xref: /illumos-gate/usr/src/uts/sun4/io/su_driver.c (revision e7cbe64f7a72dae5cb44f100db60ca88f3313c65)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*	Copyright (c) 1990, 1991 UNIX System Laboratories, Inc.	*/
22 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T	*/
23 /*	  All Rights Reserved					*/
24 
25 /*
26  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  *	Serial I/O driver for 82510/8250/16450/16550AF/16C554D chips.
34  *	Modified as sparc keyboard/mouse driver.
35  */
36 #define	SU_REGISTER_FILE_NO 0
37 #define	SU_REGOFFSET 0
38 #define	SU_REGISTER_LEN 8
39 
40 #include <sys/param.h>
41 #include <sys/types.h>
42 #include <sys/signal.h>
43 #include <sys/stream.h>
44 #include <sys/termio.h>
45 #include <sys/errno.h>
46 #include <sys/file.h>
47 #include <sys/cmn_err.h>
48 #include <sys/stropts.h>
49 #include <sys/strsubr.h>
50 #include <sys/strsun.h>
51 #include <sys/strtty.h>
52 #include <sys/debug.h>
53 #include <sys/kbio.h>
54 #include <sys/cred.h>
55 #include <sys/modctl.h>
56 #include <sys/stat.h>
57 #include <sys/consdev.h>
58 #include <sys/mkdev.h>
59 #include <sys/kmem.h>
60 #include <sys/cred.h>
61 #ifdef DEBUG
62 #include <sys/promif.h>
63 #endif
64 #include <sys/ddi.h>
65 #include <sys/sunddi.h>
66 #include <sys/sudev.h>
67 #include <sys/note.h>
68 #include <sys/timex.h>
69 #include <sys/policy.h>
70 
71 #define	async_stopc	async_ttycommon.t_stopc
72 #define	async_startc	async_ttycommon.t_startc
73 
74 #define	ASY_INIT	1
75 #define	ASY_NOINIT	0
76 
77 #ifdef DEBUG
78 #define	ASY_DEBUG_INIT	0x001
79 #define	ASY_DEBUG_INPUT	0x002
80 #define	ASY_DEBUG_EOT	0x004
81 #define	ASY_DEBUG_CLOSE	0x008
82 #define	ASY_DEBUG_HFLOW	0x010
83 #define	ASY_DEBUG_PROCS	0x020
84 #define	ASY_DEBUG_STATE	0x040
85 #define	ASY_DEBUG_INTR	0x080
86 static	int asydebug = 0;
87 #endif
88 static	int su_log = 0;
89 
90 int su_drain_check = 15000000;		/* tunable: exit drain check time */
91 
92 static	struct ppsclockev asy_ppsev;
93 
94 static	int max_asy_instance = -1;
95 static	void	*su_asycom;	/* soft state asycom pointer */
96 static	void	*su_asyncline;	/* soft state asyncline pointer */
97 static	boolean_t abort_charseq_recognize(uchar_t ch);
98 
99 static	uint_t	asysoftintr(caddr_t intarg);
100 static	uint_t	asyintr(caddr_t argasy);
101 
102 /* The async interrupt entry points */
103 static void	async_txint(struct asycom *asy, uchar_t lsr);
104 static void	async_rxint(struct asycom *asy, uchar_t lsr);
105 static void	async_msint(struct asycom *asy);
106 static int	async_softint(struct asycom *asy);
107 
108 static void	async_ioctl(struct asyncline *async, queue_t *q, mblk_t *mp,
109     boolean_t iswput);
110 static void	async_reioctl(void *);
111 static void	async_iocdata(queue_t *q, mblk_t *mp);
112 static void	async_restart(void *);
113 static void	async_start(struct asyncline *async);
114 static void	async_nstart(struct asyncline *async, int mode);
115 static void	async_resume(struct asyncline *async);
116 static int	asy_program(struct asycom *asy, int mode);
117 
118 /* Polled mode functions */
119 static void	asyputchar(cons_polledio_arg_t, uchar_t c);
120 static int	asygetchar(cons_polledio_arg_t);
121 static boolean_t	asyischar(cons_polledio_arg_t);
122 static void	asy_polled_enter(cons_polledio_arg_t);
123 static void	asy_polled_exit(cons_polledio_arg_t);
124 
125 static int	asymctl(struct asycom *, int, int);
126 static int	asytodm(int, int);
127 static int	dmtoasy(int);
128 static void	asycheckflowcontrol_hw(struct asycom *asy);
129 static boolean_t asycheckflowcontrol_sw(struct asycom *asy);
130 static void	asy_ppsevent(struct asycom *asy, int msr);
131 
132 extern kcondvar_t lbolt_cv;
133 extern int ddi_create_internal_pathname(dev_info_t *dip, char *name,
134 		int spec_type, minor_t minor_num);
135 
136 
137 /*
138  * Baud rate table. Indexed by #defines found in sys/termios.h
139  */
140 ushort_t asyspdtab[] = {
141 	0,	/* 0 baud rate */
142 	0x900,	/* 50 baud rate */
143 	0x600,	/* 75 baud rate */
144 	0x417,	/* 110 baud rate (%0.026) */
145 	0x359,	/* 134 baud rate (%0.058) */
146 	0x300,	/* 150 baud rate */
147 	0x240,	/* 200 baud rate */
148 	0x180,	/* 300 baud rate */
149 	0x0c0,	/* 600 baud rate */
150 	0x060,	/* 1200 baud rate */
151 	0x040,	/* 1800 baud rate */
152 	0x030,	/* 2400 baud rate */
153 	0x018,	/* 4800 baud rate */
154 	0x00c,	/* 9600 baud rate */
155 	0x006,	/* 19200 baud rate */
156 	0x003,	/* 38400 baud rate */
157 	0x002,	/* 57600 baud rate */
158 	0,	/* 76800 baud rate - not supported */
159 	0x001,	/* 115200 baud rate */
160 	0,	/* 153600 baud rate - not supported */
161 	0x8002,	/* 230400 baud rate - supported on specific platforms */
162 	0,	/* 307200 baud rate - not supported */
163 	0x8001	/* 460800 baud rate - supported on specific platforms */
164 };
165 
166 /*
167  * Number of speeds supported is the number of entries in
168  * the above table.
169  */
170 #define	N_SU_SPEEDS	(sizeof (asyspdtab)/sizeof (ushort_t))
171 
172 /*
173  * Human-readable baud rate table.
174  * Indexed by #defines found in sys/termios.h
175  */
176 int baudtable[] = {
177 	0,	/* 0 baud rate */
178 	50,	/* 50 baud rate */
179 	75,	/* 75 baud rate */
180 	110,	/* 110 baud rate */
181 	134,	/* 134 baud rate */
182 	150,	/* 150 baud rate */
183 	200,	/* 200 baud rate */
184 	300,	/* 300 baud rate */
185 	600,	/* 600 baud rate */
186 	1200,	/* 1200 baud rate */
187 	1800,	/* 1800 baud rate */
188 	2400,	/* 2400 baud rate */
189 	4800,	/* 4800 baud rate */
190 	9600,	/* 9600 baud rate */
191 	19200,	/* 19200 baud rate */
192 	38400,	/* 38400 baud rate */
193 	57600,	/* 57600 baud rate */
194 	76800,	/* 76800 baud rate */
195 	115200,	/* 115200 baud rate */
196 	153600,	/* 153600 baud rate */
197 	230400,	/* 230400 baud rate */
198 	307200,	/* 307200 baud rate */
199 	460800	/* 460800 baud rate */
200 };
201 
202 static int asyopen(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr);
203 static int asyclose(queue_t *q, int flag);
204 static void asywput(queue_t *q, mblk_t *mp);
205 static void asyrsrv(queue_t *q);
206 
207 struct module_info asy_info = {
208 	0,
209 	"su",
210 	0,
211 	INFPSZ,
212 	32*4096,
213 	4096
214 };
215 
216 static struct qinit asy_rint = {
217 	putq,
218 	(int (*)())asyrsrv,
219 	asyopen,
220 	asyclose,
221 	NULL,
222 	&asy_info,
223 	NULL
224 };
225 
226 static struct qinit asy_wint = {
227 	(int (*)())asywput,
228 	NULL,
229 	NULL,
230 	NULL,
231 	NULL,
232 	&asy_info,
233 	NULL
234 };
235 
236 struct streamtab asy_str_info = {
237 	&asy_rint,
238 	&asy_wint,
239 	NULL,
240 	NULL
241 };
242 
243 static int asyinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
244 		void **result);
245 static int asyprobe(dev_info_t *);
246 static int asyattach(dev_info_t *, ddi_attach_cmd_t);
247 static int asydetach(dev_info_t *, ddi_detach_cmd_t);
248 
249 static 	struct cb_ops cb_asy_ops = {
250 	nodev,			/* cb_open */
251 	nodev,			/* cb_close */
252 	nodev,			/* cb_strategy */
253 	nodev,			/* cb_print */
254 	nodev,			/* cb_dump */
255 	nodev,			/* cb_read */
256 	nodev,			/* cb_write */
257 	nodev,			/* cb_ioctl */
258 	nodev,			/* cb_devmap */
259 	nodev,			/* cb_mmap */
260 	nodev,			/* cb_segmap */
261 	nochpoll,		/* cb_chpoll */
262 	ddi_prop_op,		/* cb_prop_op */
263 	&asy_str_info,		/* cb_stream */
264 	D_MP			/* cb_flag */
265 };
266 
267 struct dev_ops asy_ops = {
268 	DEVO_REV,		/* devo_rev */
269 	0,			/* devo_refcnt */
270 	asyinfo,		/* devo_getinfo */
271 	nulldev,		/* devo_identify */
272 	asyprobe,		/* devo_probe */
273 	asyattach,		/* devo_attach */
274 	asydetach,		/* devo_detach */
275 	nodev,			/* devo_reset */
276 	&cb_asy_ops,		/* devo_cb_ops */
277 };
278 
279 /*
280  * Module linkage information for the kernel.
281  */
282 
283 static struct modldrv modldrv = {
284 	&mod_driverops, /* Type of module.  This one is a driver */
285 	"su driver %I%",
286 	&asy_ops,	/* driver ops */
287 };
288 
289 static struct modlinkage modlinkage = {
290 	MODREV_1,
291 	&modldrv,
292 	NULL
293 };
294 
295 int
296 _init(void)
297 {
298 	int status;
299 
300 	status = ddi_soft_state_init(&su_asycom, sizeof (struct asycom),
301 	    SU_INITIAL_SOFT_ITEMS);
302 	if (status != 0)
303 		return (status);
304 	status = ddi_soft_state_init(&su_asyncline, sizeof (struct asyncline),
305 	    SU_INITIAL_SOFT_ITEMS);
306 	if (status != 0) {
307 		ddi_soft_state_fini(&su_asycom);
308 		return (status);
309 	}
310 
311 	if ((status = mod_install(&modlinkage)) != 0) {
312 		ddi_soft_state_fini(&su_asycom);
313 		ddi_soft_state_fini(&su_asyncline);
314 	}
315 
316 	return (status);
317 }
318 
319 int
320 _fini(void)
321 {
322 	int i;
323 
324 	i = mod_remove(&modlinkage);
325 	if (i == 0) {
326 		ddi_soft_state_fini(&su_asycom);
327 		ddi_soft_state_fini(&su_asyncline);
328 	}
329 
330 	return (i);
331 }
332 
333 int
334 _info(struct modinfo *modinfop)
335 {
336 	return (mod_info(&modlinkage, modinfop));
337 }
338 
339 static int
340 asyprobe(dev_info_t *devi)
341 {
342 	int		instance;
343 	ddi_acc_handle_t handle;
344 	uchar_t *addr;
345 	ddi_device_acc_attr_t attr;
346 
347 	attr.devacc_attr_version = DDI_DEVICE_ATTR_V0;
348 	attr.devacc_attr_endian_flags = DDI_STRUCTURE_LE_ACC;
349 	attr.devacc_attr_dataorder = DDI_STRICTORDER_ACC;
350 	if (ddi_regs_map_setup(devi, SU_REGISTER_FILE_NO, (caddr_t *)&addr,
351 	    SU_REGOFFSET, SU_REGISTER_LEN, &attr, &handle) != DDI_SUCCESS) {
352 		cmn_err(CE_WARN, "asyprobe regs map setup failed");
353 		return (DDI_PROBE_FAILURE);
354 	}
355 #ifdef DEBUG
356 	if (asydebug)
357 		printf("Probe address mapped %p\n", (void *)addr);
358 #endif
359 
360 	/*
361 	 * Probe for the device:
362 	 * 	Ser. int. uses bits 0,1,2; FIFO uses 3,6,7; 4,5 wired low.
363 	 * 	If bit 4 or 5 appears on inb() ISR, board is not there.
364 	 */
365 	if (ddi_get8(handle, addr+ISR) & 0x30) {
366 		ddi_regs_map_free(&handle);
367 		return (DDI_PROBE_FAILURE);
368 	}
369 
370 	instance = ddi_get_instance(devi);
371 	if (max_asy_instance < instance)
372 		max_asy_instance = instance;
373 	ddi_regs_map_free(&handle);
374 
375 	return (DDI_PROBE_SUCCESS); /* hw is present */
376 }
377 
378 static int
379 asydetach(dev_info_t *devi, ddi_detach_cmd_t cmd)
380 {
381 	register int	instance;
382 	struct asycom	*asy;
383 	struct asyncline *async;
384 	char		name[16];
385 
386 	instance = ddi_get_instance(devi);	/* find out which unit */
387 
388 	asy = (struct asycom *)ddi_get_soft_state(su_asycom, instance);
389 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, instance);
390 
391 	switch (cmd) {
392 		case DDI_DETACH:
393 			break;
394 		case DDI_SUSPEND:
395 			/* grab both mutex locks */
396 			mutex_enter(asy->asy_excl);
397 			mutex_enter(asy->asy_excl_hi);
398 			if (asy->suspended) {
399 				mutex_exit(asy->asy_excl_hi);
400 				mutex_exit(asy->asy_excl);
401 				return (DDI_SUCCESS);
402 			}
403 			asy->suspended = B_TRUE;
404 
405 			/*
406 			 * The quad UART ST16C554D, version D2 (made by EXAR)
407 			 * has an anomaly of generating spurious interrupts
408 			 * when the ICR is loaded with zero. The workaround
409 			 * would be to read/write any register with DATA1 bit
410 			 * set to 0 before such write.
411 			 */
412 			if (asy->asy_hwtype == ASY16C554D)
413 				OUTB(SPR, 0);
414 
415 			/* Disable further interrupts */
416 			OUTB(ICR, 0);
417 			mutex_exit(asy->asy_excl_hi);
418 			mutex_exit(asy->asy_excl);
419 			return (DDI_SUCCESS);
420 
421 		default:
422 			return (DDI_FAILURE);
423 	}
424 
425 #ifdef DEBUG
426 	if (asydebug & ASY_DEBUG_INIT)
427 		cmn_err(CE_NOTE, "su%d: ASY%s shutdown.", instance,
428 		    asy->asy_hwtype == ASY82510 ? "82510" :
429 		    asy->asy_hwtype == ASY16550AF ? "16550AF" :
430 		    asy->asy_hwtype == ASY16C554D ? "16C554D" :
431 		    "8250");
432 #endif
433 	/*
434 	 * Before removing interrupts it is always better to disable
435 	 * interrupts if the chip gives a provision to disable the
436 	 * serial port interrupts.
437 	 */
438 	mutex_enter(asy->asy_excl);
439 	mutex_enter(asy->asy_excl_hi);
440 	/* disable interrupts, see EXAR bug */
441 	if (asy->asy_hwtype == ASY16C554D)
442 		OUTB(SPR, 0);
443 	OUTB(ICR, 0);
444 	mutex_exit(asy->asy_excl_hi);
445 	mutex_exit(asy->asy_excl);
446 
447 	/* remove minor device node(s) for this device */
448 	(void) sprintf(name, "%c", (instance+'a'));	/* serial-port */
449 	ddi_remove_minor_node(devi, name);
450 	(void) sprintf(name, "%c,cu", (instance+'a')); /* serial-port:dailout */
451 	ddi_remove_minor_node(devi, name);
452 
453 	mutex_destroy(asy->asy_excl);
454 	mutex_destroy(asy->asy_excl_hi);
455 	kmem_free(asy->asy_excl, sizeof (kmutex_t));
456 	kmem_free(asy->asy_excl_hi, sizeof (kmutex_t));
457 	cv_destroy(&async->async_flags_cv);
458 	kstat_delete(asy->sukstat);
459 	ddi_remove_intr(devi, 0, asy->asy_iblock);
460 	ddi_regs_map_free(&asy->asy_handle);
461 	ddi_remove_softintr(asy->asy_softintr_id);
462 	mutex_destroy(asy->asy_soft_lock);
463 	kmem_free(asy->asy_soft_lock, sizeof (kmutex_t));
464 	ddi_soft_state_free(su_asycom, instance);
465 	ddi_soft_state_free(su_asyncline, instance);
466 	return (DDI_SUCCESS);
467 }
468 
469 static int
470 asyattach(dev_info_t *devi, ddi_attach_cmd_t cmd)
471 {
472 	register int	instance;
473 	struct asycom	*asy;
474 	struct asyncline *async;
475 	char		name[40];
476 	ddi_device_acc_attr_t attr;
477 	enum states { EMPTY, SOFTSTATE, REGSMAP, MUTEXES, ADDINTR,
478 	    SOFTINTR, ASYINIT, KSTAT, MINORNODE };
479 	enum states state = EMPTY;
480 	char *hwtype;
481 
482 	instance = ddi_get_instance(devi);	/* find out which unit */
483 
484 	/* cannot attach a device that has not been probed first */
485 	if (instance > max_asy_instance)
486 		return (DDI_FAILURE);
487 
488 	if (cmd != DDI_RESUME) {
489 		/* Allocate soft state space */
490 		if (ddi_soft_state_zalloc(su_asycom, instance) != DDI_SUCCESS) {
491 			cmn_err(CE_WARN, "su%d: cannot allocate soft state",
492 			    instance);
493 			goto error;
494 		}
495 	}
496 	state = SOFTSTATE;
497 
498 	asy = (struct asycom *)ddi_get_soft_state(su_asycom, instance);
499 
500 	if (asy == NULL) {
501 		cmn_err(CE_WARN, "su%d: cannot get soft state", instance);
502 		goto error;
503 	}
504 
505 	switch (cmd) {
506 		case DDI_ATTACH:
507 			break;
508 		case DDI_RESUME: {
509 			struct asyncline *async;
510 
511 			/* grab both mutex locks */
512 			mutex_enter(asy->asy_excl);
513 			mutex_enter(asy->asy_excl_hi);
514 			if (!asy->suspended) {
515 				mutex_exit(asy->asy_excl_hi);
516 				mutex_exit(asy->asy_excl);
517 				return (DDI_SUCCESS);
518 			}
519 			/*
520 			 * re-setup all the registers and enable interrupts if
521 			 * needed
522 			 */
523 			async = (struct asyncline *)asy->asy_priv;
524 			if ((async) && (async->async_flags & ASYNC_ISOPEN))
525 				(void) asy_program(asy, ASY_INIT);
526 			asy->suspended = B_FALSE;
527 			mutex_exit(asy->asy_excl_hi);
528 			mutex_exit(asy->asy_excl);
529 			return (DDI_SUCCESS);
530 		}
531 		default:
532 			goto error;
533 	}
534 
535 	attr.devacc_attr_version = DDI_DEVICE_ATTR_V0;
536 	attr.devacc_attr_endian_flags = DDI_STRUCTURE_LE_ACC;
537 	attr.devacc_attr_dataorder = DDI_STRICTORDER_ACC;
538 
539 	if (ddi_regs_map_setup(devi, SU_REGISTER_FILE_NO,
540 	    (caddr_t *)&asy->asy_ioaddr, SU_REGOFFSET, SU_REGISTER_LEN,
541 	    &attr, &asy->asy_handle) != DDI_SUCCESS) {
542 		cmn_err(CE_WARN, "asyprobe regs map setup failed");
543 		goto error;
544 	}
545 	state = REGSMAP;
546 
547 #ifdef DEBUG
548 	if (asydebug)
549 		printf("su attach mapped %p\n", (void *)asy->asy_ioaddr);
550 #endif
551 
552 	/*
553 	 * Initialize the port with default settings.
