xref: /netbsd-src/sys/arch/macppc/dev/zs.c (revision 9fb66d812c00ebfb445c0b47dea128f32aa6fe96)
1 /*	$NetBSD: zs.c,v 1.51 2021/03/05 07:15:53 rin 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  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Zilog Z8530 Dual UART driver (machine-dependent part)
31  *
32  * Runs two serial lines per chip using slave drivers.
33  * Plain tty/async lines use the zs_async slave.
34  * Sun keyboard/mouse uses the zs_kbd/zs_ms slaves.
35  * Other ports use their own mice & keyboard slaves.
36  *
37  * Credits & history:
38  *
39  * With NetBSD 1.1, port-mac68k started using a port of the port-sparc
40  * (port-sun3?) zs.c driver (which was in turn based on code in the
41  * Berkeley 4.4 Lite release). Bill Studenmund did the port, with
42  * help from Allen Briggs and Gordon Ross <gwr@NetBSD.org>. Noud de
43  * Brouwer field-tested the driver at a local ISP.
44  *
45  * Bill Studenmund and Gordon Ross then ported the machine-independent
46  * z8530 driver to work with port-mac68k. NetBSD 1.2 contained an
47  * intermediate version (mac68k using a local, patched version of
48  * the m.i. drivers), with NetBSD 1.3 containing a full version.
49  */
50 
51 #include <sys/cdefs.h>
52 __KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.51 2021/03/05 07:15:53 rin Exp $");
53 
54 #include "opt_ddb.h"
55 #include "opt_kgdb.h"
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/file.h>
63 #include <sys/ioctl.h>
64 #include <sys/tty.h>
65 #include <sys/time.h>
66 #include <sys/kernel.h>
67 #include <sys/syslog.h>
68 #include <sys/intr.h>
69 #include <sys/cpu.h>
70 #ifdef KGDB
71 #include <sys/kgdb.h>
72 #endif
73 
74 #include <dev/cons.h>
75 #include <dev/ofw/openfirm.h>
76 #include <dev/ic/z8530reg.h>
77 
78 #include <machine/z8530var.h>
79 #include <machine/autoconf.h>
80 #include <machine/pio.h>
81 
82 /* Are these in a header file anywhere? */
83 /* Booter flags interface */
84 #define ZSMAC_RAW	0x01
85 #define ZSMAC_LOCALTALK	0x02
86 
87 /*
88  * Some warts needed by z8530tty.c -
89  */
90 int zs_def_cflag = (CREAD | CS8 | HUPCL);
91 
92 /*
93  * abort detection on console will now timeout after iterating on a loop
94  * the following # of times. Cheep hack. Also, abort detection is turned
95  * off after a timeout (i.e. maybe there's not a terminal hooked up).
96  */
97 #define ZSABORT_DELAY 3000000
98 
99 struct zsdevice {
100 	/* Yes, they are backwards. */
101 	struct	zschan zs_chan_b;
102 	struct	zschan zs_chan_a;
103 };
104 
105 static int zs_defspeed[2] = {
106 	38400,		/* ttyZ0 */
107 	38400,		/* ttyZ1 */
108 };
109 
110 /* console stuff */
111 void	*zs_conschan = 0;
112 int	zs_conschannel = -1;
113 #ifdef	ZS_CONSOLE_ABORT
114 int	zs_cons_canabort = 1;
115 #else
116 int	zs_cons_canabort = 0;
117 #endif /* ZS_CONSOLE_ABORT*/
118 
119 /* device to which the console is attached--if serial. */
120 /* Mac stuff */
121 
122 static int zs_get_speed(struct zs_chanstate *);
123 
124 /*
125  * Even though zsparam will set up the clock multiples, etc., we
126  * still set them here as: 1) mice & keyboards don't use zsparam,
127  * and 2) the console stuff uses these defaults before device
128  * attach.
129  */
130 
131 static uint8_t zs_init_reg[16] = {
132 	0,	/* 0: CMD (reset, etc.) */
133 	0,	/* 1: No interrupts yet. */
134 	0,	/* IVECT */
135 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
136 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
137 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
138 	0,	/* 6: TXSYNC/SYNCLO */
139 	0,	/* 7: RXSYNC/SYNCHI */
140 	0,	/* 8: alias for data port */
141 	ZSWR9_MASTER_IE,
142 	0,	/*10: Misc. TX/RX control bits */
143 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
144 	((PCLK/32)/38400)-2,	/*12: BAUDLO (default=38400) */
145 	0,			/*13: BAUDHI (default=38400) */
146 	ZSWR14_BAUD_ENA,
147 	ZSWR15_BREAK_IE,
148 };
149 
150 /****************************************************************
151  * Autoconfig
152  ****************************************************************/
153 
154 /* Definition of the driver for autoconfig. */
155 static int	zsc_match(device_t, cfdata_t, void *);
156 static void	zsc_attach(device_t, device_t, void *);
157 static int	zsc_print(void *, const char *);
158 
159 CFATTACH_DECL_NEW(zsc, sizeof(struct zsc_softc),
160     zsc_match, zsc_attach, NULL, NULL);
161 
162 extern struct cfdriver zsc_cd;
163 
164 int zsc_attached;
165 
166 int zshard(void *);
167 #ifdef ZS_TXDMA
168 static int zs_txdma_int(void *);
169 #endif
170 
171 void zscnprobe(struct consdev *);
172 void zscninit(struct consdev *);
173 int  zscngetc(dev_t);
174 void zscnputc(dev_t, int);
175 void zscnpollc(dev_t, int);
176 
177 /*
178  * Is the zs chip present?
