xref: /netbsd-src/sys/dev/ic/com.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /* $NetBSD: com.c,v 1.287 2009/01/03 03:43:22 yamt Exp $ */
2 
3 /*-
4  * Copyright (c) 1998, 1999, 2004, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1991 The Regents of the University of California.
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. Neither the name of the University nor the names of its contributors
45  *    may be used to endorse or promote products derived from this software
46  *    without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58  * SUCH DAMAGE.
59  *
60  *	@(#)com.c	7.5 (Berkeley) 5/16/91
61  */
62 
63 /*
64  * COM driver, uses National Semiconductor NS16450/NS16550AF UART
65  * Supports automatic hardware flow control on StarTech ST16C650A UART
66  */
67 
68 #include <sys/cdefs.h>
69 __KERNEL_RCSID(0, "$NetBSD: com.c,v 1.287 2009/01/03 03:43:22 yamt Exp $");
70 
71 #include "opt_com.h"
72 #include "opt_ddb.h"
73 #include "opt_kgdb.h"
74 #include "opt_lockdebug.h"
75 #include "opt_multiprocessor.h"
76 #include "opt_ntp.h"
77 
78 #include "rnd.h"
79 #if NRND > 0 && defined(RND_COM)
80 #include <sys/rnd.h>
81 #endif
82 
83 /* The COM16650 option was renamed to COM_16650. */
84 #ifdef COM16650
85 #error Obsolete COM16650 option; use COM_16650 instead.
86 #endif
87 
88 /*
89  * Override cnmagic(9) macro before including <sys/systm.h>.
90  * We need to know if cn_check_magic triggered debugger, so set a flag.
91  * Callers of cn_check_magic must declare int cn_trapped = 0;
92  * XXX: this is *ugly*!
93  */
94 #define cn_trap()				\
95 	do {					\
96 		console_debugger();		\
97 		cn_trapped = 1;			\
98 	} while (/* CONSTCOND */ 0)
99 
100 #include <sys/param.h>
101 #include <sys/systm.h>
102 #include <sys/ioctl.h>
103 #include <sys/select.h>
104 #include <sys/poll.h>
105 #include <sys/tty.h>
106 #include <sys/proc.h>
107 #include <sys/user.h>
108 #include <sys/conf.h>
109 #include <sys/file.h>
110 #include <sys/uio.h>
111 #include <sys/kernel.h>
112 #include <sys/syslog.h>
113 #include <sys/device.h>
114 #include <sys/malloc.h>
115 #include <sys/timepps.h>
116 #include <sys/vnode.h>
117 #include <sys/kauth.h>
118 #include <sys/intr.h>
119 
120 #include <sys/bus.h>
121 
122 #include <dev/ic/comreg.h>
123 #include <dev/ic/comvar.h>
124 #include <dev/ic/ns16550reg.h>
125 #include <dev/ic/st16650reg.h>
126 #ifdef COM_HAYESP
127 #include <dev/ic/hayespreg.h>
128 #endif
129 #define	com_lcr	com_cfcr
130 #include <dev/cons.h>
131 
132 #ifdef	COM_REGMAP
133 #define	CSR_WRITE_1(r, o, v)	\
134 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
135 #define	CSR_READ_1(r, o)	\
136 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
137 #define	CSR_WRITE_2(r, o, v)	\
138 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
139 #define	CSR_READ_2(r, o)	\
140 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
141 #define	CSR_WRITE_MULTI(r, o, p, n)	\
142 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], p, n)
143 #else
144 #define	CSR_WRITE_1(r, o, v)	\
145 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
146 #define	CSR_READ_1(r, o)	\
147 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, o)
148 #define	CSR_WRITE_2(r, o, v)	\
149 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, o, v)
150 #define	CSR_READ_2(r, o)	\
151 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, o)
152 #define	CSR_WRITE_MULTI(r, o, p, n)	\
153 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
154 #endif
155 
156 
157 static void com_enable_debugport(struct com_softc *);
158 
159 void	com_config(struct com_softc *);
160 void	com_shutdown(struct com_softc *);
161 int	comspeed(long, long, int);
162 static	u_char	cflag2lcr(tcflag_t);
163 int	comparam(struct tty *, struct termios *);
164 void	comstart(struct tty *);
165 int	comhwiflow(struct tty *, int);
166 
167 void	com_loadchannelregs(struct com_softc *);
168 void	com_hwiflow(struct com_softc *);
169 void	com_break(struct com_softc *, int);
170 void	com_modem(struct com_softc *, int);
171 void	tiocm_to_com(struct com_softc *, u_long, int);
172 int	com_to_tiocm(struct com_softc *);
173 void	com_iflush(struct com_softc *);
174 
175 int	com_common_getc(dev_t, struct com_regs *);
176 void	com_common_putc(dev_t, struct com_regs *, int);
177 
178 int	cominit(struct com_regs *, int, int, int, tcflag_t);
179 
180 int	comcngetc(dev_t);
181 void	comcnputc(dev_t, int);
182 void	comcnpollc(dev_t, int);
183 
184 #define	integrate	static inline
185 void 	comsoft(void *);
186 integrate void com_rxsoft(struct com_softc *, struct tty *);
187 integrate void com_txsoft(struct com_softc *, struct tty *);
188 integrate void com_stsoft(struct com_softc *, struct tty *);
189 integrate void com_schedrx(struct com_softc *);
190 void	comdiag(void *);
191 
192 extern struct cfdriver com_cd;
193 
194 dev_type_open(comopen);
195 dev_type_close(comclose);
196 dev_type_read(comread);
197 dev_type_write(comwrite);
198 dev_type_ioctl(comioctl);
199 dev_type_stop(comstop);
200 dev_type_tty(comtty);
201 dev_type_poll(compoll);
202 
203 const struct cdevsw com_cdevsw = {
204 	comopen, comclose, comread, comwrite, comioctl,
205 	comstop, comtty, compoll, nommap, ttykqfilter, D_TTY
206 };
207 
208 /*
209  * Make this an option variable one can patch.
210  * But be warned:  this must be a power of 2!
211  */
212 u_int com_rbuf_size = COM_RING_SIZE;
213 
214 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
215 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
216 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
217 
218 static struct com_regs comconsregs;
219 static int comconsattached;
220 static int comconsrate;
221 static tcflag_t comconscflag;
222 static struct cnm_state com_cnm_state;
223 
224 #ifdef KGDB
225 #include <sys/kgdb.h>
226 
227 static struct com_regs comkgdbregs;
228 static int com_kgdb_attached;
229 
230 int	com_kgdb_getc(void *);
231 void	com_kgdb_putc(void *, int);
232 #endif /* KGDB */
233 
234 #ifdef COM_REGMAP
235 /* initializer for typical 16550-ish hardware */
236 #define	COM_REG_16550	{ \
237 	com_data, com_data, com_dlbl, com_dlbh, com_ier, com_iir, com_fifo, \
238 	com_efr, com_lcr, com_mcr, com_lsr, com_msr }
239 
240 const bus_size_t com_std_map[16] = COM_REG_16550;
241 #endif /* COM_REGMAP */
242 
243 #define	COMUNIT_MASK	0x7ffff
244 #define	COMDIALOUT_MASK	0x80000
245 
246 #define	COMUNIT(x)	(minor(x) & COMUNIT_MASK)
247 #define	COMDIALOUT(x)	(minor(x) & COMDIALOUT_MASK)
248 
249 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
250 			 device_is_active((sc)->sc_dev))
251 
252 #define	BR	BUS_SPACE_BARRIER_READ
253 #define	BW	BUS_SPACE_BARRIER_WRITE
254 #define COM_BARRIER(r, f) \
255 	bus_space_barrier((r)->cr_iot, (r)->cr_ioh, 0, (r)->cr_nports, (f))
256 
257 /*ARGSUSED*/
258 int
259 comspeed(long speed, long frequency, int type)
260 {
261 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
262 
263 	int x, err;
264 	int divisor = 16;
265 
266 	if ((type == COM_TYPE_OMAP) && (speed > 230400)) {
267 	    divisor = 13;
268 	}
269 
270 #if 0
271 	if (speed == 0)
272 		return (0);
273 #endif
274 	if (speed <= 0)
275 		return (-1);
276 	x = divrnd(frequency / divisor, speed);
277 	if (x <= 0)
278 		return (-1);
279 	err = divrnd(((quad_t)frequency) * 1000 / divisor, speed * x) - 1000;
280 	if (err < 0)
281 		err = -err;
282 	if (err > COM_TOLERANCE)
283 		return (-1);
284 	return (x);
285 
286 #undef	divrnd
287 }
288 
289 #ifdef COM_DEBUG
290 int	com_debug = 0;
291 
292 void comstatus(struct com_softc *, const char *);
293 void
294 comstatus(struct com_softc *sc, const char *str)
295 {
296 	struct tty *tp = sc->sc_tty;
297 
298 	aprint_normal_dev(sc->sc_dev,
299 	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
300 	    str,
301 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
302 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
303 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
304 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
305 	    sc->sc_tx_stopped ? '+' : '-');
306 
307 	aprint_normal_dev(sc->sc_dev,
308 	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
309 	    str,
310 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
311 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
312 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
313 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
314 	    sc->sc_rx_flags);
315 }
316 #endif
317 
318 int
319 com_probe_subr(struct com_regs *regs)
320 {
321 
322 	/* force access to id reg */
323 	CSR_WRITE_1(regs, COM_REG_LCR, LCR_8BITS);
324 	CSR_WRITE_1(regs, COM_REG_IIR, 0);
325 	if ((CSR_READ_1(regs, COM_REG_LCR) != LCR_8BITS) ||
326 	    (CSR_READ_1(regs, COM_REG_IIR) & 0x38))
327 		return (0);
328 
329 	return (1);
330 }
331 
332 int
333 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
334 {
335 	struct com_regs	regs;
336 
337 	regs.cr_iot = iot;
338 	regs.cr_ioh = ioh;
339 #ifdef	COM_REGMAP
340 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
341 #endif
342 
343 	return com_probe_subr(&regs);
344 }
345 
346 /*
347  * No locking in this routine; it is only called during attach,
348  * or with the port already locked.