554 	 */
555 	asy->asy_fifo_buf = 1;
556 	asy->asy_use_fifo = FIFO_OFF;
557 
558 	/*
559 	 * Check for baudrate generator's "baud-divisor-factor" property setup
560 	 * by OBP, since different UART chips might have different baudrate
561 	 * generator divisor. e.g., in case of NSPG's Sputnik platform, the
562 	 * baud-divisor-factor is 13, it uses dedicated 16552 "DUART" chip
563 	 * instead of SuperIO. Since the baud-divisor-factor must be a positive
564 	 * integer, the divisors will always be at least as large as the values
565 	 * in asyspdtab[].  Make the default factor 1.
566 	 */
567 	asy->asy_baud_divisor_factor = ddi_prop_get_int(DDI_DEV_T_ANY, devi,
568 	    DDI_PROP_DONTPASS, "baud-divisor-factor", 1);
569 
570 	/* set speed cap */
571 	asy->asy_speed_cap = ddi_prop_get_int(DDI_DEV_T_ANY, devi,
572 	    DDI_PROP_DONTPASS, "serial-speed-cap", 115200);
573 
574 	/* check for ASY82510 chip */
575 	OUTB(ISR, 0x20);
576 	if (INB(ISR) & 0x20) { /* 82510 chip is present */
577 		/*
578 		 * Since most of the general operation of the 82510 chip
579 		 * can be done from BANK 0 (8250A/16450 compatable mode)
580 		 * we will default to BANK 0.
581 		 */
582 		asy->asy_hwtype = ASY82510;
583 		OUTB(DAT+7, 0x04); /* clear status */
584 		OUTB(ISR, 0x40); /* set to bank 2 */
585 		OUTB(MCR, 0x08); /* IMD */
586 		OUTB(DAT, 0x21); /* FMD */
587 		OUTB(ISR, 0x00); /* set to bank 0 */
588 		asy->asy_trig_level = 0;
589 	} else { /* Set the UART in FIFO mode if it has FIFO buffers */
590 		asy->asy_hwtype = ASY16550AF;
591 		OUTB(FIFOR, 0x00); /* clear fifo register */
592 		asy->asy_trig_level = 0x00; /* sets the fifo Threshold to 1 */
593 
594 		/* set/Enable FIFO */
595 		OUTB(FIFOR, FIFO_ON | FIFODMA | FIFOTXFLSH | FIFORXFLSH |
596 		    (asy->asy_trig_level & 0xff));
597 
598 		if ((INB(ISR) & 0xc0) == 0xc0)
599 			asy->asy_use_fifo = FIFO_ON;
600 		else {
601 			asy->asy_hwtype = ASY8250;
602 			OUTB(FIFOR, 0x00); /* NO FIFOs */
603 			asy->asy_trig_level = 0;
604 		}
605 	}
606 
607 	/* check for ST16C554D chip */
608 	if ((ddi_prop_lookup_string(DDI_DEV_T_ANY, devi, DDI_PROP_NOTPROM |
609 	    DDI_PROP_DONTPASS, "hwtype", &hwtype)) == DDI_PROP_SUCCESS) {
610 		if (strcmp(hwtype, "ST16C554D") == 0)
611 			asy->asy_hwtype = ASY16C554D;
612 		ddi_prop_free(hwtype);
613 	}
614 
615 	/* disable interrupts, see EXAR bug */
616 	if (asy->asy_hwtype == ASY16C554D)
617 		OUTB(SPR, 0);
618 	OUTB(ICR, 0);
619 	OUTB(LCR, DLAB); /* select baud rate generator */
620 	/* Set the baud rate to 9600 */
621 	OUTB(DAT+DLL, (ASY9600*asy->asy_baud_divisor_factor) & 0xff);
622 	OUTB(DAT+DLH, ((ASY9600*asy->asy_baud_divisor_factor) >> 8) & 0xff);
623 	OUTB(LCR, STOP1|BITS8);
624 	OUTB(MCR, (DTR | RTS| OUT2));
625 
626 	/*
627 	 * Set up the other components of the asycom structure for this port.
628 	 */
629 	asy->asy_excl = (kmutex_t *)
630 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
631 	asy->asy_excl_hi = (kmutex_t *)
632 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
633 	asy->asy_soft_lock = (kmutex_t *)
634 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
635 	asy->asy_unit = instance;
636 	asy->asy_dip = devi;
637 
638 	if (ddi_get_iblock_cookie(devi, 0, &asy->asy_iblock) != DDI_SUCCESS) {
639 		cmn_err(CE_NOTE,
640 		    "Get iblock_cookie failed-Device interrupt%x\n", instance);
641 		goto error;
642 	}
643 
644 	if (ddi_get_soft_iblock_cookie(devi, DDI_SOFTINT_HIGH,
645 	    &asy->asy_soft_iblock) != DDI_SUCCESS) {
646 		cmn_err(CE_NOTE, "Get iblock_cookie failed -soft interrupt%x\n",
647 		    instance);
648 		goto error;
649 	}
650 
651 	mutex_init(asy->asy_soft_lock, NULL, MUTEX_DRIVER,
652 	    (void *)asy->asy_soft_iblock);
653 	mutex_init(asy->asy_excl, NULL, MUTEX_DRIVER, NULL);
654 	mutex_init(asy->asy_excl_hi, NULL, MUTEX_DRIVER,
655 	    (void *)asy->asy_iblock);
656 	state = MUTEXES;
657 
658 	/*
659 	 * Install interrupt handlers for this device.
660 	 */
661 	if (ddi_add_intr(devi, 0, &(asy->asy_iblock), 0, asyintr,
662 	    (caddr_t)asy) != DDI_SUCCESS) {
663 		cmn_err(CE_CONT,
664 		    "Cannot set device interrupt for su driver\n");
665 		goto error;
666 	}
667 	state = ADDINTR;
668 
669 	if (ddi_add_softintr(devi, DDI_SOFTINT_HIGH, &(asy->asy_softintr_id),
670 	    &asy->asy_soft_iblock, 0, asysoftintr, (caddr_t)asy)
671 	    != DDI_SUCCESS) {
672 		cmn_err(CE_CONT, "Cannot set soft interrupt for su driver\n");
673 		goto error;
674 	}
675 	state = SOFTINTR;
676 
677 	/* initialize the asyncline structure */
678 	if (ddi_soft_state_zalloc(su_asyncline, instance) != DDI_SUCCESS) {
679 		cmn_err(CE_CONT, "su%d: cannot allocate soft state", instance);
680 		goto error;
681 	}
682 	state = ASYINIT;
683 
684 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, instance);
685 
686 	mutex_enter(asy->asy_excl);
687 	async->async_common = asy;
688 	cv_init(&async->async_flags_cv, NULL, CV_DEFAULT, NULL);
689 	mutex_exit(asy->asy_excl);
690 
691 	if ((asy->sukstat = kstat_create("su", instance, "serialstat",
692 	    "misc", KSTAT_TYPE_NAMED, 2, KSTAT_FLAG_VIRTUAL)) != NULL) {
693 		asy->sukstat->ks_data = &asy->kstats;
694 		kstat_named_init(&asy->kstats.ringover, "ring buffer overflow",
695 		    KSTAT_DATA_UINT64);
696 		kstat_named_init(&asy->kstats.siloover, "silo overflow",
697 		    KSTAT_DATA_UINT64);
698 		kstat_install(asy->sukstat);
699 	}
700 	state = KSTAT;
701 
702 	if (strcmp(ddi_node_name(devi), "rsc-console") == 0) {
703 		/*
704 		 * If the device is configured as the 'rsc-console'
705 		 * create the minor device for this node.
706 		 */
707 		if (ddi_create_minor_node(devi, "ssp", S_IFCHR,
708 		    asy->asy_unit | RSC_DEVICE, DDI_PSEUDO, NULL)
709 		    == DDI_FAILURE) {
710 			cmn_err(CE_WARN,
711 			    "%s%d: Failed to create node rsc-console",
712 			    ddi_get_name(devi), ddi_get_instance(devi));
713 			goto error;
714 		}
715 
716 		asy->asy_lom_console = 0;
717 		asy->asy_rsc_console = 1;
718 		asy->asy_rsc_control = 0;
719 		asy->asy_device_type = ASY_SERIAL;
720 		asy->asy_flags |= ASY_IGNORE_CD;
721 
722 	} else if (strcmp(ddi_node_name(devi), "lom-console") == 0) {
723 		/*
724 		 * If the device is configured as the 'lom-console'
725 		 * create the minor device for this node.
726 		 * Do not create a dialout device.
727 		 * Use the same minor numbers as would be used for standard
728 		 * serial instances.
729 		 */
730 		if (ddi_create_minor_node(devi, "lom-console", S_IFCHR,
731 		    instance, DDI_NT_SERIAL_LOMCON, NULL) == DDI_FAILURE) {
732 			cmn_err(CE_WARN,
733 			    "%s%d: Failed to create node lom-console",
734 			    ddi_get_name(devi), ddi_get_instance(devi));
735 			goto error;
736 		}
737 		asy->asy_lom_console = 1;
738 		asy->asy_rsc_console = 0;
739 		asy->asy_rsc_control = 0;
740 		asy->asy_device_type = ASY_SERIAL;
741 		asy->asy_flags |= ASY_IGNORE_CD;
742 
743 	} else if (strcmp(ddi_node_name(devi), "rsc-control") == 0) {
744 		/*
745 		 * If the device is configured as the 'rsc-control'
746 		 * create the minor device for this node.
747 		 */
748 		if (ddi_create_minor_node(devi, "sspctl", S_IFCHR,
749 		    asy->asy_unit | RSC_DEVICE, DDI_PSEUDO, NULL)
750 		    == DDI_FAILURE) {
751 			cmn_err(CE_WARN, "%s%d: Failed to create rsc-control",
752 			    ddi_get_name(devi), ddi_get_instance(devi));
753 			goto error;
754 		}
755 
756 		asy->asy_lom_console = 0;
757 		asy->asy_rsc_console = 0;
758 		asy->asy_rsc_control = 1;
759 		asy->asy_device_type = ASY_SERIAL;
760 		asy->asy_flags |= ASY_IGNORE_CD;
761 
762 	} else if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
763 	    "keyboard", 0)) {
764 		/*
765 		 * If the device is a keyboard, then create an internal
766 		 * pathname so that the dacf code will link the node into
767 		 * the keyboard console stream.  See dacf.conf.
768 		 */
769 		if (ddi_create_internal_pathname(devi, "keyboard",
770 		    S_IFCHR, instance) == DDI_FAILURE) {
771 			goto error;
772 		}
773 		asy->asy_flags |= ASY_IGNORE_CD;	/* ignore cd */
774 		asy->asy_device_type = ASY_KEYBOARD; 	/* Device type */
775 	} else if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
776 	    "mouse", 0)) {
777 		/*
778 		 * If the device is a mouse, then create an internal
779 		 * pathname so that the dacf code will link the node into
780 		 * the mouse stream.  See dacf.conf.
781 		 */
782 		if (ddi_create_internal_pathname(devi, "mouse", S_IFCHR,
783 		    instance) == DDI_FAILURE) {
784 			goto error;
785 		}
786 		asy->asy_flags |= ASY_IGNORE_CD;	/* ignore cd */
787 		asy->asy_device_type = ASY_MOUSE;
788 	} else {
789 		/*
790 		 * If not used for keyboard/mouse, create minor devices nodes
791 		 * for this device
792 		 */
793 		/* serial-port */
794 		(void) sprintf(name, "%c", (instance+'a'));
795 		if (ddi_create_minor_node(devi, name, S_IFCHR, instance,
796 		    DDI_NT_SERIAL_MB, NULL) == DDI_FAILURE) {
797 			goto error;
798 		}
799 		state = MINORNODE;
800 		/* serial-port:dailout */
801 		(void) sprintf(name, "%c,cu", (instance+'a'));
802 		if (ddi_create_minor_node(devi, name, S_IFCHR, instance|OUTLINE,
803 		    DDI_NT_SERIAL_MB_DO, NULL) == DDI_FAILURE) {
804 			goto error;
805 		}
806 		/* Property for ignoring DCD */
807 		if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
808 		    "ignore-cd", 0)) {
809 			asy->asy_flags |= ASY_IGNORE_CD;  /* ignore cd */
810 		} else {
811 			asy->asy_flags &= ~ASY_IGNORE_CD;
812 			/*
813 			 * if ignore-cd is not available it could be
814 			 * some old legacy platform, try to see
815 			 * whether the old legacy property exists
816 			 */
817 			(void) sprintf(name,
818 			    "port-%c-ignore-cd", (instance+ 'a'));
819 			if (ddi_getprop(DDI_DEV_T_ANY, devi,
820 			    DDI_PROP_DONTPASS, name, 0))
821 				asy->asy_flags |= ASY_IGNORE_CD;
822 		}
823 		asy->asy_device_type = ASY_SERIAL;
824 	}
825 
826 	/*
827 	 * Fill in the polled I/O structure
828 	 */
829 	asy->polledio.cons_polledio_version = CONSPOLLEDIO_V0;
830 	asy->polledio.cons_polledio_argument = (cons_polledio_arg_t)asy;
831 	asy->polledio.cons_polledio_putchar =  asyputchar;
832 	asy->polledio.cons_polledio_getchar = asygetchar;
833 	asy->polledio.cons_polledio_ischar = asyischar;
834 	asy->polledio.cons_polledio_enter = asy_polled_enter;
835 	asy->polledio.cons_polledio_exit = asy_polled_exit;
836 
837 	/* Initialize saved ICR and polled_enter */
838 	asy->polled_icr = 0;
839 	asy->polled_enter = B_FALSE;
840 
841 	ddi_report_dev(devi);
842 	return (DDI_SUCCESS);
843 
844 error:
845 	if (state == MINORNODE) {
846 		(void) sprintf(name, "%c", (instance+'a'));
847 		ddi_remove_minor_node(devi, name);
848 	}
849 	if (state >= KSTAT)
850 		kstat_delete(asy->sukstat);
851 	if (state >= ASYINIT) {
852 		cv_destroy(&async->async_flags_cv);
853 		ddi_soft_state_free(su_asyncline, instance);
854 	}
855 	if (state >= SOFTINTR)
856 		ddi_remove_softintr(asy->asy_softintr_id);
857 	if (state >= ADDINTR)
858 		ddi_remove_intr(devi, 0, asy->asy_iblock);
859 	if (state >= MUTEXES) {
860 		mutex_destroy(asy->asy_excl_hi);
861 		mutex_destroy(asy->asy_excl);
862 		mutex_destroy(asy->asy_soft_lock);
863 		kmem_free(asy->asy_excl_hi, sizeof (kmutex_t));
864 		kmem_free(asy->asy_excl, sizeof (kmutex_t));
865 		kmem_free(asy->asy_soft_lock, sizeof (kmutex_t));
866 	}
867 	if (state >= REGSMAP)
868 		ddi_regs_map_free(&asy->asy_handle);
869 	if (state >= SOFTSTATE)
870 		ddi_soft_state_free(su_asycom, instance);
871 	/* no action for EMPTY state */
872 	return (DDI_FAILURE);
873 }
874 
875 static int
876 asyinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
877 	void **result)
878 {
879 	_NOTE(ARGUNUSED(dip))
880 	register dev_t dev = (dev_t)arg;
881 	register int instance, error;
882 	struct asycom *asy;
883 
884 	if ((instance = UNIT(dev)) > max_asy_instance)
885 		return (DDI_FAILURE);
886 
887 	switch (infocmd) {
888 		case DDI_INFO_DEVT2DEVINFO:
889 			asy = (struct asycom *)ddi_get_soft_state(su_asycom,
890 			    instance);
891 			if (asy->asy_dip == NULL)
892 				error = DDI_FAILURE;
893 			else {
894 				*result = (void *) asy->asy_dip;
895 				error = DDI_SUCCESS;
896 			}
897 			break;
898 		case DDI_INFO_DEVT2INSTANCE:
899 			*result = (void *)(uintptr_t)instance;
900 			error = DDI_SUCCESS;
901 			break;
902 		default:
903 			error = DDI_FAILURE;
904 	}
905 	return (error);
906 }
907 
908 static int
909 asyopen(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr)
910 {
911 	_NOTE(ARGUNUSED(sflag))
912 	struct asycom	*asy;
913 	struct asyncline *async;
914 	int		mcr;
915 	int		unit;
916 	int 		len;
917 	struct termios 	*termiosp;
918 
919 #ifdef DEBUG
920 	if (asydebug & ASY_DEBUG_CLOSE)
921 		printf("open\n");
922 #endif
923 	unit = UNIT(*dev);
924 	if (unit > max_asy_instance)
925 		return (ENXIO);		/* unit not configured */
926 
927 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, unit);
928 	if (async == NULL)
929 		return (ENXIO);
930 
931 	asy = async->async_common;
932 	if (asy == NULL)
933 		return (ENXIO);		/* device not found by autoconfig */
934 
935 	mutex_enter(asy->asy_excl);
936 	asy->asy_priv = (caddr_t)async;
937 
938 again:
939 	mutex_enter(asy->asy_excl_hi);
940 	/*
941 	 * Block waiting for carrier to come up, unless this is a no-delay open.