179  */
180 static int
181 zsc_match(device_t parent, cfdata_t cf, void *aux)
182 {
183 	struct confargs *ca = aux;
184 
185 	if (strcmp(ca->ca_name, "escc") != 0)
186 		return 0;
187 
188 	if (zsc_attached)
189 		return 0;
190 
191 	return 1;
192 }
193 
194 /*
195  * Attach a found zs.
196  *
197  * Match slave number to zs unit number, so that misconfiguration will
198  * not set up the keyboard as ttya, etc.
199  */
200 static void
201 zsc_attach(device_t parent, device_t self, void *aux)
202 {
203 	struct zsc_softc *zsc = device_private(self);
204 	struct confargs *ca = aux;
205 	struct zsc_attach_args zsc_args;
206 	volatile struct zschan *zc;
207 	struct xzs_chanstate *xcs;
208 	struct zs_chanstate *cs;
209 	struct zsdevice *zsd;
210 	int channel;
211 	int s, chip, theflags;
212 	int node, intr[2][3];
213 	u_int regs[6];
214 	char intr_xname[INTRDEVNAMEBUF];
215 
216 	zsc_attached = 1;
217 
218 	zsc->zsc_dev = self;
219 
220 	chip = 0;
221 	ca->ca_reg[0] += ca->ca_baseaddr;
222 	zsd = mapiodev(ca->ca_reg[0], ca->ca_reg[1], false);
223 
224 	node = OF_child(ca->ca_node);	/* ch-a */
225 
226 	for (channel = 0; channel < 2; channel++) {
227 		if (OF_getprop(node, "AAPL,interrupts",
228 			       intr[channel], sizeof(intr[0])) == -1 &&
229 		    OF_getprop(node, "interrupts",
230 			       intr[channel], sizeof(intr[0])) == -1) {
231 			aprint_error(": cannot find interrupt property\n");
232 			return;
233 		}
234 
235 		if (OF_getprop(node, "reg", regs, sizeof(regs)) < 24) {
236 			aprint_error(": cannot find reg property\n");
237 			return;
238 		}
239 		regs[2] += ca->ca_baseaddr;
240 		regs[4] += ca->ca_baseaddr;
241 #ifdef ZS_TXDMA
242 		zsc->zsc_txdmareg[channel] = mapiodev(regs[2], regs[3], false);
243 		zsc->zsc_txdmacmd[channel] =
244 			dbdma_alloc(sizeof(dbdma_command_t) * 3);
245 		memset(zsc->zsc_txdmacmd[channel], 0,
246 			sizeof(dbdma_command_t) * 3);
247 		dbdma_reset(zsc->zsc_txdmareg[channel]);
248 #endif
249 		node = OF_peer(node);	/* ch-b */
250 	}
251 
252 	aprint_normal(" irq %d,%d\n", intr[0][0], intr[1][0]);
253 
254 	/*
255 	 * Initialize software state for each channel.
256 	 */
257 	for (channel = 0; channel < 2; channel++) {
258 		zsc_args.channel = channel;
259 		zsc_args.hwflags = (channel == zs_conschannel ?
