xref: /netbsd-src/sys/dev/ic/com.c (revision 87d689fb734c654d2486f87f7be32f1b53ecdbec)
1 /* $NetBSD: com.c,v 1.346 2017/12/04 09:55:37 bouyer 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 1.346 2017/12/04 09:55:37 bouyer 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_AWIN)
404 	sc->sc_type = COM_TYPE_SUNXI;
405 #elif defined(COM_HAYESP)
406 	sc->sc_type = COM_TYPE_HAYESP;
407 #elif defined(COM_PXA2X0)
408 	sc->sc_type = COM_TYPE_PXA2x0;
409 #endif
410 
411 	/* Disable interrupts before configuring the device. */
412 	if (sc->sc_type == COM_TYPE_PXA2x0)
413 		sc->sc_ier = IER_EUART;
414 	else
415 		sc->sc_ier = 0;
416 
417 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
418 
419 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
420 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
421 		comconsattached = 1;
422 
423 		if (cn_tab == NULL && comcnreattach() != 0) {
424 			printf("can't re-init serial console @%lx\n",
425 			    (u_long)comcons_info.regs.cr_iobase);
426 		}
427 
428 		switch (sc->sc_type) {
429 		case COM_TYPE_16750:
430 		case COM_TYPE_SUNXI:
431 			/* Use in comintr(). */
432  			sc->sc_lcr = cflag2lcr(comcons_info.cflag);
433 			break;
434 		}
435 
436 		/* Make sure the console is always "hardwired". */
437 		delay(10000);			/* wait for output to finish */
438 		if (is_console) {
439 			SET(sc->sc_hwflags, COM_HW_CONSOLE);
440 		}
441 
442 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
443 	}
444 
445 	/* Probe for FIFO */
446 	switch (sc->sc_type) {
447 	case COM_TYPE_HAYESP:
448 		goto fifodone;
449 
450 	case COM_TYPE_AU1x00:
451 		sc->sc_fifolen = 16;
452 		fifo_msg = "Au1X00 UART, working fifo";
453 		SET(sc->sc_hwflags, COM_HW_FIFO);
454 		goto fifodelay;
455 
456 	case COM_TYPE_16550_NOERS:
457 		sc->sc_fifolen = 16;
458 		fifo_msg = "ns16650, no ERS, working fifo";
459 		SET(sc->sc_hwflags, COM_HW_FIFO);
460 		goto fifodelay;
461 
462 	case COM_TYPE_OMAP:
463 		sc->sc_fifolen = 64;
464 		fifo_msg = "OMAP UART, working fifo";
465 		SET(sc->sc_hwflags, COM_HW_FIFO);
466 		goto fifodelay;
467 
468 	case COM_TYPE_INGENIC:
469 		sc->sc_fifolen = 16;
470 		fifo_msg = "Ingenic UART, working fifo";
471 		SET(sc->sc_hwflags, COM_HW_FIFO);
472 		SET(sc->sc_hwflags, COM_HW_NOIEN);
473 		goto fifodelay;
474 
475 	case COM_TYPE_TEGRA:
476 		sc->sc_fifolen = 8;
477 		fifo_msg = "Tegra UART, working fifo";
478 		SET(sc->sc_hwflags, COM_HW_FIFO);
479 		CSR_WRITE_1(regsp, COM_REG_FIFO,
480 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
481 		goto fifodelay;
482 
483 	case COM_TYPE_BCMAUXUART:
484 		sc->sc_fifolen = 1;
485 		fifo_msg = "BCM AUX UART, working fifo";
486 		SET(sc->sc_hwflags, COM_HW_FIFO);
487 		CSR_WRITE_1(regsp, COM_REG_FIFO,
488 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
489 		goto fifodelay;
490 	}
491 
492 	sc->sc_fifolen = 1;
493 	/* look for a NS 16550AF UART with FIFOs */
494 	if (sc->sc_type == COM_TYPE_INGENIC) {
495 		CSR_WRITE_1(regsp, COM_REG_FIFO,
496 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
497 		    FIFO_TRIGGER_14 | FIFO_UART_ON);
498 	} else
499 		CSR_WRITE_1(regsp, COM_REG_FIFO,
500 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
501 	delay(100);
502 	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
503 	    == IIR_FIFO_MASK)
504 		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
505 		    == FIFO_TRIGGER_14) {
506 			SET(sc->sc_hwflags, COM_HW_FIFO);
507 
508 			fifo_msg = "ns16550a, working fifo";
509 
510 			/*
511 			 * IIR changes into the EFR if LCR is set to LCR_EERS
512 			 * on 16650s. We also know IIR != 0 at this point.
513 			 * Write 0 into the EFR, and read it. If the result
514 			 * is 0, we have a 16650.
515 			 *
516 			 * Older 16650s were broken; the test to detect them
517 			 * is taken from the Linux driver. Apparently
518 			 * setting DLAB enable gives access to the EFR on
519 			 * these chips.
520 			 */
521 			if (sc->sc_type == COM_TYPE_16650) {
522 				lcr = CSR_READ_1(regsp, COM_REG_LCR);
523 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
524 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
525 				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
526 					CSR_WRITE_1(regsp, COM_REG_LCR,
527 					    lcr | LCR_DLAB);
528 					if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
529 						CLR(sc->sc_hwflags, COM_HW_FIFO);
530 						sc->sc_fifolen = 0;
531 					} else {
532 						SET(sc->sc_hwflags, COM_HW_FLOW);
533 						sc->sc_fifolen = 32;
534 					}
535 				} else
536 					sc->sc_fifolen = 16;
537 
538 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
539 				if (sc->sc_fifolen == 0)
540 					fifo_msg = "st16650, broken fifo";
541 				else if (sc->sc_fifolen == 32)
542 					fifo_msg = "st16650a, working fifo";
543 				else
544 					fifo_msg = "ns16550a, working fifo";
545 			}
546 
547 			/*
548 			 * TL16C750 can enable 64byte FIFO, only when DLAB
549 			 * is 1.  However, some 16750 may always enable.  For
550 			 * example, restrictions according to DLAB in a data
551 			 * sheet for SC16C750 were not described.
552 			 * Please enable 'options COM_16650', supposing you
553 			 * use SC16C750.  Probably 32 bytes of FIFO and HW FLOW
554 			 * should become effective.
555 			 */
556 			if (sc->sc_type == COM_TYPE_16750) {
557 				uint8_t iir1, iir2;
558 				uint8_t fcr = FIFO_ENABLE | FIFO_TRIGGER_14;
559 
560 				lcr = CSR_READ_1(regsp, COM_REG_LCR);
561 				CSR_WRITE_1(regsp, COM_REG_LCR,
562 				    lcr & ~LCR_DLAB);
563 				CSR_WRITE_1(regsp, COM_REG_FIFO,
564 				    fcr | FIFO_64B_ENABLE);
565 				iir1 = CSR_READ_1(regsp, COM_REG_IIR);
566 				CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
567 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr | LCR_DLAB);
568 				CSR_WRITE_1(regsp, COM_REG_FIFO,
569 				    fcr | FIFO_64B_ENABLE);
570 				iir2 = CSR_READ_1(regsp, COM_REG_IIR);
571 
572 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
573 
574 				if (!ISSET(iir1, IIR_64B_FIFO) &&
575 				    ISSET(iir2, IIR_64B_FIFO)) {
576 					/* It is TL16C750. */
577 					sc->sc_fifolen = 64;
578 					SET(sc->sc_hwflags, COM_HW_AFE);
579 				} else
580 					CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
581 
582 				if (sc->sc_fifolen == 64)
583 					fifo_msg = "tl16c750, working fifo";
584 				else
585 					fifo_msg = "ns16750, working fifo";
586 			}
587 		} else
588 			fifo_msg = "ns16550, broken fifo";
589 	else
590 		fifo_msg = "ns8250 or ns16450, no fifo";
591 	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
592 
593 fifodelay:
594 	/*
595 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
596 	 * written to com_fifo. If this chip is the console, writing zero
597 	 * results in some of the chip/FIFO description being lost, so delay
598 	 * printing it until now.
599 	 */
600 	delay(10);
601 	aprint_normal(": %s\n", fifo_msg);
602 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
603 		sc->sc_fifolen = 1;
604 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
605 	}
606 
607 fifodone:
608 
609 	tp = tty_alloc();
610 	tp->t_oproc = comstart;
611 	tp->t_param = comparam;
612 	tp->t_hwiflow = comhwiflow;
613 	tp->t_softc = sc;
614 
615 	sc->sc_tty = tp;
616 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_NOWAIT);
617 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
618 	sc->sc_rbavail = com_rbuf_size;
619 	if (sc->sc_rbuf == NULL) {
620 		aprint_error_dev(sc->sc_dev,
621 		    "unable to allocate ring buffer\n");
622 		return;
623 	}
624 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
625 
626 	tty_attach(tp);
627 
628 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
629 		SET(sc->sc_mcr, MCR_IENABLE);
630 
631 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
632 		int maj;
633 
634 		/* locate the major number */
635 		maj = cdevsw_lookup_major(&com_cdevsw);
636 
637 		tp->t_dev = cn_tab->cn_dev = makedev(maj,
638 						     device_unit(sc->sc_dev));
639 
640 		aprint_normal_dev(sc->sc_dev, "console\n");
641 	}
642 
643 #ifdef KGDB
644 	/*
645 	 * Allow kgdb to "take over" this port.  If this is
646 	 * not the console and is the kgdb device, it has
647 	 * exclusive use.  If it's the console _and_ the
648 	 * kgdb device, it doesn't.
