xref: /dflybsd-src/sys/dev/serial/sio/sio.c (revision 1365b5f1af0c1cc3894d279008de5831984b2990)
1 /*-
2  * Copyright (c) 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD: src/sys/isa/sio.c,v 1.291.2.35 2003/05/18 08:51:15 murray Exp $
34  * $DragonFly: src/sys/dev/serial/sio/sio.c,v 1.44 2008/07/23 16:39:33 dillon Exp $
35  *	from: @(#)com.c	7.5 (Berkeley) 5/16/91
36  *	from: i386/isa sio.c,v 1.234
37  */
38 
39 #include "opt_comconsole.h"
40 #include "opt_compat.h"
41 #include "opt_ddb.h"
42 #include "opt_sio.h"
43 #include "use_pci.h"
44 #ifdef __i386__
45 #include "use_puc.h"
46 #endif
47 #include "use_sio.h"
48 
49 /*
50  * Serial driver, based on 386BSD-0.1 com driver.
51  * Mostly rewritten to use pseudo-DMA.
52  * Works for National Semiconductor NS8250-NS16550AF UARTs.
53  * COM driver, based on HP dca driver.
54  *
55  * Changes for PC-Card integration:
56  *	- Added PC-Card driver table and handlers
57  */
58 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <sys/reboot.h>
61 #include <sys/malloc.h>
62 #include <sys/tty.h>
63 #include <sys/proc.h>
64 #include <sys/priv.h>
65 #include <sys/module.h>
66 #include <sys/conf.h>
67 #include <sys/dkstat.h>
68 #include <sys/fcntl.h>
69 #include <sys/interrupt.h>
70 #include <sys/kernel.h>
71 #include <sys/syslog.h>
72 #include <sys/sysctl.h>
73 #include <sys/bus.h>
74 #include <sys/rman.h>
75 #include <sys/timepps.h>
76 #include <sys/thread2.h>
77 #include <sys/devfs.h>
78 
79 #include <machine/limits.h>
80 
81 #include <bus/isa/isareg.h>
82 #include <bus/isa/isavar.h>
83 #if NPCI > 0
84 #include <bus/pci/pcireg.h>
85 #include <bus/pci/pcivar.h>
86 #endif
87 #if NPUC > 0
88 #include <dev/misc/puc/pucvar.h>
89 #endif
90 #include <machine/lock.h>
91 
92 #include <machine/clock.h>
93 #ifndef SMP
94 #include <machine/lock.h>
95 #endif
96 
97 #include "sioreg.h"
98 #include "sio_private.h"
99 
100 #ifdef COM_ESP
101 #include "../ic_layer/esp.h"
102 #endif
103 
104 #define	LOTS_OF_EVENTS	64	/* helps separate urgent events from input */
105 
106 #define	CALLOUT_MASK		0x80
107 #define	CONTROL_MASK		0x60
108 #define	CONTROL_INIT_STATE	0x20
109 #define	CONTROL_LOCK_STATE	0x40
110 #define	DEV_TO_UNIT(dev)	(MINOR_TO_UNIT(minor(dev)))
111 #define	MINOR_TO_UNIT(mynor)	((((mynor) & ~0xffffU) >> (8 + 3)) \
112 				 | ((mynor) & 0x1f))
113 #define	UNIT_TO_MINOR(unit)	((((unit) & ~0x1fU) << (8 + 3)) \
114 				 | ((unit) & 0x1f))
115 
116 #define	com_scr		7	/* scratch register for 16450-16550 (R/W) */
117 
118 #define	sio_getreg(com, off) \
119 	(bus_space_read_1((com)->bst, (com)->bsh, (off)))
120 #define	sio_setreg(com, off, value) \
121 	(bus_space_write_1((com)->bst, (com)->bsh, (off), (value)))
122 
123 /*
124  * com state bits.
125  * (CS_BUSY | CS_TTGO) and (CS_BUSY | CS_TTGO | CS_ODEVREADY) must be higher
126  * than the other bits so that they can be tested as a group without masking
127  * off the low bits.
128  *
129  * The following com and tty flags correspond closely:
130  *	CS_BUSY		= TS_BUSY (maintained by comstart(), siopoll() and
131  *				   comstop())
132  *	CS_TTGO		= ~TS_TTSTOP (maintained by comparam() and comstart())
133  *	CS_CTS_OFLOW	= CCTS_OFLOW (maintained by comparam())
134  *	CS_RTS_IFLOW	= CRTS_IFLOW (maintained by comparam())
135  * TS_FLUSH is not used.
136  * XXX I think TIOCSETA doesn't clear TS_TTSTOP when it clears IXON.
137  * XXX CS_*FLOW should be CF_*FLOW in com->flags (control flags not state).
138  */
139 #define	CS_BUSY		0x80	/* output in progress */
140 #define	CS_TTGO		0x40	/* output not stopped by XOFF */
141 #define	CS_ODEVREADY	0x20	/* external device h/w ready (CTS) */
142 #define	CS_CHECKMSR	1	/* check of MSR scheduled */
143 #define	CS_CTS_OFLOW	2	/* use CTS output flow control */
144 #define	CS_DTR_OFF	0x10	/* DTR held off */
145 #define	CS_ODONE	4	/* output completed */
146 #define	CS_RTS_IFLOW	8	/* use RTS input flow control */
147 #define	CSE_BUSYCHECK	1	/* siobusycheck() scheduled */
148 
149 static	char const * const	error_desc[] = {
150 #define	CE_OVERRUN			0
151 	"silo overflow",
152 #define	CE_INTERRUPT_BUF_OVERFLOW	1
153 	"interrupt-level buffer overflow",
154 #define	CE_TTY_BUF_OVERFLOW		2
155 	"tty-level buffer overflow",
156 };
157 
158 #ifdef COM_ESP
159 static	int	espattach	(struct com_s *com, Port_t esp_port);
160 #endif
161 static	int	sio_isa_attach	(device_t dev);
162 
163 static	timeout_t siobusycheck;
164 static	u_int	siodivisor	(u_long rclk, speed_t speed);
165 static	timeout_t siodtrwakeup;
166 static	void	comhardclose	(struct com_s *com);
167 static	void	sioinput	(struct com_s *com);
168 static	void	siointr1	(struct com_s *com);
169 static	void	siointr		(void *arg);
170 static	int	commctl		(struct com_s *com, int bits, int how);
171 static	int	comparam	(struct tty *tp, struct termios *t);
172 static	inthand2_t siopoll;
173 static	int	sio_isa_probe	(device_t dev);
174 static	void	siosettimeout	(void);
175 static	int	siosetwater	(struct com_s *com, speed_t speed);
176 static	void	comstart	(struct tty *tp);
177 static	void	comstop		(struct tty *tp, int rw);
178 static	timeout_t comwakeup;
179 static	void	disc_optim	(struct tty	*tp, struct termios *t,
180 				     struct com_s *com);
181 
182 #if NPCI > 0
183 static	int	sio_pci_attach (device_t dev);
184 static	void	sio_pci_kludge_unit (device_t dev);
185 static	int	sio_pci_probe (device_t dev);
186 #endif /* NPCI > 0 */
187 
188 #if NPUC > 0
189 static	int	sio_puc_attach (device_t dev);
190 static	int	sio_puc_probe (device_t dev);
191 #endif /* NPUC > 0 */
192 
193 static char driver_name[] = "sio";
194 
195 /* table and macro for fast conversion from a unit number to its com struct */
196 devclass_t	sio_devclass;
197 #define	com_addr(unit)	((struct com_s *) \
198 			 devclass_get_softc(sio_devclass, unit))
199 
200 static device_method_t sio_isa_methods[] = {
201 	/* Device interface */
202 	DEVMETHOD(device_probe,		sio_isa_probe),
203 	DEVMETHOD(device_attach,	sio_isa_attach),
204 
205 	{ 0, 0 }
206 };
207 
208 static driver_t sio_isa_driver = {
209 	driver_name,
210 	sio_isa_methods,
211 	sizeof(struct com_s),
212 };
213 
214 #if NPCI > 0
215 static device_method_t sio_pci_methods[] = {
216 	/* Device interface */
217 	DEVMETHOD(device_probe,		sio_pci_probe),
218 	DEVMETHOD(device_attach,	sio_pci_attach),
219 
220 	{ 0, 0 }
221 };
222 
223 static driver_t sio_pci_driver = {
224 	driver_name,
225 	sio_pci_methods,
226 	sizeof(struct com_s),
227 };
228 #endif /* NPCI > 0 */
229 
230 #if NPUC > 0
231 static device_method_t sio_puc_methods[] = {
232 	/* Device interface */
233 	DEVMETHOD(device_probe,		sio_puc_probe),
234 	DEVMETHOD(device_attach,	sio_puc_attach),
235 
236 	{ 0, 0 }
237 };
238 
239 static driver_t sio_puc_driver = {
240 	driver_name,
241 	sio_puc_methods,
242 	sizeof(struct com_s),
243 };
244 #endif /* NPUC > 0 */
245 
246 static	d_open_t	sioopen;
247 static	d_close_t	sioclose;
248 static	d_read_t	sioread;
249 static	d_write_t	siowrite;
250 static	d_ioctl_t	sioioctl;
251 
252 #define	CDEV_MAJOR	28
253 static struct dev_ops sio_ops = {
254 	{ driver_name, CDEV_MAJOR, D_TTY | D_KQFILTER },
255 	.d_open =	sioopen,
256 	.d_close =	sioclose,
257 	.d_read =	sioread,
258 	.d_write =	siowrite,
259 	.d_ioctl =	sioioctl,
260 	.d_kqfilter =	ttykqfilter,
261 	.d_revoke =	ttyrevoke
262 };
263 
264 int	comconsole = -1;
265 static	volatile speed_t	comdefaultrate = CONSPEED;
266 static	u_long			comdefaultrclk = DEFAULT_RCLK;
267 SYSCTL_ULONG(_machdep, OID_AUTO, conrclk, CTLFLAG_RW, &comdefaultrclk, 0, "");
268 static	u_int	com_events;	/* input chars + weighted output completions */
269 static	Port_t	siocniobase;
270 static	int	siocnunit;
271 static	Port_t	siogdbiobase;
272 static	int	siogdbunit = -1;
273 static	bool_t	sio_registered;
274 static	int	sio_timeout;
275 static	int	sio_timeouts_until_log;
276 static	struct	callout	sio_timeout_handle;
277 static	int	sio_numunits;
278 
279 #ifdef COM_ESP
280 /* XXX configure this properly. */
281 static	Port_t	likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, };
282 static	Port_t	likely_esp_ports[] = { 0x140, 0x180, 0x280, 0 };
283 #endif
284 
285 /*
286  * handle sysctl read/write requests for console speed
287  *
288  * In addition to setting comdefaultrate for I/O through /dev/console,
289  * also set the initial and lock values for the /dev/ttyXX device
290  * if there is one associated with the console.  Finally, if the /dev/tty
291  * device has already been open, change the speed on the open running port
292  * itself.
293  */
294 
295 static int
296 sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)
297 {
298 	int error;
299 	speed_t newspeed;
300 	struct com_s *com;
301 	struct tty *tp;
302 
303 	newspeed = comdefaultrate;
304 
305 	error = sysctl_handle_opaque(oidp, &newspeed, sizeof newspeed, req);
306 	if (error || !req->newptr)
307 		return (error);
308 
309 	comdefaultrate = newspeed;
310 
311 	if (comconsole < 0)		/* serial console not selected? */
312 		return (0);
313 
314 	com = com_addr(comconsole);
315 	if (com == NULL)
316 		return (ENXIO);
317 
318 	/*
319 	 * set the initial and lock rates for /dev/ttydXX and /dev/cuaXX
320 	 * (note, the lock rates really are boolean -- if non-zero, disallow
321 	 *  speed changes)
322 	 */
323 	com->it_in.c_ispeed  = com->it_in.c_ospeed =
324 	com->lt_in.c_ispeed  = com->lt_in.c_ospeed =
325 	com->it_out.c_ispeed = com->it_out.c_ospeed =
326 	com->lt_out.c_ispeed = com->lt_out.c_ospeed = comdefaultrate;
327 
328 	/*
329 	 * if we're open, change the running rate too
330 	 */
331 	tp = com->tp;
332 	if (tp && (tp->t_state & TS_ISOPEN)) {
333 		tp->t_termios.c_ispeed =
334 		tp->t_termios.c_ospeed = comdefaultrate;
335 		crit_enter();
336 		error = comparam(tp, &tp->t_termios);
337 		crit_exit();
338 	}
339 	return error;
340 }
341 
342 SYSCTL_PROC(_machdep, OID_AUTO, conspeed, CTLTYPE_INT | CTLFLAG_RW,
343 	    0, 0, sysctl_machdep_comdefaultrate, "I", "");
344 
345 #if NPCI > 0
346 struct pci_ids {
347 	u_int32_t	type;
348 	const char	*desc;
349 	int		rid;
350 };
351 
352 static struct pci_ids pci_ids[] = {
353 	{ 0x100812b9, "3COM PCI FaxModem", 0x10 },
354 	{ 0x2000131f, "CyberSerial (1-port) 16550", 0x10 },
355 	{ 0x01101407, "Koutech IOFLEX-2S PCI Dual Port Serial", 0x10 },
356 	{ 0x01111407, "Koutech IOFLEX-2S PCI Dual Port Serial", 0x10 },
357 	{ 0x048011c1, "Lucent kermit based PCI Modem", 0x14 },
358 	{ 0x95211415, "Oxford Semiconductor PCI Dual Port Serial", 0x10 },
359 	{ 0x7101135e, "SeaLevel Ultra 530.PCI Single Port Serial", 0x18 },
360 	{ 0x0000151f, "SmartLink 5634PCV SurfRider", 0x10 },
361 	{ 0x98459710, "Netmos Nm9845 PCI Bridge with Dual UART", 0x10 },
362 	{ 0x00000000, NULL, 0 }
363 };
364 
365 static int
366 sio_pci_attach(device_t dev)
367 {
368 	u_int32_t	type;
369 	struct pci_ids	*id;
370 
371 	type = pci_get_devid(dev);
372 	id = pci_ids;
373 	while (id->type && id->type != type)
374 		id++;
375 	if (id->desc == NULL)
376 		return (ENXIO);
377 	sio_pci_kludge_unit(dev);
378 	return (sioattach(dev, id->rid, 0UL));
379 }
380 
381 /*
382  * Don't cut and paste this to other drivers.  It is a horrible kludge
383  * which will fail to work and also be unnecessary in future versions.