260 				    ZS_HWFLAG_CONSOLE : 0);
261 		xcs = &zsc->xzsc_xcs_store[channel];
262 		cs  = &xcs->xzs_cs;
263 		zsc->zsc_cs[channel] = cs;
264 
265 		zs_lock_init(cs);
266 		cs->cs_channel = channel;
267 		cs->cs_private = NULL;
268 		cs->cs_ops = &zsops_null;
269 
270 		zc = (channel == 0) ? &zsd->zs_chan_a : &zsd->zs_chan_b;
271 
272 		cs->cs_reg_csr  = &zc->zc_csr;
273 		cs->cs_reg_data = &zc->zc_data;
274 
275 		memcpy(cs->cs_creg, zs_init_reg, 16);
276 		memcpy(cs->cs_preg, zs_init_reg, 16);
277 
278 		/* Current BAUD rate generator clock. */
279 		cs->cs_brg_clk = PCLK / 16;	/* RTxC is 230400*16, so use 230400 */
280 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE)
281 			cs->cs_defspeed = zs_get_speed(cs);
282 		else
283 			cs->cs_defspeed = zs_defspeed[channel];
284 		cs->cs_defcflag = zs_def_cflag;
285 
286 		/* Make these correspond to cs_defcflag (-crtscts) */
287 		cs->cs_rr0_dcd = ZSRR0_DCD;
288 		cs->cs_rr0_cts = 0;
289 		cs->cs_wr5_dtr = ZSWR5_DTR;
290 		cs->cs_wr5_rts = 0;
291 
292 #ifdef __notyet__
293 		cs->cs_slave_type = ZS_SLAVE_NONE;
294 #endif
295 
296 		/* Define BAUD rate stuff. */
297 		xcs->cs_clocks[0].clk = PCLK;
298 		xcs->cs_clocks[0].flags = ZSC_RTXBRG | ZSC_RTXDIV;
299 		xcs->cs_clocks[1].flags =
300 			ZSC_RTXBRG | ZSC_RTXDIV | ZSC_VARIABLE | ZSC_EXTERN;
301 		xcs->cs_clocks[2].flags = ZSC_TRXDIV | ZSC_VARIABLE;
302 		xcs->cs_clock_count = 3;
303 		if (channel == 0) {
304 			theflags = 0; /*mac68k_machine.modem_flags;*/
305 			/*xcs->cs_clocks[1].clk = mac68k_machine.modem_dcd_clk;*/
306 			/*xcs->cs_clocks[2].clk = mac68k_machine.modem_cts_clk;*/
307 			xcs->cs_clocks[1].clk = 0;
308 			xcs->cs_clocks[2].clk = 0;
309 		} else {
310 			theflags = 0; /*mac68k_machine.print_flags;*/
311 			xcs->cs_clocks[1].flags = ZSC_VARIABLE;
312 			/*
313 			 * Yes, we aren't defining ANY clock source enables for the
314 			 * printer's DCD clock in. The hardware won't let us
315 			 * use it. But a clock will freak out the chip, so we
316 			 * let you set it, telling us to bar interrupts on the line.
317 			 */
318 			/*xcs->cs_clocks[1].clk = mac68k_machine.print_dcd_clk;*/
319 			/*xcs->cs_clocks[2].clk = mac68k_machine.print_cts_clk;*/
320 			xcs->cs_clocks[1].clk = 0;
321 			xcs->cs_clocks[2].clk = 0;
322 		}
323 		if (xcs->cs_clocks[1].clk)
324 			zsc_args.hwflags |= ZS_HWFLAG_NO_DCD;
325 		if (xcs->cs_clocks[2].clk)
326 			zsc_args.hwflags |= ZS_HWFLAG_NO_CTS;
327 
328 		/* Set defaults in our "extended" chanstate. */
329 		xcs->cs_csource = 0;
330 		xcs->cs_psource = 0;
331 		xcs->cs_cclk_flag = 0;  /* Nothing fancy by default */
332 		xcs->cs_pclk_flag = 0;
333 
334 		if (theflags & ZSMAC_RAW) {
335 			zsc_args.hwflags |= ZS_HWFLAG_RAW;
336 			printf(" (raw defaults)");
337 		}
338 
339 		/*
340 		 * XXX - This might be better done with a "stub" driver
341 		 * (to replace zstty) that ignores LocalTalk for now.
342 		 */
343 		if (theflags & ZSMAC_LOCALTALK) {
344 			printf(" shielding from LocalTalk");
345 			cs->cs_defspeed = 1;
346 			cs->cs_creg[ZSRR_BAUDLO] = cs->cs_preg[ZSRR_BAUDLO] = 0xff;
347 			cs->cs_creg[ZSRR_BAUDHI] = cs->cs_preg[ZSRR_BAUDHI] = 0xff;
348 			zs_write_reg(cs, ZSRR_BAUDLO, 0xff);
349 			zs_write_reg(cs, ZSRR_BAUDHI, 0xff);
350 			/*
351 			 * If we might have LocalTalk, then make sure we have the
352 			 * Baud rate low-enough to not do any damage.
353 			 */
354 		}
355 
356 		/*
357 		 * We used to disable chip interrupts here, but we now
358 		 * do that in zscnprobe, just in case MacOS left the chip on.
359 		 */
360 
361 		xcs->cs_chip = chip;
362 
363 		/* Stash away a copy of the final H/W flags. */
364 		xcs->cs_hwflags = zsc_args.hwflags;
365 
366 		/*
367 		 * Look for a child driver for this channel.
368 		 * The child attach will setup the hardware.
369 		 */
370 		if (!config_found(self, (void *)&zsc_args, zsc_print)) {
371 			/* No sub-driver.  Just reset it. */
372 			uint8_t reset = (channel == 0) ?
