xref: /netbsd-src/sys/dev/ic/com.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /* $NetBSD: com.c,v 1.382 2022/12/09 00:35:58 knakahara 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  * Lock order:
68  *	tty_lock (IPL_VM)
69  *	-> sc->sc_lock (IPL_HIGH)
70  */
71 
72 #include <sys/cdefs.h>
73 __KERNEL_RCSID(0, "$NetBSD: com.c,v 1.382 2022/12/09 00:35:58 knakahara Exp $");
74 
75 #include "opt_com.h"
76 #include "opt_ddb.h"
77 #include "opt_kgdb.h"
78 #include "opt_lockdebug.h"
79 #include "opt_multiprocessor.h"
80 #include "opt_ntp.h"
81 
82 /* The COM16650 option was renamed to COM_16650. */
83 #ifdef COM16650
84 #error Obsolete COM16650 option; use COM_16650 instead.
85 #endif
86 
87 /*
88  * Override cnmagic(9) macro before including <sys/systm.h>.
89  * We need to know if cn_check_magic triggered debugger, so set a flag.
90  * Callers of cn_check_magic must declare int cn_trapped = 0;
91  * XXX: this is *ugly*!
92  */
93 #define cn_trap()				\
94 	do {					\
95 		console_debugger();		\
96 		cn_trapped = 1;			\
97 		(void)cn_trapped;		\
98 	} while (/* CONSTCOND */ 0)
99 
100 #include <sys/param.h>
101 #include <sys/systm.h>
102 #include <sys/ioctl.h>
103 #include <sys/select.h>
104 #include <sys/poll.h>
105 #include <sys/tty.h>
106 #include <sys/proc.h>
107 #include <sys/conf.h>
108 #include <sys/file.h>
109 #include <sys/uio.h>
110 #include <sys/kernel.h>
111 #include <sys/syslog.h>
112 #include <sys/device.h>
113 #include <sys/malloc.h>
114 #include <sys/timepps.h>
115 #include <sys/vnode.h>
116 #include <sys/kauth.h>
117 #include <sys/intr.h>
118 #ifdef RND_COM
119 #include <sys/rndsource.h>
120 #endif
121 
122 #include <sys/bus.h>
123 
124 #include <ddb/db_active.h>
125 
126 #include <dev/ic/comreg.h>
127 #include <dev/ic/comvar.h>
128 #include <dev/ic/ns16550reg.h>
129 #include <dev/ic/st16650reg.h>
130 #include <dev/ic/hayespreg.h>
131 #define	com_lcr	com_cfcr
132 #include <dev/cons.h>
133 
134 #include "ioconf.h"
135 
136 #define	CSR_READ_1(r, o)	\
137 	(r)->cr_read((r), (r)->cr_map[o])
138 #define	CSR_WRITE_1(r, o, v)	\
139 	(r)->cr_write((r), (r)->cr_map[o], (v))
140 #define	CSR_WRITE_MULTI(r, o, p, n)	\
141 	(r)->cr_write_multi((r), (r)->cr_map[o], (p), (n))
142 
143 /*
144  * XXX COM_TYPE_AU1x00 specific
145  */
146 #define	CSR_WRITE_2(r, o, v)	\
147 	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
148 #define	CSR_READ_2(r, o)	\
149 	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
150 
151 static void com_enable_debugport(struct com_softc *);
152 
153 void	com_config(struct com_softc *);
154 void	com_shutdown(struct com_softc *);
155 int	comspeed(long, long, int);
156 static	u_char	cflag2lcr(tcflag_t);
157 int	comparam(struct tty *, struct termios *);
158 void	comstart(struct tty *);
159 int	comhwiflow(struct tty *, int);
160 
161 void	com_loadchannelregs(struct com_softc *);
162 void	com_hwiflow(struct com_softc *);
163 void	com_break(struct com_softc *, int);
164 void	com_modem(struct com_softc *, int);
165 void	tiocm_to_com(struct com_softc *, u_long, int);
166 int	com_to_tiocm(struct com_softc *);
167 void	com_iflush(struct com_softc *);
168 
169 int	com_common_getc(dev_t, struct com_regs *);
170 static void	com_common_putc(dev_t, struct com_regs *, int, int);
171 
172 int	cominit(struct com_regs *, int, int, int, tcflag_t);
173 
174 static int comcnreattach(void);
175 
176 int	comcngetc(dev_t);
177 void	comcnputc(dev_t, int);
178 void	comcnpollc(dev_t, int);
179 
180 void	comsoft(void *);
181 static inline void com_rxsoft(struct com_softc *, struct tty *);
182 static inline void com_txsoft(struct com_softc *, struct tty *);
183 static inline void com_stsoft(struct com_softc *, struct tty *);
184 static inline void com_schedrx(struct com_softc *);
185 void	comdiag(void *);
186 
187 dev_type_open(comopen);
188 dev_type_close(comclose);
189 dev_type_read(comread);
190 dev_type_write(comwrite);
191 dev_type_ioctl(comioctl);
192 dev_type_stop(comstop);
193 dev_type_tty(comtty);
194 dev_type_poll(compoll);
195 
196 static struct comcons_info comcons_info;
197 
198 /*
199  * Following are all routines needed for COM to act as console
200  */
201 static struct consdev comcons = {
202 	.cn_getc = comcngetc,
203 	.cn_putc = comcnputc,
204 	.cn_pollc = comcnpollc,
205 	.cn_dev = NODEV,
206 	.cn_pri = CN_NORMAL
207 };
208 
209 
210 const struct cdevsw com_cdevsw = {
211 	.d_open = comopen,
212 	.d_close = comclose,
213 	.d_read = comread,
214 	.d_write = comwrite,
215 	.d_ioctl = comioctl,
216 	.d_stop = comstop,
217 	.d_tty = comtty,
218 	.d_poll = compoll,
219 	.d_mmap = nommap,
220 	.d_kqfilter = ttykqfilter,
221 	.d_discard = nodiscard,
222 	.d_flag = D_TTY
223 };
224 
225 /*
226  * Make this an option variable one can patch.
227  * But be warned:  this must be a power of 2!
228  */
229 u_int com_rbuf_size = COM_RING_SIZE;
230 
231 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
232 u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
233 u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
234 
235 static int comconsattached;
236 static struct cnm_state com_cnm_state;
237 
238 #ifdef KGDB
239 #include <sys/kgdb.h>
240 
241 static struct com_regs comkgdbregs;
242 static int com_kgdb_attached;
243 
244 int	com_kgdb_getc(void *);
245 void	com_kgdb_putc(void *, int);
246 #endif /* KGDB */
247 
248 /* initializer for typical 16550-ish hardware */
249 static const bus_size_t com_std_map[COM_REGMAP_NENTRIES] = {
250 	[COM_REG_RXDATA]	=	com_data,
251 	[COM_REG_TXDATA]	=	com_data,
252 	[COM_REG_DLBL]		=	com_dlbl,
253 	[COM_REG_DLBH]		=	com_dlbh,
254 	[COM_REG_IER]		=	com_ier,
255 	[COM_REG_IIR]		=	com_iir,
256 	[COM_REG_FIFO]		=	com_fifo,
257 	[COM_REG_TCR]		=	com_fifo,
258 	[COM_REG_EFR]		=	com_efr,
259 	[COM_REG_TLR]		=	com_efr,
260 	[COM_REG_LCR]		=	com_lcr,
261 	[COM_REG_MCR]		=	com_mcr,
262 	[COM_REG_LSR]		=	com_lsr,
263 	[COM_REG_MSR]		=	com_msr,
264 	[COM_REG_USR]		=	com_usr,
265 	[COM_REG_TFL]		=	com_tfl,
266 	[COM_REG_RFL]		=	com_rfl,
267 	[COM_REG_HALT]		=	com_halt,
268 	[COM_REG_MDR1]		=	com_mdr1,
269 };
270 
271 #define	COMDIALOUT_MASK	TTDIALOUT_MASK
272 
273 #define	COMUNIT(x)	TTUNIT(x)
274 #define	COMDIALOUT(x)	TTDIALOUT(x)
275 
276 #define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
277 			 device_is_active((sc)->sc_dev))
278 
279 #define	BR	BUS_SPACE_BARRIER_READ
280 #define	BW	BUS_SPACE_BARRIER_WRITE
281 #define COM_BARRIER(r, f) \
282 	bus_space_barrier((r)->cr_iot, (r)->cr_ioh, 0, (r)->cr_nports, (f))
283 
284 /*
285  * com_read_1 --
286  *	Default register read callback using single byte accesses.
