xref: /freebsd-12.1/sys/dev/sio/sio.c (revision 6469bdcd)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1991 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	from: @(#)com.c	7.5 (Berkeley) 5/16/91
32  *	from: i386/isa sio.c,v 1.234
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "opt_gdb.h"
39 #include "opt_kdb.h"
40 #include "opt_sio.h"
41 
42 /*
43  * Serial driver, based on 386BSD-0.1 com driver.
44  * Mostly rewritten to use pseudo-DMA.
45  * Works for National Semiconductor NS8250-NS16550AF UARTs.
46  * COM driver, based on HP dca driver.
47  *
48  * Changes for PC Card integration:
49  *	- Added PC Card driver table and handlers
50  */
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/bus.h>
54 #include <sys/conf.h>
55 #include <sys/fcntl.h>
56 #include <sys/interrupt.h>
57 #include <sys/kdb.h>
58 #include <sys/kernel.h>
59 #include <sys/limits.h>
60 #include <sys/lock.h>
61 #include <sys/malloc.h>
62 #include <sys/module.h>
63 #include <sys/mutex.h>
64 #include <sys/proc.h>
65 #include <sys/reboot.h>
66 #include <sys/serial.h>
67 #include <sys/sysctl.h>
68 #include <sys/syslog.h>
69 #include <sys/tty.h>
70 #include <machine/bus.h>
71 #include <sys/rman.h>
72 #include <sys/timepps.h>
73 #include <sys/uio.h>
74 #include <sys/cons.h>
75 
76 #include <isa/isavar.h>
77 
78 #include <machine/resource.h>
79 
80 #include <dev/sio/sioreg.h>
81 #include <dev/sio/siovar.h>
82 
83 #ifdef COM_ESP
84 #include <dev/ic/esp.h>
85 #endif
86 #include <dev/ic/ns16550.h>
87 
88 #define	LOTS_OF_EVENTS	64	/* helps separate urgent events from input */
89 
90 #ifdef COM_MULTIPORT
91 /* checks in flags for multiport and which is multiport "master chip"
92  * for a given card
93  */
94 #define	COM_ISMULTIPORT(flags)	((flags) & 0x01)
95 #define	COM_MPMASTER(flags)	(((flags) >> 8) & 0x0ff)
96 #define	COM_NOTAST4(flags)	((flags) & 0x04)
97 #else
98 #define	COM_ISMULTIPORT(flags)	(0)
99 #endif /* COM_MULTIPORT */
100 
101 #define	COM_C_IIR_TXRDYBUG	0x80000
102 #define	COM_CONSOLE(flags)	((flags) & 0x10)
103 #define	COM_DEBUGGER(flags)	((flags) & 0x80)
104 #define	COM_FIFOSIZE(flags)	(((flags) & 0xff000000) >> 24)
105 #define	COM_FORCECONSOLE(flags)	((flags) & 0x20)
106 #define	COM_IIR_TXRDYBUG(flags)	((flags) & COM_C_IIR_TXRDYBUG)
107 #define	COM_LLCONSOLE(flags)	((flags) & 0x40)
108 #define	COM_LOSESOUTINTS(flags)	((flags) & 0x08)
109 #define	COM_NOFIFO(flags)	((flags) & 0x02)
110 #define	COM_NOPROBE(flags)	((flags) & 0x40000)
111 #define	COM_NOSCR(flags)	((flags) & 0x100000)
112 #define	COM_PPSCTS(flags)	((flags) & 0x10000)
113 #define	COM_ST16650A(flags)	((flags) & 0x20000)
114 #define	COM_TI16754(flags)	((flags) & 0x200000)
115 
116 #define	sio_getreg(com, off) \
117 	(bus_space_read_1((com)->bst, (com)->bsh, (off)))
118 #define	sio_setreg(com, off, value) \
119 	(bus_space_write_1((com)->bst, (com)->bsh, (off), (value)))
120 
121 /*
122  * com state bits.
123  * (CS_BUSY | CS_TTGO) and (CS_BUSY | CS_TTGO | CS_ODEVREADY) must be higher
124  * than the other bits so that they can be tested as a group without masking
125  * off the low bits.
126  *
127  * The following com and tty flags correspond closely:
128  *	CS_BUSY		= TS_BUSY (maintained by comstart(), siopoll() and
129  *				   comstop())
130  *	CS_TTGO		= ~TS_TTSTOP (maintained by comparam() and comstart())
131  *	CS_CTS_OFLOW	= CCTS_OFLOW (maintained by comparam())
132  *	CS_RTS_IFLOW	= CRTS_IFLOW (maintained by comparam())
133  * TS_FLUSH is not used.
134  * XXX I think TIOCSETA doesn't clear TS_TTSTOP when it clears IXON.
135  * XXX CS_*FLOW should be CF_*FLOW in com->flags (control flags not state).
136  */
137 #define	CS_BUSY		0x80	/* output in progress */
138 #define	CS_TTGO		0x40	/* output not stopped by XOFF */
139 #define	CS_ODEVREADY	0x20	/* external device h/w ready (CTS) */
140 #define	CS_CHECKMSR	1	/* check of MSR scheduled */
141 #define	CS_CTS_OFLOW	2	/* use CTS output flow control */
142 #define	CS_ODONE	4	/* output completed */
143 #define	CS_RTS_IFLOW	8	/* use RTS input flow control */
144 #define	CSE_BUSYCHECK	1	/* siobusycheck() scheduled */
145 
146 static	char const * const	error_desc[] = {
147 #define	CE_OVERRUN			0
148 	"silo overflow",
149 #define	CE_INTERRUPT_BUF_OVERFLOW	1
150 	"interrupt-level buffer overflow",
151 #define	CE_TTY_BUF_OVERFLOW		2
152 	"tty-level buffer overflow",
153 };
154 
155 #define	CE_NTYPES			3
156 #define	CE_RECORD(com, errnum)		(++(com)->delta_error_counts[errnum])
157 
158 /* types.  XXX - should be elsewhere */
159 typedef u_int	Port_t;		/* hardware port */
160 typedef u_char	bool_t;		/* boolean */
161 
162 /* queue of linear buffers */
163 struct lbq {
164 	u_char	*l_head;	/* next char to process */
165 	u_char	*l_tail;	/* one past the last char to process */
166 	struct lbq *l_next;	/* next in queue */
167 	bool_t	l_queued;	/* nonzero if queued */
168 };
169 
170 /* com device structure */
171 struct com_s {
172 	u_char	state;		/* miscellaneous flag bits */
173 	u_char	cfcr_image;	/* copy of value written to CFCR */
174 #ifdef COM_ESP
175 	bool_t	esp;		/* is this unit a hayes esp board? */
176 #endif
177 	u_char	extra_state;	/* more flag bits, separate for order trick */
178 	u_char	fifo_image;	/* copy of value written to FIFO */
179 	bool_t	hasfifo;	/* nonzero for 16550 UARTs */
180 	bool_t	loses_outints;	/* nonzero if device loses output interrupts */
181 	u_char	mcr_image;	/* copy of value written to MCR */
182 #ifdef COM_MULTIPORT
183 	bool_t	multiport;	/* is this unit part of a multiport device? */
184 #endif /* COM_MULTIPORT */
185 	bool_t	no_irq;		/* nonzero if irq is not attached */
186 	bool_t  gone;		/* hardware disappeared */
187 	bool_t	poll;		/* nonzero if polling is required */
188 	bool_t	poll_output;	/* nonzero if polling for output is required */
189 	bool_t	st16650a;	/* nonzero if Startech 16650A compatible */
190 	int	unit;		/* unit	number */
191 	u_int	flags;		/* copy of device flags */
192 	u_int	tx_fifo_size;
193 
194 	/*
195 	 * The high level of the driver never reads status registers directly
196 	 * because there would be too many side effects to handle conveniently.
197 	 * Instead, it reads copies of the registers stored here by the
198 	 * interrupt handler.
199 	 */
200 	u_char	last_modem_status;	/* last MSR read by intr handler */
201 	u_char	prev_modem_status;	/* last MSR handled by high level */
202 
203 	u_char	*ibuf;		/* start of input buffer */
204 	u_char	*ibufend;	/* end of input buffer */
205 	u_char	*ibufold;	/* old input buffer, to be freed */
206 	u_char	*ihighwater;	/* threshold in input buffer */
207 	u_char	*iptr;		/* next free spot in input buffer */
208 	int	ibufsize;	/* size of ibuf (not include error bytes) */
209 	int	ierroff;	/* offset of error bytes in ibuf */
210 
211 	struct lbq	obufq;	/* head of queue of output buffers */
212 	struct lbq	obufs[2];	/* output buffers */
213 
214 	bus_space_tag_t		bst;
215 	bus_space_handle_t	bsh;
216 
217 	Port_t	data_port;	/* i/o ports */
218 #ifdef COM_ESP
219 	Port_t	esp_port;
220 #endif
221 	Port_t	int_ctl_port;
222 	Port_t	int_id_port;
223 	Port_t	modem_ctl_port;
224 	Port_t	line_status_port;
225 	Port_t	modem_status_port;
226 
227 	struct tty	*tp;	/* cross reference */
228 
229 	struct	pps_state pps;
230 	int	pps_bit;
231 #ifdef KDB
232 	int	alt_brk_state;
233 #endif
234 
235 	u_long	bytes_in;	/* statistics */
236 	u_long	bytes_out;
237 	u_int	delta_error_counts[CE_NTYPES];
238 	u_long	error_counts[CE_NTYPES];
239 
240 	u_long	rclk;
241 
242 	struct resource *irqres;
243 	struct resource *ioportres;
244 	int	ioportrid;
245 	void	*cookie;
246 
247 	/*
248 	 * Data area for output buffers.  Someday we should build the output
249 	 * buffer queue without copying data.
250 	 */
251 	u_char	obuf1[256];
252 	u_char	obuf2[256];
253 };
254 
255 #ifdef COM_ESP
256 static	int	espattach(struct com_s *com, Port_t esp_port);
257 #endif
258 
259 static	void	combreak(struct tty *tp, int sig);
260 static	timeout_t siobusycheck;
261 static	u_int	siodivisor(u_long rclk, speed_t speed);
262 static	void	comclose(struct tty *tp);
263 static	int	comopen(struct tty *tp, struct cdev *dev);
264 static	void	sioinput(struct com_s *com);
265 static	void	siointr1(struct com_s *com);
266 static	int	siointr(void *arg);
267 static	int	commodem(struct tty *tp, int sigon, int sigoff);
268 static	int	comparam(struct tty *tp, struct termios *t);
269 static	void	siopoll(void *);
270 static	void	siosettimeout(void);
271 static	int	siosetwater(struct com_s *com, speed_t speed);
272 static	void	comstart(struct tty *tp);
273 static	void	comstop(struct tty *tp, int rw);
274 static	timeout_t comwakeup;
275 
276 char		sio_driver_name[] = "sio";
277 static struct	mtx sio_lock;
278 static int	sio_inited;
279 
280 /* table and macro for fast conversion from a unit number to its com struct */
281 devclass_t	sio_devclass;
282 /*
283  * XXX Assmues that devclass_get_device, devclass_get_softc and
284  * device_get_softc are fast interrupt safe.  The current implementation
285  * of these functions are.
286  */
287 #define	com_addr(unit)	((struct com_s *) \
288 			 devclass_get_softc(sio_devclass, unit)) /* XXX */
289 
290 int	comconsole = -1;
291 static	volatile speed_t	comdefaultrate = CONSPEED;
292 static	u_long			comdefaultrclk = DEFAULT_RCLK;
293 SYSCTL_ULONG(_machdep, OID_AUTO, conrclk, CTLFLAG_RW, &comdefaultrclk, 0, "");
294 static	speed_t			gdbdefaultrate = GDBSPEED;
295 SYSCTL_UINT(_machdep, OID_AUTO, gdbspeed, CTLFLAG_RW,
296 	    &gdbdefaultrate, GDBSPEED, "");
297 static	u_int	com_events;	/* input chars + weighted output completions */
298 static	Port_t	siocniobase;
299 static	int	siocnunit = -1;
300 static	void	*sio_slow_ih;
301 static	void	*sio_fast_ih;
302 static	int	sio_timeout;
303 static	int	sio_timeouts_until_log;
304 static	struct	callout_handle sio_timeout_handle
305     = CALLOUT_HANDLE_INITIALIZER(&sio_timeout_handle);
306 static	int	sio_numunits;
307 
308 #ifdef GDB
309 static	Port_t	siogdbiobase = 0;
310 #endif
311 
312 #ifdef COM_ESP
313 /* XXX configure this properly. */
314 /* XXX quite broken for new-bus. */
315 static	Port_t	likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, };
316 static	Port_t	likely_esp_ports[] = { 0x140, 0x180, 0x280, 0 };
317 #endif
318 
319 /*
320  * handle sysctl read/write requests for console speed
321  *
322  * In addition to setting comdefaultrate for I/O through /dev/console,
323  * also set the initial and lock values for the /dev/ttyXX device
324  * if there is one associated with the console.  Finally, if the /dev/tty
325  * device has already been open, change the speed on the open running port
326  * itself.