649 	 */
650 	if (bus_space_is_equal(regsp->cr_iot, comkgdbregs.cr_iot) &&
651 	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
652 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
653 			com_kgdb_attached = 1;
654 
655 			SET(sc->sc_hwflags, COM_HW_KGDB);
656 		}
657 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
658 	}
659 #endif
660 
661 	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
662 
663 #ifdef RND_COM
664 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
665 			  RND_TYPE_TTY, RND_FLAG_DEFAULT);
666 #endif
667 
668 	/* if there are no enable/disable functions, assume the device
669 	   is always enabled */
670 	if (!sc->enable)
671 		sc->enabled = 1;
672 
673 	com_config(sc);
674 
675 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
676 }
677 
678 void
679 com_config(struct com_softc *sc)
680 {
681 	struct com_regs *regsp = &sc->sc_regs;
682 
683 	/* Disable interrupts before configuring the device. */
684 	if (sc->sc_type == COM_TYPE_PXA2x0)
685 		sc->sc_ier = IER_EUART;
686 	else
687 		sc->sc_ier = 0;
688 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
689 	(void) CSR_READ_1(regsp, COM_REG_IIR);
690 
691 	/* Look for a Hayes ESP board. */
692 	if (sc->sc_type == COM_TYPE_HAYESP) {
693 
694 		/* Set 16550 compatibility mode */
695 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
696 				  HAYESP_SETMODE);
697 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
698 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
699 				  HAYESP_MODE_SCALE);
700 
701 		/* Set RTS/CTS flow control */
702 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
703 				  HAYESP_SETFLOWTYPE);
704 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
705 				  HAYESP_FLOW_RTS);
706 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
707 				  HAYESP_FLOW_CTS);
708 
709 		/* Set flow control levels */
710 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
711 				  HAYESP_SETRXFLOW);
712 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
713 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
714 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
715 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
716 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
717 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
718 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
719 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
720 	}
721 
722 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
723 		com_enable_debugport(sc);
724 }
725 
726 #if 0
727 static int
728 comcngetc_detached(dev_t dev)
729 {
730 	return 0;
731 }
732 
733 static void
734 comcnputc_detached(dev_t dev, int c)
735 {
736 }
737 #endif
738 
739 int
740 com_detach(device_t self, int flags)
741 {
742 	struct com_softc *sc = device_private(self);
743 	int maj, mn;
744 
745 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
746 		return EBUSY;
747 
748 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) &&
749 	    (flags & DETACH_SHUTDOWN) != 0)
750 		return EBUSY;
751 
752 	if (sc->disable != NULL && sc->enabled != 0) {
753 		(*sc->disable)(sc);
754 		sc->enabled = 0;
755 	}
756 
757 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
758 		comconsattached = 0;
759 		cn_tab = NULL;
760 	}
761 
762 	/* locate the major number */
763 	maj = cdevsw_lookup_major(&com_cdevsw);
764 
765 	/* Nuke the vnodes for any open instances. */
766 	mn = device_unit(self);
767 	vdevgone(maj, mn, mn, VCHR);
768 
769 	mn |= COMDIALOUT_MASK;
770 	vdevgone(maj, mn, mn, VCHR);
771 
772 	if (sc->sc_rbuf == NULL) {
773 		/*
774 		 * Ring buffer allocation failed in the com_attach_subr,
775 		 * only the tty is allocated, and nothing else.
776 		 */
777 		tty_free(sc->sc_tty);
778 		return 0;
779 	}
780 
781 	/* Free the receive buffer. */
782 	free(sc->sc_rbuf, M_DEVBUF);
783 
784 	/* Detach and free the tty. */
785 	tty_detach(sc->sc_tty);
786 	tty_free(sc->sc_tty);
787 
788 	/* Unhook the soft interrupt handler. */
789 	softint_disestablish(sc->sc_si);
790 
791 #ifdef RND_COM
792 	/* Unhook the entropy source. */
793 	rnd_detach_source(&sc->rnd_source);
794 #endif
795 	callout_destroy(&sc->sc_diag_callout);
796 
797 	/* Destroy the lock. */
798 	mutex_destroy(&sc->sc_lock);
799 
800 	return (0);
801 }
802 
803 void
804 com_shutdown(struct com_softc *sc)
805 {
806 	struct tty *tp = sc->sc_tty;
807 
808 	mutex_spin_enter(&sc->sc_lock);
809 
810 	/* If we were asserting flow control, then deassert it. */
811 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
812 	com_hwiflow(sc);
813 
814 	/* Clear any break condition set with TIOCSBRK. */
815 	com_break(sc, 0);
816 
817 	/*
818 	 * Hang up if necessary.  Wait a bit, so the other side has time to
819 	 * notice even if we immediately open the port again.
820 	 * Avoid tsleeping above splhigh().
821 	 */
822 	if (ISSET(tp->t_cflag, HUPCL)) {
823 		com_modem(sc, 0);
824 		mutex_spin_exit(&sc->sc_lock);
825 		/* XXX will only timeout */
826 		(void) kpause(ttclos, false, hz, NULL);
827 		mutex_spin_enter(&sc->sc_lock);
828 	}
829 
830 	/* Turn off interrupts. */
831 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
832 		sc->sc_ier = IER_ERLS; /* interrupt on line break */
833 		if ((sc->sc_type == COM_TYPE_PXA2x0) ||
834 		    (sc->sc_type == COM_TYPE_INGENIC) ||
835 		    (sc->sc_type == COM_TYPE_TEGRA))
836 			sc->sc_ier |= IER_ERXTOUT;
837 	} else
838 		sc->sc_ier = 0;
839 
840 	if (sc->sc_type == COM_TYPE_PXA2x0)
841 		sc->sc_ier |= IER_EUART;
842 
843 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
844 
845 	mutex_spin_exit(&sc->sc_lock);
846 
847 	if (sc->disable) {
848 #ifdef DIAGNOSTIC
849 		if (!sc->enabled)
850 			panic("com_shutdown: not enabled?");
851 #endif
852 		(*sc->disable)(sc);
853 		sc->enabled = 0;
854 	}
855 }
856 
857 int
858 comopen(dev_t dev, int flag, int mode, struct lwp *l)
859 {
860 	struct com_softc *sc;
861 	struct tty *tp;
862 	int s;
863 	int error;
864 
865 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
866 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
867 		sc->sc_rbuf == NULL)
868 		return (ENXIO);
869 
870 	if (!device_is_active(sc->sc_dev))
871 		return (ENXIO);
872 
873 #ifdef KGDB
874 	/*
875 	 * If this is the kgdb port, no other use is permitted.
876 	 */
877 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
878 		return (EBUSY);
879 #endif
880 
881 	tp = sc->sc_tty;
882 
883 	/*
884 	 * If the device is exclusively for kernel use, deny userland
885 	 * open.
886 	 */
887 	if (ISSET(tp->t_state, TS_KERN_ONLY))
888 		return (EBUSY);
889 
890 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
891 		return (EBUSY);
892 
893 	s = spltty();
894 
895 	/*
896 	 * Do the following iff this is a first open.
897 	 */
898 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
899 		struct termios t;
900 
901 		tp->t_dev = dev;
902 
903 		if (sc->enable) {
904 			if ((*sc->enable)(sc)) {
905 				splx(s);
906 				aprint_error_dev(sc->sc_dev,
907 				    "device enable failed\n");
908 				return (EIO);
909 			}
910 			mutex_spin_enter(&sc->sc_lock);
911 			sc->enabled = 1;
912 			com_config(sc);
913 		} else {
914 			mutex_spin_enter(&sc->sc_lock);
915 		}
916 
917 		/* Turn on interrupts. */
918 		sc->sc_ier = IER_ERXRDY | IER_ERLS;
919 		if (!ISSET(tp->t_cflag, CLOCAL))
920 			sc->sc_ier |= IER_EMSC;
921 
922 		if (sc->sc_type == COM_TYPE_PXA2x0)
923 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
924 		else if (sc->sc_type == COM_TYPE_INGENIC ||
925 			 sc->sc_type == COM_TYPE_TEGRA)
926 			sc->sc_ier |= IER_ERXTOUT;
927 		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
928 
929 		/* Fetch the current modem control status, needed later. */
930 		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
931 
932 		/* Clear PPS capture state on first open. */
933 		mutex_spin_enter(&timecounter_lock);
934 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
935 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
936 		pps_init(&sc->sc_pps_state);
937 		mutex_spin_exit(&timecounter_lock);
938 
939 		mutex_spin_exit(&sc->sc_lock);
940 
941 		/*
942 		 * Initialize the termios status to the defaults.  Add in the
943 		 * sticky bits from TIOCSFLAGS.
