xref: /dflybsd-src/sys/dev/serial/sio/sio.c (revision 88abd8b5763f2e5d4b4db5c5dc1b5bb4c489698b)
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 #ifdef __i386__
46 #include "use_puc.h"
47 #endif
48 #include "use_sio.h"
49 
50 /*
51  * Serial driver, based on 386BSD-0.1 com driver.
52  * Mostly rewritten to use pseudo-DMA.
53  * Works for National Semiconductor NS8250-NS16550AF UARTs.
54  * COM driver, based on HP dca driver.
55  *
56  * Changes for PC-Card integration:
57  *	- Added PC-Card driver table and handlers
58  */
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/reboot.h>
62 #include <sys/malloc.h>
63 #include <sys/tty.h>
64 #include <sys/proc.h>
65 #include <sys/priv.h>
66 #include <sys/module.h>
67 #include <sys/conf.h>
68 #include <sys/dkstat.h>
69 #include <sys/fcntl.h>
70 #include <sys/interrupt.h>
71 #include <sys/kernel.h>
72 #include <sys/syslog.h>
73 #include <sys/sysctl.h>
74 #include <sys/bus.h>
75 #include <sys/rman.h>
76 #include <sys/timepps.h>
77 #include <sys/thread2.h>
78 #include <sys/devfs.h>
79 
80 #include <machine/limits.h>
81 
82 #include <bus/isa/isareg.h>
83 #include <bus/isa/isavar.h>
84 #if NPCI > 0
85 #include <bus/pci/pcireg.h>
86 #include <bus/pci/pcivar.h>
87 #endif
88 #if NPUC > 0
89 #include <dev/misc/puc/pucvar.h>
90 #endif
91 #include <machine/lock.h>
92 
93 #include <machine/clock.h>
94 #ifndef SMP
95 #include <machine/lock.h>
96 #endif
97 
98 #include "sioreg.h"
99 #include "sio_private.h"
100 
101 #ifdef COM_ESP
102 #include "../ic_layer/esp.h"
103 #endif
104 
105 #define	LOTS_OF_EVENTS	64	/* helps separate urgent events from input */
106 
107 #define	CALLOUT_MASK		0x80
108 #define	CONTROL_MASK		0x60
109 #define	CONTROL_INIT_STATE	0x20
110 #define	CONTROL_LOCK_STATE	0x40
111 #define	DEV_TO_UNIT(dev)	(MINOR_TO_UNIT(minor(dev)))
112 #define	MINOR_TO_UNIT(mynor)	((((mynor) & ~0xffffU) >> (8 + 3)) \
113 				 | ((mynor) & 0x1f))
114 #define	UNIT_TO_MINOR(unit)	((((unit) & ~0x1fU) << (8 + 3)) \
115 				 | ((unit) & 0x1f))
116 
117 #define	com_scr		7	/* scratch register for 16450-16550 (R/W) */
118 
119 #define	sio_getreg(com, off) \
120 	(bus_space_read_1((com)->bst, (com)->bsh, (off)))
121 #define	sio_setreg(com, off, value) \
122 	(bus_space_write_1((com)->bst, (com)->bsh, (off), (value)))
123 
124 /*
125  * com state bits.
126  * (CS_BUSY | CS_TTGO) and (CS_BUSY | CS_TTGO | CS_ODEVREADY) must be higher
127  * than the other bits so that they can be tested as a group without masking
128  * off the low bits.
129  *
130  * The following com and tty flags correspond closely:
131  *	CS_BUSY		= TS_BUSY (maintained by comstart(), siopoll() and
132  *				   comstop())
133  *	CS_TTGO		= ~TS_TTSTOP (maintained by comparam() and comstart())
134  *	CS_CTS_OFLOW	= CCTS_OFLOW (maintained by comparam())
135  *	CS_RTS_IFLOW	= CRTS_IFLOW (maintained by comparam())
136  * TS_FLUSH is not used.
137  * XXX I think TIOCSETA doesn't clear TS_TTSTOP when it clears IXON.
138  * XXX CS_*FLOW should be CF_*FLOW in com->flags (control flags not state).
139  */
140 #define	CS_BUSY		0x80	/* output in progress */
141 #define	CS_TTGO		0x40	/* output not stopped by XOFF */
142 #define	CS_ODEVREADY	0x20	/* external device h/w ready (CTS) */
143 #define	CS_CHECKMSR	1	/* check of MSR scheduled */
144 #define	CS_CTS_OFLOW	2	/* use CTS output flow control */
145 #define	CS_DTR_OFF	0x10	/* DTR held off */
146 #define	CS_ODONE	4	/* output completed */
147 #define	CS_RTS_IFLOW	8	/* use RTS input flow control */
148 #define	CSE_BUSYCHECK	1	/* siobusycheck() scheduled */
149 
150 static	char const * const	error_desc[] = {
151 #define	CE_OVERRUN			0
152 	"silo overflow",
153 #define	CE_INTERRUPT_BUF_OVERFLOW	1
154 	"interrupt-level buffer overflow",
155 #define	CE_TTY_BUF_OVERFLOW		2
156 	"tty-level buffer overflow",
157 };
158 
159 #ifdef COM_ESP
160 static	int	espattach	(struct com_s *com, Port_t esp_port);
161 #endif
162 static	int	sio_isa_attach	(device_t dev);
163 
164 static	timeout_t siobusycheck;
165 static	u_int	siodivisor	(u_long rclk, speed_t speed);
166 static	timeout_t siodtrwakeup;
167 static	void	comhardclose	(struct com_s *com);
168 static	void	sioinput	(struct com_s *com);
169 static	void	siointr1	(struct com_s *com);
170 static	void	siointr		(void *arg);
171 static	int	commctl		(struct com_s *com, int bits, int how);
172 static	int	comparam	(struct tty *tp, struct termios *t);
173 static	inthand2_t siopoll;
174 static	int	sio_isa_probe	(device_t dev);
175 static	void	siosettimeout	(void);
176 static	int	siosetwater	(struct com_s *com, speed_t speed);
177 static	void	comstart	(struct tty *tp);
178 static	void	comstop		(struct tty *tp, int rw);
179 static	timeout_t comwakeup;
180 static	void	disc_optim	(struct tty	*tp, struct termios *t,
181 				     struct com_s *com);
182 
183 #if NPCI > 0
184 static	int	sio_pci_attach (device_t dev);
185 static	void	sio_pci_kludge_unit (device_t dev);
186 static	int	sio_pci_probe (device_t dev);
187 #endif /* NPCI > 0 */
188 
189 #if NPUC > 0
190 static	int	sio_puc_attach (device_t dev);
191 static	int	sio_puc_probe (device_t dev);
192 #endif /* NPUC > 0 */
193 
194 static char driver_name[] = "sio";
195 
196 /* table and macro for fast conversion from a unit number to its com struct */
197 devclass_t	sio_devclass;
198 #define	com_addr(unit)	((struct com_s *) \
199 			 devclass_get_softc(sio_devclass, unit))
200 
201 static device_method_t sio_isa_methods[] = {
202 	/* Device interface */
203 	DEVMETHOD(device_probe,		sio_isa_probe),
204 	DEVMETHOD(device_attach,	sio_isa_attach),
205 
206 	{ 0, 0 }
207 };
208 
209 static driver_t sio_isa_driver = {
210 	driver_name,
211 	sio_isa_methods,
212 	sizeof(struct com_s),
213 };
214 
215 #if NPCI > 0
216 static device_method_t sio_pci_methods[] = {
217 	/* Device interface */
218 	DEVMETHOD(device_probe,		sio_pci_probe),
219 	DEVMETHOD(device_attach,	sio_pci_attach),
220 
221 	{ 0, 0 }
222 };
223 
224 static driver_t sio_pci_driver = {
225 	driver_name,
226 	sio_pci_methods,
227 	sizeof(struct com_s),
228 };
229 #endif /* NPCI > 0 */
230 
231 #if NPUC > 0
232 static device_method_t sio_puc_methods[] = {
233 	/* Device interface */
234 	DEVMETHOD(device_probe,		sio_puc_probe),
235 	DEVMETHOD(device_attach,	sio_puc_attach),
236 
237 	{ 0, 0 }
238 };
239 
240 static driver_t sio_puc_driver = {
241 	driver_name,
242 	sio_puc_methods,
243 	sizeof(struct com_s),
244 };
245 #endif /* NPUC > 0 */
246 
247 static	d_open_t	sioopen;
248 static	d_close_t	sioclose;
249 static	d_read_t	sioread;
250 static	d_write_t	siowrite;
251 static	d_ioctl_t	sioioctl;
252 
253 static struct dev_ops sio_ops = {
254 	{ driver_name, 0, D_TTY },
255 	.d_open =	sioopen,
256 	.d_close =	sioclose,
257 	.d_read =	sioread,
258 	.d_write =	siowrite,
259 	.d_ioctl =	sioioctl,
260 	.d_kqfilter =	ttykqfilter,
261 	.d_revoke =	ttyrevoke
262 };
263 
264 int	comconsole = -1;
265 static	volatile speed_t	comdefaultrate = CONSPEED;
266 static	u_long			comdefaultrclk = DEFAULT_RCLK;
267 SYSCTL_ULONG(_machdep, OID_AUTO, conrclk, CTLFLAG_RW, &comdefaultrclk, 0, "");
268 static	u_int	com_events;	/* input chars + weighted output completions */
269 static	Port_t	siocniobase;
270 static	int	siocnunit;
271 static	Port_t	siogdbiobase;
272 static	int	siogdbunit = -1;
273 static	bool_t	sio_registered;
274 static	int	sio_timeout;
275 static	int	sio_timeouts_until_log;
276 static	struct	callout	sio_timeout_handle;
277 static	int	sio_numunits;
278 
279 #ifdef COM_ESP
280 /* XXX configure this properly. */
281 static	Port_t	likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, };
282 static	Port_t	likely_esp_ports[] = { 0x140, 0x180, 0x280, 0 };
283 #endif
284 
285 /*
286  * handle sysctl read/write requests for console speed
287  *
288  * In addition to setting comdefaultrate for I/O through /dev/console,
289  * also set the initial and lock values for the /dev/ttyXX device
290  * if there is one associated with the console.  Finally, if the /dev/tty
291  * device has already been open, change the speed on the open running port
292  * itself.
293  */
294 
295 static int
296 sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)
297 {
298 	int error;
299 	speed_t newspeed;
300 	struct com_s *com;
301 	struct tty *tp;
302 
303 	lwkt_gettoken(&tty_token);
304 	newspeed = comdefaultrate;
305 
306 	error = sysctl_handle_opaque(oidp, &newspeed, sizeof newspeed, req);
307 	if (error || !req->newptr) {
308 		lwkt_reltoken(&tty_token);
309 		return (error);
310 	}
311 
312 	comdefaultrate = newspeed;
313 
314 	if (comconsole < 0) {	/* serial console not selected? */
315 		lwkt_reltoken(&tty_token);
316 		return (0);
317 	}
318 
319 	com = com_addr(comconsole);
320 	if (com == NULL) {
321 		lwkt_reltoken(&tty_token);
322 		return (ENXIO);
323 	}
324 
325 	/*
326 	 * set the initial and lock rates for /dev/ttydXX and /dev/cuaXX
327 	 * (note, the lock rates really are boolean -- if non-zero, disallow
328 	 *  speed changes)
329 	 */
330 	com->it_in.c_ispeed  = com->it_in.c_ospeed =
331 	com->lt_in.c_ispeed  = com->lt_in.c_ospeed =
332 	com->it_out.c_ispeed = com->it_out.c_ospeed =
333 	com->lt_out.c_ispeed = com->lt_out.c_ospeed = comdefaultrate;
334 
335 	/*
336 	 * if we're open, change the running rate too
337 	 */
338 	tp = com->tp;
339 	if (tp && (tp->t_state & TS_ISOPEN)) {
340 		tp->t_termios.c_ispeed =
341 		tp->t_termios.c_ospeed = comdefaultrate;
342 		crit_enter();
343 		error = comparam(tp, &tp->t_termios);
344 		crit_exit();
345 	}
346 	lwkt_reltoken(&tty_token);
347 	return error;
348 }
349 
350 SYSCTL_PROC(_machdep, OID_AUTO, conspeed, CTLTYPE_INT | CTLFLAG_RW,
351 	    0, 0, sysctl_machdep_comdefaultrate, "I", "");
352 
353 #if NPCI > 0
354 struct pci_ids {
355 	u_int32_t	type;
356 	const char	*desc;
357 	int		rid;
358 };
359 
360 static struct pci_ids pci_ids[] = {
361 	{ 0x100812b9, "3COM PCI FaxModem", 0x10 },
362 	{ 0x2000131f, "CyberSerial (1-port) 16550", 0x10 },
363 	{ 0x01101407, "Koutech IOFLEX-2S PCI Dual Port Serial", 0x10 },
364 	{ 0x01111407, "Koutech IOFLEX-2S PCI Dual Port Serial", 0x10 },
365 	{ 0x048011c1, "Lucent kermit based PCI Modem", 0x14 },
366 	{ 0x95211415, "Oxford Semiconductor PCI Dual Port Serial", 0x10 },
367 	{ 0x7101135e, "SeaLevel Ultra 530.PCI Single Port Serial", 0x18 },
368 	{ 0x0000151f, "SmartLink 5634PCV SurfRider", 0x10 },
369 	{ 0x98459710, "Netmos Nm9845 PCI Bridge with Dual UART", 0x10 },
370 	{ 0x00000000, NULL, 0 }
371 };
372 
373 static int
374 sio_pci_attach(device_t dev)
375 {
376 	u_int32_t	type;
377 	struct pci_ids	*id;
378 
379 	type = pci_get_devid(dev);
380 	id = pci_ids;
381 	while (id->type && id->type != type)
382 		id++;
383 	if (id->desc == NULL)
384 		return (ENXIO);
385 	sio_pci_kludge_unit(dev);
386 	return (sioattach(dev, id->rid, 0UL));
387 }
388 
389 /*
390  * Don't cut and paste this to other drivers.  It is a horrible kludge
391  * which will fail to work and also be unnecessary in future versions.