327  */
328 
329 static int
sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)330 sysctl_machdep_comdefaultrate(SYSCTL_HANDLER_ARGS)
331 {
332 	int error, s;
333 	speed_t newspeed;
334 	struct com_s *com;
335 	struct tty *tp;
336 
337 	newspeed = comdefaultrate;
338 
339 	error = sysctl_handle_opaque(oidp, &newspeed, sizeof newspeed, req);
340 	if (error || !req->newptr)
341 		return (error);
342 
343 	comdefaultrate = newspeed;
344 
345 	if (comconsole < 0)		/* serial console not selected? */
346 		return (0);
347 
348 	com = com_addr(comconsole);
349 	if (com == NULL)
350 		return (ENXIO);
351 
352 	tp = com->tp;
353 	if (tp == NULL)
354 		return (ENXIO);
355 
356 	/*
357 	 * set the initial and lock rates for /dev/ttydXX and /dev/cuaXX
358 	 * (note, the lock rates really are boolean -- if non-zero, disallow
359 	 *  speed changes)
360 	 */
361 	tp->t_init_in.c_ispeed  = tp->t_init_in.c_ospeed =
362 	tp->t_lock_in.c_ispeed  = tp->t_lock_in.c_ospeed =
363 	tp->t_init_out.c_ispeed = tp->t_init_out.c_ospeed =
364 	tp->t_lock_out.c_ispeed = tp->t_lock_out.c_ospeed = comdefaultrate;
365 
366 	if (tp->t_state & TS_ISOPEN) {
367 		tp->t_termios.c_ispeed =
368 		tp->t_termios.c_ospeed = comdefaultrate;
369 		s = spltty();
370 		error = comparam(tp, &tp->t_termios);
371 		splx(s);
372 	}
373 	return error;
374 }
375 
376 SYSCTL_PROC(_machdep, OID_AUTO, conspeed, CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
377 	    0, 0, sysctl_machdep_comdefaultrate, "I", "");
378 TUNABLE_INT("machdep.conspeed", __DEVOLATILE(int *, &comdefaultrate));
379 
380 #define SET_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) | (bit))
381 #define CLR_FLAG(dev, bit) device_set_flags(dev, device_get_flags(dev) & ~(bit))
382 
383 /*
384  *	Unload the driver and clear the table.
385  *	XXX this is mostly wrong.
386  *	XXX TODO:
387  *	This is usually called when the card is ejected, but
388  *	can be caused by a kldunload of a controller driver.
389  *	The idea is to reset the driver's view of the device
390  *	and ensure that any driver entry points such as
391  *	read and write do not hang.
392  */
393 int
siodetach(device_t dev)394 siodetach(device_t dev)
395 {
396 	struct com_s	*com;
397 
398 	com = (struct com_s *) device_get_softc(dev);
399 	if (com == NULL) {
400 		device_printf(dev, "NULL com in siounload\n");
401 		return (0);
402 	}
403 	com->gone = TRUE;
404 	if (com->tp)
405 		ttyfree(com->tp);
406 	if (com->irqres) {
407 		bus_teardown_intr(dev, com->irqres, com->cookie);
408 		bus_release_resource(dev, SYS_RES_IRQ, 0, com->irqres);
409 	}
410 	if (com->ioportres)
411 		bus_release_resource(dev, SYS_RES_IOPORT, com->ioportrid,
412 				     com->ioportres);
413 	if (com->ibuf != NULL)
414 		free(com->ibuf, M_DEVBUF);
415 
416 	device_set_softc(dev, NULL);
417 	free(com, M_DEVBUF);
418 	return (0);
419 }
420 
421 int
sioprobe(dev,xrid,rclk,noprobe)422 sioprobe(dev, xrid, rclk, noprobe)
423 	device_t	dev;
424 	int		xrid;
425 	u_long		rclk;
426 	int		noprobe;
427 {
428 #if 0
429 	static bool_t	already_init;
430 	device_t	xdev;
431 #endif
432 	struct com_s	*com;
433 	u_int		divisor;
434 	bool_t		failures[10];
435 	int		fn;
436 	device_t	idev;
437 	Port_t		iobase;
438 	intrmask_t	irqmap[4];
439 	intrmask_t	irqs;
440 	u_char		mcr_image;
441 	int		result;
442 	u_long		xirq;
443 	u_int		flags = device_get_flags(dev);
444 	int		rid;
445 	struct resource *port;
446 
447 	rid = xrid;
448 	port = bus_alloc_resource_anywhere(dev, SYS_RES_IOPORT, &rid,
449 					   IO_COMSIZE, RF_ACTIVE);
450 	if (!port)
451 		return (ENXIO);
452 
453 	com = malloc(sizeof(*com), M_DEVBUF, M_NOWAIT | M_ZERO);
454 	if (com == NULL) {
455 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
456 		return (ENOMEM);
457 	}
458 	device_set_softc(dev, com);
459 	com->bst = rman_get_bustag(port);
460 	com->bsh = rman_get_bushandle(port);
461 	if (rclk == 0)
462 		rclk = DEFAULT_RCLK;
463 	com->rclk = rclk;
464 
465 	while (sio_inited != 2)
466 		if (atomic_cmpset_int(&sio_inited, 0, 1)) {
467 			mtx_init(&sio_lock, sio_driver_name, NULL,
468 			    (comconsole != -1) ?
469 			    MTX_SPIN | MTX_QUIET : MTX_SPIN);
470 			atomic_store_rel_int(&sio_inited, 2);
471 		}
472 
473 #if 0
474 	/*
475 	 * XXX this is broken - when we are first called, there are no
476 	 * previously configured IO ports.  We could hard code
477 	 * 0x3f8, 0x2f8, 0x3e8, 0x2e8 etc but that's probably worse.
478 	 * This code has been doing nothing since the conversion since
479 	 * "count" is zero the first time around.
480 	 */
481 	if (!already_init) {
482 		/*
483 		 * Turn off MCR_IENABLE for all likely serial ports.  An unused
484 		 * port with its MCR_IENABLE gate open will inhibit interrupts
485 		 * from any used port that shares the interrupt vector.
486 		 * XXX the gate enable is elsewhere for some multiports.
487 		 */
488 		device_t *devs;
489 		int count, i, xioport;
490 
491 		devclass_get_devices(sio_devclass, &devs, &count);
492 		for (i = 0; i < count; i++) {
493 			xdev = devs[i];
494 			if (device_is_enabled(xdev) &&
495 			    bus_get_resource(xdev, SYS_RES_IOPORT, 0, &xioport,
496 					     NULL) == 0)
497 				outb(xioport + com_mcr, 0);
498 		}
499 		free(devs, M_TEMP);
500 		already_init = TRUE;
501 	}
502 #endif
503 
504 	if (COM_LLCONSOLE(flags)) {
505 		printf("sio%d: reserved for low-level i/o\n",
506 		       device_get_unit(dev));
507 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
508 		device_set_softc(dev, NULL);
509 		free(com, M_DEVBUF);
510 		return (ENXIO);
511 	}
512 
513 	/*
514 	 * If the device is on a multiport card and has an AST/4
515 	 * compatible interrupt control register, initialize this
516 	 * register and prepare to leave MCR_IENABLE clear in the mcr.
517 	 * Otherwise, prepare to set MCR_IENABLE in the mcr.
518 	 * Point idev to the device struct giving the correct id_irq.
519 	 * This is the struct for the master device if there is one.
520 	 */
521 	idev = dev;
522 	mcr_image = MCR_IENABLE;
523 #ifdef COM_MULTIPORT
524 	if (COM_ISMULTIPORT(flags)) {
525 		Port_t xiobase;
526 		u_long io;
527 
528 		idev = devclass_get_device(sio_devclass, COM_MPMASTER(flags));
529 		if (idev == NULL) {
530 			printf("sio%d: master device %d not configured\n",
531 			       device_get_unit(dev), COM_MPMASTER(flags));
532 			idev = dev;
533 		}
534 		if (!COM_NOTAST4(flags)) {
535 			if (bus_get_resource(idev, SYS_RES_IOPORT, 0, &io,
536 					     NULL) == 0) {
537 				xiobase = io;
538 				if (bus_get_resource(idev, SYS_RES_IRQ, 0,
539 				    NULL, NULL) == 0)
540 					outb(xiobase + com_scr, 0x80);
541 				else
542 					outb(xiobase + com_scr, 0);
543 			}
544 			mcr_image = 0;
545 		}
546 	}
547 #endif /* COM_MULTIPORT */
548 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, NULL, NULL) != 0)
549 		mcr_image = 0;
550 
551 	bzero(failures, sizeof failures);
552 	iobase = rman_get_start(port);
553 
554 	/*
555 	 * We don't want to get actual interrupts, just masked ones.
556 	 * Interrupts from this line should already be masked in the ICU,
557 	 * but mask them in the processor as well in case there are some
558 	 * (misconfigured) shared interrupts.
559 	 */
560 	mtx_lock_spin(&sio_lock);
561 /* EXTRA DELAY? */
562 
563 	/*
564 	 * For the TI16754 chips, set prescaler to 1 (4 is often the
565 	 * default after-reset value) as otherwise it's impossible to
566 	 * get highest baudrates.
567 	 */
568 	if (COM_TI16754(flags)) {
569 		u_char cfcr, efr;
570 
571 		cfcr = sio_getreg(com, com_cfcr);
572 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
573 		efr = sio_getreg(com, com_efr);
574 		/* Unlock extended features to turn off prescaler. */
575 		sio_setreg(com, com_efr, efr | EFR_EFE);
576 		/* Disable EFR. */
577 		sio_setreg(com, com_cfcr, (cfcr != CFCR_EFR_ENABLE) ? cfcr : 0);
578 		/* Turn off prescaler. */
579 		sio_setreg(com, com_mcr,
580 			   sio_getreg(com, com_mcr) & ~MCR_PRESCALE);
581 		sio_setreg(com, com_cfcr, CFCR_EFR_ENABLE);
582 		sio_setreg(com, com_efr, efr);
583 		sio_setreg(com, com_cfcr, cfcr);
584 	}
585 
586 	/*
587 	 * Initialize the speed and the word size and wait long enough to
588 	 * drain the maximum of 16 bytes of junk in device output queues.
589 	 * The speed is undefined after a master reset and must be set
590 	 * before relying on anything related to output.  There may be
591 	 * junk after a (very fast) soft reboot and (apparently) after
592 	 * master reset.
593 	 * XXX what about the UART bug avoided by waiting in comparam()?
594 	 * We don't want to wait long enough to drain at 2 bps.
595 	 */
596 	if (iobase == siocniobase)
597 		DELAY((16 + 1) * 1000000 / (comdefaultrate / 10));
598 	else {
599 		sio_setreg(com, com_cfcr, CFCR_DLAB | CFCR_8BITS);
600 		divisor = siodivisor(rclk, SIO_TEST_SPEED);
601 		sio_setreg(com, com_dlbl, divisor & 0xff);
602 		sio_setreg(com, com_dlbh, divisor >> 8);
603 		sio_setreg(com, com_cfcr, CFCR_8BITS);
604 		DELAY((16 + 1) * 1000000 / (SIO_TEST_SPEED / 10));
605 	}
606 
607 	/*
608 	 * Enable the interrupt gate and disable device interrupts.  This
609 	 * should leave the device driving the interrupt line low and
610 	 * guarantee an edge trigger if an interrupt can be generated.
611 	 */
612 /* EXTRA DELAY? */
613 	sio_setreg(com, com_mcr, mcr_image);
614 	sio_setreg(com, com_ier, 0);
615 	DELAY(1000);		/* XXX */
616 	irqmap[0] = isa_irq_pending();
617 
618 	/*
619 	 * Attempt to set loopback mode so that we can send a null byte
620 	 * without annoying any external device.
621 	 */
622 /* EXTRA DELAY? */
623 	sio_setreg(com, com_mcr, mcr_image | MCR_LOOPBACK);
624 
625 	/*
626 	 * Attempt to generate an output interrupt.  On 8250's, setting
627 	 * IER_ETXRDY generates an interrupt independent of the current
628 	 * setting and independent of whether the THR is empty.  On 16450's,
629 	 * setting IER_ETXRDY generates an interrupt independent of the
630 	 * current setting.  On 16550A's, setting IER_ETXRDY only
631 	 * generates an interrupt when IER_ETXRDY is not already set.
632 	 */
633 	sio_setreg(com, com_ier, IER_ETXRDY);
634 
635 	/*
636 	 * On some 16x50 incompatibles, setting IER_ETXRDY doesn't generate
637 	 * an interrupt.  They'd better generate one for actually doing
638 	 * output.  Loopback may be broken on the same incompatibles but
639 	 * it's unlikely to do more than allow the null byte out.
640 	 */
641 	sio_setreg(com, com_data, 0);
642 	if (iobase == siocniobase)
643 		DELAY((1 + 2) * 1000000 / (comdefaultrate / 10));
644 	else
645 		DELAY((1 + 2) * 1000000 / (SIO_TEST_SPEED / 10));
646 
647 	/*
648 	 * Turn off loopback mode so that the interrupt gate works again
649 	 * (MCR_IENABLE was hidden).  This should leave the device driving
650 	 * an interrupt line high.  It doesn't matter if the interrupt
651 	 * line oscillates while we are not looking at it, since interrupts
652 	 * are disabled.
