xref: /freebsd-11-stable/sys/dev/sio/sio.c (revision 4ab2e064d7950be84256d671a7ae93f87cc6aa36)
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 
145 static	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 */
158 typedef u_int	Port_t;		/* hardware port */
159 typedef u_char	bool_t;		/* boolean */
160 
161 /* queue of linear buffers */
162 struct 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 */
170 struct 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
255 static	int	espattach(struct com_s *com, Port_t esp_port);
256 #endif
257 
258 static	void	combreak(struct tty *tp, int sig);
259 static	timeout_t siobusycheck;
260 static	u_int	siodivisor(u_long rclk, speed_t speed);
261 static	void	comclose(struct tty *tp);
262 static	int	comopen(struct tty *tp, struct cdev *dev);
263 static	void	sioinput(struct com_s *com);
264 static	void	siointr1(struct com_s *com);
265 static	int	siointr(void *arg);
266 static	int	commodem(struct tty *tp, int sigon, int sigoff);
267 static	int	comparam(struct tty *tp, struct termios *t);
268 static	void	siopoll(void *);
269 static	void	siosettimeout(void);
270 static	int	siosetwater(struct com_s *com, speed_t speed);
271 static	void	comstart(struct tty *tp);
272 static	void	comstop(struct tty *tp, int rw);
273 static	timeout_t comwakeup;
274 
275 char		sio_driver_name[] = "sio";
276 static struct	mtx sio_lock;
277 static int	sio_inited;
278 
279 /* table and macro for fast conversion from a unit number to its com struct */
280 devclass_t	sio_devclass;
281 /*
282  * XXX Assmues that devclass_get_device, devclass_get_softc and
283  * device_get_softc are fast interrupt safe.  The current implementation
284  * of these functions are.
285  */
286 #define	com_addr(unit)	((struct com_s *) \
287 			 devclass_get_softc(sio_devclass, unit)) /* XXX */
288 
289 int	comconsole = -1;
290 static	volatile speed_t	comdefaultrate = CONSPEED;
291 static	u_long			comdefaultrclk = DEFAULT_RCLK;
292 SYSCTL_ULONG(_machdep, OID_AUTO, conrclk, CTLFLAG_RW, &comdefaultrclk, 0, "");
293 static	speed_t			gdbdefaultrate = GDBSPEED;
294 SYSCTL_UINT(_machdep, OID_AUTO, gdbspeed, CTLFLAG_RW,
295 	    &gdbdefaultrate, GDBSPEED, "");
296 static	u_int	com_events;	/* input chars + weighted output completions */
297 static	Port_t	siocniobase;
298 static	int	siocnunit = -1;
299 static	void	*sio_slow_ih;
300 static	void	*sio_fast_ih;
301 static	int	sio_timeout;
302 static	int	sio_timeouts_until_log;
303 static	struct	callout_handle sio_timeout_handle
304     = CALLOUT_HANDLE_INITIALIZER(&sio_timeout_handle);
305 static	int	sio_numunits;
306 
307 #ifdef GDB
308 static	Port_t	siogdbiobase = 0;
309 #endif
310 
311 #ifdef COM_ESP
312 /* XXX configure this properly. */
313 /* XXX quite broken for new-bus. */
314 static	Port_t	likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, };
315 static	Port_t	likely_esp_ports[] = { 0x140, 0x180, 0x280, 0 };
316 #endif
317 
318 /*
319  * handle sysctl read/write requests for console speed
320  *
321  * In addition to setting comdefaultrate for I/O through /dev/console,
322  * also set the initial and lock values for the /dev/ttyXX device
323  * if there is one associated with the console.  Finally, if the /dev/tty
324  * device has already been open, change the speed on the open running port
325  * itself.
326  */
327 
328 static int
sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)329 sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)
330 {
331 	int error, s;
332 	speed_t newspeed;
333 	struct com_s *com;
334 	struct tty *tp;
335 
336 	newspeed = comdefaultrate;
337 
338 	error = sysctl_handle_opaque(oidp, &newspeed, sizeof newspeed, req);
339 	if (error || !req->newptr)
340 		return (error);
341 
342 	comdefaultrate = newspeed;
343 
344 	if (comconsole < 0)		/* serial console not selected? */
345 		return (0);
346 
347 	com = com_addr(comconsole);
348 	if (com == NULL)
349 		return (ENXIO);
350 
351 	tp = com->tp;
352 	if (tp == NULL)
353 		return (ENXIO);
354 
355 	/*
356 	 * set the initial and lock rates for /dev/ttydXX and /dev/cuaXX
357 	 * (note, the lock rates really are boolean -- if non-zero, disallow
358 	 *  speed changes)
359 	 */
360 	tp->t_init_in.c_ispeed  = tp->t_init_in.c_ospeed =
361 	tp->t_lock_in.c_ispeed  = tp->t_lock_in.c_ospeed =
362 	tp->t_init_out.c_ispeed = tp->t_init_out.c_ospeed =
363 	tp->t_lock_out.c_ispeed = tp->t_lock_out.c_ospeed = comdefaultrate;
364 
365 	if (tp->t_state & TS_ISOPEN) {
366 		tp->t_termios.c_ispeed =
367 		tp->t_termios.c_ospeed = comdefaultrate;
368 		s = spltty();
369 		error = comparam(tp, &tp->t_termios);
370 		splx(s);
371 	}
372 	return error;
373 }
374 
375 SYSCTL_PROC(_machdep, OID_AUTO, conspeed, CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
376 	    0, 0, sysctl_machdep_comdefaultrate, "I", "");
377 TUNABLE_INT("machdep.conspeed", __DEVOLATILE(int *, &comdefaultrate));
378 
379 #define SET_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) | (bit))
380 #define CLR_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) & ~(bit))
381 
382 /*
383  *	Unload the driver and clear the table.
384  *	XXX this is mostly wrong.
385  *	XXX TODO:
386  *	This is usually called when the card is ejected, but
387  *	can be caused by a kldunload of a controller driver.
388  *	The idea is to reset the driver's view of the device
389  *	and ensure that any driver entry points such as
390  *	read and write do not hang.
391  */
392 int
siodetach(device_t dev)393 siodetach(device_t dev)
394 {
395 	struct com_s	*com;
396 
397 	com = (struct com_s *) device_get_softc(dev);
398 	if (com == NULL) {
399 		device_printf(dev, "NULL com in siounload\n");
400 		return (0);
401 	}
402 	com->gone = TRUE;
403 	if (com->tp)
404 		ttyfree(com->tp);
405 	if (com->irqres) {
406 		bus_teardown_intr(dev, com->irqres, com->cookie);
407 		bus_release_resource(dev, SYS_RES_IRQ, 0, com->irqres);
408 	}
409 	if (com->ioportres)
410 		bus_release_resource(dev, SYS_RES_IOPORT, com->ioportrid,
411 				     com->ioportres);
412 	if (com->ibuf != NULL)
413 		free(com->ibuf, M_DEVBUF);
414 
415 	device_set_softc(dev, NULL);
416 	free(com, M_DEVBUF);
417 	return (0);
418 }
419 
420 int
sioprobe(dev,xrid,rclk,noprobe)421 sioprobe(dev, xrid, rclk, noprobe)
422 	device_t	dev;
423 	int		xrid;
424 	u_long		rclk;
425 	int		noprobe;
426 {
427 #if 0
428 	static bool_t	already_init;
429 	device_t	xdev;
430 #endif
431 	struct com_s	*com;
432 	u_int		divisor;
433 	bool_t		failures[10];
434 	int		fn;
435 	device_t	idev;
436 	Port_t		iobase;
437 	intrmask_t	irqmap[4];
438 	intrmask_t	irqs;
439 	u_char		mcr_image;
440 	int		result;
441 	u_long		xirq;
442 	u_int		flags = device_get_flags(dev);
443 	int		rid;
444 	struct resource *port;
445 
446 	rid = xrid;
447 	port = bus_alloc_resource_anywhere(dev, SYS_RES_IOPORT, &rid,
448 					   IO_COMSIZE, RF_ACTIVE);
449 	if (!port)
450 		return (ENXIO);
451 
452 	com = malloc(sizeof(*com), M_DEVBUF, M_NOWAIT | M_ZERO);
453 	if (com == NULL) {
454 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
455 		return (ENOMEM);
456 	}
457 	device_set_softc(dev, com);
458 	com->bst = rman_get_bustag(port);
459 	com->bsh = rman_get_bushandle(port);
460 	if (rclk == 0)
461 		rclk = DEFAULT_RCLK;
462 	com->rclk = rclk;
463 
464 	while (sio_inited != 2)
465 		if (atomic_cmpset_int(&sio_inited, 0, 1)) {
466 			mtx_init(&sio_lock, sio_driver_name, NULL,
467 			    (comconsole != -1) ?
468 			    MTX_SPIN | MTX_QUIET : MTX_SPIN);
469 			atomic_store_rel_int(&sio_inited, 2);
470 		}
471 
472 #if 0
473 	/*
474 	 * XXX this is broken - when we are first called, there are no
475 	 * previously configured IO ports.  We could hard code
476 	 * 0x3f8, 0x2f8, 0x3e8, 0x2e8 etc but that's probably worse.
477 	 * This code has been doing nothing since the conversion since
478 	 * "count" is zero the first time around.
479 	 */
480 	if (!already_init) {
481 		/*
482 		 * Turn off MCR_IENABLE for all likely serial ports.  An unused
483 		 * port with its MCR_IENABLE gate open will inhibit interrupts
484 		 * from any used port that shares the interrupt vector.
485 		 * XXX the gate enable is elsewhere for some multiports.
486 		 */
487 		device_t *devs;
488 		int count, i, xioport;
489 
490 		devclass_get_devices(sio_devclass, &devs, &count);
491 		for (i = 0; i < count; i++) {
492 			xdev = devs[i];
493 			if (device_is_enabled(xdev) &&
494 			    bus_get_resource(xdev, SYS_RES_IOPORT, 0, &xioport,
495 					     NULL) == 0)
496 				outb(xioport + com_mcr, 0);
497 		}
498 		free(devs, M_TEMP);
499 		already_init = TRUE;
500 	}
501 #endif
502 
503 	if (COM_LLCONSOLE(flags)) {
504 		printf("sio%d: reserved for low-level i/o\n",
505 		       device_get_unit(dev));
506 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
507 		device_set_softc(dev, NULL);
508 		free(com, M_DEVBUF);
509 		return (ENXIO);
510 	}
511 
512 	/*
513 	 * If the device is on a multiport card and has an AST/4
514 	 * compatible interrupt control register, initialize this
515 	 * register and prepare to leave MCR_IENABLE clear in the mcr.
516 	 * Otherwise, prepare to set MCR_IENABLE in the mcr.
517 	 * Point idev to the device struct giving the correct id_irq.
518 	 * This is the struct for the master device if there is one.
519 	 */
520 	idev = dev;
521 	mcr_image = MCR_IENABLE;
522 #ifdef COM_MULTIPORT
523 	if (COM_ISMULTIPORT(flags)) {
524 		Port_t xiobase;
525 		u_long io;
526 
527 		idev = devclass_get_device(sio_devclass, COM_MPMASTER(flags));
528 		if (idev == NULL) {
529 			printf("sio%d: master device %d not configured\n",
530 			       device_get_unit(dev), COM_MPMASTER(flags));
531 			idev = dev;
532 		}
533 		if (!COM_NOTAST4(flags)) {
534 			if (bus_get_resource(idev, SYS_RES_IOPORT, 0, &io,
535 					     NULL) == 0) {
536 				xiobase = io;
537 				if (bus_get_resource(idev, SYS_RES_IRQ, 0,
538 				    NULL, NULL) == 0)
539 					outb(xiobase + com_scr, 0x80);
540 				else
541 					outb(xiobase + com_scr, 0);
542 			}
543 			mcr_image = 0;
544 		}
545 	}
546 #endif /* COM_MULTIPORT */
547 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, NULL, NULL) != 0)
548 		mcr_image = 0;
549 
550 	bzero(failures, sizeof failures);
551 	iobase = rman_get_start(port);
552 
553 	/*
554 	 * We don't want to get actual interrupts, just masked ones.