392  */
393 static void
394 sio_pci_kludge_unit(device_t dev)
395 {
396 	devclass_t	dc;
397 	int		err;
398 	int		start;
399 	int		unit;
400 
401 	unit = 0;
402 	start = 0;
403 	while (resource_int_value("sio", unit, "port", &start) == 0 &&
404 	    start > 0)
405 		unit++;
406 	if (device_get_unit(dev) < unit) {
407 		dc = device_get_devclass(dev);
408 		while (devclass_get_device(dc, unit))
409 			unit++;
410 		device_printf(dev, "moving to sio%d\n", unit);
411 		err = device_set_unit(dev, unit);	/* EVIL DO NOT COPY */
412 		if (err)
413 			device_printf(dev, "error moving device %d\n", err);
414 	}
415 }
416 
417 static int
418 sio_pci_probe(device_t dev)
419 {
420 	u_int32_t	type;
421 	struct pci_ids	*id;
422 
423 	type = pci_get_devid(dev);
424 	id = pci_ids;
425 	while (id->type && id->type != type)
426 		id++;
427 	if (id->desc == NULL)
428 		return (ENXIO);
429 	device_set_desc(dev, id->desc);
430 	return (sioprobe(dev, id->rid, 0UL));
431 }
432 #endif /* NPCI > 0 */
433 
434 #if NPUC > 0
435 static int
436 sio_puc_attach(device_t dev)
437 {
438 	u_int rclk;
439 
440 	if (BUS_READ_IVAR(device_get_parent(dev), dev, PUC_IVAR_FREQ,
441 	    &rclk) != 0)
442 		rclk = DEFAULT_RCLK;
443 	return (sioattach(dev, 0, rclk));
444 }
445 
446 static int
447 sio_puc_probe(device_t dev)
448 {
449 	u_int rclk;
450 
451 	if (BUS_READ_IVAR(device_get_parent(dev), dev, PUC_IVAR_FREQ,
452 	    &rclk) != 0)
453 		rclk = DEFAULT_RCLK;
454 	return (sioprobe(dev, 0, rclk));
455 }
456 #endif /* NPUC */
457 
458 static struct isa_pnp_id sio_ids[] = {
459 	{0x0005d041, "Standard PC COM port"},	/* PNP0500 */
460 	{0x0105d041, "16550A-compatible COM port"},	/* PNP0501 */
461 	{0x0205d041, "Multiport serial device (non-intelligent 16550)"}, /* PNP0502 */
462 	{0x1005d041, "Generic IRDA-compatible device"},	/* PNP0510 */
463 	{0x1105d041, "Generic IRDA-compatible device"},	/* PNP0511 */
464 	/* Devices that do not have a compatid */
465 	{0x12206804, NULL},     /* ACH2012 - 5634BTS 56K Video Ready Modem */
466 	{0x7602a904, NULL},	/* AEI0276 - 56K v.90 Fax Modem (LKT) */
467 	{0x00007905, NULL},	/* AKY0000 - 56K Plug&Play Modem */
468 	{0x21107905, NULL},	/* AKY1021 - 56K Plug&Play Modem */
469 	{0x01405407, NULL},	/* AZT4001 - AZT3000 PnP SOUND DEVICE, MODEM */
470 	{0x56039008, NULL},	/* BDP0356 - Best Data 56x2 */
471 	{0x56159008, NULL},	/* BDP1556 - B.D. Smart One 56SPS,Voice Modem*/
472 	{0x36339008, NULL},	/* BDP3336 - Best Data Prods. 336F */
473 	{0x0014490a, NULL},	/* BRI1400 - Boca 33.6 PnP */
474 	{0x0015490a, NULL},	/* BRI1500 - Internal Fax Data */
475 	{0x0034490a, NULL},	/* BRI3400 - Internal ACF Modem */
476 	{0x0094490a, NULL},	/* BRI9400 - Boca K56Flex PnP */
477 	{0x00b4490a, NULL},	/* BRIB400 - Boca 56k PnP */
478 	{0x0030320d, NULL},	/* CIR3000 - Cirrus Logic V43 */
479 	{0x0100440e, NULL},	/* CRD0001 - Cardinal MVP288IV ? */
480 	{0x01308c0e, NULL},	/* CTL3001 - Creative Labs Phoneblaster */
481 	{0x36033610, NULL},     /* DAV0336 - DAVICOM 336PNP MODEM */
482 	{0x01009416, NULL},     /* ETT0001 - E-Tech Bullet 33k6 PnP */
483 	{0x0000aa1a, NULL},	/* FUJ0000 - FUJITSU Modem 33600 PNP/I2 */
484 	{0x1200c31e, NULL},	/* GVC0012 - VF1128HV-R9 (win modem?) */
485 	{0x0303c31e, NULL},	/* GVC0303 - MaxTech 33.6 PnP D/F/V */
486 	{0x0505c31e, NULL},	/* GVC0505 - GVC 56k Faxmodem */
487 	{0x0116c31e, NULL},	/* GVC1601 - Rockwell V.34 Plug & Play Modem */
488 	{0x0050c31e, NULL},	/* GVC5000 - some GVC modem */
489 	{0x3800f91e, NULL},	/* GWY0038 - Telepath with v.90 */
490 	{0x9062f91e, NULL},	/* GWY6290 - Telepath with x2 Technology */
491 	{0x8100e425, NULL},	/* IOD0081 - I-O DATA DEVICE,INC. IFML-560 */
492 	{0x21002534, NULL},	/* MAE0021 - Jetstream Int V.90 56k Voice Series 2*/
493 	{0x0000f435, NULL},	/* MOT0000 - Motorola ModemSURFR 33.6 Intern */
494 	{0x5015f435, NULL},	/* MOT1550 - Motorola ModemSURFR 56K Modem */
495 	{0xf015f435, NULL},	/* MOT15F0 - Motorola VoiceSURFR 56K Modem */
496 	{0x6045f435, NULL},	/* MOT4560 - Motorola ? */
497 	{0x61e7a338, NULL},	/* NECE761 - 33.6Modem */
498  	{0x08804f3f, NULL},	/* OZO8008 - Zoom  (33.6k Modem) */
499 	{0x0f804f3f, NULL},	/* OZO800f - Zoom 2812 (56k Modem) */
500 	{0x39804f3f, NULL},	/* OZO8039 - Zoom 56k flex */
501 	{0x00914f3f, NULL},	/* OZO9100 - Zoom 2919 (K56 Faxmodem) */
502 	{0x3024a341, NULL},	/* PMC2430 - Pace 56 Voice Internal Modem */
503 	{0x1000eb49, NULL},	/* ROK0010 - Rockwell ? */
504 	{0x1200b23d, NULL},     /* RSS0012 - OMRON ME5614ISA */
505 	{0x5002734a, NULL},	/* RSS0250 - 5614Jx3(G) Internal Modem */
506 	{0x6202734a, NULL},	/* RSS0262 - 5614Jx3[G] V90+K56Flex Modem */
507 	{0x1010104d, NULL},	/* SHP1010 - Rockwell 33600bps Modem */
508 	{0xc100ad4d, NULL},	/* SMM00C1 - Leopard 56k PnP */
509 	{0x9012b04e, NULL},	/* SUP1290 - Supra ? */
510 	{0x1013b04e, NULL},	/* SUP1310 - SupraExpress 336i PnP */
511 	{0x8013b04e, NULL},	/* SUP1380 - SupraExpress 288i PnP Voice */
512 	{0x8113b04e, NULL},	/* SUP1381 - SupraExpress 336i PnP Voice */
513 	{0x5016b04e, NULL},	/* SUP1650 - Supra 336i Sp Intl */
514 	{0x7016b04e, NULL},	/* SUP1670 - Supra 336i V+ Intl */
515 	{0x7420b04e, NULL},	/* SUP2070 - Supra ? */
516 	{0x8020b04e, NULL},	/* SUP2080 - Supra ? */
517 	{0x8420b04e, NULL},	/* SUP2084 - SupraExpress 56i PnP */
518 	{0x7121b04e, NULL},	/* SUP2171 - SupraExpress 56i Sp? */
519 	{0x8024b04e, NULL},	/* SUP2480 - Supra ? */
520 	{0x01007256, NULL},	/* USR0001 - U.S. Robotics Inc., Sportster W */
521 	{0x02007256, NULL},	/* USR0002 - U.S. Robotics Inc. Sportster 33. */
522 	{0x04007256, NULL},	/* USR0004 - USR Sportster 14.4k */
523 	{0x06007256, NULL},	/* USR0006 - USR Sportster 33.6k */
524 	{0x11007256, NULL},	/* USR0011 - USR ? */
525 	{0x01017256, NULL},	/* USR0101 - USR ? */
526 	{0x30207256, NULL},	/* USR2030 - U.S.Robotics Inc. Sportster 560 */
527 	{0x50207256, NULL},	/* USR2050 - U.S.Robotics Inc. Sportster 33. */
528 	{0x70207256, NULL},	/* USR2070 - U.S.Robotics Inc. Sportster 560 */
529 	{0x30307256, NULL},	/* USR3030 - U.S. Robotics 56K FAX INT */
530 	{0x31307256, NULL},	/* USR3031 - U.S. Robotics 56K FAX INT */
531 	{0x50307256, NULL},	/* USR3050 - U.S. Robotics 56K FAX INT */
532 	{0x70307256, NULL},	/* USR3070 - U.S. Robotics 56K Voice INT */
533 	{0x90307256, NULL},	/* USR3090 - USR ? */
534 	{0x70917256, NULL},	/* USR9170 - U.S. Robotics 56K FAX INT */
535 	{0x90917256, NULL},	/* USR9190 - USR 56k Voice INT */
536 	{0x0300695c, NULL},	/* WCI0003 - Fax/Voice/Modem/Speakphone/Asvd */
537 	{0x01a0896a, NULL},	/* ZTIA001 - Zoom Internal V90 Faxmodem */
538 	{0x61f7896a, NULL},	/* ZTIF761 - Zoom ComStar 33.6 */
539 	{0}
540 };
541 
542 
543 
544 static int
545 sio_isa_probe(device_t dev)
546 {
547 	/* Check isapnp ids */
548 	if (ISA_PNP_PROBE(device_get_parent(dev), dev, sio_ids) == ENXIO)
549 		return (ENXIO);
550 	return (sioprobe(dev, 0, 0UL));
551 }
552 
553 int
554 sioprobe(device_t dev, int xrid, u_long rclk)
555 {
556 #if 0
557 	static bool_t	already_init;
558 	device_t	xdev;
559 #endif
560 	struct com_s	*com;
561 	u_int		divisor;
562 	bool_t		failures[10];
563 	int		fn;
564 	device_t	idev;
565 	Port_t		iobase;
566 	intrmask_t	irqmap[4];
567 	intrmask_t	irqs;
568 	u_char		mcr_image;
569 	int		result;
570 	u_long		xirq;
571 	u_int		flags = device_get_flags(dev);
572 	int		rid;
573 	struct resource *port;
574 
575 	rid = xrid;
576 	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
577 				  0, ~0, IO_COMSIZE, RF_ACTIVE);
578 	if (!port)
579 		return (ENXIO);
580 
581 	lwkt_gettoken(&tty_token);
582 	com = device_get_softc(dev);
583 	com->bst = rman_get_bustag(port);
584 	com->bsh = rman_get_bushandle(port);
585 	if (rclk == 0)
586 		rclk = DEFAULT_RCLK;
587 	com->rclk = rclk;
588 
589 #if 0
590 	/*
591 	 * XXX this is broken - when we are first called, there are no
592 	 * previously configured IO ports.  We could hard code
593 	 * 0x3f8, 0x2f8, 0x3e8, 0x2e8 etc but that's probably worse.
594 	 * This code has been doing nothing since the conversion since
595 	 * "count" is zero the first time around.
596 	 */
597 	if (!already_init) {
598 		/*
599 		 * Turn off MCR_IENABLE for all likely serial ports.  An unused
600 		 * port with its MCR_IENABLE gate open will inhibit interrupts
601 		 * from any used port that shares the interrupt vector.
602 		 * XXX the gate enable is elsewhere for some multiports.
603 		 */
604 		device_t *devs;
605 		int count, i, xioport;
606 
607 		devclass_get_devices(sio_devclass, &devs, &count);
608 		for (i = 0; i < count; i++) {
609 			xdev = devs[i];
610 			if (device_is_enabled(xdev) &&
611 			    bus_get_resource(xdev, SYS_RES_IOPORT, 0, &xioport,
612 					     NULL) == 0)
613 				outb(xioport + com_mcr, 0);
614 		}
615 		kfree(devs, M_TEMP);
616 		already_init = TRUE;
617 	}
618 #endif
619 
620 	if (COM_LLCONSOLE(flags)) {
621 		kprintf("sio%d: reserved for low-level i/o\n",
622 		       device_get_unit(dev));
623 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
624 		lwkt_reltoken(&tty_token);
625 		return (ENXIO);
626 	}
627 
628 	/*
629 	 * If the device is on a multiport card and has an AST/4
630 	 * compatible interrupt control register, initialize this
631 	 * register and prepare to leave MCR_IENABLE clear in the mcr.
632 	 * Otherwise, prepare to set MCR_IENABLE in the mcr.
633 	 * Point idev to the device struct giving the correct id_irq.
634 	 * This is the struct for the master device if there is one.
635 	 */
636 	idev = dev;
637 	mcr_image = MCR_IENABLE;
638 #ifdef COM_MULTIPORT
639 	if (COM_ISMULTIPORT(flags)) {
640 		Port_t xiobase;
641 		u_long io;
642 
643 		idev = devclass_get_device(sio_devclass, COM_MPMASTER(flags));
644 		if (idev == NULL) {
645 			kprintf("sio%d: master device %d not configured\n",
646 			       device_get_unit(dev), COM_MPMASTER(flags));
647 			idev = dev;
648 		}
649 		if (!COM_NOTAST4(flags)) {
650 			if (bus_get_resource(idev, SYS_RES_IOPORT, 0, &io,
651 					     NULL) == 0) {
652 				xiobase = io;
653 				if (bus_get_resource(idev, SYS_RES_IRQ, 0,
654 				    NULL, NULL) == 0)
655 					outb(xiobase + com_scr, 0x80);
656 				else
657 					outb(xiobase + com_scr, 0);
658 			}
659 			mcr_image = 0;
660 		}
661 	}
662 #endif /* COM_MULTIPORT */
663 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, NULL, NULL) != 0)
664 		mcr_image = 0;
665 
666 	bzero(failures, sizeof failures);
667 	iobase = rman_get_start(port);
668 
669 	/*
670 	 * We don't want to get actual interrupts, just masked ones.
671 	 * Interrupts from this line should already be masked in the ICU,
672 	 * but mask them in the processor as well in case there are some
673 	 * (misconfigured) shared interrupts.
674 	 */
675 	com_lock();
676 /* EXTRA DELAY? */
677 
678 	/*
679 	 * For the TI16754 chips, set prescaler to 1 (4 is often the
680 	 * default after-reset value) as otherwise it's impossible to
681 	 * get highest baudrates.
682 	 */
683 	if (COM_TI16754(flags)) {
684 		u_char cfcr, efr;
685 
686 		cfcr = sio_getreg(com, com_cfcr);
687 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
688 		efr = sio_getreg(com, com_efr);
689 		/* Unlock extended features to turn off prescaler. */
690 		sio_setreg(com, com_efr, efr | EFR_EFE);
691 		/* Disable EFR. */
692 		sio_setreg(com, com_cfcr, (cfcr != CFCR_EFR_ENABLE) ? cfcr : 0);
693 		/* Turn off prescaler. */
694 		sio_setreg(com, com_mcr,
695 			   sio_getreg(com, com_mcr) & ~MCR_PRESCALE);
696 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
697 		sio_setreg(com, com_efr, efr);
698 		sio_setreg(com, com_cfcr, cfcr);
699 	}
700 
701 	/*
702 	 * Initialize the speed and the word size and wait long enough to
703 	 * drain the maximum of 16 bytes of junk in device output queues.
704 	 * The speed is undefined after a master reset and must be set
705 	 * before relying on anything related to output.  There may be
706 	 * junk after a (very fast) soft reboot and (apparently) after
707 	 * master reset.
708 	 * XXX what about the UART bug avoided by waiting in comparam()?
709 	 * We don't want to to wait long enough to drain at 2 bps.
710 	 */
711 	if (iobase == siocniobase) {
712 		DELAY((16 + 1) * 1000000 / (comdefaultrate / 10));
713 	} else {
714 		sio_setreg(com, com_cfcr, CFCR_DLAB | CFCR_8BITS);
715 		divisor = siodivisor(rclk, SIO_TEST_SPEED);
716 		sio_setreg(com, com_dlbl, divisor & 0xff);
717 		sio_setreg(com, com_dlbh, divisor >> 8);
718 		sio_setreg(com, com_cfcr, CFCR_8BITS);
719 		DELAY((16 + 1) * 1000000 / (SIO_TEST_SPEED / 10));
720 	}
721 
722 	/*
723 	 * Make sure we can drain the receiver.  If we can't, the serial
724 	 * port may not exist.
725 	 */
726 	for (fn = 0; fn < 256; ++fn) {
727 		if ((sio_getreg(com, com_lsr) & LSR_RXRDY) == 0)
728 			break;
729 		(void)sio_getreg(com, com_data);
730 	}
731 	if (fn == 256) {
732 		com_unlock();
733 		lwkt_reltoken(&tty_token);
734 		kprintf("sio%d: can't drain, serial port might "
735 			"not exist, disabling\n", device_get_unit(dev));
736 		return (ENXIO);
737 	}
738 
739 	/*
740 	 * Enable the interrupt gate and disable device interupts.  This
741 	 * should leave the device driving the interrupt line low and
742 	 * guarantee an edge trigger if an interrupt can be generated.
743 	 */
744 /* EXTRA DELAY? */
745 	sio_setreg(com, com_mcr, mcr_image);
746 	sio_setreg(com, com_ier, 0);
747 	DELAY(1000);		/* XXX */
748 	irqmap[0] = isa_irq_pending();
749 
750 	/*
751 	 * Attempt to set loopback mode so that we can send a null byte
752 	 * without annoying any external device.
753 	 */
754 /* EXTRA DELAY? */
755 	sio_setreg(com, com_mcr, mcr_image | MCR_LOOPBACK);
756 
757 	/*
758 	 * Attempt to generate an output interrupt.  On 8250's, setting
759 	 * IER_ETXRDY generates an interrupt independent of the current
760 	 * setting and independent of whether the THR is empty.  On 16450's,
761 	 * setting IER_ETXRDY generates an interrupt independent of the
762 	 * current setting.  On 16550A's, setting IER_ETXRDY only
763 	 * generates an interrupt when IER_ETXRDY is not already set.