653 	 */
654 /* EXTRA DELAY? */
655 	sio_setreg(com, com_mcr, mcr_image);
656 
657 	/*
658 	 * It seems my Xircom CBEM56G Cardbus modem wants to be reset
659 	 * to 8 bits *again*, or else probe test 0 will fail.
660 	 * [email protected], 4/19/2001
661 	 */
662 	sio_setreg(com, com_cfcr, CFCR_8BITS);
663 
664 	/*
665 	 * Some PCMCIA cards (Palido 321s, DC-1S, ...) have the "TXRDY bug",
666 	 * so we probe for a buggy IIR_TXRDY implementation even in the
667 	 * noprobe case.  We don't probe for it in the !noprobe case because
668 	 * noprobe is always set for PCMCIA cards and the problem is not
669 	 * known to affect any other cards.
670 	 */
671 	if (noprobe) {
672 		/* Read IIR a few times. */
673 		for (fn = 0; fn < 2; fn ++) {
674 			DELAY(10000);
675 			failures[6] = sio_getreg(com, com_iir);
676 		}
677 
678 		/* IIR_TXRDY should be clear.  Is it? */
679 		result = 0;
680 		if (failures[6] & IIR_TXRDY) {
681 			/*
682 			 * No.  We seem to have the bug.  Does our fix for
683 			 * it work?
684 			 */
685 			sio_setreg(com, com_ier, 0);
686 			if (sio_getreg(com, com_iir) & IIR_NOPEND) {
687 				/* Yes.  We discovered the TXRDY bug! */
688 				SET_FLAG(dev, COM_C_IIR_TXRDYBUG);
689 			} else {
690 				/* No.  Just fail.  XXX */
691 				result = ENXIO;
692 				sio_setreg(com, com_mcr, 0);
693 			}
694 		} else {
695 			/* Yes.  No bug. */
696 			CLR_FLAG(dev, COM_C_IIR_TXRDYBUG);
697 		}
698 		sio_setreg(com, com_ier, 0);
699 		sio_setreg(com, com_cfcr, CFCR_8BITS);
700 		mtx_unlock_spin(&sio_lock);
701 		bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
702 		if (iobase == siocniobase)
703 			result = 0;
704 		/*
705 		 * XXX: Since we don't return 0, we shouldn't be relying on
706 		 * the softc that we set to persist to the call to attach
707 		 * since other probe routines may be called, and the malloc
708 		 * here causes subr_bus to not allocate anything for the
709 		 * other probes.  Instead, this softc is preserved and other
710 		 * probe routines can corrupt it.
711 		 */
712 		if (result != 0) {
713 			device_set_softc(dev, NULL);
714 			free(com, M_DEVBUF);
715 		}
716 		return (result == 0 ? BUS_PROBE_DEFAULT + 1 : result);
717 	}
718 
719 	/*
720 	 * Check that
721 	 *	o the CFCR, IER and MCR in UART hold the values written to them
722 	 *	  (the values happen to be all distinct - this is good for
723 	 *	  avoiding false positive tests from bus echoes).
724 	 *	o an output interrupt is generated and its vector is correct.
725 	 *	o the interrupt goes away when the IIR in the UART is read.
726 	 */
727 /* EXTRA DELAY? */
728 	failures[0] = sio_getreg(com, com_cfcr) - CFCR_8BITS;
729 	failures[1] = sio_getreg(com, com_ier) - IER_ETXRDY;
730 	failures[2] = sio_getreg(com, com_mcr) - mcr_image;
731 	DELAY(10000);		/* Some internal modems need this time */
732 	irqmap[1] = isa_irq_pending();
733 	failures[4] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_TXRDY;
734 	DELAY(1000);		/* XXX */
735 	irqmap[2] = isa_irq_pending();
736 	failures[6] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
737 
738 	/*
739 	 * Turn off all device interrupts and check that they go off properly.
740 	 * Leave MCR_IENABLE alone.  For ports without a master port, it gates
741 	 * the OUT2 output of the UART to
742 	 * the ICU input.  Closing the gate would give a floating ICU input
743 	 * (unless there is another device driving it) and spurious interrupts.
744 	 * (On the system that this was first tested on, the input floats high
745 	 * and gives a (masked) interrupt as soon as the gate is closed.)
746 	 */
747 	sio_setreg(com, com_ier, 0);
748 	sio_setreg(com, com_cfcr, CFCR_8BITS);	/* dummy to avoid bus echo */
749 	failures[7] = sio_getreg(com, com_ier);
750 	DELAY(1000);		/* XXX */
751 	irqmap[3] = isa_irq_pending();
752 	failures[9] = (sio_getreg(com, com_iir) & IIR_IMASK) - IIR_NOPEND;
753 
754 	mtx_unlock_spin(&sio_lock);
755 
756 	irqs = irqmap[1] & ~irqmap[0];
757 	if (bus_get_resource(idev, SYS_RES_IRQ, 0, &xirq, NULL) == 0 &&
758 	    ((1 << xirq) & irqs) == 0) {
759 		printf(
760 		"sio%d: configured irq %ld not in bitmap of probed irqs %#x\n",
761 		    device_get_unit(dev), xirq, irqs);
762 		printf(
763 		"sio%d: port may not be enabled\n",
764 		    device_get_unit(dev));
765 	}
766 	if (bootverbose)
767 		printf("sio%d: irq maps: %#x %#x %#x %#x\n",
768 		    device_get_unit(dev),
769 		    irqmap[0], irqmap[1], irqmap[2], irqmap[3]);
770 
771 	result = 0;
772 	for (fn = 0; fn < sizeof failures; ++fn)
773 		if (failures[fn]) {
774 			sio_setreg(com, com_mcr, 0);
775 			result = ENXIO;
776 			if (bootverbose) {
777 				printf("sio%d: probe failed test(s):",
778 				    device_get_unit(dev));
779 				for (fn = 0; fn < sizeof failures; ++fn)
780 					if (failures[fn])
781 						printf(" %d", fn);
782 				printf("\n");
783 			}
784 			break;
785 		}
786 	bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
787 	if (iobase == siocniobase)
788 		result = 0;
789 	/*
790 	 * XXX: Since we don't return 0, we shouldn't be relying on the softc
791 	 * that we set to persist to the call to attach since other probe
792 	 * routines may be called, and the malloc here causes subr_bus to not
793 	 * allocate anything for the other probes.  Instead, this softc is
794 	 * preserved and other probe routines can corrupt it.
795 	 */
796 	if (result != 0) {
797 		device_set_softc(dev, NULL);
798 		free(com, M_DEVBUF);
799 	}
800 	return (result == 0 ? BUS_PROBE_DEFAULT + 1 : result);
801 }
802 
803 #ifdef COM_ESP
804 static int
espattach(com,esp_port)805 espattach(com, esp_port)
806 	struct com_s		*com;
807 	Port_t			esp_port;
808 {
809 	u_char	dips;
810 	u_char	val;
811 
812 	/*
813 	 * Check the ESP-specific I/O port to see if we're an ESP
814 	 * card.  If not, return failure immediately.
815 	 */
816 	if ((inb(esp_port) & 0xf3) == 0) {
817 		printf(" port 0x%x is not an ESP board?\n", esp_port);
818 		return (0);
819 	}
820 
821 	/*
822 	 * We've got something that claims to be a Hayes ESP card.
823 	 * Let's hope so.
824 	 */
825 
826 	/* Get the dip-switch configuration */
827 	outb(esp_port + ESP_CMD1, ESP_GETDIPS);
828 	dips = inb(esp_port + ESP_STATUS1);
829 
830 	/*
831 	 * Bits 0,1 of dips say which COM port we are.
832 	 */
833 	if (rman_get_start(com->ioportres) == likely_com_ports[dips & 0x03])
834 		printf(" : ESP");
835 	else {
836 		printf(" esp_port has com %d\n", dips & 0x03);
837 		return (0);
838 	}
839 
840 	/*
841 	 * Check for ESP version 2.0 or later:  bits 4,5,6 = 010.
842 	 */
843 	outb(esp_port + ESP_CMD1, ESP_GETTEST);
844 	val = inb(esp_port + ESP_STATUS1);	/* clear reg 1 */
845 	val = inb(esp_port + ESP_STATUS2);
846 	if ((val & 0x70) < 0x20) {
847 		printf("-old (%o)", val & 0x70);
848 		return (0);
849 	}
850 
851 	/*
852 	 * Check for ability to emulate 16550:  bit 7 == 1
853 	 */
854 	if ((dips & 0x80) == 0) {
855 		printf(" slave");
856 		return (0);
857 	}
858 
859 	/*
860 	 * Okay, we seem to be a Hayes ESP card.  Whee.
861 	 */
862 	com->esp = TRUE;
863 	com->esp_port = esp_port;
864 	return (1);
865 }
866 #endif /* COM_ESP */
867 
868 int
sioattach(dev,xrid,rclk)869 sioattach(dev, xrid, rclk)
870 	device_t	dev;
871 	int		xrid;
872 	u_long		rclk;
873 {
874 	struct com_s	*com;
875 #ifdef COM_ESP
876 	Port_t		*espp;
877 #endif
878 	Port_t		iobase;
879 	int		unit;
880 	u_int		flags;
881 	int		rid;
882 	struct resource *port;
883 	int		ret;
884 	int		error;
885 	struct tty	*tp;
886 
887 	rid = xrid;
888 	port = bus_alloc_resource_anywhere(dev, SYS_RES_IOPORT, &rid,
889 					   IO_COMSIZE, RF_ACTIVE);
890 	if (!port)
891 		return (ENXIO);
892 
893 	iobase = rman_get_start(port);
894 	unit = device_get_unit(dev);
895 	com = device_get_softc(dev);
896 	flags = device_get_flags(dev);
897 
898 	if (unit >= sio_numunits)
899 		sio_numunits = unit + 1;
900 	/*
901 	 * sioprobe() has initialized the device registers as follows:
902 	 *	o cfcr = CFCR_8BITS.
903 	 *	  It is most important that CFCR_DLAB is off, so that the
904 	 *	  data port is not hidden when we enable interrupts.
905 	 *	o ier = 0.
906 	 *	  Interrupts are only enabled when the line is open.
907 	 *	o mcr = MCR_IENABLE, or 0 if the port has AST/4 compatible
908 	 *	  interrupt control register or the config specifies no irq.
909 	 *	  Keeping MCR_DTR and MCR_RTS off might stop the external
910 	 *	  device from sending before we are ready.
911 	 */
912 	bzero(com, sizeof *com);
913 	com->unit = unit;
914 	com->ioportres = port;
915 	com->ioportrid = rid;
916 	com->bst = rman_get_bustag(port);
917 	com->bsh = rman_get_bushandle(port);
918 	com->cfcr_image = CFCR_8BITS;
919 	com->loses_outints = COM_LOSESOUTINTS(flags) != 0;
920 	com->no_irq = bus_get_resource(dev, SYS_RES_IRQ, 0, NULL, NULL) != 0;
921 	com->tx_fifo_size = 1;
922 	com->obufs[0].l_head = com->obuf1;
923 	com->obufs[1].l_head = com->obuf2;
924 
925 	com->data_port = iobase + com_data;
926 	com->int_ctl_port = iobase + com_ier;
927 	com->int_id_port = iobase + com_iir;
928 	com->modem_ctl_port = iobase + com_mcr;
929 	com->mcr_image = inb(com->modem_ctl_port);
930 	com->line_status_port = iobase + com_lsr;
931 	com->modem_status_port = iobase + com_msr;
932 
933 	tp = com->tp = ttyalloc();
934 	tp->t_oproc = comstart;
935 	tp->t_param = comparam;
936 	tp->t_stop = comstop;
937 	tp->t_modem = commodem;
938 	tp->t_break = combreak;
939 	tp->t_close = comclose;
940 	tp->t_open = comopen;
941 	tp->t_sc = com;
942 
943 	if (rclk == 0)
944 		rclk = DEFAULT_RCLK;
945 	com->rclk = rclk;
946 
947 	if (unit == comconsole)
948 		ttyconsolemode(tp, comdefaultrate);
949 	error = siosetwater(com, tp->t_init_in.c_ispeed);
950 	mtx_unlock_spin(&sio_lock);
951 	if (error) {
952 		/*
953 		 * Leave i/o resources allocated if this is a `cn'-level
954 		 * console, so that other devices can't snarf them.