384  */
385 static void
386 sio_pci_kludge_unit(device_t dev)
387 {
388 	devclass_t	dc;
389 	int		err;
390 	int		start;
391 	int		unit;
392 
393 	unit = 0;
394 	start = 0;
395 	while (resource_int_value("sio", unit, "port", &start) == 0 &&
396 	    start > 0)
397 		unit++;
398 	if (device_get_unit(dev) < unit) {
399 		dc = device_get_devclass(dev);
400 		while (devclass_get_device(dc, unit))
401 			unit++;
402 		device_printf(dev, "moving to sio%d\n", unit);
403 		err = device_set_unit(dev, unit);	/* EVIL DO NOT COPY */
404 		if (err)
405 			device_printf(dev, "error moving device %d\n", err);
406 	}
407 }
408 
409 static int
410 sio_pci_probe(device_t dev)
411 {
412 	u_int32_t	type;
413 	struct pci_ids	*id;
414 
415 	type = pci_get_devid(dev);
416 	id = pci_ids;
417 	while (id->type && id->type != type)
418 		id++;
419 	if (id->desc == NULL)
420 		return (ENXIO);
421 	device_set_desc(dev, id->desc);
422 	return (sioprobe(dev, id->rid, 0UL));
423 }
424 #endif /* NPCI > 0 */
425 
426 #if NPUC > 0
427 static int
428 sio_puc_attach(device_t dev)
429 {
430 	u_int rclk;
431 
432 	if (BUS_READ_IVAR(device_get_parent(dev), dev, PUC_IVAR_FREQ,
433 	    &rclk) != 0)
434 		rclk = DEFAULT_RCLK;
435 	return (sioattach(dev, 0, rclk));
436 }
437 
438 static int
439 sio_puc_probe(device_t dev)
440 {
441 	u_int rclk;
442 
443 	if (BUS_READ_IVAR(device_get_parent(dev), dev, PUC_IVAR_FREQ,
444 	    &rclk) != 0)
445 		rclk = DEFAULT_RCLK;
446 	return (sioprobe(dev, 0, rclk));
447 }
448 #endif /* NPUC */
449 
450 static struct isa_pnp_id sio_ids[] = {
451 	{0x0005d041, "Standard PC COM port"},	/* PNP0500 */
452 	{0x0105d041, "16550A-compatible COM port"},	/* PNP0501 */
453 	{0x0205d041, "Multiport serial device (non-intelligent 16550)"}, /* PNP0502 */
454 	{0x1005d041, "Generic IRDA-compatible device"},	/* PNP0510 */
455 	{0x1105d041, "Generic IRDA-compatible device"},	/* PNP0511 */
456 	/* Devices that do not have a compatid */
457 	{0x12206804, NULL},     /* ACH2012 - 5634BTS 56K Video Ready Modem */
458 	{0x7602a904, NULL},	/* AEI0276 - 56K v.90 Fax Modem (LKT) */
459 	{0x00007905, NULL},	/* AKY0000 - 56K Plug&Play Modem */
460 	{0x21107905, NULL},	/* AKY1021 - 56K Plug&Play Modem */
461 	{0x01405407, NULL},	/* AZT4001 - AZT3000 PnP SOUND DEVICE, MODEM */
462 	{0x56039008, NULL},	/* BDP0356 - Best Data 56x2 */
463 	{0x56159008, NULL},	/* BDP1556 - B.D. Smart One 56SPS,Voice Modem*/
464 	{0x36339008, NULL},	/* BDP3336 - Best Data Prods. 336F */
465 	{0x0014490a, NULL},	/* BRI1400 - Boca 33.6 PnP */
466 	{0x0015490a, NULL},	/* BRI1500 - Internal Fax Data */
467 	{0x0034490a, NULL},	/* BRI3400 - Internal ACF Modem */
468 	{0x0094490a, NULL},	/* BRI9400 - Boca K56Flex PnP */
469 	{0x00b4490a, NULL},	/* BRIB400 - Boca 56k PnP */
470 	{0x0030320d, NULL},	/* CIR3000 - Cirrus Logic V43 */
471 	{0x0100440e, NULL},	/* CRD0001 - Cardinal MVP288IV ? */
472 	{0x01308c0e, NULL},	/* CTL3001 - Creative Labs Phoneblaster */
473 	{0x36033610, NULL},     /* DAV0336 - DAVICOM 336PNP MODEM */
474 	{0x01009416, NULL},     /* ETT0001 - E-Tech Bullet 33k6 PnP */
475 	{0x0000aa1a, NULL},	/* FUJ0000 - FUJITSU Modem 33600 PNP/I2 */
476 	{0x1200c31e, NULL},	/* GVC0012 - VF1128HV-R9 (win modem?) */
477 	{0x0303c31e, NULL},	/* GVC0303 - MaxTech 33.6 PnP D/F/V */
478 	{0x0505c31e, NULL},	/* GVC0505 - GVC 56k Faxmodem */
479 	{0x0116c31e, NULL},	/* GVC1601 - Rockwell V.34 Plug & Play Modem */
480 	{0x0050c31e, NULL},	/* GVC5000 - some GVC modem */
481 	{0x3800f91e, NULL},	/* GWY0038 - Telepath with v.90 */
482 	{0x9062f91e, NULL},	/* GWY6290 - Telepath with x2 Technology */
483 	{0x8100e425, NULL},	/* IOD0081 - I-O DATA DEVICE,INC. IFML-560 */
484 	{0x21002534, NULL},	/* MAE0021 - Jetstream Int V.90 56k Voice Series 2*/
485 	{0x0000f435, NULL},	/* MOT0000 - Motorola ModemSURFR 33.6 Intern */
486 	{0x5015f435, NULL},	/* MOT1550 - Motorola ModemSURFR 56K Modem */
487 	{0xf015f435, NULL},	/* MOT15F0 - Motorola VoiceSURFR 56K Modem */
488 	{0x6045f435, NULL},	/* MOT4560 - Motorola ? */
489 	{0x61e7a338, NULL},	/* NECE761 - 33.6Modem */
490  	{0x08804f3f, NULL},	/* OZO8008 - Zoom  (33.6k Modem) */
491 	{0x0f804f3f, NULL},	/* OZO800f - Zoom 2812 (56k Modem) */
492 	{0x39804f3f, NULL},	/* OZO8039 - Zoom 56k flex */
493 	{0x00914f3f, NULL},	/* OZO9100 - Zoom 2919 (K56 Faxmodem) */
494 	{0x3024a341, NULL},	/* PMC2430 - Pace 56 Voice Internal Modem */
495 	{0x1000eb49, NULL},	/* ROK0010 - Rockwell ? */
496 	{0x1200b23d, NULL},     /* RSS0012 - OMRON ME5614ISA */
497 	{0x5002734a, NULL},	/* RSS0250 - 5614Jx3(G) Internal Modem */
498 	{0x6202734a, NULL},	/* RSS0262 - 5614Jx3[G] V90+K56Flex Modem */
499 	{0x1010104d, NULL},	/* SHP1010 - Rockwell 33600bps Modem */
500 	{0xc100ad4d, NULL},	/* SMM00C1 - Leopard 56k PnP */
501 	{0x9012b04e, NULL},	/* SUP1290 - Supra ? */
502 	{0x1013b04e, NULL},	/* SUP1310 - SupraExpress 336i PnP */
503 	{0x8013b04e, NULL},	/* SUP1380 - SupraExpress 288i PnP Voice */
504 	{0x8113b04e, NULL},	/* SUP1381 - SupraExpress 336i PnP Voice */
505 	{0x5016b04e, NULL},	/* SUP1650 - Supra 336i Sp Intl */
506 	{0x7016b04e, NULL},	/* SUP1670 - Supra 336i V+ Intl */
507 	{0x7420b04e, NULL},	/* SUP2070 - Supra ? */
508 	{0x8020b04e, NULL},	/* SUP2080 - Supra ? */
509 	{0x8420b04e, NULL},	/* SUP2084 - SupraExpress 56i PnP */
510 	{0x7121b04e, NULL},	/* SUP2171 - SupraExpress 56i Sp? */
511 	{0x8024b04e, NULL},	/* SUP2480 - Supra ? */
512 	{0x01007256, NULL},	/* USR0001 - U.S. Robotics Inc., Sportster W */
513 	{0x02007256, NULL},	/* USR0002 - U.S. Robotics Inc. Sportster 33. */
514 	{0x04007256, NULL},	/* USR0004 - USR Sportster 14.4k */
515 	{0x06007256, NULL},	/* USR0006 - USR Sportster 33.6k */
516 	{0x11007256, NULL},	/* USR0011 - USR ? */
517 	{0x01017256, NULL},	/* USR0101 - USR ? */
518 	{0x30207256, NULL},	/* USR2030 - U.S.Robotics Inc. Sportster 560 */
519 	{0x50207256, NULL},	/* USR2050 - U.S.Robotics Inc. Sportster 33. */
520 	{0x70207256, NULL},	/* USR2070 - U.S.Robotics Inc. Sportster 560 */
521 	{0x30307256, NULL},	/* USR3030 - U.S. Robotics 56K FAX INT */
522 	{0x31307256, NULL},	/* USR3031 - U.S. Robotics 56K FAX INT */
523 	{0x50307256, NULL},	/* USR3050 - U.S. Robotics 56K FAX INT */
524 	{0x70307256, NULL},	/* USR3070 - U.S. Robotics 56K Voice INT */
525 	{0x90307256, NULL},	/* USR3090 - USR ? */
526 	{0x70917256, NULL},	/* USR9170 - U.S. Robotics 56K FAX INT */
527 	{0x90917256, NULL},	/* USR9190 - USR 56k Voice INT */
528 	{0x0300695c, NULL},	/* WCI0003 - Fax/Voice/Modem/Speakphone/Asvd */
529 	{0x01a0896a, NULL},	/* ZTIA001 - Zoom Internal V90 Faxmodem */
530 	{0x61f7896a, NULL},	/* ZTIF761 - Zoom ComStar 33.6 */
531 	{0}
532 };
533 
534 
535 
536 static int
537 sio_isa_probe(device_t dev)
538 {
539 	/* Check isapnp ids */
540 	if (ISA_PNP_PROBE(device_get_parent(dev), dev, sio_ids) == ENXIO)
541 		return (ENXIO);
542 	return (sioprobe(dev, 0, 0UL));
543 }
544 
545 int
546 sioprobe(device_t dev, int xrid, u_long rclk)
547 {
548 #if 0
549 	static bool_t	already_init;
550 	device_t	xdev;
551 #endif
552 	struct com_s	*com;
553 	u_int		divisor;
554 	bool_t		failures[10];
555 	int		fn;
556 	device_t	idev;
557 	Port_t		iobase;
558 	intrmask_t	irqmap[4];
559 	intrmask_t	irqs;
560 	u_char		mcr_image;
561 	int		result;
562 	u_long		xirq;
563 	u_int		flags = device_get_flags(dev);
564 	int		rid;
565 	struct resource *port;
566 
567 	rid = xrid;
568 	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
569 				  0, ~0, IO_COMSIZE, RF_ACTIVE);
570 	if (!port)
571 		return (ENXIO);
572 
573 	com = device_get_softc(dev);
574 	com->bst = rman_get_bustag(port);
575 	com->bsh = rman_get_bushandle(port);
576 	if (rclk == 0)
577 		rclk = DEFAULT_RCLK;
578 	com->rclk = rclk;
579 
580 #if 0
581 	/*
582 	 * XXX this is broken - when we are first called, there are no
583 	 * previously configured IO ports.  We could hard code
584 	 * 0x3f8, 0x2f8, 0x3e8, 0x2e8 etc but that's probably worse.
585 	 * This code has been doing nothing since the conversion since
586 	 * "count" is zero the first time around.
587 	 */
588 	if (!already_init) {
589 		/*
590 		 * Turn off MCR_IENABLE for all likely serial ports.  An unused
591 		 * port with its MCR_IENABLE gate open will inhibit interrupts
592 		 * from any used port that shares the interrupt vector.
593 		 * XXX the gate enable is elsewhere for some multiports.
594 		 */
595 		device_t *devs;
596 		int count, i, xioport;
597 
598 		devclass_get_devices(sio_devclass, &devs, &count);
599 		for (i = 0; i < count; i++) {
600 			xdev = devs[i];
601 			if (device_is_enabled(xdev) &&
602 			    bus_get_resource(xdev, SYS_RES_IOPORT, 0, &xioport,
603 					     NULL) == 0)
604 				outb(xioport + com_mcr, 0);
605 		}
606 		kfree(devs, M_TEMP);
607 		already_init = TRUE;
608 	}
609 #endif
610 
611 	if (COM_LLCONSOLE(flags)) {
612 		kprintf("sio%d: reserved for low-level i/o\n",
613 		       device_get_unit(dev));
614 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
615 		return (ENXIO);
616 	}
617 
618 	/*
619 	 * If the device is on a multiport card and has an AST/4
620 	 * compatible interrupt control register, initialize this
621 	 * register and prepare to leave MCR_IENABLE clear in the mcr.
622 	 * Otherwise, prepare to set MCR_IENABLE in the mcr.
623 	 * Point idev to the device struct giving the correct id_irq.
624 	 * This is the struct for the master device if there is one.
625 	 */
626 	idev = dev;
627 	mcr_image = MCR_IENABLE;
628 #ifdef COM_MULTIPORT
629 	if (COM_ISMULTIPORT(flags)) {
630 		Port_t xiobase;
631 		u_long io;
632 
633 		idev = devclass_get_device(sio_devclass, COM_MPMASTER(flags));
634 		if (idev == NULL) {
635 			kprintf("sio%d: master device %d not configured\n",
636 			       device_get_unit(dev), COM_MPMASTER(flags));
637 			idev = dev;
638 		}
639 		if (!COM_NOTAST4(flags)) {
640 			if (bus_get_resource(idev, SYS_RES_IOPORT, 0, &io,
641 					     NULL) == 0) {
642 				xiobase = io;
643 				if (bus_get_resource(idev, SYS_RES_IRQ, 0,
644 				    NULL, NULL) == 0)
645 					outb(xiobase + com_scr, 0x80);
646 				else
647 					outb(xiobase + com_scr, 0);
648 			}
649 			mcr_image = 0;
650 		}
651 	}
652 #endif /* COM_MULTIPORT */
653 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, NULL, NULL) != 0)
654 		mcr_image = 0;
655 
656 	bzero(failures, sizeof failures);
657 	iobase = rman_get_start(port);
658 
659 	/*
660 	 * We don't want to get actual interrupts, just masked ones.
661 	 * Interrupts from this line should already be masked in the ICU,
662 	 * but mask them in the processor as well in case there are some
663 	 * (misconfigured) shared interrupts.
664 	 */
665 	com_lock();
666 /* EXTRA DELAY? */
667 
668 	/*
669 	 * For the TI16754 chips, set prescaler to 1 (4 is often the
670 	 * default after-reset value) as otherwise it's impossible to
671 	 * get highest baudrates.
672 	 */
673 	if (COM_TI16754(flags)) {
674 		u_char cfcr, efr;
675 
676 		cfcr = sio_getreg(com, com_cfcr);
677 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
678 		efr = sio_getreg(com, com_efr);
679 		/* Unlock extended features to turn off prescaler. */
680 		sio_setreg(com, com_efr, efr | EFR_EFE);
681 		/* Disable EFR. */
682 		sio_setreg(com, com_cfcr, (cfcr != CFCR_EFR_ENABLE) ? cfcr : 0);
683 		/* Turn off prescaler. */
684 		sio_setreg(com, com_mcr,
685 			   sio_getreg(com, com_mcr) & ~MCR_PRESCALE);
686 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
687 		sio_setreg(com, com_efr, efr);
688 		sio_setreg(com, com_cfcr, cfcr);
689 	}
690 
691 	/*
692 	 * Initialize the speed and the word size and wait long enough to
693 	 * drain the maximum of 16 bytes of junk in device output queues.
694 	 * The speed is undefined after a master reset and must be set
695 	 * before relying on anything related to output.  There may be
696 	 * junk after a (very fast) soft reboot and (apparently) after
697 	 * master reset.
698 	 * XXX what about the UART bug avoided by waiting in comparam()?
699 	 * We don't want to to wait long enough to drain at 2 bps.
700 	 */
701 	if (iobase == siocniobase) {
702 		DELAY((16 + 1) * 1000000 / (comdefaultrate / 10));
703 	} else {
704 		sio_setreg(com, com_cfcr, CFCR_DLAB | CFCR_8BITS);
705 		divisor = siodivisor(rclk, SIO_TEST_SPEED);
706 		sio_setreg(com, com_dlbl, divisor & 0xff);
707 		sio_setreg(com, com_dlbh, divisor >> 8);
708 		sio_setreg(com, com_cfcr, CFCR_8BITS);
709 		DELAY((16 + 1) * 1000000 / (SIO_TEST_SPEED / 10));
710 	}
711 
712 	/*
713 	 * Make sure we can drain the receiver.  If we can't, the serial
714 	 * port may not exist.