349  */
350 static void
351 com_enable_debugport(struct com_softc *sc)
352 {
353 
354 	/* Turn on line break interrupt, set carrier. */
355 	sc->sc_ier = IER_ERXRDY;
356 	if (sc->sc_type == COM_TYPE_PXA2x0)
357 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
358 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
359 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
360 	CSR_WRITE_1(&sc->sc_regs, COM_REG_MCR, sc->sc_mcr);
361 }
362 
363 void
364 com_attach_subr(struct com_softc *sc)
365 {
366 	struct com_regs *regsp = &sc->sc_regs;
367 	struct tty *tp;
368 #ifdef COM_16650
369 	u_int8_t lcr;
370 #endif
371 	const char *fifo_msg = NULL;
372 
373 	aprint_naive("\n");
374 
375 	callout_init(&sc->sc_diag_callout, 0);
376 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
377 
378 	/* Disable interrupts before configuring the device. */
379 	if (sc->sc_type == COM_TYPE_PXA2x0)
380 		sc->sc_ier = IER_EUART;
381 	else
382 		sc->sc_ier = 0;
383 
384 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
385 
386 	if (regsp->cr_iot == comconsregs.cr_iot &&
387 	    regsp->cr_iobase == comconsregs.cr_iobase) {
388 		comconsattached = 1;
389 
390 		/* Make sure the console is always "hardwired". */
391 		delay(10000);			/* wait for output to finish */
392 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
393 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
394 	}
395 
396 	/* Probe for FIFO */
397 	switch (sc->sc_type) {
398 	case COM_TYPE_HAYESP:
399 		goto fifodone;
400 
401 	case COM_TYPE_AU1x00:
402 		sc->sc_fifolen = 16;
403 		fifo_msg = "Au1X00 UART, working fifo";
404 		SET(sc->sc_hwflags, COM_HW_FIFO);
405 		goto fifodelay;
406 
407 	case COM_TYPE_16550_NOERS:
408 		sc->sc_fifolen = 16;
409 		fifo_msg = "ns16650, no ERS, working fifo";
410 		SET(sc->sc_hwflags, COM_HW_FIFO);
411 		goto fifodelay;
412 
413  	case COM_TYPE_OMAP:
414  		sc->sc_fifolen = 64;
415  		fifo_msg = "OMAP UART, working fifo";
416  		SET(sc->sc_hwflags, COM_HW_FIFO);
417  		goto fifodelay;
418   	}
419 
420 	sc->sc_fifolen = 1;
421 	/* look for a NS 16550AF UART with FIFOs */
422 	CSR_WRITE_1(regsp, COM_REG_FIFO,
423 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
424 	delay(100);
425 	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
426 	    == IIR_FIFO_MASK)
427 		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
428 		    == FIFO_TRIGGER_14) {
429 			SET(sc->sc_hwflags, COM_HW_FIFO);
430 
431 #ifdef COM_16650
432 			/*
433 			 * IIR changes into the EFR if LCR is set to LCR_EERS
434 			 * on 16650s. We also know IIR != 0 at this point.
435 			 * Write 0 into the EFR, and read it. If the result
436 			 * is 0, we have a 16650.
437 			 *
438 			 * Older 16650s were broken; the test to detect them
439 			 * is taken from the Linux driver. Apparently
440 			 * setting DLAB enable gives access to the EFR on
441 			 * these chips.
442 			 */
443 			lcr = CSR_READ_1(regsp, COM_REG_LCR);
444 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
445 			CSR_WRITE_1(regsp, COM_REG_EFR, 0);
446 			if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
447 				CSR_WRITE_1(regsp, COM_REG_LCR,
448 				    lcr | LCR_DLAB);
449 				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
450 					CLR(sc->sc_hwflags, COM_HW_FIFO);
451 					sc->sc_fifolen = 0;
452 				} else {
453 					SET(sc->sc_hwflags, COM_HW_FLOW);
454 					sc->sc_fifolen = 32;
455 				}
456 			} else
457 #endif
458 				sc->sc_fifolen = 16;
459 
460 #ifdef COM_16650
461 			CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
462 			if (sc->sc_fifolen == 0)
463 				fifo_msg = "st16650, broken fifo";
464 			else if (sc->sc_fifolen == 32)
465 				fifo_msg = "st16650a, working fifo";
466 			else
467 #endif
468 				fifo_msg = "ns16550a, working fifo";
469 		} else
470 			fifo_msg = "ns16550, broken fifo";
471 	else
472 		fifo_msg = "ns8250 or ns16450, no fifo";
473 	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
474 fifodelay:
475 	/*
476 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
477 	 * written to com_fifo. If this chip is the console, writing zero
478 	 * results in some of the chip/FIFO description being lost, so delay
479 	 * printing it until now.
480 	 */
481 	delay(10);
482 	aprint_normal(": %s\n", fifo_msg);
483 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
484 		sc->sc_fifolen = 1;
485 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
486 	}
487 
488 fifodone:
489 
490 	tp = ttymalloc();
491 	tp->t_oproc = comstart;
492 	tp->t_param = comparam;
493 	tp->t_hwiflow = comhwiflow;
494 
495 	sc->sc_tty = tp;
496 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
497 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
498 	sc->sc_rbavail = com_rbuf_size;
499 	if (sc->sc_rbuf == NULL) {
500 		aprint_error_dev(sc->sc_dev,
501 		    "unable to allocate ring buffer\n");
502 		return;
503 	}
504 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
505 
506 	tty_attach(tp);
507 
508 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
509 		SET(sc->sc_mcr, MCR_IENABLE);
510 
511 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
512 		int maj;
513 
514 		/* locate the major number */
515 		maj = cdevsw_lookup_major(&com_cdevsw);
516 
517 		tp->t_dev = cn_tab->cn_dev = makedev(maj,
518 						     device_unit(sc->sc_dev));
519 
520 		aprint_normal_dev(sc->sc_dev, "console\n");
521 	}
522 
523 #ifdef KGDB
524 	/*
525 	 * Allow kgdb to "take over" this port.  If this is
526 	 * not the console and is the kgdb device, it has
527 	 * exclusive use.  If it's the console _and_ the
528 	 * kgdb device, it doesn't.
529 	 */
530 	if (regsp->cr_iot == comkgdbregs.cr_iot &&
531 	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
532 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
533 			com_kgdb_attached = 1;
534 
535 			SET(sc->sc_hwflags, COM_HW_KGDB);
536 		}
537 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
538 	}
539 #endif
540 
541 	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
542 
543 #if NRND > 0 && defined(RND_COM)
544 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
545 			  RND_TYPE_TTY, 0);
546 #endif
547 
548 	/* if there are no enable/disable functions, assume the device
549 	   is always enabled */
550 	if (!sc->enable)
551 		sc->enabled = 1;
552 
553 	com_config(sc);
554 
555 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
556 }
557 
558 void
559 com_config(struct com_softc *sc)
560 {
561 	struct com_regs *regsp = &sc->sc_regs;
562 
563 	/* Disable interrupts before configuring the device. */
564 	if (sc->sc_type == COM_TYPE_PXA2x0)
565 		sc->sc_ier = IER_EUART;
566 	else
567 		sc->sc_ier = 0;
568 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
569 	(void) CSR_READ_1(regsp, COM_REG_IIR);
570 
571 #ifdef COM_HAYESP
572 	/* Look for a Hayes ESP board. */
573 	if (sc->sc_type == COM_TYPE_HAYESP) {
574 
575 		/* Set 16550 compatibility mode */
576 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
577 				  HAYESP_SETMODE);
578 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
579 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
580 				  HAYESP_MODE_SCALE);
581 
582 		/* Set RTS/CTS flow control */
583 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
584 				  HAYESP_SETFLOWTYPE);
585 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
586 				  HAYESP_FLOW_RTS);
587 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
588 				  HAYESP_FLOW_CTS);
589 
590 		/* Set flow control levels */
591 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
592 				  HAYESP_SETRXFLOW);
593 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
594 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
595 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
596 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
597 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
598 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
599 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
600 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
601 	}
602 #endif
603 
604 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
605 		com_enable_debugport(sc);
606 }
607 
608 int
609 com_detach(device_t self, int flags)
610 {
611 	struct com_softc *sc = device_private(self);
612 	int maj, mn;
613 
614         if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE))
615 		return EBUSY;
616 
617 	/* locate the major number */
618 	maj = cdevsw_lookup_major(&com_cdevsw);
619 
620 	/* Nuke the vnodes for any open instances. */
621 	mn = device_unit(self);
622 	vdevgone(maj, mn, mn, VCHR);
623 
624 	mn |= COMDIALOUT_MASK;
625 	vdevgone(maj, mn, mn, VCHR);
626 
627 	if (sc->sc_rbuf == NULL) {
628 		/*
629 		 * Ring buffer allocation failed in the com_attach_subr,
630 		 * only the tty is allocated, and nothing else.
