xref: /illumos-gate/usr/src/uts/sun4/io/su_driver.c (revision d0b12b660e0741581d18f1f3a7d5268e0a5f1806)
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 2009 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  * Copyright (c) 2016 by Delphix. All rights reserved.
29  */
30 
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 	NULL,			/* devo_bus_ops */
278 	NULL,			/* devo_power */
279 	ddi_quiesce_not_supported,	/* devo_quiesce */
280 };
281 
282 /*
283  * Module linkage information for the kernel.
284  */
285 
286 static struct modldrv modldrv = {
287 	&mod_driverops, /* Type of module.  This one is a driver */
288 	"su driver",
289 	&asy_ops,	/* driver ops */
290 };
291 
292 static struct modlinkage modlinkage = {
293 	MODREV_1,
294 	&modldrv,
295 	NULL
296 };
297 
298 int
299 _init(void)
300 {
301 	int status;
302 
303 	status = ddi_soft_state_init(&su_asycom, sizeof (struct asycom),
304 	    SU_INITIAL_SOFT_ITEMS);
305 	if (status != 0)
306 		return (status);
307 	status = ddi_soft_state_init(&su_asyncline, sizeof (struct asyncline),
308 	    SU_INITIAL_SOFT_ITEMS);
309 	if (status != 0) {
310 		ddi_soft_state_fini(&su_asycom);
311 		return (status);
312 	}
313 
314 	if ((status = mod_install(&modlinkage)) != 0) {
315 		ddi_soft_state_fini(&su_asycom);
316 		ddi_soft_state_fini(&su_asyncline);
317 	}
318 
319 	return (status);
320 }
321 
322 int
323 _fini(void)
324 {
325 	int i;
326 
327 	i = mod_remove(&modlinkage);
328 	if (i == 0) {
329 		ddi_soft_state_fini(&su_asycom);
330 		ddi_soft_state_fini(&su_asyncline);
331 	}
332 
333 	return (i);
334 }
335 
336 int
337 _info(struct modinfo *modinfop)
338 {
339 	return (mod_info(&modlinkage, modinfop));
340 }
341 
342 static int
343 asyprobe(dev_info_t *devi)
344 {
345 	int		instance;
346 	ddi_acc_handle_t handle;
347 	uchar_t *addr;
348 	ddi_device_acc_attr_t attr;
349 
350 	attr.devacc_attr_version = DDI_DEVICE_ATTR_V0;
351 	attr.devacc_attr_endian_flags = DDI_STRUCTURE_LE_ACC;
352 	attr.devacc_attr_dataorder = DDI_STRICTORDER_ACC;
353 	if (ddi_regs_map_setup(devi, SU_REGISTER_FILE_NO, (caddr_t *)&addr,
354 	    SU_REGOFFSET, SU_REGISTER_LEN, &attr, &handle) != DDI_SUCCESS) {
355 		cmn_err(CE_WARN, "asyprobe regs map setup failed");
356 		return (DDI_PROBE_FAILURE);
357 	}
358 #ifdef DEBUG
359 	if (asydebug)
360 		printf("Probe address mapped %p\n", (void *)addr);
361 #endif
362 
363 	/*
364 	 * Probe for the device:
365 	 * 	Ser. int. uses bits 0,1,2; FIFO uses 3,6,7; 4,5 wired low.
366 	 * 	If bit 4 or 5 appears on inb() ISR, board is not there.
367 	 */
368 	if (ddi_get8(handle, addr+ISR) & 0x30) {
369 		ddi_regs_map_free(&handle);
370 		return (DDI_PROBE_FAILURE);
371 	}
372 
373 	instance = ddi_get_instance(devi);
374 	if (max_asy_instance < instance)
375 		max_asy_instance = instance;
376 	ddi_regs_map_free(&handle);
377 
378 	return (DDI_PROBE_SUCCESS); /* hw is present */
379 }
380 
381 static int
382 asydetach(dev_info_t *devi, ddi_detach_cmd_t cmd)
383 {
384 	register int	instance;
385 	struct asycom	*asy;
386 	struct asyncline *async;
387 	char		name[16];
388 
389 	instance = ddi_get_instance(devi);	/* find out which unit */
390 
391 	asy = (struct asycom *)ddi_get_soft_state(su_asycom, instance);
392 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, instance);
393 
394 	switch (cmd) {
395 		case DDI_DETACH:
396 			break;
397 		case DDI_SUSPEND:
398 			/* grab both mutex locks */
399 			mutex_enter(asy->asy_excl);
400 			mutex_enter(asy->asy_excl_hi);
401 			if (asy->suspended) {
402 				mutex_exit(asy->asy_excl_hi);
403 				mutex_exit(asy->asy_excl);
404 				return (DDI_SUCCESS);
405 			}
406 			asy->suspended = B_TRUE;
407 
408 			/*
409 			 * The quad UART ST16C554D, version D2 (made by EXAR)
410 			 * has an anomaly of generating spurious interrupts
411 			 * when the ICR is loaded with zero. The workaround
412 			 * would be to read/write any register with DATA1 bit
413 			 * set to 0 before such write.
414 			 */
415 			if (asy->asy_hwtype == ASY16C554D)
416 				OUTB(SPR, 0);
417 
418 			/* Disable further interrupts */
419 			OUTB(ICR, 0);
420 			mutex_exit(asy->asy_excl_hi);
421 			mutex_exit(asy->asy_excl);
422 			return (DDI_SUCCESS);
423 
424 		default:
425 			return (DDI_FAILURE);
426 	}
427 
428 #ifdef DEBUG
429 	if (asydebug & ASY_DEBUG_INIT)
430 		cmn_err(CE_NOTE, "su%d: ASY%s shutdown.", instance,
431 		    asy->asy_hwtype == ASY82510 ? "82510" :
432 		    asy->asy_hwtype == ASY16550AF ? "16550AF" :
433 		    asy->asy_hwtype == ASY16C554D ? "16C554D" :
434 		    "8250");
435 #endif
436 	/*
437 	 * Before removing interrupts it is always better to disable
438 	 * interrupts if the chip gives a provision to disable the
439 	 * serial port interrupts.
440 	 */
441 	mutex_enter(asy->asy_excl);
442 	mutex_enter(asy->asy_excl_hi);
443 	/* disable interrupts, see EXAR bug */
444 	if (asy->asy_hwtype == ASY16C554D)
445 		OUTB(SPR, 0);
446 	OUTB(ICR, 0);
447 	mutex_exit(asy->asy_excl_hi);
448 	mutex_exit(asy->asy_excl);
449 
450 	/* remove minor device node(s) for this device */
451 	(void) sprintf(name, "%c", (instance+'a'));	/* serial-port */
452 	ddi_remove_minor_node(devi, name);
453 	(void) sprintf(name, "%c,cu", (instance+'a')); /* serial-port:dailout */
454 	ddi_remove_minor_node(devi, name);
455 
456 	mutex_destroy(asy->asy_excl);
457 	mutex_destroy(asy->asy_excl_hi);
458 	kmem_free(asy->asy_excl, sizeof (kmutex_t));
459 	kmem_free(asy->asy_excl_hi, sizeof (kmutex_t));
460 	cv_destroy(&async->async_flags_cv);
461 	kstat_delete(asy->sukstat);
462 	ddi_remove_intr(devi, 0, asy->asy_iblock);
463 	ddi_regs_map_free(&asy->asy_handle);
464 	ddi_remove_softintr(asy->asy_softintr_id);
465 	mutex_destroy(asy->asy_soft_lock);
466 	kmem_free(asy->asy_soft_lock, sizeof (kmutex_t));
467 	ddi_soft_state_free(su_asycom, instance);
468 	ddi_soft_state_free(su_asyncline, instance);
469 	return (DDI_SUCCESS);
470 }
471 
472 static int
473 asyattach(dev_info_t *devi, ddi_attach_cmd_t cmd)
474 {
475 	register int	instance;
476 	struct asycom	*asy;
477 	struct asyncline *async;
478 	char		name[40];
479 	ddi_device_acc_attr_t attr;
480 	enum states { EMPTY, SOFTSTATE, REGSMAP, MUTEXES, ADDINTR,
481 	    SOFTINTR, ASYINIT, KSTAT, MINORNODE };
482 	enum states state = EMPTY;
483 	char *hwtype;
484 
485 	instance = ddi_get_instance(devi);	/* find out which unit */
486 
487 	/* cannot attach a device that has not been probed first */
488 	if (instance > max_asy_instance)
489 		return (DDI_FAILURE);
490 
491 	if (cmd != DDI_RESUME) {
492 		/* Allocate soft state space */
493 		if (ddi_soft_state_zalloc(su_asycom, instance) != DDI_SUCCESS) {
494 			cmn_err(CE_WARN, "su%d: cannot allocate soft state",
495 			    instance);
496 			goto error;
497 		}
498 	}
499 	state = SOFTSTATE;
500 
501 	asy = (struct asycom *)ddi_get_soft_state(su_asycom, instance);
502 
503 	if (asy == NULL) {
504 		cmn_err(CE_WARN, "su%d: cannot get soft state", instance);
505 		goto error;
506 	}
507 
508 	switch (cmd) {
509 		case DDI_ATTACH:
510 			break;
511 		case DDI_RESUME: {
512 			struct asyncline *async;
513 
514 			/* grab both mutex locks */
515 			mutex_enter(asy->asy_excl);
516 			mutex_enter(asy->asy_excl_hi);
517 			if (!asy->suspended) {
518 				mutex_exit(asy->asy_excl_hi);
519 				mutex_exit(asy->asy_excl);
520 				return (DDI_SUCCESS);
521 			}
522 			/*
523 			 * re-setup all the registers and enable interrupts if
524 			 * needed
525 			 */
526 			async = (struct asyncline *)asy->asy_priv;
527 			if ((async) && (async->async_flags & ASYNC_ISOPEN))
528 				(void) asy_program(asy, ASY_INIT);
529 			asy->suspended = B_FALSE;
530 			mutex_exit(asy->asy_excl_hi);
531 			mutex_exit(asy->asy_excl);
532 			return (DDI_SUCCESS);
533 		}
534 		default:
535 			goto error;
536 	}
537 
538 	attr.devacc_attr_version = DDI_DEVICE_ATTR_V0;
539 	attr.devacc_attr_endian_flags = DDI_STRUCTURE_LE_ACC;
540 	attr.devacc_attr_dataorder = DDI_STRICTORDER_ACC;
541 
542 	if (ddi_regs_map_setup(devi, SU_REGISTER_FILE_NO,
543 	    (caddr_t *)&asy->asy_ioaddr, SU_REGOFFSET, SU_REGISTER_LEN,
544 	    &attr, &asy->asy_handle) != DDI_SUCCESS) {
545 		cmn_err(CE_WARN, "asyprobe regs map setup failed");
546 		goto error;
547 	}
548 	state = REGSMAP;
549 
550 #ifdef DEBUG
551 	if (asydebug)
552 		printf("su attach mapped %p\n", (void *)asy->asy_ioaddr);
553 #endif
554 
555 	/*
556 	 * Initialize the port with default settings.
557 	 */
558 	asy->asy_fifo_buf = 1;
559 	asy->asy_use_fifo = FIFO_OFF;
560 
561 	/*
562 	 * Check for baudrate generator's "baud-divisor-factor" property setup
563 	 * by OBP, since different UART chips might have different baudrate
564 	 * generator divisor. e.g., in case of NSPG's Sputnik platform, the
565 	 * baud-divisor-factor is 13, it uses dedicated 16552 "DUART" chip
566 	 * instead of SuperIO. Since the baud-divisor-factor must be a positive
567 	 * integer, the divisors will always be at least as large as the values
568 	 * in asyspdtab[].  Make the default factor 1.
569 	 */
570 	asy->asy_baud_divisor_factor = ddi_prop_get_int(DDI_DEV_T_ANY, devi,
571 	    DDI_PROP_DONTPASS, "baud-divisor-factor", 1);
572 
573 	/* set speed cap */
574 	asy->asy_speed_cap = ddi_prop_get_int(DDI_DEV_T_ANY, devi,
575 	    DDI_PROP_DONTPASS, "serial-speed-cap", 115200);
576 
577 	/* check for ASY82510 chip */
578 	OUTB(ISR, 0x20);
579 	if (INB(ISR) & 0x20) { /* 82510 chip is present */
580 		/*
581 		 * Since most of the general operation of the 82510 chip
582 		 * can be done from BANK 0 (8250A/16450 compatable mode)
583 		 * we will default to BANK 0.
584 		 */
585 		asy->asy_hwtype = ASY82510;
586 		OUTB(DAT+7, 0x04); /* clear status */
587 		OUTB(ISR, 0x40); /* set to bank 2 */
588 		OUTB(MCR, 0x08); /* IMD */
589 		OUTB(DAT, 0x21); /* FMD */
590 		OUTB(ISR, 0x00); /* set to bank 0 */
591 		asy->asy_trig_level = 0;
592 	} else { /* Set the UART in FIFO mode if it has FIFO buffers */
593 		asy->asy_hwtype = ASY16550AF;
594 		OUTB(FIFOR, 0x00); /* clear fifo register */
595 		asy->asy_trig_level = 0x00; /* sets the fifo Threshold to 1 */
596 
597 		/* set/Enable FIFO */
598 		OUTB(FIFOR, FIFO_ON | FIFODMA | FIFOTXFLSH | FIFORXFLSH |
599 		    (asy->asy_trig_level & 0xff));
600 
601 		if ((INB(ISR) & 0xc0) == 0xc0)
602 			asy->asy_use_fifo = FIFO_ON;
603 		else {
604 			asy->asy_hwtype = ASY8250;
605 			OUTB(FIFOR, 0x00); /* NO FIFOs */
606 			asy->asy_trig_level = 0;
607 		}
608 	}
609 
610 	/* check for ST16C554D chip */
611 	if ((ddi_prop_lookup_string(DDI_DEV_T_ANY, devi, DDI_PROP_NOTPROM |
612 	    DDI_PROP_DONTPASS, "hwtype", &hwtype)) == DDI_PROP_SUCCESS) {
613 		if (strcmp(hwtype, "ST16C554D") == 0)
614 			asy->asy_hwtype = ASY16C554D;
615 		ddi_prop_free(hwtype);
616 	}
617 
618 	/* disable interrupts, see EXAR bug */
619 	if (asy->asy_hwtype == ASY16C554D)
620 		OUTB(SPR, 0);
621 	OUTB(ICR, 0);
622 	OUTB(LCR, DLAB); /* select baud rate generator */
623 	/* Set the baud rate to 9600 */
624 	OUTB(DAT+DLL, (ASY9600*asy->asy_baud_divisor_factor) & 0xff);
625 	OUTB(DAT+DLH, ((ASY9600*asy->asy_baud_divisor_factor) >> 8) & 0xff);
626 	OUTB(LCR, STOP1|BITS8);
627 	OUTB(MCR, (DTR | RTS| OUT2));
628 
629 	/*
630 	 * Set up the other components of the asycom structure for this port.
631 	 */
632 	asy->asy_excl = (kmutex_t *)
633 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
634 	asy->asy_excl_hi = (kmutex_t *)
635 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
636 	asy->asy_soft_lock = (kmutex_t *)
637 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
638 	asy->asy_unit = instance;
639 	asy->asy_dip = devi;
640 
641 	if (ddi_get_iblock_cookie(devi, 0, &asy->asy_iblock) != DDI_SUCCESS) {
642 		cmn_err(CE_NOTE,
643 		    "Get iblock_cookie failed-Device interrupt%x\n", instance);
644 		goto error;
645 	}
646 
647 	if (ddi_get_soft_iblock_cookie(devi, DDI_SOFTINT_HIGH,
648 	    &asy->asy_soft_iblock) != DDI_SUCCESS) {
649 		cmn_err(CE_NOTE, "Get iblock_cookie failed -soft interrupt%x\n",
650 		    instance);
651 		goto error;
652 	}
653 
654 	mutex_init(asy->asy_soft_lock, NULL, MUTEX_DRIVER,
655 	    (void *)asy->asy_soft_iblock);
656 	mutex_init(asy->asy_excl, NULL, MUTEX_DRIVER, NULL);
657 	mutex_init(asy->asy_excl_hi, NULL, MUTEX_DRIVER,
658 	    (void *)asy->asy_iblock);
659 	state = MUTEXES;
660 
661 	/*
662 	 * Install interrupt handlers for this device.
663 	 */
664 	if (ddi_add_intr(devi, 0, &(asy->asy_iblock), 0, asyintr,
665 	    (caddr_t)asy) != DDI_SUCCESS) {
666 		cmn_err(CE_CONT,
667 		    "Cannot set device interrupt for su driver\n");
668 		goto error;
669 	}
670 	state = ADDINTR;
671 
672 	if (ddi_add_softintr(devi, DDI_SOFTINT_HIGH, &(asy->asy_softintr_id),
673 	    &asy->asy_soft_iblock, 0, asysoftintr, (caddr_t)asy)
674 	    != DDI_SUCCESS) {
675 		cmn_err(CE_CONT, "Cannot set soft interrupt for su driver\n");
676 		goto error;
677 	}
678 	state = SOFTINTR;
679 
680 	/* initialize the asyncline structure */
681 	if (ddi_soft_state_zalloc(su_asyncline, instance) != DDI_SUCCESS) {
682 		cmn_err(CE_CONT, "su%d: cannot allocate soft state", instance);
683 		goto error;
684 	}
685 	state = ASYINIT;
686 
687 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, instance);
688 
689 	mutex_enter(asy->asy_excl);
690 	async->async_common = asy;
691 	cv_init(&async->async_flags_cv, NULL, CV_DEFAULT, NULL);
692 	mutex_exit(asy->asy_excl);
693 
694 	if ((asy->sukstat = kstat_create("su", instance, "serialstat",
695 	    "misc", KSTAT_TYPE_NAMED, 2, KSTAT_FLAG_VIRTUAL)) != NULL) {
696 		asy->sukstat->ks_data = &asy->kstats;
697 		kstat_named_init(&asy->kstats.ringover, "ring buffer overflow",
698 		    KSTAT_DATA_UINT64);
699 		kstat_named_init(&asy->kstats.siloover, "silo overflow",
700 		    KSTAT_DATA_UINT64);
701 		kstat_install(asy->sukstat);
702 	}
703 	state = KSTAT;
704 
705 	if (strcmp(ddi_node_name(devi), "rsc-console") == 0) {
706 		/*
707 		 * If the device is configured as the 'rsc-console'
708 		 * create the minor device for this node.