955 		 */
956 		if (iobase != siocniobase)
957 			bus_release_resource(dev, SYS_RES_IOPORT, rid, port);
958 		return (ENOMEM);
959 	}
960 
961 	/* attempt to determine UART type */
962 	printf("sio%d: type", unit);
963 
964 	if (!COM_ISMULTIPORT(flags) &&
965 	    !COM_IIR_TXRDYBUG(flags) && !COM_NOSCR(flags)) {
966 		u_char	scr;
967 		u_char	scr1;
968 		u_char	scr2;
969 
970 		scr = sio_getreg(com, com_scr);
971 		sio_setreg(com, com_scr, 0xa5);
972 		scr1 = sio_getreg(com, com_scr);
973 		sio_setreg(com, com_scr, 0x5a);
974 		scr2 = sio_getreg(com, com_scr);
975 		sio_setreg(com, com_scr, scr);
976 		if (scr1 != 0xa5 || scr2 != 0x5a) {
977 			printf(" 8250 or not responding");
978 			goto determined_type;
979 		}
980 	}
981 	sio_setreg(com, com_fifo, FIFO_ENABLE | FIFO_RX_HIGH);
982 	DELAY(100);
983 	switch (inb(com->int_id_port) & IIR_FIFO_MASK) {
984 	case FIFO_RX_LOW:
985 		printf(" 16450");
986 		break;
987 	case FIFO_RX_MEDL:
988 		printf(" 16450?");
989 		break;
990 	case FIFO_RX_MEDH:
991 		printf(" 16550?");
992 		break;
993 	case FIFO_RX_HIGH:
994 		if (COM_NOFIFO(flags)) {
995 			printf(" 16550A fifo disabled");
996 			break;
997 		}
998 		com->hasfifo = TRUE;
999 		if (COM_ST16650A(flags)) {
1000 			printf(" ST16650A");
1001 			com->st16650a = TRUE;
1002 			com->tx_fifo_size = 32;
1003 			break;
1004 		}
1005 		if (COM_TI16754(flags)) {
1006 			printf(" TI16754");
1007 			com->tx_fifo_size = 64;
1008 			break;
1009 		}
1010 		printf(" 16550A");
1011 #ifdef COM_ESP
1012 		for (espp = likely_esp_ports; *espp != 0; espp++)
1013 			if (espattach(com, *espp)) {
1014 				com->tx_fifo_size = 1024;
1015 				break;
1016 			}
1017 		if (com->esp)
1018 			break;
1019 #endif
1020 		com->tx_fifo_size = COM_FIFOSIZE(flags);
1021 		if (com->tx_fifo_size == 0)
1022 			com->tx_fifo_size = 16;
1023 		else
1024 			printf(" lookalike with %u bytes FIFO",
1025 			       com->tx_fifo_size);
1026 		break;
1027 	}
1028 #ifdef COM_ESP
1029 	if (com->esp) {
1030 		/*
1031 		 * Set 16550 compatibility mode.
1032 		 * We don't use the ESP_MODE_SCALE bit to increase the
1033 		 * fifo trigger levels because we can't handle large
1034 		 * bursts of input.
1035 		 * XXX flow control should be set in comparam(), not here.
1036 		 */
1037 		outb(com->esp_port + ESP_CMD1, ESP_SETMODE);
1038 		outb(com->esp_port + ESP_CMD2, ESP_MODE_RTS | ESP_MODE_FIFO);
1039 
1040 		/* Set RTS/CTS flow control. */
1041 		outb(com->esp_port + ESP_CMD1, ESP_SETFLOWTYPE);
1042 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_RTS);
1043 		outb(com->esp_port + ESP_CMD2, ESP_FLOW_CTS);
1044 
1045 		/* Set flow-control levels. */
1046 		outb(com->esp_port + ESP_CMD1, ESP_SETRXFLOW);
1047 		outb(com->esp_port + ESP_CMD2, HIBYTE(768));
1048 		outb(com->esp_port + ESP_CMD2, LOBYTE(768));
1049 		outb(com->esp_port + ESP_CMD2, HIBYTE(512));
1050 		outb(com->esp_port + ESP_CMD2, LOBYTE(512));
1051 	}
1052 #endif /* COM_ESP */
1053 	sio_setreg(com, com_fifo, 0);
1054 determined_type: ;
1055 
1056 #ifdef COM_MULTIPORT
1057 	if (COM_ISMULTIPORT(flags)) {
1058 		device_t masterdev;
1059 
1060 		com->multiport = TRUE;
1061 		printf(" (multiport");
1062 		if (unit == COM_MPMASTER(flags))
1063 			printf(" master");
1064 		printf(")");
1065 		masterdev = devclass_get_device(sio_devclass,
1066 		    COM_MPMASTER(flags));
1067 		com->no_irq = (masterdev == NULL || bus_get_resource(masterdev,
1068 		    SYS_RES_IRQ, 0, NULL, NULL) != 0);
1069 	 }
1070 #endif /* COM_MULTIPORT */
1071 	if (unit == comconsole)
1072 		printf(", console");
1073 	if (COM_IIR_TXRDYBUG(flags))
1074 		printf(" with a buggy IIR_TXRDY implementation");
1075 	printf("\n");
1076 
1077 	if (sio_fast_ih == NULL) {
1078 		swi_add(&tty_intr_event, "sio", siopoll, NULL, SWI_TTY, 0,
1079 		    &sio_fast_ih);
1080 		swi_add(&clk_intr_event, "sio", siopoll, NULL, SWI_CLOCK, 0,
1081 		    &sio_slow_ih);
1082 	}
1083 
1084 	com->flags = flags;
1085 	com->pps.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1086 	tp->t_pps = &com->pps;
1087 
1088 	if (COM_PPSCTS(flags))
1089 		com->pps_bit = MSR_CTS;
1090 	else
1091 		com->pps_bit = MSR_DCD;
1092 	pps_init(&com->pps);
1093 
1094 	rid = 0;
1095 	com->irqres = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
1096 	if (com->irqres) {
1097 		ret = bus_setup_intr(dev, com->irqres,
1098 				     INTR_TYPE_TTY,
1099 				     siointr, NULL, com,
1100 				     &com->cookie);
1101 		if (ret) {
1102 			ret = bus_setup_intr(dev,
1103 					     com->irqres, INTR_TYPE_TTY,
1104 					     NULL, (driver_intr_t *)siointr, com, &com->cookie);
1105 			if (ret == 0)
1106 				device_printf(dev, "unable to activate interrupt in fast mode - using normal mode\n");
1107 		}
1108 		if (ret)
1109 			device_printf(dev, "could not activate interrupt\n");
1110 #if defined(KDB)
1111 		/*
1112 		 * Enable interrupts for early break-to-debugger support
1113 		 * on the console.
1114 		 */
1115 		if (ret == 0 && unit == comconsole)
1116 			outb(siocniobase + com_ier, IER_ERXRDY | IER_ERLS |
1117 			    IER_EMSC);
1118 #endif
1119 	}
1120 
1121 	/* We're ready, open the doors... */
1122 	ttycreate(tp, TS_CALLOUT, "d%r", unit);
1123 
1124 	return (0);
1125 }
1126 
1127 static int
comopen(struct tty * tp,struct cdev * dev)1128 comopen(struct tty *tp, struct cdev *dev)
1129 {
1130 	struct com_s	*com;
1131 	int i;
1132 
1133 	com = tp->t_sc;
1134 	com->poll = com->no_irq;
1135 	com->poll_output = com->loses_outints;
1136 	if (com->hasfifo) {
1137 		/*
1138 		 * (Re)enable and drain fifos.
1139 		 *
1140 		 * Certain SMC chips cause problems if the fifos
1141 		 * are enabled while input is ready.  Turn off the
1142 		 * fifo if necessary to clear the input.  We test
1143 		 * the input ready bit after enabling the fifos
1144 		 * since we've already enabled them in comparam()
1145 		 * and to handle races between enabling and fresh
1146 		 * input.
1147 		 */
1148 		for (i = 0; i < 500; i++) {
1149 			sio_setreg(com, com_fifo,
1150 				   FIFO_RCV_RST | FIFO_XMT_RST
1151 				   | com->fifo_image);
1152 			/*
1153 			 * XXX the delays are for superstitious
1154 			 * historical reasons.  It must be less than
1155 			 * the character time at the maximum
1156 			 * supported speed (87 usec at 115200 bps
1157 			 * 8N1).  Otherwise we might loop endlessly
1158 			 * if data is streaming in.  We used to use
1159 			 * delays of 100.  That usually worked
1160 			 * because DELAY(100) used to usually delay
1161 			 * for about 85 usec instead of 100.
1162 			 */
1163 			DELAY(50);
1164 			if (!(inb(com->line_status_port) & LSR_RXRDY))
1165 				break;
1166 			sio_setreg(com, com_fifo, 0);
1167 			DELAY(50);
1168 			(void) inb(com->data_port);
1169 		}
1170 		if (i == 500)
1171 			return (EIO);
1172 	}
1173 
1174 	mtx_lock_spin(&sio_lock);
1175 	(void) inb(com->line_status_port);
1176 	(void) inb(com->data_port);
1177 	com->prev_modem_status = com->last_modem_status
1178 	    = inb(com->modem_status_port);
1179 	outb(com->int_ctl_port,
1180 	     IER_ERXRDY | IER_ERLS | IER_EMSC
1181 	     | (COM_IIR_TXRDYBUG(com->flags) ? 0 : IER_ETXRDY));
1182 	mtx_unlock_spin(&sio_lock);
1183 	siosettimeout();
1184 	/* XXX: should be generic ? */
1185 	if (com->prev_modem_status & MSR_DCD || ISCALLOUT(dev))
1186 		ttyld_modem(tp, 1);
1187 	return (0);
1188 }
1189 
1190 static void
comclose(tp)1191 comclose(tp)
1192 	struct tty	*tp;
1193 {
1194 	int		s;
1195 	struct com_s	*com;
1196 
1197 	s = spltty();
1198 	com = tp->t_sc;
1199 	com->poll = FALSE;
1200 	com->poll_output = FALSE;
1201 	sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1202 
1203 #if defined(KDB)
1204 	/*
1205 	 * Leave interrupts enabled and don't clear DTR if this is the
1206 	 * console. This allows us to detect break-to-debugger events
1207 	 * while the console device is closed.
1208 	 */
1209 	if (com->unit != comconsole)
1210 #endif
1211 	{
1212 		sio_setreg(com, com_ier, 0);
1213 		if (tp->t_cflag & HUPCL
1214 		    /*
1215 		     * XXX we will miss any carrier drop between here and the
1216 		     * next open.  Perhaps we should watch DCD even when the
1217 		     * port is closed; it is not sufficient to check it at
1218 		     * the next open because it might go up and down while
1219 		     * we're not watching.
1220 		     */
1221 		    || (!tp->t_actout
1222 		        && !(com->prev_modem_status & MSR_DCD)
1223 		        && !(tp->t_init_in.c_cflag & CLOCAL))
1224 		    || !(tp->t_state & TS_ISOPEN)) {
1225 			(void)commodem(tp, 0, SER_DTR);
1226 			ttydtrwaitstart(tp);
1227 		}
1228 	}
1229 	if (com->hasfifo) {
1230 		/*
1231 		 * Disable fifos so that they are off after controlled
1232 		 * reboots.  Some BIOSes fail to detect 16550s when the
1233 		 * fifos are enabled.
1234 		 */
1235 		sio_setreg(com, com_fifo, 0);
1236 	}
1237 	tp->t_actout = FALSE;
1238 	wakeup(&tp->t_actout);
1239 	wakeup(TSA_CARR_ON(tp));	/* restart any wopeners */
1240 	siosettimeout();
1241 	splx(s);
1242 }
1243 
1244 static void
siobusycheck(chan)1245 siobusycheck(chan)
1246 	void	*chan;
1247 {
1248 	struct com_s	*com;
1249 	int		s;
1250 
1251 	com = (struct com_s *)chan;
1252 
1253 	/*
1254 	 * Clear TS_BUSY if low-level output is complete.
1255 	 * spl locking is sufficient because siointr1() does not set CS_BUSY.
1256 	 * If siointr1() clears CS_BUSY after we look at it, then we'll get
1257 	 * called again.  Reading the line status port outside of siointr1()
1258 	 * is safe because CS_BUSY is clear so there are no output interrupts
1259 	 * to lose.
1260 	 */
1261 	s = spltty();
1262 	if (com->state & CS_BUSY)
1263 		com->extra_state &= ~CSE_BUSYCHECK;	/* False alarm. */
1264 	else if ((inb(com->line_status_port) & (LSR_TSRE | LSR_TXRDY))
1265 	    == (LSR_TSRE | LSR_TXRDY)) {
1266 		com->tp->t_state &= ~TS_BUSY;
1267 		ttwwakeup(com->tp);
1268 		com->extra_state &= ~CSE_BUSYCHECK;
1269 	} else
1270 		timeout(siobusycheck, com, hz / 100);
1271 	splx(s);
1272 }
1273 
1274 static u_int
siodivisor(rclk,speed)1275 siodivisor(rclk, speed)
1276 	u_long	rclk;
1277 	speed_t	speed;
1278 {
1279 	long	actual_speed;
1280 	u_int	divisor;
1281 	int	error;
1282 
1283 	if (speed == 0)
1284 		return (0);
1285 #if UINT_MAX > (ULONG_MAX - 1) / 8
1286 	if (speed > (ULONG_MAX - 1) / 8)
1287 		return (0);
1288 #endif
1289 	divisor = (rclk / (8UL * speed) + 1) / 2;
1290 	if (divisor == 0 || divisor >= 65536)
1291 		return (0);
1292 	actual_speed = rclk / (16UL * divisor);
1293 
1294 	/* 10 times error in percent: */
1295 	error = ((actual_speed - (long)speed) * 2000 / (long)speed + 1) / 2;
1296 
1297 	/* 3.0% maximum error tolerance: */
1298 	if (error < -30 || error > 30)
1299 		return (0);
1300 
1301 	return (divisor);
1302 }
1303 
1304 /*
1305  * Call this function with the sio_lock mutex held.  It will return with the
1306  * lock still held.
