xref: /netbsd/sys/dev/ic/z8530tty.c (revision bf9ec67e)
1 /*	$NetBSD: z8530tty.c,v 1.79 2002/03/17 19:40:58 atatat Exp $	*/
2 
3 /*-
4  * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998, 1999
5  *	Charles M. Hannum.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by Charles M. Hannum.
18  * 4. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1994 Gordon W. Ross
35  * Copyright (c) 1992, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * This software was developed by the Computer Systems Engineering group
39  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
40  * contributed to Berkeley.
41  *
42  * All advertising materials mentioning features or use of this software
43  * must display the following acknowledgement:
44  *	This product includes software developed by the University of
45  *	California, Lawrence Berkeley Laboratory.
46  *
47  * Redistribution and use in source and binary forms, with or without
48  * modification, are permitted provided that the following conditions
49  * are met:
50  * 1. Redistributions of source code must retain the above copyright
51  *    notice, this list of conditions and the following disclaimer.
52  * 2. Redistributions in binary form must reproduce the above copyright
53  *    notice, this list of conditions and the following disclaimer in the
54  *    documentation and/or other materials provided with the distribution.
55  * 3. All advertising materials mentioning features or use of this software
56  *    must display the following acknowledgement:
57  *	This product includes software developed by the University of
58  *	California, Berkeley and its contributors.
59  * 4. Neither the name of the University nor the names of its contributors
60  *    may be used to endorse or promote products derived from this software
61  *    without specific prior written permission.
62  *
63  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
64  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
66  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
67  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
68  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
69  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
70  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
71  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
72  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
73  * SUCH DAMAGE.
74  *
75  *	@(#)zs.c	8.1 (Berkeley) 7/19/93
76  */
77 
78 /*
79  * Zilog Z8530 Dual UART driver (tty interface)
80  *
81  * This is the "slave" driver that will be attached to
82  * the "zsc" driver for plain "tty" async. serial lines.
83  *
84  * Credits, history:
85  *
86  * The original version of this code was the sparc/dev/zs.c driver
87  * as distributed with the Berkeley 4.4 Lite release.  Since then,
88  * Gordon Ross reorganized the code into the current parent/child
89  * driver scheme, separating the Sun keyboard and mouse support
90  * into independent child drivers.
91  *
92  * RTS/CTS flow-control support was a collaboration of:
93  *	Gordon Ross <gwr@netbsd.org>,
94  *	Bill Studenmund <wrstuden@loki.stanford.edu>
95  *	Ian Dall <Ian.Dall@dsto.defence.gov.au>
96  *
97  * The driver was massively overhauled in November 1997 by Charles Hannum,
98  * fixing *many* bugs, and substantially improving performance.
99  */
100 
101 #include <sys/cdefs.h>
102 __KERNEL_RCSID(0, "$NetBSD: z8530tty.c,v 1.79 2002/03/17 19:40:58 atatat Exp $");
103 
104 #include "opt_kgdb.h"
105 
106 #include <sys/param.h>
107 #include <sys/systm.h>
108 #include <sys/proc.h>
109 #include <sys/device.h>
110 #include <sys/conf.h>
111 #include <sys/file.h>
112 #include <sys/ioctl.h>
113 #include <sys/malloc.h>
114 #include <sys/timepps.h>
115 #include <sys/tty.h>
116 #include <sys/time.h>
117 #include <sys/kernel.h>
118 #include <sys/syslog.h>
119 
120 #include <dev/ic/z8530reg.h>
121 #include <machine/z8530var.h>
122 
123 #include <dev/cons.h>
124 
125 #include "locators.h"
126 
127 /*
128  * How many input characters we can buffer.
129  * The port-specific var.h may override this.
130  * Note: must be a power of two!
131  */
132 #ifndef	ZSTTY_RING_SIZE
133 #define	ZSTTY_RING_SIZE	2048
134 #endif
135 
136 static struct cnm_state zstty_cnm_state;
137 /*
138  * Make this an option variable one can patch.
139  * But be warned:  this must be a power of 2!
140  */
141 u_int zstty_rbuf_size = ZSTTY_RING_SIZE;
142 
143 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
144 u_int zstty_rbuf_hiwat = (ZSTTY_RING_SIZE * 1) / 4;
145 u_int zstty_rbuf_lowat = (ZSTTY_RING_SIZE * 3) / 4;
146 
147 static int zsppscap =
148 	PPS_TSFMT_TSPEC |
149 	PPS_CAPTUREASSERT |
150 	PPS_CAPTURECLEAR |
151 #ifdef  PPS_SYNC
152 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
153 #endif	/* PPS_SYNC */
154 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
155 
156 struct zstty_softc {
157 	struct	device zst_dev;		/* required first: base device */
158 	struct  tty *zst_tty;
159 	struct	zs_chanstate *zst_cs;
160 
161 	struct callout zst_diag_ch;
162 
163 	u_int zst_overflows,
164 	      zst_floods,
165 	      zst_errors;
166 
167 	int zst_hwflags,	/* see z8530var.h */
168 	    zst_swflags;	/* TIOCFLAG_SOFTCAR, ... <ttycom.h> */
169 
170 	u_int zst_r_hiwat,
171 	      zst_r_lowat;
172 	u_char *volatile zst_rbget,
173 	       *volatile zst_rbput;
174 	volatile u_int zst_rbavail;
175 	u_char *zst_rbuf,
176 	       *zst_ebuf;
177 
178 	/*
179 	 * The transmit byte count and address are used for pseudo-DMA
180 	 * output in the hardware interrupt code.  PDMA can be suspended
181 	 * to get pending changes done; heldtbc is used for this.  It can
182 	 * also be stopped for ^S; this sets TS_TTSTOP in tp->t_state.
183 	 */
184 	u_char *zst_tba;		/* transmit buffer address */
185 	u_int zst_tbc,			/* transmit byte count */
186 	      zst_heldtbc;		/* held tbc while xmission stopped */
187 
188 	/* Flags to communicate with zstty_softint() */
189 	volatile u_char zst_rx_flags,	/* receiver blocked */
190 #define	RX_TTY_BLOCKED		0x01
191 #define	RX_TTY_OVERFLOWED	0x02
192 #define	RX_IBUF_BLOCKED		0x04
193 #define	RX_IBUF_OVERFLOWED	0x08
194 #define	RX_ANY_BLOCK		0x0f
195 			zst_tx_busy,	/* working on an output chunk */
196 			zst_tx_done,	/* done with one output chunk */
197 			zst_tx_stopped,	/* H/W level stop (lost CTS) */
198 			zst_st_check,	/* got a status interrupt */
199 			zst_rx_ready;
200 
201 	/* PPS signal on DCD, with or without inkernel clock disciplining */
202 	u_char  zst_ppsmask;			/* pps signal mask */
203 	u_char  zst_ppsassert;			/* pps leading edge */
204 	u_char  zst_ppsclear;			/* pps trailing edge */
205 	pps_info_t ppsinfo;
206 	pps_params_t ppsparam;
207 };
208 
209 /* Macros to clear/set/test flags. */
210 #define SET(t, f)	(t) |= (f)
211 #define CLR(t, f)	(t) &= ~(f)
212 #define ISSET(t, f)	((t) & (f))
213 
214 /* Definition of the driver for autoconfig. */
215 static int	zstty_match(struct device *, struct cfdata *, void *);
216 static void	zstty_attach(struct device *, struct device *, void *);
217 
218 struct cfattach zstty_ca = {
219 	sizeof(struct zstty_softc), zstty_match, zstty_attach
220 };
221 
222 extern struct cfdriver zstty_cd;
223 
224 struct zsops zsops_tty;
225 
226 /* Routines called from other code. */
227 cdev_decl(zs);	/* open, close, read, write, ioctl, stop, ... */
228 
229 static void zs_shutdown __P((struct zstty_softc *));
230 static void	zsstart __P((struct tty *));
231 static int	zsparam __P((struct tty *, struct termios *));
232 static void zs_modem __P((struct zstty_softc *, int));
233 static void tiocm_to_zs __P((struct zstty_softc *, u_long, int));
234 static int  zs_to_tiocm __P((struct zstty_softc *));
235 static int    zshwiflow __P((struct tty *, int));
236 static void  zs_hwiflow __P((struct zstty_softc *));
237 static void zs_maskintr __P((struct zstty_softc *));
238 
239 /* Low-level routines. */
240 static void zstty_rxint   __P((struct zs_chanstate *));
241 static void zstty_stint   __P((struct zs_chanstate *, int));
242 static void zstty_txint   __P((struct zs_chanstate *));
243 static void zstty_softint __P((struct zs_chanstate *));
244 
245 #define	ZSUNIT(x)	(minor(x) & 0x7ffff)
246 #define	ZSDIALOUT(x)	(minor(x) & 0x80000)
247 
248 /*
249  * zstty_match: how is this zs channel configured?