373 				ZSWR9_A_RESET : ZSWR9_B_RESET;
374 			s = splzs();
375 			zs_write_reg(cs, 9, reset);
376 			splx(s);
377 		}
378 	}
379 
380 	/* XXX - Now safe to install interrupt handlers. */
381 	for (channel = 0; channel < 2; channel++) {
382 		snprintf(intr_xname, sizeof(intr_xname), "%s pio%d",
383 		    device_xname(self), channel);
384 		intr_establish_xname(intr[channel][0], IST_EDGE, IPL_TTY,
385 		    zshard, zsc, intr_xname);
386 #ifdef ZS_TXDMA
387 		snprintf(intr_xname, sizeof(intr_xname), "%s dma%d",
388 		    device_xname(self), channel);
389 		intr_establish_xname(intr[channel][1], IST_EDGE, IPL_TTY,
390 		    zs_txdma_int, (void *)channel, intr_xname);
391 #endif
392 	}
393 
394 	zsc->zsc_si = softint_establish(SOFTINT_SERIAL,
395 		(void (*)(void *)) zsc_intr_soft, zsc);
396 
397 	/*
398 	 * Set the master interrupt enable and interrupt vector.
399 	 * (common to both channels, do it on A)
400 	 */
401 	cs = zsc->zsc_cs[0];
402 	s = splzs();
403 	/* interrupt vector */
404 	zs_write_reg(cs, 2, zs_init_reg[2]);
405 	/* master interrupt control (enable) */
406 	zs_write_reg(cs, 9, zs_init_reg[9]);
407 	splx(s);
408 }
409 
410 static int
411 zsc_print(void *aux, const char *name)
412 {
413 	struct zsc_attach_args *args = aux;
414 
415 	if (name != NULL)
416 		aprint_normal("%s: ", name);
417 
418 	if (args->channel != -1)
419 		aprint_normal(" channel %d", args->channel);
420 
421 	return UNCONF;
422 }
423 
424 int
425 zsmdioctl(struct zs_chanstate *cs, u_long cmd, void *data)
426 {
427 	switch (cmd) {
428 	default:
429 		return (EPASSTHROUGH);
430 	}
431 	return (0);
432 }
433 
434 void
435 zsmd_setclock(struct zs_chanstate *cs)
436 {
437 #ifdef NOTYET
438 	struct xzs_chanstate *xcs = (void *)cs;
439 
440 	if (cs->cs_channel != 0)
441 		return;
442 
443 	/*
444 	 * If the new clock has the external bit set, then select the
445 	 * external source.
446 	 */
447 	via_set_modem((xcs->cs_pclk_flag & ZSC_EXTERN) ? 1 : 0);
448 #endif
449 }
450 
451 int
452 zshard(void *arg)
453 {
454 	struct zsc_softc *zsc;
455 	int rval;
456 
457 	zsc = arg;
458 	rval = zsc_intr_hard(zsc);
459 	if ((zsc->zsc_cs[0]->cs_softreq) || (zsc->zsc_cs[1]->cs_softreq))
460 		softint_schedule(zsc->zsc_si);
461 
462 	return rval;
463 }
464 
465 #ifdef ZS_TXDMA
466 int
467 zs_txdma_int(void *arg)
468 {
469 	int ch = (int)arg;
470 	struct zsc_softc *zsc;
471 	struct zs_chanstate *cs;
472 
473 	zsc = device_lookup_private(&zsc_cd, ch);
474 	if (zsc == NULL)
475 		panic("zs_txdma_int");
476 
477 	cs = zsc->zsc_cs[ch];
478 	zstty_txdma_int(cs);
479 
480 	if (cs->cs_softreq)
481 		softint_schedule(zsc->zsc_si);
482 
483 	return 1;
484 }
485 
486 void
487 zs_dma_setup(struct zs_chanstate *cs, void *pa, int len)
488 {
489 	struct zsc_softc *zsc;
490 	dbdma_command_t *cmdp;
491 	int ch = cs->cs_channel;
492 
493 	zsc = device_lookup_private(&zsc_cd, ch);
494 	cmdp = zsc->zsc_txdmacmd[ch];
495 
496 	DBDMA_BUILD(cmdp, DBDMA_CMD_OUT_LAST, 0, len, kvtop(pa),
497 		DBDMA_INT_ALWAYS, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
498 	cmdp++;
499 	DBDMA_BUILD(cmdp, DBDMA_CMD_STOP, 0, 0, 0,
500 		DBDMA_INT_NEVER, DBDMA_WAIT_NEVER, DBDMA_BRANCH_NEVER);
501 
502 	__asm volatile("eieio");
503 
504 	dbdma_start(zsc->zsc_txdmareg[ch], zsc->zsc_txdmacmd[ch]);
505 }
506 #endif
507 
508 /*
509  * Compute the current baud rate given a ZS channel.
510  * XXX Assume internal BRG.