944 		 */
945 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
946 			t.c_ospeed = comcons_info.rate;
947 			t.c_cflag = comcons_info.cflag;
948 		} else {
949 			t.c_ospeed = TTYDEF_SPEED;
950 			t.c_cflag = TTYDEF_CFLAG;
951 		}
952 		t.c_ispeed = t.c_ospeed;
953 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
954 			SET(t.c_cflag, CLOCAL);
955 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
956 			SET(t.c_cflag, CRTSCTS);
957 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
958 			SET(t.c_cflag, MDMBUF);
959 		/* Make sure comparam() will do something. */
960 		tp->t_ospeed = 0;
961 		(void) comparam(tp, &t);
962 		tp->t_iflag = TTYDEF_IFLAG;
963 		tp->t_oflag = TTYDEF_OFLAG;
964 		tp->t_lflag = TTYDEF_LFLAG;
965 		ttychars(tp);
966 		ttsetwater(tp);
967 
968 		mutex_spin_enter(&sc->sc_lock);
969 
970 		/*
971 		 * Turn on DTR.  We must always do this, even if carrier is not
972 		 * present, because otherwise we'd have to use TIOCSDTR
973 		 * immediately after setting CLOCAL, which applications do not
974 		 * expect.  We always assert DTR while the device is open
975 		 * unless explicitly requested to deassert it.
976 		 */
977 		com_modem(sc, 1);
978 
979 		/* Clear the input ring, and unblock. */
980 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
981 		sc->sc_rbavail = com_rbuf_size;
982 		com_iflush(sc);
983 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
984 		com_hwiflow(sc);
985 
986 #ifdef COM_DEBUG
987 		if (com_debug)
988 			comstatus(sc, "comopen  ");
989 #endif
990 
991 		mutex_spin_exit(&sc->sc_lock);
992 	}
993 
994 	splx(s);
995 
996 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
997 	if (error)
998 		goto bad;
999 
1000 	error = (*tp->t_linesw->l_open)(dev, tp);
1001 	if (error)
1002 		goto bad;
1003 
1004 	return (0);
1005 
1006 bad:
1007 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1008 		/*
1009 		 * We failed to open the device, and nobody else had it opened.
1010 		 * Clean up the state as appropriate.
1011 		 */
1012 		com_shutdown(sc);
1013 	}
1014 
1015 	return (error);
1016 }
1017 
1018 int
1019 comclose(dev_t dev, int flag, int mode, struct lwp *l)
1020 {
1021 	struct com_softc *sc =
1022 	    device_lookup_private(&com_cd, COMUNIT(dev));
1023 	struct tty *tp = sc->sc_tty;
1024 
1025 	/* XXX This is for cons.c. */
1026 	if (!ISSET(tp->t_state, TS_ISOPEN))
1027 		return (0);
1028 	/*
1029 	 * If the device is exclusively for kernel use, deny userland
1030 	 * close.
1031 	 */
1032 	if (ISSET(tp->t_state, TS_KERN_ONLY))
1033 		return (0);
1034 
1035 	(*tp->t_linesw->l_close)(tp, flag);
1036 	ttyclose(tp);
1037 
1038 	if (COM_ISALIVE(sc) == 0)
1039 		return (0);
1040 
1041 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1042 		/*
1043 		 * Although we got a last close, the device may still be in
1044 		 * use; e.g. if this was the dialout node, and there are still
1045 		 * processes waiting for carrier on the non-dialout node.
1046 		 */
1047 		com_shutdown(sc);
1048 	}
1049 
1050 	return (0);
1051 }
1052 
1053 int
1054 comread(dev_t dev, struct uio *uio, int flag)
1055 {
1056 	struct com_softc *sc =
1057 	    device_lookup_private(&com_cd, COMUNIT(dev));
1058 	struct tty *tp = sc->sc_tty;
1059 
1060 	if (COM_ISALIVE(sc) == 0)
1061 		return (EIO);
1062 
1063 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
1064 }
1065 
1066 int
1067 comwrite(dev_t dev, struct uio *uio, int flag)
1068 {
1069 	struct com_softc *sc =
1070 	    device_lookup_private(&com_cd, COMUNIT(dev));
1071 	struct tty *tp = sc->sc_tty;
1072 
1073 	if (COM_ISALIVE(sc) == 0)
1074 		return (EIO);
1075 
1076 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
1077 }
1078 
1079 int
1080 compoll(dev_t dev, int events, struct lwp *l)
1081 {
1082 	struct com_softc *sc =
1083 	    device_lookup_private(&com_cd, COMUNIT(dev));
1084 	struct tty *tp = sc->sc_tty;
1085 
1086 	if (COM_ISALIVE(sc) == 0)
1087 		return (POLLHUP);
1088 
1089 	return ((*tp->t_linesw->l_poll)(tp, events, l));
1090 }
1091 
1092 struct tty *
1093 comtty(dev_t dev)
1094 {
1095 	struct com_softc *sc =
1096 	    device_lookup_private(&com_cd, COMUNIT(dev));
1097 	struct tty *tp = sc->sc_tty;
1098 
1099 	return (tp);
1100 }
1101 
1102 int
1103 comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1104 {
1105 	struct com_softc *sc;
1106 	struct tty *tp;
1107 	int error;
1108 
1109 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1110 	if (sc == NULL)
1111 		return ENXIO;
1112 	if (COM_ISALIVE(sc) == 0)
1113 		return (EIO);
1114 
1115 	tp = sc->sc_tty;
1116 
1117 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1118 	if (error != EPASSTHROUGH)
1119 		return (error);
1120 
1121 	error = ttioctl(tp, cmd, data, flag, l);
1122 	if (error != EPASSTHROUGH)
1123 		return (error);
1124 
1125 	error = 0;
1126 	switch (cmd) {
1127 	case TIOCSFLAGS:
1128 		error = kauth_authorize_device_tty(l->l_cred,
1129 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1130 		break;
1131 	default:
1132 		/* nothing */
1133 		break;
1134 	}
1135 	if (error) {
1136 		return error;
1137 	}
1138 
1139 	mutex_spin_enter(&sc->sc_lock);
1140 
1141 	switch (cmd) {
1142 	case TIOCSBRK:
1143 		com_break(sc, 1);
1144 		break;
1145 
1146 	case TIOCCBRK:
1147 		com_break(sc, 0);
1148 		break;
1149 
1150 	case TIOCSDTR:
1151 		com_modem(sc, 1);
1152 		break;
1153 
1154 	case TIOCCDTR:
1155 		com_modem(sc, 0);
1156 		break;
1157 
1158 	case TIOCGFLAGS:
1159 		*(int *)data = sc->sc_swflags;
1160 		break;
1161 
1162 	case TIOCSFLAGS:
1163 		sc->sc_swflags = *(int *)data;
1164 		break;
1165 
1166 	case TIOCMSET:
1167 	case TIOCMBIS:
1168 	case TIOCMBIC:
1169 		tiocm_to_com(sc, cmd, *(int *)data);
1170 		break;
1171 
1172 	case TIOCMGET:
1173 		*(int *)data = com_to_tiocm(sc);
1174 		break;
1175 
1176 	case PPS_IOC_CREATE:
1177 	case PPS_IOC_DESTROY:
1178 	case PPS_IOC_GETPARAMS:
1179 	case PPS_IOC_SETPARAMS:
1180 	case PPS_IOC_GETCAP:
1181 	case PPS_IOC_FETCH:
1182 #ifdef PPS_SYNC
1183 	case PPS_IOC_KCBIND:
1184 #endif
1185 		mutex_spin_enter(&timecounter_lock);
1186 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1187 		mutex_spin_exit(&timecounter_lock);
1188 		break;
1189 
1190 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1191 		mutex_spin_enter(&timecounter_lock);
1192 #ifndef PPS_TRAILING_EDGE
1193 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1194 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1195 #else
1196 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1197 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1198 #endif
1199 		mutex_spin_exit(&timecounter_lock);
1200 		break;
1201 
1202 	default:
1203 		error = EPASSTHROUGH;
1204 		break;
1205 	}
1206 
1207 	mutex_spin_exit(&sc->sc_lock);
1208 
1209 #ifdef COM_DEBUG
1210 	if (com_debug)
1211 		comstatus(sc, "comioctl ");
1212 #endif
1213 
1214 	return (error);
1215 }
1216 
1217 integrate void
1218 com_schedrx(struct com_softc *sc)
1219 {
1220 
1221 	sc->sc_rx_ready = 1;
1222 
1223 	/* Wake up the poller. */
1224 	softint_schedule(sc->sc_si);
1225 }
1226 
1227 void
1228 com_break(struct com_softc *sc, int onoff)
