 int
420 zsmdioctl(struct zs_chanstate *cs, u_long cmd, void *data)
421 {
422 	switch (cmd) {
423 	default:
424 		return (EPASSTHROUGH);
425 	}
426 	return (0);
427 }
428 
429 void
430 zsmd_setclock(struct zs_chanstate *cs)
431 {
432 #ifdef NOTYET
433 	struct xzs_chanstate *xcs = (void *)cs;
434 
435 	if (cs->cs_channel != 0)
436 		return;
437 
438 	/*
439 	 * If the new clock has the external bit set, then select the
440 	 * external source.
441 	 */
442 	via_set_modem((xcs->cs_pclk_flag & ZSC_EXTERN) ? 1 : 0);
443 #endif
444 }
445 
446 int
447 zshard(void *arg)
448 {
449 	struct zsc_softc *zsc;
450 	int rval;
451 
452 	zsc = arg;
453 	rval = zsc_intr_hard(zsc);
454 	if ((zsc->zsc_cs[0]->cs_softreq) || (zsc->zsc_cs[1]->cs_softreq))
455 		softintr_schedule(zsc->zsc_si);
456 
457 	return rval;
458 }
459 
460 #ifdef ZS_TXDMA
461 int
462 zs_txdma_int(void *arg)
463 {
464 	int ch = (int)arg;
465 	struct zsc_softc *zsc;
466 	struct zs_chanstate *cs;
467 	int unit = 0;			/* XXX */
468 
469 	zsc = zsc_cd.cd_devs[unit];
470 	if (zsc == NULL)
471 		panic("zs_txdma_int");
472 
473 	cs = zsc->zsc_cs[ch];
474 	zstty_txdma_int(cs);
475 
476 	if (cs->cs_softreq)
477 		softintr_schedule(zsc->zsc_si);
478 
479 	return 1;
480 }
481 
482 void
483 zs_dma_setup(struct zs_chanstate *cs, void *pa, int len)
484 {
485 	struct zsc_softc *zsc;
486 	dbdma_command_t *cmdp;
487 	int ch = cs->cs_channel;
488 
489 	zsc = zsc_cd.cd_devs[ch];
490 	cmdp = zsc->zsc_txdmacmd[ch];
491 
492 	DBDMA_BUILD(cmdp, DBDMA_CMD_OUT_LAST, 0, len, kvtop(pa),
493 		DBDMA_INT_ALWAYS, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
494 	cmdp++;
495 	DBDMA_BUILD(cmdp, DBDMA_CMD_STOP, 0, 0, 0,
496 		DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
497 
498 	__asm volatile("eieio");
499 
500 	dbdma_start(zsc->zsc_txdmareg[ch], zsc->zsc_txdmacmd[ch]);
501 }
502 #endif
503 
504 /*
505  * Compute the current baud rate given a ZS channel.
506  * XXX Assume internal BRG.
507  */
508 int
509 zs_get_speed(struct zs_chanstate *cs)
510 {
511 	int tconst;
512 
513 	tconst = zs_read_reg(cs, 12);
514 	tconst |= zs_read_reg(cs, 13) << 8;
515 	return TCONST_TO_BPS(cs->cs_brg_clk, tconst);
516 }
517 
518 #ifndef ZS_TOLERANCE
519 #define ZS_TOLERANCE 51
520 /* 5% in tenths of a %, plus 1 so that exactly 5% will be ok. */
521 #endif
522 
523 /*
524  * Search through the signal sources in the channel, and
525  * pick the best one for the baud rate requested. Return
526  * a -1 if not achievable in tolerance. Otherwise return 0
527  * and fill in the values.
528  *
529  * This routine draws inspiration from the Atari port's zs.c
530  * driver in NetBSD 1.1 which did the same type of source switching.
531  * Tolerance code inspired by comspeed routine in isa/com.c.
532  *
533  * By Bill Studenmund, 1996-05-12
534  */
535 int
536 zs_set_speed(struct zs_chanstate *cs, int bps)
537 {
538 	struct xzs_chanstate *xcs = (void *) cs;
539 	int i, tc, tc0 = 0, tc1, s, sf = 0;
540 	int src, rate0, rate1, err, tol;
541 
542 	if (bps == 0)
543 		return (0);
544 
545 	src = -1;		/* no valid source yet */
546 	tol = ZS_TOLERANCE;
547 
548 	/*
549 	 * Step through all the sources and see which one matches
550 	 * the best. A source has to match BETTER than tol to be chosen.