511  */
512 int
513 zs_get_speed(struct zs_chanstate *cs)
514 {
515 	int tconst;
516 
517 	tconst = zs_read_reg(cs, 12);
518 	tconst |= zs_read_reg(cs, 13) << 8;
519 	return TCONST_TO_BPS(cs->cs_brg_clk, tconst);
520 }
521 
522 #ifndef ZS_TOLERANCE
523 #define ZS_TOLERANCE 51
524 /* 5% in tenths of a %, plus 1 so that exactly 5% will be ok. */
525 #endif
526 
527 /*
528  * Search through the signal sources in the channel, and
529  * pick the best one for the baud rate requested. Return
530  * a -1 if not achievable in tolerance. Otherwise return 0
531  * and fill in the values.
532  *
533  * This routine draws inspiration from the Atari port's zs.c
534  * driver in NetBSD 1.1 which did the same type of source switching.
535  * Tolerance code inspired by comspeed routine in isa/com.c.
536  *
537  * By Bill Studenmund, 1996-05-12
538  */
539 int
540 zs_set_speed(struct zs_chanstate *cs, int bps)
541 {
542 	struct xzs_chanstate *xcs = (void *) cs;
543 	int i, tc, tc0 = 0, tc1, s, sf = 0;
544 	int src, rate0, rate1, err, tol;
545 
546 	if (bps == 0)
547 		return (0);
548 
549 	src = -1;		/* no valid source yet */
550 	tol = ZS_TOLERANCE;
551 
552 	/*
553 	 * Step through all the sources and see which one matches
554 	 * the best. A source has to match BETTER than tol to be chosen.
555 	 * Thus if two sources give the same error, the first one will be
556 	 * chosen. Also, allow for the possability that one source might run
557 	 * both the BRG and the direct divider (i.e. RTxC).
558 	 */
559 	for (i = 0; i < xcs->cs_clock_count; i++) {
560 		if (xcs->cs_clocks[i].clk <= 0)
561 			continue;	/* skip non-existent or bad clocks */
562 		if (xcs->cs_clocks[i].flags & ZSC_BRG) {
563 			/* check out BRG at /16 */
564 			tc1 = BPS_TO_TCONST(xcs->cs_clocks[i].clk >> 4, bps);
565 			if (tc1 >= 0) {
566 				rate1 = TCONST_TO_BPS(xcs->cs_clocks[i].clk >> 4, tc1);
567 				err = abs(((rate1 - bps)*1000)/bps);
568 				if (err < tol) {
569 					tol = err;
570 					src = i;
571 					sf = xcs->cs_clocks[i].flags & ~ZSC_DIV;
572 					tc0 = tc1;
573 					rate0 = rate1;
574 				}
575 			}
576 		}
577 		if (xcs->cs_clocks[i].flags & ZSC_DIV) {
578 			/*
579 			 * Check out either /1, /16, /32, or /64
580 			 * Note: for /1, you'd better be using a synchronized
581 			 * clock!
582 			 */
583 			int b0 = xcs->cs_clocks[i].clk, e0 = abs(b0-bps);
584 			int b1 = b0 >> 4, e1 = abs(b1-bps);
585 			int b2 = b1 >> 1, e2 = abs(b2-bps);
586 			int b3 = b2 >> 1, e3 = abs(b3-bps);
587 
588 			if (e0 < e1 && e0 < e2 && e0 < e3) {
589 				err = e0;
590 				rate1 = b0;
591 				tc1 = ZSWR4_CLK_X1;
592 			} else if (e0 > e1 && e1 < e2  && e1 < e3) {
593 				err = e1;
594 				rate1 = b1;
595 				tc1 = ZSWR4_CLK_X16;
596 			} else if (e0 > e2 && e1 > e2 && e2 < e3) {
597 				err = e2;
598 				rate1 = b2;
599 				tc1 = ZSWR4_CLK_X32;
600 			} else {
601 				err = e3;
602 				rate1 = b3;
603 				tc1 = ZSWR4_CLK_X64;
604 			}
605 
606 			err = (err * 1000)/bps;
607 			if (err < tol) {
608 				tol = err;
609 				src = i;
610 				sf = xcs->cs_clocks[i].flags & ~ZSC_BRG;
611 				tc0 = tc1;
612 				rate0 = rate1;
613 			}
614 		}
615 	}
616 #ifdef ZSMACDEBUG
617 	zsprintf("Checking for rate %d. Found source #%d.\n",bps, src);
618 #endif
619 	if (src == -1)
620 		return (EINVAL); /* no can do */
621 
622 	/*
623 	 * The M.I. layer likes to keep cs_brg_clk current, even though
624 	 * we are the only ones who should be touching the BRG's rate.
625 	 *
626 	 * Note: we are assuming that any ZSC_EXTERN signal source comes in
627 	 * on the RTxC pin. Correct for the mac68k obio zsc.