250  */
251 int
252 zstty_match(parent, cf, aux)
253 	struct device *parent;
254 	struct cfdata *cf;
255 	void   *aux;
256 {
257 	struct zsc_attach_args *args = aux;
258 
259 	/* Exact match is better than wildcard. */
260 	if (cf->cf_loc[ZSCCF_CHANNEL] == args->channel)
261 		return 2;
262 
263 	/* This driver accepts wildcard. */
264 	if (cf->cf_loc[ZSCCF_CHANNEL] == ZSCCF_CHANNEL_DEFAULT)
265 		return 1;
266 
267 	return 0;
268 }
269 
270 void
271 zstty_attach(parent, self, aux)
272 	struct device *parent, *self;
273 	void   *aux;
274 
275 {
276 	struct zsc_softc *zsc = (void *) parent;
277 	struct zstty_softc *zst = (void *) self;
278 	struct cfdata *cf = self->dv_cfdata;
279 	struct zsc_attach_args *args = aux;
280 	struct zs_chanstate *cs;
281 	struct tty *tp;
282 	int channel, s, tty_unit;
283 	dev_t dev;
284 	char *i, *o;
285 
286 	callout_init(&zst->zst_diag_ch);
287 	cn_init_magic(&zstty_cnm_state);
288 
289 	tty_unit = zst->zst_dev.dv_unit;
290 	channel = args->channel;
291 	cs = zsc->zsc_cs[channel];
292 	cs->cs_private = zst;
293 	cs->cs_ops = &zsops_tty;
294 
295 	zst->zst_cs = cs;
296 	zst->zst_swflags = cf->cf_flags;	/* softcar, etc. */
297 	zst->zst_hwflags = args->hwflags;
298 	dev = makedev(zs_major, tty_unit);
299 
300 	if (zst->zst_swflags)
301 		printf(" flags 0x%x", zst->zst_swflags);
302 
303 	/*
304 	 * Check whether we serve as a console device.
305 	 * XXX - split console input/output channels aren't
306 	 *	 supported yet on /dev/console
307 	 */
308 	i = o = NULL;
309 	if ((zst->zst_hwflags & ZS_HWFLAG_CONSOLE_INPUT) != 0) {
310 		i = "input";
311 		if ((args->hwflags & ZS_HWFLAG_USE_CONSDEV) != 0) {
312 			args->consdev->cn_dev = dev;
313 			cn_tab->cn_pollc = args->consdev->cn_pollc;
314 			cn_tab->cn_getc = args->consdev->cn_getc;
315 		}
316 		cn_tab->cn_dev = dev;
317 		/* Set console magic to BREAK */
318 		cn_set_magic("\047\001");
319 	}
320 	if ((zst->zst_hwflags & ZS_HWFLAG_CONSOLE_OUTPUT) != 0) {
321 		o = "output";
322 		if ((args->hwflags & ZS_HWFLAG_USE_CONSDEV) != 0) {
323 			cn_tab->cn_putc = args->consdev->cn_putc;
324 		}
325 		cn_tab->cn_dev = dev;
326 	}
327 	if (i != NULL || o != NULL)
328 		printf(" (console %s)", i ? (o ? "i/o" : i) : o);
329 
330 #ifdef KGDB
331 	if (zs_check_kgdb(cs, dev)) {
332 		/*
333 		 * Allow kgdb to "take over" this port.  Returns true
334 		 * if this serial port is in-use by kgdb.
335 		 */
336 		printf(" (kgdb)\n");
337 		/*
338 		 * This is the kgdb port (exclusive use)
339 		 * so skip the normal attach code.
340 		 */
341 		return;
342 	}
343 #endif
344 	printf("\n");
345 
346 	tp = ttymalloc();
347 	tp->t_dev = dev;
348 	tp->t_oproc = zsstart;
349 	tp->t_param = zsparam;
350 	tp->t_hwiflow = zshwiflow;
351 	tty_attach(tp);
352 
353 	zst->zst_tty = tp;
354 	zst->zst_rbuf = malloc(zstty_rbuf_size << 1, M_DEVBUF, M_WAITOK);
355 	zst->zst_ebuf = zst->zst_rbuf + (zstty_rbuf_size << 1);
356 	/* Disable the high water mark. */
357 	zst->zst_r_hiwat = 0;
358 	zst->zst_r_lowat = 0;
359 	zst->zst_rbget = zst->zst_rbput = zst->zst_rbuf;
360 	zst->zst_rbavail = zstty_rbuf_size;
361 
362 	/* if there are no enable/disable functions, assume the device
363 	   is always enabled */
364 	if (!cs->enable)
365 		cs->enabled = 1;
366 
367 	/*
368 	 * Hardware init
369 	 */
370 	if (ISSET(zst->zst_hwflags, ZS_HWFLAG_CONSOLE)) {
371 		/* Call zsparam similar to open. */
372 		struct termios t;
373 
374 		/* Wait a while for previous console output to complete */
375 		DELAY(10000);
376 
377 		/* Setup the "new" parameters in t. */
378 		t.c_ispeed = 0;
379 		t.c_ospeed = cs->cs_defspeed;
380 		t.c_cflag = cs->cs_defcflag;
381 
382 		s = splzs();
383 
384 		/*
385 		 * Turn on receiver and status interrupts.
386 		 * We defer the actual write of the register to zsparam(),
387 		 * but we must make sure status interrupts are turned on by
388 		 * the time zsparam() reads the initial rr0 state.
389 		 */
390 		SET(cs->cs_preg[1], ZSWR1_RIE | ZSWR1_SIE);
391 
392 		splx(s);
393 
394 		/* Make sure zsparam will see changes. */
395 		tp->t_ospeed = 0;
396 		(void) zsparam(tp, &t);
397 
398 		s = splzs();
399 
400 		/* Make sure DTR is on now. */
401 		zs_modem(zst, 1);
402 
403 		splx(s);
404 	} else if (!ISSET(zst->zst_hwflags, ZS_HWFLAG_NORESET)) {
405 		/* Not the console; may need reset. */
406 		int reset;
407 
408 		reset = (channel == 0) ? ZSWR9_A_RESET : ZSWR9_B_RESET;
409 
410 		s = splzs();
411 
412 		zs_write_reg(cs, 9, reset);
413 
414 		/* Will raise DTR in open. */
415 		zs_modem(zst, 0);
416 
417 		splx(s);
418 	}
419 }
420 
421 
422 /*
423  * Return pointer to our tty.
424  */
425 struct tty *
426 zstty(dev)
427 	dev_t dev;
428 {
429 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(dev));
430 
431 	return (zst->zst_tty);
432 }
433 
434 
435 void
436 zs_shutdown(zst)
437 	struct zstty_softc *zst;
438 {
439 	struct zs_chanstate *cs = zst->zst_cs;
440 	struct tty *tp = zst->zst_tty;
441 	int s;
442 
443 	s = splzs();
444 
445 	/* If we were asserting flow control, then deassert it. */
446 	SET(zst->zst_rx_flags, RX_IBUF_BLOCKED);
447 	zs_hwiflow(zst);
448 
449 	/* Clear any break condition set with TIOCSBRK. */
450 	zs_break(cs, 0);
451 
452 	/* Turn off PPS capture on last close. */
453 	zst->zst_ppsmask = 0;
454 	zst->ppsparam.mode = 0;
455 
456 	/*
457 	 * Hang up if necessary.  Wait a bit, so the other side has time to
458 	 * notice even if we immediately open the port again.