715 	 */
716 	for (fn = 0; fn < 256; ++fn) {
717 		if ((sio_getreg(com, com_lsr) & LSR_RXRDY) == 0)
718 			break;
719 		(void)sio_getreg(com, com_data);
720 	}
721 	if (fn == 256) {
722 		kprintf("sio%d: can't drain, serial port might "
723 			"not exist, disabling\n", device_get_unit(dev));
724 		com_unlock();
725 		return (ENXIO);
726 	}
727 
728 	/*
729 	 * Enable the interrupt gate and disable device interupts.  This
730 	 * should leave the device driving the interrupt line low and
731 	 * guarantee an edge trigger if an interrupt can be generated.
732 	 */
733 /* EXTRA DELAY? */
734 	sio_setreg(com, com_mcr, mcr_image);
735 	sio_setreg(com, com_ier, 0);
736 	DELAY(1000);		/* XXX */
737 	irqmap[0] = isa_irq_pending();
738 
739 	/*
740 	 * Attempt to set loopback mode so that we can send a null byte
741 	 * without annoying any external device.
742 	 */
743 /* EXTRA DELAY? */
744 	sio_setreg(com, com_mcr, mcr_image | MCR_LOOPBACK);
745 
746 	/*
747 	 * Attempt to generate an output interrupt.  On 8250's, setting
748 	 * IER_ETXRDY generates an interrupt independent of the current
749 	 * setting and independent of whether the THR is empty.  On 16450's,
750 	 * setting IER_ETXRDY generates an interrupt independent of the
751 	 * current setting.  On 16550A's, setting IER_ETXRDY only
752 	 * generates an interrupt when IER_ETXRDY is not already set.
753 	 */
754 	sio_setreg(com, com_ier, IER_ETXRDY);
755 
756 	/*
757 	 * On some 16x50 incompatibles, setting IER_ETXRDY doesn't generate
758 	 * an interrupt.  They'd better generate one for actually doing
759 	 * output.  Loopback may be broken on the same incompatibles but
760 	 * it's unlikely to do more than allow the null byte out.
761 	 */
762 	sio_setreg(com, com_data, 0);
763 	DELAY((1 + 2) * 1000000 / (SIO_TEST_SPEED / 10));
764 
765 	/*
766 	 * Turn off loopback mode so that the interrupt gate works again
767 	 * (MCR_IENABLE was hidden).  This should leave the device driving
768 	 * an interrupt line high.  It doesn't matter if the interrupt
769 	 * line oscillates while we are not looking at it, since interrupts
770 	 * are disabled.
771 	 */
772 /* EXTRA DELAY? */
773 	sio_setreg(com, com_mcr, mcr_image);
774 
775 	/*
776 	 * Some pcmcia cards have the "TXRDY bug", so we check everyone
777 	 * for IIR_TXRDY implementation ( Palido 321s, DC-1S... )
778 	 */
779 	if (COM_NOPROBE(flags)) {
780 		/* Reading IIR register twice */
781 		for (fn = 0; fn < 2; fn ++) {
782 			DELAY(10000);
783 			failures[6] = sio_getreg(com, com_iir);
784 		}
785 		/* Check IIR_TXRDY clear ? */
786 		result = 0;
787 		if (failures[6] & IIR_TXRDY) {
788 			/* Nop, Double check with clearing IER */
789 			sio_setreg(com, com_ier, 0);
790 			if (sio_getreg(com, com_iir) & IIR_NOPEND) {
791 				/* Ok. we're familia this gang */
792 				SET_FLAG(dev, COM_C_IIR_TXRDYBUG);
793 			} else {
794 				/* Unknown, Just omit this chip.. XXX */
795 				result = ENXIO;
796 				sio_setreg(com, com_mcr, 0);
797 			}
798 		} else {
799 			/* OK. this is well-known guys */
800 			CLR_FLAG(dev, COM_C_IIR_TXRDYBUG);
801 		}
802 		sio_setreg(com, com_ier, 0);
803 		sio_setreg(com, com_cfcr, CFCR_8BITS);
804 		com_unlock();
805 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
806 		return (iobase == siocniobase ? 0 : result);
807 	}
808 
809 	/*
810 	 * Check that
811 	 *	o the CFCR, IER and MCR in UART hold the values written to them
812 	 *	  (the values happen to be all distinct - this is good for
813 	 *	  avoiding false positive tests from bus echoes).
814 	 *	o an output interrupt is generated and its vector is correct.
815 	 *	o the interrupt goes away when the IIR in the UART is read.
816 	 */
817 /* EXTRA DELAY? */
818 	failures[0] = sio_getreg(com, com_cfcr) - CFCR_8BITS;
819 	failures[1] = sio_getreg(com, com_ier) - IER_ETXRDY;
820 	failures[2] = sio_getreg(com, com_mcr) - mcr_image;
821 	DELAY(10000);		/* Some internal modems need this time */
822 	irqmap[1] = isa_irq_pending();
823 	failures[4] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_TXRDY;
824 	DELAY(1000);		/* XXX */
825 	irqmap[2] = isa_irq_pending();
826 	failures[6] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
827 
828 	/*
829 	 * Turn off all device interrupts and check that they go off properly.
830 	 * Leave MCR_IENABLE alone.  For ports without a master port, it gates
831 	 * the OUT2 output of the UART to
832 	 * the ICU input.  Closing the gate would give a floating ICU input
833 	 * (unless there is another device driving it) and spurious interrupts.
834 	 * (On the system that this was first tested on, the input floats high
835 	 * and gives a (masked) interrupt as soon as the gate is closed.)
836 	 */
837 	sio_setreg(com, com_ier, 0);
838 	sio_setreg(com, com_cfcr, CFCR_8BITS);	/* dummy to avoid bus echo */
839 	failures[7] = sio_getreg(com, com_ier);
840 	DELAY(1000);		/* XXX */
841 	irqmap[3] = isa_irq_pending();
842 	failures[9] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
843 
844 	com_unlock();
845 
846 	irqs = irqmap[1] & ~irqmap[0];
847 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, &xirq, NULL) == 0 &&
848 	    ((1 << xirq) & irqs) == 0)
849 		kprintf(
850 		"sio%d: configured irq %ld not in bitmap of probed irqs %#x\n",
851 		    device_get_unit(dev), xirq, irqs);
852 	if (bootverbose)
853 		kprintf("sio%d: irq maps: %#x %#x %#x %#x\n",
854 		    device_get_unit(dev),
855 		    irqmap[0], irqmap[1], irqmap[2], irqmap[3]);
856 
857 	result = 0;
858 	for (fn = 0; fn < sizeof failures; ++fn)
859 		if (failures[fn]) {
860 			sio_setreg(com, com_mcr, 0);
861 			result = ENXIO;
862 			if (bootverbose) {
863 				kprintf("sio%d: probe failed test(s):",
864 				    device_get_unit(dev));
865 				for (fn = 0; fn < sizeof failures; ++fn)
866 					if (failures[fn])
867 						kprintf(" %d", fn);
868 				kprintf("\n");
869 			}
870 			break;
871 		}
872 	bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
873 	return (iobase == siocniobase ? 0 : result);
874 }
875 
876 #ifdef COM_ESP
877 static int
878 espattach(struct com_s *com, Port_t esp_port)
879 {
880 	u_char	dips;
881 	u_char	val;
882 
883 	/*
884 	 * Check the ESP-specific I/O port to see if we're an ESP
885 	 * card.  If not, return failure immediately.
886 	 */
887 	if ((inb(esp_port) & 0xf3) == 0) {
888 		kprintf(" port 0x%x is not an ESP board?\n", esp_port);
889 		return (0);
890 	}
891 
892 	/*
893 	 * We've got something that claims to be a Hayes ESP card.
894 	 * Let's hope so.
895 	 */
896 
897 	/* Get the dip-switch configuration */
898 	outb(esp_port + ESP_CMD1, ESP_GETDIPS);
899 	dips = inb(esp_port + ESP_STATUS1);
900 
901 	/*
902 	 * Bits 0,1 of dips say which COM port we are.
903 	 */
904 	if (rman_get_start(com->ioportres) == likely_com_ports[dips & 0x03])
905 		kprintf(" : ESP");
906 	else {
907 		kprintf(" esp_port has com %d\n", dips & 0x03);
908 		return (0);
909 	}
910 
911 	/*
912 	 * Check for ESP version 2.0 or later:  bits 4,5,6 = 010.
913 	 */
914 	outb(esp_port + ESP_CMD1, ESP_GETTEST);
915 	val = inb(esp_port + ESP_STATUS1);	/* clear reg 1 */
916 	val = inb(esp_port + ESP_STATUS2);
917 	if ((val & 0x70) < 0x20) {
918 		kprintf("-old (%o)", val & 0x70);
919 		return (0);
920 	}
921 
922 	/*
923 	 * Check for ability to emulate 16550:  bit 7 == 1
924 	 */
925 	if ((dips & 0x80) == 0) {
926 		kprintf(" slave");
927 		return (0);
928 	}
929 
930 	/*
931 	 * Okay, we seem to be a Hayes ESP card.  Whee.
932 	 */
933 	com->esp = TRUE;
934 	com->esp_port = esp_port;
935 	return (1);
936 }
937 #endif /* COM_ESP */
938 
939 static int
940 sio_isa_attach(device_t dev)
941 {
942 	return (sioattach(dev, 0, 0UL));
943 }
944 
945 int
946 sioattach(device_t dev, int xrid, u_long rclk)
947 {
948 	struct com_s	*com;
949 #ifdef COM_ESP
950 	Port_t		*espp;
951 #endif
952 	Port_t		iobase;
953 	int		minorbase;
954 	int		unit;
955 	u_int		flags;
956 	int		rid;
957 	struct resource *port;
958 	int		ret;
959 	static int	did_init;
960 
961 	if (did_init == 0) {
962 		did_init = 1;
963 		callout_init(&sio_timeout_handle);
964 	}
965 
966 	rid = xrid;
967 	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
968 				  0, ~0, IO_COMSIZE, RF_ACTIVE);
969 	if (!port)
970 		return (ENXIO);
971 
972 	iobase = rman_get_start(port);
973 	unit = device_get_unit(dev);
974 	com = device_get_softc(dev);
975 	flags = device_get_flags(dev);
976 
977 	if (unit >= sio_numunits)
978 		sio_numunits = unit + 1;
979 	/*
980 	 * sioprobe() has initialized the device registers as follows:
981 	 *	o cfcr = CFCR_8BITS.
982 	 *	  It is most important that CFCR_DLAB is off, so that the
983 	 *	  data port is not hidden when we enable interrupts.
984 	 *	o ier = 0.
985 	 *	  Interrupts are only enabled when the line is open.
986 	 *	o mcr = MCR_IENABLE, or 0 if the port has AST/4 compatible
987 	 *	  interrupt control register or the config specifies no irq.
988 	 *	  Keeping MCR_DTR and MCR_RTS off might stop the external
989 	 *	  device from sending before we are ready.
990 	 */
991 	bzero(com, sizeof *com);
992 	com->unit = unit;
993 	com->ioportres = port;
994 	com->bst = rman_get_bustag(port);
995 	com->bsh = rman_get_bushandle(port);
996 	com->cfcr_image = CFCR_8BITS;
997 	com->dtr_wait = 3 * hz;
998 	callout_init(&com->dtr_ch);
999 	callout_init(&com->busy_ch);
1000 	com->loses_outints = COM_LOSESOUTINTS(flags) != 0;
1001 	com->no_irq = bus_get_resource(dev, SYS_RES_IRQ, 0, NULL, NULL) != 0;
1002 	com->tx_fifo_size = 1;
1003 	com->obufs[0].l_head = com->obuf1;
1004 	com->obufs[1].l_head = com->obuf2;
1005 
1006 	com->data_port = iobase + com_data;
1007 	com->int_id_port = iobase + com_iir;
1008 	com->modem_ctl_port = iobase + com_mcr;
1009 	com->mcr_image = inb(com->modem_ctl_port);
1010 	com->line_status_port = iobase + com_lsr;
1011 	com->modem_status_port = iobase + com_msr;
1012 	com->intr_ctl_port = iobase + com_ier;
1013 
1014 	if (rclk == 0)
1015 		rclk = DEFAULT_RCLK;
1016 	com->rclk = rclk;
1017 
1018 	/*
1019 	 * We don't use all the flags from <sys/ttydefaults.h> since they
1020 	 * are only relevant for logins.  It's important to have echo off
1021 	 * initially so that the line doesn't start blathering before the
1022 	 * echo flag can be turned off.
1023 	 */
1024 	com->it_in.c_iflag = 0;
1025 	com->it_in.c_oflag = 0;
1026 	com->it_in.c_cflag = TTYDEF_CFLAG;
1027 	com->it_in.c_lflag = 0;
1028 	if (unit == comconsole) {
1029 		com->it_in.c_iflag = TTYDEF_IFLAG;
1030 		com->it_in.c_oflag = TTYDEF_OFLAG;
1031 		com->it_in.c_cflag = TTYDEF_CFLAG | CLOCAL;
1032 		com->it_in.c_lflag = TTYDEF_LFLAG;
1033 		com->lt_out.c_cflag = com->lt_in.c_cflag = CLOCAL;
1034 		com->lt_out.c_ispeed = com->lt_out.c_ospeed =
1035 		com->lt_in.c_ispeed = com->lt_in.c_ospeed =
1036 		com->it_in.c_ispeed = com->it_in.c_ospeed = comdefaultrate;
1037 	} else
1038 		com->it_in.c_ispeed = com->it_in.c_ospeed = TTYDEF_SPEED;
1039 	if (siosetwater(com, com->it_in.c_ispeed) != 0) {
1040 		com_unlock();
1041 		/*
1042 		 * Leave i/o resources allocated if this is a `cn'-level
1043 		 * console, so that other devices can't snarf them.
1044 		 */
1045 		if (iobase != siocniobase)
1046 			bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
1047 		return (ENOMEM);
1048 	}
1049 	com_unlock();
1050 	termioschars(&com->it_in);
1051 	com->it_out = com->it_in;
1052 
1053 	/* attempt to determine UART type */
1054 	kprintf("sio%d: type", unit);
1055 
1056 
1057 #ifdef COM_MULTIPORT
1058 	if (!COM_ISMULTIPORT(flags) && !COM_IIR_TXRDYBUG(flags))
1059 #else
1060 	if (!COM_IIR_TXRDYBUG(flags))
1061 #endif
1062 	{
1063 		u_char	scr;
1064 		u_char	scr1;
1065 		u_char	scr2;
1066 
1067 		scr = sio_getreg(com, com_scr);
1068 		sio_setreg(com, com_scr, 0xa5);
1069 		scr1 = sio_getreg(com, com_scr);
1070 		sio_setreg(com, com_scr, 0x5a);
1071 		scr2 = sio_getreg(com, com_scr);
1072 		sio_setreg(com, com_scr, scr);
1073 		if (scr1 != 0xa5 || scr2 != 0x5a) {
1074 			kprintf(" 8250");
1075 			goto determined_type;
1076 		}
1077 	}
1078 	sio_setreg(com, com_fifo, FIFO_ENABLE | FIFO_RX_HIGH);
1079 	DELAY(100);
1080 	com->st16650a = 0;
1081 	switch (inb(com->int_id_port) & IIR_FIFO_MASK) {
1082 	case FIFO_RX_LOW:
1083 		kprintf(" 16450");
1084 		break;
1085 	case FIFO_RX_MEDL:
1086 		kprintf(" 16450?");
1087 		break;
1088 	case FIFO_RX_MEDH:
1089 		kprintf(" 16550?");
1090 		break;
1091 	case FIFO_RX_HIGH:
1092 		if (COM_NOFIFO(flags)) {
1093 			kprintf(" 16550A fifo disabled");
1094 		} else {
1095 			com->hasfifo = TRUE;
1096 			if (COM_ST16650A(flags)) {
1097 				com->st16650a = 1;
1098 				com->tx_fifo_size = 32;
1099 				kprintf(" ST16650A");
1100 			} else if (COM_TI16754(flags)) {
1101 				com->tx_fifo_size = 64;
1102 				kprintf(" TI16754");
1103 			} else {
1104 				com->tx_fifo_size = COM_FIFOSIZE(flags);
1105 				kprintf(" 16550A");
1106 			}
1107 		}
1108 #ifdef COM_ESP
1109 		for (espp = likely_esp_ports; *espp != 0; espp++)
1110 			if (espattach(com, *espp)) {
1111 				com->tx_fifo_size = 1024;
1112 				break;
1113 			}
1114 #endif
1115 		if (!com->st16650a && !COM_TI16754(flags)) {
1116 			if (!com->tx_fifo_size)
1117 				com->tx_fifo_size = 16;
1118 			else
1119 				kprintf(" lookalike with %d bytes FIFO",
1120 				    com->tx_fifo_size);
1121 		}
1122 
1123 		break;
1124 	}
1125 
1126 #ifdef COM_ESP
1127 	if (com->esp) {
1128 		/*
1129 		 * Set 16550 compatibility mode.
