xref: /netbsd-src/sys/dev/ic/com.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* $NetBSD: com.c,v 1.348 2018/05/27 17:05:06 jmcneill 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 1.348 2018/05/27 17:05:06 jmcneill 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 /* The COM16650 option was renamed to COM_16650. */
79 #ifdef COM16650
80 #error Obsolete COM16650 option; use COM_16650 instead.
81 #endif
82 
83 /*
84  * Override cnmagic(9) macro before including <sys/systm.h>.
85  * We need to know if cn_check_magic triggered debugger, so set a flag.
86  * Callers of cn_check_magic must declare int cn_trapped = 0;
87  * XXX: this is *ugly*!
88  */
89 #define cn_trap()				\
90 	do {					\
91 		console_debugger();		\
92 		cn_trapped = 1;			\
93 		(void)cn_trapped;		\
94 	} while (/* CONSTCOND */ 0)
95 
96 #include <sys/param.h>
97 #include <sys/systm.h>
98 #include <sys/ioctl.h>
99 #include <sys/select.h>
100 #include <sys/poll.h>
101 #include <sys/tty.h>
102 #include <sys/proc.h>
103 #include <sys/conf.h>
104 #include <sys/file.h>
105 #include <sys/uio.h>
106 #include <sys/kernel.h>
107 #include <sys/syslog.h>
108 #include <sys/device.h>
109 #include <sys/malloc.h>
110 #include <sys/timepps.h>
111 #include <sys/vnode.h>
112 #include <sys/kauth.h>
113 #include <sys/intr.h>
114 #ifdef RND_COM
115 #include <sys/rndsource.h>
116 #endif
117 
118 
119 #include <sys/bus.h>
120 
121 #include <dev/ic/comreg.h>
122 #include <dev/ic/comvar.h>
123 #include <dev/ic/ns16550reg.h>
124 #include <dev/ic/st16650reg.h>
125 #include <dev/ic/hayespreg.h>
126 #define	com_lcr	com_cfcr
127 #include <dev/cons.h>
128 
129 #include "ioconf.h"
130 
131 #ifdef	COM_REGMAP
132 #define	CSR_WRITE_1(r, o, v)	\
133 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
134 #define	CSR_READ_1(r, o)	\
135 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
136 #define	CSR_WRITE_2(r, o, v)	\
137 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
138 #define	CSR_READ_2(r, o)	\
139 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
140 #define	CSR_WRITE_MULTI(r, o, p, n)	\
141 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], p, n)
142 #else
143 #define	CSR_WRITE_1(r, o, v)	\
144 	bus_space_write_1((r)->cr_iot, (r)->cr_ioh, o, v)
145 #define	CSR_READ_1(r, o)	\
146 	bus_space_read_1((r)->cr_iot, (r)->cr_ioh, o)
147 #define	CSR_WRITE_2(r, o, v)	\
148 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, o, v)
149 #define	CSR_READ_2(r, o)	\
150 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, o)
151 #define	CSR_WRITE_MULTI(r, o, p, n)	\
152 	bus_space_write_multi_1((r)->cr_iot, (r)->cr_ioh, o, p, n)
153 #endif
154 
155 
156 static void com_enable_debugport(struct com_softc *);
157 
158 void	com_config(struct com_softc *);
159 void	com_shutdown(struct com_softc *);
160 int	comspeed(long, long, int);
161 static	u_char	cflag2lcr(tcflag_t);
162 int	comparam(struct tty *, struct termios *);
163 void	comstart(struct tty *);
164 int	comhwiflow(struct tty *, int);
165 
166 void	com_loadchannelregs(struct com_softc *);
167 void	com_hwiflow(struct com_softc *);
168 void	com_break(struct com_softc *, int);
169 void	com_modem(struct com_softc *, int);
170 void	tiocm_to_com(struct com_softc *, u_long, int);
171 int	com_to_tiocm(struct com_softc *);
172 void	com_iflush(struct com_softc *);
173 
174 int	com_common_getc(dev_t, struct com_regs *);
175 static void	com_common_putc(dev_t, struct com_regs *, int);
176 
177 int	cominit(struct com_regs *, int, int, int, tcflag_t);
178 
179 static int comcnreattach(void);
180 
181 int	comcngetc(dev_t);
182 void	comcnputc(dev_t, int);
183 void	comcnpollc(dev_t, int);
184 
185 #define	integrate	static inline
186 void	comsoft(void *);
187 integrate void com_rxsoft(struct com_softc *, struct tty *);
188 integrate void com_txsoft(struct com_softc *, struct tty *);
189 integrate void com_stsoft(struct com_softc *, struct tty *);
190 integrate void com_schedrx(struct com_softc *);
191 void	comdiag(void *);
192 
193 dev_type_open(comopen);
194 dev_type_close(comclose);
195 dev_type_read(comread);
196 dev_type_write(comwrite);
197 dev_type_ioctl(comioctl);
198 dev_type_stop(comstop);
199 dev_type_tty(comtty);
200 dev_type_poll(compoll);
201 
202 static struct comcons_info comcons_info;
203 
204 /*
205  * Following are all routines needed for COM to act as console
206  */
207 static struct consdev comcons = {
208 	NULL, NULL, comcngetc, comcnputc, comcnpollc, NULL, NULL, NULL,
209 	NODEV, CN_NORMAL
210 };
211 
212 
213 const struct cdevsw com_cdevsw = {
214 	.d_open = comopen,
215 	.d_close = comclose,
216 	.d_read = comread,
217 	.d_write = comwrite,
218 	.d_ioctl = comioctl,
219 	.d_stop = comstop,
220 	.d_tty = comtty,
221 	.d_poll = compoll,
222 	.d_mmap = nommap,
223 	.d_kqfilter = ttykqfilter,
224 	.d_discard = nodiscard,
225 	.d_flag = D_TTY
226 };
227 
228 /*
229  * Make this an option variable one can patch.
230  * But be warned:  this must be a power of 2!
231  */
232 u_int com_rbuf_size = COM_RING_SIZE;
233 
234 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
235 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
236 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
237 
238 static int comconsattached;
239 static struct cnm_state com_cnm_state;
240 
241 #ifdef KGDB
242 #include <sys/kgdb.h>
243 
244 static struct com_regs comkgdbregs;
245 static int com_kgdb_attached;
246 
247 int	com_kgdb_getc(void *);
248 void	com_kgdb_putc(void *, int);
249 #endif /* KGDB */
250 
251 #ifdef COM_REGMAP
252 /* initializer for typical 16550-ish hardware */
253 #define	COM_REG_STD { \
254 	com_data, com_data, com_dlbl, com_dlbh, com_ier, com_iir, com_fifo, \
255 	com_efr, com_lcr, com_mcr, com_lsr, com_msr, 0, 0, 0, 0, 0, 0, 0, 0, \
256 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, com_usr, com_tfl, com_rfl, \
257 	0, 0, 0, 0, 0, 0, 0, com_halt }
258 
259 const bus_size_t com_std_map[42] = COM_REG_STD;
260 #endif /* COM_REGMAP */
261 
262 #define	COMDIALOUT_MASK	TTDIALOUT_MASK
263 
264 #define	COMUNIT(x)	TTUNIT(x)
265 #define	COMDIALOUT(x)	TTDIALOUT(x)
266 
267 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
268 			 device_is_active((sc)->sc_dev))
269 
270 #define	BR	BUS_SPACE_BARRIER_READ
271 #define	BW	BUS_SPACE_BARRIER_WRITE
272 #define COM_BARRIER(r, f) \
273 	bus_space_barrier((r)->cr_iot, (r)->cr_ioh, 0, (r)->cr_nports, (f))
274 
275 /*ARGSUSED*/
276 int
277 comspeed(long speed, long frequency, int type)
278 {
279 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
280 
281 	int x, err;
282 	int divisor = 16;
283 
284 	if ((type == COM_TYPE_OMAP) && (speed > 230400)) {
285 	    divisor = 13;
286 	}
287 
288 	if (speed == 0)
289 		return (0);
290 	if (speed < 0)
291 		return (-1);
292 	x = divrnd(frequency / divisor, speed);
293 	if (x <= 0)
294 		return (-1);
295 	err = divrnd(((quad_t)frequency) * 1000 / divisor, speed * x) - 1000;
296 	if (err < 0)
297 		err = -err;
298 	if (err > COM_TOLERANCE)
299 		return (-1);
300 	return (x);
301 
302 #undef	divrnd
303 }
304 
305 #ifdef COM_DEBUG
306 int	com_debug = 0;
307 
308 void comstatus(struct com_softc *, const char *);
309 void
310 comstatus(struct com_softc *sc, const char *str)
311 {
312 	struct tty *tp = sc->sc_tty;
313 
314 	aprint_normal_dev(sc->sc_dev,
315 	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
316 	    str,
317 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
318 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
319 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
320 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
321 	    sc->sc_tx_stopped ? '+' : '-');
322 
323 	aprint_normal_dev(sc->sc_dev,
324 	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
325 	    str,
326 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
327 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
328 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
329 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
330 	    sc->sc_rx_flags);
331 }
332 #endif
333 
334 int
335 com_probe_subr(struct com_regs *regs)
336 {
337 
338 	/* force access to id reg */
339 	CSR_WRITE_1(regs, COM_REG_LCR, LCR_8BITS);
340 	CSR_WRITE_1(regs, COM_REG_IIR, 0);
341 	if ((CSR_READ_1(regs, COM_REG_LCR) != LCR_8BITS) ||
342 	    (CSR_READ_1(regs, COM_REG_IIR) & 0x38))
343 		return (0);
344 
345 	return (1);
346 }
347 
348 int
349 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
350 {
351 	struct com_regs	regs;
352 
353 	regs.cr_iot = iot;
354 	regs.cr_ioh = ioh;
355 #ifdef	COM_REGMAP
356 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
357 #endif
358 
359 	return com_probe_subr(&regs);
360 }
361 
362 /*
363  * No locking in this routine; it is only called during attach,
364  * or with the port already locked.