631 		 */
632 		ttyfree(sc->sc_tty);
633 		return 0;
634 	}
635 
636 	/* Free the receive buffer. */
637 	free(sc->sc_rbuf, M_DEVBUF);
638 
639 	/* Detach and free the tty. */
640 	tty_detach(sc->sc_tty);
641 	ttyfree(sc->sc_tty);
642 
643 	/* Unhook the soft interrupt handler. */
644 	softint_disestablish(sc->sc_si);
645 
646 #if NRND > 0 && defined(RND_COM)
647 	/* Unhook the entropy source. */
648 	rnd_detach_source(&sc->rnd_source);
649 #endif
650 	callout_destroy(&sc->sc_diag_callout);
651 
652 	/* Destroy the lock. */
653 	mutex_destroy(&sc->sc_lock);
654 
655 	return (0);
656 }
657 
658 int
659 com_activate(device_t self, enum devact act)
660 {
661 	struct com_softc *sc = device_private(self);
662 	int rv = 0;
663 
664 	switch (act) {
665 	case DVACT_ACTIVATE:
666 		rv = EOPNOTSUPP;
667 		break;
668 
669 	case DVACT_DEACTIVATE:
670 		if (sc->sc_hwflags & (COM_HW_CONSOLE|COM_HW_KGDB)) {
671 			rv = EBUSY;
672 			break;
673 		}
674 
675 		if (sc->disable != NULL && sc->enabled != 0) {
676 			(*sc->disable)(sc);
677 			sc->enabled = 0;
678 		}
679 		break;
680 	}
681 
682 	return (rv);
683 }
684 
685 void
686 com_shutdown(struct com_softc *sc)
687 {
688 	struct tty *tp = sc->sc_tty;
689 
690 	mutex_spin_enter(&sc->sc_lock);
691 
692 	/* If we were asserting flow control, then deassert it. */
693 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
694 	com_hwiflow(sc);
695 
696 	/* Clear any break condition set with TIOCSBRK. */
697 	com_break(sc, 0);
698 
699 	/*
700 	 * Hang up if necessary.  Wait a bit, so the other side has time to
701 	 * notice even if we immediately open the port again.
702 	 * Avoid tsleeping above splhigh().
703 	 */
704 	if (ISSET(tp->t_cflag, HUPCL)) {
705 		com_modem(sc, 0);
706 		mutex_spin_exit(&sc->sc_lock);
707 		/* XXX will only timeout */
708 		(void) kpause(ttclos, false, hz, NULL);
709 		mutex_spin_enter(&sc->sc_lock);
710 	}
711 
712 	/* Turn off interrupts. */
713 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
714 		sc->sc_ier = IER_ERXRDY; /* interrupt on break */
715 		if (sc->sc_type == COM_TYPE_PXA2x0)
716 			sc->sc_ier |= IER_ERXTOUT;
717 	} else
718 		sc->sc_ier = 0;
719 
720 	if (sc->sc_type == COM_TYPE_PXA2x0)
721 		sc->sc_ier |= IER_EUART;
722 
723 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
724 
725 	mutex_spin_exit(&sc->sc_lock);
726 
727 	if (sc->disable) {
728 #ifdef DIAGNOSTIC
729 		if (!sc->enabled)
730 			panic("com_shutdown: not enabled?");
731 #endif
732 		(*sc->disable)(sc);
733 		sc->enabled = 0;
734 	}
735 }
736 
737 int
738 comopen(dev_t dev, int flag, int mode, struct lwp *l)
739 {
740 	struct com_softc *sc;
741 	struct tty *tp;
742 	int s;
743 	int error;
744 
745 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
746 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
747 		sc->sc_rbuf == NULL)
748 		return (ENXIO);
749 
750 	if (!device_is_active(sc->sc_dev))
751 		return (ENXIO);
752 
753 #ifdef KGDB
754 	/*
755 	 * If this is the kgdb port, no other use is permitted.
756 	 */
757 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
758 		return (EBUSY);
759 #endif
760 
761 	tp = sc->sc_tty;
762 
763 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
764 		return (EBUSY);
765 
766 	s = spltty();
767 
768 	/*
769 	 * Do the following iff this is a first open.
770 	 */
771 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
772 		struct termios t;
773 
774 		tp->t_dev = dev;
775 
776 
777 		if (sc->enable) {
778 			if ((*sc->enable)(sc)) {
779 				splx(s);
780 				aprint_error_dev(sc->sc_dev,
781 				    "device enable failed\n");
782 				return (EIO);
783 			}
784 			mutex_spin_enter(&sc->sc_lock);
785 			sc->enabled = 1;
786 			com_config(sc);
787 		} else {
788 			mutex_spin_enter(&sc->sc_lock);
789 		}
790 
791 		/* Turn on interrupts. */
792 		sc->sc_ier = IER_ERXRDY | IER_ERLS | IER_EMSC;
793 		if (sc->sc_type == COM_TYPE_PXA2x0)
794 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
795 		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
796 
797 		/* Fetch the current modem control status, needed later. */
798 		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
799 
800 		/* Clear PPS capture state on first open. */
801 		mutex_spin_enter(&timecounter_lock);
802 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
803 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
804 		pps_init(&sc->sc_pps_state);
805 		mutex_spin_exit(&timecounter_lock);
806 
807 		mutex_spin_exit(&sc->sc_lock);
808 
809 		/*
810 		 * Initialize the termios status to the defaults.  Add in the
811 		 * sticky bits from TIOCSFLAGS.
812 		 */
813 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
814 			t.c_ospeed = comconsrate;
815 			t.c_cflag = comconscflag;
816 		} else {
817 			t.c_ospeed = TTYDEF_SPEED;
818 			t.c_cflag = TTYDEF_CFLAG;
819 		}
820 		t.c_ispeed = t.c_ospeed;
821 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
822 			SET(t.c_cflag, CLOCAL);
823 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
824 			SET(t.c_cflag, CRTSCTS);
825 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
826 			SET(t.c_cflag, MDMBUF);
827 		/* Make sure comparam() will do something. */
828 		tp->t_ospeed = 0;
829 		(void) comparam(tp, &t);
830 		tp->t_iflag = TTYDEF_IFLAG;
831 		tp->t_oflag = TTYDEF_OFLAG;
832 		tp->t_lflag = TTYDEF_LFLAG;
833 		ttychars(tp);
834 		ttsetwater(tp);
835 
836 		mutex_spin_enter(&sc->sc_lock);
837 
838 		/*
839 		 * Turn on DTR.  We must always do this, even if carrier is not
840 		 * present, because otherwise we'd have to use TIOCSDTR
841 		 * immediately after setting CLOCAL, which applications do not
842 		 * expect.  We always assert DTR while the device is open
843 		 * unless explicitly requested to deassert it.
844 		 */
845 		com_modem(sc, 1);
846 
847 		/* Clear the input ring, and unblock. */
848 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
849 		sc->sc_rbavail = com_rbuf_size;
850 		com_iflush(sc);
851 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
852 		com_hwiflow(sc);
853 
854 #ifdef COM_DEBUG
855 		if (com_debug)
856 			comstatus(sc, "comopen  ");
857 #endif
858 
859 		mutex_spin_exit(&sc->sc_lock);
860 	}
861 
862 	splx(s);
863 
864 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
865 	if (error)
866 		goto bad;
867 
868 	error = (*tp->t_linesw->l_open)(dev, tp);
869 	if (error)
870 		goto bad;
871 
872 	return (0);
873 
874 bad:
875 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
876 		/*
877 		 * We failed to open the device, and nobody else had it opened.
878 		 * Clean up the state as appropriate.
879 		 */
880 		com_shutdown(sc);
881 	}
882 
883 	return (error);
884 }
885 
886 int
887 comclose(dev_t dev, int flag, int mode, struct lwp *l)
888 {
889 	struct com_softc *sc =
890 	    device_lookup_private(&com_cd, COMUNIT(dev));
891 	struct tty *tp = sc->sc_tty;
892 
893 	/* XXX This is for cons.c. */
894 	if (!ISSET(tp->t_state, TS_ISOPEN))
895 		return (0);
896 
897 	(*tp->t_linesw->l_close)(tp, flag);
898 	ttyclose(tp);
899 
900 	if (COM_ISALIVE(sc) == 0)
901 		return (0);
902 
903 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
904 		/*
905 		 * Although we got a last close, the device may still be in
906 		 * use; e.g. if this was the dialout node, and there are still
907 		 * processes waiting for carrier on the non-dialout node.