1130 		 * We don't use the ESP_MODE_SCALE bit to increase the
1131 		 * fifo trigger levels because we can't handle large
1132 		 * bursts of input.
1133 		 * XXX flow control should be set in comparam(), not here.
1134 		 */
1135 		outb(com->esp_port + ESP_CMD1, ESP_SETMODE);
1136 		outb(com->esp_port + ESP_CMD2, ESP_MODE_RTS | ESP_MODE_FIFO);
1137 
1138 		/* Set RTS/CTS flow control. */
1139 		outb(com->esp_port + ESP_CMD1, ESP_SETFLOWTYPE);
1140 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_RTS);
1141 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_CTS);
1142 
1143 		/* Set flow-control levels. */
1144 		outb(com->esp_port + ESP_CMD1, ESP_SETRXFLOW);
1145 		outb(com->esp_port + ESP_CMD2, HIBYTE(768));
1146 		outb(com->esp_port + ESP_CMD2, LOBYTE(768));
1147 		outb(com->esp_port + ESP_CMD2, HIBYTE(512));
1148 		outb(com->esp_port + ESP_CMD2, LOBYTE(512));
1149 	}
1150 #endif /* COM_ESP */
1151 	sio_setreg(com, com_fifo, 0);
1152 determined_type: ;
1153 
1154 #ifdef COM_MULTIPORT
1155 	if (COM_ISMULTIPORT(flags)) {
1156 		device_t masterdev;
1157 
1158 		com->multiport = TRUE;
1159 		kprintf(" (multiport");
1160 		if (unit == COM_MPMASTER(flags))
1161 			kprintf(" master");
1162 		kprintf(")");
1163 		masterdev = devclass_get_device(sio_devclass,
1164 		    COM_MPMASTER(flags));
1165 		com->no_irq = (masterdev == NULL || bus_get_resource(masterdev,
1166 		    SYS_RES_IRQ, 0, NULL, NULL) != 0);
1167 	 }
1168 #endif /* COM_MULTIPORT */
1169 	if (unit == comconsole)
1170 		kprintf(", console");
1171 	if (COM_IIR_TXRDYBUG(flags))
1172 		kprintf(" with a bogus IIR_TXRDY register");
1173 	kprintf("\n");
1174 
1175 	if (!sio_registered) {
1176 		register_swi(SWI_TTY, siopoll, NULL ,"swi_siopoll", NULL);
1177 		sio_registered = TRUE;
1178 	}
1179 	minorbase = UNIT_TO_MINOR(unit);
1180 	make_dev(&sio_ops, minorbase,
1181 	    UID_ROOT, GID_WHEEL, 0600, "ttyd%r", unit);
1182 	make_dev(&sio_ops, minorbase | CONTROL_INIT_STATE,
1183 	    UID_ROOT, GID_WHEEL, 0600, "ttyid%r", unit);
1184 	make_dev(&sio_ops, minorbase | CONTROL_LOCK_STATE,
1185 	    UID_ROOT, GID_WHEEL, 0600, "ttyld%r", unit);
1186 	make_dev(&sio_ops, minorbase | CALLOUT_MASK,
1187 	    UID_UUCP, GID_DIALER, 0660, "cuaa%r", unit);
1188 	make_dev(&sio_ops, minorbase | CALLOUT_MASK | CONTROL_INIT_STATE,
1189 	    UID_UUCP, GID_DIALER, 0660, "cuaia%r", unit);
1190 	make_dev(&sio_ops, minorbase | CALLOUT_MASK | CONTROL_LOCK_STATE,
1191 	    UID_UUCP, GID_DIALER, 0660, "cuala%r", unit);
1192 	com->flags = flags;
1193 	com->pps.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1194 	pps_init(&com->pps);
1195 
1196 	rid = 0;
1197 	com->irqres = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0ul, ~0ul, 1,
1198 	    RF_ACTIVE);
1199 	if (com->irqres) {
1200 		ret = BUS_SETUP_INTR(device_get_parent(dev), dev,
1201 				     com->irqres, 0, siointr, com,
1202 				     &com->cookie, NULL);
1203 		if (ret)
1204 			device_printf(dev, "could not activate interrupt\n");
1205 #if defined(DDB) && (defined(BREAK_TO_DEBUGGER) || \
1206     defined(ALT_BREAK_TO_DEBUGGER))
1207 		/*
1208 		 * Enable interrupts for early break-to-debugger support
1209 		 * on the console.
1210 		 */
1211 		if (ret == 0 && unit == comconsole)
1212 			outb(siocniobase + com_ier, IER_ERXRDY | IER_ERLS |
1213 			    IER_EMSC);
1214 #endif
1215 	}
1216 
1217 	return (0);
1218 }
1219 
1220 static int
1221 sioopen(struct dev_open_args *ap)
1222 {
1223 	cdev_t dev = ap->a_head.a_dev;
1224 	struct com_s	*com;
1225 	int		error;
1226 	int		mynor;
1227 	struct tty	*tp;
1228 	int		unit;
1229 
1230 	mynor = minor(dev);
1231 	unit = MINOR_TO_UNIT(mynor);
1232 	com = com_addr(unit);
1233 	if (com == NULL)
1234 		return (ENXIO);
1235 	if (com->gone)
1236 		return (ENXIO);
1237 	if (mynor & CONTROL_MASK)
1238 		return (0);
1239 	tp = dev->si_tty = com->tp = ttymalloc(com->tp);
1240 	crit_enter();
1241 	/*
1242 	 * We jump to this label after all non-interrupted sleeps to pick
1243 	 * up any changes of the device state.
1244 	 */
1245 open_top:
1246 	while (com->state & CS_DTR_OFF) {
1247 		error = tsleep(&com->dtr_wait, PCATCH, "siodtr", 0);
1248 		if (com_addr(unit) == NULL) {
1249 			crit_exit();
1250 			return (ENXIO);
1251 		}
1252 		if (error != 0 || com->gone)
1253 			goto out;
1254 	}
1255 	if (tp->t_state & TS_ISOPEN) {
1256 		/*
1257 		 * The device is open, so everything has been initialized.
1258 		 * Handle conflicts.
1259 		 */
1260 		if (mynor & CALLOUT_MASK) {
1261 			if (!com->active_out) {
1262 				error = EBUSY;
1263 				goto out;
1264 			}
1265 		} else {
1266 			if (com->active_out) {
1267 				if (ap->a_oflags & O_NONBLOCK) {
1268 					error = EBUSY;
1269 					goto out;
1270 				}
1271 				error =	tsleep(&com->active_out,
1272 					       PCATCH, "siobi", 0);
1273 				if (com_addr(unit) == NULL) {
1274 					crit_exit();
1275 					return (ENXIO);
1276 				}
1277 				if (error != 0 || com->gone)
1278 					goto out;
1279 				goto open_top;
1280 			}
1281 		}
1282 		if (tp->t_state & TS_XCLUDE && priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) {
1283 			error = EBUSY;
1284 			goto out;
1285 		}
1286 	} else {
1287 		/*
1288 		 * The device isn't open, so there are no conflicts.
1289 		 * Initialize it.  Initialization is done twice in many
1290 		 * cases: to preempt sleeping callin opens if we are
1291 		 * callout, and to complete a callin open after DCD rises.
1292 		 */
1293 		tp->t_oproc = comstart;
1294 		tp->t_param = comparam;
1295 		tp->t_stop = comstop;
1296 		tp->t_dev = dev;
1297 		tp->t_termios = mynor & CALLOUT_MASK
1298 				? com->it_out : com->it_in;
1299 		(void)commctl(com, TIOCM_DTR | TIOCM_RTS, DMSET);
1300 		com->poll = com->no_irq;
1301 		com->poll_output = com->loses_outints;
1302 		++com->wopeners;
1303 		error = comparam(tp, &tp->t_termios);
1304 		--com->wopeners;
1305 		if (error != 0)
1306 			goto out;
1307 		/*
1308 		 * XXX we should goto open_top if comparam() slept.
1309 		 */
1310 		if (com->hasfifo) {
1311 			/*
1312 			 * (Re)enable and drain fifos.
1313 			 *
1314 			 * Certain SMC chips cause problems if the fifos
1315 			 * are enabled while input is ready.  Turn off the
1316 			 * fifo if necessary to clear the input.  We test
1317 			 * the input ready bit after enabling the fifos
1318 			 * since we've already enabled them in comparam()
1319 			 * and to handle races between enabling and fresh
1320 			 * input.
1321 			 */
1322 			while (TRUE) {
1323 				sio_setreg(com, com_fifo,
1324 					   FIFO_RCV_RST | FIFO_XMT_RST
1325 					   | com->fifo_image);
1326 				/*
1327 				 * XXX the delays are for superstitious
1328 				 * historical reasons.  It must be less than
1329 				 * the character time at the maximum
1330 				 * supported speed (87 usec at 115200 bps
1331 				 * 8N1).  Otherwise we might loop endlessly
1332 				 * if data is streaming in.  We used to use
1333 				 * delays of 100.  That usually worked
1334 				 * because DELAY(100) used to usually delay
1335 				 * for about 85 usec instead of 100.
1336 				 */
1337 				DELAY(50);
1338 				if (!(inb(com->line_status_port) & LSR_RXRDY))
1339 					break;
1340 				sio_setreg(com, com_fifo, 0);
1341 				DELAY(50);
1342 				(void) inb(com->data_port);
1343 			}
1344 		}
1345 
1346 		com_lock();
1347 		(void) inb(com->line_status_port);
1348 		(void) inb(com->data_port);
1349 		com->prev_modem_status = com->last_modem_status
1350 		    = inb(com->modem_status_port);
1351 		if (COM_IIR_TXRDYBUG(com->flags)) {
1352 			outb(com->intr_ctl_port, IER_ERXRDY | IER_ERLS
1353 						| IER_EMSC);
1354 		} else {
1355 			outb(com->intr_ctl_port, IER_ERXRDY | IER_ETXRDY
1356 						| IER_ERLS | IER_EMSC);
1357 		}
1358 		com_unlock();
1359 		/*
1360 		 * Handle initial DCD.  Callout devices get a fake initial
1361 		 * DCD (trapdoor DCD).  If we are callout, then any sleeping
1362 		 * callin opens get woken up and resume sleeping on "siobi"
1363 		 * instead of "siodcd".
1364 		 */
1365 		/*
1366 		 * XXX `mynor & CALLOUT_MASK' should be
1367 		 * `tp->t_cflag & (SOFT_CARRIER | TRAPDOOR_CARRIER) where
1368 		 * TRAPDOOR_CARRIER is the default initial state for callout
1369 		 * devices and SOFT_CARRIER is like CLOCAL except it hides
1370 		 * the true carrier.
1371 		 */
1372 		if (com->prev_modem_status & MSR_DCD || mynor & CALLOUT_MASK)
1373 			(*linesw[tp->t_line].l_modem)(tp, 1);
1374 	}
1375 	/*
1376 	 * Wait for DCD if necessary.
1377 	 */
1378 	if (!(tp->t_state & TS_CARR_ON) && !(mynor & CALLOUT_MASK)
1379 	    && !(tp->t_cflag & CLOCAL) && !(ap->a_oflags & O_NONBLOCK)) {
1380 		++com->wopeners;
1381 		error = tsleep(TSA_CARR_ON(tp), PCATCH, "siodcd", 0);
1382 		if (com_addr(unit) == NULL) {
1383 			crit_exit();
1384 			return (ENXIO);
1385 		}
1386 		--com->wopeners;
1387 		if (error != 0 || com->gone)
1388 			goto out;
1389 		goto open_top;
1390 	}
1391 	error =	(*linesw[tp->t_line].l_open)(dev, tp);
1392 	disc_optim(tp, &tp->t_termios, com);
1393 	if (tp->t_state & TS_ISOPEN && mynor & CALLOUT_MASK)
1394 		com->active_out = TRUE;
1395 	siosettimeout();
1396 out:
1397 	crit_exit();
1398 	if (!(tp->t_state & TS_ISOPEN) && com->wopeners == 0)
1399 		comhardclose(com);
1400 	return (error);
1401 }
1402 
1403 static int
1404 sioclose(struct dev_close_args *ap)
1405 {
1406 	cdev_t dev = ap->a_head.a_dev;
1407 	struct com_s	*com;
1408 	int		mynor;
1409 	struct tty	*tp;
1410 
1411 	mynor = minor(dev);
1412 	if (mynor & CONTROL_MASK)
1413 		return (0);
1414 	com = com_addr(MINOR_TO_UNIT(mynor));
1415 	if (com == NULL)
1416 		return (ENODEV);
1417 	tp = com->tp;
1418 	crit_enter();
1419 	(*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
1420 	disc_optim(tp, &tp->t_termios, com);
1421 	comstop(tp, FREAD | FWRITE);
1422 	comhardclose(com);
1423 	ttyclose(tp);
1424 	siosettimeout();
1425 	crit_exit();
1426 	if (com->gone) {
1427 		kprintf("sio%d: gone\n", com->unit);
1428 		crit_enter();
1429 		if (com->ibuf != NULL)
1430 			kfree(com->ibuf, M_DEVBUF);
1431 		bzero(tp, sizeof *tp);
1432 		crit_exit();
1433 	}
1434 	return (0);
1435 }
1436 
1437 static void
1438 comhardclose(struct com_s *com)
1439 {
1440 	struct tty	*tp;
1441 	int		unit;
1442 
1443 	unit = com->unit;
1444 	crit_enter();
1445 	com->poll = FALSE;
1446 	com->poll_output = FALSE;
1447 	com->do_timestamp = FALSE;
1448 	com->do_dcd_timestamp = FALSE;
1449 	com->pps.ppsparam.mode = 0;
1450 	sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1451 	tp = com->tp;
1452 
1453 #if defined(DDB) && (defined(BREAK_TO_DEBUGGER) || \
1454     defined(ALT_BREAK_TO_DEBUGGER))
1455 	/*
1456 	 * Leave interrupts enabled and don't clear DTR if this is the
1457 	 * console. This allows us to detect break-to-debugger events
1458 	 * while the console device is closed.
1459 	 */
1460 	if (com->unit != comconsole)
1461 #endif
1462 	{
1463 		sio_setreg(com, com_ier, 0);
1464 		if (tp->t_cflag & HUPCL
1465 		    /*
1466 		     * XXX we will miss any carrier drop between here and the
1467 		     * next open.  Perhaps we should watch DCD even when the
1468 		     * port is closed; it is not sufficient to check it at
1469 		     * the next open because it might go up and down while
1470 		     * we're not watching.
