xref: /dragonfly/sys/dev/serial/sio/sio.c (revision 38c2ea22)
1 /*-
2  * (MPSAFE)
3  *
4  * Copyright (c) 1991 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $FreeBSD: src/sys/isa/sio.c,v 1.291.2.35 2003/05/18 08:51:15 murray Exp $
36  *	from: @(#)com.c	7.5 (Berkeley) 5/16/91
37  *	from: i386/isa sio.c,v 1.234
38  */
39 
40 #include "opt_comconsole.h"
41 #include "opt_compat.h"
42 #include "opt_ddb.h"
43 #include "opt_sio.h"
44 #include "use_pci.h"
45 #include "use_puc.h"
46 
47 /*
48  * Serial driver, based on 386BSD-0.1 com driver.
49  * Mostly rewritten to use pseudo-DMA.
50  * Works for National Semiconductor NS8250-NS16550AF UARTs.
51  * COM driver, based on HP dca driver.
52  *
53  * Changes for PC-Card integration:
54  *	- Added PC-Card driver table and handlers
55  */
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/reboot.h>
59 #include <sys/malloc.h>
60 #include <sys/tty.h>
61 #include <sys/proc.h>
62 #include <sys/priv.h>
63 #include <sys/module.h>
64 #include <sys/conf.h>
65 #include <sys/dkstat.h>
66 #include <sys/fcntl.h>
67 #include <sys/interrupt.h>
68 #include <sys/kernel.h>
69 #include <sys/syslog.h>
70 #include <sys/sysctl.h>
71 #include <sys/bus.h>
72 #include <sys/rman.h>
73 #include <sys/timepps.h>
74 #include <sys/thread2.h>
75 #include <sys/devfs.h>
76 
77 #include <machine/limits.h>
78 
79 #include <bus/isa/isareg.h>
80 #include <bus/isa/isavar.h>
81 #if NPCI > 0
82 #include <bus/pci/pcireg.h>
83 #include <bus/pci/pcivar.h>
84 #endif
85 #if NPUC > 0
86 #include <dev/misc/puc/pucvar.h>
87 #endif
88 #include <machine/lock.h>
89 
90 #include <machine/clock.h>
91 #ifndef SMP
92 #include <machine/lock.h>
93 #endif
94 
95 #include "sioreg.h"
96 #include "sio_private.h"
97 
98 #ifdef COM_ESP
99 #include "../ic_layer/esp.h"
100 #endif
101 
102 #define	LOTS_OF_EVENTS	64	/* helps separate urgent events from input */
103 
104 #define	CALLOUT_MASK		0x80
105 #define	CONTROL_MASK		0x60
106 #define	CONTROL_INIT_STATE	0x20
107 #define	CONTROL_LOCK_STATE	0x40
108 #define	DEV_TO_UNIT(dev)	(MINOR_TO_UNIT(minor(dev)))
109 #define	MINOR_TO_UNIT(mynor)	((((mynor) & ~0xffffU) >> (8 + 3)) \
110 				 | ((mynor) & 0x1f))
111 #define	UNIT_TO_MINOR(unit)	((((unit) & ~0x1fU) << (8 + 3)) \
112 				 | ((unit) & 0x1f))
113 
114 #define	com_scr		7	/* scratch register for 16450-16550 (R/W) */
115 
116 #define	sio_getreg(com, off) \
117 	(bus_space_read_1((com)->bst, (com)->bsh, (off)))
118 #define	sio_setreg(com, off, value) \
119 	(bus_space_write_1((com)->bst, (com)->bsh, (off), (value)))
120 
121 /*
122  * com state bits.
123  * (CS_BUSY | CS_TTGO) and (CS_BUSY | CS_TTGO | CS_ODEVREADY) must be higher
124  * than the other bits so that they can be tested as a group without masking
125  * off the low bits.
126  *
127  * The following com and tty flags correspond closely:
128  *	CS_BUSY		= TS_BUSY (maintained by comstart(), siopoll() and
129  *				   comstop())
130  *	CS_TTGO		= ~TS_TTSTOP (maintained by comparam() and comstart())
131  *	CS_CTS_OFLOW	= CCTS_OFLOW (maintained by comparam())
132  *	CS_RTS_IFLOW	= CRTS_IFLOW (maintained by comparam())
133  * TS_FLUSH is not used.
134  * XXX I think TIOCSETA doesn't clear TS_TTSTOP when it clears IXON.
135  * XXX CS_*FLOW should be CF_*FLOW in com->flags (control flags not state).
136  */
137 #define	CS_BUSY		0x80	/* output in progress */
138 #define	CS_TTGO		0x40	/* output not stopped by XOFF */
139 #define	CS_ODEVREADY	0x20	/* external device h/w ready (CTS) */
140 #define	CS_CHECKMSR	1	/* check of MSR scheduled */
141 #define	CS_CTS_OFLOW	2	/* use CTS output flow control */
142 #define	CS_DTR_OFF	0x10	/* DTR held off */
143 #define	CS_ODONE	4	/* output completed */
144 #define	CS_RTS_IFLOW	8	/* use RTS input flow control */
145 #define	CSE_BUSYCHECK	1	/* siobusycheck() scheduled */
146 
147 static	char const * const	error_desc[] = {
148 #define	CE_OVERRUN			0
149 	"silo overflow",
150 #define	CE_INTERRUPT_BUF_OVERFLOW	1
151 	"interrupt-level buffer overflow",
152 #define	CE_TTY_BUF_OVERFLOW		2
153 	"tty-level buffer overflow",
154 };
155 
156 #ifdef COM_ESP
157 static	int	espattach	(struct com_s *com, Port_t esp_port);
158 #endif
159 static	int	sio_isa_attach	(device_t dev);
160 
161 static	timeout_t siobusycheck;
162 static	u_int	siodivisor	(u_long rclk, speed_t speed);
163 static	timeout_t siodtrwakeup;
164 static	void	comhardclose	(struct com_s *com);
165 static	void	sioinput	(struct com_s *com);
166 static	void	siointr1	(struct com_s *com);
167 static	void	siointr		(void *arg);
168 static	int	commctl		(struct com_s *com, int bits, int how);
169 static	int	comparam	(struct tty *tp, struct termios *t);
170 static	inthand2_t siopoll;
171 static	int	sio_isa_probe	(device_t dev);
172 static	void	siosettimeout	(void);
173 static	int	siosetwater	(struct com_s *com, speed_t speed);
174 static	void	comstart	(struct tty *tp);
175 static	void	comstop		(struct tty *tp, int rw);
176 static	timeout_t comwakeup;
177 static	void	disc_optim	(struct tty	*tp, struct termios *t,
178 				     struct com_s *com);
179 
180 #if NPCI > 0
181 static	int	sio_pci_attach (device_t dev);
182 static	void	sio_pci_kludge_unit (device_t dev);
183 static	int	sio_pci_probe (device_t dev);
184 #endif /* NPCI > 0 */
185 
186 #if NPUC > 0
187 static	int	sio_puc_attach (device_t dev);
188 static	int	sio_puc_probe (device_t dev);
189 #endif /* NPUC > 0 */
190 
191 static char driver_name[] = "sio";
192 
193 /* table and macro for fast conversion from a unit number to its com struct */
194 devclass_t	sio_devclass;
195 #define	com_addr(unit)	((struct com_s *) \
196 			 devclass_get_softc(sio_devclass, unit))
197 
198 static device_method_t sio_isa_methods[] = {
199 	/* Device interface */
200 	DEVMETHOD(device_probe,		sio_isa_probe),
201 	DEVMETHOD(device_attach,	sio_isa_attach),
202 
203 	{ 0, 0 }
204 };
205 
206 static driver_t sio_isa_driver = {
207 	driver_name,
208 	sio_isa_methods,
209 	sizeof(struct com_s),
210 };
211 
212 #if NPCI > 0
213 static device_method_t sio_pci_methods[] = {
214 	/* Device interface */
215 	DEVMETHOD(device_probe,		sio_pci_probe),
216 	DEVMETHOD(device_attach,	sio_pci_attach),
217 
218 	{ 0, 0 }
219 };
220 
221 static driver_t sio_pci_driver = {
222 	driver_name,
223 	sio_pci_methods,
224 	sizeof(struct com_s),
225 };
226 #endif /* NPCI > 0 */
227 
228 #if NPUC > 0
229 static device_method_t sio_puc_methods[] = {
230 	/* Device interface */
231 	DEVMETHOD(device_probe,		sio_puc_probe),
232 	DEVMETHOD(device_attach,	sio_puc_attach),
233 
234 	{ 0, 0 }
235 };
236 
237 static driver_t sio_puc_driver = {
238 	driver_name,
239 	sio_puc_methods,
240 	sizeof(struct com_s),
241 };
242 #endif /* NPUC > 0 */
243 
244 static	d_open_t	sioopen;
245 static	d_close_t	sioclose;
246 static	d_read_t	sioread;
247 static	d_write_t	siowrite;
248 static	d_ioctl_t	sioioctl;
249 
250 static struct dev_ops sio_ops = {
251 	{ driver_name, 0, D_TTY },
252 	.d_open =	sioopen,
253 	.d_close =	sioclose,
254 	.d_read =	sioread,
255 	.d_write =	siowrite,
256 	.d_ioctl =	sioioctl,
257 	.d_kqfilter =	ttykqfilter,
258 	.d_revoke =	ttyrevoke
259 };
260 
261 int	comconsole = -1;
262 static	volatile speed_t	comdefaultrate = CONSPEED;
263 static	u_long			comdefaultrclk = DEFAULT_RCLK;
264 SYSCTL_ULONG(_machdep, OID_AUTO, conrclk, CTLFLAG_RW, &comdefaultrclk, 0, "");
265 static	u_int	com_events;	/* input chars + weighted output completions */
266 static	Port_t	siocniobase;
267 static	int	siocnunit;
268 static	Port_t	siogdbiobase;
269 static	int	siogdbunit = -1;
270 static	bool_t	sio_registered;
271 static	int	sio_timeout;
272 static	int	sio_timeouts_until_log;
273 static	struct	callout	sio_timeout_handle;
274 static	int	sio_numunits;
275 
276 #ifdef COM_ESP
277 /* XXX configure this properly. */
278 static	Port_t	likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, };
279 static	Port_t	likely_esp_ports[] = { 0x140, 0x180, 0x280, 0 };
280 #endif
281 
282 /*
283  * handle sysctl read/write requests for console speed
284  *
285  * In addition to setting comdefaultrate for I/O through /dev/console,
286  * also set the initial and lock values for the /dev/ttyXX device
287  * if there is one associated with the console.  Finally, if the /dev/tty
288  * device has already been open, change the speed on the open running port
289  * itself.
290  */
291 
292 static int
293 sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)
294 {
295 	int error;
296 	speed_t newspeed;
297 	struct com_s *com;
298 	struct tty *tp;
299 
300 	lwkt_gettoken(&tty_token);
301 	newspeed = comdefaultrate;
302 
303 	error = sysctl_handle_opaque(oidp, &newspeed, sizeof newspeed, req);
304 	if (error || !req->newptr) {
305 		lwkt_reltoken(&tty_token);
306 		return (error);
307 	}
308 
309 	comdefaultrate = newspeed;
310 
311 	if (comconsole < 0) {	/* serial console not selected? */
312 		lwkt_reltoken(&tty_token);
313 		return (0);
314 	}
315 
316 	com = com_addr(comconsole);
317 	if (com == NULL) {
318 		lwkt_reltoken(&tty_token);
319 		return (ENXIO);
320 	}
321 
322 	/*
323 	 * set the initial and lock rates for /dev/ttydXX and /dev/cuaXX
324 	 * (note, the lock rates really are boolean -- if non-zero, disallow
325 	 *  speed changes)
326 	 */
327 	com->it_in.c_ispeed  = com->it_in.c_ospeed =
328 	com->lt_in.c_ispeed  = com->lt_in.c_ospeed =
329 	com->it_out.c_ispeed = com->it_out.c_ospeed =
330 	com->lt_out.c_ispeed = com->lt_out.c_ospeed = comdefaultrate;
331 
332 	/*
333 	 * if we're open, change the running rate too
334 	 */
335 	tp = com->tp;
336 	if (tp && (tp->t_state & TS_ISOPEN)) {
337 		tp->t_termios.c_ispeed =
338 		tp->t_termios.c_ospeed = comdefaultrate;
339 		crit_enter();
340 		error = comparam(tp, &tp->t_termios);
341 		crit_exit();
342 	}
343 	lwkt_reltoken(&tty_token);
344 	return error;
345 }
346 
347 SYSCTL_PROC(_machdep, OID_AUTO, conspeed, CTLTYPE_INT | CTLFLAG_RW,
348 	    0, 0, sysctl_machdep_comdefaultrate, "I", "");
349 
350 #if NPCI > 0
351 struct pci_ids {
352 	u_int32_t	type;
353 	const char	*desc;
354 	int		rid;
355 };
356 
357 static struct pci_ids pci_ids[] = {
358 	{ 0x100812b9, "3COM PCI FaxModem", 0x10 },
359 	{ 0x2000131f, "CyberSerial (1-port) 16550", 0x10 },
360 	{ 0x01101407, "Koutech IOFLEX-2S PCI Dual Port Serial", 0x10 },
361 	{ 0x01111407, "Koutech IOFLEX-2S PCI Dual Port Serial", 0x10 },
362 	{ 0x048011c1, "Lucent kermit based PCI Modem", 0x14 },
363 	{ 0x95211415, "Oxford Semiconductor PCI Dual Port Serial", 0x10 },
364 	{ 0x7101135e, "SeaLevel Ultra 530.PCI Single Port Serial", 0x18 },
365 	{ 0x0000151f, "SmartLink 5634PCV SurfRider", 0x10 },
366 	{ 0x98459710, "Netmos Nm9845 PCI Bridge with Dual UART", 0x10 },
367 	{ 0x00000000, NULL, 0 }
368 };
369 
370 static int
371 sio_pci_attach(device_t dev)
372 {
373 	u_int32_t	type;
374 	struct pci_ids	*id;
375 
376 	type = pci_get_devid(dev);
377 	id = pci_ids;
378 	while (id->type && id->type != type)
379 		id++;
380 	if (id->desc == NULL)
381 		return (ENXIO);
382 	sio_pci_kludge_unit(dev);
383 	return (sioattach(dev, id->rid, 0UL));
384 }
385 
386 /*
387  * Don't cut and paste this to other drivers.  It is a horrible kludge
388  * which will fail to work and also be unnecessary in future versions.
