xref: /netbsd-src/sys/arch/evbarm/dev/plcom.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /*	$NetBSD: plcom.c,v 1.67 2023/01/24 06:56:40 mlelstv Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001 ARM Ltd
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the company may not be used to endorse or promote
16  *    products derived from this software without specific prior written
17  *    permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * Copyright (c) 1998, 1999, 2012 The NetBSD Foundation, Inc.
32  * All rights reserved.
33  *
34  * This code is derived from software contributed to The NetBSD Foundation
35  * by Charles M. Hannum and Nick Hudson.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  *
46  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
47  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
48  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
49  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
50  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
51  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
52  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
53  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
54  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
55  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
56  * POSSIBILITY OF SUCH DAMAGE.
57  */
58 
59 /*
60  * Copyright (c) 1991 The Regents of the University of California.
61  * All rights reserved.
62  *
63  * Redistribution and use in source and binary forms, with or without
64  * modification, are permitted provided that the following conditions
65  * are met:
66  * 1. Redistributions of source code must retain the above copyright
67  *    notice, this list of conditions and the following disclaimer.
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in the
70  *    documentation and/or other materials provided with the distribution.
71  * 3. Neither the name of the University nor the names of its contributors
72  *    may be used to endorse or promote products derived from this software
73  *    without specific prior written permission.
74  *
75  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
76  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
77  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
78  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
79  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
80  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
81  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
82  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
83  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
84  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
85  * SUCH DAMAGE.
86  *
87  *	@(#)com.c	7.5 (Berkeley) 5/16/91
88  */
89 
90 /*
91  * COM driver for the Prime Cell PL010 and PL011 UARTs. Both are is similar to
92  * the 16C550, but have a completely different programmer's model.
93  * Derived from the NS16550AF com driver.
94  */
95 
96 #include <sys/cdefs.h>
97 __KERNEL_RCSID(0, "$NetBSD: plcom.c,v 1.67 2023/01/24 06:56:40 mlelstv Exp $");
98 
99 #include "opt_plcom.h"
100 #include "opt_kgdb.h"
101 #include "opt_lockdebug.h"
102 #include "opt_multiprocessor.h"
103 
104 /*
105  * Override cnmagic(9) macro before including <sys/systm.h>.
106  * We need to know if cn_check_magic triggered debugger, so set a flag.
107  * Callers of cn_check_magic must declare int cn_trapped = 0;
108  * XXX: this is *ugly*!
109  */
110 #define cn_trap()				\
111 	do {					\
112 		console_debugger();		\
113 		cn_trapped = 1;			\
114 	} while (/* CONSTCOND */ 0)
115 
116 #include <sys/param.h>
117 #include <sys/systm.h>
118 #include <sys/ioctl.h>
119 #include <sys/select.h>
120 #include <sys/tty.h>
121 #include <sys/proc.h>
122 #include <sys/conf.h>
123 #include <sys/file.h>
124 #include <sys/uio.h>
125 #include <sys/kernel.h>
126 #include <sys/syslog.h>
127 #include <sys/types.h>
128 #include <sys/device.h>
129 #include <sys/kmem.h>
130 #include <sys/timepps.h>
131 #include <sys/vnode.h>
132 #include <sys/kauth.h>
133 #include <sys/intr.h>
134 #include <sys/bus.h>
135 #ifdef RND_COM
136 #include <sys/rndsource.h>
137 #endif
138 
139 #include <ddb/db_active.h>
140 
141 #include <evbarm/dev/plcomreg.h>
142 #include <evbarm/dev/plcomvar.h>
143 
144 #include <dev/cons.h>
145 
146 static void plcom_enable_debugport (struct plcom_softc *);
147 
148 void	plcom_config	(struct plcom_softc *);
149 void	plcom_shutdown	(struct plcom_softc *);
150 int	pl010comspeed	(long, long);
151 int	pl011comspeed	(long, long);
152 static	uint32_t	cflag2lcr (tcflag_t);
153 int	plcomparam	(struct tty *, struct termios *);
154 void	plcomstart	(struct tty *);
155 int	plcomhwiflow	(struct tty *, int);
156 
157 void	plcom_loadchannelregs (struct plcom_softc *);
158 void	plcom_hwiflow	(struct plcom_softc *);
159 void	plcom_break	(struct plcom_softc *, int);
160 void	plcom_modem	(struct plcom_softc *, int);
161 void	tiocm_to_plcom	(struct plcom_softc *, u_long, int);
162 int	plcom_to_tiocm	(struct plcom_softc *);
163 void	plcom_iflush	(struct plcom_softc *);
164 
165 int	plcom_common_getc (dev_t, struct plcom_instance *);
166 void	plcom_common_putc (dev_t, struct plcom_instance *, int);
167 
168 int	plcominit	(struct plcom_instance *, int, int, tcflag_t);
169 
170 dev_type_open(plcomopen);
171 dev_type_close(plcomclose);
172 dev_type_read(plcomread);
173 dev_type_write(plcomwrite);
174 dev_type_ioctl(plcomioctl);
175 dev_type_stop(plcomstop);
176 dev_type_tty(plcomtty);
177 dev_type_poll(plcompoll);
178 
179 int	plcomcngetc	(dev_t);
180 void	plcomcnputc	(dev_t, int);
181 void	plcomcnpollc	(dev_t, int);
182 void	plcomcnhalt	(dev_t);
183 
184 #define	integrate	static inline
185 void 	plcomsoft	(void *);
186 integrate void plcom_rxsoft	(struct plcom_softc *, struct tty *);
187 integrate void plcom_txsoft	(struct plcom_softc *, struct tty *);
188 integrate void plcom_stsoft	(struct plcom_softc *, struct tty *);
189 integrate void plcom_schedrx	(struct plcom_softc *);
190 void	plcomdiag		(void *);
191 
192 bool	plcom_intstatus(struct plcom_instance *, u_int *);
193 
194 extern struct cfdriver plcom_cd;
195 
196 const struct cdevsw plcom_cdevsw = {
197 	.d_open = plcomopen,
198 	.d_close = plcomclose,
199 	.d_read = plcomread,
200 	.d_write = plcomwrite,
201 	.d_ioctl = plcomioctl,
202 	.d_stop = plcomstop,
203 	.d_tty = plcomtty,
204 	.d_poll = plcompoll,
205 	.d_mmap = nommap,
206 	.d_kqfilter = ttykqfilter,
207 	.d_discard = nodiscard,
208 	.d_flag = D_TTY
209 };
210 
211 /*
212  * Make this an option variable one can patch.
213  * But be warned:  this must be a power of 2!
214  */
215 u_int plcom_rbuf_size = PLCOM_RING_SIZE;
216 
217 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
218 u_int plcom_rbuf_hiwat = (PLCOM_RING_SIZE * 1) / 4;
219 u_int plcom_rbuf_lowat = (PLCOM_RING_SIZE * 3) / 4;
220 
221 static int	plcomconsunit = -1;
222 static struct plcom_instance plcomcons_info;
223 
224 static int plcomconsattached;
225 static int plcomconsrate;
226 static tcflag_t plcomconscflag;
227 static struct cnm_state plcom_cnm_state;
228 
229 static int ppscap =
230 	PPS_TSFMT_TSPEC |
231 	PPS_CAPTUREASSERT |
232 	PPS_CAPTURECLEAR |
233 #ifdef  PPS_SYNC
234 	PPS_HARDPPSONASSERT | PPS_HARDPPSONCLEAR |
235 #endif	/* PPS_SYNC */
236 	PPS_OFFSETASSERT | PPS_OFFSETCLEAR;
237 
238 #ifdef KGDB
239 #include <sys/kgdb.h>
240 
241 static struct plcom_instance plcomkgdb_info;
242 static int plcom_kgdb_attached;
243 
244 int	plcom_kgdb_getc (void *);
245 void	plcom_kgdb_putc (void *, int);
246 #endif /* KGDB */
247 
248 #define	PLCOMDIALOUT_MASK	TTDIALOUT_MASK
249 
250 #define	PLCOMUNIT(x)	TTUNIT(x)
251 #define	PLCOMDIALOUT(x)	TTDIALOUT(x)
252 
253 #define	PLCOM_ISALIVE(sc)	((sc)->enabled != 0 && \
254 				 device_is_active((sc)->sc_dev))
255 
256 #define	BR	BUS_SPACE_BARRIER_READ
257 #define	BW	BUS_SPACE_BARRIER_WRITE
258 #define PLCOM_BARRIER(pi, f)	\
259     bus_space_barrier((pi)->pi_iot, (pi)->pi_ioh, 0, (pi)->pi_size, (f))
260 
261 static uint8_t
262 pread1(struct plcom_instance *pi, bus_size_t reg)
263 {
264 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS))
265 		return bus_space_read_1(pi->pi_iot, pi->pi_ioh, reg);
266 
267 	return bus_space_read_4(pi->pi_iot, pi->pi_ioh, reg & -4) >>
268 	    (8 * (reg & 3));
269 }
270 
271 static uint16_t
272 pread2(struct plcom_instance *pi, bus_size_t reg)
273 {
274 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS))
275 		return bus_space_read_2(pi->pi_iot, pi->pi_ioh, reg);
276 
277 	return bus_space_read_4(pi->pi_iot, pi->pi_ioh, reg & -4) >>
278 	    (8 * (reg & 3));
279 }
280 
281 static void
282 pwrite1(struct plcom_instance *pi, bus_size_t o, uint8_t val)
283 {
284 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS)) {
285 		bus_space_write_1(pi->pi_iot, pi->pi_ioh, o, val);
286 	} else {
287 		const size_t shift = 8 * (o & 3);
288 		o &= -4;
289 		uint32_t tmp = bus_space_read_4(pi->pi_iot, pi->pi_ioh, o);
290 		tmp = (val << shift) | (tmp & ~(0xff << shift));
291 		bus_space_write_4(pi->pi_iot, pi->pi_ioh, o, tmp);
292 	}
293 }
294 
295 static void
296 pwrite2(struct plcom_instance *pi, bus_size_t o, uint16_t val)
297 {
298 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS)) {
299 		bus_space_write_2(pi->pi_iot, pi->pi_ioh, o, val);
300 	} else {
301 		const size_t shift = 8 * (o & 3);
302 		o &= -4;
303 		uint32_t tmp = bus_space_read_4(pi->pi_iot, pi->pi_ioh, o);
304 		tmp = (val << shift) | (tmp & ~(0xffff << shift));
305 		bus_space_write_4(pi->pi_iot, pi->pi_ioh, o, tmp);
306 	}
307 }
308 
309 static void
310 pwritem1(struct plcom_instance *pi, bus_size_t o, const uint8_t *datap,
311     bus_size_t count)
312 {
313 	if (!ISSET(pi->pi_flags, PLC_FLAG_32BIT_ACCESS)) {
314 		bus_space_write_multi_1(pi->pi_iot, pi->pi_ioh, o, datap, count);
315 	} else {
316 		KASSERT((o & 3) == 0);
317 		while (count--) {
318 			bus_space_write_4(pi->pi_iot, pi->pi_ioh, o, *datap++);
319 		};
320 	}
321 }
322 
323 #define	PREAD1(pi, reg)		pread1(pi, reg)
324 #define	PREAD2(pi, reg)		pread2(pi, reg)
325 #define	PREAD4(pi, reg)		\
326 	bus_space_read_4((pi)->pi_iot, (pi)->pi_ioh, (reg))
327 
328 #define	PWRITE1(pi, reg, val)	pwrite1(pi, reg, val)
329 #define	PWRITEM1(pi, reg, d, c)	pwritem1(pi, reg, d, c)
330 #define	PWRITE2(pi, reg, val)	pwrite2(pi, reg, val)
331 #define	PWRITE4(pi, reg, val)	\
332 	bus_space_write_4((pi)->pi_iot, (pi)->pi_ioh, (reg), (val))
333 
334 int
335 pl010comspeed(long speed, long frequency)
336 {
337 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
338 
339 	int x, err;
340 
341 #if 0
342 	if (speed == 0)
343 		return 0;
344 #endif
345 	if (speed <= 0)
346 		return -1;
347 	x = divrnd(frequency / 16, speed);
348 	if (x <= 0)
349 		return -1;
350 	err = divrnd(((quad_t)frequency) * 1000 / 16, speed * x) - 1000;
351 	if (err < 0)
352 		err = -err;
353 	if (err > PLCOM_TOLERANCE)
354 		return -1;
355 	return x;
356 
357 #undef	divrnd
358 }
359 
360 int
361 pl011comspeed(long speed, long frequency)
362 {
363 	int denom = 16 * speed;
364 	int div = frequency / denom;
365 	int rem = frequency % denom;
366 
367 	int ibrd = div << 6;
368 	int fbrd = (((8 * rem) / speed) + 1) / 2;
369 
370 	/* Tolerance? */
371 	return ibrd | fbrd;
372 }
373 
374 #ifdef PLCOM_DEBUG
375 int	plcom_debug = 0;
376 
377 void plcomstatus (struct plcom_softc *, const char *);
378 void
379 plcomstatus(struct plcom_softc *sc, const char *str)
380 {
381 	struct tty *tp = sc->sc_tty;
382 
383 	printf("%s: %s %sclocal  %sdcd %sts_carr_on %sdtr %stx_stopped\n",
384 	    device_xname(sc->sc_dev), str,
385 	    ISSET(tp->t_cflag, CLOCAL) ? "+" : "-",
386 	    ISSET(sc->sc_msr, PL01X_MSR_DCD) ? "+" : "-",
387 	    ISSET(tp->t_state, TS_CARR_ON) ? "+" : "-",
388 	    ISSET(sc->sc_mcr, PL01X_MCR_DTR) ? "+" : "-",
389 	    sc->sc_tx_stopped ? "+" : "-");
390 
391 	printf("%s: %s %scrtscts %scts %sts_ttstop  %srts %xrx_flags\n",
392 	    device_xname(sc->sc_dev), str,
393 	    ISSET(tp->t_cflag, CRTSCTS) ? "+" : "-",
394 	    ISSET(sc->sc_msr, PL01X_MSR_CTS) ? "+" : "-",
395 	    ISSET(tp->t_state, TS_TTSTOP) ? "+" : "-",
396 	    ISSET(sc->sc_mcr, PL01X_MCR_RTS) ? "+" : "-",
397 	    sc->sc_rx_flags);
398 }
399 #endif
400 
401 #if 0
402 int
403 plcomprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
404 {
405 	int data;
406 
407 	/* Disable the UART.  */
408 	bus_space_write_1(iot, ioh, plcom_cr, 0);
409 	/* Make sure the FIFO is off.  */
410 	bus_space_write_4(iot, ioh, plcom_lcr, PL01X_LCR_8BITS);
411 	/* Disable interrupts.  */
412 	bus_space_write_1(iot, ioh, plcom_iir, 0);
413 
414 	/* Make sure we swallow anything in the receiving register.  */
415 	data = bus_space_read_1(iot, ioh, plcom_dr);
416 
417 	if (bus_space_read_4(iot, ioh, plcom_lcr) != PL01X_LCR_8BITS)
418 		return 0;
419 
420 	data = bus_space_read_1(iot, ioh, plcom_fr) & (PL01X_FR_RXFF | PL01X_FR_RXFE);
421 
422 	if (data != PL01X_FR_RXFE)
423 		return 0;
424 
425 	return 1;
426 }
427 #endif
428 
429 /*
430  * No locking in this routine; it is only called during attach,
431  * or with the port already locked.
