xref: /netbsd/sys/dev/ic/z8530tty.c (revision 2c5d8659)
1 /*	$NetBSD: z8530tty.c,v 1.135 2022/10/26 23:45:25 riastradh 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) 1992, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * This software was developed by the Computer Systems Engineering group
38  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
39  * contributed to Berkeley.
40  *
41  * All advertising materials mentioning features or use of this software
42  * must display the following acknowledgement:
43  *	This product includes software developed by the University of
44  *	California, Lawrence Berkeley Laboratory.
45  *
46  * Redistribution and use in source and binary forms, with or without
47  * modification, are permitted provided that the following conditions
48  * are met:
49  * 1. Redistributions of source code must retain the above copyright
50  *    notice, this list of conditions and the following disclaimer.
51  * 2. Redistributions in binary form must reproduce the above copyright
52  *    notice, this list of conditions and the following disclaimer in the
53  *    documentation and/or other materials provided with the distribution.
54  * 3. Neither the name of the University nor the names of its contributors
55  *    may be used to endorse or promote products derived from this software
56  *    without specific prior written permission.
57  *
58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68  * SUCH DAMAGE.
69  *
70  *	@(#)zs.c	8.1 (Berkeley) 7/19/93
71  */
72 
73 /*
74  * Copyright (c) 1994 Gordon W. Ross
75  *
76  * This software was developed by the Computer Systems Engineering group
77  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
78  * contributed to Berkeley.
79  *
80  * All advertising materials mentioning features or use of this software
81  * must display the following acknowledgement:
82  *	This product includes software developed by the University of
83  *	California, Lawrence Berkeley Laboratory.
84  *
85  * Redistribution and use in source and binary forms, with or without
86  * modification, are permitted provided that the following conditions
87  * are met:
88  * 1. Redistributions of source code must retain the above copyright
89  *    notice, this list of conditions and the following disclaimer.
90  * 2. Redistributions in binary form must reproduce the above copyright
91  *    notice, this list of conditions and the following disclaimer in the
92  *    documentation and/or other materials provided with the distribution.
93  * 3. All advertising materials mentioning features or use of this software
94  *    must display the following acknowledgement:
95  *	This product includes software developed by the University of
96  *	California, Berkeley and its contributors.
97  * 4. Neither the name of the University nor the names of its contributors
98  *    may be used to endorse or promote products derived from this software
99  *    without specific prior written permission.
100  *
101  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
102  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
103  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
104  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
105  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
106  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
107  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
108  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
109  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
110  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
111  * SUCH DAMAGE.
112  *
113  *	@(#)zs.c	8.1 (Berkeley) 7/19/93
114  */
115 
116 /*
117  * Zilog Z8530 Dual UART driver (tty interface)
118  *
119  * This is the "slave" driver that will be attached to
120  * the "zsc" driver for plain "tty" async. serial lines.
121  *
122  * Credits, history:
123  *
124  * The original version of this code was the sparc/dev/zs.c driver
125  * as distributed with the Berkeley 4.4 Lite release.  Since then,
126  * Gordon Ross reorganized the code into the current parent/child
127  * driver scheme, separating the Sun keyboard and mouse support
128  * into independent child drivers.
129  *
130  * RTS/CTS flow-control support was a collaboration of:
131  *	Gordon Ross <gwr@NetBSD.org>,
132  *	Bill Studenmund <wrstuden@loki.stanford.edu>
133  *	Ian Dall <Ian.Dall@dsto.defence.gov.au>
134  *
135  * The driver was massively overhauled in November 1997 by Charles Hannum,
136  * fixing *many* bugs, and substantially improving performance.
137  */
138 
139 #include <sys/cdefs.h>
140 __KERNEL_RCSID(0, "$NetBSD: z8530tty.c,v 1.135 2022/10/26 23:45:25 riastradh Exp $");
141 
142 #include "opt_kgdb.h"
143 #include "opt_ntp.h"
144 
145 #include <sys/param.h>
146 #include <sys/systm.h>
147 #include <sys/proc.h>
148 #include <sys/device.h>
149 #include <sys/conf.h>
150 #include <sys/file.h>
151 #include <sys/ioctl.h>
152 #include <sys/malloc.h>
153 #include <sys/timepps.h>
154 #include <sys/tty.h>
155 #include <sys/time.h>
156 #include <sys/kernel.h>
157 #include <sys/syslog.h>
158 #include <sys/kauth.h>
159 
160 #include <dev/ic/z8530reg.h>
161 #include <machine/z8530var.h>
162 
163 #include <dev/cons.h>
164 
165 #include "ioconf.h"
166 #include "locators.h"
167 
168 /*
169  * How many input characters we can buffer.
170  * The port-specific var.h may override this.
171  * Note: must be a power of two!
172  */
173 #ifndef	ZSTTY_RING_SIZE
174 #define	ZSTTY_RING_SIZE	2048
175 #endif
176 
177 static struct cnm_state zstty_cnm_state;
178 /*
179  * Make this an option variable one can patch.
180  * But be warned:  this must be a power of 2!
181  */
182 u_int zstty_rbuf_size = ZSTTY_RING_SIZE;
183 
184 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
185 u_int zstty_rbuf_hiwat = (ZSTTY_RING_SIZE * 1) / 4;
186 u_int zstty_rbuf_lowat = (ZSTTY_RING_SIZE * 3) / 4;
187 
188 struct zstty_softc {
189 	device_t zst_dev;		/* required first: base device */
190 	struct  tty *zst_tty;
191 	struct	zs_chanstate *zst_cs;
192 
193 	struct callout zst_diag_ch;
194 
195 	u_int zst_overflows,
196 	      zst_floods,
197 	      zst_errors;
198 
199 	int zst_hwflags,	/* see z8530var.h */
200 	    zst_swflags;	/* TIOCFLAG_SOFTCAR, ... <ttycom.h> */
201 
202 	u_int zst_r_hiwat,
203 	      zst_r_lowat;
204 	uint8_t *volatile zst_rbget,
205 	        *volatile zst_rbput;
206 	volatile u_int zst_rbavail;
207 	uint8_t *zst_rbuf,
208 	        *zst_ebuf;
209 
210 	/*
211 	 * The transmit byte count and address are used for pseudo-DMA
212 	 * output in the hardware interrupt code.  PDMA can be suspended
213 	 * to get pending changes done; heldtbc is used for this.  It can
214 	 * also be stopped for ^S; this sets TS_TTSTOP in tp->t_state.