389  */
390 static void
391 sio_pci_kludge_unit(device_t dev)
392 {
393 	devclass_t	dc;
394 	int		err;
395 	int		start;
396 	int		unit;
397 
398 	unit = 0;
399 	start = 0;
400 	while (resource_int_value("sio", unit, "port", &start) == 0 &&
401 	    start > 0)
402 		unit++;
403 	if (device_get_unit(dev) < unit) {
404 		dc = device_get_devclass(dev);
405 		while (devclass_get_device(dc, unit))
406 			unit++;
407 		device_printf(dev, "moving to sio%d\n", unit);
408 		err = device_set_unit(dev, unit);	/* EVIL DO NOT COPY */
409 		if (err)
410 			device_printf(dev, "error moving device %d\n", err);
411 	}
412 }
413 
414 static int
415 sio_pci_probe(device_t dev)
416 {
417 	u_int32_t	type;
418 	struct pci_ids	*id;
419 
420 	type = pci_get_devid(dev);
421 	id = pci_ids;
422 	while (id->type && id->type != type)
423 		id++;
424 	if (id->desc == NULL)
425 		return (ENXIO);
426 	device_set_desc(dev, id->desc);
427 	return (sioprobe(dev, id->rid, 0UL));
428 }
429 #endif /* NPCI > 0 */
430 
431 #if NPUC > 0
432 static int
433 sio_puc_attach(device_t dev)
434 {
435 	uintptr_t rclk;
436 
437 	if (BUS_READ_IVAR(device_get_parent(dev), dev, PUC_IVAR_FREQ,
438 	    &rclk) != 0)
439 		rclk = DEFAULT_RCLK;
440 	return (sioattach(dev, 0, rclk));
441 }
442 
443 static int
444 sio_puc_probe(device_t dev)
445 {
446 	uintptr_t rclk;
447 
448 	if (BUS_READ_IVAR(device_get_parent(dev), dev, PUC_IVAR_FREQ,
449 	    &rclk) != 0)
450 		rclk = DEFAULT_RCLK;
451 	return (sioprobe(dev, 0, rclk));
452 }
453 #endif /* NPUC */
454 
455 static struct isa_pnp_id sio_ids[] = {
456 	{0x0005d041, "Standard PC COM port"},	/* PNP0500 */
457 	{0x0105d041, "16550A-compatible COM port"},	/* PNP0501 */
458 	{0x0205d041, "Multiport serial device (non-intelligent 16550)"}, /* PNP0502 */
459 	{0x1005d041, "Generic IRDA-compatible device"},	/* PNP0510 */
460 	{0x1105d041, "Generic IRDA-compatible device"},	/* PNP0511 */
461 	/* Devices that do not have a compatid */
462 	{0x12206804, NULL},     /* ACH2012 - 5634BTS 56K Video Ready Modem */
463 	{0x7602a904, NULL},	/* AEI0276 - 56K v.90 Fax Modem (LKT) */
464 	{0x00007905, NULL},	/* AKY0000 - 56K Plug&Play Modem */
465 	{0x21107905, NULL},	/* AKY1021 - 56K Plug&Play Modem */
466 	{0x01405407, NULL},	/* AZT4001 - AZT3000 PnP SOUND DEVICE, MODEM */
467 	{0x56039008, NULL},	/* BDP0356 - Best Data 56x2 */
468 	{0x56159008, NULL},	/* BDP1556 - B.D. Smart One 56SPS,Voice Modem*/
469 	{0x36339008, NULL},	/* BDP3336 - Best Data Prods. 336F */
470 	{0x0014490a, NULL},	/* BRI1400 - Boca 33.6 PnP */
471 	{0x0015490a, NULL},	/* BRI1500 - Internal Fax Data */
472 	{0x0034490a, NULL},	/* BRI3400 - Internal ACF Modem */
473 	{0x0094490a, NULL},	/* BRI9400 - Boca K56Flex PnP */
474 	{0x00b4490a, NULL},	/* BRIB400 - Boca 56k PnP */
475 	{0x0030320d, NULL},	/* CIR3000 - Cirrus Logic V43 */
476 	{0x0100440e, NULL},	/* CRD0001 - Cardinal MVP288IV ? */
477 	{0x01308c0e, NULL},	/* CTL3001 - Creative Labs Phoneblaster */
478 	{0x36033610, NULL},     /* DAV0336 - DAVICOM 336PNP MODEM */
479 	{0x01009416, NULL},     /* ETT0001 - E-Tech Bullet 33k6 PnP */
480 	{0x0000aa1a, NULL},	/* FUJ0000 - FUJITSU Modem 33600 PNP/I2 */
481 	{0x1200c31e, NULL},	/* GVC0012 - VF1128HV-R9 (win modem?) */
482 	{0x0303c31e, NULL},	/* GVC0303 - MaxTech 33.6 PnP D/F/V */
483 	{0x0505c31e, NULL},	/* GVC0505 - GVC 56k Faxmodem */
484 	{0x0116c31e, NULL},	/* GVC1601 - Rockwell V.34 Plug & Play Modem */
485 	{0x0050c31e, NULL},	/* GVC5000 - some GVC modem */
486 	{0x3800f91e, NULL},	/* GWY0038 - Telepath with v.90 */
487 	{0x9062f91e, NULL},	/* GWY6290 - Telepath with x2 Technology */
488 	{0x8100e425, NULL},	/* IOD0081 - I-O DATA DEVICE,INC. IFML-560 */
489 	{0x21002534, NULL},	/* MAE0021 - Jetstream Int V.90 56k Voice Series 2*/
490 	{0x0000f435, NULL},	/* MOT0000 - Motorola ModemSURFR 33.6 Intern */
491 	{0x5015f435, NULL},	/* MOT1550 - Motorola ModemSURFR 56K Modem */
492 	{0xf015f435, NULL},	/* MOT15F0 - Motorola VoiceSURFR 56K Modem */
493 	{0x6045f435, NULL},	/* MOT4560 - Motorola ? */
494 	{0x61e7a338, NULL},	/* NECE761 - 33.6Modem */
495  	{0x08804f3f, NULL},	/* OZO8008 - Zoom  (33.6k Modem) */
496 	{0x0f804f3f, NULL},	/* OZO800f - Zoom 2812 (56k Modem) */
497 	{0x39804f3f, NULL},	/* OZO8039 - Zoom 56k flex */
498 	{0x00914f3f, NULL},	/* OZO9100 - Zoom 2919 (K56 Faxmodem) */
499 	{0x3024a341, NULL},	/* PMC2430 - Pace 56 Voice Internal Modem */
500 	{0x1000eb49, NULL},	/* ROK0010 - Rockwell ? */
501 	{0x1200b23d, NULL},     /* RSS0012 - OMRON ME5614ISA */
502 	{0x5002734a, NULL},	/* RSS0250 - 5614Jx3(G) Internal Modem */
503 	{0x6202734a, NULL},	/* RSS0262 - 5614Jx3[G] V90+K56Flex Modem */
504 	{0x1010104d, NULL},	/* SHP1010 - Rockwell 33600bps Modem */
505 	{0xc100ad4d, NULL},	/* SMM00C1 - Leopard 56k PnP */
506 	{0x9012b04e, NULL},	/* SUP1290 - Supra ? */
507 	{0x1013b04e, NULL},	/* SUP1310 - SupraExpress 336i PnP */
508 	{0x8013b04e, NULL},	/* SUP1380 - SupraExpress 288i PnP Voice */
509 	{0x8113b04e, NULL},	/* SUP1381 - SupraExpress 336i PnP Voice */
510 	{0x5016b04e, NULL},	/* SUP1650 - Supra 336i Sp Intl */
511 	{0x7016b04e, NULL},	/* SUP1670 - Supra 336i V+ Intl */
512 	{0x7420b04e, NULL},	/* SUP2070 - Supra ? */
513 	{0x8020b04e, NULL},	/* SUP2080 - Supra ? */
514 	{0x8420b04e, NULL},	/* SUP2084 - SupraExpress 56i PnP */
515 	{0x7121b04e, NULL},	/* SUP2171 - SupraExpress 56i Sp? */
516 	{0x8024b04e, NULL},	/* SUP2480 - Supra ? */
517 	{0x01007256, NULL},	/* USR0001 - U.S. Robotics Inc., Sportster W */
518 	{0x02007256, NULL},	/* USR0002 - U.S. Robotics Inc. Sportster 33. */
519 	{0x04007256, NULL},	/* USR0004 - USR Sportster 14.4k */
520 	{0x06007256, NULL},	/* USR0006 - USR Sportster 33.6k */
521 	{0x11007256, NULL},	/* USR0011 - USR ? */
522 	{0x01017256, NULL},	/* USR0101 - USR ? */
523 	{0x30207256, NULL},	/* USR2030 - U.S.Robotics Inc. Sportster 560 */
524 	{0x50207256, NULL},	/* USR2050 - U.S.Robotics Inc. Sportster 33. */
525 	{0x70207256, NULL},	/* USR2070 - U.S.Robotics Inc. Sportster 560 */
526 	{0x30307256, NULL},	/* USR3030 - U.S. Robotics 56K FAX INT */
527 	{0x31307256, NULL},	/* USR3031 - U.S. Robotics 56K FAX INT */
528 	{0x50307256, NULL},	/* USR3050 - U.S. Robotics 56K FAX INT */
529 	{0x70307256, NULL},	/* USR3070 - U.S. Robotics 56K Voice INT */
530 	{0x90307256, NULL},	/* USR3090 - USR ? */
531 	{0x70917256, NULL},	/* USR9170 - U.S. Robotics 56K FAX INT */
532 	{0x90917256, NULL},	/* USR9190 - USR 56k Voice INT */
533 	{0x0300695c, NULL},	/* WCI0003 - Fax/Voice/Modem/Speakphone/Asvd */
534 	{0x01a0896a, NULL},	/* ZTIA001 - Zoom Internal V90 Faxmodem */
535 	{0x61f7896a, NULL},	/* ZTIF761 - Zoom ComStar 33.6 */
536 	{0}
537 };
538 
539 
540 
541 static int
542 sio_isa_probe(device_t dev)
543 {
544 	/* Check isapnp ids */
545 	if (ISA_PNP_PROBE(device_get_parent(dev), dev, sio_ids) == ENXIO)
546 		return (ENXIO);
547 	return (sioprobe(dev, 0, 0UL));
548 }
549 
550 int
551 sioprobe(device_t dev, int xrid, u_long rclk)
552 {
553 #if 0
554 	static bool_t	already_init;
555 	device_t	xdev;
556 #endif
557 	struct com_s	*com;
558 	u_int		divisor;
559 	bool_t		failures[10];
560 	int		fn;
561 	device_t	idev;
562 	Port_t		iobase;
563 	intrmask_t	irqmap[4];
564 	intrmask_t	irqs;
565 	u_char		mcr_image;
566 	int		result;
567 	u_long		xirq;
568 	u_int		flags = device_get_flags(dev);
569 	int		rid;
570 	struct resource *port;
571 
572 	rid = xrid;
573 	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
574 				  0, ~0, IO_COMSIZE, RF_ACTIVE);
575 	if (!port)
576 		return (ENXIO);
577 
578 	lwkt_gettoken(&tty_token);
579 	com = device_get_softc(dev);
580 	com->bst = rman_get_bustag(port);
581 	com->bsh = rman_get_bushandle(port);
582 	if (rclk == 0)
583 		rclk = DEFAULT_RCLK;
584 	com->rclk = rclk;
585 
586 #if 0
587 	/*
588 	 * XXX this is broken - when we are first called, there are no
589 	 * previously configured IO ports.  We could hard code
590 	 * 0x3f8, 0x2f8, 0x3e8, 0x2e8 etc but that's probably worse.
591 	 * This code has been doing nothing since the conversion since
592 	 * "count" is zero the first time around.
593 	 */
594 	if (!already_init) {
595 		/*
596 		 * Turn off MCR_IENABLE for all likely serial ports.  An unused
597 		 * port with its MCR_IENABLE gate open will inhibit interrupts
598 		 * from any used port that shares the interrupt vector.
599 		 * XXX the gate enable is elsewhere for some multiports.
600 		 */
601 		device_t *devs;
602 		int count, i, xioport;
603 
604 		devclass_get_devices(sio_devclass, &devs, &count);
605 		for (i = 0; i < count; i++) {
606 			xdev = devs[i];
607 			if (device_is_enabled(xdev) &&
608 			    bus_get_resource(xdev, SYS_RES_IOPORT, 0, &xioport,
609 					     NULL) == 0)
610 				outb(xioport + com_mcr, 0);
611 		}
612 		kfree(devs, M_TEMP);
613 		already_init = TRUE;
614 	}
615 #endif
616 
617 	if (COM_LLCONSOLE(flags)) {
618 		kprintf("sio%d: reserved for low-level i/o\n",
619 		       device_get_unit(dev));
620 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
621 		lwkt_reltoken(&tty_token);
622 		return (ENXIO);
623 	}
624 
625 	/*
626 	 * If the device is on a multiport card and has an AST/4
627 	 * compatible interrupt control register, initialize this
628 	 * register and prepare to leave MCR_IENABLE clear in the mcr.
629 	 * Otherwise, prepare to set MCR_IENABLE in the mcr.
630 	 * Point idev to the device struct giving the correct id_irq.
631 	 * This is the struct for the master device if there is one.
632 	 */
633 	idev = dev;
634 	mcr_image = MCR_IENABLE;
635 #ifdef COM_MULTIPORT
636 	if (COM_ISMULTIPORT(flags)) {
637 		Port_t xiobase;
638 		u_long io;
639 
640 		idev = devclass_get_device(sio_devclass, COM_MPMASTER(flags));
641 		if (idev == NULL) {
642 			kprintf("sio%d: master device %d not configured\n",
643 			       device_get_unit(dev), COM_MPMASTER(flags));
644 			idev = dev;
645 		}
646 		if (!COM_NOTAST4(flags)) {
647 			if (bus_get_resource(idev, SYS_RES_IOPORT, 0, &io,
648 					     NULL) == 0) {
649 				xiobase = io;
650 				if (bus_get_resource(idev, SYS_RES_IRQ, 0,
651 				    NULL, NULL) == 0)
652 					outb(xiobase + com_scr, 0x80);
653 				else
654 					outb(xiobase + com_scr, 0);
655 			}
656 			mcr_image = 0;
657 		}
658 	}
659 #endif /* COM_MULTIPORT */
660 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, NULL, NULL) != 0)
661 		mcr_image = 0;
662 
663 	bzero(failures, sizeof failures);
664 	iobase = rman_get_start(port);
665 
666 	/*
667 	 * We don't want to get actual interrupts, just masked ones.
668 	 * Interrupts from this line should already be masked in the ICU,
669 	 * but mask them in the processor as well in case there are some
670 	 * (misconfigured) shared interrupts.
671 	 */
672 	com_lock();
673 /* EXTRA DELAY? */
674 
675 	/*
676 	 * For the TI16754 chips, set prescaler to 1 (4 is often the
677 	 * default after-reset value) as otherwise it's impossible to
678 	 * get highest baudrates.
679 	 */
680 	if (COM_TI16754(flags)) {
681 		u_char cfcr, efr;
682 
683 		cfcr = sio_getreg(com, com_cfcr);
684 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
685 		efr = sio_getreg(com, com_efr);
686 		/* Unlock extended features to turn off prescaler. */
687 		sio_setreg(com, com_efr, efr | EFR_EFE);
688 		/* Disable EFR. */
689 		sio_setreg(com, com_cfcr, (cfcr != CFCR_EFR_ENABLE) ? cfcr : 0);
690 		/* Turn off prescaler. */
691 		sio_setreg(com, com_mcr,
692 			   sio_getreg(com, com_mcr) & ~MCR_PRESCALE);
693 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
694 		sio_setreg(com, com_efr, efr);
695 		sio_setreg(com, com_cfcr, cfcr);
696 	}
697 
698 	/*
699 	 * Initialize the speed and the word size and wait long enough to
700 	 * drain the maximum of 16 bytes of junk in device output queues.
701 	 * The speed is undefined after a master reset and must be set
702 	 * before relying on anything related to output.  There may be
703 	 * junk after a (very fast) soft reboot and (apparently) after
704 	 * master reset.
705 	 * XXX what about the UART bug avoided by waiting in comparam()?
706 	 * We don't want to to wait long enough to drain at 2 bps.
707 	 */
708 	if (iobase == siocniobase) {
709 		DELAY((16 + 1) * 1000000 / (comdefaultrate / 10));
710 	} else {
711 		sio_setreg(com, com_cfcr, CFCR_DLAB | CFCR_8BITS);
712 		divisor = siodivisor(rclk, SIO_TEST_SPEED);
713 		sio_setreg(com, com_dlbl, divisor & 0xff);
714 		sio_setreg(com, com_dlbh, divisor >> 8);
715 		sio_setreg(com, com_cfcr, CFCR_8BITS);
716 		DELAY((16 + 1) * 1000000 / (SIO_TEST_SPEED / 10));
717 	}
718 
719 	/*
720 	 * Make sure we can drain the receiver.  If we can't, the serial
721 	 * port may not exist.
722 	 */
723 	for (fn = 0; fn < 256; ++fn) {
724 		if ((sio_getreg(com, com_lsr) & LSR_RXRDY) == 0)
725 			break;
726 		(void)sio_getreg(com, com_data);
727 	}
728 	if (fn == 256) {
729 		com_unlock();
730 		lwkt_reltoken(&tty_token);
731 		kprintf("sio%d: can't drain, serial port might "
732 			"not exist, disabling\n", device_get_unit(dev));
733 		return (ENXIO);
734 	}
735 
736 	/*
737 	 * Enable the interrupt gate and disable device interupts.  This
738 	 * should leave the device driving the interrupt line low and
739 	 * guarantee an edge trigger if an interrupt can be generated.
740 	 */
741 /* EXTRA DELAY? */
742 	sio_setreg(com, com_mcr, mcr_image);
743 	sio_setreg(com, com_ier, 0);
744 	DELAY(1000);		/* XXX */
745 	irqmap[0] = isa_irq_pending();
746 
747 	/*
748 	 * Attempt to set loopback mode so that we can send a null byte
749 	 * without annoying any external device.