459 	 */
460 	if (ISSET(tp->t_cflag, HUPCL)) {
461 		zs_modem(zst, 0);
462 		(void) tsleep(cs, TTIPRI, ttclos, hz);
463 	}
464 
465 	/* Turn off interrupts if not the console. */
466 	if (!ISSET(zst->zst_hwflags, ZS_HWFLAG_CONSOLE)) {
467 		CLR(cs->cs_preg[1], ZSWR1_RIE | ZSWR1_SIE);
468 		cs->cs_creg[1] = cs->cs_preg[1];
469 		zs_write_reg(cs, 1, cs->cs_creg[1]);
470 	}
471 
472 	/* Call the power management hook. */
473 	if (cs->disable) {
474 #ifdef DIAGNOSTIC
475 		if (!cs->enabled)
476 			panic("zs_shutdown: not enabled?");
477 #endif
478 		(*cs->disable)(zst->zst_cs);
479 	}
480 
481 	splx(s);
482 }
483 
484 /*
485  * Open a zs serial (tty) port.
486  */
487 int
488 zsopen(dev, flags, mode, p)
489 	dev_t dev;
490 	int flags;
491 	int mode;
492 	struct proc *p;
493 {
494 	struct zstty_softc *zst;
495 	struct zs_chanstate *cs;
496 	struct tty *tp;
497 	int s, s2;
498 	int error;
499 
500 	zst = device_lookup(&zstty_cd, ZSUNIT(dev));
501 	if (zst == NULL)
502 		return (ENXIO);
503 
504 	tp = zst->zst_tty;
505 	cs = zst->zst_cs;
506 
507 	/* If KGDB took the line, then tp==NULL */
508 	if (tp == NULL)
509 		return (EBUSY);
510 
511 	if (ISSET(tp->t_state, TS_ISOPEN) &&
512 	    ISSET(tp->t_state, TS_XCLUDE) &&
513 	    p->p_ucred->cr_uid != 0)
514 		return (EBUSY);
515 
516 	s = spltty();
517 
518 	/*
519 	 * Do the following iff this is a first open.
520 	 */
521 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
522 		struct termios t;
523 
524 		tp->t_dev = dev;
525 
526 		/* Call the power management hook. */
527 		if (cs->enable) {
528 			if ((*cs->enable)(cs)) {
529 				splx(s);
530 				printf("%s: device enable failed\n",
531 			       	zst->zst_dev.dv_xname);
532 				return (EIO);
533 			}
534 		}
535 
536 		/*
537 		 * Initialize the termios status to the defaults.  Add in the
538 		 * sticky bits from TIOCSFLAGS.
539 		 */
540 		t.c_ispeed = 0;
541 		t.c_ospeed = cs->cs_defspeed;
542 		t.c_cflag = cs->cs_defcflag;
543 		if (ISSET(zst->zst_swflags, TIOCFLAG_CLOCAL))
544 			SET(t.c_cflag, CLOCAL);
545 		if (ISSET(zst->zst_swflags, TIOCFLAG_CRTSCTS))
546 			SET(t.c_cflag, CRTSCTS);
547 		if (ISSET(zst->zst_swflags, TIOCFLAG_CDTRCTS))
548 			SET(t.c_cflag, CDTRCTS);
549 		if (ISSET(zst->zst_swflags, TIOCFLAG_MDMBUF))
550 			SET(t.c_cflag, MDMBUF);
551 
552 		s2 = splzs();
553 
554 		/*
555 		 * Turn on receiver and status interrupts.
556 		 * We defer the actual write of the register to zsparam(),
557 		 * but we must make sure status interrupts are turned on by
558 		 * the time zsparam() reads the initial rr0 state.
559 		 */
560 		SET(cs->cs_preg[1], ZSWR1_RIE | ZSWR1_SIE);
561 
562 		/* Clear PPS capture state on first open. */
563 		zst->zst_ppsmask = 0;
564 		zst->ppsparam.mode = 0;
565 
566 		splx(s2);
567 
568 		/* Make sure zsparam will see changes. */
569 		tp->t_ospeed = 0;
570 		(void) zsparam(tp, &t);
571 
572 		/*
573 		 * Note: zsparam has done: cflag, ispeed, ospeed
574 		 * so we just need to do: iflag, oflag, lflag, cc
575 		 * For "raw" mode, just leave all zeros.
576 		 */
577 		if (!ISSET(zst->zst_hwflags, ZS_HWFLAG_RAW)) {
578 			tp->t_iflag = TTYDEF_IFLAG;
579 			tp->t_oflag = TTYDEF_OFLAG;
580 			tp->t_lflag = TTYDEF_LFLAG;
581 		} else {
582 			tp->t_iflag = 0;
583 			tp->t_oflag = 0;
584 			tp->t_lflag = 0;
585 		}
586 		ttychars(tp);
587 		ttsetwater(tp);
588 
589 		s2 = splzs();
590 
591 		/*
592 		 * Turn on DTR.  We must always do this, even if carrier is not
593 		 * present, because otherwise we'd have to use TIOCSDTR
594 		 * immediately after setting CLOCAL, which applications do not
595 		 * expect.  We always assert DTR while the device is open
596 		 * unless explicitly requested to deassert it.
597 		 */
598 		zs_modem(zst, 1);
599 
600 		/* Clear the input ring, and unblock. */
601 		zst->zst_rbget = zst->zst_rbput = zst->zst_rbuf;
602 		zst->zst_rbavail = zstty_rbuf_size;
603 		zs_iflush(cs);
604 		CLR(zst->zst_rx_flags, RX_ANY_BLOCK);
605 		zs_hwiflow(zst);
606 
607 		splx(s2);
608 	}
609 
610 	splx(s);
611 
612 	error = ttyopen(tp, ZSDIALOUT(dev), ISSET(flags, O_NONBLOCK));
613 	if (error)
614 		goto bad;
615 
616 	error = (*tp->t_linesw->l_open)(dev, tp);
617 	if (error)
618 		goto bad;
619 
620 	return (0);
621 
622 bad:
623 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
624 		/*
625 		 * We failed to open the device, and nobody else had it opened.
626 		 * Clean up the state as appropriate.
627 		 */
628 		zs_shutdown(zst);
629 	}
630 
631 	return (error);
632 }
633 
634 /*
635  * Close a zs serial port.
636  */
637 int
638 zsclose(dev, flags, mode, p)
639 	dev_t dev;
640 	int flags;
641 	int mode;
642 	struct proc *p;
643 {
644 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(dev));
645 	struct tty *tp = zst->zst_tty;
646 
647 	/* XXX This is for cons.c. */
648 	if (!ISSET(tp->t_state, TS_ISOPEN))
649 		return 0;
650 
651 	(*tp->t_linesw->l_close)(tp, flags);
652 	ttyclose(tp);
653 
654 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
655 		/*
656 		 * Although we got a last close, the device may still be in
657 		 * use; e.g. if this was the dialout node, and there are still
658 		 * processes waiting for carrier on the non-dialout node.
659 		 */
660 		zs_shutdown(zst);
661 	}
662 
663 	return (0);
664 }
665 
666 /*
667  * Read/write zs serial port.