764 	 */
765 	sio_setreg(com, com_ier, IER_ETXRDY);
766 
767 	/*
768 	 * On some 16x50 incompatibles, setting IER_ETXRDY doesn't generate
769 	 * an interrupt.  They'd better generate one for actually doing
770 	 * output.  Loopback may be broken on the same incompatibles but
771 	 * it's unlikely to do more than allow the null byte out.
772 	 */
773 	sio_setreg(com, com_data, 0);
774 	DELAY((1 + 2) * 1000000 / (SIO_TEST_SPEED / 10));
775 
776 	/*
777 	 * Turn off loopback mode so that the interrupt gate works again
778 	 * (MCR_IENABLE was hidden).  This should leave the device driving
779 	 * an interrupt line high.  It doesn't matter if the interrupt
780 	 * line oscillates while we are not looking at it, since interrupts
781 	 * are disabled.
782 	 */
783 /* EXTRA DELAY? */
784 	sio_setreg(com, com_mcr, mcr_image);
785 
786 	/*
787 	 * Some pcmcia cards have the "TXRDY bug", so we check everyone
788 	 * for IIR_TXRDY implementation ( Palido 321s, DC-1S... )
789 	 */
790 	if (COM_NOPROBE(flags)) {
791 		/* Reading IIR register twice */
792 		for (fn = 0; fn < 2; fn ++) {
793 			DELAY(10000);
794 			failures[6] = sio_getreg(com, com_iir);
795 		}
796 		/* Check IIR_TXRDY clear ? */
797 		result = 0;
798 		if (failures[6] & IIR_TXRDY) {
799 			/* Nop, Double check with clearing IER */
800 			sio_setreg(com, com_ier, 0);
801 			if (sio_getreg(com, com_iir) & IIR_NOPEND) {
802 				/* Ok. we're familia this gang */
803 				SET_FLAG(dev, COM_C_IIR_TXRDYBUG);
804 			} else {
805 				/* Unknown, Just omit this chip.. XXX */
806 				result = ENXIO;
807 				sio_setreg(com, com_mcr, 0);
808 			}
809 		} else {
810 			/* OK. this is well-known guys */
811 			CLR_FLAG(dev, COM_C_IIR_TXRDYBUG);
812 		}
813 		sio_setreg(com, com_ier, 0);
814 		sio_setreg(com, com_cfcr, CFCR_8BITS);
815 		com_unlock();
816 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
817 		lwkt_reltoken(&tty_token);
818 		return (iobase == siocniobase ? 0 : result);
819 	}
820 
821 	/*
822 	 * Check that
823 	 *	o the CFCR, IER and MCR in UART hold the values written to them
824 	 *	  (the values happen to be all distinct - this is good for
825 	 *	  avoiding false positive tests from bus echoes).
826 	 *	o an output interrupt is generated and its vector is correct.
827 	 *	o the interrupt goes away when the IIR in the UART is read.
828 	 */
829 /* EXTRA DELAY? */
830 	failures[0] = sio_getreg(com, com_cfcr) - CFCR_8BITS;
831 	failures[1] = sio_getreg(com, com_ier) - IER_ETXRDY;
832 	failures[2] = sio_getreg(com, com_mcr) - mcr_image;
833 	DELAY(10000);		/* Some internal modems need this time */
834 	irqmap[1] = isa_irq_pending();
835 	failures[4] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_TXRDY;
836 	DELAY(1000);		/* XXX */
837 	irqmap[2] = isa_irq_pending();
838 	failures[6] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
839 
840 	/*
841 	 * Turn off all device interrupts and check that they go off properly.
842 	 * Leave MCR_IENABLE alone.  For ports without a master port, it gates
843 	 * the OUT2 output of the UART to
844 	 * the ICU input.  Closing the gate would give a floating ICU input
845 	 * (unless there is another device driving it) and spurious interrupts.
846 	 * (On the system that this was first tested on, the input floats high
847 	 * and gives a (masked) interrupt as soon as the gate is closed.)
848 	 */
849 	sio_setreg(com, com_ier, 0);
850 	sio_setreg(com, com_cfcr, CFCR_8BITS);	/* dummy to avoid bus echo */
851 	failures[7] = sio_getreg(com, com_ier);
852 	DELAY(1000);		/* XXX */
853 	irqmap[3] = isa_irq_pending();
854 	failures[9] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
855 
856 	com_unlock();
857 
858 	irqs = irqmap[1] & ~irqmap[0];
859 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, &xirq, NULL) == 0 &&
860 	    ((1 << xirq) & irqs) == 0)
861 		kprintf(
862 		"sio%d: configured irq %ld not in bitmap of probed irqs %#x\n",
863 		    device_get_unit(dev), xirq, irqs);
864 	if (bootverbose)
865 		kprintf("sio%d: irq maps: %#x %#x %#x %#x\n",
866 		    device_get_unit(dev),
867 		    irqmap[0], irqmap[1], irqmap[2], irqmap[3]);
868 
869 	result = 0;
870 	for (fn = 0; fn < sizeof failures; ++fn)
871 		if (failures[fn]) {
872 			sio_setreg(com, com_mcr, 0);
873 			result = ENXIO;
874 			if (bootverbose) {
875 				kprintf("sio%d: probe failed test(s):",
876 				    device_get_unit(dev));
877 				for (fn = 0; fn < sizeof failures; ++fn)
878 					if (failures[fn])
879 						kprintf(" %d", fn);
880 				kprintf("\n");
881 			}
882 			break;
883 		}
884 	bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
885 	lwkt_reltoken(&tty_token);
886 	return (iobase == siocniobase ? 0 : result);
887 }
888 
889 #ifdef COM_ESP
890 static int
891 espattach(struct com_s *com, Port_t esp_port)
892 {
893 	u_char	dips;
894 	u_char	val;
895 
896 	/*
897 	 * Check the ESP-specific I/O port to see if we're an ESP
898 	 * card.  If not, return failure immediately.
899 	 */
900 	if ((inb(esp_port) & 0xf3) == 0) {
901 		kprintf(" port 0x%x is not an ESP board?\n", esp_port);
902 		return (0);
903 	}
904 
905 	lwkt_gettoken(&tty_token);
906 	/*
907 	 * We've got something that claims to be a Hayes ESP card.
908 	 * Let's hope so.
909 	 */
910 
911 	/* Get the dip-switch configuration */
912 	outb(esp_port + ESP_CMD1, ESP_GETDIPS);
913 	dips = inb(esp_port + ESP_STATUS1);
914 
915 	/*
916 	 * Bits 0,1 of dips say which COM port we are.
917 	 */
918 	if (rman_get_start(com->ioportres) == likely_com_ports[dips & 0x03])
919 		kprintf(" : ESP");
920 	else {
921 		kprintf(" esp_port has com %d\n", dips & 0x03);
922 		lwkt_reltoken(&tty_token);
923 		return (0);
924 	}
925 
926 	/*
927 	 * Check for ESP version 2.0 or later:  bits 4,5,6 = 010.
928 	 */
929 	outb(esp_port + ESP_CMD1, ESP_GETTEST);
930 	val = inb(esp_port + ESP_STATUS1);	/* clear reg 1 */
931 	val = inb(esp_port + ESP_STATUS2);
932 	if ((val & 0x70) < 0x20) {
933 		kprintf("-old (%o)", val & 0x70);
934 		lwkt_reltoken(&tty_token);
935 		return (0);
936 	}
937 
938 	/*
939 	 * Check for ability to emulate 16550:  bit 7 == 1
940 	 */
941 	if ((dips & 0x80) == 0) {
942 		kprintf(" slave");
943 		lwkt_reltoken(&tty_token);
944 		return (0);
945 	}
946 
947 	/*
948 	 * Okay, we seem to be a Hayes ESP card.  Whee.
949 	 */
950 	com->esp = TRUE;
951 	com->esp_port = esp_port;
952 	lwkt_reltoken(&tty_token);
953 	return (1);
954 }
955 #endif /* COM_ESP */
956 
957 static int
958 sio_isa_attach(device_t dev)
959 {
960 	return (sioattach(dev, 0, 0UL));
961 }
962 
963 int
964 sioattach(device_t dev, int xrid, u_long rclk)
965 {
966 	struct com_s	*com;
967 #ifdef COM_ESP
968 	Port_t		*espp;
969 #endif
970 	Port_t		iobase;
971 	int		minorbase;
972 	int		unit;
973 	u_int		flags;
974 	int		rid;
975 	struct resource *port;
976 	int		ret;
977 	static int	did_init;
978 
979 	lwkt_gettoken(&tty_token);
980 	if (did_init == 0) {
981 		did_init = 1;
982 		callout_init_mp(&sio_timeout_handle);
983 	}
984 
985 	rid = xrid;
986 	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
987 				  0, ~0, IO_COMSIZE, RF_ACTIVE);
988 	if (!port) {
989 		lwkt_reltoken(&tty_token);
990 		return (ENXIO);
991 	}
992 
993 	iobase = rman_get_start(port);
994 	unit = device_get_unit(dev);
995 	com = device_get_softc(dev);
996 	flags = device_get_flags(dev);
997 
998 	if (unit >= sio_numunits)
999 		sio_numunits = unit + 1;
1000 	/*
1001 	 * sioprobe() has initialized the device registers as follows:
1002 	 *	o cfcr = CFCR_8BITS.
1003 	 *	  It is most important that CFCR_DLAB is off, so that the
1004 	 *	  data port is not hidden when we enable interrupts.
1005 	 *	o ier = 0.
1006 	 *	  Interrupts are only enabled when the line is open.
1007 	 *	o mcr = MCR_IENABLE, or 0 if the port has AST/4 compatible
1008 	 *	  interrupt control register or the config specifies no irq.
1009 	 *	  Keeping MCR_DTR and MCR_RTS off might stop the external
1010 	 *	  device from sending before we are ready.
1011 	 */
1012 	bzero(com, sizeof *com);
1013 	com->unit = unit;
1014 	com->ioportres = port;
1015 	com->bst = rman_get_bustag(port);
1016 	com->bsh = rman_get_bushandle(port);
1017 	com->cfcr_image = CFCR_8BITS;
1018 	com->dtr_wait = 3 * hz;
1019 	callout_init_mp(&com->dtr_ch);
1020 	callout_init_mp(&com->busy_ch);
1021 	com->loses_outints = COM_LOSESOUTINTS(flags) != 0;
1022 	com->no_irq = bus_get_resource(dev, SYS_RES_IRQ, 0, NULL, NULL) != 0;
1023 	com->tx_fifo_size = 1;
1024 	com->obufs[0].l_head = com->obuf1;
1025 	com->obufs[1].l_head = com->obuf2;
1026 
1027 	com->data_port = iobase + com_data;
1028 	com->int_id_port = iobase + com_iir;
1029 	com->modem_ctl_port = iobase + com_mcr;
1030 	com->mcr_image = inb(com->modem_ctl_port);
1031 	com->line_status_port = iobase + com_lsr;
1032 	com->modem_status_port = iobase + com_msr;
1033 	com->intr_ctl_port = iobase + com_ier;
1034 
1035 	if (rclk == 0)
1036 		rclk = DEFAULT_RCLK;
1037 	com->rclk = rclk;
1038 
1039 	/*
1040 	 * We don't use all the flags from <sys/ttydefaults.h> since they
1041 	 * are only relevant for logins.  It's important to have echo off
1042 	 * initially so that the line doesn't start blathering before the
1043 	 * echo flag can be turned off.
1044 	 */
1045 	com->it_in.c_iflag = 0;
1046 	com->it_in.c_oflag = 0;
1047 	com->it_in.c_cflag = TTYDEF_CFLAG;
1048 	com->it_in.c_lflag = 0;
1049 	if (unit == comconsole) {
1050 		com->it_in.c_iflag = TTYDEF_IFLAG;
1051 		com->it_in.c_oflag = TTYDEF_OFLAG;
1052 		com->it_in.c_cflag = TTYDEF_CFLAG | CLOCAL;
1053 		com->it_in.c_lflag = TTYDEF_LFLAG;
1054 		com->lt_out.c_cflag = com->lt_in.c_cflag = CLOCAL;
1055 		com->lt_out.c_ispeed = com->lt_out.c_ospeed =
1056 		com->lt_in.c_ispeed = com->lt_in.c_ospeed =
1057 		com->it_in.c_ispeed = com->it_in.c_ospeed = comdefaultrate;
1058 	} else
1059 		com->it_in.c_ispeed = com->it_in.c_ospeed = TTYDEF_SPEED;
1060 	if (siosetwater(com, com->it_in.c_ispeed) != 0) {
1061 		/*
1062 		 * Leave i/o resources allocated if this is a `cn'-level
1063 		 * console, so that other devices can't snarf them.
1064 		 */
1065 		if (iobase != siocniobase)
1066 			bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
1067 		lwkt_reltoken(&tty_token);
1068 		return (ENOMEM);
1069 	}
1070 	termioschars(&com->it_in);
1071 	com->it_out = com->it_in;
1072 
1073 	/* attempt to determine UART type */
1074 	kprintf("sio%d: type", unit);
1075 
1076 
1077 #ifdef COM_MULTIPORT
1078 	if (!COM_ISMULTIPORT(flags) && !COM_IIR_TXRDYBUG(flags))
1079 #else
1080 	if (!COM_IIR_TXRDYBUG(flags))
1081 #endif
1082 	{
1083 		u_char	scr;
1084 		u_char	scr1;
1085 		u_char	scr2;
1086 
1087 		scr = sio_getreg(com, com_scr);
1088 		sio_setreg(com, com_scr, 0xa5);
1089 		scr1 = sio_getreg(com, com_scr);
1090 		sio_setreg(com, com_scr, 0x5a);
1091 		scr2 = sio_getreg(com, com_scr);
1092 		sio_setreg(com, com_scr, scr);
1093 		if (scr1 != 0xa5 || scr2 != 0x5a) {
1094 			kprintf(" 8250");
1095 			goto determined_type;
1096 		}
1097 	}
1098 	sio_setreg(com, com_fifo, FIFO_ENABLE | FIFO_RX_HIGH);
1099 	DELAY(100);
1100 	com->st16650a = 0;
1101 	switch (inb(com->int_id_port) & IIR_FIFO_MASK) {
1102 	case FIFO_RX_LOW:
1103 		kprintf(" 16450");
1104 		break;
1105 	case FIFO_RX_MEDL:
1106 		kprintf(" 16450?");
1107 		break;
1108 	case FIFO_RX_MEDH:
1109 		kprintf(" 16550?");
1110 		break;
1111 	case FIFO_RX_HIGH:
1112 		if (COM_NOFIFO(flags)) {
1113 			kprintf(" 16550A fifo disabled");
1114 		} else {
1115 			com->hasfifo = TRUE;
1116 			if (COM_ST16650A(flags)) {
1117 				com->st16650a = 1;
1118 				com->tx_fifo_size = 32;
1119 				kprintf(" ST16650A");
1120 			} else if (COM_TI16754(flags)) {
1121 				com->tx_fifo_size = 64;
1122 				kprintf(" TI16754");
1123 			} else {
1124 				com->tx_fifo_size = COM_FIFOSIZE(flags);
1125 				kprintf(" 16550A");
1126 			}
1127 		}
1128 #ifdef COM_ESP
1129 		for (espp = likely_esp_ports; *espp != 0; espp++)
1130 			if (espattach(com, *espp)) {
1131 				com->tx_fifo_size = 1024;
1132 				break;
1133 			}
1134 #endif
1135 		if (!com->st16650a && !COM_TI16754(flags)) {
1136 			if (!com->tx_fifo_size)
1137 				com->tx_fifo_size = 16;
1138 			else
1139 				kprintf(" lookalike with %d bytes FIFO",
1140 				    com->tx_fifo_size);
1141 		}
1142 
1143 		break;
1144 	}
1145 
1146 #ifdef COM_ESP
1147 	if (com->esp) {
1148 		/*
1149 		 * Set 16550 compatibility mode.
1150 		 * We don't use the ESP_MODE_SCALE bit to increase the
1151 		 * fifo trigger levels because we can't handle large
1152 		 * bursts of input.
1153 		 * XXX flow control should be set in comparam(), not here.