551 	 * Thus if two sources give the same error, the first one will be
552 	 * chosen. Also, allow for the possability that one source might run
553 	 * both the BRG and the direct divider (i.e. RTxC).
554 	 */
555 	for (i = 0; i < xcs->cs_clock_count; i++) {
556 		if (xcs->cs_clocks[i].clk <= 0)
557 			continue;	/* skip non-existent or bad clocks */
558 		if (xcs->cs_clocks[i].flags & ZSC_BRG) {
559 			/* check out BRG at /16 */
560 			tc1 = BPS_TO_TCONST(xcs->cs_clocks[i].clk >> 4, bps);
561 			if (tc1 >= 0) {
562 				rate1 = TCONST_TO_BPS(xcs->cs_clocks[i].clk >> 4, tc1);
563 				err = abs(((rate1 - bps)*1000)/bps);
564 				if (err < tol) {
565 					tol = err;
566 					src = i;
567 					sf = xcs->cs_clocks[i].flags & ~ZSC_DIV;
568 					tc0 = tc1;
569 					rate0 = rate1;
570 				}
571 			}
572 		}
573 		if (xcs->cs_clocks[i].flags & ZSC_DIV) {
574 			/*
575 			 * Check out either /1, /16, /32, or /64
576 			 * Note: for /1, you'd better be using a synchronized
577 			 * clock!
578 			 */
579 			int b0 = xcs->cs_clocks[i].clk, e0 = abs(b0-bps);
580 			int b1 = b0 >> 4, e1 = abs(b1-bps);
581 			int b2 = b1 >> 1, e2 = abs(b2-bps);
582 			int b3 = b2 >> 1, e3 = abs(b3-bps);
583 
584 			if (e0 < e1 && e0 < e2 && e0 < e3) {
585 				err = e0;
586 				rate1 = b0;
587 				tc1 = ZSWR4_CLK_X1;
588 			} else if (e0 > e1 && e1 < e2  && e1 < e3) {
589 				err = e1;
590 				rate1 = b1;
591 				tc1 = ZSWR4_CLK_X16;
592 			} else if (e0 > e2 && e1 > e2 && e2 < e3) {
593 				err = e2;
594 				rate1 = b2;
595 				tc1 = ZSWR4_CLK_X32;
596 			} else {
597 				err = e3;
598 				rate1 = b3;
599 				tc1 = ZSWR4_CLK_X64;
600 			}
601 
602 			err = (err * 1000)/bps;
603 			if (err < tol) {
604 				tol = err;
605 				src = i;
606 				sf = xcs->cs_clocks[i].flags & ~ZSC_BRG;
607 				tc0 = tc1;
608 				rate0 = rate1;
609 			}
610 		}
611 	}
612 #ifdef ZSMACDEBUG
613 	zsprintf("Checking for rate %d. Found source #%d.\n",bps, src);
614 #endif
615 	if (src == -1)
616 		return (EINVAL); /* no can do */
617 
618 	/*
619 	 * The M.I. layer likes to keep cs_brg_clk current, even though
620 	 * we are the only ones who should be touching the BRG's rate.
621 	 *
622 	 * Note: we are assuming that any ZSC_EXTERN signal source comes in
623 	 * on the RTxC pin. Correct for the mac68k obio zsc.
624 	 */
625 	if (sf & ZSC_EXTERN)
626 		cs->cs_brg_clk = xcs->cs_clocks[i].clk >> 4;
627 	else
628 		cs->cs_brg_clk = PCLK / 16;
629 
630 	/*
631 	 * Now we have a source, so set it up.