365  */
366 static void
367 com_enable_debugport(struct com_softc *sc)
368 {
369 
370 	/* Turn on line break interrupt, set carrier. */
371 	sc->sc_ier = IER_ERLS;
372 	if (sc->sc_type == COM_TYPE_PXA2x0)
373 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
374 	if (sc->sc_type == COM_TYPE_INGENIC ||
375 	    sc->sc_type == COM_TYPE_TEGRA)
376 		sc->sc_ier |= IER_ERXTOUT;
377 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
378 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
379 	CSR_WRITE_1(&sc->sc_regs, COM_REG_MCR, sc->sc_mcr);
380 }
381 
382 void
383 com_attach_subr(struct com_softc *sc)
384 {
385 	struct com_regs *regsp = &sc->sc_regs;
386 	struct tty *tp;
387 	u_int8_t lcr;
388 	const char *fifo_msg = NULL;
389 	prop_dictionary_t	dict;
390 	bool is_console = true;
391 
392 	aprint_naive("\n");
393 
394 	dict = device_properties(sc->sc_dev);
395 	prop_dictionary_get_bool(dict, "is_console", &is_console);
396 	callout_init(&sc->sc_diag_callout, 0);
397 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
398 
399 #if defined(COM_16650)
400 	sc->sc_type = COM_TYPE_16650;
401 #elif defined(COM_16750)
402 	sc->sc_type = COM_TYPE_16750;
403 #elif defined(COM_HAYESP)
404 	sc->sc_type = COM_TYPE_HAYESP;
405 #elif defined(COM_PXA2X0)
406 	sc->sc_type = COM_TYPE_PXA2x0;
407 #endif
408 
409 	/* Disable interrupts before configuring the device. */
410 	if (sc->sc_type == COM_TYPE_PXA2x0)
411 		sc->sc_ier = IER_EUART;
412 	else
413 		sc->sc_ier = 0;
414 
415 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
416 
417 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
418 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
419 		comconsattached = 1;
420 
421 		if (cn_tab == NULL && comcnreattach() != 0) {
422 			printf("can't re-init serial console @%lx\n",
423 			    (u_long)comcons_info.regs.cr_iobase);
424 		}
425 
426 		switch (sc->sc_type) {
427 		case COM_TYPE_16750:
428 		case COM_TYPE_DW_APB:
429 			/* Use in comintr(). */
430  			sc->sc_lcr = cflag2lcr(comcons_info.cflag);
431 			break;
432 		}
433 
434 		/* Make sure the console is always "hardwired". */
435 		delay(10000);			/* wait for output to finish */
436 		if (is_console) {
437 			SET(sc->sc_hwflags, COM_HW_CONSOLE);
438 		}
439 
440 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
441 	}
442 
443 	/* Probe for FIFO */
444 	switch (sc->sc_type) {
445 	case COM_TYPE_HAYESP:
446 		goto fifodone;
447 
448 	case COM_TYPE_AU1x00:
449 		sc->sc_fifolen = 16;
450 		fifo_msg = "Au1X00 UART, working fifo";
451 		SET(sc->sc_hwflags, COM_HW_FIFO);
452 		goto fifodelay;
453 
454 	case COM_TYPE_16550_NOERS:
455 		sc->sc_fifolen = 16;
456 		fifo_msg = "ns16650, no ERS, working fifo";
457 		SET(sc->sc_hwflags, COM_HW_FIFO);
458 		goto fifodelay;
459 
460 	case COM_TYPE_OMAP:
461 		sc->sc_fifolen = 64;
462 		fifo_msg = "OMAP UART, working fifo";
463 		SET(sc->sc_hwflags, COM_HW_FIFO);
464 		goto fifodelay;
465 
466 	case COM_TYPE_INGENIC:
467 		sc->sc_fifolen = 16;
468 		fifo_msg = "Ingenic UART, working fifo";
469 		SET(sc->sc_hwflags, COM_HW_FIFO);
470 		SET(sc->sc_hwflags, COM_HW_NOIEN);
471 		goto fifodelay;
472 
473 	case COM_TYPE_TEGRA:
474 		sc->sc_fifolen = 8;
475 		fifo_msg = "Tegra UART, working fifo";
476 		SET(sc->sc_hwflags, COM_HW_FIFO);
477 		CSR_WRITE_1(regsp, COM_REG_FIFO,
478 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
479 		goto fifodelay;
480 
481 	case COM_TYPE_BCMAUXUART:
482 		sc->sc_fifolen = 1;
483 		fifo_msg = "BCM AUX UART, working fifo";
484 		SET(sc->sc_hwflags, COM_HW_FIFO);
485 		CSR_WRITE_1(regsp, COM_REG_FIFO,
486 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
487 		goto fifodelay;
488 	}
489 
490 	sc->sc_fifolen = 1;
491 	/* look for a NS 16550AF UART with FIFOs */
492 	if (sc->sc_type == COM_TYPE_INGENIC) {
493 		CSR_WRITE_1(regsp, COM_REG_FIFO,
494 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
495 		    FIFO_TRIGGER_14 | FIFO_UART_ON);
496 	} else
497 		CSR_WRITE_1(regsp, COM_REG_FIFO,
498 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
499 	delay(100);
500 	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
501 	    == IIR_FIFO_MASK)
502 		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
503 		    == FIFO_TRIGGER_14) {
504 			SET(sc->sc_hwflags, COM_HW_FIFO);
505 
506 			fifo_msg = "ns16550a, working fifo";
507 
508 			/*
509 			 * IIR changes into the EFR if LCR is set to LCR_EERS
510 			 * on 16650s. We also know IIR != 0 at this point.
511 			 * Write 0 into the EFR, and read it. If the result
512 			 * is 0, we have a 16650.
513 			 *
514 			 * Older 16650s were broken; the test to detect them
515 			 * is taken from the Linux driver. Apparently
516 			 * setting DLAB enable gives access to the EFR on
517 			 * these chips.
518 			 */
519 			if (sc->sc_type == COM_TYPE_16650) {
520 				lcr = CSR_READ_1(regsp, COM_REG_LCR);
521 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
522 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
523 				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
524 					CSR_WRITE_1(regsp, COM_REG_LCR,
525 					    lcr | LCR_DLAB);
526 					if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
527 						CLR(sc->sc_hwflags, COM_HW_FIFO);
528 						sc->sc_fifolen = 0;
529 					} else {
530 						SET(sc->sc_hwflags, COM_HW_FLOW);
531 						sc->sc_fifolen = 32;
532 					}
533 				} else
534 					sc->sc_fifolen = 16;
535 
536 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
537 				if (sc->sc_fifolen == 0)
538 					fifo_msg = "st16650, broken fifo";
539 				else if (sc->sc_fifolen == 32)
540 					fifo_msg = "st16650a, working fifo";
541 				else
542 					fifo_msg = "ns16550a, working fifo";
543 			}
544 
545 			/*
546 			 * TL16C750 can enable 64byte FIFO, only when DLAB
547 			 * is 1.  However, some 16750 may always enable.  For
548 			 * example, restrictions according to DLAB in a data
549 			 * sheet for SC16C750 were not described.
550 			 * Please enable 'options COM_16650', supposing you
551 			 * use SC16C750.  Probably 32 bytes of FIFO and HW FLOW
552 			 * should become effective.
553 			 */
554 			if (sc->sc_type == COM_TYPE_16750) {
555 				uint8_t iir1, iir2;
556 				uint8_t fcr = FIFO_ENABLE | FIFO_TRIGGER_14;
557 
558 				lcr = CSR_READ_1(regsp, COM_REG_LCR);
559 				CSR_WRITE_1(regsp, COM_REG_LCR,
560 				    lcr & ~LCR_DLAB);
561 				CSR_WRITE_1(regsp, COM_REG_FIFO,
562 				    fcr | FIFO_64B_ENABLE);
563 				iir1 = CSR_READ_1(regsp, COM_REG_IIR);
564 				CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
565 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr | LCR_DLAB);
566 				CSR_WRITE_1(regsp, COM_REG_FIFO,
567 				    fcr | FIFO_64B_ENABLE);
568 				iir2 = CSR_READ_1(regsp, COM_REG_IIR);
569 
570 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
571 
572 				if (!ISSET(iir1, IIR_64B_FIFO) &&
573 				    ISSET(iir2, IIR_64B_FIFO)) {
574 					/* It is TL16C750. */
575 					sc->sc_fifolen = 64;
576 					SET(sc->sc_hwflags, COM_HW_AFE);
577 				} else
578 					CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
579 
580 				if (sc->sc_fifolen == 64)
581 					fifo_msg = "tl16c750, working fifo";
582 				else
583 					fifo_msg = "ns16750, working fifo";
584 			}
585 		} else
586 			fifo_msg = "ns16550, broken fifo";
587 	else
588 		fifo_msg = "ns8250 or ns16450, no fifo";
589 	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
590 
591 fifodelay:
592 	/*
593 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
594 	 * written to com_fifo. If this chip is the console, writing zero
595 	 * results in some of the chip/FIFO description being lost, so delay
596 	 * printing it until now.
597 	 */
598 	delay(10);
599 	aprint_normal(": %s\n", fifo_msg);
600 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
601 		sc->sc_fifolen = 1;
602 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
603 	}
604 
605 fifodone:
606 
607 	tp = tty_alloc();
608 	tp->t_oproc = comstart;
609 	tp->t_param = comparam;
610 	tp->t_hwiflow = comhwiflow;
611 	tp->t_softc = sc;
612 
613 	sc->sc_tty = tp;
614 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
615 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
616 	sc->sc_rbavail = com_rbuf_size;
617 	if (sc->sc_rbuf == NULL) {
618 		aprint_error_dev(sc->sc_dev,
619 		    "unable to allocate ring buffer\n");
620 		return;
621 	}
622 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
623 
624 	tty_attach(tp);
625 
626 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
627 		SET(sc->sc_mcr, MCR_IENABLE);
628 
629 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
630 		int maj;
631 
632 		/* locate the major number */
633 		maj = cdevsw_lookup_major(&com_cdevsw);
634 
635 		tp->t_dev = cn_tab->cn_dev = makedev(maj,
636 						     device_unit(sc->sc_dev));
637 
638 		aprint_normal_dev(sc->sc_dev, "console\n");
639 	}
640 
641 #ifdef KGDB
642 	/*
643 	 * Allow kgdb to "take over" this port.  If this is
644 	 * not the console and is the kgdb device, it has
645 	 * exclusive use.  If it's the console _and_ the
646 	 * kgdb device, it doesn't.