1154 		 */
1155 		outb(com->esp_port + ESP_CMD1, ESP_SETMODE);
1156 		outb(com->esp_port + ESP_CMD2, ESP_MODE_RTS | ESP_MODE_FIFO);
1157 
1158 		/* Set RTS/CTS flow control. */
1159 		outb(com->esp_port + ESP_CMD1, ESP_SETFLOWTYPE);
1160 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_RTS);
1161 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_CTS);
1162 
1163 		/* Set flow-control levels. */
1164 		outb(com->esp_port + ESP_CMD1, ESP_SETRXFLOW);
1165 		outb(com->esp_port + ESP_CMD2, HIBYTE(768));
1166 		outb(com->esp_port + ESP_CMD2, LOBYTE(768));
1167 		outb(com->esp_port + ESP_CMD2, HIBYTE(512));
1168 		outb(com->esp_port + ESP_CMD2, LOBYTE(512));
1169 	}
1170 #endif /* COM_ESP */
1171 	sio_setreg(com, com_fifo, 0);
1172 determined_type: ;
1173 
1174 #ifdef COM_MULTIPORT
1175 	if (COM_ISMULTIPORT(flags)) {
1176 		device_t masterdev;
1177 
1178 		com->multiport = TRUE;
1179 		kprintf(" (multiport");
1180 		if (unit == COM_MPMASTER(flags))
1181 			kprintf(" master");
1182 		kprintf(")");
1183 		masterdev = devclass_get_device(sio_devclass,
1184 		    COM_MPMASTER(flags));
1185 		com->no_irq = (masterdev == NULL || bus_get_resource(masterdev,
1186 		    SYS_RES_IRQ, 0, NULL, NULL) != 0);
1187 	 }
1188 #endif /* COM_MULTIPORT */
1189 	if (unit == comconsole)
1190 		kprintf(", console");
1191 	if (COM_IIR_TXRDYBUG(flags))
1192 		kprintf(" with a bogus IIR_TXRDY register");
1193 	kprintf("\n");
1194 
1195 	if (!sio_registered) {
1196 		register_swi(SWI_TTY, siopoll, NULL ,"swi_siopoll", NULL);
1197 		sio_registered = TRUE;
1198 	}
1199 	minorbase = UNIT_TO_MINOR(unit);
1200 	make_dev(&sio_ops, minorbase,
1201 	    UID_ROOT, GID_WHEEL, 0600, "ttyd%r", unit);
1202 	make_dev(&sio_ops, minorbase | CONTROL_INIT_STATE,
1203 	    UID_ROOT, GID_WHEEL, 0600, "ttyid%r", unit);
1204 	make_dev(&sio_ops, minorbase | CONTROL_LOCK_STATE,
1205 	    UID_ROOT, GID_WHEEL, 0600, "ttyld%r", unit);
1206 	make_dev(&sio_ops, minorbase | CALLOUT_MASK,
1207 	    UID_UUCP, GID_DIALER, 0660, "cuaa%r", unit);
1208 	make_dev(&sio_ops, minorbase | CALLOUT_MASK | CONTROL_INIT_STATE,
1209 	    UID_UUCP, GID_DIALER, 0660, "cuaia%r", unit);
1210 	make_dev(&sio_ops, minorbase | CALLOUT_MASK | CONTROL_LOCK_STATE,
1211 	    UID_UUCP, GID_DIALER, 0660, "cuala%r", unit);
1212 	com->flags = flags;
1213 	com->pps.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1214 	pps_init(&com->pps);
1215 
1216 	rid = 0;
1217 	com->irqres = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0ul, ~0ul, 1,
1218 	    RF_ACTIVE);
1219 	if (com->irqres) {
1220 		ret = BUS_SETUP_INTR(device_get_parent(dev), dev,
1221 				     com->irqres, INTR_MPSAFE, siointr, com,
1222 				     &com->cookie, NULL);
1223 		if (ret)
1224 			device_printf(dev, "could not activate interrupt\n");
1225 #if defined(DDB) && (defined(BREAK_TO_DEBUGGER) || \
1226     defined(ALT_BREAK_TO_DEBUGGER))
1227 		/*
1228 		 * Enable interrupts for early break-to-debugger support
1229 		 * on the console.
1230 		 */
1231 		if (ret == 0 && unit == comconsole)
1232 			outb(siocniobase + com_ier, IER_ERXRDY | IER_ERLS |
1233 			    IER_EMSC);
1234 #endif
1235 	}
1236 
1237 	lwkt_reltoken(&tty_token);
1238 	return (0);
1239 }
1240 
1241 static int
1242 sioopen(struct dev_open_args *ap)
1243 {
1244 	cdev_t dev = ap->a_head.a_dev;
1245 	struct com_s	*com;
1246 	int		error;
1247 	int		mynor;
1248 	struct tty	*tp;
1249 	int		unit;
1250 
1251 	mynor = minor(dev);
1252 	unit = MINOR_TO_UNIT(mynor);
1253 	com = com_addr(unit);
1254 	if (com == NULL)
1255 		return (ENXIO);
1256 	if (com->gone)
1257 		return (ENXIO);
1258 	if (mynor & CONTROL_MASK)
1259 		return (0);
1260 	lwkt_gettoken(&tty_token);
1261 	tp = dev->si_tty = com->tp = ttymalloc(com->tp);
1262 	crit_enter();
1263 	/*
1264 	 * We jump to this label after all non-interrupted sleeps to pick
1265 	 * up any changes of the device state.
1266 	 */
1267 open_top:
1268 	while (com->state & CS_DTR_OFF) {
1269 		error = tsleep(&com->dtr_wait, PCATCH, "siodtr", 0);
1270 		if (com_addr(unit) == NULL) {
1271 			crit_exit();
1272 			lwkt_reltoken(&tty_token);
1273 			return (ENXIO);
1274 		}
1275 		if (error != 0 || com->gone)
1276 			goto out;
1277 	}
1278 	if (tp->t_state & TS_ISOPEN) {
1279 		/*
1280 		 * The device is open, so everything has been initialized.
1281 		 * Handle conflicts.
1282 		 */
1283 		if (mynor & CALLOUT_MASK) {
1284 			if (!com->active_out) {
1285 				error = EBUSY;
1286 				goto out;
1287 			}
1288 		} else {
1289 			if (com->active_out) {
1290 				if (ap->a_oflags & O_NONBLOCK) {
1291 					error = EBUSY;
1292 					goto out;
1293 				}
1294 				error =	tsleep(&com->active_out,
1295 					       PCATCH, "siobi", 0);
1296 				if (com_addr(unit) == NULL) {
1297 					crit_exit();
1298 					lwkt_reltoken(&tty_token);
1299 					return (ENXIO);
1300 				}
1301 				if (error != 0 || com->gone)
1302 					goto out;
1303 				goto open_top;
1304 			}
1305 		}
1306 		if (tp->t_state & TS_XCLUDE && priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) {
1307 			error = EBUSY;
1308 			goto out;
1309 		}
1310 	} else {
1311 		/*
1312 		 * The device isn't open, so there are no conflicts.
1313 		 * Initialize it.  Initialization is done twice in many
1314 		 * cases: to preempt sleeping callin opens if we are
1315 		 * callout, and to complete a callin open after DCD rises.
1316 		 */
1317 		tp->t_oproc = comstart;
1318 		tp->t_param = comparam;
1319 		tp->t_stop = comstop;
1320 		tp->t_dev = dev;
1321 		tp->t_termios = mynor & CALLOUT_MASK
1322 				? com->it_out : com->it_in;
1323 		(void)commctl(com, TIOCM_DTR | TIOCM_RTS, DMSET);
1324 		com->poll = com->no_irq;
1325 		com->poll_output = com->loses_outints;
1326 		++com->wopeners;
1327 		error = comparam(tp, &tp->t_termios);
1328 		--com->wopeners;
1329 		if (error != 0)
1330 			goto out;
1331 		/*
1332 		 * XXX we should goto open_top if comparam() slept.
1333 		 */
1334 		if (com->hasfifo) {
1335 			/*
1336 			 * (Re)enable and drain fifos.
1337 			 *
1338 			 * Certain SMC chips cause problems if the fifos
1339 			 * are enabled while input is ready.  Turn off the
1340 			 * fifo if necessary to clear the input.  We test
1341 			 * the input ready bit after enabling the fifos
1342 			 * since we've already enabled them in comparam()
1343 			 * and to handle races between enabling and fresh
1344 			 * input.
1345 			 */
1346 			while (TRUE) {
1347 				sio_setreg(com, com_fifo,
1348 					   FIFO_RCV_RST | FIFO_XMT_RST
1349 					   | com->fifo_image);
1350 				/*
1351 				 * XXX the delays are for superstitious
1352 				 * historical reasons.  It must be less than
1353 				 * the character time at the maximum
1354 				 * supported speed (87 usec at 115200 bps
1355 				 * 8N1).  Otherwise we might loop endlessly
1356 				 * if data is streaming in.  We used to use
1357 				 * delays of 100.  That usually worked
1358 				 * because DELAY(100) used to usually delay
1359 				 * for about 85 usec instead of 100.
1360 				 */
1361 				DELAY(50);
1362 				if (!(inb(com->line_status_port) & LSR_RXRDY))
1363 					break;
1364 				sio_setreg(com, com_fifo, 0);
1365 				DELAY(50);
1366 				(void) inb(com->data_port);
1367 			}
1368 		}
1369 
1370 		com_lock();
1371 		(void) inb(com->line_status_port);
1372 		(void) inb(com->data_port);
1373 		com->prev_modem_status = com->last_modem_status
1374 		    = inb(com->modem_status_port);
1375 		if (COM_IIR_TXRDYBUG(com->flags)) {
1376 			outb(com->intr_ctl_port, IER_ERXRDY | IER_ERLS
1377 						| IER_EMSC);
1378 		} else {
1379 			outb(com->intr_ctl_port, IER_ERXRDY | IER_ETXRDY
1380 						| IER_ERLS | IER_EMSC);
1381 		}
1382 		com_unlock();
1383 		/*
1384 		 * Handle initial DCD.  Callout devices get a fake initial
1385 		 * DCD (trapdoor DCD).  If we are callout, then any sleeping
1386 		 * callin opens get woken up and resume sleeping on "siobi"
1387 		 * instead of "siodcd".
1388 		 */
1389 		/*
1390 		 * XXX `mynor & CALLOUT_MASK' should be
1391 		 * `tp->t_cflag & (SOFT_CARRIER | TRAPDOOR_CARRIER) where
1392 		 * TRAPDOOR_CARRIER is the default initial state for callout
1393 		 * devices and SOFT_CARRIER is like CLOCAL except it hides
1394 		 * the true carrier.
1395 		 */
1396 		if (com->prev_modem_status & MSR_DCD || mynor & CALLOUT_MASK)
1397 			(*linesw[tp->t_line].l_modem)(tp, 1);
1398 	}
1399 	/*
1400 	 * Wait for DCD if necessary.
1401 	 */
1402 	if (!(tp->t_state & TS_CARR_ON) && !(mynor & CALLOUT_MASK)
1403 	    && !(tp->t_cflag & CLOCAL) && !(ap->a_oflags & O_NONBLOCK)) {
1404 		++com->wopeners;
1405 		error = tsleep(TSA_CARR_ON(tp), PCATCH, "siodcd", 0);
1406 		if (com_addr(unit) == NULL) {
1407 			crit_exit();
1408 			lwkt_reltoken(&tty_token);
1409 			return (ENXIO);
1410 		}
1411 		--com->wopeners;
1412 		if (error != 0 || com->gone)
1413 			goto out;
1414 		goto open_top;
1415 	}
1416 	error =	(*linesw[tp->t_line].l_open)(dev, tp);
1417 	disc_optim(tp, &tp->t_termios, com);
1418 	if (tp->t_state & TS_ISOPEN && mynor & CALLOUT_MASK)
1419 		com->active_out = TRUE;
1420 	siosettimeout();
1421 out:
1422 	crit_exit();
1423 	if (!(tp->t_state & TS_ISOPEN) && com->wopeners == 0)
1424 		comhardclose(com);
1425 	lwkt_reltoken(&tty_token);
1426 	return (error);
1427 }
1428 
1429 static int
1430 sioclose(struct dev_close_args *ap)
1431 {
1432 	cdev_t dev = ap->a_head.a_dev;
1433 	struct com_s	*com;
1434 	int		mynor;
1435 	struct tty	*tp;
1436 
1437 	mynor = minor(dev);
1438 	if (mynor & CONTROL_MASK)
1439 		return (0);
1440 	lwkt_gettoken(&tty_token);
1441 	com = com_addr(MINOR_TO_UNIT(mynor));
1442 	if (com == NULL) {
1443 		lwkt_reltoken(&tty_token);
1444 		return (ENODEV);
1445 	}
1446 	tp = com->tp;
1447 	crit_enter();
1448 	(*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
1449 	disc_optim(tp, &tp->t_termios, com);
1450 	comstop(tp, FREAD | FWRITE);
1451 	comhardclose(com);
1452 	ttyclose(tp);
1453 	siosettimeout();
1454 	crit_exit();
1455 	if (com->gone) {
1456 		kprintf("sio%d: gone\n", com->unit);
1457 		crit_enter();
1458 		if (com->ibuf != NULL)
1459 			kfree(com->ibuf, M_DEVBUF);
1460 		bzero(tp, sizeof *tp);
1461 		crit_exit();
1462 	}
1463 	lwkt_reltoken(&tty_token);
1464 	return (0);
1465 }
1466 
1467 static void
1468 comhardclose(struct com_s *com)
1469 {
1470 	struct tty	*tp;
1471 	int		unit;
1472 
1473 	unit = com->unit;
1474 	crit_enter();
1475 	lwkt_gettoken(&tty_token);
1476 	com->poll = FALSE;
1477 	com->poll_output = FALSE;
1478 	com->do_timestamp = FALSE;
1479 	com->do_dcd_timestamp = FALSE;
1480 	com->pps.ppsparam.mode = 0;
1481 	sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1482 	tp = com->tp;
1483 
1484 #if defined(DDB) && (defined(BREAK_TO_DEBUGGER) || \
1485     defined(ALT_BREAK_TO_DEBUGGER))
1486 	/*
1487 	 * Leave interrupts enabled and don't clear DTR if this is the
1488 	 * console. This allows us to detect break-to-debugger events
1489 	 * while the console device is closed.
1490 	 */
1491 	if (com->unit != comconsole)
1492 #endif
1493 	{
1494 		sio_setreg(com, com_ier, 0);
1495 		if (tp->t_cflag & HUPCL
1496 		    /*
1497 		     * XXX we will miss any carrier drop between here and the
1498 		     * next open.  Perhaps we should watch DCD even when the
1499 		     * port is closed; it is not sufficient to check it at
1500 		     * the next open because it might go up and down while
1501 		     * we're not watching.
1502 		     */
1503 		    || (!com->active_out
1504 		        && !(com->prev_modem_status & MSR_DCD)
1505 		        && !(com->it_in.c_cflag & CLOCAL))
1506 		    || !(tp->t_state & TS_ISOPEN)) {
1507 			(void)commctl(com, TIOCM_DTR, DMBIC);
1508 			if (com->dtr_wait != 0 && !(com->state & CS_DTR_OFF)) {
1509 				callout_reset(&com->dtr_ch, com->dtr_wait,
1510 						siodtrwakeup, com);
1511 				com->state |= CS_DTR_OFF;
1512 			}
1513 		}
1514 	}
1515 	if (com->hasfifo) {
1516 		/*
1517 		 * Disable fifos so that they are off after controlled
1518 		 * reboots.  Some BIOSes fail to detect 16550s when the
1519 		 * fifos are enabled.