432  */
433 static void
434 plcom_enable_debugport(struct plcom_softc *sc)
435 {
436 	struct plcom_instance *pi = &sc->sc_pi;
437 
438 	sc->sc_cr = PL01X_CR_UARTEN;
439 	SET(sc->sc_mcr, PL01X_MCR_DTR | PL01X_MCR_RTS);
440 
441 	/* Turn on line break interrupt, set carrier. */
442 	switch (pi->pi_type) {
443 	case PLCOM_TYPE_PL010:
444 		SET(sc->sc_cr, PL010_CR_RIE | PL010_CR_RTIE);
445 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
446 		if (sc->sc_set_mcr) {
447 			/* XXX device_unit() abuse */
448 			sc->sc_set_mcr(sc->sc_set_mcr_arg,
449 			    device_unit(sc->sc_dev), sc->sc_mcr);
450 		}
451 		break;
452 	case PLCOM_TYPE_PL011:
453 	case PLCOM_TYPE_GENERIC_UART:
454 		sc->sc_imsc = PL011_INT_RX | PL011_INT_RT;
455 		SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
456 		SET(sc->sc_cr, PL011_MCR(sc->sc_mcr));
457 		PWRITE2(pi, PL011COM_CR, sc->sc_cr);
458 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
459 		break;
460 	}
461 
462 }
463 
464 void
465 plcom_attach_subr(struct plcom_softc *sc)
466 {
467 	struct plcom_instance *pi = &sc->sc_pi;
468 	struct tty *tp;
469 
470 	callout_init(&sc->sc_diag_callout, 0);
471 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
472 
473 	switch (pi->pi_type) {
474 	case PLCOM_TYPE_PL010:
475 	case PLCOM_TYPE_PL011:
476 	case PLCOM_TYPE_GENERIC_UART:
477 		break;
478 	default:
479 		aprint_error_dev(sc->sc_dev,
480 		    "Unknown plcom type: %d\n", pi->pi_type);
481 		return;
482 	}
483 
484 	/* Disable interrupts before configuring the device. */
485 	sc->sc_cr = 0;
486 	sc->sc_imsc = 0;
487 
488 	if (bus_space_is_equal(pi->pi_iot, plcomcons_info.pi_iot) &&
489 	    pi->pi_iobase == plcomcons_info.pi_iobase) {
490 		plcomconsattached = 1;
491 
492 		/* Make sure the console is always "hardwired". */
493 		delay(1000);			/* wait for output to finish */
494 		SET(sc->sc_hwflags, PLCOM_HW_CONSOLE);
495 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
496 		/*
497 		 * Must re-enable the console immediately, or we will
498 		 * hang when trying to print.
499 		 */
500 		sc->sc_cr = PL01X_CR_UARTEN;
501 		switch (pi->pi_type) {
502 		case PLCOM_TYPE_PL011:
503 		case PLCOM_TYPE_GENERIC_UART:
504 			SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
505 			break;
506 		}
507 	}
508 
509 	switch (pi->pi_type) {
510 	case PLCOM_TYPE_PL011:
511 		if (pi->pi_periphid == 0) {
512 			pi->pi_periphid = PREAD1(pi, PL011COM_PID0) << 0
513 				| PREAD1(pi, PL011COM_PID1) << 8
514 				| PREAD1(pi, PL011COM_PID2) << 16
515 				| PREAD1(pi, PL011COM_PID3) << 24;
516 		}
517 		aprint_debug_dev(sc->sc_dev, "PID %08x\n", pi->pi_periphid);
518 		break;
519 	}
520 
521 	switch (pi->pi_type) {
522 	case PLCOM_TYPE_PL010:
523 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
524 		break;
525 
526 	case PLCOM_TYPE_PL011:
527 	case PLCOM_TYPE_GENERIC_UART:
528 		PWRITE2(pi, PL011COM_CR, sc->sc_cr);
529 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
530 		break;
531 	}
532 
533 	if (sc->sc_fifolen == 0) {
534 		switch (pi->pi_type) {
535 		case PLCOM_TYPE_PL010:
536 			/*
537 			 * The PL010 has a 16-byte fifo, but the tx interrupt
538 			 * triggers when there is space for 8 more bytes.
539 			*/
540 			sc->sc_fifolen = 8;
541 			break;
542 		case PLCOM_TYPE_PL011:
543 			/* Some revisions have a 32 byte TX FIFO */
544 			switch (pi->pi_periphid & (PL011_DESIGNER_MASK | PL011_HWREV_MASK)) {
545 			case PL011_DESIGNER_ARM | __SHIFTIN(0, PL011_HWREV_MASK):
546 			case PL011_DESIGNER_ARM | __SHIFTIN(1, PL011_HWREV_MASK):
547 			case PL011_DESIGNER_ARM | __SHIFTIN(2, PL011_HWREV_MASK):
548 				sc->sc_fifolen = 16;
549 				break;
550 			default:
551 				sc->sc_fifolen = 32;
552 				break;
553 			}
554 			break;
555 		case PLCOM_TYPE_GENERIC_UART:
556 			/* At least 32 byte TX FIFO */
557 			sc->sc_fifolen = 32;
558 			break;
559 		}
560 	}
561 
562 	/* Safe amount of bytes to fill when TX FIFO signals empty */
563 	sc->sc_burstlen = 1;
564 
565 	if (ISSET(sc->sc_hwflags, PLCOM_HW_TXFIFO_DISABLE)) {
566 		sc->sc_fifolen = 1;
567 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
568 	}
569 
570 	if (sc->sc_fifolen > 1) {
571 		SET(sc->sc_hwflags, PLCOM_HW_FIFO);
572 		aprint_normal_dev(sc->sc_dev, "txfifo %u bytes\n", sc->sc_fifolen);
573 	}
574 
575 	tp = tty_alloc();
576 	tp->t_oproc = plcomstart;
577 	tp->t_param = plcomparam;
578 	tp->t_hwiflow = plcomhwiflow;
579 
580 	sc->sc_tty = tp;
581 	sc->sc_rbuf = kmem_alloc(plcom_rbuf_size << 1, KM_SLEEP);
582 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
583 	sc->sc_rbavail = plcom_rbuf_size;
584 	sc->sc_ebuf = sc->sc_rbuf + (plcom_rbuf_size << 1);
585 
586 	tty_attach(tp);
587 
588 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
589 		int maj;
590 
591 		/* locate the major number */
592 		maj = cdevsw_lookup_major(&plcom_cdevsw);
593 
594 		tp->t_dev = cn_tab->cn_dev = makedev(maj, device_unit(sc->sc_dev));
595 
596 		aprint_normal_dev(sc->sc_dev, "console\n");
597 	}
598 
599 #ifdef KGDB
600 	/*
601 	 * Allow kgdb to "take over" this port.  If this is
602 	 * the kgdb device, it has exclusive use.
603 	 */
604 	if (bus_space_is_equal(pi->pi_iot, plcomkgdb_info.pi_iot) &&
605 	    pi->pi_iobase == plcomkgdb_info.pi_iobase) {
606 		if (!ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
607 			plcom_kgdb_attached = 1;
608 
609 			SET(sc->sc_hwflags, PLCOM_HW_KGDB);
610 		}
611 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
612 	}
613 #endif
614 
615 	sc->sc_si = softint_establish(SOFTINT_SERIAL, plcomsoft, sc);
616 
617 #ifdef RND_COM
618 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
619 	    RND_TYPE_TTY, RND_FLAG_DEFAULT);
620 #endif
621 
622 	/*
623 	 * if there are no enable/disable functions, assume the device
624 	 * is always enabled
625 	 */
626 	if (!sc->enable)
627 		sc->enabled = 1;
628 
629 	plcom_config(sc);
630 
631 	SET(sc->sc_hwflags, PLCOM_HW_DEV_OK);
632 }
633 
634 void
635 plcom_config(struct plcom_softc *sc)
636 {
637 	struct plcom_instance *pi = &sc->sc_pi;
638 
639 	/* Disable interrupts before configuring the device. */
640 	sc->sc_cr = 0;
641 	sc->sc_imsc = 0;
642 	switch (pi->pi_type) {
643 	case PLCOM_TYPE_PL010:
644 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
645 		break;
646 
647 	case PLCOM_TYPE_PL011:
648 	case PLCOM_TYPE_GENERIC_UART:
649 		PWRITE2(pi, PL011COM_CR, sc->sc_cr);
650 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
651 		break;
652 	}
653 
654 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
655 		plcom_enable_debugport(sc);
656 }
657 
658 int
659 plcom_detach(device_t self, int flags)
660 {
661 	struct plcom_softc *sc = device_private(self);
662 	int maj, mn;
663 
664 	if (sc->sc_hwflags & (PLCOM_HW_CONSOLE|PLCOM_HW_KGDB))
665 		return EBUSY;
666 
667 	if (sc->disable != NULL && sc->enabled != 0) {
668 		(*sc->disable)(sc);
669 		sc->enabled = 0;
670 	}
671 
672 	/* locate the major number */
673 	maj = cdevsw_lookup_major(&plcom_cdevsw);
674 
675 	/* Nuke the vnodes for any open instances. */
676 	mn = device_unit(self);
677 	vdevgone(maj, mn, mn, VCHR);
678 
679 	mn |= PLCOMDIALOUT_MASK;
680 	vdevgone(maj, mn, mn, VCHR);
681 
682 	if (sc->sc_rbuf == NULL) {
683 		/*
684 		 * Ring buffer allocation failed in the plcom_attach_subr,
685 		 * only the tty is allocated, and nothing else.
