1/*-
2 * Copyright (c) 1991 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	from: @(#)com.c	7.5 (Berkeley) 5/16/91
30 *	from: i386/isa sio.c,v 1.234
31 */
32
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD$");
35
36#include "opt_compat.h"
37#include "opt_gdb.h"
38#include "opt_kdb.h"
39#include "opt_sio.h"
40
41/*
42 * Serial driver, based on 386BSD-0.1 com driver.
43 * Mostly rewritten to use pseudo-DMA.
44 * Works for National Semiconductor NS8250-NS16550AF UARTs.
45 * COM driver, based on HP dca driver.
46 *
47 * Changes for PC Card integration:
48 *	- Added PC Card driver table and handlers
49 */
50#include <sys/param.h>
51#include <sys/systm.h>
52#include <sys/bus.h>
53#include <sys/conf.h>
54#include <sys/fcntl.h>
55#include <sys/interrupt.h>
56#include <sys/kdb.h>
57#include <sys/kernel.h>
58#include <sys/limits.h>
59#include <sys/lock.h>
60#include <sys/malloc.h>
61#include <sys/module.h>
62#include <sys/mutex.h>
63#include <sys/proc.h>
64#include <sys/reboot.h>
65#include <sys/serial.h>
66#include <sys/sysctl.h>
67#include <sys/syslog.h>
68#include <sys/tty.h>
69#include <machine/bus.h>
70#include <sys/rman.h>
71#include <sys/timepps.h>
72#include <sys/uio.h>
73#include <sys/cons.h>
74
75#include <isa/isavar.h>
76
77#include <machine/resource.h>
78
79#include <dev/sio/sioreg.h>
80#include <dev/sio/siovar.h>
81
82#ifdef COM_ESP
83#include <dev/ic/esp.h>
84#endif
85#include <dev/ic/ns16550.h>
86
87#define	LOTS_OF_EVENTS	64	/* helps separate urgent events from input */
88
89#ifdef COM_MULTIPORT
90/* checks in flags for multiport and which is multiport "master chip"
91 * for a given card
92 */
93#define	COM_ISMULTIPORT(flags)	((flags) & 0x01)
94#define	COM_MPMASTER(flags)	(((flags) >> 8) & 0x0ff)
95#define	COM_NOTAST4(flags)	((flags) & 0x04)
96#else
97#define	COM_ISMULTIPORT(flags)	(0)
98#endif /* COM_MULTIPORT */
99
100#define	COM_C_IIR_TXRDYBUG	0x80000
101#define	COM_CONSOLE(flags)	((flags) & 0x10)
102#define	COM_DEBUGGER(flags)	((flags) & 0x80)
103#define	COM_FIFOSIZE(flags)	(((flags) & 0xff000000) >> 24)
104#define	COM_FORCECONSOLE(flags)	((flags) & 0x20)
105#define	COM_IIR_TXRDYBUG(flags)	((flags) & COM_C_IIR_TXRDYBUG)
106#define	COM_LLCONSOLE(flags)	((flags) & 0x40)
107#define	COM_LOSESOUTINTS(flags)	((flags) & 0x08)
108#define	COM_NOFIFO(flags)	((flags) & 0x02)
109#define	COM_NOPROBE(flags)	((flags) & 0x40000)
110#define	COM_NOSCR(flags)	((flags) & 0x100000)
111#define	COM_PPSCTS(flags)	((flags) & 0x10000)
112#define	COM_ST16650A(flags)	((flags) & 0x20000)
113#define	COM_TI16754(flags)	((flags) & 0x200000)
114
115#define	sio_getreg(com, off) \
116	(bus_space_read_1((com)->bst, (com)->bsh, (off)))
117#define	sio_setreg(com, off, value) \
118	(bus_space_write_1((com)->bst, (com)->bsh, (off), (value)))
119
120/*
121 * com state bits.
122 * (CS_BUSY | CS_TTGO) and (CS_BUSY | CS_TTGO | CS_ODEVREADY) must be higher
123 * than the other bits so that they can be tested as a group without masking
124 * off the low bits.
125 *
126 * The following com and tty flags correspond closely:
127 *	CS_BUSY		= TS_BUSY (maintained by comstart(), siopoll() and
128 *				   comstop())
129 *	CS_TTGO		= ~TS_TTSTOP (maintained by comparam() and comstart())
130 *	CS_CTS_OFLOW	= CCTS_OFLOW (maintained by comparam())
131 *	CS_RTS_IFLOW	= CRTS_IFLOW (maintained by comparam())
132 * TS_FLUSH is not used.
133 * XXX I think TIOCSETA doesn't clear TS_TTSTOP when it clears IXON.
134 * XXX CS_*FLOW should be CF_*FLOW in com->flags (control flags not state).
135 */
136#define	CS_BUSY		0x80	/* output in progress */
137#define	CS_TTGO		0x40	/* output not stopped by XOFF */
138#define	CS_ODEVREADY	0x20	/* external device h/w ready (CTS) */
139#define	CS_CHECKMSR	1	/* check of MSR scheduled */
140#define	CS_CTS_OFLOW	2	/* use CTS output flow control */
141#define	CS_ODONE	4	/* output completed */
142#define	CS_RTS_IFLOW	8	/* use RTS input flow control */
143#define	CSE_BUSYCHECK	1	/* siobusycheck() scheduled */
144
145static	char const * const	error_desc[] = {
146#define	CE_OVERRUN			0
147	"silo overflow",
148#define	CE_INTERRUPT_BUF_OVERFLOW	1
149	"interrupt-level buffer overflow",
150#define	CE_TTY_BUF_OVERFLOW		2
151	"tty-level buffer overflow",
152};
153
154#define	CE_NTYPES			3
155#define	CE_RECORD(com, errnum)		(++(com)->delta_error_counts[errnum])
156
157/* types.  XXX - should be elsewhere */
158typedef u_int	Port_t;		/* hardware port */
159typedef u_char	bool_t;		/* boolean */
160
161/* queue of linear buffers */
162struct lbq {
163	u_char	*l_head;	/* next char to process */
164	u_char	*l_tail;	/* one past the last char to process */
165	struct lbq *l_next;	/* next in queue */
166	bool_t	l_queued;	/* nonzero if queued */
167};
168
169/* com device structure */
170struct com_s {
171	u_char	state;		/* miscellaneous flag bits */
172	u_char	cfcr_image;	/* copy of value written to CFCR */
173#ifdef COM_ESP
174	bool_t	esp;		/* is this unit a hayes esp board? */
175#endif
176	u_char	extra_state;	/* more flag bits, separate for order trick */
177	u_char	fifo_image;	/* copy of value written to FIFO */
178	bool_t	hasfifo;	/* nonzero for 16550 UARTs */
179	bool_t	loses_outints;	/* nonzero if device loses output interrupts */
180	u_char	mcr_image;	/* copy of value written to MCR */
181#ifdef COM_MULTIPORT
182	bool_t	multiport;	/* is this unit part of a multiport device? */
183#endif /* COM_MULTIPORT */
184	bool_t	no_irq;		/* nonzero if irq is not attached */
185	bool_t  gone;		/* hardware disappeared */
186	bool_t	poll;		/* nonzero if polling is required */
187	bool_t	poll_output;	/* nonzero if polling for output is required */
188	bool_t	st16650a;	/* nonzero if Startech 16650A compatible */
189	int	unit;		/* unit	number */
190	u_int	flags;		/* copy of device flags */
191	u_int	tx_fifo_size;
192
193	/*
194	 * The high level of the driver never reads status registers directly
195	 * because there would be too many side effects to handle conveniently.
196	 * Instead, it reads copies of the registers stored here by the
197	 * interrupt handler.
198	 */
199	u_char	last_modem_status;	/* last MSR read by intr handler */
200	u_char	prev_modem_status;	/* last MSR handled by high level */
201
202	u_char	*ibuf;		/* start of input buffer */
203	u_char	*ibufend;	/* end of input buffer */
204	u_char	*ibufold;	/* old input buffer, to be freed */
205	u_char	*ihighwater;	/* threshold in input buffer */
206	u_char	*iptr;		/* next free spot in input buffer */
207	int	ibufsize;	/* size of ibuf (not include error bytes) */
208	int	ierroff;	/* offset of error bytes in ibuf */
209
210	struct lbq	obufq;	/* head of queue of output buffers */
211	struct lbq	obufs[2];	/* output buffers */
212
213	bus_space_tag_t		bst;
214	bus_space_handle_t	bsh;
215
216	Port_t	data_port;	/* i/o ports */
217#ifdef COM_ESP
218	Port_t	esp_port;
219#endif
220	Port_t	int_ctl_port;
221	Port_t	int_id_port;
222	Port_t	modem_ctl_port;
223	Port_t	line_status_port;
224	Port_t	modem_status_port;
225
226	struct tty	*tp;	/* cross reference */
227
228	struct	pps_state pps;
229	int	pps_bit;
230#ifdef KDB
231	int	alt_brk_state;
232#endif
233
234	u_long	bytes_in;	/* statistics */
235	u_long	bytes_out;
236	u_int	delta_error_counts[CE_NTYPES];
237	u_long	error_counts[CE_NTYPES];
238
239	u_long	rclk;
240
241	struct resource *irqres;
242	struct resource *ioportres;
243	int	ioportrid;
244	void	*cookie;
245
246	/*
247	 * Data area for output buffers.  Someday we should build the output
248	 * buffer queue without copying data.
249	 */
250	u_char	obuf1[256];
251	u_char	obuf2[256];
252};
253
254#ifdef COM_ESP
255static	int	espattach(struct com_s *com, Port_t esp_port);
256#endif
257
258static	void	combreak(struct tty *tp, int sig);
259static	timeout_t siobusycheck;
260static	u_int	siodivisor(u_long rclk, speed_t speed);
261static	void	comclose(struct tty *tp);
262static	int	comopen(struct tty *tp, struct cdev *dev);
263static	void	sioinput(struct com_s *com);
264static	void	siointr1(struct com_s *com);
265static	int	siointr(void *arg);
266static	int	commodem(struct tty *tp, int sigon, int sigoff);
267static	int	comparam(struct tty *tp, struct termios *t);
268static	void	siopoll(void *);
269static	void	siosettimeout(void);
270static	int	siosetwater(struct com_s *com, speed_t speed);
271static	void	comstart(struct tty *tp);
272static	void	comstop(struct tty *tp, int rw);
273static	timeout_t comwakeup;
274
275char		sio_driver_name[] = "sio";
276static struct	mtx sio_lock;
277static int	sio_inited;
278
279/* table and macro for fast conversion from a unit number to its com struct */
280devclass_t	sio_devclass;
281#define	com_addr(unit)	((struct com_s *) \
282			 devclass_get_softc(sio_devclass, unit)) /* XXX */
283
284int	comconsole = -1;
285static	volatile speed_t	comdefaultrate = CONSPEED;
286static	u_long			comdefaultrclk = DEFAULT_RCLK;
287SYSCTL_ULONG(_machdep, OID_AUTO, conrclk, CTLFLAG_RW, &comdefaultrclk, 0, "");
288static	speed_t			gdbdefaultrate = GDBSPEED;
289SYSCTL_UINT(_machdep, OID_AUTO, gdbspeed, CTLFLAG_RW,
290	    &gdbdefaultrate, GDBSPEED, "");
291static	u_int	com_events;	/* input chars + weighted output completions */
292static	Port_t	siocniobase;
293static	int	siocnunit = -1;
294static	void	*sio_slow_ih;
295static	void	*sio_fast_ih;
296static	int	sio_timeout;
297static	int	sio_timeouts_until_log;
298static	struct	callout_handle sio_timeout_handle
299    = CALLOUT_HANDLE_INITIALIZER(&sio_timeout_handle);
300static	int	sio_numunits;
301
302#ifdef GDB
303static	Port_t	siogdbiobase = 0;
304#endif
305
306#ifdef COM_ESP
307/* XXX configure this properly. */
308/* XXX quite broken for new-bus. */
309static	Port_t	likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, };
310static	Port_t	likely_esp_ports[] = { 0x140, 0x180, 0x280, 0 };
311#endif
312
313/*
314 * handle sysctl read/write requests for console speed
315 *
316 * In addition to setting comdefaultrate for I/O through /dev/console,
317 * also set the initial and lock values for the /dev/ttyXX device
318 * if there is one associated with the console.  Finally, if the /dev/tty
319 * device has already been open, change the speed on the open running port
320 * itself.
