xref: /titanic_41/usr/src/uts/sun4/io/su_driver.c (revision 5aefb6555731130ca4fd295960123d71f2d21fe8)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*	Copyright (c) 1990, 1991 UNIX System Laboratories, Inc.	*/
23 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T	*/
24 /*	  All Rights Reserved					*/
25 
26 /*
27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 
31 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 
33 /*
34  *	Serial I/O driver for 82510/8250/16450/16550AF chips.
35  *	Modified as sparc keyboard/mouse driver.
36  */
37 #define	SU_REGISTER_FILE_NO 0
38 #define	SU_REGOFFSET 0
39 #define	SU_REGISTER_LEN 8
40 
41 #include <sys/param.h>
42 #include <sys/types.h>
43 #include <sys/signal.h>
44 #include <sys/stream.h>
45 #include <sys/termio.h>
46 #include <sys/errno.h>
47 #include <sys/file.h>
48 #include <sys/cmn_err.h>
49 #include <sys/stropts.h>
50 #include <sys/strsubr.h>
51 #include <sys/strsun.h>
52 #include <sys/strtty.h>
53 #include <sys/debug.h>
54 #include <sys/kbio.h>
55 #include <sys/cred.h>
56 #include <sys/modctl.h>
57 #include <sys/stat.h>
58 #include <sys/consdev.h>
59 #include <sys/mkdev.h>
60 #include <sys/kmem.h>
61 #include <sys/cred.h>
62 #ifdef DEBUG
63 #include <sys/promif.h>
64 #endif
65 #include <sys/ddi.h>
66 #include <sys/sunddi.h>
67 #include <sys/sudev.h>
68 #include <sys/note.h>
69 #include <sys/timex.h>
70 #include <sys/policy.h>
71 
72 #define	async_stopc	async_ttycommon.t_stopc
73 #define	async_startc	async_ttycommon.t_startc
74 
75 #define	ASY_INIT	1
76 #define	ASY_NOINIT	0
77 
78 #ifdef DEBUG
79 #define	ASY_DEBUG_INIT	0x001
80 #define	ASY_DEBUG_INPUT	0x002
81 #define	ASY_DEBUG_EOT	0x004
82 #define	ASY_DEBUG_CLOSE	0x008
83 #define	ASY_DEBUG_HFLOW	0x010
84 #define	ASY_DEBUG_PROCS	0x020
85 #define	ASY_DEBUG_STATE	0x040
86 #define	ASY_DEBUG_INTR	0x080
87 static	int asydebug = 0;
88 #endif
89 static	int su_log = 0;
90 
91 int su_drain_check = 15000000;		/* tunable: exit drain check time */
92 
93 static	struct ppsclockev asy_ppsev;
94 
95 static	int max_asy_instance = -1;
96 static	void	*su_asycom;	/* soft state asycom pointer */
97 static	void	*su_asyncline;	/* soft state asyncline pointer */
98 static	boolean_t abort_charseq_recognize(uchar_t ch);
99 
100 static	uint_t	asysoftintr(caddr_t intarg);
101 static	uint_t	asyintr(caddr_t argasy);
102 
103 /* The async interrupt entry points */
104 static void	async_txint(struct asycom *asy, uchar_t lsr);
105 static void	async_rxint(struct asycom *asy, uchar_t lsr);
106 static void	async_msint(struct asycom *asy);
107 static int	async_softint(struct asycom *asy);
108 
109 static void	async_ioctl(struct asyncline *async, queue_t *q, mblk_t *mp,
110     boolean_t iswput);
111 static void	async_reioctl(void *);
112 static void	async_iocdata(queue_t *q, mblk_t *mp);
113 static void	async_restart(void *);
114 static void	async_start(struct asyncline *async);
115 static void	async_nstart(struct asyncline *async, int mode);
116 static void	async_resume(struct asyncline *async);
117 static int	asy_program(struct asycom *asy, int mode);
118 
119 static int	asymctl(struct asycom *, int, int);
120 static int	asytodm(int, int);
121 static int	dmtoasy(int);
122 static void	asycheckflowcontrol_hw(struct asycom *asy);
123 static boolean_t asycheckflowcontrol_sw(struct asycom *asy);
124 static void	asy_ppsevent(struct asycom *asy, int msr);
125 
126 extern kcondvar_t lbolt_cv;
127 extern int ddi_create_internal_pathname(dev_info_t *dip, char *name,
128 		int spec_type, minor_t minor_num);
129 
130 
131 /*
132  * Baud rate table. Indexed by #defines found in sys/termios.h
133  */
134 ushort_t asyspdtab[] = {
135 	0,	/* 0 baud rate */
136 	0x900,	/* 50 baud rate */
137 	0x600,	/* 75 baud rate */
138 	0x417,	/* 110 baud rate (%0.026) */
139 	0x359,	/* 134 baud rate (%0.058) */
140 	0x300,	/* 150 baud rate */
141 	0x240,	/* 200 baud rate */
142 	0x180,	/* 300 baud rate */
143 	0x0c0,	/* 600 baud rate */
144 	0x060,	/* 1200 baud rate */
145 	0x040,	/* 1800 baud rate */
146 	0x030,	/* 2400 baud rate */
147 	0x018,	/* 4800 baud rate */
148 	0x00c,	/* 9600 baud rate */
149 	0x006,	/* 19200 baud rate */
150 	0x003,	/* 38400 baud rate */
151 	0x002,	/* 57600 baud rate */
152 	0,	/* 76800 baud rate - not supported */
153 	0x001,	/* 115200 baud rate */
154 	0,	/* 153600 baud rate - not supported */
155 	0x8002,	/* 230400 baud rate - supported on specific platforms */
156 	0,	/* 307200 baud rate - not supported */
157 	0x8001	/* 460800 baud rate - supported on specific platforms */
158 };
159 
160 /*
161  * Number of speeds supported is the number of entries in
162  * the above table.
163  */
164 #define	N_SU_SPEEDS	(sizeof (asyspdtab)/sizeof (ushort_t))
165 
166 /*
167  * Human-readable baud rate table.
168  * Indexed by #defines found in sys/termios.h
169  */
170 int baudtable[] = {
171 	0,	/* 0 baud rate */
172 	50,	/* 50 baud rate */
173 	75,	/* 75 baud rate */
174 	110,	/* 110 baud rate */
175 	134,	/* 134 baud rate */
176 	150,	/* 150 baud rate */
177 	200,	/* 200 baud rate */
178 	300,	/* 300 baud rate */
179 	600,	/* 600 baud rate */
180 	1200,	/* 1200 baud rate */
181 	1800,	/* 1800 baud rate */
182 	2400,	/* 2400 baud rate */
183 	4800,	/* 4800 baud rate */
184 	9600,	/* 9600 baud rate */
185 	19200,	/* 19200 baud rate */
186 	38400,	/* 38400 baud rate */
187 	57600,	/* 57600 baud rate */
188 	76800,	/* 76800 baud rate */
189 	115200,	/* 115200 baud rate */
190 	153600,	/* 153600 baud rate */
191 	230400,	/* 230400 baud rate */
192 	307200,	/* 307200 baud rate */
193 	460800	/* 460800 baud rate */
194 };
195 
196 static int asyopen(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr);
197 static int asyclose(queue_t *q, int flag);
198 static void asywput(queue_t *q, mblk_t *mp);
199 static void asyrsrv(queue_t *q);
200 
201 struct module_info asy_info = {
202 	0,
203 	"su",
204 	0,
205 	INFPSZ,
206 	32*4096,
207 	4096
208 };
209 
210 static struct qinit asy_rint = {
211 	putq,
212 	(int (*)())asyrsrv,
213 	asyopen,
214 	asyclose,
215 	NULL,
216 	&asy_info,
217 	NULL
218 };
219 
220 static struct qinit asy_wint = {
221 	(int (*)())asywput,
222 	NULL,
223 	NULL,
224 	NULL,
225 	NULL,
226 	&asy_info,
227 	NULL
228 };
229 
230 struct streamtab asy_str_info = {
231 	&asy_rint,
232 	&asy_wint,
233 	NULL,
234 	NULL
235 };
236 
237 static int asyinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
238 		void **result);
239 static int asyprobe(dev_info_t *);
240 static int asyattach(dev_info_t *, ddi_attach_cmd_t);
241 static int asydetach(dev_info_t *, ddi_detach_cmd_t);
242 
243 static 	struct cb_ops cb_asy_ops = {
244 	nodev,			/* cb_open */
245 	nodev,			/* cb_close */
246 	nodev,			/* cb_strategy */
247 	nodev,			/* cb_print */
248 	nodev,			/* cb_dump */
249 	nodev,			/* cb_read */
250 	nodev,			/* cb_write */
251 	nodev,			/* cb_ioctl */
252 	nodev,			/* cb_devmap */
253 	nodev,			/* cb_mmap */
254 	nodev,			/* cb_segmap */
255 	nochpoll,		/* cb_chpoll */
256 	ddi_prop_op,		/* cb_prop_op */
257 	&asy_str_info,		/* cb_stream */
258 	D_MP			/* cb_flag */
259 };
260 
261 struct dev_ops asy_ops = {
262 	DEVO_REV,		/* devo_rev */
263 	0,			/* devo_refcnt */
264 	asyinfo,		/* devo_getinfo */
265 	nulldev,		/* devo_identify */
266 	asyprobe,		/* devo_probe */
267 	asyattach,		/* devo_attach */
268 	asydetach,		/* devo_detach */
269 	nodev,			/* devo_reset */
270 	&cb_asy_ops,		/* devo_cb_ops */
271 };
272 
273 /*
274  * Module linkage information for the kernel.
275  */
276 
277 static struct modldrv modldrv = {
278 	&mod_driverops, /* Type of module.  This one is a driver */
279 	"su driver %I%",
280 	&asy_ops,	/* driver ops */
281 };
282 
283 static struct modlinkage modlinkage = {
284 	MODREV_1,
285 	&modldrv,
286 	NULL
287 };
288 
289 int
290 _init(void)
291 {
292 	int status;
293 
294 	status = ddi_soft_state_init(&su_asycom, sizeof (struct asycom),
295 	    SU_INITIAL_SOFT_ITEMS);
296 	if (status != 0)
297 	    return (status);
298 	status = ddi_soft_state_init(&su_asyncline, sizeof (struct asyncline),
299 	    SU_INITIAL_SOFT_ITEMS);
300 	if (status != 0) {
301 		ddi_soft_state_fini(&su_asycom);
302 		return (status);
303 	}
304 
305 	if ((status = mod_install(&modlinkage)) != 0) {
306 		ddi_soft_state_fini(&su_asycom);
307 		ddi_soft_state_fini(&su_asyncline);
308 	}
309 
310 	return (status);
311 }
312 
313 int
314 _fini(void)
315 {
316 	int i;
317 
318 	i = mod_remove(&modlinkage);
319 	if (i == 0) {
320 		ddi_soft_state_fini(&su_asycom);
321 		ddi_soft_state_fini(&su_asyncline);
322 	}
323 
324 	return (i);
325 }
326 
327 int
328 _info(struct modinfo *modinfop)
329 {
330 	return (mod_info(&modlinkage, modinfop));
331 }
332 
333 static int
334 asyprobe(dev_info_t *devi)
335 {
336 	int		instance;
337 	ddi_acc_handle_t handle;
338 	uchar_t *addr;
339 	ddi_device_acc_attr_t attr;
340 
341 	attr.devacc_attr_version = DDI_DEVICE_ATTR_V0;
342 	attr.devacc_attr_endian_flags = DDI_STRUCTURE_LE_ACC;
343 	attr.devacc_attr_dataorder = DDI_STRICTORDER_ACC;
344 
345 	if (ddi_regs_map_setup(devi, SU_REGISTER_FILE_NO, (caddr_t *)&addr,
346 	    SU_REGOFFSET, SU_REGISTER_LEN, &attr, &handle) != DDI_SUCCESS) {
347 		cmn_err(CE_WARN, "asyprobe regs map setup failed");
348 		return (DDI_PROBE_FAILURE);
349 	}
350 #ifdef DEBUG
351 	if (asydebug)
352 	    printf("Probe address mapped %p\n", (void *)addr);
353 #endif
354 
355 	/*
356 	 * Probe for the device:
357 	 * 	Ser. int. uses bits 0,1,2; FIFO uses 3,6,7; 4,5 wired low.
358 	 * 	If bit 4 or 5 appears on inb() ISR, board is not there.
359 	 */
360 	if (ddi_get8(handle, addr+ISR) & 0x30)
361 	    return (DDI_PROBE_FAILURE);
362 	instance = ddi_get_instance(devi);
363 	if (max_asy_instance < instance)
364 	    max_asy_instance = instance;
365 	ddi_regs_map_free(&handle);
366 
367 	return (DDI_PROBE_SUCCESS); /* hw is present */
368 }
369 
370 static int
371 asydetach(dev_info_t *devi, ddi_detach_cmd_t cmd)
372 {
373 	register int	instance;
374 	struct asycom	*asy;
375 	struct asyncline *async;
376 	char		name[16];
377 
378 	instance = ddi_get_instance(devi);	/* find out which unit */
379 
380 	asy = (struct asycom *)ddi_get_soft_state(su_asycom, instance);
381 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, instance);
382 
383 	switch (cmd) {
384 	    case DDI_DETACH:
385 		break;
386 	    case DDI_SUSPEND:
387 		/* grab both mutex locks */
388 		mutex_enter(asy->asy_excl);
389 		mutex_enter(asy->asy_excl_hi);
390 		if (asy->suspended) {
391 			mutex_exit(asy->asy_excl_hi);
392 			mutex_exit(asy->asy_excl);
393 			return (DDI_SUCCESS);
394 		}
395 		asy->suspended = B_TRUE;
396 		/* Disable further interrupts */
397 		OUTB(ICR, 0);
398 		mutex_exit(asy->asy_excl_hi);
399 		mutex_exit(asy->asy_excl);
400 		return (DDI_SUCCESS);
401 
402 	    default:
403 		return (DDI_FAILURE);
404 	}
405 
406 #ifdef DEBUG
407 	if (asydebug & ASY_DEBUG_INIT)
408 	    cmn_err(CE_NOTE, "su%d: ASY%s shutdown.", instance,
409 		asy->asy_hwtype == ASY82510 ? "82510" :
410 		asy->asy_hwtype == ASY16550AF ? "16550AF" :
411 		"8250");
412 #endif
413 	/*
414 	 * Before removing interrupts it is always better to disable
415 	 * interrupts if the chip gives a provision to disable the
416 	 * serial port interrupts.
417 	 */
418 	mutex_enter(asy->asy_excl);
419 	mutex_enter(asy->asy_excl_hi);
420 	OUTB(ICR, 0); /* disables interrupt */
421 	mutex_exit(asy->asy_excl_hi);
422 	mutex_exit(asy->asy_excl);
423 
424 	/* remove minor device node(s) for this device */
425 	(void) sprintf(name, "%c", (instance+'a'));	/* serial-port */
426 	ddi_remove_minor_node(devi, name);
427 	(void) sprintf(name, "%c,cu", (instance+'a')); /* serial-port:dailout */
428 	ddi_remove_minor_node(devi, name);
429 
430 	mutex_destroy(asy->asy_excl);
431 	mutex_destroy(asy->asy_excl_hi);
432 	kmem_free(asy->asy_excl, sizeof (kmutex_t));
433 	kmem_free(asy->asy_excl_hi, sizeof (kmutex_t));
434 	cv_destroy(&async->async_flags_cv);
435 	kstat_delete(asy->sukstat);
436 	ddi_remove_intr(devi, 0, asy->asy_iblock);
437 	ddi_regs_map_free(&asy->asy_handle);
438 	ddi_remove_softintr(asy->asy_softintr_id);
439 	mutex_destroy(asy->asy_soft_lock);
440 	kmem_free(asy->asy_soft_lock, sizeof (kmutex_t));
441 	ddi_soft_state_free(su_asycom, instance);
442 	ddi_soft_state_free(su_asyncline, instance);
443 	return (DDI_SUCCESS);
444 }
445 
446 static int
447 asyattach(dev_info_t *devi, ddi_attach_cmd_t cmd)
448 {
449 	register int	instance;
450 	struct asycom	*asy;
451 	struct asyncline *async;
452 	char		name[40];
453 	ddi_device_acc_attr_t attr;
454 	enum states { EMPTY, SOFTSTATE, REGSMAP, MUTEXES, ADDINTR,
455 	    SOFTINTR, ASYINIT, KSTAT, MINORNODE };
456 	enum states state = EMPTY;
457 
458 	instance = ddi_get_instance(devi);	/* find out which unit */
459 
460 	/* cannot attach a device that has not been probed first */
461 	if (instance > max_asy_instance)
462 	    return (DDI_FAILURE);
463 
464 	if (cmd != DDI_RESUME) {
465 		/* Allocate soft state space */
466 		if (ddi_soft_state_zalloc(su_asycom, instance) != DDI_SUCCESS) {
467 			cmn_err(CE_WARN, "su%d: cannot allocate soft state",
468 			    instance);
469 			goto error;
470 		}
471 	}
472 	state = SOFTSTATE;
473 
474 	asy = (struct asycom *)ddi_get_soft_state(su_asycom, instance);
475 
476 	if (asy == NULL) {
477 		cmn_err(CE_WARN, "su%d: cannot get soft state", instance);
478 		goto error;
479 	}
480 
481 	switch (cmd) {
482 	    case DDI_ATTACH:
483 		break;
484 	    case DDI_RESUME: {
485 		struct asyncline *async;
486 
487 		/* grab both mutex locks */
488 		mutex_enter(asy->asy_excl);
489 		mutex_enter(asy->asy_excl_hi);
490 		if (!asy->suspended) {
491 			mutex_exit(asy->asy_excl_hi);
492 			mutex_exit(asy->asy_excl);
493 			return (DDI_SUCCESS);
494 		}
495 		/* re-setup all the registers and enable interrupts if needed */
496 		async = (struct asyncline *)asy->asy_priv;
497 		if ((async) && (async->async_flags & ASYNC_ISOPEN))
498 		    (void) asy_program(asy, ASY_INIT);
499 		asy->suspended = B_FALSE;
500 		mutex_exit(asy->asy_excl_hi);
501 		mutex_exit(asy->asy_excl);
502 		return (DDI_SUCCESS);
503 	    }
504 	    default:
505 		goto error;
506 	}
507 
508 	attr.devacc_attr_version = DDI_DEVICE_ATTR_V0;
509 	attr.devacc_attr_endian_flags = DDI_STRUCTURE_LE_ACC;
510 	attr.devacc_attr_dataorder = DDI_STRICTORDER_ACC;
511 
512 	if (ddi_regs_map_setup(devi, SU_REGISTER_FILE_NO,
513 	    (caddr_t *)&asy->asy_ioaddr, SU_REGOFFSET, SU_REGISTER_LEN,
514 	    &attr, &asy->asy_handle) != DDI_SUCCESS) {
515 		cmn_err(CE_WARN, "asyprobe regs map setup failed");
516 		goto error;
517 	}
518 	state = REGSMAP;
519 
520 #ifdef DEBUG
521 	if (asydebug)
522 	    printf("su attach mapped %p\n", (void *)asy->asy_ioaddr);
523 #endif
524 
525 	/*
526 	 * Initialize the port with default settings.