668  */
669 int
670 zsread(dev, uio, flags)
671 	dev_t dev;
672 	struct uio *uio;
673 	int flags;
674 {
675 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(dev));
676 	struct tty *tp = zst->zst_tty;
677 
678 	return ((*tp->t_linesw->l_read)(tp, uio, flags));
679 }
680 
681 int
682 zswrite(dev, uio, flags)
683 	dev_t dev;
684 	struct uio *uio;
685 	int flags;
686 {
687 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(dev));
688 	struct tty *tp = zst->zst_tty;
689 
690 	return ((*tp->t_linesw->l_write)(tp, uio, flags));
691 }
692 
693 int
694 zspoll(dev, events, p)
695 	dev_t dev;
696 	int events;
697 	struct proc *p;
698 {
699 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(dev));
700 	struct tty *tp = zst->zst_tty;
701 
702 	return ((*tp->t_linesw->l_poll)(tp, events, p));
703 }
704 
705 int
706 zsioctl(dev, cmd, data, flag, p)
707 	dev_t dev;
708 	u_long cmd;
709 	caddr_t data;
710 	int flag;
711 	struct proc *p;
712 {
713 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(dev));
714 	struct zs_chanstate *cs = zst->zst_cs;
715 	struct tty *tp = zst->zst_tty;
716 	int error;
717 	int s;
718 
719 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, p);
720 	if (error != EPASSTHROUGH)
721 		return (error);
722 
723 	error = ttioctl(tp, cmd, data, flag, p);
724 	if (error != EPASSTHROUGH)
725 		return (error);
726 
727 #ifdef	ZS_MD_IOCTL
728 	error = ZS_MD_IOCTL(cs, cmd, data);
729 	if (error != EPASSTHROUGH)
730 		return (error);
731 #endif	/* ZS_MD_IOCTL */
732 
733 	error = 0;
734 
735 	s = splzs();
736 
737 	switch (cmd) {
738 	case TIOCSBRK:
739 		zs_break(cs, 1);
740 		break;
741 
742 	case TIOCCBRK:
743 		zs_break(cs, 0);
744 		break;
745 
746 	case TIOCGFLAGS:
747 		*(int *)data = zst->zst_swflags;
748 		break;
749 
750 	case TIOCSFLAGS:
751 		error = suser(p->p_ucred, &p->p_acflag);
752 		if (error)
753 			break;
754 		zst->zst_swflags = *(int *)data;
755 		break;
756 
757 	case TIOCSDTR:
758 		zs_modem(zst, 1);
759 		break;
760 
761 	case TIOCCDTR:
762 		zs_modem(zst, 0);
763 		break;
764 
765 	case TIOCMSET:
766 	case TIOCMBIS:
767 	case TIOCMBIC:
768 		tiocm_to_zs(zst, cmd, *(int *)data);
769 		break;
770 
771 	case TIOCMGET:
772 		*(int *)data = zs_to_tiocm(zst);
773 		break;
774 
775 	case PPS_IOC_CREATE:
776 		break;
777 
778 	case PPS_IOC_DESTROY:
779 		break;
780 
781 	case PPS_IOC_GETPARAMS: {
782 		pps_params_t *pp;
783 		pp = (pps_params_t *)data;
784 		*pp = zst->ppsparam;
785 		break;
786 	}
787 
788 	case PPS_IOC_SETPARAMS: {
789 		pps_params_t *pp;
790 		int mode;
791 		if (cs->cs_rr0_pps == 0) {
792 			error = EINVAL;
793 			break;
794 		}
795 		pp = (pps_params_t *)data;
796 		if (pp->mode & ~zsppscap) {
797 			error = EINVAL;
798 			break;
799 		}
800 		zst->ppsparam = *pp;
801 		/*
802 		 * compute masks from user-specified timestamp state.
803 		 */
804 		mode = zst->ppsparam.mode;
805 #ifdef	PPS_SYNC
806 		if (mode & PPS_HARDPPSONASSERT) {
807 			mode |= PPS_CAPTUREASSERT;
808 			/* XXX revoke any previous HARDPPS source */
809 		}
810 		if (mode & PPS_HARDPPSONCLEAR) {
811 			mode |= PPS_CAPTURECLEAR;
812 			/* XXX revoke any previous HARDPPS source */
813 		}
814 #endif	/* PPS_SYNC */
815 		switch (mode & PPS_CAPTUREBOTH) {
816 		case 0:
817 			zst->zst_ppsmask = 0;
818 			break;
819 
820 		case PPS_CAPTUREASSERT:
821 			zst->zst_ppsmask = ZSRR0_DCD;
822 			zst->zst_ppsassert = ZSRR0_DCD;
823 			zst->zst_ppsclear = -1;
824 			break;
825 
826 		case PPS_CAPTURECLEAR:
827 			zst->zst_ppsmask = ZSRR0_DCD;
828 			zst->zst_ppsassert = -1;
829 			zst->zst_ppsclear = 0;
830 			break;
831 
832 		case PPS_CAPTUREBOTH:
833 			zst->zst_ppsmask = ZSRR0_DCD;
834 			zst->zst_ppsassert = ZSRR0_DCD;
835 			zst->zst_ppsclear = 0;
836 			break;
837 
838 		default:
839 			error = EINVAL;
840 			break;
841 		}
842 
843 		/*
844 		 * Now update interrupts.
845 		 */
846 		zs_maskintr(zst);
847 		/*
848 		 * If nothing is being transmitted, set up new current values,
849 		 * else mark them as pending.
850 		 */
851 		if (!cs->cs_heldchange) {
852 			if (zst->zst_tx_busy) {
853 				zst->zst_heldtbc = zst->zst_tbc;
854 				zst->zst_tbc = 0;
855 				cs->cs_heldchange = 1;
856 			} else
857 				zs_loadchannelregs(cs);
858 		}
859 
860 		break;
861 	}
862 
863 	case PPS_IOC_GETCAP:
864 		*(int *)data = zsppscap;
865 		break;
866 
867 	case PPS_IOC_FETCH: {
868 		pps_info_t *pi;
869 		pi = (pps_info_t *)data;
870 		*pi = zst->ppsinfo;
871 		break;
872 	}
873 
874 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
875 		if (cs->cs_rr0_pps == 0) {
876 			error = EINVAL;
877 			break;
878 		}
879 		/*
880 		 * Some GPS clocks models use the falling rather than
881 		 * rising edge as the on-the-second signal.
882 		 * The old API has no way to specify PPS polarity.
883 		 */
884 		zst->zst_ppsmask = ZSRR0_DCD;
885 #ifndef	PPS_TRAILING_EDGE
886 		zst->zst_ppsassert = ZSRR0_DCD;
887 		zst->zst_ppsclear = -1;
888 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
889 			&zst->ppsinfo.assert_timestamp);
890 #else
891 		zst->zst_ppsassert = -1;
892 		zst->zst_ppsclear = 01;
893 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
894 			&zst->ppsinfo.clear_timestamp);
895 #endif
896 		/*
897 		 * Now update interrupts.
898 		 */
899 		zs_maskintr(zst);
900 		/*
901 		 * If nothing is being transmitted, set up new current values,
902 		 * else mark them as pending.
903 		 */
904 		if (!cs->cs_heldchange) {
905 			if (zst->zst_tx_busy) {
906 				zst->zst_heldtbc = zst->zst_tbc;
907 				zst->zst_tbc = 0;
908 				cs->cs_heldchange = 1;
909 			} else
910 				zs_loadchannelregs(cs);
911 		}
912 
913 		break;
914 
915 	default:
916 		error = EPASSTHROUGH;
917 		break;
918 	}
919 
920 	splx(s);
921 
922 	return (error);
923 }
924 
925 /*
926  * Start or restart transmission.
927  */
928 static void
929 zsstart(tp)
930 	struct tty *tp;
931 {
932 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(tp->t_dev));
933 	struct zs_chanstate *cs = zst->zst_cs;
934 	int s;
935 
936 	s = spltty();
937 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
938 		goto out;
939 	if (zst->zst_tx_stopped)
940 		goto out;
941 
942 	if (tp->t_outq.c_cc <= tp->t_lowat) {
943 		if (ISSET(tp->t_state, TS_ASLEEP)) {
944 			CLR(tp->t_state, TS_ASLEEP);
945 			wakeup((caddr_t)&tp->t_outq);
946 		}
947 		selwakeup(&tp->t_wsel);
948 		if (tp->t_outq.c_cc == 0)
949 			goto out;
950 	}
951 
952 	/* Grab the first contiguous region of buffer space. */
953 	{
954 		u_char *tba;
955 		int tbc;
956 
957 		tba = tp->t_outq.c_cf;
958 		tbc = ndqb(&tp->t_outq, 0);
959 
960 		(void) splzs();
961 
962 		zst->zst_tba = tba;
963 		zst->zst_tbc = tbc;
964 	}
965 
966 	SET(tp->t_state, TS_BUSY);
967 	zst->zst_tx_busy = 1;
968 
969 	/* Enable transmit completion interrupts if necessary. */
970 	if (!ISSET(cs->cs_preg[1], ZSWR1_TIE)) {
971 		SET(cs->cs_preg[1], ZSWR1_TIE);
972 		cs->cs_creg[1] = cs->cs_preg[1];
973 		zs_write_reg(cs, 1, cs->cs_creg[1]);
974 	}
975 
976 	/* Output the first character of the contiguous buffer. */
977 	{
978 		zs_write_data(cs, *zst->zst_tba);
979 		zst->zst_tbc--;
980 		zst->zst_tba++;
981 	}
982 out:
983 	splx(s);
984 	return;
985 }
986 
987 /*
988  * Stop output, e.g., for ^S or output flush.