215 	 */
216 	uint8_t *zst_tba;		/* transmit buffer address */
217 	u_int zst_tbc,			/* transmit byte count */
218 	      zst_heldtbc;		/* held tbc while xmission stopped */
219 
220 	/* Flags to communicate with zstty_softint() */
221 	volatile uint8_t zst_rx_flags,	/* receiver blocked */
222 #define	RX_TTY_BLOCKED		0x01
223 #define	RX_TTY_OVERFLOWED	0x02
224 #define	RX_IBUF_BLOCKED		0x04
225 #define	RX_IBUF_OVERFLOWED	0x08
226 #define	RX_ANY_BLOCK		0x0f
227 			zst_tx_busy,	/* working on an output chunk */
228 			zst_tx_done,	/* done with one output chunk */
229 			zst_tx_stopped,	/* H/W level stop (lost CTS) */
230 			zst_st_check,	/* got a status interrupt */
231 			zst_rx_ready;
232 
233 	/* PPS signal on DCD, with or without inkernel clock disciplining */
234 	uint8_t  zst_ppsmask;			/* pps signal mask */
235 	struct pps_state zst_pps_state;
236 };
237 
238 /* Definition of the driver for autoconfig. */
239 static int	zstty_match(device_t, cfdata_t, void *);
240 static void	zstty_attach(device_t, device_t, void *);
241 
242 CFATTACH_DECL_NEW(zstty, sizeof(struct zstty_softc),
243     zstty_match, zstty_attach, NULL, NULL);
244 
245 dev_type_open(zsopen);
246 dev_type_close(zsclose);
247 dev_type_read(zsread);
248 dev_type_write(zswrite);
249 dev_type_ioctl(zsioctl);
250 dev_type_stop(zsstop);
251 dev_type_tty(zstty);
252 dev_type_poll(zspoll);
253 
254 const struct cdevsw zstty_cdevsw = {
255 	.d_open = zsopen,
256 	.d_close = zsclose,
257 	.d_read = zsread,
258 	.d_write = zswrite,
259 	.d_ioctl = zsioctl,
260 	.d_stop = zsstop,
261 	.d_tty = zstty,
262 	.d_poll = zspoll,
263 	.d_mmap = nommap,
264 	.d_kqfilter = ttykqfilter,
265 	.d_discard = nodiscard,
266 	.d_flag = D_TTY
267 };
268 
269 struct zsops zsops_tty;
270 
271 static void zs_shutdown(struct zstty_softc *);
272 static void	zsstart(struct tty *);
273 static int	zsparam(struct tty *, struct termios *);
274 static void zs_modem(struct zstty_softc *, int);
275 static void tiocm_to_zs(struct zstty_softc *, u_long, int);
276 static int  zs_to_tiocm(struct zstty_softc *);
277 static int    zshwiflow(struct tty *, int);
278 static void  zs_hwiflow(struct zstty_softc *);
279 static void zs_maskintr(struct zstty_softc *);
280 
281 /* Low-level routines. */
282 static void zstty_rxint  (struct zs_chanstate *);
283 static void zstty_stint  (struct zs_chanstate *, int);
284 static void zstty_txint  (struct zs_chanstate *);
285 static void zstty_softint(struct zs_chanstate *);
286 static void zstty_softint1(struct zs_chanstate *);
287 
288 #define	ZSUNIT(x)	TTUNIT(x)
289 #define	ZSDIALOUT(x)	TTDIALOUT(x)
290 
291 struct tty *zstty_get_tty_from_dev(device_t);
292 
293 /*
294  * XXX get the (struct tty *) out of a (device_t) we trust to be a
295  * (struct zstty_softc *) - needed by sparc/dev/zs.c, sparc64/dev/zs.c,
296  * sun3/dev/zs.c and sun2/dev/zs.c will probably need it at some point
297  */
298 
299 struct tty *
zstty_get_tty_from_dev(device_t dev)300 zstty_get_tty_from_dev(device_t dev)
301 {
302 	struct zstty_softc *sc = device_private(dev);
303 
304 	return sc->zst_tty;
305 }
306 
307 /*
308  * zstty_match: how is this zs channel configured?
309  */
310 int
zstty_match(device_t parent,cfdata_t cf,void * aux)311 zstty_match(device_t parent, cfdata_t cf, void *aux)
312 {
313 	struct zsc_attach_args *args = aux;
314 
315 	/* Exact match is better than wildcard. */
316 	if (cf->zsccf_channel == args->channel)
317 		return 2;
318 
319 	/* This driver accepts wildcard. */
320 	if (cf->zsccf_channel == ZSCCF_CHANNEL_DEFAULT)
321 		return 1;
322 
323 	return 0;
324 }
325 
326 void
zstty_attach(device_t parent,device_t self,void * aux)327 zstty_attach(device_t parent, device_t self, void *aux)
328 {
329 	struct zstty_softc *zst = device_private(self);
330 	struct zsc_softc *zsc = device_private(parent);
331 	cfdata_t cf = device_cfdata(self);
332 	struct zsc_attach_args *args = aux;
333 	struct zs_chanstate *cs;
334 	struct tty *tp;
335 	int channel, tty_unit;
336 	dev_t dev;
337 	const char *i, *o;
338 	int dtr_on;
339 	int resetbit;
340 
341 	zst->zst_dev = self;
342 
343 	callout_init(&zst->zst_diag_ch, 0);
344 	cn_init_magic(&zstty_cnm_state);
345 
346 	tty_unit = device_unit(self);
347 	channel = args->channel;
348 	cs = zsc->zsc_cs[channel];
349 	cs->cs_private = zst;
350 	cs->cs_ops = &zsops_tty;
351 
352 	zst->zst_cs = cs;
353 	zst->zst_swflags = cf->cf_flags;	/* softcar, etc. */
354 	zst->zst_hwflags = args->hwflags;
355 	dev = makedev(cdevsw_lookup_major(&zstty_cdevsw), tty_unit);
356 
357 	if (zst->zst_swflags)
358 		aprint_normal(" flags 0x%x", zst->zst_swflags);
359 
360 	/*
361 	 * Check whether we serve as a console device.
362 	 * XXX - split console input/output channels aren't
363 	 *	 supported yet on /dev/console
364 	 */
365 	i = o = NULL;
366 	if ((zst->zst_hwflags & ZS_HWFLAG_CONSOLE_INPUT) != 0) {
367 		i = "input";
368 		if ((args->hwflags & ZS_HWFLAG_USE_CONSDEV) != 0) {
369 			args->consdev->cn_dev = dev;
370 			cn_tab->cn_pollc = args->consdev->cn_pollc;
371 			cn_tab->cn_getc = args->consdev->cn_getc;
372 		}
373 		cn_tab->cn_dev = dev;
374 		/* Set console magic to BREAK */
375 		cn_set_magic("\047\001");
376 	}
377 	if ((zst->zst_hwflags & ZS_HWFLAG_CONSOLE_OUTPUT) != 0) {
378 		o = "output";
379 		if ((args->hwflags & ZS_HWFLAG_USE_CONSDEV) != 0) {
380 			cn_tab->cn_putc = args->consdev->cn_putc;
381 		}
382 		cn_tab->cn_dev = dev;
383 	}
384 	if (i != NULL || o != NULL)
385 		aprint_normal(" (console %s)", i ? (o ? "i/o" : i) : o);
386 
387 #ifdef KGDB
388 	if (zs_check_kgdb(cs, dev)) {
389 		/*
390 		 * Allow kgdb to "take over" this port.  Returns true
391 		 * if this serial port is in-use by kgdb.
392 		 */
393 		aprint_normal(" (kgdb)\n");
394 		/*
395 		 * This is the kgdb port (exclusive use)
396 		 * so skip the normal attach code.
397 		 */
398 		return;
399 	}
400 #endif
401 	aprint_normal("\n");
402 
403 	tp = tty_alloc();
404 	tp->t_dev = dev;
405 	tp->t_oproc = zsstart;
406 	tp->t_param = zsparam;
407 	tp->t_hwiflow = zshwiflow;
408 	tty_attach(tp);
409 
410 	zst->zst_tty = tp;
411 	zst->zst_rbuf = malloc(zstty_rbuf_size << 1, M_DEVBUF, M_WAITOK);
412 	zst->zst_ebuf = zst->zst_rbuf + (zstty_rbuf_size << 1);
413 	/* Disable the high water mark. */
414 	zst->zst_r_hiwat = 0;
415 	zst->zst_r_lowat = 0;
416 	zst->zst_rbget = zst->zst_rbput = zst->zst_rbuf;
417 	zst->zst_rbavail = zstty_rbuf_size;
418 
419 	/* if there are no enable/disable functions, assume the device
420 	   is always enabled */
421 	if (!cs->enable)
422 		cs->enabled = 1;
423 
424 	/*
425 	 * Hardware init
426 	 */
427 	dtr_on = 0;
428 	resetbit = 0;
429 	if (ISSET(zst->zst_hwflags, ZS_HWFLAG_CONSOLE)) {
430 		/* Call zsparam similar to open. */
431 		struct termios t;
432 
433 		/* Wait a while for previous console output to complete */
434 		DELAY(10000);
435 
436 		/* Setup the "new" parameters in t. */
437 		t.c_ispeed = 0;
438 		t.c_ospeed = cs->cs_defspeed;
439 		t.c_cflag = cs->cs_defcflag;
440 
441 		/*
442 		 * Turn on receiver and status interrupts.
443 		 * We defer the actual write of the register to zsparam(),
444 		 * but we must make sure status interrupts are turned on by
445 		 * the time zsparam() reads the initial rr0 state.
446 		 */
447 		SET(cs->cs_preg[1], ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE);
448 
449 		/* Make sure zsparam will see changes. */
450 		tp->t_ospeed = 0;
451 		(void) zsparam(tp, &t);
452 
453 		/* Make sure DTR is on now. */
454 		dtr_on = 1;
455 
456 	} else if (!ISSET(zst->zst_hwflags, ZS_HWFLAG_NORESET)) {
457 		/* Not the console; may need reset. */
458 		resetbit = (channel == 0) ? ZSWR9_A_RESET : ZSWR9_B_RESET;
459 	}
460 
461 	mutex_spin_enter(&cs->cs_lock);
462 	if (resetbit)
463 		zs_write_reg(cs, 9, resetbit);
464 	zs_modem(zst, dtr_on);
465 	mutex_spin_exit(&cs->cs_lock);
466 }
467 
468 
469 /*
470  * Return pointer to our tty.