527 	 */
528 	asy->asy_fifo_buf = 1;
529 	asy->asy_use_fifo = FIFO_OFF;
530 
531 	/*
532 	 * Check for baudrate generator's "baud-divisor-factor" property setup
533 	 * by OBP, since different UART chips might have different baudrate
534 	 * generator divisor. e.g., in case of NSPG's Sputnik platform, the
535 	 * baud-divisor-factor is 13, it uses dedicated 16552 "DUART" chip
536 	 * instead of SuperIO. Since the baud-divisor-factor must be a positive
537 	 * integer, the divisors will always be at least as large as the values
538 	 * in asyspdtab[].  Make the default factor 1.
539 	 */
540 	asy->asy_baud_divisor_factor = ddi_prop_get_int(DDI_DEV_T_ANY, devi,
541 	    DDI_PROP_DONTPASS, "baud-divisor-factor", 1);
542 
543 	/* set speed cap */
544 	asy->asy_speed_cap = ddi_prop_get_int(DDI_DEV_T_ANY, devi,
545 	    DDI_PROP_DONTPASS, "serial-speed-cap", 115200);
546 
547 	/* check for ASY82510 chip */
548 	OUTB(ISR, 0x20);
549 	if (INB(ISR) & 0x20) { /* 82510 chip is present */
550 		/*
551 		 * Since most of the general operation of the 82510 chip
552 		 * can be done from BANK 0 (8250A/16450 compatable mode)
553 		 * we will default to BANK 0.
554 		 */
555 		asy->asy_hwtype = ASY82510;
556 		OUTB(DAT+7, 0x04); /* clear status */
557 		OUTB(ISR, 0x40); /* set to bank 2 */
558 		OUTB(MCR, 0x08); /* IMD */
559 		OUTB(DAT, 0x21); /* FMD */
560 		OUTB(ISR, 0x00); /* set to bank 0 */
561 		asy->asy_trig_level = 0;
562 	} else { /* Set the UART in FIFO mode if it has FIFO buffers */
563 		asy->asy_hwtype = ASY16550AF;
564 		OUTB(FIFOR, 0x00); /* clear fifo register */
565 		asy->asy_trig_level = 0x00; /* sets the fifo Threshold to 1 */
566 
567 		/* set/Enable FIFO */
568 		OUTB(FIFOR, FIFO_ON | FIFODMA | FIFOTXFLSH | FIFORXFLSH |
569 		    (asy->asy_trig_level & 0xff));
570 
571 		if ((INB(ISR) & 0xc0) == 0xc0)
572 		    asy->asy_use_fifo = FIFO_ON;
573 		else {
574 			asy->asy_hwtype = ASY8250;
575 			OUTB(FIFOR, 0x00); /* NO FIFOs */
576 			asy->asy_trig_level = 0;
577 		}
578 	}
579 
580 	OUTB(ICR, 0); /* disable all interrupts */
581 	OUTB(LCR, DLAB); /* select baud rate generator */
582 	/* Set the baud rate to 9600 */
583 	OUTB(DAT+DLL, (ASY9600*asy->asy_baud_divisor_factor) & 0xff);
584 	OUTB(DAT+DLH, ((ASY9600*asy->asy_baud_divisor_factor) >> 8) & 0xff);
585 	OUTB(LCR, STOP1|BITS8);
586 	OUTB(MCR, (DTR | RTS| OUT2));
587 
588 	/*
589 	 * Set up the other components of the asycom structure for this port.
590 	 */
591 	asy->asy_excl = (kmutex_t *)
592 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
593 	asy->asy_excl_hi = (kmutex_t *)
594 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
595 	asy->asy_soft_lock = (kmutex_t *)
596 	    kmem_zalloc(sizeof (kmutex_t), KM_SLEEP);
597 	asy->asy_unit = instance;
598 	asy->asy_dip = devi;
599 
600 	if (ddi_get_iblock_cookie(devi, 0, &asy->asy_iblock) != DDI_SUCCESS) {
601 		cmn_err(CE_NOTE,
602 		    "Get iblock_cookie failed-Device interrupt%x\n", instance);
603 		goto error;
604 	}
605 
606 	if (ddi_get_soft_iblock_cookie(devi, DDI_SOFTINT_HIGH,
607 	    &asy->asy_soft_iblock) != DDI_SUCCESS) {
608 		cmn_err(CE_NOTE, "Get iblock_cookie failed -soft interrupt%x\n",
609 		    instance);
610 		goto error;
611 	}
612 
613 	mutex_init(asy->asy_soft_lock, NULL, MUTEX_DRIVER,
614 	    (void *)asy->asy_soft_iblock);
615 	mutex_init(asy->asy_excl, NULL, MUTEX_DRIVER, NULL);
616 	mutex_init(asy->asy_excl_hi, NULL, MUTEX_DRIVER,
617 	    (void *)asy->asy_iblock);
618 	state = MUTEXES;
619 
620 	/*
621 	 * Install interrupt handlers for this device.
622 	 */
623 	if (ddi_add_intr(devi, 0, &(asy->asy_iblock), 0, asyintr,
624 	    (caddr_t)asy) != DDI_SUCCESS) {
625 		cmn_err(CE_CONT,
626 		    "Cannot set device interrupt for su driver\n");
627 		goto error;
628 	}
629 	state = ADDINTR;
630 
631 	if (ddi_add_softintr(devi, DDI_SOFTINT_HIGH, &(asy->asy_softintr_id),
632 	    &asy->asy_soft_iblock, 0, asysoftintr, (caddr_t)asy)
633 	    != DDI_SUCCESS) {
634 		cmn_err(CE_CONT, "Cannot set soft interrupt for su driver\n");
635 		goto error;
636 	}
637 	state = SOFTINTR;
638 
639 	/* initialize the asyncline structure */
640 	if (ddi_soft_state_zalloc(su_asyncline, instance) != DDI_SUCCESS) {
641 		cmn_err(CE_CONT, "su%d: cannot allocate soft state", instance);
642 		goto error;
643 	}
644 	state = ASYINIT;
645 
646 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, instance);
647 
648 	mutex_enter(asy->asy_excl);
649 	async->async_common = asy;
650 	cv_init(&async->async_flags_cv, NULL, CV_DEFAULT, NULL);
651 	mutex_exit(asy->asy_excl);
652 
653 	if ((asy->sukstat = kstat_create("su", instance, "serialstat",
654 	    "misc", KSTAT_TYPE_NAMED, 2, KSTAT_FLAG_VIRTUAL)) != NULL) {
655 		asy->sukstat->ks_data = &asy->kstats;
656 		kstat_named_init(&asy->kstats.ringover, "ring buffer overflow",
657 		    KSTAT_DATA_UINT64);
658 		kstat_named_init(&asy->kstats.siloover, "silo overflow",
659 		    KSTAT_DATA_UINT64);
660 		kstat_install(asy->sukstat);
661 	}
662 	state = KSTAT;
663 
664 	if (strcmp(ddi_node_name(devi), "rsc-console") == 0) {
665 		/*
666 		 * If the device is configured as the 'rsc-console'
667 		 * create the minor device for this node.
668 		 */
669 		if (ddi_create_minor_node(devi, "ssp", S_IFCHR,
670 		    asy->asy_unit | RSC_DEVICE, DDI_PSEUDO, NULL)
671 		    == DDI_FAILURE) {
672 			cmn_err(CE_WARN,
673 			    "%s%d: Failed to create node rsc-console",
674 			    ddi_get_name(devi), ddi_get_instance(devi));
675 			goto error;
676 		}
677 
678 		asy->asy_lom_console = 0;
679 		asy->asy_rsc_console = 1;
680 		asy->asy_rsc_control = 0;
681 		asy->asy_device_type = ASY_SERIAL;
682 		asy->asy_flags |= ASY_IGNORE_CD;
683 
684 	} else if (strcmp(ddi_node_name(devi), "lom-console") == 0) {
685 		/*
686 		 * If the device is configured as the 'lom-console'
687 		 * create the minor device for this node.
688 		 * Do not create a dialout device.
689 		 * Use the same minor numbers as would be used for standard
690 		 * serial instances.
691 		 */
692 		if (ddi_create_minor_node(devi, "lom-console", S_IFCHR,
693 		    instance, DDI_NT_SERIAL_LOMCON, NULL) == DDI_FAILURE) {
694 			cmn_err(CE_WARN,
695 			    "%s%d: Failed to create node lom-console",
696 			    ddi_get_name(devi), ddi_get_instance(devi));
697 			goto error;
698 		}
699 		asy->asy_lom_console = 1;
700 		asy->asy_rsc_console = 0;
701 		asy->asy_rsc_control = 0;
702 		asy->asy_device_type = ASY_SERIAL;
703 		asy->asy_flags |= ASY_IGNORE_CD;
704 
705 	} else if (strcmp(ddi_node_name(devi), "rsc-control") == 0) {
706 		/*
707 		 * If the device is configured as the 'rsc-control'
708 		 * create the minor device for this node.
709 		 */
710 		if (ddi_create_minor_node(devi, "sspctl", S_IFCHR,
711 		    asy->asy_unit | RSC_DEVICE, DDI_PSEUDO, NULL)
712 		    == DDI_FAILURE) {
713 			cmn_err(CE_WARN, "%s%d: Failed to create rsc-control",
714 			    ddi_get_name(devi), ddi_get_instance(devi));
715 			goto error;
716 		}
717 
718 		asy->asy_lom_console = 0;
719 		asy->asy_rsc_console = 0;
720 		asy->asy_rsc_control = 1;
721 		asy->asy_device_type = ASY_SERIAL;
722 		asy->asy_flags |= ASY_IGNORE_CD;
723 
724 	} else if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
725 		"keyboard", 0)) {
726 		/*
727 		 * If the device is a keyboard, then create an internal
728 		 * pathname so that the dacf code will link the node into
729 		 * the keyboard console stream.  See dacf.conf.
730 		 */
731 		if (ddi_create_internal_pathname(devi, "keyboard",
732 		    S_IFCHR, instance) == DDI_FAILURE) {
733 			goto error;
734 		}
735 		asy->asy_flags |= ASY_IGNORE_CD;	/* ignore cd */
736 		asy->asy_device_type = ASY_KEYBOARD; 	/* Device type */
737 	} else if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
738 		"mouse", 0)) {
739 		/*
740 		 * If the device is a mouse, then create an internal
741 		 * pathname so that the dacf code will link the node into
742 		 * the mouse stream.  See dacf.conf.
743 		 */
744 		if (ddi_create_internal_pathname(devi, "mouse", S_IFCHR,
745 		    instance) == DDI_FAILURE) {
746 			goto error;
747 		}
748 		asy->asy_flags |= ASY_IGNORE_CD;	/* ignore cd */
749 		asy->asy_device_type = ASY_MOUSE;
750 	} else {
751 		/*
752 		 * If not used for keyboard/mouse, create minor devices nodes
753 		 * for this device
754 		 */
755 		/* serial-port */
756 		(void) sprintf(name, "%c", (instance+'a'));
757 		if (ddi_create_minor_node(devi, name, S_IFCHR, instance,
758 		    DDI_NT_SERIAL_MB, NULL) == DDI_FAILURE) {
759 			goto error;
760 		}
761 		state = MINORNODE;
762 		/* serial-port:dailout */
763 		(void) sprintf(name, "%c,cu", (instance+'a'));
764 		if (ddi_create_minor_node(devi, name, S_IFCHR, instance|OUTLINE,
765 		    DDI_NT_SERIAL_MB_DO, NULL) == DDI_FAILURE) {
766 			goto error;
767 		}
768 		/* Property for ignoring DCD */
769 		if (ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS,
770 		    "ignore-cd", 0)) {
771 			asy->asy_flags |= ASY_IGNORE_CD;  /* ignore cd */
772 		} else {
773 			asy->asy_flags &= ~ASY_IGNORE_CD;
774 			/*
775 			 * if ignore-cd is not available it could be
776 			 * some old legacy platform, try to see
777 			 * whether the old legacy property exists
778 			 */
779 			(void) sprintf(name,
780 			    "port-%c-ignore-cd", (instance+ 'a'));
781 			if (ddi_getprop(DDI_DEV_T_ANY, devi,
782 			    DDI_PROP_DONTPASS, name, 0))
783 				asy->asy_flags |= ASY_IGNORE_CD;
784 		}
785 		asy->asy_device_type = ASY_SERIAL;
786 	}
787 	ddi_report_dev(devi);
788 	return (DDI_SUCCESS);
789 
790 error:
791 	if (state == MINORNODE) {
792 		(void) sprintf(name, "%c", (instance+'a'));
793 		ddi_remove_minor_node(devi, name);
794 	}
795 	if (state >= KSTAT)
796 		kstat_delete(asy->sukstat);
797 	if (state >= ASYINIT) {
798 		cv_destroy(&async->async_flags_cv);
799 		ddi_soft_state_free(su_asyncline, instance);
800 	}
801 	if (state >= SOFTINTR)
802 		ddi_remove_softintr(asy->asy_softintr_id);
803 	if (state >= ADDINTR)
804 		ddi_remove_intr(devi, 0, asy->asy_iblock);
805 	if (state >= MUTEXES) {
806 		mutex_destroy(asy->asy_excl_hi);
807 		mutex_destroy(asy->asy_excl);
808 		mutex_destroy(asy->asy_soft_lock);
809 		kmem_free(asy->asy_excl_hi, sizeof (kmutex_t));
810 		kmem_free(asy->asy_excl, sizeof (kmutex_t));
811 		kmem_free(asy->asy_soft_lock, sizeof (kmutex_t));
812 	}
813 	if (state >= REGSMAP)
814 		ddi_regs_map_free(&asy->asy_handle);
815 	if (state >= SOFTSTATE)
816 		ddi_soft_state_free(su_asycom, instance);
817 	/* no action for EMPTY state */
818 	return (DDI_FAILURE);
819 }
820 
821 static int
822 asyinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
823 	void **result)
824 {
825 	_NOTE(ARGUNUSED(dip))
826 	register dev_t dev = (dev_t)arg;
827 	register int instance, error;
828 	struct asycom *asy;
829 
830 	if ((instance = UNIT(dev)) > max_asy_instance)
831 		return (DDI_FAILURE);
832 
833 	switch (infocmd) {
834 	    case DDI_INFO_DEVT2DEVINFO:
835 		asy = (struct asycom *)ddi_get_soft_state(su_asycom, instance);
836 		if (asy->asy_dip == NULL)
837 		    error = DDI_FAILURE;
838 		else {
839 			*result = (void *) asy->asy_dip;
840 			error = DDI_SUCCESS;
841 		}
842 		break;
843 	    case DDI_INFO_DEVT2INSTANCE:
844 		*result = (void *)(uintptr_t)instance;
845 		error = DDI_SUCCESS;
846 		break;
847 	    default:
848 		error = DDI_FAILURE;
849 	}
850 	return (error);
851 }
852 
853 static int
854 asyopen(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr)
855 {
856 	_NOTE(ARGUNUSED(sflag))
857 	struct asycom	*asy;
858 	struct asyncline *async;
859 	int		mcr;
860 	int		unit;
861 	int 		len;
862 	struct termios 	*termiosp;
863 
864 #ifdef DEBUG
865 	if (asydebug & ASY_DEBUG_CLOSE)
866 		printf("open\n");
867 #endif
868 	unit = UNIT(*dev);
869 	if (unit > max_asy_instance)
870 		return (ENXIO);		/* unit not configured */
871 
872 	async = (struct asyncline *)ddi_get_soft_state(su_asyncline, unit);
873 	if (async == NULL)
874 		return (ENXIO);
875 
876 	asy = async->async_common;
877 	if (asy == NULL)
878 		return (ENXIO);		/* device not found by autoconfig */
879 
880 	mutex_enter(asy->asy_excl);
881 	asy->asy_priv = (caddr_t)async;
882 
883 again:
884 	mutex_enter(asy->asy_excl_hi);
885 	/*
886 	 * Block waiting for carrier to come up, unless this is a no-delay open.