989  */
990 void
991 zsstop(tp, flag)
992 	struct tty *tp;
993 	int flag;
994 {
995 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(tp->t_dev));
996 	int s;
997 
998 	s = splzs();
999 	if (ISSET(tp->t_state, TS_BUSY)) {
1000 		/* Stop transmitting at the next chunk. */
1001 		zst->zst_tbc = 0;
1002 		zst->zst_heldtbc = 0;
1003 		if (!ISSET(tp->t_state, TS_TTSTOP))
1004 			SET(tp->t_state, TS_FLUSH);
1005 	}
1006 	splx(s);
1007 }
1008 
1009 /*
1010  * Set ZS tty parameters from termios.
1011  * XXX - Should just copy the whole termios after
1012  * making sure all the changes could be done.
1013  */
1014 static int
1015 zsparam(tp, t)
1016 	struct tty *tp;
1017 	struct termios *t;
1018 {
1019 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(tp->t_dev));
1020 	struct zs_chanstate *cs = zst->zst_cs;
1021 	int ospeed, cflag;
1022 	u_char tmp3, tmp4, tmp5;
1023 	int s, error;
1024 
1025 	ospeed = t->c_ospeed;
1026 	cflag = t->c_cflag;
1027 
1028 	/* Check requested parameters. */
1029 	if (ospeed < 0)
1030 		return (EINVAL);
1031 	if (t->c_ispeed && t->c_ispeed != ospeed)
1032 		return (EINVAL);
1033 
1034 	/*
1035 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1036 	 * is always active.
1037 	 */
1038 	if (ISSET(zst->zst_swflags, TIOCFLAG_SOFTCAR) ||
1039 	    ISSET(zst->zst_hwflags, ZS_HWFLAG_CONSOLE)) {
1040 		SET(cflag, CLOCAL);
1041 		CLR(cflag, HUPCL);
1042 	}
1043 
1044 	/*
1045 	 * Only whack the UART when params change.
1046 	 * Some callers need to clear tp->t_ospeed
1047 	 * to make sure initialization gets done.
1048 	 */
1049 	if (tp->t_ospeed == ospeed &&
1050 	    tp->t_cflag == cflag)
1051 		return (0);
1052 
1053 	/*
1054 	 * Call MD functions to deal with changed
1055 	 * clock modes or H/W flow control modes.
1056 	 * The BRG divisor is set now. (reg 12,13)
1057 	 */
1058 	error = zs_set_speed(cs, ospeed);
1059 	if (error)
1060 		return (error);
1061 	error = zs_set_modes(cs, cflag);
1062 	if (error)
1063 		return (error);
1064 
1065 	/*
1066 	 * Block interrupts so that state will not
1067 	 * be altered until we are done setting it up.
1068 	 *
1069 	 * Initial values in cs_preg are set before
1070 	 * our attach routine is called.  The master
1071 	 * interrupt enable is handled by zsc.c
1072 	 *
1073 	 */
1074 	s = splzs();
1075 
1076 	/*
1077 	 * Recalculate which status ints to enable.
1078 	 */
1079 	zs_maskintr(zst);
1080 
1081 	/* Recompute character size bits. */
1082 	tmp3 = cs->cs_preg[3];
1083 	tmp5 = cs->cs_preg[5];
1084 	CLR(tmp3, ZSWR3_RXSIZE);
1085 	CLR(tmp5, ZSWR5_TXSIZE);
1086 	switch (ISSET(cflag, CSIZE)) {
1087 	case CS5:
1088 		SET(tmp3, ZSWR3_RX_5);
1089 		SET(tmp5, ZSWR5_TX_5);
1090 		break;
1091 	case CS6:
1092 		SET(tmp3, ZSWR3_RX_6);
1093 		SET(tmp5, ZSWR5_TX_6);
1094 		break;
1095 	case CS7:
1096 		SET(tmp3, ZSWR3_RX_7);
1097 		SET(tmp5, ZSWR5_TX_7);
1098 		break;
1099 	case CS8:
1100 		SET(tmp3, ZSWR3_RX_8);
1101 		SET(tmp5, ZSWR5_TX_8);
1102 		break;
1103 	}
1104 	cs->cs_preg[3] = tmp3;
1105 	cs->cs_preg[5] = tmp5;
1106 
1107 	/*
1108 	 * Recompute the stop bits and parity bits.  Note that
1109 	 * zs_set_speed() may have set clock selection bits etc.
1110 	 * in wr4, so those must preserved.
1111 	 */
1112 	tmp4 = cs->cs_preg[4];
1113 	CLR(tmp4, ZSWR4_SBMASK | ZSWR4_PARMASK);
1114 	if (ISSET(cflag, CSTOPB))
1115 		SET(tmp4, ZSWR4_TWOSB);
1116 	else
1117 		SET(tmp4, ZSWR4_ONESB);
1118 	if (!ISSET(cflag, PARODD))
1119 		SET(tmp4, ZSWR4_EVENP);
1120 	if (ISSET(cflag, PARENB))
1121 		SET(tmp4, ZSWR4_PARENB);
1122 	cs->cs_preg[4] = tmp4;
1123 
1124 	/* And copy to tty. */
1125 	tp->t_ispeed = 0;
1126 	tp->t_ospeed = ospeed;
1127 	tp->t_cflag = cflag;
1128 
1129 	/*
1130 	 * If nothing is being transmitted, set up new current values,
1131 	 * else mark them as pending.
1132 	 */
1133 	if (!cs->cs_heldchange) {
1134 		if (zst->zst_tx_busy) {
1135 			zst->zst_heldtbc = zst->zst_tbc;
1136 			zst->zst_tbc = 0;
1137 			cs->cs_heldchange = 1;
1138 		} else
1139 			zs_loadchannelregs(cs);
1140 	}
1141 
1142 	/*
1143 	 * If hardware flow control is disabled, turn off the buffer water
1144 	 * marks and unblock any soft flow control state.  Otherwise, enable
1145 	 * the water marks.
1146 	 */
1147 	if (!ISSET(cflag, CHWFLOW)) {
1148 		zst->zst_r_hiwat = 0;
1149 		zst->zst_r_lowat = 0;
1150 		if (ISSET(zst->zst_rx_flags, RX_TTY_OVERFLOWED)) {
1151 			CLR(zst->zst_rx_flags, RX_TTY_OVERFLOWED);
1152 			zst->zst_rx_ready = 1;
1153 			cs->cs_softreq = 1;
1154 		}
1155 		if (ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1156 			CLR(zst->zst_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1157 			zs_hwiflow(zst);
1158 		}
1159 	} else {
1160 		zst->zst_r_hiwat = zstty_rbuf_hiwat;
1161 		zst->zst_r_lowat = zstty_rbuf_lowat;
1162 	}
1163 
1164 	/*
1165 	 * Force a recheck of the hardware carrier and flow control status,
1166 	 * since we may have changed which bits we're looking at.
1167 	 */
1168 	zstty_stint(cs, 1);
1169 
1170 	splx(s);
1171 
1172 	/*
1173 	 * If hardware flow control is disabled, unblock any hard flow control
1174 	 * state.
1175 	 */
1176 	if (!ISSET(cflag, CHWFLOW)) {
1177 		if (zst->zst_tx_stopped) {
1178 			zst->zst_tx_stopped = 0;
1179 			zsstart(tp);
1180 		}
1181 	}
1182 
1183 	zstty_softint(cs);
1184 
1185 	return (0);
1186 }
1187 
1188 /*
1189  * Compute interupt enable bits and set in the pending bits. Called both
1190  * in zsparam() and when PPS (pulse per second timing) state changes.