555 	 * Interrupts from this line should already be masked in the ICU,
556 	 * but mask them in the processor as well in case there are some
557 	 * (misconfigured) shared interrupts.
558 	 */
559 	mtx_lock_spin(&sio_lock);
560 /* EXTRA DELAY? */
561 
562 	/*
563 	 * For the TI16754 chips, set prescaler to 1 (4 is often the
564 	 * default after-reset value) as otherwise it's impossible to
565 	 * get highest baudrates.
566 	 */
567 	if (COM_TI16754(flags)) {
568 		u_char cfcr, efr;
569 
570 		cfcr = sio_getreg(com, com_cfcr);
571 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
572 		efr = sio_getreg(com, com_efr);
573 		/* Unlock extended features to turn off prescaler. */
574 		sio_setreg(com, com_efr, efr | EFR_EFE);
575 		/* Disable EFR. */
576 		sio_setreg(com, com_cfcr, (cfcr != CFCR_EFR_ENABLE) ? cfcr : 0);
577 		/* Turn off prescaler. */
578 		sio_setreg(com, com_mcr,
579 			   sio_getreg(com, com_mcr) & ~MCR_PRESCALE);
580 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
581 		sio_setreg(com, com_efr, efr);
582 		sio_setreg(com, com_cfcr, cfcr);
583 	}
584 
585 	/*
586 	 * Initialize the speed and the word size and wait long enough to
587 	 * drain the maximum of 16 bytes of junk in device output queues.
588 	 * The speed is undefined after a master reset and must be set
589 	 * before relying on anything related to output.  There may be
590 	 * junk after a (very fast) soft reboot and (apparently) after
591 	 * master reset.
592 	 * XXX what about the UART bug avoided by waiting in comparam()?
593 	 * We don't want to wait long enough to drain at 2 bps.
594 	 */
595 	if (iobase == siocniobase)
596 		DELAY((16 + 1) * 1000000 / (comdefaultrate / 10));
597 	else {
598 		sio_setreg(com, com_cfcr, CFCR_DLAB | CFCR_8BITS);
599 		divisor = siodivisor(rclk, SIO_TEST_SPEED);
600 		sio_setreg(com, com_dlbl, divisor & 0xff);
601 		sio_setreg(com, com_dlbh, divisor >> 8);
602 		sio_setreg(com, com_cfcr, CFCR_8BITS);
603 		DELAY((16 + 1) * 1000000 / (SIO_TEST_SPEED / 10));
604 	}
605 
606 	/*
607 	 * Enable the interrupt gate and disable device interrupts.  This
608 	 * should leave the device driving the interrupt line low and
609 	 * guarantee an edge trigger if an interrupt can be generated.
610 	 */
611 /* EXTRA DELAY? */
612 	sio_setreg(com, com_mcr, mcr_image);
613 	sio_setreg(com, com_ier, 0);
614 	DELAY(1000);		/* XXX */
615 	irqmap[0] = isa_irq_pending();
616 
617 	/*
618 	 * Attempt to set loopback mode so that we can send a null byte
619 	 * without annoying any external device.
620 	 */
621 /* EXTRA DELAY? */
622 	sio_setreg(com, com_mcr, mcr_image | MCR_LOOPBACK);
623 
624 	/*
625 	 * Attempt to generate an output interrupt.  On 8250's, setting
626 	 * IER_ETXRDY generates an interrupt independent of the current
627 	 * setting and independent of whether the THR is empty.  On 16450's,
628 	 * setting IER_ETXRDY generates an interrupt independent of the
629 	 * current setting.  On 16550A's, setting IER_ETXRDY only
630 	 * generates an interrupt when IER_ETXRDY is not already set.
631 	 */
632 	sio_setreg(com, com_ier, IER_ETXRDY);
633 
634 	/*
635 	 * On some 16x50 incompatibles, setting IER_ETXRDY doesn't generate
636 	 * an interrupt.  They'd better generate one for actually doing
637 	 * output.  Loopback may be broken on the same incompatibles but
638 	 * it's unlikely to do more than allow the null byte out.
639 	 */
640 	sio_setreg(com, com_data, 0);
641 	if (iobase == siocniobase)
642 		DELAY((1 + 2) * 1000000 / (comdefaultrate / 10));
643 	else
644 		DELAY((1 + 2) * 1000000 / (SIO_TEST_SPEED / 10));
645 
646 	/*
647 	 * Turn off loopback mode so that the interrupt gate works again
648 	 * (MCR_IENABLE was hidden).  This should leave the device driving
649 	 * an interrupt line high.  It doesn't matter if the interrupt
650 	 * line oscillates while we are not looking at it, since interrupts
651 	 * are disabled.
652 	 */
653 /* EXTRA DELAY? */
654 	sio_setreg(com, com_mcr, mcr_image);
655 
656 	/*
657 	 * It seems my Xircom CBEM56G Cardbus modem wants to be reset
658 	 * to 8 bits *again*, or else probe test 0 will fail.
659 	 * gwk@sgi.com, 4/19/2001
660 	 */
661 	sio_setreg(com, com_cfcr, CFCR_8BITS);
662 
663 	/*
664 	 * Some PCMCIA cards (Palido 321s, DC-1S, ...) have the "TXRDY bug",
665 	 * so we probe for a buggy IIR_TXRDY implementation even in the
666 	 * noprobe case.  We don't probe for it in the !noprobe case because
667 	 * noprobe is always set for PCMCIA cards and the problem is not
668 	 * known to affect any other cards.
669 	 */
670 	if (noprobe) {
671 		/* Read IIR a few times. */
672 		for (fn = 0; fn < 2; fn ++) {
673 			DELAY(10000);
674 			failures[6] = sio_getreg(com, com_iir);
675 		}
676 
677 		/* IIR_TXRDY should be clear.  Is it? */
678 		result = 0;
679 		if (failures[6] & IIR_TXRDY) {
680 			/*
681 			 * No.  We seem to have the bug.  Does our fix for
682 			 * it work?
683 			 */
684 			sio_setreg(com, com_ier, 0);
685 			if (sio_getreg(com, com_iir) & IIR_NOPEND) {
686 				/* Yes.  We discovered the TXRDY bug! */
687 				SET_FLAG(dev, COM_C_IIR_TXRDYBUG);
688 			} else {
689 				/* No.  Just fail.  XXX */
690 				result = ENXIO;
691 				sio_setreg(com, com_mcr, 0);
692 			}
693 		} else {
694 			/* Yes.  No bug. */
695 			CLR_FLAG(dev, COM_C_IIR_TXRDYBUG);
696 		}
697 		sio_setreg(com, com_ier, 0);
698 		sio_setreg(com, com_cfcr, CFCR_8BITS);
699 		mtx_unlock_spin(&sio_lock);
700 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
701 		if (iobase == siocniobase)
702 			result = 0;
703 		/*
704 		 * XXX: Since we don't return 0, we shouldn't be relying on
705 		 * the softc that we set to persist to the call to attach
706 		 * since other probe routines may be called, and the malloc
707 		 * here causes subr_bus to not allocate anything for the
708 		 * other probes.  Instead, this softc is preserved and other
709 		 * probe routines can corrupt it.
710 		 */
711 		if (result != 0) {
712 			device_set_softc(dev, NULL);
713 			free(com, M_DEVBUF);
714 		}
715 		return (result == 0 ? BUS_PROBE_DEFAULT + 1 : result);
716 	}
717 
718 	/*
719 	 * Check that
720 	 *	o the CFCR, IER and MCR in UART hold the values written to them
721 	 *	  (the values happen to be all distinct - this is good for
722 	 *	  avoiding false positive tests from bus echoes).
723 	 *	o an output interrupt is generated and its vector is correct.
724 	 *	o the interrupt goes away when the IIR in the UART is read.
725 	 */
726 /* EXTRA DELAY? */
727 	failures[0] = sio_getreg(com, com_cfcr) - CFCR_8BITS;
728 	failures[1] = sio_getreg(com, com_ier) - IER_ETXRDY;
729 	failures[2] = sio_getreg(com, com_mcr) - mcr_image;
730 	DELAY(10000);		/* Some internal modems need this time */
731 	irqmap[1] = isa_irq_pending();
732 	failures[4] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_TXRDY;
733 	DELAY(1000);		/* XXX */
734 	irqmap[2] = isa_irq_pending();
735 	failures[6] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
736 
737 	/*
738 	 * Turn off all device interrupts and check that they go off properly.
739 	 * Leave MCR_IENABLE alone.  For ports without a master port, it gates
740 	 * the OUT2 output of the UART to
741 	 * the ICU input.  Closing the gate would give a floating ICU input
742 	 * (unless there is another device driving it) and spurious interrupts.
743 	 * (On the system that this was first tested on, the input floats high
744 	 * and gives a (masked) interrupt as soon as the gate is closed.)
745 	 */
746 	sio_setreg(com, com_ier, 0);
747 	sio_setreg(com, com_cfcr, CFCR_8BITS);	/* dummy to avoid bus echo */
748 	failures[7] = sio_getreg(com, com_ier);
749 	DELAY(1000);		/* XXX */
750 	irqmap[3] = isa_irq_pending();
751 	failures[9] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
752 
753 	mtx_unlock_spin(&sio_lock);
754 
755 	irqs = irqmap[1] & ~irqmap[0];
756 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, &xirq, NULL) == 0 &&
757 	    ((1 << xirq) & irqs) == 0) {
758 		printf(
759 		"sio%d: configured irq %ld not in bitmap of probed irqs %#x\n",
760 		    device_get_unit(dev), xirq, irqs);
761 		printf(
762 		"sio%d: port may not be enabled\n",
763 		    device_get_unit(dev));
764 	}
765 	if (bootverbose)
766 		printf("sio%d: irq maps: %#x %#x %#x %#x\n",
767 		    device_get_unit(dev),
768 		    irqmap[0], irqmap[1], irqmap[2], irqmap[3]);
769 
770 	result = 0;
771 	for (fn = 0; fn < sizeof failures; ++fn)
772 		if (failures[fn]) {
773 			sio_setreg(com, com_mcr, 0);
774 			result = ENXIO;
775 			if (bootverbose) {
776 				printf("sio%d: probe failed test(s):",
777 				    device_get_unit(dev));
778 				for (fn = 0; fn < sizeof failures; ++fn)
779 					if (failures[fn])
780 						printf(" %d", fn);
781 				printf("\n");
782 			}
783 			break;
784 		}
785 	bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
786 	if (iobase == siocniobase)
787 		result = 0;
788 	/*
789 	 * XXX: Since we don't return 0, we shouldn't be relying on the softc
790 	 * that we set to persist to the call to attach since other probe
791 	 * routines may be called, and the malloc here causes subr_bus to not
792 	 * allocate anything for the other probes.  Instead, this softc is
793 	 * preserved and other probe routines can corrupt it.
794 	 */
795 	if (result != 0) {
796 		device_set_softc(dev, NULL);
797 		free(com, M_DEVBUF);
798 	}
799 	return (result == 0 ? BUS_PROBE_DEFAULT + 1 : result);
800 }
801 
802 #ifdef COM_ESP
803 static int
espattach(com,esp_port)804 espattach(com, esp_port)
805 	struct com_s		*com;
806 	Port_t			esp_port;
807 {
808 	u_char	dips;
809 	u_char	val;
810 
811 	/*
812 	 * Check the ESP-specific I/O port to see if we're an ESP
813 	 * card.  If not, return failure immediately.
814 	 */
815 	if ((inb(esp_port) & 0xf3) == 0) {
816 		printf(" port 0x%x is not an ESP board?\n", esp_port);
817 		return (0);
818 	}
819 
820 	/*
821 	 * We've got something that claims to be a Hayes ESP card.
822 	 * Let's hope so.