709 		 */
710 		if (ddi_create_minor_node(devi, "ssp", S_IFCHR,
711 		    asy->asy_unit | RSC_DEVICE, DDI_PSEUDO, NULL)
712 		    == DDI_FAILURE) {
713 			cmn_err(CE_WARN,
714 			    "%s%d: Failed to create node rsc-console",
715 			    ddi_get_name(devi), ddi_get_instance(devi));
716 			goto error;
717 		}
718 
719 		asy->asy_lom_console = 0;
720 		asy->asy_rsc_console = 1;
721 		asy->asy_rsc_control = 0;
722 		asy->asy_device_type = ASY_SERIAL;
723 		asy->asy_flags |= ASY_IGNORE_CD;
724 
725 	} else if (strcmp(ddi_node_name(devi), "lom-console") == 0) {
726 		/*
727 		 * If the device is configured as the 'lom-console'
728 		 * create the minor device for this node.
729 		 * Do not create a dialout device.
730 		 * Use the same minor numbers as would be used for standard
731 		 * serial instances.
732 		 */
733 		if (ddi_create_minor_node(devi, "lom-console", S_IFCHR,
734 		    instance, DDI_NT_SERIAL_LOMCON, NULL) == DDI_FAILURE) {
735 			cmn_err(CE_WARN,
736 			    "%s%d: Failed to create node lom-console",
737 			    ddi_get_name(devi), ddi_get_instance(devi));
738 			goto error;
739 		}
740 		asy->asy_lom_console = 1;
741 		asy->asy_rsc_console = 0;
742 		asy->asy_rsc_control = 0;
743 		asy->asy_device_type = ASY_SERIAL;
744 		asy->asy_flags |= ASY_IGNORE_CD;
745 
746 	} else if (strcmp(ddi_node_name(devi), "rsc-control") == 0) {
747 		/*
748 		 * If the device is configured as the 'rsc-control'
749 		 * create the minor device for this node.
750 		 */
751 		if (ddi_create_minor_node(devi, "sspctl", S_IFCHR,
752 		    asy->asy_unit | RSC_DEVICE, DDI_PSEUDO, NULL)
753 		    == DDI_FAILURE) {
754 			cmn_err(CE_WARN, "%s%d: Failed to create rsc-control",
755 			    ddi_get_name(devi), ddi_get_instance(devi));
756 			goto error;
757 		}
758 
759 		asy->asy_lom_console = 0;
760 		asy->asy_rsc_console = 0;
761 		asy->asy_rsc_control = 1;
762 		asy->asy_device_type = ASY_SERIAL;
763 		asy->asy_flags |= ASY_IGNORE_CD;
764 
765 	} else if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
766 	    "keyboard", 0)) {
767 		/*
768 		 * If the device is a keyboard, then create an internal
769 		 * pathname so that the dacf code will link the node into
770 		 * the keyboard console stream.  See dacf.conf.
771 		 */
772 		if (ddi_create_internal_pathname(devi, "keyboard",
773 		    S_IFCHR, instance) == DDI_FAILURE) {
774 			goto error;
775 		}
776 		asy->asy_flags |= ASY_IGNORE_CD;	/* ignore cd */
777 		asy->asy_device_type = ASY_KEYBOARD; 	/* Device type */
778 	} else if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
779 	    "mouse", 0)) {
780 		/*
781 		 * If the device is a mouse, then create an internal
782 		 * pathname so that the dacf code will link the node into
783 		 * the mouse stream.  See dacf.conf.
784 		 */
785 		if (ddi_create_internal_pathname(devi, "mouse", S_IFCHR,
786 		    instance) == DDI_FAILURE) {
787 			goto error;
788 		}
789 		asy->asy_flags |= ASY_IGNORE_CD;	/* ignore cd */
790 		asy->asy_device_type = ASY_MOUSE;
791 	} else {
792 		/*
793 		 * If not used for keyboard/mouse, create minor devices nodes
794 		 * for this device
795 		 */
796 		/* serial-port */
797 		(void) sprintf(name, "%c", (instance+'a'));
798 		if (ddi_create_minor_node(devi, name, S_IFCHR, instance,
799 		    DDI_NT_SERIAL_MB, NULL) == DDI_FAILURE) {
800 			goto error;
801 		}
802 		state = MINORNODE;
803 		/* serial-port:dailout */
804 		(void) sprintf(name, "%c,cu", (instance+'a'));
805 		if (ddi_create_minor_node(devi, name, S_IFCHR, instance|OUTLINE,
806 		    DDI_NT_SERIAL_MB_DO, NULL) == DDI_FAILURE) {
807 			goto error;
808 		}
809 		/* Property for ignoring DCD */
810 		if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
811 		    "ignore-cd", 0)) {
812 			asy->asy_flags |= ASY_IGNORE_CD;  /* ignore cd */
813 		} else {
814 			asy->asy_flags &= ~ASY_IGNORE_CD;
815 			/*
816 			 * if ignore-cd is not available it could be
817 			 * some old legacy platform, try to see
818 			 * whether the old legacy property exists
819 			 */
820 			(void) sprintf(name,
821 			    "port-%c-ignore-cd", (instance+ 'a'));
822 			if (ddi_getprop(DDI_DEV_T_ANY, devi,
823 			    DDI_PROP_DONTPASS, name, 0))
824 				asy->asy_flags |= ASY_IGNORE_CD;
825 		}
826 		asy->asy_device_type = ASY_SERIAL;
827 	}
828 
829 	/*
830 	 * Fill in the polled I/O structure
831 	 */
832 	asy->polledio.cons_polledio_version = CONSPOLLEDIO_V0;
833 	asy->polledio.cons_polledio_argument = (cons_polledio_arg_t)asy;
834 	asy->polledio.cons_polledio_putchar =  asyputchar;
835 	asy->polledio.cons_polledio_getchar = asygetchar;
836 	asy->polledio.cons_polledio_ischar = asyischar;
837 	asy->polledio.cons_polledio_enter = asy_polled_enter;
838 	asy->polledio.cons_polledio_exit = asy_polled_exit;
839 
840 	/* Initialize saved ICR and polled_enter */
841 	asy->polled_icr = 0;
842 	asy->polled_enter = B_FALSE;
843 
844 	ddi_report_dev(devi);
845 	return (DDI_SUCCESS);
846 
847 error:
848 	if (state == MINORNODE) {
849 		(void) sprintf(name, "%c", (instance+'a'));
850 		ddi_remove_minor_node(devi, name);
851 	}
852 	if (state >= KSTAT)
853 		kstat_delete(asy->sukstat);
854 	if (state >= ASYINIT) {
855 		cv_destroy(&async->async_flags_cv);
856 		ddi_soft_state_free(su_asyncline, instance);
857 	}
858 	if (state >= SOFTINTR)
859 		ddi_remove_softintr(asy->asy_softintr_id);
860 	if (state >= ADDINTR)
861 		ddi_remove_intr(devi, 0, asy->asy_iblock);
862 	if (state >= MUTEXES) {
863 		mutex_destroy(asy->asy_excl_hi);
864 		mutex_destroy(asy->asy_excl);
865 		mutex_destroy(asy->asy_soft_lock);
866 		kmem_free(asy->asy_excl_hi, sizeof (kmutex_t));
867 		kmem_free(asy->asy_excl, sizeof (kmutex_t));
868 		kmem_free(asy->asy_soft_lock, sizeof (kmutex_t));
869 	}
870 	if (state >= REGSMAP)
871 		ddi_regs_map_free(&asy->asy_handle);
872 	if (state >= SOFTSTATE)
873 		ddi_soft_state_free(su_asycom, instance);
874 	/* no action for EMPTY state */
875 	return (DDI_FAILURE);
876 }
877 
878 static int
879 asyinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
880     void **result)
881 {
882 	_NOTE(ARGUNUSED(dip))
883 	register dev_t dev = (dev_t)arg;
884 	register int instance, error;
885 	struct asycom *asy;
886 
887 	if ((instance = UNIT(dev)) > max_asy_instance)
888 		return (DDI_FAILURE);
889 
890 	switch (infocmd) {
891 		case DDI_INFO_DEVT2DEVINFO:
892 			asy = (struct asycom *)ddi_get_soft_state(su_asycom,
893 			    instance);
894 			if (asy->asy_dip == NULL)
895 				error = DDI_FAILURE;
896 			else {
897 				*result = (void *) asy->asy_dip;
898 				error = DDI_SUCCESS;
899 			}
900 			break;
901 		case DDI_INFO_DEVT2INSTANCE:
902 			*result = (void *)(uintptr_t)instance;
903 			error = DDI_SUCCESS;
904 			break;
905 		default:
906 			error = DDI_FAILURE;
907 	}
908 	return (error);
909 }
910 
911 static int
912 asyopen(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr)
913 {
914 	_NOTE(ARGUNUSED(sflag))
915 	struct asycom	*asy;
916 	struct asyncline *async;
917 	int		mcr;
918 	int		unit;
919 	int 		len;
920 	struct termios 	*termiosp;
921 
922 #ifdef DEBUG
923 	if (asydebug & ASY_DEBUG_CLOSE)
924 		printf("open\n");
925 #endif
926 	unit = UNIT(*dev);
927 	if (unit > max_asy_instance)
928 		return (ENXIO);		/* unit not configured */
929 
930 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, unit);
931 	if (async == NULL)
932 		return (ENXIO);
933 
934 	asy = async->async_common;
935 	if (asy == NULL)
936 		return (ENXIO);		/* device not found by autoconfig */
937 
938 	mutex_enter(asy->asy_excl);
939 	asy->asy_priv = (caddr_t)async;
940 
941 again:
942 	mutex_enter(asy->asy_excl_hi);
943 	/*
944 	 * Block waiting for carrier to come up, unless this is a no-delay open.
945 	 */
946 	if (!(async->async_flags & ASYNC_ISOPEN)) {
947 		/*
948 		 * If this port is for a RSC console or control
949 		 * use the following termio info
950 		 */
951 		if (asy->asy_rsc_console || asy->asy_rsc_control) {
952 			async->async_ttycommon.t_cflag = CIBAUDEXT | CBAUDEXT |
953 			    (B115200 & CBAUD);
954 			async->async_ttycommon.t_cflag |= ((B115200 << IBSHIFT)
955 			    & CIBAUD);
956 			async->async_ttycommon.t_cflag |= CS8 | CREAD | CLOCAL;
957 		} else if (asy->asy_lom_console) {
958 			async->async_ttycommon.t_cflag = B9600 & CBAUD;
959 			async->async_ttycommon.t_cflag |= ((B9600 << IBSHIFT)
960 			    & CIBAUD);
961 			async->async_ttycommon.t_cflag |= CS8 | CREAD | CLOCAL;
962 		} else {
963 
964 			/*
965 			 * Set the default termios settings (cflag).
966 			 * Others are set in ldterm.  Release the spin
967 			 * mutex as we can block here, reaquire before
968 			 * calling asy_program.
969 			 */
970 			mutex_exit(asy->asy_excl_hi);
971 			if (ddi_getlongprop(DDI_DEV_T_ANY, ddi_root_node(),
972 			    0, "ttymodes", (caddr_t)&termiosp, &len)
973 			    == DDI_PROP_SUCCESS &&
974 			    len == sizeof (struct termios)) {
975 				async->async_ttycommon.t_cflag =
976 				    termiosp->c_cflag;
977 				kmem_free(termiosp, len);
978 			} else {
979 				cmn_err(CE_WARN,
980 					"su: couldn't get ttymodes property!");
981 			}
982 			mutex_enter(asy->asy_excl_hi);
983 		}
984 		async->async_ttycommon.t_iflag = 0;
985 		async->async_ttycommon.t_iocpending = NULL;
986 		async->async_ttycommon.t_size.ws_row = 0;
987 		async->async_ttycommon.t_size.ws_col = 0;
988 		async->async_ttycommon.t_size.ws_xpixel = 0;
989 		async->async_ttycommon.t_size.ws_ypixel = 0;
990 		async->async_dev = *dev;
991 		async->async_wbufcid = 0;
992 
993 		async->async_startc = CSTART;
994 		async->async_stopc = CSTOP;
995 		(void) asy_program(asy, ASY_INIT);
996 	} else if ((async->async_ttycommon.t_flags & TS_XCLUDE) &&
997 	    secpolicy_excl_open(cr) != 0) {
998 		mutex_exit(asy->asy_excl_hi);
999 		mutex_exit(asy->asy_excl);
1000 		return (EBUSY);
1001 	} else if ((*dev & OUTLINE) && !(async->async_flags & ASYNC_OUT)) {
1002 		mutex_exit(asy->asy_excl_hi);
1003 		mutex_exit(asy->asy_excl);
1004 		return (EBUSY);
1005 	}
1006 
1007 	if (*dev & OUTLINE)
1008 		async->async_flags |= ASYNC_OUT;
1009 
1010 	/* Raise DTR on every open */
1011 	mcr = INB(MCR);
1012 	OUTB(MCR, mcr|DTR);
1013 
1014 	/*
1015 	 * Check carrier.
1016 	 */
1017 	if (asy->asy_flags & ASY_IGNORE_CD)
1018 		async->async_ttycommon.t_flags |= TS_SOFTCAR;
1019 	if ((async->async_ttycommon.t_flags & TS_SOFTCAR) ||
1020 	    (INB(MSR) & DCD))
1021 		async->async_flags |= ASYNC_CARR_ON;
1022 	else
1023 		async->async_flags &= ~ASYNC_CARR_ON;
1024 	mutex_exit(asy->asy_excl_hi);
1025 
1026 	/*
1027 	 * If FNDELAY and FNONBLOCK are clear, block until carrier up.
1028 	 * Quit on interrupt.
1029 	 */
1030 	if (!(flag & (FNDELAY|FNONBLOCK)) &&
1031 	    !(async->async_ttycommon.t_cflag & CLOCAL)) {
1032 		if (!(async->async_flags & (ASYNC_CARR_ON|ASYNC_OUT)) ||
1033 		    ((async->async_flags & ASYNC_OUT) &&
1034 		    !(*dev & OUTLINE))) {
1035 				async->async_flags |= ASYNC_WOPEN;
1036 				if (cv_wait_sig(&async->async_flags_cv,
1037 				    asy->asy_excl) == 0) {
1038 					async->async_flags &= ~ASYNC_WOPEN;
1039 					mutex_exit(asy->asy_excl);
1040 					return (EINTR);
1041 				}
1042 				async->async_flags &= ~ASYNC_WOPEN;
1043 				goto again;
1044 		}
1045 	} else if ((async->async_flags & ASYNC_OUT) && !(*dev & OUTLINE)) {
1046 		mutex_exit(asy->asy_excl);
1047 		return (EBUSY);
1048 	}
1049 
1050 	if (asy->suspended) {
1051 		mutex_exit(asy->asy_excl);
1052 		(void) ddi_dev_is_needed(asy->asy_dip, 0, 1);
1053 		mutex_enter(asy->asy_excl);
1054 	}
1055 
1056 	async->async_ttycommon.t_readq = rq;
1057 	async->async_ttycommon.t_writeq = WR(rq);
1058 	rq->q_ptr = WR(rq)->q_ptr = (caddr_t)async;
1059 	mutex_exit(asy->asy_excl);
1060 	qprocson(rq);
1061 	async->async_flags |= ASYNC_ISOPEN;
1062 	async->async_polltid = 0;
1063 	return (0);
1064 }
1065 
1066 static void
1067 async_progress_check(void *arg)
1068 {
1069 	struct asyncline *async = arg;
1070 	struct asycom	 *asy = async->async_common;
1071 	mblk_t *bp;
1072 
1073 	/*
1074 	 * We define "progress" as either waiting on a timed break or delay, or
1075 	 * having had at least one transmitter interrupt.  If none of these are
1076 	 * true, then just terminate the output and wake up that close thread.
1077 	 */
1078 	mutex_enter(asy->asy_excl);
1079 	mutex_enter(asy->asy_excl_hi);
1080 	if (!(async->async_flags & (ASYNC_BREAK|ASYNC_DELAY|ASYNC_PROGRESS))) {
1081 		async->async_ocnt = 0;
1082 		async->async_flags &= ~ASYNC_BUSY;
1083 		async->async_timer = 0;
1084 		bp = async->async_xmitblk;
1085 		async->async_xmitblk = NULL;
1086 		mutex_exit(asy->asy_excl_hi);
1087 		if (bp != NULL)
1088 			freeb(bp);
1089 		/*
1090 		 * Since this timer is running, we know that we're in exit(2).