750 	 */
751 /* EXTRA DELAY? */
752 	sio_setreg(com, com_mcr, mcr_image | MCR_LOOPBACK);
753 
754 	/*
755 	 * Attempt to generate an output interrupt.  On 8250's, setting
756 	 * IER_ETXRDY generates an interrupt independent of the current
757 	 * setting and independent of whether the THR is empty.  On 16450's,
758 	 * setting IER_ETXRDY generates an interrupt independent of the
759 	 * current setting.  On 16550A's, setting IER_ETXRDY only
760 	 * generates an interrupt when IER_ETXRDY is not already set.
761 	 */
762 	sio_setreg(com, com_ier, IER_ETXRDY);
763 
764 	/*
765 	 * On some 16x50 incompatibles, setting IER_ETXRDY doesn't generate
766 	 * an interrupt.  They'd better generate one for actually doing
767 	 * output.  Loopback may be broken on the same incompatibles but
768 	 * it's unlikely to do more than allow the null byte out.
769 	 */
770 	sio_setreg(com, com_data, 0);
771 	DELAY((1 + 2) * 1000000 / (SIO_TEST_SPEED / 10));
772 
773 	/*
774 	 * Turn off loopback mode so that the interrupt gate works again
775 	 * (MCR_IENABLE was hidden).  This should leave the device driving
776 	 * an interrupt line high.  It doesn't matter if the interrupt
777 	 * line oscillates while we are not looking at it, since interrupts
778 	 * are disabled.
779 	 */
780 /* EXTRA DELAY? */
781 	sio_setreg(com, com_mcr, mcr_image);
782 
783 	/*
784 	 * Some pcmcia cards have the "TXRDY bug", so we check everyone
785 	 * for IIR_TXRDY implementation ( Palido 321s, DC-1S... )
786 	 */
787 	if (COM_NOPROBE(flags)) {
788 		/* Reading IIR register twice */
789 		for (fn = 0; fn < 2; fn ++) {
790 			DELAY(10000);
791 			failures[6] = sio_getreg(com, com_iir);
792 		}
793 		/* Check IIR_TXRDY clear ? */
794 		result = 0;
795 		if (failures[6] & IIR_TXRDY) {
796 			/* Nop, Double check with clearing IER */
797 			sio_setreg(com, com_ier, 0);
798 			if (sio_getreg(com, com_iir) & IIR_NOPEND) {
799 				/* Ok. we're familia this gang */
800 				SET_FLAG(dev, COM_C_IIR_TXRDYBUG);
801 			} else {
802 				/* Unknown, Just omit this chip.. XXX */
803 				result = ENXIO;
804 				sio_setreg(com, com_mcr, 0);
805 			}
806 		} else {
807 			/* OK. this is well-known guys */
808 			CLR_FLAG(dev, COM_C_IIR_TXRDYBUG);
809 		}
810 		sio_setreg(com, com_ier, 0);
811 		sio_setreg(com, com_cfcr, CFCR_8BITS);
812 		com_unlock();
813 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
814 		lwkt_reltoken(&tty_token);
815 		return (iobase == siocniobase ? 0 : result);
816 	}
817 
818 	/*
819 	 * Check that
820 	 *	o the CFCR, IER and MCR in UART hold the values written to them
821 	 *	  (the values happen to be all distinct - this is good for
822 	 *	  avoiding false positive tests from bus echoes).
823 	 *	o an output interrupt is generated and its vector is correct.
824 	 *	o the interrupt goes away when the IIR in the UART is read.
825 	 */
826 /* EXTRA DELAY? */
827 	failures[0] = sio_getreg(com, com_cfcr) - CFCR_8BITS;
828 	failures[1] = sio_getreg(com, com_ier) - IER_ETXRDY;
829 	failures[2] = sio_getreg(com, com_mcr) - mcr_image;
830 	DELAY(10000);		/* Some internal modems need this time */
831 	irqmap[1] = isa_irq_pending();
832 	failures[4] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_TXRDY;
833 	DELAY(1000);		/* XXX */
834 	irqmap[2] = isa_irq_pending();
835 	failures[6] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
836 
837 	/*
838 	 * Turn off all device interrupts and check that they go off properly.
839 	 * Leave MCR_IENABLE alone.  For ports without a master port, it gates
840 	 * the OUT2 output of the UART to
841 	 * the ICU input.  Closing the gate would give a floating ICU input
842 	 * (unless there is another device driving it) and spurious interrupts.
843 	 * (On the system that this was first tested on, the input floats high
844 	 * and gives a (masked) interrupt as soon as the gate is closed.)
845 	 */
846 	sio_setreg(com, com_ier, 0);
847 	sio_setreg(com, com_cfcr, CFCR_8BITS);	/* dummy to avoid bus echo */
848 	failures[7] = sio_getreg(com, com_ier);
849 	DELAY(1000);		/* XXX */
850 	irqmap[3] = isa_irq_pending();
851 	failures[9] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
852 
853 	com_unlock();
854 
855 	irqs = irqmap[1] & ~irqmap[0];
856 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, &xirq, NULL) == 0 &&
857 	    ((1 << xirq) & irqs) == 0)
858 		kprintf(
859 		"sio%d: configured irq %ld not in bitmap of probed irqs %#x\n",
860 		    device_get_unit(dev), xirq, irqs);
861 	if (bootverbose)
862 		kprintf("sio%d: irq maps: %#x %#x %#x %#x\n",
863 		    device_get_unit(dev),
864 		    irqmap[0], irqmap[1], irqmap[2], irqmap[3]);
865 
866 	result = 0;
867 	for (fn = 0; fn < sizeof failures; ++fn)
868 		if (failures[fn]) {
869 			sio_setreg(com, com_mcr, 0);
870 			result = ENXIO;
871 			if (bootverbose) {
872 				kprintf("sio%d: probe failed test(s):",
873 				    device_get_unit(dev));
874 				for (fn = 0; fn < sizeof failures; ++fn)
875 					if (failures[fn])
876 						kprintf(" %d", fn);
877 				kprintf("\n");
878 			}
879 			break;
880 		}
881 	bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
882 	lwkt_reltoken(&tty_token);
883 	return (iobase == siocniobase ? 0 : result);
884 }
885 
886 #ifdef COM_ESP
887 static int
888 espattach(struct com_s *com, Port_t esp_port)
889 {
890 	u_char	dips;
891 	u_char	val;
892 
893 	/*
894 	 * Check the ESP-specific I/O port to see if we're an ESP
895 	 * card.  If not, return failure immediately.
896 	 */
897 	if ((inb(esp_port) & 0xf3) == 0) {
898 		kprintf(" port 0x%x is not an ESP board?\n", esp_port);
899 		return (0);
900 	}
901 
902 	lwkt_gettoken(&tty_token);
903 	/*
904 	 * We've got something that claims to be a Hayes ESP card.
905 	 * Let's hope so.
906 	 */
907 
908 	/* Get the dip-switch configuration */
909 	outb(esp_port + ESP_CMD1, ESP_GETDIPS);
910 	dips = inb(esp_port + ESP_STATUS1);
911 
912 	/*
913 	 * Bits 0,1 of dips say which COM port we are.
914 	 */
915 	if (rman_get_start(com->ioportres) == likely_com_ports[dips & 0x03])
916 		kprintf(" : ESP");
917 	else {
918 		kprintf(" esp_port has com %d\n", dips & 0x03);
919 		lwkt_reltoken(&tty_token);
920 		return (0);
921 	}
922 
923 	/*
924 	 * Check for ESP version 2.0 or later:  bits 4,5,6 = 010.
925 	 */
926 	outb(esp_port + ESP_CMD1, ESP_GETTEST);
927 	val = inb(esp_port + ESP_STATUS1);	/* clear reg 1 */
928 	val = inb(esp_port + ESP_STATUS2);
929 	if ((val & 0x70) < 0x20) {
930 		kprintf("-old (%o)", val & 0x70);
931 		lwkt_reltoken(&tty_token);
932 		return (0);
933 	}
934 
935 	/*
936 	 * Check for ability to emulate 16550:  bit 7 == 1
937 	 */
938 	if ((dips & 0x80) == 0) {
939 		kprintf(" slave");
940 		lwkt_reltoken(&tty_token);
941 		return (0);
942 	}
943 
944 	/*
945 	 * Okay, we seem to be a Hayes ESP card.  Whee.
946 	 */
947 	com->esp = TRUE;
948 	com->esp_port = esp_port;
949 	lwkt_reltoken(&tty_token);
950 	return (1);
951 }
952 #endif /* COM_ESP */
953 
954 static int
955 sio_isa_attach(device_t dev)
956 {
957 	return (sioattach(dev, 0, 0UL));
958 }
959 
960 int
961 sioattach(device_t dev, int xrid, u_long rclk)
962 {
963 	struct com_s	*com;
964 #ifdef COM_ESP
965 	Port_t		*espp;
966 #endif
967 	Port_t		iobase;
968 	int		minorbase;
969 	int		unit;
970 	u_int		flags;
971 	int		rid;
972 	struct resource *port;
973 	int		ret;
974 	static int	did_init;
975 
976 	lwkt_gettoken(&tty_token);
977 	if (did_init == 0) {
978 		did_init = 1;
979 		callout_init_mp(&sio_timeout_handle);
980 	}
981 
982 	rid = xrid;
983 	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
984 				  0, ~0, IO_COMSIZE, RF_ACTIVE);
985 	if (!port) {
986 		lwkt_reltoken(&tty_token);
987 		return (ENXIO);
988 	}
989 
990 	iobase = rman_get_start(port);
991 	unit = device_get_unit(dev);
992 	com = device_get_softc(dev);
993 	flags = device_get_flags(dev);
994 
995 	if (unit >= sio_numunits)
996 		sio_numunits = unit + 1;
997 	/*
998 	 * sioprobe() has initialized the device registers as follows:
999 	 *	o cfcr = CFCR_8BITS.
1000 	 *	  It is most important that CFCR_DLAB is off, so that the
1001 	 *	  data port is not hidden when we enable interrupts.
1002 	 *	o ier = 0.
1003 	 *	  Interrupts are only enabled when the line is open.
1004 	 *	o mcr = MCR_IENABLE, or 0 if the port has AST/4 compatible
1005 	 *	  interrupt control register or the config specifies no irq.
1006 	 *	  Keeping MCR_DTR and MCR_RTS off might stop the external
1007 	 *	  device from sending before we are ready.
1008 	 */
1009 	bzero(com, sizeof *com);
1010 	com->unit = unit;
1011 	com->ioportres = port;
1012 	com->bst = rman_get_bustag(port);
1013 	com->bsh = rman_get_bushandle(port);
1014 	com->cfcr_image = CFCR_8BITS;
1015 	com->dtr_wait = 3 * hz;
1016 	callout_init_mp(&com->dtr_ch);
1017 	callout_init_mp(&com->busy_ch);
1018 	com->loses_outints = COM_LOSESOUTINTS(flags) != 0;
1019 	com->no_irq = bus_get_resource(dev, SYS_RES_IRQ, 0, NULL, NULL) != 0;
1020 	com->tx_fifo_size = 1;
1021 	com->obufs[0].l_head = com->obuf1;
1022 	com->obufs[1].l_head = com->obuf2;
1023 
1024 	com->data_port = iobase + com_data;
1025 	com->int_id_port = iobase + com_iir;
1026 	com->modem_ctl_port = iobase + com_mcr;
1027 	com->mcr_image = inb(com->modem_ctl_port);
1028 	com->line_status_port = iobase + com_lsr;
1029 	com->modem_status_port = iobase + com_msr;
1030 	com->intr_ctl_port = iobase + com_ier;
1031 
1032 	if (rclk == 0)
1033 		rclk = DEFAULT_RCLK;
1034 	com->rclk = rclk;
1035 
1036 	/*
1037 	 * We don't use all the flags from <sys/ttydefaults.h> since they
1038 	 * are only relevant for logins.  It's important to have echo off
1039 	 * initially so that the line doesn't start blathering before the
1040 	 * echo flag can be turned off.
1041 	 */
1042 	com->it_in.c_iflag = 0;
1043 	com->it_in.c_oflag = 0;
1044 	com->it_in.c_cflag = TTYDEF_CFLAG;
1045 	com->it_in.c_lflag = 0;
1046 	if (unit == comconsole) {
1047 		com->it_in.c_iflag = TTYDEF_IFLAG;
1048 		com->it_in.c_oflag = TTYDEF_OFLAG;
1049 		com->it_in.c_cflag = TTYDEF_CFLAG | CLOCAL;
1050 		com->it_in.c_lflag = TTYDEF_LFLAG;
1051 		com->lt_out.c_cflag = com->lt_in.c_cflag = CLOCAL;
1052 		com->lt_out.c_ispeed = com->lt_out.c_ospeed =
1053 		com->lt_in.c_ispeed = com->lt_in.c_ospeed =
1054 		com->it_in.c_ispeed = com->it_in.c_ospeed = comdefaultrate;
1055 	} else
1056 		com->it_in.c_ispeed = com->it_in.c_ospeed = TTYDEF_SPEED;
1057 	if (siosetwater(com, com->it_in.c_ispeed) != 0) {
1058 		/*
1059 		 * Leave i/o resources allocated if this is a `cn'-level
1060 		 * console, so that other devices can't snarf them.
1061 		 */
1062 		if (iobase != siocniobase)
1063 			bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
1064 		lwkt_reltoken(&tty_token);
1065 		return (ENOMEM);
1066 	}
1067 	termioschars(&com->it_in);
1068 	com->it_out = com->it_in;
1069 
1070 	/* attempt to determine UART type */
1071 	kprintf("sio%d: type", unit);
1072 
1073 
1074 #ifdef COM_MULTIPORT
1075 	if (!COM_ISMULTIPORT(flags) && !COM_IIR_TXRDYBUG(flags))
1076 #else
1077 	if (!COM_IIR_TXRDYBUG(flags))
1078 #endif
1079 	{
1080 		u_char	scr;
1081 		u_char	scr1;
1082 		u_char	scr2;
1083 
1084 		scr = sio_getreg(com, com_scr);
1085 		sio_setreg(com, com_scr, 0xa5);
1086 		scr1 = sio_getreg(com, com_scr);
1087 		sio_setreg(com, com_scr, 0x5a);
1088 		scr2 = sio_getreg(com, com_scr);
1089 		sio_setreg(com, com_scr, scr);
1090 		if (scr1 != 0xa5 || scr2 != 0x5a) {
1091 			kprintf(" 8250");
1092 			goto determined_type;
1093 		}
1094 	}
1095 	sio_setreg(com, com_fifo, FIFO_ENABLE | FIFO_RX_HIGH);
1096 	DELAY(100);
1097 	com->st16650a = 0;
1098 	switch (inb(com->int_id_port) & IIR_FIFO_MASK) {
1099 	case FIFO_RX_LOW:
1100 		kprintf(" 16450");
1101 		break;
1102 	case FIFO_RX_MEDL:
1103 		kprintf(" 16450?");
1104 		break;
1105 	case FIFO_RX_MEDH:
1106 		kprintf(" 16550?");
1107 		break;
1108 	case FIFO_RX_HIGH:
1109 		if (COM_NOFIFO(flags)) {
1110 			kprintf(" 16550A fifo disabled");
1111 		} else {
1112 			com->hasfifo = TRUE;
1113 			if (COM_ST16650A(flags)) {
1114 				com->st16650a = 1;
1115 				com->tx_fifo_size = 32;
1116 				kprintf(" ST16650A");
1117 			} else if (COM_TI16754(flags)) {
1118 				com->tx_fifo_size = 64;
1119 				kprintf(" TI16754");
1120 			} else {
1121 				com->tx_fifo_size = COM_FIFOSIZE(flags);
1122 				kprintf(" 16550A");
1123 			}
1124 		}
1125 #ifdef COM_ESP
1126 		for (espp = likely_esp_ports; *espp != 0; espp++)
1127 			if (espattach(com, *espp)) {
1128 				com->tx_fifo_size = 1024;
1129 				break;
1130 			}
1131 #endif
1132 		if (!com->st16650a && !COM_TI16754(flags)) {
1133 			if (!com->tx_fifo_size)
1134 				com->tx_fifo_size = 16;
1135 			else
1136 				kprintf(" lookalike with %d bytes FIFO",
1137 				    com->tx_fifo_size);
1138 		}
1139 
1140 		break;
1141 	}
1142 
1143 #ifdef COM_ESP
1144 	if (com->esp) {
1145 		/*
1146 		 * Set 16550 compatibility mode.