823 	 */
824 
825 	/* Get the dip-switch configuration */
826 	outb(esp_port + ESP_CMD1, ESP_GETDIPS);
827 	dips = inb(esp_port + ESP_STATUS1);
828 
829 	/*
830 	 * Bits 0,1 of dips say which COM port we are.
831 	 */
832 	if (rman_get_start(com->ioportres) == likely_com_ports[dips & 0x03])
833 		printf(" : ESP");
834 	else {
835 		printf(" esp_port has com %d\n", dips & 0x03);
836 		return (0);
837 	}
838 
839 	/*
840 	 * Check for ESP version 2.0 or later:  bits 4,5,6 = 010.
841 	 */
842 	outb(esp_port + ESP_CMD1, ESP_GETTEST);
843 	val = inb(esp_port + ESP_STATUS1);	/* clear reg 1 */
844 	val = inb(esp_port + ESP_STATUS2);
845 	if ((val & 0x70) < 0x20) {
846 		printf("-old (%o)", val & 0x70);
847 		return (0);
848 	}
849 
850 	/*
851 	 * Check for ability to emulate 16550:  bit 7 == 1
852 	 */
853 	if ((dips & 0x80) == 0) {
854 		printf(" slave");
855 		return (0);
856 	}
857 
858 	/*
859 	 * Okay, we seem to be a Hayes ESP card.  Whee.
860 	 */
861 	com->esp = TRUE;
862 	com->esp_port = esp_port;
863 	return (1);
864 }
865 #endif /* COM_ESP */
866 
867 int
sioattach(dev,xrid,rclk)868 sioattach(dev, xrid, rclk)
869 	device_t	dev;
870 	int		xrid;
871 	u_long		rclk;
872 {
873 	struct com_s	*com;
874 #ifdef COM_ESP
875 	Port_t		*espp;
876 #endif
877 	Port_t		iobase;
878 	int		unit;
879 	u_int		flags;
880 	int		rid;
881 	struct resource *port;
882 	int		ret;
883 	int		error;
884 	struct tty	*tp;
885 
886 	rid = xrid;
887 	port = bus_alloc_resource_anywhere(dev, SYS_RES_IOPORT, &rid,
888 					   IO_COMSIZE, RF_ACTIVE);
889 	if (!port)
890 		return (ENXIO);
891 
892 	iobase = rman_get_start(port);
893 	unit = device_get_unit(dev);
894 	com = device_get_softc(dev);
895 	flags = device_get_flags(dev);
896 
897 	if (unit >= sio_numunits)
898 		sio_numunits = unit + 1;
899 	/*
900 	 * sioprobe() has initialized the device registers as follows:
901 	 *	o cfcr = CFCR_8BITS.
902 	 *	  It is most important that CFCR_DLAB is off, so that the
903 	 *	  data port is not hidden when we enable interrupts.
904 	 *	o ier = 0.
905 	 *	  Interrupts are only enabled when the line is open.
906 	 *	o mcr = MCR_IENABLE, or 0 if the port has AST/4 compatible
907 	 *	  interrupt control register or the config specifies no irq.
908 	 *	  Keeping MCR_DTR and MCR_RTS off might stop the external
909 	 *	  device from sending before we are ready.
910 	 */
911 	bzero(com, sizeof *com);
912 	com->unit = unit;
913 	com->ioportres = port;
914 	com->ioportrid = rid;
915 	com->bst = rman_get_bustag(port);
916 	com->bsh = rman_get_bushandle(port);
917 	com->cfcr_image = CFCR_8BITS;
918 	com->loses_outints = COM_LOSESOUTINTS(flags) != 0;
919 	com->no_irq = bus_get_resource(dev, SYS_RES_IRQ, 0, NULL, NULL) != 0;
920 	com->tx_fifo_size = 1;
921 	com->obufs[0].l_head = com->obuf1;
922 	com->obufs[1].l_head = com->obuf2;
923 
924 	com->data_port = iobase + com_data;
925 	com->int_ctl_port = iobase + com_ier;
926 	com->int_id_port = iobase + com_iir;
927 	com->modem_ctl_port = iobase + com_mcr;
928 	com->mcr_image = inb(com->modem_ctl_port);
929 	com->line_status_port = iobase + com_lsr;
930 	com->modem_status_port = iobase + com_msr;
931 
932 	tp = com->tp = ttyalloc();
933 	tp->t_oproc = comstart;
934 	tp->t_param = comparam;
935 	tp->t_stop = comstop;
936 	tp->t_modem = commodem;
937 	tp->t_break = combreak;
938 	tp->t_close = comclose;
939 	tp->t_open = comopen;
940 	tp->t_sc = com;
941 
942 	if (rclk == 0)
943 		rclk = DEFAULT_RCLK;
944 	com->rclk = rclk;
945 
946 	if (unit == comconsole)
947 		ttyconsolemode(tp, comdefaultrate);
948 	error = siosetwater(com, tp->t_init_in.c_ispeed);
949 	mtx_unlock_spin(&sio_lock);
950 	if (error) {
951 		/*
952 		 * Leave i/o resources allocated if this is a `cn'-level
953 		 * console, so that other devices can't snarf them.
954 		 */
955 		if (iobase != siocniobase)
956 			bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
957 		return (ENOMEM);
958 	}
959 
960 	/* attempt to determine UART type */
961 	printf("sio%d: type", unit);
962 
963 	if (!COM_ISMULTIPORT(flags) &&
964 	    !COM_IIR_TXRDYBUG(flags) && !COM_NOSCR(flags)) {
965 		u_char	scr;
966 		u_char	scr1;
967 		u_char	scr2;
968 
969 		scr = sio_getreg(com, com_scr);
970 		sio_setreg(com, com_scr, 0xa5);
971 		scr1 = sio_getreg(com, com_scr);
972 		sio_setreg(com, com_scr, 0x5a);
973 		scr2 = sio_getreg(com, com_scr);
974 		sio_setreg(com, com_scr, scr);
975 		if (scr1 != 0xa5 || scr2 != 0x5a) {
976 			printf(" 8250 or not responding");
977 			goto determined_type;
978 		}
979 	}
980 	sio_setreg(com, com_fifo, FIFO_ENABLE | FIFO_RX_HIGH);
981 	DELAY(100);
982 	switch (inb(com->int_id_port) & IIR_FIFO_MASK) {
983 	case FIFO_RX_LOW:
984 		printf(" 16450");
985 		break;
986 	case FIFO_RX_MEDL:
987 		printf(" 16450?");
988 		break;
989 	case FIFO_RX_MEDH:
990 		printf(" 16550?");
991 		break;
992 	case FIFO_RX_HIGH:
993 		if (COM_NOFIFO(flags)) {
994 			printf(" 16550A fifo disabled");
995 			break;
996 		}
997 		com->hasfifo = TRUE;
998 		if (COM_ST16650A(flags)) {
999 			printf(" ST16650A");
1000 			com->st16650a = TRUE;
1001 			com->tx_fifo_size = 32;
1002 			break;
1003 		}
1004 		if (COM_TI16754(flags)) {
1005 			printf(" TI16754");
1006 			com->tx_fifo_size = 64;
1007 			break;
1008 		}
1009 		printf(" 16550A");
1010 #ifdef COM_ESP
1011 		for (espp = likely_esp_ports; *espp != 0; espp++)
1012 			if (espattach(com, *espp)) {
1013 				com->tx_fifo_size = 1024;
1014 				break;
1015 			}
1016 		if (com->esp)
1017 			break;
1018 #endif
1019 		com->tx_fifo_size = COM_FIFOSIZE(flags);
1020 		if (com->tx_fifo_size == 0)
1021 			com->tx_fifo_size = 16;
1022 		else
1023 			printf(" lookalike with %u bytes FIFO",
1024 			       com->tx_fifo_size);
1025 		break;
1026 	}
1027 #ifdef COM_ESP
1028 	if (com->esp) {
1029 		/*
1030 		 * Set 16550 compatibility mode.
1031 		 * We don't use the ESP_MODE_SCALE bit to increase the
1032 		 * fifo trigger levels because we can't handle large
1033 		 * bursts of input.
1034 		 * XXX flow control should be set in comparam(), not here.
1035 		 */
1036 		outb(com->esp_port + ESP_CMD1, ESP_SETMODE);
1037 		outb(com->esp_port + ESP_CMD2, ESP_MODE_RTS | ESP_MODE_FIFO);
1038 
1039 		/* Set RTS/CTS flow control. */
1040 		outb(com->esp_port + ESP_CMD1, ESP_SETFLOWTYPE);
1041 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_RTS);
1042 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_CTS);
1043 
1044 		/* Set flow-control levels. */
1045 		outb(com->esp_port + ESP_CMD1, ESP_SETRXFLOW);
1046 		outb(com->esp_port + ESP_CMD2, HIBYTE(768));
1047 		outb(com->esp_port + ESP_CMD2, LOBYTE(768));
1048 		outb(com->esp_port + ESP_CMD2, HIBYTE(512));
1049 		outb(com->esp_port + ESP_CMD2, LOBYTE(512));
1050 	}
1051 #endif /* COM_ESP */
1052 	sio_setreg(com, com_fifo, 0);
1053 determined_type: ;
1054 
1055 #ifdef COM_MULTIPORT
1056 	if (COM_ISMULTIPORT(flags)) {
1057 		device_t masterdev;
1058 
1059 		com->multiport = TRUE;
1060 		printf(" (multiport");
1061 		if (unit == COM_MPMASTER(flags))
1062 			printf(" master");
1063 		printf(")");
1064 		masterdev = devclass_get_device(sio_devclass,
1065 		    COM_MPMASTER(flags));
1066 		com->no_irq = (masterdev == NULL || bus_get_resource(masterdev,
1067 		    SYS_RES_IRQ, 0, NULL, NULL) != 0);
1068 	 }
1069 #endif /* COM_MULTIPORT */
1070 	if (unit == comconsole)
1071 		printf(", console");
1072 	if (COM_IIR_TXRDYBUG(flags))
1073 		printf(" with a buggy IIR_TXRDY implementation");
1074 	printf("\n");
1075 
1076 	if (sio_fast_ih == NULL) {
1077 		swi_add(&tty_intr_event, "sio", siopoll, NULL, SWI_TTY, 0,
1078 		    &sio_fast_ih);
1079 		swi_add(&clk_intr_event, "sio", siopoll, NULL, SWI_CLOCK, 0,
1080 		    &sio_slow_ih);
1081 	}
1082 
1083 	com->flags = flags;
1084 	com->pps.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1085 	tp->t_pps = &com->pps;
1086 
1087 	if (COM_PPSCTS(flags))
1088 		com->pps_bit = MSR_CTS;
1089 	else
1090 		com->pps_bit = MSR_DCD;
1091 	pps_init(&com->pps);
1092 
1093 	rid = 0;
1094 	com->irqres = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
1095 	if (com->irqres) {
1096 		ret = bus_setup_intr(dev, com->irqres,
1097 				     INTR_TYPE_TTY,
1098 				     siointr, NULL, com,
1099 				     &com->cookie);
1100 		if (ret) {
1101 			ret = bus_setup_intr(dev,
1102 					     com->irqres, INTR_TYPE_TTY,
1103 					     NULL, (driver_intr_t *)siointr, com, &com->cookie);
1104 			if (ret == 0)
1105 				device_printf(dev, "unable to activate interrupt in fast mode - using normal mode\n");
1106 		}
1107 		if (ret)
1108 			device_printf(dev, "could not activate interrupt\n");
1109 #if defined(KDB)
1110 		/*
1111 		 * Enable interrupts for early break-to-debugger support
1112 		 * on the console.