287  */
288 static uint8_t
289 com_read_1(struct com_regs *regs, u_int reg)
290 {
291 	return bus_space_read_1(regs->cr_iot, regs->cr_ioh, reg);
292 }
293 
294 /*
295  * com_write_1 --
296  *	Default register write callback using single byte accesses.
297  */
298 static void
299 com_write_1(struct com_regs *regs, u_int reg, uint8_t val)
300 {
301 	bus_space_write_1(regs->cr_iot, regs->cr_ioh, reg, val);
302 }
303 
304 /*
305  * com_write_multi_1 --
306  *	Default register multi write callback using single byte accesses.
307  */
308 static void
309 com_write_multi_1(struct com_regs *regs, u_int reg, const uint8_t *datap,
310     bus_size_t count)
311 {
312 	bus_space_write_multi_1(regs->cr_iot, regs->cr_ioh, reg, datap, count);
313 }
314 
315 /*
316  * com_read_4 --
317  *	Default register read callback using dword accesses.
318  */
319 static uint8_t
320 com_read_4(struct com_regs *regs, u_int reg)
321 {
322 	return bus_space_read_4(regs->cr_iot, regs->cr_ioh, reg) & 0xff;
323 }
324 
325 /*
326  * com_write_4 --
327  *	Default register write callback using dword accesses.
328  */
329 static void
330 com_write_4(struct com_regs *regs, u_int reg, uint8_t val)
331 {
332 	bus_space_write_4(regs->cr_iot, regs->cr_ioh, reg, val);
333 }
334 
335 /*
336  * com_write_multi_4 --
337  *	Default register multi write callback using dword accesses.
338  */
339 static void
340 com_write_multi_4(struct com_regs *regs, u_int reg, const uint8_t *datap,
341     bus_size_t count)
342 {
343 	while (count-- > 0) {
344 		bus_space_write_4(regs->cr_iot, regs->cr_ioh, reg, *datap++);
345 	}
346 }
347 
348 /*
349  * com_init_regs --
350  *	Driver front-ends use this to initialize our register map
351  *	in the standard fashion.  They may then tailor the map to
352  *	their own particular requirements.
353  */
354 void
355 com_init_regs(struct com_regs *regs, bus_space_tag_t st, bus_space_handle_t sh,
356 	      bus_addr_t addr)
357 {
358 
359 	memset(regs, 0, sizeof(*regs));
360 	regs->cr_iot = st;
361 	regs->cr_ioh = sh;
362 	regs->cr_iobase = addr;
363 	regs->cr_nports = COM_NPORTS;
364 	regs->cr_read = com_read_1;
365 	regs->cr_write = com_write_1;
366 	regs->cr_write_multi = com_write_multi_1;
367 	memcpy(regs->cr_map, com_std_map, sizeof(regs->cr_map));
368 }
369 
370 /*
371  * com_init_regs_stride --
372  *	Convenience function for front-ends that have a stride between
373  *	registers.
374  */
375 void
376 com_init_regs_stride(struct com_regs *regs, bus_space_tag_t st,
377 		     bus_space_handle_t sh, bus_addr_t addr, u_int regshift)
378 {
379 
380 	com_init_regs(regs, st, sh, addr);
381 	for (size_t i = 0; i < __arraycount(regs->cr_map); i++) {
382 		regs->cr_map[i] <<= regshift;
383 	}
384 	regs->cr_nports <<= regshift;
385 }
386 
387 /*
388  * com_init_regs_stride_width --
389  *	Convenience function for front-ends that have a stride between
390  *	registers and specific I/O width requirements.
391  */
392 void
393 com_init_regs_stride_width(struct com_regs *regs, bus_space_tag_t st,
394 			   bus_space_handle_t sh, bus_addr_t addr,
395 			   u_int regshift, u_int width)
396 {
397 
398 	com_init_regs(regs, st, sh, addr);
399 	for (size_t i = 0; i < __arraycount(regs->cr_map); i++) {
400 		regs->cr_map[i] <<= regshift;
401 	}
402 	regs->cr_nports <<= regshift;
403 
404 	switch (width) {
405 	case 1:
406 		/* Already set by com_init_regs */
407 		break;
408 	case 4:
409 		regs->cr_read = com_read_4;
410 		regs->cr_write = com_write_4;
411 		regs->cr_write_multi = com_write_multi_4;
412 		break;
413 	default:
414 		panic("com: unsupported I/O width %d", width);
415 	}
416 }
417 
418 /*ARGSUSED*/
419 int
420 comspeed(long speed, long frequency, int type)
421 {
422 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
423 
424 	int x, err;
425 	int divisor = 16;
426 
427 	if ((type == COM_TYPE_OMAP) && (speed > 230400)) {
428 	    divisor = 13;
429 	}
430 
431 	if (speed == 0)
432 		return (0);
433 	if (speed < 0)
434 		return (-1);
435 	x = divrnd(frequency / divisor, speed);
436 	if (x <= 0)
437 		return (-1);
438 	err = divrnd(((quad_t)frequency) * 1000 / divisor, speed * x) - 1000;
439 	if (err < 0)
440 		err = -err;
441 	if (err > COM_TOLERANCE)
442 		return (-1);
443 	return (x);
444 
445 #undef	divrnd
446 }
447 
448 #ifdef COM_DEBUG
449 int	com_debug = 0;
450 
451 void comstatus(struct com_softc *, const char *);
452 void
453 comstatus(struct com_softc *sc, const char *str)
454 {
455 	struct tty *tp = sc->sc_tty;
456 
457 	aprint_normal_dev(sc->sc_dev,
458 	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
459 	    str,
460 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
461 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
462 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
463 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
464 	    sc->sc_tx_stopped ? '+' : '-');
465 
466 	aprint_normal_dev(sc->sc_dev,
467 	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
468 	    str,
469 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
470 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
471 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
472 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
473 	    sc->sc_rx_flags);
474 }
475 #endif
476 
477 int
478 com_probe_subr(struct com_regs *regs)
479 {
480 
481 	/* force access to id reg */
482 	CSR_WRITE_1(regs, COM_REG_LCR, LCR_8BITS);
483 	CSR_WRITE_1(regs, COM_REG_IIR, 0);
484 	if ((CSR_READ_1(regs, COM_REG_LCR) != LCR_8BITS) ||
485 	    (CSR_READ_1(regs, COM_REG_IIR) & 0x38))
486 		return (0);
487 
488 	return (1);
489 }
490 
491 int
492 comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
493 {
494 	struct com_regs	regs;
495 
496 	com_init_regs(&regs, iot, ioh, 0/*XXX*/);
497 
498 	return com_probe_subr(&regs);
499 }
500 
501 /*
502  * No locking in this routine; it is only called during attach,
503  * or with the port already locked.