628 	 */
629 	if (sf & ZSC_EXTERN)
630 		cs->cs_brg_clk = xcs->cs_clocks[i].clk >> 4;
631 	else
632 		cs->cs_brg_clk = PCLK / 16;
633 
634 	/*
635 	 * Now we have a source, so set it up.
636 	 */
637 	s = splzs();
638 	xcs->cs_psource = src;
639 	xcs->cs_pclk_flag = sf;
640 	bps = rate0;
641 	if (sf & ZSC_BRG) {
642 		cs->cs_preg[4] = ZSWR4_CLK_X16;
643 		cs->cs_preg[11]= ZSWR11_RXCLK_BAUD | ZSWR11_TXCLK_BAUD;
644 		if (sf & ZSC_PCLK) {
645 			cs->cs_preg[14] = ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK;
646 		} else {
647 			cs->cs_preg[14] = ZSWR14_BAUD_ENA;
648 		}
649 		tc = tc0;
650 	} else {
651 		cs->cs_preg[4] = tc0;
652 		if (sf & ZSC_RTXDIV) {
653 			cs->cs_preg[11] = ZSWR11_RXCLK_RTXC | ZSWR11_TXCLK_RTXC;
654 		} else {
655 			cs->cs_preg[11] = ZSWR11_RXCLK_TRXC | ZSWR11_TXCLK_TRXC;
656 		}
657 		cs->cs_preg[14]= 0;
658 		tc = 0xffff;
659 	}
660 	/* Set the BAUD rate divisor. */
661 	cs->cs_preg[12] = tc;
662 	cs->cs_preg[13] = tc >> 8;
663 	splx(s);
664 
665 #ifdef ZSMACDEBUG
666 	zsprintf("Rate is %7d, tc is %7d, source no. %2d, flags %4x\n", \
667 	    bps, tc, src, sf);
668 	zsprintf("Registers are: 4 %x, 11 %x, 14 %x\n\n",
669 		cs->cs_preg[4], cs->cs_preg[11], cs->cs_preg[14]);
670 #endif
671 
672 	cs->cs_preg[5] |= ZSWR5_RTS;	/* Make sure the drivers are on! */
673 
674 	/* Caller will stuff the pending registers. */
675 	return (0);
676 }
677 
678 int
679 zs_set_modes(struct zs_chanstate *cs, int cflag)
680 {
681 	struct xzs_chanstate *xcs = (void*)cs;
682 	int s;
683 
684 	/*
685 	 * Make sure we don't enable hfc on a signal line we're ignoring.
686 	 * As we enable CTS interrupts only if we have CRTSCTS or CDTRCTS,
687 	 * this code also effectivly turns off ZSWR15_CTS_IE.
688 	 *
689 	 * Also, disable DCD interrupts if we've been told to ignore
690 	 * the DCD pin. Happens on mac68k because the input line for
691 	 * DCD can also be used as a clock input.  (Just set CLOCAL.)
692 	 *
693 	 * If someone tries to turn an invalid flow mode on, Just Say No
694 	 * (Suggested by gwr)
695 	 */
696 	if ((cflag & CDTRCTS) && (cflag & (CRTSCTS | MDMBUF)))
697 		return (EINVAL);
698 	if (xcs->cs_hwflags & ZS_HWFLAG_NO_DCD) {
699 		if (cflag & MDMBUF)
700 			return (EINVAL);
701 		cflag |= CLOCAL;
702 	}
703 	if ((xcs->cs_hwflags & ZS_HWFLAG_NO_CTS) && (cflag & (CRTSCTS | CDTRCTS)))
704 		return (EINVAL);
705 
706 	/*
707 	 * Output hardware flow control on the chip is horrendous:
708 	 * if carrier detect drops, the receiver is disabled, and if
709 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
710 	 * Therefore, NEVER set the HFC bit, and instead use the
711 	 * status interrupt to detect CTS changes.
712 	 */
713 	s = splzs();
714 	if ((cflag & (CLOCAL | MDMBUF)) != 0)
715 		cs->cs_rr0_dcd = 0;
716 	else
717 		cs->cs_rr0_dcd = ZSRR0_DCD;
718 	/*
719 	 * The mac hardware only has one output, DTR (HSKo in Mac
720 	 * parlance). In HFC mode, we use it for the functions
721 	 * typically served by RTS and DTR on other ports, so we
722 	 * have to fake the upper layer out some.
723 	 *
724 	 * CRTSCTS we use CTS as an input which tells us when to shut up.
725 	 * We make no effort to shut up the other side of the connection.
726 	 * DTR is used to hang up the modem.
727 	 *
728 	 * In CDTRCTS, we use CTS to tell us to stop, but we use DTR to
729 	 * shut up the other side.