686 		 */
687 		tty_free(sc->sc_tty);
688 		return 0;
689 	}
690 
691 	/* Free the receive buffer. */
692 	kmem_free(sc->sc_rbuf, sc->sc_ebuf - sc->sc_rbuf);
693 
694 	/* Detach and free the tty. */
695 	tty_detach(sc->sc_tty);
696 	tty_free(sc->sc_tty);
697 
698 	/* Unhook the soft interrupt handler. */
699 	softint_disestablish(sc->sc_si);
700 
701 #ifdef RND_COM
702 	/* Unhook the entropy source. */
703 	rnd_detach_source(&sc->rnd_source);
704 #endif
705 	callout_destroy(&sc->sc_diag_callout);
706 
707 	/* Destroy the lock. */
708 	mutex_destroy(&sc->sc_lock);
709 
710 	return 0;
711 }
712 
713 int
714 plcom_activate(device_t self, enum devact act)
715 {
716 	struct plcom_softc *sc = device_private(self);
717 
718 	switch (act) {
719 	case DVACT_DEACTIVATE:
720 		sc->enabled = 0;
721 		return 0;
722 	default:
723 		return EOPNOTSUPP;
724 	}
725 }
726 
727 void
728 plcom_shutdown(struct plcom_softc *sc)
729 {
730 	struct plcom_instance *pi = &sc->sc_pi;
731 	struct tty *tp = sc->sc_tty;
732 	mutex_spin_enter(&sc->sc_lock);
733 
734 	/* If we were asserting flow control, then deassert it. */
735 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
736 	plcom_hwiflow(sc);
737 
738 	/* Clear any break condition set with TIOCSBRK. */
739 	plcom_break(sc, 0);
740 
741 	/* Turn off PPS capture on last close. */
742 	mutex_spin_enter(&timecounter_lock);
743 	sc->sc_ppsmask = 0;
744 	sc->ppsparam.mode = 0;
745 	mutex_spin_exit(&timecounter_lock);
746 
747 	/*
748 	 * Hang up if necessary.  Wait a bit, so the other side has time to
749 	 * notice even if we immediately open the port again.
750 	 * Avoid tsleeping above splhigh().
751 	 */
752 	if (ISSET(tp->t_cflag, HUPCL)) {
753 		plcom_modem(sc, 0);
754 		microuptime(&sc->sc_hup_pending);
755 		sc->sc_hup_pending.tv_sec++;
756 	}
757 
758 	sc->sc_cr = 0;
759 	sc->sc_imsc = 0;
760 	/* Turn off interrupts. */
761 	if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
762 		/* interrupt on break */
763 
764 		sc->sc_cr = PL01X_CR_UARTEN;
765 		sc->sc_imsc = 0;
766 		switch (pi->pi_type) {
767 		case PLCOM_TYPE_PL010:
768 			SET(sc->sc_cr, PL010_CR_RIE | PL010_CR_RTIE);
769 			break;
770 		case PLCOM_TYPE_PL011:
771 		case PLCOM_TYPE_GENERIC_UART:
772 			SET(sc->sc_cr, PL011_CR_RXE);
773 			SET(sc->sc_imsc, PL011_INT_RT | PL011_INT_RX);
774 			break;
775 		}
776 	}
777 	switch (pi->pi_type) {
778 	case PLCOM_TYPE_PL010:
779 		SET(sc->sc_cr, PL010_CR_RIE | PL010_CR_RTIE);
780 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
781 		break;
782 	case PLCOM_TYPE_PL011:
783 	case PLCOM_TYPE_GENERIC_UART:
784 		SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
785 		SET(sc->sc_imsc, PL011_INT_RT | PL011_INT_RX);
786 		PWRITE2(pi, PL011COM_CR, sc->sc_cr);
787 		PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
788 		break;
789 	}
790 
791 	mutex_spin_exit(&sc->sc_lock);
792 	if (sc->disable) {
793 #ifdef DIAGNOSTIC
794 		if (!sc->enabled)
795 			panic("plcom_shutdown: not enabled?");
796 #endif
797 		(*sc->disable)(sc);
798 		sc->enabled = 0;
799 	}
800 }
801 
802 int
803 plcomopen(dev_t dev, int flag, int mode, struct lwp *l)
804 {
805 	struct plcom_softc *sc;
806 	struct plcom_instance *pi;
807 	struct tty *tp;
808 	int s;
809 	int error;
810 
811 	sc = device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
812 	if (sc == NULL || !ISSET(sc->sc_hwflags, PLCOM_HW_DEV_OK) ||
813 		sc->sc_rbuf == NULL)
814 		return ENXIO;
815 
816 	if (!device_is_active(sc->sc_dev))
817 		return ENXIO;
818 
819 	pi = &sc->sc_pi;
820 
821 #ifdef KGDB
822 	/*
823 	 * If this is the kgdb port, no other use is permitted.
824 	 */
825 	if (ISSET(sc->sc_hwflags, PLCOM_HW_KGDB))
826 		return EBUSY;
827 #endif
828 
829 	tp = sc->sc_tty;
830 
831 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
832 		return (EBUSY);
833 
834 	s = spltty();
835 
836 	/*
837 	 * Do the following iff this is a first open.
838 	 */
839 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
840 		struct termios t;
841 		struct timeval now, diff;
842 
843 		tp->t_dev = dev;
844 
845 		if (sc->enable) {
846 			if ((*sc->enable)(sc)) {
847 				splx(s);
848 				aprint_error_dev(sc->sc_dev,
849 				    "device enable failed\n");
850 				return EIO;
851 			}
852 			mutex_spin_enter(&sc->sc_lock);
853 			sc->enabled = 1;
854 			plcom_config(sc);
855 		} else {
856 			mutex_spin_enter(&sc->sc_lock);
857 		}
858 
859 		if (timerisset(&sc->sc_hup_pending)) {
860 			microuptime(&now);
861 			while (timercmp(&now, &sc->sc_hup_pending, <)) {
862 				timersub(&sc->sc_hup_pending, &now, &diff);
863 				const int ms = diff.tv_sec * 100 +
864 				    diff.tv_usec / 1000;
865 				kpause(ttclos, false, uimax(mstohz(ms), 1),
866 				    &sc->sc_lock);
867 				microuptime(&now);
868 			}
869 			timerclear(&sc->sc_hup_pending);
870 		}
871 
872 		/* Turn on interrupts. */
873 		/* IER_ERXRDY | IER_ERLS | IER_EMSC;  */
874 		/* Fetch the current modem control status, needed later. */
875 		sc->sc_cr = PL01X_CR_UARTEN;
876 		switch (pi->pi_type) {
877 		case PLCOM_TYPE_PL010:
878 			SET(sc->sc_cr,
879 			    PL010_CR_RIE | PL010_CR_RTIE | PL010_CR_MSIE);
880 			PWRITE1(pi, PL010COM_CR, sc->sc_cr);
881 			sc->sc_msr = PREAD1(pi, PL01XCOM_FR);
882 			break;
883 		case PLCOM_TYPE_PL011:
884 		case PLCOM_TYPE_GENERIC_UART:
885 			SET(sc->sc_cr, PL011_CR_RXE | PL011_CR_TXE);
886 			SET(sc->sc_imsc, PL011_INT_RT | PL011_INT_RX |
887 			    PL011_INT_MSMASK);
888 			PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
889 			sc->sc_msr = PREAD4(pi, PL01XCOM_FR);
890 			break;
891 		}
892 
893 		/* Clear PPS capture state on first open. */
894 
895 		mutex_spin_enter(&timecounter_lock);
896 		sc->sc_ppsmask = 0;
897 		sc->ppsparam.mode = 0;
898 		mutex_spin_exit(&timecounter_lock);
899 
900 		mutex_spin_exit(&sc->sc_lock);
901 
902 		/*
903 		 * Initialize the termios status to the defaults.  Add in the
904 		 * sticky bits from TIOCSFLAGS.
905 		 */
906 		if (ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
907 			t.c_ospeed = plcomconsrate;
908 			t.c_cflag = plcomconscflag;
909 		} else {
910 			t.c_ospeed = TTYDEF_SPEED;
911 			t.c_cflag = TTYDEF_CFLAG;
912 		}
913 		t.c_ispeed = t.c_ospeed;
914 
915 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
916 			SET(t.c_cflag, CLOCAL);
917 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
918 			SET(t.c_cflag, CRTSCTS);
919 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
920 			SET(t.c_cflag, MDMBUF);
921 		/* Make sure plcomparam() will do something. */
922 		tp->t_ospeed = 0;
923 		(void) plcomparam(tp, &t);
924 		tp->t_iflag = TTYDEF_IFLAG;
925 		tp->t_oflag = TTYDEF_OFLAG;
926 		tp->t_lflag = TTYDEF_LFLAG;
927 		ttychars(tp);
928 		ttsetwater(tp);
929 
930 		mutex_spin_enter(&sc->sc_lock);
931 
932 		/*
933 		 * Turn on DTR.  We must always do this, even if carrier is not
934 		 * present, because otherwise we'd have to use TIOCSDTR
935 		 * immediately after setting CLOCAL, which applications do not
936 		 * expect.  We always assert DTR while the device is open
937 		 * unless explicitly requested to deassert it.
938 		 */
939 		plcom_modem(sc, 1);
940 
941 		/* Clear the input ring, and unblock. */
942 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
943 		sc->sc_rbavail = plcom_rbuf_size;
944 		plcom_iflush(sc);
945 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
946 		plcom_hwiflow(sc);
947 
948 #ifdef PLCOM_DEBUG
949 		if (plcom_debug)
950 			plcomstatus(sc, "plcomopen  ");
951 #endif
952 
953 		mutex_spin_exit(&sc->sc_lock);
954 	}
955 
956 	splx(s);
957 
958 	error = ttyopen(tp, PLCOMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
959 	if (error)
960 		goto bad;
961 
962 	error = (*tp->t_linesw->l_open)(dev, tp);
963 	if (error)
964 		goto bad;
965 
966 	return 0;
967 
968 bad:
969 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
970 		/*
971 		 * We failed to open the device, and nobody else had it opened.
972 		 * Clean up the state as appropriate.
973 		 */
974 		plcom_shutdown(sc);
975 	}
976 
977 	return error;
978 }
979 
980 int
981 plcomclose(dev_t dev, int flag, int mode, struct lwp *l)
982 {
983 	struct plcom_softc *sc =
984 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
985 	struct tty *tp = sc->sc_tty;
986 
987 	/* XXX This is for cons.c. */
988 	if (!ISSET(tp->t_state, TS_ISOPEN))
989 		return 0;
990 
991 	(*tp->t_linesw->l_close)(tp, flag);
992 	ttyclose(tp);
993 
994 	if (PLCOM_ISALIVE(sc) == 0)
995 		return 0;
996 
997 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
998 		/*
999 		 * Although we got a last close, the device may still be in
1000 		 * use; e.g. if this was the dialout node, and there are still
1001 		 * processes waiting for carrier on the non-dialout node.