504  */
505 static void
506 com_enable_debugport(struct com_softc *sc)
507 {
508 
509 	/* Turn on line break interrupt, set carrier. */
510 	sc->sc_ier = IER_ERLS;
511 	if (sc->sc_type == COM_TYPE_PXA2x0)
512 		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
513 	if (sc->sc_type == COM_TYPE_INGENIC ||
514 	    sc->sc_type == COM_TYPE_TEGRA)
515 		sc->sc_ier |= IER_ERXTOUT;
516 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
517 	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
518 	CSR_WRITE_1(&sc->sc_regs, COM_REG_MCR, sc->sc_mcr);
519 }
520 
521 static void
522 com_intr_poll(void *arg)
523 {
524 	struct com_softc * const sc = arg;
525 
526 	comintr(sc);
527 
528 	callout_schedule(&sc->sc_poll_callout, sc->sc_poll_ticks);
529 }
530 
531 void
532 com_attach_subr(struct com_softc *sc)
533 {
534 	struct com_regs *regsp = &sc->sc_regs;
535 	struct tty *tp;
536 	uint32_t cpr;
537 	uint8_t lcr;
538 	const char *fifo_msg = NULL;
539 	prop_dictionary_t dict;
540 	bool is_console = true;
541 	bool force_console = false;
542 
543 	aprint_naive("\n");
544 
545 	dict = device_properties(sc->sc_dev);
546 	prop_dictionary_get_bool(dict, "is_console", &is_console);
547 	prop_dictionary_get_bool(dict, "force_console", &force_console);
548 	callout_init(&sc->sc_diag_callout, 0);
549 	callout_init(&sc->sc_poll_callout, 0);
550 	callout_setfunc(&sc->sc_poll_callout, com_intr_poll, sc);
551 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
552 
553 #if defined(COM_16650)
554 	sc->sc_type = COM_TYPE_16650;
555 #elif defined(COM_16750)
556 	sc->sc_type = COM_TYPE_16750;
557 #elif defined(COM_HAYESP)
558 	sc->sc_type = COM_TYPE_HAYESP;
559 #elif defined(COM_PXA2X0)
560 	sc->sc_type = COM_TYPE_PXA2x0;
561 #endif
562 
563 	/* Disable interrupts before configuring the device. */
564 	if (sc->sc_type == COM_TYPE_PXA2x0)
565 		sc->sc_ier = IER_EUART;
566 	else
567 		sc->sc_ier = 0;
568 
569 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
570 
571 	if ((bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
572 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) || force_console) {
573 		comconsattached = 1;
574 
575 		if (force_console)
576 			memcpy(regsp, &comcons_info.regs, sizeof(*regsp));
577 
578 		if (cn_tab == NULL && comcnreattach() != 0) {
579 			printf("can't re-init serial console @%lx\n",
580 			    (u_long)comcons_info.regs.cr_iobase);
581 		}
582 
583 		switch (sc->sc_type) {
584 		case COM_TYPE_16750:
585 		case COM_TYPE_DW_APB:
586 			/* Use in comintr(). */
587  			sc->sc_lcr = cflag2lcr(comcons_info.cflag);
588 			break;
589 		}
590 
591 		/* Make sure the console is always "hardwired". */
592 		delay(10000);			/* wait for output to finish */
593 		if (is_console) {
594 			SET(sc->sc_hwflags, COM_HW_CONSOLE);
595 		}
596 
597 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
598 	}
599 
600 	/* Probe for FIFO */
601 	switch (sc->sc_type) {
602 	case COM_TYPE_HAYESP:
603 		goto fifodone;
604 
605 	case COM_TYPE_AU1x00:
606 		sc->sc_fifolen = 16;
607 		fifo_msg = "Au1X00 UART";
608 		SET(sc->sc_hwflags, COM_HW_FIFO);
609 		goto fifodelay;
610 
611 	case COM_TYPE_16550_NOERS:
612 		sc->sc_fifolen = 16;
613 		fifo_msg = "ns16650, no ERS";
614 		SET(sc->sc_hwflags, COM_HW_FIFO);
615 		goto fifodelay;
616 
617 	case COM_TYPE_OMAP:
618 		sc->sc_fifolen = 64;
619 		fifo_msg = "OMAP UART";
620 		SET(sc->sc_hwflags, COM_HW_FIFO);
621 		goto fifodelay;
622 
623 	case COM_TYPE_INGENIC:
624 		sc->sc_fifolen = 16;
625 		fifo_msg = "Ingenic UART";
626 		SET(sc->sc_hwflags, COM_HW_FIFO);
627 		SET(sc->sc_hwflags, COM_HW_NOIEN);
628 		goto fifodelay;
629 
630 	case COM_TYPE_TEGRA:
631 		sc->sc_fifolen = 8;
632 		fifo_msg = "Tegra UART";
633 		SET(sc->sc_hwflags, COM_HW_FIFO);
634 		CSR_WRITE_1(regsp, COM_REG_FIFO,
635 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
636 		goto fifodelay;
637 
638 	case COM_TYPE_BCMAUXUART:
639 		sc->sc_fifolen = 1;
640 		fifo_msg = "BCM AUX UART";
641 		SET(sc->sc_hwflags, COM_HW_FIFO);
642 		CSR_WRITE_1(regsp, COM_REG_FIFO,
643 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
644 		goto fifodelay;
645 
646 	case COM_TYPE_DW_APB:
647 		if (!prop_dictionary_get_uint(dict, "fifolen", &sc->sc_fifolen)) {
648 			cpr = bus_space_read_4(sc->sc_regs.cr_iot,
649 			    sc->sc_regs.cr_ioh, DW_APB_UART_CPR);
650 			sc->sc_fifolen = __SHIFTOUT(cpr, UART_CPR_FIFO_MODE) * 16;
651 		}
652 		if (sc->sc_fifolen == 0) {
653 			sc->sc_fifolen = 1;
654 			fifo_msg = "DesignWare APB UART, no fifo";
655 			CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
656 		} else {
657 			fifo_msg = "DesignWare APB UART";
658 			SET(sc->sc_hwflags, COM_HW_FIFO);
659 			CSR_WRITE_1(regsp, COM_REG_FIFO,
660 			    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
661 		}
662 		goto fifodelay;
663 	}
664 
665 	sc->sc_fifolen = 1;
666 	/* look for a NS 16550AF UART with FIFOs */
667 	if (sc->sc_type == COM_TYPE_INGENIC) {
668 		CSR_WRITE_1(regsp, COM_REG_FIFO,
669 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
670 		    FIFO_TRIGGER_14 | FIFO_UART_ON);
671 	} else
672 		CSR_WRITE_1(regsp, COM_REG_FIFO,
673 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
674 	delay(100);
675 	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
676 	    == IIR_FIFO_MASK)
677 		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
678 		    == FIFO_TRIGGER_14) {
679 			SET(sc->sc_hwflags, COM_HW_FIFO);
680 
681 			fifo_msg = "ns16550a";
682 			sc->sc_fifolen = 16;
683 
684 			/*
685 			 * IIR changes into the EFR if LCR is set to LCR_EERS
686 			 * on 16650s. We also know IIR != 0 at this point.
687 			 * Write 0 into the EFR, and read it. If the result
688 			 * is 0, we have a 16650.
689 			 *
690 			 * Older 16650s were broken; the test to detect them
691 			 * is taken from the Linux driver. Apparently
692 			 * setting DLAB enable gives access to the EFR on
693 			 * these chips.
694 			 */
695 			if (sc->sc_type == COM_TYPE_16650) {
696 				lcr = CSR_READ_1(regsp, COM_REG_LCR);
697 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
698 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
699 				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
700 					CSR_WRITE_1(regsp, COM_REG_LCR,
701 					    lcr | LCR_DLAB);
702 					if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
703 						CLR(sc->sc_hwflags, COM_HW_FIFO);
704 						sc->sc_fifolen = 0;
705 					} else {
706 						SET(sc->sc_hwflags, COM_HW_FLOW);
707 						sc->sc_fifolen = 32;
708 					}
709 				} else
710 					sc->sc_fifolen = 16;
711 
712 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
713 				if (sc->sc_fifolen == 0)
714 					fifo_msg = "st16650, broken fifo";
715 				else if (sc->sc_fifolen == 32)
716 					fifo_msg = "st16650a";
717 				else
718 					fifo_msg = "ns16550a";
719 			}
720 
721 			/*
722 			 * TL16C750 can enable 64byte FIFO, only when DLAB
723 			 * is 1.  However, some 16750 may always enable.  For
724 			 * example, restrictions according to DLAB in a data
725 			 * sheet for SC16C750 were not described.
726 			 * Please enable 'options COM_16650', supposing you
727 			 * use SC16C750.  Probably 32 bytes of FIFO and HW FLOW
728 			 * should become effective.