942 	 */
943 	if (!(async->async_flags & ASYNC_ISOPEN)) {
944 		/*
945 		 * If this port is for a RSC console or control
946 		 * use the following termio info
947 		 */
948 		if (asy->asy_rsc_console || asy->asy_rsc_control) {
949 			async->async_ttycommon.t_cflag = CIBAUDEXT | CBAUDEXT |
950 			    (B115200 & CBAUD);
951 			async->async_ttycommon.t_cflag |= ((B115200 << IBSHIFT)
952 			    & CIBAUD);
953 			async->async_ttycommon.t_cflag |= CS8 | CREAD | CLOCAL;
954 		} else if (asy->asy_lom_console) {
955 			async->async_ttycommon.t_cflag = B9600 & CBAUD;
956 			async->async_ttycommon.t_cflag |= ((B9600 << IBSHIFT)
957 			    & CIBAUD);
958 			async->async_ttycommon.t_cflag |= CS8 | CREAD | CLOCAL;
959 		} else {
960 
961 			/*
962 			 * Set the default termios settings (cflag).
963 			 * Others are set in ldterm.  Release the spin
964 			 * mutex as we can block here, reaquire before
965 			 * calling asy_program.
966 			 */
967 			mutex_exit(asy->asy_excl_hi);
968 			if (ddi_getlongprop(DDI_DEV_T_ANY, ddi_root_node(),
969 			    0, "ttymodes", (caddr_t)&termiosp, &len)
970 			    == DDI_PROP_SUCCESS &&
971 			    len == sizeof (struct termios)) {
972 				async->async_ttycommon.t_cflag =
973 				    termiosp->c_cflag;
974 				kmem_free(termiosp, len);
975 			} else {
976 				cmn_err(CE_WARN,
977 					"su: couldn't get ttymodes property!");
978 			}
979 			mutex_enter(asy->asy_excl_hi);
980 		}
981 		async->async_ttycommon.t_iflag = 0;
982 		async->async_ttycommon.t_iocpending = NULL;
983 		async->async_ttycommon.t_size.ws_row = 0;
984 		async->async_ttycommon.t_size.ws_col = 0;
985 		async->async_ttycommon.t_size.ws_xpixel = 0;
986 		async->async_ttycommon.t_size.ws_ypixel = 0;
987 		async->async_dev = *dev;
988 		async->async_wbufcid = 0;
989 
990 		async->async_startc = CSTART;
991 		async->async_stopc = CSTOP;
992 		(void) asy_program(asy, ASY_INIT);
993 	} else if ((async->async_ttycommon.t_flags & TS_XCLUDE) &&
994 	    secpolicy_excl_open(cr) != 0) {
995 		mutex_exit(asy->asy_excl_hi);
996 		mutex_exit(asy->asy_excl);
997 		return (EBUSY);
998 	} else if ((*dev & OUTLINE) && !(async->async_flags & ASYNC_OUT)) {
999 		mutex_exit(asy->asy_excl_hi);
1000 		mutex_exit(asy->asy_excl);
1001 		return (EBUSY);
1002 	}
1003 
1004 	if (*dev & OUTLINE)
1005 		async->async_flags |= ASYNC_OUT;
1006 
1007 	/* Raise DTR on every open */
1008 	mcr = INB(MCR);
1009 	OUTB(MCR, mcr|DTR);
1010 
1011 	/*
1012 	 * Check carrier.
1013 	 */
1014 	if (asy->asy_flags & ASY_IGNORE_CD)
1015 		async->async_ttycommon.t_flags |= TS_SOFTCAR;
1016 	if ((async->async_ttycommon.t_flags & TS_SOFTCAR) ||
1017 	    (INB(MSR) & DCD))
1018 		async->async_flags |= ASYNC_CARR_ON;
1019 	else
1020 		async->async_flags &= ~ASYNC_CARR_ON;
1021 	mutex_exit(asy->asy_excl_hi);
1022 
1023 	/*
1024 	 * If FNDELAY and FNONBLOCK are clear, block until carrier up.
1025 	 * Quit on interrupt.
1026 	 */
1027 	if (!(flag & (FNDELAY|FNONBLOCK)) &&
1028 	    !(async->async_ttycommon.t_cflag & CLOCAL)) {
1029 		if (!(async->async_flags & (ASYNC_CARR_ON|ASYNC_OUT)) ||
1030 		    ((async->async_flags & ASYNC_OUT) &&
1031 		    !(*dev & OUTLINE))) {
1032 				async->async_flags |= ASYNC_WOPEN;
1033 				if (cv_wait_sig(&async->async_flags_cv,
1034 				    asy->asy_excl) == 0) {
1035 					async->async_flags &= ~ASYNC_WOPEN;
1036 					mutex_exit(asy->asy_excl);
1037 					return (EINTR);
1038 				}
1039 				async->async_flags &= ~ASYNC_WOPEN;
1040 				goto again;
1041 		}
1042 	} else if ((async->async_flags & ASYNC_OUT) && !(*dev & OUTLINE)) {
1043 		mutex_exit(asy->asy_excl);
1044 		return (EBUSY);
1045 	}
1046 
1047 	if (asy->suspended) {
1048 		mutex_exit(asy->asy_excl);
1049 		(void) ddi_dev_is_needed(asy->asy_dip, 0, 1);
1050 		mutex_enter(asy->asy_excl);
1051 	}
1052 
1053 	async->async_ttycommon.t_readq = rq;
1054 	async->async_ttycommon.t_writeq = WR(rq);
1055 	rq->q_ptr = WR(rq)->q_ptr = (caddr_t)async;
1056 	mutex_exit(asy->asy_excl);
1057 	qprocson(rq);
1058 	async->async_flags |= ASYNC_ISOPEN;
1059 	async->async_polltid = 0;
1060 	return (0);
1061 }
1062 
1063 static void
1064 async_progress_check(void *arg)
1065 {
1066 	struct asyncline *async = arg;
1067 	struct asycom	 *asy = async->async_common;
1068 	mblk_t *bp;
1069 
1070 	/*
1071 	 * We define "progress" as either waiting on a timed break or delay, or
1072 	 * having had at least one transmitter interrupt.  If none of these are
1073 	 * true, then just terminate the output and wake up that close thread.
1074 	 */
1075 	mutex_enter(asy->asy_excl);
1076 	mutex_enter(asy->asy_excl_hi);
1077 	if (!(async->async_flags & (ASYNC_BREAK|ASYNC_DELAY|ASYNC_PROGRESS))) {
1078 		async->async_ocnt = 0;
1079 		async->async_flags &= ~ASYNC_BUSY;
1080 		async->async_timer = 0;
1081 		bp = async->async_xmitblk;
1082 		async->async_xmitblk = NULL;
1083 		mutex_exit(asy->asy_excl_hi);
1084 		if (bp != NULL)
1085 			freeb(bp);
1086 		/*
1087 		 * Since this timer is running, we know that we're in exit(2).
1088 		 * That means that the user can't possibly be waiting on any
1089 		 * valid ioctl(2) completion anymore, and we should just flush
1090 		 * everything.
1091 		 */
1092 		flushq(async->async_ttycommon.t_writeq, FLUSHALL);
1093 		cv_broadcast(&async->async_flags_cv);
1094 	} else {
1095 		async->async_flags &= ~ASYNC_PROGRESS;
1096 		async->async_timer = timeout(async_progress_check, async,
1097 		    drv_usectohz(su_drain_check));
1098 		mutex_exit(asy->asy_excl_hi);
1099 	}
1100 	mutex_exit(asy->asy_excl);
1101 }
1102 
1103 /*
1104  * Close routine.
1105  */
1106 static int
1107 asyclose(queue_t *q, int flag)
1108 {
1109 	struct asyncline *async;
1110 	struct asycom	 *asy;
1111 	int icr, lcr;
1112 	int		nohupcl;
1113 
1114 
1115 #ifdef DEBUG
1116 	if (asydebug & ASY_DEBUG_CLOSE)
1117 		printf("close\n");
1118 #endif
1119 	async = q->q_ptr;
1120 	ASSERT(async != NULL);
1121 	asy = async->async_common;
1122 
1123 	/* get the nohupcl OBP property of this device */
1124 	nohupcl = ddi_getprop(DDI_DEV_T_ANY, asy->asy_dip, DDI_PROP_DONTPASS,
1125 	    "nohupcl", 0);
1126 
1127 	mutex_enter(asy->asy_excl);
1128 	async->async_flags |= ASYNC_CLOSING;
1129 
1130 	/*
1131 	 * Turn off PPS handling early to avoid events occuring during
1132 	 * close.  Also reset the DCD edge monitoring bit.
1133 	 */
1134 	mutex_enter(asy->asy_excl_hi);
1135 	asy->asy_flags &= ~(ASY_PPS | ASY_PPS_EDGE);
1136 	mutex_exit(asy->asy_excl_hi);
1137 
1138 	/*
1139 	 * There are two flavors of break -- timed (M_BREAK or TCSBRK) and
1140 	 * untimed (TIOCSBRK).  For the timed case, these are enqueued on our
1141 	 * write queue and there's a timer running, so we don't have to worry
1142 	 * about them.  For the untimed case, though, the user obviously made a
1143 	 * mistake, because these are handled immediately.  We'll terminate the
1144 	 * break now and honor his implicit request by discarding the rest of
1145 	 * the data.
1146 	 */
1147 	if (!(async->async_flags & ASYNC_BREAK)) {
1148 		mutex_enter(asy->asy_excl_hi);
1149 		lcr = INB(LCR);
1150 		if (lcr & SETBREAK) {
1151 			OUTB(LCR, (lcr & ~SETBREAK));
1152 		}
1153 		mutex_exit(asy->asy_excl_hi);
1154 		if (lcr & SETBREAK)
1155 			goto nodrain;
1156 	}
1157 
1158 	/*
1159 	 * If the user told us not to delay the close ("non-blocking"), then
1160 	 * don't bother trying to drain.
1161 	 *
1162 	 * If the user did M_STOP (ASYNC_STOPPED), there's no hope of ever
1163 	 * getting an M_START (since these messages aren't enqueued), and the
1164 	 * only other way to clear the stop condition is by loss of DCD, which
1165 	 * would discard the queue data.  Thus, we drop the output data if
1166 	 * ASYNC_STOPPED is set.
1167 	 */
1168 	if ((flag & (FNDELAY|FNONBLOCK)) ||
1169 	    (async->async_flags & ASYNC_STOPPED)) {
1170 		goto nodrain;
1171 	}
1172 
1173 	/*
1174 	 * If there's any pending output, then we have to try to drain it.
1175 	 * There are two main cases to be handled:
1176 	 *	- called by close(2): need to drain until done or until
1177 	 *	  a signal is received.  No timeout.
1178 	 *	- called by exit(2): need to drain while making progress
1179 	 *	  or until a timeout occurs.  No signals.
1180 	 *
1181 	 * If we can't rely on receiving a signal to get us out of a hung
1182 	 * session, then we have to use a timer.  In this case, we set a timer
1183 	 * to check for progress in sending the output data -- all that we ask
1184 	 * (at each interval) is that there's been some progress made.  Since
1185 	 * the interrupt routine grabs buffers from the write queue, we can't
1186 	 * trust async_ocnt.  Instead, we use a flag.
1187 	 *
1188 	 * Note that loss of carrier will cause the output queue to be flushed,
1189 	 * and we'll wake up again and finish normally.
1190 	 */
1191 	if (!ddi_can_receive_sig() && su_drain_check != 0) {
1192 		async->async_flags &= ~ASYNC_PROGRESS;
1193 		async->async_timer = timeout(async_progress_check, async,
1194 		    drv_usectohz(su_drain_check));
1195 	}
1196 
1197 	while (async->async_ocnt > 0 ||
1198 	    async->async_ttycommon.t_writeq->q_first != NULL ||
1199 	    (async->async_flags & (ASYNC_BUSY|ASYNC_BREAK|ASYNC_DELAY))) {
1200 		if (cv_wait_sig(&async->async_flags_cv, asy->asy_excl) == 0)
1201 			break;
1202 	}
1203 	if (async->async_timer != 0) {
1204 		(void) untimeout(async->async_timer);
1205 		async->async_timer = 0;
1206 	}
1207 
1208 nodrain:
1209 	mutex_enter(asy->asy_excl_hi);
1210 
1211 	/* turn off the loopback mode */
1212 	if ((async->async_dev != rconsdev) &&
1213 	    (async->async_dev != kbddev) &&
1214 	    (async->async_dev != stdindev)) {
1215 		OUTB(MCR, INB(MCR) & ~ ASY_LOOP);
1216 	}
1217 
1218 	async->async_ocnt = 0;
1219 	if (async->async_xmitblk != NULL)
1220 		freeb(async->async_xmitblk);
1221 	async->async_xmitblk = NULL;
1222 
1223 	/*
1224 	 * If the "nohupcl" OBP property is set for this device, do
1225 	 * not turn off DTR and RTS no matter what.  Otherwise, if the
1226 	 * line has HUPCL set or is incompletely opened, turn off DTR
1227 	 * and RTS to fix the modem line.
1228 	 */
1229 	if (!nohupcl && ((async->async_ttycommon.t_cflag & HUPCL) ||
1230 	    (async->async_flags & ASYNC_WOPEN))) {
1231 		/* turn off DTR, RTS but NOT interrupt to 386 */
1232 		OUTB(MCR, OUT2);
1233 		mutex_exit(asy->asy_excl_hi);
1234 		/*
1235 		 * Don't let an interrupt in the middle of close
1236 		 * bounce us back to the top; just continue closing
1237 		 * as if nothing had happened.
1238 		 */
1239 		if (cv_wait_sig(&lbolt_cv, asy->asy_excl) == 0)
1240 			goto out;
1241 		mutex_enter(asy->asy_excl_hi);
1242 	}
1243 
1244 	/*
1245 	 * If nobody's using it now, turn off receiver interrupts.
1246 	 */
1247 	if ((async->async_flags & (ASYNC_WOPEN|ASYNC_ISOPEN)) == 0) {
1248 		icr = INB(ICR);
1249 		OUTB(ICR, (icr & ~RIEN));
1250 	}
1251 	mutex_exit(asy->asy_excl_hi);
1252 out:
1253 	/*
1254 	 * Clear out device state.
1255 	 */
1256 	async->async_flags = 0;
1257 	ttycommon_close(&async->async_ttycommon);
1258 	cv_broadcast(&async->async_flags_cv);
1259 
1260 	/*
1261 	 * Clear ASY_DOINGSOFT and ASY_NEEDSOFT in case we were in
1262 	 * async_softint or an interrupt was pending when the process
1263 	 * using the port exited.
1264 	 */
1265 	asy->asy_flags &= ~ASY_DOINGSOFT & ~ASY_NEEDSOFT;
1266 
1267 	/*
1268 	 * Cancel outstanding "bufcall" request.
1269 	 */
1270 	if (async->async_wbufcid) {
1271 		unbufcall(async->async_wbufcid);
1272 		async->async_wbufcid = 0;
1273 	}
1274 
1275 	/*
1276 	 * If inperim is true, it means the port is closing while there's
1277 	 * a pending software interrupt.  async_flags has been zeroed out,
1278 	 * so this instance of leaveq() needs to be called before we call
1279 	 * qprocsoff() to disable services on the q.  If inperim is false,
1280 	 * leaveq() has already been called or we're not in a perimeter.
1281 	 */
1282 	if (asy->inperim == B_TRUE) {
1283 		asy->inperim = B_FALSE;
1284 		mutex_exit(asy->asy_excl);
1285 		leaveq(q);
1286 	} else {
1287 		mutex_exit(asy->asy_excl);
1288 	}
1289 
1290 	/* Note that qprocsoff can't be done until after interrupts are off */
1291 	qprocsoff(q);
1292 	q->q_ptr = WR(q)->q_ptr = NULL;
1293 	async->async_ttycommon.t_readq = NULL;
1294 	async->async_ttycommon.t_writeq = NULL;
1295 
1296 	return (0);
1297 }
1298 
1299 /*
1300  * Checks to see if the serial port is still transmitting
1301  * characters.  It returns true when there are characters
1302  * queued to transmit,  when the holding register contains
1303  * a byte, or when the shifting register still contains
1304  * data to send.
1305  *
1306  */
1307 static boolean_t
1308 asy_isbusy(struct asycom *asy)
1309 {
1310 	struct asyncline *async;
1311 
1312 #ifdef DEBUG
1313 	if (asydebug & ASY_DEBUG_EOT)
1314 		printf("isbusy\n");
1315 #endif
1316 	async = (struct asyncline *)asy->asy_priv;
1317 	ASSERT(mutex_owned(asy->asy_excl));
1318 	ASSERT(mutex_owned(asy->asy_excl_hi));
1319 	return ((async->async_ocnt > 0) ||
1320 	    ((INB(LSR) & XSRE) == 0));
1321 }
1322 
1323 /*
1324  * Program the ASY port. Most of the async operation is based on the values
1325  * of 'c_iflag' and 'c_cflag'.
1326  */
1327 static int
1328 asy_program(struct asycom *asy, int mode)
1329 {
1330 	struct asyncline *async;
1331 	int baudrate, c_flag;
1332 	int icr, lcr;
1333 	int ocflags;
1334 	int error = 0;
1335 
1336 	ASSERT(mutex_owned(asy->asy_excl));
1337 	ASSERT(mutex_owned(asy->asy_excl_hi));
1338 
1339 #ifdef DEBUG
1340 	if (asydebug & ASY_DEBUG_PROCS)
1341 		printf("program\n");
1342 #endif
1343 	async = (struct asyncline *)asy->asy_priv;
1344 
1345 	baudrate = async->async_ttycommon.t_cflag & CBAUD;
1346 	if (async->async_ttycommon.t_cflag & CBAUDEXT)
1347 		baudrate += 16;
1348 
1349 	/* Limit baudrate so it can't index out of baudtable */
1350 	if (baudrate >= N_SU_SPEEDS) baudrate = B9600;
1351 
1352 	/*
1353 	 * If baud rate requested is greater than the speed cap
1354 	 * or is an unsupported baud rate then reset t_cflag baud
1355 	 * to the last valid baud rate.  If this is the initial
1356 	 * pass through asy_program then set it to 9600.