887 	 */
888 	if (!(async->async_flags & ASYNC_ISOPEN)) {
889 		/*
890 		 * If this port is for a RSC console or control
891 		 * use the following termio info
892 		 */
893 		if (asy->asy_rsc_console || asy->asy_rsc_control) {
894 			async->async_ttycommon.t_cflag = CIBAUDEXT | CBAUDEXT |
895 			    (B115200 & CBAUD);
896 			async->async_ttycommon.t_cflag |= ((B115200 << IBSHIFT)
897 			    & CIBAUD);
898 			async->async_ttycommon.t_cflag |= CS8 | CREAD | CLOCAL;
899 		} else if (asy->asy_lom_console) {
900 			async->async_ttycommon.t_cflag = B9600 & CBAUD;
901 			async->async_ttycommon.t_cflag |= ((B9600 << IBSHIFT)
902 			    & CIBAUD);
903 			async->async_ttycommon.t_cflag |= CS8 | CREAD | CLOCAL;
904 		} else {
905 
906 			/*
907 			 * Set the default termios settings (cflag).
908 			 * Others are set in ldterm.  Release the spin
909 			 * mutex as we can block here, reaquire before
910 			 * calling asy_program.
911 			 */
912 			mutex_exit(asy->asy_excl_hi);
913 			if (ddi_getlongprop(DDI_DEV_T_ANY, ddi_root_node(),
914 			    0, "ttymodes", (caddr_t)&termiosp, &len)
915 			    == DDI_PROP_SUCCESS &&
916 			    len == sizeof (struct termios)) {
917 				async->async_ttycommon.t_cflag =
918 				    termiosp->c_cflag;
919 				kmem_free(termiosp, len);
920 			} else {
921 				cmn_err(CE_WARN,
922 					"su: couldn't get ttymodes property!");
923 			}
924 			mutex_enter(asy->asy_excl_hi);
925 		}
926 		async->async_ttycommon.t_iflag = 0;
927 		async->async_ttycommon.t_iocpending = NULL;
928 		async->async_ttycommon.t_size.ws_row = 0;
929 		async->async_ttycommon.t_size.ws_col = 0;
930 		async->async_ttycommon.t_size.ws_xpixel = 0;
931 		async->async_ttycommon.t_size.ws_ypixel = 0;
932 		async->async_dev = *dev;
933 		async->async_wbufcid = 0;
934 
935 		async->async_startc = CSTART;
936 		async->async_stopc = CSTOP;
937 		(void) asy_program(asy, ASY_INIT);
938 	} else if ((async->async_ttycommon.t_flags & TS_XCLUDE) &&
939 					    secpolicy_excl_open(cr) != 0) {
940 		mutex_exit(asy->asy_excl_hi);
941 		mutex_exit(asy->asy_excl);
942 		return (EBUSY);
943 	} else if ((*dev & OUTLINE) && !(async->async_flags & ASYNC_OUT)) {
944 		mutex_exit(asy->asy_excl_hi);
945 		mutex_exit(asy->asy_excl);
946 		return (EBUSY);
947 	}
948 
949 	if (*dev & OUTLINE)
950 		async->async_flags |= ASYNC_OUT;
951 
952 	/* Raise DTR on every open */
953 	mcr = INB(MCR);
954 	OUTB(MCR, mcr|DTR);
955 
956 	/*
957 	 * Check carrier.
958 	 */
959 	if (asy->asy_flags & ASY_IGNORE_CD)
960 		async->async_ttycommon.t_flags |= TS_SOFTCAR;
961 	if ((async->async_ttycommon.t_flags & TS_SOFTCAR) ||
962 					(INB(MSR) & DCD))
963 		async->async_flags |= ASYNC_CARR_ON;
964 	else
965 		async->async_flags &= ~ASYNC_CARR_ON;
966 	mutex_exit(asy->asy_excl_hi);
967 
968 	/*
969 	 * If FNDELAY and FNONBLOCK are clear, block until carrier up.
970 	 * Quit on interrupt.
971 	 */
972 	if (!(flag & (FNDELAY|FNONBLOCK)) &&
973 			!(async->async_ttycommon.t_cflag & CLOCAL)) {
974 		if (!(async->async_flags & (ASYNC_CARR_ON|ASYNC_OUT)) ||
975 				((async->async_flags & ASYNC_OUT) &&
976 				!(*dev & OUTLINE))) {
977 			async->async_flags |= ASYNC_WOPEN;
978 			if (cv_wait_sig(&async->async_flags_cv,
979 			    asy->asy_excl) == 0) {
980 				async->async_flags &= ~ASYNC_WOPEN;
981 				mutex_exit(asy->asy_excl);
982 				return (EINTR);
983 			}
984 			async->async_flags &= ~ASYNC_WOPEN;
985 			goto again;
986 		}
987 	} else if ((async->async_flags & ASYNC_OUT) && !(*dev & OUTLINE)) {
988 			mutex_exit(asy->asy_excl);
989 			return (EBUSY);
990 	}
991 
992 	if (asy->suspended) {
993 		mutex_exit(asy->asy_excl);
994 		(void) ddi_dev_is_needed(asy->asy_dip, 0, 1);
995 		mutex_enter(asy->asy_excl);
996 	}
997 
998 	async->async_ttycommon.t_readq = rq;
999 	async->async_ttycommon.t_writeq = WR(rq);
1000 	rq->q_ptr = WR(rq)->q_ptr = (caddr_t)async;
1001 	mutex_exit(asy->asy_excl);
1002 	qprocson(rq);
1003 	async->async_flags |= ASYNC_ISOPEN;
1004 	async->async_polltid = 0;
1005 	return (0);
1006 }
1007 
1008 static void
1009 async_progress_check(void *arg)
1010 {
1011 	struct asyncline *async = arg;
1012 	struct asycom	 *asy = async->async_common;
1013 	mblk_t *bp;
1014 
1015 	/*
1016 	 * We define "progress" as either waiting on a timed break or delay, or
1017 	 * having had at least one transmitter interrupt.  If none of these are
1018 	 * true, then just terminate the output and wake up that close thread.
1019 	 */
1020 	mutex_enter(asy->asy_excl);
1021 	mutex_enter(asy->asy_excl_hi);
1022 	if (!(async->async_flags & (ASYNC_BREAK|ASYNC_DELAY|ASYNC_PROGRESS))) {
1023 		async->async_ocnt = 0;
1024 		async->async_flags &= ~ASYNC_BUSY;
1025 		async->async_timer = 0;
1026 		bp = async->async_xmitblk;
1027 		async->async_xmitblk = NULL;
1028 		mutex_exit(asy->asy_excl_hi);
1029 		if (bp != NULL)
1030 			freeb(bp);
1031 		/*
1032 		 * Since this timer is running, we know that we're in exit(2).
1033 		 * That means that the user can't possibly be waiting on any
1034 		 * valid ioctl(2) completion anymore, and we should just flush
1035 		 * everything.
1036 		 */
1037 		flushq(async->async_ttycommon.t_writeq, FLUSHALL);
1038 		cv_broadcast(&async->async_flags_cv);
1039 	} else {
1040 		async->async_flags &= ~ASYNC_PROGRESS;
1041 		async->async_timer = timeout(async_progress_check, async,
1042 		    drv_usectohz(su_drain_check));
1043 		mutex_exit(asy->asy_excl_hi);
1044 	}
1045 	mutex_exit(asy->asy_excl);
1046 }
1047 
1048 /*
1049  * Close routine.
1050  */
1051 static int
1052 asyclose(queue_t *q, int flag)
1053 {
1054 	struct asyncline *async;
1055 	struct asycom	 *asy;
1056 	int icr, lcr;
1057 	int		nohupcl;
1058 
1059 
1060 #ifdef DEBUG
1061 	if (asydebug & ASY_DEBUG_CLOSE)
1062 		printf("close\n");
1063 #endif
1064 	async = q->q_ptr;
1065 	ASSERT(async != NULL);
1066 	asy = async->async_common;
1067 
1068 	/* get the nohupcl OBP property of this device */
1069 	nohupcl = ddi_getprop(DDI_DEV_T_ANY, asy->asy_dip, DDI_PROP_DONTPASS,
1070 	    "nohupcl", 0);
1071 
1072 	mutex_enter(asy->asy_excl);
1073 	async->async_flags |= ASYNC_CLOSING;
1074 
1075 	/*
1076 	 * Turn off PPS handling early to avoid events occuring during
1077 	 * close.  Also reset the DCD edge monitoring bit.
1078 	 */
1079 	mutex_enter(asy->asy_excl_hi);
1080 	asy->asy_flags &= ~(ASY_PPS | ASY_PPS_EDGE);
1081 	mutex_exit(asy->asy_excl_hi);
1082 
1083 	/*
1084 	 * There are two flavors of break -- timed (M_BREAK or TCSBRK) and
1085 	 * untimed (TIOCSBRK).  For the timed case, these are enqueued on our
1086 	 * write queue and there's a timer running, so we don't have to worry
1087 	 * about them.  For the untimed case, though, the user obviously made a
1088 	 * mistake, because these are handled immediately.  We'll terminate the
1089 	 * break now and honor his implicit request by discarding the rest of
1090 	 * the data.
1091 	 */
1092 	if (!(async->async_flags & ASYNC_BREAK)) {
1093 		mutex_enter(asy->asy_excl_hi);
1094 		lcr = INB(LCR);
1095 		if (lcr & SETBREAK) {
1096 			OUTB(LCR, (lcr & ~SETBREAK));
1097 		}
1098 		mutex_exit(asy->asy_excl_hi);
1099 		if (lcr & SETBREAK)
1100 			goto nodrain;
1101 	}
1102 
1103 	/*
1104 	 * If the user told us not to delay the close ("non-blocking"), then
1105 	 * don't bother trying to drain.
1106 	 *
1107 	 * If the user did M_STOP (ASYNC_STOPPED), there's no hope of ever
1108 	 * getting an M_START (since these messages aren't enqueued), and the
1109 	 * only other way to clear the stop condition is by loss of DCD, which
1110 	 * would discard the queue data.  Thus, we drop the output data if
1111 	 * ASYNC_STOPPED is set.
1112 	 */
1113 	if ((flag & (FNDELAY|FNONBLOCK)) ||
1114 	    (async->async_flags & ASYNC_STOPPED)) {
1115 		goto nodrain;
1116 	}
1117 
1118 	/*
1119 	 * If there's any pending output, then we have to try to drain it.
1120 	 * There are two main cases to be handled:
1121 	 *	- called by close(2): need to drain until done or until
1122 	 *	  a signal is received.  No timeout.
1123 	 *	- called by exit(2): need to drain while making progress
1124 	 *	  or until a timeout occurs.  No signals.
1125 	 *
1126 	 * If we can't rely on receiving a signal to get us out of a hung
1127 	 * session, then we have to use a timer.  In this case, we set a timer
1128 	 * to check for progress in sending the output data -- all that we ask
1129 	 * (at each interval) is that there's been some progress made.  Since
1130 	 * the interrupt routine grabs buffers from the write queue, we can't
1131 	 * trust async_ocnt.  Instead, we use a flag.
1132 	 *
1133 	 * Note that loss of carrier will cause the output queue to be flushed,
1134 	 * and we'll wake up again and finish normally.
1135 	 */
1136 	if (!ddi_can_receive_sig() && su_drain_check != 0) {
1137 		async->async_flags &= ~ASYNC_PROGRESS;
1138 		async->async_timer = timeout(async_progress_check, async,
1139 		    drv_usectohz(su_drain_check));
1140 	}
1141 
1142 	while (async->async_ocnt > 0 ||
1143 	    async->async_ttycommon.t_writeq->q_first != NULL ||
1144 	    (async->async_flags & (ASYNC_BUSY|ASYNC_BREAK|ASYNC_DELAY))) {
1145 		if (cv_wait_sig(&async->async_flags_cv, asy->asy_excl) == 0)
1146 			break;
1147 	}
1148 	if (async->async_timer != 0) {
1149 		(void) untimeout(async->async_timer);
1150 		async->async_timer = 0;
1151 	}
1152 
1153 nodrain:
1154 	mutex_enter(asy->asy_excl_hi);
1155 
1156 	/* turn off the loopback mode */
1157 	if ((async->async_dev != rconsdev) &&
1158 	    (async->async_dev != kbddev) &&
1159 	    (async->async_dev != stdindev)) {
1160 		OUTB(MCR, INB(MCR) & ~ ASY_LOOP);
1161 	}
1162 
1163 	async->async_ocnt = 0;
1164 	if (async->async_xmitblk != NULL)
1165 		freeb(async->async_xmitblk);
1166 	async->async_xmitblk = NULL;
1167 
1168 	/*
1169 	 * If the "nohupcl" OBP property is set for this device, do
1170 	 * not turn off DTR and RTS no matter what.  Otherwise, if the
1171 	 * line has HUPCL set or is incompletely opened, turn off DTR
1172 	 * and RTS to fix the modem line.
1173 	 */
1174 	if (!nohupcl && ((async->async_ttycommon.t_cflag & HUPCL) ||
1175 	    (async->async_flags & ASYNC_WOPEN))) {
1176 		/* turn off DTR, RTS but NOT interrupt to 386 */
1177 		OUTB(MCR, OUT2);
1178 		mutex_exit(asy->asy_excl_hi);
1179 		/*
1180 		 * Don't let an interrupt in the middle of close
1181 		 * bounce us back to the top; just continue closing
1182 		 * as if nothing had happened.
1183 		 */
1184 		if (cv_wait_sig(&lbolt_cv, asy->asy_excl) == 0)
1185 			goto out;
1186 		mutex_enter(asy->asy_excl_hi);
1187 	}
1188 
1189 	/*
1190 	 * If nobody's using it now, turn off receiver interrupts.
1191 	 */
1192 	if ((async->async_flags & (ASYNC_WOPEN|ASYNC_ISOPEN)) == 0) {
1193 		icr = INB(ICR);
1194 		OUTB(ICR, (icr & ~RIEN));
1195 	}
1196 	mutex_exit(asy->asy_excl_hi);
1197 out:
1198 	/*
1199 	 * Clear out device state.
1200 	 */
1201 	async->async_flags = 0;
1202 	ttycommon_close(&async->async_ttycommon);
1203 	cv_broadcast(&async->async_flags_cv);
1204 
1205 	/*
1206 	 * Clear ASY_DOINGSOFT and ASY_NEEDSOFT in case we were in
1207 	 * async_softint or an interrupt was pending when the process
1208 	 * using the port exited.
1209 	 */
1210 	asy->asy_flags &= ~ASY_DOINGSOFT & ~ASY_NEEDSOFT;
1211 
1212 	/*
1213 	 * Cancel outstanding "bufcall" request.
1214 	 */
1215 	if (async->async_wbufcid) {
1216 		unbufcall(async->async_wbufcid);
1217 		async->async_wbufcid = 0;
1218 	}
1219 
1220 	/*
1221 	 * If inperim is true, it means the port is closing while there's
1222 	 * a pending software interrupt.  async_flags has been zeroed out,
1223 	 * so this instance of leaveq() needs to be called before we call
1224 	 * qprocsoff() to disable services on the q.  If inperim is false,
1225 	 * leaveq() has already been called or we're not in a perimeter.
1226 	 */
1227 	if (asy->inperim == B_TRUE) {
1228 		asy->inperim = B_FALSE;
1229 		mutex_exit(asy->asy_excl);
1230 		leaveq(q);
1231 	} else {
1232 		mutex_exit(asy->asy_excl);
1233 	}
1234 
1235 	/* Note that qprocsoff can't be done until after interrupts are off */
1236 	qprocsoff(q);
1237 	q->q_ptr = WR(q)->q_ptr = NULL;
1238 	async->async_ttycommon.t_readq = NULL;
1239 	async->async_ttycommon.t_writeq = NULL;
1240 
1241 	return (0);
1242 }
1243 
1244 /*
1245  * Checks to see if the serial port is still transmitting
1246  * characters.  It returns true when there are characters
1247  * queued to transmit,  when the holding register contains
1248  * a byte, or when the shifting register still contains
1249  * data to send.
1250  *
1251  */
1252 static boolean_t
1253 asy_isbusy(struct asycom *asy)
1254 {
1255 	struct asyncline *async;
1256 
1257 #ifdef DEBUG
1258 	if (asydebug & ASY_DEBUG_EOT)
1259 		printf("isbusy\n");
1260 #endif
1261 	async = (struct asyncline *)asy->asy_priv;
1262 	ASSERT(mutex_owned(asy->asy_excl));
1263 	ASSERT(mutex_owned(asy->asy_excl_hi));
1264 	return ((async->async_ocnt > 0) ||
1265 			((INB(LSR) & XSRE) == 0));
1266 }
1267 
1268 /*
1269  * Program the ASY port. Most of the async operation is based on the values
1270  * of 'c_iflag' and 'c_cflag'.