1307  */
1308 static void
sioinput(com)1309 sioinput(com)
1310 	struct com_s	*com;
1311 {
1312 	u_char		*buf;
1313 	int		incc;
1314 	u_char		line_status;
1315 	int		recv_data;
1316 	struct tty	*tp;
1317 
1318 	buf = com->ibuf;
1319 	tp = com->tp;
1320 	if (!(tp->t_state & TS_ISOPEN) || !(tp->t_cflag & CREAD)) {
1321 		com_events -= (com->iptr - com->ibuf);
1322 		com->iptr = com->ibuf;
1323 		return;
1324 	}
1325 	if (tp->t_state & TS_CAN_BYPASS_L_RINT) {
1326 		/*
1327 		 * Avoid the grotesquely inefficient lineswitch routine
1328 		 * (ttyinput) in "raw" mode.  It usually takes about 450
1329 		 * instructions (that's without canonical processing or echo!).
1330 		 * slinput is reasonably fast (usually 40 instructions plus
1331 		 * call overhead).
1332 		 */
1333 		do {
1334 			/*
1335 			 * This may look odd, but it is using save-and-enable
1336 			 * semantics instead of the save-and-disable semantics
1337 			 * that are used everywhere else.
1338 			 */
1339 			mtx_unlock_spin(&sio_lock);
1340 			incc = com->iptr - buf;
1341 			if (tp->t_rawq.c_cc + incc > tp->t_ihiwat
1342 			    && (com->state & CS_RTS_IFLOW
1343 				|| tp->t_iflag & IXOFF)
1344 			    && !(tp->t_state & TS_TBLOCK))
1345 				ttyblock(tp);
1346 			com->delta_error_counts[CE_TTY_BUF_OVERFLOW]
1347 				+= b_to_q((char *)buf, incc, &tp->t_rawq);
1348 			buf += incc;
1349 			tk_nin += incc;
1350 			tk_rawcc += incc;
1351 			tp->t_rawcc += incc;
1352 			ttwakeup(tp);
1353 			if (tp->t_state & TS_TTSTOP
1354 			    && (tp->t_iflag & IXANY
1355 				|| tp->t_cc[VSTART] == tp->t_cc[VSTOP])) {
1356 				tp->t_state &= ~TS_TTSTOP;
1357 				tp->t_lflag &= ~FLUSHO;
1358 				comstart(tp);
1359 			}
1360 			mtx_lock_spin(&sio_lock);
1361 		} while (buf < com->iptr);
1362 	} else {
1363 		do {
1364 			/*
1365 			 * This may look odd, but it is using save-and-enable
1366 			 * semantics instead of the save-and-disable semantics
1367 			 * that are used everywhere else.
1368 			 */
1369 			mtx_unlock_spin(&sio_lock);
1370 			line_status = buf[com->ierroff];
1371 			recv_data = *buf++;
1372 			if (line_status
1373 			    & (LSR_BI | LSR_FE | LSR_OE | LSR_PE)) {
1374 				if (line_status & LSR_BI)
1375 					recv_data |= TTY_BI;
1376 				if (line_status & LSR_FE)
1377 					recv_data |= TTY_FE;
1378 				if (line_status & LSR_OE)
1379 					recv_data |= TTY_OE;
1380 				if (line_status & LSR_PE)
1381 					recv_data |= TTY_PE;
1382 			}
1383 			ttyld_rint(tp, recv_data);
1384 			mtx_lock_spin(&sio_lock);
1385 		} while (buf < com->iptr);
1386 	}
1387 	com_events -= (com->iptr - com->ibuf);
1388 	com->iptr = com->ibuf;
1389 
1390 	/*
1391 	 * There is now room for another low-level buffer full of input,
1392 	 * so enable RTS if it is now disabled and there is room in the
1393 	 * high-level buffer.
1394 	 */
1395 	if ((com->state & CS_RTS_IFLOW) && !(com->mcr_image & MCR_RTS) &&
1396 	    !(tp->t_state & TS_TBLOCK))
1397 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1398 }
1399 
1400 static int
siointr(arg)1401 siointr(arg)
1402 	void		*arg;
1403 {
1404 	struct com_s	*com;
1405 
1406 #ifndef COM_MULTIPORT
1407 	com = (struct com_s *)arg;
1408 
1409 	mtx_lock_spin(&sio_lock);
1410 	siointr1(com);
1411 	mtx_unlock_spin(&sio_lock);
1412 #else /* COM_MULTIPORT */
1413 	bool_t		possibly_more_intrs;
1414 	int		unit;
1415 
1416 	/*
1417 	 * Loop until there is no activity on any port.  This is necessary
1418 	 * to get an interrupt edge more than to avoid another interrupt.
1419 	 * If the IRQ signal is just an OR of the IRQ signals from several
1420 	 * devices, then the edge from one may be lost because another is
1421 	 * on.
1422 	 */
1423 	mtx_lock_spin(&sio_lock);
1424 	do {
1425 		possibly_more_intrs = FALSE;
1426 		for (unit = 0; unit < sio_numunits; ++unit) {
1427 			com = com_addr(unit);
1428 			/*
1429 			 * XXX COM_LOCK();
1430 			 * would it work here, or be counter-productive?
1431 			 */
1432 			if (com != NULL
1433 			    && !com->gone
1434 			    && (inb(com->int_id_port) & IIR_IMASK)
1435 			       != IIR_NOPEND) {
1436 				siointr1(com);
1437 				possibly_more_intrs = TRUE;
1438 			}
1439 			/* XXX COM_UNLOCK(); */
1440 		}
1441 	} while (possibly_more_intrs);
1442 	mtx_unlock_spin(&sio_lock);
1443 #endif /* COM_MULTIPORT */
1444 	return(FILTER_HANDLED);
1445 }
1446 
1447 static struct timespec siots[8];
1448 static int siotso;
1449 static int volatile siotsunit = -1;
1450 
1451 static int
sysctl_siots(SYSCTL_HANDLER_ARGS)1452 sysctl_siots(SYSCTL_HANDLER_ARGS)
1453 {
1454 	char buf[128];
1455 	long long delta;
1456 	size_t len;
1457 	int error, i, tso;
1458 
1459 	for (i = 1, tso = siotso; i < tso; i++) {
1460 		delta = (long long)(siots[i].tv_sec - siots[i - 1].tv_sec) *
1461 		    1000000000 +
1462 		    (siots[i].tv_nsec - siots[i - 1].tv_nsec);
1463 		len = sprintf(buf, "%lld\n", delta);
1464 		if (delta >= 110000)
1465 			len += sprintf(buf + len - 1, ": *** %ld.%09ld\n",
1466 			    (long)siots[i].tv_sec, siots[i].tv_nsec) - 1;
1467 		if (i == tso - 1)
1468 			buf[len - 1] = '\0';
1469 		error = SYSCTL_OUT(req, buf, len);
1470 		if (error != 0)
1471 			return (error);
1472 	}
1473 	return (0);
1474 }
1475 
1476 SYSCTL_PROC(_machdep, OID_AUTO, siots, CTLTYPE_STRING | CTLFLAG_RD,
1477     0, 0, sysctl_siots, "A", "sio timestamps");
1478 
1479 static void
siointr1(com)1480 siointr1(com)
1481 	struct com_s	*com;
1482 {
1483 	u_char	int_ctl;
1484 	u_char	int_ctl_new;
1485 	u_char	line_status;
1486 	u_char	modem_status;
1487 	u_char	*ioptr;
1488 	u_char	recv_data;
1489 
1490 #ifdef KDB
1491 again:
1492 #endif
1493 
1494 	if (COM_IIR_TXRDYBUG(com->flags)) {
1495 		int_ctl = inb(com->int_ctl_port);
1496 		int_ctl_new = int_ctl;
1497 	} else {
1498 		int_ctl = 0;
1499 		int_ctl_new = 0;
1500 	}
1501 
1502 	while (!com->gone) {
1503 		if (com->pps.ppsparam.mode & PPS_CAPTUREBOTH) {
1504 			modem_status = inb(com->modem_status_port);
1505 		        if ((modem_status ^ com->last_modem_status) &
1506 			    com->pps_bit) {
1507 				pps_capture(&com->pps);
1508 				pps_event(&com->pps,
1509 				    (modem_status & com->pps_bit) ?
1510 				    PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
1511 			}
1512 		}
1513 		line_status = inb(com->line_status_port);
1514 
1515 		/* input event? (check first to help avoid overruns) */
1516 		while (line_status & LSR_RCV_MASK) {
1517 			/* break/unnattached error bits or real input? */
1518 			if (!(line_status & LSR_RXRDY))
1519 				recv_data = 0;
1520 			else
1521 				recv_data = inb(com->data_port);
1522 #ifdef KDB
1523 			if (com->unit == comconsole &&
1524 			    kdb_alt_break(recv_data, &com->alt_brk_state) != 0)
1525 				goto again;
1526 #endif /* KDB */
1527 			if (line_status & (LSR_BI | LSR_FE | LSR_PE)) {
1528 				/*
1529 				 * Don't store BI if IGNBRK or FE/PE if IGNPAR.
1530 				 * Otherwise, push the work to a higher level
1531 				 * (to handle PARMRK) if we're bypassing.
1532 				 * Otherwise, convert BI/FE and PE+INPCK to 0.
1533 				 *
1534 				 * This makes bypassing work right in the
1535 				 * usual "raw" case (IGNBRK set, and IGNPAR
1536 				 * and INPCK clear).
1537 				 *
1538 				 * Note: BI together with FE/PE means just BI.
1539 				 */
1540 				if (line_status & LSR_BI) {
1541 #if defined(KDB)
1542 					if (com->unit == comconsole) {
1543 						kdb_break();
1544 						goto cont;
1545 					}
1546 #endif
1547 					if (com->tp == NULL
1548 					    || com->tp->t_iflag & IGNBRK)
1549 						goto cont;
1550 				} else {
1551 					if (com->tp == NULL
1552 					    || com->tp->t_iflag & IGNPAR)
1553 						goto cont;
1554 				}
1555 				if (com->tp->t_state & TS_CAN_BYPASS_L_RINT
1556 				    && (line_status & (LSR_BI | LSR_FE)
1557 					|| com->tp->t_iflag & INPCK))
1558 					recv_data = 0;
1559 			}
1560 			++com->bytes_in;
1561 			if (com->tp != NULL &&
1562 			    com->tp->t_hotchar != 0 && recv_data == com->tp->t_hotchar)
1563 				swi_sched(sio_fast_ih, 0);
1564 			ioptr = com->iptr;
1565 			if (ioptr >= com->ibufend)
1566 				CE_RECORD(com, CE_INTERRUPT_BUF_OVERFLOW);
1567 			else {
1568 				if (com->tp != NULL && com->tp->t_do_timestamp)
1569 					microtime(&com->tp->t_timestamp);
1570 				++com_events;
1571 				swi_sched(sio_slow_ih, SWI_DELAY);
1572 #if 0 /* for testing input latency vs efficiency */
1573 if (com->iptr - com->ibuf == 8)
1574 	swi_sched(sio_fast_ih, 0);
1575 #endif
1576 				ioptr[0] = recv_data;
1577 				ioptr[com->ierroff] = line_status;
1578 				com->iptr = ++ioptr;
1579 				if (ioptr == com->ihighwater
1580 				    && com->state & CS_RTS_IFLOW)
1581 					outb(com->modem_ctl_port,
1582 					     com->mcr_image &= ~MCR_RTS);
1583 				if (line_status & LSR_OE)
1584 					CE_RECORD(com, CE_OVERRUN);
1585 			}
1586 cont:
1587 			if (line_status & LSR_TXRDY
1588 			    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY))
1589 				goto txrdy;
1590 
1591 			/*
1592 			 * "& 0x7F" is to avoid the gcc-1.40 generating a slow
1593 			 * jump from the top of the loop to here
1594 			 */
1595 			line_status = inb(com->line_status_port) & 0x7F;
1596 		}
1597 
1598 		/* modem status change? (always check before doing output) */
1599 		modem_status = inb(com->modem_status_port);
1600 		if (modem_status != com->last_modem_status) {
1601 			/*
1602 			 * Schedule high level to handle DCD changes.  Note
1603 			 * that we don't use the delta bits anywhere.  Some
1604 			 * UARTs mess them up, and it's easy to remember the
1605 			 * previous bits and calculate the delta.