1091 		 * That means that the user can't possibly be waiting on any
1092 		 * valid ioctl(2) completion anymore, and we should just flush
1093 		 * everything.
1094 		 */
1095 		flushq(async->async_ttycommon.t_writeq, FLUSHALL);
1096 		cv_broadcast(&async->async_flags_cv);
1097 	} else {
1098 		async->async_flags &= ~ASYNC_PROGRESS;
1099 		async->async_timer = timeout(async_progress_check, async,
1100 		    drv_usectohz(su_drain_check));
1101 		mutex_exit(asy->asy_excl_hi);
1102 	}
1103 	mutex_exit(asy->asy_excl);
1104 }
1105 
1106 /*
1107  * Close routine.
1108  */
1109 static int
1110 asyclose(queue_t *q, int flag)
1111 {
1112 	struct asyncline *async;
1113 	struct asycom	 *asy;
1114 	int icr, lcr;
1115 	int		nohupcl;
1116 
1117 
1118 #ifdef DEBUG
1119 	if (asydebug & ASY_DEBUG_CLOSE)
1120 		printf("close\n");
1121 #endif
1122 	async = q->q_ptr;
1123 	ASSERT(async != NULL);
1124 	asy = async->async_common;
1125 
1126 	/* get the nohupcl OBP property of this device */
1127 	nohupcl = ddi_getprop(DDI_DEV_T_ANY, asy->asy_dip, DDI_PROP_DONTPASS,
1128 	    "nohupcl", 0);
1129 
1130 	mutex_enter(asy->asy_excl);
1131 	async->async_flags |= ASYNC_CLOSING;
1132 
1133 	/*
1134 	 * Turn off PPS handling early to avoid events occuring during
1135 	 * close.  Also reset the DCD edge monitoring bit.
1136 	 */
1137 	mutex_enter(asy->asy_excl_hi);
1138 	asy->asy_flags &= ~(ASY_PPS | ASY_PPS_EDGE);
1139 	mutex_exit(asy->asy_excl_hi);
1140 
1141 	/*
1142 	 * There are two flavors of break -- timed (M_BREAK or TCSBRK) and
1143 	 * untimed (TIOCSBRK).  For the timed case, these are enqueued on our
1144 	 * write queue and there's a timer running, so we don't have to worry
1145 	 * about them.  For the untimed case, though, the user obviously made a
1146 	 * mistake, because these are handled immediately.  We'll terminate the
1147 	 * break now and honor their implicit request by discarding the rest of
1148 	 * the data.
1149 	 */
1150 	if (!(async->async_flags & ASYNC_BREAK)) {
1151 		mutex_enter(asy->asy_excl_hi);
1152 		lcr = INB(LCR);
1153 		if (lcr & SETBREAK) {
1154 			OUTB(LCR, (lcr & ~SETBREAK));
1155 		}
1156 		mutex_exit(asy->asy_excl_hi);
1157 		if (lcr & SETBREAK)
1158 			goto nodrain;
1159 	}
1160 
1161 	/*
1162 	 * If the user told us not to delay the close ("non-blocking"), then
1163 	 * don't bother trying to drain.
1164 	 *
1165 	 * If the user did M_STOP (ASYNC_STOPPED), there's no hope of ever
1166 	 * getting an M_START (since these messages aren't enqueued), and the
1167 	 * only other way to clear the stop condition is by loss of DCD, which
1168 	 * would discard the queue data.  Thus, we drop the output data if
1169 	 * ASYNC_STOPPED is set.
1170 	 */
1171 	if ((flag & (FNDELAY|FNONBLOCK)) ||
1172 	    (async->async_flags & ASYNC_STOPPED)) {
1173 		goto nodrain;
1174 	}
1175 
1176 	/*
1177 	 * If there's any pending output, then we have to try to drain it.
1178 	 * There are two main cases to be handled:
1179 	 *	- called by close(2): need to drain until done or until
1180 	 *	  a signal is received.  No timeout.
1181 	 *	- called by exit(2): need to drain while making progress
1182 	 *	  or until a timeout occurs.  No signals.
1183 	 *
1184 	 * If we can't rely on receiving a signal to get us out of a hung
1185 	 * session, then we have to use a timer.  In this case, we set a timer
1186 	 * to check for progress in sending the output data -- all that we ask
1187 	 * (at each interval) is that there's been some progress made.  Since
1188 	 * the interrupt routine grabs buffers from the write queue, we can't
1189 	 * trust async_ocnt.  Instead, we use a flag.
1190 	 *
1191 	 * Note that loss of carrier will cause the output queue to be flushed,
1192 	 * and we'll wake up again and finish normally.
1193 	 */
1194 	if (!ddi_can_receive_sig() && su_drain_check != 0) {
1195 		async->async_flags &= ~ASYNC_PROGRESS;
1196 		async->async_timer = timeout(async_progress_check, async,
1197 		    drv_usectohz(su_drain_check));
1198 	}
1199 
1200 	while (async->async_ocnt > 0 ||
1201 	    async->async_ttycommon.t_writeq->q_first != NULL ||
1202 	    (async->async_flags & (ASYNC_BUSY|ASYNC_BREAK|ASYNC_DELAY))) {
1203 		if (cv_wait_sig(&async->async_flags_cv, asy->asy_excl) == 0)
1204 			break;
1205 	}
1206 	if (async->async_timer != 0) {
1207 		(void) untimeout(async->async_timer);
1208 		async->async_timer = 0;
1209 	}
1210 
1211 nodrain:
1212 	mutex_enter(asy->asy_excl_hi);
1213 
1214 	/* turn off the loopback mode */
1215 	if ((async->async_dev != rconsdev) &&
1216 	    (async->async_dev != kbddev) &&
1217 	    (async->async_dev != stdindev)) {
1218 		OUTB(MCR, INB(MCR) & ~ ASY_LOOP);
1219 	}
1220 
1221 	async->async_ocnt = 0;
1222 	if (async->async_xmitblk != NULL)
1223 		freeb(async->async_xmitblk);
1224 	async->async_xmitblk = NULL;
1225 
1226 	/*
1227 	 * If the "nohupcl" OBP property is set for this device, do
1228 	 * not turn off DTR and RTS no matter what.  Otherwise, if the
1229 	 * line has HUPCL set or is incompletely opened, turn off DTR
1230 	 * and RTS to fix the modem line.
1231 	 */
1232 	if (!nohupcl && ((async->async_ttycommon.t_cflag & HUPCL) ||
1233 	    (async->async_flags & ASYNC_WOPEN))) {
1234 		/* turn off DTR, RTS but NOT interrupt to 386 */
1235 		OUTB(MCR, OUT2);
1236 		mutex_exit(asy->asy_excl_hi);
1237 		/*
1238 		 * Don't let an interrupt in the middle of close
1239 		 * bounce us back to the top; just continue closing
1240 		 * as if nothing had happened.
1241 		 */
1242 		if (cv_wait_sig(&lbolt_cv, asy->asy_excl) == 0)
1243 			goto out;
1244 		mutex_enter(asy->asy_excl_hi);
1245 	}
1246 
1247 	/*
1248 	 * If nobody's using it now, turn off receiver interrupts.
1249 	 */
1250 	if ((async->async_flags & (ASYNC_WOPEN|ASYNC_ISOPEN)) == 0) {
1251 		icr = INB(ICR);
1252 		OUTB(ICR, (icr & ~RIEN));
1253 	}
1254 	mutex_exit(asy->asy_excl_hi);
1255 out:
1256 	/*
1257 	 * Clear out device state.
1258 	 */
1259 	async->async_flags = 0;
1260 	ttycommon_close(&async->async_ttycommon);
1261 	cv_broadcast(&async->async_flags_cv);
1262 
1263 	/*
1264 	 * Clear ASY_DOINGSOFT and ASY_NEEDSOFT in case we were in
1265 	 * async_softint or an interrupt was pending when the process
1266 	 * using the port exited.
1267 	 */
1268 	asy->asy_flags &= ~ASY_DOINGSOFT & ~ASY_NEEDSOFT;
1269 
1270 	/*
1271 	 * Cancel outstanding "bufcall" request.
1272 	 */
1273 	if (async->async_wbufcid) {
1274 		unbufcall(async->async_wbufcid);
1275 		async->async_wbufcid = 0;
1276 	}
1277 
1278 	/*
1279 	 * If inperim is true, it means the port is closing while there's
1280 	 * a pending software interrupt.  async_flags has been zeroed out,
1281 	 * so this instance of leaveq() needs to be called before we call
1282 	 * qprocsoff() to disable services on the q.  If inperim is false,
1283 	 * leaveq() has already been called or we're not in a perimeter.
1284 	 */
1285 	if (asy->inperim == B_TRUE) {
1286 		asy->inperim = B_FALSE;
1287 		mutex_exit(asy->asy_excl);
1288 		leaveq(q);
1289 	} else {
1290 		mutex_exit(asy->asy_excl);
1291 	}
1292 
1293 	/* Note that qprocsoff can't be done until after interrupts are off */
1294 	qprocsoff(q);
1295 	q->q_ptr = WR(q)->q_ptr = NULL;
1296 	async->async_ttycommon.t_readq = NULL;
1297 	async->async_ttycommon.t_writeq = NULL;
1298 
1299 	return (0);
1300 }
1301 
1302 /*
1303  * Checks to see if the serial port is still transmitting
1304  * characters.  It returns true when there are characters
1305  * queued to transmit,  when the holding register contains
1306  * a byte, or when the shifting register still contains
1307  * data to send.
1308  *
1309  */
1310 static boolean_t
1311 asy_isbusy(struct asycom *asy)
1312 {
1313 	struct asyncline *async;
1314 
1315 #ifdef DEBUG
1316 	if (asydebug & ASY_DEBUG_EOT)
1317 		printf("isbusy\n");
1318 #endif
1319 	async = (struct asyncline *)asy->asy_priv;
1320 	ASSERT(mutex_owned(asy->asy_excl));
1321 	ASSERT(mutex_owned(asy->asy_excl_hi));
1322 	return ((async->async_ocnt > 0) ||
1323 	    ((INB(LSR) & XSRE) == 0));
1324 }
1325 
1326 /*
1327  * Program the ASY port. Most of the async operation is based on the values
1328  * of 'c_iflag' and 'c_cflag'.
1329  */
1330 static int
1331 asy_program(struct asycom *asy, int mode)
1332 {
1333 	struct asyncline *async;
1334 	int baudrate, c_flag;
1335 	int icr, lcr;
1336 	int ocflags;
1337 	int error = 0;
1338 
1339 	ASSERT(mutex_owned(asy->asy_excl));
1340 	ASSERT(mutex_owned(asy->asy_excl_hi));
1341 
1342 #ifdef DEBUG
1343 	if (asydebug & ASY_DEBUG_PROCS)
1344 		printf("program\n");
1345 #endif
1346 	async = (struct asyncline *)asy->asy_priv;
1347 
1348 	baudrate = async->async_ttycommon.t_cflag & CBAUD;
1349 	if (async->async_ttycommon.t_cflag & CBAUDEXT)
1350 		baudrate += 16;
1351 
1352 	/* Limit baudrate so it can't index out of baudtable */
1353 	if (baudrate >= N_SU_SPEEDS) baudrate = B9600;
1354 
1355 	/*
1356 	 * If baud rate requested is greater than the speed cap
1357 	 * or is an unsupported baud rate then reset t_cflag baud
1358 	 * to the last valid baud rate.  If this is the initial
1359 	 * pass through asy_program then set it to 9600.
1360 	 */
1361 	if (((baudrate > 0) && (asyspdtab[baudrate] == 0)) ||
1362 	    (baudtable[baudrate] > asy->asy_speed_cap)) {
1363 		async->async_ttycommon.t_cflag &= ~CBAUD & ~CBAUDEXT &
1364 		    ~CIBAUD & ~CIBAUDEXT;
1365 		if (mode == ASY_INIT) {
1366 			async->async_ttycommon.t_cflag |= B9600;
1367 			async->async_ttycommon.t_cflag |= B9600 << IBSHIFT;
1368 			baudrate = B9600;
1369 		} else {
1370 			async->async_ttycommon.t_cflag |=
1371 			    (asy->asy_ocflags & (CBAUD | CBAUDEXT |
1372 			    CIBAUD | CIBAUDEXT));
1373 			error = EINVAL;
1374 			goto end;
1375 		}
1376 	}
1377 
1378 	/*
1379 	 * If CIBAUD and CIBAUDEXT are zero then we should set them to
1380 	 * the equivelant output baud bits.  Else, if CIBAUD and CIBAUDEXT
1381 	 * don't match CBAUD and CBAUDEXT respectively then we should
1382 	 * notify the requestor that we do not support split speeds.
1383 	 */
1384 	if ((async->async_ttycommon.t_cflag  & (CIBAUD|CIBAUDEXT)) == 0) {
1385 		async->async_ttycommon.t_cflag |=
1386 		    (async->async_ttycommon.t_cflag & CBAUD) << IBSHIFT;
1387 		if (async->async_ttycommon.t_cflag & CBAUDEXT)
1388 			async->async_ttycommon.t_cflag |= CIBAUDEXT;
1389 	} else {
1390 		if ((((async->async_ttycommon.t_cflag & CBAUD) << IBSHIFT) !=
1391 		    (async->async_ttycommon.t_cflag & CIBAUD)) ||
1392 		    !(((async->async_ttycommon.t_cflag & (CBAUDEXT |
1393 		    CIBAUDEXT)) == (CBAUDEXT | CIBAUDEXT)) ||
1394 		    ((async->async_ttycommon.t_cflag & (CBAUDEXT |
1395 		    CIBAUDEXT)) == 0))) {
1396 			async->async_ttycommon.t_cflag &= ~CBAUD & ~CBAUDEXT &
1397 			    ~CIBAUD & ~CIBAUDEXT;
1398 			async->async_ttycommon.t_cflag |=
1399 			    (asy->asy_ocflags & (CBAUD | CBAUDEXT |
1400 			    CIBAUD | CIBAUDEXT));
1401 			error = EINVAL;
1402 			goto end;
1403 		}
1404 	}
1405 
1406 	c_flag = async->async_ttycommon.t_cflag &
1407 	    (CLOCAL | CREAD | CSTOPB | CSIZE | PARENB | PARODD | CBAUD |
1408 	    CBAUDEXT | CIBAUD | CIBAUDEXT);
1409 
1410 	/* disable interrupts, see EXAR bug */
1411 	if (asy->asy_hwtype == ASY16C554D)
1412 		OUTB(SPR, 0);
1413 	OUTB(ICR, 0);
1414 
1415 	ocflags = asy->asy_ocflags;
1416 
1417 	/* flush/reset the status registers */
1418 	if (mode == ASY_INIT) {
1419 		(void) INB(DAT);
1420 		(void) INB(ISR);
1421 		(void) INB(LSR);
1422 		(void) INB(MSR);
1423 	}
1424 
1425 	if (ocflags != (c_flag & ~CLOCAL) || mode == ASY_INIT) {
1426 		/* Set line control */
1427 		lcr = INB(LCR);
1428 		lcr &= ~(WLS0|WLS1|STB|PEN|EPS);
1429 
1430 		if (c_flag & CSTOPB)
1431 			lcr |= STB;	/* 2 stop bits */
1432 
1433 		if (c_flag & PARENB)
1434 			lcr |= PEN;
1435 
1436 		if ((c_flag & PARODD) == 0)
1437 			lcr |= EPS;
1438 
1439 		switch (c_flag & CSIZE) {
1440 		case CS5:
1441 			lcr |= BITS5;
1442 			break;
1443 		case CS6:
1444 			lcr |= BITS6;
1445 			break;
1446 		case CS7:
1447 			lcr |= BITS7;
1448 			break;
1449 		case CS8:
1450 			lcr |= BITS8;
1451 			break;
1452 		}
1453 
1454 		/* set the baud rate when the rate is NOT B0 */
1455 		if (baudrate != 0) {
1456 			OUTB(LCR, DLAB);
1457 			OUTB(DAT, (asyspdtab[baudrate] *
1458 			    asy->asy_baud_divisor_factor) & 0xff);
1459 			OUTB(ICR, ((asyspdtab[baudrate] *
1460 			    asy->asy_baud_divisor_factor) >> 8) & 0xff);
1461 		}
1462 		/* set the line control modes */
1463 		OUTB(LCR, lcr);
1464 
1465 		/*
1466 		 * if transitioning from CREAD off to CREAD on,
1467 		 * flush the FIFO buffer if we have one.
1468 		 */
1469 		if ((ocflags & CREAD) == 0 && (c_flag & CREAD)) {
1470 			if (asy->asy_use_fifo == FIFO_ON) {
1471 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFORXFLSH |
1472 				    (asy->asy_trig_level & 0xff));
1473 			}
1474 		}
1475 
1476 		/* remember the new cflags */
1477 		asy->asy_ocflags = c_flag & ~CLOCAL;
1478 	}
1479 
1480 	/* whether or not CLOCAL is set, modify the modem control lines */
1481 	if (baudrate == 0)
1482 		/* B0 has been issued, lower DTR */
1483 		OUTB(MCR, RTS|OUT2);
1484 	else
1485 		/* raise DTR */
1486 		OUTB(MCR, DTR|RTS|OUT2);
1487 
1488 	/*
1489 	 * Call the modem status interrupt handler to check for the carrier
1490 	 * in case CLOCAL was turned off after the carrier came on.
1491 	 * (Note: Modem status interrupt is not enabled if CLOCAL is ON.)