1471 		     */
1472 		    || (!com->active_out
1473 		        && !(com->prev_modem_status & MSR_DCD)
1474 		        && !(com->it_in.c_cflag & CLOCAL))
1475 		    || !(tp->t_state & TS_ISOPEN)) {
1476 			(void)commctl(com, TIOCM_DTR, DMBIC);
1477 			if (com->dtr_wait != 0 && !(com->state & CS_DTR_OFF)) {
1478 				callout_reset(&com->dtr_ch, com->dtr_wait,
1479 						siodtrwakeup, com);
1480 				com->state |= CS_DTR_OFF;
1481 			}
1482 		}
1483 	}
1484 	if (com->hasfifo) {
1485 		/*
1486 		 * Disable fifos so that they are off after controlled
1487 		 * reboots.  Some BIOSes fail to detect 16550s when the
1488 		 * fifos are enabled.
1489 		 */
1490 		sio_setreg(com, com_fifo, 0);
1491 	}
1492 	com->active_out = FALSE;
1493 	wakeup(&com->active_out);
1494 	wakeup(TSA_CARR_ON(tp));	/* restart any wopeners */
1495 	crit_exit();
1496 }
1497 
1498 static int
1499 sioread(struct dev_read_args *ap)
1500 {
1501 	cdev_t dev = ap->a_head.a_dev;
1502 	int		mynor;
1503 	struct com_s	*com;
1504 
1505 	mynor = minor(dev);
1506 	if (mynor & CONTROL_MASK)
1507 		return (ENODEV);
1508 	com = com_addr(MINOR_TO_UNIT(mynor));
1509 	if (com == NULL || com->gone)
1510 		return (ENODEV);
1511 	return ((*linesw[com->tp->t_line].l_read)(com->tp, ap->a_uio, ap->a_ioflag));
1512 }
1513 
1514 static int
1515 siowrite(struct dev_write_args *ap)
1516 {
1517 	cdev_t dev = ap->a_head.a_dev;
1518 	int		mynor;
1519 	struct com_s	*com;
1520 	int		unit;
1521 
1522 	mynor = minor(dev);
1523 	if (mynor & CONTROL_MASK)
1524 		return (ENODEV);
1525 
1526 	unit = MINOR_TO_UNIT(mynor);
1527 	com = com_addr(unit);
1528 	if (com == NULL || com->gone)
1529 		return (ENODEV);
1530 	/*
1531 	 * (XXX) We disallow virtual consoles if the physical console is
1532 	 * a serial port.  This is in case there is a display attached that
1533 	 * is not the console.  In that situation we don't need/want the X
1534 	 * server taking over the console.
1535 	 */
1536 	if (constty != NULL && unit == comconsole)
1537 		constty = NULL;
1538 	return ((*linesw[com->tp->t_line].l_write)(com->tp, ap->a_uio, ap->a_ioflag));
1539 }
1540 
1541 static void
1542 siobusycheck(void *chan)
1543 {
1544 	struct com_s	*com;
1545 
1546 	com = (struct com_s *)chan;
1547 
1548 	/*
1549 	 * Clear TS_BUSY if low-level output is complete.
1550 	 * spl locking is sufficient because siointr1() does not set CS_BUSY.
1551 	 * If siointr1() clears CS_BUSY after we look at it, then we'll get
1552 	 * called again.  Reading the line status port outside of siointr1()
1553 	 * is safe because CS_BUSY is clear so there are no output interrupts
1554 	 * to lose.
1555 	 */
1556 	crit_enter();
1557 	if (com->state & CS_BUSY)
1558 		com->extra_state &= ~CSE_BUSYCHECK;	/* False alarm. */
1559 	else if ((inb(com->line_status_port) & (LSR_TSRE | LSR_TXRDY))
1560 	    == (LSR_TSRE | LSR_TXRDY)) {
1561 		com->tp->t_state &= ~TS_BUSY;
1562 		ttwwakeup(com->tp);
1563 		com->extra_state &= ~CSE_BUSYCHECK;
1564 	} else {
1565 		callout_reset(&com->busy_ch, hz / 100, siobusycheck, com);
1566 	}
1567 	crit_exit();
1568 }
1569 
1570 static u_int
1571 siodivisor(u_long rclk, speed_t speed)
1572 {
1573 	long	actual_speed;
1574 	u_int	divisor;
1575 	int	error;
1576 
1577 	if (speed == 0 || speed > ((speed_t)-1 - 1) / 8)
1578 		return (0);
1579 	divisor = (rclk / (8UL * speed) + 1) / 2;
1580 	if (divisor == 0 || divisor >= 65536)
1581 		return (0);
1582 	actual_speed = rclk / (16UL * divisor);
1583 
1584 	/* 10 times error in percent: */
1585 	error = ((actual_speed - (long)speed) * 2000 / (long)speed + 1) / 2;
1586 
1587 	/* 3.0% maximum error tolerance: */
1588 	if (error < -30 || error > 30)
1589 		return (0);
1590 
1591 	return (divisor);
1592 }
1593 
1594 static void
1595 siodtrwakeup(void *chan)
1596 {
1597 	struct com_s	*com;
1598 
1599 	com = (struct com_s *)chan;
1600 	com->state &= ~CS_DTR_OFF;
1601 	wakeup(&com->dtr_wait);
1602 }
1603 
1604 static void
1605 sioinput(struct com_s *com)
1606 {
1607 	u_char		*buf;
1608 	int		incc;
1609 	u_char		line_status;
1610 	int		recv_data;
1611 	struct tty	*tp;
1612 
1613 	buf = com->ibuf;
1614 	tp = com->tp;
1615 	if (!(tp->t_state & TS_ISOPEN) || !(tp->t_cflag & CREAD)) {
1616 		com_events -= (com->iptr - com->ibuf);
1617 		com->iptr = com->ibuf;
1618 		return;
1619 	}
1620 	if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
1621 		/*
1622 		 * Avoid the grotesquely inefficient lineswitch routine
1623 		 * (ttyinput) in "raw" mode.  It usually takes about 450
1624 		 * instructions (that's without canonical processing or echo!).
1625 		 * slinput is reasonably fast (usually 40 instructions plus
1626 		 * call overhead).
1627 		 */
1628 		do {
1629 			com_unlock();
1630 			incc = com->iptr - buf;
1631 			if (tp->t_rawq.c_cc + incc > tp->t_ihiwat
1632 			    && (com->state & CS_RTS_IFLOW
1633 				|| tp->t_iflag & IXOFF)
1634 			    && !(tp->t_state & TS_TBLOCK))
1635 				ttyblock(tp);
1636 			com->delta_error_counts[CE_TTY_BUF_OVERFLOW]
1637 				+= b_to_q((char *)buf, incc, &tp->t_rawq);
1638 			buf += incc;
1639 			tk_nin += incc;
1640 			tk_rawcc += incc;
1641 			tp->t_rawcc += incc;
1642 			ttwakeup(tp);
1643 			if (tp->t_state & TS_TTSTOP
1644 			    && (tp->t_iflag & IXANY
1645 				|| tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
1646 				tp->t_state &= ~TS_TTSTOP;
1647 				tp->t_lflag &= ~FLUSHO;
1648 				comstart(tp);
1649 			}
1650 			com_lock();
1651 		} while (buf < com->iptr);
1652 	} else {
1653 		do {
1654 			com_unlock();
1655 			line_status = buf[com->ierroff];
1656 			recv_data = *buf++;
1657 			if (line_status
1658 			    & (LSR_BI | LSR_FE | LSR_OE | LSR_PE)) {
1659 				if (line_status & LSR_BI)
1660 					recv_data |= TTY_BI;
1661 				if (line_status & LSR_FE)
1662 					recv_data |= TTY_FE;
1663 				if (line_status & LSR_OE)
1664 					recv_data |= TTY_OE;
1665 				if (line_status & LSR_PE)
1666 					recv_data |= TTY_PE;
1667 			}
1668 			(*linesw[tp->t_line].l_rint)(recv_data, tp);
1669 			com_lock();
1670 		} while (buf < com->iptr);
1671 	}
1672 	com_events -= (com->iptr - com->ibuf);
1673 	com->iptr = com->ibuf;
1674 
1675 	/*
1676 	 * There is now room for another low-level buffer full of input,
1677 	 * so enable RTS if it is now disabled and there is room in the
1678 	 * high-level buffer.
1679 	 */
1680 	if ((com->state & CS_RTS_IFLOW) && !(com->mcr_image & MCR_RTS) &&
1681 	    !(tp->t_state & TS_TBLOCK))
1682 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1683 }
1684 
1685 void
1686 siointr(void *arg)
1687 {
1688 #ifndef COM_MULTIPORT
1689 	com_lock();
1690 	siointr1((struct com_s *) arg);
1691 	com_unlock();
1692 #else /* COM_MULTIPORT */
1693 	bool_t		possibly_more_intrs;
1694 	int		unit;
1695 	struct com_s	*com;
1696 
1697 	/*
1698 	 * Loop until there is no activity on any port.  This is necessary
1699 	 * to get an interrupt edge more than to avoid another interrupt.
1700 	 * If the IRQ signal is just an OR of the IRQ signals from several
1701 	 * devices, then the edge from one may be lost because another is
1702 	 * on.
1703 	 */
1704 	com_lock();
1705 	do {
1706 		possibly_more_intrs = FALSE;
1707 		for (unit = 0; unit < sio_numunits; ++unit) {
1708 			com = com_addr(unit);
1709 			/*
1710 			 * XXX com_lock();
1711 			 * would it work here, or be counter-productive?
1712 			 */
1713 			if (com != NULL
1714 			    && !com->gone
1715 			    && (inb(com->int_id_port) & IIR_IMASK)
1716 			       != IIR_NOPEND) {
1717 				siointr1(com);
1718 				possibly_more_intrs = TRUE;
1719 			}
1720 			/* XXX com_unlock(); */
1721 		}
1722 	} while (possibly_more_intrs);
1723 	com_unlock();
1724 #endif /* COM_MULTIPORT */
1725 }
1726 
1727 static void
1728 siointr1(struct com_s *com)
1729 {
1730 	u_char	line_status;
1731 	u_char	modem_status;
1732 	u_char	*ioptr;
1733 	u_char	recv_data;
1734 	u_char	int_ctl;
1735 	u_char	int_ctl_new;
1736 	u_int	count;
1737 
1738 	int_ctl = inb(com->intr_ctl_port);
1739 	int_ctl_new = int_ctl;
1740 
1741 	while (!com->gone) {
1742 		if (com->pps.ppsparam.mode & PPS_CAPTUREBOTH) {
1743 			modem_status = inb(com->modem_status_port);
1744 		        if ((modem_status ^ com->last_modem_status) & MSR_DCD) {
1745 				count = sys_cputimer->count();
1746 				pps_event(&com->pps, count,
1747 				    (modem_status & MSR_DCD) ?
1748 				    PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
1749 			}
1750 		}
1751 		line_status = inb(com->line_status_port);
1752 
1753 		/* input event? (check first to help avoid overruns) */
1754 		while (line_status & LSR_RCV_MASK) {
1755 			/* break/unnattached error bits or real input? */
1756 			if (!(line_status & LSR_RXRDY))
1757 				recv_data = 0;
1758 			else
1759 				recv_data = inb(com->data_port);
1760 #if defined(DDB) && defined(ALT_BREAK_TO_DEBUGGER)
1761 			/*
1762 			 * Solaris implements a new BREAK which is initiated
1763 			 * by a character sequence CR ~ ^b which is similar
1764 			 * to a familiar pattern used on Sun servers by the
1765 			 * Remote Console.
1766 			 */
1767 #define	KEY_CRTLB	2	/* ^B */
1768 #define	KEY_CR		13	/* CR '\r' */
1769 #define	KEY_TILDE	126	/* ~ */
1770 
1771 			if (com->unit == comconsole) {
1772 				static int brk_state1 = 0, brk_state2 = 0;
1773 				if (recv_data == KEY_CR) {
1774 					brk_state1 = recv_data;
1775 					brk_state2 = 0;
1776 				} else if (brk_state1 == KEY_CR && (recv_data == KEY_TILDE || recv_data == KEY_CRTLB)) {
1777 					if (recv_data == KEY_TILDE)
1778 						brk_state2 = recv_data;
1779 					else if (brk_state2 == KEY_TILDE && recv_data == KEY_CRTLB) {
1780 							breakpoint();
1781 							brk_state1 = brk_state2 = 0;
1782 							goto cont;
1783 					} else
1784 						brk_state2 = 0;
1785 				} else
1786 					brk_state1 = 0;
1787 			}
1788 #endif
1789 			if (line_status & (LSR_BI | LSR_FE | LSR_PE)) {
1790 				/*
1791 				 * Don't store BI if IGNBRK or FE/PE if IGNPAR.
1792 				 * Otherwise, push the work to a higher level
1793 				 * (to handle PARMRK) if we're bypassing.
1794 				 * Otherwise, convert BI/FE and PE+INPCK to 0.
1795 				 *
1796 				 * This makes bypassing work right in the
1797 				 * usual "raw" case (IGNBRK set, and IGNPAR
1798 				 * and INPCK clear).
1799 				 *
1800 				 * Note: BI together with FE/PE means just BI.
1801 				 */
1802 				if (line_status & LSR_BI) {
1803 #if defined(DDB) && defined(BREAK_TO_DEBUGGER)
1804 					if (com->unit == comconsole) {
1805 						breakpoint();
1806 						goto cont;
1807 					}
1808 #endif
1809 					if (com->tp == NULL
1810 					    || com->tp->t_iflag & IGNBRK)
1811 						goto cont;
1812 				} else {
1813 					if (com->tp == NULL
1814 					    || com->tp->t_iflag & IGNPAR)
1815 						goto cont;
1816 				}
1817 				if (com->tp->t_state & TS_CAN_BYPASS_L_RINT
1818 				    && (line_status & (LSR_BI | LSR_FE)
1819 					|| com->tp->t_iflag & INPCK))
1820 					recv_data = 0;
1821 			}
1822 			++com->bytes_in;
1823 			if (com->hotchar != 0 && recv_data == com->hotchar)
1824 				setsofttty();
1825 			ioptr = com->iptr;
1826 			if (ioptr >= com->ibufend)
1827 				CE_RECORD(com, CE_INTERRUPT_BUF_OVERFLOW);
1828 			else {
1829 				if (com->do_timestamp)
1830 					microtime(&com->timestamp);
1831 				++com_events;
1832 				schedsofttty();
1833 #if 0 /* for testing input latency vs efficiency */
1834 if (com->iptr - com->ibuf == 8)
1835 	setsofttty();
1836 #endif
1837 				ioptr[0] = recv_data;
1838 				ioptr[com->ierroff] = line_status;
1839 				com->iptr = ++ioptr;
1840 				if (ioptr == com->ihighwater
1841 				    && com->state & CS_RTS_IFLOW)
1842 					outb(com->modem_ctl_port,
1843 					     com->mcr_image &= ~MCR_RTS);
1844 				if (line_status & LSR_OE)
1845 					CE_RECORD(com, CE_OVERRUN);
1846 			}
1847 cont:
1848 			/*
1849 			 * "& 0x7F" is to avoid the gcc-1.40 generating a slow
1850 			 * jump from the top of the loop to here
1851 			 */
1852 			line_status = inb(com->line_status_port) & 0x7F;
1853 		}
1854 
1855 		/* modem status change? (always check before doing output) */
1856 		modem_status = inb(com->modem_status_port);
1857 		if (modem_status != com->last_modem_status) {
1858 			if (com->do_dcd_timestamp
1859 			    && !(com->last_modem_status & MSR_DCD)
1860 			    && modem_status & MSR_DCD)
1861 				microtime(&com->dcd_timestamp);
1862 
1863 			/*
1864 			 * Schedule high level to handle DCD changes.  Note
1865 			 * that we don't use the delta bits anywhere.  Some
1866 			 * UARTs mess them up, and it's easy to remember the
1867 			 * previous bits and calculate the delta.