1357 	 */
1358 	if (((baudrate > 0) && (asyspdtab[baudrate] == 0)) ||
1359 	    (baudtable[baudrate] > asy->asy_speed_cap)) {
1360 		async->async_ttycommon.t_cflag &= ~CBAUD & ~CBAUDEXT &
1361 		    ~CIBAUD & ~CIBAUDEXT;
1362 		if (mode == ASY_INIT) {
1363 			async->async_ttycommon.t_cflag |= B9600;
1364 			async->async_ttycommon.t_cflag |= B9600 << IBSHIFT;
1365 			baudrate = B9600;
1366 		} else {
1367 			async->async_ttycommon.t_cflag |=
1368 			    (asy->asy_ocflags & (CBAUD | CBAUDEXT |
1369 			    CIBAUD | CIBAUDEXT));
1370 			error = EINVAL;
1371 			goto end;
1372 		}
1373 	}
1374 
1375 	/*
1376 	 * If CIBAUD and CIBAUDEXT are zero then we should set them to
1377 	 * the equivelant output baud bits.  Else, if CIBAUD and CIBAUDEXT
1378 	 * don't match CBAUD and CBAUDEXT respectively then we should
1379 	 * notify the requestor that we do not support split speeds.
1380 	 */
1381 	if ((async->async_ttycommon.t_cflag  & (CIBAUD|CIBAUDEXT)) == 0) {
1382 		async->async_ttycommon.t_cflag |=
1383 		    (async->async_ttycommon.t_cflag & CBAUD) << IBSHIFT;
1384 		if (async->async_ttycommon.t_cflag & CBAUDEXT)
1385 			async->async_ttycommon.t_cflag |= CIBAUDEXT;
1386 	} else {
1387 		if ((((async->async_ttycommon.t_cflag & CBAUD) << IBSHIFT) !=
1388 		    (async->async_ttycommon.t_cflag & CIBAUD)) ||
1389 		    !(((async->async_ttycommon.t_cflag & (CBAUDEXT |
1390 		    CIBAUDEXT)) == (CBAUDEXT | CIBAUDEXT)) ||
1391 		    ((async->async_ttycommon.t_cflag & (CBAUDEXT |
1392 		    CIBAUDEXT)) == 0))) {
1393 			async->async_ttycommon.t_cflag &= ~CBAUD & ~CBAUDEXT &
1394 			    ~CIBAUD & ~CIBAUDEXT;
1395 			async->async_ttycommon.t_cflag |=
1396 			    (asy->asy_ocflags & (CBAUD | CBAUDEXT |
1397 			    CIBAUD | CIBAUDEXT));
1398 			error = EINVAL;
1399 			goto end;
1400 		}
1401 	}
1402 
1403 	c_flag = async->async_ttycommon.t_cflag &
1404 	    (CLOCAL | CREAD | CSTOPB | CSIZE | PARENB | PARODD | CBAUD |
1405 	    CBAUDEXT | CIBAUD | CIBAUDEXT);
1406 
1407 	/* disable interrupts, see EXAR bug */
1408 	if (asy->asy_hwtype == ASY16C554D)
1409 		OUTB(SPR, 0);
1410 	OUTB(ICR, 0);
1411 
1412 	ocflags = asy->asy_ocflags;
1413 
1414 	/* flush/reset the status registers */
1415 	if (mode == ASY_INIT) {
1416 		(void) INB(DAT);
1417 		(void) INB(ISR);
1418 		(void) INB(LSR);
1419 		(void) INB(MSR);
1420 	}
1421 
1422 	if (ocflags != (c_flag & ~CLOCAL) || mode == ASY_INIT) {
1423 		/* Set line control */
1424 		lcr = INB(LCR);
1425 		lcr &= ~(WLS0|WLS1|STB|PEN|EPS);
1426 
1427 		if (c_flag & CSTOPB)
1428 			lcr |= STB;	/* 2 stop bits */
1429 
1430 		if (c_flag & PARENB)
1431 			lcr |= PEN;
1432 
1433 		if ((c_flag & PARODD) == 0)
1434 			lcr |= EPS;
1435 
1436 		switch (c_flag & CSIZE) {
1437 		case CS5:
1438 			lcr |= BITS5;
1439 			break;
1440 		case CS6:
1441 			lcr |= BITS6;
1442 			break;
1443 		case CS7:
1444 			lcr |= BITS7;
1445 			break;
1446 		case CS8:
1447 			lcr |= BITS8;
1448 			break;
1449 		}
1450 
1451 		/* set the baud rate when the rate is NOT B0 */
1452 		if (baudrate != 0) {
1453 			OUTB(LCR, DLAB);
1454 			OUTB(DAT, (asyspdtab[baudrate] *
1455 			    asy->asy_baud_divisor_factor) & 0xff);
1456 			OUTB(ICR, ((asyspdtab[baudrate] *
1457 			    asy->asy_baud_divisor_factor) >> 8) & 0xff);
1458 		}
1459 		/* set the line control modes */
1460 		OUTB(LCR, lcr);
1461 
1462 		/*
1463 		 * if transitioning from CREAD off to CREAD on,
1464 		 * flush the FIFO buffer if we have one.
1465 		 */
1466 		if ((ocflags & CREAD) == 0 && (c_flag & CREAD)) {
1467 			if (asy->asy_use_fifo == FIFO_ON) {
1468 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFORXFLSH |
1469 				    (asy->asy_trig_level & 0xff));
1470 			}
1471 		}
1472 
1473 		/* remember the new cflags */
1474 		asy->asy_ocflags = c_flag & ~CLOCAL;
1475 	}
1476 
1477 	/* whether or not CLOCAL is set, modify the modem control lines */
1478 	if (baudrate == 0)
1479 		/* B0 has been issued, lower DTR */
1480 		OUTB(MCR, RTS|OUT2);
1481 	else
1482 		/* raise DTR */
1483 		OUTB(MCR, DTR|RTS|OUT2);
1484 
1485 	/*
1486 	 * Call the modem status interrupt handler to check for the carrier
1487 	 * in case CLOCAL was turned off after the carrier came on.
1488 	 * (Note: Modem status interrupt is not enabled if CLOCAL is ON.)
1489 	 */
1490 	async_msint(asy);
1491 
1492 	/* Set interrupt control */
1493 	if ((c_flag & CLOCAL) && !(async->async_ttycommon.t_cflag & CRTSCTS))
1494 		/*
1495 		 * direct-wired line ignores DCD, so we don't enable modem
1496 		 * status interrupts.
1497 		 */
1498 		icr = (TIEN | SIEN);
1499 	else
1500 		icr = (TIEN | SIEN | MIEN);
1501 
1502 	if (c_flag & CREAD)
1503 		icr |= RIEN;
1504 
1505 	OUTB(ICR, icr);
1506 end:
1507 	return (error);
1508 }
1509 
1510 /*
1511  * Polled mode support -- all functions called with interrupts
1512  * disabled.
1513  */
1514 
1515 static void
1516 asyputchar(cons_polledio_arg_t arg, uchar_t c)
1517 {
1518 	struct asycom *asy = (struct asycom *)arg;
1519 
1520 	/*
1521 	 * If we see a line feed make sure to also
1522 	 * put out a carriage return.
1523 	 */
1524 	if (c == '\n')
1525 		asyputchar(arg, '\r');
1526 
1527 	while ((INB(LSR) & XHRE) == 0) {
1528 		/* wait for the transmission to complete */
1529 		drv_usecwait(10);
1530 	}
1531 
1532 	/* ouput the character */
1533 	OUTB(DAT, c);
1534 }
1535 
1536 /*
1537  * Determines if there is a character avaialable for
1538  * reading.
1539  */
1540 static boolean_t
1541 asyischar(cons_polledio_arg_t arg)
1542 {
1543 	struct asycom *asy = (struct asycom *)arg;
1544 	return ((INB(LSR) & RCA) != 0);
1545 }
1546 
1547 static int
1548 asygetchar(cons_polledio_arg_t arg)
1549 {
1550 	struct asycom *asy = (struct asycom *)arg;
1551 
1552 	/*
1553 	 * Spin waiting for a character to be
1554 	 * available to read.
1555 	 */
1556 	while (!asyischar(arg))
1557 		drv_usecwait(10);
1558 
1559 	return (INB(DAT));
1560 }
1561 
1562 /*
1563  * Called when machine is transitioning to polled mode
1564  */
1565 static void
1566 asy_polled_enter(cons_polledio_arg_t arg)
1567 {
1568 	struct asycom *asy = (struct asycom *)arg;
1569 
1570 	mutex_enter(asy->asy_excl);
1571 	mutex_enter(asy->asy_excl_hi);
1572 
1573 	/*
1574 	 * If this is the first time that asy_polled_enter()
1575 	 * has been called, during this transition request,
1576 	 * save the ICR. Clear the software interrupt
1577 	 * flags since we won't be able to handle these when
1578 	 * we are in polled mode.
1579 	 */
1580 	if (!asy->polled_enter) {
1581 		asy->polled_enter = B_TRUE;
1582 		asy->polled_icr = INB(ICR);
1583 
1584 		/* Disable HW interrupts */
1585 		if (asy->asy_hwtype == ASY16C554D)
1586 			OUTB(SPR, 0);
1587 		OUTB(ICR, 0);
1588 
1589 		asy->asy_flags &= ~ASY_DOINGSOFT & ~ASY_NEEDSOFT;
1590 	}
1591 	mutex_exit(asy->asy_excl_hi);
1592 	mutex_exit(asy->asy_excl);
1593 }
1594 
1595 /*
1596  * Called when machine is transitioning from polled mode.
1597  */
1598 static void
1599 asy_polled_exit(cons_polledio_arg_t arg)
1600 {
1601 	struct asycom *asy = (struct asycom *)arg;
1602 
1603 	mutex_enter(asy->asy_excl);
1604 	mutex_enter(asy->asy_excl_hi);
1605 
1606 	/* Restore the ICR */
1607 	OUTB(ICR, asy->polled_icr);
1608 
1609 	/*
1610 	 * We have finished this polled IO transition.
1611 	 * Set polled_enter to B_FALSE to note this.
1612 	 */
1613 	asy->polled_enter = B_FALSE;
1614 	mutex_exit(asy->asy_excl_hi);
1615 	mutex_exit(asy->asy_excl);
1616 }
1617 
1618 /*
1619  * asyintr() is the High Level Interrupt Handler.
1620  *
1621  * There are four different interrupt types indexed by ISR register values:
1622  *		0: modem
1623  *		1: Tx holding register is empty, ready for next char
1624  *		2: Rx register now holds a char to be picked up
1625  *		3: error or break on line
1626  * This routine checks the Bit 0 (interrupt-not-pending) to determine if
1627  * the interrupt is from this port.
1628  */
1629 uint_t
1630 asyintr(caddr_t argasy)
1631 {
1632 	struct asycom		*asy = (struct asycom *)argasy;
1633 	struct asyncline	*async;
1634 	int			ret_status = DDI_INTR_UNCLAIMED;
1635 	uchar_t			interrupt_id, lsr;
1636 
1637 	interrupt_id = INB(ISR) & 0x0F;
1638 	async = (struct asyncline *)asy->asy_priv;
1639 	if ((async == NULL) ||
1640 	    !(async->async_flags & (ASYNC_ISOPEN|ASYNC_WOPEN))) {
1641 		if (interrupt_id & NOINTERRUPT)  {
1642 			return (DDI_INTR_UNCLAIMED);
1643 		} else {
1644 			lsr = INB(LSR);
1645 			if ((lsr & BRKDET) &&
1646 			    ((abort_enable == KIOCABORTENABLE) &&
1647 			    (async->async_dev == rconsdev)))
1648 				abort_sequence_enter((char *)NULL);
1649 			else {
1650 				/* reset line status */
1651 				(void) INB(LSR);
1652 				/* discard any data */
1653 				(void) INB(DAT);
1654 				/* reset modem status */
1655 				(void) INB(MSR);
1656 				return (DDI_INTR_CLAIMED);
1657 			}
1658 		}
1659 	}
1660 	/*
1661 	 * Spurious interrupts happen in this driver
1662 	 * because of the transmission on serial port not handled
1663 	 * properly.
1664 	 *
1665 	 * The reasons for Spurious interrupts are:
1666 	 *    1. There is a path in async_nstart which transmits
1667 	 *	 characters without going through interrupt services routine
1668 	 *	 which causes spurious interrupts to happen.
1669 	 *    2. In the async_txint more than one character is sent
1670 	 *	 in one interrupt service.
1671 	 *    3. In async_rxint more than one characters are received in
1672 	 *	 in one interrupt service.
1673 	 *
1674 	 * Hence we have flags to indicate that such scenerio has happened.
1675 	 * and claim only such interrupts and others we donot claim it
1676 	 * as it could be a indicator of some hardware problem.
1677 	 *
1678 	 */
1679 	if (interrupt_id & NOINTERRUPT) {
1680 		mutex_enter(asy->asy_excl_hi);
1681 		if ((asy->asy_xmit_count > 1) ||
1682 		    (asy->asy_out_of_band_xmit > 0) ||
1683 		    (asy->asy_rx_count > 1)) {
1684 			asy->asy_xmit_count = 0;
1685 			asy->asy_out_of_band_xmit = 0;
1686 			asy->asy_rx_count = 0;
1687 			mutex_exit(asy->asy_excl_hi);
1688 			return (DDI_INTR_CLAIMED);
1689 		} else {
1690 			mutex_exit(asy->asy_excl_hi);
1691 			return (DDI_INTR_UNCLAIMED);
1692 		}
1693 	}
1694 	ret_status = DDI_INTR_CLAIMED;
1695 	mutex_enter(asy->asy_excl_hi);
1696 	if (asy->asy_hwtype == ASY82510)
1697 		OUTB(ISR, 0x00); /* set bank 0 */
1698 
1699 #ifdef DEBUG
1700 	if (asydebug & ASY_DEBUG_INTR)
1701 		prom_printf("l");
1702 #endif
1703 	lsr = INB(LSR);
1704 	switch (interrupt_id) {
1705 	case RxRDY:
1706 	case RSTATUS:
1707 	case FFTMOUT:
1708 		/* receiver interrupt or receiver errors */
1709 		async_rxint(asy, lsr);
1710 		break;
1711 	case TxRDY:
1712 		/* transmit interrupt */
1713 		async_txint(asy, lsr);
1714 		break;
1715 	case MSTATUS:
1716 		/* modem status interrupt */
1717 		async_msint(asy);
1718 		break;
1719 	}
1720 	mutex_exit(asy->asy_excl_hi);
1721 	return (ret_status);
1722 }
1723 
1724 /*
1725  * Transmitter interrupt service routine.
1726  * If there is more data to transmit in the current pseudo-DMA block,
1727  * send the next character if output is not stopped or draining.
1728  * Otherwise, queue up a soft interrupt.
1729  *
1730  * XXX -  Needs review for HW FIFOs.
1731  */
1732 static void
1733 async_txint(struct asycom *asy, uchar_t lsr)
1734 {
1735 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1736 	int		fifo_len;
1737 	int		xmit_progress;
1738 
1739 	asycheckflowcontrol_hw(asy);
1740 
1741 	/*
1742 	 * If ASYNC_BREAK has been set, return to asyintr()'s context to
1743 	 * claim the interrupt without performing any action.
1744 	 */
1745 	if (async->async_flags & ASYNC_BREAK)
1746 		return;
1747 
1748 	fifo_len = asy->asy_fifo_buf; /* with FIFO buffers */
1749 
1750 	/*
1751 	 * Check for flow control and do the needed action.
1752 	 */
1753 	if (asycheckflowcontrol_sw(asy)) {
1754 		return;
1755 	}
1756 
1757 	if (async->async_ocnt > 0 &&
1758 	    !(async->async_flags & (ASYNC_HW_OUT_FLW|ASYNC_STOPPED))) {
1759 		xmit_progress = 0;
1760 		while (fifo_len > 0 && async->async_ocnt > 0) {
1761 			if (lsr & XHRE) {
1762 				OUTB(DAT, *async->async_optr++);
1763 				fifo_len--;
1764 				async->async_ocnt--;
1765 				xmit_progress++;
1766 			}
1767 			/*
1768 			 * Reading the lsr, (moved reading at the end of
1769 			 * while loop) as already we have read once at
1770 			 * the beginning of interrupt service
1771 			 */
1772 			lsr = INB(LSR);
1773 		}
1774 		asy->asy_xmit_count = xmit_progress;
1775 		if (xmit_progress > 0)
1776 			async->async_flags |= ASYNC_PROGRESS;
1777 	}
1778 
1779 	if (fifo_len == 0) {
1780 		return;
1781 	}
1782 
1783 
1784 	ASYSETSOFT(asy);
1785 }
1786 
1787 /*
1788  * Receiver interrupt: RxRDY interrupt, FIFO timeout interrupt or receive
1789  * error interrupt.
1790  * Try to put the character into the circular buffer for this line; if it
1791  * overflows, indicate a circular buffer overrun. If this port is always
1792  * to be serviced immediately, or the character is a STOP character, or
1793  * more than 15 characters have arrived, queue up a soft interrupt to
1794  * drain the circular buffer.
1795  * XXX - needs review for hw FIFOs support.
1796  */
1797 
1798 static void
1799 async_rxint(struct asycom *asy, uchar_t lsr)
1800 {
1801 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1802 	uchar_t c = 0;
1803 	uint_t s = 0, needsoft = 0;
1804 	register tty_common_t *tp;
1805 
1806 	tp = &async->async_ttycommon;
1807 	if (!(tp->t_cflag & CREAD)) {
1808 		if (lsr & (RCA|PARERR|FRMERR|BRKDET|OVRRUN)) {
1809 			(void) (INB(DAT) & 0xff);
1810 		}
1811 		return; /* line is not open for read? */
1812 	}
1813 	asy->asy_rx_count = 0;
1814 	while (lsr & (RCA|PARERR|FRMERR|BRKDET|OVRRUN)) {
1815 		c = 0;
1816 		s = 0;
1817 		asy->asy_rx_count++;
1818 		if (lsr & RCA) {
1819 			c = INB(DAT) & 0xff;
1820 			/*
1821 			 * Even a single character is received
1822 			 * we need Soft interrupt to pass it to
1823 			 * higher layers.