1492 	 */
1493 	async_msint(asy);
1494 
1495 	/* Set interrupt control */
1496 	if ((c_flag & CLOCAL) && !(async->async_ttycommon.t_cflag & CRTSCTS))
1497 		/*
1498 		 * direct-wired line ignores DCD, so we don't enable modem
1499 		 * status interrupts.
1500 		 */
1501 		icr = (TIEN | SIEN);
1502 	else
1503 		icr = (TIEN | SIEN | MIEN);
1504 
1505 	if (c_flag & CREAD)
1506 		icr |= RIEN;
1507 
1508 	OUTB(ICR, icr);
1509 end:
1510 	return (error);
1511 }
1512 
1513 /*
1514  * Polled mode support -- all functions called with interrupts
1515  * disabled.
1516  */
1517 
1518 static void
1519 asyputchar(cons_polledio_arg_t arg, uchar_t c)
1520 {
1521 	struct asycom *asy = (struct asycom *)arg;
1522 
1523 	/*
1524 	 * If we see a line feed make sure to also
1525 	 * put out a carriage return.
1526 	 */
1527 	if (c == '\n')
1528 		asyputchar(arg, '\r');
1529 
1530 	while ((INB(LSR) & XHRE) == 0) {
1531 		/* wait for the transmission to complete */
1532 		drv_usecwait(10);
1533 	}
1534 
1535 	/* ouput the character */
1536 	OUTB(DAT, c);
1537 }
1538 
1539 /*
1540  * Determines if there is a character avaialable for
1541  * reading.
1542  */
1543 static boolean_t
1544 asyischar(cons_polledio_arg_t arg)
1545 {
1546 	struct asycom *asy = (struct asycom *)arg;
1547 	return ((INB(LSR) & RCA) != 0);
1548 }
1549 
1550 static int
1551 asygetchar(cons_polledio_arg_t arg)
1552 {
1553 	struct asycom *asy = (struct asycom *)arg;
1554 
1555 	/*
1556 	 * Spin waiting for a character to be
1557 	 * available to read.
1558 	 */
1559 	while (!asyischar(arg))
1560 		drv_usecwait(10);
1561 
1562 	return (INB(DAT));
1563 }
1564 
1565 /*
1566  * Called when machine is transitioning to polled mode
1567  */
1568 static void
1569 asy_polled_enter(cons_polledio_arg_t arg)
1570 {
1571 	struct asycom *asy = (struct asycom *)arg;
1572 
1573 	mutex_enter(asy->asy_excl);
1574 	mutex_enter(asy->asy_excl_hi);
1575 
1576 	/*
1577 	 * If this is the first time that asy_polled_enter()
1578 	 * has been called, during this transition request,
1579 	 * save the ICR. Clear the software interrupt
1580 	 * flags since we won't be able to handle these when
1581 	 * we are in polled mode.
1582 	 */
1583 	if (!asy->polled_enter) {
1584 		asy->polled_enter = B_TRUE;
1585 		asy->polled_icr = INB(ICR);
1586 
1587 		/* Disable HW interrupts */
1588 		if (asy->asy_hwtype == ASY16C554D)
1589 			OUTB(SPR, 0);
1590 		OUTB(ICR, 0);
1591 
1592 		asy->asy_flags &= ~ASY_DOINGSOFT & ~ASY_NEEDSOFT;
1593 	}
1594 	mutex_exit(asy->asy_excl_hi);
1595 	mutex_exit(asy->asy_excl);
1596 }
1597 
1598 /*
1599  * Called when machine is transitioning from polled mode.
1600  */
1601 static void
1602 asy_polled_exit(cons_polledio_arg_t arg)
1603 {
1604 	struct asycom *asy = (struct asycom *)arg;
1605 
1606 	mutex_enter(asy->asy_excl);
1607 	mutex_enter(asy->asy_excl_hi);
1608 
1609 	/* Restore the ICR */
1610 	OUTB(ICR, asy->polled_icr);
1611 
1612 	/*
1613 	 * We have finished this polled IO transition.
1614 	 * Set polled_enter to B_FALSE to note this.
1615 	 */
1616 	asy->polled_enter = B_FALSE;
1617 	mutex_exit(asy->asy_excl_hi);
1618 	mutex_exit(asy->asy_excl);
1619 }
1620 
1621 /*
1622  * asyintr() is the High Level Interrupt Handler.
1623  *
1624  * There are four different interrupt types indexed by ISR register values:
1625  *		0: modem
1626  *		1: Tx holding register is empty, ready for next char
1627  *		2: Rx register now holds a char to be picked up
1628  *		3: error or break on line
1629  * This routine checks the Bit 0 (interrupt-not-pending) to determine if
1630  * the interrupt is from this port.
1631  */
1632 uint_t
1633 asyintr(caddr_t argasy)
1634 {
1635 	struct asycom		*asy = (struct asycom *)argasy;
1636 	struct asyncline	*async;
1637 	int			ret_status = DDI_INTR_UNCLAIMED;
1638 	uchar_t			interrupt_id, lsr;
1639 
1640 	interrupt_id = INB(ISR) & 0x0F;
1641 	async = (struct asyncline *)asy->asy_priv;
1642 	if ((async == NULL) ||
1643 	    !(async->async_flags & (ASYNC_ISOPEN|ASYNC_WOPEN))) {
1644 		if (interrupt_id & NOINTERRUPT)  {
1645 			return (DDI_INTR_UNCLAIMED);
1646 		} else {
1647 			lsr = INB(LSR);
1648 			if ((lsr & BRKDET) &&
1649 			    ((abort_enable == KIOCABORTENABLE) &&
1650 			    (async->async_dev == rconsdev)))
1651 				abort_sequence_enter((char *)NULL);
1652 			else {
1653 				/* reset line status */
1654 				(void) INB(LSR);
1655 				/* discard any data */
1656 				(void) INB(DAT);
1657 				/* reset modem status */
1658 				(void) INB(MSR);
1659 				return (DDI_INTR_CLAIMED);
1660 			}
1661 		}
1662 	}
1663 	/*
1664 	 * Spurious interrupts happen in this driver
1665 	 * because of the transmission on serial port not handled
1666 	 * properly.
1667 	 *
1668 	 * The reasons for Spurious interrupts are:
1669 	 *    1. There is a path in async_nstart which transmits
1670 	 *	 characters without going through interrupt services routine
1671 	 *	 which causes spurious interrupts to happen.
1672 	 *    2. In the async_txint more than one character is sent
1673 	 *	 in one interrupt service.
1674 	 *    3. In async_rxint more than one characters are received in
1675 	 *	 in one interrupt service.
1676 	 *
1677 	 * Hence we have flags to indicate that such scenerio has happened.
1678 	 * and claim only such interrupts and others we donot claim it
1679 	 * as it could be a indicator of some hardware problem.
1680 	 *
1681 	 */
1682 	if (interrupt_id & NOINTERRUPT) {
1683 		mutex_enter(asy->asy_excl_hi);
1684 		if ((asy->asy_xmit_count > 1) ||
1685 		    (asy->asy_out_of_band_xmit > 0) ||
1686 		    (asy->asy_rx_count > 1)) {
1687 			asy->asy_xmit_count = 0;
1688 			asy->asy_out_of_band_xmit = 0;
1689 			asy->asy_rx_count = 0;
1690 			mutex_exit(asy->asy_excl_hi);
1691 			return (DDI_INTR_CLAIMED);
1692 		} else {
1693 			mutex_exit(asy->asy_excl_hi);
1694 			return (DDI_INTR_UNCLAIMED);
1695 		}
1696 	}
1697 	ret_status = DDI_INTR_CLAIMED;
1698 	mutex_enter(asy->asy_excl_hi);
1699 	if (asy->asy_hwtype == ASY82510)
1700 		OUTB(ISR, 0x00); /* set bank 0 */
1701 
1702 #ifdef DEBUG
1703 	if (asydebug & ASY_DEBUG_INTR)
1704 		prom_printf("l");
1705 #endif
1706 	lsr = INB(LSR);
1707 	switch (interrupt_id) {
1708 	case RxRDY:
1709 	case RSTATUS:
1710 	case FFTMOUT:
1711 		/* receiver interrupt or receiver errors */
1712 		async_rxint(asy, lsr);
1713 		break;
1714 	case TxRDY:
1715 		/* transmit interrupt */
1716 		async_txint(asy, lsr);
1717 		break;
1718 	case MSTATUS:
1719 		/* modem status interrupt */
1720 		async_msint(asy);
1721 		break;
1722 	}
1723 	mutex_exit(asy->asy_excl_hi);
1724 	return (ret_status);
1725 }
1726 
1727 /*
1728  * Transmitter interrupt service routine.
1729  * If there is more data to transmit in the current pseudo-DMA block,
1730  * send the next character if output is not stopped or draining.
1731  * Otherwise, queue up a soft interrupt.
1732  *
1733  * XXX -  Needs review for HW FIFOs.
1734  */
1735 static void
1736 async_txint(struct asycom *asy, uchar_t lsr)
1737 {
1738 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1739 	int		fifo_len;
1740 	int		xmit_progress;
1741 
1742 	asycheckflowcontrol_hw(asy);
1743 
1744 	/*
1745 	 * If ASYNC_BREAK has been set, return to asyintr()'s context to
1746 	 * claim the interrupt without performing any action.
1747 	 */
1748 	if (async->async_flags & ASYNC_BREAK)
1749 		return;
1750 
1751 	fifo_len = asy->asy_fifo_buf; /* with FIFO buffers */
1752 
1753 	/*
1754 	 * Check for flow control and do the needed action.
1755 	 */
1756 	if (asycheckflowcontrol_sw(asy)) {
1757 		return;
1758 	}
1759 
1760 	if (async->async_ocnt > 0 &&
1761 	    !(async->async_flags & (ASYNC_HW_OUT_FLW|ASYNC_STOPPED))) {
1762 		xmit_progress = 0;
1763 		while (fifo_len > 0 && async->async_ocnt > 0) {
1764 			if (lsr & XHRE) {
1765 				OUTB(DAT, *async->async_optr++);
1766 				fifo_len--;
1767 				async->async_ocnt--;
1768 				xmit_progress++;
1769 			}
1770 			/*
1771 			 * Reading the lsr, (moved reading at the end of
1772 			 * while loop) as already we have read once at
1773 			 * the beginning of interrupt service
1774 			 */
1775 			lsr = INB(LSR);
1776 		}
1777 		asy->asy_xmit_count = xmit_progress;
1778 		if (xmit_progress > 0)
1779 			async->async_flags |= ASYNC_PROGRESS;
1780 	}
1781 
1782 	if (fifo_len == 0) {
1783 		return;
1784 	}
1785 
1786 
1787 	ASYSETSOFT(asy);
1788 }
1789 
1790 /*
1791  * Receiver interrupt: RxRDY interrupt, FIFO timeout interrupt or receive
1792  * error interrupt.
1793  * Try to put the character into the circular buffer for this line; if it
1794  * overflows, indicate a circular buffer overrun. If this port is always
1795  * to be serviced immediately, or the character is a STOP character, or
1796  * more than 15 characters have arrived, queue up a soft interrupt to
1797  * drain the circular buffer.
1798  * XXX - needs review for hw FIFOs support.
1799  */
1800 
1801 static void
1802 async_rxint(struct asycom *asy, uchar_t lsr)
1803 {
1804 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1805 	uchar_t c = 0;
1806 	uint_t s = 0, needsoft = 0;
1807 	register tty_common_t *tp;
1808 
1809 	tp = &async->async_ttycommon;
1810 	if (!(tp->t_cflag & CREAD)) {
1811 		if (lsr & (RCA|PARERR|FRMERR|BRKDET|OVRRUN)) {
1812 			(void) (INB(DAT) & 0xff);
1813 		}
1814 		return; /* line is not open for read? */
1815 	}
1816 	asy->asy_rx_count = 0;
1817 	while (lsr & (RCA|PARERR|FRMERR|BRKDET|OVRRUN)) {
1818 		c = 0;
1819 		s = 0;
1820 		asy->asy_rx_count++;
1821 		if (lsr & RCA) {
1822 			c = INB(DAT) & 0xff;
1823 			/*
1824 			 * Even a single character is received
1825 			 * we need Soft interrupt to pass it to
1826 			 * higher layers.
1827 			 */
1828 			needsoft = 1;
1829 		}
1830 
1831 		/* Check for character break sequence */
1832 		if ((abort_enable == KIOCABORTALTERNATE) &&
1833 		    (async->async_dev == rconsdev)) {
1834 			if (abort_charseq_recognize(c))
1835 				abort_sequence_enter((char *)NULL);
1836 			}
1837 
1838 		/* Handle framing errors */
1839 		if (lsr & (PARERR|FRMERR|BRKDET|OVRRUN)) {
1840 			if (lsr & PARERR) {
1841 				if (tp->t_iflag & INPCK) /* parity enabled */
1842 					s |= PERROR;
1843 			}
1844 			if (lsr & (FRMERR|BRKDET))
1845 				s |= FRERROR;
1846 			if (lsr & OVRRUN) {
1847 				async->async_hw_overrun = 1;
1848 				s |= OVERRUN;
1849 			}
1850 		}
1851 
1852 		if (s == 0)
1853 			if ((tp->t_iflag & PARMRK) &&
1854 			    !(tp->t_iflag & (IGNPAR|ISTRIP)) &&
1855 			    (c == 0377))
1856 				if (RING_POK(async, 2)) {
1857 					RING_PUT(async, 0377);
1858 					RING_PUT(async, c);
1859 				} else
1860 					async->async_sw_overrun = 1;
1861 			else
1862 				if (RING_POK(async, 1))
1863 					RING_PUT(async, c);
1864 				else
1865 					async->async_sw_overrun = 1;
1866 		else
1867 			if (s & FRERROR) { /* Handle framing errors */
1868 				if (c == 0)  {
1869 		/* Look for break on kbd, stdin, or rconsdev */
1870 					if ((async->async_dev == kbddev) ||
1871 					    ((async->async_dev == rconsdev) ||
1872 					    (async->async_dev == stdindev)) &&
1873 					    (abort_enable !=
1874 					    KIOCABORTALTERNATE))
1875 						abort_sequence_enter((char *)0);
1876 					else
1877 						async->async_break++;
1878 				} else {
1879 					if (RING_POK(async, 1))
1880 						RING_MARK(async, c, s);
1881 					else
1882 						async->async_sw_overrun = 1;
1883 				}
1884 			} else  { /* Parity errors  handled by ldterm */
1885 				if (RING_POK(async, 1))
1886 					RING_MARK(async, c, s);
1887 				else
1888 					async->async_sw_overrun = 1;
1889 			}
1890 		lsr = INB(LSR);
1891 		if (asy->asy_rx_count > 16) break;
1892 	}
1893 	/* Check whether there is a request for hw/sw inbound/input flow ctrl */
1894 	if ((async->async_ttycommon.t_cflag & CRTSXOFF) ||
1895 	    (async->async_ttycommon.t_iflag & IXOFF))
1896 		if ((int)(RING_CNT(async)) > (RINGSIZE * 3)/4) {
1897 #ifdef DEBUG
1898 			if (asydebug & ASY_DEBUG_HFLOW)
1899 				printf("asy%d: hardware flow stop input.\n",
1900 				    UNIT(async->async_dev));
1901 #endif
1902 			async->async_flags |= ASYNC_HW_IN_FLOW;
1903 			async->async_flowc = async->async_stopc;
1904 			async->async_ringbuf_overflow = 1;
1905 		}
1906 
1907 	if ((async->async_flags & ASYNC_SERVICEIMM) || needsoft ||
1908 	    (RING_FRAC(async)) || (async->async_polltid == 0))
1909 		ASYSETSOFT(asy);	/* need a soft interrupt */
1910 }
1911 
1912 /*
1913  * Interrupt on port: handle PPS event.  This function is only called
1914  * for a port on which PPS event handling has been enabled.
1915  */
1916 static void
1917 asy_ppsevent(struct asycom *asy, int msr)
1918 {
1919 	if (asy->asy_flags & ASY_PPS_EDGE) {
1920 		/* Have seen leading edge, now look for and record drop */
1921 		if ((msr & DCD) == 0)
1922 			asy->asy_flags &= ~ASY_PPS_EDGE;
1923 		/*
1924 		 * Waiting for leading edge, look for rise; stamp event and
1925 		 * calibrate kernel clock.
1926 		 */
1927 	} else if (msr & DCD) {
1928 		/*
1929 		 * This code captures a timestamp at the designated
1930 		 * transition of the PPS signal (DCD asserted).  The
1931 		 * code provides a pointer to the timestamp, as well
1932 		 * as the hardware counter value at the capture.
1933 		 *
1934 		 * Note: the kernel has nano based time values while
1935 		 * NTP requires micro based, an in-line fast algorithm
1936 		 * to convert nsec to usec is used here -- see hrt2ts()
1937 		 * in common/os/timers.c for a full description.