1868 			 */
1869 			com->last_modem_status = modem_status;
1870 			if (!(com->state & CS_CHECKMSR)) {
1871 				com_events += LOTS_OF_EVENTS;
1872 				com->state |= CS_CHECKMSR;
1873 				setsofttty();
1874 			}
1875 
1876 			/* handle CTS change immediately for crisp flow ctl */
1877 			if (com->state & CS_CTS_OFLOW) {
1878 				if (modem_status & MSR_CTS)
1879 					com->state |= CS_ODEVREADY;
1880 				else
1881 					com->state &= ~CS_ODEVREADY;
1882 			}
1883 		}
1884 
1885 		/* output queued and everything ready? */
1886 		if (line_status & LSR_TXRDY
1887 		    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY)) {
1888 			ioptr = com->obufq.l_head;
1889 			if (com->tx_fifo_size > 1) {
1890 				u_int	ocount;
1891 
1892 				ocount = com->obufq.l_tail - ioptr;
1893 				if (ocount > com->tx_fifo_size)
1894 					ocount = com->tx_fifo_size;
1895 				com->bytes_out += ocount;
1896 				do
1897 					outb(com->data_port, *ioptr++);
1898 				while (--ocount != 0);
1899 			} else {
1900 				outb(com->data_port, *ioptr++);
1901 				++com->bytes_out;
1902 			}
1903 			com->obufq.l_head = ioptr;
1904 			if (COM_IIR_TXRDYBUG(com->flags)) {
1905 				int_ctl_new = int_ctl | IER_ETXRDY;
1906 			}
1907 			if (ioptr >= com->obufq.l_tail) {
1908 				struct lbq	*qp;
1909 
1910 				qp = com->obufq.l_next;
1911 				qp->l_queued = FALSE;
1912 				qp = qp->l_next;
1913 				if (qp != NULL) {
1914 					com->obufq.l_head = qp->l_head;
1915 					com->obufq.l_tail = qp->l_tail;
1916 					com->obufq.l_next = qp;
1917 				} else {
1918 					/* output just completed */
1919 					if (COM_IIR_TXRDYBUG(com->flags)) {
1920 						int_ctl_new = int_ctl & ~IER_ETXRDY;
1921 					}
1922 					com->state &= ~CS_BUSY;
1923 				}
1924 				if (!(com->state & CS_ODONE)) {
1925 					com_events += LOTS_OF_EVENTS;
1926 					com->state |= CS_ODONE;
1927 					setsofttty();	/* handle at high level ASAP */
1928 				}
1929 			}
1930 			if (COM_IIR_TXRDYBUG(com->flags) && (int_ctl != int_ctl_new)) {
1931 				outb(com->intr_ctl_port, int_ctl_new);
1932 			}
1933 		}
1934 
1935 		/* finished? */
1936 #ifndef COM_MULTIPORT
1937 		if ((inb(com->int_id_port) & IIR_IMASK) == IIR_NOPEND)
1938 #endif /* COM_MULTIPORT */
1939 			return;
1940 	}
1941 }
1942 
1943 static int
1944 sioioctl(struct dev_ioctl_args *ap)
1945 {
1946 	cdev_t dev = ap->a_head.a_dev;
1947 	caddr_t data = ap->a_data;
1948 	struct com_s	*com;
1949 	int		error;
1950 	int		mynor;
1951 	struct tty	*tp;
1952 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
1953 	u_long		oldcmd;
1954 	struct termios	term;
1955 #endif
1956 	mynor = minor(dev);
1957 
1958 	com = com_addr(MINOR_TO_UNIT(mynor));
1959 	if (com == NULL || com->gone)
1960 		return (ENODEV);
1961 	if (mynor & CONTROL_MASK) {
1962 		struct termios	*ct;
1963 
1964 		switch (mynor & CONTROL_MASK) {
1965 		case CONTROL_INIT_STATE:
1966 			ct = mynor & CALLOUT_MASK ? &com->it_out : &com->it_in;
1967 			break;
1968 		case CONTROL_LOCK_STATE:
1969 			ct = mynor & CALLOUT_MASK ? &com->lt_out : &com->lt_in;
1970 			break;
1971 		default:
1972 			return (ENODEV);	/* /dev/nodev */
1973 		}
1974 		switch (ap->a_cmd) {
1975 		case TIOCSETA:
1976 			error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
1977 			if (error != 0)
1978 				return (error);
1979 			*ct = *(struct termios *)data;
1980 			return (0);
1981 		case TIOCGETA:
1982 			*(struct termios *)data = *ct;
1983 			return (0);
1984 		case TIOCGETD:
1985 			*(int *)data = TTYDISC;
1986 			return (0);
1987 		case TIOCGWINSZ:
1988 			bzero(data, sizeof(struct winsize));
1989 			return (0);
1990 		default:
1991 			return (ENOTTY);
1992 		}
1993 	}
1994 	tp = com->tp;
1995 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
1996 	term = tp->t_termios;
1997 	oldcmd = ap->a_cmd;
1998 	error = ttsetcompat(tp, &ap->a_cmd, data, &term);
1999 	if (error != 0)
2000 		return (error);
2001 	if (ap->a_cmd != oldcmd)
2002 		data = (caddr_t)&term;
2003 #endif
2004 	if (ap->a_cmd == TIOCSETA || ap->a_cmd == TIOCSETAW ||
2005 	    ap->a_cmd == TIOCSETAF) {
2006 		int	cc;
2007 		struct termios *dt = (struct termios *)data;
2008 		struct termios *lt = mynor & CALLOUT_MASK
2009 				     ? &com->lt_out : &com->lt_in;
2010 
2011 		dt->c_iflag = (tp->t_iflag & lt->c_iflag)
2012 			      | (dt->c_iflag & ~lt->c_iflag);
2013 		dt->c_oflag = (tp->t_oflag & lt->c_oflag)
2014 			      | (dt->c_oflag & ~lt->c_oflag);
2015 		dt->c_cflag = (tp->t_cflag & lt->c_cflag)
2016 			      | (dt->c_cflag & ~lt->c_cflag);
2017 		dt->c_lflag = (tp->t_lflag & lt->c_lflag)
2018 			      | (dt->c_lflag & ~lt->c_lflag);
2019 		for (cc = 0; cc < NCCS; ++cc)
2020 			if (lt->c_cc[cc] != 0)
2021 				dt->c_cc[cc] = tp->t_cc[cc];
2022 		if (lt->c_ispeed != 0)
2023 			dt->c_ispeed = tp->t_ispeed;
2024 		if (lt->c_ospeed != 0)
2025 			dt->c_ospeed = tp->t_ospeed;
2026 	}
2027 	error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, data, ap->a_fflag, ap->a_cred);
2028 	if (error != ENOIOCTL)
2029 		return (error);
2030 	crit_enter();
2031 	error = ttioctl(tp, ap->a_cmd, data, ap->a_fflag);
2032 	disc_optim(tp, &tp->t_termios, com);
2033 	if (error != ENOIOCTL) {
2034 		crit_exit();
2035 		return (error);
2036 	}
2037 	switch (ap->a_cmd) {
2038 	case TIOCSBRK:
2039 		sio_setreg(com, com_cfcr, com->cfcr_image |= CFCR_SBREAK);
2040 		break;
2041 	case TIOCCBRK:
2042 		sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
2043 		break;
2044 	case TIOCSDTR:
2045 		(void)commctl(com, TIOCM_DTR, DMBIS);
2046 		break;
2047 	case TIOCCDTR:
2048 		(void)commctl(com, TIOCM_DTR, DMBIC);
2049 		break;
2050 	/*
2051 	 * XXX should disallow changing MCR_RTS if CS_RTS_IFLOW is set.  The
2052 	 * changes get undone on the next call to comparam().
2053 	 */
2054 	case TIOCMSET:
2055 		(void)commctl(com, *(int *)data, DMSET);
2056 		break;
2057 	case TIOCMBIS:
2058 		(void)commctl(com, *(int *)data, DMBIS);
2059 		break;
2060 	case TIOCMBIC:
2061 		(void)commctl(com, *(int *)data, DMBIC);
2062 		break;
2063 	case TIOCMGET:
2064 		*(int *)data = commctl(com, 0, DMGET);
2065 		break;
2066 	case TIOCMSDTRWAIT:
2067 		/* must be root since the wait applies to following logins */
2068 		error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
2069 		if (error != 0) {
2070 			crit_exit();
2071 			return (error);
2072 		}
2073 		com->dtr_wait = *(int *)data * hz / 100;
2074 		break;
2075 	case TIOCMGDTRWAIT:
2076 		*(int *)data = com->dtr_wait * 100 / hz;
2077 		break;
2078 	case TIOCTIMESTAMP:
2079 		com->do_timestamp = TRUE;
2080 		*(struct timeval *)data = com->timestamp;
2081 		break;
2082 	case TIOCDCDTIMESTAMP:
2083 		com->do_dcd_timestamp = TRUE;
2084 		*(struct timeval *)data = com->dcd_timestamp;
2085 		break;
2086 	default:
2087 		crit_exit();
2088 		error = pps_ioctl(ap->a_cmd, data, &com->pps);
2089 		if (error == ENODEV)
2090 			error = ENOTTY;
2091 		return (error);
2092 	}
2093 	crit_exit();
2094 	return (0);
2095 }
2096 
2097 static void
2098 siopoll(void *dummy, void *frame)
2099 {
2100 	int		unit;
2101 
2102 	if (com_events == 0)
2103 		return;
2104 repeat:
2105 	for (unit = 0; unit < sio_numunits; ++unit) {
2106 		struct com_s	*com;
2107 		int		incc;
2108 		struct tty	*tp;
2109 
2110 		com = com_addr(unit);
2111 		if (com == NULL)
2112 			continue;
2113 		tp = com->tp;
2114 		if (tp == NULL || com->gone) {
2115 			/*
2116 			 * Discard any events related to never-opened or
2117 			 * going-away devices.
2118 			 */
2119 			com_lock();
2120 			incc = com->iptr - com->ibuf;
2121 			com->iptr = com->ibuf;
2122 			if (com->state & CS_CHECKMSR) {
2123 				incc += LOTS_OF_EVENTS;
2124 				com->state &= ~CS_CHECKMSR;
2125 			}
2126 			com_events -= incc;
2127 			com_unlock();
2128 			continue;
2129 		}
2130 		if (com->iptr != com->ibuf) {
2131 			com_lock();
2132 			sioinput(com);
2133 			com_unlock();
2134 		}
2135 		if (com->state & CS_CHECKMSR) {
2136 			u_char	delta_modem_status;
2137 
2138 			com_lock();
2139 			delta_modem_status = com->last_modem_status
2140 					     ^ com->prev_modem_status;
2141 			com->prev_modem_status = com->last_modem_status;
2142 			com_events -= LOTS_OF_EVENTS;
2143 			com->state &= ~CS_CHECKMSR;
2144 			com_unlock();
2145 			if (delta_modem_status & MSR_DCD)
2146 				(*linesw[tp->t_line].l_modem)
2147 					(tp, com->prev_modem_status & MSR_DCD);
2148 		}
2149 		if (com->state & CS_ODONE) {
2150 			com_lock();
2151 			com_events -= LOTS_OF_EVENTS;
2152 			com->state &= ~CS_ODONE;
2153 			com_unlock();
2154 			if (!(com->state & CS_BUSY)
2155 			    && !(com->extra_state & CSE_BUSYCHECK)) {
2156 				callout_reset(&com->busy_ch, hz / 100,
2157 						siobusycheck, com);
2158 				com->extra_state |= CSE_BUSYCHECK;
2159 			}
2160 			(*linesw[tp->t_line].l_start)(tp);
2161 		}
2162 		if (com_events == 0)
2163 			break;
2164 	}
2165 	if (com_events >= LOTS_OF_EVENTS)
2166 		goto repeat;
2167 }
2168 
2169 static int
2170 comparam(struct tty *tp, struct termios *t)
2171 {
2172 	u_int		cfcr;
2173 	int		cflag;
2174 	struct com_s	*com;
2175 	u_int		divisor;
2176 	u_char		dlbh;
2177 	u_char		dlbl;
2178 	int		unit;
2179 
2180 	unit = DEV_TO_UNIT(tp->t_dev);
2181 	com = com_addr(unit);
2182 	if (com == NULL)
2183 		return (ENODEV);
2184 
2185 	/* do historical conversions */
2186 	if (t->c_ispeed == 0)
2187 		t->c_ispeed = t->c_ospeed;
2188 
2189 	/* check requested parameters */
2190 	if (t->c_ospeed == 0)
2191 		divisor = 0;
2192 	else {
2193 		if (t->c_ispeed != t->c_ospeed)
2194 			return (EINVAL);
2195 		divisor = siodivisor(com->rclk, t->c_ispeed);
2196 		if (divisor == 0)
2197 			return (EINVAL);
2198 	}
2199 
2200 	/* parameters are OK, convert them to the com struct and the device */
2201 	crit_enter();
2202 	if (divisor == 0)
2203 		(void)commctl(com, TIOCM_DTR, DMBIC);	/* hang up line */
2204 	else
2205 		(void)commctl(com, TIOCM_DTR, DMBIS);
2206 	cflag = t->c_cflag;
2207 	switch (cflag & CSIZE) {
2208 	case CS5:
2209 		cfcr = CFCR_5BITS;
2210 		break;
2211 	case CS6:
2212 		cfcr = CFCR_6BITS;
2213 		break;
2214 	case CS7:
2215 		cfcr = CFCR_7BITS;
2216 		break;
2217 	default:
2218 		cfcr = CFCR_8BITS;
2219 		break;
2220 	}
2221 	if (cflag & PARENB) {
2222 		cfcr |= CFCR_PENAB;
2223 		if (!(cflag & PARODD))
2224 			cfcr |= CFCR_PEVEN;
2225 	}
2226 	if (cflag & CSTOPB)
2227 		cfcr |= CFCR_STOPB;
2228 
2229 	if (com->hasfifo && divisor != 0) {
2230 		/*
2231 		 * Use a fifo trigger level low enough so that the input
2232 		 * latency from the fifo is less than about 16 msec and
2233 		 * the total latency is less than about 30 msec.  These
2234 		 * latencies are reasonable for humans.  Serial comms
2235 		 * protocols shouldn't expect anything better since modem
2236 		 * latencies are larger.
2237 		 *
2238 		 * Interrupts can be held up for long periods of time
2239 		 * due to inefficiencies in other parts of the kernel,
2240 		 * certain video cards, etc.  Setting the FIFO trigger
2241 		 * point to MEDH instead of HIGH gives us 694uS of slop
2242 		 * (8 character times) instead of 173uS (2 character times)
2243 		 * @ 115200 bps.
2244 		 */
2245 		com->fifo_image = t->c_ospeed <= 4800
2246 				  ? FIFO_ENABLE : FIFO_ENABLE | FIFO_RX_MEDH;
2247 #ifdef COM_ESP
2248 		/*
2249 		 * The Hayes ESP card needs the fifo DMA mode bit set
2250 		 * in compatibility mode.  If not, it will interrupt
2251 		 * for each character received.
2252 		 */
2253 		if (com->esp)
2254 			com->fifo_image |= FIFO_DMA_MODE;
2255 #endif
2256 		sio_setreg(com, com_fifo, com->fifo_image);
2257 	}
2258 
2259 	/*
2260 	 * This returns with interrupts disabled so that we can complete
2261 	 * the speed change atomically.  Keeping interrupts disabled is
2262 	 * especially important while com_data is hidden.