1271  */
1272 static int
1273 asy_program(struct asycom *asy, int mode)
1274 {
1275 	struct asyncline *async;
1276 	int baudrate, c_flag;
1277 	int icr, lcr;
1278 	int ocflags;
1279 	int error = 0;
1280 
1281 	ASSERT(mutex_owned(asy->asy_excl));
1282 	ASSERT(mutex_owned(asy->asy_excl_hi));
1283 
1284 #ifdef DEBUG
1285 	if (asydebug & ASY_DEBUG_PROCS)
1286 		printf("program\n");
1287 #endif
1288 	async = (struct asyncline *)asy->asy_priv;
1289 
1290 	baudrate = async->async_ttycommon.t_cflag & CBAUD;
1291 	if (async->async_ttycommon.t_cflag & CBAUDEXT)
1292 		baudrate += 16;
1293 
1294 	/* Limit baudrate so it can't index out of baudtable */
1295 	if (baudrate >= N_SU_SPEEDS) baudrate = B9600;
1296 
1297 	/*
1298 	 * If baud rate requested is greater than the speed cap
1299 	 * or is an unsupported baud rate then reset t_cflag baud
1300 	 * to the last valid baud rate.  If this is the initial
1301 	 * pass through asy_program then set it to 9600.
1302 	 */
1303 	if (((baudrate > 0) && (asyspdtab[baudrate] == 0)) ||
1304 	    (baudtable[baudrate] > asy->asy_speed_cap)) {
1305 		async->async_ttycommon.t_cflag &= ~CBAUD & ~CBAUDEXT &
1306 		    ~CIBAUD & ~CIBAUDEXT;
1307 		if (mode == ASY_INIT) {
1308 			async->async_ttycommon.t_cflag |= B9600;
1309 			baudrate = B9600;
1310 		} else {
1311 			async->async_ttycommon.t_cflag |=
1312 			    (asy->asy_ocflags & (CBAUD | CBAUDEXT |
1313 			    CIBAUD | CIBAUDEXT));
1314 		}
1315 		error = EINVAL;
1316 		goto end;
1317 	}
1318 
1319 	/* set the baud rate */
1320 	if (async->async_ttycommon.t_cflag & (CIBAUD|CIBAUDEXT)) {
1321 		async->async_ttycommon.t_cflag &= ~(CIBAUD);
1322 		if (baudrate > CBAUD) {
1323 			async->async_ttycommon.t_cflag |= CIBAUDEXT;
1324 			async->async_ttycommon.t_cflag |=
1325 				(((baudrate - CBAUD -1)<< IBSHIFT) & CIBAUD);
1326 		} else {
1327 			async->async_ttycommon.t_cflag &= ~CIBAUDEXT;
1328 			async->async_ttycommon.t_cflag |=
1329 				((baudrate << IBSHIFT) & CIBAUD);
1330 		}
1331 	}
1332 
1333 	c_flag = async->async_ttycommon.t_cflag &
1334 	    (CLOCAL | CREAD | CSTOPB | CSIZE | PARENB | PARODD | CBAUD |
1335 	    CBAUDEXT | CIBAUD | CIBAUDEXT);
1336 	OUTB(ICR, 0);	/* disable interrupts */
1337 
1338 	ocflags = asy->asy_ocflags;
1339 
1340 	/* flush/reset the status registers */
1341 	if (mode == ASY_INIT) {
1342 		(void) INB(DAT);
1343 		(void) INB(ISR);
1344 		(void) INB(LSR);
1345 		(void) INB(MSR);
1346 	}
1347 
1348 	if (ocflags != (c_flag & ~CLOCAL) || mode == ASY_INIT) {
1349 		/* Set line control */
1350 		lcr = INB(LCR);
1351 		lcr &= ~(WLS0|WLS1|STB|PEN|EPS);
1352 
1353 		if (c_flag & CSTOPB)
1354 			lcr |= STB;	/* 2 stop bits */
1355 
1356 		if (c_flag & PARENB)
1357 			lcr |= PEN;
1358 
1359 		if ((c_flag & PARODD) == 0)
1360 			lcr |= EPS;
1361 
1362 		switch (c_flag & CSIZE) {
1363 		case CS5:
1364 			lcr |= BITS5;
1365 			break;
1366 		case CS6:
1367 			lcr |= BITS6;
1368 			break;
1369 		case CS7:
1370 			lcr |= BITS7;
1371 			break;
1372 		case CS8:
1373 			lcr |= BITS8;
1374 			break;
1375 		}
1376 
1377 		/* set the baud rate when the rate is NOT B0 */
1378 		if (baudrate != 0) {
1379 			OUTB(LCR, DLAB);
1380 			OUTB(DAT, (asyspdtab[baudrate] *
1381 				asy->asy_baud_divisor_factor) & 0xff);
1382 			OUTB(ICR, ((asyspdtab[baudrate] *
1383 				asy->asy_baud_divisor_factor) >> 8) & 0xff);
1384 		}
1385 		/* set the line control modes */
1386 		OUTB(LCR, lcr);
1387 
1388 		/*
1389 		 * if transitioning from CREAD off to CREAD on,
1390 		 * flush the FIFO buffer if we have one.
1391 		 */
1392 		if ((ocflags & CREAD) == 0 && (c_flag & CREAD)) {
1393 			if (asy->asy_use_fifo == FIFO_ON) {
1394 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFORXFLSH |
1395 				    (asy->asy_trig_level & 0xff));
1396 			}
1397 		}
1398 
1399 		/* remember the new cflags */
1400 		asy->asy_ocflags = c_flag & ~CLOCAL;
1401 	}
1402 
1403 	/* whether or not CLOCAL is set, modify the modem control lines */
1404 	if (baudrate == 0)
1405 		/* B0 has been issued, lower DTR */
1406 		OUTB(MCR, RTS|OUT2);
1407 	else
1408 		/* raise DTR */
1409 		OUTB(MCR, DTR|RTS|OUT2);
1410 
1411 	/*
1412 	 * Call the modem status interrupt handler to check for the carrier
1413 	 * in case CLOCAL was turned off after the carrier came on.
1414 	 * (Note: Modem status interrupt is not enabled if CLOCAL is ON.)
1415 	 */
1416 	async_msint(asy);
1417 
1418 	/* Set interrupt control */
1419 	if ((c_flag & CLOCAL) && !(async->async_ttycommon.t_cflag & CRTSCTS))
1420 		/*
1421 		 * direct-wired line ignores DCD, so we don't enable modem
1422 		 * status interrupts.
1423 		 */
1424 		icr = (TIEN | SIEN);
1425 	else
1426 		icr = (TIEN | SIEN | MIEN);
1427 
1428 	if (c_flag & CREAD)
1429 		icr |= RIEN;
1430 
1431 	OUTB(ICR, icr);
1432 end:
1433 	return (error);
1434 }
1435 
1436 /*
1437  * asyintr() is the High Level Interrupt Handler.
1438  *
1439  * There are four different interrupt types indexed by ISR register values:
1440  *		0: modem
1441  *		1: Tx holding register is empty, ready for next char
1442  *		2: Rx register now holds a char to be picked up
1443  *		3: error or break on line
1444  * This routine checks the Bit 0 (interrupt-not-pending) to determine if
1445  * the interrupt is from this port.
1446  */
1447 uint_t
1448 asyintr(caddr_t argasy)
1449 {
1450 	struct asycom		*asy = (struct asycom *)argasy;
1451 	struct asyncline	*async;
1452 	int			ret_status = DDI_INTR_UNCLAIMED;
1453 	uchar_t			interrupt_id, lsr;
1454 
1455 	interrupt_id = INB(ISR) & 0x0F;
1456 	async = (struct asyncline *)asy->asy_priv;
1457 	if ((async == NULL) ||
1458 		!(async->async_flags & (ASYNC_ISOPEN|ASYNC_WOPEN))) {
1459 		if (interrupt_id & NOINTERRUPT)  {
1460 			return (DDI_INTR_UNCLAIMED);
1461 		} else {
1462 			lsr = INB(LSR);
1463 			if ((lsr & BRKDET) &&
1464 			    ((abort_enable == KIOCABORTENABLE) &&
1465 			    (async->async_dev == rconsdev)))
1466 				abort_sequence_enter((char *)NULL);
1467 			else {
1468 				/* reset line status */
1469 				(void) INB(LSR);
1470 				/* discard any data */
1471 				(void) INB(DAT);
1472 				/* reset modem status */
1473 				(void) INB(MSR);
1474 				return (DDI_INTR_CLAIMED);
1475 			}
1476 		}
1477 	}
1478 	/*
1479 	 * Spurious interrupts happen in this driver
1480 	 * because of the transmission on serial port not handled
1481 	 * properly.
1482 	 *
1483 	 * The reasons for Spurious interrupts are:
1484 	 *    1. There is a path in async_nstart which transmits
1485 	 *	 characters without going through interrupt services routine
1486 	 *	 which causes spurious interrupts to happen.
1487 	 *    2. In the async_txint more than one character is sent
1488 	 *	 in one interrupt service.
1489 	 *    3. In async_rxint more than one characters are received in
1490 	 *	 in one interrupt service.
1491 	 *
1492 	 * Hence we have flags to indicate that such scenerio has happened.
1493 	 * and claim only such interrupts and others we donot claim it
1494 	 * as it could be a indicator of some hardware problem.
1495 	 *
1496 	 */
1497 	if (interrupt_id & NOINTERRUPT) {
1498 		mutex_enter(asy->asy_excl_hi);
1499 		if ((asy->asy_xmit_count > 1) ||
1500 			    (asy->asy_out_of_band_xmit > 0) ||
1501 				(asy->asy_rx_count > 1)) {
1502 			asy->asy_xmit_count = 0;
1503 			asy->asy_out_of_band_xmit = 0;
1504 			asy->asy_rx_count = 0;
1505 			mutex_exit(asy->asy_excl_hi);
1506 			return (DDI_INTR_CLAIMED);
1507 		} else {
1508 			mutex_exit(asy->asy_excl_hi);
1509 			return (DDI_INTR_UNCLAIMED);
1510 		}
1511 	}
1512 	ret_status = DDI_INTR_CLAIMED;
1513 	mutex_enter(asy->asy_excl_hi);
1514 	if (asy->asy_hwtype == ASY82510)
1515 		OUTB(ISR, 0x00); /* set bank 0 */
1516 
1517 #ifdef DEBUG
1518 	if (asydebug & ASY_DEBUG_INTR)
1519 		prom_printf("l");
1520 #endif
1521 	lsr = INB(LSR);
1522 	switch (interrupt_id) {
1523 	case RxRDY:
1524 	case RSTATUS:
1525 	case FFTMOUT:
1526 		/* receiver interrupt or receiver errors */
1527 		async_rxint(asy, lsr);
1528 		break;
1529 	case TxRDY:
1530 		/* transmit interrupt */
1531 		async_txint(asy, lsr);
1532 		break;
1533 	case MSTATUS:
1534 		/* modem status interrupt */
1535 		async_msint(asy);
1536 		break;
1537 	}
1538 	mutex_exit(asy->asy_excl_hi);
1539 	return (ret_status);
1540 }
1541 
1542 /*
1543  * Transmitter interrupt service routine.
1544  * If there is more data to transmit in the current pseudo-DMA block,
1545  * send the next character if output is not stopped or draining.
1546  * Otherwise, queue up a soft interrupt.
1547  *
1548  * XXX -  Needs review for HW FIFOs.
1549  */
1550 static void
1551 async_txint(struct asycom *asy, uchar_t lsr)
1552 {
1553 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1554 	int		fifo_len;
1555 	int		xmit_progress;
1556 
1557 	asycheckflowcontrol_hw(asy);
1558 
1559 	/*
1560 	 * If ASYNC_BREAK has been set, return to asyintr()'s context to
1561 	 * claim the interrupt without performing any action.
1562 	 */
1563 	if (async->async_flags & ASYNC_BREAK)
1564 		return;
1565 
1566 	fifo_len = asy->asy_fifo_buf; /* with FIFO buffers */
1567 
1568 	/*
1569 	 * Check for flow control and do the needed action.
1570 	 */
1571 	if (asycheckflowcontrol_sw(asy)) {
1572 		return;
1573 	}
1574 
1575 	if (async->async_ocnt > 0 &&
1576 	    !(async->async_flags & (ASYNC_HW_OUT_FLW|ASYNC_STOPPED))) {
1577 		xmit_progress = 0;
1578 		while (fifo_len > 0 && async->async_ocnt > 0) {
1579 			if (lsr & XHRE) {
1580 				OUTB(DAT, *async->async_optr++);
1581 				fifo_len--;
1582 				async->async_ocnt--;
1583 				xmit_progress++;
1584 			}
1585 			/*
1586 			 * Reading the lsr, (moved reading at the end of
1587 			 * while loop) as already we have read once at
1588 			 * the beginning of interrupt service
1589 			 */
1590 			lsr = INB(LSR);
1591 		}
1592 		asy->asy_xmit_count = xmit_progress;
1593 		if (xmit_progress > 0)
1594 			async->async_flags |= ASYNC_PROGRESS;
1595 	}
1596 
1597 	if (fifo_len == 0) {
1598 		return;
1599 	}
1600 
1601 
1602 	ASYSETSOFT(asy);
1603 }
1604 
1605 /*
1606  * Receiver interrupt: RxRDY interrupt, FIFO timeout interrupt or receive
1607  * error interrupt.
1608  * Try to put the character into the circular buffer for this line; if it
1609  * overflows, indicate a circular buffer overrun. If this port is always
1610  * to be serviced immediately, or the character is a STOP character, or
1611  * more than 15 characters have arrived, queue up a soft interrupt to
1612  * drain the circular buffer.
1613  * XXX - needs review for hw FIFOs support.
1614  */
1615 
1616 static void
1617 async_rxint(struct asycom *asy, uchar_t lsr)
1618 {
1619 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1620 	uchar_t c = 0;
1621 	uint_t s = 0, needsoft = 0;
1622 	register tty_common_t *tp;
1623 
1624 	tp = &async->async_ttycommon;
1625 	if (!(tp->t_cflag & CREAD)) {
1626 		if (lsr & (RCA|PARERR|FRMERR|BRKDET|OVRRUN)) {
1627 			(void) (INB(DAT) & 0xff);
1628 		}
1629 		return; /* line is not open for read? */
1630 	}
1631 	asy->asy_rx_count = 0;
1632 	while (lsr & (RCA|PARERR|FRMERR|BRKDET|OVRRUN)) {
1633 		c = 0;
1634 		s = 0;
1635 		asy->asy_rx_count++;
1636 		if (lsr & RCA) {
1637 			c = INB(DAT) & 0xff;
1638 			/*
1639 			 * Even a single character is received
1640 			 * we need Soft interrupt to pass it to
1641 			 * higher layers.
1642 			 */
1643 			needsoft = 1;
1644 		}
1645 
1646 		/* Check for character break sequence */
1647 		if ((abort_enable == KIOCABORTALTERNATE) &&
1648 		    (async->async_dev == rconsdev)) {
1649 			if (abort_charseq_recognize(c))
1650 				abort_sequence_enter((char *)NULL);
1651 			}
1652 
1653 		/* Handle framing errors */
1654 		if (lsr & (PARERR|FRMERR|BRKDET|OVRRUN)) {
1655 			if (lsr & PARERR) {
1656 				if (tp->t_iflag & INPCK) /* parity enabled */
1657 					s |= PERROR;
1658 			}
1659 			if (lsr & (FRMERR|BRKDET))
1660 				s |= FRERROR;
1661 			if (lsr & OVRRUN) {
1662 				async->async_hw_overrun = 1;
1663 				s |= OVERRUN;
1664 			}
1665 		}
1666 
1667 		if (s == 0)
1668 			if ((tp->t_iflag & PARMRK) &&
1669 					!(tp->t_iflag & (IGNPAR|ISTRIP)) &&
1670 						(c == 0377))
1671 				if (RING_POK(async, 2)) {
1672 					RING_PUT(async, 0377);
1673 					RING_PUT(async, c);
1674 				} else
1675 					async->async_sw_overrun = 1;
1676 			else
1677 				if (RING_POK(async, 1))
1678 					RING_PUT(async, c);
1679 				else
1680 					async->async_sw_overrun = 1;
1681 		else
1682 			if (s & FRERROR) { /* Handle framing errors */
1683 				if (c == 0)  {
1684 		/* Look for break on kbd, stdin, or rconsdev */
1685 					if ((async->async_dev == kbddev) ||
1686 					    ((async->async_dev == rconsdev) ||
1687 					    (async->async_dev == stdindev)) &&
1688 					    (abort_enable !=
1689 					    KIOCABORTALTERNATE))
1690 						abort_sequence_enter((char *)0);
1691 					else
1692 						async->async_break++;
1693 				} else {
1694 					if (RING_POK(async, 1))
1695 						RING_MARK(async, c, s);
1696 					else
1697 						async->async_sw_overrun = 1;
1698 				}
1699 			} else  { /* Parity errors  handled by ldterm */
1700 				if (RING_POK(async, 1))
1701 					RING_MARK(async, c, s);
1702 				else
1703 					async->async_sw_overrun = 1;
1704 			}
1705 		lsr = INB(LSR);
1706 		if (asy->asy_rx_count > 16) break;
1707 	}
1708 	/* Check whether there is a request for hw/sw inbound/input flow ctrl */
1709 	if ((async->async_ttycommon.t_cflag & CRTSXOFF) ||
1710 		(async->async_ttycommon.t_iflag & IXOFF))
1711 		if ((int)(RING_CNT(async)) > (RINGSIZE * 3)/4) {
1712 #ifdef DEBUG
1713 			if (asydebug & ASY_DEBUG_HFLOW)
1714 				printf("asy%d: hardware flow stop input.\n",
1715 				UNIT(async->async_dev));
1716 #endif
1717 			async->async_flags |= ASYNC_HW_IN_FLOW;
1718 			async->async_flowc = async->async_stopc;
1719 			async->async_ringbuf_overflow = 1;
1720 		}
1721 
1722 	if ((async->async_flags & ASYNC_SERVICEIMM) || needsoft ||
1723 			(RING_FRAC(async)) || (async->async_polltid == 0))
1724 		ASYSETSOFT(asy);	/* need a soft interrupt */
1725 }
1726 
1727 /*
1728  * Interrupt on port: handle PPS event.  This function is only called
1729  * for a port on which PPS event handling has been enabled.