471  */
472 struct tty *
zstty(dev_t dev)473 zstty(dev_t dev)
474 {
475 	struct zstty_softc *zst;
476 
477 	zst = device_lookup_private(&zstty_cd, ZSUNIT(dev));
478 
479 	return (zst->zst_tty);
480 }
481 
482 
483 void
zs_shutdown(struct zstty_softc * zst)484 zs_shutdown(struct zstty_softc *zst)
485 {
486 	struct zs_chanstate *cs = zst->zst_cs;
487 	struct tty *tp = zst->zst_tty;
488 
489 	mutex_spin_enter(&cs->cs_lock);
490 
491 	/* If we were asserting flow control, then deassert it. */
492 	SET(zst->zst_rx_flags, RX_IBUF_BLOCKED);
493 	zs_hwiflow(zst);
494 
495 	/* Clear any break condition set with TIOCSBRK. */
496 	zs_break(cs, 0);
497 
498 	/*
499 	 * Hang up if necessary.  Wait a bit, so the other side has time to
500 	 * notice even if we immediately open the port again.
501 	 */
502 	if (ISSET(tp->t_cflag, HUPCL)) {
503 		zs_modem(zst, 0);
504 		mutex_spin_exit(&cs->cs_lock);
505 		/*
506 		 * XXX -    another process is not prevented from opening
507 		 *	    the device during our sleep.
508 		 */
509 		(void) tsleep(cs, TTIPRI, ttclos, hz);
510 		/* Re-check state in case we were opened during our sleep */
511 		if (ISSET(tp->t_state, TS_ISOPEN) || tp->t_wopen != 0)
512 			return;
513 
514 		mutex_spin_enter(&cs->cs_lock);
515 	}
516 
517 	/* Turn off interrupts if not the console. */
518 	if (!ISSET(zst->zst_hwflags, ZS_HWFLAG_CONSOLE)) {
519 		CLR(cs->cs_preg[1], ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE);
520 		cs->cs_creg[1] = cs->cs_preg[1];
521 		zs_write_reg(cs, 1, cs->cs_creg[1]);
522 	}
523 
524 	/* Call the power management hook. */
525 	if (cs->disable) {
526 #ifdef DIAGNOSTIC
527 		if (!cs->enabled)
528 			panic("%s: not enabled?", __func__);
529 #endif
530 		(*cs->disable)(zst->zst_cs);
531 	}
532 
533 	mutex_spin_exit(&cs->cs_lock);
534 }
535 
536 /*
537  * Open a zs serial (tty) port.
538  */
539 int
zsopen(dev_t dev,int flags,int mode,struct lwp * l)540 zsopen(dev_t dev, int flags, int mode, struct lwp *l)
541 {
542 	struct zstty_softc *zst;
543 	struct zs_chanstate *cs;
544 	struct tty *tp;
545 	int error;
546 
547 	zst = device_lookup_private(&zstty_cd, ZSUNIT(dev));
548 	if (zst == NULL)
549 		return (ENXIO);
550 
551 	tp = zst->zst_tty;
552 	cs = zst->zst_cs;
553 
554 	/* If KGDB took the line, then tp==NULL */
555 	if (tp == NULL)
556 		return (EBUSY);
557 
558 	/*
559 	 * If the device is exclusively for kernel use, deny userland
560 	 * open.
561 	 */
562 	if (ISSET(tp->t_state, TS_KERN_ONLY))
563 		return (EBUSY);
564 
565 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
566 		return (EBUSY);
567 
568 	ttylock(tp);
569 
570 	/*
571 	 * Do the following iff this is a first open.
572 	 */
573 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
574 		struct termios t;
575 
576 		tp->t_dev = dev;
577 
578 		/* Call the power management hook. */
579 		if (cs->enable) {
580 			if ((*cs->enable)(cs)) {
581 				ttyunlock(tp);
582 				printf("%s: device enable failed\n",
583 				    device_xname(zst->zst_dev));
584 				return (EIO);
585 			}
586 		}
587 
588 		/*
589 		 * Initialize the termios status to the defaults.  Add in the
590 		 * sticky bits from TIOCSFLAGS.
591 		 */
592 		t.c_ispeed = 0;
593 		t.c_ospeed = cs->cs_defspeed;
594 		t.c_cflag = cs->cs_defcflag;
595 		if (ISSET(zst->zst_swflags, TIOCFLAG_CLOCAL))
596 			SET(t.c_cflag, CLOCAL);
597 		if (ISSET(zst->zst_swflags, TIOCFLAG_CRTSCTS))
598 			SET(t.c_cflag, CRTSCTS);
599 		if (ISSET(zst->zst_swflags, TIOCFLAG_CDTRCTS))
600 			SET(t.c_cflag, CDTRCTS);
601 		if (ISSET(zst->zst_swflags, TIOCFLAG_MDMBUF))
602 			SET(t.c_cflag, MDMBUF);
603 
604 		mutex_spin_enter(&cs->cs_lock);
605 
606 		/*
607 		 * Turn on receiver and status interrupts.
608 		 * We defer the actual write of the register to zsparam(),
609 		 * but we must make sure status interrupts are turned on by
610 		 * the time zsparam() reads the initial rr0 state.
611 		 */
612 		SET(cs->cs_preg[1], ZSWR1_RIE | ZSWR1_TIE | ZSWR1_SIE);
613 
614 		/* Clear PPS capture state on first open. */
615 		mutex_spin_enter(&timecounter_lock);
616 		zst->zst_ppsmask = 0;
617 		memset(&zst->zst_pps_state, 0, sizeof(zst->zst_pps_state));
618 		zst->zst_pps_state.ppscap =
619 		    PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
620 		pps_init(&zst->zst_pps_state);
621 		mutex_spin_exit(&timecounter_lock);
622 
623 		mutex_spin_exit(&cs->cs_lock);
624 
625 		/* Make sure zsparam will see changes. */
626 		tp->t_ospeed = 0;
627 		ttyunlock(tp);
628 		(void) zsparam(tp, &t);
629 		ttylock(tp);
630 
631 		/*
632 		 * Note: zsparam has done: cflag, ispeed, ospeed
633 		 * so we just need to do: iflag, oflag, lflag, cc
634 		 * For "raw" mode, just leave all zeros.
635 		 */
636 		if (!ISSET(zst->zst_hwflags, ZS_HWFLAG_RAW)) {
637 			tp->t_iflag = TTYDEF_IFLAG;
638 			tp->t_oflag = TTYDEF_OFLAG;
639 			tp->t_lflag = TTYDEF_LFLAG;
640 		} else {
641 			tp->t_iflag = 0;
642 			tp->t_oflag = 0;
643 			tp->t_lflag = 0;
644 		}
645 		ttychars(tp);
646 		ttsetwater(tp);
647 
648 		mutex_spin_enter(&cs->cs_lock);
649 
650 		/*
651 		 * Turn on DTR.  We must always do this, even if carrier is not
652 		 * present, because otherwise we'd have to use TIOCSDTR
653 		 * immediately after setting CLOCAL, which applications do not
654 		 * expect.  We always assert DTR while the device is open
655 		 * unless explicitly requested to deassert it.
656 		 */
657 		zs_modem(zst, 1);
658 
659 		/* Clear the input ring, and unblock. */
660 		zst->zst_rbget = zst->zst_rbput = zst->zst_rbuf;
661 		zst->zst_rbavail = zstty_rbuf_size;
662 		zs_iflush(cs);
663 		CLR(zst->zst_rx_flags, RX_ANY_BLOCK);
664 		zs_hwiflow(zst);
665 
666 		mutex_spin_exit(&cs->cs_lock);
667 	}
668 
669 	ttyunlock(tp);
670 
671 	error = ttyopen(tp, ZSDIALOUT(dev), ISSET(flags, O_NONBLOCK));
672 	if (error)
673 		goto bad;
674 
675 	error = (*tp->t_linesw->l_open)(dev, tp);
676 	if (error)
677 		goto bad;
678 
679 	return (0);
680 
681 bad:
682 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
683 		/*
684 		 * We failed to open the device, and nobody else had it opened.