1520 		 */
1521 		sio_setreg(com, com_fifo, 0);
1522 	}
1523 	com->active_out = FALSE;
1524 	wakeup(&com->active_out);
1525 	wakeup(TSA_CARR_ON(tp));	/* restart any wopeners */
1526 	lwkt_reltoken(&tty_token);
1527 	crit_exit();
1528 }
1529 
1530 static int
1531 sioread(struct dev_read_args *ap)
1532 {
1533 	cdev_t dev = ap->a_head.a_dev;
1534 	int		mynor, ret;
1535 	struct com_s	*com;
1536 
1537 	lwkt_gettoken(&tty_token);
1538 	mynor = minor(dev);
1539 	if (mynor & CONTROL_MASK) {
1540 		lwkt_reltoken(&tty_token);
1541 		return (ENODEV);
1542 	}
1543 	com = com_addr(MINOR_TO_UNIT(mynor));
1544 	if (com == NULL || com->gone) {
1545 		lwkt_reltoken(&tty_token);
1546 		return (ENODEV);
1547 	}
1548 	ret = ((*linesw[com->tp->t_line].l_read)(com->tp, ap->a_uio, ap->a_ioflag));
1549 	lwkt_reltoken(&tty_token);
1550 	return ret;
1551 }
1552 
1553 static int
1554 siowrite(struct dev_write_args *ap)
1555 {
1556 	cdev_t dev = ap->a_head.a_dev;
1557 	int		mynor;
1558 	struct com_s	*com;
1559 	int		unit, ret;
1560 
1561 	lwkt_gettoken(&tty_token);
1562 	mynor = minor(dev);
1563 	if (mynor & CONTROL_MASK) {
1564 		lwkt_reltoken(&tty_token);
1565 		return (ENODEV);
1566 	}
1567 
1568 	unit = MINOR_TO_UNIT(mynor);
1569 	com = com_addr(unit);
1570 	if (com == NULL || com->gone) {
1571 		lwkt_reltoken(&tty_token);
1572 		return (ENODEV);
1573 	}
1574 	/*
1575 	 * (XXX) We disallow virtual consoles if the physical console is
1576 	 * a serial port.  This is in case there is a display attached that
1577 	 * is not the console.  In that situation we don't need/want the X
1578 	 * server taking over the console.
1579 	 */
1580 	if (constty != NULL && unit == comconsole)
1581 		constty = NULL;
1582 	ret = ((*linesw[com->tp->t_line].l_write)(com->tp, ap->a_uio, ap->a_ioflag));
1583 	lwkt_reltoken(&tty_token);
1584 	return ret;
1585 }
1586 
1587 static void
1588 siobusycheck(void *chan)
1589 {
1590 	struct com_s	*com;
1591 
1592 	lwkt_gettoken(&tty_token);
1593 	com = (struct com_s *)chan;
1594 
1595 	/*
1596 	 * Clear TS_BUSY if low-level output is complete.
1597 	 * spl locking is sufficient because siointr1() does not set CS_BUSY.
1598 	 * If siointr1() clears CS_BUSY after we look at it, then we'll get
1599 	 * called again.  Reading the line status port outside of siointr1()
1600 	 * is safe because CS_BUSY is clear so there are no output interrupts
1601 	 * to lose.
1602 	 */
1603 	crit_enter();
1604 	if (com->state & CS_BUSY)
1605 		com->extra_state &= ~CSE_BUSYCHECK;	/* False alarm. */
1606 	else if ((inb(com->line_status_port) & (LSR_TSRE | LSR_TXRDY))
1607 	    == (LSR_TSRE | LSR_TXRDY)) {
1608 		com->tp->t_state &= ~TS_BUSY;
1609 		ttwwakeup(com->tp);
1610 		com->extra_state &= ~CSE_BUSYCHECK;
1611 	} else {
1612 		callout_reset(&com->busy_ch, hz / 100, siobusycheck, com);
1613 	}
1614 	crit_exit();
1615 	lwkt_reltoken(&tty_token);
1616 }
1617 
1618 static u_int
1619 siodivisor(u_long rclk, speed_t speed)
1620 {
1621 	long	actual_speed;
1622 	u_int	divisor;
1623 	int	error;
1624 
1625 	if (speed == 0 || speed > ((speed_t)-1 - 1) / 8)
1626 		return (0);
1627 	divisor = (rclk / (8UL * speed) + 1) / 2;
1628 	if (divisor == 0 || divisor >= 65536)
1629 		return (0);
1630 	actual_speed = rclk / (16UL * divisor);
1631 
1632 	/* 10 times error in percent: */
1633 	error = ((actual_speed - (long)speed) * 2000 / (long)speed + 1) / 2;
1634 
1635 	/* 3.0% maximum error tolerance: */
1636 	if (error < -30 || error > 30)
1637 		return (0);
1638 
1639 	return (divisor);
1640 }
1641 
1642 static void
1643 siodtrwakeup(void *chan)
1644 {
1645 	struct com_s	*com;
1646 
1647 	lwkt_gettoken(&tty_token);
1648 	com = (struct com_s *)chan;
1649 	com->state &= ~CS_DTR_OFF;
1650 	wakeup(&com->dtr_wait);
1651 	lwkt_reltoken(&tty_token);
1652 }
1653 
1654 /*
1655  * NOTE: Normally called with tty_token held but might not be when
1656  *	 operating as the console.
1657  *
1658  *	 Must be called with com_lock
1659  */
1660 static void
1661 sioinput(struct com_s *com)
1662 {
1663 	u_char		*buf;
1664 	int		incc;
1665 	u_char		line_status;
1666 	int		recv_data;
1667 	struct tty	*tp;
1668 
1669 	buf = com->ibuf;
1670 	tp = com->tp;
1671 	if (!(tp->t_state & TS_ISOPEN) || !(tp->t_cflag & CREAD)) {
1672 		com_events -= (com->iptr - com->ibuf);
1673 		com->iptr = com->ibuf;
1674 		return;
1675 	}
1676 	if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
1677 		/*
1678 		 * Avoid the grotesquely inefficient lineswitch routine
1679 		 * (ttyinput) in "raw" mode.  It usually takes about 450
1680 		 * instructions (that's without canonical processing or echo!).
1681 		 * slinput is reasonably fast (usually 40 instructions plus
1682 		 * call overhead).
1683 		 */
1684 		do {
1685 			com_unlock();
1686 			incc = com->iptr - buf;
1687 			if (tp->t_rawq.c_cc + incc > tp->t_ihiwat
1688 			    && (com->state & CS_RTS_IFLOW
1689 				|| tp->t_iflag & IXOFF)
1690 			    && !(tp->t_state & TS_TBLOCK))
1691 				ttyblock(tp);
1692 			com->delta_error_counts[CE_TTY_BUF_OVERFLOW]
1693 				+= b_to_q((char *)buf, incc, &tp->t_rawq);
1694 			buf += incc;
1695 			tk_nin += incc;
1696 			tk_rawcc += incc;
1697 			tp->t_rawcc += incc;
1698 			ttwakeup(tp);
1699 			if (tp->t_state & TS_TTSTOP
1700 			    && (tp->t_iflag & IXANY
1701 				|| tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
1702 				tp->t_state &= ~TS_TTSTOP;
1703 				tp->t_lflag &= ~FLUSHO;
1704 				comstart(tp);
1705 			}
1706 			com_lock();
1707 		} while (buf < com->iptr);
1708 	} else {
1709 		do {
1710 			com_unlock();
1711 			line_status = buf[com->ierroff];
1712 			recv_data = *buf++;
1713 			if (line_status
1714 			    & (LSR_BI | LSR_FE | LSR_OE | LSR_PE)) {
1715 				if (line_status & LSR_BI)
1716 					recv_data |= TTY_BI;
1717 				if (line_status & LSR_FE)
1718 					recv_data |= TTY_FE;
1719 				if (line_status & LSR_OE)
1720 					recv_data |= TTY_OE;
1721 				if (line_status & LSR_PE)
1722 					recv_data |= TTY_PE;
1723 			}
1724 			(*linesw[tp->t_line].l_rint)(recv_data, tp);
1725 			com_lock();
1726 		} while (buf < com->iptr);
1727 	}
1728 	com_events -= (com->iptr - com->ibuf);
1729 	com->iptr = com->ibuf;
1730 
1731 	/*
1732 	 * There is now room for another low-level buffer full of input,
1733 	 * so enable RTS if it is now disabled and there is room in the
1734 	 * high-level buffer.
1735 	 */
1736 	if ((com->state & CS_RTS_IFLOW) && !(com->mcr_image & MCR_RTS) &&
1737 	    !(tp->t_state & TS_TBLOCK))
1738 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1739 }
1740 
1741 void
1742 siointr(void *arg)
1743 {
1744 	lwkt_gettoken(&tty_token);
1745 #ifndef COM_MULTIPORT
1746 	com_lock();
1747 	siointr1((struct com_s *) arg);
1748 	com_unlock();
1749 #else /* COM_MULTIPORT */
1750 	bool_t		possibly_more_intrs;
1751 	int		unit;
1752 	struct com_s	*com;
1753 
1754 	/*
1755 	 * Loop until there is no activity on any port.  This is necessary
1756 	 * to get an interrupt edge more than to avoid another interrupt.
1757 	 * If the IRQ signal is just an OR of the IRQ signals from several
1758 	 * devices, then the edge from one may be lost because another is
1759 	 * on.
1760 	 */
1761 	com_lock();
1762 	do {
1763 		possibly_more_intrs = FALSE;
1764 		for (unit = 0; unit < sio_numunits; ++unit) {
1765 			com = com_addr(unit);
1766 			/*
1767 			 * XXX com_lock();
1768 			 * would it work here, or be counter-productive?
1769 			 */
1770 			if (com != NULL
1771 			    && !com->gone
1772 			    && (inb(com->int_id_port) & IIR_IMASK)
1773 			       != IIR_NOPEND) {
1774 				siointr1(com);
1775 				possibly_more_intrs = TRUE;
1776 			}
1777 			/* XXX com_unlock(); */
1778 		}
1779 	} while (possibly_more_intrs);
1780 	com_unlock();
1781 #endif /* COM_MULTIPORT */
1782 	lwkt_reltoken(&tty_token);
1783 }
1784 
1785 /*
1786  * Called with tty_token held and com_lock held.
1787  */
1788 static void
1789 siointr1(struct com_s *com)
1790 {
1791 	u_char	line_status;
1792 	u_char	modem_status;
1793 	u_char	*ioptr;
1794 	u_char	recv_data;
1795 	u_char	int_ctl;
1796 	u_char	int_ctl_new;
1797 	u_int	count;
1798 
1799 	int_ctl = inb(com->intr_ctl_port);
1800 	int_ctl_new = int_ctl;
1801 
1802 	while (!com->gone) {
1803 		if (com->pps.ppsparam.mode & PPS_CAPTUREBOTH) {
1804 			modem_status = inb(com->modem_status_port);
1805 		        if ((modem_status ^ com->last_modem_status) & MSR_DCD) {
1806 				count = sys_cputimer->count();
1807 				pps_event(&com->pps, count,
1808 				    (modem_status & MSR_DCD) ?
1809 				    PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
1810 			}
1811 		}
1812 		line_status = inb(com->line_status_port);
1813 
1814 		/* input event? (check first to help avoid overruns) */
1815 		while (line_status & LSR_RCV_MASK) {
1816 			/* break/unnattached error bits or real input? */
1817 			if (!(line_status & LSR_RXRDY))
1818 				recv_data = 0;
1819 			else
1820 				recv_data = inb(com->data_port);
1821 #if defined(DDB) && defined(ALT_BREAK_TO_DEBUGGER)
1822 			/*
1823 			 * Solaris implements a new BREAK which is initiated
1824 			 * by a character sequence CR ~ ^b which is similar
1825 			 * to a familiar pattern used on Sun servers by the
1826 			 * Remote Console.
1827 			 */
1828 #define	KEY_CRTLB	2	/* ^B */
1829 #define	KEY_CR		13	/* CR '\r' */
1830 #define	KEY_TILDE	126	/* ~ */
1831 
1832 			if (com->unit == comconsole) {
1833 				static int brk_state1 = 0, brk_state2 = 0;
1834 				if (recv_data == KEY_CR) {
1835 					brk_state1 = recv_data;
1836 					brk_state2 = 0;
1837 				} else if (brk_state1 == KEY_CR && (recv_data == KEY_TILDE || recv_data == KEY_CRTLB)) {
1838 					if (recv_data == KEY_TILDE)
1839 						brk_state2 = recv_data;
1840 					else if (brk_state2 == KEY_TILDE && recv_data == KEY_CRTLB) {
1841 							com_unlock();
1842 							breakpoint();
1843 							com_lock();
1844 							brk_state1 = brk_state2 = 0;
1845 							goto cont;
1846 					} else
1847 						brk_state2 = 0;
1848 				} else
1849 					brk_state1 = 0;
1850 			}
1851 #endif
1852 			if (line_status & (LSR_BI | LSR_FE | LSR_PE)) {
1853 				/*
1854 				 * Don't store BI if IGNBRK or FE/PE if IGNPAR.
1855 				 * Otherwise, push the work to a higher level
1856 				 * (to handle PARMRK) if we're bypassing.
1857 				 * Otherwise, convert BI/FE and PE+INPCK to 0.
1858 				 *
1859 				 * This makes bypassing work right in the
1860 				 * usual "raw" case (IGNBRK set, and IGNPAR
1861 				 * and INPCK clear).
1862 				 *
1863 				 * Note: BI together with FE/PE means just BI.
1864 				 */
1865 				if (line_status & LSR_BI) {
1866 #if defined(DDB) && defined(BREAK_TO_DEBUGGER)
1867 					if (com->unit == comconsole) {
1868 						com_unlock();
1869 						breakpoint();
1870 						com_lock();
1871 						goto cont;
1872 					}
1873 #endif
1874 					if (com->tp == NULL
1875 					    || com->tp->t_iflag & IGNBRK)
1876 						goto cont;
1877 				} else {
1878 					if (com->tp == NULL
1879 					    || com->tp->t_iflag & IGNPAR)
1880 						goto cont;
1881 				}
1882 				if (com->tp->t_state & TS_CAN_BYPASS_L_RINT
1883 				    && (line_status & (LSR_BI | LSR_FE)
1884 					|| com->tp->t_iflag & INPCK))
1885 					recv_data = 0;
1886 			}
1887 			++com->bytes_in;
1888 			if (com->hotchar != 0 && recv_data == com->hotchar)
1889 				setsofttty();
1890 			ioptr = com->iptr;
1891 			if (ioptr >= com->ibufend)
1892 				CE_RECORD(com, CE_INTERRUPT_BUF_OVERFLOW);
1893 			else {
1894 				if (com->do_timestamp)
1895 					microtime(&com->timestamp);
1896 				++com_events;
1897 				schedsofttty();
1898 #if 0 /* for testing input latency vs efficiency */
1899 if (com->iptr - com->ibuf == 8)
1900 	setsofttty();
1901 #endif
1902 				ioptr[0] = recv_data;
1903 				ioptr[com->ierroff] = line_status;
1904 				com->iptr = ++ioptr;
1905 				if (ioptr == com->ihighwater
1906 				    && com->state & CS_RTS_IFLOW)
1907 					outb(com->modem_ctl_port,
1908 					     com->mcr_image &= ~MCR_RTS);
1909 				if (line_status & LSR_OE)
1910 					CE_RECORD(com, CE_OVERRUN);
1911 			}
1912 cont:
1913 			/*
1914 			 * "& 0x7F" is to avoid the gcc-1.40 generating a slow
1915 			 * jump from the top of the loop to here
1916 			 */
1917 			line_status = inb(com->line_status_port) & 0x7F;
1918 		}
1919 
1920 		/* modem status change? (always check before doing output) */
1921 		modem_status = inb(com->modem_status_port);
1922 		if (modem_status != com->last_modem_status) {
1923 			if (com->do_dcd_timestamp
1924 			    && !(com->last_modem_status & MSR_DCD)
1925 			    && modem_status & MSR_DCD)
1926 				microtime(&com->dcd_timestamp);
1927 
1928 			/*
1929 			 * Schedule high level to handle DCD changes.  Note
1930 			 * that we don't use the delta bits anywhere.  Some
1931 			 * UARTs mess them up, and it's easy to remember the
1932 			 * previous bits and calculate the delta.