321 */
322
323static int
324sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)
325{
326	int error, s;
327	speed_t newspeed;
328	struct com_s *com;
329	struct tty *tp;
330
331	newspeed = comdefaultrate;
332
333	error = sysctl_handle_opaque(oidp, &newspeed, sizeof newspeed, req);
334	if (error || !req->newptr)
335		return (error);
336
337	comdefaultrate = newspeed;
338
339	if (comconsole < 0)		/* serial console not selected? */
340		return (0);
341
342	com = com_addr(comconsole);
343	if (com == NULL)
344		return (ENXIO);
345
346	tp = com->tp;
347	if (tp == NULL)
348		return (ENXIO);
349
350	/*
351	 * set the initial and lock rates for /dev/ttydXX and /dev/cuaXX
352	 * (note, the lock rates really are boolean -- if non-zero, disallow
353	 *  speed changes)
354	 */
355	tp->t_init_in.c_ispeed  = tp->t_init_in.c_ospeed =
356	tp->t_lock_in.c_ispeed  = tp->t_lock_in.c_ospeed =
357	tp->t_init_out.c_ispeed = tp->t_init_out.c_ospeed =
358	tp->t_lock_out.c_ispeed = tp->t_lock_out.c_ospeed = comdefaultrate;
359
360	if (tp->t_state & TS_ISOPEN) {
361		tp->t_termios.c_ispeed =
362		tp->t_termios.c_ospeed = comdefaultrate;
363		s = spltty();
364		error = comparam(tp, &tp->t_termios);
365		splx(s);
366	}
367	return error;
368}
369
370SYSCTL_PROC(_machdep, OID_AUTO, conspeed, CTLTYPE_INT | CTLFLAG_RW,
371	    0, 0, sysctl_machdep_comdefaultrate, "I", "");
372TUNABLE_INT("machdep.conspeed", __DEVOLATILE(int *, &comdefaultrate));
373
374#define SET_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) | (bit))
375#define CLR_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) & ~(bit))
376
377/*
378 *	Unload the driver and clear the table.
379 *	XXX this is mostly wrong.
380 *	XXX TODO:
381 *	This is usually called when the card is ejected, but
382 *	can be caused by a kldunload of a controller driver.
383 *	The idea is to reset the driver's view of the device
384 *	and ensure that any driver entry points such as
385 *	read and write do not hang.
386 */
387int
388siodetach(device_t dev)
389{
390	struct com_s	*com;
391
392	com = (struct com_s *) device_get_softc(dev);
393	if (com == NULL) {
394		device_printf(dev, "NULL com in siounload\n");
395		return (0);
396	}
397	com->gone = TRUE;
398	if (com->tp)
399		ttyfree(com->tp);
400	if (com->irqres) {
401		bus_teardown_intr(dev, com->irqres, com->cookie);
402		bus_release_resource(dev, SYS_RES_IRQ, 0, com->irqres);
403	}
404	if (com->ioportres)
405		bus_release_resource(dev, SYS_RES_IOPORT, com->ioportrid,
406				     com->ioportres);
407	if (com->ibuf != NULL)
408		free(com->ibuf, M_DEVBUF);
409
410	device_set_softc(dev, NULL);
411	free(com, M_DEVBUF);
412	return (0);
413}
414
415int
416sioprobe(dev, xrid, rclk, noprobe)
417	device_t	dev;
418	int		xrid;
419	u_long		rclk;
420	int		noprobe;
421{
422#if 0
423	static bool_t	already_init;
424	device_t	xdev;
425#endif
426	struct com_s	*com;
427	u_int		divisor;
428	bool_t		failures[10];
429	int		fn;
430	device_t	idev;
431	Port_t		iobase;
432	intrmask_t	irqmap[4];
433	intrmask_t	irqs;
434	u_char		mcr_image;
435	int		result;
436	u_long		xirq;
437	u_int		flags = device_get_flags(dev);
438	int		rid;
439	struct resource *port;
440
441	rid = xrid;
442	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
443				  0, ~0, IO_COMSIZE, RF_ACTIVE);
444	if (!port)
445		return (ENXIO);
446
447	com = malloc(sizeof(*com), M_DEVBUF, M_NOWAIT | M_ZERO);
448	if (com == NULL) {
449		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
450		return (ENOMEM);
451	}
452	device_set_softc(dev, com);
453	com->bst = rman_get_bustag(port);
454	com->bsh = rman_get_bushandle(port);
455	if (rclk == 0)
456		rclk = DEFAULT_RCLK;
457	com->rclk = rclk;
458
459	while (sio_inited != 2)
460		if (atomic_cmpset_int(&sio_inited, 0, 1)) {
461			mtx_init(&sio_lock, sio_driver_name, NULL,
462			    (comconsole != -1) ?
463			    MTX_SPIN | MTX_QUIET : MTX_SPIN);
464			atomic_store_rel_int(&sio_inited, 2);
465		}
466
467#if 0
468	/*
469	 * XXX this is broken - when we are first called, there are no
470	 * previously configured IO ports.  We could hard code
471	 * 0x3f8, 0x2f8, 0x3e8, 0x2e8 etc but that's probably worse.
472	 * This code has been doing nothing since the conversion since
473	 * "count" is zero the first time around.
474	 */
475	if (!already_init) {
476		/*
477		 * Turn off MCR_IENABLE for all likely serial ports.  An unused
478		 * port with its MCR_IENABLE gate open will inhibit interrupts
479		 * from any used port that shares the interrupt vector.
480		 * XXX the gate enable is elsewhere for some multiports.
481		 */
482		device_t *devs;
483		int count, i, xioport;
484
485		devclass_get_devices(sio_devclass, &devs, &count);
486		for (i = 0; i < count; i++) {
487			xdev = devs[i];
488			if (device_is_enabled(xdev) &&
489			    bus_get_resource(xdev, SYS_RES_IOPORT, 0, &xioport,
490					     NULL) == 0)
491				outb(xioport + com_mcr, 0);
492		}
493		free(devs, M_TEMP);
494		already_init = TRUE;
495	}
496#endif
497
498	if (COM_LLCONSOLE(flags)) {
499		printf("sio%d: reserved for low-level i/o\n",
500		       device_get_unit(dev));
501		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
502		device_set_softc(dev, NULL);
503		free(com, M_DEVBUF);
504		return (ENXIO);
505	}
506
507	/*
508	 * If the device is on a multiport card and has an AST/4
509	 * compatible interrupt control register, initialize this
510	 * register and prepare to leave MCR_IENABLE clear in the mcr.
511	 * Otherwise, prepare to set MCR_IENABLE in the mcr.
512	 * Point idev to the device struct giving the correct id_irq.
513	 * This is the struct for the master device if there is one.
514	 */
515	idev = dev;
516	mcr_image = MCR_IENABLE;
517#ifdef COM_MULTIPORT
518	if (COM_ISMULTIPORT(flags)) {
519		Port_t xiobase;
520		u_long io;
521
522		idev = devclass_get_device(sio_devclass, COM_MPMASTER(flags));
523		if (idev == NULL) {
524			printf("sio%d: master device %d not configured\n",
525			       device_get_unit(dev), COM_MPMASTER(flags));
526			idev = dev;
527		}
528		if (!COM_NOTAST4(flags)) {
529			if (bus_get_resource(idev, SYS_RES_IOPORT, 0, &io,
530					     NULL) == 0) {
531				xiobase = io;
532				if (bus_get_resource(idev, SYS_RES_IRQ, 0,
533				    NULL, NULL) == 0)
534					outb(xiobase + com_scr, 0x80);
535				else
536					outb(xiobase + com_scr, 0);
537			}
538			mcr_image = 0;
539		}
540	}
541#endif /* COM_MULTIPORT */
542	if (bus_get_resource(idev, SYS_RES_IRQ, 0, NULL, NULL) != 0)
543		mcr_image = 0;
544
545	bzero(failures, sizeof failures);
546	iobase = rman_get_start(port);
547
548	/*
549	 * We don't want to get actual interrupts, just masked ones.
550	 * Interrupts from this line should already be masked in the ICU,
551	 * but mask them in the processor as well in case there are some
552	 * (misconfigured) shared interrupts.
553	 */
554	mtx_lock_spin(&sio_lock);
555/* EXTRA DELAY? */
556
557	/*
558	 * For the TI16754 chips, set prescaler to 1 (4 is often the
559	 * default after-reset value) as otherwise it's impossible to
560	 * get highest baudrates.
561	 */
562	if (COM_TI16754(flags)) {
563		u_char cfcr, efr;
564
565		cfcr = sio_getreg(com, com_cfcr);
566		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
567		efr = sio_getreg(com, com_efr);
568		/* Unlock extended features to turn off prescaler. */
569		sio_setreg(com, com_efr, efr | EFR_EFE);
570		/* Disable EFR. */
571		sio_setreg(com, com_cfcr, (cfcr != CFCR_EFR_ENABLE) ? cfcr : 0);
572		/* Turn off prescaler. */
573		sio_setreg(com, com_mcr,
574			   sio_getreg(com, com_mcr) & ~MCR_PRESCALE);
575		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
576		sio_setreg(com, com_efr, efr);
577		sio_setreg(com, com_cfcr, cfcr);
578	}
579
580	/*
581	 * Initialize the speed and the word size and wait long enough to
582	 * drain the maximum of 16 bytes of junk in device output queues.
583	 * The speed is undefined after a master reset and must be set
584	 * before relying on anything related to output.  There may be
585	 * junk after a (very fast) soft reboot and (apparently) after
586	 * master reset.
587	 * XXX what about the UART bug avoided by waiting in comparam()?
588	 * We don't want to to wait long enough to drain at 2 bps.
589	 */
590	if (iobase == siocniobase)
591		DELAY((16 + 1) * 1000000 / (comdefaultrate / 10));
592	else {
593		sio_setreg(com, com_cfcr, CFCR_DLAB | CFCR_8BITS);
594		divisor = siodivisor(rclk, SIO_TEST_SPEED);
595		sio_setreg(com, com_dlbl, divisor & 0xff);
596		sio_setreg(com, com_dlbh, divisor >> 8);
597		sio_setreg(com, com_cfcr, CFCR_8BITS);
598		DELAY((16 + 1) * 1000000 / (SIO_TEST_SPEED / 10));
599	}
600
601	/*
602	 * Enable the interrupt gate and disable device interrupts.  This
603	 * should leave the device driving the interrupt line low and
604	 * guarantee an edge trigger if an interrupt can be generated.
605	 */
606/* EXTRA DELAY? */
607	sio_setreg(com, com_mcr, mcr_image);
608	sio_setreg(com, com_ier, 0);
609	DELAY(1000);		/* XXX */
610	irqmap[0] = isa_irq_pending();
611
612	/*
613	 * Attempt to set loopback mode so that we can send a null byte
614	 * without annoying any external device.
615	 */
616/* EXTRA DELAY? */
617	sio_setreg(com, com_mcr, mcr_image | MCR_LOOPBACK);
618
619	/*
620	 * Attempt to generate an output interrupt.  On 8250's, setting
621	 * IER_ETXRDY generates an interrupt independent of the current
622	 * setting and independent of whether the THR is empty.  On 16450's,
623	 * setting IER_ETXRDY generates an interrupt independent of the
624	 * current setting.  On 16550A's, setting IER_ETXRDY only
625	 * generates an interrupt when IER_ETXRDY is not already set.
626	 */
627	sio_setreg(com, com_ier, IER_ETXRDY);
628
629	/*
630	 * On some 16x50 incompatibles, setting IER_ETXRDY doesn't generate
631	 * an interrupt.  They'd better generate one for actually doing
632	 * output.  Loopback may be broken on the same incompatibles but
633	 * it's unlikely to do more than allow the null byte out.
634	 */
635	sio_setreg(com, com_data, 0);
636	if (iobase == siocniobase)
637		DELAY((1 + 2) * 1000000 / (comdefaultrate / 10));
638	else
639		DELAY((1 + 2) * 1000000 / (SIO_TEST_SPEED / 10));
640
641	/*
642	 * Turn off loopback mode so that the interrupt gate works again
643	 * (MCR_IENABLE was hidden).  This should leave the device driving
644	 * an interrupt line high.  It doesn't matter if the interrupt
645	 * line oscillates while we are not looking at it, since interrupts
646	 * are disabled.