685 		 * Clean up the state as appropriate.
686 		 */
687 		zs_shutdown(zst);
688 	}
689 
690 	return (error);
691 }
692 
693 /*
694  * Close a zs serial port.
695  */
696 int
zsclose(dev_t dev,int flags,int mode,struct lwp * l)697 zsclose(dev_t dev, int flags, int mode, struct lwp *l)
698 {
699 	struct zstty_softc *zst;
700 	struct tty *tp;
701 
702 	zst = device_lookup_private(&zstty_cd, ZSUNIT(dev));
703 	tp = zst->zst_tty;
704 
705 	/* XXX This is for cons.c. */
706 	if (!ISSET(tp->t_state, TS_ISOPEN))
707 		return 0;
708 
709 	(*tp->t_linesw->l_close)(tp, flags);
710 	ttyclose(tp);
711 
712 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
713 		/*
714 		 * Although we got a last close, the device may still be in
715 		 * use; e.g. if this was the dialout node, and there are still
716 		 * processes waiting for carrier on the non-dialout node.
717 		 */
718 		zs_shutdown(zst);
719 	}
720 
721 	return (0);
722 }
723 
724 /*
725  * Read/write zs serial port.
726  */
727 int
zsread(dev_t dev,struct uio * uio,int flags)728 zsread(dev_t dev, struct uio *uio, int flags)
729 {
730 	struct zstty_softc *zst;
731 	struct tty *tp;
732 
733 	zst = device_lookup_private(&zstty_cd, ZSUNIT(dev));
734 	tp = zst->zst_tty;
735 
736 	return ((*tp->t_linesw->l_read)(tp, uio, flags));
737 }
738 
739 int
zswrite(dev_t dev,struct uio * uio,int flags)740 zswrite(dev_t dev, struct uio *uio, int flags)
741 {
742 	struct zstty_softc *zst;
743 	struct tty *tp;
744 
745 	zst = device_lookup_private(&zstty_cd, ZSUNIT(dev));
746 	tp = zst->zst_tty;
747 
748 	return ((*tp->t_linesw->l_write)(tp, uio, flags));
749 }
750 
751 int
zspoll(dev_t dev,int events,struct lwp * l)752 zspoll(dev_t dev, int events, struct lwp *l)
753 {
754 	struct zstty_softc *zst;
755 	struct tty *tp;
756 
757 	zst = device_lookup_private(&zstty_cd, ZSUNIT(dev));
758 	tp = zst->zst_tty;
759 
760 	return ((*tp->t_linesw->l_poll)(tp, events, l));
761 }
762 
763 int
zsioctl(dev_t dev,u_long cmd,void * data,int flag,struct lwp * l)764 zsioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
765 {
766 	struct zstty_softc *zst;
767 	struct zs_chanstate *cs;
768 	struct tty *tp;
769 	int error;
770 
771 	zst = device_lookup_private(&zstty_cd, ZSUNIT(dev));
772 	cs = zst->zst_cs;
773 	tp = zst->zst_tty;
774 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
775 	if (error != EPASSTHROUGH)
776 		return (error);
777 
778 	error = ttioctl(tp, cmd, data, flag, l);
779 	if (error != EPASSTHROUGH)
780 		return (error);
781 
782 #ifdef	ZS_MD_IOCTL
783 	error = ZS_MD_IOCTL(cs, cmd, data);
784 	if (error != EPASSTHROUGH)
785 		return (error);
786 #endif	/* ZS_MD_IOCTL */
787 
788 	error = 0;
789 
790 	mutex_spin_enter(&cs->cs_lock);
791 
792 	switch (cmd) {
793 	case TIOCSBRK:
794 		zs_break(cs, 1);
795 		break;
796 
797 	case TIOCCBRK:
798 		zs_break(cs, 0);
799 		break;
800 
801 	case TIOCGFLAGS:
802 		*(int *)data = zst->zst_swflags;
803 		break;
804 
805 	case TIOCSFLAGS:
806 		error = kauth_authorize_device_tty(l->l_cred,
807 			KAUTH_DEVICE_TTY_PRIVSET, tp);
808 		if (error)
809 			break;
810 		zst->zst_swflags = *(int *)data;
811 		break;
812 
813 	case TIOCSDTR:
814 		zs_modem(zst, 1);
815 		break;
816 
817 	case TIOCCDTR:
818 		zs_modem(zst, 0);
819 		break;
820 
821 	case TIOCMSET:
822 	case TIOCMBIS:
823 	case TIOCMBIC:
824 		tiocm_to_zs(zst, cmd, *(int *)data);
825 		break;
826 
827 	case TIOCMGET:
828 		*(int *)data = zs_to_tiocm(zst);
829 		break;
830 
831 	case PPS_IOC_CREATE:
832 	case PPS_IOC_DESTROY:
833 	case PPS_IOC_GETPARAMS:
834 	case PPS_IOC_SETPARAMS:
835 	case PPS_IOC_GETCAP:
836 	case PPS_IOC_FETCH:
837 #ifdef PPS_SYNC
838 	case PPS_IOC_KCBIND:
839 #endif
840 		mutex_spin_enter(&timecounter_lock);
841 		error = pps_ioctl(cmd, data, &zst->zst_pps_state);
842 		if (zst->zst_pps_state.ppsparam.mode & PPS_CAPTUREBOTH)
843 			zst->zst_ppsmask = ZSRR0_DCD;
844 		else
845 			zst->zst_ppsmask = 0;
846 		mutex_spin_exit(&timecounter_lock);
847 		break;
848 
849 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
850 		if (cs->cs_rr0_pps == 0) {
851 			error = EINVAL;
852 			break;
853 		}
854 		mutex_spin_enter(&timecounter_lock);
855 #ifndef PPS_TRAILING_EDGE
856 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
857 		    &zst->zst_pps_state.ppsinfo.assert_timestamp);
858 #else
859 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
860 		    &zst->zst_pps_state.ppsinfo.clear_timestamp);
861 #endif
862 		mutex_spin_exit(&timecounter_lock);
863 		/*
864 		 * Now update interrupts.
865 		 */
866 		zs_maskintr(zst);
867 		/*
868 		 * If nothing is being transmitted, set up new current values,
869 		 * else mark them as pending.
870 		 */
871 		if (!cs->cs_heldchange) {
872 			if (zst->zst_tx_busy) {
873 				zst->zst_heldtbc = zst->zst_tbc;
874 				zst->zst_tbc = 0;
875 				cs->cs_heldchange = 1;
876 			} else
877 				zs_loadchannelregs(cs);
878 		}
879 
880 		break;
881 
882 	default:
883 		error = EPASSTHROUGH;
884 		break;
885 	}
886 
887 	mutex_spin_exit(&cs->cs_lock);
888 
889 	return (error);
890 }
891 
892 /*
893  * Start or restart transmission.
894  */
895 static void
zsstart(struct tty * tp)896 zsstart(struct tty *tp)
897 {
898 	struct zstty_softc *zst;
899 	struct zs_chanstate *cs;
900 	u_char *tba;
901 	int tbc;
902 
903 	zst = device_lookup_private(&zstty_cd, ZSUNIT(tp->t_dev));
904 	cs = zst->zst_cs;
905 
906 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
907 		return;
908 	if (zst->zst_tx_stopped)
909 		return;
910 	if (!ttypull(tp))
911 		return;
912 
913 	/* Grab the first contiguous region of buffer space. */
914 	tba = tp->t_outq.c_cf;
915 	tbc = ndqb(&tp->t_outq, 0);
916 
917 	mutex_spin_enter(&cs->cs_lock);
918 
919 	zst->zst_tba = tba;
920 	zst->zst_tbc = tbc;
921 	SET(tp->t_state, TS_BUSY);
922 	zst->zst_tx_busy = 1;
923 
924 #ifdef ZS_TXDMA
925 	if (zst->zst_tbc > 1) {
926 		zs_dma_setup(cs, zst->zst_tba, zst->zst_tbc);
927 		mutex_spin_exit(&cs->cs_lock);
928 		return;
929 	}
930 #endif
931 
932 	/* Output the first character of the contiguous buffer. */
933 	zs_write_data(cs, *zst->zst_tba);
934 	zst->zst_tbc--;
935 	zst->zst_tba++;
936 
937 	mutex_spin_exit(&cs->cs_lock);
938 }
939 
940 /*
941  * Stop output, e.g., for ^S or output flush.