1147 		 * We don't use the ESP_MODE_SCALE bit to increase the
1148 		 * fifo trigger levels because we can't handle large
1149 		 * bursts of input.
1150 		 * XXX flow control should be set in comparam(), not here.
1151 		 */
1152 		outb(com->esp_port + ESP_CMD1, ESP_SETMODE);
1153 		outb(com->esp_port + ESP_CMD2, ESP_MODE_RTS | ESP_MODE_FIFO);
1154 
1155 		/* Set RTS/CTS flow control. */
1156 		outb(com->esp_port + ESP_CMD1, ESP_SETFLOWTYPE);
1157 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_RTS);
1158 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_CTS);
1159 
1160 		/* Set flow-control levels. */
1161 		outb(com->esp_port + ESP_CMD1, ESP_SETRXFLOW);
1162 		outb(com->esp_port + ESP_CMD2, HIBYTE(768));
1163 		outb(com->esp_port + ESP_CMD2, LOBYTE(768));
1164 		outb(com->esp_port + ESP_CMD2, HIBYTE(512));
1165 		outb(com->esp_port + ESP_CMD2, LOBYTE(512));
1166 	}
1167 #endif /* COM_ESP */
1168 	sio_setreg(com, com_fifo, 0);
1169 determined_type: ;
1170 
1171 #ifdef COM_MULTIPORT
1172 	if (COM_ISMULTIPORT(flags)) {
1173 		device_t masterdev;
1174 
1175 		com->multiport = TRUE;
1176 		kprintf(" (multiport");
1177 		if (unit == COM_MPMASTER(flags))
1178 			kprintf(" master");
1179 		kprintf(")");
1180 		masterdev = devclass_get_device(sio_devclass,
1181 		    COM_MPMASTER(flags));
1182 		com->no_irq = (masterdev == NULL || bus_get_resource(masterdev,
1183 		    SYS_RES_IRQ, 0, NULL, NULL) != 0);
1184 	 }
1185 #endif /* COM_MULTIPORT */
1186 	if (unit == comconsole)
1187 		kprintf(", console");
1188 	if (COM_IIR_TXRDYBUG(flags))
1189 		kprintf(" with a bogus IIR_TXRDY register");
1190 	kprintf("\n");
1191 
1192 	if (!sio_registered) {
1193 		register_swi(SWI_TTY, siopoll, NULL ,"swi_siopoll", NULL, -1);
1194 		sio_registered = TRUE;
1195 	}
1196 	minorbase = UNIT_TO_MINOR(unit);
1197 	make_dev(&sio_ops, minorbase,
1198 	    UID_ROOT, GID_WHEEL, 0600, "ttyd%r", unit);
1199 	make_dev(&sio_ops, minorbase | CONTROL_INIT_STATE,
1200 	    UID_ROOT, GID_WHEEL, 0600, "ttyid%r", unit);
1201 	make_dev(&sio_ops, minorbase | CONTROL_LOCK_STATE,
1202 	    UID_ROOT, GID_WHEEL, 0600, "ttyld%r", unit);
1203 	make_dev(&sio_ops, minorbase | CALLOUT_MASK,
1204 	    UID_UUCP, GID_DIALER, 0660, "cuaa%r", unit);
1205 	make_dev(&sio_ops, minorbase | CALLOUT_MASK | CONTROL_INIT_STATE,
1206 	    UID_UUCP, GID_DIALER, 0660, "cuaia%r", unit);
1207 	make_dev(&sio_ops, minorbase | CALLOUT_MASK | CONTROL_LOCK_STATE,
1208 	    UID_UUCP, GID_DIALER, 0660, "cuala%r", unit);
1209 	com->flags = flags;
1210 	com->pps.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1211 	pps_init(&com->pps);
1212 
1213 	rid = 0;
1214 	com->irqres = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0ul, ~0ul, 1,
1215 	    RF_ACTIVE);
1216 	if (com->irqres) {
1217 		ret = BUS_SETUP_INTR(device_get_parent(dev), dev,
1218 				     com->irqres, INTR_MPSAFE, siointr, com,
1219 				     &com->cookie, NULL, NULL);
1220 		if (ret)
1221 			device_printf(dev, "could not activate interrupt\n");
1222 #if defined(DDB) && (defined(BREAK_TO_DEBUGGER) || \
1223     defined(ALT_BREAK_TO_DEBUGGER))
1224 		/*
1225 		 * Enable interrupts for early break-to-debugger support
1226 		 * on the console.
1227 		 */
1228 		if (ret == 0 && unit == comconsole)
1229 			outb(siocniobase + com_ier, IER_ERXRDY | IER_ERLS |
1230 			    IER_EMSC);
1231 #endif
1232 	}
1233 
1234 	lwkt_reltoken(&tty_token);
1235 	return (0);
1236 }
1237 
1238 static int
1239 sioopen(struct dev_open_args *ap)
1240 {
1241 	cdev_t dev = ap->a_head.a_dev;
1242 	struct com_s	*com;
1243 	int		error;
1244 	int		mynor;
1245 	struct tty	*tp;
1246 	int		unit;
1247 
1248 	mynor = minor(dev);
1249 	unit = MINOR_TO_UNIT(mynor);
1250 	com = com_addr(unit);
1251 	if (com == NULL)
1252 		return (ENXIO);
1253 	if (com->gone)
1254 		return (ENXIO);
1255 	if (mynor & CONTROL_MASK)
1256 		return (0);
1257 	lwkt_gettoken(&tty_token);
1258 	tp = dev->si_tty = com->tp = ttymalloc(com->tp);
1259 	crit_enter();
1260 	/*
1261 	 * We jump to this label after all non-interrupted sleeps to pick
1262 	 * up any changes of the device state.
1263 	 */
1264 open_top:
1265 	while (com->state & CS_DTR_OFF) {
1266 		error = tsleep(&com->dtr_wait, PCATCH, "siodtr", 0);
1267 		if (com_addr(unit) == NULL) {
1268 			crit_exit();
1269 			lwkt_reltoken(&tty_token);
1270 			return (ENXIO);
1271 		}
1272 		if (error != 0 || com->gone)
1273 			goto out;
1274 	}
1275 	if (tp->t_state & TS_ISOPEN) {
1276 		/*
1277 		 * The device is open, so everything has been initialized.
1278 		 * Handle conflicts.
1279 		 */
1280 		if (mynor & CALLOUT_MASK) {
1281 			if (!com->active_out) {
1282 				error = EBUSY;
1283 				goto out;
1284 			}
1285 		} else {
1286 			if (com->active_out) {
1287 				if (ap->a_oflags & O_NONBLOCK) {
1288 					error = EBUSY;
1289 					goto out;
1290 				}
1291 				error =	tsleep(&com->active_out,
1292 					       PCATCH, "siobi", 0);
1293 				if (com_addr(unit) == NULL) {
1294 					crit_exit();
1295 					lwkt_reltoken(&tty_token);
1296 					return (ENXIO);
1297 				}
1298 				if (error != 0 || com->gone)
1299 					goto out;
1300 				goto open_top;
1301 			}
1302 		}
1303 		if (tp->t_state & TS_XCLUDE && priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) {
1304 			error = EBUSY;
1305 			goto out;
1306 		}
1307 	} else {
1308 		/*
1309 		 * The device isn't open, so there are no conflicts.
1310 		 * Initialize it.  Initialization is done twice in many
1311 		 * cases: to preempt sleeping callin opens if we are
1312 		 * callout, and to complete a callin open after DCD rises.
1313 		 */
1314 		tp->t_oproc = comstart;
1315 		tp->t_param = comparam;
1316 		tp->t_stop = comstop;
1317 		tp->t_dev = dev;
1318 		tp->t_termios = mynor & CALLOUT_MASK
1319 				? com->it_out : com->it_in;
1320 		(void)commctl(com, TIOCM_DTR | TIOCM_RTS, DMSET);
1321 		com->poll = com->no_irq;
1322 		com->poll_output = com->loses_outints;
1323 		++com->wopeners;
1324 		error = comparam(tp, &tp->t_termios);
1325 		--com->wopeners;
1326 		if (error != 0)
1327 			goto out;
1328 		/*
1329 		 * XXX we should goto open_top if comparam() slept.
1330 		 */
1331 		if (com->hasfifo) {
1332 			/*
1333 			 * (Re)enable and drain fifos.
1334 			 *
1335 			 * Certain SMC chips cause problems if the fifos
1336 			 * are enabled while input is ready.  Turn off the
1337 			 * fifo if necessary to clear the input.  We test
1338 			 * the input ready bit after enabling the fifos
1339 			 * since we've already enabled them in comparam()
1340 			 * and to handle races between enabling and fresh
1341 			 * input.
1342 			 */
1343 			while (TRUE) {
1344 				sio_setreg(com, com_fifo,
1345 					   FIFO_RCV_RST | FIFO_XMT_RST
1346 					   | com->fifo_image);
1347 				/*
1348 				 * XXX the delays are for superstitious
1349 				 * historical reasons.  It must be less than
1350 				 * the character time at the maximum
1351 				 * supported speed (87 usec at 115200 bps
1352 				 * 8N1).  Otherwise we might loop endlessly
1353 				 * if data is streaming in.  We used to use
1354 				 * delays of 100.  That usually worked
1355 				 * because DELAY(100) used to usually delay
1356 				 * for about 85 usec instead of 100.
1357 				 */
1358 				DELAY(50);
1359 				if (!(inb(com->line_status_port) & LSR_RXRDY))
1360 					break;
1361 				sio_setreg(com, com_fifo, 0);
1362 				DELAY(50);
1363 				(void) inb(com->data_port);
1364 			}
1365 		}
1366 
1367 		com_lock();
1368 		(void) inb(com->line_status_port);
1369 		(void) inb(com->data_port);
1370 		com->prev_modem_status = com->last_modem_status
1371 		    = inb(com->modem_status_port);
1372 		if (COM_IIR_TXRDYBUG(com->flags)) {
1373 			outb(com->intr_ctl_port, IER_ERXRDY | IER_ERLS
1374 						| IER_EMSC);
1375 		} else {
1376 			outb(com->intr_ctl_port, IER_ERXRDY | IER_ETXRDY
1377 						| IER_ERLS | IER_EMSC);
1378 		}
1379 		com_unlock();
1380 		/*
1381 		 * Handle initial DCD.  Callout devices get a fake initial
1382 		 * DCD (trapdoor DCD).  If we are callout, then any sleeping
1383 		 * callin opens get woken up and resume sleeping on "siobi"
1384 		 * instead of "siodcd".
1385 		 */
1386 		/*
1387 		 * XXX `mynor & CALLOUT_MASK' should be
1388 		 * `tp->t_cflag & (SOFT_CARRIER | TRAPDOOR_CARRIER) where
1389 		 * TRAPDOOR_CARRIER is the default initial state for callout
1390 		 * devices and SOFT_CARRIER is like CLOCAL except it hides
1391 		 * the true carrier.
1392 		 */
1393 		if (com->prev_modem_status & MSR_DCD || mynor & CALLOUT_MASK)
1394 			(*linesw[tp->t_line].l_modem)(tp, 1);
1395 	}
1396 	/*
1397 	 * Wait for DCD if necessary.
1398 	 */
1399 	if (!(tp->t_state & TS_CARR_ON) && !(mynor & CALLOUT_MASK)
1400 	    && !(tp->t_cflag & CLOCAL) && !(ap->a_oflags & O_NONBLOCK)) {
1401 		++com->wopeners;
1402 		error = tsleep(TSA_CARR_ON(tp), PCATCH, "siodcd", 0);
1403 		if (com_addr(unit) == NULL) {
1404 			crit_exit();
1405 			lwkt_reltoken(&tty_token);
1406 			return (ENXIO);
1407 		}
1408 		--com->wopeners;
1409 		if (error != 0 || com->gone)
1410 			goto out;
1411 		goto open_top;
1412 	}
1413 	error =	(*linesw[tp->t_line].l_open)(dev, tp);
1414 	disc_optim(tp, &tp->t_termios, com);
1415 	if (tp->t_state & TS_ISOPEN && mynor & CALLOUT_MASK)
1416 		com->active_out = TRUE;
1417 	siosettimeout();
1418 out:
1419 	crit_exit();
1420 	if (!(tp->t_state & TS_ISOPEN) && com->wopeners == 0)
1421 		comhardclose(com);
1422 	lwkt_reltoken(&tty_token);
1423 	return (error);
1424 }
1425 
1426 static int
1427 sioclose(struct dev_close_args *ap)
1428 {
1429 	cdev_t dev = ap->a_head.a_dev;
1430 	struct com_s	*com;
1431 	int		mynor;
1432 	struct tty	*tp;
1433 
1434 	mynor = minor(dev);
1435 	if (mynor & CONTROL_MASK)
1436 		return (0);
1437 	lwkt_gettoken(&tty_token);
1438 	com = com_addr(MINOR_TO_UNIT(mynor));
1439 	if (com == NULL) {
1440 		lwkt_reltoken(&tty_token);
1441 		return (ENODEV);
1442 	}
1443 	tp = com->tp;
1444 	crit_enter();
1445 	(*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
1446 	disc_optim(tp, &tp->t_termios, com);
1447 	comstop(tp, FREAD | FWRITE);
1448 	comhardclose(com);
1449 	ttyclose(tp);
1450 	siosettimeout();
1451 	crit_exit();
1452 	if (com->gone) {
1453 		kprintf("sio%d: gone\n", com->unit);
1454 		crit_enter();
1455 		if (com->ibuf != NULL)
1456 			kfree(com->ibuf, M_DEVBUF);
1457 		bzero(tp, sizeof *tp);
1458 		crit_exit();
1459 	}
1460 	lwkt_reltoken(&tty_token);
1461 	return (0);
1462 }
1463 
1464 static void
1465 comhardclose(struct com_s *com)
1466 {
1467 	struct tty	*tp;
1468 	int		unit;
1469 
1470 	unit = com->unit;
1471 	crit_enter();
1472 	lwkt_gettoken(&tty_token);
1473 	com->poll = FALSE;
1474 	com->poll_output = FALSE;
1475 	com->do_timestamp = FALSE;
1476 	com->do_dcd_timestamp = FALSE;
1477 	com->pps.ppsparam.mode = 0;
1478 	sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1479 	tp = com->tp;
1480 
1481 #if defined(DDB) && (defined(BREAK_TO_DEBUGGER) || \
1482     defined(ALT_BREAK_TO_DEBUGGER))
1483 	/*
1484 	 * Leave interrupts enabled and don't clear DTR if this is the
1485 	 * console. This allows us to detect break-to-debugger events
1486 	 * while the console device is closed.
1487 	 */
1488 	if (com->unit != comconsole)
1489 #endif
1490 	{
1491 		sio_setreg(com, com_ier, 0);
1492 		if (tp->t_cflag & HUPCL
1493 		    /*
1494 		     * XXX we will miss any carrier drop between here and the
1495 		     * next open.  Perhaps we should watch DCD even when the
1496 		     * port is closed; it is not sufficient to check it at
1497 		     * the next open because it might go up and down while
1498 		     * we're not watching.
1499 		     */
1500 		    || (!com->active_out
1501 		        && !(com->prev_modem_status & MSR_DCD)
1502 		        && !(com->it_in.c_cflag & CLOCAL))
1503 		    || !(tp->t_state & TS_ISOPEN)) {
1504 			(void)commctl(com, TIOCM_DTR, DMBIC);
1505 			if (com->dtr_wait != 0 && !(com->state & CS_DTR_OFF)) {
1506 				callout_reset(&com->dtr_ch, com->dtr_wait,
1507 						siodtrwakeup, com);
1508 				com->state |= CS_DTR_OFF;
1509 			}
1510 		}
1511 	}
1512 	if (com->hasfifo) {
1513 		/*
1514 		 * Disable fifos so that they are off after controlled
1515 		 * reboots.  Some BIOSes fail to detect 16550s when the
1516 		 * fifos are enabled.