647	 */
648/* EXTRA DELAY? */
649	sio_setreg(com, com_mcr, mcr_image);
650
651	/*
652	 * It seems my Xircom CBEM56G Cardbus modem wants to be reset
653	 * to 8 bits *again*, or else probe test 0 will fail.
654	 * gwk@sgi.com, 4/19/2001
655	 */
656	sio_setreg(com, com_cfcr, CFCR_8BITS);
657
658	/*
659	 * Some PCMCIA cards (Palido 321s, DC-1S, ...) have the "TXRDY bug",
660	 * so we probe for a buggy IIR_TXRDY implementation even in the
661	 * noprobe case.  We don't probe for it in the !noprobe case because
662	 * noprobe is always set for PCMCIA cards and the problem is not
663	 * known to affect any other cards.
664	 */
665	if (noprobe) {
666		/* Read IIR a few times. */
667		for (fn = 0; fn < 2; fn ++) {
668			DELAY(10000);
669			failures[6] = sio_getreg(com, com_iir);
670		}
671
672		/* IIR_TXRDY should be clear.  Is it? */
673		result = 0;
674		if (failures[6] & IIR_TXRDY) {
675			/*
676			 * No.  We seem to have the bug.  Does our fix for
677			 * it work?
678			 */
679			sio_setreg(com, com_ier, 0);
680			if (sio_getreg(com, com_iir) & IIR_NOPEND) {
681				/* Yes.  We discovered the TXRDY bug! */
682				SET_FLAG(dev, COM_C_IIR_TXRDYBUG);
683			} else {
684				/* No.  Just fail.  XXX */
685				result = ENXIO;
686				sio_setreg(com, com_mcr, 0);
687			}
688		} else {
689			/* Yes.  No bug. */
690			CLR_FLAG(dev, COM_C_IIR_TXRDYBUG);
691		}
692		sio_setreg(com, com_ier, 0);
693		sio_setreg(com, com_cfcr, CFCR_8BITS);
694		mtx_unlock_spin(&sio_lock);
695		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
696		if (iobase == siocniobase)
697			result = 0;
698		/*
699		 * XXX: Since we don't return 0, we shouldn't be relying on
700		 * the softc that we set to persist to the call to attach
701		 * since other probe routines may be called, and the malloc
702		 * here causes subr_bus to not allocate anything for the
703		 * other probes.  Instead, this softc is preserved and other
704		 * probe routines can corrupt it.
705		 */
706		if (result != 0) {
707			device_set_softc(dev, NULL);
708			free(com, M_DEVBUF);
709		}
710		return (result == 0 ? BUS_PROBE_DEFAULT + 1 : result);
711	}
712
713	/*
714	 * Check that
715	 *	o the CFCR, IER and MCR in UART hold the values written to them
716	 *	  (the values happen to be all distinct - this is good for
717	 *	  avoiding false positive tests from bus echoes).
718	 *	o an output interrupt is generated and its vector is correct.
719	 *	o the interrupt goes away when the IIR in the UART is read.
720	 */
721/* EXTRA DELAY? */
722	failures[0] = sio_getreg(com, com_cfcr) - CFCR_8BITS;
723	failures[1] = sio_getreg(com, com_ier) - IER_ETXRDY;
724	failures[2] = sio_getreg(com, com_mcr) - mcr_image;
725	DELAY(10000);		/* Some internal modems need this time */
726	irqmap[1] = isa_irq_pending();
727	failures[4] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_TXRDY;
728	DELAY(1000);		/* XXX */
729	irqmap[2] = isa_irq_pending();
730	failures[6] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
731
732	/*
733	 * Turn off all device interrupts and check that they go off properly.
734	 * Leave MCR_IENABLE alone.  For ports without a master port, it gates
735	 * the OUT2 output of the UART to
736	 * the ICU input.  Closing the gate would give a floating ICU input
737	 * (unless there is another device driving it) and spurious interrupts.
738	 * (On the system that this was first tested on, the input floats high
739	 * and gives a (masked) interrupt as soon as the gate is closed.)
740	 */
741	sio_setreg(com, com_ier, 0);
742	sio_setreg(com, com_cfcr, CFCR_8BITS);	/* dummy to avoid bus echo */
743	failures[7] = sio_getreg(com, com_ier);
744	DELAY(1000);		/* XXX */
745	irqmap[3] = isa_irq_pending();
746	failures[9] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
747
748	mtx_unlock_spin(&sio_lock);
749
750	irqs = irqmap[1] & ~irqmap[0];
751	if (bus_get_resource(idev, SYS_RES_IRQ, 0, &xirq, NULL) == 0 &&
752	    ((1 << xirq) & irqs) == 0) {
753		printf(
754		"sio%d: configured irq %ld not in bitmap of probed irqs %#x\n",
755		    device_get_unit(dev), xirq, irqs);
756		printf(
757		"sio%d: port may not be enabled\n",
758		    device_get_unit(dev));
759	}
760	if (bootverbose)
761		printf("sio%d: irq maps: %#x %#x %#x %#x\n",
762		    device_get_unit(dev),
763		    irqmap[0], irqmap[1], irqmap[2], irqmap[3]);
764
765	result = 0;
766	for (fn = 0; fn < sizeof failures; ++fn)
767		if (failures[fn]) {
768			sio_setreg(com, com_mcr, 0);
769			result = ENXIO;
770			if (bootverbose) {
771				printf("sio%d: probe failed test(s):",
772				    device_get_unit(dev));
773				for (fn = 0; fn < sizeof failures; ++fn)
774					if (failures[fn])
775						printf(" %d", fn);
776				printf("\n");
777			}
778			break;
779		}
780	bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
781	if (iobase == siocniobase)
782		result = 0;
783	/*
784	 * XXX: Since we don't return 0, we shouldn't be relying on the softc
785	 * that we set to persist to the call to attach since other probe
786	 * routines may be called, and the malloc here causes subr_bus to not
787	 * allocate anything for the other probes.  Instead, this softc is
788	 * preserved and other probe routines can corrupt it.
789	 */
790	if (result != 0) {
791		device_set_softc(dev, NULL);
792		free(com, M_DEVBUF);
793	}
794	return (result == 0 ? BUS_PROBE_DEFAULT + 1 : result);
795}
796
797#ifdef COM_ESP
798static int
799espattach(com, esp_port)
800	struct com_s		*com;
801	Port_t			esp_port;
802{
803	u_char	dips;
804	u_char	val;
805
806	/*
807	 * Check the ESP-specific I/O port to see if we're an ESP
808	 * card.  If not, return failure immediately.
809	 */
810	if ((inb(esp_port) & 0xf3) == 0) {
811		printf(" port 0x%x is not an ESP board?\n", esp_port);
812		return (0);
813	}
814
815	/*
816	 * We've got something that claims to be a Hayes ESP card.
817	 * Let's hope so.
818	 */
819
820	/* Get the dip-switch configuration */
821	outb(esp_port + ESP_CMD1, ESP_GETDIPS);
822	dips = inb(esp_port + ESP_STATUS1);
823
824	/*
825	 * Bits 0,1 of dips say which COM port we are.
826	 */
827	if (rman_get_start(com->ioportres) == likely_com_ports[dips & 0x03])
828		printf(" : ESP");
829	else {
830		printf(" esp_port has com %d\n", dips & 0x03);
831		return (0);
832	}
833
834	/*
835	 * Check for ESP version 2.0 or later:  bits 4,5,6 = 010.
836	 */
837	outb(esp_port + ESP_CMD1, ESP_GETTEST);
838	val = inb(esp_port + ESP_STATUS1);	/* clear reg 1 */
839	val = inb(esp_port + ESP_STATUS2);
840	if ((val & 0x70) < 0x20) {
841		printf("-old (%o)", val & 0x70);
842		return (0);
843	}
844
845	/*
846	 * Check for ability to emulate 16550:  bit 7 == 1
847	 */
848	if ((dips & 0x80) == 0) {
849		printf(" slave");
850		return (0);
851	}
852
853	/*
854	 * Okay, we seem to be a Hayes ESP card.  Whee.
855	 */
856	com->esp = TRUE;
857	com->esp_port = esp_port;
858	return (1);
859}
860#endif /* COM_ESP */
861
862int
863sioattach(dev, xrid, rclk)
864	device_t	dev;
865	int		xrid;
866	u_long		rclk;
867{
868	struct com_s	*com;
869#ifdef COM_ESP
870	Port_t		*espp;
871#endif
872	Port_t		iobase;
873	int		unit;
874	u_int		flags;
875	int		rid;
876	struct resource *port;
877	int		ret;
878	int		error;
879	struct tty	*tp;
880
881	rid = xrid;
882	port = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid,
883				  0, ~0, IO_COMSIZE, RF_ACTIVE);
884	if (!port)
885		return (ENXIO);
886
887	iobase = rman_get_start(port);
888	unit = device_get_unit(dev);
889	com = device_get_softc(dev);
890	flags = device_get_flags(dev);
891
892	if (unit >= sio_numunits)
893		sio_numunits = unit + 1;
894	/*
895	 * sioprobe() has initialized the device registers as follows:
896	 *	o cfcr = CFCR_8BITS.
897	 *	  It is most important that CFCR_DLAB is off, so that the
898	 *	  data port is not hidden when we enable interrupts.
899	 *	o ier = 0.
900	 *	  Interrupts are only enabled when the line is open.
901	 *	o mcr = MCR_IENABLE, or 0 if the port has AST/4 compatible
902	 *	  interrupt control register or the config specifies no irq.
903	 *	  Keeping MCR_DTR and MCR_RTS off might stop the external
904	 *	  device from sending before we are ready.
905	 */
906	bzero(com, sizeof *com);
907	com->unit = unit;
908	com->ioportres = port;
909	com->ioportrid = rid;
910	com->bst = rman_get_bustag(port);
911	com->bsh = rman_get_bushandle(port);
912	com->cfcr_image = CFCR_8BITS;
913	com->loses_outints = COM_LOSESOUTINTS(flags) != 0;
914	com->no_irq = bus_get_resource(dev, SYS_RES_IRQ, 0, NULL, NULL) != 0;
915	com->tx_fifo_size = 1;
916	com->obufs[0].l_head = com->obuf1;
917	com->obufs[1].l_head = com->obuf2;
918
919	com->data_port = iobase + com_data;
920	com->int_ctl_port = iobase + com_ier;
921	com->int_id_port = iobase + com_iir;
922	com->modem_ctl_port = iobase + com_mcr;
923	com->mcr_image = inb(com->modem_ctl_port);
924	com->line_status_port = iobase + com_lsr;
925	com->modem_status_port = iobase + com_msr;
926
927	tp = com->tp = ttyalloc();
928	tp->t_oproc = comstart;
929	tp->t_param = comparam;
930	tp->t_stop = comstop;
931	tp->t_modem = commodem;
932	tp->t_break = combreak;
933	tp->t_close = comclose;
934	tp->t_open = comopen;
935	tp->t_sc = com;
936
937	if (rclk == 0)
938		rclk = DEFAULT_RCLK;
939	com->rclk = rclk;
940
941	if (unit == comconsole)
942		ttyconsolemode(tp, comdefaultrate);
943	error = siosetwater(com, tp->t_init_in.c_ispeed);
944	mtx_unlock_spin(&sio_lock);
945	if (error) {
946		/*
947		 * Leave i/o resources allocated if this is a `cn'-level
948		 * console, so that other devices can't snarf them.