1229 {
1230 
1231 	if (onoff)
1232 		SET(sc->sc_lcr, LCR_SBREAK);
1233 	else
1234 		CLR(sc->sc_lcr, LCR_SBREAK);
1235 
1236 	if (!sc->sc_heldchange) {
1237 		if (sc->sc_tx_busy) {
1238 			sc->sc_heldtbc = sc->sc_tbc;
1239 			sc->sc_tbc = 0;
1240 			sc->sc_heldchange = 1;
1241 		} else
1242 			com_loadchannelregs(sc);
1243 	}
1244 }
1245 
1246 void
1247 com_modem(struct com_softc *sc, int onoff)
1248 {
1249 
1250 	if (sc->sc_mcr_dtr == 0)
1251 		return;
1252 
1253 	if (onoff)
1254 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1255 	else
1256 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1257 
1258 	if (!sc->sc_heldchange) {
1259 		if (sc->sc_tx_busy) {
1260 			sc->sc_heldtbc = sc->sc_tbc;
1261 			sc->sc_tbc = 0;
1262 			sc->sc_heldchange = 1;
1263 		} else
1264 			com_loadchannelregs(sc);
1265 	}
1266 }
1267 
1268 void
1269 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1270 {
1271 	u_char combits;
1272 
1273 	combits = 0;
1274 	if (ISSET(ttybits, TIOCM_DTR))
1275 		SET(combits, MCR_DTR);
1276 	if (ISSET(ttybits, TIOCM_RTS))
1277 		SET(combits, MCR_RTS);
1278 
1279 	switch (how) {
1280 	case TIOCMBIC:
1281 		CLR(sc->sc_mcr, combits);
1282 		break;
1283 
1284 	case TIOCMBIS:
1285 		SET(sc->sc_mcr, combits);
1286 		break;
1287 
1288 	case TIOCMSET:
1289 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1290 		SET(sc->sc_mcr, combits);
1291 		break;
1292 	}
1293 
1294 	if (!sc->sc_heldchange) {
1295 		if (sc->sc_tx_busy) {
1296 			sc->sc_heldtbc = sc->sc_tbc;
1297 			sc->sc_tbc = 0;
1298 			sc->sc_heldchange = 1;
1299 		} else
1300 			com_loadchannelregs(sc);
1301 	}
1302 }
1303 
1304 int
1305 com_to_tiocm(struct com_softc *sc)
1306 {
1307 	u_char combits;
1308 	int ttybits = 0;
1309 
1310 	combits = sc->sc_mcr;
1311 	if (ISSET(combits, MCR_DTR))
1312 		SET(ttybits, TIOCM_DTR);
1313 	if (ISSET(combits, MCR_RTS))
1314 		SET(ttybits, TIOCM_RTS);
1315 
1316 	combits = sc->sc_msr;
1317 	if (sc->sc_type == COM_TYPE_INGENIC) {
1318 		SET(ttybits, TIOCM_CD);
1319 	} else {
1320 		if (ISSET(combits, MSR_DCD))
1321 			SET(ttybits, TIOCM_CD);
1322 	}
1323 	if (ISSET(combits, MSR_CTS))
1324 		SET(ttybits, TIOCM_CTS);
1325 	if (ISSET(combits, MSR_DSR))
1326 		SET(ttybits, TIOCM_DSR);
1327 	if (ISSET(combits, MSR_RI | MSR_TERI))
1328 		SET(ttybits, TIOCM_RI);
1329 
1330 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1331 		SET(ttybits, TIOCM_LE);
1332 
1333 	return (ttybits);
1334 }
1335 
1336 static u_char
1337 cflag2lcr(tcflag_t cflag)
1338 {
1339 	u_char lcr = 0;
1340 
1341 	switch (ISSET(cflag, CSIZE)) {
1342 	case CS5:
1343 		SET(lcr, LCR_5BITS);
1344 		break;
1345 	case CS6:
1346 		SET(lcr, LCR_6BITS);
1347 		break;
1348 	case CS7:
1349 		SET(lcr, LCR_7BITS);
1350 		break;
1351 	case CS8:
1352 		SET(lcr, LCR_8BITS);
1353 		break;
1354 	}
1355 	if (ISSET(cflag, PARENB)) {
1356 		SET(lcr, LCR_PENAB);
1357 		if (!ISSET(cflag, PARODD))
1358 			SET(lcr, LCR_PEVEN);
1359 	}
1360 	if (ISSET(cflag, CSTOPB))
1361 		SET(lcr, LCR_STOPB);
1362 
1363 	return (lcr);
1364 }
1365 
1366 int
1367 comparam(struct tty *tp, struct termios *t)
1368 {
1369 	struct com_softc *sc =
1370 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1371 	int ospeed;
1372 	u_char lcr;
1373 
1374 	if (COM_ISALIVE(sc) == 0)
1375 		return (EIO);
1376 
1377 	if (sc->sc_type == COM_TYPE_HAYESP) {
1378 		int prescaler, speed;
1379 
1380 		/*
1381 		 * Calculate UART clock prescaler.  It should be in
1382 		 * range of 0 .. 3.
1383 		 */
1384 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1385 		    prescaler++, speed /= 2)
1386 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1387 					       sc->sc_type)) > 0)
1388 				break;
1389 
1390 		if (prescaler == 4)
1391 			return (EINVAL);
1392 		sc->sc_prescaler = prescaler;
1393 	} else
1394 		ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1395 
1396 	/* Check requested parameters. */
1397 	if (ospeed < 0)
1398 		return (EINVAL);
1399 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1400 		return (EINVAL);
1401 
1402 	/*
1403 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1404 	 * is always active.
1405 	 */
1406 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1407 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1408 		SET(t->c_cflag, CLOCAL);
1409 		CLR(t->c_cflag, HUPCL);
1410 	}
1411 
1412 	/*
1413 	 * If there were no changes, don't do anything.  This avoids dropping
1414 	 * input and improves performance when all we did was frob things like
1415 	 * VMIN and VTIME.
1416 	 */
1417 	if (tp->t_ospeed == t->c_ospeed &&
1418 	    tp->t_cflag == t->c_cflag)
1419 		return (0);
1420 
1421 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1422 
1423 	mutex_spin_enter(&sc->sc_lock);
1424 
1425 	sc->sc_lcr = lcr;
1426 
1427 	/*
1428 	 * If we're not in a mode that assumes a connection is present, then
1429 	 * ignore carrier changes.
1430 	 */
1431 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1432 		sc->sc_msr_dcd = 0;
1433 	else
1434 		sc->sc_msr_dcd = MSR_DCD;
1435 	/*
1436 	 * Set the flow control pins depending on the current flow control
1437 	 * mode.
1438 	 */
1439 	if (ISSET(t->c_cflag, CRTSCTS)) {
1440 		sc->sc_mcr_dtr = MCR_DTR;
1441 		sc->sc_mcr_rts = MCR_RTS;
1442 		sc->sc_msr_cts = MSR_CTS;
1443 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1444 			SET(sc->sc_mcr, MCR_AFE);
1445 		} else {
1446 			sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1447 		}
1448 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1449 		/*
1450 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1451 		 * carrier detection.
1452 		 */
1453 		sc->sc_mcr_dtr = 0;
1454 		sc->sc_mcr_rts = MCR_DTR;
1455 		sc->sc_msr_cts = MSR_DCD;
1456 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1457 			CLR(sc->sc_mcr, MCR_AFE);
1458 		} else {
1459 			sc->sc_efr = 0;
1460 		}
1461 	} else {
1462 		/*
1463 		 * If no flow control, then always set RTS.  This will make
1464 		 * the other side happy if it mistakenly thinks we're doing
1465 		 * RTS/CTS flow control.
1466 		 */
1467 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1468 		sc->sc_mcr_rts = 0;
1469 		sc->sc_msr_cts = 0;
1470 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1471 			CLR(sc->sc_mcr, MCR_AFE);
1472 		} else {
1473 			sc->sc_efr = 0;
1474 		}
1475 		if (ISSET(sc->sc_mcr, MCR_DTR))
1476 			SET(sc->sc_mcr, MCR_RTS);
1477 		else
1478 			CLR(sc->sc_mcr, MCR_RTS);
1479 	}
1480 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1481 
1482 	if (t->c_ospeed == 0 && tp->t_ospeed != 0)
1483 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1484 	else if (t->c_ospeed != 0 && tp->t_ospeed == 0)
1485 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1486 
1487 	sc->sc_dlbl = ospeed;
1488 	sc->sc_dlbh = ospeed >> 8;
1489 
1490 	/*
1491 	 * Set the FIFO threshold based on the receive speed.
1492 	 *
1493 	 *  * If it's a low speed, it's probably a mouse or some other
1494 	 *    interactive device, so set the threshold low.
1495 	 *  * If it's a high speed, trim the trigger level down to prevent
1496 	 *    overflows.
1497 	 *  * Otherwise set it a bit higher.