1938 		 */
1939 		struct timeval *tvp = &asy_ppsev.tv;
1940 		timestruc_t ts;
1941 		long nsec, usec;
1942 
1943 		asy->asy_flags |= ASY_PPS_EDGE;
1944 		gethrestime(&ts);
1945 		nsec = ts.tv_nsec;
1946 		usec = nsec + (nsec >> 2);
1947 		usec = nsec + (usec >> 1);
1948 		usec = nsec + (usec >> 2);
1949 		usec = nsec + (usec >> 4);
1950 		usec = nsec - (usec >> 3);
1951 		usec = nsec + (usec >> 2);
1952 		usec = nsec + (usec >> 3);
1953 		usec = nsec + (usec >> 4);
1954 		usec = nsec + (usec >> 1);
1955 		usec = nsec + (usec >> 6);
1956 		tvp->tv_usec = usec >> 10;
1957 		tvp->tv_sec = ts.tv_sec;
1958 
1959 		++asy_ppsev.serial;
1960 
1961 		/*
1962 		 * Because the kernel keeps a high-resolution time,
1963 		 * pass the current highres timestamp in tvp and zero
1964 		 * in usec.
1965 		 */
1966 		ddi_hardpps(tvp, 0);
1967 	}
1968 }
1969 
1970 /*
1971  * Modem status interrupt.
1972  *
1973  * (Note: It is assumed that the MSR hasn't been read by asyintr().)
1974  */
1975 
1976 static void
1977 async_msint(struct asycom *asy)
1978 {
1979 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1980 	int msr;
1981 
1982 	msr = INB(MSR);	/* this resets the interrupt */
1983 	asy->asy_cached_msr = msr;
1984 #ifdef DEBUG
1985 	if (asydebug & ASY_DEBUG_STATE) {
1986 		printf("   transition: %3s %3s %3s %3s\n"
1987 		    "current state: %3s %3s %3s %3s\n",
1988 		    (msr & DCTS) ? "CTS" : "   ",
1989 		    (msr & DDSR) ? "DSR" : "   ",
1990 		    (msr & DRI) ?  "RI " : "   ",
1991 		    (msr & DDCD) ? "DCD" : "   ",
1992 		    (msr & CTS) ?  "CTS" : "   ",
1993 		    (msr & DSR) ?  "DSR" : "   ",
1994 		    (msr & RI) ?   "RI " : "   ",
1995 		    (msr & DCD) ?  "DCD" : "   ");
1996 	}
1997 #endif
1998 	if (async->async_ttycommon.t_cflag & CRTSCTS && !(msr & CTS)) {
1999 #ifdef DEBUG
2000 		if (asydebug & ASY_DEBUG_HFLOW)
2001 			printf("asy%d: hflow start\n",
2002 			    UNIT(async->async_dev));
2003 #endif
2004 		async->async_flags |= ASYNC_HW_OUT_FLW;
2005 	}
2006 	if (asy->asy_hwtype == ASY82510)
2007 		OUTB(MSR, (msr & 0xF0));
2008 
2009 	/* Handle PPS event */
2010 	if (asy->asy_flags & ASY_PPS)
2011 		asy_ppsevent(asy, msr);
2012 
2013 	async->async_ext++;
2014 	ASYSETSOFT(asy);
2015 }
2016 
2017 /*
2018  * Handle a second-stage interrupt.
2019  */
2020 uint_t
2021 asysoftintr(caddr_t intarg)
2022 {
2023 	struct asycom *asy = (struct asycom *)intarg;
2024 	struct asyncline *async;
2025 	int rv;
2026 	int cc;
2027 	/*
2028 	 * Test and clear soft interrupt.
2029 	 */
2030 	mutex_enter(asy->asy_soft_lock);
2031 #ifdef DEBUG
2032 	if (asydebug & ASY_DEBUG_PROCS)
2033 		printf("softintr\n");
2034 #endif
2035 	rv = asy->asysoftpend;
2036 	if (rv != 0)
2037 		asy->asysoftpend = 0;
2038 	mutex_exit(asy->asy_soft_lock);
2039 
2040 	if (rv) {
2041 		if (asy->asy_priv == NULL)
2042 			return (rv);
2043 		async = (struct asyncline *)asy->asy_priv;
2044 		mutex_enter(asy->asy_excl_hi);
2045 		if (asy->asy_flags & ASY_NEEDSOFT) {
2046 			asy->asy_flags &= ~ASY_NEEDSOFT;
2047 			mutex_exit(asy->asy_excl_hi);
2048 			(void) async_softint(asy);
2049 			mutex_enter(asy->asy_excl_hi);
2050 		}
2051 		/*
2052 		 * There are some instances where the softintr is not
2053 		 * scheduled and hence not called. It so happened that makes
2054 		 * the last few characters to be stuck in ringbuffer.
2055 		 * Hence, call once again the  handler so that the last few
2056 		 * characters are cleared.
2057 		 */
2058 		cc = RING_CNT(async);
2059 		mutex_exit(asy->asy_excl_hi);
2060 		if (cc > 0) {
2061 			(void) async_softint(asy);
2062 		}
2063 	}
2064 	return (rv);
2065 }
2066 
2067 /*
2068  * Handle a software interrupt.
2069  */
2070 static int
2071 async_softint(struct asycom *asy)
2072 {
2073 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
2074 	uint_t	cc;
2075 	mblk_t	*bp;
2076 	queue_t	*q;
2077 	uchar_t	val;
2078 	uchar_t	c;
2079 	tty_common_t	*tp;
2080 
2081 #ifdef DEBUG
2082 	if (asydebug & ASY_DEBUG_PROCS)
2083 		printf("process\n");
2084 #endif
2085 	mutex_enter(asy->asy_excl);
2086 	if (asy->asy_flags & ASY_DOINGSOFT) {
2087 		mutex_exit(asy->asy_excl);
2088 		return (0);
2089 	}
2090 	tp = &async->async_ttycommon;
2091 	q = tp->t_readq;
2092 	if (q != NULL) {
2093 		mutex_exit(asy->asy_excl);
2094 		enterq(q);
2095 		mutex_enter(asy->asy_excl);
2096 	}
2097 	mutex_enter(asy->asy_excl_hi);
2098 	asy->asy_flags |= ASY_DOINGSOFT;
2099 
2100 	if (INB(ICR) & MIEN)
2101 		val = asy->asy_cached_msr & 0xFF;
2102 	else
2103 		val = INB(MSR) & 0xFF;
2104 
2105 	if (async->async_ttycommon.t_cflag & CRTSCTS) {
2106 		if ((val & CTS) && (async->async_flags & ASYNC_HW_OUT_FLW)) {
2107 #ifdef DEBUG
2108 			if (asydebug & ASY_DEBUG_HFLOW)
2109 				printf("asy%d: hflow start\n",
2110 				    UNIT(async->async_dev));
2111 #endif
2112 			async->async_flags &= ~ASYNC_HW_OUT_FLW;
2113 			mutex_exit(asy->asy_excl_hi);
2114 			if (async->async_ocnt > 0) {
2115 				mutex_enter(asy->asy_excl_hi);
2116 				async_resume(async);
2117 				mutex_exit(asy->asy_excl_hi);
2118 			} else {
2119 				async_start(async);
2120 			}
2121 			mutex_enter(asy->asy_excl_hi);
2122 		}
2123 	}
2124 	if (async->async_ext) {
2125 		async->async_ext = 0;
2126 		/* check for carrier up */
2127 		if ((val & DCD) || (tp->t_flags & TS_SOFTCAR)) {
2128 			/* carrier present */
2129 			if ((async->async_flags & ASYNC_CARR_ON) == 0) {
2130 				async->async_flags |= ASYNC_CARR_ON;
2131 				mutex_exit(asy->asy_excl_hi);
2132 				mutex_exit(asy->asy_excl);
2133 				if (async->async_flags & ASYNC_ISOPEN)
2134 					(void) putctl(q, M_UNHANGUP);
2135 				cv_broadcast(&async->async_flags_cv);
2136 				mutex_enter(asy->asy_excl);
2137 				mutex_enter(asy->asy_excl_hi);
2138 			}
2139 		} else {
2140 			if ((async->async_flags & ASYNC_CARR_ON) &&
2141 			    !(tp->t_cflag & CLOCAL)) {
2142 				int flushflag;
2143 
2144 				/*
2145 				 * Carrier went away.
2146 				 * Drop DTR, abort any output in
2147 				 * progress, indicate that output is
2148 				 * not stopped, and send a hangup
2149 				 * notification upstream.
2150 				 *
2151 				 * If we're in the midst of close, then flush
2152 				 * everything.  Don't leave stale ioctls lying
2153 				 * about.
2154 				 */
2155 				val = INB(MCR);
2156 				OUTB(MCR, (val & ~DTR));
2157 				flushflag = (async->async_flags &
2158 				    ASYNC_CLOSING) ? FLUSHALL : FLUSHDATA;
2159 				if (tp->t_writeq != NULL) {
2160 					flushq(tp->t_writeq, flushflag);
2161 				}
2162 				if (async->async_xmitblk != NULL) {
2163 					freeb(async->async_xmitblk);
2164 					async->async_xmitblk = NULL;
2165 				}
2166 				if (async->async_flags & ASYNC_BUSY) {
2167 					async->async_ocnt = 0;
2168 					async->async_flags &= ~ASYNC_BUSY;
2169 				}
2170 				async->async_flags &= ~ASYNC_STOPPED;
2171 				if (async->async_flags & ASYNC_ISOPEN) {
2172 					mutex_exit(asy->asy_excl_hi);
2173 					mutex_exit(asy->asy_excl);
2174 					(void) putctl(q, M_HANGUP);
2175 					mutex_enter(asy->asy_excl);
2176 					mutex_enter(asy->asy_excl_hi);
2177 				}
2178 				async->async_flags &= ~ASYNC_CARR_ON;
2179 				mutex_exit(asy->asy_excl_hi);
2180 				cv_broadcast(&async->async_flags_cv);
2181 				mutex_enter(asy->asy_excl_hi);
2182 			}
2183 		}
2184 	}
2185 
2186 	/*
2187 	 * If data has been added to the circular buffer, remove
2188 	 * it from the buffer, and send it up the stream if there's
2189 	 * somebody listening. Try to do it 16 bytes at a time. If we
2190 	 * have more than 16 bytes to move, move 16 byte chunks and
2191 	 * leave the rest for next time around (maybe it will grow).
2192 	 */
2193 	if (!(async->async_flags & ASYNC_ISOPEN)) {
2194 		RING_INIT(async);
2195 		goto rv;
2196 	}
2197 	if ((cc = RING_CNT(async)) == 0) {
2198 		goto rv;
2199 	}
2200 	mutex_exit(asy->asy_excl_hi);
2201 
2202 	if (!canput(q)) {
2203 		if ((async->async_flags & ASYNC_HW_IN_FLOW) == 0) {
2204 #ifdef DEBUG
2205 			if (!(asydebug & ASY_DEBUG_HFLOW)) {
2206 				printf("asy%d: hflow stop input.\n",
2207 				    UNIT(async->async_dev));
2208 				if (canputnext(q))
2209 					printf("asy%d: next queue is "
2210 					    "ready\n",
2211 					    UNIT(async->async_dev));
2212 			}
2213 #endif
2214 			mutex_enter(asy->asy_excl_hi);
2215 			async->async_flags |= ASYNC_HW_IN_FLOW;
2216 			async->async_flowc = async->async_stopc;
2217 		} else mutex_enter(asy->asy_excl_hi);
2218 		goto rv;
2219 	}
2220 
2221 	if (async->async_ringbuf_overflow) {
2222 		if ((async->async_flags & ASYNC_HW_IN_FLOW) &&
2223 		    ((int)(RING_CNT(async)) < (RINGSIZE/4))) {
2224 #ifdef DEBUG
2225 			if (asydebug & ASY_DEBUG_HFLOW)
2226 				printf("asy%d: hflow start input.\n",
2227 				    UNIT(async->async_dev));
2228 #endif
2229 			mutex_enter(asy->asy_excl_hi);
2230 			async->async_flags &= ~ASYNC_HW_IN_FLOW;
2231 			async->async_flowc = async->async_startc;
2232 			async->async_ringbuf_overflow = 0;
2233 			goto rv;
2234 		}
2235 	}
2236 #ifdef DEBUG
2237 	if (asydebug & ASY_DEBUG_INPUT)
2238 		printf("asy%d: %d char(s) in queue.\n",
2239 		    UNIT(async->async_dev), cc);
2240 #endif
2241 	/*
2242 	 * Before you pull the characters from the RING BUF
2243 	 * Check whether you can put into the queue again
2244 	 */
2245 	if ((!canputnext(q)) || (!canput(q))) {
2246 		mutex_enter(asy->asy_excl_hi);
2247 		if ((async->async_flags & ASYNC_HW_IN_FLOW) == 0) {
2248 			async->async_flags |= ASYNC_HW_IN_FLOW;
2249 			async->async_flowc = async->async_stopc;
2250 			async->async_queue_full = 1;
2251 		}
2252 		goto rv;
2253 	}
2254 	mutex_enter(asy->asy_excl_hi);
2255 	if (async->async_queue_full) {
2256 		/*
2257 		 * Last time the Stream queue didnot allow
2258 		 * now it allows so, relax, the flow control
2259 		 */
2260 		if (async->async_flags & ASYNC_HW_IN_FLOW) {
2261 			async->async_flags &= ~ASYNC_HW_IN_FLOW;
2262 			async->async_queue_full = 0;
2263 			async->async_flowc = async->async_startc;
2264 			goto rv;
2265 		} else
2266 			async->async_queue_full = 0;
2267 	}
2268 	mutex_exit(asy->asy_excl_hi);
2269 	if (!(bp = allocb(cc, BPRI_MED))) {
2270 		ttycommon_qfull(&async->async_ttycommon, q);
2271 		mutex_enter(asy->asy_excl_hi);
2272 		goto rv;
2273 	}
2274 	mutex_enter(asy->asy_excl_hi);
2275 	do {
2276 		if (RING_ERR(async, S_ERRORS)) {
2277 			RING_UNMARK(async);
2278 			c = RING_GET(async);
2279 			break;
2280 		} else {
2281 			*bp->b_wptr++ = RING_GET(async);
2282 		}
2283 	} while (--cc);
2284 
2285 	mutex_exit(asy->asy_excl_hi);
2286 	mutex_exit(asy->asy_excl);
2287 	if (bp->b_wptr > bp->b_rptr) {
2288 		if (!canputnext(q)) {
2289 			if (!canput(q)) {
2290 				/*
2291 				 * Even after taking all precautions that
2292 				 * Still we are unable to queue, then we
2293 				 * cannot do anything, just drop the block
2294 				 */
2295 				cmn_err(CE_NOTE,
2296 				    "su%d: local queue full\n",
2297 				    UNIT(async->async_dev));
2298 				freemsg(bp);
2299 				mutex_enter(asy->asy_excl_hi);
2300 				if ((async->async_flags &
2301 				    ASYNC_HW_IN_FLOW) == 0) {
2302 					async->async_flags |=
2303 					    ASYNC_HW_IN_FLOW;
2304 					async->async_flowc =
2305 					    async->async_stopc;
2306 					async->async_queue_full = 1;
2307 				}
2308 				mutex_exit(asy->asy_excl_hi);
2309 			} else {
2310 				(void) putq(q, bp);
2311 			}
2312 		} else {
2313 			putnext(q, bp);
2314 		}
2315 	} else {
2316 		freemsg(bp);
2317 	}
2318 	/*
2319 	 * If we have a parity error, then send
2320 	 * up an M_BREAK with the "bad"
2321 	 * character as an argument. Let ldterm
2322 	 * figure out what to do with the error.
2323 	 */
2324 	if (cc)
2325 		(void) putctl1(q, M_BREAK, c);
2326 	mutex_enter(asy->asy_excl);
2327 	mutex_enter(asy->asy_excl_hi);
2328 rv:
2329 	/*
2330 	 * If a transmission has finished, indicate that it's finished,
2331 	 * and start that line up again.
2332 	 */
2333 	if (async->async_break) {
2334 		async->async_break = 0;
2335 		if (async->async_flags & ASYNC_ISOPEN) {
2336 			mutex_exit(asy->asy_excl_hi);
2337 			mutex_exit(asy->asy_excl);
2338 			(void) putctl(q, M_BREAK);
2339 			mutex_enter(asy->asy_excl);
2340 			mutex_enter(asy->asy_excl_hi);
2341 		}
2342 	}
2343 	if ((async->async_ocnt <= 0 && (async->async_flags & ASYNC_BUSY)) ||
2344 	    (async->async_flowc != '\0')) {
2345 		async->async_flags &= ~ASYNC_BUSY;
2346 		mutex_exit(asy->asy_excl_hi);
2347 		if (async->async_xmitblk)
2348 			freeb(async->async_xmitblk);
2349 		async->async_xmitblk = NULL;
2350 		if (async->async_flags & ASYNC_ISOPEN) {
2351 			asy->inperim = B_TRUE;
2352 			mutex_exit(asy->asy_excl);
2353 			enterq(async->async_ttycommon.t_writeq);
2354 			mutex_enter(asy->asy_excl);
2355 		}
2356 		async_start(async);
2357 		/*
2358 		 * We need to check for inperim and ISOPEN due to
2359 		 * multi-threading implications; it's possible to close the
2360 		 * port and nullify async_flags while completing the software
2361 		 * interrupt.  If the port is closed, leaveq() will have already
2362 		 * been called.  We don't want to call it twice.
2363 		 */
2364 		if ((asy->inperim) && (async->async_flags & ASYNC_ISOPEN)) {
2365 			mutex_exit(asy->asy_excl);
2366 			leaveq(async->async_ttycommon.t_writeq);
2367 			mutex_enter(asy->asy_excl);
2368 			asy->inperim = B_FALSE;
2369 		}
2370 		if (!(async->async_flags & ASYNC_BUSY))
2371 			cv_broadcast(&async->async_flags_cv);
2372 		mutex_enter(asy->asy_excl_hi);
2373 	}
2374 	/*
2375 	 * A note about these overrun bits: all they do is *tell* someone
2376 	 * about an error- They do not track multiple errors. In fact,
2377 	 * you could consider them latched register bits if you like.