1002 		 */
1003 		plcom_shutdown(sc);
1004 	}
1005 
1006 	return 0;
1007 }
1008 
1009 int
1010 plcomread(dev_t dev, struct uio *uio, int flag)
1011 {
1012 	struct plcom_softc *sc =
1013 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
1014 	struct tty *tp = sc->sc_tty;
1015 
1016 	if (PLCOM_ISALIVE(sc) == 0)
1017 		return EIO;
1018 
1019 	return (*tp->t_linesw->l_read)(tp, uio, flag);
1020 }
1021 
1022 int
1023 plcomwrite(dev_t dev, struct uio *uio, int flag)
1024 {
1025 	struct plcom_softc *sc =
1026 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
1027 	struct tty *tp = sc->sc_tty;
1028 
1029 	if (PLCOM_ISALIVE(sc) == 0)
1030 		return EIO;
1031 
1032 	return (*tp->t_linesw->l_write)(tp, uio, flag);
1033 }
1034 
1035 int
1036 plcompoll(dev_t dev, int events, struct lwp *l)
1037 {
1038 	struct plcom_softc *sc =
1039 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
1040 	struct tty *tp = sc->sc_tty;
1041 
1042 	if (PLCOM_ISALIVE(sc) == 0)
1043 		return EIO;
1044 
1045 	return (*tp->t_linesw->l_poll)(tp, events, l);
1046 }
1047 
1048 struct tty *
1049 plcomtty(dev_t dev)
1050 {
1051 	struct plcom_softc *sc =
1052 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
1053 	struct tty *tp = sc->sc_tty;
1054 
1055 	return tp;
1056 }
1057 
1058 int
1059 plcomioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1060 {
1061 	struct plcom_softc *sc =
1062 		device_lookup_private(&plcom_cd, PLCOMUNIT(dev));
1063 	struct tty *tp;
1064 	int error;
1065 
1066 	if (sc == NULL)
1067 		return ENXIO;
1068 	if (PLCOM_ISALIVE(sc) == 0)
1069 		return EIO;
1070 
1071 	tp = sc->sc_tty;
1072 
1073 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1074 	if (error != EPASSTHROUGH)
1075 		return error;
1076 
1077 	error = ttioctl(tp, cmd, data, flag, l);
1078 	if (error != EPASSTHROUGH)
1079 		return error;
1080 
1081 	error = 0;
1082 	switch (cmd) {
1083 	case TIOCSFLAGS:
1084 		error = kauth_authorize_device_tty(l->l_cred,
1085 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1086 		break;
1087 	default:
1088 		/* nothing */
1089 		break;
1090 	}
1091 	if (error) {
1092 		return error;
1093 	}
1094 
1095 	mutex_spin_enter(&sc->sc_lock);
1096 	switch (cmd) {
1097 	case TIOCSBRK:
1098 		plcom_break(sc, 1);
1099 		break;
1100 
1101 	case TIOCCBRK:
1102 		plcom_break(sc, 0);
1103 		break;
1104 
1105 	case TIOCSDTR:
1106 		plcom_modem(sc, 1);
1107 		break;
1108 
1109 	case TIOCCDTR:
1110 		plcom_modem(sc, 0);
1111 		break;
1112 
1113 	case TIOCGFLAGS:
1114 		*(int *)data = sc->sc_swflags;
1115 		break;
1116 
1117 	case TIOCSFLAGS:
1118 		sc->sc_swflags = *(int *)data;
1119 		break;
1120 
1121 	case TIOCMSET:
1122 	case TIOCMBIS:
1123 	case TIOCMBIC:
1124 		tiocm_to_plcom(sc, cmd, *(int *)data);
1125 		break;
1126 
1127 	case TIOCMGET:
1128 		*(int *)data = plcom_to_tiocm(sc);
1129 		break;
1130 
1131 	case PPS_IOC_CREATE:
1132 		break;
1133 
1134 	case PPS_IOC_DESTROY:
1135 		break;
1136 
1137 	case PPS_IOC_GETPARAMS: {
1138 		pps_params_t *pp;
1139 		pp = (pps_params_t *)data;
1140 		mutex_spin_enter(&timecounter_lock);
1141 		*pp = sc->ppsparam;
1142 		mutex_spin_exit(&timecounter_lock);
1143 		break;
1144 	}
1145 
1146 	case PPS_IOC_SETPARAMS: {
1147 	  	pps_params_t *pp;
1148 		int mode;
1149 		pp = (pps_params_t *)data;
1150 		mutex_spin_enter(&timecounter_lock);
1151 		if (pp->mode & ~ppscap) {
1152 			error = EINVAL;
1153 			mutex_spin_exit(&timecounter_lock);
1154 			break;
1155 		}
1156 		sc->ppsparam = *pp;
1157 	 	/*
1158 		 * Compute msr masks from user-specified timestamp state.
1159 		 */
1160 		mode = sc->ppsparam.mode;
1161 #ifdef	PPS_SYNC
1162 		if (mode & PPS_HARDPPSONASSERT) {
1163 			mode |= PPS_CAPTUREASSERT;
1164 			/* XXX revoke any previous HARDPPS source */
1165 		}
1166 		if (mode & PPS_HARDPPSONCLEAR) {
1167 			mode |= PPS_CAPTURECLEAR;
1168 			/* XXX revoke any previous HARDPPS source */
1169 		}
1170 #endif	/* PPS_SYNC */
1171 		switch (mode & PPS_CAPTUREBOTH) {
1172 		case 0:
1173 			sc->sc_ppsmask = 0;
1174 			break;
1175 
1176 		case PPS_CAPTUREASSERT:
1177 			sc->sc_ppsmask = PL01X_MSR_DCD;
1178 			sc->sc_ppsassert = PL01X_MSR_DCD;
1179 			sc->sc_ppsclear = -1;
1180 			break;
1181 
1182 		case PPS_CAPTURECLEAR:
1183 			sc->sc_ppsmask = PL01X_MSR_DCD;
1184 			sc->sc_ppsassert = -1;
1185 			sc->sc_ppsclear = 0;
1186 			break;
1187 
1188 		case PPS_CAPTUREBOTH:
1189 			sc->sc_ppsmask = PL01X_MSR_DCD;
1190 			sc->sc_ppsassert = PL01X_MSR_DCD;
1191 			sc->sc_ppsclear = 0;
1192 			break;
1193 
1194 		default:
1195 			error = EINVAL;
1196 			break;
1197 		}
1198 		mutex_spin_exit(&timecounter_lock);
1199 		break;
1200 	}
1201 
1202 	case PPS_IOC_GETCAP:
1203 		*(int*)data = ppscap;
1204 		break;
1205 
1206 	case PPS_IOC_FETCH: {
1207 		pps_info_t *pi;
1208 		pi = (pps_info_t *)data;
1209 		mutex_spin_enter(&timecounter_lock);
1210 		*pi = sc->ppsinfo;
1211 		mutex_spin_exit(&timecounter_lock);
1212 		break;
1213 	}
1214 
1215 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1216 		/*
1217 		 * Some GPS clocks models use the falling rather than
1218 		 * rising edge as the on-the-second signal.
1219 		 * The old API has no way to specify PPS polarity.
1220 		 */
1221 		mutex_spin_enter(&timecounter_lock);
1222 		sc->sc_ppsmask = PL01X_MSR_DCD;
1223 #ifndef PPS_TRAILING_EDGE
1224 		sc->sc_ppsassert = PL01X_MSR_DCD;
1225 		sc->sc_ppsclear = -1;
1226 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1227 		    &sc->ppsinfo.assert_timestamp);
1228 #else
1229 		sc->sc_ppsassert = -1
1230 		sc->sc_ppsclear = 0;
1231 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1232 		    &sc->ppsinfo.clear_timestamp);
1233 #endif
1234 		mutex_spin_exit(&timecounter_lock);
1235 		break;
1236 
1237 	default:
1238 		error = EPASSTHROUGH;
1239 		break;
1240 	}
1241 
1242 	mutex_spin_exit(&sc->sc_lock);
1243 
1244 #ifdef PLCOM_DEBUG
1245 	if (plcom_debug)
1246 		plcomstatus(sc, "plcomioctl ");
1247 #endif
1248 
1249 	return error;
1250 }
1251 
1252 integrate void
1253 plcom_schedrx(struct plcom_softc *sc)
1254 {
1255 
1256 	sc->sc_rx_ready = 1;
1257 
1258 	/* Wake up the poller. */
1259 	softint_schedule(sc->sc_si);
1260 }
1261 
1262 void
1263 plcom_break(struct plcom_softc *sc, int onoff)
1264 {
1265 
1266 	if (onoff)
1267 		SET(sc->sc_lcr, PL01X_LCR_BRK);
1268 	else
1269 		CLR(sc->sc_lcr, PL01X_LCR_BRK);
1270 
1271 	if (!sc->sc_heldchange) {
1272 		if (sc->sc_tx_busy) {
1273 			sc->sc_heldtbc = sc->sc_tbc;
1274 			sc->sc_tbc = 0;
1275 			sc->sc_heldchange = 1;
1276 		} else
1277 			plcom_loadchannelregs(sc);
1278 	}
1279 }
1280 
1281 void
1282 plcom_modem(struct plcom_softc *sc, int onoff)
1283 {
1284 
1285 	if (sc->sc_mcr_dtr == 0)
1286 		return;
1287 
1288 	if (onoff)
1289 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1290 	else
1291 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1292 
1293 	if (!sc->sc_heldchange) {
1294 		if (sc->sc_tx_busy) {
1295 			sc->sc_heldtbc = sc->sc_tbc;
1296 			sc->sc_tbc = 0;
1297 			sc->sc_heldchange = 1;
1298 		} else
1299 			plcom_loadchannelregs(sc);
1300 	}
1301 }
1302 
1303 void
1304 tiocm_to_plcom(struct plcom_softc *sc, u_long how, int ttybits)
1305 {
1306 	u_char plcombits;
1307 
1308 	plcombits = 0;
1309 	if (ISSET(ttybits, TIOCM_DTR))
1310 		SET(plcombits, PL01X_MCR_DTR);
1311 	if (ISSET(ttybits, TIOCM_RTS))
1312 		SET(plcombits, PL01X_MCR_RTS);
1313 
1314 	switch (how) {
1315 	case TIOCMBIC:
1316 		CLR(sc->sc_mcr, plcombits);
1317 		break;
1318 
1319 	case TIOCMBIS:
1320 		SET(sc->sc_mcr, plcombits);
1321 		break;
1322 
1323 	case TIOCMSET:
1324 		CLR(sc->sc_mcr, PL01X_MCR_DTR | PL01X_MCR_RTS);
1325 		SET(sc->sc_mcr, plcombits);
1326 		break;
1327 	}
1328 
1329 	if (!sc->sc_heldchange) {
1330 		if (sc->sc_tx_busy) {
1331 			sc->sc_heldtbc = sc->sc_tbc;
1332 			sc->sc_tbc = 0;
1333 			sc->sc_heldchange = 1;
1334 		} else
1335 			plcom_loadchannelregs(sc);
1336 	}
1337 }
1338 
1339 int
1340 plcom_to_tiocm(struct plcom_softc *sc)
1341 {
1342 	u_char plcombits;
1343 	int ttybits = 0;
1344 
1345 	plcombits = sc->sc_mcr;
1346 	if (ISSET(plcombits, PL01X_MCR_DTR))
1347 		SET(ttybits, TIOCM_DTR);
1348 	if (ISSET(plcombits, PL01X_MCR_RTS))
1349 		SET(ttybits, TIOCM_RTS);
1350 
1351 	plcombits = sc->sc_msr;
1352 	if (ISSET(plcombits, PL01X_MSR_DCD))
1353 		SET(ttybits, TIOCM_CD);
1354 	if (ISSET(plcombits, PL01X_MSR_CTS))
1355 		SET(ttybits, TIOCM_CTS);
1356 	if (ISSET(plcombits, PL01X_MSR_DSR))
1357 		SET(ttybits, TIOCM_DSR);
1358 	if (ISSET(plcombits, PL011_MSR_RI))
1359 		SET(ttybits, TIOCM_RI);
1360 
1361 	if (sc->sc_cr != 0)
1362 		SET(ttybits, TIOCM_LE);
1363 
1364 	return ttybits;
1365 }
1366 
1367 static uint32_t
1368 cflag2lcr(tcflag_t cflag)
1369 {
1370 	uint32_t lcr = 0;
1371 
1372 	switch (ISSET(cflag, CSIZE)) {
1373 	case CS5:
1374 		SET(lcr, PL01X_LCR_5BITS);
1375 		break;
1376 	case CS6:
1377 		SET(lcr, PL01X_LCR_6BITS);
1378 		break;
1379 	case CS7:
1380 		SET(lcr, PL01X_LCR_7BITS);
1381 		break;
1382 	case CS8:
1383 		SET(lcr, PL01X_LCR_8BITS);
1384 		break;
1385 	}
1386 	if (ISSET(cflag, PARENB)) {
1387 		SET(lcr, PL01X_LCR_PEN);
1388 		if (!ISSET(cflag, PARODD))
1389 			SET(lcr, PL01X_LCR_EPS);
1390 	}
1391 	if (ISSET(cflag, CSTOPB))
1392 		SET(lcr, PL01X_LCR_STP2);
1393 
1394 	return lcr;
1395 }
1396 
1397 int
1398 plcomparam(struct tty *tp, struct termios *t)
1399 {
1400 	struct plcom_softc *sc =
1401 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1402 	struct plcom_instance *pi = &sc->sc_pi;
1403 	int ospeed = -1, lvl;
1404 	uint32_t lcr;
1405 
1406 	if (PLCOM_ISALIVE(sc) == 0)
1407 		return EIO;
1408 
1409 	switch (pi->pi_type) {
1410 	case PLCOM_TYPE_PL010:
1411 		ospeed = pl010comspeed(t->c_ospeed, sc->sc_frequency);
1412 		break;
1413 	case PLCOM_TYPE_PL011:
1414 	case PLCOM_TYPE_GENERIC_UART:
1415 		ospeed = pl011comspeed(t->c_ospeed, sc->sc_frequency);
1416 		break;
1417 	}
1418 
1419 	/* Check requested parameters. */
1420 	if (ospeed < 0)
1421 		return EINVAL;
1422 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1423 		return EINVAL;
1424 
1425 	/*
1426 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1427 	 * is always active.