647 	 */
648 	if (bus_space_is_equal(regsp->cr_iot, comkgdbregs.cr_iot) &&
649 	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
650 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
651 			com_kgdb_attached = 1;
652 
653 			SET(sc->sc_hwflags, COM_HW_KGDB);
654 		}
655 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
656 	}
657 #endif
658 
659 	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
660 
661 #ifdef RND_COM
662 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
663 			  RND_TYPE_TTY, RND_FLAG_DEFAULT);
664 #endif
665 
666 	/* if there are no enable/disable functions, assume the device
667 	   is always enabled */
668 	if (!sc->enable)
669 		sc->enabled = 1;
670 
671 	com_config(sc);
672 
673 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
674 }
675 
676 void
677 com_config(struct com_softc *sc)
678 {
679 	struct com_regs *regsp = &sc->sc_regs;
680 
681 	/* Disable interrupts before configuring the device. */
682 	if (sc->sc_type == COM_TYPE_PXA2x0)
683 		sc->sc_ier = IER_EUART;
684 	else
685 		sc->sc_ier = 0;
686 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
687 	(void) CSR_READ_1(regsp, COM_REG_IIR);
688 
689 	/* Look for a Hayes ESP board. */
690 	if (sc->sc_type == COM_TYPE_HAYESP) {
691 
692 		/* Set 16550 compatibility mode */
693 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
694 				  HAYESP_SETMODE);
695 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
696 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
697 				  HAYESP_MODE_SCALE);
698 
699 		/* Set RTS/CTS flow control */
700 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
701 				  HAYESP_SETFLOWTYPE);
702 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
703 				  HAYESP_FLOW_RTS);
704 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
705 				  HAYESP_FLOW_CTS);
706 
707 		/* Set flow control levels */
708 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
709 				  HAYESP_SETRXFLOW);
710 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
711 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
712 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
713 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
714 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
715 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
716 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
717 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
718 	}
719 
720 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
721 		com_enable_debugport(sc);
722 }
723 
724 #if 0
725 static int
726 comcngetc_detached(dev_t dev)
727 {
728 	return 0;
729 }
730 
731 static void
732 comcnputc_detached(dev_t dev, int c)
733 {
734 }
735 #endif
736 
737 int
738 com_detach(device_t self, int flags)
739 {
740 	struct com_softc *sc = device_private(self);
741 	int maj, mn;
742 
743 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
744 		return EBUSY;
745 
746 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) &&
747 	    (flags & DETACH_SHUTDOWN) != 0)
748 		return EBUSY;
749 
750 	if (sc->disable != NULL && sc->enabled != 0) {
751 		(*sc->disable)(sc);
752 		sc->enabled = 0;
753 	}
754 
755 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
756 		comconsattached = 0;
757 		cn_tab = NULL;
758 	}
759 
760 	/* locate the major number */
761 	maj = cdevsw_lookup_major(&com_cdevsw);
762 
763 	/* Nuke the vnodes for any open instances. */
764 	mn = device_unit(self);
765 	vdevgone(maj, mn, mn, VCHR);
766 
767 	mn |= COMDIALOUT_MASK;
768 	vdevgone(maj, mn, mn, VCHR);
769 
770 	if (sc->sc_rbuf == NULL) {
771 		/*
772 		 * Ring buffer allocation failed in the com_attach_subr,
773 		 * only the tty is allocated, and nothing else.
774 		 */
775 		tty_free(sc->sc_tty);
776 		return 0;
777 	}
778 
779 	/* Free the receive buffer. */
780 	free(sc->sc_rbuf, M_DEVBUF);
781 
782 	/* Detach and free the tty. */
783 	tty_detach(sc->sc_tty);
784 	tty_free(sc->sc_tty);
785 
786 	/* Unhook the soft interrupt handler. */
787 	softint_disestablish(sc->sc_si);
788 
789 #ifdef RND_COM
790 	/* Unhook the entropy source. */
791 	rnd_detach_source(&sc->rnd_source);
792 #endif
793 	callout_destroy(&sc->sc_diag_callout);
794 
795 	/* Destroy the lock. */
796 	mutex_destroy(&sc->sc_lock);
797 
798 	return (0);
799 }
800 
801 void
802 com_shutdown(struct com_softc *sc)
803 {
804 	struct tty *tp = sc->sc_tty;
805 
806 	mutex_spin_enter(&sc->sc_lock);
807 
808 	/* If we were asserting flow control, then deassert it. */
809 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
810 	com_hwiflow(sc);
811 
812 	/* Clear any break condition set with TIOCSBRK. */
813 	com_break(sc, 0);
814 
815 	/*
816 	 * Hang up if necessary.  Wait a bit, so the other side has time to
817 	 * notice even if we immediately open the port again.
818 	 * Avoid tsleeping above splhigh().
819 	 */
820 	if (ISSET(tp->t_cflag, HUPCL)) {
821 		com_modem(sc, 0);
822 		mutex_spin_exit(&sc->sc_lock);
823 		/* XXX will only timeout */
824 		(void) kpause(ttclos, false, hz, NULL);
825 		mutex_spin_enter(&sc->sc_lock);
826 	}
827 
828 	/* Turn off interrupts. */
829 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
830 		sc->sc_ier = IER_ERLS; /* interrupt on line break */
831 		if ((sc->sc_type == COM_TYPE_PXA2x0) ||
832 		    (sc->sc_type == COM_TYPE_INGENIC) ||
833 		    (sc->sc_type == COM_TYPE_TEGRA))
834 			sc->sc_ier |= IER_ERXTOUT;
835 	} else
836 		sc->sc_ier = 0;
837 
838 	if (sc->sc_type == COM_TYPE_PXA2x0)
839 		sc->sc_ier |= IER_EUART;
840 
841 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
842 
843 	mutex_spin_exit(&sc->sc_lock);
844 
845 	if (sc->disable) {
846 #ifdef DIAGNOSTIC
847 		if (!sc->enabled)
848 			panic("com_shutdown: not enabled?");
849 #endif
850 		(*sc->disable)(sc);
851 		sc->enabled = 0;
852 	}
853 }
854 
855 int
856 comopen(dev_t dev, int flag, int mode, struct lwp *l)
857 {
858 	struct com_softc *sc;
859 	struct tty *tp;
860 	int s;
861 	int error;
862 
863 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
864 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
865 		sc->sc_rbuf == NULL)
866 		return (ENXIO);
867 
868 	if (!device_is_active(sc->sc_dev))
869 		return (ENXIO);
870 
871 #ifdef KGDB
872 	/*
873 	 * If this is the kgdb port, no other use is permitted.
874 	 */
875 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
876 		return (EBUSY);
877 #endif
878 
879 	tp = sc->sc_tty;
880 
881 	/*
882 	 * If the device is exclusively for kernel use, deny userland
883 	 * open.
884 	 */
885 	if (ISSET(tp->t_state, TS_KERN_ONLY))
886 		return (EBUSY);
887 
888 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
889 		return (EBUSY);
890 
891 	s = spltty();
892 
893 	/*
894 	 * Do the following iff this is a first open.
895 	 */
896 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
897 		struct termios t;
898 
899 		tp->t_dev = dev;
900 
901 		if (sc->enable) {
902 			if ((*sc->enable)(sc)) {
903 				splx(s);
904 				aprint_error_dev(sc->sc_dev,
905 				    "device enable failed\n");
906 				return (EIO);
907 			}
908 			mutex_spin_enter(&sc->sc_lock);
909 			sc->enabled = 1;
910 			com_config(sc);
911 		} else {
912 			mutex_spin_enter(&sc->sc_lock);
913 		}
914 
915 		/* Turn on interrupts. */
916 		sc->sc_ier = IER_ERXRDY | IER_ERLS;
917 		if (!ISSET(tp->t_cflag, CLOCAL))
918 			sc->sc_ier |= IER_EMSC;
919 
920 		if (sc->sc_type == COM_TYPE_PXA2x0)
921 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
922 		else if (sc->sc_type == COM_TYPE_INGENIC ||
923 			 sc->sc_type == COM_TYPE_TEGRA)
924 			sc->sc_ier |= IER_ERXTOUT;
925 		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
926 
927 		/* Fetch the current modem control status, needed later. */
928 		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
929 
930 		/* Clear PPS capture state on first open. */
931 		mutex_spin_enter(&timecounter_lock);
932 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
933 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
934 		pps_init(&sc->sc_pps_state);
935 		mutex_spin_exit(&timecounter_lock);
936 
937 		mutex_spin_exit(&sc->sc_lock);
938 
939 		/*
940 		 * Initialize the termios status to the defaults.  Add in the
941 		 * sticky bits from TIOCSFLAGS.
942 		 */
943 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
944 			t.c_ospeed = comcons_info.rate;
945 			t.c_cflag = comcons_info.cflag;
946 		} else {
947 			t.c_ospeed = TTYDEF_SPEED;
948 			t.c_cflag = TTYDEF_CFLAG;
949 		}
950 		t.c_ispeed = t.c_ospeed;
951 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
952 			SET(t.c_cflag, CLOCAL);
953 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
954 			SET(t.c_cflag, CRTSCTS);
955 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
956 			SET(t.c_cflag, MDMBUF);
957 		/* Make sure comparam() will do something. */
958 		tp->t_ospeed = 0;
959 		(void) comparam(tp, &t);
960 		tp->t_iflag = TTYDEF_IFLAG;
961 		tp->t_oflag = TTYDEF_OFLAG;
962 		tp->t_lflag = TTYDEF_LFLAG;
963 		ttychars(tp);
964 		ttsetwater(tp);
965 
966 		mutex_spin_enter(&sc->sc_lock);
967 
968 		/*
969 		 * Turn on DTR.  We must always do this, even if carrier is not
970 		 * present, because otherwise we'd have to use TIOCSDTR
971 		 * immediately after setting CLOCAL, which applications do not
972 		 * expect.  We always assert DTR while the device is open
973 		 * unless explicitly requested to deassert it.
974 		 */
975 		com_modem(sc, 1);
976 
977 		/* Clear the input ring, and unblock. */
978 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
979 		sc->sc_rbavail = com_rbuf_size;
980 		com_iflush(sc);
981 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
982 		com_hwiflow(sc);
983 
984 #ifdef COM_DEBUG
985 		if (com_debug)
986 			comstatus(sc, "comopen  ");
987 #endif
988 
989 		mutex_spin_exit(&sc->sc_lock);
990 	}
991 
992 	splx(s);
993 
994 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
995 	if (error)
996 		goto bad;
997 
998 	error = (*tp->t_linesw->l_open)(dev, tp);
999 	if (error)
1000 		goto bad;
1001 
1002 	return (0);
1003 
1004 bad:
1005 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1006 		/*
1007 		 * We failed to open the device, and nobody else had it opened.
