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      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 (at) NetBSD.org>,
    132  *	Bill Studenmund <wrstuden (at) loki.stanford.edu>
    133  *	Ian Dall <Ian.Dall (at) 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 *
    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
    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
    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 *
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
    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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   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
   1699 zstty_softint(struct zs_chanstate *cs)
   1700 {
   1701 
   1702 	zstty_softint1(cs);
   1703 }
   1704 
   1705 static void
   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
   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