2263 	 */
2264 	(void) siosetwater(com, t->c_ispeed);
2265 
2266 	if (divisor != 0) {
2267 		sio_setreg(com, com_cfcr, cfcr | CFCR_DLAB);
2268 		/*
2269 		 * Only set the divisor registers if they would change,
2270 		 * since on some 16550 incompatibles (UMC8669F), setting
2271 		 * them while input is arriving them loses sync until
2272 		 * data stops arriving.
2273 		 */
2274 		dlbl = divisor & 0xFF;
2275 		if (sio_getreg(com, com_dlbl) != dlbl)
2276 			sio_setreg(com, com_dlbl, dlbl);
2277 		dlbh = divisor >> 8;
2278 		if (sio_getreg(com, com_dlbh) != dlbh)
2279 			sio_setreg(com, com_dlbh, dlbh);
2280 	}
2281 
2282 	sio_setreg(com, com_cfcr, com->cfcr_image = cfcr);
2283 
2284 	if (!(tp->t_state & TS_TTSTOP))
2285 		com->state |= CS_TTGO;
2286 
2287 	if (cflag & CRTS_IFLOW) {
2288 		if (com->st16650a) {
2289 			sio_setreg(com, com_cfcr, 0xbf);
2290 			sio_setreg(com, com_fifo,
2291 				   sio_getreg(com, com_fifo) | 0x40);
2292 		}
2293 		com->state |= CS_RTS_IFLOW;
2294 		/*
2295 		 * If CS_RTS_IFLOW just changed from off to on, the change
2296 		 * needs to be propagated to MCR_RTS.  This isn't urgent,
2297 		 * so do it later by calling comstart() instead of repeating
2298 		 * a lot of code from comstart() here.
2299 		 */
2300 	} else if (com->state & CS_RTS_IFLOW) {
2301 		com->state &= ~CS_RTS_IFLOW;
2302 		/*
2303 		 * CS_RTS_IFLOW just changed from on to off.  Force MCR_RTS
2304 		 * on here, since comstart() won't do it later.
2305 		 */
2306 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2307 		if (com->st16650a) {
2308 			sio_setreg(com, com_cfcr, 0xbf);
2309 			sio_setreg(com, com_fifo,
2310 				   sio_getreg(com, com_fifo) & ~0x40);
2311 		}
2312 	}
2313 
2314 
2315 	/*
2316 	 * Set up state to handle output flow control.
2317 	 * XXX - worth handling MDMBUF (DCD) flow control at the lowest level?
2318 	 * Now has 10+ msec latency, while CTS flow has 50- usec latency.
2319 	 */
2320 	com->state |= CS_ODEVREADY;
2321 	com->state &= ~CS_CTS_OFLOW;
2322 	if (cflag & CCTS_OFLOW) {
2323 		com->state |= CS_CTS_OFLOW;
2324 		if (!(com->last_modem_status & MSR_CTS))
2325 			com->state &= ~CS_ODEVREADY;
2326 		if (com->st16650a) {
2327 			sio_setreg(com, com_cfcr, 0xbf);
2328 			sio_setreg(com, com_fifo,
2329 				   sio_getreg(com, com_fifo) | 0x80);
2330 		}
2331 	} else {
2332 		if (com->st16650a) {
2333 			sio_setreg(com, com_cfcr, 0xbf);
2334 			sio_setreg(com, com_fifo,
2335 				   sio_getreg(com, com_fifo) & ~0x80);
2336 		}
2337 	}
2338 
2339 	sio_setreg(com, com_cfcr, com->cfcr_image);
2340 
2341 	/* XXX shouldn't call functions while intrs are disabled. */
2342 	disc_optim(tp, t, com);
2343 	/*
2344 	 * Recover from fiddling with CS_TTGO.  We used to call siointr1()
2345 	 * unconditionally, but that defeated the careful discarding of
2346 	 * stale input in sioopen().
2347 	 */
2348 	if (com->state >= (CS_BUSY | CS_TTGO))
2349 		siointr1(com);
2350 
2351 	com_unlock();
2352 	crit_exit();
2353 	comstart(tp);
2354 	if (com->ibufold != NULL) {
2355 		kfree(com->ibufold, M_DEVBUF);
2356 		com->ibufold = NULL;
2357 	}
2358 	return (0);
2359 }
2360 
2361 static int
2362 siosetwater(struct com_s *com, speed_t speed)
2363 {
2364 	int		cp4ticks;
2365 	u_char		*ibuf;
2366 	int		ibufsize;
2367 	struct tty	*tp;
2368 
2369 	/*
2370 	 * Make the buffer size large enough to handle a softtty interrupt
2371 	 * latency of about 2 ticks without loss of throughput or data
2372 	 * (about 3 ticks if input flow control is not used or not honoured,
2373 	 * but a bit less for CS5-CS7 modes).
2374 	 */
2375 	cp4ticks = speed / 10 / hz * 4;
2376 	for (ibufsize = 128; ibufsize < cp4ticks;)
2377 		ibufsize <<= 1;
2378 	if (ibufsize == com->ibufsize) {
2379 		com_lock();
2380 		return (0);
2381 	}
2382 
2383 	/*
2384 	 * Allocate input buffer.  The extra factor of 2 in the size is
2385 	 * to allow for an error byte for each input byte.
2386 	 */
2387 	ibuf = kmalloc(2 * ibufsize, M_DEVBUF, M_WAITOK | M_ZERO);
2388 
2389 	/* Initialize non-critical variables. */
2390 	com->ibufold = com->ibuf;
2391 	com->ibufsize = ibufsize;
2392 	tp = com->tp;
2393 	if (tp != NULL) {
2394 		tp->t_ififosize = 2 * ibufsize;
2395 		tp->t_ispeedwat = (speed_t)-1;
2396 		tp->t_ospeedwat = (speed_t)-1;
2397 	}
2398 
2399 	/*
2400 	 * Read current input buffer, if any.  Continue with interrupts
2401 	 * disabled.
2402 	 */
2403 	com_lock();
2404 	if (com->iptr != com->ibuf)
2405 		sioinput(com);
2406 
2407 	/*-
2408 	 * Initialize critical variables, including input buffer watermarks.
2409 	 * The external device is asked to stop sending when the buffer
2410 	 * exactly reaches high water, or when the high level requests it.
2411 	 * The high level is notified immediately (rather than at a later
2412 	 * clock tick) when this watermark is reached.
2413 	 * The buffer size is chosen so the watermark should almost never
2414 	 * be reached.
2415 	 * The low watermark is invisibly 0 since the buffer is always
2416 	 * emptied all at once.
2417 	 */
2418 	com->iptr = com->ibuf = ibuf;
2419 	com->ibufend = ibuf + ibufsize;
2420 	com->ierroff = ibufsize;
2421 	com->ihighwater = ibuf + 3 * ibufsize / 4;
2422 	return (0);
2423 }
2424 
2425 static void
2426 comstart(struct tty *tp)
2427 {
2428 	struct com_s	*com;
2429 	int		unit;
2430 
2431 	unit = DEV_TO_UNIT(tp->t_dev);
2432 	com = com_addr(unit);
2433 	if (com == NULL)
2434 		return;
2435 	crit_enter();
2436 	com_lock();
2437 	if (tp->t_state & TS_TTSTOP)
2438 		com->state &= ~CS_TTGO;
2439 	else
2440 		com->state |= CS_TTGO;
2441 	if (tp->t_state & TS_TBLOCK) {
2442 		if (com->mcr_image & MCR_RTS && com->state & CS_RTS_IFLOW)
2443 			outb(com->modem_ctl_port, com->mcr_image &= ~MCR_RTS);
2444 	} else {
2445 		if (!(com->mcr_image & MCR_RTS) && com->iptr < com->ihighwater
2446 		    && com->state & CS_RTS_IFLOW)
2447 			outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2448 	}
2449 	com_unlock();
2450 	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
2451 		ttwwakeup(tp);
2452 		crit_exit();
2453 		return;
2454 	}
2455 	if (tp->t_outq.c_cc != 0) {
2456 		struct lbq	*qp;
2457 		struct lbq	*next;
2458 
2459 		if (!com->obufs[0].l_queued) {
2460 			com->obufs[0].l_tail
2461 			    = com->obuf1 + q_to_b(&tp->t_outq, com->obuf1,
2462 						  sizeof com->obuf1);
2463 			com->obufs[0].l_next = NULL;
2464 			com->obufs[0].l_queued = TRUE;
2465 			com_lock();
2466 			if (com->state & CS_BUSY) {
2467 				qp = com->obufq.l_next;
2468 				while ((next = qp->l_next) != NULL)
2469 					qp = next;
2470 				qp->l_next = &com->obufs[0];
2471 			} else {
2472 				com->obufq.l_head = com->obufs[0].l_head;
2473 				com->obufq.l_tail = com->obufs[0].l_tail;
2474 				com->obufq.l_next = &com->obufs[0];
2475 				com->state |= CS_BUSY;
2476 			}
2477 			com_unlock();
2478 		}
2479 		if (tp->t_outq.c_cc != 0 && !com->obufs[1].l_queued) {
2480 			com->obufs[1].l_tail
2481 			    = com->obuf2 + q_to_b(&tp->t_outq, com->obuf2,
2482 						  sizeof com->obuf2);
2483 			com->obufs[1].l_next = NULL;
2484 			com->obufs[1].l_queued = TRUE;
2485 			com_lock();
2486 			if (com->state & CS_BUSY) {
2487 				qp = com->obufq.l_next;
2488 				while ((next = qp->l_next) != NULL)
2489 					qp = next;
2490 				qp->l_next = &com->obufs[1];
2491 			} else {
2492 				com->obufq.l_head = com->obufs[1].l_head;
2493 				com->obufq.l_tail = com->obufs[1].l_tail;
2494 				com->obufq.l_next = &com->obufs[1];
2495 				com->state |= CS_BUSY;
2496 			}
2497 			com_unlock();
2498 		}
2499 		tp->t_state |= TS_BUSY;
2500 	}
2501 	com_lock();
2502 	if (com->state >= (CS_BUSY | CS_TTGO))
2503 		siointr1(com);	/* fake interrupt to start output */
2504 	com_unlock();
2505 	ttwwakeup(tp);
2506 	crit_exit();
2507 }
2508 
2509 static void
2510 comstop(struct tty *tp, int rw)
2511 {
2512 	struct com_s	*com;
2513 
2514 	com = com_addr(DEV_TO_UNIT(tp->t_dev));
2515 	if (com == NULL || com->gone)
2516 		return;
2517 	com_lock();
2518 	if (rw & FWRITE) {
2519 		if (com->hasfifo)
2520 #ifdef COM_ESP
2521 		    /* XXX avoid h/w bug. */
2522 		    if (!com->esp)
2523 #endif
2524 			sio_setreg(com, com_fifo,
2525 				   FIFO_XMT_RST | com->fifo_image);
2526 		com->obufs[0].l_queued = FALSE;
2527 		com->obufs[1].l_queued = FALSE;
2528 		if (com->state & CS_ODONE)
2529 			com_events -= LOTS_OF_EVENTS;
2530 		com->state &= ~(CS_ODONE | CS_BUSY);
2531 		com->tp->t_state &= ~TS_BUSY;
2532 	}
2533 	if (rw & FREAD) {
2534 		if (com->hasfifo)
2535 #ifdef COM_ESP
2536 		    /* XXX avoid h/w bug. */
2537 		    if (!com->esp)
2538 #endif
2539 			sio_setreg(com, com_fifo,
2540 				   FIFO_RCV_RST | com->fifo_image);
2541 		com_events -= (com->iptr - com->ibuf);
2542 		com->iptr = com->ibuf;
2543 	}
2544 	com_unlock();
2545 	comstart(tp);
2546 }
2547 
2548 static int
2549 commctl(struct com_s *com, int bits, int how)
2550 {
2551 	int	mcr;
2552 	int	msr;
2553 
2554 	if (how == DMGET) {
2555 		bits = TIOCM_LE;	/* XXX - always enabled while open */
2556 		mcr = com->mcr_image;
2557 		if (mcr & MCR_DTR)
2558 			bits |= TIOCM_DTR;
2559 		if (mcr & MCR_RTS)
2560 			bits |= TIOCM_RTS;
2561 		msr = com->prev_modem_status;
2562 		if (msr & MSR_CTS)
2563 			bits |= TIOCM_CTS;
2564 		if (msr & MSR_DCD)
2565 			bits |= TIOCM_CD;
2566 		if (msr & MSR_DSR)
2567 			bits |= TIOCM_DSR;
2568 		/*
2569 		 * XXX - MSR_RI is naturally volatile, and we make MSR_TERI
2570 		 * more volatile by reading the modem status a lot.  Perhaps
2571 		 * we should latch both bits until the status is read here.
2572 		 */
2573 		if (msr & (MSR_RI | MSR_TERI))
2574 			bits |= TIOCM_RI;
2575 		return (bits);
2576 	}
2577 	mcr = 0;
2578 	if (bits & TIOCM_DTR)
2579 		mcr |= MCR_DTR;
2580 	if (bits & TIOCM_RTS)
2581 		mcr |= MCR_RTS;
2582 	if (com->gone)
2583 		return(0);
2584 	com_lock();
2585 	switch (how) {
2586 	case DMSET:
2587 		outb(com->modem_ctl_port,
2588 		     com->mcr_image = mcr | (com->mcr_image & MCR_IENABLE));
2589 		break;
2590 	case DMBIS:
2591 		outb(com->modem_ctl_port, com->mcr_image |= mcr);
2592 		break;
2593 	case DMBIC:
2594 		outb(com->modem_ctl_port, com->mcr_image &= ~mcr);
2595 		break;
2596 	}
2597 	com_unlock();
2598 	return (0);
2599 }
2600 
2601 static void
2602 siosettimeout(void)
2603 {
2604 	struct com_s	*com;
2605 	bool_t		someopen;
2606 	int		unit;
2607 
2608 	/*
2609 	 * Set our timeout period to 1 second if no polled devices are open.
2610 	 * Otherwise set it to max(1/200, 1/hz).
2611 	 * Enable timeouts iff some device is open.
2612 	 */
2613 	callout_stop(&sio_timeout_handle);
2614 	sio_timeout = hz;
2615 	someopen = FALSE;
2616 	for (unit = 0; unit < sio_numunits; ++unit) {
2617 		com = com_addr(unit);
2618 		if (com != NULL && com->tp != NULL
2619 		    && com->tp->t_state & TS_ISOPEN && !com->gone) {
2620 			someopen = TRUE;
2621 			if (com->poll || com->poll_output) {
2622 				sio_timeout = hz > 200 ? hz / 200 : 1;
2623 				break;
2624 			}
2625 		}
2626 	}
2627 	if (someopen) {
2628 		sio_timeouts_until_log = hz / sio_timeout;
2629 		callout_reset(&sio_timeout_handle, sio_timeout,
2630 				comwakeup, NULL);
2631 	} else {
2632 		/* Flush error messages, if any. */
2633 		sio_timeouts_until_log = 1;
2634 		comwakeup(NULL);
2635 		callout_stop(&sio_timeout_handle);
2636 	}
2637 }
2638 
2639 static void
2640 comwakeup(void *chan)
2641 {
2642 	struct com_s	*com;
2643 	int		unit;
2644 
2645 	callout_reset(&sio_timeout_handle, sio_timeout, comwakeup, NULL);
2646 
2647 	/*
2648 	 * Recover from lost output interrupts.
2649 	 * Poll any lines that don't use interrupts.
2650 	 */
2651 	for (unit = 0; unit < sio_numunits; ++unit) {
2652 		com = com_addr(unit);
2653 		if (com != NULL && !com->gone
2654 		    && (com->state >= (CS_BUSY | CS_TTGO) || com->poll)) {
2655 			com_lock();
2656 			siointr1(com);
2657 			com_unlock();
2658 		}
2659 	}
2660 
2661 	/*
2662 	 * Check for and log errors, but not too often.