1606 			 */
1607 			com->last_modem_status = modem_status;
1608 			if (!(com->state & CS_CHECKMSR)) {
1609 				com_events += LOTS_OF_EVENTS;
1610 				com->state |= CS_CHECKMSR;
1611 				swi_sched(sio_fast_ih, 0);
1612 			}
1613 
1614 			/* handle CTS change immediately for crisp flow ctl */
1615 			if (com->state & CS_CTS_OFLOW) {
1616 				if (modem_status & MSR_CTS)
1617 					com->state |= CS_ODEVREADY;
1618 				else
1619 					com->state &= ~CS_ODEVREADY;
1620 			}
1621 		}
1622 
1623 txrdy:
1624 		/* output queued and everything ready? */
1625 		if (line_status & LSR_TXRDY
1626 		    && com->state >= (CS_BUSY | CS_TTGO | CS_ODEVREADY)) {
1627 			ioptr = com->obufq.l_head;
1628 			if (com->tx_fifo_size > 1 && com->unit != siotsunit) {
1629 				u_int	ocount;
1630 
1631 				ocount = com->obufq.l_tail - ioptr;
1632 				if (ocount > com->tx_fifo_size)
1633 					ocount = com->tx_fifo_size;
1634 				com->bytes_out += ocount;
1635 				do
1636 					outb(com->data_port, *ioptr++);
1637 				while (--ocount != 0);
1638 			} else {
1639 				outb(com->data_port, *ioptr++);
1640 				++com->bytes_out;
1641 				if (com->unit == siotsunit
1642 				    && siotso < nitems(siots))
1643 					nanouptime(&siots[siotso++]);
1644 			}
1645 			com->obufq.l_head = ioptr;
1646 			if (COM_IIR_TXRDYBUG(com->flags))
1647 				int_ctl_new = int_ctl | IER_ETXRDY;
1648 			if (ioptr >= com->obufq.l_tail) {
1649 				struct lbq	*qp;
1650 
1651 				qp = com->obufq.l_next;
1652 				qp->l_queued = FALSE;
1653 				qp = qp->l_next;
1654 				if (qp != NULL) {
1655 					com->obufq.l_head = qp->l_head;
1656 					com->obufq.l_tail = qp->l_tail;
1657 					com->obufq.l_next = qp;
1658 				} else {
1659 					/* output just completed */
1660 					if (COM_IIR_TXRDYBUG(com->flags))
1661 						int_ctl_new = int_ctl
1662 							      & ~IER_ETXRDY;
1663 					com->state &= ~CS_BUSY;
1664 				}
1665 				if (!(com->state & CS_ODONE)) {
1666 					com_events += LOTS_OF_EVENTS;
1667 					com->state |= CS_ODONE;
1668 					/* handle at high level ASAP */
1669 					swi_sched(sio_fast_ih, 0);
1670 				}
1671 			}
1672 			if (COM_IIR_TXRDYBUG(com->flags)
1673 			    && int_ctl != int_ctl_new)
1674 				outb(com->int_ctl_port, int_ctl_new);
1675 		}
1676 
1677 		/* finished? */
1678 #ifndef COM_MULTIPORT
1679 		if ((inb(com->int_id_port) & IIR_IMASK) == IIR_NOPEND)
1680 #endif /* COM_MULTIPORT */
1681 			return;
1682 	}
1683 }
1684 
1685 /* software interrupt handler for SWI_TTY */
1686 static void
siopoll(void * dummy)1687 siopoll(void *dummy)
1688 {
1689 	int		unit;
1690 
1691 	if (com_events == 0)
1692 		return;
1693 repeat:
1694 	for (unit = 0; unit < sio_numunits; ++unit) {
1695 		struct com_s	*com;
1696 		int		incc;
1697 		struct tty	*tp;
1698 
1699 		com = com_addr(unit);
1700 		if (com == NULL)
1701 			continue;
1702 		tp = com->tp;
1703 		if (tp == NULL || com->gone) {
1704 			/*
1705 			 * Discard any events related to never-opened or
1706 			 * going-away devices.
1707 			 */
1708 			mtx_lock_spin(&sio_lock);
1709 			incc = com->iptr - com->ibuf;
1710 			com->iptr = com->ibuf;
1711 			if (com->state & CS_CHECKMSR) {
1712 				incc += LOTS_OF_EVENTS;
1713 				com->state &= ~CS_CHECKMSR;
1714 			}
1715 			com_events -= incc;
1716 			mtx_unlock_spin(&sio_lock);
1717 			continue;
1718 		}
1719 		if (com->iptr != com->ibuf) {
1720 			mtx_lock_spin(&sio_lock);
1721 			sioinput(com);
1722 			mtx_unlock_spin(&sio_lock);
1723 		}
1724 		if (com->state & CS_CHECKMSR) {
1725 			u_char	delta_modem_status;
1726 
1727 			mtx_lock_spin(&sio_lock);
1728 			delta_modem_status = com->last_modem_status
1729 					     ^ com->prev_modem_status;
1730 			com->prev_modem_status = com->last_modem_status;
1731 			com_events -= LOTS_OF_EVENTS;
1732 			com->state &= ~CS_CHECKMSR;
1733 			mtx_unlock_spin(&sio_lock);
1734 			if (delta_modem_status & MSR_DCD)
1735 				ttyld_modem(tp,
1736 				    com->prev_modem_status & MSR_DCD);
1737 		}
1738 		if (com->state & CS_ODONE) {
1739 			mtx_lock_spin(&sio_lock);
1740 			com_events -= LOTS_OF_EVENTS;
1741 			com->state &= ~CS_ODONE;
1742 			mtx_unlock_spin(&sio_lock);
1743 			if (!(com->state & CS_BUSY)
1744 			    && !(com->extra_state & CSE_BUSYCHECK)) {
1745 				timeout(siobusycheck, com, hz / 100);
1746 				com->extra_state |= CSE_BUSYCHECK;
1747 			}
1748 			ttyld_start(tp);
1749 		}
1750 		if (com_events == 0)
1751 			break;
1752 	}
1753 	if (com_events >= LOTS_OF_EVENTS)
1754 		goto repeat;
1755 }
1756 
1757 static void
combreak(tp,sig)1758 combreak(tp, sig)
1759 	struct tty 	*tp;
1760 	int		sig;
1761 {
1762 	struct com_s	*com;
1763 
1764 	com = tp->t_sc;
1765 
1766 	if (sig)
1767 		sio_setreg(com, com_cfcr, com->cfcr_image |= CFCR_SBREAK);
1768 	else
1769 		sio_setreg(com, com_cfcr, com->cfcr_image &= ~CFCR_SBREAK);
1770 }
1771 
1772 static int
comparam(tp,t)1773 comparam(tp, t)
1774 	struct tty	*tp;
1775 	struct termios	*t;
1776 {
1777 	u_int		cfcr;
1778 	int		cflag;
1779 	struct com_s	*com;
1780 	u_int		divisor;
1781 	u_char		dlbh;
1782 	u_char		dlbl;
1783 	u_char		efr_flowbits;
1784 	int		s;
1785 
1786 	com = tp->t_sc;
1787 	if (com == NULL)
1788 		return (ENODEV);
1789 
1790 	/* check requested parameters */
1791 	if (t->c_ispeed != (t->c_ospeed != 0 ? t->c_ospeed : tp->t_ospeed))
1792 		return (EINVAL);
1793 	divisor = siodivisor(com->rclk, t->c_ispeed);
1794 	if (divisor == 0)
1795 		return (EINVAL);
1796 
1797 	/* parameters are OK, convert them to the com struct and the device */
1798 	s = spltty();
1799 	if (t->c_ospeed == 0)
1800 		(void)commodem(tp, 0, SER_DTR);	/* hang up line */
1801 	else
1802 		(void)commodem(tp, SER_DTR, 0);
1803 	cflag = t->c_cflag;
1804 	switch (cflag & CSIZE) {
1805 	case CS5:
1806 		cfcr = CFCR_5BITS;
1807 		break;
1808 	case CS6:
1809 		cfcr = CFCR_6BITS;
1810 		break;
1811 	case CS7:
1812 		cfcr = CFCR_7BITS;
1813 		break;
1814 	default:
1815 		cfcr = CFCR_8BITS;
1816 		break;
1817 	}
1818 	if (cflag & PARENB) {
1819 		cfcr |= CFCR_PENAB;
1820 		if (!(cflag & PARODD))
1821 			cfcr |= CFCR_PEVEN;
1822 	}
1823 	if (cflag & CSTOPB)
1824 		cfcr |= CFCR_STOPB;
1825 
1826 	if (com->hasfifo) {
1827 		/*
1828 		 * Use a fifo trigger level low enough so that the input
1829 		 * latency from the fifo is less than about 16 msec and
1830 		 * the total latency is less than about 30 msec.  These
1831 		 * latencies are reasonable for humans.  Serial comms
1832 		 * protocols shouldn't expect anything better since modem
1833 		 * latencies are larger.
1834 		 *
1835 		 * The fifo trigger level cannot be set at RX_HIGH for high
1836 		 * speed connections without further work on reducing
1837 		 * interrupt disablement times in other parts of the system,
1838 		 * without producing silo overflow errors.
1839 		 */
1840 		com->fifo_image = com->unit == siotsunit ? 0
1841 				  : t->c_ispeed <= 4800
1842 				  ? FIFO_ENABLE : FIFO_ENABLE | FIFO_RX_MEDH;
1843 #ifdef COM_ESP
1844 		/*
1845 		 * The Hayes ESP card needs the fifo DMA mode bit set
1846 		 * in compatibility mode.  If not, it will interrupt
1847 		 * for each character received.
1848 		 */
1849 		if (com->esp)
1850 			com->fifo_image |= FIFO_DMA_MODE;
1851 #endif
1852 		sio_setreg(com, com_fifo, com->fifo_image);
1853 	}
1854 
1855 	/*
1856 	 * This returns with interrupts disabled so that we can complete
1857 	 * the speed change atomically.  Keeping interrupts disabled is
1858 	 * especially important while com_data is hidden.
1859 	 */
1860 	(void) siosetwater(com, t->c_ispeed);
1861 
1862 	sio_setreg(com, com_cfcr, cfcr | CFCR_DLAB);
1863 	/*
1864 	 * Only set the divisor registers if they would change, since on
1865 	 * some 16550 incompatibles (UMC8669F), setting them while input
1866 	 * is arriving loses sync until data stops arriving.
1867 	 */
1868 	dlbl = divisor & 0xFF;
1869 	if (sio_getreg(com, com_dlbl) != dlbl)
1870 		sio_setreg(com, com_dlbl, dlbl);
1871 	dlbh = divisor >> 8;
1872 	if (sio_getreg(com, com_dlbh) != dlbh)
1873 		sio_setreg(com, com_dlbh, dlbh);
1874 
1875 	efr_flowbits = 0;
1876 
1877 	if (cflag & CRTS_IFLOW) {
1878 		com->state |= CS_RTS_IFLOW;
1879 		efr_flowbits |= EFR_AUTORTS;
1880 		/*
1881 		 * If CS_RTS_IFLOW just changed from off to on, the change
1882 		 * needs to be propagated to MCR_RTS.  This isn't urgent,
1883 		 * so do it later by calling comstart() instead of repeating
1884 		 * a lot of code from comstart() here.
1885 		 */
1886 	} else if (com->state & CS_RTS_IFLOW) {
1887 		com->state &= ~CS_RTS_IFLOW;
1888 		/*
1889 		 * CS_RTS_IFLOW just changed from on to off.  Force MCR_RTS
1890 		 * on here, since comstart() won't do it later.
1891 		 */
1892 		outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
1893 	}
1894 
1895 	/*
1896 	 * Set up state to handle output flow control.
1897 	 * XXX - worth handling MDMBUF (DCD) flow control at the lowest level?
1898 	 * Now has 10+ msec latency, while CTS flow has 50- usec latency.
1899 	 */
1900 	com->state |= CS_ODEVREADY;
1901 	com->state &= ~CS_CTS_OFLOW;
1902 	if (cflag & CCTS_OFLOW) {
1903 		com->state |= CS_CTS_OFLOW;
1904 		efr_flowbits |= EFR_AUTOCTS;
1905 		if (!(com->last_modem_status & MSR_CTS))
1906 			com->state &= ~CS_ODEVREADY;
1907 	}
1908 
1909 	if (com->st16650a) {
1910 		sio_setreg(com, com_lcr, LCR_EFR_ENABLE);
1911 		sio_setreg(com, com_efr,
1912 			   (sio_getreg(com, com_efr)
1913 			    & ~(EFR_AUTOCTS | EFR_AUTORTS)) | efr_flowbits);
1914 	}
1915 	sio_setreg(com, com_cfcr, com->cfcr_image = cfcr);
1916 
1917 	/* XXX shouldn't call functions while intrs are disabled. */
1918 	ttyldoptim(tp);
1919 
1920 	mtx_unlock_spin(&sio_lock);
1921 	splx(s);
1922 	comstart(tp);
1923 	if (com->ibufold != NULL) {
1924 		free(com->ibufold, M_DEVBUF);
1925 		com->ibufold = NULL;
1926 	}
1927 	return (0);
1928 }
1929 
1930 /*
1931  * This function must be called with the sio_lock mutex released and will
1932  * return with it obtained.
1933  */
1934 static int
siosetwater(com,speed)1935 siosetwater(com, speed)
1936 	struct com_s	*com;
1937 	speed_t		speed;
1938 {
1939 	int		cp4ticks;
1940 	u_char		*ibuf;
1941 	int		ibufsize;
1942 	struct tty	*tp;
1943 
1944 	/*
1945 	 * Make the buffer size large enough to handle a softtty interrupt
1946 	 * latency of about 2 ticks without loss of throughput or data
1947 	 * (about 3 ticks if input flow control is not used or not honoured,
1948 	 * but a bit less for CS5-CS7 modes).
1949 	 */
1950 	cp4ticks = speed / 10 / hz * 4;
1951 	for (ibufsize = 128; ibufsize < cp4ticks;)
1952 		ibufsize <<= 1;
1953 	if (ibufsize == com->ibufsize) {
1954 		mtx_lock_spin(&sio_lock);
1955 		return (0);
1956 	}
1957 
1958 	/*
1959 	 * Allocate input buffer.  The extra factor of 2 in the size is
1960 	 * to allow for an error byte for each input byte.