729 			 */
730 			if (sc->sc_type == COM_TYPE_16750) {
731 				uint8_t iir1, iir2;
732 				uint8_t fcr = FIFO_ENABLE | FIFO_TRIGGER_14;
733 
734 				lcr = CSR_READ_1(regsp, COM_REG_LCR);
735 				CSR_WRITE_1(regsp, COM_REG_LCR,
736 				    lcr & ~LCR_DLAB);
737 				CSR_WRITE_1(regsp, COM_REG_FIFO,
738 				    fcr | FIFO_64B_ENABLE);
739 				iir1 = CSR_READ_1(regsp, COM_REG_IIR);
740 				CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
741 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr | LCR_DLAB);
742 				CSR_WRITE_1(regsp, COM_REG_FIFO,
743 				    fcr | FIFO_64B_ENABLE);
744 				iir2 = CSR_READ_1(regsp, COM_REG_IIR);
745 
746 				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
747 
748 				if (!ISSET(iir1, IIR_64B_FIFO) &&
749 				    ISSET(iir2, IIR_64B_FIFO)) {
750 					/* It is TL16C750. */
751 					sc->sc_fifolen = 64;
752 					SET(sc->sc_hwflags, COM_HW_AFE);
753 				} else
754 					CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
755 
756 				if (sc->sc_fifolen == 64)
757 					fifo_msg = "tl16c750";
758 				else
759 					fifo_msg = "ns16750";
760 			}
761 		} else
762 			fifo_msg = "ns16550, broken fifo";
763 	else
764 		fifo_msg = "ns8250 or ns16450, no fifo";
765 	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
766 
767 fifodelay:
768 	/*
769 	 * Some chips will clear down both Tx and Rx FIFOs when zero is
770 	 * written to com_fifo. If this chip is the console, writing zero
771 	 * results in some of the chip/FIFO description being lost, so delay
772 	 * printing it until now.
773 	 */
774 	delay(10);
775 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
776 		aprint_normal(": %s, %d-byte FIFO\n", fifo_msg, sc->sc_fifolen);
777 	} else {
778 		aprint_normal(": %s\n", fifo_msg);
779 	}
780 	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
781 		sc->sc_fifolen = 1;
782 		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
783 	}
784 
785 fifodone:
786 
787 	tp = tty_alloc();
788 	tp->t_oproc = comstart;
789 	tp->t_param = comparam;
790 	tp->t_hwiflow = comhwiflow;
791 	tp->t_softc = sc;
792 
793 	sc->sc_tty = tp;
794 	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_WAITOK);
795 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
796 	sc->sc_rbavail = com_rbuf_size;
797 	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
798 
799 	tty_attach(tp);
800 
801 	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
802 		SET(sc->sc_mcr, MCR_IENABLE);
803 
804 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
805 		int maj;
806 
807 		/* locate the major number */
808 		maj = cdevsw_lookup_major(&com_cdevsw);
809 
810 		tp->t_dev = cn_tab->cn_dev = makedev(maj,
811 						     device_unit(sc->sc_dev));
812 
813 		aprint_normal_dev(sc->sc_dev, "console\n");
814 	}
815 
816 #ifdef KGDB
817 	/*
818 	 * Allow kgdb to "take over" this port.  If this is
819 	 * not the console and is the kgdb device, it has
820 	 * exclusive use.  If it's the console _and_ the
821 	 * kgdb device, it doesn't.
822 	 */
823 	if (bus_space_is_equal(regsp->cr_iot, comkgdbregs.cr_iot) &&
824 	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
825 		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
826 			com_kgdb_attached = 1;
827 
828 			SET(sc->sc_hwflags, COM_HW_KGDB);
829 		}
830 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
831 	}
832 #endif
833 
834 	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
835 
836 #ifdef RND_COM
837 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
838 			  RND_TYPE_TTY, RND_FLAG_DEFAULT);
839 #endif
840 
841 	/* if there are no enable/disable functions, assume the device
842 	   is always enabled */
843 	if (!sc->enable)
844 		sc->enabled = 1;
845 
846 	com_config(sc);
847 
848 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
849 
850 	if (sc->sc_poll_ticks != 0)
851 		callout_schedule(&sc->sc_poll_callout, sc->sc_poll_ticks);
852 }
853 
854 void
855 com_config(struct com_softc *sc)
856 {
857 	struct com_regs *regsp = &sc->sc_regs;
858 
859 	/* Disable interrupts before configuring the device. */
860 	if (sc->sc_type == COM_TYPE_PXA2x0)
861 		sc->sc_ier = IER_EUART;
862 	else
863 		sc->sc_ier = 0;
864 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
865 	(void) CSR_READ_1(regsp, COM_REG_IIR);
866 
867 	/* Look for a Hayes ESP board. */
868 	if (sc->sc_type == COM_TYPE_HAYESP) {
869 
870 		/* Set 16550 compatibility mode */
871 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
872 				  HAYESP_SETMODE);
873 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
874 				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
875 				  HAYESP_MODE_SCALE);
876 
877 		/* Set RTS/CTS flow control */
878 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
879 				  HAYESP_SETFLOWTYPE);
880 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
881 				  HAYESP_FLOW_RTS);
882 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
883 				  HAYESP_FLOW_CTS);
884 
885 		/* Set flow control levels */
886 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
887 				  HAYESP_SETRXFLOW);
888 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
889 				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
890 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
891 				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
892 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
893 				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
894 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
895 				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
896 	}
897 
898 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
899 		com_enable_debugport(sc);
900 }
901 
902 int
903 com_detach(device_t self, int flags)
904 {
905 	struct com_softc *sc = device_private(self);
906 	int maj, mn;
907 
908 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
909 		return EBUSY;
910 
911 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) &&
912 	    (flags & DETACH_SHUTDOWN) != 0)
913 		return EBUSY;
914 
915 	if (sc->disable != NULL && sc->enabled != 0) {
916 		(*sc->disable)(sc);
917 		sc->enabled = 0;
918 	}
919 
920 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
921 		comconsattached = 0;
922 		cn_tab = NULL;
923 	}
924 
925 	/* locate the major number */
926 	maj = cdevsw_lookup_major(&com_cdevsw);
927 
928 	/* Nuke the vnodes for any open instances. */
929 	mn = device_unit(self);
930 	vdevgone(maj, mn, mn, VCHR);
931 
932 	mn |= COMDIALOUT_MASK;
933 	vdevgone(maj, mn, mn, VCHR);
934 
935 	if (sc->sc_rbuf == NULL) {
936 		/*
937 		 * Ring buffer allocation failed in the com_attach_subr,
938 		 * only the tty is allocated, and nothing else.
939 		 */
940 		tty_free(sc->sc_tty);
941 		return 0;
942 	}
943 
944 	/* Free the receive buffer. */
945 	free(sc->sc_rbuf, M_DEVBUF);
946 
947 	/* Detach and free the tty. */
948 	tty_detach(sc->sc_tty);
949 	tty_free(sc->sc_tty);
950 
951 	/* Unhook the soft interrupt handler. */
952 	softint_disestablish(sc->sc_si);
953 
954 #ifdef RND_COM
955 	/* Unhook the entropy source. */
956 	rnd_detach_source(&sc->rnd_source);
957 #endif
958 	callout_destroy(&sc->sc_diag_callout);
959 
960 	/* Destroy the lock. */
961 	mutex_destroy(&sc->sc_lock);
962 
963 	return (0);
964 }
965 
966 void
967 com_shutdown(struct com_softc *sc)
968 {
969 	struct tty *tp = sc->sc_tty;
970 
971 	mutex_spin_enter(&sc->sc_lock);
972 
973 	/* If we were asserting flow control, then deassert it. */
974 	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
975 	com_hwiflow(sc);
976 
977 	/* Clear any break condition set with TIOCSBRK. */
978 	com_break(sc, 0);
979 
980 	/*
981 	 * Hang up if necessary.  Record when we hung up, so if we
982 	 * immediately open the port again, we will wait a bit until
983 	 * the other side has had time to notice that we hung up.