949		 */
950		if (iobase != siocniobase)
951			bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
952		return (ENOMEM);
953	}
954
955	/* attempt to determine UART type */
956	printf("sio%d: type", unit);
957
958	if (!COM_ISMULTIPORT(flags) &&
959	    !COM_IIR_TXRDYBUG(flags) && !COM_NOSCR(flags)) {
960		u_char	scr;
961		u_char	scr1;
962		u_char	scr2;
963
964		scr = sio_getreg(com, com_scr);
965		sio_setreg(com, com_scr, 0xa5);
966		scr1 = sio_getreg(com, com_scr);
967		sio_setreg(com, com_scr, 0x5a);
968		scr2 = sio_getreg(com, com_scr);
969		sio_setreg(com, com_scr, scr);
970		if (scr1 != 0xa5 || scr2 != 0x5a) {
971			printf(" 8250 or not responding");
972			goto determined_type;
973		}
974	}
975	sio_setreg(com, com_fifo, FIFO_ENABLE | FIFO_RX_HIGH);
976	DELAY(100);
977	switch (inb(com->int_id_port) & IIR_FIFO_MASK) {
978	case FIFO_RX_LOW:
979		printf(" 16450");
980		break;
981	case FIFO_RX_MEDL:
982		printf(" 16450?");
983		break;
984	case FIFO_RX_MEDH:
985		printf(" 16550?");
986		break;
987	case FIFO_RX_HIGH:
988		if (COM_NOFIFO(flags)) {
989			printf(" 16550A fifo disabled");
990			break;
991		}
992		com->hasfifo = TRUE;
993		if (COM_ST16650A(flags)) {
994			printf(" ST16650A");
995			com->st16650a = TRUE;
996			com->tx_fifo_size = 32;
997			break;
998		}
999		if (COM_TI16754(flags)) {
1000			printf(" TI16754");
1001			com->tx_fifo_size = 64;
1002			break;
1003		}
1004		printf(" 16550A");
1005#ifdef COM_ESP
1006		for (espp = likely_esp_ports; *espp != 0; espp++)
1007			if (espattach(com, *espp)) {
1008				com->tx_fifo_size = 1024;
1009				break;
1010			}
1011		if (com->esp)
1012			break;
1013#endif
1014		com->tx_fifo_size = COM_FIFOSIZE(flags);
1015		if (com->tx_fifo_size == 0)
1016			com->tx_fifo_size = 16;
1017		else
1018			printf(" lookalike with %u bytes FIFO",
1019			       com->tx_fifo_size);
1020		break;
1021	}
1022#ifdef COM_ESP
1023	if (com->esp) {
1024		/*
1025		 * Set 16550 compatibility mode.
1026		 * We don't use the ESP_MODE_SCALE bit to increase the
1027		 * fifo trigger levels because we can't handle large
1028		 * bursts of input.
1029		 * XXX flow control should be set in comparam(), not here.
1030		 */
1031		outb(com->esp_port + ESP_CMD1, ESP_SETMODE);
1032		outb(com->esp_port + ESP_CMD2, ESP_MODE_RTS | ESP_MODE_FIFO);
1033
1034		/* Set RTS/CTS flow control. */
1035		outb(com->esp_port + ESP_CMD1, ESP_SETFLOWTYPE);
1036		outb(com->esp_port + ESP_CMD2, ESP_FLOW_RTS);
1037		outb(com->esp_port + ESP_CMD2, ESP_FLOW_CTS);
1038
1039		/* Set flow-control levels. */
1040		outb(com->esp_port + ESP_CMD1, ESP_SETRXFLOW);
1041		outb(com->esp_port + ESP_CMD2, HIBYTE(768));
1042		outb(com->esp_port + ESP_CMD2, LOBYTE(768));
1043		outb(com->esp_port + ESP_CMD2, HIBYTE(512));
1044		outb(com->esp_port + ESP_CMD2, LOBYTE(512));
1045	}
1046#endif /* COM_ESP */
1047	sio_setreg(com, com_fifo, 0);
1048determined_type: ;
1049
1050#ifdef COM_MULTIPORT
1051	if (COM_ISMULTIPORT(flags)) {
1052		device_t masterdev;
1053
1054		com->multiport = TRUE;
1055		printf(" (multiport");
1056		if (unit == COM_MPMASTER(flags))
1057			printf(" master");
1058		printf(")");
1059		masterdev = devclass_get_device(sio_devclass,
1060		    COM_MPMASTER(flags));
1061		com->no_irq = (masterdev == NULL || bus_get_resource(masterdev,
1062		    SYS_RES_IRQ, 0, NULL, NULL) != 0);
1063	 }
1064#endif /* COM_MULTIPORT */
1065	if (unit == comconsole)
1066		printf(", console");
1067	if (COM_IIR_TXRDYBUG(flags))
1068		printf(" with a buggy IIR_TXRDY implementation");
1069	printf("\n");
1070
1071	if (sio_fast_ih == NULL) {
1072		swi_add(&tty_intr_event, "sio", siopoll, NULL, SWI_TTY, 0,
1073		    &sio_fast_ih);
1074		swi_add(&clk_intr_event, "sio", siopoll, NULL, SWI_CLOCK, 0,
1075		    &sio_slow_ih);
1076	}
1077
1078	com->flags = flags;
1079	com->pps.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1080	tp->t_pps = &com->pps;
1081
1082	if (COM_PPSCTS(flags))
1083		com->pps_bit = MSR_CTS;
1084	else
1085		com->pps_bit = MSR_DCD;
1086	pps_init(&com->pps);
1087
1088	rid = 0;
1089	com->irqres = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
1090	if (com->irqres) {
1091		ret = bus_setup_intr(dev, com->irqres,
1092				     INTR_TYPE_TTY,
1093				     siointr, NULL, com,
1094				     &com->cookie);
1095		if (ret) {
1096			ret = bus_setup_intr(dev,
1097					     com->irqres, INTR_TYPE_TTY,
1098					     NULL, (driver_intr_t *)siointr, com, &com->cookie);
1099			if (ret == 0)
1100				device_printf(dev, "unable to activate interrupt in fast mode - using normal mode\n");
1101		}
1102		if (ret)
1103			device_printf(dev, "could not activate interrupt\n");
1104#if defined(KDB)
1105		/*
1106		 * Enable interrupts for early break-to-debugger support
1107		 * on the console.
1108		 */
1109		if (ret == 0 && unit == comconsole)
1110			outb(siocniobase + com_ier, IER_ERXRDY | IER_ERLS |
1111			    IER_EMSC);
1112#endif
1113	}
1114
1115	/* We're ready, open the doors... */
1116	ttycreate(tp, TS_CALLOUT, "d%r", unit);
1117
1118	return (0);
1119}
1120
1121static int
1122comopen(struct tty *tp, struct cdev *dev)
1123{
1124	struct com_s	*com;
1125	int i;
1126
1127	com = tp->t_sc;
1128	com->poll = com->no_irq;
1129	com->poll_output = com->loses_outints;
1130	if (com->hasfifo) {
1131		/*
1132		 * (Re)enable and drain fifos.
1133		 *
1134		 * Certain SMC chips cause problems if the fifos
1135		 * are enabled while input is ready.  Turn off the
1136		 * fifo if necessary to clear the input.  We test
1137		 * the input ready bit after enabling the fifos
1138		 * since we've already enabled them in comparam()
1139		 * and to handle races between enabling and fresh
1140		 * input.
1141		 */
1142		for (i = 0; i < 500; i++) {
1143			sio_setreg(com, com_fifo,
1144				   FIFO_RCV_RST | FIFO_XMT_RST
1145				   | com->fifo_image);
1146			/*
1147			 * XXX the delays are for superstitious
1148			 * historical reasons.  It must be less than
1149			 * the character time at the maximum
1150			 * supported speed (87 usec at 115200 bps
1151			 * 8N1).  Otherwise we might loop endlessly
1152			 * if data is streaming in.  We used to use
1153			 * delays of 100.  That usually worked
1154			 * because DELAY(100) used to usually delay
1155			 * for about 85 usec instead of 100.
1156			 */
1157			DELAY(50);
1158			if (!(inb(com->line_status_port) & LSR_RXRDY))
1159				break;
1160			sio_setreg(com, com_fifo, 0);
1161			DELAY(50);
1162			(void) inb(com->data_port);
1163		}
1164		if (i == 500)
1165			return (EIO);
1166	}
1167
1168	mtx_lock_spin(&sio_lock);
1169	(void) inb(com->line_status_port);
1170	(void) inb(com->data_port);
1171	com->prev_modem_status = com->last_modem_status
1172	    = inb(com->modem_status_port);
1173	outb(com->int_ctl_port,
1174	     IER_ERXRDY | IER_ERLS | IER_EMSC
1175	     | (COM_IIR_TXRDYBUG(com->flags) ? 0 : IER_ETXRDY));
1176	mtx_unlock_spin(&sio_lock);
1177	siosettimeout();
1178	/* XXX: should be generic ? */
1179	if (com->prev_modem_status & MSR_DCD || ISCALLOUT(dev))
1180		ttyld_modem(tp, 1);
1181	return (0);
1182}
1183
1184static void
1185comclose(tp)
1186	struct tty	*tp;
1187{
1188	int		s;
1189	struct com_s	*com;
1190
1191	s = spltty();
1192	com = tp->t_sc;
1193	com->poll = FALSE;
1194	com->poll_output = FALSE;
1195	sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1196
1197#if defined(KDB)
1198	/*
1199	 * Leave interrupts enabled and don't clear DTR if this is the
1200	 * console. This allows us to detect break-to-debugger events
1201	 * while the console device is closed.
1202	 */
1203	if (com->unit != comconsole)
1204#endif
1205	{
1206		sio_setreg(com, com_ier, 0);
1207		if (tp->t_cflag & HUPCL
1208		    /*
1209		     * XXX we will miss any carrier drop between here and the
1210		     * next open.  Perhaps we should watch DCD even when the
1211		     * port is closed; it is not sufficient to check it at
1212		     * the next open because it might go up and down while
1213		     * we're not watching.
1214		     */
1215		    || (!tp->t_actout
1216		        && !(com->prev_modem_status & MSR_DCD)
1217		        && !(tp->t_init_in.c_cflag & CLOCAL))
1218		    || !(tp->t_state & TS_ISOPEN)) {
1219			(void)commodem(tp, 0, SER_DTR);
1220			ttydtrwaitstart(tp);
1221		}
1222	}
1223	if (com->hasfifo) {
1224		/*
1225		 * Disable fifos so that they are off after controlled
1226		 * reboots.  Some BIOSes fail to detect 16550s when the
1227		 * fifos are enabled.
1228		 */
1229		sio_setreg(com, com_fifo, 0);
1230	}
1231	tp->t_actout = FALSE;
1232	wakeup(&tp->t_actout);
1233	wakeup(TSA_CARR_ON(tp));	/* restart any wopeners */
1234	siosettimeout();
1235	splx(s);
1236}
1237
1238static void
1239siobusycheck(chan)
1240	void	*chan;
1241{
1242	struct com_s	*com;
1243	int		s;
1244
1245	com = (struct com_s *)chan;
1246
1247	/*
1248	 * Clear TS_BUSY if low-level output is complete.
1249	 * spl locking is sufficient because siointr1() does not set CS_BUSY.
1250	 * If siointr1() clears CS_BUSY after we look at it, then we'll get
1251	 * called again.  Reading the line status port outside of siointr1()
1252	 * is safe because CS_BUSY is clear so there are no output interrupts
1253	 * to lose.
1254	 */
1255	s = spltty();
1256	if (com->state & CS_BUSY)
1257		com->extra_state &= ~CSE_BUSYCHECK;	/* False alarm. */
1258	else if ((inb(com->line_status_port) & (LSR_TSRE | LSR_TXRDY))
1259	    == (LSR_TSRE | LSR_TXRDY)) {
1260		com->tp->t_state &= ~TS_BUSY;
1261		ttwwakeup(com->tp);
1262		com->extra_state &= ~CSE_BUSYCHECK;
1263	} else
1264		timeout(siobusycheck, com, hz / 100);
1265	splx(s);
1266}
1267
1268static u_int
1269siodivisor(rclk, speed)
1270	u_long	rclk;
1271	speed_t	speed;
1272{
1273	long	actual_speed;
1274	u_int	divisor;
1275	int	error;
1276
1277	if (speed == 0)
1278		return (0);
1279#if UINT_MAX > (ULONG_MAX - 1) / 8
1280	if (speed > (ULONG_MAX - 1) / 8)
1281		return (0);
1282#endif
1283	divisor = (rclk / (8UL * speed) + 1) / 2;
1284	if (divisor == 0 || divisor >= 65536)
1285		return (0);
1286	actual_speed = rclk / (16UL * divisor);
1287
1288	/* 10 times error in percent: */
1289	error = ((actual_speed - (long)speed) * 2000 / (long)speed + 1) / 2;
1290
1291	/* 3.0% maximum error tolerance: */
1292	if (error < -30 || error > 30)
1293		return (0);
1294
1295	return (divisor);
1296}
1297
1298/*
1299 * Call this function with the sio_lock mutex held.  It will return with the
1300 * lock still held.