1961 	 */
1962 	ibuf = malloc(2 * ibufsize, M_DEVBUF, M_NOWAIT);
1963 	if (ibuf == NULL) {
1964 		mtx_lock_spin(&sio_lock);
1965 		return (ENOMEM);
1966 	}
1967 
1968 	/* Initialize non-critical variables. */
1969 	com->ibufold = com->ibuf;
1970 	com->ibufsize = ibufsize;
1971 	tp = com->tp;
1972 	if (tp != NULL) {
1973 		tp->t_ififosize = 2 * ibufsize;
1974 		tp->t_ispeedwat = (speed_t)-1;
1975 		tp->t_ospeedwat = (speed_t)-1;
1976 	}
1977 
1978 	/*
1979 	 * Read current input buffer, if any.  Continue with interrupts
1980 	 * disabled.
1981 	 */
1982 	mtx_lock_spin(&sio_lock);
1983 	if (com->iptr != com->ibuf)
1984 		sioinput(com);
1985 
1986 	/*-
1987 	 * Initialize critical variables, including input buffer watermarks.
1988 	 * The external device is asked to stop sending when the buffer
1989 	 * exactly reaches high water, or when the high level requests it.
1990 	 * The high level is notified immediately (rather than at a later
1991 	 * clock tick) when this watermark is reached.
1992 	 * The buffer size is chosen so the watermark should almost never
1993 	 * be reached.
1994 	 * The low watermark is invisibly 0 since the buffer is always
1995 	 * emptied all at once.
1996 	 */
1997 	com->iptr = com->ibuf = ibuf;
1998 	com->ibufend = ibuf + ibufsize;
1999 	com->ierroff = ibufsize;
2000 	com->ihighwater = ibuf + 3 * ibufsize / 4;
2001 	return (0);
2002 }
2003 
2004 static void
comstart(tp)2005 comstart(tp)
2006 	struct tty	*tp;
2007 {
2008 	struct com_s	*com;
2009 	int		s;
2010 
2011 	com = tp->t_sc;
2012 	if (com == NULL)
2013 		return;
2014 	s = spltty();
2015 	mtx_lock_spin(&sio_lock);
2016 	if (tp->t_state & TS_TTSTOP)
2017 		com->state &= ~CS_TTGO;
2018 	else
2019 		com->state |= CS_TTGO;
2020 	if (tp->t_state & TS_TBLOCK) {
2021 		if (com->mcr_image & MCR_RTS && com->state & CS_RTS_IFLOW)
2022 			outb(com->modem_ctl_port, com->mcr_image &= ~MCR_RTS);
2023 	} else {
2024 		if (!(com->mcr_image & MCR_RTS) && com->iptr < com->ihighwater
2025 		    && com->state & CS_RTS_IFLOW)
2026 			outb(com->modem_ctl_port, com->mcr_image |= MCR_RTS);
2027 	}
2028 	mtx_unlock_spin(&sio_lock);
2029 	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
2030 		ttwwakeup(tp);
2031 		splx(s);
2032 		return;
2033 	}
2034 	if (tp->t_outq.c_cc != 0) {
2035 		struct lbq	*qp;
2036 		struct lbq	*next;
2037 
2038 		if (!com->obufs[0].l_queued) {
2039 			com->obufs[0].l_tail
2040 			    = com->obuf1 + q_to_b(&tp->t_outq, com->obuf1,
2041 						  sizeof com->obuf1);
2042 			com->obufs[0].l_next = NULL;
2043 			com->obufs[0].l_queued = TRUE;
2044 			mtx_lock_spin(&sio_lock);
2045 			if (com->state & CS_BUSY) {
2046 				qp = com->obufq.l_next;
2047 				while ((next = qp->l_next) != NULL)
2048 					qp = next;
2049 				qp->l_next = &com->obufs[0];
2050 			} else {
2051 				com->obufq.l_head = com->obufs[0].l_head;
2052 				com->obufq.l_tail = com->obufs[0].l_tail;
2053 				com->obufq.l_next = &com->obufs[0];
2054 				com->state |= CS_BUSY;
2055 			}
2056 			mtx_unlock_spin(&sio_lock);
2057 		}
2058 		if (tp->t_outq.c_cc != 0 && !com->obufs[1].l_queued) {
2059 			com->obufs[1].l_tail
2060 			    = com->obuf2 + q_to_b(&tp->t_outq, com->obuf2,
2061 						  sizeof com->obuf2);
2062 			com->obufs[1].l_next = NULL;
2063 			com->obufs[1].l_queued = TRUE;
2064 			mtx_lock_spin(&sio_lock);
2065 			if (com->state & CS_BUSY) {
2066 				qp = com->obufq.l_next;
2067 				while ((next = qp->l_next) != NULL)
2068 					qp = next;
2069 				qp->l_next = &com->obufs[1];
2070 			} else {
2071 				com->obufq.l_head = com->obufs[1].l_head;
2072 				com->obufq.l_tail = com->obufs[1].l_tail;
2073 				com->obufq.l_next = &com->obufs[1];
2074 				com->state |= CS_BUSY;
2075 			}
2076 			mtx_unlock_spin(&sio_lock);
2077 		}
2078 		tp->t_state |= TS_BUSY;
2079 	}
2080 	mtx_lock_spin(&sio_lock);
2081 	if (com->state >= (CS_BUSY | CS_TTGO))
2082 		siointr1(com);	/* fake interrupt to start output */
2083 	mtx_unlock_spin(&sio_lock);
2084 	ttwwakeup(tp);
2085 	splx(s);
2086 }
2087 
2088 static void
comstop(tp,rw)2089 comstop(tp, rw)
2090 	struct tty	*tp;
2091 	int		rw;
2092 {
2093 	struct com_s	*com;
2094 
2095 	com = tp->t_sc;
2096 	if (com == NULL || com->gone)
2097 		return;
2098 	mtx_lock_spin(&sio_lock);
2099 	if (rw & FWRITE) {
2100 		if (com->hasfifo)
2101 #ifdef COM_ESP
2102 		    /* XXX avoid h/w bug. */
2103 		    if (!com->esp)
2104 #endif
2105 			sio_setreg(com, com_fifo,
2106 				   FIFO_XMT_RST | com->fifo_image);
2107 		com->obufs[0].l_queued = FALSE;
2108 		com->obufs[1].l_queued = FALSE;
2109 		if (com->state & CS_ODONE)
2110 			com_events -= LOTS_OF_EVENTS;
2111 		com->state &= ~(CS_ODONE | CS_BUSY);
2112 		com->tp->t_state &= ~TS_BUSY;
2113 	}
2114 	if (rw & FREAD) {
2115 		if (com->hasfifo)
2116 #ifdef COM_ESP
2117 		    /* XXX avoid h/w bug. */
2118 		    if (!com->esp)
2119 #endif
2120 			sio_setreg(com, com_fifo,
2121 				   FIFO_RCV_RST | com->fifo_image);
2122 		com_events -= (com->iptr - com->ibuf);
2123 		com->iptr = com->ibuf;
2124 	}
2125 	mtx_unlock_spin(&sio_lock);
2126 	comstart(tp);
2127 }
2128 
2129 static int
commodem(struct tty * tp,int sigon,int sigoff)2130 commodem(struct tty *tp, int sigon, int sigoff)
2131 {
2132 	struct com_s	*com;
2133 	int	bitand, bitor, msr;
2134 
2135 	com = tp->t_sc;
2136 	if (com->gone)
2137 		return(0);
2138 	if (sigon != 0 || sigoff != 0) {
2139 		bitand = bitor = 0;
2140 		if (sigoff & SER_DTR)
2141 			bitand |= MCR_DTR;
2142 		if (sigoff & SER_RTS)
2143 			bitand |= MCR_RTS;
2144 		if (sigon & SER_DTR)
2145 			bitor |= MCR_DTR;
2146 		if (sigon & SER_RTS)
2147 			bitor |= MCR_RTS;
2148 		bitand = ~bitand;
2149 		mtx_lock_spin(&sio_lock);
2150 		com->mcr_image &= bitand;
2151 		com->mcr_image |= bitor;
2152 		outb(com->modem_ctl_port, com->mcr_image);
2153 		mtx_unlock_spin(&sio_lock);
2154 		return (0);
2155 	} else {
2156 		bitor = 0;
2157 		if (com->mcr_image & MCR_DTR)
2158 			bitor |= SER_DTR;
2159 		if (com->mcr_image & MCR_RTS)
2160 			bitor |= SER_RTS;
2161 		msr = com->prev_modem_status;
2162 		if (msr & MSR_CTS)
2163 			bitor |= SER_CTS;
2164 		if (msr & MSR_DCD)
2165 			bitor |= SER_DCD;
2166 		if (msr & MSR_DSR)
2167 			bitor |= SER_DSR;
2168 		if (msr & MSR_DSR)
2169 			bitor |= SER_DSR;
2170 		if (msr & (MSR_RI | MSR_TERI))
2171 			bitor |= SER_RI;
2172 		return (bitor);
2173 	}
2174 }
2175 
2176 static void
siosettimeout()2177 siosettimeout()
2178 {
2179 	struct com_s	*com;
2180 	bool_t		someopen;
2181 	int		unit;
2182 
2183 	/*
2184 	 * Set our timeout period to 1 second if no polled devices are open.
2185 	 * Otherwise set it to max(1/200, 1/hz).
2186 	 * Enable timeouts iff some device is open.
2187 	 */
2188 	untimeout(comwakeup, (void *)NULL, sio_timeout_handle);
2189 	sio_timeout = hz;
2190 	someopen = FALSE;
2191 	for (unit = 0; unit < sio_numunits; ++unit) {
2192 		com = com_addr(unit);
2193 		if (com != NULL && com->tp != NULL
2194 		    && com->tp->t_state & TS_ISOPEN && !com->gone) {
2195 			someopen = TRUE;
2196 			if (com->poll || com->poll_output) {
2197 				sio_timeout = hz > 200 ? hz / 200 : 1;
2198 				break;
2199 			}
2200 		}
2201 	}
2202 	if (someopen) {
2203 		sio_timeouts_until_log = hz / sio_timeout;
2204 		sio_timeout_handle = timeout(comwakeup, (void *)NULL,
2205 					     sio_timeout);
2206 	} else {
2207 		/* Flush error messages, if any. */
2208 		sio_timeouts_until_log = 1;
2209 		comwakeup((void *)NULL);
2210 		untimeout(comwakeup, (void *)NULL, sio_timeout_handle);
2211 	}
2212 }
2213 
2214 static void
comwakeup(chan)2215 comwakeup(chan)
2216 	void	*chan;
2217 {
2218 	struct com_s	*com;
2219 	int		unit;
2220 
2221 	sio_timeout_handle = timeout(comwakeup, (void *)NULL, sio_timeout);
2222 
2223 	/*
2224 	 * Recover from lost output interrupts.
2225 	 * Poll any lines that don't use interrupts.
2226 	 */
2227 	for (unit = 0; unit < sio_numunits; ++unit) {
2228 		com = com_addr(unit);
2229 		if (com != NULL && !com->gone
2230 		    && (com->state >= (CS_BUSY | CS_TTGO) || com->poll)) {
2231 			mtx_lock_spin(&sio_lock);
2232 			siointr1(com);
2233 			mtx_unlock_spin(&sio_lock);
2234 		}
2235 	}
2236 
2237 	/*
2238 	 * Check for and log errors, but not too often.
2239 	 */
2240 	if (--sio_timeouts_until_log > 0)
2241 		return;
2242 	sio_timeouts_until_log = hz / sio_timeout;
2243 	for (unit = 0; unit < sio_numunits; ++unit) {
2244 		int	errnum;
2245 
2246 		com = com_addr(unit);
2247 		if (com == NULL)
2248 			continue;
2249 		if (com->gone)
2250 			continue;
2251 		for (errnum = 0; errnum < CE_NTYPES; ++errnum) {
2252 			u_int	delta;
2253 			u_long	total;
2254 
2255 			mtx_lock_spin(&sio_lock);
2256 			delta = com->delta_error_counts[errnum];
2257 			com->delta_error_counts[errnum] = 0;
2258 			mtx_unlock_spin(&sio_lock);
2259 			if (delta == 0)
2260 				continue;
2261 			total = com->error_counts[errnum] += delta;
2262 			log(LOG_ERR, "sio%d: %u more %s%s (total %lu)\n",
2263 			    unit, delta, error_desc[errnum],
2264 			    delta == 1 ? "" : "s", total);
2265 		}
2266 	}
2267 }
2268 
2269 /*
2270  * Following are all routines needed for SIO to act as console
2271  */
2272 struct siocnstate {
2273 	u_char	dlbl;
2274 	u_char	dlbh;
2275 	u_char	ier;
2276 	u_char	cfcr;
2277 	u_char	mcr;
2278 };
2279 
2280 /*
2281  * This is a function in order to not replicate "ttyd%d" more
2282  * places than absolutely necessary.