1191  * Must be called at splzs().
1192  */
1193 static void
1194 zs_maskintr(zst)
1195 	struct zstty_softc *zst;
1196 {
1197 	struct zs_chanstate *cs = zst->zst_cs;
1198 	int tmp15;
1199 
1200 	cs->cs_rr0_mask = cs->cs_rr0_cts | cs->cs_rr0_dcd;
1201 	if (zst->zst_ppsmask != 0)
1202 		cs->cs_rr0_mask |= cs->cs_rr0_pps;
1203 	tmp15 = cs->cs_preg[15];
1204 	if (ISSET(cs->cs_rr0_mask, ZSRR0_DCD))
1205 		SET(tmp15, ZSWR15_DCD_IE);
1206 	else
1207 		CLR(tmp15, ZSWR15_DCD_IE);
1208 	if (ISSET(cs->cs_rr0_mask, ZSRR0_CTS))
1209 		SET(tmp15, ZSWR15_CTS_IE);
1210 	else
1211 		CLR(tmp15, ZSWR15_CTS_IE);
1212 	cs->cs_preg[15] = tmp15;
1213 }
1214 
1215 
1216 /*
1217  * Raise or lower modem control (DTR/RTS) signals.  If a character is
1218  * in transmission, the change is deferred.
1219  */
1220 static void
1221 zs_modem(zst, onoff)
1222 	struct zstty_softc *zst;
1223 	int onoff;
1224 {
1225 	struct zs_chanstate *cs = zst->zst_cs;
1226 
1227 	if (cs->cs_wr5_dtr == 0)
1228 		return;
1229 
1230 	if (onoff)
1231 		SET(cs->cs_preg[5], cs->cs_wr5_dtr);
1232 	else
1233 		CLR(cs->cs_preg[5], cs->cs_wr5_dtr);
1234 
1235 	if (!cs->cs_heldchange) {
1236 		if (zst->zst_tx_busy) {
1237 			zst->zst_heldtbc = zst->zst_tbc;
1238 			zst->zst_tbc = 0;
1239 			cs->cs_heldchange = 1;
1240 		} else
1241 			zs_loadchannelregs(cs);
1242 	}
1243 }
1244 
1245 static void
1246 tiocm_to_zs(zst, how, ttybits)
1247 	struct zstty_softc *zst;
1248 	u_long how;
1249 	int ttybits;
1250 {
1251 	struct zs_chanstate *cs = zst->zst_cs;
1252 	u_char zsbits;
1253 
1254 	zsbits = 0;
1255 	if (ISSET(ttybits, TIOCM_DTR))
1256 		SET(zsbits, ZSWR5_DTR);
1257 	if (ISSET(ttybits, TIOCM_RTS))
1258 		SET(zsbits, ZSWR5_RTS);
1259 
1260 	switch (how) {
1261 	case TIOCMBIC:
1262 		CLR(cs->cs_preg[5], zsbits);
1263 		break;
1264 
1265 	case TIOCMBIS:
1266 		SET(cs->cs_preg[5], zsbits);
1267 		break;
1268 
1269 	case TIOCMSET:
1270 		CLR(cs->cs_preg[5], ZSWR5_RTS | ZSWR5_DTR);
1271 		SET(cs->cs_preg[5], zsbits);
1272 		break;
1273 	}
1274 
1275 	if (!cs->cs_heldchange) {
1276 		if (zst->zst_tx_busy) {
1277 			zst->zst_heldtbc = zst->zst_tbc;
1278 			zst->zst_tbc = 0;
1279 			cs->cs_heldchange = 1;
1280 		} else
1281 			zs_loadchannelregs(cs);
1282 	}
1283 }
1284 
1285 static int
1286 zs_to_tiocm(zst)
1287 	struct zstty_softc *zst;
1288 {
1289 	struct zs_chanstate *cs = zst->zst_cs;
1290 	u_char zsbits;
1291 	int ttybits = 0;
1292 
1293 	zsbits = cs->cs_preg[5];
1294 	if (ISSET(zsbits, ZSWR5_DTR))
1295 		SET(ttybits, TIOCM_DTR);
1296 	if (ISSET(zsbits, ZSWR5_RTS))
1297 		SET(ttybits, TIOCM_RTS);
1298 
1299 	zsbits = cs->cs_rr0;
1300 	if (ISSET(zsbits, ZSRR0_DCD))
1301 		SET(ttybits, TIOCM_CD);
1302 	if (ISSET(zsbits, ZSRR0_CTS))
1303 		SET(ttybits, TIOCM_CTS);
1304 
1305 	return (ttybits);
1306 }
1307 
1308 /*
1309  * Try to block or unblock input using hardware flow-control.
1310  * This is called by kern/tty.c if MDMBUF|CRTSCTS is set, and
1311  * if this function returns non-zero, the TS_TBLOCK flag will
1312  * be set or cleared according to the "block" arg passed.
1313  */
1314 int
1315 zshwiflow(tp, block)
1316 	struct tty *tp;
1317 	int block;
1318 {
1319 	struct zstty_softc *zst = device_lookup(&zstty_cd, ZSUNIT(tp->t_dev));
1320 	struct zs_chanstate *cs = zst->zst_cs;
1321 	int s;
1322 
1323 	if (cs->cs_wr5_rts == 0)
1324 		return (0);
1325 
1326 	s = splzs();
1327 	if (block) {
1328 		if (!ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED)) {
1329 			SET(zst->zst_rx_flags, RX_TTY_BLOCKED);
1330 			zs_hwiflow(zst);
1331 		}
1332 	} else {
1333 		if (ISSET(zst->zst_rx_flags, RX_TTY_OVERFLOWED)) {
1334 			CLR(zst->zst_rx_flags, RX_TTY_OVERFLOWED);
1335 			zst->zst_rx_ready = 1;
1336 			cs->cs_softreq = 1;
1337 		}
1338 		if (ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED)) {
1339 			CLR(zst->zst_rx_flags, RX_TTY_BLOCKED);
1340 			zs_hwiflow(zst);
1341 		}
1342 	}
1343 	splx(s);
1344 	return (1);
1345 }
1346 
1347 /*
1348  * Internal version of zshwiflow
1349  * called at splzs
1350  */
1351 static void
1352 zs_hwiflow(zst)
1353 	struct zstty_softc *zst;
1354 {
1355 	struct zs_chanstate *cs = zst->zst_cs;
1356 
1357 	if (cs->cs_wr5_rts == 0)
1358 		return;
1359 
1360 	if (ISSET(zst->zst_rx_flags, RX_ANY_BLOCK)) {
1361 		CLR(cs->cs_preg[5], cs->cs_wr5_rts);
1362 		CLR(cs->cs_creg[5], cs->cs_wr5_rts);
1363 	} else {
1364 		SET(cs->cs_preg[5], cs->cs_wr5_rts);
1365 		SET(cs->cs_creg[5], cs->cs_wr5_rts);
1366 	}
1367 	zs_write_reg(cs, 5, cs->cs_creg[5]);
1368 }
1369 
1370 
1371 /****************************************************************
1372  * Interface to the lower layer (zscc)
1373  ****************************************************************/
1374 
1375 #define	integrate	static inline
1376 integrate void zstty_rxsoft __P((struct zstty_softc *, struct tty *));
1377 integrate void zstty_txsoft __P((struct zstty_softc *, struct tty *));
1378 integrate void zstty_stsoft __P((struct zstty_softc *, struct tty *));
1379 static void zstty_diag __P((void *));
1380 
1381 /*
1382  * receiver ready interrupt.
1383  * called at splzs
1384  */
1385 static void
1386 zstty_rxint(cs)
1387 	struct zs_chanstate *cs;
1388 {
1389 	struct zstty_softc *zst = cs->cs_private;
1390 	u_char *put, *end;
1391 	u_int cc;
1392 	u_char rr0, rr1, c;
1393 
1394 	end = zst->zst_ebuf;
1395 	put = zst->zst_rbput;
1396 	cc = zst->zst_rbavail;
1397 
1398 	while (cc > 0) {
1399 		/*
1400 		 * First read the status, because reading the received char
1401 		 * destroys the status of this char.