1517 		 */
1518 		sio_setreg(com, com_fifo, 0);
1519 	}
1520 	com->active_out = FALSE;
1521 	wakeup(&com->active_out);
1522 	wakeup(TSA_CARR_ON(tp));	/* restart any wopeners */
1523 	lwkt_reltoken(&tty_token);
1524 	crit_exit();
1525 }
1526 
1527 static int
1528 sioread(struct dev_read_args *ap)
1529 {
1530 	cdev_t dev = ap->a_head.a_dev;
1531 	int		mynor, ret;
1532 	struct com_s	*com;
1533 
1534 	lwkt_gettoken(&tty_token);
1535 	mynor = minor(dev);
1536 	if (mynor & CONTROL_MASK) {
1537 		lwkt_reltoken(&tty_token);
1538 		return (ENODEV);
1539 	}
1540 	com = com_addr(MINOR_TO_UNIT(mynor));
1541 	if (com == NULL || com->gone) {
1542 		lwkt_reltoken(&tty_token);
1543 		return (ENODEV);
1544 	}
1545 	ret = ((*linesw[com->tp->t_line].l_read)(com->tp, ap->a_uio, ap->a_ioflag));
1546 	lwkt_reltoken(&tty_token);
1547 	return ret;
1548 }
1549 
1550 static int
1551 siowrite(struct dev_write_args *ap)
1552 {
1553 	cdev_t dev = ap->a_head.a_dev;
1554 	int		mynor;
1555 	struct com_s	*com;
1556 	int		unit, ret;
1557 
1558 	lwkt_gettoken(&tty_token);
1559 	mynor = minor(dev);
1560 	if (mynor & CONTROL_MASK) {
1561 		lwkt_reltoken(&tty_token);
1562 		return (ENODEV);
1563 	}
1564 
1565 	unit = MINOR_TO_UNIT(mynor);
1566 	com = com_addr(unit);
1567 	if (com == NULL || com->gone) {
1568 		lwkt_reltoken(&tty_token);
1569 		return (ENODEV);
1570 	}
1571 	/*
1572 	 * (XXX) We disallow virtual consoles if the physical console is
1573 	 * a serial port.  This is in case there is a display attached that
1574 	 * is not the console.  In that situation we don't need/want the X
1575 	 * server taking over the console.
1576 	 */
1577 	if (constty != NULL && unit == comconsole)
1578 		constty = NULL;
1579 	ret = ((*linesw[com->tp->t_line].l_write)(com->tp, ap->a_uio, ap->a_ioflag));
1580 	lwkt_reltoken(&tty_token);
1581 	return ret;
1582 }
1583 
1584 static void
1585 siobusycheck(void *chan)
1586 {
1587 	struct com_s	*com;
1588 
1589 	lwkt_gettoken(&tty_token);
1590 	com = (struct com_s *)chan;
1591 
1592 	/*
1593 	 * Clear TS_BUSY if low-level output is complete.
1594 	 * spl locking is sufficient because siointr1() does not set CS_BUSY.
1595 	 * If siointr1() clears CS_BUSY after we look at it, then we'll get
1596 	 * called again.  Reading the line status port outside of siointr1()
1597 	 * is safe because CS_BUSY is clear so there are no output interrupts
1598 	 * to lose.
1599 	 */
1600 	crit_enter();
1601 	if (com->state & CS_BUSY)
1602 		com->extra_state &= ~CSE_BUSYCHECK;	/* False alarm. */
1603 	else if ((inb(com->line_status_port) & (LSR_TSRE | LSR_TXRDY))
1604 	    == (LSR_TSRE | LSR_TXRDY)) {
1605 		com->tp->t_state &= ~TS_BUSY;
1606 		ttwwakeup(com->tp);
1607 		com->extra_state &= ~CSE_BUSYCHECK;
1608 	} else {
1609 		callout_reset(&com->busy_ch, hz / 100, siobusycheck, com);
1610 	}
1611 	crit_exit();
1612 	lwkt_reltoken(&tty_token);
1613 }
1614 
1615 static u_int
1616 siodivisor(u_long rclk, speed_t speed)
1617 {
1618 	long	actual_speed;
1619 	u_int	divisor;
1620 	int	error;
1621 
1622 	if (speed == 0 || speed > ((speed_t)-1 - 1) / 8)
1623 		return (0);
1624 	divisor = (rclk / (8UL * speed) + 1) / 2;
1625 	if (divisor == 0 || divisor >= 65536)
1626 		return (0);
1627 	actual_speed = rclk / (16UL * divisor);
1628 
1629 	/* 10 times error in percent: */
1630 	error = ((actual_speed - (long)speed) * 2000 / (long)speed + 1) / 2;
1631 
1632 	/* 3.0% maximum error tolerance: */
1633 	if (error < -30 || error > 30)
1634 		return (0);
1635 
1636 	return (divisor);
1637 }
1638 
1639 static void
1640 siodtrwakeup(void *chan)
1641 {
1642 	struct com_s	*com;
1643 
1644 	lwkt_gettoken(&tty_token);
1645 	com = (struct com_s *)chan;
1646 	com->state &= ~CS_DTR_OFF;
1647 	wakeup(&com->dtr_wait);
1648 	lwkt_reltoken(&tty_token);
1649 }
1650 
1651 /*
1652  * NOTE: Normally called with tty_token held but might not be when
1653  *	 operating as the console.
1654  *
1655  *	 Must be called with com_lock
1656  */
1657 static void
1658 sioinput(struct com_s *com)
1659 {
1660 	u_char		*buf;
1661 	int		incc;
1662 	u_char		line_status;
1663 	int		recv_data;
1664 	struct tty	*tp;
1665 
1666 	buf = com->ibuf;
1667 	tp = com->tp;
1668 	if (!(tp->t_state & TS_ISOPEN) || !(tp->t_cflag & CREAD)) {
1669 		com_events -= (com->iptr - com->ibuf);
1670 		com->iptr = com->ibuf;
1671 		return;
1672 	}
1673 	if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
1674 		/*
1675 		 * Avoid the grotesquely inefficient lineswitch routine
1676 		 * (ttyinput) in "raw" mode.  It usually takes about 450
1677 		 * instructions (that's without canonical processing or echo!).
1678 		 * slinput is reasonably fast (usually 40 instructions plus
1679 		 * call overhead).
1680 		 */
1681 		do {
1682 			com_unlock();
1683 			incc = com->iptr - buf;
1684 			if (tp->t_rawq.c_cc + incc > tp->t_ihiwat
1685 			    && (com->state & CS_RTS_IFLOW
1686 				|| tp->t_iflag & IXOFF)
1687 			    && !(tp->t_state & TS_TBLOCK))
1688 				ttyblock(tp);
1689 			com->delta_error_counts[CE_TTY_BUF_OVERFLOW]
1690 				+= b_to_q((char *)buf, incc, &tp->t_rawq);
1691 			buf += incc;
1692 			tk_nin += incc;
1693 			tk_rawcc += incc;
1694 			tp->t_rawcc += incc;
1695 			ttwakeup(tp);
1696 			if (tp->t_state & TS_TTSTOP
1697 			    && (tp->t_iflag & IXANY
1698 				|| tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
1699 				tp->t_state &= ~TS_TTSTOP;
1700 				tp->t_lflag &= ~FLUSHO;
1701 				comstart(tp);
1702 			}
1703 			com_lock();
1704 		} while (buf < com->iptr);
1705 	} else {
1706 		do {
1707 			com_unlock();
1708 			line_status = buf[com->ierroff];
1709 			recv_data = *buf++;
1710 			if (line_status
1711 			    & (LSR_BI | LSR_FE | LSR_OE | LSR_PE)) {
1712 				if (line_status & LSR_BI)
1713 					recv_data |= TTY_BI;
1714 				if (line_status & LSR_FE)
1715 					recv_data |= TTY_FE;
1716 				if (line_status & LSR_OE)
1717 					recv_data |= TTY_OE;
1718 				if (line_status & LSR_PE)
1719 					recv_data |= TTY_PE;
1720 			}
1721 			(*linesw[tp->t_line].l_rint)(recv_data, tp);
1722 			com_lock();
1723 		} while (buf < com->iptr);
1724 	}
1725 	com_events -= (com->iptr - com->ibuf);
1726 	com->iptr = com->ibuf;
1727 
1728 	/*
1729 	 * There is now room for another low-level buffer full of input,
1730 	 * so enable RTS if it is now disabled and there is room in the
1731 	 * high-level buffer.
1732 	 */
1733 	if ((com->state & CS_RTS_IFLOW) && !(com->mcr_image & MCR_RTS) &&
1734 	    !(tp->t_state & TS_TBLOCK))
1735 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1736 }
1737 
1738 void
1739 siointr(void *arg)
1740 {
1741 	lwkt_gettoken(&tty_token);
1742 #ifndef COM_MULTIPORT
1743 	com_lock();
1744 	siointr1((struct com_s *) arg);
1745 	com_unlock();
1746 #else /* COM_MULTIPORT */
1747 	bool_t		possibly_more_intrs;
1748 	int		unit;
1749 	struct com_s	*com;
1750 
1751 	/*
1752 	 * Loop until there is no activity on any port.  This is necessary
1753 	 * to get an interrupt edge more than to avoid another interrupt.
1754 	 * If the IRQ signal is just an OR of the IRQ signals from several
1755 	 * devices, then the edge from one may be lost because another is
1756 	 * on.
1757 	 */
1758 	com_lock();
1759 	do {
1760 		possibly_more_intrs = FALSE;
1761 		for (unit = 0; unit < sio_numunits; ++unit) {
1762 			com = com_addr(unit);
1763 			/*
1764 			 * XXX com_lock();
1765 			 * would it work here, or be counter-productive?
1766 			 */
1767 			if (com != NULL
1768 			    && !com->gone
1769 			    && (inb(com->int_id_port) & IIR_IMASK)
1770 			       != IIR_NOPEND) {
1771 				siointr1(com);
1772 				possibly_more_intrs = TRUE;
1773 			}
1774 			/* XXX com_unlock(); */
1775 		}
1776 	} while (possibly_more_intrs);
1777 	com_unlock();
1778 #endif /* COM_MULTIPORT */
1779 	lwkt_reltoken(&tty_token);
1780 }
1781 
1782 /*
1783  * Called with tty_token held and com_lock held.
1784  */
1785 static void
1786 siointr1(struct com_s *com)
1787 {
1788 	u_char	line_status;
1789 	u_char	modem_status;
1790 	u_char	*ioptr;
1791 	u_char	recv_data;
1792 	u_char	int_ctl;
1793 	u_char	int_ctl_new;
1794 	u_int	count;
1795 
1796 	int_ctl = inb(com->intr_ctl_port);
1797 	int_ctl_new = int_ctl;
1798 
1799 	while (!com->gone) {
1800 		if (com->pps.ppsparam.mode & PPS_CAPTUREBOTH) {
1801 			modem_status = inb(com->modem_status_port);
1802 		        if ((modem_status ^ com->last_modem_status) & MSR_DCD) {
1803 				count = sys_cputimer->count();
1804 				pps_event(&com->pps, count,
1805 				    (modem_status & MSR_DCD) ?
1806 				    PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
1807 			}
1808 		}
1809 		line_status = inb(com->line_status_port);
1810 
1811 		/* input event? (check first to help avoid overruns) */
1812 		while (line_status & LSR_RCV_MASK) {
1813 			/* break/unnattached error bits or real input? */
1814 			if (!(line_status & LSR_RXRDY))
1815 				recv_data = 0;
1816 			else
1817 				recv_data = inb(com->data_port);
1818 #if defined(DDB) && defined(ALT_BREAK_TO_DEBUGGER)
1819 			/*
1820 			 * Solaris implements a new BREAK which is initiated
1821 			 * by a character sequence CR ~ ^b which is similar
1822 			 * to a familiar pattern used on Sun servers by the
1823 			 * Remote Console.
1824 			 */
1825 #define	KEY_CRTLB	2	/* ^B */
1826 #define	KEY_CR		13	/* CR '\r' */
1827 #define	KEY_TILDE	126	/* ~ */
1828 
1829 			if (com->unit == comconsole) {
1830 				static int brk_state1 = 0, brk_state2 = 0;
1831 				if (recv_data == KEY_CR) {
1832 					brk_state1 = recv_data;
1833 					brk_state2 = 0;
1834 				} else if (brk_state1 == KEY_CR && (recv_data == KEY_TILDE || recv_data == KEY_CRTLB)) {
1835 					if (recv_data == KEY_TILDE)
1836 						brk_state2 = recv_data;
1837 					else if (brk_state2 == KEY_TILDE && recv_data == KEY_CRTLB) {
1838 							com_unlock();
1839 							breakpoint();
1840 							com_lock();
1841 							brk_state1 = brk_state2 = 0;
1842 							goto cont;
1843 					} else
1844 						brk_state2 = 0;
1845 				} else
1846 					brk_state1 = 0;
1847 			}
1848 #endif
1849 			if (line_status & (LSR_BI | LSR_FE | LSR_PE)) {
1850 				/*
1851 				 * Don't store BI if IGNBRK or FE/PE if IGNPAR.
1852 				 * Otherwise, push the work to a higher level
1853 				 * (to handle PARMRK) if we're bypassing.
1854 				 * Otherwise, convert BI/FE and PE+INPCK to 0.
1855 				 *
1856 				 * This makes bypassing work right in the
1857 				 * usual "raw" case (IGNBRK set, and IGNPAR
1858 				 * and INPCK clear).
1859 				 *
1860 				 * Note: BI together with FE/PE means just BI.
1861 				 */
1862 				if (line_status & LSR_BI) {
1863 #if defined(DDB) && defined(BREAK_TO_DEBUGGER)
1864 					if (com->unit == comconsole) {
1865 						com_unlock();
1866 						breakpoint();
1867 						com_lock();
1868 						goto cont;
1869 					}
1870 #endif
1871 					if (com->tp == NULL
1872 					    || com->tp->t_iflag & IGNBRK)
1873 						goto cont;
1874 				} else {
1875 					if (com->tp == NULL
1876 					    || com->tp->t_iflag & IGNPAR)
1877 						goto cont;
1878 				}
1879 				if (com->tp->t_state & TS_CAN_BYPASS_L_RINT
1880 				    && (line_status & (LSR_BI | LSR_FE)
1881 					|| com->tp->t_iflag & INPCK))
1882 					recv_data = 0;
1883 			}
1884 			++com->bytes_in;
1885 			if (com->hotchar != 0 && recv_data == com->hotchar)
1886 				setsofttty();
1887 			ioptr = com->iptr;
1888 			if (ioptr >= com->ibufend)
1889 				CE_RECORD(com, CE_INTERRUPT_BUF_OVERFLOW);
1890 			else {
1891 				if (com->do_timestamp)
1892 					microtime(&com->timestamp);
1893 				++com_events;
1894 				schedsofttty();
1895 #if 0 /* for testing input latency vs efficiency */
1896 if (com->iptr - com->ibuf == 8)
1897 	setsofttty();
1898 #endif
1899 				ioptr[0] = recv_data;
1900 				ioptr[com->ierroff] = line_status;
1901 				com->iptr = ++ioptr;
1902 				if (ioptr == com->ihighwater
1903 				    && com->state & CS_RTS_IFLOW)
1904 					outb(com->modem_ctl_port,
1905 					     com->mcr_image &= ~MCR_RTS);
1906 				if (line_status & LSR_OE)
1907 					CE_RECORD(com, CE_OVERRUN);
1908 			}
1909 cont:
1910 			/*
1911 			 * "& 0x7F" is to avoid the gcc-1.40 generating a slow
1912 			 * jump from the top of the loop to here
1913 			 */
1914 			line_status = inb(com->line_status_port) & 0x7F;
1915 		}
1916 
1917 		/* modem status change? (always check before doing output) */
1918 		modem_status = inb(com->modem_status_port);
1919 		if (modem_status != com->last_modem_status) {
1920 			if (com->do_dcd_timestamp
1921 			    && !(com->last_modem_status & MSR_DCD)
1922 			    && modem_status & MSR_DCD)
1923 				microtime(&com->dcd_timestamp);
1924 
1925 			/*
1926 			 * Schedule high level to handle DCD changes.  Note
1927 			 * that we don't use the delta bits anywhere.  Some
1928 			 * UARTs mess them up, and it's easy to remember the
1929 			 * previous bits and calculate the delta.