2283  */
2284 static void
siocnset(struct consdev * cd,int unit)2285 siocnset(struct consdev *cd, int unit)
2286 {
2287 
2288 	cd->cn_unit = unit;
2289 	sprintf(cd->cn_name, "ttyd%d", unit);
2290 }
2291 
2292 static speed_t siocngetspeed(Port_t, u_long rclk);
2293 static void siocnclose(struct siocnstate *sp, Port_t iobase);
2294 static void siocnopen(struct siocnstate *sp, Port_t iobase, int speed);
2295 static void siocntxwait(Port_t iobase);
2296 
2297 static cn_probe_t sio_cnprobe;
2298 static cn_init_t sio_cninit;
2299 static cn_term_t sio_cnterm;
2300 static cn_getc_t sio_cngetc;
2301 static cn_putc_t sio_cnputc;
2302 static cn_grab_t sio_cngrab;
2303 static cn_ungrab_t sio_cnungrab;
2304 
2305 CONSOLE_DRIVER(sio);
2306 
2307 static void
siocntxwait(iobase)2308 siocntxwait(iobase)
2309 	Port_t	iobase;
2310 {
2311 	int	timo;
2312 
2313 	/*
2314 	 * Wait for any pending transmission to finish.  Required to avoid
2315 	 * the UART lockup bug when the speed is changed, and for normal
2316 	 * transmits.
2317 	 */
2318 	timo = 100000;
2319 	while ((inb(iobase + com_lsr) & (LSR_TSRE | LSR_TXRDY))
2320 	       != (LSR_TSRE | LSR_TXRDY) && --timo != 0)
2321 		;
2322 }
2323 
2324 /*
2325  * Read the serial port specified and try to figure out what speed
2326  * it's currently running at.  We're assuming the serial port has
2327  * been initialized and is basically idle.  This routine is only intended
2328  * to be run at system startup.
2329  *
2330  * If the value read from the serial port doesn't make sense, return 0.
2331  */
2332 
2333 static speed_t
siocngetspeed(iobase,rclk)2334 siocngetspeed(iobase, rclk)
2335 	Port_t	iobase;
2336 	u_long	rclk;
2337 {
2338 	u_int	divisor;
2339 	u_char	dlbh;
2340 	u_char	dlbl;
2341 	u_char  cfcr;
2342 
2343 	cfcr = inb(iobase + com_cfcr);
2344 	outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2345 
2346 	dlbl = inb(iobase + com_dlbl);
2347 	dlbh = inb(iobase + com_dlbh);
2348 
2349 	outb(iobase + com_cfcr, cfcr);
2350 
2351 	divisor = dlbh << 8 | dlbl;
2352 
2353 	/* XXX there should be more sanity checking. */
2354 	if (divisor == 0)
2355 		return (CONSPEED);
2356 	return (rclk / (16UL * divisor));
2357 }
2358 
2359 static void
siocnopen(sp,iobase,speed)2360 siocnopen(sp, iobase, speed)
2361 	struct siocnstate	*sp;
2362 	Port_t			iobase;
2363 	int			speed;
2364 {
2365 	u_int	divisor;
2366 	u_char	dlbh;
2367 	u_char	dlbl;
2368 
2369 	/*
2370 	 * Save all the device control registers except the fifo register
2371 	 * and set our default ones (cs8 -parenb speed=comdefaultrate).
2372 	 * We can't save the fifo register since it is read-only.
2373 	 */
2374 	sp->ier = inb(iobase + com_ier);
2375 	outb(iobase + com_ier, 0);	/* spltty() doesn't stop siointr() */
2376 	siocntxwait(iobase);
2377 	sp->cfcr = inb(iobase + com_cfcr);
2378 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2379 	sp->dlbl = inb(iobase + com_dlbl);
2380 	sp->dlbh = inb(iobase + com_dlbh);
2381 	/*
2382 	 * Only set the divisor registers if they would change, since on
2383 	 * some 16550 incompatibles (Startech), setting them clears the
2384 	 * data input register.  This also reduces the effects of the
2385 	 * UMC8669F bug.
2386 	 */
2387 	divisor = siodivisor(comdefaultrclk, speed);
2388 	dlbl = divisor & 0xFF;
2389 	if (sp->dlbl != dlbl)
2390 		outb(iobase + com_dlbl, dlbl);
2391 	dlbh = divisor >> 8;
2392 	if (sp->dlbh != dlbh)
2393 		outb(iobase + com_dlbh, dlbh);
2394 	outb(iobase + com_cfcr, CFCR_8BITS);
2395 	sp->mcr = inb(iobase + com_mcr);
2396 	/*
2397 	 * We don't want interrupts, but must be careful not to "disable"
2398 	 * them by clearing the MCR_IENABLE bit, since that might cause
2399 	 * an interrupt by floating the IRQ line.
2400 	 */
2401 	outb(iobase + com_mcr, (sp->mcr & MCR_IENABLE) | MCR_DTR | MCR_RTS);
2402 }
2403 
2404 static void
siocnclose(sp,iobase)2405 siocnclose(sp, iobase)
2406 	struct siocnstate	*sp;
2407 	Port_t			iobase;
2408 {
2409 	/*
2410 	 * Restore the device control registers.
2411 	 */
2412 	siocntxwait(iobase);
2413 	outb(iobase + com_cfcr, CFCR_DLAB | CFCR_8BITS);
2414 	if (sp->dlbl != inb(iobase + com_dlbl))
2415 		outb(iobase + com_dlbl, sp->dlbl);
2416 	if (sp->dlbh != inb(iobase + com_dlbh))
2417 		outb(iobase + com_dlbh, sp->dlbh);
2418 	outb(iobase + com_cfcr, sp->cfcr);
2419 	/*
2420 	 * XXX damp oscillations of MCR_DTR and MCR_RTS by not restoring them.
2421 	 */
2422 	outb(iobase + com_mcr, sp->mcr | MCR_DTR | MCR_RTS);
2423 	outb(iobase + com_ier, sp->ier);
2424 }
2425 
2426 static void
sio_cnprobe(cp)2427 sio_cnprobe(cp)
2428 	struct consdev	*cp;
2429 {
2430 	speed_t			boot_speed;
2431 	u_char			cfcr;
2432 	u_int			divisor;
2433 	int			s, unit;
2434 	struct siocnstate	sp;
2435 
2436 	/*
2437 	 * Find our first enabled console, if any.  If it is a high-level
2438 	 * console device, then initialize it and return successfully.
2439 	 * If it is a low-level console device, then initialize it and
2440 	 * return unsuccessfully.  It must be initialized in both cases
2441 	 * for early use by console drivers and debuggers.  Initializing
2442 	 * the hardware is not necessary in all cases, since the i/o
2443 	 * routines initialize it on the fly, but it is necessary if
2444 	 * input might arrive while the hardware is switched back to an
2445 	 * uninitialized state.  We can't handle multiple console devices
2446 	 * yet because our low-level routines don't take a device arg.
2447 	 * We trust the user to set the console flags properly so that we
2448 	 * don't need to probe.
2449 	 */
2450 	cp->cn_pri = CN_DEAD;
2451 
2452 	for (unit = 0; unit < 16; unit++) { /* XXX need to know how many */
2453 		int flags;
2454 
2455 		if (resource_disabled("sio", unit))
2456 			continue;
2457 		if (resource_int_value("sio", unit, "flags", &flags))
2458 			continue;
2459 		if (COM_CONSOLE(flags) || COM_DEBUGGER(flags)) {
2460 			int port;
2461 			Port_t iobase;
2462 
2463 			if (resource_int_value("sio", unit, "port", &port))
2464 				continue;
2465 			iobase = port;
2466 			s = spltty();
2467 			if ((boothowto & RB_SERIAL) && COM_CONSOLE(flags)) {
2468 				boot_speed =
2469 				    siocngetspeed(iobase, comdefaultrclk);
2470 				if (boot_speed)
2471 					comdefaultrate = boot_speed;
2472 			}
2473 
2474 			/*
2475 			 * Initialize the divisor latch.  We can't rely on
2476 			 * siocnopen() to do this the first time, since it
2477 			 * avoids writing to the latch if the latch appears
2478 			 * to have the correct value.  Also, if we didn't
2479 			 * just read the speed from the hardware, then we
2480 			 * need to set the speed in hardware so that
2481 			 * switching it later is null.
2482 			 */
2483 			cfcr = inb(iobase + com_cfcr);
2484 			outb(iobase + com_cfcr, CFCR_DLAB | cfcr);
2485 			divisor = siodivisor(comdefaultrclk, comdefaultrate);
2486 			outb(iobase + com_dlbl, divisor & 0xff);
2487 			outb(iobase + com_dlbh, divisor >> 8);
2488 			outb(iobase + com_cfcr, cfcr);
2489 
2490 			siocnopen(&sp, iobase, comdefaultrate);
2491 
2492 			splx(s);
2493 			if (COM_CONSOLE(flags) && !COM_LLCONSOLE(flags)) {
2494 				siocnset(cp, unit);
2495 				cp->cn_pri = COM_FORCECONSOLE(flags)
2496 					     || boothowto & RB_SERIAL
2497 					     ? CN_REMOTE : CN_NORMAL;
2498 				siocniobase = iobase;
2499 				siocnunit = unit;
2500 			}
2501 #ifdef GDB
2502 			if (COM_DEBUGGER(flags))
2503 				siogdbiobase = iobase;
2504 #endif
2505 		}
2506 	}
2507 }
2508 
2509 static void
sio_cninit(cp)2510 sio_cninit(cp)
2511 	struct consdev	*cp;
2512 {
2513 	comconsole = cp->cn_unit;
2514 }
2515 
2516 static void
sio_cnterm(cp)2517 sio_cnterm(cp)
2518 	struct consdev	*cp;
2519 {
2520 	comconsole = -1;
2521 }
2522 
2523 static void
sio_cngrab(struct consdev * cp)2524 sio_cngrab(struct consdev *cp)
2525 {
2526 }
2527 
2528 static void
sio_cnungrab(struct consdev * cp)2529 sio_cnungrab(struct consdev *cp)
2530 {
2531 }
2532 
2533 static int
sio_cngetc(struct consdev * cd)2534 sio_cngetc(struct consdev *cd)
2535 {
2536 	int	c;
2537 	Port_t	iobase;
2538 	int	s;
2539 	struct siocnstate	sp;
2540 	speed_t	speed;
2541 
2542 	if (cd != NULL && cd->cn_unit == siocnunit) {
2543 		iobase = siocniobase;
2544 		speed = comdefaultrate;
2545 	} else {
2546 #ifdef GDB
2547 		iobase = siogdbiobase;
2548 		speed = gdbdefaultrate;
2549 #else
2550 		return (-1);
2551 #endif
2552 	}
2553 	s = spltty();
2554 	siocnopen(&sp, iobase, speed);
2555 	if (inb(iobase + com_lsr) & LSR_RXRDY)
2556 		c = inb(iobase + com_data);
2557 	else
2558 		c = -1;
2559 	siocnclose(&sp, iobase);
2560 	splx(s);
2561 	return (c);
2562 }
2563 
2564 static void
sio_cnputc(struct consdev * cd,int c)2565 sio_cnputc(struct consdev *cd, int c)
2566 {
2567 	int	need_unlock;
2568 	int	s;
2569 	struct siocnstate	sp;
2570 	Port_t	iobase;
2571 	speed_t	speed;
2572 
2573 	if (cd != NULL && cd->cn_unit == siocnunit) {
2574 		iobase = siocniobase;
2575 		speed = comdefaultrate;
2576 	} else {
2577 #ifdef GDB
2578 		iobase = siogdbiobase;
2579 		speed = gdbdefaultrate;
2580 #else
2581 		return;
2582 #endif
2583 	}
2584 	s = spltty();
2585 	need_unlock = 0;
2586 	if (!kdb_active && sio_inited == 2 && !mtx_owned(&sio_lock)) {
2587 		mtx_lock_spin(&sio_lock);
2588 		need_unlock = 1;
2589 	}
2590 	siocnopen(&sp, iobase, speed);
2591 	siocntxwait(iobase);
2592 	outb(iobase + com_data, c);
2593 	siocnclose(&sp, iobase);
2594 	if (need_unlock)
2595 		mtx_unlock_spin(&sio_lock);
2596 	splx(s);
2597 }
2598 
2599 /*
2600  * Remote gdb(1) support.
2601  */
2602 
2603 #if defined(GDB)
2604 
2605 #include <gdb/gdb.h>
2606 
2607 static gdb_probe_f siogdbprobe;
2608 static gdb_init_f siogdbinit;
2609 static gdb_term_f siogdbterm;
2610 static gdb_getc_f siogdbgetc;
2611 static gdb_putc_f siogdbputc;
2612 
2613 GDB_DBGPORT(sio, siogdbprobe, siogdbinit, siogdbterm, siogdbgetc, siogdbputc);
2614 
2615 static int
siogdbprobe(void)2616 siogdbprobe(void)
2617 {
2618 	return ((siogdbiobase != 0) ? 0 : -1);
2619 }
2620 
2621 static void
siogdbinit(void)2622 siogdbinit(void)
2623 {
2624 }
2625 
2626 static void
siogdbterm(void)2627 siogdbterm(void)
2628 {
2629 }
2630 
2631 static void
siogdbputc(int c)2632 siogdbputc(int c)
2633 {
2634 	sio_cnputc(NULL, c);
2635 }
2636 
2637 static int
siogdbgetc(void)2638 siogdbgetc(void)
2639 {
2640 	return (sio_cngetc(NULL));
2641 }
2642 
2643 #endif
2644