1402 		 */
1403 		rr1 = zs_read_reg(cs, 1);
1404 		c = zs_read_data(cs);
1405 
1406 		if (ISSET(rr1, ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
1407 			/* Clear the receive error. */
1408 			zs_write_csr(cs, ZSWR0_RESET_ERRORS);
1409 		}
1410 
1411 		cn_check_magic(zst->zst_tty->t_dev, c, zstty_cnm_state);
1412 		put[0] = c;
1413 		put[1] = rr1;
1414 		put += 2;
1415 		if (put >= end)
1416 			put = zst->zst_rbuf;
1417 		cc--;
1418 
1419 		rr0 = zs_read_csr(cs);
1420 		if (!ISSET(rr0, ZSRR0_RX_READY))
1421 			break;
1422 	}
1423 
1424 	/*
1425 	 * Current string of incoming characters ended because
1426 	 * no more data was available or we ran out of space.
1427 	 * Schedule a receive event if any data was received.
1428 	 * If we're out of space, turn off receive interrupts.
1429 	 */
1430 	zst->zst_rbput = put;
1431 	zst->zst_rbavail = cc;
1432 	if (!ISSET(zst->zst_rx_flags, RX_TTY_OVERFLOWED)) {
1433 		zst->zst_rx_ready = 1;
1434 		cs->cs_softreq = 1;
1435 	}
1436 
1437 	/*
1438 	 * See if we are in danger of overflowing a buffer. If
1439 	 * so, use hardware flow control to ease the pressure.
1440 	 */
1441 	if (!ISSET(zst->zst_rx_flags, RX_IBUF_BLOCKED) &&
1442 	    cc < zst->zst_r_hiwat) {
1443 		SET(zst->zst_rx_flags, RX_IBUF_BLOCKED);
1444 		zs_hwiflow(zst);
1445 	}
1446 
1447 	/*
1448 	 * If we're out of space, disable receive interrupts
1449 	 * until the queue has drained a bit.
1450 	 */
1451 	if (!cc) {
1452 		SET(zst->zst_rx_flags, RX_IBUF_OVERFLOWED);
1453 		CLR(cs->cs_preg[1], ZSWR1_RIE);
1454 		cs->cs_creg[1] = cs->cs_preg[1];
1455 		zs_write_reg(cs, 1, cs->cs_creg[1]);
1456 	}
1457 
1458 #if 0
1459 	printf("%xH%04d\n", zst->zst_rx_flags, zst->zst_rbavail);
1460 #endif
1461 }
1462 
1463 /*
1464  * transmitter ready interrupt.  (splzs)
1465  */
1466 static void
1467 zstty_txint(cs)
1468 	struct zs_chanstate *cs;
1469 {
1470 	struct zstty_softc *zst = cs->cs_private;
1471 
1472 	/*
1473 	 * If we've delayed a parameter change, do it now, and restart
1474 	 * output.
1475 	 */
1476 	if (cs->cs_heldchange) {
1477 		zs_loadchannelregs(cs);
1478 		cs->cs_heldchange = 0;
1479 		zst->zst_tbc = zst->zst_heldtbc;
1480 		zst->zst_heldtbc = 0;
1481 	}
1482 
1483 	/* Output the next character in the buffer, if any. */
1484 	if (zst->zst_tbc > 0) {
1485 		zs_write_data(cs, *zst->zst_tba);
1486 		zst->zst_tbc--;
1487 		zst->zst_tba++;
1488 	} else {
1489 		/* Disable transmit completion interrupts if necessary. */
1490 		if (ISSET(cs->cs_preg[1], ZSWR1_TIE)) {
1491 			CLR(cs->cs_preg[1], ZSWR1_TIE);
1492 			cs->cs_creg[1] = cs->cs_preg[1];
1493 			zs_write_reg(cs, 1, cs->cs_creg[1]);
1494 		}
1495 		if (zst->zst_tx_busy) {
1496 			zst->zst_tx_busy = 0;
1497 			zst->zst_tx_done = 1;
1498 			cs->cs_softreq = 1;
1499 		}
1500 	}
1501 }
1502 
1503 /*
1504  * status change interrupt.  (splzs)
1505  */
1506 static void
1507 zstty_stint(cs, force)
1508 	struct zs_chanstate *cs;
1509 	int force;
1510 {
1511 	struct zstty_softc *zst = cs->cs_private;
1512 	u_char rr0, delta;
1513 
1514 	rr0 = zs_read_csr(cs);
1515 	zs_write_csr(cs, ZSWR0_RESET_STATUS);
1516 
1517 	/*
1518 	 * Check here for console break, so that we can abort
1519 	 * even when interrupts are locking up the machine.
1520 	 */
1521 	if (ISSET(rr0, ZSRR0_BREAK))
1522 		cn_check_magic(zst->zst_tty->t_dev, CNC_BREAK, zstty_cnm_state);
1523 
1524 	if (!force)
1525 		delta = rr0 ^ cs->cs_rr0;
1526 	else
1527 		delta = cs->cs_rr0_mask;
1528 	cs->cs_rr0 = rr0;
1529 
1530 	if (ISSET(delta, cs->cs_rr0_mask)) {
1531 		SET(cs->cs_rr0_delta, delta);
1532 
1533 		/*
1534 		 * Pulse-per-second clock signal on edge of DCD?
1535 		 */
1536 		if (ISSET(delta, zst->zst_ppsmask)) {
1537 			struct timeval tv;
1538 			if (ISSET(rr0, zst->zst_ppsmask) == zst->zst_ppsassert) {
1539 				/* XXX nanotime() */
1540 				microtime(&tv);
1541 				TIMEVAL_TO_TIMESPEC(&tv,
1542 					&zst->ppsinfo.assert_timestamp);
1543 				if (zst->ppsparam.mode & PPS_OFFSETASSERT) {
1544 					timespecadd(&zst->ppsinfo.assert_timestamp,
1545 					    &zst->ppsparam.assert_offset,
1546 					    &zst->ppsinfo.assert_timestamp);
1547 				}
1548 
1549 #ifdef PPS_SYNC
1550 				if (zst->ppsparam.mode & PPS_HARDPPSONASSERT)
1551 					hardpps(&tv, tv.tv_usec);
1552 #endif
1553 				zst->ppsinfo.assert_sequence++;
1554 				zst->ppsinfo.current_mode = zst->ppsparam.mode;
1555 			} else if (ISSET(rr0, zst->zst_ppsmask) ==
1556 						zst->zst_ppsclear) {
1557 				/* XXX nanotime() */
1558 				microtime(&tv);
1559 				TIMEVAL_TO_TIMESPEC(&tv,
1560 					&zst->ppsinfo.clear_timestamp);
1561 				if (zst->ppsparam.mode & PPS_OFFSETCLEAR) {
1562 					timespecadd(&zst->ppsinfo.clear_timestamp,
1563 						&zst->ppsparam.clear_offset,
1564 						&zst->ppsinfo.clear_timestamp);
1565 				}
1566 
1567 #ifdef PPS_SYNC
1568 				if (zst->ppsparam.mode & PPS_HARDPPSONCLEAR)
1569 					hardpps(&tv, tv.tv_usec);
1570 #endif
1571 				zst->ppsinfo.clear_sequence++;
1572 				zst->ppsinfo.current_mode = zst->ppsparam.mode;
1573 			}
1574 		}
1575 
1576 		/*
1577 		 * Stop output immediately if we lose the output
1578 		 * flow control signal or carrier detect.