1008 		 * Clean up the state as appropriate.
1009 		 */
1010 		com_shutdown(sc);
1011 	}
1012 
1013 	return (error);
1014 }
1015 
1016 int
1017 comclose(dev_t dev, int flag, int mode, struct lwp *l)
1018 {
1019 	struct com_softc *sc =
1020 	    device_lookup_private(&com_cd, COMUNIT(dev));
1021 	struct tty *tp = sc->sc_tty;
1022 
1023 	/* XXX This is for cons.c. */
1024 	if (!ISSET(tp->t_state, TS_ISOPEN))
1025 		return (0);
1026 	/*
1027 	 * If the device is exclusively for kernel use, deny userland
1028 	 * close.
1029 	 */
1030 	if (ISSET(tp->t_state, TS_KERN_ONLY))
1031 		return (0);
1032 
1033 	(*tp->t_linesw->l_close)(tp, flag);
1034 	ttyclose(tp);
1035 
1036 	if (COM_ISALIVE(sc) == 0)
1037 		return (0);
1038 
1039 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1040 		/*
1041 		 * Although we got a last close, the device may still be in
1042 		 * use; e.g. if this was the dialout node, and there are still
1043 		 * processes waiting for carrier on the non-dialout node.
1044 		 */
1045 		com_shutdown(sc);
1046 	}
1047 
1048 	return (0);
1049 }
1050 
1051 int
1052 comread(dev_t dev, struct uio *uio, int flag)
1053 {
1054 	struct com_softc *sc =
1055 	    device_lookup_private(&com_cd, COMUNIT(dev));
1056 	struct tty *tp = sc->sc_tty;
1057 
1058 	if (COM_ISALIVE(sc) == 0)
1059 		return (EIO);
1060 
1061 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
1062 }
1063 
1064 int
1065 comwrite(dev_t dev, struct uio *uio, int flag)
1066 {
1067 	struct com_softc *sc =
1068 	    device_lookup_private(&com_cd, COMUNIT(dev));
1069 	struct tty *tp = sc->sc_tty;
1070 
1071 	if (COM_ISALIVE(sc) == 0)
1072 		return (EIO);
1073 
1074 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
1075 }
1076 
1077 int
1078 compoll(dev_t dev, int events, struct lwp *l)
1079 {
1080 	struct com_softc *sc =
1081 	    device_lookup_private(&com_cd, COMUNIT(dev));
1082 	struct tty *tp = sc->sc_tty;
1083 
1084 	if (COM_ISALIVE(sc) == 0)
1085 		return (POLLHUP);
1086 
1087 	return ((*tp->t_linesw->l_poll)(tp, events, l));
1088 }
1089 
1090 struct tty *
1091 comtty(dev_t dev)
1092 {
1093 	struct com_softc *sc =
1094 	    device_lookup_private(&com_cd, COMUNIT(dev));
1095 	struct tty *tp = sc->sc_tty;
1096 
1097 	return (tp);
1098 }
1099 
1100 int
1101 comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1102 {
1103 	struct com_softc *sc;
1104 	struct tty *tp;
1105 	int error;
1106 
1107 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1108 	if (sc == NULL)
1109 		return ENXIO;
1110 	if (COM_ISALIVE(sc) == 0)
1111 		return (EIO);
1112 
1113 	tp = sc->sc_tty;
1114 
1115 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1116 	if (error != EPASSTHROUGH)
1117 		return (error);
1118 
1119 	error = ttioctl(tp, cmd, data, flag, l);
1120 	if (error != EPASSTHROUGH)
1121 		return (error);
1122 
1123 	error = 0;
1124 	switch (cmd) {
1125 	case TIOCSFLAGS:
1126 		error = kauth_authorize_device_tty(l->l_cred,
1127 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1128 		break;
1129 	default:
1130 		/* nothing */
1131 		break;
1132 	}
1133 	if (error) {
1134 		return error;
1135 	}
1136 
1137 	mutex_spin_enter(&sc->sc_lock);
1138 
1139 	switch (cmd) {
1140 	case TIOCSBRK:
1141 		com_break(sc, 1);
1142 		break;
1143 
1144 	case TIOCCBRK:
1145 		com_break(sc, 0);
1146 		break;
1147 
1148 	case TIOCSDTR:
1149 		com_modem(sc, 1);
1150 		break;
1151 
1152 	case TIOCCDTR:
1153 		com_modem(sc, 0);
1154 		break;
1155 
1156 	case TIOCGFLAGS:
1157 		*(int *)data = sc->sc_swflags;
1158 		break;
1159 
1160 	case TIOCSFLAGS:
1161 		sc->sc_swflags = *(int *)data;
1162 		break;
1163 
1164 	case TIOCMSET:
1165 	case TIOCMBIS:
1166 	case TIOCMBIC:
1167 		tiocm_to_com(sc, cmd, *(int *)data);
1168 		break;
1169 
1170 	case TIOCMGET:
1171 		*(int *)data = com_to_tiocm(sc);
1172 		break;
1173 
1174 	case PPS_IOC_CREATE:
1175 	case PPS_IOC_DESTROY:
1176 	case PPS_IOC_GETPARAMS:
1177 	case PPS_IOC_SETPARAMS:
1178 	case PPS_IOC_GETCAP:
1179 	case PPS_IOC_FETCH:
1180 #ifdef PPS_SYNC
1181 	case PPS_IOC_KCBIND:
1182 #endif
1183 		mutex_spin_enter(&timecounter_lock);
1184 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1185 		mutex_spin_exit(&timecounter_lock);
1186 		break;
1187 
1188 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1189 		mutex_spin_enter(&timecounter_lock);
1190 #ifndef PPS_TRAILING_EDGE
1191 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1192 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1193 #else
1194 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1195 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1196 #endif
1197 		mutex_spin_exit(&timecounter_lock);
1198 		break;
1199 
1200 	default:
1201 		error = EPASSTHROUGH;
1202 		break;
1203 	}
1204 
1205 	mutex_spin_exit(&sc->sc_lock);
1206 
1207 #ifdef COM_DEBUG
1208 	if (com_debug)
1209 		comstatus(sc, "comioctl ");
1210 #endif
1211 
1212 	return (error);
1213 }
1214 
1215 integrate void
1216 com_schedrx(struct com_softc *sc)
1217 {
1218 
1219 	sc->sc_rx_ready = 1;
1220 
1221 	/* Wake up the poller. */
1222 	softint_schedule(sc->sc_si);
1223 }
1224 
1225 void
1226 com_break(struct com_softc *sc, int onoff)
1227 {
1228 
1229 	if (onoff)
1230 		SET(sc->sc_lcr, LCR_SBREAK);
1231 	else
1232 		CLR(sc->sc_lcr, LCR_SBREAK);
1233 
1234 	if (!sc->sc_heldchange) {
1235 		if (sc->sc_tx_busy) {
1236 			sc->sc_heldtbc = sc->sc_tbc;
1237 			sc->sc_tbc = 0;
1238 			sc->sc_heldchange = 1;
1239 		} else
1240 			com_loadchannelregs(sc);
1241 	}
1242 }
1243 
1244 void
1245 com_modem(struct com_softc *sc, int onoff)
1246 {
1247 
1248 	if (sc->sc_mcr_dtr == 0)
1249 		return;
1250 
1251 	if (onoff)
1252 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1253 	else
1254 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1255 
1256 	if (!sc->sc_heldchange) {
1257 		if (sc->sc_tx_busy) {
1258 			sc->sc_heldtbc = sc->sc_tbc;
1259 			sc->sc_tbc = 0;
1260 			sc->sc_heldchange = 1;
1261 		} else
1262 			com_loadchannelregs(sc);
1263 	}
1264 }
1265 
1266 void
1267 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1268 {
1269 	u_char combits;
1270 
1271 	combits = 0;
1272 	if (ISSET(ttybits, TIOCM_DTR))
1273 		SET(combits, MCR_DTR);
1274 	if (ISSET(ttybits, TIOCM_RTS))
1275 		SET(combits, MCR_RTS);
1276 
1277 	switch (how) {
1278 	case TIOCMBIC:
1279 		CLR(sc->sc_mcr, combits);
1280 		break;
1281 
1282 	case TIOCMBIS:
1283 		SET(sc->sc_mcr, combits);
1284 		break;
1285 
1286 	case TIOCMSET:
1287 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1288 		SET(sc->sc_mcr, combits);
1289 		break;
1290 	}
1291 
1292 	if (!sc->sc_heldchange) {
1293 		if (sc->sc_tx_busy) {
1294 			sc->sc_heldtbc = sc->sc_tbc;
1295 			sc->sc_tbc = 0;
1296 			sc->sc_heldchange = 1;
1297 		} else
1298 			com_loadchannelregs(sc);
1299 	}
1300 }
1301 
1302 int
1303 com_to_tiocm(struct com_softc *sc)
1304 {
1305 	u_char combits;
1306 	int ttybits = 0;
1307 
1308 	combits = sc->sc_mcr;
1309 	if (ISSET(combits, MCR_DTR))
1310 		SET(ttybits, TIOCM_DTR);
1311 	if (ISSET(combits, MCR_RTS))
1312 		SET(ttybits, TIOCM_RTS);
1313 
1314 	combits = sc->sc_msr;
1315 	if (sc->sc_type == COM_TYPE_INGENIC) {
1316 		SET(ttybits, TIOCM_CD);
1317 	} else {
1318 		if (ISSET(combits, MSR_DCD))
1319 			SET(ttybits, TIOCM_CD);
1320 	}
1321 	if (ISSET(combits, MSR_CTS))
1322 		SET(ttybits, TIOCM_CTS);
1323 	if (ISSET(combits, MSR_DSR))
1324 		SET(ttybits, TIOCM_DSR);
1325 	if (ISSET(combits, MSR_RI | MSR_TERI))
1326 		SET(ttybits, TIOCM_RI);
1327 
1328 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1329 		SET(ttybits, TIOCM_LE);
1330 
1331 	return (ttybits);
1332 }
1333 
1334 static u_char
1335 cflag2lcr(tcflag_t cflag)
1336 {
1337 	u_char lcr = 0;
1338 
1339 	switch (ISSET(cflag, CSIZE)) {
1340 	case CS5:
1341 		SET(lcr, LCR_5BITS);
1342 		break;
1343 	case CS6:
1344 		SET(lcr, LCR_6BITS);
1345 		break;
1346 	case CS7:
1347 		SET(lcr, LCR_7BITS);
1348 		break;
1349 	case CS8:
1350 		SET(lcr, LCR_8BITS);
1351 		break;
1352 	}
1353 	if (ISSET(cflag, PARENB)) {
1354 		SET(lcr, LCR_PENAB);
1355 		if (!ISSET(cflag, PARODD))
1356 			SET(lcr, LCR_PEVEN);
1357 	}
1358 	if (ISSET(cflag, CSTOPB))
1359 		SET(lcr, LCR_STOPB);
1360 
1361 	return (lcr);
1362 }
1363 
1364 int
1365 comparam(struct tty *tp, struct termios *t)
1366 {
1367 	struct com_softc *sc =
1368 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1369 	int ospeed;
1370 	u_char lcr;
1371 
1372 	if (COM_ISALIVE(sc) == 0)
1373 		return (EIO);
1374 
1375 	if (sc->sc_type == COM_TYPE_HAYESP) {
1376 		int prescaler, speed;
1377 
1378 		/*
1379 		 * Calculate UART clock prescaler.  It should be in
1380 		 * range of 0 .. 3.