1824 			 */
1825 			needsoft = 1;
1826 		}
1827 
1828 		/* Check for character break sequence */
1829 		if ((abort_enable == KIOCABORTALTERNATE) &&
1830 		    (async->async_dev == rconsdev)) {
1831 			if (abort_charseq_recognize(c))
1832 				abort_sequence_enter((char *)NULL);
1833 			}
1834 
1835 		/* Handle framing errors */
1836 		if (lsr & (PARERR|FRMERR|BRKDET|OVRRUN)) {
1837 			if (lsr & PARERR) {
1838 				if (tp->t_iflag & INPCK) /* parity enabled */
1839 					s |= PERROR;
1840 			}
1841 			if (lsr & (FRMERR|BRKDET))
1842 				s |= FRERROR;
1843 			if (lsr & OVRRUN) {
1844 				async->async_hw_overrun = 1;
1845 				s |= OVERRUN;
1846 			}
1847 		}
1848 
1849 		if (s == 0)
1850 			if ((tp->t_iflag & PARMRK) &&
1851 			    !(tp->t_iflag & (IGNPAR|ISTRIP)) &&
1852 			    (c == 0377))
1853 				if (RING_POK(async, 2)) {
1854 					RING_PUT(async, 0377);
1855 					RING_PUT(async, c);
1856 				} else
1857 					async->async_sw_overrun = 1;
1858 			else
1859 				if (RING_POK(async, 1))
1860 					RING_PUT(async, c);
1861 				else
1862 					async->async_sw_overrun = 1;
1863 		else
1864 			if (s & FRERROR) { /* Handle framing errors */
1865 				if (c == 0)  {
1866 		/* Look for break on kbd, stdin, or rconsdev */
1867 					if ((async->async_dev == kbddev) ||
1868 					    ((async->async_dev == rconsdev) ||
1869 					    (async->async_dev == stdindev)) &&
1870 					    (abort_enable !=
1871 					    KIOCABORTALTERNATE))
1872 						abort_sequence_enter((char *)0);
1873 					else
1874 						async->async_break++;
1875 				} else {
1876 					if (RING_POK(async, 1))
1877 						RING_MARK(async, c, s);
1878 					else
1879 						async->async_sw_overrun = 1;
1880 				}
1881 			} else  { /* Parity errors  handled by ldterm */
1882 				if (RING_POK(async, 1))
1883 					RING_MARK(async, c, s);
1884 				else
1885 					async->async_sw_overrun = 1;
1886 			}
1887 		lsr = INB(LSR);
1888 		if (asy->asy_rx_count > 16) break;
1889 	}
1890 	/* Check whether there is a request for hw/sw inbound/input flow ctrl */
1891 	if ((async->async_ttycommon.t_cflag & CRTSXOFF) ||
1892 	    (async->async_ttycommon.t_iflag & IXOFF))
1893 		if ((int)(RING_CNT(async)) > (RINGSIZE * 3)/4) {
1894 #ifdef DEBUG
1895 			if (asydebug & ASY_DEBUG_HFLOW)
1896 				printf("asy%d: hardware flow stop input.\n",
1897 				    UNIT(async->async_dev));
1898 #endif
1899 			async->async_flags |= ASYNC_HW_IN_FLOW;
1900 			async->async_flowc = async->async_stopc;
1901 			async->async_ringbuf_overflow = 1;
1902 		}
1903 
1904 	if ((async->async_flags & ASYNC_SERVICEIMM) || needsoft ||
1905 	    (RING_FRAC(async)) || (async->async_polltid == 0))
1906 		ASYSETSOFT(asy);	/* need a soft interrupt */
1907 }
1908 
1909 /*
1910  * Interrupt on port: handle PPS event.  This function is only called
1911  * for a port on which PPS event handling has been enabled.
1912  */
1913 static void
1914 asy_ppsevent(struct asycom *asy, int msr)
1915 {
1916 	if (asy->asy_flags & ASY_PPS_EDGE) {
1917 		/* Have seen leading edge, now look for and record drop */
1918 		if ((msr & DCD) == 0)
1919 			asy->asy_flags &= ~ASY_PPS_EDGE;
1920 		/*
1921 		 * Waiting for leading edge, look for rise; stamp event and
1922 		 * calibrate kernel clock.
1923 		 */
1924 	} else if (msr & DCD) {
1925 		/*
1926 		 * This code captures a timestamp at the designated
1927 		 * transition of the PPS signal (DCD asserted).  The
1928 		 * code provides a pointer to the timestamp, as well
1929 		 * as the hardware counter value at the capture.
1930 		 *
1931 		 * Note: the kernel has nano based time values while
1932 		 * NTP requires micro based, an in-line fast algorithm
1933 		 * to convert nsec to usec is used here -- see hrt2ts()
1934 		 * in common/os/timers.c for a full description.
1935 		 */
1936 		struct timeval *tvp = &asy_ppsev.tv;
1937 		timestruc_t ts;
1938 		long nsec, usec;
1939 
1940 		asy->asy_flags |= ASY_PPS_EDGE;
1941 		gethrestime(&ts);
1942 		nsec = ts.tv_nsec;
1943 		usec = nsec + (nsec >> 2);
1944 		usec = nsec + (usec >> 1);
1945 		usec = nsec + (usec >> 2);
1946 		usec = nsec + (usec >> 4);
1947 		usec = nsec - (usec >> 3);
1948 		usec = nsec + (usec >> 2);
1949 		usec = nsec + (usec >> 3);
1950 		usec = nsec + (usec >> 4);
1951 		usec = nsec + (usec >> 1);
1952 		usec = nsec + (usec >> 6);
1953 		tvp->tv_usec = usec >> 10;
1954 		tvp->tv_sec = ts.tv_sec;
1955 
1956 		++asy_ppsev.serial;
1957 
1958 		/*
1959 		 * Because the kernel keeps a high-resolution time,
1960 		 * pass the current highres timestamp in tvp and zero
1961 		 * in usec.
1962 		 */
1963 		ddi_hardpps(tvp, 0);
1964 	}
1965 }
1966 
1967 /*
1968  * Modem status interrupt.
1969  *
1970  * (Note: It is assumed that the MSR hasn't been read by asyintr().)
1971  */
1972 
1973 static void
1974 async_msint(struct asycom *asy)
1975 {
1976 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1977 	int msr;
1978 
1979 	msr = INB(MSR);	/* this resets the interrupt */
1980 	asy->asy_cached_msr = msr;
1981 #ifdef DEBUG
1982 	if (asydebug & ASY_DEBUG_STATE) {
1983 		printf("   transition: %3s %3s %3s %3s\n"
1984 		    "current state: %3s %3s %3s %3s\n",
1985 		    (msr & DCTS) ? "CTS" : "   ",
1986 		    (msr & DDSR) ? "DSR" : "   ",
1987 		    (msr & DRI) ?  "RI " : "   ",
1988 		    (msr & DDCD) ? "DCD" : "   ",
1989 		    (msr & CTS) ?  "CTS" : "   ",
1990 		    (msr & DSR) ?  "DSR" : "   ",
1991 		    (msr & RI) ?   "RI " : "   ",
1992 		    (msr & DCD) ?  "DCD" : "   ");
1993 	}
1994 #endif
1995 	if (async->async_ttycommon.t_cflag & CRTSCTS && !(msr & CTS)) {
1996 #ifdef DEBUG
1997 		if (asydebug & ASY_DEBUG_HFLOW)
1998 			printf("asy%d: hflow start\n",
1999 			    UNIT(async->async_dev));
2000 #endif
2001 		async->async_flags |= ASYNC_HW_OUT_FLW;
2002 	}
2003 	if (asy->asy_hwtype == ASY82510)
2004 		OUTB(MSR, (msr & 0xF0));
2005 
2006 	/* Handle PPS event */
2007 	if (asy->asy_flags & ASY_PPS)
2008 		asy_ppsevent(asy, msr);
2009 
2010 	async->async_ext++;
2011 	ASYSETSOFT(asy);
2012 }
2013 
2014 /*
2015  * Handle a second-stage interrupt.
2016  */
2017 uint_t
2018 asysoftintr(caddr_t intarg)
2019 {
2020 	struct asycom *asy = (struct asycom *)intarg;
2021 	struct asyncline *async;
2022 	int rv;
2023 	int cc;
2024 	/*
2025 	 * Test and clear soft interrupt.
2026 	 */
2027 	mutex_enter(asy->asy_soft_lock);
2028 #ifdef DEBUG
2029 	if (asydebug & ASY_DEBUG_PROCS)
2030 		printf("softintr\n");
2031 #endif
2032 	rv = asy->asysoftpend;
2033 	if (rv != 0)
2034 		asy->asysoftpend = 0;
2035 	mutex_exit(asy->asy_soft_lock);
2036 
2037 	if (rv) {
2038 		if (asy->asy_priv == NULL)
2039 			return (rv);
2040 		async = (struct asyncline *)asy->asy_priv;
2041 		mutex_enter(asy->asy_excl_hi);
2042 		if (asy->asy_flags & ASY_NEEDSOFT) {
2043 			asy->asy_flags &= ~ASY_NEEDSOFT;
2044 			mutex_exit(asy->asy_excl_hi);
2045 			(void) async_softint(asy);
2046 			mutex_enter(asy->asy_excl_hi);
2047 		}
2048 		/*
2049 		 * There are some instances where the softintr is not
2050 		 * scheduled and hence not called. It so happened that makes
2051 		 * the last few characters to be stuck in ringbuffer.
2052 		 * Hence, call once again the  handler so that the last few
2053 		 * characters are cleared.
2054 		 */
2055 		cc = RING_CNT(async);
2056 		mutex_exit(asy->asy_excl_hi);
2057 		if (cc > 0) {
2058 			(void) async_softint(asy);
2059 		}
2060 	}
2061 	return (rv);
2062 }
2063 
2064 /*
2065  * Handle a software interrupt.
2066  */
2067 static int
2068 async_softint(struct asycom *asy)
2069 {
2070 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
2071 	uint_t	cc;
2072 	mblk_t	*bp;
2073 	queue_t	*q;
2074 	uchar_t	val;
2075 	uchar_t	c;
2076 	tty_common_t	*tp;
2077 
2078 #ifdef DEBUG
2079 	if (asydebug & ASY_DEBUG_PROCS)
2080 		printf("process\n");
2081 #endif
2082 	mutex_enter(asy->asy_excl);
2083 	if (asy->asy_flags & ASY_DOINGSOFT) {
2084 		mutex_exit(asy->asy_excl);
2085 		return (0);
2086 	}
2087 	tp = &async->async_ttycommon;
2088 	q = tp->t_readq;
2089 	if (q != NULL) {
2090 		mutex_exit(asy->asy_excl);
2091 		enterq(q);
2092 		mutex_enter(asy->asy_excl);
2093 	}
2094 	mutex_enter(asy->asy_excl_hi);
2095 	asy->asy_flags |= ASY_DOINGSOFT;
2096 
2097 	if (INB(ICR) & MIEN)
2098 		val = asy->asy_cached_msr & 0xFF;
2099 	else
2100 		val = INB(MSR) & 0xFF;
2101 
2102 	if (async->async_ttycommon.t_cflag & CRTSCTS) {
2103 		if ((val & CTS) && (async->async_flags & ASYNC_HW_OUT_FLW)) {
2104 #ifdef DEBUG
2105 			if (asydebug & ASY_DEBUG_HFLOW)
2106 				printf("asy%d: hflow start\n",
2107 				    UNIT(async->async_dev));
2108 #endif
2109 			async->async_flags &= ~ASYNC_HW_OUT_FLW;
2110 			mutex_exit(asy->asy_excl_hi);
2111 			if (async->async_ocnt > 0) {
2112 				mutex_enter(asy->asy_excl_hi);
2113 				async_resume(async);
2114 				mutex_exit(asy->asy_excl_hi);
2115 			} else {
2116 				async_start(async);
2117 			}
2118 			mutex_enter(asy->asy_excl_hi);
2119 		}
2120 	}
2121 	if (async->async_ext) {
2122 		async->async_ext = 0;
2123 		/* check for carrier up */
2124 		if ((val & DCD) || (tp->t_flags & TS_SOFTCAR)) {
2125 			/* carrier present */
2126 			if ((async->async_flags & ASYNC_CARR_ON) == 0) {
2127 				async->async_flags |= ASYNC_CARR_ON;
2128 				mutex_exit(asy->asy_excl_hi);
2129 				mutex_exit(asy->asy_excl);
2130 				if (async->async_flags & ASYNC_ISOPEN)
2131 					(void) putctl(q, M_UNHANGUP);
2132 				cv_broadcast(&async->async_flags_cv);
2133 				mutex_enter(asy->asy_excl);
2134 				mutex_enter(asy->asy_excl_hi);
2135 			}
2136 		} else {
2137 			if ((async->async_flags & ASYNC_CARR_ON) &&
2138 			    !(tp->t_cflag & CLOCAL)) {
2139 				int flushflag;
2140 
2141 				/*
2142 				 * Carrier went away.
2143 				 * Drop DTR, abort any output in
2144 				 * progress, indicate that output is
2145 				 * not stopped, and send a hangup
2146 				 * notification upstream.
2147 				 *
2148 				 * If we're in the midst of close, then flush
2149 				 * everything.  Don't leave stale ioctls lying
2150 				 * about.
2151 				 */
2152 				val = INB(MCR);
2153 				OUTB(MCR, (val & ~DTR));
2154 				flushflag = (async->async_flags &
2155 				    ASYNC_CLOSING) ? FLUSHALL : FLUSHDATA;
2156 				flushq(tp->t_writeq, flushflag);
2157 				if (async->async_xmitblk != NULL) {
2158 					freeb(async->async_xmitblk);
2159 					async->async_xmitblk = NULL;
2160 				}
2161 				if (async->async_flags & ASYNC_BUSY) {
2162 					async->async_ocnt = 0;
2163 					async->async_flags &= ~ASYNC_BUSY;
2164 				}
2165 				async->async_flags &= ~ASYNC_STOPPED;
2166 				if (async->async_flags & ASYNC_ISOPEN) {
2167 					mutex_exit(asy->asy_excl_hi);
2168 					mutex_exit(asy->asy_excl);
2169 					(void) putctl(q, M_HANGUP);
2170 					mutex_enter(asy->asy_excl);
2171 					mutex_enter(asy->asy_excl_hi);
2172 				}
2173 				async->async_flags &= ~ASYNC_CARR_ON;
2174 				mutex_exit(asy->asy_excl_hi);
2175 				cv_broadcast(&async->async_flags_cv);
2176 				mutex_enter(asy->asy_excl_hi);
2177 			}
2178 		}
2179 	}
2180 
2181 	/*
2182 	 * If data has been added to the circular buffer, remove
2183 	 * it from the buffer, and send it up the stream if there's
2184 	 * somebody listening. Try to do it 16 bytes at a time. If we
2185 	 * have more than 16 bytes to move, move 16 byte chunks and
2186 	 * leave the rest for next time around (maybe it will grow).
2187 	 */
2188 	if (!(async->async_flags & ASYNC_ISOPEN)) {
2189 		RING_INIT(async);
2190 		goto rv;
2191 	}
2192 	if ((cc = RING_CNT(async)) == 0) {
2193 		goto rv;
2194 	}
2195 	mutex_exit(asy->asy_excl_hi);
2196 
2197 	if (!canput(q)) {
2198 		if ((async->async_flags & ASYNC_HW_IN_FLOW) == 0) {
2199 #ifdef DEBUG
2200 			if (!(asydebug & ASY_DEBUG_HFLOW)) {
2201 				printf("asy%d: hflow stop input.\n",
2202 				    UNIT(async->async_dev));
2203 				if (canputnext(q))
2204 					printf("asy%d: next queue is "
2205 					    "ready\n",
2206 					    UNIT(async->async_dev));
2207 			}
2208 #endif
2209 			mutex_enter(asy->asy_excl_hi);
2210 			async->async_flags |= ASYNC_HW_IN_FLOW;
2211 			async->async_flowc = async->async_stopc;
2212 		} else mutex_enter(asy->asy_excl_hi);
2213 		goto rv;
2214 	}
2215 
2216 	if (async->async_ringbuf_overflow) {
2217 		if ((async->async_flags & ASYNC_HW_IN_FLOW) &&
2218 		    ((int)(RING_CNT(async)) < (RINGSIZE/4))) {
2219 #ifdef DEBUG
2220 			if (asydebug & ASY_DEBUG_HFLOW)
2221 				printf("asy%d: hflow start input.\n",
2222 				    UNIT(async->async_dev));
2223 #endif
2224 			mutex_enter(asy->asy_excl_hi);
2225 			async->async_flags &= ~ASYNC_HW_IN_FLOW;
2226 			async->async_flowc = async->async_startc;
2227 			async->async_ringbuf_overflow = 0;
2228 			goto rv;
2229 		}
2230 	}
2231 #ifdef DEBUG
2232 	if (asydebug & ASY_DEBUG_INPUT)
2233 		printf("asy%d: %d char(s) in queue.\n",
2234 		    UNIT(async->async_dev), cc);
2235 #endif
2236 	/*
2237 	 * Before you pull the characters from the RING BUF
2238 	 * Check whether you can put into the queue again
2239 	 */
2240 	if ((!canputnext(q)) || (!canput(q))) {
2241 		mutex_enter(asy->asy_excl_hi);
2242 		if ((async->async_flags & ASYNC_HW_IN_FLOW) == 0) {
2243 			async->async_flags |= ASYNC_HW_IN_FLOW;
2244 			async->async_flowc = async->async_stopc;
2245 			async->async_queue_full = 1;
2246 		}
2247 		goto rv;
2248 	}
2249 	mutex_enter(asy->asy_excl_hi);
2250 	if (async->async_queue_full) {
2251 		/*
2252 		 * Last time the Stream queue didnot allow
2253 		 * now it allows so, relax, the flow control
2254 		 */
2255 		if (async->async_flags & ASYNC_HW_IN_FLOW) {
2256 			async->async_flags &= ~ASYNC_HW_IN_FLOW;
2257 			async->async_queue_full = 0;
2258 			async->async_flowc = async->async_startc;
2259 			goto rv;
2260 		} else
2261 			async->async_queue_full = 0;
2262 	}
2263 	mutex_exit(asy->asy_excl_hi);
2264 	if (!(bp = allocb(cc, BPRI_MED))) {
2265 		ttycommon_qfull(&async->async_ttycommon, q);
2266 		mutex_enter(asy->asy_excl_hi);
2267 		goto rv;
2268 	}
2269 	mutex_enter(asy->asy_excl_hi);
2270 	do {
2271 		if (RING_ERR(async, S_ERRORS)) {
2272 			RING_UNMARK(async);
2273 			c = RING_GET(async);
2274 			break;
2275 		} else {
2276 			*bp->b_wptr++ = RING_GET(async);
2277 		}
2278 	} while (--cc);
2279 
2280 	mutex_exit(asy->asy_excl_hi);
2281 	mutex_exit(asy->asy_excl);
2282 	if (bp->b_wptr > bp->b_rptr) {
2283 		if (!canputnext(q)) {
2284 			if (!canput(q)) {
2285 				/*
2286 				 * Even after taking all precautions that
2287 				 * Still we are unable to queue, then we
2288 				 * cannot do anything, just drop the block
2289 				 */
2290 				cmn_err(CE_NOTE,
2291 				    "su%d: local queue full\n",
2292 				    UNIT(async->async_dev));
2293 				freemsg(bp);
2294 				mutex_enter(asy->asy_excl_hi);
2295 				if ((async->async_flags &
2296 				    ASYNC_HW_IN_FLOW) == 0) {
2297 					async->async_flags |=
2298 					    ASYNC_HW_IN_FLOW;
2299 					async->async_flowc =
2300 					    async->async_stopc;
2301 					async->async_queue_full = 1;
2302 				}
2303 				mutex_exit(asy->asy_excl_hi);
2304 			} else {
2305 				(void) putq(q, bp);
2306 			}
2307 		} else {
2308 			putnext(q, bp);
2309 		}
2310 	} else {
2311 		freemsg(bp);
2312 	}
2313 	/*
2314 	 * If we have a parity error, then send
2315 	 * up an M_BREAK with the "bad"
2316 	 * character as an argument. Let ldterm
2317 	 * figure out what to do with the error.