2378 	 * We are only interested in printing the error message once for
2379 	 * any cluster of overrun errors.
2380 	 */
2381 	if (async->async_hw_overrun) {
2382 		if (async->async_flags & ASYNC_ISOPEN) {
2383 			if (su_log > 0) {
2384 				mutex_exit(asy->asy_excl_hi);
2385 				mutex_exit(asy->asy_excl);
2386 				cmn_err(CE_NOTE, "su%d: silo overflow\n",
2387 				    UNIT(async->async_dev));
2388 				mutex_enter(asy->asy_excl);
2389 				mutex_enter(asy->asy_excl_hi);
2390 			}
2391 			INC64_KSTAT(asy, siloover);
2392 		}
2393 		async->async_hw_overrun = 0;
2394 	}
2395 	if (async->async_sw_overrun) {
2396 		if (async->async_flags & ASYNC_ISOPEN) {
2397 			if (su_log > 0) {
2398 				mutex_exit(asy->asy_excl_hi);
2399 				mutex_exit(asy->asy_excl);
2400 				cmn_err(CE_NOTE, "su%d: ring buffer overflow\n",
2401 				    UNIT(async->async_dev));
2402 				mutex_enter(asy->asy_excl);
2403 				mutex_enter(asy->asy_excl_hi);
2404 			}
2405 			INC64_KSTAT(asy, ringover);
2406 		}
2407 		async->async_sw_overrun = 0;
2408 	}
2409 	asy->asy_flags &= ~ASY_DOINGSOFT;
2410 	mutex_exit(asy->asy_excl_hi);
2411 	mutex_exit(asy->asy_excl);
2412 	if (q != NULL)
2413 		leaveq(q);
2414 	return (0);
2415 }
2416 
2417 /*
2418  * Restart output on a line after a delay or break timer expired.
2419  */
2420 static void
2421 async_restart(void *arg)
2422 {
2423 	struct asyncline *async = arg;
2424 	struct asycom *asy = async->async_common;
2425 	queue_t *q;
2426 	uchar_t lcr;
2427 
2428 	/*
2429 	 * If break timer expired, turn off the break bit.
2430 	 */
2431 #ifdef DEBUG
2432 	if (asydebug & ASY_DEBUG_PROCS)
2433 		printf("restart\n");
2434 #endif
2435 	mutex_enter(asy->asy_excl);
2436 	if (async->async_flags & ASYNC_BREAK) {
2437 		unsigned int rate;
2438 
2439 		mutex_enter(asy->asy_excl_hi);
2440 		lcr = INB(LCR);
2441 		OUTB(LCR, (lcr & ~SETBREAK));
2442 
2443 		/*
2444 		 * Go to sleep for the time it takes for at least one
2445 		 * stop bit to be received by the device at the other
2446 		 * end of the line as stated in the RS-232 specification.
2447 		 * The wait period is equal to:
2448 		 * 2 clock cycles * (1 MICROSEC / baud rate)
2449 		 */
2450 		rate = async->async_ttycommon.t_cflag & CBAUD;
2451 		if (async->async_ttycommon.t_cflag & CBAUDEXT)
2452 			rate += 16;
2453 		if (rate >= N_SU_SPEEDS || rate == B0) {
2454 			rate = B9600;
2455 		}
2456 
2457 		mutex_exit(asy->asy_excl_hi);
2458 		mutex_exit(asy->asy_excl);
2459 		drv_usecwait(2 * MICROSEC / baudtable[rate]);
2460 		mutex_enter(asy->asy_excl);
2461 	}
2462 	async->async_flags &= ~(ASYNC_DELAY|ASYNC_BREAK|ASYNC_DRAINING);
2463 	if ((q = async->async_ttycommon.t_writeq) != NULL) {
2464 		mutex_exit(asy->asy_excl);
2465 		enterq(q);
2466 		mutex_enter(asy->asy_excl);
2467 	}
2468 	async_start(async);
2469 	mutex_exit(asy->asy_excl);
2470 	if (q != NULL)
2471 		leaveq(q);
2472 
2473 	/* cleared break or delay flag; may have made some output progress */
2474 	cv_broadcast(&async->async_flags_cv);
2475 }
2476 
2477 static void
2478 async_start(struct asyncline *async)
2479 {
2480 	async_nstart(async, 0);
2481 }
2482 
2483 /*
2484  * Start output on a line, unless it's busy, frozen, or otherwise.
2485  */
2486 static void
2487 async_nstart(struct asyncline *async, int mode)
2488 {
2489 	register struct asycom *asy = async->async_common;
2490 	register int cc;
2491 	register queue_t *q;
2492 	mblk_t *bp, *nbp;
2493 	uchar_t *xmit_addr;
2494 	uchar_t	val;
2495 	int	fifo_len = 1;
2496 	int	xmit_progress;
2497 
2498 #ifdef DEBUG
2499 	if (asydebug & ASY_DEBUG_PROCS)
2500 		printf("start\n");
2501 #endif
2502 	if (asy->asy_use_fifo == FIFO_ON)
2503 		fifo_len = asy->asy_fifo_buf; /* with FIFO buffers */
2504 
2505 	ASSERT(mutex_owned(asy->asy_excl));
2506 	mutex_enter(asy->asy_excl_hi);
2507 	asycheckflowcontrol_hw(asy);
2508 
2509 	/*
2510 	 * If the chip is busy (i.e., we're waiting for a break timeout
2511 	 * to expire, or for the current transmission to finish, or for
2512 	 * output to finish draining from chip), don't grab anything new.
2513 	 */
2514 	if (async->async_flags & (ASYNC_BREAK|ASYNC_BUSY|ASYNC_DRAINING)) {
2515 		mutex_exit(asy->asy_excl_hi);
2516 #ifdef DEBUG
2517 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2518 			printf("asy%d: start %s.\n",
2519 			    UNIT(async->async_dev),
2520 			    async->async_flags & ASYNC_BREAK
2521 			    ? "break" : "busy");
2522 #endif
2523 		return;
2524 	}
2525 
2526 	/*
2527 	 * If we have a flow-control character to transmit, do it now.
2528 	 */
2529 	if (asycheckflowcontrol_sw(asy)) {
2530 		mutex_exit(asy->asy_excl_hi);
2531 		return;
2532 	}
2533 	mutex_exit(asy->asy_excl_hi);
2534 	/*
2535 	 * If we're waiting for a delay timeout to expire, don't grab
2536 	 * anything new.
2537 	 */
2538 	if (async->async_flags & ASYNC_DELAY) {
2539 #ifdef DEBUG
2540 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2541 			printf("asy%d: start ASYNC_DELAY.\n",
2542 			    UNIT(async->async_dev));
2543 #endif
2544 		return;
2545 	}
2546 
2547 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
2548 #ifdef DEBUG
2549 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2550 			printf("asy%d: start writeq is null.\n",
2551 			    UNIT(async->async_dev));
2552 #endif
2553 		return;	/* not attached to a stream */
2554 	}
2555 
2556 	for (;;) {
2557 		if ((bp = getq(q)) == NULL)
2558 			return;	/* no data to transmit */
2559 
2560 		/*
2561 		 * We have a message block to work on.
2562 		 * Check whether it's a break, a delay, or an ioctl (the latter
2563 		 * occurs if the ioctl in question was waiting for the output
2564 		 * to drain).  If it's one of those, process it immediately.
2565 		 */
2566 		switch (bp->b_datap->db_type) {
2567 
2568 		case M_BREAK:
2569 			/*
2570 			 * Set the break bit, and arrange for "async_restart"
2571 			 * to be called in 1/4 second; it will turn the
2572 			 * break bit off, and call "async_start" to grab
2573 			 * the next message.
2574 			 */
2575 			mutex_enter(asy->asy_excl_hi);
2576 			val = INB(LCR);
2577 			OUTB(LCR, (val | SETBREAK));
2578 			mutex_exit(asy->asy_excl_hi);
2579 			async->async_flags |= ASYNC_BREAK;
2580 			(void) timeout(async_restart, async, hz / 4);
2581 			freemsg(bp);
2582 			return;	/* wait for this to finish */
2583 
2584 		case M_DELAY:
2585 			/*
2586 			 * Arrange for "async_restart" to be called when the
2587 			 * delay expires; it will turn ASYNC_DELAY off,
2588 			 * and call "async_start" to grab the next message.
2589 			 */
2590 			(void) timeout(async_restart, async,
2591 			    (clock_t)(*(unsigned char *)bp->b_rptr + 6));
2592 			async->async_flags |= ASYNC_DELAY;
2593 			freemsg(bp);
2594 			return;	/* wait for this to finish */
2595 
2596 		case M_IOCTL:
2597 			/*
2598 			 * This ioctl needs to wait for the output ahead of
2599 			 * it to drain.  Try to do it, and then either
2600 			 * redo the ioctl at a later time or grab the next
2601 			 * message after it.
2602 			 */
2603 
2604 			mutex_enter(asy->asy_excl_hi);
2605 			if (asy_isbusy(asy)) {
2606 				/*
2607 				 * Get the divisor by calculating the rate
2608 				 */
2609 				unsigned int rate;
2610 
2611 				mutex_exit(asy->asy_excl_hi);
2612 				rate = async->async_ttycommon.t_cflag & CBAUD;
2613 				if (async->async_ttycommon.t_cflag & CBAUDEXT)
2614 					rate += 16;
2615 				if (rate >= N_SU_SPEEDS || rate == B0) {
2616 					rate = B9600;
2617 				}
2618 
2619 				/*
2620 				 * We need to do a callback as the port will
2621 				 * be set to drain
2622 				 */
2623 				async->async_flags |= ASYNC_DRAINING;
2624 
2625 				/*
2626 				 * Put the message we just processed back onto
2627 				 * the end of the queue
2628 				 */
2629 				if (putq(q, bp) == 0)
2630 					freemsg(bp);
2631 
2632 				/*
2633 				 * We need to delay until the TSR and THR
2634 				 * have been exhausted.  We base the delay on
2635 				 * the amount of time it takes to transmit
2636 				 * 2 chars at the current baud rate in
2637 				 * microseconds.
2638 				 *
2639 				 * Therefore, the wait period is:
2640 				 *
2641 				 * (#TSR bits + #THR bits) *
2642 				 * 	1 MICROSEC / baud rate
2643 				 */
2644 				(void) timeout(async_restart, async,
2645 				    drv_usectohz(16 * MICROSEC /
2646 				    baudtable[rate]));
2647 				return;
2648 			}
2649 			mutex_exit(asy->asy_excl_hi);
2650 			mutex_exit(asy->asy_excl);
2651 			async_ioctl(async, q, bp, B_FALSE);
2652 			mutex_enter(asy->asy_excl);
2653 			continue;
2654 		}
2655 
2656 		while (bp != NULL && (cc = bp->b_wptr - bp->b_rptr) == 0) {
2657 			nbp = bp->b_cont;
2658 			freeb(bp);
2659 			bp = nbp;
2660 		}
2661 		if (bp != NULL)
2662 			break;
2663 	}
2664 
2665 	/*
2666 	 * We have data to transmit.  If output is stopped, put
2667 	 * it back and try again later.
2668 	 */
2669 	if (async->async_flags & (ASYNC_HW_OUT_FLW|ASYNC_STOPPED)) {
2670 #ifdef DEBUG
2671 		if (asydebug & ASY_DEBUG_HFLOW &&
2672 		    async->async_flags & ASYNC_HW_OUT_FLW)
2673 			printf("asy%d: output hflow in effect.\n",
2674 			    UNIT(async->async_dev));
2675 #endif
2676 		mutex_exit(asy->asy_excl);
2677 		(void) putbq(q, bp);
2678 		/*
2679 		 * We entered the routine owning the lock, we need to
2680 		 * exit the routine owning the lock.
2681 		 */
2682 		mutex_enter(asy->asy_excl);
2683 		return;
2684 	}
2685 
2686 	async->async_xmitblk = bp;
2687 	xmit_addr = bp->b_rptr;
2688 	bp = bp->b_cont;
2689 	if (bp != NULL) {
2690 		mutex_exit(asy->asy_excl);
2691 		(void) putbq(q, bp);	/* not done with this message yet */
2692 		mutex_enter(asy->asy_excl);
2693 	}
2694 
2695 	/*
2696 	 * In 5-bit mode, the high order bits are used
2697 	 * to indicate character sizes less than five,
2698 	 * so we need to explicitly mask before transmitting
2699 	 */
2700 	if ((async->async_ttycommon.t_cflag & CSIZE) == CS5) {
2701 		register unsigned char *p = xmit_addr;
2702 		register int cnt = cc;
2703 
2704 		while (cnt--)
2705 			*p++ &= (unsigned char) 0x1f;
2706 	}
2707 
2708 	/*
2709 	 * Set up this block for pseudo-DMA.
2710 	 */
2711 	mutex_enter(asy->asy_excl_hi);
2712 	async->async_optr = xmit_addr;
2713 	async->async_ocnt = cc;
2714 	/*
2715 	 * If the transmitter is ready, shove some
2716 	 * characters out.
2717 	 */
2718 	xmit_progress = 0;
2719 	while (fifo_len-- && async->async_ocnt) {
2720 		if (INB(LSR) & XHRE) {
2721 			OUTB(DAT, *async->async_optr++);
2722 			async->async_ocnt--;
2723 			xmit_progress++;
2724 		}
2725 	}
2726 	asy->asy_out_of_band_xmit = xmit_progress;
2727 	if (xmit_progress > 0)
2728 		async->async_flags |= ASYNC_PROGRESS;
2729 	async->async_flags |= ASYNC_BUSY;
2730 	mutex_exit(asy->asy_excl_hi);
2731 }
2732 
2733 /*
2734  * Resume output by poking the transmitter.
2735  */
2736 static void
2737 async_resume(struct asyncline *async)
2738 {
2739 	register struct asycom *asy = async->async_common;
2740 
2741 	ASSERT(mutex_owned(asy->asy_excl_hi));
2742 #ifdef DEBUG
2743 	if (asydebug & ASY_DEBUG_PROCS)
2744 		printf("resume\n");
2745 #endif
2746 
2747 	asycheckflowcontrol_hw(asy);
2748 
2749 	if (INB(LSR) & XHRE) {
2750 		if (asycheckflowcontrol_sw(asy)) {
2751 			return;
2752 		} else if (async->async_ocnt > 0) {
2753 			OUTB(DAT, *async->async_optr++);
2754 			async->async_ocnt--;
2755 			async->async_flags |= ASYNC_PROGRESS;
2756 		}
2757 	}
2758 }
2759 
2760 /*
2761  * Process an "ioctl" message sent down to us.
2762  * Note that we don't need to get any locks until we are ready to access
2763  * the hardware.  Nothing we access until then is going to be altered
2764  * outside of the STREAMS framework, so we should be safe.
2765  */
2766 static void
2767 async_ioctl(struct asyncline *async, queue_t *wq, mblk_t *mp, boolean_t iswput)
2768 {
2769 	register struct asycom *asy = async->async_common;
2770 	register tty_common_t  *tp = &async->async_ttycommon;
2771 	register struct iocblk *iocp;
2772 	register unsigned datasize;
2773 	size_t ioc_count;
2774 	mblk_t *datamp;
2775 	int error = 0;
2776 	uchar_t val, icr;
2777 #ifdef DEBUG
2778 	if (asydebug & ASY_DEBUG_PROCS)
2779 		printf("ioctl\n");
2780 #endif
2781 
2782 	if (tp->t_iocpending != NULL) {
2783 		/*
2784 		 * We were holding an "ioctl" response pending the
2785 		 * availability of an "mblk" to hold data to be passed up;
2786 		 * another "ioctl" came through, which means that "ioctl"
2787 		 * must have timed out or been aborted.
2788 		 */
2789 		freemsg(async->async_ttycommon.t_iocpending);
2790 		async->async_ttycommon.t_iocpending = NULL;
2791 	}
2792 
2793 	iocp = (struct iocblk *)mp->b_rptr;
2794 
2795 	/*
2796 	 * Save off the ioc count in case we need to restore it
2797 	 * because we are queuing a message block.
2798 	 */
2799 	ioc_count = iocp->ioc_count;
2800 
2801 	/*
2802 	 * For TIOCMGET, TIOCMBIC, TIOCMBIS, TIOCMSET, and PPS, do NOT call
2803 	 * ttycommon_ioctl() because this function frees up the message block
2804 	 * (mp->b_cont) that contains the address of the user variable where
2805 	 * we need to pass back the bit array.
2806 	 *
2807 	 * Similarly, ttycommon_ioctl() does not know about CONSOPENPOLLEDIO
2808 	 * and CONSCLOSEPOLLEDIO, so don't let ttycommon_ioctl() touch them.
2809 	 */
2810 	if (iocp->ioc_cmd == TIOCMGET ||
2811 	    iocp->ioc_cmd == TIOCMBIC ||
2812 	    iocp->ioc_cmd == TIOCMBIS ||
2813 	    iocp->ioc_cmd == TIOCMSET ||
2814 	    iocp->ioc_cmd == TIOCGPPS ||
2815 	    iocp->ioc_cmd == TIOCSPPS ||
2816 	    iocp->ioc_cmd == TIOCGPPSEV ||
2817 	    iocp->ioc_cmd == CONSOPENPOLLEDIO ||
2818 	    iocp->ioc_cmd == CONSCLOSEPOLLEDIO)
2819 		error = -1; /* Do Nothing */
2820 	else
2821 
2822 	/*
2823 	 * The only way in which "ttycommon_ioctl" can fail is if the "ioctl"
2824 	 * requires a response containing data to be returned to the user,
2825 	 * and no mblk could be allocated for the data.