1113 		 */
1114 		if (ret == 0 && unit == comconsole)
1115 			outb(siocniobase + com_ier, IER_ERXRDY | IER_ERLS |
1116 			    IER_EMSC);
1117 #endif
1118 	}
1119 
1120 	/* We're ready, open the doors... */
1121 	ttycreate(tp, TS_CALLOUT, "d%r", unit);
1122 
1123 	return (0);
1124 }
1125 
1126 static int
comopen(struct tty * tp,struct cdev * dev)1127 comopen(struct tty *tp, struct cdev *dev)
1128 {
1129 	struct com_s	*com;
1130 	int i;
1131 
1132 	com = tp->t_sc;
1133 	com->poll = com->no_irq;
1134 	com->poll_output = com->loses_outints;
1135 	if (com->hasfifo) {
1136 		/*
1137 		 * (Re)enable and drain fifos.
1138 		 *
1139 		 * Certain SMC chips cause problems if the fifos
1140 		 * are enabled while input is ready.  Turn off the
1141 		 * fifo if necessary to clear the input.  We test
1142 		 * the input ready bit after enabling the fifos
1143 		 * since we've already enabled them in comparam()
1144 		 * and to handle races between enabling and fresh
1145 		 * input.
1146 		 */
1147 		for (i = 0; i < 500; i++) {
1148 			sio_setreg(com, com_fifo,
1149 				   FIFO_RCV_RST | FIFO_XMT_RST
1150 				   | com->fifo_image);
1151 			/*
1152 			 * XXX the delays are for superstitious
1153 			 * historical reasons.  It must be less than
1154 			 * the character time at the maximum
1155 			 * supported speed (87 usec at 115200 bps
1156 			 * 8N1).  Otherwise we might loop endlessly
1157 			 * if data is streaming in.  We used to use
1158 			 * delays of 100.  That usually worked
1159 			 * because DELAY(100) used to usually delay
1160 			 * for about 85 usec instead of 100.
1161 			 */
1162 			DELAY(50);
1163 			if (!(inb(com->line_status_port) & LSR_RXRDY))
1164 				break;
1165 			sio_setreg(com, com_fifo, 0);
1166 			DELAY(50);
1167 			(void) inb(com->data_port);
1168 		}
1169 		if (i == 500)
1170 			return (EIO);
1171 	}
1172 
1173 	mtx_lock_spin(&sio_lock);
1174 	(void) inb(com->line_status_port);
1175 	(void) inb(com->data_port);
1176 	com->prev_modem_status = com->last_modem_status
1177 	    = inb(com->modem_status_port);
1178 	outb(com->int_ctl_port,
1179 	     IER_ERXRDY | IER_ERLS | IER_EMSC
1180 	     | (COM_IIR_TXRDYBUG(com->flags) ? 0 : IER_ETXRDY));
1181 	mtx_unlock_spin(&sio_lock);
1182 	siosettimeout();
1183 	/* XXX: should be generic ? */
1184 	if (com->prev_modem_status & MSR_DCD || ISCALLOUT(dev))
1185 		ttyld_modem(tp, 1);
1186 	return (0);
1187 }
1188 
1189 static void
comclose(tp)1190 comclose(tp)
1191 	struct tty	*tp;
1192 {
1193 	int		s;
1194 	struct com_s	*com;
1195 
1196 	s = spltty();
1197 	com = tp->t_sc;
1198 	com->poll = FALSE;
1199 	com->poll_output = FALSE;
1200 	sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1201 
1202 #if defined(KDB)
1203 	/*
1204 	 * Leave interrupts enabled and don't clear DTR if this is the
1205 	 * console. This allows us to detect break-to-debugger events
1206 	 * while the console device is closed.
1207 	 */
1208 	if (com->unit != comconsole)
1209 #endif
1210 	{
1211 		sio_setreg(com, com_ier, 0);
1212 		if (tp->t_cflag & HUPCL
1213 		    /*
1214 		     * XXX we will miss any carrier drop between here and the
1215 		     * next open.  Perhaps we should watch DCD even when the
1216 		     * port is closed; it is not sufficient to check it at
1217 		     * the next open because it might go up and down while
1218 		     * we're not watching.
1219 		     */
1220 		    || (!tp->t_actout
1221 		        && !(com->prev_modem_status & MSR_DCD)
1222 		        && !(tp->t_init_in.c_cflag & CLOCAL))
1223 		    || !(tp->t_state & TS_ISOPEN)) {
1224 			(void)commodem(tp, 0, SER_DTR);
1225 			ttydtrwaitstart(tp);
1226 		}
1227 	}
1228 	if (com->hasfifo) {
1229 		/*
1230 		 * Disable fifos so that they are off after controlled
1231 		 * reboots.  Some BIOSes fail to detect 16550s when the
1232 		 * fifos are enabled.
1233 		 */
1234 		sio_setreg(com, com_fifo, 0);
1235 	}
1236 	tp->t_actout = FALSE;
1237 	wakeup(&tp->t_actout);
1238 	wakeup(TSA_CARR_ON(tp));	/* restart any wopeners */
1239 	siosettimeout();
1240 	splx(s);
1241 }
1242 
1243 static void
siobusycheck(chan)1244 siobusycheck(chan)
1245 	void	*chan;
1246 {
1247 	struct com_s	*com;
1248 	int		s;
1249 
1250 	com = (struct com_s *)chan;
1251 
1252 	/*
1253 	 * Clear TS_BUSY if low-level output is complete.
1254 	 * spl locking is sufficient because siointr1() does not set CS_BUSY.
1255 	 * If siointr1() clears CS_BUSY after we look at it, then we'll get
1256 	 * called again.  Reading the line status port outside of siointr1()
1257 	 * is safe because CS_BUSY is clear so there are no output interrupts
1258 	 * to lose.
1259 	 */
1260 	s = spltty();
1261 	if (com->state & CS_BUSY)
1262 		com->extra_state &= ~CSE_BUSYCHECK;	/* False alarm. */
1263 	else if ((inb(com->line_status_port) & (LSR_TSRE | LSR_TXRDY))
1264 	    == (LSR_TSRE | LSR_TXRDY)) {
1265 		com->tp->t_state &= ~TS_BUSY;
1266 		ttwwakeup(com->tp);
1267 		com->extra_state &= ~CSE_BUSYCHECK;
1268 	} else
1269 		timeout(siobusycheck, com, hz / 100);
1270 	splx(s);
1271 }
1272 
1273 static u_int
siodivisor(rclk,speed)1274 siodivisor(rclk, speed)
1275 	u_long	rclk;
1276 	speed_t	speed;
1277 {
1278 	long	actual_speed;
1279 	u_int	divisor;
1280 	int	error;
1281 
1282 	if (speed == 0)
1283 		return (0);
1284 #if UINT_MAX > (ULONG_MAX - 1) / 8
1285 	if (speed > (ULONG_MAX - 1) / 8)
1286 		return (0);
1287 #endif
1288 	divisor = (rclk / (8UL * speed) + 1) / 2;
1289 	if (divisor == 0 || divisor >= 65536)
1290 		return (0);
1291 	actual_speed = rclk / (16UL * divisor);
1292 
1293 	/* 10 times error in percent: */
1294 	error = ((actual_speed - (long)speed) * 2000 / (long)speed + 1) / 2;
1295 
1296 	/* 3.0% maximum error tolerance: */
1297 	if (error < -30 || error > 30)
1298 		return (0);
1299 
1300 	return (divisor);
1301 }
1302 
1303 /*
1304  * Call this function with the sio_lock mutex held.  It will return with the
1305  * lock still held.
1306  */
1307 static void
sioinput(com)1308 sioinput(com)
1309 	struct com_s	*com;
1310 {
1311 	u_char		*buf;
1312 	int		incc;
1313 	u_char		line_status;
1314 	int		recv_data;
1315 	struct tty	*tp;
1316 
1317 	buf = com->ibuf;
1318 	tp = com->tp;
1319 	if (!(tp->t_state & TS_ISOPEN) || !(tp->t_cflag & CREAD)) {
1320 		com_events -= (com->iptr - com->ibuf);
1321 		com->iptr = com->ibuf;
1322 		return;
1323 	}
1324 	if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
1325 		/*
1326 		 * Avoid the grotesquely inefficient lineswitch routine
1327 		 * (ttyinput) in "raw" mode.  It usually takes about 450
1328 		 * instructions (that's without canonical processing or echo!).
1329 		 * slinput is reasonably fast (usually 40 instructions plus
1330 		 * call overhead).
1331 		 */
1332 		do {
1333 			/*
1334 			 * This may look odd, but it is using save-and-enable
1335 			 * semantics instead of the save-and-disable semantics
1336 			 * that are used everywhere else.
1337 			 */
1338 			mtx_unlock_spin(&sio_lock);
1339 			incc = com->iptr - buf;
1340 			if (tp->t_rawq.c_cc + incc > tp->t_ihiwat
1341 			    && (com->state & CS_RTS_IFLOW
1342 				|| tp->t_iflag & IXOFF)
1343 			    && !(tp->t_state & TS_TBLOCK))
1344 				ttyblock(tp);
1345 			com->delta_error_counts[CE_TTY_BUF_OVERFLOW]
1346 				+= b_to_q((char *)buf, incc, &tp->t_rawq);
1347 			buf += incc;
1348 			tk_nin += incc;
1349 			tk_rawcc += incc;
1350 			tp->t_rawcc += incc;
1351 			ttwakeup(tp);
1352 			if (tp->t_state & TS_TTSTOP
1353 			    && (tp->t_iflag & IXANY
1354 				|| tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
1355 				tp->t_state &= ~TS_TTSTOP;
1356 				tp->t_lflag &= ~FLUSHO;
1357 				comstart(tp);
1358 			}
1359 			mtx_lock_spin(&sio_lock);
1360 		} while (buf < com->iptr);
1361 	} else {
1362 		do {
1363 			/*
1364 			 * This may look odd, but it is using save-and-enable
1365 			 * semantics instead of the save-and-disable semantics
1366 			 * that are used everywhere else.
1367 			 */
1368 			mtx_unlock_spin(&sio_lock);
1369 			line_status = buf[com->ierroff];
1370 			recv_data = *buf++;
1371 			if (line_status
1372 			    & (LSR_BI | LSR_FE | LSR_OE | LSR_PE)) {
1373 				if (line_status & LSR_BI)
1374 					recv_data |= TTY_BI;
1375 				if (line_status & LSR_FE)
1376 					recv_data |= TTY_FE;
1377 				if (line_status & LSR_OE)
1378 					recv_data |= TTY_OE;
1379 				if (line_status & LSR_PE)
1380 					recv_data |= TTY_PE;
1381 			}
1382 			ttyld_rint(tp, recv_data);
1383 			mtx_lock_spin(&sio_lock);
1384 		} while (buf < com->iptr);
1385 	}
1386 	com_events -= (com->iptr - com->ibuf);
1387 	com->iptr = com->ibuf;
1388 
1389 	/*
1390 	 * There is now room for another low-level buffer full of input,
1391 	 * so enable RTS if it is now disabled and there is room in the
1392 	 * high-level buffer.
1393 	 */
1394 	if ((com->state & CS_RTS_IFLOW) && !(com->mcr_image & MCR_RTS) &&
1395 	    !(tp->t_state & TS_TBLOCK))
1396 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1397 }
1398 
1399 static int
siointr(arg)1400 siointr(arg)
1401 	void		*arg;
1402 {
1403 	struct com_s	*com;
1404 
1405 #ifndef COM_MULTIPORT
1406 	com = (struct com_s *)arg;
1407 
1408 	mtx_lock_spin(&sio_lock);
1409 	siointr1(com);
1410 	mtx_unlock_spin(&sio_lock);
1411 #else /* COM_MULTIPORT */
1412 	bool_t		possibly_more_intrs;
1413 	int		unit;
1414 
1415 	/*
1416 	 * Loop until there is no activity on any port.  This is necessary
1417 	 * to get an interrupt edge more than to avoid another interrupt.
1418 	 * If the IRQ signal is just an OR of the IRQ signals from several
1419 	 * devices, then the edge from one may be lost because another is
1420 	 * on.
1421 	 */
1422 	mtx_lock_spin(&sio_lock);
1423 	do {
1424 		possibly_more_intrs = FALSE;
1425 		for (unit = 0; unit < sio_numunits; ++unit) {
1426 			com = com_addr(unit);
1427 			/*
1428 			 * XXX COM_LOCK();
1429 			 * would it work here, or be counter-productive?