1930 			 */
1931 			com->last_modem_status = modem_status;
1932 			if (!(com->state & CS_CHECKMSR)) {
1933 				com_events += LOTS_OF_EVENTS;
1934 				com->state |= CS_CHECKMSR;
1935 				setsofttty();
1936 			}
1937 
1938 			/* handle CTS change immediately for crisp flow ctl */
1939 			if (com->state & CS_CTS_OFLOW) {
1940 				if (modem_status & MSR_CTS)
1941 					com->state |= CS_ODEVREADY;
1942 				else
1943 					com->state &= ~CS_ODEVREADY;
1944 			}
1945 		}
1946 
1947 		/* output queued and everything ready? */
1948 		if (line_status & LSR_TXRDY
1949 		    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY)) {
1950 			ioptr = com->obufq.l_head;
1951 			if (com->tx_fifo_size > 1) {
1952 				u_int	ocount;
1953 
1954 				ocount = com->obufq.l_tail - ioptr;
1955 				if (ocount > com->tx_fifo_size)
1956 					ocount = com->tx_fifo_size;
1957 				com->bytes_out += ocount;
1958 				do
1959 					outb(com->data_port, *ioptr++);
1960 				while (--ocount != 0);
1961 			} else {
1962 				outb(com->data_port, *ioptr++);
1963 				++com->bytes_out;
1964 			}
1965 			com->obufq.l_head = ioptr;
1966 			if (COM_IIR_TXRDYBUG(com->flags)) {
1967 				int_ctl_new = int_ctl | IER_ETXRDY;
1968 			}
1969 			if (ioptr >= com->obufq.l_tail) {
1970 				struct lbq	*qp;
1971 
1972 				qp = com->obufq.l_next;
1973 				qp->l_queued = FALSE;
1974 				qp = qp->l_next;
1975 				if (qp != NULL) {
1976 					com->obufq.l_head = qp->l_head;
1977 					com->obufq.l_tail = qp->l_tail;
1978 					com->obufq.l_next = qp;
1979 				} else {
1980 					/* output just completed */
1981 					if (COM_IIR_TXRDYBUG(com->flags)) {
1982 						int_ctl_new = int_ctl & ~IER_ETXRDY;
1983 					}
1984 					com->state &= ~CS_BUSY;
1985 				}
1986 				if (!(com->state & CS_ODONE)) {
1987 					com_events += LOTS_OF_EVENTS;
1988 					com->state |= CS_ODONE;
1989 					setsofttty();	/* handle at high level ASAP */
1990 				}
1991 			}
1992 			if (COM_IIR_TXRDYBUG(com->flags) && (int_ctl != int_ctl_new)) {
1993 				outb(com->intr_ctl_port, int_ctl_new);
1994 			}
1995 		}
1996 
1997 		/* finished? */
1998 #ifndef COM_MULTIPORT
1999 		if ((inb(com->int_id_port) & IIR_IMASK) == IIR_NOPEND)
2000 #endif /* COM_MULTIPORT */
2001 		{
2002 			return;
2003 		}
2004 	}
2005 }
2006 
2007 static int
2008 sioioctl(struct dev_ioctl_args *ap)
2009 {
2010 	cdev_t dev = ap->a_head.a_dev;
2011 	caddr_t data = ap->a_data;
2012 	struct com_s	*com;
2013 	int		error;
2014 	int		mynor;
2015 	struct tty	*tp;
2016 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
2017 	u_long		oldcmd;
2018 	struct termios	term;
2019 #endif
2020 	lwkt_gettoken(&tty_token);
2021 	mynor = minor(dev);
2022 
2023 	com = com_addr(MINOR_TO_UNIT(mynor));
2024 	if (com == NULL || com->gone) {
2025 		lwkt_reltoken(&tty_token);
2026 		return (ENODEV);
2027 	}
2028 	if (mynor & CONTROL_MASK) {
2029 		struct termios	*ct;
2030 
2031 		switch (mynor & CONTROL_MASK) {
2032 		case CONTROL_INIT_STATE:
2033 			ct = mynor & CALLOUT_MASK ? &com->it_out : &com->it_in;
2034 			break;
2035 		case CONTROL_LOCK_STATE:
2036 			ct = mynor & CALLOUT_MASK ? &com->lt_out : &com->lt_in;
2037 			break;
2038 		default:
2039 			lwkt_reltoken(&tty_token);
2040 			return (ENODEV);	/* /dev/nodev */
2041 		}
2042 		switch (ap->a_cmd) {
2043 		case TIOCSETA:
2044 			error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
2045 			if (error != 0)
2046 				return (error);
2047 			*ct = *(struct termios *)data;
2048 			lwkt_reltoken(&tty_token);
2049 			return (0);
2050 		case TIOCGETA:
2051 			*(struct termios *)data = *ct;
2052 			lwkt_reltoken(&tty_token);
2053 			return (0);
2054 		case TIOCGETD:
2055 			*(int *)data = TTYDISC;
2056 			lwkt_reltoken(&tty_token);
2057 			return (0);
2058 		case TIOCGWINSZ:
2059 			bzero(data, sizeof(struct winsize));
2060 			lwkt_reltoken(&tty_token);
2061 			return (0);
2062 		default:
2063 			lwkt_reltoken(&tty_token);
2064 			return (ENOTTY);
2065 		}
2066 	}
2067 	tp = com->tp;
2068 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
2069 	term = tp->t_termios;
2070 	oldcmd = ap->a_cmd;
2071 	error = ttsetcompat(tp, &ap->a_cmd, data, &term);
2072 	if (error != 0) {
2073 		lwkt_reltoken(&tty_token);
2074 		return (error);
2075 	}
2076 	if (ap->a_cmd != oldcmd)
2077 		data = (caddr_t)&term;
2078 #endif
2079 	if (ap->a_cmd == TIOCSETA || ap->a_cmd == TIOCSETAW ||
2080 	    ap->a_cmd == TIOCSETAF) {
2081 		int	cc;
2082 		struct termios *dt = (struct termios *)data;
2083 		struct termios *lt = mynor & CALLOUT_MASK
2084 				     ? &com->lt_out : &com->lt_in;
2085 
2086 		dt->c_iflag = (tp->t_iflag & lt->c_iflag)
2087 			      | (dt->c_iflag & ~lt->c_iflag);
2088 		dt->c_oflag = (tp->t_oflag & lt->c_oflag)
2089 			      | (dt->c_oflag & ~lt->c_oflag);
2090 		dt->c_cflag = (tp->t_cflag & lt->c_cflag)
2091 			      | (dt->c_cflag & ~lt->c_cflag);
2092 		dt->c_lflag = (tp->t_lflag & lt->c_lflag)
2093 			      | (dt->c_lflag & ~lt->c_lflag);
2094 		for (cc = 0; cc < NCCS; ++cc)
2095 			if (lt->c_cc[cc] != 0)
2096 				dt->c_cc[cc] = tp->t_cc[cc];
2097 		if (lt->c_ispeed != 0)
2098 			dt->c_ispeed = tp->t_ispeed;
2099 		if (lt->c_ospeed != 0)
2100 			dt->c_ospeed = tp->t_ospeed;
2101 	}
2102 	error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, data, ap->a_fflag, ap->a_cred);
2103 	if (error != ENOIOCTL) {
2104 		lwkt_reltoken(&tty_token);
2105 		return (error);
2106 	}
2107 	crit_enter();
2108 	error = ttioctl(tp, ap->a_cmd, data, ap->a_fflag);
2109 	disc_optim(tp, &tp->t_termios, com);
2110 	if (error != ENOIOCTL) {
2111 		crit_exit();
2112 		lwkt_reltoken(&tty_token);
2113 		return (error);
2114 	}
2115 	switch (ap->a_cmd) {
2116 	case TIOCSBRK:
2117 		sio_setreg(com, com_cfcr, com->cfcr_image |= CFCR_SBREAK);
2118 		break;
2119 	case TIOCCBRK:
2120 		sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
2121 		break;
2122 	case TIOCSDTR:
2123 		(void)commctl(com, TIOCM_DTR, DMBIS);
2124 		break;
2125 	case TIOCCDTR:
2126 		(void)commctl(com, TIOCM_DTR, DMBIC);
2127 		break;
2128 	/*
2129 	 * XXX should disallow changing MCR_RTS if CS_RTS_IFLOW is set.  The
2130 	 * changes get undone on the next call to comparam().
2131 	 */
2132 	case TIOCMSET:
2133 		(void)commctl(com, *(int *)data, DMSET);
2134 		break;
2135 	case TIOCMBIS:
2136 		(void)commctl(com, *(int *)data, DMBIS);
2137 		break;
2138 	case TIOCMBIC:
2139 		(void)commctl(com, *(int *)data, DMBIC);
2140 		break;
2141 	case TIOCMGET:
2142 		*(int *)data = commctl(com, 0, DMGET);
2143 		break;
2144 	case TIOCMSDTRWAIT:
2145 		/* must be root since the wait applies to following logins */
2146 		error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
2147 		if (error != 0) {
2148 			crit_exit();
2149 			lwkt_reltoken(&tty_token);
2150 			return (error);
2151 		}
2152 		com->dtr_wait = *(int *)data * hz / 100;
2153 		break;
2154 	case TIOCMGDTRWAIT:
2155 		*(int *)data = com->dtr_wait * 100 / hz;
2156 		break;
2157 	case TIOCTIMESTAMP:
2158 		com->do_timestamp = TRUE;
2159 		*(struct timeval *)data = com->timestamp;
2160 		break;
2161 	case TIOCDCDTIMESTAMP:
2162 		com->do_dcd_timestamp = TRUE;
2163 		*(struct timeval *)data = com->dcd_timestamp;
2164 		break;
2165 	default:
2166 		crit_exit();
2167 		error = pps_ioctl(ap->a_cmd, data, &com->pps);
2168 		if (error == ENODEV)
2169 			error = ENOTTY;
2170 		lwkt_reltoken(&tty_token);
2171 		return (error);
2172 	}
2173 	crit_exit();
2174 	lwkt_reltoken(&tty_token);
2175 	return (0);
2176 }
2177 
2178 static void
2179 siopoll(void *dummy, void *frame)
2180 {
2181 	int		unit;
2182 
2183 	lwkt_gettoken(&tty_token);
2184 	if (com_events == 0) {
2185 		lwkt_reltoken(&tty_token);
2186 		return;
2187 	}
2188 
2189 repeat:
2190 	for (unit = 0; unit < sio_numunits; ++unit) {
2191 		struct com_s	*com;
2192 		int		incc;
2193 		struct tty	*tp;
2194 
2195 		com = com_addr(unit);
2196 		if (com == NULL)
2197 			continue;
2198 		tp = com->tp;
2199 		if (tp == NULL || com->gone) {
2200 			/*
2201 			 * Discard any events related to never-opened or
2202 			 * going-away devices.
2203 			 */
2204 			com_lock();
2205 			incc = com->iptr - com->ibuf;
2206 			com->iptr = com->ibuf;
2207 			if (com->state & CS_CHECKMSR) {
2208 				incc += LOTS_OF_EVENTS;
2209 				com->state &= ~CS_CHECKMSR;
2210 			}
2211 			com_events -= incc;
2212 			com_unlock();
2213 			continue;
2214 		}
2215 		if (com->iptr != com->ibuf) {
2216 			com_lock();
2217 			sioinput(com);
2218 			com_unlock();
2219 		}
2220 		if (com->state & CS_CHECKMSR) {
2221 			u_char	delta_modem_status;
2222 
2223 			com_lock();
2224 			delta_modem_status = com->last_modem_status
2225 					     ^ com->prev_modem_status;
2226 			com->prev_modem_status = com->last_modem_status;
2227 			com_events -= LOTS_OF_EVENTS;
2228 			com->state &= ~CS_CHECKMSR;
2229 			com_unlock();
2230 			if (delta_modem_status & MSR_DCD)
2231 				(*linesw[tp->t_line].l_modem)
2232 					(tp, com->prev_modem_status & MSR_DCD);
2233 		}
2234 		if (com->state & CS_ODONE) {
2235 			com_lock();
2236 			com_events -= LOTS_OF_EVENTS;
2237 			com->state &= ~CS_ODONE;
2238 			com_unlock();
2239 			if (!(com->state & CS_BUSY)
2240 			    && !(com->extra_state & CSE_BUSYCHECK)) {
2241 				callout_reset(&com->busy_ch, hz / 100,
2242 						siobusycheck, com);
2243 				com->extra_state |= CSE_BUSYCHECK;
2244 			}
2245 			(*linesw[tp->t_line].l_start)(tp);
2246 		}
2247 		if (com_events == 0)
2248 			break;
2249 	}
2250 	if (com_events >= LOTS_OF_EVENTS)
2251 		goto repeat;
2252 	lwkt_reltoken(&tty_token);
2253 }
2254 
2255 /*
2256  * Called with tty_token held but no com_lock
2257  */
2258 static int
2259 comparam(struct tty *tp, struct termios *t)
2260 {
2261 	u_int		cfcr;
2262 	int		cflag;
2263 	struct com_s	*com;
2264 	u_int		divisor;
2265 	u_char		dlbh;
2266 	u_char		dlbl;
2267 	int		unit;
2268 
2269 	unit = DEV_TO_UNIT(tp->t_dev);
2270 	com = com_addr(unit);
2271 	if (com == NULL) {
2272 		return (ENODEV);
2273 	}
2274 
2275 	/* do historical conversions */
2276 	if (t->c_ispeed == 0)
2277 		t->c_ispeed = t->c_ospeed;
2278 
2279 	/* check requested parameters */
2280 	if (t->c_ospeed == 0)
2281 		divisor = 0;
2282 	else {
2283 		if (t->c_ispeed != t->c_ospeed)
2284 			return (EINVAL);
2285 		divisor = siodivisor(com->rclk, t->c_ispeed);
2286 		if (divisor == 0)
2287 			return (EINVAL);
2288 	}
2289 
2290 	/* parameters are OK, convert them to the com struct and the device */
2291 	crit_enter();
2292 	if (divisor == 0)
2293 		(void)commctl(com, TIOCM_DTR, DMBIC);	/* hang up line */
2294 	else
2295 		(void)commctl(com, TIOCM_DTR, DMBIS);
2296 	cflag = t->c_cflag;
2297 	switch (cflag & CSIZE) {
2298 	case CS5:
2299 		cfcr = CFCR_5BITS;
2300 		break;
2301 	case CS6:
2302 		cfcr = CFCR_6BITS;
2303 		break;
2304 	case CS7:
2305 		cfcr = CFCR_7BITS;
2306 		break;
2307 	default:
2308 		cfcr = CFCR_8BITS;
2309 		break;
2310 	}
2311 	if (cflag & PARENB) {
2312 		cfcr |= CFCR_PENAB;
2313 		if (!(cflag & PARODD))
2314 			cfcr |= CFCR_PEVEN;
2315 	}
2316 	if (cflag & CSTOPB)
2317 		cfcr |= CFCR_STOPB;
2318 
2319 	if (com->hasfifo && divisor != 0) {
2320 		/*
2321 		 * Use a fifo trigger level low enough so that the input
2322 		 * latency from the fifo is less than about 16 msec and
2323 		 * the total latency is less than about 30 msec.  These
2324 		 * latencies are reasonable for humans.  Serial comms
2325 		 * protocols shouldn't expect anything better since modem
2326 		 * latencies are larger.
2327 		 *
2328 		 * Interrupts can be held up for long periods of time
2329 		 * due to inefficiencies in other parts of the kernel,
2330 		 * certain video cards, etc.  Setting the FIFO trigger
2331 		 * point to MEDH instead of HIGH gives us 694uS of slop
2332 		 * (8 character times) instead of 173uS (2 character times)
2333 		 * @ 115200 bps.
2334 		 */
2335 		com->fifo_image = t->c_ospeed <= 4800
2336 				  ? FIFO_ENABLE : FIFO_ENABLE | FIFO_RX_MEDH;
2337 #ifdef COM_ESP
2338 		/*
2339 		 * The Hayes ESP card needs the fifo DMA mode bit set
2340 		 * in compatibility mode.  If not, it will interrupt
2341 		 * for each character received.
2342 		 */
2343 		if (com->esp)
2344 			com->fifo_image |= FIFO_DMA_MODE;
2345 #endif
2346 		sio_setreg(com, com_fifo, com->fifo_image);
2347 	}
2348 
2349 	/*
2350 	 * This returns with interrupts disabled so that we can complete
2351 	 * the speed change atomically.  Keeping interrupts disabled is
2352 	 * especially important while com_data is hidden.
2353 	 */
2354 	(void) siosetwater(com, t->c_ispeed);
2355 
2356 	if (divisor != 0) {
2357 		sio_setreg(com, com_cfcr, cfcr | CFCR_DLAB);
2358 		/*
2359 		 * Only set the divisor registers if they would change,
2360 		 * since on some 16550 incompatibles (UMC8669F), setting
2361 		 * them while input is arriving them loses sync until
2362 		 * data stops arriving.