942  */
943 void
zsstop(struct tty * tp,int flag)944 zsstop(struct tty *tp, int flag)
945 {
946 	struct zstty_softc *zst;
947 
948 	zst = device_lookup_private(&zstty_cd, ZSUNIT(tp->t_dev));
949 
950 	mutex_spin_enter(&zst->zst_cs->cs_lock);
951 	if (ISSET(tp->t_state, TS_BUSY)) {
952 		/* Stop transmitting at the next chunk. */
953 		zst->zst_tbc = 0;
954 		zst->zst_heldtbc = 0;
955 		if (!ISSET(tp->t_state, TS_TTSTOP))
956 			SET(tp->t_state, TS_FLUSH);
957 	}
958 	mutex_spin_exit(&zst->zst_cs->cs_lock);
959 }
960 
961 /*
962  * Set ZS tty parameters from termios.
963  * XXX - Should just copy the whole termios after
964  * making sure all the changes could be done.
965  */
966 static int
zsparam(struct tty * tp,struct termios * t)967 zsparam(struct tty *tp, struct termios *t)
968 {
969 	struct zstty_softc *zst;
970 	struct zs_chanstate *cs;
971 	int ospeed;
972 	tcflag_t cflag;
973 	uint8_t tmp3, tmp4, tmp5;
974 	int error;
975 
976 	zst = device_lookup_private(&zstty_cd, ZSUNIT(tp->t_dev));
977 	cs = zst->zst_cs;
978 	ospeed = t->c_ospeed;
979 	cflag = t->c_cflag;
980 
981 	/* Check requested parameters. */
982 	if (ospeed < 0)
983 		return (EINVAL);
984 	if (t->c_ispeed && t->c_ispeed != ospeed)
985 		return (EINVAL);
986 
987 	/*
988 	 * For the console, always force CLOCAL and !HUPCL, so that the port
989 	 * is always active.
990 	 */
991 	if (ISSET(zst->zst_swflags, TIOCFLAG_SOFTCAR) ||
992 	    ISSET(zst->zst_hwflags, ZS_HWFLAG_CONSOLE)) {
993 		SET(cflag, CLOCAL);
994 		CLR(cflag, HUPCL);
995 	}
996 
997 	/*
998 	 * Only whack the UART when params change.
999 	 * Some callers need to clear tp->t_ospeed
1000 	 * to make sure initialization gets done.
1001 	 */
1002 	if (tp->t_ospeed == ospeed &&
1003 	    tp->t_cflag == cflag)
1004 		return (0);
1005 
1006 	/*
1007 	 * Call MD functions to deal with changed
1008 	 * clock modes or H/W flow control modes.
1009 	 * The BRG divisor is set now. (reg 12,13)
1010 	 */
1011 	error = zs_set_speed(cs, ospeed);
1012 	if (error)
1013 		return (error);
1014 	error = zs_set_modes(cs, cflag);
1015 	if (error)
1016 		return (error);
1017 
1018 	/*
1019 	 * Block interrupts so that state will not
1020 	 * be altered until we are done setting it up.
1021 	 *
1022 	 * Initial values in cs_preg are set before
1023 	 * our attach routine is called.  The master
1024 	 * interrupt enable is handled by zsc.c
1025 	 *
1026 	 */
1027 	mutex_spin_enter(&cs->cs_lock);
1028 
1029 	/*
1030 	 * Recalculate which status ints to enable.
1031 	 */
1032 	zs_maskintr(zst);
1033 
1034 	/* Recompute character size bits. */
1035 	tmp3 = cs->cs_preg[3];
1036 	tmp5 = cs->cs_preg[5];
1037 	CLR(tmp3, ZSWR3_RXSIZE);
1038 	CLR(tmp5, ZSWR5_TXSIZE);
1039 	switch (ISSET(cflag, CSIZE)) {
1040 	case CS5:
1041 		SET(tmp3, ZSWR3_RX_5);
1042 		SET(tmp5, ZSWR5_TX_5);
1043 		break;
1044 	case CS6:
1045 		SET(tmp3, ZSWR3_RX_6);
1046 		SET(tmp5, ZSWR5_TX_6);
1047 		break;
1048 	case CS7:
1049 		SET(tmp3, ZSWR3_RX_7);
1050 		SET(tmp5, ZSWR5_TX_7);
1051 		break;
1052 	case CS8:
1053 		SET(tmp3, ZSWR3_RX_8);
1054 		SET(tmp5, ZSWR5_TX_8);
1055 		break;
1056 	}
1057 	cs->cs_preg[3] = tmp3;
1058 	cs->cs_preg[5] = tmp5;
1059 
1060 	/*
1061 	 * Recompute the stop bits and parity bits.  Note that
1062 	 * zs_set_speed() may have set clock selection bits etc.
1063 	 * in wr4, so those must preserved.
1064 	 */
1065 	tmp4 = cs->cs_preg[4];
1066 	CLR(tmp4, ZSWR4_SBMASK | ZSWR4_PARMASK);
1067 	if (ISSET(cflag, CSTOPB))
1068 		SET(tmp4, ZSWR4_TWOSB);
1069 	else
1070 		SET(tmp4, ZSWR4_ONESB);
1071 	if (!ISSET(cflag, PARODD))
1072 		SET(tmp4, ZSWR4_EVENP);
1073 	if (ISSET(cflag, PARENB))
1074 		SET(tmp4, ZSWR4_PARENB);
1075 	cs->cs_preg[4] = tmp4;
1076 
1077 	/* And copy to tty. */
1078 	tp->t_ispeed = 0;
1079 	tp->t_ospeed = ospeed;
1080 	tp->t_cflag = cflag;
1081 
1082 	/*
1083 	 * If nothing is being transmitted, set up new current values,
1084 	 * else mark them as pending.
1085 	 */
1086 	if (!cs->cs_heldchange) {
1087 		if (zst->zst_tx_busy) {
1088 			zst->zst_heldtbc = zst->zst_tbc;
1089 			zst->zst_tbc = 0;
1090 			cs->cs_heldchange = 1;
1091 		} else
1092 			zs_loadchannelregs(cs);
1093 	}
1094 
1095 	/*
1096 	 * If hardware flow control is disabled, turn off the buffer water
1097 	 * marks and unblock any soft flow control state.  Otherwise, enable
1098 	 * the water marks.
1099 	 */
1100 	if (!ISSET(cflag, CHWFLOW)) {
1101 		zst->zst_r_hiwat = 0;
1102 		zst->zst_r_lowat = 0;
1103 		if (ISSET(zst->zst_rx_flags, RX_TTY_OVERFLOWED)) {
1104 			CLR(zst->zst_rx_flags, RX_TTY_OVERFLOWED);
1105 			zst->zst_rx_ready = 1;
1106 			cs->cs_softreq = 1;
1107 		}
1108 		if (ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1109 			CLR(zst->zst_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1110 			zs_hwiflow(zst);
1111 		}
1112 	} else {
1113 		zst->zst_r_hiwat = zstty_rbuf_hiwat;
1114 		zst->zst_r_lowat = zstty_rbuf_lowat;
1115 	}
1116 
1117 	/*
1118 	 * Force a recheck of the hardware carrier and flow control status,
1119 	 * since we may have changed which bits we're looking at.
1120 	 */
1121 	zstty_stint(cs, 1);
1122 
1123 	mutex_spin_exit(&cs->cs_lock);
1124 
1125 	/*
1126 	 * If hardware flow control is disabled, unblock any hard flow control
1127 	 * state.
1128 	 */
1129 	if (!ISSET(cflag, CHWFLOW)) {
1130 		if (zst->zst_tx_stopped) {
1131 			zst->zst_tx_stopped = 0;
1132 			zsstart(tp);
1133 		}
1134 	}
1135 
1136 	zstty_softint1(cs);
1137 
1138 	return (0);
1139 }
1140 
1141 /*
1142  * Compute interrupt enable bits and set in the pending bits. Called both
1143  * in zsparam() and when PPS (pulse per second timing) state changes.
1144  * Must be called at splzs().