1498 	 */
1499 	if (sc->sc_type == COM_TYPE_HAYESP) {
1500 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1501 	} else if (sc->sc_type == COM_TYPE_TEGRA) {
1502 		sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1503 	} else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1504 		if (t->c_ospeed <= 1200)
1505 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1506 		else if (t->c_ospeed <= 38400)
1507 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1508 		else
1509 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1510 	} else {
1511 		sc->sc_fifo = 0;
1512 	}
1513 
1514 	if (sc->sc_type == COM_TYPE_INGENIC)
1515 		sc->sc_fifo |= FIFO_UART_ON;
1516 
1517 	/* And copy to tty. */
1518 	tp->t_ispeed = t->c_ospeed;
1519 	tp->t_ospeed = t->c_ospeed;
1520 	tp->t_cflag = t->c_cflag;
1521 
1522 	if (!sc->sc_heldchange) {
1523 		if (sc->sc_tx_busy) {
1524 			sc->sc_heldtbc = sc->sc_tbc;
1525 			sc->sc_tbc = 0;
1526 			sc->sc_heldchange = 1;
1527 		} else
1528 			com_loadchannelregs(sc);
1529 	}
1530 
1531 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1532 		/* Disable the high water mark. */
1533 		sc->sc_r_hiwat = 0;
1534 		sc->sc_r_lowat = 0;
1535 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1536 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1537 			com_schedrx(sc);
1538 		}
1539 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1540 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1541 			com_hwiflow(sc);
1542 		}
1543 	} else {
1544 		sc->sc_r_hiwat = com_rbuf_hiwat;
1545 		sc->sc_r_lowat = com_rbuf_lowat;
1546 	}
1547 
1548 	mutex_spin_exit(&sc->sc_lock);
1549 
1550 	/*
1551 	 * Update the tty layer's idea of the carrier bit, in case we changed
1552 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1553 	 * explicit request.
1554 	 */
1555 	if (sc->sc_type == COM_TYPE_INGENIC) {
1556 		/* no DCD here */
1557 		(void) (*tp->t_linesw->l_modem)(tp, 1);
1558 	} else
1559 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1560 
1561 #ifdef COM_DEBUG
1562 	if (com_debug)
1563 		comstatus(sc, "comparam ");
1564 #endif
1565 
1566 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1567 		if (sc->sc_tx_stopped) {
1568 			sc->sc_tx_stopped = 0;
1569 			comstart(tp);
1570 		}
1571 	}
1572 
1573 	return (0);
1574 }
1575 
1576 void
1577 com_iflush(struct com_softc *sc)
1578 {
1579 	struct com_regs	*regsp = &sc->sc_regs;
1580 	uint8_t fifo;
1581 #ifdef DIAGNOSTIC
1582 	int reg;
1583 #endif
1584 	int timo;
1585 
1586 #ifdef DIAGNOSTIC
1587 	reg = 0xffff;
1588 #endif
1589 	timo = 50000;
1590 	/* flush any pending I/O */
1591 	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1592 	    && --timo)
1593 #ifdef DIAGNOSTIC
1594 		reg =
1595 #else
1596 		    (void)
1597 #endif
1598 		    CSR_READ_1(regsp, COM_REG_RXDATA);
1599 #ifdef DIAGNOSTIC
1600 	if (!timo)
1601 		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1602 #endif
1603 
1604 	switch (sc->sc_type) {
1605 	case COM_TYPE_16750:
1606 	case COM_TYPE_SUNXI:
1607 		/*
1608 		 * Reset all Rx/Tx FIFO, preserve current FIFO length.
1609 		 * This should prevent triggering busy interrupt while
1610 		 * manipulating divisors.
1611 		 */
1612 		fifo = CSR_READ_1(regsp, COM_REG_FIFO) & (FIFO_TRIGGER_1 |
1613 		    FIFO_TRIGGER_4 | FIFO_TRIGGER_8 | FIFO_TRIGGER_14);
1614 		CSR_WRITE_1(regsp, COM_REG_FIFO,
1615 		    fifo | FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST);
1616 		delay(100);
1617 		break;
1618 	}
1619 }
1620 
1621 void
1622 com_loadchannelregs(struct com_softc *sc)
1623 {
1624 	struct com_regs *regsp = &sc->sc_regs;
1625 
1626 	/* XXXXX necessary? */
1627 	com_iflush(sc);
1628 
1629 	if (sc->sc_type == COM_TYPE_PXA2x0)
1630 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1631 	else
1632 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1633 
1634 	if (sc->sc_type == COM_TYPE_OMAP) {
1635 		/* disable before changing settings */
1636 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
1637 	}
1638 
1639 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1640 		KASSERT(sc->sc_type != COM_TYPE_AU1x00);
1641 		KASSERT(sc->sc_type != COM_TYPE_16550_NOERS);
1642 		/* no EFR on alchemy */
1643 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1644 		CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1645 	}
1646 	if (sc->sc_type == COM_TYPE_AU1x00) {
1647 		/* alchemy has single separate 16-bit clock divisor register */
1648 		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1649 		    (sc->sc_dlbh << 8));
1650 	} else {
1651 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1652 		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1653 		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1654 	}
1655 	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1656 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1657 	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1658 	if (sc->sc_type == COM_TYPE_HAYESP) {
1659 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1660 		    HAYESP_SETPRESCALER);
1661 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1662 		    sc->sc_prescaler);
1663 	}
1664 	if (sc->sc_type == COM_TYPE_OMAP) {
1665 		/* setup the fifos.  the FCR value is not used as long
1666 		   as SCR[6] and SCR[7] are 0, which they are at reset
1667 		   and we never touch the SCR register */
1668 		uint8_t rx_fifo_trig = 40;
1669 		uint8_t tx_fifo_trig = 60;
1670 		uint8_t rx_start = 8;
1671 		uint8_t rx_halt = 60;
1672 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
1673 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
1674 
1675 		/* enable access to TCR & TLR */
1676 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr | MCR_TCR_TLR);
1677 
1678 		/* write tcr and tlr values */
1679 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
1680 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
1681 
1682 		/* disable access to TCR & TLR */
1683 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr);
1684 
1685 		/* enable again, but mode is based on speed */
1686 		if (sc->sc_tty->t_termios.c_ospeed > 230400) {
1687 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
1688 		} else {
1689 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
1690 		}
1691 	}
1692 
1693 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1694 }
1695 
1696 int
1697 comhwiflow(struct tty *tp, int block)
1698 {
1699 	struct com_softc *sc =
1700 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1701 
1702 	if (COM_ISALIVE(sc) == 0)
1703 		return (0);
1704 
1705 	if (sc->sc_mcr_rts == 0)
1706 		return (0);
1707 
1708 	mutex_spin_enter(&sc->sc_lock);
1709 
1710 	if (block) {
1711 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1712 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1713 			com_hwiflow(sc);
1714 		}
1715 	} else {
1716 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1717 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1718 			com_schedrx(sc);
1719 		}
1720 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1721 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1722 			com_hwiflow(sc);
1723 		}
1724 	}
1725 
1726 	mutex_spin_exit(&sc->sc_lock);
1727 	return (1);
1728 }
1729 
1730 /*
1731  * (un)block input via hw flowcontrol
1732  */
1733 void
1734 com_hwiflow(struct com_softc *sc)
1735 {
1736 	struct com_regs *regsp= &sc->sc_regs;
1737 
1738 	if (sc->sc_mcr_rts == 0)
1739 		return;
1740 
1741 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1742 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1743 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1744 	} else {
1745 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1746 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1747 	}
1748 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1749 }
1750 
1751 
1752 void
1753 comstart(struct tty *tp)
1754 {
1755 	struct com_softc *sc =
1756 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1757 	struct com_regs *regsp = &sc->sc_regs;
1758 	int s;
1759 
1760 	if (COM_ISALIVE(sc) == 0)
1761 		return;
1762 
1763 	s = spltty();
1764 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1765 		goto out;
1766 	if (sc->sc_tx_stopped)
1767 		goto out;
1768 	if (!ttypull(tp))
1769 		goto out;
1770 
1771 	/* Grab the first contiguous region of buffer space. */
1772 	{
1773 		u_char *tba;
1774 		int tbc;
1775 
1776 		tba = tp->t_outq.c_cf;
1777 		tbc = ndqb(&tp->t_outq, 0);
1778 
1779 		mutex_spin_enter(&sc->sc_lock);
1780 
1781 		sc->sc_tba = tba;
1782 		sc->sc_tbc = tbc;
1783 	}
1784 
1785 	SET(tp->t_state, TS_BUSY);
1786 	sc->sc_tx_busy = 1;
1787 
1788 	/* Enable transmit completion interrupts if necessary. */
1789 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1790 		SET(sc->sc_ier, IER_ETXRDY);
1791 		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1792 	}
1793 
1794 	/* Output the first chunk of the contiguous buffer. */
1795 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1796 		u_int n;
1797 
1798 		n = sc->sc_tbc;
1799 		if (n > sc->sc_fifolen)
1800 			n = sc->sc_fifolen;
1801 		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1802 		sc->sc_tbc -= n;
1803 		sc->sc_tba += n;
1804 	}
1805 
1806 	mutex_spin_exit(&sc->sc_lock);
1807 out:
1808 	splx(s);
1809 	return;
1810 }
1811 
1812 /*
1813  * Stop output on a line.