1933 			 */
1934 			com->last_modem_status = modem_status;
1935 			if (!(com->state & CS_CHECKMSR)) {
1936 				com_events += LOTS_OF_EVENTS;
1937 				com->state |= CS_CHECKMSR;
1938 				setsofttty();
1939 			}
1940 
1941 			/* handle CTS change immediately for crisp flow ctl */
1942 			if (com->state & CS_CTS_OFLOW) {
1943 				if (modem_status & MSR_CTS)
1944 					com->state |= CS_ODEVREADY;
1945 				else
1946 					com->state &= ~CS_ODEVREADY;
1947 			}
1948 		}
1949 
1950 		/* output queued and everything ready? */
1951 		if (line_status & LSR_TXRDY
1952 		    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY)) {
1953 			ioptr = com->obufq.l_head;
1954 			if (com->tx_fifo_size > 1) {
1955 				u_int	ocount;
1956 
1957 				ocount = com->obufq.l_tail - ioptr;
1958 				if (ocount > com->tx_fifo_size)
1959 					ocount = com->tx_fifo_size;
1960 				com->bytes_out += ocount;
1961 				do
1962 					outb(com->data_port, *ioptr++);
1963 				while (--ocount != 0);
1964 			} else {
1965 				outb(com->data_port, *ioptr++);
1966 				++com->bytes_out;
1967 			}
1968 			com->obufq.l_head = ioptr;
1969 			if (COM_IIR_TXRDYBUG(com->flags)) {
1970 				int_ctl_new = int_ctl | IER_ETXRDY;
1971 			}
1972 			if (ioptr >= com->obufq.l_tail) {
1973 				struct lbq	*qp;
1974 
1975 				qp = com->obufq.l_next;
1976 				qp->l_queued = FALSE;
1977 				qp = qp->l_next;
1978 				if (qp != NULL) {
1979 					com->obufq.l_head = qp->l_head;
1980 					com->obufq.l_tail = qp->l_tail;
1981 					com->obufq.l_next = qp;
1982 				} else {
1983 					/* output just completed */
1984 					if (COM_IIR_TXRDYBUG(com->flags)) {
1985 						int_ctl_new = int_ctl & ~IER_ETXRDY;
1986 					}
1987 					com->state &= ~CS_BUSY;
1988 				}
1989 				if (!(com->state & CS_ODONE)) {
1990 					com_events += LOTS_OF_EVENTS;
1991 					com->state |= CS_ODONE;
1992 					setsofttty();	/* handle at high level ASAP */
1993 				}
1994 			}
1995 			if (COM_IIR_TXRDYBUG(com->flags) && (int_ctl != int_ctl_new)) {
1996 				outb(com->intr_ctl_port, int_ctl_new);
1997 			}
1998 		}
1999 
2000 		/* finished? */
2001 #ifndef COM_MULTIPORT
2002 		if ((inb(com->int_id_port) & IIR_IMASK) == IIR_NOPEND)
2003 #endif /* COM_MULTIPORT */
2004 		{
2005 			return;
2006 		}
2007 	}
2008 }
2009 
2010 static int
2011 sioioctl(struct dev_ioctl_args *ap)
2012 {
2013 	cdev_t dev = ap->a_head.a_dev;
2014 	caddr_t data = ap->a_data;
2015 	struct com_s	*com;
2016 	int		error;
2017 	int		mynor;
2018 	struct tty	*tp;
2019 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
2020 	u_long		oldcmd;
2021 	struct termios	term;
2022 #endif
2023 	lwkt_gettoken(&tty_token);
2024 	mynor = minor(dev);
2025 
2026 	com = com_addr(MINOR_TO_UNIT(mynor));
2027 	if (com == NULL || com->gone) {
2028 		lwkt_reltoken(&tty_token);
2029 		return (ENODEV);
2030 	}
2031 	if (mynor & CONTROL_MASK) {
2032 		struct termios	*ct;
2033 
2034 		switch (mynor & CONTROL_MASK) {
2035 		case CONTROL_INIT_STATE:
2036 			ct = mynor & CALLOUT_MASK ? &com->it_out : &com->it_in;
2037 			break;
2038 		case CONTROL_LOCK_STATE:
2039 			ct = mynor & CALLOUT_MASK ? &com->lt_out : &com->lt_in;
2040 			break;
2041 		default:
2042 			lwkt_reltoken(&tty_token);
2043 			return (ENODEV);	/* /dev/nodev */
2044 		}
2045 		switch (ap->a_cmd) {
2046 		case TIOCSETA:
2047 			error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
2048 			if (error != 0)
2049 				return (error);
2050 			*ct = *(struct termios *)data;
2051 			lwkt_reltoken(&tty_token);
2052 			return (0);
2053 		case TIOCGETA:
2054 			*(struct termios *)data = *ct;
2055 			lwkt_reltoken(&tty_token);
2056 			return (0);
2057 		case TIOCGETD:
2058 			*(int *)data = TTYDISC;
2059 			lwkt_reltoken(&tty_token);
2060 			return (0);
2061 		case TIOCGWINSZ:
2062 			bzero(data, sizeof(struct winsize));
2063 			lwkt_reltoken(&tty_token);
2064 			return (0);
2065 		default:
2066 			lwkt_reltoken(&tty_token);
2067 			return (ENOTTY);
2068 		}
2069 	}
2070 	tp = com->tp;
2071 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
2072 	term = tp->t_termios;
2073 	oldcmd = ap->a_cmd;
2074 	error = ttsetcompat(tp, &ap->a_cmd, data, &term);
2075 	if (error != 0) {
2076 		lwkt_reltoken(&tty_token);
2077 		return (error);
2078 	}
2079 	if (ap->a_cmd != oldcmd)
2080 		data = (caddr_t)&term;
2081 #endif
2082 	if (ap->a_cmd == TIOCSETA || ap->a_cmd == TIOCSETAW ||
2083 	    ap->a_cmd == TIOCSETAF) {
2084 		int	cc;
2085 		struct termios *dt = (struct termios *)data;
2086 		struct termios *lt = mynor & CALLOUT_MASK
2087 				     ? &com->lt_out : &com->lt_in;
2088 
2089 		dt->c_iflag = (tp->t_iflag & lt->c_iflag)
2090 			      | (dt->c_iflag & ~lt->c_iflag);
2091 		dt->c_oflag = (tp->t_oflag & lt->c_oflag)
2092 			      | (dt->c_oflag & ~lt->c_oflag);
2093 		dt->c_cflag = (tp->t_cflag & lt->c_cflag)
2094 			      | (dt->c_cflag & ~lt->c_cflag);
2095 		dt->c_lflag = (tp->t_lflag & lt->c_lflag)
2096 			      | (dt->c_lflag & ~lt->c_lflag);
2097 		for (cc = 0; cc < NCCS; ++cc)
2098 			if (lt->c_cc[cc] != 0)
2099 				dt->c_cc[cc] = tp->t_cc[cc];
2100 		if (lt->c_ispeed != 0)
2101 			dt->c_ispeed = tp->t_ispeed;
2102 		if (lt->c_ospeed != 0)
2103 			dt->c_ospeed = tp->t_ospeed;
2104 	}
2105 	error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, data, ap->a_fflag, ap->a_cred);
2106 	if (error != ENOIOCTL) {
2107 		lwkt_reltoken(&tty_token);
2108 		return (error);
2109 	}
2110 	crit_enter();
2111 	error = ttioctl(tp, ap->a_cmd, data, ap->a_fflag);
2112 	disc_optim(tp, &tp->t_termios, com);
2113 	if (error != ENOIOCTL) {
2114 		crit_exit();
2115 		lwkt_reltoken(&tty_token);
2116 		return (error);
2117 	}
2118 	switch (ap->a_cmd) {
2119 	case TIOCSBRK:
2120 		sio_setreg(com, com_cfcr, com->cfcr_image |= CFCR_SBREAK);
2121 		break;
2122 	case TIOCCBRK:
2123 		sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
2124 		break;
2125 	case TIOCSDTR:
2126 		(void)commctl(com, TIOCM_DTR, DMBIS);
2127 		break;
2128 	case TIOCCDTR:
2129 		(void)commctl(com, TIOCM_DTR, DMBIC);
2130 		break;
2131 	/*
2132 	 * XXX should disallow changing MCR_RTS if CS_RTS_IFLOW is set.  The
2133 	 * changes get undone on the next call to comparam().
2134 	 */
2135 	case TIOCMSET:
2136 		(void)commctl(com, *(int *)data, DMSET);
2137 		break;
2138 	case TIOCMBIS:
2139 		(void)commctl(com, *(int *)data, DMBIS);
2140 		break;
2141 	case TIOCMBIC:
2142 		(void)commctl(com, *(int *)data, DMBIC);
2143 		break;
2144 	case TIOCMGET:
2145 		*(int *)data = commctl(com, 0, DMGET);
2146 		break;
2147 	case TIOCMSDTRWAIT:
2148 		/* must be root since the wait applies to following logins */
2149 		error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
2150 		if (error != 0) {
2151 			crit_exit();
2152 			lwkt_reltoken(&tty_token);
2153 			return (error);
2154 		}
2155 		com->dtr_wait = *(int *)data * hz / 100;
2156 		break;
2157 	case TIOCMGDTRWAIT:
2158 		*(int *)data = com->dtr_wait * 100 / hz;
2159 		break;
2160 	case TIOCTIMESTAMP:
2161 		com->do_timestamp = TRUE;
2162 		*(struct timeval *)data = com->timestamp;
2163 		break;
2164 	case TIOCDCDTIMESTAMP:
2165 		com->do_dcd_timestamp = TRUE;
2166 		*(struct timeval *)data = com->dcd_timestamp;
2167 		break;
2168 	default:
2169 		crit_exit();
2170 		error = pps_ioctl(ap->a_cmd, data, &com->pps);
2171 		if (error == ENODEV)
2172 			error = ENOTTY;
2173 		lwkt_reltoken(&tty_token);
2174 		return (error);
2175 	}
2176 	crit_exit();
2177 	lwkt_reltoken(&tty_token);
2178 	return (0);
2179 }
2180 
2181 static void
2182 siopoll(void *dummy, void *frame)
2183 {
2184 	int		unit;
2185 
2186 	lwkt_gettoken(&tty_token);
2187 	if (com_events == 0) {
2188 		lwkt_reltoken(&tty_token);
2189 		return;
2190 	}
2191 
2192 repeat:
2193 	for (unit = 0; unit < sio_numunits; ++unit) {
2194 		struct com_s	*com;
2195 		int		incc;
2196 		struct tty	*tp;
2197 
2198 		com = com_addr(unit);
2199 		if (com == NULL)
2200 			continue;
2201 		tp = com->tp;
2202 		if (tp == NULL || com->gone) {
2203 			/*
2204 			 * Discard any events related to never-opened or
2205 			 * going-away devices.
2206 			 */
2207 			com_lock();
2208 			incc = com->iptr - com->ibuf;
2209 			com->iptr = com->ibuf;
2210 			if (com->state & CS_CHECKMSR) {
2211 				incc += LOTS_OF_EVENTS;
2212 				com->state &= ~CS_CHECKMSR;
2213 			}
2214 			com_events -= incc;
2215 			com_unlock();
2216 			continue;
2217 		}
2218 		if (com->iptr != com->ibuf) {
2219 			com_lock();
2220 			sioinput(com);
2221 			com_unlock();
2222 		}
2223 		if (com->state & CS_CHECKMSR) {
2224 			u_char	delta_modem_status;
2225 
2226 			com_lock();
2227 			delta_modem_status = com->last_modem_status
2228 					     ^ com->prev_modem_status;
2229 			com->prev_modem_status = com->last_modem_status;
2230 			com_events -= LOTS_OF_EVENTS;
2231 			com->state &= ~CS_CHECKMSR;
2232 			com_unlock();
2233 			if (delta_modem_status & MSR_DCD)
2234 				(*linesw[tp->t_line].l_modem)
2235 					(tp, com->prev_modem_status & MSR_DCD);
2236 		}
2237 		if (com->state & CS_ODONE) {
2238 			com_lock();
2239 			com_events -= LOTS_OF_EVENTS;
2240 			com->state &= ~CS_ODONE;
2241 			com_unlock();
2242 			if (!(com->state & CS_BUSY)
2243 			    && !(com->extra_state & CSE_BUSYCHECK)) {
2244 				callout_reset(&com->busy_ch, hz / 100,
2245 						siobusycheck, com);
2246 				com->extra_state |= CSE_BUSYCHECK;
2247 			}
2248 			(*linesw[tp->t_line].l_start)(tp);
2249 		}
2250 		if (com_events == 0)
2251 			break;
2252 	}
2253 	if (com_events >= LOTS_OF_EVENTS)
2254 		goto repeat;
2255 	lwkt_reltoken(&tty_token);
2256 }
2257 
2258 /*
2259  * Called with tty_token held but no com_lock
2260  */
2261 static int
2262 comparam(struct tty *tp, struct termios *t)
2263 {
2264 	u_int		cfcr;
2265 	int		cflag;
2266 	struct com_s	*com;
2267 	u_int		divisor;
2268 	u_char		dlbh;
2269 	u_char		dlbl;
2270 	int		unit;
2271 
2272 	unit = DEV_TO_UNIT(tp->t_dev);
2273 	com = com_addr(unit);
2274 	if (com == NULL) {
2275 		return (ENODEV);
2276 	}
2277 
2278 	/* do historical conversions */
2279 	if (t->c_ispeed == 0)
2280 		t->c_ispeed = t->c_ospeed;
2281 
2282 	/* check requested parameters */
2283 	if (t->c_ospeed == 0)
2284 		divisor = 0;
2285 	else {
2286 		if (t->c_ispeed != t->c_ospeed)
2287 			return (EINVAL);
2288 		divisor = siodivisor(com->rclk, t->c_ispeed);
2289 		if (divisor == 0)
2290 			return (EINVAL);
2291 	}
2292 
2293 	/* parameters are OK, convert them to the com struct and the device */
2294 	crit_enter();
2295 	if (divisor == 0)
2296 		(void)commctl(com, TIOCM_DTR, DMBIC);	/* hang up line */
2297 	else
2298 		(void)commctl(com, TIOCM_DTR, DMBIS);
2299 	cflag = t->c_cflag;
2300 	switch (cflag & CSIZE) {
2301 	case CS5:
2302 		cfcr = CFCR_5BITS;
2303 		break;
2304 	case CS6:
2305 		cfcr = CFCR_6BITS;
2306 		break;
2307 	case CS7:
2308 		cfcr = CFCR_7BITS;
2309 		break;
2310 	default:
2311 		cfcr = CFCR_8BITS;
2312 		break;
2313 	}
2314 	if (cflag & PARENB) {
2315 		cfcr |= CFCR_PENAB;
2316 		if (!(cflag & PARODD))
2317 			cfcr |= CFCR_PEVEN;
2318 	}
2319 	if (cflag & CSTOPB)
2320 		cfcr |= CFCR_STOPB;
2321 
2322 	if (com->hasfifo && divisor != 0) {
2323 		/*
2324 		 * Use a fifo trigger level low enough so that the input
2325 		 * latency from the fifo is less than about 16 msec and
2326 		 * the total latency is less than about 30 msec.  These
2327 		 * latencies are reasonable for humans.  Serial comms
2328 		 * protocols shouldn't expect anything better since modem
2329 		 * latencies are larger.
2330 		 *
2331 		 * Interrupts can be held up for long periods of time
2332 		 * due to inefficiencies in other parts of the kernel,
2333 		 * certain video cards, etc.  Setting the FIFO trigger
2334 		 * point to MEDH instead of HIGH gives us 694uS of slop
2335 		 * (8 character times) instead of 173uS (2 character times)
2336 		 * @ 115200 bps.
2337 		 */
2338 		com->fifo_image = t->c_ospeed <= 4800
2339 				  ? FIFO_ENABLE : FIFO_ENABLE | FIFO_RX_MEDH;
2340 #ifdef COM_ESP
2341 		/*
2342 		 * The Hayes ESP card needs the fifo DMA mode bit set
2343 		 * in compatibility mode.  If not, it will interrupt
2344 		 * for each character received.
2345 		 */
2346 		if (com->esp)
2347 			com->fifo_image |= FIFO_DMA_MODE;
2348 #endif
2349 		sio_setreg(com, com_fifo, com->fifo_image);
2350 	}
2351 
2352 	/*
2353 	 * This returns with interrupts disabled so that we can complete
2354 	 * the speed change atomically.  Keeping interrupts disabled is
2355 	 * especially important while com_data is hidden.
2356 	 */
2357 	(void) siosetwater(com, t->c_ispeed);
2358 
2359 	if (divisor != 0) {
2360 		sio_setreg(com, com_cfcr, cfcr | CFCR_DLAB);
2361 		/*
2362 		 * Only set the divisor registers if they would change,
2363 		 * since on some 16550 incompatibles (UMC8669F), setting
2364 		 * them while input is arriving them loses sync until
2365 		 * data stops arriving.