1381 		 */
1382 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1383 		    prescaler++, speed /= 2)
1384 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1385 					       sc->sc_type)) > 0)
1386 				break;
1387 
1388 		if (prescaler == 4)
1389 			return (EINVAL);
1390 		sc->sc_prescaler = prescaler;
1391 	} else
1392 		ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1393 
1394 	/* Check requested parameters. */
1395 	if (ospeed < 0)
1396 		return (EINVAL);
1397 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1398 		return (EINVAL);
1399 
1400 	/*
1401 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1402 	 * is always active.
1403 	 */
1404 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1405 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1406 		SET(t->c_cflag, CLOCAL);
1407 		CLR(t->c_cflag, HUPCL);
1408 	}
1409 
1410 	/*
1411 	 * If there were no changes, don't do anything.  This avoids dropping
1412 	 * input and improves performance when all we did was frob things like
1413 	 * VMIN and VTIME.
1414 	 */
1415 	if (tp->t_ospeed == t->c_ospeed &&
1416 	    tp->t_cflag == t->c_cflag)
1417 		return (0);
1418 
1419 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1420 
1421 	mutex_spin_enter(&sc->sc_lock);
1422 
1423 	sc->sc_lcr = lcr;
1424 
1425 	/*
1426 	 * If we're not in a mode that assumes a connection is present, then
1427 	 * ignore carrier changes.
1428 	 */
1429 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1430 		sc->sc_msr_dcd = 0;
1431 	else
1432 		sc->sc_msr_dcd = MSR_DCD;
1433 	/*
1434 	 * Set the flow control pins depending on the current flow control
1435 	 * mode.
1436 	 */
1437 	if (ISSET(t->c_cflag, CRTSCTS)) {
1438 		sc->sc_mcr_dtr = MCR_DTR;
1439 		sc->sc_mcr_rts = MCR_RTS;
1440 		sc->sc_msr_cts = MSR_CTS;
1441 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1442 			SET(sc->sc_mcr, MCR_AFE);
1443 		} else {
1444 			sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1445 		}
1446 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1447 		/*
1448 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1449 		 * carrier detection.
1450 		 */
1451 		sc->sc_mcr_dtr = 0;
1452 		sc->sc_mcr_rts = MCR_DTR;
1453 		sc->sc_msr_cts = MSR_DCD;
1454 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1455 			CLR(sc->sc_mcr, MCR_AFE);
1456 		} else {
1457 			sc->sc_efr = 0;
1458 		}
1459 	} else {
1460 		/*
1461 		 * If no flow control, then always set RTS.  This will make
1462 		 * the other side happy if it mistakenly thinks we're doing
1463 		 * RTS/CTS flow control.
1464 		 */
1465 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1466 		sc->sc_mcr_rts = 0;
1467 		sc->sc_msr_cts = 0;
1468 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1469 			CLR(sc->sc_mcr, MCR_AFE);
1470 		} else {
1471 			sc->sc_efr = 0;
1472 		}
1473 		if (ISSET(sc->sc_mcr, MCR_DTR))
1474 			SET(sc->sc_mcr, MCR_RTS);
1475 		else
1476 			CLR(sc->sc_mcr, MCR_RTS);
1477 	}
1478 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1479 
1480 	if (t->c_ospeed == 0 && tp->t_ospeed != 0)
1481 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1482 	else if (t->c_ospeed != 0 && tp->t_ospeed == 0)
1483 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1484 
1485 	sc->sc_dlbl = ospeed;
1486 	sc->sc_dlbh = ospeed >> 8;
1487 
1488 	/*
1489 	 * Set the FIFO threshold based on the receive speed.
1490 	 *
1491 	 *  * If it's a low speed, it's probably a mouse or some other
1492 	 *    interactive device, so set the threshold low.
1493 	 *  * If it's a high speed, trim the trigger level down to prevent
1494 	 *    overflows.
1495 	 *  * Otherwise set it a bit higher.
1496 	 */
1497 	if (sc->sc_type == COM_TYPE_HAYESP) {
1498 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1499 	} else if (sc->sc_type == COM_TYPE_TEGRA) {
1500 		sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1501 	} else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1502 		if (t->c_ospeed <= 1200)
1503 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1504 		else if (t->c_ospeed <= 38400)
1505 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1506 		else
1507 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1508 	} else {
1509 		sc->sc_fifo = 0;
1510 	}
1511 
1512 	if (sc->sc_type == COM_TYPE_INGENIC)
1513 		sc->sc_fifo |= FIFO_UART_ON;
1514 
1515 	/* And copy to tty. */
1516 	tp->t_ispeed = t->c_ospeed;
1517 	tp->t_ospeed = t->c_ospeed;
1518 	tp->t_cflag = t->c_cflag;
1519 
1520 	if (!sc->sc_heldchange) {
1521 		if (sc->sc_tx_busy) {
1522 			sc->sc_heldtbc = sc->sc_tbc;
1523 			sc->sc_tbc = 0;
1524 			sc->sc_heldchange = 1;
1525 		} else
1526 			com_loadchannelregs(sc);
1527 	}
1528 
1529 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1530 		/* Disable the high water mark. */
1531 		sc->sc_r_hiwat = 0;
1532 		sc->sc_r_lowat = 0;
1533 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1534 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1535 			com_schedrx(sc);
1536 		}
1537 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1538 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1539 			com_hwiflow(sc);
1540 		}
1541 	} else {
1542 		sc->sc_r_hiwat = com_rbuf_hiwat;
1543 		sc->sc_r_lowat = com_rbuf_lowat;
1544 	}
1545 
1546 	mutex_spin_exit(&sc->sc_lock);
1547 
1548 	/*
1549 	 * Update the tty layer's idea of the carrier bit, in case we changed
1550 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1551 	 * explicit request.
1552 	 */
1553 	if (sc->sc_type == COM_TYPE_INGENIC) {
1554 		/* no DCD here */
1555 		(void) (*tp->t_linesw->l_modem)(tp, 1);
1556 	} else
1557 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1558 
1559 #ifdef COM_DEBUG
1560 	if (com_debug)
1561 		comstatus(sc, "comparam ");
1562 #endif
1563 
1564 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1565 		if (sc->sc_tx_stopped) {
1566 			sc->sc_tx_stopped = 0;
1567 			comstart(tp);
1568 		}
1569 	}
1570 
1571 	return (0);
1572 }
1573 
1574 void
1575 com_iflush(struct com_softc *sc)
1576 {
1577 	struct com_regs	*regsp = &sc->sc_regs;
1578 	uint8_t fifo;
1579 #ifdef DIAGNOSTIC
1580 	int reg;
1581 #endif
1582 	int timo;
1583 
1584 #ifdef DIAGNOSTIC
1585 	reg = 0xffff;
1586 #endif
1587 	timo = 50000;
1588 	/* flush any pending I/O */
1589 	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1590 	    && --timo)
1591 #ifdef DIAGNOSTIC
1592 		reg =
1593 #else
1594 		    (void)
1595 #endif
1596 		    CSR_READ_1(regsp, COM_REG_RXDATA);
1597 #ifdef DIAGNOSTIC
1598 	if (!timo)
1599 		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1600 #endif
1601 
1602 	switch (sc->sc_type) {
1603 	case COM_TYPE_16750:
1604 	case COM_TYPE_DW_APB:
1605 		/*
1606 		 * Reset all Rx/Tx FIFO, preserve current FIFO length.
1607 		 * This should prevent triggering busy interrupt while
1608 		 * manipulating divisors.