2318 	 */
2319 	if (cc)
2320 		(void) putctl1(q, M_BREAK, c);
2321 	mutex_enter(asy->asy_excl);
2322 	mutex_enter(asy->asy_excl_hi);
2323 rv:
2324 	/*
2325 	 * If a transmission has finished, indicate that it's finished,
2326 	 * and start that line up again.
2327 	 */
2328 	if (async->async_break) {
2329 		async->async_break = 0;
2330 		if (async->async_flags & ASYNC_ISOPEN) {
2331 			mutex_exit(asy->asy_excl_hi);
2332 			mutex_exit(asy->asy_excl);
2333 			(void) putctl(q, M_BREAK);
2334 			mutex_enter(asy->asy_excl);
2335 			mutex_enter(asy->asy_excl_hi);
2336 		}
2337 	}
2338 	if ((async->async_ocnt <= 0 && (async->async_flags & ASYNC_BUSY)) ||
2339 	    (async->async_flowc != '\0')) {
2340 		async->async_flags &= ~ASYNC_BUSY;
2341 		mutex_exit(asy->asy_excl_hi);
2342 		if (async->async_xmitblk)
2343 			freeb(async->async_xmitblk);
2344 		async->async_xmitblk = NULL;
2345 		if (async->async_flags & ASYNC_ISOPEN) {
2346 			asy->inperim = B_TRUE;
2347 			mutex_exit(asy->asy_excl);
2348 			enterq(async->async_ttycommon.t_writeq);
2349 			mutex_enter(asy->asy_excl);
2350 		}
2351 		async_start(async);
2352 		/*
2353 		 * We need to check for inperim and ISOPEN due to
2354 		 * multi-threading implications; it's possible to close the
2355 		 * port and nullify async_flags while completing the software
2356 		 * interrupt.  If the port is closed, leaveq() will have already
2357 		 * been called.  We don't want to call it twice.
2358 		 */
2359 		if ((asy->inperim) && (async->async_flags & ASYNC_ISOPEN)) {
2360 			mutex_exit(asy->asy_excl);
2361 			leaveq(async->async_ttycommon.t_writeq);
2362 			mutex_enter(asy->asy_excl);
2363 			asy->inperim = B_FALSE;
2364 		}
2365 		if (!(async->async_flags & ASYNC_BUSY))
2366 			cv_broadcast(&async->async_flags_cv);
2367 		mutex_enter(asy->asy_excl_hi);
2368 	}
2369 	/*
2370 	 * A note about these overrun bits: all they do is *tell* someone
2371 	 * about an error- They do not track multiple errors. In fact,
2372 	 * you could consider them latched register bits if you like.
2373 	 * We are only interested in printing the error message once for
2374 	 * any cluster of overrun errrors.
2375 	 */
2376 	if (async->async_hw_overrun) {
2377 		if (async->async_flags & ASYNC_ISOPEN) {
2378 			if (su_log > 0) {
2379 				mutex_exit(asy->asy_excl_hi);
2380 				mutex_exit(asy->asy_excl);
2381 				cmn_err(CE_NOTE, "su%d: silo overflow\n",
2382 				    UNIT(async->async_dev));
2383 				mutex_enter(asy->asy_excl);
2384 				mutex_enter(asy->asy_excl_hi);
2385 			}
2386 			INC64_KSTAT(asy, siloover);
2387 		}
2388 		async->async_hw_overrun = 0;
2389 	}
2390 	if (async->async_sw_overrun) {
2391 		if (async->async_flags & ASYNC_ISOPEN) {
2392 			if (su_log > 0) {
2393 				mutex_exit(asy->asy_excl_hi);
2394 				mutex_exit(asy->asy_excl);
2395 				cmn_err(CE_NOTE, "su%d: ring buffer overflow\n",
2396 				    UNIT(async->async_dev));
2397 				mutex_enter(asy->asy_excl);
2398 				mutex_enter(asy->asy_excl_hi);
2399 			}
2400 			INC64_KSTAT(asy, ringover);
2401 		}
2402 		async->async_sw_overrun = 0;
2403 	}
2404 	asy->asy_flags &= ~ASY_DOINGSOFT;
2405 	mutex_exit(asy->asy_excl_hi);
2406 	mutex_exit(asy->asy_excl);
2407 	if (q != NULL)
2408 		leaveq(q);
2409 	return (0);
2410 }
2411 
2412 /*
2413  * Restart output on a line after a delay or break timer expired.
2414  */
2415 static void
2416 async_restart(void *arg)
2417 {
2418 	struct asyncline *async = arg;
2419 	struct asycom *asy = async->async_common;
2420 	queue_t *q;
2421 	uchar_t lcr;
2422 
2423 	/*
2424 	 * If break timer expired, turn off the break bit.
2425 	 */
2426 #ifdef DEBUG
2427 	if (asydebug & ASY_DEBUG_PROCS)
2428 		printf("restart\n");
2429 #endif
2430 	mutex_enter(asy->asy_excl);
2431 	if (async->async_flags & ASYNC_BREAK) {
2432 		unsigned int rate;
2433 
2434 		mutex_enter(asy->asy_excl_hi);
2435 		lcr = INB(LCR);
2436 		OUTB(LCR, (lcr & ~SETBREAK));
2437 
2438 		/*
2439 		 * Go to sleep for the time it takes for at least one
2440 		 * stop bit to be received by the device at the other
2441 		 * end of the line as stated in the RS-232 specification.
2442 		 * The wait period is equal to:
2443 		 * 2 clock cycles * (1 MICROSEC / baud rate)
2444 		 */
2445 		rate = async->async_ttycommon.t_cflag & CBAUD;
2446 		if (async->async_ttycommon.t_cflag & CBAUDEXT)
2447 			rate += 16;
2448 		if (rate >= N_SU_SPEEDS || rate == B0) {
2449 			rate = B9600;
2450 		}
2451 
2452 		mutex_exit(asy->asy_excl_hi);
2453 		mutex_exit(asy->asy_excl);
2454 		drv_usecwait(2 * MICROSEC / baudtable[rate]);
2455 		mutex_enter(asy->asy_excl);
2456 	}
2457 	async->async_flags &= ~(ASYNC_DELAY|ASYNC_BREAK|ASYNC_DRAINING);
2458 	if ((q = async->async_ttycommon.t_writeq) != NULL) {
2459 		mutex_exit(asy->asy_excl);
2460 		enterq(q);
2461 		mutex_enter(asy->asy_excl);
2462 	}
2463 	async_start(async);
2464 	mutex_exit(asy->asy_excl);
2465 	if (q != NULL)
2466 		leaveq(q);
2467 
2468 	/* cleared break or delay flag; may have made some output progress */
2469 	cv_broadcast(&async->async_flags_cv);
2470 }
2471 
2472 static void
2473 async_start(struct asyncline *async)
2474 {
2475 	async_nstart(async, 0);
2476 }
2477 
2478 /*
2479  * Start output on a line, unless it's busy, frozen, or otherwise.
2480  */
2481 static void
2482 async_nstart(struct asyncline *async, int mode)
2483 {
2484 	register struct asycom *asy = async->async_common;
2485 	register int cc;
2486 	register queue_t *q;
2487 	mblk_t *bp, *nbp;
2488 	uchar_t *xmit_addr;
2489 	uchar_t	val;
2490 	int	fifo_len = 1;
2491 	int	xmit_progress;
2492 
2493 #ifdef DEBUG
2494 	if (asydebug & ASY_DEBUG_PROCS)
2495 		printf("start\n");
2496 #endif
2497 	if (asy->asy_use_fifo == FIFO_ON)
2498 		fifo_len = asy->asy_fifo_buf; /* with FIFO buffers */
2499 
2500 	ASSERT(mutex_owned(asy->asy_excl));
2501 	mutex_enter(asy->asy_excl_hi);
2502 	asycheckflowcontrol_hw(asy);
2503 
2504 	/*
2505 	 * If the chip is busy (i.e., we're waiting for a break timeout
2506 	 * to expire, or for the current transmission to finish, or for
2507 	 * output to finish draining from chip), don't grab anything new.
2508 	 */
2509 	if (async->async_flags & (ASYNC_BREAK|ASYNC_BUSY|ASYNC_DRAINING)) {
2510 		mutex_exit(asy->asy_excl_hi);
2511 #ifdef DEBUG
2512 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2513 			printf("asy%d: start %s.\n",
2514 			    UNIT(async->async_dev),
2515 			    async->async_flags & ASYNC_BREAK
2516 			    ? "break" : "busy");
2517 #endif
2518 		return;
2519 	}
2520 
2521 	/*
2522 	 * If we have a flow-control character to transmit, do it now.
2523 	 */
2524 	if (asycheckflowcontrol_sw(asy)) {
2525 		mutex_exit(asy->asy_excl_hi);
2526 		return;
2527 	}
2528 	mutex_exit(asy->asy_excl_hi);
2529 	/*
2530 	 * If we're waiting for a delay timeout to expire, don't grab
2531 	 * anything new.
2532 	 */
2533 	if (async->async_flags & ASYNC_DELAY) {
2534 #ifdef DEBUG
2535 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2536 			printf("asy%d: start ASYNC_DELAY.\n",
2537 			    UNIT(async->async_dev));
2538 #endif
2539 		return;
2540 	}
2541 
2542 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
2543 #ifdef DEBUG
2544 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2545 			printf("asy%d: start writeq is null.\n",
2546 			    UNIT(async->async_dev));
2547 #endif
2548 		return;	/* not attached to a stream */
2549 	}
2550 
2551 	for (;;) {
2552 		if ((bp = getq(q)) == NULL)
2553 			return;	/* no data to transmit */
2554 
2555 		/*
2556 		 * We have a message block to work on.
2557 		 * Check whether it's a break, a delay, or an ioctl (the latter
2558 		 * occurs if the ioctl in question was waiting for the output
2559 		 * to drain).  If it's one of those, process it immediately.
2560 		 */
2561 		switch (bp->b_datap->db_type) {
2562 
2563 		case M_BREAK:
2564 			/*
2565 			 * Set the break bit, and arrange for "async_restart"
2566 			 * to be called in 1/4 second; it will turn the
2567 			 * break bit off, and call "async_start" to grab
2568 			 * the next message.
2569 			 */
2570 			mutex_enter(asy->asy_excl_hi);
2571 			val = INB(LCR);
2572 			OUTB(LCR, (val | SETBREAK));
2573 			mutex_exit(asy->asy_excl_hi);
2574 			async->async_flags |= ASYNC_BREAK;
2575 			(void) timeout(async_restart, async, hz / 4);
2576 			freemsg(bp);
2577 			return;	/* wait for this to finish */
2578 
2579 		case M_DELAY:
2580 			/*
2581 			 * Arrange for "async_restart" to be called when the
2582 			 * delay expires; it will turn ASYNC_DELAY off,
2583 			 * and call "async_start" to grab the next message.
2584 			 */
2585 			(void) timeout(async_restart, async,
2586 			    (clock_t)(*(unsigned char *)bp->b_rptr + 6));
2587 			async->async_flags |= ASYNC_DELAY;
2588 			freemsg(bp);
2589 			return;	/* wait for this to finish */
2590 
2591 		case M_IOCTL:
2592 			/*
2593 			 * This ioctl needs to wait for the output ahead of
2594 			 * it to drain.  Try to do it, and then either
2595 			 * redo the ioctl at a later time or grab the next
2596 			 * message after it.
2597 			 */
2598 
2599 			mutex_enter(asy->asy_excl_hi);
2600 			if (asy_isbusy(asy)) {
2601 				/*
2602 				 * Get the divisor by calculating the rate
2603 				 */
2604 				unsigned int rate;
2605 
2606 				mutex_exit(asy->asy_excl_hi);
2607 				rate = async->async_ttycommon.t_cflag & CBAUD;
2608 				if (async->async_ttycommon.t_cflag & CBAUDEXT)
2609 					rate += 16;
2610 				if (rate >= N_SU_SPEEDS || rate == B0) {
2611 					rate = B9600;
2612 				}
2613 
2614 				/*
2615 				 * We need to do a callback as the port will
2616 				 * be set to drain
2617 				 */
2618 				async->async_flags |= ASYNC_DRAINING;
2619 
2620 				/*
2621 				 * Put the message we just processed back onto
2622 				 * the end of the queue
2623 				 */
2624 				if (putq(q, bp) == 0)
2625 					freemsg(bp);
2626 
2627 				/*
2628 				 * We need to delay until the TSR and THR
2629 				 * have been exhausted.  We base the delay on
2630 				 * the amount of time it takes to transmit
2631 				 * 2 chars at the current baud rate in
2632 				 * microseconds.
2633 				 *
2634 				 * Therefore, the wait period is:
2635 				 *
2636 				 * (#TSR bits + #THR bits) *
2637 				 * 	1 MICROSEC / baud rate
2638 				 */
2639 				(void) timeout(async_restart, async,
2640 				    drv_usectohz(16 * MICROSEC /
2641 				    baudtable[rate]));
2642 				return;
2643 			}
2644 			mutex_exit(asy->asy_excl_hi);
2645 			mutex_exit(asy->asy_excl);
2646 			async_ioctl(async, q, bp, B_FALSE);
2647 			mutex_enter(asy->asy_excl);
2648 			continue;
2649 		}
2650 
2651 		while (bp != NULL && (cc = bp->b_wptr - bp->b_rptr) == 0) {
2652 			nbp = bp->b_cont;
2653 			freeb(bp);
2654 			bp = nbp;
2655 		}
2656 		if (bp != NULL)
2657 			break;
2658 	}
2659 
2660 	/*
2661 	 * We have data to transmit.  If output is stopped, put
2662 	 * it back and try again later.
2663 	 */
2664 	if (async->async_flags & (ASYNC_HW_OUT_FLW|ASYNC_STOPPED)) {
2665 #ifdef DEBUG
2666 		if (asydebug & ASY_DEBUG_HFLOW &&
2667 		    async->async_flags & ASYNC_HW_OUT_FLW)
2668 			printf("asy%d: output hflow in effect.\n",
2669 			    UNIT(async->async_dev));
2670 #endif
2671 		mutex_exit(asy->asy_excl);
2672 		(void) putbq(q, bp);
2673 		/*
2674 		 * We entered the routine owning the lock, we need to
2675 		 * exit the routine owning the lock.
2676 		 */
2677 		mutex_enter(asy->asy_excl);
2678 		return;
2679 	}
2680 
2681 	async->async_xmitblk = bp;
2682 	xmit_addr = bp->b_rptr;
2683 	bp = bp->b_cont;
2684 	if (bp != NULL) {
2685 		mutex_exit(asy->asy_excl);
2686 		(void) putbq(q, bp);	/* not done with this message yet */
2687 		mutex_enter(asy->asy_excl);
2688 	}
2689 
2690 	/*
2691 	 * In 5-bit mode, the high order bits are used
2692 	 * to indicate character sizes less than five,
2693 	 * so we need to explicitly mask before transmitting
2694 	 */
2695 	if ((async->async_ttycommon.t_cflag & CSIZE) == CS5) {
2696 		register unsigned char *p = xmit_addr;
2697 		register int cnt = cc;
2698 
2699 		while (cnt--)
2700 			*p++ &= (unsigned char) 0x1f;
2701 	}
2702 
2703 	/*
2704 	 * Set up this block for pseudo-DMA.
2705 	 */
2706 	mutex_enter(asy->asy_excl_hi);
2707 	async->async_optr = xmit_addr;
2708 	async->async_ocnt = cc;
2709 	/*
2710 	 * If the transmitter is ready, shove some
2711 	 * characters out.
2712 	 */
2713 	xmit_progress = 0;
2714 	while (fifo_len-- && async->async_ocnt) {
2715 		if (INB(LSR) & XHRE) {
2716 			OUTB(DAT, *async->async_optr++);
2717 			async->async_ocnt--;
2718 			xmit_progress++;
2719 		}
2720 	}
2721 	asy->asy_out_of_band_xmit = xmit_progress;
2722 	if (xmit_progress > 0)
2723 		async->async_flags |= ASYNC_PROGRESS;
2724 	async->async_flags |= ASYNC_BUSY;
2725 	mutex_exit(asy->asy_excl_hi);
2726 }
2727 
2728 /*
2729  * Resume output by poking the transmitter.
2730  */
2731 static void
2732 async_resume(struct asyncline *async)
2733 {
2734 	register struct asycom *asy = async->async_common;
2735 
2736 	ASSERT(mutex_owned(asy->asy_excl_hi));
2737 #ifdef DEBUG
2738 	if (asydebug & ASY_DEBUG_PROCS)
2739 		printf("resume\n");
2740 #endif
2741 
2742 	asycheckflowcontrol_hw(asy);
2743 
2744 	if (INB(LSR) & XHRE) {
2745 		if (asycheckflowcontrol_sw(asy)) {
2746 			return;
2747 		} else if (async->async_ocnt > 0) {
2748 			OUTB(DAT, *async->async_optr++);
2749 			async->async_ocnt--;
2750 			async->async_flags |= ASYNC_PROGRESS;
2751 		}
2752 	}
2753 }
2754 
2755 /*
2756  * Process an "ioctl" message sent down to us.
2757  * Note that we don't need to get any locks until we are ready to access
2758  * the hardware.  Nothing we access until then is going to be altered
2759  * outside of the STREAMS framework, so we should be safe.