1814  */
1815 void
1816 comstop(struct tty *tp, int flag)
1817 {
1818 	struct com_softc *sc =
1819 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1820 
1821 	mutex_spin_enter(&sc->sc_lock);
1822 	if (ISSET(tp->t_state, TS_BUSY)) {
1823 		/* Stop transmitting at the next chunk. */
1824 		sc->sc_tbc = 0;
1825 		sc->sc_heldtbc = 0;
1826 		if (!ISSET(tp->t_state, TS_TTSTOP))
1827 			SET(tp->t_state, TS_FLUSH);
1828 	}
1829 	mutex_spin_exit(&sc->sc_lock);
1830 }
1831 
1832 void
1833 comdiag(void *arg)
1834 {
1835 	struct com_softc *sc = arg;
1836 	int overflows, floods;
1837 
1838 	mutex_spin_enter(&sc->sc_lock);
1839 	overflows = sc->sc_overflows;
1840 	sc->sc_overflows = 0;
1841 	floods = sc->sc_floods;
1842 	sc->sc_floods = 0;
1843 	sc->sc_errors = 0;
1844 	mutex_spin_exit(&sc->sc_lock);
1845 
1846 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1847 	    device_xname(sc->sc_dev),
1848 	    overflows, overflows == 1 ? "" : "s",
1849 	    floods, floods == 1 ? "" : "s");
1850 }
1851 
1852 integrate void
1853 com_rxsoft(struct com_softc *sc, struct tty *tp)
1854 {
1855 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1856 	u_char *get, *end;
1857 	u_int cc, scc;
1858 	u_char lsr;
1859 	int code;
1860 
1861 	end = sc->sc_ebuf;
1862 	get = sc->sc_rbget;
1863 	scc = cc = com_rbuf_size - sc->sc_rbavail;
1864 
1865 	if (cc == com_rbuf_size) {
1866 		sc->sc_floods++;
1867 		if (sc->sc_errors++ == 0)
1868 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1869 			    comdiag, sc);
1870 	}
1871 
1872 	/* If not yet open, drop the entire buffer content here */
1873 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1874 		get += cc << 1;
1875 		if (get >= end)
1876 			get -= com_rbuf_size << 1;
1877 		cc = 0;
1878 	}
1879 	while (cc) {
1880 		code = get[0];
1881 		lsr = get[1];
1882 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
1883 			if (ISSET(lsr, LSR_OE)) {
1884 				sc->sc_overflows++;
1885 				if (sc->sc_errors++ == 0)
1886 					callout_reset(&sc->sc_diag_callout,
1887 					    60 * hz, comdiag, sc);
1888 			}
1889 			if (ISSET(lsr, LSR_BI | LSR_FE))
1890 				SET(code, TTY_FE);
1891 			if (ISSET(lsr, LSR_PE))
1892 				SET(code, TTY_PE);
1893 		}
1894 		if ((*rint)(code, tp) == -1) {
1895 			/*
1896 			 * The line discipline's buffer is out of space.
1897 			 */
1898 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1899 				/*
1900 				 * We're either not using flow control, or the
1901 				 * line discipline didn't tell us to block for
1902 				 * some reason.  Either way, we have no way to
1903 				 * know when there's more space available, so
1904 				 * just drop the rest of the data.
1905 				 */
1906 				get += cc << 1;
1907 				if (get >= end)
1908 					get -= com_rbuf_size << 1;
1909 				cc = 0;
1910 			} else {
1911 				/*
1912 				 * Don't schedule any more receive processing
1913 				 * until the line discipline tells us there's
1914 				 * space available (through comhwiflow()).
1915 				 * Leave the rest of the data in the input
1916 				 * buffer.
1917 				 */
1918 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1919 			}
1920 			break;
1921 		}
1922 		get += 2;
1923 		if (get >= end)
1924 			get = sc->sc_rbuf;
1925 		cc--;
1926 	}
1927 
1928 	if (cc != scc) {
1929 		sc->sc_rbget = get;
1930 		mutex_spin_enter(&sc->sc_lock);
1931 
1932 		cc = sc->sc_rbavail += scc - cc;
1933 		/* Buffers should be ok again, release possible block. */
1934 		if (cc >= sc->sc_r_lowat) {
1935 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1936 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1937 				SET(sc->sc_ier, IER_ERXRDY);
1938 				if (sc->sc_type == COM_TYPE_PXA2x0)
1939 					SET(sc->sc_ier, IER_ERXTOUT);
1940 				if (sc->sc_type == COM_TYPE_INGENIC ||
1941 				    sc->sc_type == COM_TYPE_TEGRA)
1942 					SET(sc->sc_ier, IER_ERXTOUT);
1943 
1944 				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER,
1945 				    sc->sc_ier);
1946 			}
1947 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1948 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1949 				com_hwiflow(sc);
1950 			}
1951 		}
1952 		mutex_spin_exit(&sc->sc_lock);
1953 	}
1954 }
1955 
1956 integrate void
1957 com_txsoft(struct com_softc *sc, struct tty *tp)
1958 {
1959 
1960 	CLR(tp->t_state, TS_BUSY);
1961 	if (ISSET(tp->t_state, TS_FLUSH))
1962 		CLR(tp->t_state, TS_FLUSH);
1963 	else
1964 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1965 	(*tp->t_linesw->l_start)(tp);
1966 }
1967 
1968 integrate void
1969 com_stsoft(struct com_softc *sc, struct tty *tp)
1970 {
1971 	u_char msr, delta;
1972 
1973 	mutex_spin_enter(&sc->sc_lock);
1974 	msr = sc->sc_msr;
1975 	delta = sc->sc_msr_delta;
1976 	sc->sc_msr_delta = 0;
1977 	mutex_spin_exit(&sc->sc_lock);
1978 
1979 	if (ISSET(delta, sc->sc_msr_dcd)) {
1980 		/*
1981 		 * Inform the tty layer that carrier detect changed.
1982 		 */
1983 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1984 	}
1985 
1986 	if (ISSET(delta, sc->sc_msr_cts)) {
1987 		/* Block or unblock output according to flow control. */
1988 		if (ISSET(msr, sc->sc_msr_cts)) {
1989 			sc->sc_tx_stopped = 0;
1990 			(*tp->t_linesw->l_start)(tp);
1991 		} else {
1992 			sc->sc_tx_stopped = 1;
1993 		}
1994 	}
1995 
1996 #ifdef COM_DEBUG
1997 	if (com_debug)
1998 		comstatus(sc, "com_stsoft");
1999 #endif
2000 }
2001 
2002 void
2003 comsoft(void *arg)
2004 {
2005 	struct com_softc *sc = arg;
2006 	struct tty *tp;
2007 
2008 	if (COM_ISALIVE(sc) == 0)
2009 		return;
2010 
2011 	tp = sc->sc_tty;
2012 
2013 	if (sc->sc_rx_ready) {
2014 		sc->sc_rx_ready = 0;
2015 		com_rxsoft(sc, tp);
2016 	}
2017 
2018 	if (sc->sc_st_check) {
2019 		sc->sc_st_check = 0;
2020 		com_stsoft(sc, tp);
2021 	}
2022 
2023 	if (sc->sc_tx_done) {
2024 		sc->sc_tx_done = 0;
2025 		com_txsoft(sc, tp);
2026 	}
2027 }
2028 
2029 int
2030 comintr(void *arg)
2031 {
2032 	struct com_softc *sc = arg;
2033 	struct com_regs *regsp = &sc->sc_regs;
2034 
2035 	u_char *put, *end;
2036 	u_int cc;
2037 	u_char lsr, iir;
2038 
2039 	if (COM_ISALIVE(sc) == 0)
2040 		return (0);
2041 
2042 	KASSERT(regsp != NULL);
2043 
2044 	mutex_spin_enter(&sc->sc_lock);
2045 	iir = CSR_READ_1(regsp, COM_REG_IIR);
2046 
2047 	/* Handle ns16750-specific busy interrupt. */
2048 	if (sc->sc_type == COM_TYPE_16750 &&
2049 	    (iir & IIR_BUSY) == IIR_BUSY) {
2050 		for (int timeout = 10000;
2051 		    (CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0; timeout--)
2052 			if (timeout <= 0) {
2053 				aprint_error_dev(sc->sc_dev,
2054 				    "timeout while waiting for BUSY interrupt "
2055 				    "acknowledge\n");
2056 				mutex_spin_exit(&sc->sc_lock);
2057 				return (0);
2058 			}
2059 
2060 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2061 		iir = CSR_READ_1(regsp, COM_REG_IIR);
2062 	}
2063 
2064 	/* Allwinner BUSY interrupt */
2065 	if (sc->sc_type == COM_TYPE_SUNXI &&
2066 	    (iir & IIR_BUSY) == IIR_BUSY) {
2067 		if ((CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0) {
2068 			CSR_WRITE_1(regsp, COM_REG_HALT, HALT_CHCFG_EN);
2069 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2070 			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2071 			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2072 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2073 			CSR_WRITE_1(regsp, COM_REG_HALT,
2074 			    HALT_CHCFG_EN | HALT_CHCFG_UD);
2075 			for (int timeout = 10000000;
2076 			    (CSR_READ_1(regsp, COM_REG_HALT) & HALT_CHCFG_UD) != 0;
2077 			    timeout--) {
2078 				if (timeout <= 0) {
2079 					aprint_error_dev(sc->sc_dev,
2080 					    "timeout while waiting for HALT "
2081 					    "update acknowledge 0x%x 0x%x\n",
2082 					    CSR_READ_1(regsp, COM_REG_HALT),
2083 					    CSR_READ_1(regsp, COM_REG_USR));
2084 					break;
2085 				}
2086 			}
2087 			CSR_WRITE_1(regsp, COM_REG_HALT, 0);
2088 			(void)CSR_READ_1(regsp, COM_REG_USR);
2089 		} else {
2090 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2091 			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2092 			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2093 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2094 		}
2095 	}
2096 
2097 	if (ISSET(iir, IIR_NOPEND)) {
2098 		mutex_spin_exit(&sc->sc_lock);
2099 		return (0);
2100 	}
2101 
2102 	end = sc->sc_ebuf;
2103 	put = sc->sc_rbput;
2104 	cc = sc->sc_rbavail;
2105 
2106 again:	do {
2107 		u_char	msr, delta;
2108 
2109 		lsr = CSR_READ_1(regsp, COM_REG_LSR);
2110 		if (ISSET(lsr, LSR_BI)) {
2111 			int cn_trapped = 0; /* see above: cn_trap() */
2112 
2113 			cn_check_magic(sc->sc_tty->t_dev,
2114 				       CNC_BREAK, com_cnm_state);
2115 			if (cn_trapped)
2116 				continue;
2117 #if defined(KGDB) && !defined(DDB)
2118 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2119 				kgdb_connect(1);
2120 				continue;
2121 			}
2122 #endif
2123 		}
2124 
2125 		if (sc->sc_type == COM_TYPE_BCMAUXUART && ISSET(iir, IIR_RXRDY))
2126 			lsr |= LSR_RXRDY;
2127 
2128 		if (ISSET(lsr, LSR_RCV_MASK) &&
2129 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2130 			while (cc > 0) {
2131 				int cn_trapped = 0;
2132 				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
2133 				put[1] = lsr;
2134 				cn_check_magic(sc->sc_tty->t_dev,
2135 					       put[0], com_cnm_state);
2136 				if (cn_trapped)
2137 					goto next;
2138 				put += 2;
2139 				if (put >= end)
2140 					put = sc->sc_rbuf;
2141 				cc--;
2142 			next:
2143 				lsr = CSR_READ_1(regsp, COM_REG_LSR);
2144 				if (!ISSET(lsr, LSR_RCV_MASK))
2145 					break;
2146 			}
2147 
2148 			/*
2149 			 * Current string of incoming characters ended because
2150 			 * no more data was available or we ran out of space.