1609 		 */
1610 		fifo = CSR_READ_1(regsp, COM_REG_FIFO) & (FIFO_TRIGGER_1 |
1611 		    FIFO_TRIGGER_4 | FIFO_TRIGGER_8 | FIFO_TRIGGER_14);
1612 		CSR_WRITE_1(regsp, COM_REG_FIFO,
1613 		    fifo | FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST);
1614 		delay(100);
1615 		break;
1616 	}
1617 }
1618 
1619 void
1620 com_loadchannelregs(struct com_softc *sc)
1621 {
1622 	struct com_regs *regsp = &sc->sc_regs;
1623 
1624 	/* XXXXX necessary? */
1625 	com_iflush(sc);
1626 
1627 	if (sc->sc_type == COM_TYPE_PXA2x0)
1628 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1629 	else
1630 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1631 
1632 	if (sc->sc_type == COM_TYPE_OMAP) {
1633 		/* disable before changing settings */
1634 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
1635 	}
1636 
1637 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1638 		KASSERT(sc->sc_type != COM_TYPE_AU1x00);
1639 		KASSERT(sc->sc_type != COM_TYPE_16550_NOERS);
1640 		/* no EFR on alchemy */
1641 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1642 		CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1643 	}
1644 	if (sc->sc_type == COM_TYPE_AU1x00) {
1645 		/* alchemy has single separate 16-bit clock divisor register */
1646 		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1647 		    (sc->sc_dlbh << 8));
1648 	} else {
1649 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1650 		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1651 		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1652 	}
1653 	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1654 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1655 	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1656 	if (sc->sc_type == COM_TYPE_HAYESP) {
1657 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1658 		    HAYESP_SETPRESCALER);
1659 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1660 		    sc->sc_prescaler);
1661 	}
1662 	if (sc->sc_type == COM_TYPE_OMAP) {
1663 		/* setup the fifos.  the FCR value is not used as long
1664 		   as SCR[6] and SCR[7] are 0, which they are at reset
1665 		   and we never touch the SCR register */
1666 		uint8_t rx_fifo_trig = 40;
1667 		uint8_t tx_fifo_trig = 60;
1668 		uint8_t rx_start = 8;
1669 		uint8_t rx_halt = 60;
1670 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
1671 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
1672 
1673 		/* enable access to TCR & TLR */
1674 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr | MCR_TCR_TLR);
1675 
1676 		/* write tcr and tlr values */
1677 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
1678 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
1679 
1680 		/* disable access to TCR & TLR */
1681 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr);
1682 
1683 		/* enable again, but mode is based on speed */
1684 		if (sc->sc_tty->t_termios.c_ospeed > 230400) {
1685 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
1686 		} else {
1687 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
1688 		}
1689 	}
1690 
1691 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1692 }
1693 
1694 int
1695 comhwiflow(struct tty *tp, int block)
1696 {
1697 	struct com_softc *sc =
1698 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1699 
1700 	if (COM_ISALIVE(sc) == 0)
1701 		return (0);
1702 
1703 	if (sc->sc_mcr_rts == 0)
1704 		return (0);
1705 
1706 	mutex_spin_enter(&sc->sc_lock);
1707 
1708 	if (block) {
1709 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1710 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1711 			com_hwiflow(sc);
1712 		}
1713 	} else {
1714 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1715 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1716 			com_schedrx(sc);
1717 		}
1718 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1719 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1720 			com_hwiflow(sc);
1721 		}
1722 	}
1723 
1724 	mutex_spin_exit(&sc->sc_lock);
1725 	return (1);
1726 }
1727 
1728 /*
1729  * (un)block input via hw flowcontrol
1730  */
1731 void
1732 com_hwiflow(struct com_softc *sc)
1733 {
1734 	struct com_regs *regsp= &sc->sc_regs;
1735 
1736 	if (sc->sc_mcr_rts == 0)
1737 		return;
1738 
1739 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1740 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1741 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1742 	} else {
1743 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1744 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1745 	}
1746 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1747 }
1748 
1749 
1750 void
1751 comstart(struct tty *tp)
1752 {
1753 	struct com_softc *sc =
1754 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1755 	struct com_regs *regsp = &sc->sc_regs;
1756 	int s;
1757 
1758 	if (COM_ISALIVE(sc) == 0)
1759 		return;
1760 
1761 	s = spltty();
1762 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1763 		goto out;
1764 	if (sc->sc_tx_stopped)
1765 		goto out;
1766 	if (!ttypull(tp))
1767 		goto out;
1768 
1769 	/* Grab the first contiguous region of buffer space. */
1770 	{
1771 		u_char *tba;
1772 		int tbc;
1773 
1774 		tba = tp->t_outq.c_cf;
1775 		tbc = ndqb(&tp->t_outq, 0);
1776 
1777 		mutex_spin_enter(&sc->sc_lock);
1778 
1779 		sc->sc_tba = tba;
1780 		sc->sc_tbc = tbc;
1781 	}
1782 
1783 	SET(tp->t_state, TS_BUSY);
1784 	sc->sc_tx_busy = 1;
1785 
1786 	/* Enable transmit completion interrupts if necessary. */
1787 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1788 		SET(sc->sc_ier, IER_ETXRDY);
1789 		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1790 	}
1791 
1792 	/* Output the first chunk of the contiguous buffer. */
1793 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1794 		u_int n;
1795 
1796 		n = sc->sc_tbc;
1797 		if (n > sc->sc_fifolen)
1798 			n = sc->sc_fifolen;
1799 		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1800 		sc->sc_tbc -= n;
1801 		sc->sc_tba += n;
1802 	}
1803 
1804 	mutex_spin_exit(&sc->sc_lock);
1805 out:
1806 	splx(s);
1807 	return;
1808 }
1809 
1810 /*
1811  * Stop output on a line.
1812  */
1813 void
1814 comstop(struct tty *tp, int flag)
1815 {
1816 	struct com_softc *sc =
1817 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1818 
1819 	mutex_spin_enter(&sc->sc_lock);
1820 	if (ISSET(tp->t_state, TS_BUSY)) {
1821 		/* Stop transmitting at the next chunk. */
1822 		sc->sc_tbc = 0;
1823 		sc->sc_heldtbc = 0;
1824 		if (!ISSET(tp->t_state, TS_TTSTOP))
1825 			SET(tp->t_state, TS_FLUSH);
1826 	}
1827 	mutex_spin_exit(&sc->sc_lock);
1828 }
1829 
1830 void
1831 comdiag(void *arg)
1832 {
1833 	struct com_softc *sc = arg;
1834 	int overflows, floods;
1835 
1836 	mutex_spin_enter(&sc->sc_lock);
1837 	overflows = sc->sc_overflows;
1838 	sc->sc_overflows = 0;
1839 	floods = sc->sc_floods;
1840 	sc->sc_floods = 0;
1841 	sc->sc_errors = 0;
1842 	mutex_spin_exit(&sc->sc_lock);
1843 
1844 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1845 	    device_xname(sc->sc_dev),
1846 	    overflows, overflows == 1 ? "" : "s",
1847 	    floods, floods == 1 ? "" : "s");
1848 }
1849 
1850 integrate void
1851 com_rxsoft(struct com_softc *sc, struct tty *tp)
1852 {
1853 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1854 	u_char *get, *end;
1855 	u_int cc, scc;
1856 	u_char lsr;
1857 	int code;
1858 
1859 	end = sc->sc_ebuf;
1860 	get = sc->sc_rbget;
1861 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1862 
1863 	if (cc == com_rbuf_size) {
1864 		sc->sc_floods++;
1865 		if (sc->sc_errors++ == 0)
1866 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1867 			    comdiag, sc);
1868 	}
1869 
1870 	/* If not yet open, drop the entire buffer content here */
1871 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1872 		get += cc << 1;
1873 		if (get >= end)
1874 			get -= com_rbuf_size << 1;
1875 		cc = 0;
1876 	}
1877 	while (cc) {
1878 		code = get[0];
1879 		lsr = get[1];
1880 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1881 			if (ISSET(lsr, LSR_OE)) {
1882 				sc->sc_overflows++;
1883 				if (sc->sc_errors++ == 0)
1884 					callout_reset(&sc->sc_diag_callout,
1885 					    60 * hz, comdiag, sc);
1886 			}
1887 			if (ISSET(lsr, LSR_BI | LSR_FE))
1888 				SET(code, TTY_FE);
1889 			if (ISSET(lsr, LSR_PE))
1890 				SET(code, TTY_PE);
1891 		}
1892 		if ((*rint)(code, tp) == -1) {
1893 			/*
1894 			 * The line discipline's buffer is out of space.
1895 			 */
1896 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1897 				/*
1898 				 * We're either not using flow control, or the
1899 				 * line discipline didn't tell us to block for
1900 				 * some reason.  Either way, we have no way to
1901 				 * know when there's more space available, so
1902 				 * just drop the rest of the data.
1903 				 */
1904 				get += cc << 1;
1905 				if (get >= end)
1906 					get -= com_rbuf_size << 1;
1907 				cc = 0;
1908 			} else {
1909 				/*
1910 				 * Don't schedule any more receive processing
1911 				 * until the line discipline tells us there's
1912 				 * space available (through comhwiflow()).
1913 				 * Leave the rest of the data in the input
1914 				 * buffer.
1915 				 */
1916 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1917 			}
1918 			break;
1919 		}
1920 		get += 2;
1921 		if (get >= end)
1922 			get = sc->sc_rbuf;
1923 		cc--;
1924 	}
1925 
1926 	if (cc != scc) {
1927 		sc->sc_rbget = get;
1928 		mutex_spin_enter(&sc->sc_lock);
1929 
1930 		cc = sc->sc_rbavail += scc - cc;
1931 		/* Buffers should be ok again, release possible block. */
1932 		if (cc >= sc->sc_r_lowat) {
1933 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1934 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1935 				SET(sc->sc_ier, IER_ERXRDY);
1936 				if (sc->sc_type == COM_TYPE_PXA2x0)
1937 					SET(sc->sc_ier, IER_ERXTOUT);
1938 				if (sc->sc_type == COM_TYPE_INGENIC ||
1939 				    sc->sc_type == COM_TYPE_TEGRA)
1940 					SET(sc->sc_ier, IER_ERXTOUT);
1941 
1942 				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER,
1943 				    sc->sc_ier);
1944 			}
1945 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1946 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1947 				com_hwiflow(sc);
1948 			}
1949 		}
1950 		mutex_spin_exit(&sc->sc_lock);
1951 	}
1952 }
1953 
1954 integrate void
1955 com_txsoft(struct com_softc *sc, struct tty *tp)
1956 {
1957 
1958 	CLR(tp->t_state, TS_BUSY);
1959 	if (ISSET(tp->t_state, TS_FLUSH))
1960 		CLR(tp->t_state, TS_FLUSH);
1961 	else
1962 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1963 	(*tp->t_linesw->l_start)(tp);
1964 }
1965 
1966 integrate void
1967 com_stsoft(struct com_softc *sc, struct tty *tp)
1968 {
1969 	u_char msr, delta;
1970 
1971 	mutex_spin_enter(&sc->sc_lock);
1972 	msr = sc->sc_msr;
1973 	delta = sc->sc_msr_delta;
1974 	sc->sc_msr_delta = 0;
1975 	mutex_spin_exit(&sc->sc_lock);
1976 
1977 	if (ISSET(delta, sc->sc_msr_dcd)) {
1978 		/*
1979 		 * Inform the tty layer that carrier detect changed.