632 	 */
633 	s = splzs();
634 	xcs->cs_psource = src;
635 	xcs->cs_pclk_flag = sf;
636 	bps = rate0;
637 	if (sf & ZSC_BRG) {
638 		cs->cs_preg[4] = ZSWR4_CLK_X16;
639 		cs->cs_preg[11]= ZSWR11_RXCLK_BAUD | ZSWR11_TXCLK_BAUD;
640 		if (sf & ZSC_PCLK) {
641 			cs->cs_preg[14] = ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK;
642 		} else {
643 			cs->cs_preg[14] = ZSWR14_BAUD_ENA;
644 		}
645 		tc = tc0;
646 	} else {
647 		cs->cs_preg[4] = tc0;
648 		if (sf & ZSC_RTXDIV) {
649 			cs->cs_preg[11] = ZSWR11_RXCLK_RTXC | ZSWR11_TXCLK_RTXC;
650 		} else {
651 			cs->cs_preg[11] = ZSWR11_RXCLK_TRXC | ZSWR11_TXCLK_TRXC;
652 		}
653 		cs->cs_preg[14]= 0;
654 		tc = 0xffff;
655 	}
656 	/* Set the BAUD rate divisor. */
657 	cs->cs_preg[12] = tc;
658 	cs->cs_preg[13] = tc >> 8;
659 	splx(s);
660 
661 #ifdef ZSMACDEBUG
662 	zsprintf("Rate is %7d, tc is %7d, source no. %2d, flags %4x\n", \
663 	    bps, tc, src, sf);
664 	zsprintf("Registers are: 4 %x, 11 %x, 14 %x\n\n",
665 		cs->cs_preg[4], cs->cs_preg[11], cs->cs_preg[14]);
666 #endif
667 
668 	cs->cs_preg[5] |= ZSWR5_RTS;	/* Make sure the drivers are on! */
669 
670 	/* Caller will stuff the pending registers. */
671 	return (0);
672 }
673 
674 int
675 zs_set_modes(struct zs_chanstate *cs, int cflag)
676 {
677 	struct xzs_chanstate *xcs = (void*)cs;
678 	int s;
679 
680 	/*
681 	 * Make sure we don't enable hfc on a signal line we're ignoring.
682 	 * As we enable CTS interrupts only if we have CRTSCTS or CDTRCTS,
683 	 * this code also effectivly turns off ZSWR15_CTS_IE.
684 	 *
685 	 * Also, disable DCD interrupts if we've been told to ignore
686 	 * the DCD pin. Happens on mac68k because the input line for
687 	 * DCD can also be used as a clock input.  (Just set CLOCAL.)
688 	 *
689 	 * If someone tries to turn an invalid flow mode on, Just Say No
690 	 * (Suggested by gwr)
691 	 */
692 	if ((cflag & CDTRCTS) && (cflag & (CRTSCTS | MDMBUF)))
693 		return (EINVAL);
694 	if (xcs->cs_hwflags & ZS_HWFLAG_NO_DCD) {
695 		if (cflag & MDMBUF)
696 			return (EINVAL);
697 		cflag |= CLOCAL;
698 	}
699 	if ((xcs->cs_hwflags & ZS_HWFLAG_NO_CTS) && (cflag & (CRTSCTS | CDTRCTS)))
700 		return (EINVAL);
701 
702 	/*
703 	 * Output hardware flow control on the chip is horrendous:
704 	 * if carrier detect drops, the receiver is disabled, and if
705 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
706 	 * Therefore, NEVER set the HFC bit, and instead use the
707 	 * status interrupt to detect CTS changes.
708 	 */
709 	s = splzs();
710 	if ((cflag & (CLOCAL | MDMBUF)) != 0)
711 		cs->cs_rr0_dcd = 0;
712 	else
713 		cs->cs_rr0_dcd = ZSRR0_DCD;
714 	/*
715 	 * The mac hardware only has one output, DTR (HSKo in Mac
716 	 * parlance). In HFC mode, we use it for the functions
717 	 * typically served by RTS and DTR on other ports, so we
718 	 * have to fake the upper layer out some.
719 	 *
720 	 * CRTSCTS we use CTS as an input which tells us when to shut up.
721 	 * We make no effort to shut up the other side of the connection.
722 	 * DTR is used to hang up the modem.
723 	 *
724 	 * In CDTRCTS, we use CTS to tell us to stop, but we use DTR to
725 	 * shut up the other side.
726 	 */
727 	if ((cflag & CRTSCTS) != 0) {
728 		cs->cs_wr5_dtr = ZSWR5_DTR;
729 		cs->cs_wr5_rts = 0;
730 		cs->cs_rr0_cts = ZSRR0_CTS;
731 	} else if ((cflag & CDTRCTS) != 0) {
732 		cs->cs_wr5_dtr = 0;
733 		cs->cs_wr5_rts = ZSWR5_DTR;
734 		cs->cs_rr0_cts = ZSRR0_CTS;
735 	} else if ((cflag & MDMBUF) != 0) {
736 		cs->cs_wr5_dtr = 0;
737 		cs->cs_wr5_rts = ZSWR5_DTR;
738 		cs->cs_rr0_cts = ZSRR0_DCD;
739 	} else {
740 		cs->cs_wr5_dtr = ZSWR5_DTR;
741 		cs->cs_wr5_rts = 0;
742 		cs->cs_rr0_cts = 0;
743 	}
744 	splx(s);
745 
746 	/* Caller will stuff the pending registers. */
747 	return (0);
748 }
749 
750 
751 /*
752  * Read or write the chip with suitable delays.