1430 			 */
1431 			if (com != NULL
1432 			    && !com->gone
1433 			    && (inb(com->int_id_port) & IIR_IMASK)
1434 			       != IIR_NOPEND) {
1435 				siointr1(com);
1436 				possibly_more_intrs = TRUE;
1437 			}
1438 			/* XXX COM_UNLOCK(); */
1439 		}
1440 	} while (possibly_more_intrs);
1441 	mtx_unlock_spin(&sio_lock);
1442 #endif /* COM_MULTIPORT */
1443 	return(FILTER_HANDLED);
1444 }
1445 
1446 static struct timespec siots[8];
1447 static int siotso;
1448 static int volatile siotsunit = -1;
1449 
1450 static int
sysctl_siots(SYSCTL_HANDLER_ARGS)1451 sysctl_siots(SYSCTL_HANDLER_ARGS)
1452 {
1453 	char buf[128];
1454 	long long delta;
1455 	size_t len;
1456 	int error, i, tso;
1457 
1458 	for (i = 1, tso = siotso; i < tso; i++) {
1459 		delta = (long long)(siots[i].tv_sec - siots[i - 1].tv_sec) *
1460 		    1000000000 +
1461 		    (siots[i].tv_nsec - siots[i - 1].tv_nsec);
1462 		len = sprintf(buf, "%lld\n", delta);
1463 		if (delta >= 110000)
1464 			len += sprintf(buf + len - 1, ": *** %ld.%09ld\n",
1465 			    (long)siots[i].tv_sec, siots[i].tv_nsec) - 1;
1466 		if (i == tso - 1)
1467 			buf[len - 1] = '\0';
1468 		error = SYSCTL_OUT(req, buf, len);
1469 		if (error != 0)
1470 			return (error);
1471 	}
1472 	return (0);
1473 }
1474 
1475 SYSCTL_PROC(_machdep, OID_AUTO, siots, CTLTYPE_STRING | CTLFLAG_RD,
1476     0, 0, sysctl_siots, "A", "sio timestamps");
1477 
1478 static void
siointr1(com)1479 siointr1(com)
1480 	struct com_s	*com;
1481 {
1482 	u_char	int_ctl;
1483 	u_char	int_ctl_new;
1484 	u_char	line_status;
1485 	u_char	modem_status;
1486 	u_char	*ioptr;
1487 	u_char	recv_data;
1488 
1489 #ifdef KDB
1490 again:
1491 #endif
1492 
1493 	if (COM_IIR_TXRDYBUG(com->flags)) {
1494 		int_ctl = inb(com->int_ctl_port);
1495 		int_ctl_new = int_ctl;
1496 	} else {
1497 		int_ctl = 0;
1498 		int_ctl_new = 0;
1499 	}
1500 
1501 	while (!com->gone) {
1502 		if (com->pps.ppsparam.mode & PPS_CAPTUREBOTH) {
1503 			modem_status = inb(com->modem_status_port);
1504 		        if ((modem_status ^ com->last_modem_status) &
1505 			    com->pps_bit) {
1506 				pps_capture(&com->pps);
1507 				pps_event(&com->pps,
1508 				    (modem_status & com->pps_bit) ?
1509 				    PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
1510 			}
1511 		}
1512 		line_status = inb(com->line_status_port);
1513 
1514 		/* input event? (check first to help avoid overruns) */
1515 		while (line_status & LSR_RCV_MASK) {
1516 			/* break/unnattached error bits or real input? */
1517 			if (!(line_status & LSR_RXRDY))
1518 				recv_data = 0;
1519 			else
1520 				recv_data = inb(com->data_port);
1521 #ifdef KDB
1522 			if (com->unit == comconsole &&
1523 			    kdb_alt_break(recv_data, &com->alt_brk_state) != 0)
1524 				goto again;
1525 #endif /* KDB */
1526 			if (line_status & (LSR_BI | LSR_FE | LSR_PE)) {
1527 				/*
1528 				 * Don't store BI if IGNBRK or FE/PE if IGNPAR.
1529 				 * Otherwise, push the work to a higher level
1530 				 * (to handle PARMRK) if we're bypassing.
1531 				 * Otherwise, convert BI/FE and PE+INPCK to 0.
1532 				 *
1533 				 * This makes bypassing work right in the
1534 				 * usual "raw" case (IGNBRK set, and IGNPAR
1535 				 * and INPCK clear).
1536 				 *
1537 				 * Note: BI together with FE/PE means just BI.
1538 				 */
1539 				if (line_status & LSR_BI) {
1540 #if defined(KDB)
1541 					if (com->unit == comconsole) {
1542 						kdb_break();
1543 						goto cont;
1544 					}
1545 #endif
1546 					if (com->tp == NULL
1547 					    || com->tp->t_iflag & IGNBRK)
1548 						goto cont;
1549 				} else {
1550 					if (com->tp == NULL
1551 					    || com->tp->t_iflag & IGNPAR)
1552 						goto cont;
1553 				}
1554 				if (com->tp->t_state & TS_CAN_BYPASS_L_RINT
1555 				    && (line_status & (LSR_BI | LSR_FE)
1556 					|| com->tp->t_iflag & INPCK))
1557 					recv_data = 0;
1558 			}
1559 			++com->bytes_in;
1560 			if (com->tp != NULL &&
1561 			    com->tp->t_hotchar != 0 && recv_data == com->tp->t_hotchar)
1562 				swi_sched(sio_fast_ih, 0);
1563 			ioptr = com->iptr;
1564 			if (ioptr >= com->ibufend)
1565 				CE_RECORD(com, CE_INTERRUPT_BUF_OVERFLOW);
1566 			else {
1567 				if (com->tp != NULL && com->tp->t_do_timestamp)
1568 					microtime(&com->tp->t_timestamp);
1569 				++com_events;
1570 				swi_sched(sio_slow_ih, SWI_DELAY);
1571 #if 0 /* for testing input latency vs efficiency */
1572 if (com->iptr - com->ibuf == 8)
1573 	swi_sched(sio_fast_ih, 0);
1574 #endif
1575 				ioptr[0] = recv_data;
1576 				ioptr[com->ierroff] = line_status;
1577 				com->iptr = ++ioptr;
1578 				if (ioptr == com->ihighwater
1579 				    && com->state & CS_RTS_IFLOW)
1580 					outb(com->modem_ctl_port,
1581 					     com->mcr_image &= ~MCR_RTS);
1582 				if (line_status & LSR_OE)
1583 					CE_RECORD(com, CE_OVERRUN);
1584 			}
1585 cont:
1586 			if (line_status & LSR_TXRDY
1587 			    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY))
1588 				goto txrdy;
1589 
1590 			/*
1591 			 * "& 0x7F" is to avoid the gcc-1.40 generating a slow
1592 			 * jump from the top of the loop to here
1593 			 */
1594 			line_status = inb(com->line_status_port) & 0x7F;
1595 		}
1596 
1597 		/* modem status change? (always check before doing output) */
1598 		modem_status = inb(com->modem_status_port);
1599 		if (modem_status != com->last_modem_status) {
1600 			/*
1601 			 * Schedule high level to handle DCD changes.  Note
1602 			 * that we don't use the delta bits anywhere.  Some
1603 			 * UARTs mess them up, and it's easy to remember the
1604 			 * previous bits and calculate the delta.
1605 			 */
1606 			com->last_modem_status = modem_status;
1607 			if (!(com->state & CS_CHECKMSR)) {
1608 				com_events += LOTS_OF_EVENTS;
1609 				com->state |= CS_CHECKMSR;
1610 				swi_sched(sio_fast_ih, 0);
1611 			}
1612 
1613 			/* handle CTS change immediately for crisp flow ctl */
1614 			if (com->state & CS_CTS_OFLOW) {
1615 				if (modem_status & MSR_CTS)
1616 					com->state |= CS_ODEVREADY;
1617 				else
1618 					com->state &= ~CS_ODEVREADY;
1619 			}
1620 		}
1621 
1622 txrdy:
1623 		/* output queued and everything ready? */
1624 		if (line_status & LSR_TXRDY
1625 		    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY)) {
1626 			ioptr = com->obufq.l_head;
1627 			if (com->tx_fifo_size > 1 && com->unit != siotsunit) {
1628 				u_int	ocount;
1629 
1630 				ocount = com->obufq.l_tail - ioptr;
1631 				if (ocount > com->tx_fifo_size)
1632 					ocount = com->tx_fifo_size;
1633 				com->bytes_out += ocount;
1634 				do
1635 					outb(com->data_port, *ioptr++);
1636 				while (--ocount != 0);
1637 			} else {
1638 				outb(com->data_port, *ioptr++);
1639 				++com->bytes_out;
1640 				if (com->unit == siotsunit
1641 				    && siotso < nitems(siots))
1642 					nanouptime(&siots[siotso++]);
1643 			}
1644 			com->obufq.l_head = ioptr;
1645 			if (COM_IIR_TXRDYBUG(com->flags))
1646 				int_ctl_new = int_ctl | IER_ETXRDY;
1647 			if (ioptr >= com->obufq.l_tail) {
1648 				struct lbq	*qp;
1649 
1650 				qp = com->obufq.l_next;
1651 				qp->l_queued = FALSE;
1652 				qp = qp->l_next;
1653 				if (qp != NULL) {
1654 					com->obufq.l_head = qp->l_head;
1655 					com->obufq.l_tail = qp->l_tail;
1656 					com->obufq.l_next = qp;
1657 				} else {
1658 					/* output just completed */
1659 					if (COM_IIR_TXRDYBUG(com->flags))
1660 						int_ctl_new = int_ctl
1661 							      & ~IER_ETXRDY;
1662 					com->state &= ~CS_BUSY;
1663 				}
1664 				if (!(com->state & CS_ODONE)) {
1665 					com_events += LOTS_OF_EVENTS;
1666 					com->state |= CS_ODONE;
1667 					/* handle at high level ASAP */
1668 					swi_sched(sio_fast_ih, 0);
1669 				}
1670 			}
1671 			if (COM_IIR_TXRDYBUG(com->flags)
1672 			    && int_ctl != int_ctl_new)
1673 				outb(com->int_ctl_port, int_ctl_new);
1674 		}
1675 
1676 		/* finished? */
1677 #ifndef COM_MULTIPORT
1678 		if ((inb(com->int_id_port) & IIR_IMASK) == IIR_NOPEND)
1679 #endif /* COM_MULTIPORT */
1680 			return;
1681 	}
1682 }
1683 
1684 /* software interrupt handler for SWI_TTY */
1685 static void
siopoll(void * dummy)1686 siopoll(void *dummy)
1687 {
1688 	int		unit;
1689 
1690 	if (com_events == 0)
1691 		return;
1692 repeat:
1693 	for (unit = 0; unit < sio_numunits; ++unit) {
1694 		struct com_s	*com;
1695 		int		incc;
1696 		struct tty	*tp;
1697 
1698 		com = com_addr(unit);
1699 		if (com == NULL)
1700 			continue;
1701 		tp = com->tp;
1702 		if (tp == NULL || com->gone) {
1703 			/*
1704 			 * Discard any events related to never-opened or
1705 			 * going-away devices.