1579 		 */
1580 		if (ISSET(~rr0, cs->cs_rr0_mask)) {
1581 			zst->zst_tbc = 0;
1582 			zst->zst_heldtbc = 0;
1583 		}
1584 
1585 		zst->zst_st_check = 1;
1586 		cs->cs_softreq = 1;
1587 	}
1588 }
1589 
1590 void
1591 zstty_diag(arg)
1592 	void *arg;
1593 {
1594 	struct zstty_softc *zst = arg;
1595 	int overflows, floods;
1596 	int s;
1597 
1598 	s = splzs();
1599 	overflows = zst->zst_overflows;
1600 	zst->zst_overflows = 0;
1601 	floods = zst->zst_floods;
1602 	zst->zst_floods = 0;
1603 	zst->zst_errors = 0;
1604 	splx(s);
1605 
1606 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1607 	    zst->zst_dev.dv_xname,
1608 	    overflows, overflows == 1 ? "" : "s",
1609 	    floods, floods == 1 ? "" : "s");
1610 }
1611 
1612 integrate void
1613 zstty_rxsoft(zst, tp)
1614 	struct zstty_softc *zst;
1615 	struct tty *tp;
1616 {
1617 	struct zs_chanstate *cs = zst->zst_cs;
1618 	int (*rint) __P((int c, struct tty *tp)) = tp->t_linesw->l_rint;
1619 	u_char *get, *end;
1620 	u_int cc, scc;
1621 	u_char rr1;
1622 	int code;
1623 	int s;
1624 
1625 	end = zst->zst_ebuf;
1626 	get = zst->zst_rbget;
1627 	scc = cc = zstty_rbuf_size - zst->zst_rbavail;
1628 
1629 	if (cc == zstty_rbuf_size) {
1630 		zst->zst_floods++;
1631 		if (zst->zst_errors++ == 0)
1632 			callout_reset(&zst->zst_diag_ch, 60 * hz,
1633 			    zstty_diag, zst);
1634 	}
1635 
1636 	/* If not yet open, drop the entire buffer content here */
1637 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1638 		get += cc << 1;
1639 		if (get >= end)
1640 			get -= zstty_rbuf_size << 1;
1641 		cc = 0;
1642 	}
1643 	while (cc) {
1644 		code = get[0];
1645 		rr1 = get[1];
1646 		if (ISSET(rr1, ZSRR1_DO | ZSRR1_FE | ZSRR1_PE)) {
1647 			if (ISSET(rr1, ZSRR1_DO)) {
1648 				zst->zst_overflows++;
1649 				if (zst->zst_errors++ == 0)
1650 					callout_reset(&zst->zst_diag_ch,
1651 					    60 * hz, zstty_diag, zst);
1652 			}
1653 			if (ISSET(rr1, ZSRR1_FE))
1654 				SET(code, TTY_FE);
1655 			if (ISSET(rr1, ZSRR1_PE))
1656 				SET(code, TTY_PE);
1657 		}
1658 		if ((*rint)(code, tp) == -1) {
1659 			/*
1660 			 * The line discipline's buffer is out of space.
1661 			 */
1662 			if (!ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED)) {
1663 				/*
1664 				 * We're either not using flow control, or the
1665 				 * line discipline didn't tell us to block for
1666 				 * some reason.  Either way, we have no way to
1667 				 * know when there's more space available, so
1668 				 * just drop the rest of the data.
1669 				 */
1670 				get += cc << 1;
1671 				if (get >= end)
1672 					get -= zstty_rbuf_size << 1;
1673 				cc = 0;
1674 			} else {
1675 				/*
1676 				 * Don't schedule any more receive processing
1677 				 * until the line discipline tells us there's
1678 				 * space available (through comhwiflow()).
1679 				 * Leave the rest of the data in the input
1680 				 * buffer.
1681 				 */
1682 				SET(zst->zst_rx_flags, RX_TTY_OVERFLOWED);
1683 			}
1684 			break;
1685 		}
1686 		get += 2;
1687 		if (get >= end)
1688 			get = zst->zst_rbuf;
1689 		cc--;
1690 	}
1691 
1692 	if (cc != scc) {
1693 		zst->zst_rbget = get;
1694 		s = splzs();
1695 		cc = zst->zst_rbavail += scc - cc;
1696 		/* Buffers should be ok again, release possible block. */
1697 		if (cc >= zst->zst_r_lowat) {
1698 			if (ISSET(zst->zst_rx_flags, RX_IBUF_OVERFLOWED)) {
1699 				CLR(zst->zst_rx_flags, RX_IBUF_OVERFLOWED);
1700 				SET(cs->cs_preg[1], ZSWR1_RIE);
1701 				cs->cs_creg[1] = cs->cs_preg[1];
1702 				zs_write_reg(cs, 1, cs->cs_creg[1]);
1703 			}
1704 			if (ISSET(zst->zst_rx_flags, RX_IBUF_BLOCKED)) {
1705 				CLR(zst->zst_rx_flags, RX_IBUF_BLOCKED);
1706 				zs_hwiflow(zst);
1707 			}
1708 		}
1709 		splx(s);
1710 	}
1711 
1712 #if 0
1713 	printf("%xS%04d\n", zst->zst_rx_flags, zst->zst_rbavail);
1714 #endif
1715 }
1716 
1717 integrate void
1718 zstty_txsoft(zst, tp)
1719 	struct zstty_softc *zst;
1720 	struct tty *tp;
1721 {
1722 
1723 	CLR(tp->t_state, TS_BUSY);
1724 	if (ISSET(tp->t_state, TS_FLUSH))
1725 		CLR(tp->t_state, TS_FLUSH);
1726 	else
1727 		ndflush(&tp->t_outq, (int)(zst->zst_tba - tp->t_outq.c_cf));
1728 	(*tp->t_linesw->l_start)(tp);
1729 }
1730 
1731 integrate void
1732 zstty_stsoft(zst, tp)
1733 	struct zstty_softc *zst;
1734 	struct tty *tp;
1735 {
1736 	struct zs_chanstate *cs = zst->zst_cs;
1737 	u_char rr0, delta;
1738 	int s;
1739 
1740 	s = splzs();
1741 	rr0 = cs->cs_rr0;
1742 	delta = cs->cs_rr0_delta;
1743 	cs->cs_rr0_delta = 0;
1744 	splx(s);
1745 
1746 	if (ISSET(delta, cs->cs_rr0_dcd)) {
1747 		/*
1748 		 * Inform the tty layer that carrier detect changed.
1749 		 */
1750 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(rr0, ZSRR0_DCD));
1751 	}
1752 
1753 	if (ISSET(delta, cs->cs_rr0_cts)) {
1754 		/* Block or unblock output according to flow control. */
1755 		if (ISSET(rr0, cs->cs_rr0_cts)) {
1756 			zst->zst_tx_stopped = 0;
1757 			(*tp->t_linesw->l_start)(tp);
1758 		} else {
1759 			zst->zst_tx_stopped = 1;
1760 		}
1761 	}
1762 }
1763 
1764 /*
1765  * Software interrupt.  Called at zssoft
1766  *
1767  * The main job to be done here is to empty the input ring
1768  * by passing its contents up to the tty layer.  The ring is
1769  * always emptied during this operation, therefore the ring
1770  * must not be larger than the space after "high water" in
1771  * the tty layer, or the tty layer might drop our input.
1772  *
1773  * Note: an "input blockage" condition is assumed to exist if
1774  * EITHER the TS_TBLOCK flag or zst_rx_blocked flag is set.
1775  */
1776 static void
1777 zstty_softint(cs)
1778 	struct zs_chanstate *cs;
1779 {
1780 	struct zstty_softc *zst = cs->cs_private;
1781 	struct tty *tp = zst->zst_tty;
1782 	int s;
1783 
1784 	s = spltty();
1785 
1786 	if (zst->zst_rx_ready) {
1787 		zst->zst_rx_ready = 0;
1788 		zstty_rxsoft(zst, tp);
1789 	}
1790 
1791 	if (zst->zst_st_check) {
1792 		zst->zst_st_check = 0;
1793 		zstty_stsoft(zst, tp);
1794 	}
1795 
1796 	if (zst->zst_tx_done) {
1797 		zst->zst_tx_done = 0;
1798 		zstty_txsoft(zst, tp);
1799 	}
1800 
1801 	splx(s);
1802 }
1803 
1804 struct zsops zsops_tty = {
1805 	zstty_rxint,	/* receive char available */
1806 	zstty_stint,	/* external/status */
1807 	zstty_txint,	/* xmit buffer empty */
1808 	zstty_softint,	/* process software interrupt */
1809 };
1810