2663 	 */
2664 	if (--sio_timeouts_until_log > 0)
2665 		return;
2666 	sio_timeouts_until_log = hz / sio_timeout;
2667 	for (unit = 0; unit < sio_numunits; ++unit) {
2668 		int	errnum;
2669 
2670 		com = com_addr(unit);
2671 		if (com == NULL)
2672 			continue;
2673 		if (com->gone)
2674 			continue;
2675 		for (errnum = 0; errnum < CE_NTYPES; ++errnum) {
2676 			u_int	delta;
2677 			u_long	total;
2678 
2679 			com_lock();
2680 			delta = com->delta_error_counts[errnum];
2681 			com->delta_error_counts[errnum] = 0;
2682 			com_unlock();
2683 			if (delta == 0)
2684 				continue;
2685 			total = com->error_counts[errnum] += delta;
2686 			log(LOG_ERR, "sio%d: %u more %s%s (total %lu)\n",
2687 			    unit, delta, error_desc[errnum],
2688 			    delta == 1 ? "" : "s", total);
2689 		}
2690 	}
2691 }
2692 
2693 static void
2694 disc_optim(struct tty *tp, struct termios *t, struct com_s *com)
2695 {
2696 	if (!(t->c_iflag & (ICRNL | IGNCR | IMAXBEL | INLCR | ISTRIP | IXON))
2697 	    && (!(t->c_iflag & BRKINT) || (t->c_iflag & IGNBRK))
2698 	    && (!(t->c_iflag & PARMRK)
2699 		|| (t->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
2700 	    && !(t->c_lflag & (ECHO | ICANON | IEXTEN | ISIG | PENDIN))
2701 	    && linesw[tp->t_line].l_rint == ttyinput)
2702 		tp->t_state |= TS_CAN_BYPASS_L_RINT;
2703 	else
2704 		tp->t_state &= ~TS_CAN_BYPASS_L_RINT;
2705 	com->hotchar = linesw[tp->t_line].l_hotchar;
2706 }
2707 
2708 /*
2709  * Following are all routines needed for SIO to act as console
2710  */
2711 #include <sys/cons.h>
2712 
2713 struct siocnstate {
2714 	u_char	dlbl;
2715 	u_char	dlbh;
2716 	u_char	ier;
2717 	u_char	cfcr;
2718 	u_char	mcr;
2719 };
2720 
2721 static speed_t siocngetspeed (Port_t, u_long rclk);
2722 static void siocnclose	(struct siocnstate *sp, Port_t iobase);
2723 static void siocnopen	(struct siocnstate *sp, Port_t iobase, int speed);
2724 static void siocntxwait	(Port_t iobase);
2725 
2726 static cn_probe_t siocnprobe;
2727 static cn_init_t siocninit;
2728 static cn_init_fini_t siocninit_fini;
2729 static cn_checkc_t siocncheckc;
2730 static cn_getc_t siocngetc;
2731 static cn_putc_t siocnputc;
2732 
2733 #if defined(__i386__) || defined(__x86_64__)
2734 CONS_DRIVER(sio, siocnprobe, siocninit, siocninit_fini,
2735 	    NULL, siocngetc, siocncheckc, siocnputc, NULL);
2736 #endif
2737 
2738 /* To get the GDB related variables */
2739 #if DDB > 0
2740 #include <ddb/ddb.h>
2741 #endif
2742 
2743 static void
2744 siocntxwait(Port_t iobase)
2745 {
2746 	int	timo;
2747 
2748 	/*
2749 	 * Wait for any pending transmission to finish.  Required to avoid
2750 	 * the UART lockup bug when the speed is changed, and for normal
2751 	 * transmits.
2752 	 */
2753 	timo = 100000;
2754 	while ((inb(iobase + com_lsr) & (LSR_TSRE | LSR_TXRDY))
2755 	       != (LSR_TSRE | LSR_TXRDY) && --timo != 0)
2756 		;
2757 }
2758 
2759 /*
2760  * Read the serial port specified and try to figure out what speed
2761  * it's currently running at.  We're assuming the serial port has
2762  * been initialized and is basicly idle.  This routine is only intended
2763  * to be run at system startup.
2764  *
2765  * If the value read from the serial port doesn't make sense, return 0.
2766  */
2767 
2768 static speed_t
2769 siocngetspeed(Port_t iobase, u_long rclk)
2770 {
2771 	u_int	divisor;
2772 	u_char	dlbh;
2773 	u_char	dlbl;
2774 	u_char  cfcr;
2775 
2776 	cfcr = inb(iobase + com_cfcr);
2777 	outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2778 
2779 	dlbl = inb(iobase + com_dlbl);
2780 	dlbh = inb(iobase + com_dlbh);
2781 
2782 	outb(iobase + com_cfcr, cfcr);
2783 
2784 	divisor = dlbh << 8 | dlbl;
2785 
2786 	/* XXX there should be more sanity checking. */
2787 	if (divisor == 0)
2788 		return (CONSPEED);
2789 	return (rclk / (16UL * divisor));
2790 }
2791 
2792 static void
2793 siocnopen(struct siocnstate *sp, Port_t iobase, int speed)
2794 {
2795 	u_int	divisor;
2796 	u_char	dlbh;
2797 	u_char	dlbl;
2798 
2799 	/*
2800 	 * Save all the device control registers except the fifo register
2801 	 * and set our default ones (cs8 -parenb speed=comdefaultrate).
2802 	 * We can't save the fifo register since it is read-only.
2803 	 */
2804 	sp->ier = inb(iobase + com_ier);
2805 	outb(iobase + com_ier, 0);	/* spltty() doesn't stop siointr() */
2806 	siocntxwait(iobase);
2807 	sp->cfcr = inb(iobase + com_cfcr);
2808 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2809 	sp->dlbl = inb(iobase + com_dlbl);
2810 	sp->dlbh = inb(iobase + com_dlbh);
2811 	/*
2812 	 * Only set the divisor registers if they would change, since on
2813 	 * some 16550 incompatibles (Startech), setting them clears the
2814 	 * data input register.  This also reduces the effects of the
2815 	 * UMC8669F bug.
2816 	 */
2817 	divisor = siodivisor(comdefaultrclk, speed);
2818 	dlbl = divisor & 0xFF;
2819 	if (sp->dlbl != dlbl)
2820 		outb(iobase + com_dlbl, dlbl);
2821 	dlbh = divisor >> 8;
2822 	if (sp->dlbh != dlbh)
2823 		outb(iobase + com_dlbh, dlbh);
2824 	outb(iobase + com_cfcr, CFCR_8BITS);
2825 	sp->mcr = inb(iobase + com_mcr);
2826 	/*
2827 	 * We don't want interrupts, but must be careful not to "disable"
2828 	 * them by clearing the MCR_IENABLE bit, since that might cause
2829 	 * an interrupt by floating the IRQ line.
2830 	 */
2831 	outb(iobase + com_mcr, (sp->mcr & MCR_IENABLE) | MCR_DTR | MCR_RTS);
2832 }
2833 
2834 static void
2835 siocnclose(struct siocnstate *sp, Port_t iobase)
2836 {
2837 	/*
2838 	 * Restore the device control registers.
2839 	 */
2840 	siocntxwait(iobase);
2841 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2842 	if (sp->dlbl != inb(iobase + com_dlbl))
2843 		outb(iobase + com_dlbl, sp->dlbl);
2844 	if (sp->dlbh != inb(iobase + com_dlbh))
2845 		outb(iobase + com_dlbh, sp->dlbh);
2846 	outb(iobase + com_cfcr, sp->cfcr);
2847 	/*
2848 	 * XXX damp oscillations of MCR_DTR and MCR_RTS by not restoring them.
2849 	 */
2850 	outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
2851 	outb(iobase + com_ier, sp->ier);
2852 }
2853 
2854 static void
2855 siocnprobe(struct consdev *cp)
2856 {
2857 	speed_t			boot_speed;
2858 	u_char			cfcr;
2859 	u_int			divisor;
2860 	int			unit;
2861 	struct siocnstate	sp;
2862 
2863 	/*
2864 	 * Find our first enabled console, if any.  If it is a high-level
2865 	 * console device, then initialize it and return successfully.
2866 	 * If it is a low-level console device, then initialize it and
2867 	 * return unsuccessfully.  It must be initialized in both cases
2868 	 * for early use by console drivers and debuggers.  Initializing
2869 	 * the hardware is not necessary in all cases, since the i/o
2870 	 * routines initialize it on the fly, but it is necessary if
2871 	 * input might arrive while the hardware is switched back to an
2872 	 * uninitialized state.  We can't handle multiple console devices
2873 	 * yet because our low-level routines don't take a device arg.
2874 	 * We trust the user to set the console flags properly so that we
2875 	 * don't need to probe.
2876 	 */
2877 	cp->cn_pri = CN_DEAD;
2878 
2879 	for (unit = 0; unit < 16; unit++) { /* XXX need to know how many */
2880 		int flags;
2881 		int disabled;
2882 		if (resource_int_value("sio", unit, "disabled", &disabled) == 0) {
2883 			if (disabled)
2884 				continue;
2885 		}
2886 		if (resource_int_value("sio", unit, "flags", &flags))
2887 			continue;
2888 		if (COM_CONSOLE(flags) || COM_DEBUGGER(flags)) {
2889 			int port;
2890 			Port_t iobase;
2891 
2892 			if (resource_int_value("sio", unit, "port", &port))
2893 				continue;
2894 			iobase = port;
2895 			crit_enter();
2896 			if (boothowto & RB_SERIAL) {
2897 				boot_speed =
2898 				    siocngetspeed(iobase, comdefaultrclk);
2899 				if (boot_speed)
2900 					comdefaultrate = boot_speed;
2901 			}
2902 
2903 			/*
2904 			 * Initialize the divisor latch.  We can't rely on
2905 			 * siocnopen() to do this the first time, since it
2906 			 * avoids writing to the latch if the latch appears
2907 			 * to have the correct value.  Also, if we didn't
2908 			 * just read the speed from the hardware, then we
2909 			 * need to set the speed in hardware so that
2910 			 * switching it later is null.
2911 			 */
2912 			cfcr = inb(iobase + com_cfcr);
2913 			outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2914 			divisor = siodivisor(comdefaultrclk, comdefaultrate);
2915 			outb(iobase + com_dlbl, divisor & 0xff);
2916 			outb(iobase + com_dlbh, divisor >> 8);
2917 			outb(iobase + com_cfcr, cfcr);
2918 
2919 			siocnopen(&sp, iobase, comdefaultrate);
2920 
2921 			crit_exit();
2922 			if (COM_CONSOLE(flags) && !COM_LLCONSOLE(flags)) {
2923 				cp->cn_probegood = 1;
2924 				cp->cn_private = (void *)(intptr_t)unit;
2925 				cp->cn_pri = COM_FORCECONSOLE(flags)
2926 					     || boothowto & RB_SERIAL
2927 					     ? CN_REMOTE : CN_NORMAL;
2928 				siocniobase = iobase;
2929 				siocnunit = unit;
2930 			}
2931 			if (COM_DEBUGGER(flags) && gdb_tab == NULL) {
2932 				kprintf("sio%d: gdb debugging port\n", unit);
2933 				siogdbiobase = iobase;
2934 				siogdbunit = unit;
2935 #if DDB > 0
2936 				cp->cn_gdbprivate = (void *)(intptr_t)unit;
2937 				gdb_tab = cp;
2938 #endif
2939 			}
2940 		}
2941 	}
2942 #if defined(__i386__) || defined(__x86_64__)
2943 #if DDB > 0
2944 	/*
2945 	 * XXX Ugly Compatability.
2946 	 * If no gdb port has been specified, set it to be the console
2947 	 * as some configuration files don't specify the gdb port.
2948 	 */
2949 	if (gdb_tab == NULL && (boothowto & RB_GDB)) {
2950 		kprintf("Warning: no GDB port specified. Defaulting to sio%d.\n",
2951 			siocnunit);
2952 		kprintf("Set flag 0x80 on desired GDB port in your\n");
2953 		kprintf("configuration file (currently sio only).\n");
2954 		siogdbiobase = siocniobase;
2955 		siogdbunit = siocnunit;
2956 		cp->cn_gdbprivate = (void *)(intptr_t)siocnunit;
2957 		gdb_tab = cp;
2958 	}
2959 #endif
2960 #endif
2961 }
2962 
2963 static void
2964 siocninit(struct consdev *cp)
2965 {
2966 	comconsole = (int)(intptr_t)cp->cn_private;
2967 }
2968 
2969 static void
2970 siocninit_fini(struct consdev *cp)
2971 {
2972 	cdev_t dev;
2973 	int unit;
2974 
2975 	if (cp->cn_probegood) {
2976 		unit = (int)(intptr_t)cp->cn_private;
2977 		/*
2978 		 * Call devfs_find_device_by_name on ttydX to find the correct device,
2979 		 * as it should have been created already at this point by the
2980 		 * attach routine.
2981 		 * If it isn't found, the serial port was not attached at all and we
2982 		 * shouldn't be here, so assert this case.
2983 		 */
2984 		dev = devfs_find_device_by_name("ttyd%r", unit);
2985 
2986 		KKASSERT(dev != NULL);
2987 		cp->cn_dev = dev;
2988 	}
2989 }
2990 
2991 static int
2992 siocncheckc(void *private)
2993 {
2994 	int	c;
2995 	int	unit = (int)(intptr_t)private;
2996 	Port_t	iobase;
2997 	struct siocnstate	sp;
2998 
2999 	if (unit == siogdbunit)
3000 		iobase = siogdbiobase;
3001 	else
3002 		iobase = siocniobase;
3003 	crit_enter();
3004 	siocnopen(&sp, iobase, comdefaultrate);
3005 	if (inb(iobase + com_lsr) & LSR_RXRDY)
3006 		c = inb(iobase + com_data);
3007 	else
3008 		c = -1;
3009 	siocnclose(&sp, iobase);
3010 	crit_exit();
3011 	return (c);
3012 }
3013 
3014 
3015 int
3016 siocngetc(void *private)
3017 {
3018 	int	c;
3019 	int	unit = (int)(intptr_t)private;
3020 	Port_t	iobase;
3021 	struct siocnstate	sp;
3022 
3023 	if (unit == siogdbunit)
3024 		iobase = siogdbiobase;
3025 	else
3026 		iobase = siocniobase;
3027 	crit_enter();
3028 	siocnopen(&sp, iobase, comdefaultrate);
3029 	while (!(inb(iobase + com_lsr) & LSR_RXRDY))
3030 		;
3031 	c = inb(iobase + com_data);
3032 	siocnclose(&sp, iobase);
3033 	crit_exit();
3034 	return (c);
3035 }
3036 
3037 void
3038 siocnputc(void *private, int c)
3039 {
3040 	int	unit = (int)(intptr_t)private;
3041 	struct siocnstate	sp;
3042 	Port_t	iobase;
3043 
3044 	if (unit == siogdbunit)
3045 		iobase = siogdbiobase;
3046 	else
3047 		iobase = siocniobase;
3048 	crit_enter();
3049 	siocnopen(&sp, iobase, comdefaultrate);
3050 	siocntxwait(iobase);
3051 	outb(iobase + com_data, c);
3052 	siocnclose(&sp, iobase);
3053 	crit_exit();
3054 }
3055 
3056 DRIVER_MODULE(sio, isa, sio_isa_driver, sio_devclass, 0, 0);
3057 DRIVER_MODULE(sio, acpi, sio_isa_driver, sio_devclass, 0, 0);
3058 #if NPCI > 0
3059 DRIVER_MODULE(sio, pci, sio_pci_driver, sio_devclass, 0, 0);
3060 #endif
3061 #if NPUC > 0
3062 DRIVER_MODULE(sio, puc, sio_puc_driver, sio_devclass, 0, 0);
3063 #endif
3064