1428 	 */
1429 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1430 	    ISSET(sc->sc_hwflags, PLCOM_HW_CONSOLE)) {
1431 		SET(t->c_cflag, CLOCAL);
1432 		CLR(t->c_cflag, HUPCL);
1433 	}
1434 
1435 	/*
1436 	 * If there were no changes, don't do anything.  This avoids dropping
1437 	 * input and improves performance when all we did was frob things like
1438 	 * VMIN and VTIME.
1439 	 */
1440 	if (tp->t_ospeed == t->c_ospeed &&
1441 	    tp->t_cflag == t->c_cflag)
1442 		return 0;
1443 
1444 	lcr = ISSET(sc->sc_lcr, PL01X_LCR_BRK) | cflag2lcr(t->c_cflag);
1445 
1446 	mutex_spin_enter(&sc->sc_lock);
1447 
1448 	sc->sc_lcr = lcr;
1449 
1450 	/*
1451 	 * PL010 has a fixed-length FIFO trigger point.
1452 	 */
1453 	if (ISSET(sc->sc_hwflags, PLCOM_HW_FIFO))
1454 		sc->sc_fifo = 1;
1455 	else
1456 		sc->sc_fifo = 0;
1457 
1458 	if (sc->sc_fifo) {
1459 		SET(sc->sc_lcr, PL01X_LCR_FEN);
1460 
1461 		switch (pi->pi_type) {
1462 		case PLCOM_TYPE_PL010:
1463 			sc->sc_ifls = 0;
1464 			break;
1465 		case PLCOM_TYPE_PL011:
1466 		case PLCOM_TYPE_GENERIC_UART:
1467 			lvl = PL011_IFLS_3QUARTERS;
1468 			sc->sc_ifls = PL011_IFLS_RXIFLS(lvl);
1469 
1470 			lvl = PL011_IFLS_1QUARTER;
1471 			sc->sc_ifls |= PL011_IFLS_TXIFLS(lvl);
1472 			sc->sc_burstlen = uimin(sc->sc_fifolen * 3 / 4, 1);
1473 			break;
1474 		}
1475 	} else
1476 		sc->sc_ifls = 0;
1477 
1478 	/*
1479 	 * If we're not in a mode that assumes a connection is present, then
1480 	 * ignore carrier changes.
1481 	 */
1482 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1483 		sc->sc_msr_dcd = 0;
1484 	else
1485 		sc->sc_msr_dcd = PL01X_MSR_DCD;
1486 	/*
1487 	 * Set the flow control pins depending on the current flow control
1488 	 * mode.
1489 	 */
1490 	if (ISSET(t->c_cflag, CRTSCTS)) {
1491 		sc->sc_mcr_dtr = PL01X_MCR_DTR;
1492 
1493 		switch (pi->pi_type) {
1494 		case PLCOM_TYPE_PL010:
1495 			sc->sc_mcr_rts = PL01X_MCR_RTS;
1496 			sc->sc_msr_cts = PL01X_MSR_CTS;
1497 			break;
1498 		case PLCOM_TYPE_PL011:
1499 		case PLCOM_TYPE_GENERIC_UART:
1500 			sc->sc_mcr_rts = 0;
1501 			sc->sc_msr_cts = 0;
1502 			SET(sc->sc_cr, PL011_CR_CTSEN | PL011_CR_RTSEN);
1503 			break;
1504 		}
1505 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1506 		/*
1507 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1508 		 * carrier detection.
1509 		 */
1510 		sc->sc_mcr_dtr = 0;
1511 		sc->sc_mcr_rts = PL01X_MCR_DTR;
1512 		sc->sc_msr_cts = PL01X_MSR_DCD;
1513 
1514 		switch (pi->pi_type) {
1515 		case PLCOM_TYPE_PL011:
1516 			CLR(sc->sc_cr, PL011_CR_CTSEN | PL011_CR_RTSEN);
1517 			break;
1518 		}
1519 	} else {
1520 		/*
1521 		 * If no flow control, then always set RTS.  This will make
1522 		 * the other side happy if it mistakenly thinks we're doing
1523 		 * RTS/CTS flow control.
1524 		 */
1525 		sc->sc_mcr_dtr = PL01X_MCR_DTR | PL01X_MCR_RTS;
1526 		sc->sc_mcr_rts = 0;
1527 		sc->sc_msr_cts = 0;
1528 		if (ISSET(sc->sc_mcr, PL01X_MCR_DTR))
1529 			SET(sc->sc_mcr, PL01X_MCR_RTS);
1530 		else
1531 			CLR(sc->sc_mcr, PL01X_MCR_RTS);
1532 		switch (pi->pi_type) {
1533 		case PLCOM_TYPE_PL011:
1534 		case PLCOM_TYPE_GENERIC_UART:
1535 			CLR(sc->sc_cr, PL011_CR_CTSEN | PL011_CR_RTSEN);
1536 			break;
1537 		}
1538 	}
1539 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1540 
1541 #if 0
1542 	if (ospeed == 0)
1543 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1544 	else
1545 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1546 #endif
1547 
1548 	switch (pi->pi_type) {
1549 	case PLCOM_TYPE_PL010:
1550 		sc->sc_ratel = ospeed & 0xff;
1551 		sc->sc_rateh = (ospeed >> 8) & 0xff;
1552 		break;
1553 	case PLCOM_TYPE_PL011:
1554 	case PLCOM_TYPE_GENERIC_UART:
1555 		sc->sc_ratel = ospeed & ((1 << 6) - 1);
1556 		sc->sc_rateh = ospeed >> 6;
1557 		break;
1558 	}
1559 
1560 	/* And copy to tty. */
1561 	tp->t_ispeed = t->c_ospeed;
1562 	tp->t_ospeed = t->c_ospeed;
1563 	tp->t_cflag = t->c_cflag;
1564 
1565 	if (!sc->sc_heldchange) {
1566 		if (sc->sc_tx_busy) {
1567 			sc->sc_heldtbc = sc->sc_tbc;
1568 			sc->sc_tbc = 0;
1569 			sc->sc_heldchange = 1;
1570 		} else
1571 			plcom_loadchannelregs(sc);
1572 	}
1573 
1574 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1575 		/* Disable the high water mark. */
1576 		sc->sc_r_hiwat = 0;
1577 		sc->sc_r_lowat = 0;
1578 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1579 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1580 			plcom_schedrx(sc);
1581 		}
1582 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1583 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1584 			plcom_hwiflow(sc);
1585 		}
1586 	} else {
1587 		sc->sc_r_hiwat = plcom_rbuf_hiwat;
1588 		sc->sc_r_lowat = plcom_rbuf_lowat;
1589 	}
1590 
1591 	mutex_spin_exit(&sc->sc_lock);
1592 
1593 	/*
1594 	 * Update the tty layer's idea of the carrier bit, in case we changed
1595 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1596 	 * explicit request.
1597 	 */
1598 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, PL01X_MSR_DCD));
1599 
1600 #ifdef PLCOM_DEBUG
1601 	if (plcom_debug)
1602 		plcomstatus(sc, "plcomparam ");
1603 #endif
1604 
1605 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1606 		if (sc->sc_tx_stopped) {
1607 			sc->sc_tx_stopped = 0;
1608 			plcomstart(tp);
1609 		}
1610 	}
1611 
1612 	return 0;
1613 }
1614 
1615 void
1616 plcom_iflush(struct plcom_softc *sc)
1617 {
1618 	struct plcom_instance *pi = &sc->sc_pi;
1619 #ifdef DIAGNOSTIC
1620 	int reg;
1621 #endif
1622 	int timo;
1623 
1624 #ifdef DIAGNOSTIC
1625 	reg = 0xffff;
1626 #endif
1627 	timo = 50000;
1628 	/* flush any pending I/O */
1629 	while (! ISSET(PREAD1(pi, PL01XCOM_FR), PL01X_FR_RXFE)
1630 	    && --timo)
1631 #ifdef DIAGNOSTIC
1632 		reg =
1633 #else
1634 		    (void)
1635 #endif
1636 		    PREAD1(pi, PL01XCOM_DR);
1637 #ifdef DIAGNOSTIC
1638 	if (!timo)
1639 		aprint_error_dev(sc->sc_dev, ": %s timeout %02x\n", __func__,
1640 		    reg);
1641 #endif
1642 }
1643 
1644 void
1645 plcom_loadchannelregs(struct plcom_softc *sc)
1646 {
1647 	struct plcom_instance *pi = &sc->sc_pi;
1648 	uint16_t ifls;
1649 
1650 	/* XXXXX necessary? */
1651 	plcom_iflush(sc);
1652 
1653 	switch (pi->pi_type) {
1654 	case PLCOM_TYPE_PL010:
1655 		PWRITE1(pi, PL010COM_CR, 0);
1656 		if (sc->sc_frequency != 0) {
1657 			PWRITE1(pi, PL010COM_DLBL, sc->sc_ratel);
1658 			PWRITE1(pi, PL010COM_DLBH, sc->sc_rateh);
1659 		}
1660 		PWRITE1(pi, PL010COM_LCR, sc->sc_lcr);
1661 
1662 		/* XXX device_unit() abuse */
1663 		if (sc->sc_set_mcr)
1664 			sc->sc_set_mcr(sc->sc_set_mcr_arg,
1665 			    device_unit(sc->sc_dev),
1666 			    sc->sc_mcr_active = sc->sc_mcr);
1667 
1668 		PWRITE1(pi, PL010COM_CR, sc->sc_cr);
1669 		break;
1670 
1671 	case PLCOM_TYPE_PL011:
1672 	case PLCOM_TYPE_GENERIC_UART:
1673 		PWRITE2(pi, PL011COM_CR, 0);
1674 		if (sc->sc_frequency != 0) {
1675 			PWRITE1(pi, PL011COM_FBRD, sc->sc_ratel);
1676 			PWRITE4(pi, PL011COM_IBRD, sc->sc_rateh);
1677 		}
1678 
1679 		/* Bits 6..15 are reserved, don't modify, read as zero */
1680 		ifls = PREAD2(pi, PL011COM_IFLS) & ~PL011_IFLS_MASK;
1681 		ifls |= sc->sc_ifls & PL011_IFLS_MASK;
1682 		PWRITE2(pi, PL011COM_IFLS, ifls);
1683 
1684 		PWRITE1(pi, PL011COM_LCRH, sc->sc_lcr);
1685 		sc->sc_mcr_active = sc->sc_mcr;
1686 		CLR(sc->sc_cr, PL011_MCR(PL01X_MCR_RTS | PL01X_MCR_DTR));
1687 		SET(sc->sc_cr, PL011_MCR(sc->sc_mcr_active));
1688 		PWRITE2(pi, PL011COM_CR, sc->sc_cr);
1689 		break;
1690 	}
1691 }
1692 
1693 int
1694 plcomhwiflow(struct tty *tp, int block)
1695 {
1696 	struct plcom_softc *sc =
1697 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1698 
1699 	if (PLCOM_ISALIVE(sc) == 0)
1700 		return 0;
1701 
1702 	if (sc->sc_mcr_rts == 0)
1703 		return 0;
1704 
1705 	mutex_spin_enter(&sc->sc_lock);
1706 
1707 	if (block) {
1708 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1709 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1710 			plcom_hwiflow(sc);
1711 		}
1712 	} else {