1301 */
1302static void
1303sioinput(com)
1304	struct com_s	*com;
1305{
1306	u_char		*buf;
1307	int		incc;
1308	u_char		line_status;
1309	int		recv_data;
1310	struct tty	*tp;
1311
1312	buf = com->ibuf;
1313	tp = com->tp;
1314	if (!(tp->t_state & TS_ISOPEN) || !(tp->t_cflag & CREAD)) {
1315		com_events -= (com->iptr - com->ibuf);
1316		com->iptr = com->ibuf;
1317		return;
1318	}
1319	if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
1320		/*
1321		 * Avoid the grotesquely inefficient lineswitch routine
1322		 * (ttyinput) in "raw" mode.  It usually takes about 450
1323		 * instructions (that's without canonical processing or echo!).
1324		 * slinput is reasonably fast (usually 40 instructions plus
1325		 * call overhead).
1326		 */
1327		do {
1328			/*
1329			 * This may look odd, but it is using save-and-enable
1330			 * semantics instead of the save-and-disable semantics
1331			 * that are used everywhere else.
1332			 */
1333			mtx_unlock_spin(&sio_lock);
1334			incc = com->iptr - buf;
1335			if (tp->t_rawq.c_cc + incc > tp->t_ihiwat
1336			    && (com->state & CS_RTS_IFLOW
1337				|| tp->t_iflag & IXOFF)
1338			    && !(tp->t_state & TS_TBLOCK))
1339				ttyblock(tp);
1340			com->delta_error_counts[CE_TTY_BUF_OVERFLOW]
1341				+= b_to_q((char *)buf, incc, &tp->t_rawq);
1342			buf += incc;
1343			tk_nin += incc;
1344			tk_rawcc += incc;
1345			tp->t_rawcc += incc;
1346			ttwakeup(tp);
1347			if (tp->t_state & TS_TTSTOP
1348			    && (tp->t_iflag & IXANY
1349				|| tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
1350				tp->t_state &= ~TS_TTSTOP;
1351				tp->t_lflag &= ~FLUSHO;
1352				comstart(tp);
1353			}
1354			mtx_lock_spin(&sio_lock);
1355		} while (buf < com->iptr);
1356	} else {
1357		do {
1358			/*
1359			 * This may look odd, but it is using save-and-enable
1360			 * semantics instead of the save-and-disable semantics
1361			 * that are used everywhere else.
1362			 */
1363			mtx_unlock_spin(&sio_lock);
1364			line_status = buf[com->ierroff];
1365			recv_data = *buf++;
1366			if (line_status
1367			    & (LSR_BI | LSR_FE | LSR_OE | LSR_PE)) {
1368				if (line_status & LSR_BI)
1369					recv_data |= TTY_BI;
1370				if (line_status & LSR_FE)
1371					recv_data |= TTY_FE;
1372				if (line_status & LSR_OE)
1373					recv_data |= TTY_OE;
1374				if (line_status & LSR_PE)
1375					recv_data |= TTY_PE;
1376			}
1377			ttyld_rint(tp, recv_data);
1378			mtx_lock_spin(&sio_lock);
1379		} while (buf < com->iptr);
1380	}
1381	com_events -= (com->iptr - com->ibuf);
1382	com->iptr = com->ibuf;
1383
1384	/*
1385	 * There is now room for another low-level buffer full of input,
1386	 * so enable RTS if it is now disabled and there is room in the
1387	 * high-level buffer.
1388	 */
1389	if ((com->state & CS_RTS_IFLOW) && !(com->mcr_image & MCR_RTS) &&
1390	    !(tp->t_state & TS_TBLOCK))
1391		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1392}
1393
1394static int
1395siointr(arg)
1396	void		*arg;
1397{
1398	struct com_s	*com;
1399
1400#ifndef COM_MULTIPORT
1401	com = (struct com_s *)arg;
1402
1403	mtx_lock_spin(&sio_lock);
1404	siointr1(com);
1405	mtx_unlock_spin(&sio_lock);
1406#else /* COM_MULTIPORT */
1407	bool_t		possibly_more_intrs;
1408	int		unit;
1409
1410	/*
1411	 * Loop until there is no activity on any port.  This is necessary
1412	 * to get an interrupt edge more than to avoid another interrupt.
1413	 * If the IRQ signal is just an OR of the IRQ signals from several
1414	 * devices, then the edge from one may be lost because another is
1415	 * on.
1416	 */
1417	mtx_lock_spin(&sio_lock);
1418	do {
1419		possibly_more_intrs = FALSE;
1420		for (unit = 0; unit < sio_numunits; ++unit) {
1421			com = com_addr(unit);
1422			/*
1423			 * XXX COM_LOCK();
1424			 * would it work here, or be counter-productive?
1425			 */
1426			if (com != NULL
1427			    && !com->gone
1428			    && (inb(com->int_id_port) & IIR_IMASK)
1429			       != IIR_NOPEND) {
1430				siointr1(com);
1431				possibly_more_intrs = TRUE;
1432			}
1433			/* XXX COM_UNLOCK(); */
1434		}
1435	} while (possibly_more_intrs);
1436	mtx_unlock_spin(&sio_lock);
1437#endif /* COM_MULTIPORT */
1438	return(FILTER_HANDLED);
1439}
1440
1441static struct timespec siots[8];
1442static int siotso;
1443static int volatile siotsunit = -1;
1444
1445static int
1446sysctl_siots(SYSCTL_HANDLER_ARGS)
1447{
1448	char buf[128];
1449	long long delta;
1450	size_t len;
1451	int error, i, tso;
1452
1453	for (i = 1, tso = siotso; i < tso; i++) {
1454		delta = (long long)(siots[i].tv_sec - siots[i - 1].tv_sec) *
1455		    1000000000 +
1456		    (siots[i].tv_nsec - siots[i - 1].tv_nsec);
1457		len = sprintf(buf, "%lld\n", delta);
1458		if (delta >= 110000)
1459			len += sprintf(buf + len - 1, ": *** %ld.%09ld\n",
1460			    (long)siots[i].tv_sec, siots[i].tv_nsec) - 1;
1461		if (i == tso - 1)
1462			buf[len - 1] = '\0';
1463		error = SYSCTL_OUT(req, buf, len);
1464		if (error != 0)
1465			return (error);
1466	}
1467	return (0);
1468}
1469
1470SYSCTL_PROC(_machdep, OID_AUTO, siots, CTLTYPE_STRING | CTLFLAG_RD,
1471    0, 0, sysctl_siots, "A", "sio timestamps");
1472
1473static void
1474siointr1(com)
1475	struct com_s	*com;
1476{
1477	u_char	int_ctl;
1478	u_char	int_ctl_new;
1479	u_char	line_status;
1480	u_char	modem_status;
1481	u_char	*ioptr;
1482	u_char	recv_data;
1483
1484#ifdef KDB
1485again:
1486#endif
1487
1488	if (COM_IIR_TXRDYBUG(com->flags)) {
1489		int_ctl = inb(com->int_ctl_port);
1490		int_ctl_new = int_ctl;
1491	} else {
1492		int_ctl = 0;
1493		int_ctl_new = 0;
1494	}
1495
1496	while (!com->gone) {
1497		if (com->pps.ppsparam.mode & PPS_CAPTUREBOTH) {
1498			modem_status = inb(com->modem_status_port);
1499		        if ((modem_status ^ com->last_modem_status) &
1500			    com->pps_bit) {
1501				pps_capture(&com->pps);
1502				pps_event(&com->pps,
1503				    (modem_status & com->pps_bit) ?
1504				    PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
1505			}
1506		}
1507		line_status = inb(com->line_status_port);
1508
1509		/* input event? (check first to help avoid overruns) */
1510		while (line_status & LSR_RCV_MASK) {
1511			/* break/unnattached error bits or real input? */
1512			if (!(line_status & LSR_RXRDY))
1513				recv_data = 0;
1514			else
1515				recv_data = inb(com->data_port);
1516#ifdef KDB
1517			if (com->unit == comconsole &&
1518			    kdb_alt_break(recv_data, &com->alt_brk_state) != 0)
1519				goto again;
1520#endif /* KDB */
1521			if (line_status & (LSR_BI | LSR_FE | LSR_PE)) {
1522				/*
1523				 * Don't store BI if IGNBRK or FE/PE if IGNPAR.
1524				 * Otherwise, push the work to a higher level
1525				 * (to handle PARMRK) if we're bypassing.
1526				 * Otherwise, convert BI/FE and PE+INPCK to 0.
1527				 *
1528				 * This makes bypassing work right in the
1529				 * usual "raw" case (IGNBRK set, and IGNPAR
1530				 * and INPCK clear).
1531				 *
1532				 * Note: BI together with FE/PE means just BI.
1533				 */
1534				if (line_status & LSR_BI) {
1535#if defined(KDB)
1536					if (com->unit == comconsole) {
1537						kdb_break();
1538						goto cont;
1539					}
1540#endif
1541					if (com->tp == NULL
1542					    || com->tp->t_iflag & IGNBRK)
1543						goto cont;
1544				} else {
1545					if (com->tp == NULL
1546					    || com->tp->t_iflag & IGNPAR)
1547						goto cont;
1548				}
1549				if (com->tp->t_state & TS_CAN_BYPASS_L_RINT
1550				    && (line_status & (LSR_BI | LSR_FE)
1551					|| com->tp->t_iflag & INPCK))
1552					recv_data = 0;
1553			}
1554			++com->bytes_in;
1555			if (com->tp != NULL &&
1556			    com->tp->t_hotchar != 0 && recv_data == com->tp->t_hotchar)
1557				swi_sched(sio_fast_ih, 0);
1558			ioptr = com->iptr;
1559			if (ioptr >= com->ibufend)
1560				CE_RECORD(com, CE_INTERRUPT_BUF_OVERFLOW);
1561			else {
1562				if (com->tp != NULL && com->tp->t_do_timestamp)
1563					microtime(&com->tp->t_timestamp);
1564				++com_events;
1565				swi_sched(sio_slow_ih, SWI_DELAY);
1566#if 0 /* for testing input latency vs efficiency */
1567if (com->iptr - com->ibuf == 8)
1568	swi_sched(sio_fast_ih, 0);
1569#endif
1570				ioptr[0] = recv_data;
1571				ioptr[com->ierroff] = line_status;
1572				com->iptr = ++ioptr;
1573				if (ioptr == com->ihighwater
1574				    && com->state & CS_RTS_IFLOW)
1575					outb(com->modem_ctl_port,
1576					     com->mcr_image &= ~MCR_RTS);
1577				if (line_status & LSR_OE)
1578					CE_RECORD(com, CE_OVERRUN);
1579			}
1580cont:
1581			if (line_status & LSR_TXRDY
1582			    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY))
1583				goto txrdy;
1584
1585			/*
1586			 * "& 0x7F" is to avoid the gcc-1.40 generating a slow
1587			 * jump from the top of the loop to here
1588			 */
1589			line_status = inb(com->line_status_port) & 0x7F;
1590		}
1591
1592		/* modem status change? (always check before doing output) */
1593		modem_status = inb(com->modem_status_port);
1594		if (modem_status != com->last_modem_status) {
1595			/*
1596			 * Schedule high level to handle DCD changes.  Note
1597			 * that we don't use the delta bits anywhere.  Some
1598			 * UARTs mess them up, and it's easy to remember the
1599			 * previous bits and calculate the delta.