2760  */
2761 static void
2762 async_ioctl(struct asyncline *async, queue_t *wq, mblk_t *mp, boolean_t iswput)
2763 {
2764 	register struct asycom *asy = async->async_common;
2765 	register tty_common_t  *tp = &async->async_ttycommon;
2766 	register struct iocblk *iocp;
2767 	register unsigned datasize;
2768 	size_t ioc_count;
2769 	mblk_t *datamp;
2770 	int error = 0;
2771 	uchar_t val, icr;
2772 #ifdef DEBUG
2773 	if (asydebug & ASY_DEBUG_PROCS)
2774 		printf("ioctl\n");
2775 #endif
2776 
2777 	if (tp->t_iocpending != NULL) {
2778 		/*
2779 		 * We were holding an "ioctl" response pending the
2780 		 * availability of an "mblk" to hold data to be passed up;
2781 		 * another "ioctl" came through, which means that "ioctl"
2782 		 * must have timed out or been aborted.
2783 		 */
2784 		freemsg(async->async_ttycommon.t_iocpending);
2785 		async->async_ttycommon.t_iocpending = NULL;
2786 	}
2787 
2788 	iocp = (struct iocblk *)mp->b_rptr;
2789 
2790 	/*
2791 	 * Save off the ioc count in case we need to restore it
2792 	 * because we are queuing a message block.
2793 	 */
2794 	ioc_count = iocp->ioc_count;
2795 
2796 	/*
2797 	 * For TIOCMGET, TIOCMBIC, TIOCMBIS, TIOCMSET, and PPS, do NOT call
2798 	 * ttycommon_ioctl() because this function frees up the message block
2799 	 * (mp->b_cont) that contains the address of the user variable where
2800 	 * we need to pass back the bit array.
2801 	 *
2802 	 * Similarly, ttycommon_ioctl() does not know about CONSOPENPOLLEDIO
2803 	 * and CONSCLOSEPOLLEDIO, so don't let ttycommon_ioctl() touch them.
2804 	 */
2805 	if (iocp->ioc_cmd == TIOCMGET ||
2806 	    iocp->ioc_cmd == TIOCMBIC ||
2807 	    iocp->ioc_cmd == TIOCMBIS ||
2808 	    iocp->ioc_cmd == TIOCMSET ||
2809 	    iocp->ioc_cmd == TIOCGPPS ||
2810 	    iocp->ioc_cmd == TIOCSPPS ||
2811 	    iocp->ioc_cmd == TIOCGPPSEV ||
2812 	    iocp->ioc_cmd == CONSOPENPOLLEDIO ||
2813 	    iocp->ioc_cmd == CONSCLOSEPOLLEDIO)
2814 		error = -1; /* Do Nothing */
2815 	else
2816 
2817 	/*
2818 	 * The only way in which "ttycommon_ioctl" can fail is if the "ioctl"
2819 	 * requires a response containing data to be returned to the user,
2820 	 * and no mblk could be allocated for the data.
2821 	 * No such "ioctl" alters our state.  Thus, we always go ahead and
2822 	 * do any state-changes the "ioctl" calls for.  If we couldn't allocate
2823 	 * the data, "ttycommon_ioctl" has stashed the "ioctl" away safely, so
2824 	 * we just call "bufcall" to request that we be called back when we
2825 	 * stand a better chance of allocating the data.
2826 	 */
2827 	if ((datasize = ttycommon_ioctl(tp, wq, mp, &error)) != 0) {
2828 		if (async->async_wbufcid)
2829 			unbufcall(async->async_wbufcid);
2830 		async->async_wbufcid = bufcall(datasize, BPRI_HI, async_reioctl,
2831 		    async);
2832 		return;
2833 	}
2834 
2835 	mutex_enter(asy->asy_excl);
2836 
2837 	if (error == 0) {
2838 		/*
2839 		 * "ttycommon_ioctl" did most of the work; we just use the
2840 		 * data it set up.
2841 		 */
2842 		switch (iocp->ioc_cmd) {
2843 
2844 		case TCSETS:
2845 			if (!(asy->asy_rsc_console || asy->asy_rsc_control ||
2846 			    asy->asy_lom_console)) {
2847 				mutex_enter(asy->asy_excl_hi);
2848 				error = asy_program(asy, ASY_NOINIT);
2849 				mutex_exit(asy->asy_excl_hi);
2850 			}
2851 			break;
2852 		case TCSETSF:
2853 		case TCSETSW:
2854 		case TCSETA:
2855 		case TCSETAW:
2856 		case TCSETAF:
2857 			if (!(asy->asy_rsc_console || asy->asy_rsc_control ||
2858 			    asy->asy_lom_console)) {
2859 				mutex_enter(asy->asy_excl_hi);
2860 				if (iswput && asy_isbusy(asy)) {
2861 					/*
2862 					 * ttycommon_ioctl sets the db_type to
2863 					 * M_IOCACK and ioc_count to zero
2864 					 * we need to undo this when we
2865 					 * queue a control message. This will
2866 					 * allow the control messages to be
2867 					 * processed again when the chip
2868 					 * becomes available.
2869 					 */
2870 					mp->b_datap->db_type = M_IOCTL;
2871 					iocp->ioc_count = ioc_count;
2872 
2873 					if (putq(wq, mp) == 0)
2874 						freemsg(mp);
2875 					mutex_exit(asy->asy_excl_hi);
2876 					mutex_exit(asy->asy_excl);
2877 					return;
2878 				}
2879 
2880 				/*
2881 				 * TCSETA, TCSETAW, and TCSETAF make use of
2882 				 * the termio structure and therefore have
2883 				 * no concept of any speed except what can
2884 				 * be represented by CBAUD. This is because
2885 				 * of legacy SVR4 code. Therefore, if we see
2886 				 * one of the aforementioned IOCTL commands
2887 				 * we should zero out CBAUDEXT, CIBAUD, and
2888 				 * CIBAUDEXT as to not break legacy
2889 				 * functionality. This is because CBAUDEXT,
2890 				 * CIBAUD, and CIBAUDEXT can't be stored in
2891 				 * an unsigned short. By zeroing out CBAUDEXT,
2892 				 * CIBAUD, and CIBAUDEXT in the t_cflag of the
2893 				 * termios structure asy_program() will set the
2894 				 * input baud rate to the output baud rate.
2895 				 */
2896 				if (iocp->ioc_cmd == TCSETA ||
2897 				    iocp->ioc_cmd == TCSETAW ||
2898 				    iocp->ioc_cmd == TCSETAF)
2899 					tp->t_cflag &= ~(CIBAUD |
2900 					    CIBAUDEXT | CBAUDEXT);
2901 
2902 				error = asy_program(asy, ASY_NOINIT);
2903 				mutex_exit(asy->asy_excl_hi);
2904 			}
2905 			break;
2906 		case TIOCSSOFTCAR:
2907 			/* Set the driver state appropriately */
2908 			mutex_enter(asy->asy_excl_hi);
2909 			if (tp->t_flags & TS_SOFTCAR)
2910 				asy->asy_flags |= ASY_IGNORE_CD;
2911 			else
2912 				asy->asy_flags &= ~ASY_IGNORE_CD;
2913 			mutex_exit(asy->asy_excl_hi);
2914 			break;
2915 		}
2916 	} else if (error < 0) {
2917 		/*
2918 		 * "ttycommon_ioctl" didn't do anything; we process it here.
2919 		 */
2920 		error = 0;
2921 		switch (iocp->ioc_cmd) {
2922 
2923 		case TIOCGPPS:
2924 			/*
2925 			 * Get PPS on/off.
2926 			 */
2927 			if (mp->b_cont != NULL)
2928 				freemsg(mp->b_cont);
2929 
2930 			mp->b_cont = allocb(sizeof (int), BPRI_HI);
2931 			if (mp->b_cont == NULL) {
2932 				error = ENOMEM;
2933 				break;
2934 			}
2935 			if (asy->asy_flags & ASY_PPS)
2936 				*(int *)mp->b_cont->b_wptr = 1;
2937 			else
2938 				*(int *)mp->b_cont->b_wptr = 0;
2939 			mp->b_cont->b_wptr += sizeof (int);
2940 			mp->b_datap->db_type = M_IOCACK;
2941 			iocp->ioc_count = sizeof (int);
2942 			break;
2943 
2944 		case TIOCSPPS:
2945 			/*
2946 			 * Set PPS on/off.
2947 			 */
2948 			error = miocpullup(mp, sizeof (int));
2949 			if (error != 0)
2950 				break;
2951 
2952 			mutex_enter(asy->asy_excl_hi);
2953 			if (*(int *)mp->b_cont->b_rptr)
2954 				asy->asy_flags |= ASY_PPS;
2955 			else
2956 				asy->asy_flags &= ~ASY_PPS;
2957 			/* Reset edge sense */
2958 			asy->asy_flags &= ~ASY_PPS_EDGE;
2959 			mutex_exit(asy->asy_excl_hi);
2960 			mp->b_datap->db_type = M_IOCACK;
2961 			break;
2962 
2963 		case TIOCGPPSEV: {
2964 			/*
2965 			 * Get PPS event data.
2966 			 */
2967 			mblk_t *bp;
2968 			void *buf;
2969 #ifdef _SYSCALL32_IMPL
2970 			struct ppsclockev32 p32;
2971 #endif
2972 			struct ppsclockev ppsclockev;
2973 
2974 			if (mp->b_cont != NULL) {
2975 				freemsg(mp->b_cont);
2976 				mp->b_cont = NULL;
2977 			}
2978 
2979 			if ((asy->asy_flags & ASY_PPS) == 0) {
2980 				error = ENXIO;
2981 				break;
2982 			}
2983 
2984 			/* Protect from incomplete asy_ppsev */
2985 			mutex_enter(asy->asy_excl_hi);
2986 			ppsclockev = asy_ppsev;
2987 			mutex_exit(asy->asy_excl_hi);
2988 
2989 #ifdef _SYSCALL32_IMPL
2990 			if ((iocp->ioc_flag & IOC_MODELS) != IOC_NATIVE) {
2991 				TIMEVAL_TO_TIMEVAL32(&p32.tv, &ppsclockev.tv);
2992 				p32.serial = ppsclockev.serial;
2993 				buf = &p32;
2994 				iocp->ioc_count = sizeof (struct ppsclockev32);
2995 			} else
2996 #endif
2997 			{
2998 				buf = &ppsclockev;
2999 				iocp->ioc_count = sizeof (struct ppsclockev);
3000 			}
3001 
3002 			if ((bp = allocb(iocp->ioc_count, BPRI_HI)) == NULL) {
3003 				error = ENOMEM;
3004 				break;
3005 			}
3006 			mp->b_cont = bp;
3007 
3008 			bcopy(buf, bp->b_wptr, iocp->ioc_count);
3009 			bp->b_wptr += iocp->ioc_count;
3010 			mp->b_datap->db_type = M_IOCACK;
3011 			break;
3012 		}
3013 
3014 		case TCSBRK:
3015 			error = miocpullup(mp, sizeof (int));
3016 			if (error != 0)
3017 				break;
3018 
3019 			mutex_enter(asy->asy_excl_hi);
3020 			if (*(int *)mp->b_cont->b_rptr == 0) {
3021 				/*
3022 				 * Get the divisor by calculating the rate
3023 				 */
3024 				unsigned int rate, divisor;
3025 				rate = async->async_ttycommon.t_cflag & CBAUD;
3026 				if (async->async_ttycommon.t_cflag & CBAUDEXT)
3027 					rate += 16;
3028 				if (rate >= N_SU_SPEEDS) rate = B9600;
3029 				divisor = asyspdtab[rate] & 0xfff;
3030 
3031 				/*
3032 				 * To ensure that erroneous characters are
3033 				 * not sent out when the break is set, SB
3034 				 * recommends three steps:
3035 				 *
3036 				 * 1) pad the TSR with 0 bits
3037 				 * 2) When the TSR is full, set break
3038 				 * 3) When the TSR has been flushed, unset
3039 				 *    the break when transmission must be
3040 				 *    restored.
3041 				 *
3042 				 * We loop until the TSR is empty and then
3043 				 * set the break.  ASYNC_BREAK has been set
3044 				 * to ensure that no characters are
3045 				 * transmitted while the TSR is being
3046 				 * flushed and SOUT is being used for the
3047 				 * break signal.
3048 				 *
3049 				 * The wait period is equal to
3050 				 * clock / (baud * 16) * 16 * 2.
3051 				 */
3052 				async->async_flags |= ASYNC_BREAK;
3053 				while ((INB(LSR) & XSRE) == 0) {
3054 					mutex_exit(asy->asy_excl_hi);
3055 					mutex_exit(asy->asy_excl);
3056 					drv_usecwait(32*divisor);
3057 					mutex_enter(asy->asy_excl);
3058 					mutex_enter(asy->asy_excl_hi);
3059 				}
3060 
3061 				/*
3062 				 * Set the break bit, and arrange for
3063 				 * "async_restart" to be called in 1/4 second;
3064 				 * it will turn the break bit off, and call
3065 				 * "async_start" to grab the next message.
3066 				 */
3067 				val = INB(LCR);
3068 				OUTB(LCR, (val | SETBREAK));
3069 				mutex_exit(asy->asy_excl_hi);
3070 				(void) timeout(async_restart, async, hz / 4);
3071 			} else {
3072 #ifdef DEBUG
3073 				if (asydebug & ASY_DEBUG_CLOSE)
3074 					printf("asy%d: wait for flush.\n",
3075 					    UNIT(async->async_dev));
3076 #endif
3077 				if (iswput && asy_isbusy(asy)) {
3078 					if (putq(wq, mp) == 0)
3079 						freemsg(mp);
3080 					mutex_exit(asy->asy_excl_hi);
3081 					mutex_exit(asy->asy_excl);
3082 					return;
3083 				}
3084 				mutex_exit(asy->asy_excl_hi);
3085 #ifdef DEBUG
3086 				if (asydebug & ASY_DEBUG_CLOSE)
3087 					printf("asy%d: ldterm satisfied.\n",
3088 					    UNIT(async->async_dev));
3089 #endif
3090 			}
3091 			break;
3092 
3093 		case TIOCSBRK:
3094 			mutex_enter(asy->asy_excl_hi);
3095 			val = INB(LCR);
3096 			OUTB(LCR, (val | SETBREAK));
3097 			mutex_exit(asy->asy_excl_hi);
3098 			mutex_exit(asy->asy_excl);
3099 			miocack(wq, mp, 0, 0);
3100 			return;
3101 
3102 		case TIOCCBRK:
3103 			mutex_enter(asy->asy_excl_hi);
3104 			val = INB(LCR);
3105 			OUTB(LCR, (val & ~SETBREAK));
3106 			mutex_exit(asy->asy_excl_hi);
3107 			mutex_exit(asy->asy_excl);
3108 			miocack(wq, mp, 0, 0);
3109 			return;
3110 
3111 		case TIOCMSET:
3112 		case TIOCMBIS:
3113 		case TIOCMBIC:
3114 			if (iocp->ioc_count == TRANSPARENT)
3115 				mcopyin(mp, NULL, sizeof (int), NULL);
3116 			else {
3117 				error = miocpullup(mp, sizeof (int));
3118 				if (error != 0)
3119 					break;
3120 
3121 				mutex_enter(asy->asy_excl_hi);
3122 
3123 				(void) asymctl(asy,
3124 				    dmtoasy(*(int *)mp->b_cont->b_rptr),
3125 				    iocp->ioc_cmd);
3126 
3127 				mutex_exit(asy->asy_excl_hi);
3128 				iocp->ioc_error = 0;
3129 				mp->b_datap->db_type = M_IOCACK;
3130 			}
3131 			break;
3132 
3133 		case TIOCSILOOP:
3134 			mutex_enter(asy->asy_excl_hi);
3135 			/*
3136 			 * If somebody misues this Ioctl when used for
3137 			 * driving keyboard and mouse indicate not supported
3138 			 */
3139 			if ((asy->asy_device_type == ASY_KEYBOARD) ||
3140 			    (asy->asy_device_type == ASY_MOUSE)) {
3141 				mutex_exit(asy->asy_excl_hi);
3142 				error = ENOTTY;
3143 				break;
3144 			}
3145 
3146 			/* should not use when we're the console */
3147 			if ((async->async_dev == kbddev) ||
3148 			    (async->async_dev == rconsdev) ||
3149 			    (async->async_dev == stdindev)) {
3150 				mutex_exit(asy->asy_excl_hi);
3151 				error = EINVAL;
3152 				break;
3153 			}
3154 
3155 			val = INB(MCR);
3156 			icr = INB(ICR);
3157 			/*
3158 			 * Disable the Modem Status Interrupt
3159 			 * The reason for disabling is  the status of
3160 			 * modem signal are in the higher 4 bits instead of
3161 			 * lower four bits when in loopback mode,
3162 			 * so, donot worry about Modem interrupt when
3163 			 * you are planning to set
3164 			 * this in loopback mode until it is cleared by
3165 			 * another ioctl to get out of the loopback mode
3166 			 */
3167 			OUTB(ICR, icr & ~ MIEN);
3168 			OUTB(MCR, val | ASY_LOOP);
3169 			mutex_exit(asy->asy_excl_hi);
3170 			iocp->ioc_error = 0;
3171 			mp->b_datap->db_type = M_IOCACK;
3172 			break;
3173 
3174 		case TIOCMGET:
3175 			datamp = allocb(sizeof (int), BPRI_MED);
3176 			if (datamp == NULL) {
3177 				error = EAGAIN;
3178 				break;
3179 			}
3180 
3181 			mutex_enter(asy->asy_excl_hi);
3182 			*(int *)datamp->b_rptr = asymctl(asy, 0, TIOCMGET);
3183 			mutex_exit(asy->asy_excl_hi);
3184 
3185 			if (iocp->ioc_count == TRANSPARENT) {
3186 				mcopyout(mp, NULL, sizeof (int), NULL, datamp);
3187 			} else {
3188 				if (mp->b_cont != NULL)
3189 					freemsg(mp->b_cont);
3190 				mp->b_cont = datamp;
3191 				mp->b_cont->b_wptr += sizeof (int);
3192 				mp->b_datap->db_type = M_IOCACK;
3193 				iocp->ioc_count = sizeof (int);
3194 			}
3195 			break;
3196 
3197 		case CONSOPENPOLLEDIO:
3198 			/*
3199 			 * If we are driving a keyboard there is nothing
3200 			 * upstream to translate the scan codes. Therefore,
3201 			 * set the error code to ENOTSUP and NAK the request
3202 			 */
3203 			if (asy->asy_device_type == ASY_KEYBOARD) {
3204 				error = ENOTSUP;
3205 				break;
3206 			}
3207 
3208 			error = miocpullup(mp, sizeof (struct cons_polledio *));
3209 			if (error != 0)
3210 				break;
3211 
3212 			/*
3213 			 * send up a message block containing the
3214 			 * cons_polledio structure. This provides
3215 			 * handles to the putchar, getchar, ischar,
3216 			 * polledio_enter and polledio_exit functions.
