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z8530tty.c revision 1.79
      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 (at) netbsd.org>,
     94  *	Bill Studenmund <wrstuden (at) loki.stanford.edu>
     95  *	Ian Dall <Ian.Dall (at) 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