908 		 */
909 		com_shutdown(sc);
910 	}
911 
912 	return (0);
913 }
914 
915 int
916 comread(dev_t dev, struct uio *uio, int flag)
917 {
918 	struct com_softc *sc =
919 	    device_lookup_private(&com_cd, COMUNIT(dev));
920 	struct tty *tp = sc->sc_tty;
921 
922 	if (COM_ISALIVE(sc) == 0)
923 		return (EIO);
924 
925 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
926 }
927 
928 int
929 comwrite(dev_t dev, struct uio *uio, int flag)
930 {
931 	struct com_softc *sc =
932 	    device_lookup_private(&com_cd, COMUNIT(dev));
933 	struct tty *tp = sc->sc_tty;
934 
935 	if (COM_ISALIVE(sc) == 0)
936 		return (EIO);
937 
938 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
939 }
940 
941 int
942 compoll(dev_t dev, int events, struct lwp *l)
943 {
944 	struct com_softc *sc =
945 	    device_lookup_private(&com_cd, COMUNIT(dev));
946 	struct tty *tp = sc->sc_tty;
947 
948 	if (COM_ISALIVE(sc) == 0)
949 		return (POLLHUP);
950 
951 	return ((*tp->t_linesw->l_poll)(tp, events, l));
952 }
953 
954 struct tty *
955 comtty(dev_t dev)
956 {
957 	struct com_softc *sc =
958 	    device_lookup_private(&com_cd, COMUNIT(dev));
959 	struct tty *tp = sc->sc_tty;
960 
961 	return (tp);
962 }
963 
964 int
965 comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
966 {
967 	struct com_softc *sc;
968 	struct tty *tp;
969 	int error;
970 
971 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
972 	if (sc == NULL)
973 		return ENXIO;
974 	if (COM_ISALIVE(sc) == 0)
975 		return (EIO);
976 
977 	tp = sc->sc_tty;
978 
979 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
980 	if (error != EPASSTHROUGH)
981 		return (error);
982 
983 	error = ttioctl(tp, cmd, data, flag, l);
984 	if (error != EPASSTHROUGH)
985 		return (error);
986 
987 	error = 0;
988 	switch (cmd) {
989 	case TIOCSFLAGS:
990 		error = kauth_authorize_device_tty(l->l_cred,
991 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
992 		break;
993 	default:
994 		/* nothing */
995 		break;
996 	}
997 	if (error) {
998 		return error;
999 	}
1000 
1001 	mutex_spin_enter(&sc->sc_lock);
1002 
1003 	switch (cmd) {
1004 	case TIOCSBRK:
1005 		com_break(sc, 1);
1006 		break;
1007 
1008 	case TIOCCBRK:
1009 		com_break(sc, 0);
1010 		break;
1011 
1012 	case TIOCSDTR:
1013 		com_modem(sc, 1);
1014 		break;
1015 
1016 	case TIOCCDTR:
1017 		com_modem(sc, 0);
1018 		break;
1019 
1020 	case TIOCGFLAGS:
1021 		*(int *)data = sc->sc_swflags;
1022 		break;
1023 
1024 	case TIOCSFLAGS:
1025 		sc->sc_swflags = *(int *)data;
1026 		break;
1027 
1028 	case TIOCMSET:
1029 	case TIOCMBIS:
1030 	case TIOCMBIC:
1031 		tiocm_to_com(sc, cmd, *(int *)data);
1032 		break;
1033 
1034 	case TIOCMGET:
1035 		*(int *)data = com_to_tiocm(sc);
1036 		break;
1037 
1038 	case PPS_IOC_CREATE:
1039 	case PPS_IOC_DESTROY:
1040 	case PPS_IOC_GETPARAMS:
1041 	case PPS_IOC_SETPARAMS:
1042 	case PPS_IOC_GETCAP:
1043 	case PPS_IOC_FETCH:
1044 #ifdef PPS_SYNC
1045 	case PPS_IOC_KCBIND:
1046 #endif
1047 		mutex_spin_enter(&timecounter_lock);
1048 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1049 		mutex_spin_exit(&timecounter_lock);
1050 		break;
1051 
1052 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1053 		mutex_spin_enter(&timecounter_lock);
1054 #ifndef PPS_TRAILING_EDGE
1055 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1056 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1057 #else
1058 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1059 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1060 #endif
1061 		mutex_spin_exit(&timecounter_lock);
1062 		break;
1063 
1064 	default:
1065 		error = EPASSTHROUGH;
1066 		break;
1067 	}
1068 
1069 	mutex_spin_exit(&sc->sc_lock);
1070 
1071 #ifdef COM_DEBUG
1072 	if (com_debug)
1073 		comstatus(sc, "comioctl ");
1074 #endif
1075 
1076 	return (error);
1077 }
1078 
1079 integrate void
1080 com_schedrx(struct com_softc *sc)
1081 {
1082 
1083 	sc->sc_rx_ready = 1;
1084 
1085 	/* Wake up the poller. */
1086 	softint_schedule(sc->sc_si);
1087 }
1088 
1089 void
1090 com_break(struct com_softc *sc, int onoff)
1091 {
1092 
1093 	if (onoff)
1094 		SET(sc->sc_lcr, LCR_SBREAK);
1095 	else
1096 		CLR(sc->sc_lcr, LCR_SBREAK);
1097 
1098 	if (!sc->sc_heldchange) {
1099 		if (sc->sc_tx_busy) {
1100 			sc->sc_heldtbc = sc->sc_tbc;
1101 			sc->sc_tbc = 0;
1102 			sc->sc_heldchange = 1;
1103 		} else
1104 			com_loadchannelregs(sc);
1105 	}
1106 }
1107 
1108 void
1109 com_modem(struct com_softc *sc, int onoff)
1110 {
1111 
1112 	if (sc->sc_mcr_dtr == 0)
1113 		return;
1114 
1115 	if (onoff)
1116 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1117 	else
1118 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1119 
1120 	if (!sc->sc_heldchange) {
1121 		if (sc->sc_tx_busy) {
1122 			sc->sc_heldtbc = sc->sc_tbc;
1123 			sc->sc_tbc = 0;
1124 			sc->sc_heldchange = 1;
1125 		} else
1126 			com_loadchannelregs(sc);
1127 	}
1128 }
1129 
1130 void
1131 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1132 {
1133 	u_char combits;
1134 
1135 	combits = 0;
1136 	if (ISSET(ttybits, TIOCM_DTR))
1137 		SET(combits, MCR_DTR);
1138 	if (ISSET(ttybits, TIOCM_RTS))
1139 		SET(combits, MCR_RTS);
1140 
1141 	switch (how) {
1142 	case TIOCMBIC:
1143 		CLR(sc->sc_mcr, combits);
1144 		break;
1145 
1146 	case TIOCMBIS:
1147 		SET(sc->sc_mcr, combits);
1148 		break;
1149 
1150 	case TIOCMSET:
1151 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1152 		SET(sc->sc_mcr, combits);
1153 		break;
1154 	}
1155 
1156 	if (!sc->sc_heldchange) {
1157 		if (sc->sc_tx_busy) {
1158 			sc->sc_heldtbc = sc->sc_tbc;
1159 			sc->sc_tbc = 0;
1160 			sc->sc_heldchange = 1;
1161 		} else
1162 			com_loadchannelregs(sc);
1163 	}
1164 }
1165 
1166 int
1167 com_to_tiocm(struct com_softc *sc)
1168 {
1169 	u_char combits;
1170 	int ttybits = 0;
1171 
1172 	combits = sc->sc_mcr;
1173 	if (ISSET(combits, MCR_DTR))
1174 		SET(ttybits, TIOCM_DTR);
1175 	if (ISSET(combits, MCR_RTS))
1176 		SET(ttybits, TIOCM_RTS);
1177 
1178 	combits = sc->sc_msr;
1179 	if (ISSET(combits, MSR_DCD))
1180 		SET(ttybits, TIOCM_CD);
1181 	if (ISSET(combits, MSR_CTS))
1182 		SET(ttybits, TIOCM_CTS);
1183 	if (ISSET(combits, MSR_DSR))
1184 		SET(ttybits, TIOCM_DSR);
1185 	if (ISSET(combits, MSR_RI | MSR_TERI))
1186 		SET(ttybits, TIOCM_RI);
1187 
1188 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1189 		SET(ttybits, TIOCM_LE);
1190 
1191 	return (ttybits);
1192 }
1193 
1194 static u_char
1195 cflag2lcr(tcflag_t cflag)
1196 {
1197 	u_char lcr = 0;
1198 
1199 	switch (ISSET(cflag, CSIZE)) {
1200 	case CS5:
1201 		SET(lcr, LCR_5BITS);
1202 		break;
1203 	case CS6:
1204 		SET(lcr, LCR_6BITS);
1205 		break;
1206 	case CS7:
1207 		SET(lcr, LCR_7BITS);
1208 		break;
1209 	case CS8:
1210 		SET(lcr, LCR_8BITS);
1211 		break;
1212 	}
1213 	if (ISSET(cflag, PARENB)) {
1214 		SET(lcr, LCR_PENAB);
1215 		if (!ISSET(cflag, PARODD))
1216 			SET(lcr, LCR_PEVEN);
1217 	}
1218 	if (ISSET(cflag, CSTOPB))
1219 		SET(lcr, LCR_STOPB);
1220 
1221 	return (lcr);
1222 }
1223 
1224 int
1225 comparam(struct tty *tp, struct termios *t)
1226 {
1227 	struct com_softc *sc =
1228 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1229 	int ospeed;
1230 	u_char lcr;
1231 
1232 	if (COM_ISALIVE(sc) == 0)
1233 		return (EIO);
1234 
1235 #ifdef COM_HAYESP
1236 	if (sc->sc_type == COM_TYPE_HAYESP) {
1237 		int prescaler, speed;
1238 
1239 		/*
1240 		 * Calculate UART clock prescaler.  It should be in
1241 		 * range of 0 .. 3.