1145  */
1146 static void
zs_maskintr(struct zstty_softc * zst)1147 zs_maskintr(struct zstty_softc *zst)
1148 {
1149 	struct zs_chanstate *cs = zst->zst_cs;
1150 	uint8_t tmp15;
1151 
1152 	cs->cs_rr0_mask = cs->cs_rr0_cts | cs->cs_rr0_dcd;
1153 	if (zst->zst_ppsmask != 0)
1154 		cs->cs_rr0_mask |= cs->cs_rr0_pps;
1155 	tmp15 = cs->cs_preg[15];
1156 	if (ISSET(cs->cs_rr0_mask, ZSRR0_DCD))
1157 		SET(tmp15, ZSWR15_DCD_IE);
1158 	else
1159 		CLR(tmp15, ZSWR15_DCD_IE);
1160 	if (ISSET(cs->cs_rr0_mask, ZSRR0_CTS))
1161 		SET(tmp15, ZSWR15_CTS_IE);
1162 	else
1163 		CLR(tmp15, ZSWR15_CTS_IE);
1164 	cs->cs_preg[15] = tmp15;
1165 }
1166 
1167 
1168 /*
1169  * Raise or lower modem control (DTR/RTS) signals.  If a character is
1170  * in transmission, the change is deferred.
1171  * Called at splzs() and with the channel lock held.
1172  */
1173 static void
zs_modem(struct zstty_softc * zst,int onoff)1174 zs_modem(struct zstty_softc *zst, int onoff)
1175 {
1176 	struct zs_chanstate *cs = zst->zst_cs, *ccs;
1177 
1178 	if (cs->cs_wr5_dtr == 0)
1179 		return;
1180 
1181 	ccs = (cs->cs_ctl_chan != NULL ? cs->cs_ctl_chan : cs);
1182 
1183 	if (onoff)
1184 		SET(ccs->cs_preg[5], cs->cs_wr5_dtr);
1185 	else
1186 		CLR(ccs->cs_preg[5], cs->cs_wr5_dtr);
1187 
1188 	if (!cs->cs_heldchange) {
1189 		if (zst->zst_tx_busy) {
1190 			zst->zst_heldtbc = zst->zst_tbc;
1191 			zst->zst_tbc = 0;
1192 			cs->cs_heldchange = 1;
1193 		} else
1194 			zs_loadchannelregs(cs);
1195 	}
1196 }
1197 
1198 /*
1199  * Set modem bits.
1200  * Called at splzs() and with the channel lock held.
1201  */
1202 static void
tiocm_to_zs(struct zstty_softc * zst,u_long how,int ttybits)1203 tiocm_to_zs(struct zstty_softc *zst, u_long how, int ttybits)
1204 {
1205 	struct zs_chanstate *cs = zst->zst_cs, *ccs;
1206 	uint8_t zsbits;
1207 
1208 	ccs = (cs->cs_ctl_chan != NULL ? cs->cs_ctl_chan : cs);
1209 
1210 	zsbits = 0;
1211 	if (ISSET(ttybits, TIOCM_DTR))
1212 		SET(zsbits, ZSWR5_DTR);
1213 	if (ISSET(ttybits, TIOCM_RTS))
1214 		SET(zsbits, ZSWR5_RTS);
1215 
1216 	switch (how) {
1217 	case TIOCMBIC:
1218 		CLR(ccs->cs_preg[5], zsbits);
1219 		break;
1220 
1221 	case TIOCMBIS:
1222 		SET(ccs->cs_preg[5], zsbits);
1223 		break;
1224 
1225 	case TIOCMSET:
1226 		CLR(ccs->cs_preg[5], ZSWR5_RTS | ZSWR5_DTR);
1227 		SET(ccs->cs_preg[5], zsbits);
1228 		break;
1229 	}
1230 
1231 	if (!cs->cs_heldchange) {
1232 		if (zst->zst_tx_busy) {
1233 			zst->zst_heldtbc = zst->zst_tbc;
1234 			zst->zst_tbc = 0;
1235 			cs->cs_heldchange = 1;
1236 		} else
1237 			zs_loadchannelregs(cs);
1238 	}
1239 }
1240 
1241 /*
1242  * Get modem bits.
1243  * Called at splzs() and with the channel lock held.
1244  */
1245 static int
zs_to_tiocm(struct zstty_softc * zst)1246 zs_to_tiocm(struct zstty_softc *zst)
1247 {
1248 	struct zs_chanstate *cs = zst->zst_cs, *ccs;
1249 	uint8_t zsbits;
1250 	int ttybits = 0;
1251 
1252 	ccs = (cs->cs_ctl_chan != NULL ? cs->cs_ctl_chan : cs);
1253 
1254 	zsbits = ccs->cs_preg[5];
1255 	if (ISSET(zsbits, ZSWR5_DTR))
1256 		SET(ttybits, TIOCM_DTR);
1257 	if (ISSET(zsbits, ZSWR5_RTS))
1258 		SET(ttybits, TIOCM_RTS);
1259 
1260 	zsbits = cs->cs_rr0;
1261 	if (ISSET(zsbits, ZSRR0_DCD))
1262 		SET(ttybits, TIOCM_CD);
1263 	if (ISSET(zsbits, ZSRR0_CTS))
1264 		SET(ttybits, TIOCM_CTS);
1265 
1266 	return (ttybits);
1267 }
1268 
1269 /*
1270  * Try to block or unblock input using hardware flow-control.
1271  * This is called by kern/tty.c if MDMBUF|CRTSCTS is set, and
1272  * if this function returns non-zero, the TS_TBLOCK flag will
1273  * be set or cleared according to the "block" arg passed.
1274  */
1275 int
zshwiflow(struct tty * tp,int block)1276 zshwiflow(struct tty *tp, int block)
1277 {
1278 	struct zstty_softc *zst;
1279 	struct zs_chanstate *cs;
1280 
1281 	zst = device_lookup_private(&zstty_cd, ZSUNIT(tp->t_dev));
1282 	cs = zst->zst_cs;
1283 
1284 	if (cs->cs_wr5_rts == 0)
1285 		return (0);
1286 
1287 	mutex_spin_enter(&cs->cs_lock);
1288 	if (block) {
1289 		if (!ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED)) {
1290 			SET(zst->zst_rx_flags, RX_TTY_BLOCKED);
1291 			zs_hwiflow(zst);
1292 		}
1293 	} else {
1294 		if (ISSET(zst->zst_rx_flags, RX_TTY_OVERFLOWED)) {
1295 			CLR(zst->zst_rx_flags, RX_TTY_OVERFLOWED);
1296 			zst->zst_rx_ready = 1;
1297 			cs->cs_softreq = 1;
1298 		}
1299 		if (ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED)) {
1300 			CLR(zst->zst_rx_flags, RX_TTY_BLOCKED);
1301 			zs_hwiflow(zst);
1302 		}
1303 	}
1304 	mutex_spin_exit(&cs->cs_lock);
1305 	return (1);
1306 }
1307 
1308 /*
1309  * Internal version of zshwiflow
1310  * Called at splzs() and with the channel lock held.
1311  */
1312 static void
zs_hwiflow(struct zstty_softc * zst)1313 zs_hwiflow(struct zstty_softc *zst)
1314 {
1315 	struct zs_chanstate *cs = zst->zst_cs, *ccs;
1316 
1317 	if (cs->cs_wr5_rts == 0)
1318 		return;
1319 
1320 	ccs = (cs->cs_ctl_chan != NULL ? cs->cs_ctl_chan : cs);
1321 
1322 	if (ISSET(zst->zst_rx_flags, RX_ANY_BLOCK)) {
1323 		CLR(ccs->cs_preg[5], cs->cs_wr5_rts);
1324 		CLR(ccs->cs_creg[5], cs->cs_wr5_rts);
1325 	} else {
1326 		SET(ccs->cs_preg[5], cs->cs_wr5_rts);
1327 		SET(ccs->cs_creg[5], cs->cs_wr5_rts);
1328 	}
1329 	zs_write_reg(ccs, 5, ccs->cs_creg[5]);
1330 }
1331 
1332 
1333 /****************************************************************
1334  * Interface to the lower layer (zscc)
1335  ****************************************************************/
1336 
1337 #define	integrate	static inline
1338 integrate void zstty_rxsoft(struct zstty_softc *, struct tty *);
1339 integrate void zstty_txsoft(struct zstty_softc *, struct tty *);
1340 integrate void zstty_stsoft(struct zstty_softc *, struct tty *);
1341 static void zstty_diag(void *);
1342 
1343 /*
1344  * Receiver Ready interrupt.