2366 		 */
2367 		dlbl = divisor & 0xFF;
2368 		if (sio_getreg(com, com_dlbl) != dlbl)
2369 			sio_setreg(com, com_dlbl, dlbl);
2370 		dlbh = divisor >> 8;
2371 		if (sio_getreg(com, com_dlbh) != dlbh)
2372 			sio_setreg(com, com_dlbh, dlbh);
2373 	}
2374 
2375 	sio_setreg(com, com_cfcr, com->cfcr_image = cfcr);
2376 
2377 	if (!(tp->t_state & TS_TTSTOP))
2378 		com->state |= CS_TTGO;
2379 
2380 	if (cflag & CRTS_IFLOW) {
2381 		if (com->st16650a) {
2382 			sio_setreg(com, com_cfcr, 0xbf);
2383 			sio_setreg(com, com_fifo,
2384 				   sio_getreg(com, com_fifo) | 0x40);
2385 		}
2386 		com->state |= CS_RTS_IFLOW;
2387 		/*
2388 		 * If CS_RTS_IFLOW just changed from off to on, the change
2389 		 * needs to be propagated to MCR_RTS.  This isn't urgent,
2390 		 * so do it later by calling comstart() instead of repeating
2391 		 * a lot of code from comstart() here.
2392 		 */
2393 	} else if (com->state & CS_RTS_IFLOW) {
2394 		com->state &= ~CS_RTS_IFLOW;
2395 		/*
2396 		 * CS_RTS_IFLOW just changed from on to off.  Force MCR_RTS
2397 		 * on here, since comstart() won't do it later.
2398 		 */
2399 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2400 		if (com->st16650a) {
2401 			sio_setreg(com, com_cfcr, 0xbf);
2402 			sio_setreg(com, com_fifo,
2403 				   sio_getreg(com, com_fifo) & ~0x40);
2404 		}
2405 	}
2406 
2407 
2408 	/*
2409 	 * Set up state to handle output flow control.
2410 	 * XXX - worth handling MDMBUF (DCD) flow control at the lowest level?
2411 	 * Now has 10+ msec latency, while CTS flow has 50- usec latency.
2412 	 */
2413 	com->state |= CS_ODEVREADY;
2414 	com->state &= ~CS_CTS_OFLOW;
2415 	if (cflag & CCTS_OFLOW) {
2416 		com->state |= CS_CTS_OFLOW;
2417 		if (!(com->last_modem_status & MSR_CTS))
2418 			com->state &= ~CS_ODEVREADY;
2419 		if (com->st16650a) {
2420 			sio_setreg(com, com_cfcr, 0xbf);
2421 			sio_setreg(com, com_fifo,
2422 				   sio_getreg(com, com_fifo) | 0x80);
2423 		}
2424 	} else {
2425 		if (com->st16650a) {
2426 			sio_setreg(com, com_cfcr, 0xbf);
2427 			sio_setreg(com, com_fifo,
2428 				   sio_getreg(com, com_fifo) & ~0x80);
2429 		}
2430 	}
2431 
2432 	sio_setreg(com, com_cfcr, com->cfcr_image);
2433 
2434 	/* XXX shouldn't call functions while intrs are disabled. */
2435 	disc_optim(tp, t, com);
2436 	/*
2437 	 * Recover from fiddling with CS_TTGO.  We used to call siointr1()
2438 	 * unconditionally, but that defeated the careful discarding of
2439 	 * stale input in sioopen().
2440 	 */
2441 	if (com->state >= (CS_BUSY | CS_TTGO)) {
2442 		com_lock();
2443 		siointr1(com);
2444 		com_unlock();
2445 	}
2446 	crit_exit();
2447 	comstart(tp);
2448 	if (com->ibufold != NULL) {
2449 		kfree(com->ibufold, M_DEVBUF);
2450 		com->ibufold = NULL;
2451 	}
2452 	return (0);
2453 }
2454 
2455 /*
2456  * called with tty_token held
2457  */
2458 static int
2459 siosetwater(struct com_s *com, speed_t speed)
2460 {
2461 	int		cp4ticks;
2462 	u_char		*ibuf;
2463 	int		ibufsize;
2464 	struct tty	*tp;
2465 
2466 	/*
2467 	 * Make the buffer size large enough to handle a softtty interrupt
2468 	 * latency of about 2 ticks without loss of throughput or data
2469 	 * (about 3 ticks if input flow control is not used or not honoured,
2470 	 * but a bit less for CS5-CS7 modes).
2471 	 */
2472 	cp4ticks = speed / 10 / hz * 4;
2473 	for (ibufsize = 128; ibufsize < cp4ticks;)
2474 		ibufsize <<= 1;
2475 	if (ibufsize == com->ibufsize)
2476 		return (0);
2477 
2478 	/*
2479 	 * Allocate input buffer.  The extra factor of 2 in the size is
2480 	 * to allow for an error byte for each input byte.
2481 	 */
2482 	ibuf = kmalloc(2 * ibufsize, M_DEVBUF, M_WAITOK | M_ZERO);
2483 
2484 	/* Initialize non-critical variables. */
2485 	com->ibufold = com->ibuf;
2486 	com->ibufsize = ibufsize;
2487 	tp = com->tp;
2488 	if (tp != NULL) {
2489 		tp->t_ififosize = 2 * ibufsize;
2490 		tp->t_ispeedwat = (speed_t)-1;
2491 		tp->t_ospeedwat = (speed_t)-1;
2492 	}
2493 
2494 	/*
2495 	 * Read current input buffer.
2496 	 */
2497 	com_lock();
2498 	if (com->iptr != com->ibuf)
2499 		sioinput(com);
2500 
2501 	/*-
2502 	 * Initialize critical variables, including input buffer watermarks.
2503 	 * The external device is asked to stop sending when the buffer
2504 	 * exactly reaches high water, or when the high level requests it.
2505 	 * The high level is notified immediately (rather than at a later
2506 	 * clock tick) when this watermark is reached.
2507 	 * The buffer size is chosen so the watermark should almost never
2508 	 * be reached.
2509 	 * The low watermark is invisibly 0 since the buffer is always
2510 	 * emptied all at once.
2511 	 */
2512 	com->iptr = com->ibuf = ibuf;
2513 	com->ibufend = ibuf + ibufsize;
2514 	com->ierroff = ibufsize;
2515 	com->ihighwater = ibuf + 3 * ibufsize / 4;
2516 	com_unlock();
2517 	return (0);
2518 }
2519 
2520 static void
2521 comstart(struct tty *tp)
2522 {
2523 	struct com_s	*com;
2524 	int		unit;
2525 
2526 	lwkt_gettoken(&tty_token);
2527 	unit = DEV_TO_UNIT(tp->t_dev);
2528 	com = com_addr(unit);
2529 	if (com == NULL) {
2530 		lwkt_reltoken(&tty_token);
2531 		return;
2532 	}
2533 	crit_enter();
2534 	com_lock();
2535 	if (tp->t_state & TS_TTSTOP)
2536 		com->state &= ~CS_TTGO;
2537 	else
2538 		com->state |= CS_TTGO;
2539 	if (tp->t_state & TS_TBLOCK) {
2540 		if (com->mcr_image & MCR_RTS && com->state & CS_RTS_IFLOW)
2541 			outb(com->modem_ctl_port, com->mcr_image &= ~MCR_RTS);
2542 	} else {
2543 		if (!(com->mcr_image & MCR_RTS) && com->iptr < com->ihighwater
2544 		    && com->state & CS_RTS_IFLOW)
2545 			outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2546 	}
2547 	com_unlock();
2548 	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
2549 		ttwwakeup(tp);
2550 		crit_exit();
2551 		lwkt_reltoken(&tty_token);
2552 		return;
2553 	}
2554 	if (tp->t_outq.c_cc != 0) {
2555 		struct lbq	*qp;
2556 		struct lbq	*next;
2557 
2558 		if (!com->obufs[0].l_queued) {
2559 			com->obufs[0].l_tail
2560 			    = com->obuf1 + q_to_b(&tp->t_outq, com->obuf1,
2561 						  sizeof com->obuf1);
2562 			com->obufs[0].l_next = NULL;
2563 			com->obufs[0].l_queued = TRUE;
2564 			com_lock();
2565 			if (com->state & CS_BUSY) {
2566 				qp = com->obufq.l_next;
2567 				while ((next = qp->l_next) != NULL)
2568 					qp = next;
2569 				qp->l_next = &com->obufs[0];
2570 			} else {
2571 				com->obufq.l_head = com->obufs[0].l_head;
2572 				com->obufq.l_tail = com->obufs[0].l_tail;
2573 				com->obufq.l_next = &com->obufs[0];
2574 				com->state |= CS_BUSY;
2575 			}
2576 			com_unlock();
2577 		}
2578 		if (tp->t_outq.c_cc != 0 && !com->obufs[1].l_queued) {
2579 			com->obufs[1].l_tail
2580 			    = com->obuf2 + q_to_b(&tp->t_outq, com->obuf2,
2581 						  sizeof com->obuf2);
2582 			com->obufs[1].l_next = NULL;
2583 			com->obufs[1].l_queued = TRUE;
2584 			com_lock();
2585 			if (com->state & CS_BUSY) {
2586 				qp = com->obufq.l_next;
2587 				while ((next = qp->l_next) != NULL)
2588 					qp = next;
2589 				qp->l_next = &com->obufs[1];
2590 			} else {
2591 				com->obufq.l_head = com->obufs[1].l_head;
2592 				com->obufq.l_tail = com->obufs[1].l_tail;
2593 				com->obufq.l_next = &com->obufs[1];
2594 				com->state |= CS_BUSY;
2595 			}
2596 			com_unlock();
2597 		}
2598 		tp->t_state |= TS_BUSY;
2599 	}
2600 	com_lock();
2601 	if (com->state >= (CS_BUSY | CS_TTGO))
2602 		siointr1(com);	/* fake interrupt to start output */
2603 	com_unlock();
2604 	ttwwakeup(tp);
2605 	crit_exit();
2606 	lwkt_reltoken(&tty_token);
2607 }
2608 
2609 static void
2610 comstop(struct tty *tp, int rw)
2611 {
2612 	struct com_s	*com;
2613 
2614 	lwkt_gettoken(&tty_token);
2615 	com = com_addr(DEV_TO_UNIT(tp->t_dev));
2616 	if (com == NULL || com->gone) {
2617 		lwkt_reltoken(&tty_token);
2618 		return;
2619 	}
2620 	com_lock();
2621 	if (rw & FWRITE) {
2622 		if (com->hasfifo)
2623 #ifdef COM_ESP
2624 		    /* XXX avoid h/w bug. */
2625 		    if (!com->esp)
2626 #endif
2627 			sio_setreg(com, com_fifo,
2628 				   FIFO_XMT_RST | com->fifo_image);
2629 		com->obufs[0].l_queued = FALSE;
2630 		com->obufs[1].l_queued = FALSE;
2631 		if (com->state & CS_ODONE)
2632 			com_events -= LOTS_OF_EVENTS;
2633 		com->state &= ~(CS_ODONE | CS_BUSY);
2634 		com->tp->t_state &= ~TS_BUSY;
2635 	}
2636 	if (rw & FREAD) {
2637 		if (com->hasfifo)
2638 #ifdef COM_ESP
2639 		    /* XXX avoid h/w bug. */
2640 		    if (!com->esp)
2641 #endif
2642 			sio_setreg(com, com_fifo,
2643 				   FIFO_RCV_RST | com->fifo_image);
2644 		com_events -= (com->iptr - com->ibuf);
2645 		com->iptr = com->ibuf;
2646 	}
2647 	com_unlock();
2648 	comstart(tp);
2649 	lwkt_reltoken(&tty_token);
2650 }
2651 
2652 static int
2653 commctl(struct com_s *com, int bits, int how)
2654 {
2655 	int	mcr;
2656 	int	msr;
2657 
2658 	lwkt_gettoken(&tty_token);
2659 	if (how == DMGET) {
2660 		bits = TIOCM_LE;	/* XXX - always enabled while open */
2661 		mcr = com->mcr_image;
2662 		if (mcr & MCR_DTR)
2663 			bits |= TIOCM_DTR;
2664 		if (mcr & MCR_RTS)
2665 			bits |= TIOCM_RTS;
2666 		msr = com->prev_modem_status;
2667 		if (msr & MSR_CTS)
2668 			bits |= TIOCM_CTS;
2669 		if (msr & MSR_DCD)
2670 			bits |= TIOCM_CD;
2671 		if (msr & MSR_DSR)
2672 			bits |= TIOCM_DSR;
2673 		/*
2674 		 * XXX - MSR_RI is naturally volatile, and we make MSR_TERI
2675 		 * more volatile by reading the modem status a lot.  Perhaps
2676 		 * we should latch both bits until the status is read here.
2677 		 */
2678 		if (msr & (MSR_RI | MSR_TERI))
2679 			bits |= TIOCM_RI;
2680 		lwkt_reltoken(&tty_token);
2681 		return (bits);
2682 	}
2683 	mcr = 0;
2684 	if (bits & TIOCM_DTR)
2685 		mcr |= MCR_DTR;
2686 	if (bits & TIOCM_RTS)
2687 		mcr |= MCR_RTS;
2688 	if (com->gone) {
2689 		lwkt_reltoken(&tty_token);
2690 		return(0);
2691 	}
2692 	com_lock();
2693 	switch (how) {
2694 	case DMSET:
2695 		outb(com->modem_ctl_port,
2696 		     com->mcr_image = mcr | (com->mcr_image & MCR_IENABLE));
2697 		break;
2698 	case DMBIS:
2699 		outb(com->modem_ctl_port, com->mcr_image |= mcr);
2700 		break;
2701 	case DMBIC:
2702 		outb(com->modem_ctl_port, com->mcr_image &= ~mcr);
2703 		break;
2704 	}
2705 	com_unlock();
2706 	lwkt_reltoken(&tty_token);
2707 	return (0);
2708 }
2709 
2710 /*
2711  * NOTE: Must be called with tty_token held
2712  */
2713 static void
2714 siosettimeout(void)
2715 {
2716 	struct com_s	*com;
2717 	bool_t		someopen;
2718 	int		unit;
2719 
2720 	ASSERT_LWKT_TOKEN_HELD(&tty_token);
2721 	/*
2722 	 * Set our timeout period to 1 second if no polled devices are open.
2723 	 * Otherwise set it to max(1/200, 1/hz).
2724 	 * Enable timeouts iff some device is open.
2725 	 */
2726 	callout_stop(&sio_timeout_handle);
2727 	sio_timeout = hz;
2728 	someopen = FALSE;
2729 	for (unit = 0; unit < sio_numunits; ++unit) {
2730 		com = com_addr(unit);
2731 		if (com != NULL && com->tp != NULL
2732 		    && com->tp->t_state & TS_ISOPEN && !com->gone) {
2733 			someopen = TRUE;
2734 			if (com->poll || com->poll_output) {
2735 				sio_timeout = hz > 200 ? hz / 200 : 1;
2736 				break;
2737 			}
2738 		}
2739 	}
2740 	if (someopen) {
2741 		sio_timeouts_until_log = hz / sio_timeout;
2742 		callout_reset(&sio_timeout_handle, sio_timeout,
2743 				comwakeup, NULL);
2744 	} else {
2745 		/* Flush error messages, if any. */
2746 		sio_timeouts_until_log = 1;
2747 		comwakeup(NULL);
2748 		callout_stop(&sio_timeout_handle);
2749 	}
2750 }
2751 
2752 /*
2753  * NOTE: Must be called with tty_token held
2754  */
2755 static void
2756 comwakeup(void *chan)
2757 {
2758 	struct com_s	*com;
2759 	int		unit;
2760 
2761 	/*
2762 	 * Can be called from a callout too so just get the token
2763 	 */
2764 	lwkt_gettoken(&tty_token);
2765 	callout_reset(&sio_timeout_handle, sio_timeout, comwakeup, NULL);
2766 
2767 	/*
2768 	 * Recover from lost output interrupts.
2769 	 * Poll any lines that don't use interrupts.
2770 	 */
2771 	for (unit = 0; unit < sio_numunits; ++unit) {
2772 		com = com_addr(unit);
2773 		if (com != NULL && !com->gone
2774 		    && (com->state >= (CS_BUSY | CS_TTGO) || com->poll)) {
2775 			com_lock();
2776 			siointr1(com);
2777 			com_unlock();
2778 		}
2779 	}
2780 
2781 	/*
2782 	 * Check for and log errors, but not too often.