1980 		 */
1981 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1982 	}
1983 
1984 	if (ISSET(delta, sc->sc_msr_cts)) {
1985 		/* Block or unblock output according to flow control. */
1986 		if (ISSET(msr, sc->sc_msr_cts)) {
1987 			sc->sc_tx_stopped = 0;
1988 			(*tp->t_linesw->l_start)(tp);
1989 		} else {
1990 			sc->sc_tx_stopped = 1;
1991 		}
1992 	}
1993 
1994 #ifdef COM_DEBUG
1995 	if (com_debug)
1996 		comstatus(sc, "com_stsoft");
1997 #endif
1998 }
1999 
2000 void
2001 comsoft(void *arg)
2002 {
2003 	struct com_softc *sc = arg;
2004 	struct tty *tp;
2005 
2006 	if (COM_ISALIVE(sc) == 0)
2007 		return;
2008 
2009 	tp = sc->sc_tty;
2010 
2011 	if (sc->sc_rx_ready) {
2012 		sc->sc_rx_ready = 0;
2013 		com_rxsoft(sc, tp);
2014 	}
2015 
2016 	if (sc->sc_st_check) {
2017 		sc->sc_st_check = 0;
2018 		com_stsoft(sc, tp);
2019 	}
2020 
2021 	if (sc->sc_tx_done) {
2022 		sc->sc_tx_done = 0;
2023 		com_txsoft(sc, tp);
2024 	}
2025 }
2026 
2027 int
2028 comintr(void *arg)
2029 {
2030 	struct com_softc *sc = arg;
2031 	struct com_regs *regsp = &sc->sc_regs;
2032 
2033 	u_char *put, *end;
2034 	u_int cc;
2035 	u_char lsr, iir;
2036 
2037 	if (COM_ISALIVE(sc) == 0)
2038 		return (0);
2039 
2040 	KASSERT(regsp != NULL);
2041 
2042 	mutex_spin_enter(&sc->sc_lock);
2043 	iir = CSR_READ_1(regsp, COM_REG_IIR);
2044 
2045 	/* Handle ns16750-specific busy interrupt. */
2046 	if (sc->sc_type == COM_TYPE_16750 &&
2047 	    (iir & IIR_BUSY) == IIR_BUSY) {
2048 		for (int timeout = 10000;
2049 		    (CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0; timeout--)
2050 			if (timeout <= 0) {
2051 				aprint_error_dev(sc->sc_dev,
2052 				    "timeout while waiting for BUSY interrupt "
2053 				    "acknowledge\n");
2054 				mutex_spin_exit(&sc->sc_lock);
2055 				return (0);
2056 			}
2057 
2058 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2059 		iir = CSR_READ_1(regsp, COM_REG_IIR);
2060 	}
2061 
2062 	/* DesignWare APB UART BUSY interrupt */
2063 	if (sc->sc_type == COM_TYPE_DW_APB &&
2064 	    (iir & IIR_BUSY) == IIR_BUSY) {
2065 		if ((CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0) {
2066 			CSR_WRITE_1(regsp, COM_REG_HALT, HALT_CHCFG_EN);
2067 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2068 			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2069 			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2070 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2071 			CSR_WRITE_1(regsp, COM_REG_HALT,
2072 			    HALT_CHCFG_EN | HALT_CHCFG_UD);
2073 			for (int timeout = 10000000;
2074 			    (CSR_READ_1(regsp, COM_REG_HALT) & HALT_CHCFG_UD) != 0;
2075 			    timeout--) {
2076 				if (timeout <= 0) {
2077 					aprint_error_dev(sc->sc_dev,
2078 					    "timeout while waiting for HALT "
2079 					    "update acknowledge 0x%x 0x%x\n",
2080 					    CSR_READ_1(regsp, COM_REG_HALT),
2081 					    CSR_READ_1(regsp, COM_REG_USR));
2082 					break;
2083 				}
2084 			}
2085 			CSR_WRITE_1(regsp, COM_REG_HALT, 0);
2086 			(void)CSR_READ_1(regsp, COM_REG_USR);
2087 		} else {
2088 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2089 			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2090 			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2091 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2092 		}
2093 	}
2094 
2095 	if (ISSET(iir, IIR_NOPEND)) {
2096 		mutex_spin_exit(&sc->sc_lock);
2097 		return (0);
2098 	}
2099 
2100 	end = sc->sc_ebuf;
2101 	put = sc->sc_rbput;
2102 	cc = sc->sc_rbavail;
2103 
2104 again:	do {
2105 		u_char	msr, delta;
2106 
2107 		lsr = CSR_READ_1(regsp, COM_REG_LSR);
2108 		if (ISSET(lsr, LSR_BI)) {
2109 			int cn_trapped = 0; /* see above: cn_trap() */
2110 
2111 			cn_check_magic(sc->sc_tty->t_dev,
2112 				       CNC_BREAK, com_cnm_state);
2113 			if (cn_trapped)
2114 				continue;
2115 #if defined(KGDB) && !defined(DDB)
2116 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2117 				kgdb_connect(1);
2118 				continue;
2119 			}
2120 #endif
2121 		}
2122 
2123 		if (sc->sc_type == COM_TYPE_BCMAUXUART && ISSET(iir, IIR_RXRDY))
2124 			lsr |= LSR_RXRDY;
2125 
2126 		if (ISSET(lsr, LSR_RCV_MASK) &&
2127 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2128 			while (cc > 0) {
2129 				int cn_trapped = 0;
2130 				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
2131 				put[1] = lsr;
2132 				cn_check_magic(sc->sc_tty->t_dev,
2133 					       put[0], com_cnm_state);
2134 				if (cn_trapped)
2135 					goto next;
2136 				put += 2;
2137 				if (put >= end)
2138 					put = sc->sc_rbuf;
2139 				cc--;
2140 			next:
2141 				lsr = CSR_READ_1(regsp, COM_REG_LSR);
2142 				if (!ISSET(lsr, LSR_RCV_MASK))
2143 					break;
2144 			}
2145 
2146 			/*
2147 			 * Current string of incoming characters ended because
2148 			 * no more data was available or we ran out of space.
2149 			 * Schedule a receive event if any data was received.
2150 			 * If we're out of space, turn off receive interrupts.
2151 			 */
2152 			sc->sc_rbput = put;
2153 			sc->sc_rbavail = cc;
2154 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2155 				sc->sc_rx_ready = 1;
2156 
2157 			/*
2158 			 * See if we are in danger of overflowing a buffer. If
2159 			 * so, use hardware flow control to ease the pressure.
2160 			 */
2161 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2162 			    cc < sc->sc_r_hiwat) {
2163 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2164 				com_hwiflow(sc);
2165 			}
2166 
2167 			/*
2168 			 * If we're out of space, disable receive interrupts
2169 			 * until the queue has drained a bit.
2170 			 */
2171 			if (!cc) {
2172 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2173 				switch (sc->sc_type) {
2174 				case COM_TYPE_PXA2x0:
2175 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
2176 					break;
2177 				case COM_TYPE_INGENIC:
2178 				case COM_TYPE_TEGRA:
2179 					CLR(sc->sc_ier,
2180 					    IER_ERXRDY | IER_ERXTOUT);
2181 					break;
2182 				default:
2183 					CLR(sc->sc_ier, IER_ERXRDY);
2184 					break;
2185 				}
2186 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2187 			}
2188 		} else {
2189 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
2190 				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
2191 				continue;
2192 			}
2193 		}
2194 
2195 		msr = CSR_READ_1(regsp, COM_REG_MSR);
2196 		delta = msr ^ sc->sc_msr;
2197 		sc->sc_msr = msr;
2198 		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
2199 		    (delta & MSR_DCD)) {
2200 			mutex_spin_enter(&timecounter_lock);
2201 			pps_capture(&sc->sc_pps_state);
2202 			pps_event(&sc->sc_pps_state,
2203 			    (msr & MSR_DCD) ?
2204 			    PPS_CAPTUREASSERT :
2205 			    PPS_CAPTURECLEAR);
2206 			mutex_spin_exit(&timecounter_lock);
2207 		}
2208 
2209 		/*
2210 		 * Process normal status changes
2211 		 */
2212 		if (ISSET(delta, sc->sc_msr_mask)) {
2213 			SET(sc->sc_msr_delta, delta);
2214 
2215 			/*
2216 			 * Stop output immediately if we lose the output
2217 			 * flow control signal or carrier detect.
2218 			 */
2219 			if (ISSET(~msr, sc->sc_msr_mask)) {
2220 				sc->sc_tbc = 0;
2221 				sc->sc_heldtbc = 0;
2222 #ifdef COM_DEBUG
2223 				if (com_debug)
2224 					comstatus(sc, "comintr  ");
2225 #endif
2226 			}
2227 
2228 			sc->sc_st_check = 1;
2229 		}
2230 	} while (!ISSET((iir =
2231 	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
2232 	    /*
2233 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
2234 	     * by IIR read, so we can't do this way: `process all interrupts,
2235 	     * then do TX if possible'.
2236 	     */
2237 	    (iir & IIR_IMASK) != IIR_TXRDY);
2238 
2239 	/*
2240 	 * Read LSR again, since there may be an interrupt between
2241 	 * the last LSR read and IIR read above.
2242 	 */
2243 	lsr = CSR_READ_1(regsp, COM_REG_LSR);
2244 
2245 	/*
2246 	 * See if data can be transmitted as well.
2247 	 * Schedule tx done event if no data left
2248 	 * and tty was marked busy.
2249 	 */
2250 	if (ISSET(lsr, LSR_TXRDY)) {
2251 		/*
2252 		 * If we've delayed a parameter change, do it now, and restart
2253 		 * output.
2254 		 */
2255 		if (sc->sc_heldchange) {
2256 			com_loadchannelregs(sc);
2257 			sc->sc_heldchange = 0;
2258 			sc->sc_tbc = sc->sc_heldtbc;
2259 			sc->sc_heldtbc = 0;
2260 		}
2261 
2262 		/* Output the next chunk of the contiguous buffer, if any. */
2263 		if (sc->sc_tbc > 0) {
2264 			u_int n;
2265 
2266 			n = sc->sc_tbc;
2267 			if (n > sc->sc_fifolen)
2268 				n = sc->sc_fifolen;
2269 			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
2270 			sc->sc_tbc -= n;
2271 			sc->sc_tba += n;
2272 		} else {
2273 			/* Disable transmit completion interrupts if necessary. */
2274 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2275 				CLR(sc->sc_ier, IER_ETXRDY);
2276 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2277 			}
2278 			if (sc->sc_tx_busy) {
2279 				sc->sc_tx_busy = 0;
2280 				sc->sc_tx_done = 1;
2281 			}
2282 		}
2283 	}
2284 
2285 	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
2286 		goto again;
2287 
2288 	mutex_spin_exit(&sc->sc_lock);
2289 
2290 	/* Wake up the poller. */
2291 	softint_schedule(sc->sc_si);
2292 
2293 #ifdef RND_COM
2294 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2295 #endif
2296 
2297 	return (1);
2298 }
2299 
2300 /*
2301  * The following functions are polled getc and putc routines, shared
2302  * by the console and kgdb glue.