1242 		 */
1243 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1244 		    prescaler++, speed /= 2)
1245 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1246 					       sc->sc_type)) > 0)
1247 				break;
1248 
1249 		if (prescaler == 4)
1250 			return (EINVAL);
1251 		sc->sc_prescaler = prescaler;
1252 	} else
1253 #endif
1254 	ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1255 
1256 	/* Check requested parameters. */
1257 	if (ospeed < 0)
1258 		return (EINVAL);
1259 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1260 		return (EINVAL);
1261 
1262 	/*
1263 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1264 	 * is always active.
1265 	 */
1266 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1267 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1268 		SET(t->c_cflag, CLOCAL);
1269 		CLR(t->c_cflag, HUPCL);
1270 	}
1271 
1272 	/*
1273 	 * If there were no changes, don't do anything.  This avoids dropping
1274 	 * input and improves performance when all we did was frob things like
1275 	 * VMIN and VTIME.
1276 	 */
1277 	if (tp->t_ospeed == t->c_ospeed &&
1278 	    tp->t_cflag == t->c_cflag)
1279 		return (0);
1280 
1281 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1282 
1283 	mutex_spin_enter(&sc->sc_lock);
1284 
1285 	sc->sc_lcr = lcr;
1286 
1287 	/*
1288 	 * If we're not in a mode that assumes a connection is present, then
1289 	 * ignore carrier changes.
1290 	 */
1291 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1292 		sc->sc_msr_dcd = 0;
1293 	else
1294 		sc->sc_msr_dcd = MSR_DCD;
1295 	/*
1296 	 * Set the flow control pins depending on the current flow control
1297 	 * mode.
1298 	 */
1299 	if (ISSET(t->c_cflag, CRTSCTS)) {
1300 		sc->sc_mcr_dtr = MCR_DTR;
1301 		sc->sc_mcr_rts = MCR_RTS;
1302 		sc->sc_msr_cts = MSR_CTS;
1303 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1304 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1305 		/*
1306 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1307 		 * carrier detection.
1308 		 */
1309 		sc->sc_mcr_dtr = 0;
1310 		sc->sc_mcr_rts = MCR_DTR;
1311 		sc->sc_msr_cts = MSR_DCD;
1312 		sc->sc_efr = 0;
1313 	} else {
1314 		/*
1315 		 * If no flow control, then always set RTS.  This will make
1316 		 * the other side happy if it mistakenly thinks we're doing
1317 		 * RTS/CTS flow control.
1318 		 */
1319 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1320 		sc->sc_mcr_rts = 0;
1321 		sc->sc_msr_cts = 0;
1322 		sc->sc_efr = 0;
1323 		if (ISSET(sc->sc_mcr, MCR_DTR))
1324 			SET(sc->sc_mcr, MCR_RTS);
1325 		else
1326 			CLR(sc->sc_mcr, MCR_RTS);
1327 	}
1328 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1329 
1330 #if 0
1331 	if (ospeed == 0)
1332 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1333 	else
1334 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1335 #endif
1336 
1337 	sc->sc_dlbl = ospeed;
1338 	sc->sc_dlbh = ospeed >> 8;
1339 
1340 	/*
1341 	 * Set the FIFO threshold based on the receive speed.
1342 	 *
1343 	 *  * If it's a low speed, it's probably a mouse or some other
1344 	 *    interactive device, so set the threshold low.
1345 	 *  * If it's a high speed, trim the trigger level down to prevent
1346 	 *    overflows.
1347 	 *  * Otherwise set it a bit higher.
1348 	 */
1349 	if (sc->sc_type == COM_TYPE_HAYESP)
1350 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1351 	else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1352 		if (t->c_ospeed <= 1200)
1353 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1354 		else if (t->c_ospeed <= 38400)
1355 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1356 		else
1357 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1358 	} else
1359 		sc->sc_fifo = 0;
1360 
1361 	/* And copy to tty. */
1362 	tp->t_ispeed = t->c_ospeed;
1363 	tp->t_ospeed = t->c_ospeed;
1364 	tp->t_cflag = t->c_cflag;
1365 
1366 	if (!sc->sc_heldchange) {
1367 		if (sc->sc_tx_busy) {
1368 			sc->sc_heldtbc = sc->sc_tbc;
1369 			sc->sc_tbc = 0;
1370 			sc->sc_heldchange = 1;
1371 		} else
1372 			com_loadchannelregs(sc);
1373 	}
1374 
1375 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1376 		/* Disable the high water mark. */
1377 		sc->sc_r_hiwat = 0;
1378 		sc->sc_r_lowat = 0;
1379 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1380 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1381 			com_schedrx(sc);
1382 		}
1383 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1384 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1385 			com_hwiflow(sc);
1386 		}
1387 	} else {
1388 		sc->sc_r_hiwat = com_rbuf_hiwat;
1389 		sc->sc_r_lowat = com_rbuf_lowat;
1390 	}
1391 
1392 	mutex_spin_exit(&sc->sc_lock);
1393 
1394 	/*
1395 	 * Update the tty layer's idea of the carrier bit, in case we changed
1396 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1397 	 * explicit request.
1398 	 */
1399 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1400 
1401 #ifdef COM_DEBUG
1402 	if (com_debug)
1403 		comstatus(sc, "comparam ");
1404 #endif
1405 
1406 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1407 		if (sc->sc_tx_stopped) {
1408 			sc->sc_tx_stopped = 0;
1409 			comstart(tp);
1410 		}
1411 	}
1412 
1413 	return (0);
1414 }
1415 
1416 void
1417 com_iflush(struct com_softc *sc)
1418 {
1419 	struct com_regs	*regsp = &sc->sc_regs;
1420 #ifdef DIAGNOSTIC
1421 	int reg;
1422 #endif
1423 	int timo;
1424 
1425 #ifdef DIAGNOSTIC
1426 	reg = 0xffff;
1427 #endif
1428 	timo = 50000;
1429 	/* flush any pending I/O */
1430 	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1431 	    && --timo)
1432 #ifdef DIAGNOSTIC
1433 		reg =
1434 #else
1435 		    (void)
1436 #endif
1437 		    CSR_READ_1(regsp, COM_REG_RXDATA);
1438 #ifdef DIAGNOSTIC
1439 	if (!timo)
1440 		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1441 #endif
1442 }
1443 
1444 void
1445 com_loadchannelregs(struct com_softc *sc)
1446 {
1447 	struct com_regs *regsp = &sc->sc_regs;
1448 
1449 	/* XXXXX necessary? */
1450 	com_iflush(sc);
1451 
1452 	if (sc->sc_type == COM_TYPE_PXA2x0)
1453 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1454 	else
1455 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1456 
1457 	if (sc->sc_type == COM_TYPE_OMAP) {
1458 		/* disable before changing settings */
1459 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
1460 	}
1461 
1462 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1463 		KASSERT(sc->sc_type != COM_TYPE_AU1x00);
1464 		KASSERT(sc->sc_type != COM_TYPE_16550_NOERS);
1465 		/* no EFR on alchemy */
1466 		CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1467 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1468 	}
1469 	if (sc->sc_type == COM_TYPE_AU1x00) {
1470 		/* alchemy has single separate 16-bit clock divisor register */
1471 		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1472 		    (sc->sc_dlbh << 8));
1473 	} else {
1474 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1475 		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1476 		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1477 	}
1478 	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1479 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1480 	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1481 #ifdef COM_HAYESP
1482 	if (sc->sc_type == COM_TYPE_HAYESP) {
1483 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1484 		    HAYESP_SETPRESCALER);
1485 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1486 		    sc->sc_prescaler);
1487 	}
1488 #endif
1489 	if (sc->sc_type == COM_TYPE_OMAP) {
1490 		/* setup the fifos.  the FCR value is not used as long
1491 		   as SCR[6] and SCR[7] are 0, which they are at reset
1492 		   and we never touch the SCR register */
1493 		uint8_t rx_fifo_trig = 40;
1494 		uint8_t tx_fifo_trig = 60;
1495 		uint8_t rx_start = 8;
1496 		uint8_t rx_halt = 60;
1497 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
1498 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
1499 
1500 		/* enable access to TCR & TLR */
1501 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr | MCR_TCR_TLR);
1502 
1503 		/* write tcr and tlr values */
1504 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