1730  */
1731 static void
1732 asy_ppsevent(struct asycom *asy, int msr)
1733 {
1734 	if (asy->asy_flags & ASY_PPS_EDGE) {
1735 		/* Have seen leading edge, now look for and record drop */
1736 		if ((msr & DCD) == 0)
1737 			asy->asy_flags &= ~ASY_PPS_EDGE;
1738 		/*
1739 		 * Waiting for leading edge, look for rise; stamp event and
1740 		 * calibrate kernel clock.
1741 		 */
1742 	} else if (msr & DCD) {
1743 		/*
1744 		 * This code captures a timestamp at the designated
1745 		 * transition of the PPS signal (DCD asserted).  The
1746 		 * code provides a pointer to the timestamp, as well
1747 		 * as the hardware counter value at the capture.
1748 		 *
1749 		 * Note: the kernel has nano based time values while
1750 		 * NTP requires micro based, an in-line fast algorithm
1751 		 * to convert nsec to usec is used here -- see hrt2ts()
1752 		 * in common/os/timers.c for a full description.
1753 		 */
1754 		struct timeval *tvp = &asy_ppsev.tv;
1755 		timestruc_t ts;
1756 		long nsec, usec;
1757 
1758 		asy->asy_flags |= ASY_PPS_EDGE;
1759 		gethrestime(&ts);
1760 		nsec = ts.tv_nsec;
1761 		usec = nsec + (nsec >> 2);
1762 		usec = nsec + (usec >> 1);
1763 		usec = nsec + (usec >> 2);
1764 		usec = nsec + (usec >> 4);
1765 		usec = nsec - (usec >> 3);
1766 		usec = nsec + (usec >> 2);
1767 		usec = nsec + (usec >> 3);
1768 		usec = nsec + (usec >> 4);
1769 		usec = nsec + (usec >> 1);
1770 		usec = nsec + (usec >> 6);
1771 		tvp->tv_usec = usec >> 10;
1772 		tvp->tv_sec = ts.tv_sec;
1773 
1774 		++asy_ppsev.serial;
1775 
1776 		/*
1777 		 * Because the kernel keeps a high-resolution time,
1778 		 * pass the current highres timestamp in tvp and zero
1779 		 * in usec.
1780 		 */
1781 		ddi_hardpps(tvp, 0);
1782 	}
1783 }
1784 
1785 /*
1786  * Modem status interrupt.
1787  *
1788  * (Note: It is assumed that the MSR hasn't been read by asyintr().)
1789  */
1790 
1791 static void
1792 async_msint(struct asycom *asy)
1793 {
1794 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1795 	int msr;
1796 
1797 	msr = INB(MSR);	/* this resets the interrupt */
1798 	asy->asy_cached_msr = msr;
1799 #ifdef DEBUG
1800 	if (asydebug & ASY_DEBUG_STATE) {
1801 		printf("   transition: %3s %3s %3s %3s\n"
1802 			"current state: %3s %3s %3s %3s\n",
1803 			(msr & DCTS) ? "CTS" : "   ",
1804 			(msr & DDSR) ? "DSR" : "   ",
1805 			(msr & DRI) ?  "RI " : "   ",
1806 			(msr & DDCD) ? "DCD" : "   ",
1807 			(msr & CTS) ?  "CTS" : "   ",
1808 			(msr & DSR) ?  "DSR" : "   ",
1809 			(msr & RI) ?   "RI " : "   ",
1810 			(msr & DCD) ?  "DCD" : "   ");
1811 	}
1812 #endif
1813 	if (async->async_ttycommon.t_cflag & CRTSCTS && !(msr & CTS)) {
1814 #ifdef DEBUG
1815 		if (asydebug & ASY_DEBUG_HFLOW)
1816 			printf("asy%d: hflow start\n",
1817 				UNIT(async->async_dev));
1818 #endif
1819 		async->async_flags |= ASYNC_HW_OUT_FLW;
1820 	}
1821 	if (asy->asy_hwtype == ASY82510)
1822 		OUTB(MSR, (msr & 0xF0));
1823 
1824 	/* Handle PPS event */
1825 	if (asy->asy_flags & ASY_PPS)
1826 		asy_ppsevent(asy, msr);
1827 
1828 	async->async_ext++;
1829 	ASYSETSOFT(asy);
1830 }
1831 
1832 /*
1833  * Handle a second-stage interrupt.
1834  */
1835 uint_t
1836 asysoftintr(caddr_t intarg)
1837 {
1838 	struct asycom *asy = (struct asycom *)intarg;
1839 	struct asyncline *async;
1840 	int rv;
1841 	int cc;
1842 	/*
1843 	 * Test and clear soft interrupt.
1844 	 */
1845 	mutex_enter(asy->asy_soft_lock);
1846 #ifdef DEBUG
1847 	if (asydebug & ASY_DEBUG_PROCS)
1848 		printf("softintr\n");
1849 #endif
1850 	rv = asy->asysoftpend;
1851 	if (rv != 0)
1852 		asy->asysoftpend = 0;
1853 	mutex_exit(asy->asy_soft_lock);
1854 
1855 	if (rv) {
1856 		if (asy->asy_priv == NULL)
1857 			return (rv);
1858 		async = (struct asyncline *)asy->asy_priv;
1859 		mutex_enter(asy->asy_excl_hi);
1860 		if (asy->asy_flags & ASY_NEEDSOFT) {
1861 			asy->asy_flags &= ~ASY_NEEDSOFT;
1862 			mutex_exit(asy->asy_excl_hi);
1863 			(void) async_softint(asy);
1864 			mutex_enter(asy->asy_excl_hi);
1865 		}
1866 		/*
1867 		 * There are some instances where the softintr is not
1868 		 * scheduled and hence not called. It so happened that makes
1869 		 * the last few characters to be stuck in ringbuffer.
1870 		 * Hence, call once again the  handler so that the last few
1871 		 * characters are cleared.
1872 		 */
1873 		cc = RING_CNT(async);
1874 		mutex_exit(asy->asy_excl_hi);
1875 		if (cc > 0) {
1876 			(void) async_softint(asy);
1877 		}
1878 	}
1879 	return (rv);
1880 }
1881 
1882 /*
1883  * Handle a software interrupt.
1884  */
1885 static int
1886 async_softint(struct asycom *asy)
1887 {
1888 	struct asyncline *async = (struct asyncline *)asy->asy_priv;
1889 	uint_t	cc;
1890 	mblk_t	*bp;
1891 	queue_t	*q;
1892 	uchar_t	val;
1893 	uchar_t	c;
1894 	tty_common_t	*tp;
1895 
1896 #ifdef DEBUG
1897 	if (asydebug & ASY_DEBUG_PROCS)
1898 		printf("process\n");
1899 #endif
1900 	mutex_enter(asy->asy_excl);
1901 	if (asy->asy_flags & ASY_DOINGSOFT) {
1902 		mutex_exit(asy->asy_excl);
1903 		return (0);
1904 	}
1905 	tp = &async->async_ttycommon;
1906 	q = tp->t_readq;
1907 	if (q != NULL) {
1908 		mutex_exit(asy->asy_excl);
1909 		enterq(q);
1910 		mutex_enter(asy->asy_excl);
1911 	}
1912 	mutex_enter(asy->asy_excl_hi);
1913 	asy->asy_flags |= ASY_DOINGSOFT;
1914 
1915 	if (INB(ICR) & MIEN)
1916 		val = asy->asy_cached_msr & 0xFF;
1917 	else
1918 		val = INB(MSR) & 0xFF;
1919 
1920 	if (async->async_ttycommon.t_cflag & CRTSCTS) {
1921 		if ((val & CTS) && (async->async_flags & ASYNC_HW_OUT_FLW)) {
1922 #ifdef DEBUG
1923 			if (asydebug & ASY_DEBUG_HFLOW)
1924 				printf("asy%d: hflow start\n",
1925 					UNIT(async->async_dev));
1926 #endif
1927 			async->async_flags &= ~ASYNC_HW_OUT_FLW;
1928 			mutex_exit(asy->asy_excl_hi);
1929 			if (async->async_ocnt > 0) {
1930 				mutex_enter(asy->asy_excl_hi);
1931 				async_resume(async);
1932 				mutex_exit(asy->asy_excl_hi);
1933 			} else {
1934 				async_start(async);
1935 			}
1936 			mutex_enter(asy->asy_excl_hi);
1937 		}
1938 	}
1939 	if (async->async_ext) {
1940 		async->async_ext = 0;
1941 		/* check for carrier up */
1942 		if ((val & DCD) || (tp->t_flags & TS_SOFTCAR)) {
1943 			/* carrier present */
1944 			if ((async->async_flags & ASYNC_CARR_ON) == 0) {
1945 				async->async_flags |= ASYNC_CARR_ON;
1946 				mutex_exit(asy->asy_excl_hi);
1947 				mutex_exit(asy->asy_excl);
1948 				if (async->async_flags & ASYNC_ISOPEN)
1949 					(void) putctl(q, M_UNHANGUP);
1950 				cv_broadcast(&async->async_flags_cv);
1951 				mutex_enter(asy->asy_excl);
1952 				mutex_enter(asy->asy_excl_hi);
1953 			}
1954 		} else {
1955 			if ((async->async_flags & ASYNC_CARR_ON) &&
1956 			    !(tp->t_cflag & CLOCAL)) {
1957 				int flushflag;
1958 
1959 				/*
1960 				 * Carrier went away.
1961 				 * Drop DTR, abort any output in
1962 				 * progress, indicate that output is
1963 				 * not stopped, and send a hangup
1964 				 * notification upstream.
1965 				 *
1966 				 * If we're in the midst of close, then flush
1967 				 * everything.  Don't leave stale ioctls lying
1968 				 * about.
1969 				 */
1970 				val = INB(MCR);
1971 				OUTB(MCR, (val & ~DTR));
1972 				flushflag = (async->async_flags &
1973 				    ASYNC_CLOSING) ? FLUSHALL : FLUSHDATA;
1974 				flushq(tp->t_writeq, flushflag);
1975 				if (async->async_xmitblk != NULL) {
1976 					freeb(async->async_xmitblk);
1977 					async->async_xmitblk = NULL;
1978 				}
1979 				if (async->async_flags & ASYNC_BUSY) {
1980 					async->async_ocnt = 0;
1981 					async->async_flags &= ~ASYNC_BUSY;
1982 				}
1983 				async->async_flags &= ~ASYNC_STOPPED;
1984 				if (async->async_flags & ASYNC_ISOPEN) {
1985 					mutex_exit(asy->asy_excl_hi);
1986 					mutex_exit(asy->asy_excl);
1987 					(void) putctl(q, M_HANGUP);
1988 					mutex_enter(asy->asy_excl);
1989 					mutex_enter(asy->asy_excl_hi);
1990 				}
1991 			}
1992 			async->async_flags &= ~ASYNC_CARR_ON;
1993 			mutex_exit(asy->asy_excl_hi);
1994 			cv_broadcast(&async->async_flags_cv);
1995 			mutex_enter(asy->asy_excl_hi);
1996 		}
1997 	}
1998 
1999 	/*
2000 	 * If data has been added to the circular buffer, remove
2001 	 * it from the buffer, and send it up the stream if there's
2002 	 * somebody listening. Try to do it 16 bytes at a time. If we
2003 	 * have more than 16 bytes to move, move 16 byte chunks and
2004 	 * leave the rest for next time around (maybe it will grow).
2005 	 */
2006 	if (!(async->async_flags & ASYNC_ISOPEN)) {
2007 		RING_INIT(async);
2008 		goto rv;
2009 	}
2010 	if ((cc = RING_CNT(async)) == 0) {
2011 		goto rv;
2012 	}
2013 	mutex_exit(asy->asy_excl_hi);
2014 
2015 	if (!canput(q)) {
2016 		if ((async->async_flags & ASYNC_HW_IN_FLOW) == 0) {
2017 #ifdef DEBUG
2018 			if (!(asydebug & ASY_DEBUG_HFLOW)) {
2019 				printf("asy%d: hflow stop input.\n",
2020 				UNIT(async->async_dev));
2021 				if (canputnext(q))
2022 					printf("asy%d: next queue is "
2023 						"ready\n",
2024 					UNIT(async->async_dev));
2025 			}
2026 #endif
2027 			mutex_enter(asy->asy_excl_hi);
2028 			async->async_flags |= ASYNC_HW_IN_FLOW;
2029 			async->async_flowc = async->async_stopc;
2030 		} else mutex_enter(asy->asy_excl_hi);
2031 		goto rv;
2032 	}
2033 
2034 	if (async->async_ringbuf_overflow) {
2035 		if ((async->async_flags & ASYNC_HW_IN_FLOW) &&
2036 				((int)(RING_CNT(async)) < (RINGSIZE/4))) {
2037 #ifdef DEBUG
2038 			if (asydebug & ASY_DEBUG_HFLOW)
2039 				printf("asy%d: hflow start input.\n",
2040 				UNIT(async->async_dev));
2041 #endif
2042 			mutex_enter(asy->asy_excl_hi);
2043 			async->async_flags &= ~ASYNC_HW_IN_FLOW;
2044 			async->async_flowc = async->async_startc;
2045 			async->async_ringbuf_overflow = 0;
2046 			goto rv;
2047 		}
2048 	}
2049 #ifdef DEBUG
2050 	if (asydebug & ASY_DEBUG_INPUT)
2051 		printf("asy%d: %d char(s) in queue.\n",
2052 			UNIT(async->async_dev), cc);
2053 #endif
2054 	/*
2055 	 * Before you pull the characters from the RING BUF
2056 	 * Check whether you can put into the queue again
2057 	 */
2058 	if ((!canputnext(q)) || (!canput(q))) {
2059 		mutex_enter(asy->asy_excl_hi);
2060 		if ((async->async_flags & ASYNC_HW_IN_FLOW) == 0) {
2061 			async->async_flags |= ASYNC_HW_IN_FLOW;
2062 			async->async_flowc = async->async_stopc;
2063 			async->async_queue_full = 1;
2064 		}
2065 		goto rv;
2066 	}
2067 	mutex_enter(asy->asy_excl_hi);
2068 	if (async->async_queue_full) {
2069 		/*
2070 		 * Last time the Stream queue didnot allow
2071 		 * now it allows so, relax, the flow control
2072 		 */
2073 		if (async->async_flags & ASYNC_HW_IN_FLOW) {
2074 			async->async_flags &= ~ASYNC_HW_IN_FLOW;
2075 			async->async_queue_full = 0;
2076 			async->async_flowc = async->async_startc;
2077 			goto rv;
2078 		} else
2079 			async->async_queue_full = 0;
2080 	}
2081 	mutex_exit(asy->asy_excl_hi);
2082 	if (!(bp = allocb(cc, BPRI_MED))) {
2083 		ttycommon_qfull(&async->async_ttycommon, q);
2084 		mutex_enter(asy->asy_excl_hi);
2085 		goto rv;
2086 	}
2087 	mutex_enter(asy->asy_excl_hi);
2088 	do {
2089 		if (RING_ERR(async, S_ERRORS)) {
2090 			RING_UNMARK(async);
2091 			c = RING_GET(async);
2092 			break;
2093 		} else {
2094 			*bp->b_wptr++ = RING_GET(async);
2095 		}
2096 	} while (--cc);
2097 
2098 	mutex_exit(asy->asy_excl_hi);
2099 	mutex_exit(asy->asy_excl);
2100 	if (bp->b_wptr > bp->b_rptr) {
2101 		if (!canputnext(q)) {
2102 			if (!canput(q)) {
2103 				/*
2104 				 * Even after taking all precautions that
2105 				 * Still we are unable to queue, then we
2106 				 * cannot do anything, just drop the block
2107 				 */
2108 				cmn_err(CE_NOTE,
2109 					"su%d: local queue full\n",
2110 					UNIT(async->async_dev));
2111 				freemsg(bp);
2112 				mutex_enter(asy->asy_excl_hi);
2113 				if ((async->async_flags &
2114 					ASYNC_HW_IN_FLOW) == 0) {
2115 					async->async_flags |=
2116 						ASYNC_HW_IN_FLOW;
2117 					async->async_flowc =
2118 						async->async_stopc;
2119 					async->async_queue_full = 1;
2120 				}
2121 				mutex_exit(asy->asy_excl_hi);
2122 			} else {
2123 				(void) putq(q, bp);
2124 			}
2125 		} else {
2126 			putnext(q, bp);
2127 		}
2128 	} else {
2129 		freemsg(bp);
2130 	}
2131 	/*
2132 	 * If we have a parity error, then send
2133 	 * up an M_BREAK with the "bad"
2134 	 * character as an argument. Let ldterm
2135 	 * figure out what to do with the error.