730 	 */
731 	if ((cflag & CRTSCTS) != 0) {
732 		cs->cs_wr5_dtr = ZSWR5_DTR;
733 		cs->cs_wr5_rts = 0;
734 		cs->cs_rr0_cts = ZSRR0_CTS;
735 	} else if ((cflag & CDTRCTS) != 0) {
736 		cs->cs_wr5_dtr = 0;
737 		cs->cs_wr5_rts = ZSWR5_DTR;
738 		cs->cs_rr0_cts = ZSRR0_CTS;
739 	} else if ((cflag & MDMBUF) != 0) {
740 		cs->cs_wr5_dtr = 0;
741 		cs->cs_wr5_rts = ZSWR5_DTR;
742 		cs->cs_rr0_cts = ZSRR0_DCD;
743 	} else {
744 		cs->cs_wr5_dtr = ZSWR5_DTR;
745 		cs->cs_wr5_rts = 0;
746 		cs->cs_rr0_cts = 0;
747 	}
748 	splx(s);
749 
750 	/* Caller will stuff the pending registers. */
751 	return (0);
752 }
753 
754 
755 /*
756  * Read or write the chip with suitable delays.
757  * MacII hardware has the delay built in.
758  * No need for extra delay. :-) However, some clock-chirped
759  * macs, or zsc's on serial add-on boards might need it.
760  */
761 #define	ZS_DELAY()
762 
763 uint8_t
764 zs_read_reg(struct zs_chanstate *cs, uint8_t reg)
765 {
766 	uint8_t val;
767 
768 	out8(cs->cs_reg_csr, reg);
769 	ZS_DELAY();
770 	val = in8(cs->cs_reg_csr);
771 	ZS_DELAY();
772 	return val;
773 }
774 
775 void
776 zs_write_reg(struct zs_chanstate *cs, uint8_t reg, uint8_t val)
777 {
778 	out8(cs->cs_reg_csr, reg);
779 	ZS_DELAY();
780 	out8(cs->cs_reg_csr, val);
781 	ZS_DELAY();
782 }
783 
784 uint8_t
785 zs_read_csr(struct zs_chanstate *cs)
786 {
787 	uint8_t val;
788 
789 	val = in8(cs->cs_reg_csr);
790 	ZS_DELAY();
791 	/* make up for the fact CTS is wired backwards */
792 	val ^= ZSRR0_CTS;
793 	return val;
794 }
795 
796 void
797 zs_write_csr(struct zs_chanstate *cs, uint8_t val)
798 {
799 	/* Note, the csr does not write CTS... */
800 	out8(cs->cs_reg_csr, val);
801 	ZS_DELAY();
802 }
803 
804 uint8_t
805 zs_read_data(struct zs_chanstate *cs)
806 {
807 	uint8_t val;
808 
809 	val = in8(cs->cs_reg_data);
810 	ZS_DELAY();
811 	return val;
812 }
813 
814 void
815 zs_write_data(struct zs_chanstate *cs, uint8_t val)
816 {
817 	out8(cs->cs_reg_data, val);
818 	ZS_DELAY();
819 }
820 
821 /****************************************************************
822  * Console support functions (powermac specific!)
823  * Note: this code is allowed to know about the layout of
824  * the chip registers, and uses that to keep things simple.
825  * XXX - I think I like the mvme167 code better. -gwr
826  * XXX - Well :-P  :-)  -wrs
827  ****************************************************************/
828 
829 #define zscnpollc	nullcnpollc
830 cons_decl(zs);
831 
832 static int stdin, stdout;
833 
834 /*
835  * Console functions.
836  */
837 
838 /*
839  * zscnprobe is the routine which gets called as the kernel is trying to
840  * figure out where the console should be. Each io driver which might
841  * be the console (as defined in mac68k/conf.c) gets probed. The probe
842  * fills in the consdev structure. Important parts are the device #,
843  * and the console priority. Values are CN_DEAD (don't touch me),
844  * CN_NORMAL (I'm here, but elsewhere might be better), CN_INTERNAL
845  * (the video, better than CN_NORMAL), and CN_REMOTE (pick me!)
846  *
847  * As the mac's a bit different, we do extra work here. We mainly check
848  * to see if we have serial echo going on. Also chould check for default
849  * speeds.
850  */
851 
852 /*
853  * Polled input char.
854  */
855 int
856 zs_getc(void *v)
857 {
858 	volatile struct zschan *zc = v;
859 	int s, c, rr0;
860 
861 	s = splhigh();
862 	/* Wait for a character to arrive. */
863 	do {
864 		rr0 = in8(&zc->zc_csr);
865 		ZS_DELAY();
866 	} while ((rr0 & ZSRR0_RX_READY) == 0);
867 
868 	c = in8(&zc->zc_data);
869 	ZS_DELAY();
870 	splx(s);
871 
872 	/*
873 	 * This is used by the kd driver to read scan codes,
874 	 * so don't translate '\r' ==> '\n' here...
875 	 */
876 	return (c);
877 }
878 
879 /*
880  * Polled output char.