2363 		 */
2364 		dlbl = divisor & 0xFF;
2365 		if (sio_getreg(com, com_dlbl) != dlbl)
2366 			sio_setreg(com, com_dlbl, dlbl);
2367 		dlbh = divisor >> 8;
2368 		if (sio_getreg(com, com_dlbh) != dlbh)
2369 			sio_setreg(com, com_dlbh, dlbh);
2370 	}
2371 
2372 	sio_setreg(com, com_cfcr, com->cfcr_image = cfcr);
2373 
2374 	if (!(tp->t_state & TS_TTSTOP))
2375 		com->state |= CS_TTGO;
2376 
2377 	if (cflag & CRTS_IFLOW) {
2378 		if (com->st16650a) {
2379 			sio_setreg(com, com_cfcr, 0xbf);
2380 			sio_setreg(com, com_fifo,
2381 				   sio_getreg(com, com_fifo) | 0x40);
2382 		}
2383 		com->state |= CS_RTS_IFLOW;
2384 		/*
2385 		 * If CS_RTS_IFLOW just changed from off to on, the change
2386 		 * needs to be propagated to MCR_RTS.  This isn't urgent,
2387 		 * so do it later by calling comstart() instead of repeating
2388 		 * a lot of code from comstart() here.
2389 		 */
2390 	} else if (com->state & CS_RTS_IFLOW) {
2391 		com->state &= ~CS_RTS_IFLOW;
2392 		/*
2393 		 * CS_RTS_IFLOW just changed from on to off.  Force MCR_RTS
2394 		 * on here, since comstart() won't do it later.
2395 		 */
2396 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2397 		if (com->st16650a) {
2398 			sio_setreg(com, com_cfcr, 0xbf);
2399 			sio_setreg(com, com_fifo,
2400 				   sio_getreg(com, com_fifo) & ~0x40);
2401 		}
2402 	}
2403 
2404 
2405 	/*
2406 	 * Set up state to handle output flow control.
2407 	 * XXX - worth handling MDMBUF (DCD) flow control at the lowest level?
2408 	 * Now has 10+ msec latency, while CTS flow has 50- usec latency.
2409 	 */
2410 	com->state |= CS_ODEVREADY;
2411 	com->state &= ~CS_CTS_OFLOW;
2412 	if (cflag & CCTS_OFLOW) {
2413 		com->state |= CS_CTS_OFLOW;
2414 		if (!(com->last_modem_status & MSR_CTS))
2415 			com->state &= ~CS_ODEVREADY;
2416 		if (com->st16650a) {
2417 			sio_setreg(com, com_cfcr, 0xbf);
2418 			sio_setreg(com, com_fifo,
2419 				   sio_getreg(com, com_fifo) | 0x80);
2420 		}
2421 	} else {
2422 		if (com->st16650a) {
2423 			sio_setreg(com, com_cfcr, 0xbf);
2424 			sio_setreg(com, com_fifo,
2425 				   sio_getreg(com, com_fifo) & ~0x80);
2426 		}
2427 	}
2428 
2429 	sio_setreg(com, com_cfcr, com->cfcr_image);
2430 
2431 	/* XXX shouldn't call functions while intrs are disabled. */
2432 	disc_optim(tp, t, com);
2433 	/*
2434 	 * Recover from fiddling with CS_TTGO.  We used to call siointr1()
2435 	 * unconditionally, but that defeated the careful discarding of
2436 	 * stale input in sioopen().
2437 	 */
2438 	if (com->state >= (CS_BUSY | CS_TTGO)) {
2439 		com_lock();
2440 		siointr1(com);
2441 		com_unlock();
2442 	}
2443 	crit_exit();
2444 	comstart(tp);
2445 	if (com->ibufold != NULL) {
2446 		kfree(com->ibufold, M_DEVBUF);
2447 		com->ibufold = NULL;
2448 	}
2449 	return (0);
2450 }
2451 
2452 /*
2453  * called with tty_token held
2454  */
2455 static int
2456 siosetwater(struct com_s *com, speed_t speed)
2457 {
2458 	int		cp4ticks;
2459 	u_char		*ibuf;
2460 	int		ibufsize;
2461 	struct tty	*tp;
2462 
2463 	/*
2464 	 * Make the buffer size large enough to handle a softtty interrupt
2465 	 * latency of about 2 ticks without loss of throughput or data
2466 	 * (about 3 ticks if input flow control is not used or not honoured,
2467 	 * but a bit less for CS5-CS7 modes).
2468 	 */
2469 	cp4ticks = speed / 10 / hz * 4;
2470 	for (ibufsize = 128; ibufsize < cp4ticks;)
2471 		ibufsize <<= 1;
2472 	if (ibufsize == com->ibufsize)
2473 		return (0);
2474 
2475 	/*
2476 	 * Allocate input buffer.  The extra factor of 2 in the size is
2477 	 * to allow for an error byte for each input byte.
2478 	 */
2479 	ibuf = kmalloc(2 * ibufsize, M_DEVBUF, M_WAITOK | M_ZERO);
2480 
2481 	/* Initialize non-critical variables. */
2482 	com->ibufold = com->ibuf;
2483 	com->ibufsize = ibufsize;
2484 	tp = com->tp;
2485 	if (tp != NULL) {
2486 		tp->t_ififosize = 2 * ibufsize;
2487 		tp->t_ispeedwat = (speed_t)-1;
2488 		tp->t_ospeedwat = (speed_t)-1;
2489 	}
2490 
2491 	/*
2492 	 * Read current input buffer.
2493 	 */
2494 	com_lock();
2495 	if (com->iptr != com->ibuf)
2496 		sioinput(com);
2497 
2498 	/*-
2499 	 * Initialize critical variables, including input buffer watermarks.
2500 	 * The external device is asked to stop sending when the buffer
2501 	 * exactly reaches high water, or when the high level requests it.
2502 	 * The high level is notified immediately (rather than at a later
2503 	 * clock tick) when this watermark is reached.
2504 	 * The buffer size is chosen so the watermark should almost never
2505 	 * be reached.
2506 	 * The low watermark is invisibly 0 since the buffer is always
2507 	 * emptied all at once.
2508 	 */
2509 	com->iptr = com->ibuf = ibuf;
2510 	com->ibufend = ibuf + ibufsize;
2511 	com->ierroff = ibufsize;
2512 	com->ihighwater = ibuf + 3 * ibufsize / 4;
2513 	com_unlock();
2514 	return (0);
2515 }
2516 
2517 static void
2518 comstart(struct tty *tp)
2519 {
2520 	struct com_s	*com;
2521 	int		unit;
2522 
2523 	lwkt_gettoken(&tty_token);
2524 	unit = DEV_TO_UNIT(tp->t_dev);
2525 	com = com_addr(unit);
2526 	if (com == NULL) {
2527 		lwkt_reltoken(&tty_token);
2528 		return;
2529 	}
2530 	crit_enter();
2531 	com_lock();
2532 	if (tp->t_state & TS_TTSTOP)
2533 		com->state &= ~CS_TTGO;
2534 	else
2535 		com->state |= CS_TTGO;
2536 	if (tp->t_state & TS_TBLOCK) {
2537 		if (com->mcr_image & MCR_RTS && com->state & CS_RTS_IFLOW)
2538 			outb(com->modem_ctl_port, com->mcr_image &= ~MCR_RTS);
2539 	} else {
2540 		if (!(com->mcr_image & MCR_RTS) && com->iptr < com->ihighwater
2541 		    && com->state & CS_RTS_IFLOW)
2542 			outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2543 	}
2544 	com_unlock();
2545 	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
2546 		ttwwakeup(tp);
2547 		crit_exit();
2548 		lwkt_reltoken(&tty_token);
2549 		return;
2550 	}
2551 	if (tp->t_outq.c_cc != 0) {
2552 		struct lbq	*qp;
2553 		struct lbq	*next;
2554 
2555 		if (!com->obufs[0].l_queued) {
2556 			com->obufs[0].l_tail
2557 			    = com->obuf1 + q_to_b(&tp->t_outq, com->obuf1,
2558 						  sizeof com->obuf1);
2559 			com->obufs[0].l_next = NULL;
2560 			com->obufs[0].l_queued = TRUE;
2561 			com_lock();
2562 			if (com->state & CS_BUSY) {
2563 				qp = com->obufq.l_next;
2564 				while ((next = qp->l_next) != NULL)
2565 					qp = next;
2566 				qp->l_next = &com->obufs[0];
2567 			} else {
2568 				com->obufq.l_head = com->obufs[0].l_head;
2569 				com->obufq.l_tail = com->obufs[0].l_tail;
2570 				com->obufq.l_next = &com->obufs[0];
2571 				com->state |= CS_BUSY;
2572 			}
2573 			com_unlock();
2574 		}
2575 		if (tp->t_outq.c_cc != 0 && !com->obufs[1].l_queued) {
2576 			com->obufs[1].l_tail
2577 			    = com->obuf2 + q_to_b(&tp->t_outq, com->obuf2,
2578 						  sizeof com->obuf2);
2579 			com->obufs[1].l_next = NULL;
2580 			com->obufs[1].l_queued = TRUE;
2581 			com_lock();
2582 			if (com->state & CS_BUSY) {
2583 				qp = com->obufq.l_next;
2584 				while ((next = qp->l_next) != NULL)
2585 					qp = next;
2586 				qp->l_next = &com->obufs[1];
2587 			} else {
2588 				com->obufq.l_head = com->obufs[1].l_head;
2589 				com->obufq.l_tail = com->obufs[1].l_tail;
2590 				com->obufq.l_next = &com->obufs[1];
2591 				com->state |= CS_BUSY;
2592 			}
2593 			com_unlock();
2594 		}
2595 		tp->t_state |= TS_BUSY;
2596 	}
2597 	com_lock();
2598 	if (com->state >= (CS_BUSY | CS_TTGO))
2599 		siointr1(com);	/* fake interrupt to start output */
2600 	com_unlock();
2601 	ttwwakeup(tp);
2602 	crit_exit();
2603 	lwkt_reltoken(&tty_token);
2604 }
2605 
2606 static void
2607 comstop(struct tty *tp, int rw)
2608 {
2609 	struct com_s	*com;
2610 
2611 	lwkt_gettoken(&tty_token);
2612 	com = com_addr(DEV_TO_UNIT(tp->t_dev));
2613 	if (com == NULL || com->gone) {
2614 		lwkt_reltoken(&tty_token);
2615 		return;
2616 	}
2617 	com_lock();
2618 	if (rw & FWRITE) {
2619 		if (com->hasfifo)
2620 #ifdef COM_ESP
2621 		    /* XXX avoid h/w bug. */
2622 		    if (!com->esp)
2623 #endif
2624 			sio_setreg(com, com_fifo,
2625 				   FIFO_XMT_RST | com->fifo_image);
2626 		com->obufs[0].l_queued = FALSE;
2627 		com->obufs[1].l_queued = FALSE;
2628 		if (com->state & CS_ODONE)
2629 			com_events -= LOTS_OF_EVENTS;
2630 		com->state &= ~(CS_ODONE | CS_BUSY);
2631 		com->tp->t_state &= ~TS_BUSY;
2632 	}
2633 	if (rw & FREAD) {
2634 		if (com->hasfifo)
2635 #ifdef COM_ESP
2636 		    /* XXX avoid h/w bug. */
2637 		    if (!com->esp)
2638 #endif
2639 			sio_setreg(com, com_fifo,
2640 				   FIFO_RCV_RST | com->fifo_image);
2641 		com_events -= (com->iptr - com->ibuf);
2642 		com->iptr = com->ibuf;
2643 	}
2644 	com_unlock();
2645 	comstart(tp);
2646 	lwkt_reltoken(&tty_token);
2647 }
2648 
2649 static int
2650 commctl(struct com_s *com, int bits, int how)
2651 {
2652 	int	mcr;
2653 	int	msr;
2654 
2655 	lwkt_gettoken(&tty_token);
2656 	if (how == DMGET) {
2657 		bits = TIOCM_LE;	/* XXX - always enabled while open */
2658 		mcr = com->mcr_image;
2659 		if (mcr & MCR_DTR)
2660 			bits |= TIOCM_DTR;
2661 		if (mcr & MCR_RTS)
2662 			bits |= TIOCM_RTS;
2663 		msr = com->prev_modem_status;
2664 		if (msr & MSR_CTS)
2665 			bits |= TIOCM_CTS;
2666 		if (msr & MSR_DCD)
2667 			bits |= TIOCM_CD;
2668 		if (msr & MSR_DSR)
2669 			bits |= TIOCM_DSR;
2670 		/*
2671 		 * XXX - MSR_RI is naturally volatile, and we make MSR_TERI
2672 		 * more volatile by reading the modem status a lot.  Perhaps
2673 		 * we should latch both bits until the status is read here.
2674 		 */
2675 		if (msr & (MSR_RI | MSR_TERI))
2676 			bits |= TIOCM_RI;
2677 		lwkt_reltoken(&tty_token);
2678 		return (bits);
2679 	}
2680 	mcr = 0;
2681 	if (bits & TIOCM_DTR)
2682 		mcr |= MCR_DTR;
2683 	if (bits & TIOCM_RTS)
2684 		mcr |= MCR_RTS;
2685 	if (com->gone) {
2686 		lwkt_reltoken(&tty_token);
2687 		return(0);
2688 	}
2689 	com_lock();
2690 	switch (how) {
2691 	case DMSET:
2692 		outb(com->modem_ctl_port,
2693 		     com->mcr_image = mcr | (com->mcr_image & MCR_IENABLE));
2694 		break;
2695 	case DMBIS:
2696 		outb(com->modem_ctl_port, com->mcr_image |= mcr);
2697 		break;
2698 	case DMBIC:
2699 		outb(com->modem_ctl_port, com->mcr_image &= ~mcr);
2700 		break;
2701 	}
2702 	com_unlock();
2703 	lwkt_reltoken(&tty_token);
2704 	return (0);
2705 }
2706 
2707 /*
2708  * NOTE: Must be called with tty_token held
2709  */
2710 static void
2711 siosettimeout(void)
2712 {
2713 	struct com_s	*com;
2714 	bool_t		someopen;
2715 	int		unit;
2716 
2717 	ASSERT_LWKT_TOKEN_HELD(&tty_token);
2718 	/*
2719 	 * Set our timeout period to 1 second if no polled devices are open.
2720 	 * Otherwise set it to max(1/200, 1/hz).
2721 	 * Enable timeouts iff some device is open.
2722 	 */
2723 	callout_stop(&sio_timeout_handle);
2724 	sio_timeout = hz;
2725 	someopen = FALSE;
2726 	for (unit = 0; unit < sio_numunits; ++unit) {
2727 		com = com_addr(unit);
2728 		if (com != NULL && com->tp != NULL
2729 		    && com->tp->t_state & TS_ISOPEN && !com->gone) {
2730 			someopen = TRUE;
2731 			if (com->poll || com->poll_output) {
2732 				sio_timeout = hz > 200 ? hz / 200 : 1;
2733 				break;
2734 			}
2735 		}
2736 	}
2737 	if (someopen) {
2738 		sio_timeouts_until_log = hz / sio_timeout;
2739 		callout_reset(&sio_timeout_handle, sio_timeout,
2740 				comwakeup, NULL);
2741 	} else {
2742 		/* Flush error messages, if any. */
2743 		sio_timeouts_until_log = 1;
2744 		comwakeup(NULL);
2745 		callout_stop(&sio_timeout_handle);
2746 	}
2747 }
2748 
2749 /*
2750  * NOTE: Must be called with tty_token held
2751  */
2752 static void
2753 comwakeup(void *chan)
2754 {
2755 	struct com_s	*com;
2756 	int		unit;
2757 
2758 	/*
2759 	 * Can be called from a callout too so just get the token
2760 	 */
2761 	lwkt_gettoken(&tty_token);
2762 	callout_reset(&sio_timeout_handle, sio_timeout, comwakeup, NULL);
2763 
2764 	/*
2765 	 * Recover from lost output interrupts.
2766 	 * Poll any lines that don't use interrupts.
2767 	 */
2768 	for (unit = 0; unit < sio_numunits; ++unit) {
2769 		com = com_addr(unit);
2770 		if (com != NULL && !com->gone
2771 		    && (com->state >= (CS_BUSY | CS_TTGO) || com->poll)) {
2772 			com_lock();
2773 			siointr1(com);
2774 			com_unlock();
2775 		}
2776 	}
2777 
2778 	/*
2779 	 * Check for and log errors, but not too often.