3217 			 */
3218 			*(struct cons_polledio **)mp->b_cont->b_rptr =
3219 			    &asy->polledio;
3220 
3221 			mp->b_datap->db_type = M_IOCACK;
3222 			break;
3223 
3224 		case CONSCLOSEPOLLEDIO:
3225 			/*
3226 			 * If we are driving a keyboard we never successfully
3227 			 * called CONSOPENPOLLEDIO so set the error to
3228 			 * ENOTSUP and NAK the request.
3229 			 */
3230 			if (asy->asy_device_type == ASY_KEYBOARD) {
3231 				error = ENOTSUP;
3232 				break;
3233 			}
3234 
3235 			mp->b_datap->db_type = M_IOCACK;
3236 			iocp->ioc_error = 0;
3237 			iocp->ioc_rval = 0;
3238 			break;
3239 
3240 		default: /* unexpected ioctl type */
3241 			/*
3242 			 * If we don't understand it, it's an error.  NAK it.
3243 			 */
3244 			error = EINVAL;
3245 			break;
3246 		}
3247 	}
3248 	if (error != 0) {
3249 		iocp->ioc_error = error;
3250 		mp->b_datap->db_type = M_IOCNAK;
3251 	}
3252 	mutex_exit(asy->asy_excl);
3253 	qreply(wq, mp);
3254 }
3255 
3256 static void
3257 asyrsrv(queue_t *q)
3258 {
3259 	mblk_t *bp;
3260 	struct asyncline *async;
3261 
3262 	async = (struct asyncline *)q->q_ptr;
3263 
3264 	while (canputnext(q) && (bp = getq(q)))
3265 		putnext(q, bp);
3266 	ASYSETSOFT(async->async_common);
3267 	async->async_polltid = 0;
3268 }
3269 
3270 /*
3271  * Put procedure for write queue.
3272  * Respond to M_STOP, M_START, M_IOCTL, and M_FLUSH messages here;
3273  * set the flow control character for M_STOPI and M_STARTI messages;
3274  * queue up M_BREAK, M_DELAY, and M_DATA messages for processing
3275  * by the start routine, and then call the start routine; discard
3276  * everything else.  Note that this driver does not incorporate any
3277  * mechanism to negotiate to handle the canonicalization process.
3278  * It expects that these functions are handled in upper module(s),
3279  * as we do in ldterm.
3280  */
3281 static void
3282 asywput(queue_t *q, mblk_t *mp)
3283 {
3284 	register struct asyncline *async;
3285 	register struct asycom *asy;
3286 	int error;
3287 
3288 	async = (struct asyncline *)q->q_ptr;
3289 	asy = async->async_common;
3290 
3291 	switch (mp->b_datap->db_type) {
3292 
3293 	case M_STOP:
3294 		/*
3295 		 * Since we don't do real DMA, we can just let the
3296 		 * chip coast to a stop after applying the brakes.
3297 		 */
3298 		mutex_enter(asy->asy_excl);
3299 		async->async_flags |= ASYNC_STOPPED;
3300 		mutex_exit(asy->asy_excl);
3301 		freemsg(mp);
3302 		break;
3303 
3304 	case M_START:
3305 		mutex_enter(asy->asy_excl);
3306 		if (async->async_flags & ASYNC_STOPPED) {
3307 			async->async_flags &= ~ASYNC_STOPPED;
3308 			/*
3309 			 * If an output operation is in progress,
3310 			 * resume it.  Otherwise, prod the start
3311 			 * routine.
3312 			 */
3313 			if (async->async_ocnt > 0) {
3314 				mutex_enter(asy->asy_excl_hi);
3315 				async_resume(async);
3316 				mutex_exit(asy->asy_excl_hi);
3317 			} else {
3318 				async_start(async);
3319 			}
3320 		}
3321 		mutex_exit(asy->asy_excl);
3322 		freemsg(mp);
3323 		break;
3324 
3325 	case M_IOCTL:
3326 		switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
3327 
3328 		case TCSBRK:
3329 			error = miocpullup(mp, sizeof (int));
3330 			if (error != 0) {
3331 				miocnak(q, mp, 0, error);
3332 				return;
3333 			}
3334 
3335 			if (*(int *)mp->b_cont->b_rptr != 0) {
3336 #ifdef DEBUG
3337 				if (asydebug & ASY_DEBUG_CLOSE)
3338 					printf("asy%d: flush request.\n",
3339 					    UNIT(async->async_dev));
3340 #endif
3341 				(void) putq(q, mp);
3342 				mutex_enter(asy->asy_excl);
3343 				async_nstart(async, 1);
3344 				mutex_exit(asy->asy_excl);
3345 				break;
3346 			}
3347 			/*FALLTHROUGH*/
3348 		case TCSETSW:
3349 		case TCSETSF:
3350 		case TCSETAW:
3351 		case TCSETAF:
3352 			/*
3353 			 * The changes do not take effect until all
3354 			 * output queued before them is drained.
3355 			 * Put this message on the queue, so that
3356 			 * "async_start" will see it when it's done
3357 			 * with the output before it.  Poke the
3358 			 * start routine, just in case.
3359 			 */
3360 			(void) putq(q, mp);
3361 			mutex_enter(asy->asy_excl);
3362 			async_start(async);
3363 			mutex_exit(asy->asy_excl);
3364 			break;
3365 
3366 		default:
3367 			/*
3368 			 * Do it now.
3369 			 */
3370 			async_ioctl(async, q, mp, B_TRUE);
3371 			break;
3372 		}
3373 		break;
3374 
3375 	case M_FLUSH:
3376 		if (*mp->b_rptr & FLUSHW) {
3377 			mutex_enter(asy->asy_excl);
3378 
3379 			/*
3380 			 * Abort any output in progress.
3381 			 */
3382 			mutex_enter(asy->asy_excl_hi);
3383 			if (async->async_flags & ASYNC_BUSY) {
3384 				async->async_ocnt = 0;
3385 				async->async_flags &= ~ASYNC_BUSY;
3386 			}
3387 			mutex_exit(asy->asy_excl_hi);
3388 
3389 			/* Flush FIFO buffers */
3390 			if (asy->asy_use_fifo == FIFO_ON) {
3391 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFOTXFLSH |
3392 				    (asy->asy_trig_level & 0xff));
3393 			}
3394 
3395 			/*
3396 			 * Flush our write queue.
3397 			 */
3398 			flushq(q, FLUSHDATA);	/* XXX doesn't flush M_DELAY */
3399 			if (async->async_xmitblk != NULL) {
3400 				freeb(async->async_xmitblk);
3401 				async->async_xmitblk = NULL;
3402 			}
3403 
3404 			mutex_exit(asy->asy_excl);
3405 			*mp->b_rptr &= ~FLUSHW;	/* it has been flushed */
3406 		}
3407 		if (*mp->b_rptr & FLUSHR) {
3408 			/* Flush FIFO buffers */
3409 			if (asy->asy_use_fifo == FIFO_ON) {
3410 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFORXFLSH |
3411 				    (asy->asy_trig_level & 0xff));
3412 			}
3413 			flushq(RD(q), FLUSHDATA);
3414 			qreply(q, mp);	/* give the read queues a crack at it */
3415 		} else {
3416 			freemsg(mp);
3417 		}
3418 
3419 		/*
3420 		 * We must make sure we process messages that survive the
3421 		 * write-side flush.  Without this call, the close protocol
3422 		 * with ldterm can hang forever.  (ldterm will have sent us a
3423 		 * TCSBRK ioctl that it expects a response to.)
3424 		 */
3425 		mutex_enter(asy->asy_excl);
3426 		async_start(async);
3427 		mutex_exit(asy->asy_excl);
3428 		break;
3429 	case M_BREAK:
3430 	case M_DELAY:
3431 	case M_DATA:
3432 		/*
3433 		 * Queue the message up to be transmitted,
3434 		 * and poke the start routine.
3435 		 */
3436 		(void) putq(q, mp);
3437 		mutex_enter(asy->asy_excl);
3438 		async_start(async);
3439 		mutex_exit(asy->asy_excl);
3440 		break;
3441 
3442 	case M_STOPI:
3443 		mutex_enter(asy->asy_excl);
3444 		async->async_flowc = async->async_stopc;
3445 		async_start(async);		/* poke the start routine */
3446 		mutex_exit(asy->asy_excl);
3447 		freemsg(mp);
3448 		break;
3449 
3450 	case M_STARTI:
3451 		mutex_enter(asy->asy_excl);
3452 		async->async_flowc = async->async_startc;
3453 		async_start(async);		/* poke the start routine */
3454 		mutex_exit(asy->asy_excl);
3455 		freemsg(mp);
3456 		break;
3457 
3458 	case M_CTL:
3459 		if (MBLKL(mp) >= sizeof (struct iocblk) &&
3460 		    ((struct iocblk *)mp->b_rptr)->ioc_cmd == MC_POSIXQUERY) {
3461 			((struct iocblk *)mp->b_rptr)->ioc_cmd = MC_HAS_POSIX;
3462 			qreply(q, mp);
3463 		} else {
3464 			/*
3465 			 * These MC_SERVICE type messages are used by upper
3466 			 * modules to tell this driver to send input up
3467 			 * immediately, or that it can wait for normal
3468 			 * processing that may or may not be done.  Sun
3469 			 * requires these for the mouse module.
3470 			 * (XXX - for x86?)
3471 			 */
3472 			mutex_enter(asy->asy_excl);
3473 			switch (*mp->b_rptr) {
3474 
3475 			case MC_SERVICEIMM:
3476 				async->async_flags |= ASYNC_SERVICEIMM;
3477 				break;
3478 
3479 			case MC_SERVICEDEF:
3480 				async->async_flags &= ~ASYNC_SERVICEIMM;
3481 				break;
3482 			}
3483 			mutex_exit(asy->asy_excl);
3484 			freemsg(mp);
3485 		}
3486 		break;
3487 
3488 	case M_IOCDATA:
3489 		async_iocdata(q, mp);
3490 		break;
3491 
3492 	default:
3493 		freemsg(mp);
3494 		break;
3495 	}
3496 }
3497 
3498 /*
3499  * Retry an "ioctl", now that "bufcall" claims we may be able to allocate
3500  * the buffer we need.
3501  */
3502 static void
3503 async_reioctl(void *arg)
3504 {
3505 	struct asyncline *async = arg;
3506 	struct asycom *asy = async->async_common;
3507 	queue_t	*q;
3508 	mblk_t		*mp;
3509 
3510 	/*
3511 	 * The bufcall is no longer pending.
3512 	 */
3513 	mutex_enter(asy->asy_excl);
3514 	async->async_wbufcid = 0;
3515 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
3516 		mutex_exit(asy->asy_excl);
3517 		return;
3518 	}
3519 	if ((mp = async->async_ttycommon.t_iocpending) != NULL) {
3520 		/* not pending any more */
3521 		async->async_ttycommon.t_iocpending = NULL;
3522 		mutex_exit(asy->asy_excl);
3523 		/* not in STREAMS queue; we no longer know if we're in wput */
3524 		async_ioctl(async, q, mp, B_TRUE);
3525 	} else
3526 		mutex_exit(asy->asy_excl);
3527 }
3528 
3529 static void
3530 async_iocdata(queue_t *q, mblk_t *mp)
3531 {
3532 	struct asyncline	*async = (struct asyncline *)q->q_ptr;
3533 	struct asycom		*asy;
3534 	struct copyresp *csp;
3535 
3536 	asy = async->async_common;
3537 	csp = (struct copyresp *)mp->b_rptr;
3538 
3539 	if (csp->cp_rval != 0) {
3540 		freemsg(mp);
3541 		return;
3542 	}
3543 
3544 	mutex_enter(asy->asy_excl);
3545 
3546 	switch (csp->cp_cmd) {
3547 	case TIOCMSET:
3548 	case TIOCMBIS:
3549 	case TIOCMBIC:
3550 		if (mp->b_cont == NULL) {
3551 			mutex_exit(asy->asy_excl);
3552 			miocnak(q, mp, 0, EINVAL);
3553 			break;
3554 		}
3555 
3556 		mutex_enter(asy->asy_excl_hi);
3557 		(void) asymctl(asy, dmtoasy(*(int *)mp->b_cont->b_rptr),
3558 		    csp->cp_cmd);
3559 		mutex_exit(asy->asy_excl_hi);
3560 
3561 		freemsg(mp->b_cont);
3562 		mp->b_cont = NULL;
3563 		mutex_exit(asy->asy_excl);
3564 		miocack(q, mp, 0, 0);
3565 		break;
3566 
3567 	case TIOCMGET:
3568 		if (mp->b_cont != NULL) {
3569 			freemsg(mp->b_cont);
3570 			mp->b_cont = NULL;
3571 		}
3572 		mutex_exit(asy->asy_excl);
3573 		miocack(q, mp, 0, 0);
3574 		break;
3575 
3576 	default:
3577 		mutex_exit(asy->asy_excl);
3578 		miocnak(q, mp, 0, EINVAL);
3579 		break;
3580 	}
3581 }
3582 
3583 
3584 /*
3585  * Set or get the modem control status.
3586  */
3587 static int
3588 asymctl(struct asycom *asy, int bits, int how)
3589 {
3590 	register int mcr_r, msr_r;
3591 
3592 	ASSERT(mutex_owned(asy->asy_excl_hi));
3593 	ASSERT(mutex_owned(asy->asy_excl));
3594 
3595 	/* Read Modem Control Registers */
3596 	mcr_r = INB(MCR);
3597 
3598 	switch (how) {
3599 
3600 	case TIOCMSET:
3601 		mcr_r = bits;
3602 		break;
3603 
3604 	case TIOCMBIS:
3605 		mcr_r |= bits;			/* Set bits from input	*/
3606 		break;
3607 
3608 	case TIOCMBIC:
3609 		mcr_r &= ~bits;			/* Set ~bits from input	*/
3610 		break;
3611 
3612 	case TIOCMGET:
3613 		/* Read Modem Status Registers */
3614 		if (INB(ICR) & MIEN)
3615 			msr_r = asy->asy_cached_msr;
3616 		else
3617 			msr_r = INB(MSR);
3618 		return (asytodm(mcr_r, msr_r));
3619 	}
3620 
3621 	OUTB(MCR, mcr_r);
3622 
3623 	return (mcr_r);
3624 }
3625 
3626 static int
3627 asytodm(int mcr_r, int msr_r)
3628 {
3629 	register int b = 0;
3630 
3631 
3632 	/* MCR registers */
3633 	if (mcr_r & RTS)
3634 		b |= TIOCM_RTS;
3635 
3636 	if (mcr_r & DTR)
3637 		b |= TIOCM_DTR;
3638 
3639 	/* MSR registers */
3640 	if (msr_r & DCD)
3641 		b |= TIOCM_CAR;
3642 
3643 	if (msr_r & CTS)
3644 		b |= TIOCM_CTS;
3645 
3646 	if (msr_r & DSR)
3647 		b |= TIOCM_DSR;
3648 
3649 	if (msr_r & RI)
3650 		b |= TIOCM_RNG;
3651 
3652 	return (b);
3653 }
3654 
3655 static int
3656 dmtoasy(int bits)
3657 {
3658 	register int b = 0;
3659 
3660 #ifdef	CAN_NOT_SET	/* only DTR and RTS can be set */
3661 	if (bits & TIOCM_CAR)
3662 		b |= DCD;
3663 	if (bits & TIOCM_CTS)
3664 		b |= CTS;
3665 	if (bits & TIOCM_DSR)
3666 		b |= DSR;
3667 	if (bits & TIOCM_RNG)
3668 		b |= RI;
3669 #endif
3670 
3671 	if (bits & TIOCM_RTS)
3672 		b |= RTS;
3673 	if (bits & TIOCM_DTR)
3674 		b |= DTR;
3675 
3676 	return (b);
3677 }
3678 
3679 static void
3680 asycheckflowcontrol_hw(struct asycom *asy)
3681 {
3682 	struct asyncline *async;
3683 	uchar_t	mcr, flag;
3684 
3685 	ASSERT(mutex_owned(asy->asy_excl_hi));
3686 
3687 	async = (struct asyncline *)asy->asy_priv;
3688 	ASSERT(async != NULL);
3689 
3690 	if (async->async_ttycommon.t_cflag & CRTSXOFF) {
3691 		mcr = INB(MCR);
3692 		flag = (async->async_flags & ASYNC_HW_IN_FLOW) ? 0 : RTS;
3693 		if (((mcr ^ flag) & RTS) != 0) {
3694 			OUTB(MCR, (mcr ^ RTS));
3695 		}
3696 	}
3697 }
3698 
3699 static boolean_t
3700 asycheckflowcontrol_sw(struct asycom *asy)
3701 {
3702 	uchar_t		ss;
3703 	struct asyncline *async;
3704 	int rval = B_FALSE;
3705 
3706 	ASSERT(mutex_owned(asy->asy_excl_hi));
3707 
3708 	async = (struct asyncline *)asy->asy_priv;
3709 	ASSERT(async != NULL);
3710 
3711 	if ((ss = async->async_flowc) != '\0' && (INB(LSR) & XHRE)) {
3712 		/*
3713 		 * If we get this far, then we know that flowc is non-zero and
3714 		 * that there's transmit room available.  We've "handled" the
3715 		 * request now, so clear it.  If the user didn't ask for IXOFF,
3716 		 * then don't actually send anything, but wait for the next
3717 		 * opportunity.
3718 		 */
3719 		async->async_flowc = '\0';
3720 		if (async->async_ttycommon.t_iflag & IXOFF) {
3721 			async->async_flags |= ASYNC_BUSY;
3722 			OUTB(DAT, ss);
3723 			rval = B_TRUE;
3724 		}
3725 	}
3726 
3727 	return (rval);
3728 }
3729 
3730 /*
3731  * Check for abort character sequence
3732  */
3733 static boolean_t
3734 abort_charseq_recognize(uchar_t ch)
3735 {
3736 	static int state = 0;
3737 #define	CNTRL(c) ((c)&037)
3738 	static char sequence[] = { '\r', '~', CNTRL('b') };
3739 
3740 	if (ch == sequence[state]) {
3741 		if (++state >= sizeof (sequence)) {
3742 			state = 0;
3743 			return (B_TRUE);
3744 		}
3745 	} else {
3746 		state = (ch == sequence[0]) ? 1 : 0;
3747 	}
3748 	return (B_FALSE);
3749 }
3750