1345  * Called at splzs() and with the channel lock held.
1346  */
1347 static void
zstty_rxint(struct zs_chanstate * cs)1348 zstty_rxint(struct zs_chanstate *cs)
1349 {
1350 	struct zstty_softc *zst = cs->cs_private;
1351 	uint8_t *put, *end;
1352 	u_int cc;
1353 	uint8_t rr0, rr1, c;
1354 
1355 	end = zst->zst_ebuf;
1356 	put = zst->zst_rbput;
1357 	cc = zst->zst_rbavail;
1358 
1359 	while (cc > 0) {
1360 		/*
1361 		 * First read the status, because reading the received char
1362 		 * destroys the status of this char.
1363 		 */
1364 		rr1 = zs_read_reg(cs, 1);
1365 		c = zs_read_data(cs);
1366 
1367 		if (ISSET(rr1, ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
1368 			/* Clear the receive error. */
1369 			zs_write_csr(cs, ZSWR0_RESET_ERRORS);
1370 		}
1371 
1372 		cn_check_magic(zst->zst_tty->t_dev, c, zstty_cnm_state);
1373 		put[0] = c;
1374 		put[1] = rr1;
1375 		put += 2;
1376 		if (put >= end)
1377 			put = zst->zst_rbuf;
1378 		cc--;
1379 
1380 		rr0 = zs_read_csr(cs);
1381 		if (!ISSET(rr0, ZSRR0_RX_READY))
1382 			break;
1383 	}
1384 
1385 	/*
1386 	 * Current string of incoming characters ended because
1387 	 * no more data was available or we ran out of space.
1388 	 * Schedule a receive event if any data was received.
1389 	 * If we're out of space, turn off receive interrupts.
1390 	 */
1391 	zst->zst_rbput = put;
1392 	zst->zst_rbavail = cc;
1393 	if (!ISSET(zst->zst_rx_flags, RX_TTY_OVERFLOWED)) {
1394 		zst->zst_rx_ready = 1;
1395 		cs->cs_softreq = 1;
1396 	}
1397 
1398 	/*
1399 	 * See if we are in danger of overflowing a buffer. If
1400 	 * so, use hardware flow control to ease the pressure.
1401 	 */
1402 	if (!ISSET(zst->zst_rx_flags, RX_IBUF_BLOCKED) &&
1403 	    cc < zst->zst_r_hiwat) {
1404 		SET(zst->zst_rx_flags, RX_IBUF_BLOCKED);
1405 		zs_hwiflow(zst);
1406 	}
1407 
1408 	/*
1409 	 * If we're out of space, disable receive interrupts
1410 	 * until the queue has drained a bit.
1411 	 */
1412 	if (!cc) {
1413 		SET(zst->zst_rx_flags, RX_IBUF_OVERFLOWED);
1414 		CLR(cs->cs_preg[1], ZSWR1_RIE);
1415 		cs->cs_creg[1] = cs->cs_preg[1];
1416 		zs_write_reg(cs, 1, cs->cs_creg[1]);
1417 	}
1418 
1419 #if 0
1420 	printf("%xH%04d\n", zst->zst_rx_flags, zst->zst_rbavail);
1421 #endif
1422 }
1423 
1424 /*
1425  * Transmitter Ready interrupt.
1426  * Called at splzs() and with the channel lock held.
1427  */
1428 static void
zstty_txint(struct zs_chanstate * cs)1429 zstty_txint(struct zs_chanstate *cs)
1430 {
1431 	struct zstty_softc *zst = cs->cs_private;
1432 
1433 	zs_write_csr(cs, ZSWR0_RESET_TXINT);
1434 
1435 	/*
1436 	 * If we've delayed a parameter change, do it now, and restart
1437 	 * output.
1438 	 */
1439 	if (cs->cs_heldchange) {
1440 		zs_loadchannelregs(cs);
1441 		cs->cs_heldchange = 0;
1442 		zst->zst_tbc = zst->zst_heldtbc;
1443 		zst->zst_heldtbc = 0;
1444 	}
1445 
1446 	/* Output the next character in the buffer, if any. */
1447 	if (zst->zst_tbc > 0) {
1448 		zs_write_data(cs, *zst->zst_tba);
1449 		zst->zst_tbc--;
1450 		zst->zst_tba++;
1451 	} else {
1452 		if (zst->zst_tx_busy) {
1453 			zst->zst_tx_busy = 0;
1454 			zst->zst_tx_done = 1;
1455 			cs->cs_softreq = 1;
1456 		}
1457 	}
1458 }
1459 
1460 /*
1461  * Status Change interrupt.
1462  * Called at splzs() and with the channel lock held.
1463  */
1464 static void
zstty_stint(struct zs_chanstate * cs,int force)1465 zstty_stint(struct zs_chanstate *cs, int force)
1466 {
1467 	struct zstty_softc *zst = cs->cs_private;
1468 	uint8_t rr0, delta;
1469 
1470 	rr0 = zs_read_csr(cs);
1471 	zs_write_csr(cs, ZSWR0_RESET_STATUS);
1472 
1473 	/*
1474 	 * Check here for console break, so that we can abort
1475 	 * even when interrupts are locking up the machine.
1476 	 */
1477 	if (ISSET(rr0, ZSRR0_BREAK))
1478 		cn_check_magic(zst->zst_tty->t_dev, CNC_BREAK, zstty_cnm_state);
1479 
1480 	if (!force)
1481 		delta = rr0 ^ cs->cs_rr0;
1482 	else
1483 		delta = cs->cs_rr0_mask;
1484 	cs->cs_rr0 = rr0;
1485 
1486 	if (ISSET(delta, cs->cs_rr0_mask)) {
1487 		SET(cs->cs_rr0_delta, delta);
1488 
1489 		/*
1490 		 * Pulse-per-second clock signal on edge of DCD?
1491 		 */
1492 		if (ISSET(delta, zst->zst_ppsmask)) {
1493 			if (zst->zst_pps_state.ppsparam.mode &
1494 			    PPS_CAPTUREBOTH) {
1495 				mutex_spin_enter(&timecounter_lock);
1496 				pps_capture(&zst->zst_pps_state);
1497 				pps_event(&zst->zst_pps_state,
1498 				    (ISSET(cs->cs_rr0, zst->zst_ppsmask))
1499 				    ? PPS_CAPTUREASSERT
1500 				    : PPS_CAPTURECLEAR);
1501 				mutex_spin_exit(&timecounter_lock);
1502 			}
1503 		}
1504 
1505 		/*
1506 		 * Stop output immediately if we lose the output
1507 		 * flow control signal or carrier detect.
1508 		 */
1509 		if (ISSET(~rr0, cs->cs_rr0_mask)) {
1510 			zst->zst_tbc = 0;
1511 			zst->zst_heldtbc = 0;
1512 		}
1513 
1514 		zst->zst_st_check = 1;
1515 		cs->cs_softreq = 1;
1516 	}
1517 }
1518 
1519 void
zstty_diag(void * arg)1520 zstty_diag(void *arg)
1521 {
1522 	struct zstty_softc *zst = arg;
1523 	int overflows, floods;
1524 
1525 	mutex_spin_enter(&zst->zst_cs->cs_lock);
1526 	overflows = zst->zst_overflows;
1527 	zst->zst_overflows = 0;
1528 	floods = zst->zst_floods;
1529 	zst->zst_floods = 0;
1530 	zst->zst_errors = 0;
1531 	mutex_spin_exit(&zst->zst_cs->cs_lock);
1532 
1533 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1534 	    device_xname(zst->zst_dev),
1535 	    overflows, overflows == 1 ? "" : "s",
1536 	    floods, floods == 1 ? "" : "s");
1537 }
1538 
1539 integrate void
zstty_rxsoft(struct zstty_softc * zst,struct tty * tp)1540 zstty_rxsoft(struct zstty_softc *zst, struct tty *tp)
1541 {
1542 	struct zs_chanstate *cs = zst->zst_cs;
1543 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1544 	uint8_t *get, *end;
1545 	u_int cc, scc;
1546 	uint8_t rr1;
1547 	int code;
1548 
1549 	end = zst->zst_ebuf;
1550 	get = zst->zst_rbget;
1551 	scc = cc = zstty_rbuf_size - zst->zst_rbavail;
1552 
1553 	if (cc == zstty_rbuf_size) {
1554 		zst->zst_floods++;
1555 		if (zst->zst_errors++ == 0)
1556 			callout_reset(&zst->zst_diag_ch, 60 * hz,
1557 			    zstty_diag, zst);
1558 	}
1559 
1560 	/* If not yet open, drop the entire buffer content here */
1561 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1562 		get += cc << 1;
1563 		if (get >= end)
1564 			get -= zstty_rbuf_size << 1;
1565 		cc = 0;
1566 	}
1567 	while (cc) {
1568 		code = get[0];
1569 		rr1 = get[1];
1570 		if (ISSET(rr1, ZSRR1_DO | ZSRR1_FE | ZSRR1_PE)) {
1571 			if (ISSET(rr1, ZSRR1_DO)) {
1572 				zst->zst_overflows++;
1573 				if (zst->zst_errors++ == 0)
1574 					callout_reset(&zst->zst_diag_ch,
1575 					    60 * hz, zstty_diag, zst);
1576 			}
1577 			if (ISSET(rr1, ZSRR1_FE))
1578 				SET(code, TTY_FE);
1579 			if (ISSET(rr1, ZSRR1_PE))
1580 				SET(code, TTY_PE);
1581 		}
1582 		if ((*rint)(code, tp) == -1) {
1583 			/*
1584 			 * The line discipline's buffer is out of space.