881  */
882 void
883 zs_putc(void *v, int c)
884 {
885 	volatile struct zschan *zc = v;
886 	int s, rr0;
887 	long wait = 0;
888 
889 	s = splhigh();
890 	/* Wait for transmitter to become ready. */
891 	do {
892 		rr0 = in8(&zc->zc_csr);
893 		ZS_DELAY();
894 	} while (((rr0 & ZSRR0_TX_READY) == 0) && (wait++ < 1000000));
895 
896 	if ((rr0 & ZSRR0_TX_READY) != 0) {
897 		out8(&zc->zc_data, c);
898 		ZS_DELAY();
899 	}
900 	splx(s);
901 }
902 
903 
904 /*
905  * Polled console input putchar.
906  */
907 int
908 zscngetc(dev_t dev)
909 {
910 	volatile struct zschan *zc = zs_conschan;
911 	int c;
912 
913 	if (zc) {
914 		c = zs_getc(__UNVOLATILE(zc));
915 	} else {
916 		char ch = 0;
917 		OF_read(stdin, &ch, 1);
918 		c = ch;
919 	}
920 	return c;
921 }
922 
923 /*
924  * Polled console output putchar.
925  */
926 void
927 zscnputc(dev_t dev, int c)
928 {
929 	volatile struct zschan *zc = zs_conschan;
930 
931 	if (zc) {
932 		zs_putc(__UNVOLATILE(zc), c);
933 	} else {
934 		char ch = c;
935 		OF_write(stdout, &ch, 1);
936 	}
937 }
938 
939 /*
940  * Handle user request to enter kernel debugger.
941  */
942 void
943 zs_abort(struct zs_chanstate *cs)
944 {
945 	volatile struct zschan *zc = zs_conschan;
946 	int rr0;
947 	long wait = 0;
948 
949 	if (zs_cons_canabort == 0)
950 		return;
951 
952 	/* Wait for end of break to avoid PROM abort. */
953 	do {
954 		rr0 = in8(&zc->zc_csr);
955 		ZS_DELAY();
956 	} while ((rr0 & ZSRR0_BREAK) && (wait++ < ZSABORT_DELAY));
957 
958 	if (wait > ZSABORT_DELAY) {
959 		zs_cons_canabort = 0;
960 	/* If we time out, turn off the abort ability! */
961 	}
962 
963 #if defined(KGDB)
964 	kgdb_connect(1);
965 #elif defined(DDB)
966 	Debugger();
967 #endif
968 }
969 
970 extern int ofccngetc(dev_t);
971 extern void ofccnputc(dev_t, int);
972 
973 struct consdev consdev_zs = {
974 	zscnprobe,
975 	zscninit,
976 	zscngetc,
977 	zscnputc,
978 	zscnpollc,
979 };
980 
981 void
982 zscnprobe(struct consdev *cp)
983 {
984 	int chosen, pkg;
985 	char name[16];
986 
987 	if ((chosen = OF_finddevice("/chosen")) == -1)
988 		return;
989 
990 	if (OF_getprop(chosen, "stdin", &stdin, sizeof(stdin)) == -1)
991 		return;
992 	if (OF_getprop(chosen, "stdout", &stdout, sizeof(stdout)) == -1)
993 		return;
994 
995 	if ((pkg = OF_instance_to_package(stdin)) == -1)
996 		return;
997 
998 	memset(name, 0, sizeof(name));
999 	if (OF_getprop(pkg, "device_type", name, sizeof(name)) == -1)
1000 		return;
1001 
1002 	if (strcmp(name, "serial") != 0)
1003 		return;
1004 
1005 	memset(name, 0, sizeof(name));
1006 	if (OF_getprop(pkg, "name", name, sizeof(name)) == -1)
1007 		return;
1008 
1009 	cp->cn_pri = CN_REMOTE;
1010 }
1011 
1012 void
1013 zscninit(struct consdev *cp)
1014 {
1015 	int escc, escc_ch, obio, zs_offset;
1016 	u_int32_t reg[5];
1017 	char name[16];
1018 
1019 	if ((escc_ch = OF_instance_to_package(stdin)) == -1)
1020 		return;
1021 
1022 	memset(name, 0, sizeof(name));
1023 	if (OF_getprop(escc_ch, "name", name, sizeof(name)) == -1)
1024 		return;
1025 
1026 	zs_conschannel = strcmp(name, "ch-b") == 0;
1027 
1028 	if (OF_getprop(escc_ch, "reg", reg, sizeof(reg)) < 4)
1029 		return;
1030 	zs_offset = reg[0];
1031 
1032 	escc = OF_parent(escc_ch);
1033 	obio = OF_parent(escc);
1034 
1035 	if (OF_getprop(obio, "assigned-addresses", reg, sizeof(reg)) < 12)
1036 		return;
1037 	zs_conschan = (void *)(reg[2] + zs_offset);
1038 }
1039