2783 	 */
2784 	if (--sio_timeouts_until_log > 0) {
2785 		lwkt_reltoken(&tty_token);
2786 		return;
2787 	}
2788 	sio_timeouts_until_log = hz / sio_timeout;
2789 	for (unit = 0; unit < sio_numunits; ++unit) {
2790 		int	errnum;
2791 
2792 		com = com_addr(unit);
2793 		if (com == NULL)
2794 			continue;
2795 		if (com->gone)
2796 			continue;
2797 		for (errnum = 0; errnum < CE_NTYPES; ++errnum) {
2798 			u_int	delta;
2799 			u_long	total;
2800 
2801 			com_lock();
2802 			delta = com->delta_error_counts[errnum];
2803 			com->delta_error_counts[errnum] = 0;
2804 			com_unlock();
2805 			if (delta == 0)
2806 				continue;
2807 			total = com->error_counts[errnum] += delta;
2808 			log(LOG_ERR, "sio%d: %u more %s%s (total %lu)\n",
2809 			    unit, delta, error_desc[errnum],
2810 			    delta == 1 ? "" : "s", total);
2811 		}
2812 	}
2813 	lwkt_reltoken(&tty_token);
2814 }
2815 
2816 static void
2817 disc_optim(struct tty *tp, struct termios *t, struct com_s *com)
2818 {
2819 	lwkt_gettoken(&tty_token);
2820 	if (!(t->c_iflag & (ICRNL | IGNCR | IMAXBEL | INLCR | ISTRIP | IXON))
2821 	    && (!(t->c_iflag & BRKINT) || (t->c_iflag & IGNBRK))
2822 	    && (!(t->c_iflag & PARMRK)
2823 		|| (t->c_iflag & (IGNPAR | IGNBRK)) == (IGNPAR | IGNBRK))
2824 	    && !(t->c_lflag & (ECHO | ICANON | IEXTEN | ISIG | PENDIN))
2825 	    && linesw[tp->t_line].l_rint == ttyinput)
2826 		tp->t_state |= TS_CAN_BYPASS_L_RINT;
2827 	else
2828 		tp->t_state &= ~TS_CAN_BYPASS_L_RINT;
2829 	com->hotchar = linesw[tp->t_line].l_hotchar;
2830 	lwkt_reltoken(&tty_token);
2831 }
2832 
2833 /*
2834  * Following are all routines needed for SIO to act as console
2835  */
2836 #include <sys/cons.h>
2837 
2838 struct siocnstate {
2839 	u_char	dlbl;
2840 	u_char	dlbh;
2841 	u_char	ier;
2842 	u_char	cfcr;
2843 	u_char	mcr;
2844 };
2845 
2846 static speed_t siocngetspeed (Port_t, u_long rclk);
2847 static void siocnclose	(struct siocnstate *sp, Port_t iobase);
2848 static void siocnopen	(struct siocnstate *sp, Port_t iobase, int speed);
2849 static void siocntxwait	(Port_t iobase);
2850 
2851 static cn_probe_t siocnprobe;
2852 static cn_init_t siocninit;
2853 static cn_init_fini_t siocninit_fini;
2854 static cn_checkc_t siocncheckc;
2855 static cn_getc_t siocngetc;
2856 static cn_putc_t siocnputc;
2857 
2858 #if defined(__i386__) || defined(__x86_64__)
2859 CONS_DRIVER(sio, siocnprobe, siocninit, siocninit_fini,
2860 	    NULL, siocngetc, siocncheckc, siocnputc, NULL);
2861 #endif
2862 
2863 /* To get the GDB related variables */
2864 #if DDB > 0
2865 #include <ddb/ddb.h>
2866 #endif
2867 
2868 static void
2869 siocntxwait(Port_t iobase)
2870 {
2871 	int	timo;
2872 
2873 	/*
2874 	 * Wait for any pending transmission to finish.  Required to avoid
2875 	 * the UART lockup bug when the speed is changed, and for normal
2876 	 * transmits.
2877 	 */
2878 	timo = 100000;
2879 	while ((inb(iobase + com_lsr) & (LSR_TSRE | LSR_TXRDY))
2880 	       != (LSR_TSRE | LSR_TXRDY) && --timo != 0)
2881 		;
2882 }
2883 
2884 /*
2885  * Read the serial port specified and try to figure out what speed
2886  * it's currently running at.  We're assuming the serial port has
2887  * been initialized and is basicly idle.  This routine is only intended
2888  * to be run at system startup.
2889  *
2890  * If the value read from the serial port doesn't make sense, return 0.
2891  */
2892 /*
2893  * NOTE: Must be called with tty_token held
2894  */
2895 static speed_t
2896 siocngetspeed(Port_t iobase, u_long rclk)
2897 {
2898 	u_int	divisor;
2899 	u_char	dlbh;
2900 	u_char	dlbl;
2901 	u_char  cfcr;
2902 
2903 	cfcr = inb(iobase + com_cfcr);
2904 	outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2905 
2906 	dlbl = inb(iobase + com_dlbl);
2907 	dlbh = inb(iobase + com_dlbh);
2908 
2909 	outb(iobase + com_cfcr, cfcr);
2910 
2911 	divisor = dlbh << 8 | dlbl;
2912 
2913 	/* XXX there should be more sanity checking. */
2914 	if (divisor == 0)
2915 		return (CONSPEED);
2916 	return (rclk / (16UL * divisor));
2917 }
2918 
2919 static void
2920 siocnopen(struct siocnstate *sp, Port_t iobase, int speed)
2921 {
2922 	u_int	divisor;
2923 	u_char	dlbh;
2924 	u_char	dlbl;
2925 
2926 	/*
2927 	 * Save all the device control registers except the fifo register
2928 	 * and set our default ones (cs8 -parenb speed=comdefaultrate).
2929 	 * We can't save the fifo register since it is read-only.
2930 	 */
2931 	sp->ier = inb(iobase + com_ier);
2932 	outb(iobase + com_ier, 0);	/* spltty() doesn't stop siointr() */
2933 	siocntxwait(iobase);
2934 	sp->cfcr = inb(iobase + com_cfcr);
2935 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2936 	sp->dlbl = inb(iobase + com_dlbl);
2937 	sp->dlbh = inb(iobase + com_dlbh);
2938 	/*
2939 	 * Only set the divisor registers if they would change, since on
2940 	 * some 16550 incompatibles (Startech), setting them clears the
2941 	 * data input register.  This also reduces the effects of the
2942 	 * UMC8669F bug.
2943 	 */
2944 	divisor = siodivisor(comdefaultrclk, speed);
2945 	dlbl = divisor & 0xFF;
2946 	if (sp->dlbl != dlbl)
2947 		outb(iobase + com_dlbl, dlbl);
2948 	dlbh = divisor >> 8;
2949 	if (sp->dlbh != dlbh)
2950 		outb(iobase + com_dlbh, dlbh);
2951 	outb(iobase + com_cfcr, CFCR_8BITS);
2952 	sp->mcr = inb(iobase + com_mcr);
2953 	/*
2954 	 * We don't want interrupts, but must be careful not to "disable"
2955 	 * them by clearing the MCR_IENABLE bit, since that might cause
2956 	 * an interrupt by floating the IRQ line.
2957 	 */
2958 	outb(iobase + com_mcr, (sp->mcr & MCR_IENABLE) | MCR_DTR | MCR_RTS);
2959 }
2960 
2961 static void
2962 siocnclose(struct siocnstate *sp, Port_t iobase)
2963 {
2964 	/*
2965 	 * Restore the device control registers.
2966 	 */
2967 	siocntxwait(iobase);
2968 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2969 	if (sp->dlbl != inb(iobase + com_dlbl))
2970 		outb(iobase + com_dlbl, sp->dlbl);
2971 	if (sp->dlbh != inb(iobase + com_dlbh))
2972 		outb(iobase + com_dlbh, sp->dlbh);
2973 	outb(iobase + com_cfcr, sp->cfcr);
2974 	/*
2975 	 * XXX damp oscillations of MCR_DTR and MCR_RTS by not restoring them.
2976 	 */
2977 	outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
2978 	outb(iobase + com_ier, sp->ier);
2979 }
2980 
2981 static void
2982 siocnprobe(struct consdev *cp)
2983 {
2984 	speed_t			boot_speed;
2985 	u_char			cfcr;
2986 	u_int			divisor;
2987 	int			unit;
2988 	struct siocnstate	sp;
2989 
2990 	/*
2991 	 * Find our first enabled console, if any.  If it is a high-level
2992 	 * console device, then initialize it and return successfully.
2993 	 * If it is a low-level console device, then initialize it and
2994 	 * return unsuccessfully.  It must be initialized in both cases
2995 	 * for early use by console drivers and debuggers.  Initializing
2996 	 * the hardware is not necessary in all cases, since the i/o
2997 	 * routines initialize it on the fly, but it is necessary if
2998 	 * input might arrive while the hardware is switched back to an
2999 	 * uninitialized state.  We can't handle multiple console devices
3000 	 * yet because our low-level routines don't take a device arg.
3001 	 * We trust the user to set the console flags properly so that we
3002 	 * don't need to probe.
3003 	 */
3004 	cp->cn_pri = CN_DEAD;
3005 
3006 	for (unit = 0; unit < 16; unit++) { /* XXX need to know how many */
3007 		int flags;
3008 		int disabled;
3009 		if (resource_int_value("sio", unit, "disabled", &disabled) == 0) {
3010 			if (disabled)
3011 				continue;
3012 		}
3013 		if (resource_int_value("sio", unit, "flags", &flags))
3014 			continue;
3015 		if (COM_CONSOLE(flags) || COM_DEBUGGER(flags)) {
3016 			int port;
3017 			Port_t iobase;
3018 
3019 			if (resource_int_value("sio", unit, "port", &port))
3020 				continue;
3021 			iobase = port;
3022 			crit_enter();
3023 			if (boothowto & RB_SERIAL) {
3024 				boot_speed =
3025 				    siocngetspeed(iobase, comdefaultrclk);
3026 				if (boot_speed)
3027 					comdefaultrate = boot_speed;
3028 			}
3029 
3030 			/*
3031 			 * Initialize the divisor latch.  We can't rely on
3032 			 * siocnopen() to do this the first time, since it
3033 			 * avoids writing to the latch if the latch appears
3034 			 * to have the correct value.  Also, if we didn't
3035 			 * just read the speed from the hardware, then we
3036 			 * need to set the speed in hardware so that
3037 			 * switching it later is null.
3038 			 */
3039 			com_lock();
3040 			cfcr = inb(iobase + com_cfcr);
3041 			outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
3042 			divisor = siodivisor(comdefaultrclk, comdefaultrate);
3043 			outb(iobase + com_dlbl, divisor & 0xff);
3044 			outb(iobase + com_dlbh, divisor >> 8);
3045 			outb(iobase + com_cfcr, cfcr);
3046 
3047 			siocnopen(&sp, iobase, comdefaultrate);
3048 			com_unlock();
3049 
3050 			crit_exit();
3051 			if (COM_CONSOLE(flags) && !COM_LLCONSOLE(flags)) {
3052 				cp->cn_probegood = 1;
3053 				cp->cn_private = (void *)(intptr_t)unit;
3054 				cp->cn_pri = COM_FORCECONSOLE(flags)
3055 					     || boothowto & RB_SERIAL
3056 					     ? CN_REMOTE : CN_NORMAL;
3057 				siocniobase = iobase;
3058 				siocnunit = unit;
3059 			}
3060 			if (COM_DEBUGGER(flags) && gdb_tab == NULL) {
3061 				kprintf("sio%d: gdb debugging port\n", unit);
3062 				siogdbiobase = iobase;
3063 				siogdbunit = unit;
3064 #if DDB > 0
3065 				cp->cn_gdbprivate = (void *)(intptr_t)unit;
3066 				gdb_tab = cp;
3067 #endif
3068 			}
3069 		}
3070 	}
3071 #if defined(__i386__) || defined(__x86_64__)
3072 #if DDB > 0
3073 	/*
3074 	 * XXX Ugly Compatability.
3075 	 * If no gdb port has been specified, set it to be the console
3076 	 * as some configuration files don't specify the gdb port.
3077 	 */
3078 	if (gdb_tab == NULL && (boothowto & RB_GDB)) {
3079 		kprintf("Warning: no GDB port specified. Defaulting to sio%d.\n",
3080 			siocnunit);
3081 		kprintf("Set flag 0x80 on desired GDB port in your\n");
3082 		kprintf("configuration file (currently sio only).\n");
3083 		siogdbiobase = siocniobase;
3084 		siogdbunit = siocnunit;
3085 		cp->cn_gdbprivate = (void *)(intptr_t)siocnunit;
3086 		gdb_tab = cp;
3087 	}
3088 #endif
3089 #endif
3090 }
3091 
3092 static void
3093 siocninit(struct consdev *cp)
3094 {
3095 	comconsole = (int)(intptr_t)cp->cn_private;
3096 }
3097 
3098 static void
3099 siocninit_fini(struct consdev *cp)
3100 {
3101 	cdev_t dev;
3102 	int unit;
3103 
3104 	if (cp->cn_probegood) {
3105 		unit = (int)(intptr_t)cp->cn_private;
3106 		/*
3107 		 * Call devfs_find_device_by_name on ttydX to find the correct device,
3108 		 * as it should have been created already at this point by the
3109 		 * attach routine.
3110 		 * If it isn't found, the serial port was not attached at all and we
3111 		 * shouldn't be here, so assert this case.
3112 		 */
3113 		dev = devfs_find_device_by_name("ttyd%r", unit);
3114 
3115 		KKASSERT(dev != NULL);
3116 		cp->cn_dev = dev;
3117 	}
3118 }
3119 
3120 static int
3121 siocncheckc(void *private)
3122 {
3123 	int	c;
3124 	int	unit = (int)(intptr_t)private;
3125 	Port_t	iobase;
3126 	struct siocnstate	sp;
3127 
3128 	if (unit == siogdbunit)
3129 		iobase = siogdbiobase;
3130 	else
3131 		iobase = siocniobase;
3132 	com_lock();
3133 	crit_enter();
3134 	siocnopen(&sp, iobase, comdefaultrate);
3135 	if (inb(iobase + com_lsr) & LSR_RXRDY)
3136 		c = inb(iobase + com_data);
3137 	else
3138 		c = -1;
3139 	siocnclose(&sp, iobase);
3140 	crit_exit();
3141 	com_unlock();
3142 	return (c);
3143 }
3144 
3145 
3146 int
3147 siocngetc(void *private)
3148 {
3149 	int	c;
3150 	int	unit = (int)(intptr_t)private;
3151 	Port_t	iobase;
3152 	struct siocnstate	sp;
3153 
3154 	if (unit == siogdbunit)
3155 		iobase = siogdbiobase;
3156 	else
3157 		iobase = siocniobase;
3158 	com_lock();
3159 	crit_enter();
3160 	siocnopen(&sp, iobase, comdefaultrate);
3161 	while (!(inb(iobase + com_lsr) & LSR_RXRDY))
3162 		;
3163 	c = inb(iobase + com_data);
3164 	siocnclose(&sp, iobase);
3165 	crit_exit();
3166 	com_unlock();
3167 	return (c);
3168 }
3169 
3170 void
3171 siocnputc(void *private, int c)
3172 {
3173 	int	unit = (int)(intptr_t)private;
3174 	struct siocnstate	sp;
3175 	Port_t	iobase;
3176 
3177 	if (unit == siogdbunit)
3178 		iobase = siogdbiobase;
3179 	else
3180 		iobase = siocniobase;
3181 	com_lock();
3182 	crit_enter();
3183 	siocnopen(&sp, iobase, comdefaultrate);
3184 	siocntxwait(iobase);
3185 	outb(iobase + com_data, c);
3186 	siocnclose(&sp, iobase);
3187 	crit_exit();
3188 	com_unlock();
3189 }
3190 
3191 DRIVER_MODULE(sio, isa, sio_isa_driver, sio_devclass, 0, 0);
3192 DRIVER_MODULE(sio, acpi, sio_isa_driver, sio_devclass, 0, 0);
3193 #if NPCI > 0
3194 DRIVER_MODULE(sio, pci, sio_pci_driver, sio_devclass, 0, 0);
3195 #endif
3196 #if NPUC > 0
3197 DRIVER_MODULE(sio, puc, sio_puc_driver, sio_devclass, 0, 0);
3198 #endif
3199