1505 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
1506 
1507 		/* disable access to TCR & TLR */
1508 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr);
1509 
1510 		/* enable again, but mode is based on speed */
1511 		if (sc->sc_tty->t_termios.c_ospeed > 230400) {
1512 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
1513 		} else {
1514 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
1515 		}
1516 	}
1517 
1518 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1519 }
1520 
1521 int
1522 comhwiflow(struct tty *tp, int block)
1523 {
1524 	struct com_softc *sc =
1525 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1526 
1527 	if (COM_ISALIVE(sc) == 0)
1528 		return (0);
1529 
1530 	if (sc->sc_mcr_rts == 0)
1531 		return (0);
1532 
1533 	mutex_spin_enter(&sc->sc_lock);
1534 
1535 	if (block) {
1536 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1537 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1538 			com_hwiflow(sc);
1539 		}
1540 	} else {
1541 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1542 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1543 			com_schedrx(sc);
1544 		}
1545 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1546 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1547 			com_hwiflow(sc);
1548 		}
1549 	}
1550 
1551 	mutex_spin_exit(&sc->sc_lock);
1552 	return (1);
1553 }
1554 
1555 /*
1556  * (un)block input via hw flowcontrol
1557  */
1558 void
1559 com_hwiflow(struct com_softc *sc)
1560 {
1561 	struct com_regs *regsp= &sc->sc_regs;
1562 
1563 	if (sc->sc_mcr_rts == 0)
1564 		return;
1565 
1566 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1567 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1568 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1569 	} else {
1570 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1571 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1572 	}
1573 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1574 }
1575 
1576 
1577 void
1578 comstart(struct tty *tp)
1579 {
1580 	struct com_softc *sc =
1581 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1582 	struct com_regs *regsp = &sc->sc_regs;
1583 	int s;
1584 
1585 	if (COM_ISALIVE(sc) == 0)
1586 		return;
1587 
1588 	s = spltty();
1589 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1590 		goto out;
1591 	if (sc->sc_tx_stopped)
1592 		goto out;
1593 	if (!ttypull(tp))
1594 		goto out;
1595 
1596 	/* Grab the first contiguous region of buffer space. */
1597 	{
1598 		u_char *tba;
1599 		int tbc;
1600 
1601 		tba = tp->t_outq.c_cf;
1602 		tbc = ndqb(&tp->t_outq, 0);
1603 
1604 		mutex_spin_enter(&sc->sc_lock);
1605 
1606 		sc->sc_tba = tba;
1607 		sc->sc_tbc = tbc;
1608 	}
1609 
1610 	SET(tp->t_state, TS_BUSY);
1611 	sc->sc_tx_busy = 1;
1612 
1613 	/* Enable transmit completion interrupts if necessary. */
1614 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1615 		SET(sc->sc_ier, IER_ETXRDY);
1616 		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1617 	}
1618 
1619 	/* Output the first chunk of the contiguous buffer. */
1620 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1621 		u_int n;
1622 
1623 		n = sc->sc_tbc;
1624 		if (n > sc->sc_fifolen)
1625 			n = sc->sc_fifolen;
1626 		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1627 		sc->sc_tbc -= n;
1628 		sc->sc_tba += n;
1629 	}
1630 
1631 	mutex_spin_exit(&sc->sc_lock);
1632 out:
1633 	splx(s);
1634 	return;
1635 }
1636 
1637 /*
1638  * Stop output on a line.
1639  */
1640 void
1641 comstop(struct tty *tp, int flag)
1642 {
1643 	struct com_softc *sc =
1644 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1645 
1646 	mutex_spin_enter(&sc->sc_lock);
1647 	if (ISSET(tp->t_state, TS_BUSY)) {
1648 		/* Stop transmitting at the next chunk. */
1649 		sc->sc_tbc = 0;
1650 		sc->sc_heldtbc = 0;
1651 		if (!ISSET(tp->t_state, TS_TTSTOP))
1652 			SET(tp->t_state, TS_FLUSH);
1653 	}
1654 	mutex_spin_exit(&sc->sc_lock);
1655 }
1656 
1657 void
1658 comdiag(void *arg)
1659 {
1660 	struct com_softc *sc = arg;
1661 	int overflows, floods;
1662 
1663 	mutex_spin_enter(&sc->sc_lock);
1664 	overflows = sc->sc_overflows;
1665 	sc->sc_overflows = 0;
1666 	floods = sc->sc_floods;
1667 	sc->sc_floods = 0;
1668 	sc->sc_errors = 0;
1669 	mutex_spin_exit(&sc->sc_lock);
1670 
1671 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1672 	    device_xname(sc->sc_dev),
1673 	    overflows, overflows == 1 ? "" : "s",
1674 	    floods, floods == 1 ? "" : "s");
1675 }
1676 
1677 integrate void
1678 com_rxsoft(struct com_softc *sc, struct tty *tp)
1679 {
1680 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1681 	u_char *get, *end;
1682 	u_int cc, scc;
1683 	u_char lsr;
1684 	int code;
1685 
1686 	end = sc->sc_ebuf;
1687 	get = sc->sc_rbget;
1688 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1689 
1690 	if (cc == com_rbuf_size) {
1691 		sc->sc_floods++;
1692 		if (sc->sc_errors++ == 0)
1693 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1694 			    comdiag, sc);
1695 	}
1696 
1697 	/* If not yet open, drop the entire buffer content here */
1698 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1699 		get += cc << 1;
1700 		if (get >= end)
1701 			get -= com_rbuf_size << 1;
1702 		cc = 0;
1703 	}
1704 	while (cc) {
1705 		code = get[0];
1706 		lsr = get[1];
1707 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1708 			if (ISSET(lsr, LSR_OE)) {
1709 				sc->sc_overflows++;
1710 				if (sc->sc_errors++ == 0)
1711 					callout_reset(&sc->sc_diag_callout,
1712 					    60 * hz, comdiag, sc);
1713 			}
1714 			if (ISSET(lsr, LSR_BI | LSR_FE))
1715 				SET(code, TTY_FE);
1716 			if (ISSET(lsr, LSR_PE))
1717 				SET(code, TTY_PE);
1718 		}
1719 		if ((*rint)(code, tp) == -1) {
1720 			/*
1721 			 * The line discipline's buffer is out of space.
1722 			 */
1723 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1724 				/*
1725 				 * We're either not using flow control, or the
1726 				 * line discipline didn't tell us to block for
1727 				 * some reason.  Either way, we have no way to
1728 				 * know when there's more space available, so
1729 				 * just drop the rest of the data.
1730 				 */
1731 				get += cc << 1;
1732 				if (get >= end)
1733 					get -= com_rbuf_size << 1;
1734 				cc = 0;
1735 			} else {
1736 				/*
1737 				 * Don't schedule any more receive processing
1738 				 * until the line discipline tells us there's
1739 				 * space available (through comhwiflow()).
1740 				 * Leave the rest of the data in the input
1741 				 * buffer.
1742 				 */
1743 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1744 			}
1745 			break;
1746 		}
1747 		get += 2;
1748 		if (get >= end)
1749 			get = sc->sc_rbuf;
1750 		cc--;
1751 	}
1752 
1753 	if (cc != scc) {
1754 		sc->sc_rbget = get;
1755 		mutex_spin_enter(&sc->sc_lock);
1756 
1757 		cc = sc->sc_rbavail += scc - cc;
1758 		/* Buffers should be ok again, release possible block. */
1759 		if (cc >= sc->sc_r_lowat) {
1760 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1761 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1762 				SET(sc->sc_ier, IER_ERXRDY);
1763 #ifdef COM_PXA2X0
1764 				if (sc->sc_type == COM_TYPE_PXA2x0)
1765 					SET(sc->sc_ier, IER_ERXTOUT);
1766 #endif
1767 				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1768 			}
1769 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1770 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1771 				com_hwiflow(sc);
1772 			}
1773 		}
1774 		mutex_spin_exit(&sc->sc_lock);
1775 	}
1776 }
1777 
1778 integrate void
1779 com_txsoft(struct com_softc *sc, struct tty *tp)
1780 {
1781 
1782 	CLR(tp->t_state, TS_BUSY);
1783 	if (ISSET(tp->t_state, TS_FLUSH))
1784 		CLR(tp->t_state, TS_FLUSH);
1785 	else
1786 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1787 	(*tp->t_linesw->l_start)(tp);
1788 }
1789 
1790 integrate void
1791 com_stsoft(struct com_softc *sc, struct tty *tp)
1792 {
1793 	u_char msr, delta;
1794 
1795 	mutex_spin_enter(&sc->sc_lock);
1796 	msr = sc->sc_msr;
1797 	delta = sc->sc_msr_delta;
1798 	sc->sc_msr_delta = 0;
1799 	mutex_spin_exit(&sc->sc_lock);
1800 
1801 	if (ISSET(delta, sc->sc_msr_dcd)) {
1802 		/*
1803 		 * Inform the tty layer that carrier detect changed.