984 	 */
985 	if (ISSET(tp->t_cflag, HUPCL)) {
986 		com_modem(sc, 0);
987 		microuptime(&sc->sc_hup_pending);
988 		sc->sc_hup_pending.tv_sec++;
989 	}
990 
991 	/* Turn off interrupts. */
992 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
993 		sc->sc_ier = IER_ERLS; /* interrupt on line break */
994 		if ((sc->sc_type == COM_TYPE_PXA2x0) ||
995 		    (sc->sc_type == COM_TYPE_INGENIC) ||
996 		    (sc->sc_type == COM_TYPE_TEGRA))
997 			sc->sc_ier |= IER_ERXTOUT;
998 	} else
999 		sc->sc_ier = 0;
1000 
1001 	if (sc->sc_type == COM_TYPE_PXA2x0)
1002 		sc->sc_ier |= IER_EUART;
1003 
1004 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1005 
1006 	mutex_spin_exit(&sc->sc_lock);
1007 
1008 	if (sc->disable) {
1009 #ifdef DIAGNOSTIC
1010 		if (!sc->enabled)
1011 			panic("com_shutdown: not enabled?");
1012 #endif
1013 		(*sc->disable)(sc);
1014 		sc->enabled = 0;
1015 	}
1016 }
1017 
1018 int
1019 comopen(dev_t dev, int flag, int mode, struct lwp *l)
1020 {
1021 	struct com_softc *sc;
1022 	struct tty *tp;
1023 	int s;
1024 	int error;
1025 
1026 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1027 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
1028 		sc->sc_rbuf == NULL)
1029 		return (ENXIO);
1030 
1031 	if (!device_is_active(sc->sc_dev))
1032 		return (ENXIO);
1033 
1034 #ifdef KGDB
1035 	/*
1036 	 * If this is the kgdb port, no other use is permitted.
1037 	 */
1038 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
1039 		return (EBUSY);
1040 #endif
1041 
1042 	tp = sc->sc_tty;
1043 
1044 	/*
1045 	 * If the device is exclusively for kernel use, deny userland
1046 	 * open.
1047 	 */
1048 	if (ISSET(tp->t_state, TS_KERN_ONLY))
1049 		return (EBUSY);
1050 
1051 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
1052 		return (EBUSY);
1053 
1054 	s = spltty();
1055 
1056 	/*
1057 	 * Do the following iff this is a first open.
1058 	 */
1059 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1060 		struct termios t;
1061 		struct timeval now, diff;
1062 
1063 		tp->t_dev = dev;
1064 
1065 		if (sc->enable) {
1066 			if ((*sc->enable)(sc)) {
1067 				splx(s);
1068 				aprint_error_dev(sc->sc_dev,
1069 				    "device enable failed\n");
1070 				return (EIO);
1071 			}
1072 			mutex_spin_enter(&sc->sc_lock);
1073 			sc->enabled = 1;
1074 			com_config(sc);
1075 		} else {
1076 			mutex_spin_enter(&sc->sc_lock);
1077 		}
1078 
1079 		if (timerisset(&sc->sc_hup_pending)) {
1080 			microuptime(&now);
1081 			while (timercmp(&now, &sc->sc_hup_pending, <)) {
1082 				timersub(&sc->sc_hup_pending, &now, &diff);
1083 				const int ms = diff.tv_sec * 1000 +
1084 				    diff.tv_usec / 1000;
1085 				kpause(ttclos, false, uimax(mstohz(ms), 1),
1086 				    &sc->sc_lock);
1087 				microuptime(&now);
1088 			}
1089 			timerclear(&sc->sc_hup_pending);
1090 		}
1091 
1092 		/* Turn on interrupts. */
1093 		sc->sc_ier = IER_ERXRDY | IER_ERLS;
1094 		if (!ISSET(tp->t_cflag, CLOCAL))
1095 			sc->sc_ier |= IER_EMSC;
1096 
1097 		if (sc->sc_type == COM_TYPE_PXA2x0)
1098 			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
1099 		else if (sc->sc_type == COM_TYPE_INGENIC ||
1100 			 sc->sc_type == COM_TYPE_TEGRA)
1101 			sc->sc_ier |= IER_ERXTOUT;
1102 		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1103 
1104 		/* Fetch the current modem control status, needed later. */
1105 		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
1106 
1107 		/* Clear PPS capture state on first open. */
1108 		mutex_spin_enter(&timecounter_lock);
1109 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
1110 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1111 		pps_init(&sc->sc_pps_state);
1112 		mutex_spin_exit(&timecounter_lock);
1113 
1114 		mutex_spin_exit(&sc->sc_lock);
1115 
1116 		/*
1117 		 * Initialize the termios status to the defaults.  Add in the
1118 		 * sticky bits from TIOCSFLAGS.
1119 		 */
1120 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1121 			t.c_ospeed = comcons_info.rate;
1122 			t.c_cflag = comcons_info.cflag;
1123 		} else {
1124 			t.c_ospeed = TTYDEF_SPEED;
1125 			t.c_cflag = TTYDEF_CFLAG;
1126 		}
1127 		t.c_ispeed = t.c_ospeed;
1128 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
1129 			SET(t.c_cflag, CLOCAL);
1130 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
1131 			SET(t.c_cflag, CRTSCTS);
1132 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
1133 			SET(t.c_cflag, MDMBUF);
1134 		/* Make sure comparam() will do something. */
1135 		tp->t_ospeed = 0;
1136 		(void) comparam(tp, &t);
1137 		tp->t_iflag = TTYDEF_IFLAG;
1138 		tp->t_oflag = TTYDEF_OFLAG;
1139 		tp->t_lflag = TTYDEF_LFLAG;
1140 		ttychars(tp);
1141 		ttsetwater(tp);
1142 
1143 		mutex_spin_enter(&sc->sc_lock);
1144 
1145 		/*
1146 		 * Turn on DTR.  We must always do this, even if carrier is not
1147 		 * present, because otherwise we'd have to use TIOCSDTR
1148 		 * immediately after setting CLOCAL, which applications do not
1149 		 * expect.  We always assert DTR while the device is open
1150 		 * unless explicitly requested to deassert it.
1151 		 */
1152 		com_modem(sc, 1);
1153 
1154 		/* Clear the input ring, and unblock. */
1155 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
1156 		sc->sc_rbavail = com_rbuf_size;
1157 		com_iflush(sc);
1158 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
1159 		com_hwiflow(sc);
1160 
1161 #ifdef COM_DEBUG
1162 		if (com_debug)
1163 			comstatus(sc, "comopen  ");
1164 #endif
1165 
1166 		mutex_spin_exit(&sc->sc_lock);
1167 	}
1168 
1169 	splx(s);
1170 
1171 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
1172 	if (error)
1173 		goto bad;
1174 
1175 	error = (*tp->t_linesw->l_open)(dev, tp);
1176 	if (error)
1177 		goto bad;
1178 
1179 	return (0);
1180 
1181 bad:
1182 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1183 		/*
1184 		 * We failed to open the device, and nobody else had it opened.
1185 		 * Clean up the state as appropriate.
1186 		 */
1187 		com_shutdown(sc);
1188 	}
1189 
1190 	return (error);
1191 }
1192 
1193 int
1194 comclose(dev_t dev, int flag, int mode, struct lwp *l)
1195 {
1196 	struct com_softc *sc =
1197 	    device_lookup_private(&com_cd, COMUNIT(dev));
1198 	struct tty *tp = sc->sc_tty;
1199 
1200 	/* XXX This is for cons.c. */
1201 	if (!ISSET(tp->t_state, TS_ISOPEN))
1202 		return (0);
1203 	/*
1204 	 * If the device is exclusively for kernel use, deny userland
1205 	 * close.
1206 	 */
1207 	if (ISSET(tp->t_state, TS_KERN_ONLY))
1208 		return (0);
1209 
1210 	(*tp->t_linesw->l_close)(tp, flag);
1211 	ttyclose(tp);
1212 
1213 	if (COM_ISALIVE(sc) == 0)
1214 		return (0);
1215 
1216 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1217 		/*
1218 		 * Although we got a last close, the device may still be in
1219 		 * use; e.g. if this was the dialout node, and there are still
1220 		 * processes waiting for carrier on the non-dialout node.