2136 	 */
2137 	if (cc)
2138 		(void) putctl1(q, M_BREAK, c);
2139 	mutex_enter(asy->asy_excl);
2140 	mutex_enter(asy->asy_excl_hi);
2141 rv:
2142 	/*
2143 	 * If a transmission has finished, indicate that it's finished,
2144 	 * and start that line up again.
2145 	 */
2146 	if (async->async_break) {
2147 		async->async_break = 0;
2148 		if (async->async_flags & ASYNC_ISOPEN) {
2149 			mutex_exit(asy->asy_excl_hi);
2150 			mutex_exit(asy->asy_excl);
2151 			(void) putctl(q, M_BREAK);
2152 			mutex_enter(asy->asy_excl);
2153 			mutex_enter(asy->asy_excl_hi);
2154 		}
2155 	}
2156 	if ((async->async_ocnt <= 0 && (async->async_flags & ASYNC_BUSY)) ||
2157 	    (async->async_flowc != '\0')) {
2158 		async->async_flags &= ~ASYNC_BUSY;
2159 		mutex_exit(asy->asy_excl_hi);
2160 		if (async->async_xmitblk)
2161 			freeb(async->async_xmitblk);
2162 		async->async_xmitblk = NULL;
2163 		if (async->async_flags & ASYNC_ISOPEN) {
2164 			asy->inperim = B_TRUE;
2165 			mutex_exit(asy->asy_excl);
2166 			enterq(async->async_ttycommon.t_writeq);
2167 			mutex_enter(asy->asy_excl);
2168 		}
2169 		async_start(async);
2170 		/*
2171 		 * We need to check for inperim and ISOPEN due to
2172 		 * multi-threading implications; it's possible to close the
2173 		 * port and nullify async_flags while completing the software
2174 		 * interrupt.  If the port is closed, leaveq() will have already
2175 		 * been called.  We don't want to call it twice.
2176 		 */
2177 		if ((asy->inperim) && (async->async_flags & ASYNC_ISOPEN)) {
2178 			mutex_exit(asy->asy_excl);
2179 			leaveq(async->async_ttycommon.t_writeq);
2180 			mutex_enter(asy->asy_excl);
2181 			asy->inperim = B_FALSE;
2182 		}
2183 		if (!(async->async_flags & ASYNC_BUSY))
2184 			cv_broadcast(&async->async_flags_cv);
2185 		mutex_enter(asy->asy_excl_hi);
2186 	}
2187 	/*
2188 	 * A note about these overrun bits: all they do is *tell* someone
2189 	 * about an error- They do not track multiple errors. In fact,
2190 	 * you could consider them latched register bits if you like.
2191 	 * We are only interested in printing the error message once for
2192 	 * any cluster of overrun errrors.
2193 	 */
2194 	if (async->async_hw_overrun) {
2195 		if (async->async_flags & ASYNC_ISOPEN) {
2196 			if (su_log > 0) {
2197 				mutex_exit(asy->asy_excl_hi);
2198 				mutex_exit(asy->asy_excl);
2199 				cmn_err(CE_NOTE, "su%d: silo overflow\n",
2200 				    UNIT(async->async_dev));
2201 				mutex_enter(asy->asy_excl);
2202 				mutex_enter(asy->asy_excl_hi);
2203 			}
2204 			INC64_KSTAT(asy, siloover);
2205 		}
2206 		async->async_hw_overrun = 0;
2207 	}
2208 	if (async->async_sw_overrun) {
2209 		if (async->async_flags & ASYNC_ISOPEN) {
2210 			if (su_log > 0) {
2211 				mutex_exit(asy->asy_excl_hi);
2212 				mutex_exit(asy->asy_excl);
2213 				cmn_err(CE_NOTE, "su%d: ring buffer overflow\n",
2214 				    UNIT(async->async_dev));
2215 				mutex_enter(asy->asy_excl);
2216 				mutex_enter(asy->asy_excl_hi);
2217 			}
2218 			INC64_KSTAT(asy, ringover);
2219 		}
2220 		async->async_sw_overrun = 0;
2221 	}
2222 	asy->asy_flags &= ~ASY_DOINGSOFT;
2223 	mutex_exit(asy->asy_excl_hi);
2224 	mutex_exit(asy->asy_excl);
2225 	if (q != NULL)
2226 		leaveq(q);
2227 	return (0);
2228 }
2229 
2230 /*
2231  * Restart output on a line after a delay or break timer expired.
2232  */
2233 static void
2234 async_restart(void *arg)
2235 {
2236 	struct asyncline *async = arg;
2237 	struct asycom *asy = async->async_common;
2238 	queue_t *q;
2239 	uchar_t lcr;
2240 
2241 	/*
2242 	 * If break timer expired, turn off the break bit.
2243 	 */
2244 #ifdef DEBUG
2245 	if (asydebug & ASY_DEBUG_PROCS)
2246 		printf("restart\n");
2247 #endif
2248 	mutex_enter(asy->asy_excl);
2249 	if (async->async_flags & ASYNC_BREAK) {
2250 		unsigned int rate;
2251 
2252 		mutex_enter(asy->asy_excl_hi);
2253 		lcr = INB(LCR);
2254 		OUTB(LCR, (lcr & ~SETBREAK));
2255 
2256 		/*
2257 		 * Go to sleep for the time it takes for at least one
2258 		 * stop bit to be received by the device at the other
2259 		 * end of the line as stated in the RS-232 specification.
2260 		 * The wait period is equal to:
2261 		 * 2 clock cycles * (1 MICROSEC / baud rate)
2262 		 */
2263 		rate = async->async_ttycommon.t_cflag & CBAUD;
2264 		if (async->async_ttycommon.t_cflag & CBAUDEXT)
2265 			rate += 16;
2266 		if (rate >= N_SU_SPEEDS || rate == B0) {
2267 			rate = B9600;
2268 		}
2269 
2270 		mutex_exit(asy->asy_excl_hi);
2271 		mutex_exit(asy->asy_excl);
2272 		drv_usecwait(2 * MICROSEC / baudtable[rate]);
2273 		mutex_enter(asy->asy_excl);
2274 	}
2275 	async->async_flags &= ~(ASYNC_DELAY|ASYNC_BREAK|ASYNC_DRAINING);
2276 	if ((q = async->async_ttycommon.t_writeq) != NULL) {
2277 		mutex_exit(asy->asy_excl);
2278 		enterq(q);
2279 		mutex_enter(asy->asy_excl);
2280 	}
2281 	async_start(async);
2282 	mutex_exit(asy->asy_excl);
2283 	if (q != NULL)
2284 		leaveq(q);
2285 
2286 	/* cleared break or delay flag; may have made some output progress */
2287 	cv_broadcast(&async->async_flags_cv);
2288 }
2289 
2290 static void
2291 async_start(struct asyncline *async)
2292 {
2293 	async_nstart(async, 0);
2294 }
2295 
2296 /*
2297  * Start output on a line, unless it's busy, frozen, or otherwise.
2298  */
2299 static void
2300 async_nstart(struct asyncline *async, int mode)
2301 {
2302 	register struct asycom *asy = async->async_common;
2303 	register int cc;
2304 	register queue_t *q;
2305 	mblk_t *bp, *nbp;
2306 	uchar_t *xmit_addr;
2307 	uchar_t	val;
2308 	int	fifo_len = 1;
2309 	int	xmit_progress;
2310 
2311 #ifdef DEBUG
2312 	if (asydebug & ASY_DEBUG_PROCS)
2313 		printf("start\n");
2314 #endif
2315 	if (asy->asy_use_fifo == FIFO_ON)
2316 		fifo_len = asy->asy_fifo_buf; /* with FIFO buffers */
2317 
2318 	ASSERT(mutex_owned(asy->asy_excl));
2319 	mutex_enter(asy->asy_excl_hi);
2320 	asycheckflowcontrol_hw(asy);
2321 
2322 	/*
2323 	 * If the chip is busy (i.e., we're waiting for a break timeout
2324 	 * to expire, or for the current transmission to finish, or for
2325 	 * output to finish draining from chip), don't grab anything new.
2326 	 */
2327 	if (async->async_flags & (ASYNC_BREAK|ASYNC_BUSY|ASYNC_DRAINING)) {
2328 		mutex_exit(asy->asy_excl_hi);
2329 #ifdef DEBUG
2330 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2331 			printf("asy%d: start %s.\n",
2332 				UNIT(async->async_dev),
2333 				async->async_flags & ASYNC_BREAK
2334 				? "break" : "busy");
2335 #endif
2336 		return;
2337 	}
2338 
2339 	/*
2340 	 * If we have a flow-control character to transmit, do it now.
2341 	 */
2342 	if (asycheckflowcontrol_sw(asy)) {
2343 		mutex_exit(asy->asy_excl_hi);
2344 		return;
2345 	}
2346 	mutex_exit(asy->asy_excl_hi);
2347 	/*
2348 	 * If we're waiting for a delay timeout to expire, don't grab
2349 	 * anything new.
2350 	 */
2351 	if (async->async_flags & ASYNC_DELAY) {
2352 #ifdef DEBUG
2353 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2354 			printf("asy%d: start ASYNC_DELAY.\n",
2355 				UNIT(async->async_dev));
2356 #endif
2357 		return;
2358 	}
2359 
2360 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
2361 #ifdef DEBUG
2362 		if (mode && asydebug & ASY_DEBUG_CLOSE)
2363 			printf("asy%d: start writeq is null.\n",
2364 				UNIT(async->async_dev));
2365 #endif
2366 		return;	/* not attached to a stream */
2367 	}
2368 
2369 	for (;;) {
2370 		if ((bp = getq(q)) == NULL)
2371 			return;	/* no data to transmit */
2372 
2373 		/*
2374 		 * We have a message block to work on.
2375 		 * Check whether it's a break, a delay, or an ioctl (the latter
2376 		 * occurs if the ioctl in question was waiting for the output
2377 		 * to drain).  If it's one of those, process it immediately.
2378 		 */
2379 		switch (bp->b_datap->db_type) {
2380 
2381 		case M_BREAK:
2382 			/*
2383 			 * Set the break bit, and arrange for "async_restart"
2384 			 * to be called in 1/4 second; it will turn the
2385 			 * break bit off, and call "async_start" to grab
2386 			 * the next message.
2387 			 */
2388 			mutex_enter(asy->asy_excl_hi);
2389 			val = INB(LCR);
2390 			OUTB(LCR, (val | SETBREAK));
2391 			mutex_exit(asy->asy_excl_hi);
2392 			async->async_flags |= ASYNC_BREAK;
2393 			(void) timeout(async_restart, async, hz / 4);
2394 			freemsg(bp);
2395 			return;	/* wait for this to finish */
2396 
2397 		case M_DELAY:
2398 			/*
2399 			 * Arrange for "async_restart" to be called when the
2400 			 * delay expires; it will turn ASYNC_DELAY off,
2401 			 * and call "async_start" to grab the next message.
2402 			 */
2403 			(void) timeout(async_restart, async,
2404 				(clock_t)(*(unsigned char *)bp->b_rptr + 6));
2405 			async->async_flags |= ASYNC_DELAY;
2406 			freemsg(bp);
2407 			return;	/* wait for this to finish */
2408 
2409 		case M_IOCTL:
2410 			/*
2411 			 * This ioctl needs to wait for the output ahead of
2412 			 * it to drain.  Try to do it, and then either
2413 			 * redo the ioctl at a later time or grab the next
2414 			 * message after it.
2415 			 */
2416 
2417 			mutex_enter(asy->asy_excl_hi);
2418 			if (asy_isbusy(asy)) {
2419 				/*
2420 				 * Get the divisor by calculating the rate
2421 				 */
2422 				unsigned int rate;
2423 
2424 				mutex_exit(asy->asy_excl_hi);
2425 				rate = async->async_ttycommon.t_cflag & CBAUD;
2426 				if (async->async_ttycommon.t_cflag & CBAUDEXT)
2427 					rate += 16;
2428 				if (rate >= N_SU_SPEEDS || rate == B0) {
2429 					rate = B9600;
2430 				}
2431 
2432 				/*
2433 				 * We need to do a callback as the port will
2434 				 * be set to drain
2435 				 */
2436 				async->async_flags |= ASYNC_DRAINING;
2437 
2438 				/*
2439 				 * Put the message we just processed back onto
2440 				 * the end of the queue
2441 				 */
2442 				if (putq(q, bp) == 0)
2443 					freemsg(bp);
2444 
2445 				/*
2446 				 * We need to delay until the TSR and THR
2447 				 * have been exhausted.  We base the delay on
2448 				 * the amount of time it takes to transmit
2449 				 * 2 chars at the current baud rate in
2450 				 * microseconds.
2451 				 *
2452 				 * Therefore, the wait period is:
2453 				 *
2454 				 * (#TSR bits + #THR bits) *
2455 				 * 	1 MICROSEC / baud rate
2456 				 */
2457 				(void) timeout(async_restart, async,
2458 					drv_usectohz(16 * MICROSEC /
2459 						baudtable[rate]));
2460 				return;
2461 			}
2462 			mutex_exit(asy->asy_excl_hi);
2463 			mutex_exit(asy->asy_excl);
2464 			async_ioctl(async, q, bp, B_FALSE);
2465 			mutex_enter(asy->asy_excl);
2466 			continue;
2467 		}
2468 
2469 		while (bp != NULL && (cc = bp->b_wptr - bp->b_rptr) == 0) {
2470 			nbp = bp->b_cont;
2471 			freeb(bp);
2472 			bp = nbp;
2473 		}
2474 		if (bp != NULL)
2475 			break;
2476 	}
2477 
2478 	/*
2479 	 * We have data to transmit.  If output is stopped, put
2480 	 * it back and try again later.
2481 	 */
2482 	if (async->async_flags & (ASYNC_HW_OUT_FLW|ASYNC_STOPPED)) {
2483 #ifdef DEBUG
2484 		if (asydebug & ASY_DEBUG_HFLOW &&
2485 					async->async_flags & ASYNC_HW_OUT_FLW)
2486 			printf("asy%d: output hflow in effect.\n",
2487 				UNIT(async->async_dev));
2488 #endif
2489 		mutex_exit(asy->asy_excl);
2490 		(void) putbq(q, bp);
2491 		/*
2492 		 * We entered the routine owning the lock, we need to
2493 		 * exit the routine owning the lock.
2494 		 */
2495 		mutex_enter(asy->asy_excl);
2496 		return;
2497 	}
2498 
2499 	async->async_xmitblk = bp;
2500 	xmit_addr = bp->b_rptr;
2501 	bp = bp->b_cont;
2502 	if (bp != NULL) {
2503 		mutex_exit(asy->asy_excl);
2504 		(void) putbq(q, bp);	/* not done with this message yet */
2505 		mutex_enter(asy->asy_excl);
2506 	}
2507 
2508 	/*
2509 	 * In 5-bit mode, the high order bits are used
2510 	 * to indicate character sizes less than five,
2511 	 * so we need to explicitly mask before transmitting
2512 	 */
2513 	if ((async->async_ttycommon.t_cflag & CSIZE) == CS5) {
2514 		register unsigned char *p = xmit_addr;
2515 		register int cnt = cc;
2516 
2517 		while (cnt--)
2518 			*p++ &= (unsigned char) 0x1f;
2519 	}
2520 
2521 	/*
2522 	 * Set up this block for pseudo-DMA.
2523 	 */
2524 	mutex_enter(asy->asy_excl_hi);
2525 	async->async_optr = xmit_addr;
2526 	async->async_ocnt = cc;
2527 	/*
2528 	 * If the transmitter is ready, shove some
2529 	 * characters out.
2530 	 */
2531 	xmit_progress = 0;
2532 	while (fifo_len-- && async->async_ocnt) {
2533 		if (INB(LSR) & XHRE) {
2534 			OUTB(DAT, *async->async_optr++);
2535 			async->async_ocnt--;
2536 			xmit_progress++;
2537 		}
2538 	}
2539 	asy->asy_out_of_band_xmit = xmit_progress;
2540 	if (xmit_progress > 0)
2541 		async->async_flags |= ASYNC_PROGRESS;
2542 	async->async_flags |= ASYNC_BUSY;
2543 	mutex_exit(asy->asy_excl_hi);
2544 }
2545 
2546 /*
2547  * Resume output by poking the transmitter.