2826 	 * No such "ioctl" alters our state.  Thus, we always go ahead and
2827 	 * do any state-changes the "ioctl" calls for.  If we couldn't allocate
2828 	 * the data, "ttycommon_ioctl" has stashed the "ioctl" away safely, so
2829 	 * we just call "bufcall" to request that we be called back when we
2830 	 * stand a better chance of allocating the data.
2831 	 */
2832 	if ((datasize = ttycommon_ioctl(tp, wq, mp, &error)) != 0) {
2833 		if (async->async_wbufcid)
2834 			unbufcall(async->async_wbufcid);
2835 		async->async_wbufcid = bufcall(datasize, BPRI_HI, async_reioctl,
2836 		    async);
2837 		return;
2838 	}
2839 
2840 	mutex_enter(asy->asy_excl);
2841 
2842 	if (error == 0) {
2843 		/*
2844 		 * "ttycommon_ioctl" did most of the work; we just use the
2845 		 * data it set up.
2846 		 */
2847 		switch (iocp->ioc_cmd) {
2848 
2849 		case TCSETS:
2850 			if (!(asy->asy_rsc_console || asy->asy_rsc_control ||
2851 			    asy->asy_lom_console)) {
2852 				mutex_enter(asy->asy_excl_hi);
2853 				error = asy_program(asy, ASY_NOINIT);
2854 				mutex_exit(asy->asy_excl_hi);
2855 			}
2856 			break;
2857 		case TCSETSF:
2858 		case TCSETSW:
2859 		case TCSETA:
2860 		case TCSETAW:
2861 		case TCSETAF:
2862 			if (!(asy->asy_rsc_console || asy->asy_rsc_control ||
2863 			    asy->asy_lom_console)) {
2864 				mutex_enter(asy->asy_excl_hi);
2865 				if (iswput && asy_isbusy(asy)) {
2866 					/*
2867 					 * ttycommon_ioctl sets the db_type to
2868 					 * M_IOCACK and ioc_count to zero
2869 					 * we need to undo this when we
2870 					 * queue a control message. This will
2871 					 * allow the control messages to be
2872 					 * processed again when the chip
2873 					 * becomes available.
2874 					 */
2875 					mp->b_datap->db_type = M_IOCTL;
2876 					iocp->ioc_count = ioc_count;
2877 
2878 					if (putq(wq, mp) == 0)
2879 						freemsg(mp);
2880 					mutex_exit(asy->asy_excl_hi);
2881 					mutex_exit(asy->asy_excl);
2882 					return;
2883 				}
2884 
2885 				/*
2886 				 * TCSETA, TCSETAW, and TCSETAF make use of
2887 				 * the termio structure and therefore have
2888 				 * no concept of any speed except what can
2889 				 * be represented by CBAUD. This is because
2890 				 * of legacy SVR4 code. Therefore, if we see
2891 				 * one of the aforementioned IOCTL commands
2892 				 * we should zero out CBAUDEXT, CIBAUD, and
2893 				 * CIBAUDEXT as to not break legacy
2894 				 * functionality. This is because CBAUDEXT,
2895 				 * CIBAUD, and CIBAUDEXT can't be stored in
2896 				 * an unsigned short. By zeroing out CBAUDEXT,
2897 				 * CIBAUD, and CIBAUDEXT in the t_cflag of the
2898 				 * termios structure asy_program() will set the
2899 				 * input baud rate to the output baud rate.
2900 				 */
2901 				if (iocp->ioc_cmd == TCSETA ||
2902 				    iocp->ioc_cmd == TCSETAW ||
2903 				    iocp->ioc_cmd == TCSETAF)
2904 					tp->t_cflag &= ~(CIBAUD |
2905 					    CIBAUDEXT | CBAUDEXT);
2906 
2907 				error = asy_program(asy, ASY_NOINIT);
2908 				mutex_exit(asy->asy_excl_hi);
2909 			}
2910 			break;
2911 		case TIOCSSOFTCAR:
2912 			/* Set the driver state appropriately */
2913 			mutex_enter(asy->asy_excl_hi);
2914 			if (tp->t_flags & TS_SOFTCAR)
2915 				asy->asy_flags |= ASY_IGNORE_CD;
2916 			else
2917 				asy->asy_flags &= ~ASY_IGNORE_CD;
2918 			mutex_exit(asy->asy_excl_hi);
2919 			break;
2920 		}
2921 	} else if (error < 0) {
2922 		/*
2923 		 * "ttycommon_ioctl" didn't do anything; we process it here.
2924 		 */
2925 		error = 0;
2926 		switch (iocp->ioc_cmd) {
2927 
2928 		case TIOCGPPS:
2929 			/*
2930 			 * Get PPS on/off.
2931 			 */
2932 			if (mp->b_cont != NULL)
2933 				freemsg(mp->b_cont);
2934 
2935 			mp->b_cont = allocb(sizeof (int), BPRI_HI);
2936 			if (mp->b_cont == NULL) {
2937 				error = ENOMEM;
2938 				break;
2939 			}
2940 			if (asy->asy_flags & ASY_PPS)
2941 				*(int *)mp->b_cont->b_wptr = 1;
2942 			else
2943 				*(int *)mp->b_cont->b_wptr = 0;
2944 			mp->b_cont->b_wptr += sizeof (int);
2945 			mp->b_datap->db_type = M_IOCACK;
2946 			iocp->ioc_count = sizeof (int);
2947 			break;
2948 
2949 		case TIOCSPPS:
2950 			/*
2951 			 * Set PPS on/off.
2952 			 */
2953 			error = miocpullup(mp, sizeof (int));
2954 			if (error != 0)
2955 				break;
2956 
2957 			mutex_enter(asy->asy_excl_hi);
2958 			if (*(int *)mp->b_cont->b_rptr)
2959 				asy->asy_flags |= ASY_PPS;
2960 			else
2961 				asy->asy_flags &= ~ASY_PPS;
2962 			/* Reset edge sense */
2963 			asy->asy_flags &= ~ASY_PPS_EDGE;
2964 			mutex_exit(asy->asy_excl_hi);
2965 			mp->b_datap->db_type = M_IOCACK;
2966 			break;
2967 
2968 		case TIOCGPPSEV: {
2969 			/*
2970 			 * Get PPS event data.
2971 			 */
2972 			mblk_t *bp;
2973 			void *buf;
2974 #ifdef _SYSCALL32_IMPL
2975 			struct ppsclockev32 p32;
2976 #endif
2977 			struct ppsclockev ppsclockev;
2978 
2979 			if (mp->b_cont != NULL) {
2980 				freemsg(mp->b_cont);
2981 				mp->b_cont = NULL;
2982 			}
2983 
2984 			if ((asy->asy_flags & ASY_PPS) == 0) {
2985 				error = ENXIO;
2986 				break;
2987 			}
2988 
2989 			/* Protect from incomplete asy_ppsev */
2990 			mutex_enter(asy->asy_excl_hi);
2991 			ppsclockev = asy_ppsev;
2992 			mutex_exit(asy->asy_excl_hi);
2993 
2994 #ifdef _SYSCALL32_IMPL
2995 			if ((iocp->ioc_flag & IOC_MODELS) != IOC_NATIVE) {
2996 				TIMEVAL_TO_TIMEVAL32(&p32.tv, &ppsclockev.tv);
2997 				p32.serial = ppsclockev.serial;
2998 				buf = &p32;
2999 				iocp->ioc_count = sizeof (struct ppsclockev32);
3000 			} else
3001 #endif
3002 			{
3003 				buf = &ppsclockev;
3004 				iocp->ioc_count = sizeof (struct ppsclockev);
3005 			}
3006 
3007 			if ((bp = allocb(iocp->ioc_count, BPRI_HI)) == NULL) {
3008 				error = ENOMEM;
3009 				break;
3010 			}
3011 			mp->b_cont = bp;
3012 
3013 			bcopy(buf, bp->b_wptr, iocp->ioc_count);
3014 			bp->b_wptr += iocp->ioc_count;
3015 			mp->b_datap->db_type = M_IOCACK;
3016 			break;
3017 		}
3018 
3019 		case TCSBRK:
3020 			error = miocpullup(mp, sizeof (int));
3021 			if (error != 0)
3022 				break;
3023 
3024 			mutex_enter(asy->asy_excl_hi);
3025 			if (*(int *)mp->b_cont->b_rptr == 0) {
3026 				/*
3027 				 * Get the divisor by calculating the rate
3028 				 */
3029 				unsigned int rate, divisor;
3030 				rate = async->async_ttycommon.t_cflag & CBAUD;
3031 				if (async->async_ttycommon.t_cflag & CBAUDEXT)
3032 					rate += 16;
3033 				if (rate >= N_SU_SPEEDS) rate = B9600;
3034 				divisor = asyspdtab[rate] & 0xfff;
3035 
3036 				/*
3037 				 * To ensure that erroneous characters are
3038 				 * not sent out when the break is set, SB
3039 				 * recommends three steps:
3040 				 *
3041 				 * 1) pad the TSR with 0 bits
3042 				 * 2) When the TSR is full, set break
3043 				 * 3) When the TSR has been flushed, unset
3044 				 *    the break when transmission must be
3045 				 *    restored.
3046 				 *
3047 				 * We loop until the TSR is empty and then
3048 				 * set the break.  ASYNC_BREAK has been set
3049 				 * to ensure that no characters are
3050 				 * transmitted while the TSR is being
3051 				 * flushed and SOUT is being used for the
3052 				 * break signal.
3053 				 *
3054 				 * The wait period is equal to
3055 				 * clock / (baud * 16) * 16 * 2.
3056 				 */
3057 				async->async_flags |= ASYNC_BREAK;
3058 				while ((INB(LSR) & XSRE) == 0) {
3059 					mutex_exit(asy->asy_excl_hi);
3060 					mutex_exit(asy->asy_excl);
3061 					drv_usecwait(32*divisor);
3062 					mutex_enter(asy->asy_excl);
3063 					mutex_enter(asy->asy_excl_hi);
3064 				}
3065 
3066 				/*
3067 				 * Set the break bit, and arrange for
3068 				 * "async_restart" to be called in 1/4 second;
3069 				 * it will turn the break bit off, and call
3070 				 * "async_start" to grab the next message.
3071 				 */
3072 				val = INB(LCR);
3073 				OUTB(LCR, (val | SETBREAK));
3074 				mutex_exit(asy->asy_excl_hi);
3075 				(void) timeout(async_restart, async, hz / 4);
3076 			} else {
3077 #ifdef DEBUG
3078 				if (asydebug & ASY_DEBUG_CLOSE)
3079 					printf("asy%d: wait for flush.\n",
3080 					    UNIT(async->async_dev));
3081 #endif
3082 				if (iswput && asy_isbusy(asy)) {
3083 					if (putq(wq, mp) == 0)
3084 						freemsg(mp);
3085 					mutex_exit(asy->asy_excl_hi);
3086 					mutex_exit(asy->asy_excl);
3087 					return;
3088 				}
3089 				mutex_exit(asy->asy_excl_hi);
3090 #ifdef DEBUG
3091 				if (asydebug & ASY_DEBUG_CLOSE)
3092 					printf("asy%d: ldterm satisfied.\n",
3093 					    UNIT(async->async_dev));
3094 #endif
3095 			}
3096 			break;
3097 
3098 		case TIOCSBRK:
3099 			mutex_enter(asy->asy_excl_hi);
3100 			val = INB(LCR);
3101 			OUTB(LCR, (val | SETBREAK));
3102 			mutex_exit(asy->asy_excl_hi);
3103 			mutex_exit(asy->asy_excl);
3104 			miocack(wq, mp, 0, 0);
3105 			return;
3106 
3107 		case TIOCCBRK:
3108 			mutex_enter(asy->asy_excl_hi);
3109 			val = INB(LCR);
3110 			OUTB(LCR, (val & ~SETBREAK));
3111 			mutex_exit(asy->asy_excl_hi);
3112 			mutex_exit(asy->asy_excl);
3113 			miocack(wq, mp, 0, 0);
3114 			return;
3115 
3116 		case TIOCMSET:
3117 		case TIOCMBIS:
3118 		case TIOCMBIC:
3119 			if (iocp->ioc_count == TRANSPARENT)
3120 				mcopyin(mp, NULL, sizeof (int), NULL);
3121 			else {
3122 				error = miocpullup(mp, sizeof (int));
3123 				if (error != 0)
3124 					break;
3125 
3126 				mutex_enter(asy->asy_excl_hi);
3127 
3128 				(void) asymctl(asy,
3129 				    dmtoasy(*(int *)mp->b_cont->b_rptr),
3130 				    iocp->ioc_cmd);
3131 
3132 				mutex_exit(asy->asy_excl_hi);
3133 				iocp->ioc_error = 0;
3134 				mp->b_datap->db_type = M_IOCACK;
3135 			}
3136 			break;
3137 
3138 		case TIOCSILOOP:
3139 			mutex_enter(asy->asy_excl_hi);
3140 			/*
3141 			 * If somebody misues this Ioctl when used for
3142 			 * driving keyboard and mouse indicate not supported
3143 			 */
3144 			if ((asy->asy_device_type == ASY_KEYBOARD) ||
3145 			    (asy->asy_device_type == ASY_MOUSE)) {
3146 				mutex_exit(asy->asy_excl_hi);
3147 				error = ENOTTY;
3148 				break;
3149 			}
3150 
3151 			/* should not use when we're the console */
3152 			if ((async->async_dev == kbddev) ||
3153 			    (async->async_dev == rconsdev) ||
3154 			    (async->async_dev == stdindev)) {
3155 				mutex_exit(asy->asy_excl_hi);
3156 				error = EINVAL;
3157 				break;
3158 			}
3159 
3160 			val = INB(MCR);
3161 			icr = INB(ICR);
3162 			/*
3163 			 * Disable the Modem Status Interrupt
3164 			 * The reason for disabling is  the status of
3165 			 * modem signal are in the higher 4 bits instead of
3166 			 * lower four bits when in loopback mode,
3167 			 * so, donot worry about Modem interrupt when
3168 			 * you are planning to set
3169 			 * this in loopback mode until it is cleared by
3170 			 * another ioctl to get out of the loopback mode
3171 			 */
3172 			OUTB(ICR, icr & ~ MIEN);
3173 			OUTB(MCR, val | ASY_LOOP);
3174 			mutex_exit(asy->asy_excl_hi);
3175 			iocp->ioc_error = 0;
3176 			mp->b_datap->db_type = M_IOCACK;
3177 			break;
3178 
3179 		case TIOCMGET:
3180 			datamp = allocb(sizeof (int), BPRI_MED);
3181 			if (datamp == NULL) {
3182 				error = EAGAIN;
3183 				break;
3184 			}
3185 
3186 			mutex_enter(asy->asy_excl_hi);
3187 			*(int *)datamp->b_rptr = asymctl(asy, 0, TIOCMGET);
3188 			mutex_exit(asy->asy_excl_hi);
3189 
3190 			if (iocp->ioc_count == TRANSPARENT) {
3191 				mcopyout(mp, NULL, sizeof (int), NULL, datamp);
3192 			} else {
3193 				if (mp->b_cont != NULL)
3194 					freemsg(mp->b_cont);
3195 				mp->b_cont = datamp;
3196 				mp->b_cont->b_wptr += sizeof (int);
3197 				mp->b_datap->db_type = M_IOCACK;
3198 				iocp->ioc_count = sizeof (int);
3199 			}
3200 			break;
3201 
3202 		case CONSOPENPOLLEDIO:
3203 			/*
3204 			 * If we are driving a keyboard there is nothing
3205 			 * upstream to translate the scan codes. Therefore,
3206 			 * set the error code to ENOTSUP and NAK the request
3207 			 */
3208 			if (asy->asy_device_type == ASY_KEYBOARD) {
3209 				error = ENOTSUP;
3210 				break;
3211 			}
3212 
3213 			error = miocpullup(mp, sizeof (struct cons_polledio *));
3214 			if (error != 0)
3215 				break;
3216 
3217 			/*
3218 			 * send up a message block containing the
3219 			 * cons_polledio structure. This provides
3220 			 * handles to the putchar, getchar, ischar,
3221 			 * polledio_enter and polledio_exit functions.
3222 			 */
3223 			*(struct cons_polledio **)mp->b_cont->b_rptr =
3224 			    &asy->polledio;
3225 
3226 			mp->b_datap->db_type = M_IOCACK;
3227 			break;
3228 
3229 		case CONSCLOSEPOLLEDIO:
3230 			/*
3231 			 * If we are driving a keyboard we never successfully
3232 			 * called CONSOPENPOLLEDIO so set the error to
3233 			 * ENOTSUP and NAK the request.
3234 			 */
3235 			if (asy->asy_device_type == ASY_KEYBOARD) {
3236 				error = ENOTSUP;
3237 				break;
3238 			}
3239 
3240 			mp->b_datap->db_type = M_IOCACK;
3241 			iocp->ioc_error = 0;
3242 			iocp->ioc_rval = 0;
3243 			break;
3244 
3245 		default: /* unexpected ioctl type */
3246 			/*
3247 			 * If we don't understand it, it's an error.  NAK it.