1600			 */
1601			com->last_modem_status = modem_status;
1602			if (!(com->state & CS_CHECKMSR)) {
1603				com_events += LOTS_OF_EVENTS;
1604				com->state |= CS_CHECKMSR;
1605				swi_sched(sio_fast_ih, 0);
1606			}
1607
1608			/* handle CTS change immediately for crisp flow ctl */
1609			if (com->state & CS_CTS_OFLOW) {
1610				if (modem_status & MSR_CTS)
1611					com->state |= CS_ODEVREADY;
1612				else
1613					com->state &= ~CS_ODEVREADY;
1614			}
1615		}
1616
1617txrdy:
1618		/* output queued and everything ready? */
1619		if (line_status & LSR_TXRDY
1620		    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY)) {
1621			ioptr = com->obufq.l_head;
1622			if (com->tx_fifo_size > 1 && com->unit != siotsunit) {
1623				u_int	ocount;
1624
1625				ocount = com->obufq.l_tail - ioptr;
1626				if (ocount > com->tx_fifo_size)
1627					ocount = com->tx_fifo_size;
1628				com->bytes_out += ocount;
1629				do
1630					outb(com->data_port, *ioptr++);
1631				while (--ocount != 0);
1632			} else {
1633				outb(com->data_port, *ioptr++);
1634				++com->bytes_out;
1635				if (com->unit == siotsunit
1636				    && siotso < sizeof siots / sizeof siots[0])
1637					nanouptime(&siots[siotso++]);
1638			}
1639			com->obufq.l_head = ioptr;
1640			if (COM_IIR_TXRDYBUG(com->flags))
1641				int_ctl_new = int_ctl | IER_ETXRDY;
1642			if (ioptr >= com->obufq.l_tail) {
1643				struct lbq	*qp;
1644
1645				qp = com->obufq.l_next;
1646				qp->l_queued = FALSE;
1647				qp = qp->l_next;
1648				if (qp != NULL) {
1649					com->obufq.l_head = qp->l_head;
1650					com->obufq.l_tail = qp->l_tail;
1651					com->obufq.l_next = qp;
1652				} else {
1653					/* output just completed */
1654					if (COM_IIR_TXRDYBUG(com->flags))
1655						int_ctl_new = int_ctl
1656							      & ~IER_ETXRDY;
1657					com->state &= ~CS_BUSY;
1658				}
1659				if (!(com->state & CS_ODONE)) {
1660					com_events += LOTS_OF_EVENTS;
1661					com->state |= CS_ODONE;
1662					/* handle at high level ASAP */
1663					swi_sched(sio_fast_ih, 0);
1664				}
1665			}
1666			if (COM_IIR_TXRDYBUG(com->flags)
1667			    && int_ctl != int_ctl_new)
1668				outb(com->int_ctl_port, int_ctl_new);
1669		}
1670
1671		/* finished? */
1672#ifndef COM_MULTIPORT
1673		if ((inb(com->int_id_port) & IIR_IMASK) == IIR_NOPEND)
1674#endif /* COM_MULTIPORT */
1675			return;
1676	}
1677}
1678
1679/* software interrupt handler for SWI_TTY */
1680static void
1681siopoll(void *dummy)
1682{
1683	int		unit;
1684
1685	if (com_events == 0)
1686		return;
1687repeat:
1688	for (unit = 0; unit < sio_numunits; ++unit) {
1689		struct com_s	*com;
1690		int		incc;
1691		struct tty	*tp;
1692
1693		com = com_addr(unit);
1694		if (com == NULL)
1695			continue;
1696		tp = com->tp;
1697		if (tp == NULL || com->gone) {
1698			/*
1699			 * Discard any events related to never-opened or
1700			 * going-away devices.
1701			 */
1702			mtx_lock_spin(&sio_lock);
1703			incc = com->iptr - com->ibuf;
1704			com->iptr = com->ibuf;
1705			if (com->state & CS_CHECKMSR) {
1706				incc += LOTS_OF_EVENTS;
1707				com->state &= ~CS_CHECKMSR;
1708			}
1709			com_events -= incc;
1710			mtx_unlock_spin(&sio_lock);
1711			continue;
1712		}
1713		if (com->iptr != com->ibuf) {
1714			mtx_lock_spin(&sio_lock);
1715			sioinput(com);
1716			mtx_unlock_spin(&sio_lock);
1717		}
1718		if (com->state & CS_CHECKMSR) {
1719			u_char	delta_modem_status;
1720
1721			mtx_lock_spin(&sio_lock);
1722			delta_modem_status = com->last_modem_status
1723					     ^ com->prev_modem_status;
1724			com->prev_modem_status = com->last_modem_status;
1725			com_events -= LOTS_OF_EVENTS;
1726			com->state &= ~CS_CHECKMSR;
1727			mtx_unlock_spin(&sio_lock);
1728			if (delta_modem_status & MSR_DCD)
1729				ttyld_modem(tp,
1730				    com->prev_modem_status & MSR_DCD);
1731		}
1732		if (com->state & CS_ODONE) {
1733			mtx_lock_spin(&sio_lock);
1734			com_events -= LOTS_OF_EVENTS;
1735			com->state &= ~CS_ODONE;
1736			mtx_unlock_spin(&sio_lock);
1737			if (!(com->state & CS_BUSY)
1738			    && !(com->extra_state & CSE_BUSYCHECK)) {
1739				timeout(siobusycheck, com, hz / 100);
1740				com->extra_state |= CSE_BUSYCHECK;
1741			}
1742			ttyld_start(tp);
1743		}
1744		if (com_events == 0)
1745			break;
1746	}
1747	if (com_events >= LOTS_OF_EVENTS)
1748		goto repeat;
1749}
1750
1751static void
1752combreak(tp, sig)
1753	struct tty 	*tp;
1754	int		sig;
1755{
1756	struct com_s	*com;
1757
1758	com = tp->t_sc;
1759
1760	if (sig)
1761		sio_setreg(com, com_cfcr, com->cfcr_image |= CFCR_SBREAK);
1762	else
1763		sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1764}
1765
1766static int
1767comparam(tp, t)
1768	struct tty	*tp;
1769	struct termios	*t;
1770{
1771	u_int		cfcr;
1772	int		cflag;
1773	struct com_s	*com;
1774	u_int		divisor;
1775	u_char		dlbh;
1776	u_char		dlbl;
1777	u_char		efr_flowbits;
1778	int		s;
1779
1780	com = tp->t_sc;
1781	if (com == NULL)
1782		return (ENODEV);
1783
1784	/* check requested parameters */
1785	if (t->c_ispeed != (t->c_ospeed != 0 ? t->c_ospeed : tp->t_ospeed))
1786		return (EINVAL);
1787	divisor = siodivisor(com->rclk, t->c_ispeed);
1788	if (divisor == 0)
1789		return (EINVAL);
1790
1791	/* parameters are OK, convert them to the com struct and the device */
1792	s = spltty();
1793	if (t->c_ospeed == 0)
1794		(void)commodem(tp, 0, SER_DTR);	/* hang up line */
1795	else
1796		(void)commodem(tp, SER_DTR, 0);
1797	cflag = t->c_cflag;
1798	switch (cflag & CSIZE) {
1799	case CS5:
1800		cfcr = CFCR_5BITS;
1801		break;
1802	case CS6:
1803		cfcr = CFCR_6BITS;
1804		break;
1805	case CS7:
1806		cfcr = CFCR_7BITS;
1807		break;
1808	default:
1809		cfcr = CFCR_8BITS;
1810		break;
1811	}
1812	if (cflag & PARENB) {
1813		cfcr |= CFCR_PENAB;
1814		if (!(cflag & PARODD))
1815			cfcr |= CFCR_PEVEN;
1816	}
1817	if (cflag & CSTOPB)
1818		cfcr |= CFCR_STOPB;
1819
1820	if (com->hasfifo) {
1821		/*
1822		 * Use a fifo trigger level low enough so that the input
1823		 * latency from the fifo is less than about 16 msec and
1824		 * the total latency is less than about 30 msec.  These
1825		 * latencies are reasonable for humans.  Serial comms
1826		 * protocols shouldn't expect anything better since modem
1827		 * latencies are larger.
1828		 *
1829		 * The fifo trigger level cannot be set at RX_HIGH for high
1830		 * speed connections without further work on reducing
1831		 * interrupt disablement times in other parts of the system,
1832		 * without producing silo overflow errors.
1833		 */
1834		com->fifo_image = com->unit == siotsunit ? 0
1835				  : t->c_ispeed <= 4800
1836				  ? FIFO_ENABLE : FIFO_ENABLE | FIFO_RX_MEDH;
1837#ifdef COM_ESP
1838		/*
1839		 * The Hayes ESP card needs the fifo DMA mode bit set
1840		 * in compatibility mode.  If not, it will interrupt
1841		 * for each character received.
1842		 */
1843		if (com->esp)
1844			com->fifo_image |= FIFO_DMA_MODE;
1845#endif
1846		sio_setreg(com, com_fifo, com->fifo_image);
1847	}
1848
1849	/*
1850	 * This returns with interrupts disabled so that we can complete
1851	 * the speed change atomically.  Keeping interrupts disabled is
1852	 * especially important while com_data is hidden.
1853	 */
1854	(void) siosetwater(com, t->c_ispeed);
1855
1856	sio_setreg(com, com_cfcr, cfcr | CFCR_DLAB);
1857	/*
1858	 * Only set the divisor registers if they would change, since on
1859	 * some 16550 incompatibles (UMC8669F), setting them while input
1860	 * is arriving loses sync until data stops arriving.
1861	 */
1862	dlbl = divisor & 0xFF;
1863	if (sio_getreg(com, com_dlbl) != dlbl)
1864		sio_setreg(com, com_dlbl, dlbl);
1865	dlbh = divisor >> 8;
1866	if (sio_getreg(com, com_dlbh) != dlbh)
1867		sio_setreg(com, com_dlbh, dlbh);
1868
1869	efr_flowbits = 0;
1870
1871	if (cflag & CRTS_IFLOW) {
1872		com->state |= CS_RTS_IFLOW;
1873		efr_flowbits |= EFR_AUTORTS;
1874		/*
1875		 * If CS_RTS_IFLOW just changed from off to on, the change
1876		 * needs to be propagated to MCR_RTS.  This isn't urgent,
1877		 * so do it later by calling comstart() instead of repeating
1878		 * a lot of code from comstart() here.
1879		 */
1880	} else if (com->state & CS_RTS_IFLOW) {
1881		com->state &= ~CS_RTS_IFLOW;
1882		/*
1883		 * CS_RTS_IFLOW just changed from on to off.  Force MCR_RTS
1884		 * on here, since comstart() won't do it later.
1885		 */
1886		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1887	}
1888
1889	/*
1890	 * Set up state to handle output flow control.
1891	 * XXX - worth handling MDMBUF (DCD) flow control at the lowest level?
1892	 * Now has 10+ msec latency, while CTS flow has 50- usec latency.
1893	 */
1894	com->state |= CS_ODEVREADY;
1895	com->state &= ~CS_CTS_OFLOW;
1896	if (cflag & CCTS_OFLOW) {
1897		com->state |= CS_CTS_OFLOW;
1898		efr_flowbits |= EFR_AUTOCTS;
1899		if (!(com->last_modem_status & MSR_CTS))
1900			com->state &= ~CS_ODEVREADY;
1901	}
1902
1903	if (com->st16650a) {
1904		sio_setreg(com, com_lcr, LCR_EFR_ENABLE);
1905		sio_setreg(com, com_efr,
1906			   (sio_getreg(com, com_efr)
1907			    & ~(EFR_AUTOCTS | EFR_AUTORTS)) | efr_flowbits);
1908	}
1909	sio_setreg(com, com_cfcr, com->cfcr_image = cfcr);
1910
1911	/* XXX shouldn't call functions while intrs are disabled. */
1912	ttyldoptim(tp);
1913
1914	mtx_unlock_spin(&sio_lock);
1915	splx(s);
1916	comstart(tp);
1917	if (com->ibufold != NULL) {
1918		free(com->ibufold, M_DEVBUF);
1919		com->ibufold = NULL;
1920	}
1921	return (0);
1922}
1923
1924/*
1925 * This function must be called with the sio_lock mutex released and will
1926 * return with it obtained.
1927 */
1928static int
1929siosetwater(com, speed)
1930	struct com_s	*com;
1931	speed_t		speed;
1932{
1933	int		cp4ticks;
1934	u_char		*ibuf;
1935	int		ibufsize;
1936	struct tty	*tp;
1937
1938	/*
1939	 * Make the buffer size large enough to handle a softtty interrupt
1940	 * latency of about 2 ticks without loss of throughput or data
1941	 * (about 3 ticks if input flow control is not used or not honoured,
1942	 * but a bit less for CS5-CS7 modes).