2548  */
2549 static void
2550 async_resume(struct asyncline *async)
2551 {
2552 	register struct asycom *asy = async->async_common;
2553 
2554 	ASSERT(mutex_owned(asy->asy_excl_hi));
2555 #ifdef DEBUG
2556 	if (asydebug & ASY_DEBUG_PROCS)
2557 		printf("resume\n");
2558 #endif
2559 
2560 	asycheckflowcontrol_hw(asy);
2561 
2562 	if (INB(LSR) & XHRE) {
2563 		if (asycheckflowcontrol_sw(asy)) {
2564 			return;
2565 		} else if (async->async_ocnt > 0) {
2566 			OUTB(DAT, *async->async_optr++);
2567 			async->async_ocnt--;
2568 			async->async_flags |= ASYNC_PROGRESS;
2569 		}
2570 	}
2571 }
2572 
2573 /*
2574  * Process an "ioctl" message sent down to us.
2575  * Note that we don't need to get any locks until we are ready to access
2576  * the hardware.  Nothing we access until then is going to be altered
2577  * outside of the STREAMS framework, so we should be safe.
2578  */
2579 static void
2580 async_ioctl(struct asyncline *async, queue_t *wq, mblk_t *mp, boolean_t iswput)
2581 {
2582 	register struct asycom *asy = async->async_common;
2583 	register tty_common_t  *tp = &async->async_ttycommon;
2584 	register struct iocblk *iocp;
2585 	register unsigned datasize;
2586 	mblk_t *datamp;
2587 	int error = 0;
2588 	uchar_t val, icr;
2589 #ifdef DEBUG
2590 	if (asydebug & ASY_DEBUG_PROCS)
2591 		printf("ioctl\n");
2592 #endif
2593 
2594 	if (tp->t_iocpending != NULL) {
2595 		/*
2596 		 * We were holding an "ioctl" response pending the
2597 		 * availability of an "mblk" to hold data to be passed up;
2598 		 * another "ioctl" came through, which means that "ioctl"
2599 		 * must have timed out or been aborted.
2600 		 */
2601 		freemsg(async->async_ttycommon.t_iocpending);
2602 		async->async_ttycommon.t_iocpending = NULL;
2603 	}
2604 
2605 	iocp = (struct iocblk *)mp->b_rptr;
2606 
2607 	/*
2608 	 * For TIOCMGET, TIOCMBIC, TIOCMBIS, TIOCMSET, and PPS, do NOT call
2609 	 * ttycommon_ioctl() because this function frees up the message block
2610 	 * (mp->b_cont) that contains the address of the user variable where
2611 	 * we need to pass back the bit array.
2612 	 */
2613 	if (iocp->ioc_cmd == TIOCMGET ||
2614 		iocp->ioc_cmd == TIOCMBIC ||
2615 		iocp->ioc_cmd == TIOCMBIS ||
2616 		iocp->ioc_cmd == TIOCMSET ||
2617 		iocp->ioc_cmd == TIOCGPPS ||
2618 		iocp->ioc_cmd == TIOCSPPS ||
2619 		iocp->ioc_cmd == TIOCGPPSEV)
2620 		error = -1; /* Do Nothing */
2621 	else
2622 
2623 	/*
2624 	 * The only way in which "ttycommon_ioctl" can fail is if the "ioctl"
2625 	 * requires a response containing data to be returned to the user,
2626 	 * and no mblk could be allocated for the data.
2627 	 * No such "ioctl" alters our state.  Thus, we always go ahead and
2628 	 * do any state-changes the "ioctl" calls for.  If we couldn't allocate
2629 	 * the data, "ttycommon_ioctl" has stashed the "ioctl" away safely, so
2630 	 * we just call "bufcall" to request that we be called back when we
2631 	 * stand a better chance of allocating the data.
2632 	 */
2633 	if ((datasize = ttycommon_ioctl(tp, wq, mp, &error)) != 0) {
2634 		if (async->async_wbufcid)
2635 			unbufcall(async->async_wbufcid);
2636 		async->async_wbufcid = bufcall(datasize, BPRI_HI, async_reioctl,
2637 		    async);
2638 		return;
2639 	}
2640 
2641 	mutex_enter(asy->asy_excl);
2642 
2643 	if (error == 0) {
2644 		/*
2645 		 * "ttycommon_ioctl" did most of the work; we just use the
2646 		 * data it set up.
2647 		 */
2648 		switch (iocp->ioc_cmd) {
2649 
2650 		case TCSETS:
2651 			if (!(asy->asy_rsc_console || asy->asy_rsc_control ||
2652 			    asy->asy_lom_console)) {
2653 				mutex_enter(asy->asy_excl_hi);
2654 				error = asy_program(asy, ASY_NOINIT);
2655 				mutex_exit(asy->asy_excl_hi);
2656 			}
2657 			break;
2658 		case TCSETSF:
2659 		case TCSETSW:
2660 		case TCSETA:
2661 		case TCSETAW:
2662 		case TCSETAF:
2663 			if (!(asy->asy_rsc_console || asy->asy_rsc_control ||
2664 			    asy->asy_lom_console)) {
2665 				mutex_enter(asy->asy_excl_hi);
2666 				if (iswput && asy_isbusy(asy)) {
2667 					if (putq(wq, mp) == 0)
2668 						freemsg(mp);
2669 					mutex_exit(asy->asy_excl_hi);
2670 					mutex_exit(asy->asy_excl);
2671 					return;
2672 				}
2673 				error = asy_program(asy, ASY_NOINIT);
2674 				mutex_exit(asy->asy_excl_hi);
2675 			}
2676 			break;
2677 		case TIOCSSOFTCAR:
2678 			/* Set the driver state appropriately */
2679 			mutex_enter(asy->asy_excl_hi);
2680 			if (tp->t_flags & TS_SOFTCAR)
2681 				asy->asy_flags |= ASY_IGNORE_CD;
2682 			else
2683 				asy->asy_flags &= ~ASY_IGNORE_CD;
2684 			mutex_exit(asy->asy_excl_hi);
2685 			break;
2686 		}
2687 	} else if (error < 0) {
2688 		/*
2689 		 * "ttycommon_ioctl" didn't do anything; we process it here.
2690 		 */
2691 		error = 0;
2692 		switch (iocp->ioc_cmd) {
2693 
2694 		case TIOCGPPS:
2695 			/*
2696 			 * Get PPS on/off.
2697 			 */
2698 			if (mp->b_cont != NULL)
2699 				freemsg(mp->b_cont);
2700 
2701 			mp->b_cont = allocb(sizeof (int), BPRI_HI);
2702 			if (mp->b_cont == NULL) {
2703 				error = ENOMEM;
2704 				break;
2705 			}
2706 			if (asy->asy_flags & ASY_PPS)
2707 				*(int *)mp->b_cont->b_wptr = 1;
2708 			else
2709 				*(int *)mp->b_cont->b_wptr = 0;
2710 			mp->b_cont->b_wptr += sizeof (int);
2711 			mp->b_datap->db_type = M_IOCACK;
2712 			iocp->ioc_count = sizeof (int);
2713 			break;
2714 
2715 		case TIOCSPPS:
2716 			/*
2717 			 * Set PPS on/off.
2718 			 */
2719 			error = miocpullup(mp, sizeof (int));
2720 			if (error != 0)
2721 				break;
2722 
2723 			mutex_enter(asy->asy_excl_hi);
2724 			if (*(int *)mp->b_cont->b_rptr)
2725 				asy->asy_flags |= ASY_PPS;
2726 			else
2727 				asy->asy_flags &= ~ASY_PPS;
2728 			/* Reset edge sense */
2729 			asy->asy_flags &= ~ASY_PPS_EDGE;
2730 			mutex_exit(asy->asy_excl_hi);
2731 			mp->b_datap->db_type = M_IOCACK;
2732 			break;
2733 
2734 		case TIOCGPPSEV: {
2735 			/*
2736 			 * Get PPS event data.
2737 			 */
2738 			mblk_t *bp;
2739 			void *buf;
2740 #ifdef _SYSCALL32_IMPL
2741 			struct ppsclockev32 p32;
2742 #endif
2743 			struct ppsclockev ppsclockev;
2744 
2745 			if (mp->b_cont != NULL) {
2746 				freemsg(mp->b_cont);
2747 				mp->b_cont = NULL;
2748 			}
2749 
2750 			if ((asy->asy_flags & ASY_PPS) == 0) {
2751 				error = ENXIO;
2752 				break;
2753 			}
2754 
2755 			/* Protect from incomplete asy_ppsev */
2756 			mutex_enter(asy->asy_excl_hi);
2757 			ppsclockev = asy_ppsev;
2758 			mutex_exit(asy->asy_excl_hi);
2759 
2760 #ifdef _SYSCALL32_IMPL
2761 			if ((iocp->ioc_flag & IOC_MODELS) != IOC_NATIVE) {
2762 				TIMEVAL_TO_TIMEVAL32(&p32.tv, &ppsclockev.tv);
2763 				p32.serial = ppsclockev.serial;
2764 				buf = &p32;
2765 				iocp->ioc_count = sizeof (struct ppsclockev32);
2766 			} else
2767 #endif
2768 			{
2769 				buf = &ppsclockev;
2770 				iocp->ioc_count = sizeof (struct ppsclockev);
2771 			}
2772 
2773 			if ((bp = allocb(iocp->ioc_count, BPRI_HI)) == NULL) {
2774 				error = ENOMEM;
2775 				break;
2776 			}
2777 			mp->b_cont = bp;
2778 
2779 			bcopy(buf, bp->b_wptr, iocp->ioc_count);
2780 			bp->b_wptr += iocp->ioc_count;
2781 			mp->b_datap->db_type = M_IOCACK;
2782 			break;
2783 		}
2784 
2785 		case TCSBRK:
2786 			error = miocpullup(mp, sizeof (int));
2787 			if (error != 0)
2788 				break;
2789 
2790 			mutex_enter(asy->asy_excl_hi);
2791 			if (*(int *)mp->b_cont->b_rptr == 0) {
2792 				/*
2793 				 * Get the divisor by calculating the rate
2794 				 */
2795 				unsigned int rate, divisor;
2796 				rate = async->async_ttycommon.t_cflag & CBAUD;
2797 				if (async->async_ttycommon.t_cflag & CBAUDEXT)
2798 					rate += 16;
2799 				if (rate >= N_SU_SPEEDS) rate = B9600;
2800 				divisor = asyspdtab[rate] & 0xfff;
2801 
2802 				/*
2803 				 * To ensure that erroneous characters are
2804 				 * not sent out when the break is set, SB
2805 				 * recommends three steps:
2806 				 *
2807 				 * 1) pad the TSR with 0 bits
2808 				 * 2) When the TSR is full, set break
2809 				 * 3) When the TSR has been flushed, unset
2810 				 *    the break when transmission must be
2811 				 *    restored.
2812 				 *
2813 				 * We loop until the TSR is empty and then
2814 				 * set the break.  ASYNC_BREAK has been set
2815 				 * to ensure that no characters are
2816 				 * transmitted while the TSR is being
2817 				 * flushed and SOUT is being used for the
2818 				 * break signal.
2819 				 *
2820 				 * The wait period is equal to
2821 				 * clock / (baud * 16) * 16 * 2.
2822 				 */
2823 				async->async_flags |= ASYNC_BREAK;
2824 				while ((INB(LSR) & XSRE) == 0) {
2825 					mutex_exit(asy->asy_excl_hi);
2826 					mutex_exit(asy->asy_excl);
2827 					drv_usecwait(32*divisor);
2828 					mutex_enter(asy->asy_excl);
2829 					mutex_enter(asy->asy_excl_hi);
2830 				}
2831 
2832 				/*
2833 				 * Set the break bit, and arrange for
2834 				 * "async_restart" to be called in 1/4 second;
2835 				 * it will turn the break bit off, and call
2836 				 * "async_start" to grab the next message.
2837 				 */
2838 				val = INB(LCR);
2839 				OUTB(LCR, (val | SETBREAK));
2840 				mutex_exit(asy->asy_excl_hi);
2841 				(void) timeout(async_restart, async, hz / 4);
2842 			} else {
2843 #ifdef DEBUG
2844 				if (asydebug & ASY_DEBUG_CLOSE)
2845 					printf("asy%d: wait for flush.\n",
2846 					UNIT(async->async_dev));
2847 #endif
2848 				if (iswput && asy_isbusy(asy)) {
2849 					if (putq(wq, mp) == 0)
2850 						freemsg(mp);
2851 					mutex_exit(asy->asy_excl_hi);
2852 					mutex_exit(asy->asy_excl);
2853 					return;
2854 				}
2855 				mutex_exit(asy->asy_excl_hi);
2856 #ifdef DEBUG
2857 				if (asydebug & ASY_DEBUG_CLOSE)
2858 					printf("asy%d: ldterm satisfied.\n",
2859 					UNIT(async->async_dev));
2860 #endif
2861 			}
2862 			break;
2863 
2864 		case TIOCSBRK:
2865 			mutex_enter(asy->asy_excl_hi);
2866 			val = INB(LCR);
2867 			OUTB(LCR, (val | SETBREAK));
2868 			mutex_exit(asy->asy_excl_hi);
2869 			mutex_exit(asy->asy_excl);
2870 			miocack(wq, mp, 0, 0);
2871 			return;
2872 
2873 		case TIOCCBRK:
2874 			mutex_enter(asy->asy_excl_hi);
2875 			val = INB(LCR);
2876 			OUTB(LCR, (val & ~SETBREAK));
2877 			mutex_exit(asy->asy_excl_hi);
2878 			mutex_exit(asy->asy_excl);
2879 			miocack(wq, mp, 0, 0);
2880 			return;
2881 
2882 		case TIOCMSET:
2883 		case TIOCMBIS:
2884 		case TIOCMBIC:
2885 			if (iocp->ioc_count == TRANSPARENT)
2886 				mcopyin(mp, NULL, sizeof (int), NULL);
2887 			else {
2888 				error = miocpullup(mp, sizeof (int));
2889 				if (error != 0)
2890 					break;
2891 
2892 				mutex_enter(asy->asy_excl_hi);
2893 
2894 				(void) asymctl(asy,
2895 					dmtoasy(*(int *)mp->b_cont->b_rptr),
2896 					iocp->ioc_cmd);
2897 
2898 				mutex_exit(asy->asy_excl_hi);
2899 				iocp->ioc_error = 0;
2900 				mp->b_datap->db_type = M_IOCACK;
2901 			}
2902 			break;
2903 
2904 		case TIOCSILOOP:
2905 			mutex_enter(asy->asy_excl_hi);
2906 			/*
2907 			 * If somebody misues this Ioctl when used for
2908 			 * driving keyboard and mouse indicate not supported
2909 			 */
2910 			if ((asy->asy_device_type == ASY_KEYBOARD) ||
2911 				(asy->asy_device_type == ASY_MOUSE)) {
2912 				mutex_exit(asy->asy_excl_hi);
2913 				error = ENOTTY;
2914 				break;
2915 			}
2916 
2917 			/* should not use when we're the console */
2918 			if ((async->async_dev == kbddev) ||
2919 			    (async->async_dev == rconsdev) ||
2920 			    (async->async_dev == stdindev)) {
2921 				mutex_exit(asy->asy_excl_hi);
2922 				error = EINVAL;
2923 				break;
2924 			}
2925 
2926 			val = INB(MCR);
2927 			icr = INB(ICR);
2928 			/*
2929 			 * Disable the Modem Status Interrupt
2930 			 * The reason for disabling is  the status of
2931 			 * modem signal are in the higher 4 bits instead of
2932 			 * lower four bits when in loopback mode,
2933 			 * so, donot worry about Modem interrupt when
2934 			 * you are planning to set
2935 			 * this in loopback mode until it is cleared by
2936 			 * another ioctl to get out of the loopback mode
2937 			 */
2938 			OUTB(ICR, icr & ~ MIEN);
2939 			OUTB(MCR, val | ASY_LOOP);
2940 			mutex_exit(asy->asy_excl_hi);
2941 			iocp->ioc_error = 0;
2942 			mp->b_datap->db_type = M_IOCACK;
2943 			break;
2944 
2945 		case TIOCMGET:
2946 			datamp = allocb(sizeof (int), BPRI_MED);
2947 			if (datamp == NULL) {
2948 				error = EAGAIN;
2949 				break;
2950 			}
2951 
2952 			mutex_enter(asy->asy_excl_hi);
2953 			*(int *)datamp->b_rptr = asymctl(asy, 0, TIOCMGET);
2954 			mutex_exit(asy->asy_excl_hi);
2955 
2956 			if (iocp->ioc_count == TRANSPARENT) {
2957 				mcopyout(mp, NULL, sizeof (int), NULL, datamp);
2958 			} else {
2959 				if (mp->b_cont != NULL)
2960 					freemsg(mp->b_cont);
2961 				mp->b_cont = datamp;
2962 				mp->b_cont->b_wptr += sizeof (int);
2963 				mp->b_datap->db_type = M_IOCACK;
2964 				iocp->ioc_count = sizeof (int);
2965 			}
2966 			break;
2967 
2968 		default: /* unexpected ioctl type */
2969 			/*
2970 			 * If we don't understand it, it's an error.  NAK it.