2303  *
2304  * The read-ahead code is so that you can detect pending in-band
2305  * cn_magic in polled mode while doing output rather than having to
2306  * wait until the kernel decides it needs input.
2307  */
2308 
2309 #define MAX_READAHEAD	20
2310 static int com_readahead[MAX_READAHEAD];
2311 static int com_readaheadcount = 0;
2312 
2313 int
2314 com_common_getc(dev_t dev, struct com_regs *regsp)
2315 {
2316 	int s = splserial();
2317 	u_char stat, c;
2318 
2319 	/* got a character from reading things earlier */
2320 	if (com_readaheadcount > 0) {
2321 		int i;
2322 
2323 		c = com_readahead[0];
2324 		for (i = 1; i < com_readaheadcount; i++) {
2325 			com_readahead[i-1] = com_readahead[i];
2326 		}
2327 		com_readaheadcount--;
2328 		splx(s);
2329 		return (c);
2330 	}
2331 
2332 	/* don't block until a character becomes available */
2333 	if (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2334 		splx(s);
2335 		return -1;
2336 	}
2337 
2338 	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2339 	stat = CSR_READ_1(regsp, COM_REG_IIR);
2340 	{
2341 		int cn_trapped = 0;	/* required by cn_trap, see above */
2342 #ifdef DDB
2343 		extern int db_active;
2344 		if (!db_active)
2345 #endif
2346 			cn_check_magic(dev, c, com_cnm_state);
2347 	}
2348 	splx(s);
2349 	return (c);
2350 }
2351 
2352 static void
2353 com_common_putc(dev_t dev, struct com_regs *regsp, int c)
2354 {
2355 	int s = splserial();
2356 	int cin, stat, timo;
2357 
2358 	if (com_readaheadcount < MAX_READAHEAD
2359 	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2360 		int cn_trapped = 0;
2361 		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2362 		stat = CSR_READ_1(regsp, COM_REG_IIR);
2363 		cn_check_magic(dev, cin, com_cnm_state);
2364 		com_readahead[com_readaheadcount++] = cin;
2365 	}
2366 
2367 	/* wait for any pending transmission to finish */
2368 	timo = 150000;
2369 	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2370 		continue;
2371 
2372 	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2373 	COM_BARRIER(regsp, BR | BW);
2374 
2375 	splx(s);
2376 }
2377 
2378 /*
2379  * Initialize UART for use as console or KGDB line.
2380  */
2381 int
2382 cominit(struct com_regs *regsp, int rate, int frequency, int type,
2383     tcflag_t cflag)
2384 {
2385 
2386 	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2387 		&regsp->cr_ioh))
2388 		return (ENOMEM); /* ??? */
2389 
2390 	if (type == COM_TYPE_OMAP) {
2391 		/* disable before changing settings */
2392 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
2393 	}
2394 
2395 	rate = comspeed(rate, frequency, type);
2396 	if (__predict_true(rate != -1)) {
2397 		if (type == COM_TYPE_AU1x00) {
2398 			CSR_WRITE_2(regsp, COM_REG_DLBL, rate);
2399 		} else {
2400 			/* no EFR on alchemy */
2401 			if ((type != COM_TYPE_16550_NOERS) &&
2402 			    (type != COM_TYPE_INGENIC)) {
2403 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2404 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2405 			}
2406 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2407 			CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2408 			CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2409 		}
2410 	}
2411 	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2412 	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2413 
2414 	if (type == COM_TYPE_INGENIC) {
2415 		CSR_WRITE_1(regsp, COM_REG_FIFO,
2416 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2417 		    FIFO_TRIGGER_1 | FIFO_UART_ON);
2418 	} else {
2419 		CSR_WRITE_1(regsp, COM_REG_FIFO,
2420 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2421 		    FIFO_TRIGGER_1);
2422 	}
2423 
2424 	if (type == COM_TYPE_OMAP) {
2425 		/* setup the fifos.  the FCR value is not used as long
2426 		   as SCR[6] and SCR[7] are 0, which they are at reset
2427 		   and we never touch the SCR register */
2428 		uint8_t rx_fifo_trig = 40;
2429 		uint8_t tx_fifo_trig = 60;
2430 		uint8_t rx_start = 8;
2431 		uint8_t rx_halt = 60;
2432 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
2433 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
2434 
2435 		/* enable access to TCR & TLR */
2436 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS | MCR_TCR_TLR);
2437 
2438 		/* write tcr and tlr values */
2439 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
2440 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
2441 
2442 		/* disable access to TCR & TLR */
2443 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2444 
2445 		/* enable again, but mode is based on speed */
2446 		if (rate > 230400) {
2447 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
2448 		} else {
2449 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
2450 		}
2451 	}
2452 
2453 	if (type == COM_TYPE_PXA2x0)
2454 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2455 	else
2456 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2457 
2458 	return (0);
2459 }
2460 
2461 int
2462 comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2463     tcflag_t cflag)
2464 {
2465 	int res;
2466 
2467 	comcons_info.regs = *regsp;
2468 
2469 	res = cominit(&comcons_info.regs, rate, frequency, type, cflag);
2470 	if (res)
2471 		return (res);
2472 
2473 	cn_tab = &comcons;
2474 	cn_init_magic(&com_cnm_state);
2475 	cn_set_magic("\047\001"); /* default magic is BREAK */
2476 
2477 	comcons_info.frequency = frequency;
2478 	comcons_info.type = type;
2479 	comcons_info.rate = rate;
2480 	comcons_info.cflag = cflag;
2481 
2482 	return (0);
2483 }
2484 
2485 int
2486 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2487     int type, tcflag_t cflag)
2488 {
2489 	struct com_regs	regs;
2490 
2491 	memset(&regs, 0, sizeof regs);
2492 	regs.cr_iot = iot;
2493 	regs.cr_iobase = iobase;
2494 	regs.cr_nports = COM_NPORTS;
2495 #ifdef	COM_REGMAP
2496 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2497 #endif
2498 
2499 	return comcnattach1(&regs, rate, frequency, type, cflag);
2500 }
2501 
2502 static int
2503 comcnreattach(void)
2504 {
2505 	return comcnattach1(&comcons_info.regs, comcons_info.rate,
2506 	    comcons_info.frequency, comcons_info.type, comcons_info.cflag);
2507 }
2508 
2509 int
2510 comcngetc(dev_t dev)
2511 {
2512 
2513 	return (com_common_getc(dev, &comcons_info.regs));
2514 }
2515 
2516 /*
2517  * Console kernel output character routine.
2518  */
2519 void
2520 comcnputc(dev_t dev, int c)
2521 {
2522 
2523 	com_common_putc(dev, &comcons_info.regs, c);
2524 }
2525 
2526 void
2527 comcnpollc(dev_t dev, int on)
2528 {
2529 
2530 	com_readaheadcount = 0;
2531 }
2532 
2533 #ifdef KGDB
2534 int
2535 com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2536     tcflag_t cflag)
2537 {
2538 	int res;
2539 
2540 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
2541 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
2542 #if !defined(DDB)
2543 		return (EBUSY); /* cannot share with console */
2544 #else
2545 		comkgdbregs = *regsp;
2546 		comkgdbregs.cr_ioh = comcons_info.regs.cr_ioh;
2547 #endif
2548 	} else {
2549 		comkgdbregs = *regsp;
2550 		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2551 		if (res)
2552 			return (res);
2553 
2554 		/*
2555 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2556 		 * expects this to be initialized
2557 		 */
2558 		cn_init_magic(&com_cnm_state);
2559 		cn_set_magic("\047\001");
2560 	}
2561 
2562 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2563 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2564 
2565 	return (0);
2566 }
2567 
2568 int
2569 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2570     int frequency, int type, tcflag_t cflag)
2571 {
2572 	struct com_regs regs;
2573 
2574 	regs.cr_iot = iot;
2575 	regs.cr_nports = COM_NPORTS;
2576 	regs.cr_iobase = iobase;
2577 #ifdef COM_REGMAP
2578 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2579 #endif
2580 
2581 	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2582 }
2583 
2584 /* ARGSUSED */
2585 int
2586 com_kgdb_getc(void *arg)
2587 {
2588 
2589 	return (com_common_getc(NODEV, &comkgdbregs));
2590 }
2591 
2592 /* ARGSUSED */
2593 void
2594 com_kgdb_putc(void *arg, int c)
2595 {
2596 
2597 	com_common_putc(NODEV, &comkgdbregs, c);
2598 }
2599 #endif /* KGDB */
2600 
2601 /* helper function to identify the com ports used by
2602  console or KGDB (and not yet autoconf attached) */
2603 int
2604 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2605 {
2606 	bus_space_handle_t help;
2607 
2608 	if (!comconsattached &&
2609 	    bus_space_is_equal(iot, comcons_info.regs.cr_iot) &&
2610 	    iobase == comcons_info.regs.cr_iobase)
2611 		help = comcons_info.regs.cr_ioh;
2612 #ifdef KGDB
2613 	else if (!com_kgdb_attached &&
2614 	    bus_space_is_equal(iot, comkgdbregs.cr_iot) &&
2615 	    iobase == comkgdbregs.cr_iobase)
2616 		help = comkgdbregs.cr_ioh;
2617 #endif
2618 	else
2619 		return (0);
2620 
2621 	if (ioh)
2622 		*ioh = help;
2623 	return (1);
2624 }
2625 
2626 /*
2627  * this routine exists to serve as a shutdown hook for systems that
2628  * have firmware which doesn't interact properly with a com device in
2629  * FIFO mode.
2630  */
2631 bool
2632 com_cleanup(device_t self, int how)
2633 {
2634 	struct com_softc *sc = device_private(self);
2635 
2636 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2637 		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2638 
2639 	return true;
2640 }
2641 
2642 bool
2643 com_suspend(device_t self, const pmf_qual_t *qual)
2644 {
2645 	struct com_softc *sc = device_private(self);
2646 
2647 #if 0
2648 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) && cn_tab == &comcons)
2649 		cn_tab = &comcons_suspend;
2650 #endif
2651 
2652 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2653 	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2654 
2655 	return true;
2656 }
2657 
2658 bool
2659 com_resume(device_t self, const pmf_qual_t *qual)
2660 {
2661 	struct com_softc *sc = device_private(self);
2662 
2663 	mutex_spin_enter(&sc->sc_lock);
2664 	com_loadchannelregs(sc);
2665 	mutex_spin_exit(&sc->sc_lock);
2666 
2667 	return true;
2668 }
2669