1943	 */
1944	cp4ticks = speed / 10 / hz * 4;
1945	for (ibufsize = 128; ibufsize < cp4ticks;)
1946		ibufsize <<= 1;
1947	if (ibufsize == com->ibufsize) {
1948		mtx_lock_spin(&sio_lock);
1949		return (0);
1950	}
1951
1952	/*
1953	 * Allocate input buffer.  The extra factor of 2 in the size is
1954	 * to allow for an error byte for each input byte.
1955	 */
1956	ibuf = malloc(2 * ibufsize, M_DEVBUF, M_NOWAIT);
1957	if (ibuf == NULL) {
1958		mtx_lock_spin(&sio_lock);
1959		return (ENOMEM);
1960	}
1961
1962	/* Initialize non-critical variables. */
1963	com->ibufold = com->ibuf;
1964	com->ibufsize = ibufsize;
1965	tp = com->tp;
1966	if (tp != NULL) {
1967		tp->t_ififosize = 2 * ibufsize;
1968		tp->t_ispeedwat = (speed_t)-1;
1969		tp->t_ospeedwat = (speed_t)-1;
1970	}
1971
1972	/*
1973	 * Read current input buffer, if any.  Continue with interrupts
1974	 * disabled.
1975	 */
1976	mtx_lock_spin(&sio_lock);
1977	if (com->iptr != com->ibuf)
1978		sioinput(com);
1979
1980	/*-
1981	 * Initialize critical variables, including input buffer watermarks.
1982	 * The external device is asked to stop sending when the buffer
1983	 * exactly reaches high water, or when the high level requests it.
1984	 * The high level is notified immediately (rather than at a later
1985	 * clock tick) when this watermark is reached.
1986	 * The buffer size is chosen so the watermark should almost never
1987	 * be reached.
1988	 * The low watermark is invisibly 0 since the buffer is always
1989	 * emptied all at once.
1990	 */
1991	com->iptr = com->ibuf = ibuf;
1992	com->ibufend = ibuf + ibufsize;
1993	com->ierroff = ibufsize;
1994	com->ihighwater = ibuf + 3 * ibufsize / 4;
1995	return (0);
1996}
1997
1998static void
1999comstart(tp)
2000	struct tty	*tp;
2001{
2002	struct com_s	*com;
2003	int		s;
2004
2005	com = tp->t_sc;
2006	if (com == NULL)
2007		return;
2008	s = spltty();
2009	mtx_lock_spin(&sio_lock);
2010	if (tp->t_state & TS_TTSTOP)
2011		com->state &= ~CS_TTGO;
2012	else
2013		com->state |= CS_TTGO;
2014	if (tp->t_state & TS_TBLOCK) {
2015		if (com->mcr_image & MCR_RTS && com->state & CS_RTS_IFLOW)
2016			outb(com->modem_ctl_port, com->mcr_image &= ~MCR_RTS);
2017	} else {
2018		if (!(com->mcr_image & MCR_RTS) && com->iptr < com->ihighwater
2019		    && com->state & CS_RTS_IFLOW)
2020			outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2021	}
2022	mtx_unlock_spin(&sio_lock);
2023	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
2024		ttwwakeup(tp);
2025		splx(s);
2026		return;
2027	}
2028	if (tp->t_outq.c_cc != 0) {
2029		struct lbq	*qp;
2030		struct lbq	*next;
2031
2032		if (!com->obufs[0].l_queued) {
2033			com->obufs[0].l_tail
2034			    = com->obuf1 + q_to_b(&tp->t_outq, com->obuf1,
2035						  sizeof com->obuf1);
2036			com->obufs[0].l_next = NULL;
2037			com->obufs[0].l_queued = TRUE;
2038			mtx_lock_spin(&sio_lock);
2039			if (com->state & CS_BUSY) {
2040				qp = com->obufq.l_next;
2041				while ((next = qp->l_next) != NULL)
2042					qp = next;
2043				qp->l_next = &com->obufs[0];
2044			} else {
2045				com->obufq.l_head = com->obufs[0].l_head;
2046				com->obufq.l_tail = com->obufs[0].l_tail;
2047				com->obufq.l_next = &com->obufs[0];
2048				com->state |= CS_BUSY;
2049			}
2050			mtx_unlock_spin(&sio_lock);
2051		}
2052		if (tp->t_outq.c_cc != 0 && !com->obufs[1].l_queued) {
2053			com->obufs[1].l_tail
2054			    = com->obuf2 + q_to_b(&tp->t_outq, com->obuf2,
2055						  sizeof com->obuf2);
2056			com->obufs[1].l_next = NULL;
2057			com->obufs[1].l_queued = TRUE;
2058			mtx_lock_spin(&sio_lock);
2059			if (com->state & CS_BUSY) {
2060				qp = com->obufq.l_next;
2061				while ((next = qp->l_next) != NULL)
2062					qp = next;
2063				qp->l_next = &com->obufs[1];
2064			} else {
2065				com->obufq.l_head = com->obufs[1].l_head;
2066				com->obufq.l_tail = com->obufs[1].l_tail;
2067				com->obufq.l_next = &com->obufs[1];
2068				com->state |= CS_BUSY;
2069			}
2070			mtx_unlock_spin(&sio_lock);
2071		}
2072		tp->t_state |= TS_BUSY;
2073	}
2074	mtx_lock_spin(&sio_lock);
2075	if (com->state >= (CS_BUSY | CS_TTGO))
2076		siointr1(com);	/* fake interrupt to start output */
2077	mtx_unlock_spin(&sio_lock);
2078	ttwwakeup(tp);
2079	splx(s);
2080}
2081
2082static void
2083comstop(tp, rw)
2084	struct tty	*tp;
2085	int		rw;
2086{
2087	struct com_s	*com;
2088
2089	com = tp->t_sc;
2090	if (com == NULL || com->gone)
2091		return;
2092	mtx_lock_spin(&sio_lock);
2093	if (rw & FWRITE) {
2094		if (com->hasfifo)
2095#ifdef COM_ESP
2096		    /* XXX avoid h/w bug. */
2097		    if (!com->esp)
2098#endif
2099			sio_setreg(com, com_fifo,
2100				   FIFO_XMT_RST | com->fifo_image);
2101		com->obufs[0].l_queued = FALSE;
2102		com->obufs[1].l_queued = FALSE;
2103		if (com->state & CS_ODONE)
2104			com_events -= LOTS_OF_EVENTS;
2105		com->state &= ~(CS_ODONE | CS_BUSY);
2106		com->tp->t_state &= ~TS_BUSY;
2107	}
2108	if (rw & FREAD) {
2109		if (com->hasfifo)
2110#ifdef COM_ESP
2111		    /* XXX avoid h/w bug. */
2112		    if (!com->esp)
2113#endif
2114			sio_setreg(com, com_fifo,
2115				   FIFO_RCV_RST | com->fifo_image);
2116		com_events -= (com->iptr - com->ibuf);
2117		com->iptr = com->ibuf;
2118	}
2119	mtx_unlock_spin(&sio_lock);
2120	comstart(tp);
2121}
2122
2123static int
2124commodem(struct tty *tp, int sigon, int sigoff)
2125{
2126	struct com_s	*com;
2127	int	bitand, bitor, msr;
2128
2129	com = tp->t_sc;
2130	if (com->gone)
2131		return(0);
2132	if (sigon != 0 || sigoff != 0) {
2133		bitand = bitor = 0;
2134		if (sigoff & SER_DTR)
2135			bitand |= MCR_DTR;
2136		if (sigoff & SER_RTS)
2137			bitand |= MCR_RTS;
2138		if (sigon & SER_DTR)
2139			bitor |= MCR_DTR;
2140		if (sigon & SER_RTS)
2141			bitor |= MCR_RTS;
2142		bitand = ~bitand;
2143		mtx_lock_spin(&sio_lock);
2144		com->mcr_image &= bitand;
2145		com->mcr_image |= bitor;
2146		outb(com->modem_ctl_port, com->mcr_image);
2147		mtx_unlock_spin(&sio_lock);
2148		return (0);
2149	} else {
2150		bitor = 0;
2151		if (com->mcr_image & MCR_DTR)
2152			bitor |= SER_DTR;
2153		if (com->mcr_image & MCR_RTS)
2154			bitor |= SER_RTS;
2155		msr = com->prev_modem_status;
2156		if (msr & MSR_CTS)
2157			bitor |= SER_CTS;
2158		if (msr & MSR_DCD)
2159			bitor |= SER_DCD;
2160		if (msr & MSR_DSR)
2161			bitor |= SER_DSR;
2162		if (msr & MSR_DSR)
2163			bitor |= SER_DSR;
2164		if (msr & (MSR_RI | MSR_TERI))
2165			bitor |= SER_RI;
2166		return (bitor);
2167	}
2168}
2169
2170static void
2171siosettimeout()
2172{
2173	struct com_s	*com;
2174	bool_t		someopen;
2175	int		unit;
2176
2177	/*
2178	 * Set our timeout period to 1 second if no polled devices are open.
2179	 * Otherwise set it to max(1/200, 1/hz).
2180	 * Enable timeouts iff some device is open.
2181	 */
2182	untimeout(comwakeup, (void *)NULL, sio_timeout_handle);
2183	sio_timeout = hz;
2184	someopen = FALSE;
2185	for (unit = 0; unit < sio_numunits; ++unit) {
2186		com = com_addr(unit);
2187		if (com != NULL && com->tp != NULL
2188		    && com->tp->t_state & TS_ISOPEN && !com->gone) {
2189			someopen = TRUE;
2190			if (com->poll || com->poll_output) {
2191				sio_timeout = hz > 200 ? hz / 200 : 1;
2192				break;
2193			}
2194		}
2195	}
2196	if (someopen) {
2197		sio_timeouts_until_log = hz / sio_timeout;
2198		sio_timeout_handle = timeout(comwakeup, (void *)NULL,
2199					     sio_timeout);
2200	} else {
2201		/* Flush error messages, if any. */
2202		sio_timeouts_until_log = 1;
2203		comwakeup((void *)NULL);
2204		untimeout(comwakeup, (void *)NULL, sio_timeout_handle);
2205	}
2206}
2207
2208static void
2209comwakeup(chan)
2210	void	*chan;
2211{
2212	struct com_s	*com;
2213	int		unit;
2214
2215	sio_timeout_handle = timeout(comwakeup, (void *)NULL, sio_timeout);
2216
2217	/*
2218	 * Recover from lost output interrupts.
2219	 * Poll any lines that don't use interrupts.
2220	 */
2221	for (unit = 0; unit < sio_numunits; ++unit) {
2222		com = com_addr(unit);
2223		if (com != NULL && !com->gone
2224		    && (com->state >= (CS_BUSY | CS_TTGO) || com->poll)) {
2225			mtx_lock_spin(&sio_lock);
2226			siointr1(com);
2227			mtx_unlock_spin(&sio_lock);
2228		}
2229	}
2230
2231	/*
2232	 * Check for and log errors, but not too often.
2233	 */
2234	if (--sio_timeouts_until_log > 0)
2235		return;
2236	sio_timeouts_until_log = hz / sio_timeout;
2237	for (unit = 0; unit < sio_numunits; ++unit) {
2238		int	errnum;
2239
2240		com = com_addr(unit);
2241		if (com == NULL)
2242			continue;
2243		if (com->gone)
2244			continue;
2245		for (errnum = 0; errnum < CE_NTYPES; ++errnum) {
2246			u_int	delta;
2247			u_long	total;
2248
2249			mtx_lock_spin(&sio_lock);
2250			delta = com->delta_error_counts[errnum];
2251			com->delta_error_counts[errnum] = 0;
2252			mtx_unlock_spin(&sio_lock);
2253			if (delta == 0)
2254				continue;
2255			total = com->error_counts[errnum] += delta;
2256			log(LOG_ERR, "sio%d: %u more %s%s (total %lu)\n",
2257			    unit, delta, error_desc[errnum],
2258			    delta == 1 ? "" : "s", total);
2259		}
2260	}
2261}
2262
2263/*
2264 * Following are all routines needed for SIO to act as console
2265 */
2266struct siocnstate {
2267	u_char	dlbl;
2268	u_char	dlbh;
2269	u_char	ier;
2270	u_char	cfcr;
2271	u_char	mcr;
2272};
2273
2274/*
2275 * This is a function in order to not replicate "ttyd%d" more
2276 * places than absolutely necessary.