1713 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1714 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1715 			plcom_schedrx(sc);
1716 		}
1717 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1718 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1719 			plcom_hwiflow(sc);
1720 		}
1721 	}
1722 
1723 	mutex_spin_exit(&sc->sc_lock);
1724 	return 1;
1725 }
1726 
1727 /*
1728  * (un)block input via hw flowcontrol
1729  */
1730 void
1731 plcom_hwiflow(struct plcom_softc *sc)
1732 {
1733 	struct plcom_instance *pi = &sc->sc_pi;
1734 
1735 	if (sc->sc_mcr_rts == 0)
1736 		return;
1737 
1738 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1739 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1740 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1741 	} else {
1742 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1743 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1744 	}
1745 	switch (pi->pi_type) {
1746 	case PLCOM_TYPE_PL010:
1747 		if (sc->sc_set_mcr)
1748 			/* XXX device_unit() abuse */
1749 			sc->sc_set_mcr(sc->sc_set_mcr_arg,
1750 			     device_unit(sc->sc_dev), sc->sc_mcr_active);
1751 		break;
1752 	case PLCOM_TYPE_PL011:
1753 	case PLCOM_TYPE_GENERIC_UART:
1754 		CLR(sc->sc_cr, PL011_MCR(PL01X_MCR_RTS | PL01X_MCR_DTR));
1755 		SET(sc->sc_cr, PL011_MCR(sc->sc_mcr_active));
1756 		PWRITE2(pi, PL011COM_CR, sc->sc_cr);
1757 		break;
1758 	}
1759 }
1760 
1761 
1762 void
1763 plcomstart(struct tty *tp)
1764 {
1765 	struct plcom_softc *sc =
1766 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1767 	struct plcom_instance *pi = &sc->sc_pi;
1768 	int s;
1769 
1770 	if (PLCOM_ISALIVE(sc) == 0)
1771 		return;
1772 
1773 	s = spltty();
1774 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1775 		goto out;
1776 	if (sc->sc_tx_stopped)
1777 		goto out;
1778 
1779 	if (!ttypull(tp))
1780 		goto out;
1781 
1782 	/* Grab the first contiguous region of buffer space. */
1783 	{
1784 		u_char *tba;
1785 		int tbc;
1786 
1787 		tba = tp->t_outq.c_cf;
1788 		tbc = ndqb(&tp->t_outq, 0);
1789 
1790 		mutex_spin_enter(&sc->sc_lock);
1791 
1792 		sc->sc_tba = tba;
1793 		sc->sc_tbc = tbc;
1794 	}
1795 
1796 	SET(tp->t_state, TS_BUSY);
1797 	sc->sc_tx_busy = 1;
1798 
1799 	/* Enable transmit completion interrupts if necessary. */
1800 	switch (pi->pi_type) {
1801 	case PLCOM_TYPE_PL010:
1802 		if (!ISSET(sc->sc_cr, PL010_CR_TIE)) {
1803 			SET(sc->sc_cr, PL010_CR_TIE);
1804 			PWRITE1(pi, PL010COM_CR, sc->sc_cr);
1805 		}
1806 		break;
1807 	case PLCOM_TYPE_PL011:
1808 	case PLCOM_TYPE_GENERIC_UART:
1809 		if (!ISSET(sc->sc_imsc, PL011_INT_TX)) {
1810 			SET(sc->sc_imsc, PL011_INT_TX);
1811 			PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
1812 		}
1813 		break;
1814 	}
1815 
1816 	/* Output the first chunk of the contiguous buffer. */
1817 	{
1818 		int n;
1819 
1820 		n = sc->sc_tbc;
1821 		if (n > sc->sc_burstlen)
1822 			n = sc->sc_burstlen;
1823 		PWRITEM1(pi, PL01XCOM_DR, sc->sc_tba, n);
1824 		sc->sc_tbc -= n;
1825 		sc->sc_tba += n;
1826 	}
1827 	mutex_spin_exit(&sc->sc_lock);
1828 out:
1829 	splx(s);
1830 	return;
1831 }
1832 
1833 /*
1834  * Stop output on a line.
1835  */
1836 void
1837 plcomstop(struct tty *tp, int flag)
1838 {
1839 	struct plcom_softc *sc =
1840 		device_lookup_private(&plcom_cd, PLCOMUNIT(tp->t_dev));
1841 
1842 	mutex_spin_enter(&sc->sc_lock);
1843 	if (ISSET(tp->t_state, TS_BUSY)) {
1844 		/* Stop transmitting at the next chunk. */
1845 		sc->sc_tbc = 0;
1846 		sc->sc_heldtbc = 0;
1847 		if (!ISSET(tp->t_state, TS_TTSTOP))
1848 			SET(tp->t_state, TS_FLUSH);
1849 	}
1850 	mutex_spin_exit(&sc->sc_lock);
1851 }
1852 
1853 void
1854 plcomdiag(void *arg)
1855 {
1856 	struct plcom_softc *sc = arg;
1857 	int overflows, floods;
1858 
1859 	mutex_spin_enter(&sc->sc_lock);
1860 	overflows = sc->sc_overflows;
1861 	sc->sc_overflows = 0;
1862 	floods = sc->sc_floods;
1863 	sc->sc_floods = 0;
1864 	sc->sc_errors = 0;
1865 	mutex_spin_exit(&sc->sc_lock);
1866 
1867 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1868 	    device_xname(sc->sc_dev),
1869 	    overflows, overflows == 1 ? "" : "s",
1870 	    floods, floods == 1 ? "" : "s");
1871 }
1872 
1873 integrate void
1874 plcom_rxsoft(struct plcom_softc *sc, struct tty *tp)
1875 {
1876 	int (*rint) (int, struct tty *) = tp->t_linesw->l_rint;
1877 	struct plcom_instance *pi = &sc->sc_pi;
1878 	u_char *get, *end;
1879 	u_int cc, scc;
1880 	u_char rsr;
1881 	int code;
1882 
1883 	end = sc->sc_ebuf;
1884 	get = sc->sc_rbget;
1885 	scc = cc = plcom_rbuf_size - sc->sc_rbavail;
1886 
1887 	if (cc == plcom_rbuf_size) {
1888 		sc->sc_floods++;
1889 		if (sc->sc_errors++ == 0)
1890 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1891 			    plcomdiag, sc);
1892 	}
1893 
1894 	while (cc) {
1895 		code = get[0];
1896 		rsr = get[1];
1897 		if (ISSET(rsr, PL01X_RSR_ERROR)) {
1898 			if (ISSET(rsr, PL01X_RSR_OE)) {
1899 				sc->sc_overflows++;
1900 				if (sc->sc_errors++ == 0)
1901 					callout_reset(&sc->sc_diag_callout,
1902 					    60 * hz, plcomdiag, sc);
1903 			}
1904 			if (ISSET(rsr, PL01X_RSR_BE | PL01X_RSR_FE))
1905 				SET(code, TTY_FE);
1906 			if (ISSET(rsr, PL01X_RSR_PE))
1907 				SET(code, TTY_PE);
1908 		}
1909 		if ((*rint)(code, tp) == -1) {
1910 			/*
1911 			 * The line discipline's buffer is out of space.
1912 			 */
1913 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1914 				/*
1915 				 * We're either not using flow control, or the
1916 				 * line discipline didn't tell us to block for
1917 				 * some reason.  Either way, we have no way to
1918 				 * know when there's more space available, so
1919 				 * just drop the rest of the data.
1920 				 */
1921 				get += cc << 1;
1922 				if (get >= end)
1923 					get -= plcom_rbuf_size << 1;
1924 				cc = 0;
1925 			} else {
1926 				/*
1927 				 * Don't schedule any more receive processing
1928 				 * until the line discipline tells us there's
1929 				 * space available (through plcomhwiflow()).
1930 				 * Leave the rest of the data in the input
1931 				 * buffer.
1932 				 */
1933 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1934 			}
1935 			break;
1936 		}
1937 		get += 2;
1938 		if (get >= end)
1939 			get = sc->sc_rbuf;
1940 		cc--;
1941 	}
1942 	if (cc != scc) {
1943 		sc->sc_rbget = get;
1944 		mutex_spin_enter(&sc->sc_lock);
1945 
1946 		cc = sc->sc_rbavail += scc - cc;
1947 		/* Buffers should be ok again, release possible block. */
1948 		if (cc >= sc->sc_r_lowat) {
1949 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1950 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1951 				switch (pi->pi_type) {
1952 				case PLCOM_TYPE_PL010:
1953 					SET(sc->sc_cr,
1954 					    PL010_CR_RIE | PL010_CR_RTIE);
1955 					PWRITE1(pi, PL010COM_CR, sc->sc_cr);
1956 					break;
1957 				case PLCOM_TYPE_PL011:
1958 				case PLCOM_TYPE_GENERIC_UART:
1959 					SET(sc->sc_imsc,
1960 					    PL011_INT_RX | PL011_INT_RT);
1961 					PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
1962 					break;
1963 				}
1964 			}
1965 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1966 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1967 				plcom_hwiflow(sc);
1968 			}
1969 		}
1970 		mutex_spin_exit(&sc->sc_lock);
1971 	}
1972 }
1973 
1974 integrate void
1975 plcom_txsoft(struct plcom_softc *sc, struct tty *tp)
1976 {
1977 
1978 	CLR(tp->t_state, TS_BUSY);
1979 	if (ISSET(tp->t_state, TS_FLUSH))
1980 		CLR(tp->t_state, TS_FLUSH);
1981 	else
1982 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1983 	(*tp->t_linesw->l_start)(tp);
1984 }
1985 
1986 integrate void
1987 plcom_stsoft(struct plcom_softc *sc, struct tty *tp)
1988 {
1989 	u_char msr, delta;
1990 
1991 	mutex_spin_enter(&sc->sc_lock);
1992 	msr = sc->sc_msr;
1993 	delta = sc->sc_msr_delta;
1994 	sc->sc_msr_delta = 0;
1995 	mutex_spin_exit(&sc->sc_lock);
1996 
1997 	if (ISSET(delta, sc->sc_msr_dcd)) {
1998 		/*
1999 		 * Inform the tty layer that carrier detect changed.