1804 		 */
1805 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1806 	}
1807 
1808 	if (ISSET(delta, sc->sc_msr_cts)) {
1809 		/* Block or unblock output according to flow control. */
1810 		if (ISSET(msr, sc->sc_msr_cts)) {
1811 			sc->sc_tx_stopped = 0;
1812 			(*tp->t_linesw->l_start)(tp);
1813 		} else {
1814 			sc->sc_tx_stopped = 1;
1815 		}
1816 	}
1817 
1818 #ifdef COM_DEBUG
1819 	if (com_debug)
1820 		comstatus(sc, "com_stsoft");
1821 #endif
1822 }
1823 
1824 void
1825 comsoft(void *arg)
1826 {
1827 	struct com_softc *sc = arg;
1828 	struct tty *tp;
1829 
1830 	if (COM_ISALIVE(sc) == 0)
1831 		return;
1832 
1833 	tp = sc->sc_tty;
1834 
1835 	if (sc->sc_rx_ready) {
1836 		sc->sc_rx_ready = 0;
1837 		com_rxsoft(sc, tp);
1838 	}
1839 
1840 	if (sc->sc_st_check) {
1841 		sc->sc_st_check = 0;
1842 		com_stsoft(sc, tp);
1843 	}
1844 
1845 	if (sc->sc_tx_done) {
1846 		sc->sc_tx_done = 0;
1847 		com_txsoft(sc, tp);
1848 	}
1849 }
1850 
1851 int
1852 comintr(void *arg)
1853 {
1854 	struct com_softc *sc = arg;
1855 	struct com_regs *regsp = &sc->sc_regs;
1856 
1857 	u_char *put, *end;
1858 	u_int cc;
1859 	u_char lsr, iir;
1860 
1861 	if (COM_ISALIVE(sc) == 0)
1862 		return (0);
1863 
1864 	mutex_spin_enter(&sc->sc_lock);
1865 	iir = CSR_READ_1(regsp, COM_REG_IIR);
1866 	if (ISSET(iir, IIR_NOPEND)) {
1867 		mutex_spin_exit(&sc->sc_lock);
1868 		return (0);
1869 	}
1870 
1871 	end = sc->sc_ebuf;
1872 	put = sc->sc_rbput;
1873 	cc = sc->sc_rbavail;
1874 
1875 again:	do {
1876 		u_char	msr, delta;
1877 
1878 		lsr = CSR_READ_1(regsp, COM_REG_LSR);
1879 		if (ISSET(lsr, LSR_BI)) {
1880 			int cn_trapped = 0;
1881 
1882 			cn_check_magic(sc->sc_tty->t_dev,
1883 				       CNC_BREAK, com_cnm_state);
1884 			if (cn_trapped)
1885 				continue;
1886 #if defined(KGDB) && !defined(DDB)
1887 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
1888 				kgdb_connect(1);
1889 				continue;
1890 			}
1891 #endif
1892 		}
1893 
1894 		if (ISSET(lsr, LSR_RCV_MASK) &&
1895 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1896 			while (cc > 0) {
1897 				int cn_trapped = 0;
1898 				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
1899 				put[1] = lsr;
1900 				cn_check_magic(sc->sc_tty->t_dev,
1901 					       put[0], com_cnm_state);
1902 				if (cn_trapped)
1903 					goto next;
1904 				put += 2;
1905 				if (put >= end)
1906 					put = sc->sc_rbuf;
1907 				cc--;
1908 			next:
1909 				lsr = CSR_READ_1(regsp, COM_REG_LSR);
1910 				if (!ISSET(lsr, LSR_RCV_MASK))
1911 					break;
1912 			}
1913 
1914 			/*
1915 			 * Current string of incoming characters ended because
1916 			 * no more data was available or we ran out of space.
1917 			 * Schedule a receive event if any data was received.
1918 			 * If we're out of space, turn off receive interrupts.
1919 			 */
1920 			sc->sc_rbput = put;
1921 			sc->sc_rbavail = cc;
1922 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1923 				sc->sc_rx_ready = 1;
1924 
1925 			/*
1926 			 * See if we are in danger of overflowing a buffer. If
1927 			 * so, use hardware flow control to ease the pressure.
1928 			 */
1929 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
1930 			    cc < sc->sc_r_hiwat) {
1931 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1932 				com_hwiflow(sc);
1933 			}
1934 
1935 			/*
1936 			 * If we're out of space, disable receive interrupts
1937 			 * until the queue has drained a bit.
1938 			 */
1939 			if (!cc) {
1940 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1941 #ifdef COM_PXA2X0
1942 				if (sc->sc_type == COM_TYPE_PXA2x0)
1943 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
1944 				else
1945 #endif
1946 					CLR(sc->sc_ier, IER_ERXRDY);
1947 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1948 			}
1949 		} else {
1950 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
1951 				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
1952 				continue;
1953 			}
1954 		}
1955 
1956 		msr = CSR_READ_1(regsp, COM_REG_MSR);
1957 		delta = msr ^ sc->sc_msr;
1958 		sc->sc_msr = msr;
1959 		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
1960 		    (delta & MSR_DCD)) {
1961 			mutex_spin_enter(&timecounter_lock);
1962 			pps_capture(&sc->sc_pps_state);
1963 			pps_event(&sc->sc_pps_state,
1964 			    (msr & MSR_DCD) ?
1965 			    PPS_CAPTUREASSERT :
1966 			    PPS_CAPTURECLEAR);
1967 			mutex_spin_exit(&timecounter_lock);
1968 		}
1969 
1970 		/*
1971 		 * Process normal status changes
1972 		 */
1973 		if (ISSET(delta, sc->sc_msr_mask)) {
1974 			SET(sc->sc_msr_delta, delta);
1975 
1976 			/*
1977 			 * Stop output immediately if we lose the output
1978 			 * flow control signal or carrier detect.
1979 			 */
1980 			if (ISSET(~msr, sc->sc_msr_mask)) {
1981 				sc->sc_tbc = 0;
1982 				sc->sc_heldtbc = 0;
1983 #ifdef COM_DEBUG
1984 				if (com_debug)
1985 					comstatus(sc, "comintr  ");
1986 #endif
1987 			}
1988 
1989 			sc->sc_st_check = 1;
1990 		}
1991 	} while (!ISSET((iir =
1992 	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
1993 	    /*
1994 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
1995 	     * by IIR read, so we can't do this way: `process all interrupts,
1996 	     * then do TX if possble'.
1997 	     */
1998 	    (iir & IIR_IMASK) != IIR_TXRDY);
1999 
2000 	/*
2001 	 * Read LSR again, since there may be an interrupt between
2002 	 * the last LSR read and IIR read above.
2003 	 */
2004 	lsr = CSR_READ_1(regsp, COM_REG_LSR);
2005 
2006 	/*
2007 	 * See if data can be transmitted as well.
2008 	 * Schedule tx done event if no data left
2009 	 * and tty was marked busy.
2010 	 */
2011 	if (ISSET(lsr, LSR_TXRDY)) {
2012 		/*
2013 		 * If we've delayed a parameter change, do it now, and restart
2014 		 * output.
2015 		 */
2016 		if (sc->sc_heldchange) {
2017 			com_loadchannelregs(sc);
2018 			sc->sc_heldchange = 0;
2019 			sc->sc_tbc = sc->sc_heldtbc;
2020 			sc->sc_heldtbc = 0;
2021 		}
2022 
2023 		/* Output the next chunk of the contiguous buffer, if any. */
2024 		if (sc->sc_tbc > 0) {
2025 			u_int n;
2026 
2027 			n = sc->sc_tbc;
2028 			if (n > sc->sc_fifolen)
2029 				n = sc->sc_fifolen;
2030 			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
2031 			sc->sc_tbc -= n;
2032 			sc->sc_tba += n;
2033 		} else {
2034 			/* Disable transmit completion interrupts if necessary. */
2035 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2036 				CLR(sc->sc_ier, IER_ETXRDY);
2037 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2038 			}
2039 			if (sc->sc_tx_busy) {
2040 				sc->sc_tx_busy = 0;
2041 				sc->sc_tx_done = 1;
2042 			}
2043 		}
2044 	}
2045 
2046 	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
2047 		goto again;
2048 
2049 	mutex_spin_exit(&sc->sc_lock);
2050 
2051 	/* Wake up the poller. */
2052 	softint_schedule(sc->sc_si);
2053 
2054 #if NRND > 0 && defined(RND_COM)
2055 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2056 #endif
2057 
2058 	return (1);
2059 }
2060 
2061 /*
2062  * The following functions are polled getc and putc routines, shared
2063  * by the console and kgdb glue.
2064  *
2065  * The read-ahead code is so that you can detect pending in-band
2066  * cn_magic in polled mode while doing output rather than having to
2067  * wait until the kernel decides it needs input.