2780 	 */
2781 	if (--sio_timeouts_until_log > 0) {
2782 		lwkt_reltoken(&tty_token);
2783 		return;
2784 	}
2785 	sio_timeouts_until_log = hz / sio_timeout;
2786 	for (unit = 0; unit < sio_numunits; ++unit) {
2787 		int	errnum;
2788 
2789 		com = com_addr(unit);
2790 		if (com == NULL)
2791 			continue;
2792 		if (com->gone)
2793 			continue;
2794 		for (errnum = 0; errnum < CE_NTYPES; ++errnum) {
2795 			u_int	delta;
2796 			u_long	total;
2797 
2798 			com_lock();
2799 			delta = com->delta_error_counts[errnum];
2800 			com->delta_error_counts[errnum] = 0;
2801 			com_unlock();
2802 			if (delta == 0)
2803 				continue;
2804 			total = com->error_counts[errnum] += delta;
2805 			log(LOG_ERR, "sio%d: %u more %s%s (total %lu)\n",
2806 			    unit, delta, error_desc[errnum],
2807 			    delta == 1 ? "" : "s", total);
2808 		}
2809 	}
2810 	lwkt_reltoken(&tty_token);
2811 }
2812 
2813 static void
2814 disc_optim(struct tty *tp, struct termios *t, struct com_s *com)
2815 {
2816 	lwkt_gettoken(&tty_token);
2817 	if (!(t->c_iflag & (ICRNL | IGNCR | IMAXBEL | INLCR | ISTRIP | IXON))
2818 	    && (!(t->c_iflag & BRKINT) || (t->c_iflag & IGNBRK))
2819 	    && (!(t->c_iflag & PARMRK)
2820 		|| (t->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
2821 	    && !(t->c_lflag & (ECHO | ICANON | IEXTEN | ISIG | PENDIN))
2822 	    && linesw[tp->t_line].l_rint == ttyinput)
2823 		tp->t_state |= TS_CAN_BYPASS_L_RINT;
2824 	else
2825 		tp->t_state &= ~TS_CAN_BYPASS_L_RINT;
2826 	com->hotchar = linesw[tp->t_line].l_hotchar;
2827 	lwkt_reltoken(&tty_token);
2828 }
2829 
2830 /*
2831  * Following are all routines needed for SIO to act as console
2832  */
2833 #include <sys/cons.h>
2834 
2835 struct siocnstate {
2836 	u_char	dlbl;
2837 	u_char	dlbh;
2838 	u_char	ier;
2839 	u_char	cfcr;
2840 	u_char	mcr;
2841 };
2842 
2843 static speed_t siocngetspeed (Port_t, u_long rclk);
2844 static void siocnclose	(struct siocnstate *sp, Port_t iobase);
2845 static void siocnopen	(struct siocnstate *sp, Port_t iobase, int speed);
2846 static void siocntxwait	(Port_t iobase);
2847 
2848 static cn_probe_t siocnprobe;
2849 static cn_init_t siocninit;
2850 static cn_init_fini_t siocninit_fini;
2851 static cn_checkc_t siocncheckc;
2852 static cn_getc_t siocngetc;
2853 static cn_putc_t siocnputc;
2854 
2855 #if defined(__i386__) || defined(__x86_64__)
2856 CONS_DRIVER(sio, siocnprobe, siocninit, siocninit_fini,
2857 	    NULL, siocngetc, siocncheckc, siocnputc, NULL);
2858 #endif
2859 
2860 /* To get the GDB related variables */
2861 #if DDB > 0
2862 #include <ddb/ddb.h>
2863 #endif
2864 
2865 static void
2866 siocntxwait(Port_t iobase)
2867 {
2868 	int	timo;
2869 
2870 	/*
2871 	 * Wait for any pending transmission to finish.  Required to avoid
2872 	 * the UART lockup bug when the speed is changed, and for normal
2873 	 * transmits.
2874 	 */
2875 	timo = 100000;
2876 	while ((inb(iobase + com_lsr) & (LSR_TSRE | LSR_TXRDY))
2877 	       != (LSR_TSRE | LSR_TXRDY) && --timo != 0)
2878 		;
2879 }
2880 
2881 /*
2882  * Read the serial port specified and try to figure out what speed
2883  * it's currently running at.  We're assuming the serial port has
2884  * been initialized and is basicly idle.  This routine is only intended
2885  * to be run at system startup.
2886  *
2887  * If the value read from the serial port doesn't make sense, return 0.
2888  */
2889 /*
2890  * NOTE: Must be called with tty_token held
2891  */
2892 static speed_t
2893 siocngetspeed(Port_t iobase, u_long rclk)
2894 {
2895 	u_int	divisor;
2896 	u_char	dlbh;
2897 	u_char	dlbl;
2898 	u_char  cfcr;
2899 
2900 	cfcr = inb(iobase + com_cfcr);
2901 	outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2902 
2903 	dlbl = inb(iobase + com_dlbl);
2904 	dlbh = inb(iobase + com_dlbh);
2905 
2906 	outb(iobase + com_cfcr, cfcr);
2907 
2908 	divisor = dlbh << 8 | dlbl;
2909 
2910 	/* XXX there should be more sanity checking. */
2911 	if (divisor == 0)
2912 		return (CONSPEED);
2913 	return (rclk / (16UL * divisor));
2914 }
2915 
2916 static void
2917 siocnopen(struct siocnstate *sp, Port_t iobase, int speed)
2918 {
2919 	u_int	divisor;
2920 	u_char	dlbh;
2921 	u_char	dlbl;
2922 
2923 	/*
2924 	 * Save all the device control registers except the fifo register
2925 	 * and set our default ones (cs8 -parenb speed=comdefaultrate).
2926 	 * We can't save the fifo register since it is read-only.
2927 	 */
2928 	sp->ier = inb(iobase + com_ier);
2929 	outb(iobase + com_ier, 0);	/* spltty() doesn't stop siointr() */
2930 	siocntxwait(iobase);
2931 	sp->cfcr = inb(iobase + com_cfcr);
2932 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2933 	sp->dlbl = inb(iobase + com_dlbl);
2934 	sp->dlbh = inb(iobase + com_dlbh);
2935 	/*
2936 	 * Only set the divisor registers if they would change, since on
2937 	 * some 16550 incompatibles (Startech), setting them clears the
2938 	 * data input register.  This also reduces the effects of the
2939 	 * UMC8669F bug.
2940 	 */
2941 	divisor = siodivisor(comdefaultrclk, speed);
2942 	dlbl = divisor & 0xFF;
2943 	if (sp->dlbl != dlbl)
2944 		outb(iobase + com_dlbl, dlbl);
2945 	dlbh = divisor >> 8;
2946 	if (sp->dlbh != dlbh)
2947 		outb(iobase + com_dlbh, dlbh);
2948 	outb(iobase + com_cfcr, CFCR_8BITS);
2949 	sp->mcr = inb(iobase + com_mcr);
2950 	/*
2951 	 * We don't want interrupts, but must be careful not to "disable"
2952 	 * them by clearing the MCR_IENABLE bit, since that might cause
2953 	 * an interrupt by floating the IRQ line.
2954 	 */
2955 	outb(iobase + com_mcr, (sp->mcr & MCR_IENABLE) | MCR_DTR | MCR_RTS);
2956 }
2957 
2958 static void
2959 siocnclose(struct siocnstate *sp, Port_t iobase)
2960 {
2961 	/*
2962 	 * Restore the device control registers.
2963 	 */
2964 	siocntxwait(iobase);
2965 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2966 	if (sp->dlbl != inb(iobase + com_dlbl))
2967 		outb(iobase + com_dlbl, sp->dlbl);
2968 	if (sp->dlbh != inb(iobase + com_dlbh))
2969 		outb(iobase + com_dlbh, sp->dlbh);
2970 	outb(iobase + com_cfcr, sp->cfcr);
2971 	/*
2972 	 * XXX damp oscillations of MCR_DTR and MCR_RTS by not restoring them.
2973 	 */
2974 	outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
2975 	outb(iobase + com_ier, sp->ier);
2976 }
2977 
2978 static void
2979 siocnprobe(struct consdev *cp)
2980 {
2981 	speed_t			boot_speed;
2982 	u_char			cfcr;
2983 	u_int			divisor;
2984 	int			unit;
2985 	struct siocnstate	sp;
2986 
2987 	/*
2988 	 * Find our first enabled console, if any.  If it is a high-level
2989 	 * console device, then initialize it and return successfully.
2990 	 * If it is a low-level console device, then initialize it and
2991 	 * return unsuccessfully.  It must be initialized in both cases
2992 	 * for early use by console drivers and debuggers.  Initializing
2993 	 * the hardware is not necessary in all cases, since the i/o
2994 	 * routines initialize it on the fly, but it is necessary if
2995 	 * input might arrive while the hardware is switched back to an
2996 	 * uninitialized state.  We can't handle multiple console devices
2997 	 * yet because our low-level routines don't take a device arg.
2998 	 * We trust the user to set the console flags properly so that we
2999 	 * don't need to probe.
3000 	 */
3001 	cp->cn_pri = CN_DEAD;
3002 
3003 	for (unit = 0; unit < 16; unit++) { /* XXX need to know how many */
3004 		int flags;
3005 		int disabled;
3006 		if (resource_int_value("sio", unit, "disabled", &disabled) == 0) {
3007 			if (disabled)
3008 				continue;
3009 		}
3010 		if (resource_int_value("sio", unit, "flags", &flags))
3011 			continue;
3012 		if (COM_CONSOLE(flags) || COM_DEBUGGER(flags)) {
3013 			int port;
3014 			Port_t iobase;
3015 
3016 			if (resource_int_value("sio", unit, "port", &port))
3017 				continue;
3018 			iobase = port;
3019 			crit_enter();
3020 			if (boothowto & RB_SERIAL) {
3021 				boot_speed =
3022 				    siocngetspeed(iobase, comdefaultrclk);
3023 				if (boot_speed)
3024 					comdefaultrate = boot_speed;
3025 			}
3026 
3027 			/*
3028 			 * Initialize the divisor latch.  We can't rely on
3029 			 * siocnopen() to do this the first time, since it
3030 			 * avoids writing to the latch if the latch appears
3031 			 * to have the correct value.  Also, if we didn't
3032 			 * just read the speed from the hardware, then we
3033 			 * need to set the speed in hardware so that
3034 			 * switching it later is null.
3035 			 */
3036 			com_lock();
3037 			cfcr = inb(iobase + com_cfcr);
3038 			outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
3039 			divisor = siodivisor(comdefaultrclk, comdefaultrate);
3040 			outb(iobase + com_dlbl, divisor & 0xff);
3041 			outb(iobase + com_dlbh, divisor >> 8);
3042 			outb(iobase + com_cfcr, cfcr);
3043 
3044 			siocnopen(&sp, iobase, comdefaultrate);
3045 			com_unlock();
3046 
3047 			crit_exit();
3048 			if (COM_CONSOLE(flags) && !COM_LLCONSOLE(flags)) {
3049 				cp->cn_probegood = 1;
3050 				cp->cn_private = (void *)(intptr_t)unit;
3051 				cp->cn_pri = COM_FORCECONSOLE(flags)
3052 					     || boothowto & RB_SERIAL
3053 					     ? CN_REMOTE : CN_NORMAL;
3054 				siocniobase = iobase;
3055 				siocnunit = unit;
3056 			}
3057 			if (COM_DEBUGGER(flags) && gdb_tab == NULL) {
3058 				kprintf("sio%d: gdb debugging port\n", unit);
3059 				siogdbiobase = iobase;
3060 				siogdbunit = unit;
3061 #if DDB > 0
3062 				cp->cn_gdbprivate = (void *)(intptr_t)unit;
3063 				gdb_tab = cp;
3064 #endif
3065 			}
3066 		}
3067 	}
3068 #if defined(__i386__) || defined(__x86_64__)
3069 #if DDB > 0
3070 	/*
3071 	 * XXX Ugly Compatability.
3072 	 * If no gdb port has been specified, set it to be the console
3073 	 * as some configuration files don't specify the gdb port.
3074 	 */
3075 	if (gdb_tab == NULL && (boothowto & RB_GDB)) {
3076 		kprintf("Warning: no GDB port specified. Defaulting to sio%d.\n",
3077 			siocnunit);
3078 		kprintf("Set flag 0x80 on desired GDB port in your\n");
3079 		kprintf("configuration file (currently sio only).\n");
3080 		siogdbiobase = siocniobase;
3081 		siogdbunit = siocnunit;
3082 		cp->cn_gdbprivate = (void *)(intptr_t)siocnunit;
3083 		gdb_tab = cp;
3084 	}
3085 #endif
3086 #endif
3087 }
3088 
3089 static void
3090 siocninit(struct consdev *cp)
3091 {
3092 	comconsole = (int)(intptr_t)cp->cn_private;
3093 }
3094 
3095 static void
3096 siocninit_fini(struct consdev *cp)
3097 {
3098 	cdev_t dev;
3099 	int unit;
3100 
3101 	if (cp->cn_probegood) {
3102 		unit = (int)(intptr_t)cp->cn_private;
3103 		/*
3104 		 * Call devfs_find_device_by_name on ttydX to find the correct device,
3105 		 * as it should have been created already at this point by the
3106 		 * attach routine.
3107 		 * If it isn't found, the serial port was not attached at all and we
3108 		 * shouldn't be here, so assert this case.
3109 		 */
3110 		dev = devfs_find_device_by_name("ttyd%r", unit);
3111 
3112 		KKASSERT(dev != NULL);
3113 		cp->cn_dev = dev;
3114 	}
3115 }
3116 
3117 static int
3118 siocncheckc(void *private)
3119 {
3120 	int	c;
3121 	int	unit = (int)(intptr_t)private;
3122 	Port_t	iobase;
3123 	struct siocnstate	sp;
3124 
3125 	if (unit == siogdbunit)
3126 		iobase = siogdbiobase;
3127 	else
3128 		iobase = siocniobase;
3129 	com_lock();
3130 	crit_enter();
3131 	siocnopen(&sp, iobase, comdefaultrate);
3132 	if (inb(iobase + com_lsr) & LSR_RXRDY)
3133 		c = inb(iobase + com_data);
3134 	else
3135 		c = -1;
3136 	siocnclose(&sp, iobase);
3137 	crit_exit();
3138 	com_unlock();
3139 	return (c);
3140 }
3141 
3142 
3143 int
3144 siocngetc(void *private)
3145 {
3146 	int	c;
3147 	int	unit = (int)(intptr_t)private;
3148 	Port_t	iobase;
3149 	struct siocnstate	sp;
3150 
3151 	if (unit == siogdbunit)
3152 		iobase = siogdbiobase;
3153 	else
3154 		iobase = siocniobase;
3155 	com_lock();
3156 	crit_enter();
3157 	siocnopen(&sp, iobase, comdefaultrate);
3158 	while (!(inb(iobase + com_lsr) & LSR_RXRDY))
3159 		;
3160 	c = inb(iobase + com_data);
3161 	siocnclose(&sp, iobase);
3162 	crit_exit();
3163 	com_unlock();
3164 	return (c);
3165 }
3166 
3167 void
3168 siocnputc(void *private, int c)
3169 {
3170 	int	unit = (int)(intptr_t)private;
3171 	struct siocnstate	sp;
3172 	Port_t	iobase;
3173 
3174 	if (unit == siogdbunit)
3175 		iobase = siogdbiobase;
3176 	else
3177 		iobase = siocniobase;
3178 	com_lock();
3179 	crit_enter();
3180 	siocnopen(&sp, iobase, comdefaultrate);
3181 	siocntxwait(iobase);
3182 	outb(iobase + com_data, c);
3183 	siocnclose(&sp, iobase);
3184 	crit_exit();
3185 	com_unlock();
3186 }
3187 
3188 DRIVER_MODULE(sio, isa, sio_isa_driver, sio_devclass, NULL, NULL);
3189 DRIVER_MODULE(sio, acpi, sio_isa_driver, sio_devclass, NULL, NULL);
3190 #if NPCI > 0
3191 DRIVER_MODULE(sio, pci, sio_pci_driver, sio_devclass, NULL, NULL);
3192 #endif
3193 #if NPUC > 0
3194 DRIVER_MODULE(sio, puc, sio_puc_driver, sio_devclass, NULL, NULL);
3195 #endif
3196