1221 		 */
1222 		com_shutdown(sc);
1223 	}
1224 
1225 	return (0);
1226 }
1227 
1228 int
1229 comread(dev_t dev, struct uio *uio, int flag)
1230 {
1231 	struct com_softc *sc =
1232 	    device_lookup_private(&com_cd, COMUNIT(dev));
1233 	struct tty *tp = sc->sc_tty;
1234 
1235 	if (COM_ISALIVE(sc) == 0)
1236 		return (EIO);
1237 
1238 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
1239 }
1240 
1241 int
1242 comwrite(dev_t dev, struct uio *uio, int flag)
1243 {
1244 	struct com_softc *sc =
1245 	    device_lookup_private(&com_cd, COMUNIT(dev));
1246 	struct tty *tp = sc->sc_tty;
1247 
1248 	if (COM_ISALIVE(sc) == 0)
1249 		return (EIO);
1250 
1251 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
1252 }
1253 
1254 int
1255 compoll(dev_t dev, int events, struct lwp *l)
1256 {
1257 	struct com_softc *sc =
1258 	    device_lookup_private(&com_cd, COMUNIT(dev));
1259 	struct tty *tp = sc->sc_tty;
1260 
1261 	if (COM_ISALIVE(sc) == 0)
1262 		return (POLLHUP);
1263 
1264 	return ((*tp->t_linesw->l_poll)(tp, events, l));
1265 }
1266 
1267 struct tty *
1268 comtty(dev_t dev)
1269 {
1270 	struct com_softc *sc =
1271 	    device_lookup_private(&com_cd, COMUNIT(dev));
1272 	struct tty *tp = sc->sc_tty;
1273 
1274 	return (tp);
1275 }
1276 
1277 int
1278 comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1279 {
1280 	struct com_softc *sc;
1281 	struct tty *tp;
1282 	int error;
1283 
1284 	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1285 	if (sc == NULL)
1286 		return ENXIO;
1287 	if (COM_ISALIVE(sc) == 0)
1288 		return (EIO);
1289 
1290 	tp = sc->sc_tty;
1291 
1292 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1293 	if (error != EPASSTHROUGH)
1294 		return (error);
1295 
1296 	error = ttioctl(tp, cmd, data, flag, l);
1297 	if (error != EPASSTHROUGH)
1298 		return (error);
1299 
1300 	error = 0;
1301 	switch (cmd) {
1302 	case TIOCSFLAGS:
1303 		error = kauth_authorize_device_tty(l->l_cred,
1304 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1305 		break;
1306 	default:
1307 		/* nothing */
1308 		break;
1309 	}
1310 	if (error) {
1311 		return error;
1312 	}
1313 
1314 	mutex_spin_enter(&sc->sc_lock);
1315 
1316 	switch (cmd) {
1317 	case TIOCSBRK:
1318 		com_break(sc, 1);
1319 		break;
1320 
1321 	case TIOCCBRK:
1322 		com_break(sc, 0);
1323 		break;
1324 
1325 	case TIOCSDTR:
1326 		com_modem(sc, 1);
1327 		break;
1328 
1329 	case TIOCCDTR:
1330 		com_modem(sc, 0);
1331 		break;
1332 
1333 	case TIOCGFLAGS:
1334 		*(int *)data = sc->sc_swflags;
1335 		break;
1336 
1337 	case TIOCSFLAGS:
1338 		sc->sc_swflags = *(int *)data;
1339 		break;
1340 
1341 	case TIOCMSET:
1342 	case TIOCMBIS:
1343 	case TIOCMBIC:
1344 		tiocm_to_com(sc, cmd, *(int *)data);
1345 		break;
1346 
1347 	case TIOCMGET:
1348 		*(int *)data = com_to_tiocm(sc);
1349 		break;
1350 
1351 	case PPS_IOC_CREATE:
1352 	case PPS_IOC_DESTROY:
1353 	case PPS_IOC_GETPARAMS:
1354 	case PPS_IOC_SETPARAMS:
1355 	case PPS_IOC_GETCAP:
1356 	case PPS_IOC_FETCH:
1357 #ifdef PPS_SYNC
1358 	case PPS_IOC_KCBIND:
1359 #endif
1360 		mutex_spin_enter(&timecounter_lock);
1361 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1362 		mutex_spin_exit(&timecounter_lock);
1363 		break;
1364 
1365 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1366 		mutex_spin_enter(&timecounter_lock);
1367 #ifndef PPS_TRAILING_EDGE
1368 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1369 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1370 #else
1371 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1372 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1373 #endif
1374 		mutex_spin_exit(&timecounter_lock);
1375 		break;
1376 
1377 	default:
1378 		error = EPASSTHROUGH;
1379 		break;
1380 	}
1381 
1382 	mutex_spin_exit(&sc->sc_lock);
1383 
1384 #ifdef COM_DEBUG
1385 	if (com_debug)
1386 		comstatus(sc, "comioctl ");
1387 #endif
1388 
1389 	return (error);
1390 }
1391 
1392 static inline void
1393 com_schedrx(struct com_softc *sc)
1394 {
1395 
1396 	sc->sc_rx_ready = 1;
1397 
1398 	/* Wake up the poller. */
1399 	softint_schedule(sc->sc_si);
1400 }
1401 
1402 void
1403 com_break(struct com_softc *sc, int onoff)
1404 {
1405 
1406 	if (onoff)
1407 		SET(sc->sc_lcr, LCR_SBREAK);
1408 	else
1409 		CLR(sc->sc_lcr, LCR_SBREAK);
1410 
1411 	if (!sc->sc_heldchange) {
1412 		if (sc->sc_tx_busy) {
1413 			sc->sc_heldtbc = sc->sc_tbc;
1414 			sc->sc_tbc = 0;
1415 			sc->sc_heldchange = 1;
1416 		} else
1417 			com_loadchannelregs(sc);
1418 	}
1419 }
1420 
1421 void
1422 com_modem(struct com_softc *sc, int onoff)
1423 {
1424 
1425 	if (sc->sc_mcr_dtr == 0)
1426 		return;
1427 
1428 	if (onoff)
1429 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1430 	else
1431 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1432 
1433 	if (!sc->sc_heldchange) {
1434 		if (sc->sc_tx_busy) {
1435 			sc->sc_heldtbc = sc->sc_tbc;
1436 			sc->sc_tbc = 0;
1437 			sc->sc_heldchange = 1;
1438 		} else
1439 			com_loadchannelregs(sc);
1440 	}
1441 }
1442 
1443 void
1444 tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1445 {
1446 	u_char combits;
1447 
1448 	combits = 0;
1449 	if (ISSET(ttybits, TIOCM_DTR))
1450 		SET(combits, MCR_DTR);
1451 	if (ISSET(ttybits, TIOCM_RTS))
1452 		SET(combits, MCR_RTS);
1453 
1454 	switch (how) {
1455 	case TIOCMBIC:
1456 		CLR(sc->sc_mcr, combits);
1457 		break;
1458 
1459 	case TIOCMBIS:
1460 		SET(sc->sc_mcr, combits);
1461 		break;
1462 
1463 	case TIOCMSET:
1464 		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1465 		SET(sc->sc_mcr, combits);
1466 		break;
1467 	}
1468 
1469 	if (!sc->sc_heldchange) {
1470 		if (sc->sc_tx_busy) {
1471 			sc->sc_heldtbc = sc->sc_tbc;
1472 			sc->sc_tbc = 0;
1473 			sc->sc_heldchange = 1;
1474 		} else
1475 			com_loadchannelregs(sc);
1476 	}
1477 }
1478 
1479 int
1480 com_to_tiocm(struct com_softc *sc)
1481 {
1482 	u_char combits;
1483 	int ttybits = 0;
1484 
1485 	combits = sc->sc_mcr;
1486 	if (ISSET(combits, MCR_DTR))
1487 		SET(ttybits, TIOCM_DTR);
1488 	if (ISSET(combits, MCR_RTS))
1489 		SET(ttybits, TIOCM_RTS);
1490 
1491 	combits = sc->sc_msr;
1492 	if (sc->sc_type == COM_TYPE_INGENIC) {
1493 		SET(ttybits, TIOCM_CD);
1494 	} else {
1495 		if (ISSET(combits, MSR_DCD))
1496 			SET(ttybits, TIOCM_CD);
1497 	}
1498 	if (ISSET(combits, MSR_CTS))
1499 		SET(ttybits, TIOCM_CTS);
1500 	if (ISSET(combits, MSR_DSR))
1501 		SET(ttybits, TIOCM_DSR);
1502 	if (ISSET(combits, MSR_RI | MSR_TERI))
1503 		SET(ttybits, TIOCM_RI);
1504 
1505 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1506 		SET(ttybits, TIOCM_LE);
1507 
1508 	return (ttybits);
1509 }
1510 
1511 static u_char
1512 cflag2lcr(tcflag_t cflag)
1513 {
1514 	u_char lcr = 0;
1515 
1516 	switch (ISSET(cflag, CSIZE)) {
1517 	case CS5:
1518 		SET(lcr, LCR_5BITS);
1519 		break;
1520 	case CS6:
1521 		SET(lcr, LCR_6BITS);
1522 		break;
1523 	case CS7:
1524 		SET(lcr, LCR_7BITS);
1525 		break;
1526 	case CS8:
1527 		SET(lcr, LCR_8BITS);
1528 		break;
1529 	}
1530 	if (ISSET(cflag, PARENB)) {
1531 		SET(lcr, LCR_PENAB);
1532 		if (!ISSET(cflag, PARODD))
1533 			SET(lcr, LCR_PEVEN);
1534 	}
1535 	if (ISSET(cflag, CSTOPB))
1536 		SET(lcr, LCR_STOPB);
1537 
1538 	return (lcr);
1539 }
1540 
1541 int
1542 comparam(struct tty *tp, struct termios *t)
1543 {
1544 	struct com_softc *sc =
1545 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1546 	int ospeed;
1547 	u_char lcr;
1548 
1549 	if (COM_ISALIVE(sc) == 0)
1550 		return (EIO);
1551 
1552 	if (sc->sc_type == COM_TYPE_HAYESP) {
1553 		int prescaler, speed;
1554 
1555 		/*
1556 		 * Calculate UART clock prescaler.  It should be in
1557 		 * range of 0 .. 3.