3248 			 */
3249 			error = EINVAL;
3250 			break;
3251 		}
3252 	}
3253 	if (error != 0) {
3254 		iocp->ioc_error = error;
3255 		mp->b_datap->db_type = M_IOCNAK;
3256 	}
3257 	mutex_exit(asy->asy_excl);
3258 	qreply(wq, mp);
3259 }
3260 
3261 static void
3262 asyrsrv(queue_t *q)
3263 {
3264 	mblk_t *bp;
3265 	struct asyncline *async;
3266 
3267 	async = (struct asyncline *)q->q_ptr;
3268 
3269 	while (canputnext(q) && (bp = getq(q)))
3270 		putnext(q, bp);
3271 	ASYSETSOFT(async->async_common);
3272 	async->async_polltid = 0;
3273 }
3274 
3275 /*
3276  * Put procedure for write queue.
3277  * Respond to M_STOP, M_START, M_IOCTL, and M_FLUSH messages here;
3278  * set the flow control character for M_STOPI and M_STARTI messages;
3279  * queue up M_BREAK, M_DELAY, and M_DATA messages for processing
3280  * by the start routine, and then call the start routine; discard
3281  * everything else.  Note that this driver does not incorporate any
3282  * mechanism to negotiate to handle the canonicalization process.
3283  * It expects that these functions are handled in upper module(s),
3284  * as we do in ldterm.
3285  */
3286 static void
3287 asywput(queue_t *q, mblk_t *mp)
3288 {
3289 	register struct asyncline *async;
3290 	register struct asycom *asy;
3291 	int error;
3292 
3293 	async = (struct asyncline *)q->q_ptr;
3294 	asy = async->async_common;
3295 
3296 	switch (mp->b_datap->db_type) {
3297 
3298 	case M_STOP:
3299 		/*
3300 		 * Since we don't do real DMA, we can just let the
3301 		 * chip coast to a stop after applying the brakes.
3302 		 */
3303 		mutex_enter(asy->asy_excl);
3304 		async->async_flags |= ASYNC_STOPPED;
3305 		mutex_exit(asy->asy_excl);
3306 		freemsg(mp);
3307 		break;
3308 
3309 	case M_START:
3310 		mutex_enter(asy->asy_excl);
3311 		if (async->async_flags & ASYNC_STOPPED) {
3312 			async->async_flags &= ~ASYNC_STOPPED;
3313 			/*
3314 			 * If an output operation is in progress,
3315 			 * resume it.  Otherwise, prod the start
3316 			 * routine.
3317 			 */
3318 			if (async->async_ocnt > 0) {
3319 				mutex_enter(asy->asy_excl_hi);
3320 				async_resume(async);
3321 				mutex_exit(asy->asy_excl_hi);
3322 			} else {
3323 				async_start(async);
3324 			}
3325 		}
3326 		mutex_exit(asy->asy_excl);
3327 		freemsg(mp);
3328 		break;
3329 
3330 	case M_IOCTL:
3331 		switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
3332 
3333 		case TCSBRK:
3334 			error = miocpullup(mp, sizeof (int));
3335 			if (error != 0) {
3336 				miocnak(q, mp, 0, error);
3337 				return;
3338 			}
3339 
3340 			if (*(int *)mp->b_cont->b_rptr != 0) {
3341 #ifdef DEBUG
3342 				if (asydebug & ASY_DEBUG_CLOSE)
3343 					printf("asy%d: flush request.\n",
3344 					    UNIT(async->async_dev));
3345 #endif
3346 				(void) putq(q, mp);
3347 				mutex_enter(asy->asy_excl);
3348 				async_nstart(async, 1);
3349 				mutex_exit(asy->asy_excl);
3350 				break;
3351 			}
3352 			/*FALLTHROUGH*/
3353 		case TCSETSW:
3354 		case TCSETSF:
3355 		case TCSETAW:
3356 		case TCSETAF:
3357 			/*
3358 			 * The changes do not take effect until all
3359 			 * output queued before them is drained.
3360 			 * Put this message on the queue, so that
3361 			 * "async_start" will see it when it's done
3362 			 * with the output before it.  Poke the
3363 			 * start routine, just in case.
3364 			 */
3365 			(void) putq(q, mp);
3366 			mutex_enter(asy->asy_excl);
3367 			async_start(async);
3368 			mutex_exit(asy->asy_excl);
3369 			break;
3370 
3371 		default:
3372 			/*
3373 			 * Do it now.
3374 			 */
3375 			async_ioctl(async, q, mp, B_TRUE);
3376 			break;
3377 		}
3378 		break;
3379 
3380 	case M_FLUSH:
3381 		if (*mp->b_rptr & FLUSHW) {
3382 			mutex_enter(asy->asy_excl);
3383 
3384 			/*
3385 			 * Abort any output in progress.
3386 			 */
3387 			mutex_enter(asy->asy_excl_hi);
3388 			if (async->async_flags & ASYNC_BUSY) {
3389 				async->async_ocnt = 0;
3390 				async->async_flags &= ~ASYNC_BUSY;
3391 			}
3392 			mutex_exit(asy->asy_excl_hi);
3393 
3394 			/* Flush FIFO buffers */
3395 			if (asy->asy_use_fifo == FIFO_ON) {
3396 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFOTXFLSH |
3397 				    (asy->asy_trig_level & 0xff));
3398 			}
3399 
3400 			/*
3401 			 * Flush our write queue.
3402 			 */
3403 			flushq(q, FLUSHDATA);	/* XXX doesn't flush M_DELAY */
3404 			if (async->async_xmitblk != NULL) {
3405 				freeb(async->async_xmitblk);
3406 				async->async_xmitblk = NULL;
3407 			}
3408 
3409 			mutex_exit(asy->asy_excl);
3410 			*mp->b_rptr &= ~FLUSHW;	/* it has been flushed */
3411 		}
3412 		if (*mp->b_rptr & FLUSHR) {
3413 			/* Flush FIFO buffers */
3414 			if (asy->asy_use_fifo == FIFO_ON) {
3415 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFORXFLSH |
3416 				    (asy->asy_trig_level & 0xff));
3417 			}
3418 			flushq(RD(q), FLUSHDATA);
3419 			qreply(q, mp);	/* give the read queues a crack at it */
3420 		} else {
3421 			freemsg(mp);
3422 		}
3423 
3424 		/*
3425 		 * We must make sure we process messages that survive the
3426 		 * write-side flush.  Without this call, the close protocol
3427 		 * with ldterm can hang forever.  (ldterm will have sent us a
3428 		 * TCSBRK ioctl that it expects a response to.)
3429 		 */
3430 		mutex_enter(asy->asy_excl);
3431 		async_start(async);
3432 		mutex_exit(asy->asy_excl);
3433 		break;
3434 	case M_BREAK:
3435 	case M_DELAY:
3436 	case M_DATA:
3437 		/*
3438 		 * Queue the message up to be transmitted,
3439 		 * and poke the start routine.
3440 		 */
3441 		(void) putq(q, mp);
3442 		mutex_enter(asy->asy_excl);
3443 		async_start(async);
3444 		mutex_exit(asy->asy_excl);
3445 		break;
3446 
3447 	case M_STOPI:
3448 		mutex_enter(asy->asy_excl);
3449 		async->async_flowc = async->async_stopc;
3450 		async_start(async);		/* poke the start routine */
3451 		mutex_exit(asy->asy_excl);
3452 		freemsg(mp);
3453 		break;
3454 
3455 	case M_STARTI:
3456 		mutex_enter(asy->asy_excl);
3457 		async->async_flowc = async->async_startc;
3458 		async_start(async);		/* poke the start routine */
3459 		mutex_exit(asy->asy_excl);
3460 		freemsg(mp);
3461 		break;
3462 
3463 	case M_CTL:
3464 		if (MBLKL(mp) >= sizeof (struct iocblk) &&
3465 		    ((struct iocblk *)mp->b_rptr)->ioc_cmd == MC_POSIXQUERY) {
3466 			((struct iocblk *)mp->b_rptr)->ioc_cmd = MC_HAS_POSIX;
3467 			qreply(q, mp);
3468 		} else {
3469 			/*
3470 			 * These MC_SERVICE type messages are used by upper
3471 			 * modules to tell this driver to send input up
3472 			 * immediately, or that it can wait for normal
3473 			 * processing that may or may not be done.  Sun
3474 			 * requires these for the mouse module.
3475 			 * (XXX - for x86?)
3476 			 */
3477 			mutex_enter(asy->asy_excl);
3478 			switch (*mp->b_rptr) {
3479 
3480 			case MC_SERVICEIMM:
3481 				async->async_flags |= ASYNC_SERVICEIMM;
3482 				break;
3483 
3484 			case MC_SERVICEDEF:
3485 				async->async_flags &= ~ASYNC_SERVICEIMM;
3486 				break;
3487 			}
3488 			mutex_exit(asy->asy_excl);
3489 			freemsg(mp);
3490 		}
3491 		break;
3492 
3493 	case M_IOCDATA:
3494 		async_iocdata(q, mp);
3495 		break;
3496 
3497 	default:
3498 		freemsg(mp);
3499 		break;
3500 	}
3501 }
3502 
3503 /*
3504  * Retry an "ioctl", now that "bufcall" claims we may be able to allocate
3505  * the buffer we need.
3506  */
3507 static void
3508 async_reioctl(void *arg)
3509 {
3510 	struct asyncline *async = arg;
3511 	struct asycom *asy = async->async_common;
3512 	queue_t	*q;
3513 	mblk_t		*mp;
3514 
3515 	/*
3516 	 * The bufcall is no longer pending.
3517 	 */
3518 	mutex_enter(asy->asy_excl);
3519 	async->async_wbufcid = 0;
3520 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
3521 		mutex_exit(asy->asy_excl);
3522 		return;
3523 	}
3524 	if ((mp = async->async_ttycommon.t_iocpending) != NULL) {
3525 		/* not pending any more */
3526 		async->async_ttycommon.t_iocpending = NULL;
3527 		mutex_exit(asy->asy_excl);
3528 		/* not in STREAMS queue; we no longer know if we're in wput */
3529 		async_ioctl(async, q, mp, B_TRUE);
3530 	} else
3531 		mutex_exit(asy->asy_excl);
3532 }
3533 
3534 static void
3535 async_iocdata(queue_t *q, mblk_t *mp)
3536 {
3537 	struct asyncline	*async = (struct asyncline *)q->q_ptr;
3538 	struct asycom		*asy;
3539 	struct copyresp *csp;
3540 
3541 	asy = async->async_common;
3542 	csp = (struct copyresp *)mp->b_rptr;
3543 
3544 	if (csp->cp_rval != 0) {
3545 		freemsg(mp);
3546 		return;
3547 	}
3548 
3549 	mutex_enter(asy->asy_excl);
3550 
3551 	switch (csp->cp_cmd) {
3552 	case TIOCMSET:
3553 	case TIOCMBIS:
3554 	case TIOCMBIC:
3555 		if (mp->b_cont == NULL) {
3556 			mutex_exit(asy->asy_excl);
3557 			miocnak(q, mp, 0, EINVAL);
3558 			break;
3559 		}
3560 
3561 		mutex_enter(asy->asy_excl_hi);
3562 		(void) asymctl(asy, dmtoasy(*(int *)mp->b_cont->b_rptr),
3563 		    csp->cp_cmd);
3564 		mutex_exit(asy->asy_excl_hi);
3565 
3566 		freemsg(mp->b_cont);
3567 		mp->b_cont = NULL;
3568 		mutex_exit(asy->asy_excl);
3569 		miocack(q, mp, 0, 0);
3570 		break;
3571 
3572 	case TIOCMGET:
3573 		if (mp->b_cont != NULL) {
3574 			freemsg(mp->b_cont);
3575 			mp->b_cont = NULL;
3576 		}
3577 		mutex_exit(asy->asy_excl);
3578 		miocack(q, mp, 0, 0);
3579 		break;
3580 
3581 	default:
3582 		mutex_exit(asy->asy_excl);
3583 		miocnak(q, mp, 0, EINVAL);
3584 		break;
3585 	}
3586 }
3587 
3588 
3589 /*
3590  * Set or get the modem control status.
3591  */
3592 static int
3593 asymctl(struct asycom *asy, int bits, int how)
3594 {
3595 	register int mcr_r, msr_r;
3596 
3597 	ASSERT(mutex_owned(asy->asy_excl_hi));
3598 	ASSERT(mutex_owned(asy->asy_excl));
3599 
3600 	/* Read Modem Control Registers */
3601 	mcr_r = INB(MCR);
3602 
3603 	switch (how) {
3604 
3605 	case TIOCMSET:
3606 		mcr_r = bits;
3607 		break;
3608 
3609 	case TIOCMBIS:
3610 		mcr_r |= bits;			/* Set bits from input	*/
3611 		break;
3612 
3613 	case TIOCMBIC:
3614 		mcr_r &= ~bits;			/* Set ~bits from input	*/
3615 		break;
3616 
3617 	case TIOCMGET:
3618 		/* Read Modem Status Registers */
3619 		if (INB(ICR) & MIEN)
3620 			msr_r = asy->asy_cached_msr;
3621 		else
3622 			msr_r = INB(MSR);
3623 		return (asytodm(mcr_r, msr_r));
3624 	}
3625 
3626 	OUTB(MCR, mcr_r);
3627 
3628 	return (mcr_r);
3629 }
3630 
3631 static int
3632 asytodm(int mcr_r, int msr_r)
3633 {
3634 	register int b = 0;
3635 
3636 
3637 	/* MCR registers */
3638 	if (mcr_r & RTS)
3639 		b |= TIOCM_RTS;
3640 
3641 	if (mcr_r & DTR)
3642 		b |= TIOCM_DTR;
3643 
3644 	/* MSR registers */
3645 	if (msr_r & DCD)
3646 		b |= TIOCM_CAR;
3647 
3648 	if (msr_r & CTS)
3649 		b |= TIOCM_CTS;
3650 
3651 	if (msr_r & DSR)
3652 		b |= TIOCM_DSR;
3653 
3654 	if (msr_r & RI)
3655 		b |= TIOCM_RNG;
3656 
3657 	return (b);
3658 }
3659 
3660 static int
3661 dmtoasy(int bits)
3662 {
3663 	register int b = 0;
3664 
3665 #ifdef	CAN_NOT_SET	/* only DTR and RTS can be set */
3666 	if (bits & TIOCM_CAR)
3667 		b |= DCD;
3668 	if (bits & TIOCM_CTS)
3669 		b |= CTS;
3670 	if (bits & TIOCM_DSR)
3671 		b |= DSR;
3672 	if (bits & TIOCM_RNG)
3673 		b |= RI;
3674 #endif
3675 
3676 	if (bits & TIOCM_RTS)
3677 		b |= RTS;
3678 	if (bits & TIOCM_DTR)
3679 		b |= DTR;
3680 
3681 	return (b);
3682 }
3683 
3684 static void
3685 asycheckflowcontrol_hw(struct asycom *asy)
3686 {
3687 	struct asyncline *async;
3688 	uchar_t	mcr, flag;
3689 
3690 	ASSERT(mutex_owned(asy->asy_excl_hi));
3691 
3692 	async = (struct asyncline *)asy->asy_priv;
3693 	ASSERT(async != NULL);
3694 
3695 	if (async->async_ttycommon.t_cflag & CRTSXOFF) {
3696 		mcr = INB(MCR);
3697 		flag = (async->async_flags & ASYNC_HW_IN_FLOW) ? 0 : RTS;
3698 		if (((mcr ^ flag) & RTS) != 0) {
3699 			OUTB(MCR, (mcr ^ RTS));
3700 		}
3701 	}
3702 }
3703 
3704 static boolean_t
3705 asycheckflowcontrol_sw(struct asycom *asy)
3706 {
3707 	uchar_t		ss;
3708 	struct asyncline *async;
3709 	int rval = B_FALSE;
3710 
3711 	ASSERT(mutex_owned(asy->asy_excl_hi));
3712 
3713 	async = (struct asyncline *)asy->asy_priv;
3714 	ASSERT(async != NULL);
3715 
3716 	if ((ss = async->async_flowc) != '\0' && (INB(LSR) & XHRE)) {
3717 		/*
3718 		 * If we get this far, then we know that flowc is non-zero and
3719 		 * that there's transmit room available.  We've "handled" the
3720 		 * request now, so clear it.  If the user didn't ask for IXOFF,
3721 		 * then don't actually send anything, but wait for the next
3722 		 * opportunity.
3723 		 */
3724 		async->async_flowc = '\0';
3725 		if (async->async_ttycommon.t_iflag & IXOFF) {
3726 			async->async_flags |= ASYNC_BUSY;
3727 			OUTB(DAT, ss);
3728 			rval = B_TRUE;
3729 		}
3730 	}
3731 
3732 	return (rval);
3733 }
3734 
3735 /*
3736  * Check for abort character sequence
3737  */
3738 static boolean_t
3739 abort_charseq_recognize(uchar_t ch)
3740 {
3741 	static int state = 0;
3742 #define	CNTRL(c) ((c)&037)
3743 	static char sequence[] = { '\r', '~', CNTRL('b') };
3744 
3745 	if (ch == sequence[state]) {
3746 		if (++state >= sizeof (sequence)) {
3747 			state = 0;
3748 			return (B_TRUE);
3749 		}
3750 	} else {
3751 		state = (ch == sequence[0]) ? 1 : 0;
3752 	}
3753 	return (B_FALSE);
3754 }
3755