1585 			 */
1586 			if (!ISSET(zst->zst_rx_flags, RX_TTY_BLOCKED)) {
1587 				/*
1588 				 * We're either not using flow control, or the
1589 				 * line discipline didn't tell us to block for
1590 				 * some reason.  Either way, we have no way to
1591 				 * know when there's more space available, so
1592 				 * just drop the rest of the data.
1593 				 */
1594 				get += cc << 1;
1595 				if (get >= end)
1596 					get -= zstty_rbuf_size << 1;
1597 				cc = 0;
1598 			} else {
1599 				/*
1600 				 * Don't schedule any more receive processing
1601 				 * until the line discipline tells us there's
1602 				 * space available (through comhwiflow()).
1603 				 * Leave the rest of the data in the input
1604 				 * buffer.
1605 				 */
1606 				SET(zst->zst_rx_flags, RX_TTY_OVERFLOWED);
1607 			}
1608 			break;
1609 		}
1610 		get += 2;
1611 		if (get >= end)
1612 			get = zst->zst_rbuf;
1613 		cc--;
1614 	}
1615 
1616 	if (cc != scc) {
1617 		zst->zst_rbget = get;
1618 		mutex_spin_enter(&cs->cs_lock);
1619 		cc = zst->zst_rbavail += scc - cc;
1620 		/* Buffers should be ok again, release possible block. */
1621 		if (cc >= zst->zst_r_lowat) {
1622 			if (ISSET(zst->zst_rx_flags, RX_IBUF_OVERFLOWED)) {
1623 				CLR(zst->zst_rx_flags, RX_IBUF_OVERFLOWED);
1624 				SET(cs->cs_preg[1], ZSWR1_RIE);
1625 				cs->cs_creg[1] = cs->cs_preg[1];
1626 				zs_write_reg(cs, 1, cs->cs_creg[1]);
1627 			}
1628 			if (ISSET(zst->zst_rx_flags, RX_IBUF_BLOCKED)) {
1629 				CLR(zst->zst_rx_flags, RX_IBUF_BLOCKED);
1630 				zs_hwiflow(zst);
1631 			}
1632 		}
1633 		mutex_spin_exit(&cs->cs_lock);
1634 	}
1635 
1636 #if 0
1637 	printf("%xS%04d\n", zst->zst_rx_flags, zst->zst_rbavail);
1638 #endif
1639 }
1640 
1641 integrate void
zstty_txsoft(struct zstty_softc * zst,struct tty * tp)1642 zstty_txsoft(struct zstty_softc *zst, struct tty *tp)
1643 {
1644 	struct zs_chanstate *cs = zst->zst_cs;
1645 
1646 	mutex_spin_enter(&cs->cs_lock);
1647 	CLR(tp->t_state, TS_BUSY);
1648 	if (ISSET(tp->t_state, TS_FLUSH))
1649 		CLR(tp->t_state, TS_FLUSH);
1650 	else
1651 		ndflush(&tp->t_outq, (int)(zst->zst_tba - tp->t_outq.c_cf));
1652 	mutex_spin_exit(&cs->cs_lock);
1653 	(*tp->t_linesw->l_start)(tp);
1654 }
1655 
1656 integrate void
zstty_stsoft(struct zstty_softc * zst,struct tty * tp)1657 zstty_stsoft(struct zstty_softc *zst, struct tty *tp)
1658 {
1659 	struct zs_chanstate *cs = zst->zst_cs;
1660 	uint8_t rr0, delta;
1661 
1662 	mutex_spin_enter(&cs->cs_lock);
1663 	rr0 = cs->cs_rr0;
1664 	delta = cs->cs_rr0_delta;
1665 	cs->cs_rr0_delta = 0;
1666 	mutex_spin_exit(&cs->cs_lock);
1667 
1668 	if (ISSET(delta, cs->cs_rr0_dcd)) {
1669 		/*
1670 		 * Inform the tty layer that carrier detect changed.
1671 		 */
1672 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(rr0, ZSRR0_DCD));
1673 	}
1674 
1675 	if (ISSET(delta, cs->cs_rr0_cts)) {
1676 		/* Block or unblock output according to flow control. */
1677 		if (ISSET(rr0, cs->cs_rr0_cts)) {
1678 			zst->zst_tx_stopped = 0;
1679 			(*tp->t_linesw->l_start)(tp);
1680 		} else {
1681 			zst->zst_tx_stopped = 1;
1682 		}
1683 	}
1684 }
1685 
1686 /*
1687  * Software interrupt.  Called at zssoft
1688  *
1689  * The main job to be done here is to empty the input ring
1690  * by passing its contents up to the tty layer.  The ring is
1691  * always emptied during this operation, therefore the ring
1692  * must not be larger than the space after "high water" in
1693  * the tty layer, or the tty layer might drop our input.
1694  *
1695  * Note: an "input blockage" condition is assumed to exist if
1696  * EITHER the TS_TBLOCK flag or zst_rx_blocked flag is set.
1697  */
1698 static void
zstty_softint(struct zs_chanstate * cs)1699 zstty_softint(struct zs_chanstate *cs)
1700 {
1701 
1702 	zstty_softint1(cs);
1703 }
1704 
1705 static void
zstty_softint1(struct zs_chanstate * cs)1706 zstty_softint1(struct zs_chanstate *cs)
1707 {
1708 	struct zstty_softc *zst = cs->cs_private;
1709 	struct tty *tp = zst->zst_tty;
1710 
1711 
1712 	if (zst->zst_rx_ready) {
1713 		zst->zst_rx_ready = 0;
1714 		zstty_rxsoft(zst, tp);
1715 	}
1716 
1717 	if (zst->zst_st_check) {
1718 		zst->zst_st_check = 0;
1719 		zstty_stsoft(zst, tp);
1720 	}
1721 
1722 	if (zst->zst_tx_done) {
1723 		zst->zst_tx_done = 0;
1724 		zstty_txsoft(zst, tp);
1725 	}
1726 }
1727 
1728 struct zsops zsops_tty = {
1729 	zstty_rxint,	/* receive char available */
1730 	zstty_stint,	/* external/status */
1731 	zstty_txint,	/* xmit buffer empty */
1732 	zstty_softint,	/* process software interrupt */
1733 };
1734 
1735 #ifdef ZS_TXDMA
1736 void
zstty_txdma_int(void * arg)1737 zstty_txdma_int(void *arg)
1738 {
1739 	struct zs_chanstate *cs = arg;
1740 	struct zstty_softc *zst = cs->cs_private;
1741 
1742 	zst->zst_tba += zst->zst_tbc;
1743 	zst->zst_tbc = 0;
1744 
1745 	if (zst->zst_tx_busy) {
1746 		zst->zst_tx_busy = 0;
1747 		zst->zst_tx_done = 1;
1748 		cs->cs_softreq = 1;
1749 	}
1750 }
1751 #endif
1752