2971 			 */
2972 			error = EINVAL;
2973 			break;
2974 		}
2975 	}
2976 	if (error != 0) {
2977 		iocp->ioc_error = error;
2978 		mp->b_datap->db_type = M_IOCNAK;
2979 	}
2980 	mutex_exit(asy->asy_excl);
2981 	qreply(wq, mp);
2982 }
2983 
2984 static void
2985 asyrsrv(queue_t *q)
2986 {
2987 	mblk_t *bp;
2988 	struct asyncline *async;
2989 
2990 	async = (struct asyncline *)q->q_ptr;
2991 
2992 	while (canputnext(q) && (bp = getq(q)))
2993 		putnext(q, bp);
2994 	ASYSETSOFT(async->async_common);
2995 	async->async_polltid = 0;
2996 }
2997 
2998 /*
2999  * Put procedure for write queue.
3000  * Respond to M_STOP, M_START, M_IOCTL, and M_FLUSH messages here;
3001  * set the flow control character for M_STOPI and M_STARTI messages;
3002  * queue up M_BREAK, M_DELAY, and M_DATA messages for processing
3003  * by the start routine, and then call the start routine; discard
3004  * everything else.  Note that this driver does not incorporate any
3005  * mechanism to negotiate to handle the canonicalization process.
3006  * It expects that these functions are handled in upper module(s),
3007  * as we do in ldterm.
3008  */
3009 static void
3010 asywput(queue_t *q, mblk_t *mp)
3011 {
3012 	register struct asyncline *async;
3013 	register struct asycom *asy;
3014 	int error;
3015 
3016 	async = (struct asyncline *)q->q_ptr;
3017 	asy = async->async_common;
3018 
3019 	switch (mp->b_datap->db_type) {
3020 
3021 	case M_STOP:
3022 		/*
3023 		 * Since we don't do real DMA, we can just let the
3024 		 * chip coast to a stop after applying the brakes.
3025 		 */
3026 		mutex_enter(asy->asy_excl);
3027 		async->async_flags |= ASYNC_STOPPED;
3028 		mutex_exit(asy->asy_excl);
3029 		freemsg(mp);
3030 		break;
3031 
3032 	case M_START:
3033 		mutex_enter(asy->asy_excl);
3034 		if (async->async_flags & ASYNC_STOPPED) {
3035 			async->async_flags &= ~ASYNC_STOPPED;
3036 			/*
3037 			 * If an output operation is in progress,
3038 			 * resume it.  Otherwise, prod the start
3039 			 * routine.
3040 			 */
3041 			if (async->async_ocnt > 0) {
3042 				mutex_enter(asy->asy_excl_hi);
3043 				async_resume(async);
3044 				mutex_exit(asy->asy_excl_hi);
3045 			} else {
3046 				async_start(async);
3047 			}
3048 		}
3049 		mutex_exit(asy->asy_excl);
3050 		freemsg(mp);
3051 		break;
3052 
3053 	case M_IOCTL:
3054 		switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
3055 
3056 		case TCSBRK:
3057 			error = miocpullup(mp, sizeof (int));
3058 			if (error != 0) {
3059 				miocnak(q, mp, 0, error);
3060 				return;
3061 			}
3062 
3063 			if (*(int *)mp->b_cont->b_rptr != 0) {
3064 #ifdef DEBUG
3065 				if (asydebug & ASY_DEBUG_CLOSE)
3066 					printf("asy%d: flush request.\n",
3067 					    UNIT(async->async_dev));
3068 #endif
3069 				(void) putq(q, mp);
3070 				mutex_enter(asy->asy_excl);
3071 				async_nstart(async, 1);
3072 				mutex_exit(asy->asy_excl);
3073 				break;
3074 			}
3075 			/*FALLTHROUGH*/
3076 		case TCSETSW:
3077 		case TCSETSF:
3078 		case TCSETAW:
3079 		case TCSETAF:
3080 			/*
3081 			 * The changes do not take effect until all
3082 			 * output queued before them is drained.
3083 			 * Put this message on the queue, so that
3084 			 * "async_start" will see it when it's done
3085 			 * with the output before it.  Poke the
3086 			 * start routine, just in case.
3087 			 */
3088 			(void) putq(q, mp);
3089 			mutex_enter(asy->asy_excl);
3090 			async_start(async);
3091 			mutex_exit(asy->asy_excl);
3092 			break;
3093 
3094 		default:
3095 			/*
3096 			 * Do it now.
3097 			 */
3098 			async_ioctl(async, q, mp, B_TRUE);
3099 			break;
3100 		}
3101 		break;
3102 
3103 	case M_FLUSH:
3104 		if (*mp->b_rptr & FLUSHW) {
3105 			mutex_enter(asy->asy_excl);
3106 
3107 			/*
3108 			 * Abort any output in progress.
3109 			 */
3110 			mutex_enter(asy->asy_excl_hi);
3111 			if (async->async_flags & ASYNC_BUSY) {
3112 				async->async_ocnt = 0;
3113 				async->async_flags &= ~ASYNC_BUSY;
3114 			}
3115 			mutex_exit(asy->asy_excl_hi);
3116 
3117 			/* Flush FIFO buffers */
3118 			if (asy->asy_use_fifo == FIFO_ON) {
3119 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFOTXFLSH |
3120 				    (asy->asy_trig_level & 0xff));
3121 			}
3122 
3123 			/*
3124 			 * Flush our write queue.
3125 			 */
3126 			flushq(q, FLUSHDATA);	/* XXX doesn't flush M_DELAY */
3127 			if (async->async_xmitblk != NULL) {
3128 				freeb(async->async_xmitblk);
3129 				async->async_xmitblk = NULL;
3130 			}
3131 
3132 			mutex_exit(asy->asy_excl);
3133 			*mp->b_rptr &= ~FLUSHW;	/* it has been flushed */
3134 		}
3135 		if (*mp->b_rptr & FLUSHR) {
3136 			/* Flush FIFO buffers */
3137 			if (asy->asy_use_fifo == FIFO_ON) {
3138 				OUTB(FIFOR, FIFO_ON | FIFODMA | FIFORXFLSH |
3139 				    (asy->asy_trig_level & 0xff));
3140 			}
3141 			flushq(RD(q), FLUSHDATA);
3142 			qreply(q, mp);	/* give the read queues a crack at it */
3143 		} else {
3144 			freemsg(mp);
3145 		}
3146 
3147 		/*
3148 		 * We must make sure we process messages that survive the
3149 		 * write-side flush.  Without this call, the close protocol
3150 		 * with ldterm can hang forever.  (ldterm will have sent us a
3151 		 * TCSBRK ioctl that it expects a response to.)
3152 		 */
3153 		mutex_enter(asy->asy_excl);
3154 		async_start(async);
3155 		mutex_exit(asy->asy_excl);
3156 		break;
3157 	case M_BREAK:
3158 	case M_DELAY:
3159 	case M_DATA:
3160 		/*
3161 		 * Queue the message up to be transmitted,
3162 		 * and poke the start routine.
3163 		 */
3164 		(void) putq(q, mp);
3165 		mutex_enter(asy->asy_excl);
3166 		async_start(async);
3167 		mutex_exit(asy->asy_excl);
3168 		break;
3169 
3170 	case M_STOPI:
3171 		mutex_enter(asy->asy_excl);
3172 		async->async_flowc = async->async_stopc;
3173 		async_start(async);		/* poke the start routine */
3174 		mutex_exit(asy->asy_excl);
3175 		freemsg(mp);
3176 		break;
3177 
3178 	case M_STARTI:
3179 		mutex_enter(asy->asy_excl);
3180 		async->async_flowc = async->async_startc;
3181 		async_start(async);		/* poke the start routine */
3182 		mutex_exit(asy->asy_excl);
3183 		freemsg(mp);
3184 		break;
3185 
3186 	case M_CTL:
3187 		if (MBLKL(mp) >= sizeof (struct iocblk) &&
3188 		    ((struct iocblk *)mp->b_rptr)->ioc_cmd == MC_POSIXQUERY) {
3189 			((struct iocblk *)mp->b_rptr)->ioc_cmd = MC_HAS_POSIX;
3190 			qreply(q, mp);
3191 		} else {
3192 			/*
3193 			 * These MC_SERVICE type messages are used by upper
3194 			 * modules to tell this driver to send input up
3195 			 * immediately, or that it can wait for normal
3196 			 * processing that may or may not be done.  Sun
3197 			 * requires these for the mouse module.
3198 			 * (XXX - for x86?)
3199 			 */
3200 			mutex_enter(asy->asy_excl);
3201 			switch (*mp->b_rptr) {
3202 
3203 			case MC_SERVICEIMM:
3204 				async->async_flags |= ASYNC_SERVICEIMM;
3205 				break;
3206 
3207 			case MC_SERVICEDEF:
3208 				async->async_flags &= ~ASYNC_SERVICEIMM;
3209 				break;
3210 			}
3211 			mutex_exit(asy->asy_excl);
3212 			freemsg(mp);
3213 		}
3214 		break;
3215 
3216 	case M_IOCDATA:
3217 		async_iocdata(q, mp);
3218 		break;
3219 
3220 	default:
3221 		freemsg(mp);
3222 		break;
3223 	}
3224 }
3225 
3226 /*
3227  * Retry an "ioctl", now that "bufcall" claims we may be able to allocate
3228  * the buffer we need.
3229  */
3230 static void
3231 async_reioctl(void *arg)
3232 {
3233 	struct asyncline *async = arg;
3234 	struct asycom *asy = async->async_common;
3235 	queue_t	*q;
3236 	mblk_t		*mp;
3237 
3238 	/*
3239 	 * The bufcall is no longer pending.
3240 	 */
3241 	mutex_enter(asy->asy_excl);
3242 	async->async_wbufcid = 0;
3243 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
3244 		mutex_exit(asy->asy_excl);
3245 		return;
3246 	}
3247 	if ((mp = async->async_ttycommon.t_iocpending) != NULL) {
3248 		/* not pending any more */
3249 		async->async_ttycommon.t_iocpending = NULL;
3250 		mutex_exit(asy->asy_excl);
3251 		/* not in STREAMS queue; we no longer know if we're in wput */
3252 		async_ioctl(async, q, mp, B_TRUE);
3253 	} else
3254 		mutex_exit(asy->asy_excl);
3255 }
3256 
3257 static void
3258 async_iocdata(queue_t *q, mblk_t *mp)
3259 {
3260 	struct asyncline	*async = (struct asyncline *)q->q_ptr;
3261 	struct asycom		*asy;
3262 	struct copyresp *csp;
3263 
3264 	asy = async->async_common;
3265 	csp = (struct copyresp *)mp->b_rptr;
3266 
3267 	if (csp->cp_rval != 0) {
3268 		freemsg(mp);
3269 		return;
3270 	}
3271 
3272 	mutex_enter(asy->asy_excl);
3273 
3274 	switch (csp->cp_cmd) {
3275 	case TIOCMSET:
3276 	case TIOCMBIS:
3277 	case TIOCMBIC:
3278 		if (mp->b_cont == NULL) {
3279 			mutex_exit(asy->asy_excl);
3280 			miocnak(q, mp, 0, EINVAL);
3281 			break;
3282 		}
3283 
3284 		mutex_enter(asy->asy_excl_hi);
3285 		(void) asymctl(asy, dmtoasy(*(int *)mp->b_cont->b_rptr),
3286 			csp->cp_cmd);
3287 		mutex_exit(asy->asy_excl_hi);
3288 
3289 		freemsg(mp->b_cont);
3290 		mp->b_cont = NULL;
3291 		mutex_exit(asy->asy_excl);
3292 		miocack(q, mp, 0, 0);
3293 		break;
3294 
3295 	case TIOCMGET:
3296 		if (mp->b_cont != NULL) {
3297 			freemsg(mp->b_cont);
3298 			mp->b_cont = NULL;
3299 		}
3300 		mutex_exit(asy->asy_excl);
3301 		miocack(q, mp, 0, 0);
3302 		break;
3303 
3304 	default:
3305 		mutex_exit(asy->asy_excl);
3306 		miocnak(q, mp, 0, EINVAL);
3307 		break;
3308 	}
3309 }
3310 
3311 
3312 /*
3313  * Set or get the modem control status.
3314  */
3315 static int
3316 asymctl(struct asycom *asy, int bits, int how)
3317 {
3318 	register int mcr_r, msr_r;
3319 
3320 	ASSERT(mutex_owned(asy->asy_excl_hi));
3321 	ASSERT(mutex_owned(asy->asy_excl));
3322 
3323 	/* Read Modem Control Registers */
3324 	mcr_r = INB(MCR);
3325 
3326 	switch (how) {
3327 
3328 	case TIOCMSET:
3329 		mcr_r = bits;
3330 		break;
3331 
3332 	case TIOCMBIS:
3333 		mcr_r |= bits;			/* Set bits from input	*/
3334 		break;
3335 
3336 	case TIOCMBIC:
3337 		mcr_r &= ~bits;			/* Set ~bits from input	*/
3338 		break;
3339 
3340 	case TIOCMGET:
3341 		/* Read Modem Status Registers */
3342 		if (INB(ICR) & MIEN)
3343 			msr_r = asy->asy_cached_msr;
3344 		else
3345 			msr_r = INB(MSR);
3346 		return (asytodm(mcr_r, msr_r));
3347 	}
3348 
3349 	OUTB(MCR, mcr_r);
3350 
3351 	return (mcr_r);
3352 }
3353 
3354 static int
3355 asytodm(int mcr_r, int msr_r)
3356 {
3357 	register int b = 0;
3358 
3359 
3360 	/* MCR registers */
3361 	if (mcr_r & RTS)
3362 		b |= TIOCM_RTS;
3363 
3364 	if (mcr_r & DTR)
3365 		b |= TIOCM_DTR;
3366 
3367 	/* MSR registers */
3368 	if (msr_r & DCD)
3369 		b |= TIOCM_CAR;
3370 
3371 	if (msr_r & CTS)
3372 		b |= TIOCM_CTS;
3373 
3374 	if (msr_r & DSR)
3375 		b |= TIOCM_DSR;
3376 
3377 	if (msr_r & RI)
3378 		b |= TIOCM_RNG;
3379 
3380 	return (b);
3381 }
3382 
3383 static int
3384 dmtoasy(int bits)
3385 {
3386 	register int b = 0;
3387 
3388 #ifdef	CAN_NOT_SET	/* only DTR and RTS can be set */
3389 	if (bits & TIOCM_CAR)
3390 		b |= DCD;
3391 	if (bits & TIOCM_CTS)
3392 		b |= CTS;
3393 	if (bits & TIOCM_DSR)
3394 		b |= DSR;
3395 	if (bits & TIOCM_RNG)
3396 		b |= RI;
3397 #endif
3398 
3399 	if (bits & TIOCM_RTS)
3400 		b |= RTS;
3401 	if (bits & TIOCM_DTR)
3402 		b |= DTR;
3403 
3404 	return (b);
3405 }
3406 
3407 static void
3408 asycheckflowcontrol_hw(struct asycom *asy)
3409 {
3410 	struct asyncline *async;
3411 	uchar_t	mcr, flag;
3412 
3413 	ASSERT(mutex_owned(asy->asy_excl_hi));
3414 
3415 	async = (struct asyncline *)asy->asy_priv;
3416 	ASSERT(async != NULL);
3417 
3418 	if (async->async_ttycommon.t_cflag & CRTSXOFF) {
3419 		mcr = INB(MCR);
3420 		flag = (async->async_flags & ASYNC_HW_IN_FLOW) ? 0 : RTS;
3421 		if (((mcr ^ flag) & RTS) != 0) {
3422 			OUTB(MCR, (mcr ^ RTS));
3423 		}
3424 	}
3425 }
3426 
3427 static boolean_t
3428 asycheckflowcontrol_sw(struct asycom *asy)
3429 {
3430 	uchar_t		ss;
3431 	struct asyncline *async;
3432 	int rval = B_FALSE;
3433 
3434 	ASSERT(mutex_owned(asy->asy_excl_hi));
3435 
3436 	async = (struct asyncline *)asy->asy_priv;
3437 	ASSERT(async != NULL);
3438 
3439 	if ((ss = async->async_flowc) != '\0' && (INB(LSR) & XHRE)) {
3440 		/*
3441 		 * If we get this far, then we know that flowc is non-zero and
3442 		 * that there's transmit room available.  We've "handled" the
3443 		 * request now, so clear it.  If the user didn't ask for IXOFF,
3444 		 * then don't actually send anything, but wait for the next
3445 		 * opportunity.
3446 		 */
3447 		async->async_flowc = '\0';
3448 		if (async->async_ttycommon.t_iflag & IXOFF) {
3449 			async->async_flags |= ASYNC_BUSY;
3450 			OUTB(DAT, ss);
3451 			rval = B_TRUE;
3452 		}
3453 	}
3454 
3455 	return (rval);
3456 }
3457 
3458 /*
3459  * Check for abort character sequence
3460  */
3461 static boolean_t
3462 abort_charseq_recognize(uchar_t ch)
3463 {
3464 	static int state = 0;
3465 #define	CNTRL(c) ((c)&037)
3466 	static char sequence[] = { '\r', '~', CNTRL('b') };
3467 
3468 	if (ch == sequence[state]) {
3469 		if (++state >= sizeof (sequence)) {
3470 			state = 0;
3471 			return (B_TRUE);
3472 		}
3473 	} else {
3474 		state = (ch == sequence[0]) ? 1 : 0;
3475 	}
3476 	return (B_FALSE);
3477 }
3478