1706 			 */
1707 			mtx_lock_spin(&sio_lock);
1708 			incc = com->iptr - com->ibuf;
1709 			com->iptr = com->ibuf;
1710 			if (com->state & CS_CHECKMSR) {
1711 				incc += LOTS_OF_EVENTS;
1712 				com->state &= ~CS_CHECKMSR;
1713 			}
1714 			com_events -= incc;
1715 			mtx_unlock_spin(&sio_lock);
1716 			continue;
1717 		}
1718 		if (com->iptr != com->ibuf) {
1719 			mtx_lock_spin(&sio_lock);
1720 			sioinput(com);
1721 			mtx_unlock_spin(&sio_lock);
1722 		}
1723 		if (com->state & CS_CHECKMSR) {
1724 			u_char	delta_modem_status;
1725 
1726 			mtx_lock_spin(&sio_lock);
1727 			delta_modem_status = com->last_modem_status
1728 					     ^ com->prev_modem_status;
1729 			com->prev_modem_status = com->last_modem_status;
1730 			com_events -= LOTS_OF_EVENTS;
1731 			com->state &= ~CS_CHECKMSR;
1732 			mtx_unlock_spin(&sio_lock);
1733 			if (delta_modem_status & MSR_DCD)
1734 				ttyld_modem(tp,
1735 				    com->prev_modem_status & MSR_DCD);
1736 		}
1737 		if (com->state & CS_ODONE) {
1738 			mtx_lock_spin(&sio_lock);
1739 			com_events -= LOTS_OF_EVENTS;
1740 			com->state &= ~CS_ODONE;
1741 			mtx_unlock_spin(&sio_lock);
1742 			if (!(com->state & CS_BUSY)
1743 			    && !(com->extra_state & CSE_BUSYCHECK)) {
1744 				timeout(siobusycheck, com, hz / 100);
1745 				com->extra_state |= CSE_BUSYCHECK;
1746 			}
1747 			ttyld_start(tp);
1748 		}
1749 		if (com_events == 0)
1750 			break;
1751 	}
1752 	if (com_events >= LOTS_OF_EVENTS)
1753 		goto repeat;
1754 }
1755 
1756 static void
combreak(tp,sig)1757 combreak(tp, sig)
1758 	struct tty 	*tp;
1759 	int		sig;
1760 {
1761 	struct com_s	*com;
1762 
1763 	com = tp->t_sc;
1764 
1765 	if (sig)
1766 		sio_setreg(com, com_cfcr, com->cfcr_image |= CFCR_SBREAK);
1767 	else
1768 		sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1769 }
1770 
1771 static int
comparam(tp,t)1772 comparam(tp, t)
1773 	struct tty	*tp;
1774 	struct termios	*t;
1775 {
1776 	u_int		cfcr;
1777 	int		cflag;
1778 	struct com_s	*com;
1779 	u_int		divisor;
1780 	u_char		dlbh;
1781 	u_char		dlbl;
1782 	u_char		efr_flowbits;
1783 	int		s;
1784 
1785 	com = tp->t_sc;
1786 	if (com == NULL)
1787 		return (ENODEV);
1788 
1789 	/* check requested parameters */
1790 	if (t->c_ispeed != (t->c_ospeed != 0 ? t->c_ospeed : tp->t_ospeed))
1791 		return (EINVAL);
1792 	divisor = siodivisor(com->rclk, t->c_ispeed);
1793 	if (divisor == 0)
1794 		return (EINVAL);
1795 
1796 	/* parameters are OK, convert them to the com struct and the device */
1797 	s = spltty();
1798 	if (t->c_ospeed == 0)
1799 		(void)commodem(tp, 0, SER_DTR);	/* hang up line */
1800 	else
1801 		(void)commodem(tp, SER_DTR, 0);
1802 	cflag = t->c_cflag;
1803 	switch (cflag & CSIZE) {
1804 	case CS5:
1805 		cfcr = CFCR_5BITS;
1806 		break;
1807 	case CS6:
1808 		cfcr = CFCR_6BITS;
1809 		break;
1810 	case CS7:
1811 		cfcr = CFCR_7BITS;
1812 		break;
1813 	default:
1814 		cfcr = CFCR_8BITS;
1815 		break;
1816 	}
1817 	if (cflag & PARENB) {
1818 		cfcr |= CFCR_PENAB;
1819 		if (!(cflag & PARODD))
1820 			cfcr |= CFCR_PEVEN;
1821 	}
1822 	if (cflag & CSTOPB)
1823 		cfcr |= CFCR_STOPB;
1824 
1825 	if (com->hasfifo) {
1826 		/*
1827 		 * Use a fifo trigger level low enough so that the input
1828 		 * latency from the fifo is less than about 16 msec and
1829 		 * the total latency is less than about 30 msec.  These
1830 		 * latencies are reasonable for humans.  Serial comms
1831 		 * protocols shouldn't expect anything better since modem
1832 		 * latencies are larger.
1833 		 *
1834 		 * The fifo trigger level cannot be set at RX_HIGH for high
1835 		 * speed connections without further work on reducing
1836 		 * interrupt disablement times in other parts of the system,
1837 		 * without producing silo overflow errors.
1838 		 */
1839 		com->fifo_image = com->unit == siotsunit ? 0
1840 				  : t->c_ispeed <= 4800
1841 				  ? FIFO_ENABLE : FIFO_ENABLE | FIFO_RX_MEDH;
1842 #ifdef COM_ESP
1843 		/*
1844 		 * The Hayes ESP card needs the fifo DMA mode bit set
1845 		 * in compatibility mode.  If not, it will interrupt
1846 		 * for each character received.
1847 		 */
1848 		if (com->esp)
1849 			com->fifo_image |= FIFO_DMA_MODE;
1850 #endif
1851 		sio_setreg(com, com_fifo, com->fifo_image);
1852 	}
1853 
1854 	/*
1855 	 * This returns with interrupts disabled so that we can complete
1856 	 * the speed change atomically.  Keeping interrupts disabled is
1857 	 * especially important while com_data is hidden.
1858 	 */
1859 	(void) siosetwater(com, t->c_ispeed);
1860 
1861 	sio_setreg(com, com_cfcr, cfcr | CFCR_DLAB);
1862 	/*
1863 	 * Only set the divisor registers if they would change, since on
1864 	 * some 16550 incompatibles (UMC8669F), setting them while input
1865 	 * is arriving loses sync until data stops arriving.
1866 	 */
1867 	dlbl = divisor & 0xFF;
1868 	if (sio_getreg(com, com_dlbl) != dlbl)
1869 		sio_setreg(com, com_dlbl, dlbl);
1870 	dlbh = divisor >> 8;
1871 	if (sio_getreg(com, com_dlbh) != dlbh)
1872 		sio_setreg(com, com_dlbh, dlbh);
1873 
1874 	efr_flowbits = 0;
1875 
1876 	if (cflag & CRTS_IFLOW) {
1877 		com->state |= CS_RTS_IFLOW;
1878 		efr_flowbits |= EFR_AUTORTS;
1879 		/*
1880 		 * If CS_RTS_IFLOW just changed from off to on, the change
1881 		 * needs to be propagated to MCR_RTS.  This isn't urgent,
1882 		 * so do it later by calling comstart() instead of repeating
1883 		 * a lot of code from comstart() here.
1884 		 */
1885 	} else if (com->state & CS_RTS_IFLOW) {
1886 		com->state &= ~CS_RTS_IFLOW;
1887 		/*
1888 		 * CS_RTS_IFLOW just changed from on to off.  Force MCR_RTS
1889 		 * on here, since comstart() won't do it later.
1890 		 */
1891 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1892 	}
1893 
1894 	/*
1895 	 * Set up state to handle output flow control.
1896 	 * XXX - worth handling MDMBUF (DCD) flow control at the lowest level?
1897 	 * Now has 10+ msec latency, while CTS flow has 50- usec latency.
1898 	 */
1899 	com->state |= CS_ODEVREADY;
1900 	com->state &= ~CS_CTS_OFLOW;
1901 	if (cflag & CCTS_OFLOW) {
1902 		com->state |= CS_CTS_OFLOW;
1903 		efr_flowbits |= EFR_AUTOCTS;
1904 		if (!(com->last_modem_status & MSR_CTS))
1905 			com->state &= ~CS_ODEVREADY;
1906 	}
1907 
1908 	if (com->st16650a) {
1909 		sio_setreg(com, com_lcr, LCR_EFR_ENABLE);
1910 		sio_setreg(com, com_efr,
1911 			   (sio_getreg(com, com_efr)
1912 			    & ~(EFR_AUTOCTS | EFR_AUTORTS)) | efr_flowbits);
1913 	}
1914 	sio_setreg(com, com_cfcr, com->cfcr_image = cfcr);
1915 
1916 	/* XXX shouldn't call functions while intrs are disabled. */
1917 	ttyldoptim(tp);
1918 
1919 	mtx_unlock_spin(&sio_lock);
1920 	splx(s);
1921 	comstart(tp);
1922 	if (com->ibufold != NULL) {
1923 		free(com->ibufold, M_DEVBUF);
1924 		com->ibufold = NULL;
1925 	}
1926 	return (0);
1927 }
1928 
1929 /*
1930  * This function must be called with the sio_lock mutex released and will
1931  * return with it obtained.
1932  */
1933 static int
siosetwater(com,speed)1934 siosetwater(com, speed)
1935 	struct com_s	*com;
1936 	speed_t		speed;
1937 {
1938 	int		cp4ticks;
1939 	u_char		*ibuf;
1940 	int		ibufsize;
1941 	struct tty	*tp;
1942 
1943 	/*
1944 	 * Make the buffer size large enough to handle a softtty interrupt
1945 	 * latency of about 2 ticks without loss of throughput or data
1946 	 * (about 3 ticks if input flow control is not used or not honoured,
1947 	 * but a bit less for CS5-CS7 modes).
1948 	 */
1949 	cp4ticks = speed / 10 / hz * 4;
1950 	for (ibufsize = 128; ibufsize < cp4ticks;)
1951 		ibufsize <<= 1;
1952 	if (ibufsize == com->ibufsize) {
1953 		mtx_lock_spin(&sio_lock);
1954 		return (0);
1955 	}
1956 
1957 	/*
1958 	 * Allocate input buffer.  The extra factor of 2 in the size is
1959 	 * to allow for an error byte for each input byte.
1960 	 */
1961 	ibuf = malloc(2 * ibufsize, M_DEVBUF, M_NOWAIT);
1962 	if (ibuf == NULL) {
1963 		mtx_lock_spin(&sio_lock);
1964 		return (ENOMEM);
1965 	}
1966 
1967 	/* Initialize non-critical variables. */
1968 	com->ibufold = com->ibuf;
1969 	com->ibufsize = ibufsize;
1970 	tp = com->tp;
1971 	if (tp != NULL) {
1972 		tp->t_ififosize = 2 * ibufsize;
1973 		tp->t_ispeedwat = (speed_t)-1;
1974 		tp->t_ospeedwat = (speed_t)-1;
1975 	}
1976 
1977 	/*
1978 	 * Read current input buffer, if any.  Continue with interrupts
1979 	 * disabled.
1980 	 */
1981 	mtx_lock_spin(&sio_lock);
1982 	if (com->iptr != com->ibuf)
1983 		sioinput(com);
1984 
1985 	/*-
1986 	 * Initialize critical variables, including input buffer watermarks.
1987 	 * The external device is asked to stop sending when the buffer
1988 	 * exactly reaches high water, or when the high level requests it.
1989 	 * The high level is notified immediately (rather than at a later
1990 	 * clock tick) when this watermark is reached.
1991 	 * The buffer size is chosen so the watermark should almost never
1992 	 * be reached.
1993 	 * The low watermark is invisibly 0 since the buffer is always
1994 	 * emptied all at once.