1558 		 */
1559 		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1560 		    prescaler++, speed /= 2)
1561 			if ((ospeed = comspeed(speed, sc->sc_frequency,
1562 					       sc->sc_type)) > 0)
1563 				break;
1564 
1565 		if (prescaler == 4)
1566 			return (EINVAL);
1567 		sc->sc_prescaler = prescaler;
1568 	} else
1569 		ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1570 
1571 	/* Check requested parameters. */
1572 	if (ospeed < 0)
1573 		return (EINVAL);
1574 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1575 		return (EINVAL);
1576 
1577 	/*
1578 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1579 	 * is always active.
1580 	 */
1581 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1582 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1583 		SET(t->c_cflag, CLOCAL);
1584 		CLR(t->c_cflag, HUPCL);
1585 	}
1586 
1587 	/*
1588 	 * If there were no changes, don't do anything.  This avoids dropping
1589 	 * input and improves performance when all we did was frob things like
1590 	 * VMIN and VTIME.
1591 	 */
1592 	if (tp->t_ospeed == t->c_ospeed &&
1593 	    tp->t_cflag == t->c_cflag)
1594 		return (0);
1595 
1596 	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1597 
1598 	mutex_spin_enter(&sc->sc_lock);
1599 
1600 	sc->sc_lcr = lcr;
1601 
1602 	/*
1603 	 * If we're not in a mode that assumes a connection is present, then
1604 	 * ignore carrier changes.
1605 	 */
1606 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1607 		sc->sc_msr_dcd = 0;
1608 	else
1609 		sc->sc_msr_dcd = MSR_DCD;
1610 	/*
1611 	 * Set the flow control pins depending on the current flow control
1612 	 * mode.
1613 	 */
1614 	if (ISSET(t->c_cflag, CRTSCTS)) {
1615 		sc->sc_mcr_dtr = MCR_DTR;
1616 		sc->sc_mcr_rts = MCR_RTS;
1617 		sc->sc_msr_cts = MSR_CTS;
1618 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1619 			SET(sc->sc_mcr, MCR_AFE);
1620 		} else {
1621 			sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1622 		}
1623 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1624 		/*
1625 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1626 		 * carrier detection.
1627 		 */
1628 		sc->sc_mcr_dtr = 0;
1629 		sc->sc_mcr_rts = MCR_DTR;
1630 		sc->sc_msr_cts = MSR_DCD;
1631 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1632 			CLR(sc->sc_mcr, MCR_AFE);
1633 		} else {
1634 			sc->sc_efr = 0;
1635 		}
1636 	} else {
1637 		/*
1638 		 * If no flow control, then always set RTS.  This will make
1639 		 * the other side happy if it mistakenly thinks we're doing
1640 		 * RTS/CTS flow control.
1641 		 */
1642 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1643 		sc->sc_mcr_rts = 0;
1644 		sc->sc_msr_cts = 0;
1645 		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1646 			CLR(sc->sc_mcr, MCR_AFE);
1647 		} else {
1648 			sc->sc_efr = 0;
1649 		}
1650 		if (ISSET(sc->sc_mcr, MCR_DTR))
1651 			SET(sc->sc_mcr, MCR_RTS);
1652 		else
1653 			CLR(sc->sc_mcr, MCR_RTS);
1654 	}
1655 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1656 
1657 	if (t->c_ospeed == 0 && tp->t_ospeed != 0)
1658 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1659 	else if (t->c_ospeed != 0 && tp->t_ospeed == 0)
1660 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1661 
1662 	sc->sc_dlbl = ospeed;
1663 	sc->sc_dlbh = ospeed >> 8;
1664 
1665 	/*
1666 	 * Set the FIFO threshold based on the receive speed.
1667 	 *
1668 	 *  * If it's a low speed, it's probably a mouse or some other
1669 	 *    interactive device, so set the threshold low.
1670 	 *  * If it's a high speed, trim the trigger level down to prevent
1671 	 *    overflows.
1672 	 *  * Otherwise set it a bit higher.
1673 	 */
1674 	if (sc->sc_type == COM_TYPE_HAYESP) {
1675 		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1676 	} else if (sc->sc_type == COM_TYPE_TEGRA) {
1677 		sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1678 	} else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1679 		if (t->c_ospeed <= 1200)
1680 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1681 		else if (t->c_ospeed <= 38400)
1682 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1683 		else
1684 			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1685 	} else {
1686 		sc->sc_fifo = 0;
1687 	}
1688 
1689 	if (sc->sc_type == COM_TYPE_INGENIC)
1690 		sc->sc_fifo |= FIFO_UART_ON;
1691 
1692 	/* And copy to tty. */
1693 	tp->t_ispeed = t->c_ospeed;
1694 	tp->t_ospeed = t->c_ospeed;
1695 	tp->t_cflag = t->c_cflag;
1696 
1697 	if (!sc->sc_heldchange) {
1698 		if (sc->sc_tx_busy) {
1699 			sc->sc_heldtbc = sc->sc_tbc;
1700 			sc->sc_tbc = 0;
1701 			sc->sc_heldchange = 1;
1702 		} else
1703 			com_loadchannelregs(sc);
1704 	}
1705 
1706 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1707 		/* Disable the high water mark. */
1708 		sc->sc_r_hiwat = 0;
1709 		sc->sc_r_lowat = 0;
1710 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1711 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1712 			com_schedrx(sc);
1713 		}
1714 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1715 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1716 			com_hwiflow(sc);
1717 		}
1718 	} else {
1719 		sc->sc_r_hiwat = com_rbuf_hiwat;
1720 		sc->sc_r_lowat = com_rbuf_lowat;
1721 	}
1722 
1723 	mutex_spin_exit(&sc->sc_lock);
1724 
1725 	/*
1726 	 * Update the tty layer's idea of the carrier bit, in case we changed
1727 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1728 	 * explicit request.