2000 		 */
2001 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, PL01X_MSR_DCD));
2002 	}
2003 
2004 	if (ISSET(delta, sc->sc_msr_cts)) {
2005 		/* Block or unblock output according to flow control. */
2006 		if (ISSET(msr, sc->sc_msr_cts)) {
2007 			sc->sc_tx_stopped = 0;
2008 			(*tp->t_linesw->l_start)(tp);
2009 		} else {
2010 			sc->sc_tx_stopped = 1;
2011 		}
2012 	}
2013 
2014 #ifdef PLCOM_DEBUG
2015 	if (plcom_debug)
2016 		plcomstatus(sc, "plcom_stsoft");
2017 #endif
2018 }
2019 
2020 void
2021 plcomsoft(void *arg)
2022 {
2023 	struct plcom_softc *sc = arg;
2024 	struct tty *tp;
2025 
2026 	if (PLCOM_ISALIVE(sc) == 0)
2027 		return;
2028 
2029 	tp = sc->sc_tty;
2030 
2031 	if (sc->sc_rx_ready) {
2032 		sc->sc_rx_ready = 0;
2033 		plcom_rxsoft(sc, tp);
2034 	}
2035 
2036 	if (sc->sc_st_check) {
2037 		sc->sc_st_check = 0;
2038 		plcom_stsoft(sc, tp);
2039 	}
2040 
2041 	if (sc->sc_tx_done) {
2042 		sc->sc_tx_done = 0;
2043 		plcom_txsoft(sc, tp);
2044 	}
2045 }
2046 
2047 bool
2048 plcom_intstatus(struct plcom_instance *pi, u_int *istatus)
2049 {
2050 	bool ret = false;
2051 	u_int stat = 0;
2052 
2053 	switch (pi->pi_type) {
2054 	case PLCOM_TYPE_PL010:
2055 		stat = PREAD1(pi, PL010COM_IIR);
2056 		ret = ISSET(stat, PL010_IIR_IMASK);
2057 		break;
2058 	case PLCOM_TYPE_PL011:
2059 	case PLCOM_TYPE_GENERIC_UART:
2060 		stat = PREAD4(pi, PL011COM_MIS);
2061 		ret = ISSET(stat, PL011_INT_ALLMASK);
2062 		break;
2063 	}
2064 	*istatus = stat;
2065 
2066 	return ret;
2067 }
2068 
2069 int
2070 plcomintr(void *arg)
2071 {
2072 	struct plcom_softc *sc = arg;
2073 	struct plcom_instance *pi = &sc->sc_pi;
2074 	u_char *put, *end;
2075 	u_int cc;
2076 	u_int istatus = 0;
2077 	u_char rsr;
2078 	bool intr = false;
2079 
2080 	PLCOM_BARRIER(pi, BR | BW);
2081 
2082 	if (PLCOM_ISALIVE(sc) == 0)
2083 		return 0;
2084 
2085 	mutex_spin_enter(&sc->sc_lock);
2086 	intr = plcom_intstatus(pi, &istatus);
2087 	if (!intr) {
2088 		mutex_spin_exit(&sc->sc_lock);
2089 		return 0;
2090 	}
2091 
2092 	end = sc->sc_ebuf;
2093 	put = sc->sc_rbput;
2094 	cc = sc->sc_rbavail;
2095 
2096 	do {
2097 		u_int msr = 0, delta, fr;
2098 		bool rxintr = false, txintr = false, msintr;
2099 
2100 		/* don't need RI here*/
2101 		fr = PREAD1(pi, PL01XCOM_FR);
2102 
2103 		if (!ISSET(fr, PL01X_FR_RXFE) &&
2104 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2105 			while (cc > 0) {
2106 				int cn_trapped = 0;
2107 				put[0] = PREAD1(pi, PL01XCOM_DR);
2108 				rsr = PREAD1(pi, PL01XCOM_RSR);
2109 				/* Clear any error status.  */
2110 				if (ISSET(rsr, PL01X_RSR_ERROR))
2111 					PWRITE1(pi, PL01XCOM_ECR, 0);
2112 
2113 				if (ISSET(rsr, PL01X_RSR_BE)) {
2114 					cn_trapped = 0;
2115 					cn_check_magic(sc->sc_tty->t_dev,
2116 					    CNC_BREAK, plcom_cnm_state);
2117 					if (cn_trapped)
2118 						continue;
2119 #if defined(KGDB)
2120 					if (ISSET(sc->sc_hwflags,
2121 					    PLCOM_HW_KGDB)) {
2122 						kgdb_connect(1);
2123 						continue;
2124 					}
2125 #endif
2126 				}
2127 
2128 				put[1] = rsr;
2129 				cn_trapped = 0;
2130 				cn_check_magic(sc->sc_tty->t_dev, put[0],
2131 				    plcom_cnm_state);
2132 				if (cn_trapped) {
2133 					fr = PREAD1(pi, PL01XCOM_FR);
2134 					if (ISSET(fr, PL01X_FR_RXFE))
2135 						break;
2136 
2137 					continue;
2138 				}
2139 				put += 2;
2140 				if (put >= end)
2141 					put = sc->sc_rbuf;
2142 				cc--;
2143 
2144 				/* don't need RI here*/
2145 				fr = PREAD1(pi, PL01XCOM_FR);
2146 				if (ISSET(fr, PL01X_FR_RXFE))
2147 					break;
2148 			}
2149 
2150 			/*
2151 			 * Current string of incoming characters ended because
2152 			 * no more data was available or we ran out of space.
2153 			 * Schedule a receive event if any data was received.
2154 			 * If we're out of space, turn off receive interrupts.
2155 			 */
2156 			sc->sc_rbput = put;
2157 			sc->sc_rbavail = cc;
2158 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2159 				sc->sc_rx_ready = 1;
2160 
2161 			/*
2162 			 * See if we are in danger of overflowing a buffer. If
2163 			 * so, use hardware flow control to ease the pressure.
2164 			 */
2165 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2166 			    cc < sc->sc_r_hiwat) {
2167 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2168 				plcom_hwiflow(sc);
2169 			}
2170 
2171 			/*
2172 			 * If we're out of space, disable receive interrupts
2173 			 * until the queue has drained a bit.
2174 			 */
2175 			if (!cc) {
2176 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2177 				switch (pi->pi_type) {
2178 				case PLCOM_TYPE_PL010:
2179 					CLR(sc->sc_cr,
2180 					    PL010_CR_RIE | PL010_CR_RTIE);
2181 					PWRITE1(pi, PL010COM_CR, sc->sc_cr);
2182 					break;
2183 				case PLCOM_TYPE_PL011:
2184 				case PLCOM_TYPE_GENERIC_UART:
2185 					CLR(sc->sc_imsc,
2186 					    PL011_INT_RT | PL011_INT_RX);
2187 					PWRITE4(pi, PL011COM_IMSC, sc->sc_imsc);
2188 					break;
2189 				}
2190 			}
2191 		} else {
2192 			switch (pi->pi_type) {
2193 			case PLCOM_TYPE_PL010:
2194 				rxintr = ISSET(istatus, PL010_IIR_RIS);
2195 				if (rxintr) {
2196 					PWRITE1(pi, PL010COM_CR, 0);
2197 					delay(10);
2198 					PWRITE1(pi, PL010COM_CR, sc->sc_cr);
2199 					continue;
2200 				}
2201 				break;
2202 			case PLCOM_TYPE_PL011:
2203 			case PLCOM_TYPE_GENERIC_UART:
2204 				rxintr = ISSET(istatus, PL011_INT_RX);
2205 				if (rxintr) {
2206 					PWRITE2(pi, PL011COM_CR, 0);
2207 					delay(10);
2208 					PWRITE2(pi, PL011COM_CR, sc->sc_cr);
2209 					continue;
2210 				}
2211 				break;
2212 			}
2213 		}
2214 
2215 		switch (pi->pi_type) {
2216 		case PLCOM_TYPE_PL010:
2217 			msr = PREAD1(pi, PL01XCOM_FR);
2218 			break;
2219 		case PLCOM_TYPE_PL011:
2220 		case PLCOM_TYPE_GENERIC_UART:
2221 			msr = PREAD4(pi, PL01XCOM_FR);
2222 			break;
2223 		}
2224 		delta = msr ^ sc->sc_msr;
2225 		sc->sc_msr = msr;
2226 
2227 		/* Clear any pending modem status interrupt.  */
2228 		switch (pi->pi_type) {
2229 		case PLCOM_TYPE_PL010:
2230 			msintr = ISSET(istatus, PL010_IIR_MIS);
2231 			if (msintr) {
2232 				PWRITE1(pi, PL010COM_ICR, 0);
2233 			}
2234 			break;
2235 		case PLCOM_TYPE_PL011:
2236 		case PLCOM_TYPE_GENERIC_UART:
2237 			msintr = ISSET(istatus, PL011_INT_MSMASK);
2238 			if (msintr) {
2239 				PWRITE4(pi, PL011COM_ICR, PL011_INT_MSMASK);
2240 			}
2241 			break;
2242 		}
2243 		/*
2244 		 * Pulse-per-second (PSS) signals on edge of DCD?
2245 		 * Process these even if line discipline is ignoring DCD.
2246 		 */
2247 		if (delta & sc->sc_ppsmask) {
2248 			struct timeval tv;
2249 			mutex_spin_enter(&timecounter_lock);
2250 		    	if ((msr & sc->sc_ppsmask) == sc->sc_ppsassert) {
2251 				/* XXX nanotime() */
2252 				microtime(&tv);
2253 				TIMEVAL_TO_TIMESPEC(&tv,
2254 				    &sc->ppsinfo.assert_timestamp);
2255 				if (sc->ppsparam.mode & PPS_OFFSETASSERT) {
2256 					timespecadd(&sc->ppsinfo.assert_timestamp,
2257 					    &sc->ppsparam.assert_offset,
2258 						    &sc->ppsinfo.assert_timestamp);
2259 				}
2260 
2261 #ifdef PPS_SYNC
2262 				if (sc->ppsparam.mode & PPS_HARDPPSONASSERT)
2263 					hardpps(&tv, tv.tv_usec);
2264 #endif
2265 				sc->ppsinfo.assert_sequence++;
2266 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2267 
2268 			} else if ((msr & sc->sc_ppsmask) == sc->sc_ppsclear) {
2269 				/* XXX nanotime() */
2270 				microtime(&tv);
2271 				TIMEVAL_TO_TIMESPEC(&tv,
2272 				    &sc->ppsinfo.clear_timestamp);
2273 				if (sc->ppsparam.mode & PPS_OFFSETCLEAR) {
2274 					timespecadd(&sc->ppsinfo.clear_timestamp,
2275 					    &sc->ppsparam.clear_offset,
2276 					    &sc->ppsinfo.clear_timestamp);
2277 				}
2278 
2279 #ifdef PPS_SYNC
2280 				if (sc->ppsparam.mode & PPS_HARDPPSONCLEAR)
2281 					hardpps(&tv, tv.tv_usec);
2282 #endif
2283 				sc->ppsinfo.clear_sequence++;
2284 				sc->ppsinfo.current_mode = sc->ppsparam.mode;
2285 			}
2286 			mutex_spin_exit(&timecounter_lock);
2287 		}
2288 
2289 		/*
2290 		 * Process normal status changes
2291 		 */
2292 		if (ISSET(delta, sc->sc_msr_mask)) {
2293 			SET(sc->sc_msr_delta, delta);
2294 
2295 			/*
2296 			 * Stop output immediately if we lose the output
2297 			 * flow control signal or carrier detect.
2298 			 */
2299 			if (ISSET(~msr, sc->sc_msr_mask)) {
2300 				sc->sc_tbc = 0;
2301 				sc->sc_heldtbc = 0;
2302 #ifdef PLCOM_DEBUG
2303 				if (plcom_debug)
2304 					plcomstatus(sc, "plcomintr  ");
2305 #endif
2306 			}
2307 
2308 			sc->sc_st_check = 1;
2309 		}
2310 
2311 		/*
2312 		 * Done handling any receive interrupts. See if data
2313 		 * can be transmitted as well. Schedule tx done
2314 		 * event if no data left and tty was marked busy.
2315 		 */
2316 
2317 		switch (pi->pi_type) {
2318 		case PLCOM_TYPE_PL010:
2319 			txintr = ISSET(istatus, PL010_IIR_TIS);
2320 			break;
2321 		case PLCOM_TYPE_PL011:
2322 			txintr = ISSET(istatus, PL011_INT_TX);
2323 			break;
2324 		}
2325 		if (txintr) {
2326 			/*
2327 			 * If we've delayed a parameter change, do it
2328 			 * now, and restart * output.
2329 			 */
2330 // PWRITE4(pi, PL011COM_ICR, PL011_INT_TX);
2331 			if (sc->sc_heldchange) {
2332 				plcom_loadchannelregs(sc);
2333 				sc->sc_heldchange = 0;
2334 				sc->sc_tbc = sc->sc_heldtbc;
2335 				sc->sc_heldtbc = 0;
2336 			}
2337 
2338 			/*
2339 			 * Output the next chunk of the contiguous
2340 			 * buffer, if any.
2341 			 */
2342 			if (sc->sc_tbc > 0) {
2343 				int n;
2344 
2345 				n = sc->sc_tbc;
2346 				if (n > sc->sc_burstlen)
2347 					n = sc->sc_burstlen;
2348 				PWRITEM1(pi, PL01XCOM_DR, sc->sc_tba, n);
2349 				sc->sc_tbc -= n;
2350 				sc->sc_tba += n;
2351 			} else {
2352 				/*
2353 				 * Disable transmit completion
2354 				 * interrupts if necessary.