1995 	 */
1996 	com->iptr = com->ibuf = ibuf;
1997 	com->ibufend = ibuf + ibufsize;
1998 	com->ierroff = ibufsize;
1999 	com->ihighwater = ibuf + 3 * ibufsize / 4;
2000 	return (0);
2001 }
2002 
2003 static void
comstart(tp)2004 comstart(tp)
2005 	struct tty	*tp;
2006 {
2007 	struct com_s	*com;
2008 	int		s;
2009 
2010 	com = tp->t_sc;
2011 	if (com == NULL)
2012 		return;
2013 	s = spltty();
2014 	mtx_lock_spin(&sio_lock);
2015 	if (tp->t_state & TS_TTSTOP)
2016 		com->state &= ~CS_TTGO;
2017 	else
2018 		com->state |= CS_TTGO;
2019 	if (tp->t_state & TS_TBLOCK) {
2020 		if (com->mcr_image & MCR_RTS && com->state & CS_RTS_IFLOW)
2021 			outb(com->modem_ctl_port, com->mcr_image &= ~MCR_RTS);
2022 	} else {
2023 		if (!(com->mcr_image & MCR_RTS) && com->iptr < com->ihighwater
2024 		    && com->state & CS_RTS_IFLOW)
2025 			outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2026 	}
2027 	mtx_unlock_spin(&sio_lock);
2028 	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
2029 		ttwwakeup(tp);
2030 		splx(s);
2031 		return;
2032 	}
2033 	if (tp->t_outq.c_cc != 0) {
2034 		struct lbq	*qp;
2035 		struct lbq	*next;
2036 
2037 		if (!com->obufs[0].l_queued) {
2038 			com->obufs[0].l_tail
2039 			    = com->obuf1 + q_to_b(&tp->t_outq, com->obuf1,
2040 						  sizeof com->obuf1);
2041 			com->obufs[0].l_next = NULL;
2042 			com->obufs[0].l_queued = TRUE;
2043 			mtx_lock_spin(&sio_lock);
2044 			if (com->state & CS_BUSY) {
2045 				qp = com->obufq.l_next;
2046 				while ((next = qp->l_next) != NULL)
2047 					qp = next;
2048 				qp->l_next = &com->obufs[0];
2049 			} else {
2050 				com->obufq.l_head = com->obufs[0].l_head;
2051 				com->obufq.l_tail = com->obufs[0].l_tail;
2052 				com->obufq.l_next = &com->obufs[0];
2053 				com->state |= CS_BUSY;
2054 			}
2055 			mtx_unlock_spin(&sio_lock);
2056 		}
2057 		if (tp->t_outq.c_cc != 0 && !com->obufs[1].l_queued) {
2058 			com->obufs[1].l_tail
2059 			    = com->obuf2 + q_to_b(&tp->t_outq, com->obuf2,
2060 						  sizeof com->obuf2);
2061 			com->obufs[1].l_next = NULL;
2062 			com->obufs[1].l_queued = TRUE;
2063 			mtx_lock_spin(&sio_lock);
2064 			if (com->state & CS_BUSY) {
2065 				qp = com->obufq.l_next;
2066 				while ((next = qp->l_next) != NULL)
2067 					qp = next;
2068 				qp->l_next = &com->obufs[1];
2069 			} else {
2070 				com->obufq.l_head = com->obufs[1].l_head;
2071 				com->obufq.l_tail = com->obufs[1].l_tail;
2072 				com->obufq.l_next = &com->obufs[1];
2073 				com->state |= CS_BUSY;
2074 			}
2075 			mtx_unlock_spin(&sio_lock);
2076 		}
2077 		tp->t_state |= TS_BUSY;
2078 	}
2079 	mtx_lock_spin(&sio_lock);
2080 	if (com->state >= (CS_BUSY | CS_TTGO))
2081 		siointr1(com);	/* fake interrupt to start output */
2082 	mtx_unlock_spin(&sio_lock);
2083 	ttwwakeup(tp);
2084 	splx(s);
2085 }
2086 
2087 static void
comstop(tp,rw)2088 comstop(tp, rw)
2089 	struct tty	*tp;
2090 	int		rw;
2091 {
2092 	struct com_s	*com;
2093 
2094 	com = tp->t_sc;
2095 	if (com == NULL || com->gone)
2096 		return;
2097 	mtx_lock_spin(&sio_lock);
2098 	if (rw & FWRITE) {
2099 		if (com->hasfifo)
2100 #ifdef COM_ESP
2101 		    /* XXX avoid h/w bug. */
2102 		    if (!com->esp)
2103 #endif
2104 			sio_setreg(com, com_fifo,
2105 				   FIFO_XMT_RST | com->fifo_image);
2106 		com->obufs[0].l_queued = FALSE;
2107 		com->obufs[1].l_queued = FALSE;
2108 		if (com->state & CS_ODONE)
2109 			com_events -= LOTS_OF_EVENTS;
2110 		com->state &= ~(CS_ODONE | CS_BUSY);
2111 		com->tp->t_state &= ~TS_BUSY;
2112 	}
2113 	if (rw & FREAD) {
2114 		if (com->hasfifo)
2115 #ifdef COM_ESP
2116 		    /* XXX avoid h/w bug. */
2117 		    if (!com->esp)
2118 #endif
2119 			sio_setreg(com, com_fifo,
2120 				   FIFO_RCV_RST | com->fifo_image);
2121 		com_events -= (com->iptr - com->ibuf);
2122 		com->iptr = com->ibuf;
2123 	}
2124 	mtx_unlock_spin(&sio_lock);
2125 	comstart(tp);
2126 }
2127 
2128 static int
commodem(struct tty * tp,int sigon,int sigoff)2129 commodem(struct tty *tp, int sigon, int sigoff)
2130 {
2131 	struct com_s	*com;
2132 	int	bitand, bitor, msr;
2133 
2134 	com = tp->t_sc;
2135 	if (com->gone)
2136 		return(0);
2137 	if (sigon != 0 || sigoff != 0) {
2138 		bitand = bitor = 0;
2139 		if (sigoff & SER_DTR)
2140 			bitand |= MCR_DTR;
2141 		if (sigoff & SER_RTS)
2142 			bitand |= MCR_RTS;
2143 		if (sigon & SER_DTR)
2144 			bitor |= MCR_DTR;
2145 		if (sigon & SER_RTS)
2146 			bitor |= MCR_RTS;
2147 		bitand = ~bitand;
2148 		mtx_lock_spin(&sio_lock);
2149 		com->mcr_image &= bitand;
2150 		com->mcr_image |= bitor;
2151 		outb(com->modem_ctl_port, com->mcr_image);
2152 		mtx_unlock_spin(&sio_lock);
2153 		return (0);
2154 	} else {
2155 		bitor = 0;
2156 		if (com->mcr_image & MCR_DTR)
2157 			bitor |= SER_DTR;
2158 		if (com->mcr_image & MCR_RTS)
2159 			bitor |= SER_RTS;
2160 		msr = com->prev_modem_status;
2161 		if (msr & MSR_CTS)
2162 			bitor |= SER_CTS;
2163 		if (msr & MSR_DCD)
2164 			bitor |= SER_DCD;
2165 		if (msr & MSR_DSR)
2166 			bitor |= SER_DSR;
2167 		if (msr & MSR_DSR)
2168 			bitor |= SER_DSR;
2169 		if (msr & (MSR_RI | MSR_TERI))
2170 			bitor |= SER_RI;
2171 		return (bitor);
2172 	}
2173 }
2174 
2175 static void
siosettimeout()2176 siosettimeout()
2177 {
2178 	struct com_s	*com;
2179 	bool_t		someopen;
2180 	int		unit;
2181 
2182 	/*
2183 	 * Set our timeout period to 1 second if no polled devices are open.
2184 	 * Otherwise set it to max(1/200, 1/hz).
2185 	 * Enable timeouts iff some device is open.
2186 	 */
2187 	untimeout(comwakeup, (void *)NULL, sio_timeout_handle);
2188 	sio_timeout = hz;
2189 	someopen = FALSE;
2190 	for (unit = 0; unit < sio_numunits; ++unit) {
2191 		com = com_addr(unit);
2192 		if (com != NULL && com->tp != NULL
2193 		    && com->tp->t_state & TS_ISOPEN && !com->gone) {
2194 			someopen = TRUE;
2195 			if (com->poll || com->poll_output) {
2196 				sio_timeout = hz > 200 ? hz / 200 : 1;
2197 				break;
2198 			}
2199 		}
2200 	}
2201 	if (someopen) {
2202 		sio_timeouts_until_log = hz / sio_timeout;
2203 		sio_timeout_handle = timeout(comwakeup, (void *)NULL,
2204 					     sio_timeout);
2205 	} else {
2206 		/* Flush error messages, if any. */
2207 		sio_timeouts_until_log = 1;
2208 		comwakeup((void *)NULL);
2209 		untimeout(comwakeup, (void *)NULL, sio_timeout_handle);
2210 	}
2211 }
2212 
2213 static void
comwakeup(chan)2214 comwakeup(chan)
2215 	void	*chan;
2216 {
2217 	struct com_s	*com;
2218 	int		unit;
2219 
2220 	sio_timeout_handle = timeout(comwakeup, (void *)NULL, sio_timeout);
2221 
2222 	/*
2223 	 * Recover from lost output interrupts.
2224 	 * Poll any lines that don't use interrupts.
2225 	 */
2226 	for (unit = 0; unit < sio_numunits; ++unit) {
2227 		com = com_addr(unit);
2228 		if (com != NULL && !com->gone
2229 		    && (com->state >= (CS_BUSY | CS_TTGO) || com->poll)) {
2230 			mtx_lock_spin(&sio_lock);
2231 			siointr1(com);
2232 			mtx_unlock_spin(&sio_lock);
2233 		}
2234 	}
2235 
2236 	/*
2237 	 * Check for and log errors, but not too often.
2238 	 */
2239 	if (--sio_timeouts_until_log > 0)
2240 		return;
2241 	sio_timeouts_until_log = hz / sio_timeout;
2242 	for (unit = 0; unit < sio_numunits; ++unit) {
2243 		int	errnum;
2244 
2245 		com = com_addr(unit);
2246 		if (com == NULL)
2247 			continue;
2248 		if (com->gone)
2249 			continue;
2250 		for (errnum = 0; errnum < CE_NTYPES; ++errnum) {
2251 			u_int	delta;
2252 			u_long	total;
2253 
2254 			mtx_lock_spin(&sio_lock);
2255 			delta = com->delta_error_counts[errnum];
2256 			com->delta_error_counts[errnum] = 0;
2257 			mtx_unlock_spin(&sio_lock);
2258 			if (delta == 0)
2259 				continue;
2260 			total = com->error_counts[errnum] += delta;
2261 			log(LOG_ERR, "sio%d: %u more %s%s (total %lu)\n",
2262 			    unit, delta, error_desc[errnum],
2263 			    delta == 1 ? "" : "s", total);
2264 		}
2265 	}
2266 }
2267 
2268 /*
2269  * Following are all routines needed for SIO to act as console
2270  */
2271 struct siocnstate {
2272 	u_char	dlbl;
2273 	u_char	dlbh;
2274 	u_char	ier;
2275 	u_char	cfcr;
2276 	u_char	mcr;
2277 };
2278 
2279 /*
2280  * This is a function in order to not replicate "ttyd%d" more
2281  * places than absolutely necessary.
2282  */
2283 static void
siocnset(struct consdev * cd,int unit)2284 siocnset(struct consdev *cd, int unit)
2285 {
2286 
2287 	cd->cn_unit = unit;
2288 	sprintf(cd->cn_name, "ttyd%d", unit);
2289 }
2290 
2291 static speed_t siocngetspeed(Port_t, u_long rclk);
2292 static void siocnclose(struct siocnstate *sp, Port_t iobase);
2293 static void siocnopen(struct siocnstate *sp, Port_t iobase, int speed);
2294 static void siocntxwait(Port_t iobase);
2295 
2296 static cn_probe_t sio_cnprobe;
2297 static cn_init_t sio_cninit;
2298 static cn_term_t sio_cnterm;
2299 static cn_getc_t sio_cngetc;
2300 static cn_putc_t sio_cnputc;
2301 static cn_grab_t sio_cngrab;
2302 static cn_ungrab_t sio_cnungrab;
2303 
2304 CONSOLE_DRIVER(sio);
2305 
2306 static void
siocntxwait(iobase)2307 siocntxwait(iobase)
2308 	Port_t	iobase;
2309 {
2310 	int	timo;
2311 
2312 	/*
2313 	 * Wait for any pending transmission to finish.  Required to avoid
2314 	 * the UART lockup bug when the speed is changed, and for normal
2315 	 * transmits.