2151 			 * Schedule a receive event if any data was received.
2152 			 * If we're out of space, turn off receive interrupts.
2153 			 */
2154 			sc->sc_rbput = put;
2155 			sc->sc_rbavail = cc;
2156 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2157 				sc->sc_rx_ready = 1;
2158 
2159 			/*
2160 			 * See if we are in danger of overflowing a buffer. If
2161 			 * so, use hardware flow control to ease the pressure.
2162 			 */
2163 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2164 			    cc < sc->sc_r_hiwat) {
2165 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2166 				com_hwiflow(sc);
2167 			}
2168 
2169 			/*
2170 			 * If we're out of space, disable receive interrupts
2171 			 * until the queue has drained a bit.
2172 			 */
2173 			if (!cc) {
2174 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2175 				switch (sc->sc_type) {
2176 				case COM_TYPE_PXA2x0:
2177 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
2178 					break;
2179 				case COM_TYPE_INGENIC:
2180 				case COM_TYPE_TEGRA:
2181 					CLR(sc->sc_ier,
2182 					    IER_ERXRDY | IER_ERXTOUT);
2183 					break;
2184 				default:
2185 					CLR(sc->sc_ier, IER_ERXRDY);
2186 					break;
2187 				}
2188 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2189 			}
2190 		} else {
2191 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
2192 				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
2193 				continue;
2194 			}
2195 		}
2196 
2197 		msr = CSR_READ_1(regsp, COM_REG_MSR);
2198 		delta = msr ^ sc->sc_msr;
2199 		sc->sc_msr = msr;
2200 		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
2201 		    (delta & MSR_DCD)) {
2202 			mutex_spin_enter(&timecounter_lock);
2203 			pps_capture(&sc->sc_pps_state);
2204 			pps_event(&sc->sc_pps_state,
2205 			    (msr & MSR_DCD) ?
2206 			    PPS_CAPTUREASSERT :
2207 			    PPS_CAPTURECLEAR);
2208 			mutex_spin_exit(&timecounter_lock);
2209 		}
2210 
2211 		/*
2212 		 * Process normal status changes
2213 		 */
2214 		if (ISSET(delta, sc->sc_msr_mask)) {
2215 			SET(sc->sc_msr_delta, delta);
2216 
2217 			/*
2218 			 * Stop output immediately if we lose the output
2219 			 * flow control signal or carrier detect.
2220 			 */
2221 			if (ISSET(~msr, sc->sc_msr_mask)) {
2222 				sc->sc_tbc = 0;
2223 				sc->sc_heldtbc = 0;
2224 #ifdef COM_DEBUG
2225 				if (com_debug)
2226 					comstatus(sc, "comintr  ");
2227 #endif
2228 			}
2229 
2230 			sc->sc_st_check = 1;
2231 		}
2232 	} while (!ISSET((iir =
2233 	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
2234 	    /*
2235 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
2236 	     * by IIR read, so we can't do this way: `process all interrupts,
2237 	     * then do TX if possible'.
2238 	     */
2239 	    (iir & IIR_IMASK) != IIR_TXRDY);
2240 
2241 	/*
2242 	 * Read LSR again, since there may be an interrupt between
2243 	 * the last LSR read and IIR read above.
2244 	 */
2245 	lsr = CSR_READ_1(regsp, COM_REG_LSR);
2246 
2247 	/*
2248 	 * See if data can be transmitted as well.
2249 	 * Schedule tx done event if no data left
2250 	 * and tty was marked busy.
2251 	 */
2252 	if (ISSET(lsr, LSR_TXRDY)) {
2253 		/*
2254 		 * If we've delayed a parameter change, do it now, and restart
2255 		 * output.
2256 		 */
2257 		if (sc->sc_heldchange) {
2258 			com_loadchannelregs(sc);
2259 			sc->sc_heldchange = 0;
2260 			sc->sc_tbc = sc->sc_heldtbc;
2261 			sc->sc_heldtbc = 0;
2262 		}
2263 
2264 		/* Output the next chunk of the contiguous buffer, if any. */
2265 		if (sc->sc_tbc > 0) {
2266 			u_int n;
2267 
2268 			n = sc->sc_tbc;
2269 			if (n > sc->sc_fifolen)
2270 				n = sc->sc_fifolen;
2271 			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
2272 			sc->sc_tbc -= n;
2273 			sc->sc_tba += n;
2274 		} else {
2275 			/* Disable transmit completion interrupts if necessary. */
2276 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2277 				CLR(sc->sc_ier, IER_ETXRDY);
2278 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2279 			}
2280 			if (sc->sc_tx_busy) {
2281 				sc->sc_tx_busy = 0;
2282 				sc->sc_tx_done = 1;
2283 			}
2284 		}
2285 	}
2286 
2287 	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
2288 		goto again;
2289 
2290 	mutex_spin_exit(&sc->sc_lock);
2291 
2292 	/* Wake up the poller. */
2293 	softint_schedule(sc->sc_si);
2294 
2295 #ifdef RND_COM
2296 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2297 #endif
2298 
2299 	return (1);
2300 }
2301 
2302 /*
2303  * The following functions are polled getc and putc routines, shared
2304  * by the console and kgdb glue.
2305  *
2306  * The read-ahead code is so that you can detect pending in-band
2307  * cn_magic in polled mode while doing output rather than having to
2308  * wait until the kernel decides it needs input.
2309  */
2310 
2311 #define MAX_READAHEAD	20
2312 static int com_readahead[MAX_READAHEAD];
2313 static int com_readaheadcount = 0;
2314 
2315 int
2316 com_common_getc(dev_t dev, struct com_regs *regsp)
2317 {
2318 	int s = splserial();
2319 	u_char stat, c;
2320 
2321 	/* got a character from reading things earlier */
2322 	if (com_readaheadcount > 0) {
2323 		int i;
2324 
2325 		c = com_readahead[0];
2326 		for (i = 1; i < com_readaheadcount; i++) {
2327 			com_readahead[i-1] = com_readahead[i];
2328 		}
2329 		com_readaheadcount--;
2330 		splx(s);
2331 		return (c);
2332 	}
2333 
2334 	/* don't block until a character becomes available */
2335 	if (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2336 		splx(s);
2337 		return -1;
2338 	}
2339 
2340 	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2341 	stat = CSR_READ_1(regsp, COM_REG_IIR);
2342 	{
2343 		int cn_trapped = 0;	/* required by cn_trap, see above */
2344 #ifdef DDB
2345 		extern int db_active;
2346 		if (!db_active)
2347 #endif
2348 			cn_check_magic(dev, c, com_cnm_state);
2349 	}
2350 	splx(s);
2351 	return (c);
2352 }
2353 
2354 static void
2355 com_common_putc(dev_t dev, struct com_regs *regsp, int c)
2356 {
2357 	int s = splserial();
2358 	int cin, stat, timo;
2359 
2360 	if (com_readaheadcount < MAX_READAHEAD
2361 	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2362 		int cn_trapped = 0;
2363 		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2364 		stat = CSR_READ_1(regsp, COM_REG_IIR);
2365 		cn_check_magic(dev, cin, com_cnm_state);
2366 		com_readahead[com_readaheadcount++] = cin;
2367 	}
2368 
2369 	/* wait for any pending transmission to finish */
2370 	timo = 150000;
2371 	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2372 		continue;
2373 
2374 	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2375 	COM_BARRIER(regsp, BR | BW);
2376 
2377 	splx(s);
2378 }
2379 
2380 /*
2381  * Initialize UART for use as console or KGDB line.