2355 				 */
2356 				switch (pi->pi_type) {
2357 				case PLCOM_TYPE_PL010:
2358 					if (ISSET(sc->sc_cr, PL010_CR_TIE)) {
2359 						CLR(sc->sc_cr, PL010_CR_TIE);
2360 						PWRITE1(pi, PL010COM_CR,
2361 						    sc->sc_cr);
2362 					}
2363 					break;
2364 				case PLCOM_TYPE_PL011:
2365 				case PLCOM_TYPE_GENERIC_UART:
2366 					if (ISSET(sc->sc_imsc, PL011_INT_TX)) {
2367 						CLR(sc->sc_imsc, PL011_INT_TX);
2368 						PWRITE4(pi, PL011COM_IMSC,
2369 						    sc->sc_imsc);
2370 					}
2371 					break;
2372 				}
2373 				if (sc->sc_tx_busy) {
2374 					sc->sc_tx_busy = 0;
2375 					sc->sc_tx_done = 1;
2376 				}
2377 			}
2378 		}
2379 
2380 	} while (plcom_intstatus(pi, &istatus));
2381 
2382 	mutex_spin_exit(&sc->sc_lock);
2383 
2384 	/* Wake up the poller. */
2385 	if ((sc->sc_rx_ready | sc->sc_st_check | sc->sc_tx_done) != 0)
2386 		softint_schedule(sc->sc_si);
2387 
2388 #ifdef RND_COM
2389 	rnd_add_uint32(&sc->rnd_source, istatus | rsr);
2390 #endif
2391 
2392 	PLCOM_BARRIER(pi, BR | BW);
2393 
2394 	return 1;
2395 }
2396 
2397 /*
2398  * The following functions are polled getc and putc routines, shared
2399  * by the console and kgdb glue.
2400  *
2401  * The read-ahead code is so that you can detect pending in-band
2402  * cn_magic in polled mode while doing output rather than having to
2403  * wait until the kernel decides it needs input.
2404  */
2405 
2406 #define MAX_READAHEAD	20
2407 static int plcom_readahead[MAX_READAHEAD];
2408 static int plcom_readaheadcount = 0;
2409 
2410 int
2411 plcom_common_getc(dev_t dev, struct plcom_instance *pi)
2412 {
2413 	int s = splserial();
2414 	u_char c;
2415 
2416 	/* got a character from reading things earlier */
2417 	if (plcom_readaheadcount > 0) {
2418 		int i;
2419 
2420 		c = plcom_readahead[0];
2421 		for (i = 1; i < plcom_readaheadcount; i++) {
2422 			plcom_readahead[i-1] = plcom_readahead[i];
2423 		}
2424 		plcom_readaheadcount--;
2425 		splx(s);
2426 		return c;
2427 	}
2428 
2429 	if (ISSET(PREAD1(pi, PL01XCOM_FR), PL01X_FR_RXFE)) {
2430 		splx(s);
2431 		return -1;
2432 	}
2433 
2434 	c = PREAD1(pi, PL01XCOM_DR);
2435 	{
2436 		int cn_trapped __unused = 0;
2437 
2438 		if (!db_active)
2439 			cn_check_magic(dev, c, plcom_cnm_state);
2440 	}
2441 	splx(s);
2442 	return c;
2443 }
2444 
2445 void
2446 plcom_common_putc(dev_t dev, struct plcom_instance *pi, int c)
2447 {
2448 	int s = splserial();
2449 	int timo;
2450 
2451 	int cin, stat;
2452 	if (plcom_readaheadcount < MAX_READAHEAD
2453 	     && !ISSET(stat = PREAD1(pi, PL01XCOM_FR), PL01X_FR_RXFE)) {
2454 		int cn_trapped __unused = 0;
2455 		cin = PREAD1(pi, PL01XCOM_DR);
2456 		cn_check_magic(dev, cin, plcom_cnm_state);
2457 		plcom_readahead[plcom_readaheadcount++] = cin;
2458 	}
2459 
2460 	/* wait for any pending transmission to finish */
2461 	timo = 150000;
2462 	while (ISSET(PREAD1(pi, PL01XCOM_FR), PL01X_FR_TXFF) && --timo)
2463 		continue;
2464 
2465 	PWRITE1(pi, PL01XCOM_DR, c);
2466 	PLCOM_BARRIER(pi, BR | BW);
2467 
2468 	splx(s);
2469 }
2470 
2471 /*
2472  * Initialize UART for use as console or KGDB line.
2473  */
2474 int
2475 plcominit(struct plcom_instance *pi, int rate, int frequency, tcflag_t cflag)
2476 {
2477 	uint32_t lcr;
2478 
2479 	switch (pi->pi_type) {
2480 	case PLCOM_TYPE_PL010:
2481 		if (pi->pi_size == 0)
2482 			pi->pi_size = PL010COM_UART_SIZE;
2483 		break;
2484 	case PLCOM_TYPE_PL011:
2485 	case PLCOM_TYPE_GENERIC_UART:
2486 		if (pi->pi_size == 0)
2487 			pi->pi_size = PL011COM_UART_SIZE;
2488 		break;
2489 	default:
2490 		panic("Unknown plcom type");
2491 	}
2492 
2493 	if (bus_space_map(pi->pi_iot, pi->pi_iobase, pi->pi_size, 0,
2494 	    &pi->pi_ioh))
2495 		return ENOMEM; /* ??? */
2496 
2497 	lcr = cflag2lcr(cflag) | PL01X_LCR_FEN;
2498 	switch (pi->pi_type) {
2499 	case PLCOM_TYPE_PL010:
2500 		PWRITE1(pi, PL010COM_CR, 0);
2501 
2502 		if (rate && frequency) {
2503 			rate = pl010comspeed(rate, frequency);
2504 			PWRITE1(pi, PL010COM_DLBL, (rate & 0xff));
2505 			PWRITE1(pi, PL010COM_DLBH, ((rate >> 8) & 0xff));
2506 		}
2507 		PWRITE1(pi, PL010COM_LCR, lcr);
2508 		PWRITE1(pi, PL010COM_CR, PL01X_CR_UARTEN);
2509 		break;
2510 	case PLCOM_TYPE_PL011:
2511 	case PLCOM_TYPE_GENERIC_UART:
2512 		PWRITE2(pi, PL011COM_CR, 0);
2513 
2514 		if (rate && frequency) {
2515 			rate = pl011comspeed(rate, frequency);
2516 			PWRITE1(pi, PL011COM_FBRD, rate & ((1 << 6) - 1));
2517 			PWRITE4(pi, PL011COM_IBRD, rate >> 6);
2518 		}
2519 		PWRITE1(pi, PL011COM_LCRH, lcr);
2520 		PWRITE2(pi, PL011COM_CR,
2521 		    PL01X_CR_UARTEN | PL011_CR_RXE | PL011_CR_TXE);
2522 		break;
2523 	}
2524 
2525 #if 0
2526 	/* Ought to do something like this, but we have no sc to
2527 	   dereference. */
2528 	/* XXX device_unit() abuse */
2529 	sc->sc_set_mcr(sc->sc_set_mcr_arg, device_unit(sc->sc_dev),
2530 	    PL01X_MCR_DTR | PL01X_MCR_RTS);
2531 #endif
2532 
2533 	return 0;
2534 }
2535 
2536 /*
2537  * Following are all routines needed for PLCOM to act as console
2538  */
2539 struct consdev plcomcons = {
2540 	NULL, NULL, plcomcngetc, plcomcnputc, plcomcnpollc, NULL,
2541 	plcomcnhalt, NULL, NODEV, CN_NORMAL
2542 };
2543 
2544 int
2545 plcomcnattach(struct plcom_instance *pi, int rate, int frequency,
2546     tcflag_t cflag, int unit)
2547 {
2548 	int res;
2549 
2550 	plcomcons_info = *pi;
2551 
2552 	res = plcominit(&plcomcons_info, rate, frequency, cflag);
2553 	if (res)
2554 		return res;
2555 
2556 	cn_tab = &plcomcons;
2557 	cn_init_magic(&plcom_cnm_state);
2558 	cn_set_magic("\047\001"); /* default magic is BREAK */
2559 
2560 	plcomconsunit = unit;
2561 	plcomconsrate = rate;
2562 	plcomconscflag = cflag;
2563 
2564 	return 0;
2565 }
2566 
2567 void
2568 plcomcndetach(void)
2569 {
2570 
2571 	bus_space_unmap(plcomcons_info.pi_iot, plcomcons_info.pi_ioh,
2572 	    plcomcons_info.pi_size);
2573 	plcomcons_info.pi_iot = NULL;
2574 
2575 	cn_tab = NULL;
2576 }
2577 
2578 int
2579 plcomcngetc(dev_t dev)
2580 {
2581 	return plcom_common_getc(dev, &plcomcons_info);
2582 }
2583 
2584 /*
2585  * Console kernel output character routine.
2586  */
2587 void
2588 plcomcnputc(dev_t dev, int c)
2589 {
2590 	plcom_common_putc(dev, &plcomcons_info, c);
2591 }
2592 
2593 void
2594 plcomcnpollc(dev_t dev, int on)
2595 {
2596 
2597 	plcom_readaheadcount = 0;
2598 }
2599 
2600 void
2601 plcomcnhalt(dev_t dev)
2602 {
2603 	struct plcom_instance *pi = &plcomcons_info;
2604 
2605 	switch (pi->pi_type) {
2606 	case PLCOM_TYPE_PL010:
2607 		PWRITE1(pi, PL010COM_CR, PL01X_CR_UARTEN);
2608 		break;
2609 	case PLCOM_TYPE_PL011:
2610 	case PLCOM_TYPE_GENERIC_UART:
2611 		PWRITE2(pi, PL011COM_CR,
2612 		    PL01X_CR_UARTEN | PL011_CR_RXE | PL011_CR_TXE);
2613 		PWRITE4(pi, PL011COM_IMSC, 0);
2614 		break;
2615 	}
2616 }
2617 
2618 #ifdef KGDB
2619 int
2620 plcom_kgdb_attach(struct plcom_instance *pi, int rate, int frequency,
2621     tcflag_t cflag, int unit)
2622 {
2623 	int res;
2624 
2625 	if (pi->pi_iot == plcomcons_info.pi_iot &&
2626 	    pi->pi_iobase == plcomcons_info.pi_iobase)
2627 		return EBUSY; /* cannot share with console */
2628 
2629 	res = plcominit(pi, rate, frequency, cflag);
2630 	if (res)
2631 		return res;
2632 
2633 	kgdb_attach(plcom_kgdb_getc, plcom_kgdb_putc, NULL);
2634 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2635 
2636 	plcomkgdb_info.pi_iot = pi->pi_iot;
2637 	plcomkgdb_info.pi_ioh = pi->pi_ioh;
2638 	plcomkgdb_info.pi_iobase = pi->pi_iobase;
2639 
2640 	return 0;
2641 }
2642 
2643 /* ARGSUSED */
2644 int
2645 plcom_kgdb_getc(void *arg)
2646 {
2647 	return plcom_common_getc(NODEV, &plcomkgdb_info);
2648 }
2649 
2650 /* ARGSUSED */
2651 void
2652 plcom_kgdb_putc(void *arg, int c)
2653 {
2654 	plcom_common_putc(NODEV, &plcomkgdb_info, c);
2655 }
2656 #endif /* KGDB */
2657 
2658 /* helper function to identify the plcom ports used by
2659  console or KGDB (and not yet autoconf attached) */
2660 int
2661 plcom_is_console(bus_space_tag_t iot, bus_addr_t iobase,
2662     bus_space_handle_t *ioh)
2663 {
2664 	bus_space_handle_t help;
2665 
2666 	if (!plcomconsattached &&
2667 	    bus_space_is_equal(iot, plcomcons_info.pi_iot) &&
2668 	    iobase == plcomcons_info.pi_iobase)
2669 		help = plcomcons_info.pi_ioh;
2670 #ifdef KGDB
2671 	else if (!plcom_kgdb_attached &&
2672 	    bus_space_is_equal(iot, plcomkgdb_info.pi_iot) &&
2673 	    iobase == plcomkgdb_info.pi_iobase)
2674 		help = plcomkgdb_info.pi_ioh;
2675 #endif
2676 	else
2677 		return 0;
2678 
2679 	if (ioh)
2680 		*ioh = help;
2681 	return 1;
2682 }
2683