753  * MacII hardware has the delay built in.
754  * No need for extra delay. :-) However, some clock-chirped
755  * macs, or zsc's on serial add-on boards might need it.
756  */
757 #define	ZS_DELAY()
758 
759 u_char
760 zs_read_reg(struct zs_chanstate *cs, u_char reg)
761 {
762 	u_char val;
763 
764 	out8(cs->cs_reg_csr, reg);
765 	ZS_DELAY();
766 	val = in8(cs->cs_reg_csr);
767 	ZS_DELAY();
768 	return val;
769 }
770 
771 void
772 zs_write_reg(struct zs_chanstate *cs, u_char reg, u_char val)
773 {
774 	out8(cs->cs_reg_csr, reg);
775 	ZS_DELAY();
776 	out8(cs->cs_reg_csr, val);
777 	ZS_DELAY();
778 }
779 
780 u_char
781 zs_read_csr(struct zs_chanstate *cs)
782 {
783 	u_char val;
784 
785 	val = in8(cs->cs_reg_csr);
786 	ZS_DELAY();
787 	/* make up for the fact CTS is wired backwards */
788 	val ^= ZSRR0_CTS;
789 	return val;
790 }
791 
792 void
793 zs_write_csr(struct zs_chanstate *cs, u_char val)
794 {
795 	/* Note, the csr does not write CTS... */
796 	out8(cs->cs_reg_csr, val);
797 	ZS_DELAY();
798 }
799 
800 u_char
801 zs_read_data(struct zs_chanstate *cs)
802 {
803 	u_char val;
804 
805 	val = in8(cs->cs_reg_data);
806 	ZS_DELAY();
807 	return val;
808 }
809 
810 void
811 zs_write_data(struct zs_chanstate *cs, u_char val)
812 {
813 	out8(cs->cs_reg_data, val);
814 	ZS_DELAY();
815 }
816 
817 /****************************************************************
818  * Console support functions (powermac specific!)
819  * Note: this code is allowed to know about the layout of
820  * the chip registers, and uses that to keep things simple.
821  * XXX - I think I like the mvme167 code better. -gwr
822  * XXX - Well :-P  :-)  -wrs
823  ****************************************************************/
824 
825 #define zscnpollc	nullcnpollc
826 cons_decl(zs);
827 
828 static int stdin, stdout;
829 
830 /*
831  * Console functions.
832  */
833 
834 /*
835  * zscnprobe is the routine which gets called as the kernel is trying to
836  * figure out where the console should be. Each io driver which might
837  * be the console (as defined in mac68k/conf.c) gets probed. The probe
838  * fills in the consdev structure. Important parts are the device #,
839  * and the console priority. Values are CN_DEAD (don't touch me),
840  * CN_NORMAL (I'm here, but elsewhere might be better), CN_INTERNAL
841  * (the video, better than CN_NORMAL), and CN_REMOTE (pick me!)
842  *
843  * As the mac's a bit different, we do extra work here. We mainly check
844  * to see if we have serial echo going on. Also chould check for default
845  * speeds.
846  */
847 
848 /*
849  * Polled input char.
850  */
851 int
852 zs_getc(void *v)
853 {
854 	volatile struct zschan *zc = v;
855 	int s, c, rr0;
856 
857 	s = splhigh();
858 	/* Wait for a character to arrive. */
859 	do {
860 		rr0 = in8(&zc->zc_csr);
861 		ZS_DELAY();
862 	} while ((rr0 & ZSRR0_RX_READY) == 0);
863 
864 	c = in8(&zc->zc_data);
865 	ZS_DELAY();
866 	splx(s);
867 
868 	/*
869 	 * This is used by the kd driver to read scan codes,
870 	 * so don't translate '\r' ==> '\n' here...
871 	 */
872 	return (c);
873 }
874 
875 /*
876  * Polled output char.
877  */
878 void
879 zs_putc(void *v, int c)
880 {
881 	volatile struct zschan *zc = v;
882 	int s, rr0;
883 	long wait = 0;
884 
885 	s = splhigh();
886 	/* Wait for transmitter to become ready. */
887 	do {
888 		rr0 = in8(&zc->zc_csr);
889 		ZS_DELAY();
890 	} while (((rr0 & ZSRR0_TX_READY) == 0) && (wait++ < 1000000));
891 
892 	if ((rr0 & ZSRR0_TX_READY) != 0) {
893 		out8(&zc->zc_data, c);
894 		ZS_DELAY();
895 	}
896 	splx(s);
897 }
898 
899 
900 /*
901  * Polled console input putchar.