2316 	 */
2317 	timo = 100000;
2318 	while ((inb(iobase + com_lsr) & (LSR_TSRE | LSR_TXRDY))
2319 	       != (LSR_TSRE | LSR_TXRDY) && --timo != 0)
2320 		;
2321 }
2322 
2323 /*
2324  * Read the serial port specified and try to figure out what speed
2325  * it's currently running at.  We're assuming the serial port has
2326  * been initialized and is basically idle.  This routine is only intended
2327  * to be run at system startup.
2328  *
2329  * If the value read from the serial port doesn't make sense, return 0.
2330  */
2331 
2332 static speed_t
siocngetspeed(iobase,rclk)2333 siocngetspeed(iobase, rclk)
2334 	Port_t	iobase;
2335 	u_long	rclk;
2336 {
2337 	u_int	divisor;
2338 	u_char	dlbh;
2339 	u_char	dlbl;
2340 	u_char  cfcr;
2341 
2342 	cfcr = inb(iobase + com_cfcr);
2343 	outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2344 
2345 	dlbl = inb(iobase + com_dlbl);
2346 	dlbh = inb(iobase + com_dlbh);
2347 
2348 	outb(iobase + com_cfcr, cfcr);
2349 
2350 	divisor = dlbh << 8 | dlbl;
2351 
2352 	/* XXX there should be more sanity checking. */
2353 	if (divisor == 0)
2354 		return (CONSPEED);
2355 	return (rclk / (16UL * divisor));
2356 }
2357 
2358 static void
siocnopen(sp,iobase,speed)2359 siocnopen(sp, iobase, speed)
2360 	struct siocnstate	*sp;
2361 	Port_t			iobase;
2362 	int			speed;
2363 {
2364 	u_int	divisor;
2365 	u_char	dlbh;
2366 	u_char	dlbl;
2367 
2368 	/*
2369 	 * Save all the device control registers except the fifo register
2370 	 * and set our default ones (cs8 -parenb speed=comdefaultrate).
2371 	 * We can't save the fifo register since it is read-only.
2372 	 */
2373 	sp->ier = inb(iobase + com_ier);
2374 	outb(iobase + com_ier, 0);	/* spltty() doesn't stop siointr() */
2375 	siocntxwait(iobase);
2376 	sp->cfcr = inb(iobase + com_cfcr);
2377 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2378 	sp->dlbl = inb(iobase + com_dlbl);
2379 	sp->dlbh = inb(iobase + com_dlbh);
2380 	/*
2381 	 * Only set the divisor registers if they would change, since on
2382 	 * some 16550 incompatibles (Startech), setting them clears the
2383 	 * data input register.  This also reduces the effects of the
2384 	 * UMC8669F bug.
2385 	 */
2386 	divisor = siodivisor(comdefaultrclk, speed);
2387 	dlbl = divisor & 0xFF;
2388 	if (sp->dlbl != dlbl)
2389 		outb(iobase + com_dlbl, dlbl);
2390 	dlbh = divisor >> 8;
2391 	if (sp->dlbh != dlbh)
2392 		outb(iobase + com_dlbh, dlbh);
2393 	outb(iobase + com_cfcr, CFCR_8BITS);
2394 	sp->mcr = inb(iobase + com_mcr);
2395 	/*
2396 	 * We don't want interrupts, but must be careful not to "disable"
2397 	 * them by clearing the MCR_IENABLE bit, since that might cause
2398 	 * an interrupt by floating the IRQ line.
2399 	 */
2400 	outb(iobase + com_mcr, (sp->mcr & MCR_IENABLE) | MCR_DTR | MCR_RTS);
2401 }
2402 
2403 static void
siocnclose(sp,iobase)2404 siocnclose(sp, iobase)
2405 	struct siocnstate	*sp;
2406 	Port_t			iobase;
2407 {
2408 	/*
2409 	 * Restore the device control registers.
2410 	 */
2411 	siocntxwait(iobase);
2412 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2413 	if (sp->dlbl != inb(iobase + com_dlbl))
2414 		outb(iobase + com_dlbl, sp->dlbl);
2415 	if (sp->dlbh != inb(iobase + com_dlbh))
2416 		outb(iobase + com_dlbh, sp->dlbh);
2417 	outb(iobase + com_cfcr, sp->cfcr);
2418 	/*
2419 	 * XXX damp oscillations of MCR_DTR and MCR_RTS by not restoring them.
2420 	 */
2421 	outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
2422 	outb(iobase + com_ier, sp->ier);
2423 }
2424 
2425 static void
sio_cnprobe(cp)2426 sio_cnprobe(cp)
2427 	struct consdev	*cp;
2428 {
2429 	speed_t			boot_speed;
2430 	u_char			cfcr;
2431 	u_int			divisor;
2432 	int			s, unit;
2433 	struct siocnstate	sp;
2434 
2435 	/*
2436 	 * Find our first enabled console, if any.  If it is a high-level
2437 	 * console device, then initialize it and return successfully.
2438 	 * If it is a low-level console device, then initialize it and
2439 	 * return unsuccessfully.  It must be initialized in both cases
2440 	 * for early use by console drivers and debuggers.  Initializing
2441 	 * the hardware is not necessary in all cases, since the i/o
2442 	 * routines initialize it on the fly, but it is necessary if
2443 	 * input might arrive while the hardware is switched back to an
2444 	 * uninitialized state.  We can't handle multiple console devices
2445 	 * yet because our low-level routines don't take a device arg.
2446 	 * We trust the user to set the console flags properly so that we
2447 	 * don't need to probe.
2448 	 */
2449 	cp->cn_pri = CN_DEAD;
2450 
2451 	for (unit = 0; unit < 16; unit++) { /* XXX need to know how many */
2452 		int flags;
2453 
2454 		if (resource_disabled("sio", unit))
2455 			continue;
2456 		if (resource_int_value("sio", unit, "flags", &flags))
2457 			continue;
2458 		if (COM_CONSOLE(flags) || COM_DEBUGGER(flags)) {
2459 			int port;
2460 			Port_t iobase;
2461 
2462 			if (resource_int_value("sio", unit, "port", &port))
2463 				continue;
2464 			iobase = port;
2465 			s = spltty();
2466 			if ((boothowto & RB_SERIAL) && COM_CONSOLE(flags)) {
2467 				boot_speed =
2468 				    siocngetspeed(iobase, comdefaultrclk);
2469 				if (boot_speed)
2470 					comdefaultrate = boot_speed;
2471 			}
2472 
2473 			/*
2474 			 * Initialize the divisor latch.  We can't rely on
2475 			 * siocnopen() to do this the first time, since it
2476 			 * avoids writing to the latch if the latch appears
2477 			 * to have the correct value.  Also, if we didn't
2478 			 * just read the speed from the hardware, then we
2479 			 * need to set the speed in hardware so that
2480 			 * switching it later is null.
2481 			 */
2482 			cfcr = inb(iobase + com_cfcr);
2483 			outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2484 			divisor = siodivisor(comdefaultrclk, comdefaultrate);
2485 			outb(iobase + com_dlbl, divisor & 0xff);
2486 			outb(iobase + com_dlbh, divisor >> 8);
2487 			outb(iobase + com_cfcr, cfcr);
2488 
2489 			siocnopen(&sp, iobase, comdefaultrate);
2490 
2491 			splx(s);
2492 			if (COM_CONSOLE(flags) && !COM_LLCONSOLE(flags)) {
2493 				siocnset(cp, unit);
2494 				cp->cn_pri = COM_FORCECONSOLE(flags)
2495 					     || boothowto & RB_SERIAL
2496 					     ? CN_REMOTE : CN_NORMAL;
2497 				siocniobase = iobase;
2498 				siocnunit = unit;
2499 			}
2500 #ifdef GDB
2501 			if (COM_DEBUGGER(flags))
2502 				siogdbiobase = iobase;
2503 #endif
2504 		}
2505 	}
2506 }
2507 
2508 static void
sio_cninit(cp)2509 sio_cninit(cp)
2510 	struct consdev	*cp;
2511 {
2512 	comconsole = cp->cn_unit;
2513 }
2514 
2515 static void
sio_cnterm(cp)2516 sio_cnterm(cp)
2517 	struct consdev	*cp;
2518 {
2519 	comconsole = -1;
2520 }
2521 
2522 static void
sio_cngrab(struct consdev * cp)2523 sio_cngrab(struct consdev *cp)
2524 {
2525 }
2526 
2527 static void
sio_cnungrab(struct consdev * cp)2528 sio_cnungrab(struct consdev *cp)
2529 {
2530 }
2531 
2532 static int
sio_cngetc(struct consdev * cd)2533 sio_cngetc(struct consdev *cd)
2534 {
2535 	int	c;
2536 	Port_t	iobase;
2537 	int	s;
2538 	struct siocnstate	sp;
2539 	speed_t	speed;
2540 
2541 	if (cd != NULL && cd->cn_unit == siocnunit) {
2542 		iobase = siocniobase;
2543 		speed = comdefaultrate;
2544 	} else {
2545 #ifdef GDB
2546 		iobase = siogdbiobase;
2547 		speed = gdbdefaultrate;
2548 #else
2549 		return (-1);
2550 #endif
2551 	}
2552 	s = spltty();
2553 	siocnopen(&sp, iobase, speed);
2554 	if (inb(iobase + com_lsr) & LSR_RXRDY)
2555 		c = inb(iobase + com_data);
2556 	else
2557 		c = -1;
2558 	siocnclose(&sp, iobase);
2559 	splx(s);
2560 	return (c);
2561 }
2562 
2563 static void
sio_cnputc(struct consdev * cd,int c)2564 sio_cnputc(struct consdev *cd, int c)
2565 {
2566 	int	need_unlock;
2567 	int	s;
2568 	struct siocnstate	sp;
2569 	Port_t	iobase;
2570 	speed_t	speed;
2571 
2572 	if (cd != NULL && cd->cn_unit == siocnunit) {
2573 		iobase = siocniobase;
2574 		speed = comdefaultrate;
2575 	} else {
2576 #ifdef GDB
2577 		iobase = siogdbiobase;
2578 		speed = gdbdefaultrate;
2579 #else
2580 		return;
2581 #endif
2582 	}
2583 	s = spltty();
2584 	need_unlock = 0;
2585 	if (!kdb_active && sio_inited == 2 && !mtx_owned(&sio_lock)) {
2586 		mtx_lock_spin(&sio_lock);
2587 		need_unlock = 1;
2588 	}
2589 	siocnopen(&sp, iobase, speed);
2590 	siocntxwait(iobase);
2591 	outb(iobase + com_data, c);
2592 	siocnclose(&sp, iobase);
2593 	if (need_unlock)
2594 		mtx_unlock_spin(&sio_lock);
2595 	splx(s);
2596 }
2597 
2598 /*
2599  * Remote gdb(1) support.
2600  */
2601 
2602 #if defined(GDB)
2603 
2604 #include <gdb/gdb.h>
2605 
2606 static gdb_probe_f siogdbprobe;
2607 static gdb_init_f siogdbinit;
2608 static gdb_term_f siogdbterm;
2609 static gdb_getc_f siogdbgetc;
2610 static gdb_putc_f siogdbputc;
2611 
2612 GDB_DBGPORT(sio, siogdbprobe, siogdbinit, siogdbterm, siogdbgetc, siogdbputc);
2613 
2614 static int
siogdbprobe(void)2615 siogdbprobe(void)
2616 {
2617 	return ((siogdbiobase != 0) ? 0 : -1);
2618 }
2619 
2620 static void
siogdbinit(void)2621 siogdbinit(void)
2622 {
2623 }
2624 
2625 static void
siogdbterm(void)2626 siogdbterm(void)
2627 {
2628 }
2629 
2630 static void
siogdbputc(int c)2631 siogdbputc(int c)
2632 {
2633 	sio_cnputc(NULL, c);
2634 }
2635 
2636 static int
siogdbgetc(void)2637 siogdbgetc(void)
2638 {
2639 	return (sio_cngetc(NULL));
2640 }
2641 
2642 #endif
2643