2382  */
2383 int
2384 cominit(struct com_regs *regsp, int rate, int frequency, int type,
2385     tcflag_t cflag)
2386 {
2387 
2388 	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2389 		&regsp->cr_ioh))
2390 		return (ENOMEM); /* ??? */
2391 
2392 	if (type == COM_TYPE_OMAP) {
2393 		/* disable before changing settings */
2394 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
2395 	}
2396 
2397 	rate = comspeed(rate, frequency, type);
2398 	if (__predict_true(rate != -1)) {
2399 		if (type == COM_TYPE_AU1x00) {
2400 			CSR_WRITE_2(regsp, COM_REG_DLBL, rate);
2401 		} else {
2402 			/* no EFR on alchemy */
2403 			if ((type != COM_TYPE_16550_NOERS) &&
2404 			    (type != COM_TYPE_INGENIC)) {
2405 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2406 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2407 			}
2408 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2409 			CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2410 			CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2411 		}
2412 	}
2413 	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2414 	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2415 
2416 	if (type == COM_TYPE_INGENIC) {
2417 		CSR_WRITE_1(regsp, COM_REG_FIFO,
2418 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2419 		    FIFO_TRIGGER_1 | FIFO_UART_ON);
2420 	} else {
2421 		CSR_WRITE_1(regsp, COM_REG_FIFO,
2422 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2423 		    FIFO_TRIGGER_1);
2424 	}
2425 
2426 	if (type == COM_TYPE_OMAP) {
2427 		/* setup the fifos.  the FCR value is not used as long
2428 		   as SCR[6] and SCR[7] are 0, which they are at reset
2429 		   and we never touch the SCR register */
2430 		uint8_t rx_fifo_trig = 40;
2431 		uint8_t tx_fifo_trig = 60;
2432 		uint8_t rx_start = 8;
2433 		uint8_t rx_halt = 60;
2434 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
2435 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
2436 
2437 		/* enable access to TCR & TLR */
2438 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS | MCR_TCR_TLR);
2439 
2440 		/* write tcr and tlr values */
2441 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
2442 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
2443 
2444 		/* disable access to TCR & TLR */
2445 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2446 
2447 		/* enable again, but mode is based on speed */
2448 		if (rate > 230400) {
2449 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
2450 		} else {
2451 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
2452 		}
2453 	}
2454 
2455 	if (type == COM_TYPE_PXA2x0)
2456 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2457 	else
2458 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2459 
2460 	return (0);
2461 }
2462 
2463 int
2464 comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2465     tcflag_t cflag)
2466 {
2467 	int res;
2468 
2469 	comcons_info.regs = *regsp;
2470 
2471 	res = cominit(&comcons_info.regs, rate, frequency, type, cflag);
2472 	if (res)
2473 		return (res);
2474 
2475 	cn_tab = &comcons;
2476 	cn_init_magic(&com_cnm_state);
2477 	cn_set_magic("\047\001"); /* default magic is BREAK */
2478 
2479 	comcons_info.frequency = frequency;
2480 	comcons_info.type = type;
2481 	comcons_info.rate = rate;
2482 	comcons_info.cflag = cflag;
2483 
2484 	return (0);
2485 }
2486 
2487 int
2488 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2489     int type, tcflag_t cflag)
2490 {
2491 	struct com_regs	regs;
2492 
2493 	memset(&regs, 0, sizeof regs);
2494 	regs.cr_iot = iot;
2495 	regs.cr_iobase = iobase;
2496 	regs.cr_nports = COM_NPORTS;
2497 #ifdef	COM_REGMAP
2498 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2499 #endif
2500 
2501 	return comcnattach1(&regs, rate, frequency, type, cflag);
2502 }
2503 
2504 static int
2505 comcnreattach(void)
2506 {
2507 	return comcnattach1(&comcons_info.regs, comcons_info.rate,
2508 	    comcons_info.frequency, comcons_info.type, comcons_info.cflag);
2509 }
2510 
2511 int
2512 comcngetc(dev_t dev)
2513 {
2514 
2515 	return (com_common_getc(dev, &comcons_info.regs));
2516 }
2517 
2518 /*
2519  * Console kernel output character routine.
2520  */
2521 void
2522 comcnputc(dev_t dev, int c)
2523 {
2524 
2525 	com_common_putc(dev, &comcons_info.regs, c);
2526 }
2527 
2528 void
2529 comcnpollc(dev_t dev, int on)
2530 {
2531 
2532 	com_readaheadcount = 0;
2533 }
2534 
2535 #ifdef KGDB
2536 int
2537 com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2538     tcflag_t cflag)
2539 {
2540 	int res;
2541 
2542 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
2543 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
2544 #if !defined(DDB)
2545 		return (EBUSY); /* cannot share with console */
2546 #else
2547 		comkgdbregs = *regsp;
2548 		comkgdbregs.cr_ioh = comcons_info.regs.cr_ioh;
2549 #endif
2550 	} else {
2551 		comkgdbregs = *regsp;
2552 		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2553 		if (res)
2554 			return (res);
2555 
2556 		/*
2557 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2558 		 * expects this to be initialized
2559 		 */
2560 		cn_init_magic(&com_cnm_state);
2561 		cn_set_magic("\047\001");
2562 	}
2563 
2564 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2565 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2566 
2567 	return (0);
2568 }
2569 
2570 int
2571 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2572     int frequency, int type, tcflag_t cflag)
2573 {
2574 	struct com_regs regs;
2575 
2576 	regs.cr_iot = iot;
2577 	regs.cr_nports = COM_NPORTS;
2578 	regs.cr_iobase = iobase;
2579 #ifdef COM_REGMAP
2580 	memcpy(regs.cr_map, com_std_map, sizeof (regs.cr_map));
2581 #endif
2582 
2583 	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2584 }
2585 
2586 /* ARGSUSED */
2587 int
2588 com_kgdb_getc(void *arg)
2589 {
2590 
2591 	return (com_common_getc(NODEV, &comkgdbregs));
2592 }
2593 
2594 /* ARGSUSED */
2595 void
2596 com_kgdb_putc(void *arg, int c)
2597 {
2598 
2599 	com_common_putc(NODEV, &comkgdbregs, c);
2600 }
2601 #endif /* KGDB */
2602 
2603 /* helper function to identify the com ports used by
2604  console or KGDB (and not yet autoconf attached) */
2605 int
2606 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2607 {
2608 	bus_space_handle_t help;
2609 
2610 	if (!comconsattached &&
2611 	    bus_space_is_equal(iot, comcons_info.regs.cr_iot) &&
2612 	    iobase == comcons_info.regs.cr_iobase)
2613 		help = comcons_info.regs.cr_ioh;
2614 #ifdef KGDB
2615 	else if (!com_kgdb_attached &&
2616 	    bus_space_is_equal(iot, comkgdbregs.cr_iot) &&
2617 	    iobase == comkgdbregs.cr_iobase)
2618 		help = comkgdbregs.cr_ioh;
2619 #endif
2620 	else
2621 		return (0);
2622 
2623 	if (ioh)
2624 		*ioh = help;
2625 	return (1);
2626 }
2627 
2628 /*
2629  * this routine exists to serve as a shutdown hook for systems that
2630  * have firmware which doesn't interact properly with a com device in
2631  * FIFO mode.
2632  */
2633 bool
2634 com_cleanup(device_t self, int how)
2635 {
2636 	struct com_softc *sc = device_private(self);
2637 
2638 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2639 		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2640 
2641 	return true;
2642 }
2643 
2644 bool
2645 com_suspend(device_t self, const pmf_qual_t *qual)
2646 {
2647 	struct com_softc *sc = device_private(self);
2648 
2649 #if 0
2650 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) && cn_tab == &comcons)
2651 		cn_tab = &comcons_suspend;
2652 #endif
2653 
2654 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2655 	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2656 
2657 	return true;
2658 }
2659 
2660 bool
2661 com_resume(device_t self, const pmf_qual_t *qual)
2662 {
2663 	struct com_softc *sc = device_private(self);
2664 
2665 	mutex_spin_enter(&sc->sc_lock);
2666 	com_loadchannelregs(sc);
2667 	mutex_spin_exit(&sc->sc_lock);
2668 
2669 	return true;
2670 }
2671