2068  */
2069 
2070 #define MAX_READAHEAD	20
2071 static int com_readahead[MAX_READAHEAD];
2072 static int com_readaheadcount = 0;
2073 
2074 int
2075 com_common_getc(dev_t dev, struct com_regs *regsp)
2076 {
2077 	int s = splserial();
2078 	u_char stat, c;
2079 
2080 	/* got a character from reading things earlier */
2081 	if (com_readaheadcount > 0) {
2082 		int i;
2083 
2084 		c = com_readahead[0];
2085 		for (i = 1; i < com_readaheadcount; i++) {
2086 			com_readahead[i-1] = com_readahead[i];
2087 		}
2088 		com_readaheadcount--;
2089 		splx(s);
2090 		return (c);
2091 	}
2092 
2093 	/* block until a character becomes available */
2094 	while (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY))
2095 		;
2096 
2097 	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2098 	stat = CSR_READ_1(regsp, COM_REG_IIR);
2099 	{
2100 		int cn_trapped = 0; /* unused */
2101 #ifdef DDB
2102 		extern int db_active;
2103 		if (!db_active)
2104 #endif
2105 			cn_check_magic(dev, c, com_cnm_state);
2106 	}
2107 	splx(s);
2108 	return (c);
2109 }
2110 
2111 void
2112 com_common_putc(dev_t dev, struct com_regs *regsp, int c)
2113 {
2114 	int s = splserial();
2115 	int cin, stat, timo;
2116 
2117 	if (com_readaheadcount < MAX_READAHEAD
2118 	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2119 		int cn_trapped = 0;
2120 		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2121 		stat = CSR_READ_1(regsp, COM_REG_IIR);
2122 		cn_check_magic(dev, cin, com_cnm_state);
2123 		com_readahead[com_readaheadcount++] = cin;
2124 	}
2125 
2126 	/* wait for any pending transmission to finish */
2127 	timo = 150000;
2128 	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2129 		continue;
2130 
2131 	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2132 	COM_BARRIER(regsp, BR | BW);
2133 
2134 	splx(s);
2135 }
2136 
2137 /*
2138  * Initialize UART for use as console or KGDB line.
2139  */
2140 int
2141 cominit(struct com_regs *regsp, int rate, int frequency, int type,
2142     tcflag_t cflag)
2143 {
2144 
2145 	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2146 		&regsp->cr_ioh))
2147 		return (ENOMEM); /* ??? */
2148 
2149 	if (type == COM_TYPE_OMAP) {
2150 		/* disable before changing settings */
2151 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
2152 	}
2153 
2154 	rate = comspeed(rate, frequency, type);
2155 	if (type != COM_TYPE_AU1x00) {
2156 		/* no EFR on alchemy */
2157 		if (type != COM_TYPE_16550_NOERS) {
2158 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2159 			CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2160 		}
2161 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2162 		CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2163 		CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2164 	} else {
2165 		CSR_WRITE_1(regsp, COM_REG_DLBL, rate);
2166 	}
2167 	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2168 	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2169 	CSR_WRITE_1(regsp, COM_REG_FIFO,
2170 	    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
2171 
2172 	if (type == COM_TYPE_OMAP) {
2173 		/* setup the fifos.  the FCR value is not used as long
2174 		   as SCR[6] and SCR[7] are 0, which they are at reset
2175 		   and we never touch the SCR register */
2176 		uint8_t rx_fifo_trig = 40;
2177 		uint8_t tx_fifo_trig = 60;
2178 		uint8_t rx_start = 8;
2179 		uint8_t rx_halt = 60;
2180 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
2181 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
2182 
2183 		/* enable access to TCR & TLR */
2184 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS | MCR_TCR_TLR);
2185 
2186 		/* write tcr and tlr values */
2187 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
2188 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
2189 
2190 		/* disable access to TCR & TLR */
2191 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2192 
2193 		/* enable again, but mode is based on speed */
2194 		if (rate > 230400) {
2195 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
2196 		} else {
2197 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
2198 		}
2199 	}
2200 
2201 #ifdef COM_PXA2X0
2202 	if (type == COM_TYPE_PXA2x0)
2203 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2204 	else
2205 #endif
2206 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2207 
2208 	return (0);
2209 }
2210 
2211 /*
2212  * Following are all routines needed for COM to act as console
2213  */
2214 struct consdev comcons = {
2215 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
2216 	NODEV, CN_NORMAL
2217 };
2218 
2219 
2220 int
2221 comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2222     tcflag_t cflag)
2223 {
2224 	int res;
2225 
2226 	comconsregs = *regsp;
2227 
2228 	res = cominit(&comconsregs, rate, frequency, type, cflag);
2229 	if (res)
2230 		return (res);
2231 
2232 	cn_tab = &comcons;
2233 	cn_init_magic(&com_cnm_state);
2234 	cn_set_magic("\047\001"); /* default magic is BREAK */
2235 
2236 	comconsrate = rate;
2237 	comconscflag = cflag;
2238 
2239 	return (0);
2240 }
2241 
2242 int
2243 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2244     int type, tcflag_t cflag)
2245 {
2246 	struct com_regs	regs;
2247 
2248 	memset(&regs, 0, sizeof regs);
2249 	regs.cr_iot = iot;
2250 	regs.cr_iobase = iobase;
2251 	regs.cr_nports = COM_NPORTS;
2252 #ifdef	COM_REGMAP
2253 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2254 #endif
2255 
2256 	return comcnattach1(&regs, rate, frequency, type, cflag);
2257 }
2258 
2259 int
2260 comcngetc(dev_t dev)
2261 {
2262 
2263 	return (com_common_getc(dev, &comconsregs));
2264 }
2265 
2266 /*
2267  * Console kernel output character routine.
2268  */
2269 void
2270 comcnputc(dev_t dev, int c)
2271 {
2272 
2273 	com_common_putc(dev, &comconsregs, c);
2274 }
2275 
2276 void
2277 comcnpollc(dev_t dev, int on)
2278 {
2279 
2280 }
2281 
2282 #ifdef KGDB
2283 int
2284 com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2285     tcflag_t cflag)
2286 {
2287 	int res;
2288 
2289 	if (regsp->cr_iot == comconsregs.cr_iot &&
2290 	    regsp->cr_iobase == comconsregs.cr_iobase) {
2291 #if !defined(DDB)
2292 		return (EBUSY); /* cannot share with console */
2293 #else
2294 		comkgdbregs = *regsp;
2295 		comkgdbregs.cr_ioh = comconsregs.cr_ioh;
2296 #endif
2297 	} else {
2298 		comkgdbregs = *regsp;
2299 		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2300 		if (res)
2301 			return (res);
2302 
2303 		/*
2304 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2305 		 * expects this to be initialized
2306 		 */
2307 		cn_init_magic(&com_cnm_state);
2308 		cn_set_magic("\047\001");
2309 	}
2310 
2311 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2312 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2313 
2314 	return (0);
2315 }
2316 
2317 int
2318 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2319     int frequency, int type, tcflag_t cflag)
2320 {
2321 	struct com_regs regs;
2322 
2323 	regs.cr_iot = iot;
2324 	regs.cr_nports = COM_NPORTS;
2325 	regs.cr_iobase = iobase;
2326 #ifdef COM_REGMAP
2327 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2328 #endif
2329 
2330 	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2331 }
2332 
2333 /* ARGSUSED */
2334 int
2335 com_kgdb_getc(void *arg)
2336 {
2337 
2338 	return (com_common_getc(NODEV, &comkgdbregs));
2339 }
2340 
2341 /* ARGSUSED */
2342 void
2343 com_kgdb_putc(void *arg, int c)
2344 {
2345 
2346 	com_common_putc(NODEV, &comkgdbregs, c);
2347 }
2348 #endif /* KGDB */
2349 
2350 /* helper function to identify the com ports used by
2351  console or KGDB (and not yet autoconf attached) */
2352 int
2353 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2354 {
2355 	bus_space_handle_t help;
2356 
2357 	if (!comconsattached &&
2358 	    iot == comconsregs.cr_iot && iobase == comconsregs.cr_iobase)
2359 		help = comconsregs.cr_ioh;
2360 #ifdef KGDB
2361 	else if (!com_kgdb_attached &&
2362 	    iot == comkgdbregs.cr_iot && iobase == comkgdbregs.cr_iobase)
2363 		help = comkgdbregs.cr_ioh;
2364 #endif
2365 	else
2366 		return (0);
2367 
2368 	if (ioh)
2369 		*ioh = help;
2370 	return (1);
2371 }
2372 
2373 /*
2374  * this routine exists to serve as a shutdown hook for systems that
2375  * have firmware which doesn't interact properly with a com device in
2376  * FIFO mode.
2377  */
2378 bool
2379 com_cleanup(device_t self, int how)
2380 {
2381 	struct com_softc *sc = device_private(self);
2382 
2383 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2384 		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2385 
2386 	return true;
2387 }
2388 
2389 bool
2390 com_suspend(device_t self PMF_FN_ARGS)
2391 {
2392 	struct com_softc *sc = device_private(self);
2393 
2394 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2395 	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2396 
2397 	return true;
2398 }
2399 
2400 bool
2401 com_resume(device_t self PMF_FN_ARGS)
2402 {
2403 	struct com_softc *sc = device_private(self);
2404 
2405 	mutex_spin_enter(&sc->sc_lock);
2406 	com_loadchannelregs(sc);
2407 	mutex_spin_exit(&sc->sc_lock);
2408 
2409 	return true;
2410 }
2411