2277 */
2278static void
2279siocnset(struct consdev *cd, int unit)
2280{
2281
2282	cd->cn_unit = unit;
2283	sprintf(cd->cn_name, "ttyd%d", unit);
2284}
2285
2286static speed_t siocngetspeed(Port_t, u_long rclk);
2287static void siocnclose(struct siocnstate *sp, Port_t iobase);
2288static void siocnopen(struct siocnstate *sp, Port_t iobase, int speed);
2289static void siocntxwait(Port_t iobase);
2290
2291static cn_probe_t sio_cnprobe;
2292static cn_init_t sio_cninit;
2293static cn_term_t sio_cnterm;
2294static cn_getc_t sio_cngetc;
2295static cn_putc_t sio_cnputc;
2296static cn_grab_t sio_cngrab;
2297static cn_ungrab_t sio_cnungrab;
2298
2299CONSOLE_DRIVER(sio);
2300
2301static void
2302siocntxwait(iobase)
2303	Port_t	iobase;
2304{
2305	int	timo;
2306
2307	/*
2308	 * Wait for any pending transmission to finish.  Required to avoid
2309	 * the UART lockup bug when the speed is changed, and for normal
2310	 * transmits.
2311	 */
2312	timo = 100000;
2313	while ((inb(iobase + com_lsr) & (LSR_TSRE | LSR_TXRDY))
2314	       != (LSR_TSRE | LSR_TXRDY) && --timo != 0)
2315		;
2316}
2317
2318/*
2319 * Read the serial port specified and try to figure out what speed
2320 * it's currently running at.  We're assuming the serial port has
2321 * been initialized and is basicly idle.  This routine is only intended
2322 * to be run at system startup.
2323 *
2324 * If the value read from the serial port doesn't make sense, return 0.
2325 */
2326
2327static speed_t
2328siocngetspeed(iobase, rclk)
2329	Port_t	iobase;
2330	u_long	rclk;
2331{
2332	u_int	divisor;
2333	u_char	dlbh;
2334	u_char	dlbl;
2335	u_char  cfcr;
2336
2337	cfcr = inb(iobase + com_cfcr);
2338	outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2339
2340	dlbl = inb(iobase + com_dlbl);
2341	dlbh = inb(iobase + com_dlbh);
2342
2343	outb(iobase + com_cfcr, cfcr);
2344
2345	divisor = dlbh << 8 | dlbl;
2346
2347	/* XXX there should be more sanity checking. */
2348	if (divisor == 0)
2349		return (CONSPEED);
2350	return (rclk / (16UL * divisor));
2351}
2352
2353static void
2354siocnopen(sp, iobase, speed)
2355	struct siocnstate	*sp;
2356	Port_t			iobase;
2357	int			speed;
2358{
2359	u_int	divisor;
2360	u_char	dlbh;
2361	u_char	dlbl;
2362
2363	/*
2364	 * Save all the device control registers except the fifo register
2365	 * and set our default ones (cs8 -parenb speed=comdefaultrate).
2366	 * We can't save the fifo register since it is read-only.
2367	 */
2368	sp->ier = inb(iobase + com_ier);
2369	outb(iobase + com_ier, 0);	/* spltty() doesn't stop siointr() */
2370	siocntxwait(iobase);
2371	sp->cfcr = inb(iobase + com_cfcr);
2372	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2373	sp->dlbl = inb(iobase + com_dlbl);
2374	sp->dlbh = inb(iobase + com_dlbh);
2375	/*
2376	 * Only set the divisor registers if they would change, since on
2377	 * some 16550 incompatibles (Startech), setting them clears the
2378	 * data input register.  This also reduces the effects of the
2379	 * UMC8669F bug.
2380	 */
2381	divisor = siodivisor(comdefaultrclk, speed);
2382	dlbl = divisor & 0xFF;
2383	if (sp->dlbl != dlbl)
2384		outb(iobase + com_dlbl, dlbl);
2385	dlbh = divisor >> 8;
2386	if (sp->dlbh != dlbh)
2387		outb(iobase + com_dlbh, dlbh);
2388	outb(iobase + com_cfcr, CFCR_8BITS);
2389	sp->mcr = inb(iobase + com_mcr);
2390	/*
2391	 * We don't want interrupts, but must be careful not to "disable"
2392	 * them by clearing the MCR_IENABLE bit, since that might cause
2393	 * an interrupt by floating the IRQ line.
2394	 */
2395	outb(iobase + com_mcr, (sp->mcr & MCR_IENABLE) | MCR_DTR | MCR_RTS);
2396}
2397
2398static void
2399siocnclose(sp, iobase)
2400	struct siocnstate	*sp;
2401	Port_t			iobase;
2402{
2403	/*
2404	 * Restore the device control registers.
2405	 */
2406	siocntxwait(iobase);
2407	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2408	if (sp->dlbl != inb(iobase + com_dlbl))
2409		outb(iobase + com_dlbl, sp->dlbl);
2410	if (sp->dlbh != inb(iobase + com_dlbh))
2411		outb(iobase + com_dlbh, sp->dlbh);
2412	outb(iobase + com_cfcr, sp->cfcr);
2413	/*
2414	 * XXX damp oscillations of MCR_DTR and MCR_RTS by not restoring them.
2415	 */
2416	outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
2417	outb(iobase + com_ier, sp->ier);
2418}
2419
2420static void
2421sio_cnprobe(cp)
2422	struct consdev	*cp;
2423{
2424	speed_t			boot_speed;
2425	u_char			cfcr;
2426	u_int			divisor;
2427	int			s, unit;
2428	struct siocnstate	sp;
2429
2430	/*
2431	 * Find our first enabled console, if any.  If it is a high-level
2432	 * console device, then initialize it and return successfully.
2433	 * If it is a low-level console device, then initialize it and
2434	 * return unsuccessfully.  It must be initialized in both cases
2435	 * for early use by console drivers and debuggers.  Initializing
2436	 * the hardware is not necessary in all cases, since the i/o
2437	 * routines initialize it on the fly, but it is necessary if
2438	 * input might arrive while the hardware is switched back to an
2439	 * uninitialized state.  We can't handle multiple console devices
2440	 * yet because our low-level routines don't take a device arg.
2441	 * We trust the user to set the console flags properly so that we
2442	 * don't need to probe.
2443	 */
2444	cp->cn_pri = CN_DEAD;
2445
2446	for (unit = 0; unit < 16; unit++) { /* XXX need to know how many */
2447		int flags;
2448
2449		if (resource_disabled("sio", unit))
2450			continue;
2451		if (resource_int_value("sio", unit, "flags", &flags))
2452			continue;
2453		if (COM_CONSOLE(flags) || COM_DEBUGGER(flags)) {
2454			int port;
2455			Port_t iobase;
2456
2457			if (resource_int_value("sio", unit, "port", &port))
2458				continue;
2459			iobase = port;
2460			s = spltty();
2461			if ((boothowto & RB_SERIAL) && COM_CONSOLE(flags)) {
2462				boot_speed =
2463				    siocngetspeed(iobase, comdefaultrclk);
2464				if (boot_speed)
2465					comdefaultrate = boot_speed;
2466			}
2467
2468			/*
2469			 * Initialize the divisor latch.  We can't rely on
2470			 * siocnopen() to do this the first time, since it
2471			 * avoids writing to the latch if the latch appears
2472			 * to have the correct value.  Also, if we didn't
2473			 * just read the speed from the hardware, then we
2474			 * need to set the speed in hardware so that
2475			 * switching it later is null.
2476			 */
2477			cfcr = inb(iobase + com_cfcr);
2478			outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2479			divisor = siodivisor(comdefaultrclk, comdefaultrate);
2480			outb(iobase + com_dlbl, divisor & 0xff);
2481			outb(iobase + com_dlbh, divisor >> 8);
2482			outb(iobase + com_cfcr, cfcr);
2483
2484			siocnopen(&sp, iobase, comdefaultrate);
2485
2486			splx(s);
2487			if (COM_CONSOLE(flags) && !COM_LLCONSOLE(flags)) {
2488				siocnset(cp, unit);
2489				cp->cn_pri = COM_FORCECONSOLE(flags)
2490					     || boothowto & RB_SERIAL
2491					     ? CN_REMOTE : CN_NORMAL;
2492				siocniobase = iobase;
2493				siocnunit = unit;
2494			}
2495#ifdef GDB
2496			if (COM_DEBUGGER(flags))
2497				siogdbiobase = iobase;
2498#endif
2499		}
2500	}
2501}
2502
2503static void
2504sio_cninit(cp)
2505	struct consdev	*cp;
2506{
2507	comconsole = cp->cn_unit;
2508}
2509
2510static void
2511sio_cnterm(cp)
2512	struct consdev	*cp;
2513{
2514	comconsole = -1;
2515}
2516
2517static void
2518sio_cngrab(struct consdev *cp)
2519{
2520}
2521
2522static void
2523sio_cnungrab(struct consdev *cp)
2524{
2525}
2526
2527static int
2528sio_cngetc(struct consdev *cd)
2529{
2530	int	c;
2531	Port_t	iobase;
2532	int	s;
2533	struct siocnstate	sp;
2534	speed_t	speed;
2535
2536	if (cd != NULL && cd->cn_unit == siocnunit) {
2537		iobase = siocniobase;
2538		speed = comdefaultrate;
2539	} else {
2540#ifdef GDB
2541		iobase = siogdbiobase;
2542		speed = gdbdefaultrate;
2543#else
2544		return (-1);
2545#endif
2546	}
2547	s = spltty();
2548	siocnopen(&sp, iobase, speed);
2549	if (inb(iobase + com_lsr) & LSR_RXRDY)
2550		c = inb(iobase + com_data);
2551	else
2552		c = -1;
2553	siocnclose(&sp, iobase);
2554	splx(s);
2555	return (c);
2556}
2557
2558static void
2559sio_cnputc(struct consdev *cd, int c)
2560{
2561	int	need_unlock;
2562	int	s;
2563	struct siocnstate	sp;
2564	Port_t	iobase;
2565	speed_t	speed;
2566
2567	if (cd != NULL && cd->cn_unit == siocnunit) {
2568		iobase = siocniobase;
2569		speed = comdefaultrate;
2570	} else {
2571#ifdef GDB
2572		iobase = siogdbiobase;
2573		speed = gdbdefaultrate;
2574#else
2575		return;
2576#endif
2577	}
2578	s = spltty();
2579	need_unlock = 0;
2580	if (!kdb_active && sio_inited == 2 && !mtx_owned(&sio_lock)) {
2581		mtx_lock_spin(&sio_lock);
2582		need_unlock = 1;
2583	}
2584	siocnopen(&sp, iobase, speed);
2585	siocntxwait(iobase);
2586	outb(iobase + com_data, c);
2587	siocnclose(&sp, iobase);
2588	if (need_unlock)
2589		mtx_unlock_spin(&sio_lock);
2590	splx(s);
2591}
2592
2593/*
2594 * Remote gdb(1) support.
2595 */
2596
2597#if defined(GDB)
2598
2599#include <gdb/gdb.h>
2600
2601static gdb_probe_f siogdbprobe;
2602static gdb_init_f siogdbinit;
2603static gdb_term_f siogdbterm;
2604static gdb_getc_f siogdbgetc;
2605static gdb_putc_f siogdbputc;
2606
2607GDB_DBGPORT(sio, siogdbprobe, siogdbinit, siogdbterm, siogdbgetc, siogdbputc);
2608
2609static int
2610siogdbprobe(void)
2611{
2612	return ((siogdbiobase != 0) ? 0 : -1);
2613}
2614
2615static void
2616siogdbinit(void)
2617{
2618}
2619
2620static void
2621siogdbterm(void)
2622{
2623}
2624
2625static void
2626siogdbputc(int c)
2627{
2628	sio_cnputc(NULL, c);
2629}
2630
2631static int
2632siogdbgetc(void)
2633{
2634	return (sio_cngetc(NULL));
2635}
2636
2637#endif
2638