902  */
903 int
904 zscngetc(dev_t dev)
905 {
906 	volatile struct zschan *zc = zs_conschan;
907 	int c;
908 
909 	if (zc) {
910 		c = zs_getc(__UNVOLATILE(zc));
911 	} else {
912 		char ch = 0;
913 		OF_read(stdin, &ch, 1);
914 		c = ch;
915 	}
916 	return c;
917 }
918 
919 /*
920  * Polled console output putchar.
921  */
922 void
923 zscnputc(dev_t dev, int c)
924 {
925 	volatile struct zschan *zc = zs_conschan;
926 
927 	if (zc) {
928 		zs_putc(__UNVOLATILE(zc), c);
929 	} else {
930 		char ch = c;
931 		OF_write(stdout, &ch, 1);
932 	}
933 }
934 
935 /*
936  * Handle user request to enter kernel debugger.
937  */
938 void
939 zs_abort(struct zs_chanstate *cs)
940 {
941 	volatile struct zschan *zc = zs_conschan;
942 	int rr0;
943 	long wait = 0;
944 
945 	if (zs_cons_canabort == 0)
946 		return;
947 
948 	/* Wait for end of break to avoid PROM abort. */
949 	do {
950 		rr0 = in8(&zc->zc_csr);
951 		ZS_DELAY();
952 	} while ((rr0 & ZSRR0_BREAK) && (wait++ < ZSABORT_DELAY));
953 
954 	if (wait > ZSABORT_DELAY) {
955 		zs_cons_canabort = 0;
956 	/* If we time out, turn off the abort ability! */
957 	}
958 
959 #if defined(KGDB)
960 	kgdb_connect(1);
961 #elif defined(DDB)
962 	Debugger();
963 #endif
964 }
965 
966 extern int ofccngetc(dev_t);
967 extern void ofccnputc(dev_t, int);
968 
969 struct consdev consdev_zs = {
970 	zscnprobe,
971 	zscninit,
972 	zscngetc,
973 	zscnputc,
974 	zscnpollc,
975 };
976 
977 void
978 zscnprobe(struct consdev *cp)
979 {
980 	int chosen, pkg;
981 	char name[16];
982 
983 	if ((chosen = OF_finddevice("/chosen")) == -1)
984 		return;
985 
986 	if (OF_getprop(chosen, "stdin", &stdin, sizeof(stdin)) == -1)
987 		return;
988 	if (OF_getprop(chosen, "stdout", &stdout, sizeof(stdout)) == -1)
989 		return;
990 
991 	if ((pkg = OF_instance_to_package(stdin)) == -1)
992 		return;
993 
994 	memset(name, 0, sizeof(name));
995 	if (OF_getprop(pkg, "device_type", name, sizeof(name)) == -1)
996 		return;
997 
998 	if (strcmp(name, "serial") != 0)
999 		return;
1000 
1001 	memset(name, 0, sizeof(name));
1002 	if (OF_getprop(pkg, "name", name, sizeof(name)) == -1)
1003 		return;
1004 
1005 	cp->cn_pri = CN_REMOTE;
1006 }
1007 
1008 void
1009 zscninit(struct consdev *cp)
1010 {
1011 	int escc, escc_ch, obio, zs_offset;
1012 	u_int32_t reg[5];
1013 	char name[16];
1014 
1015 	if ((escc_ch = OF_instance_to_package(stdin)) == -1)
1016 		return;
1017 
1018 	memset(name, 0, sizeof(name));
1019 	if (OF_getprop(escc_ch, "name", name, sizeof(name)) == -1)
1020 		return;
1021 
1022 	zs_conschannel = strcmp(name, "ch-b") == 0;
1023 
1024 	if (OF_getprop(escc_ch, "reg", reg, sizeof(reg)) < 4)
1025 		return;
1026 	zs_offset = reg[0];
1027 
1028 	escc = OF_parent(escc_ch);
1029 	obio = OF_parent(escc);
1030 
1031 	if (OF_getprop(obio, "assigned-addresses", reg, sizeof(reg)) < 12)
1032 		return;
1033 	zs_conschan = (void *)(reg[2] + zs_offset);
1034 }
1035