1729 	 */
1730 	if (sc->sc_type == COM_TYPE_INGENIC) {
1731 		/* no DCD here */
1732 		(void) (*tp->t_linesw->l_modem)(tp, 1);
1733 	} else
1734 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1735 
1736 #ifdef COM_DEBUG
1737 	if (com_debug)
1738 		comstatus(sc, "comparam ");
1739 #endif
1740 
1741 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1742 		if (sc->sc_tx_stopped) {
1743 			sc->sc_tx_stopped = 0;
1744 			comstart(tp);
1745 		}
1746 	}
1747 
1748 	return (0);
1749 }
1750 
1751 void
1752 com_iflush(struct com_softc *sc)
1753 {
1754 	struct com_regs	*regsp = &sc->sc_regs;
1755 	uint8_t fifo;
1756 #ifdef DIAGNOSTIC
1757 	int reg;
1758 #endif
1759 	int timo;
1760 
1761 #ifdef DIAGNOSTIC
1762 	reg = 0xffff;
1763 #endif
1764 	timo = 50000;
1765 	/* flush any pending I/O */
1766 	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1767 	    && --timo)
1768 #ifdef DIAGNOSTIC
1769 		reg =
1770 #else
1771 		    (void)
1772 #endif
1773 		    CSR_READ_1(regsp, COM_REG_RXDATA);
1774 #ifdef DIAGNOSTIC
1775 	if (!timo)
1776 		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1777 #endif
1778 
1779 	switch (sc->sc_type) {
1780 	case COM_TYPE_16750:
1781 	case COM_TYPE_DW_APB:
1782 		/*
1783 		 * Reset all Rx/Tx FIFO, preserve current FIFO length.
1784 		 * This should prevent triggering busy interrupt while
1785 		 * manipulating divisors.
1786 		 */
1787 		fifo = CSR_READ_1(regsp, COM_REG_FIFO) & (FIFO_TRIGGER_1 |
1788 		    FIFO_TRIGGER_4 | FIFO_TRIGGER_8 | FIFO_TRIGGER_14);
1789 		CSR_WRITE_1(regsp, COM_REG_FIFO,
1790 		    fifo | FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST);
1791 		delay(100);
1792 		break;
1793 	}
1794 }
1795 
1796 void
1797 com_loadchannelregs(struct com_softc *sc)
1798 {
1799 	struct com_regs *regsp = &sc->sc_regs;
1800 
1801 	/* XXXXX necessary? */
1802 	com_iflush(sc);
1803 
1804 	if (sc->sc_type == COM_TYPE_PXA2x0)
1805 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1806 	else
1807 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1808 
1809 	if (sc->sc_type == COM_TYPE_OMAP) {
1810 		/* disable before changing settings */
1811 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
1812 	}
1813 
1814 	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1815 		KASSERT(sc->sc_type != COM_TYPE_AU1x00);
1816 		KASSERT(sc->sc_type != COM_TYPE_16550_NOERS);
1817 		/* no EFR on alchemy */
1818 		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1819 		CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1820 	}
1821 	if (sc->sc_type == COM_TYPE_AU1x00) {
1822 		/* alchemy has single separate 16-bit clock divisor register */
1823 		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1824 		    (sc->sc_dlbh << 8));
1825 	} else {
1826 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1827 		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1828 		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1829 	}
1830 	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1831 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1832 	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1833 	if (sc->sc_type == COM_TYPE_HAYESP) {
1834 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1835 		    HAYESP_SETPRESCALER);
1836 		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1837 		    sc->sc_prescaler);
1838 	}
1839 	if (sc->sc_type == COM_TYPE_OMAP) {
1840 		/* setup the fifos.  the FCR value is not used as long
1841 		   as SCR[6] and SCR[7] are 0, which they are at reset
1842 		   and we never touch the SCR register */
1843 		uint8_t rx_fifo_trig = 40;
1844 		uint8_t tx_fifo_trig = 60;
1845 		uint8_t rx_start = 8;
1846 		uint8_t rx_halt = 60;
1847 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
1848 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
1849 
1850 		/* enable access to TCR & TLR */
1851 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr | MCR_TCR_TLR);
1852 
1853 		/* write tcr and tlr values */
1854 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
1855 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
1856 
1857 		/* disable access to TCR & TLR */
1858 		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr);
1859 
1860 		/* enable again, but mode is based on speed */
1861 		if (sc->sc_tty->t_termios.c_ospeed > 230400) {
1862 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
1863 		} else {
1864 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
1865 		}
1866 	}
1867 
1868 	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1869 }
1870 
1871 int
1872 comhwiflow(struct tty *tp, int block)
1873 {
1874 	struct com_softc *sc =
1875 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1876 
1877 	if (COM_ISALIVE(sc) == 0)
1878 		return (0);
1879 
1880 	if (sc->sc_mcr_rts == 0)
1881 		return (0);
1882 
1883 	mutex_spin_enter(&sc->sc_lock);
1884 
1885 	if (block) {
1886 		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1887 			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1888 			com_hwiflow(sc);
1889 		}
1890 	} else {
1891 		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1892 			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1893 			com_schedrx(sc);
1894 		}
1895 		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1896 			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1897 			com_hwiflow(sc);
1898 		}
1899 	}
1900 
1901 	mutex_spin_exit(&sc->sc_lock);
1902 	return (1);
1903 }
1904 
1905 /*
1906  * (un)block input via hw flowcontrol
1907  */
1908 void
1909 com_hwiflow(struct com_softc *sc)
1910 {
1911 	struct com_regs *regsp= &sc->sc_regs;
1912 
1913 	if (sc->sc_mcr_rts == 0)
1914 		return;
1915 
1916 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1917 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1918 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1919 	} else {
1920 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1921 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1922 	}
1923 	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1924 }
1925 
1926 
1927 void
1928 comstart(struct tty *tp)
1929 {
1930 	struct com_softc *sc =
1931 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1932 	struct com_regs *regsp = &sc->sc_regs;
1933 
1934 	if (COM_ISALIVE(sc) == 0)
1935 		return;
1936 
1937 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1938 		return;
1939 	if (sc->sc_tx_stopped)
1940 		return;
1941 	if (!ttypull(tp))
1942 		return;
1943 
1944 	/* Grab the first contiguous region of buffer space. */
1945 	{
1946 		u_char *tba;
1947 		int tbc;
1948 
1949 		tba = tp->t_outq.c_cf;
1950 		tbc = ndqb(&tp->t_outq, 0);
1951 
1952 		mutex_spin_enter(&sc->sc_lock);
1953 
1954 		sc->sc_tba = tba;
1955 		sc->sc_tbc = tbc;
1956 	}
1957 
1958 	SET(tp->t_state, TS_BUSY);
1959 	sc->sc_tx_busy = 1;
1960 
1961 	/* Enable transmit completion interrupts if necessary. */
1962 	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1963 		SET(sc->sc_ier, IER_ETXRDY);
1964 		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1965 	}
1966 
1967 	/* Output the first chunk of the contiguous buffer. */
1968 	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1969 		u_int n;
1970 
1971 		n = sc->sc_tbc;
1972 		if (n > sc->sc_fifolen)
1973 			n = sc->sc_fifolen;
1974 		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1975 		sc->sc_tbc -= n;
1976 		sc->sc_tba += n;
1977 	}
1978 
1979 	mutex_spin_exit(&sc->sc_lock);
1980 }
1981 
1982 /*
1983  * Stop output on a line.
1984  */
1985 void
1986 comstop(struct tty *tp, int flag)
1987 {
1988 	struct com_softc *sc =
1989 	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1990 
1991 	mutex_spin_enter(&sc->sc_lock);
1992 	if (ISSET(tp->t_state, TS_BUSY)) {
1993 		/* Stop transmitting at the next chunk. */
1994 		sc->sc_tbc = 0;
1995 		sc->sc_heldtbc = 0;
1996 		if (!ISSET(tp->t_state, TS_TTSTOP))
1997 			SET(tp->t_state, TS_FLUSH);
1998 	}
1999 	mutex_spin_exit(&sc->sc_lock);
2000 }
2001 
2002 void
2003 comdiag(void *arg)
2004 {
2005 	struct com_softc *sc = arg;
2006 	int overflows, floods;
2007 
2008 	mutex_spin_enter(&sc->sc_lock);
2009 	overflows = sc->sc_overflows;
2010 	sc->sc_overflows = 0;
2011 	floods = sc->sc_floods;
2012 	sc->sc_floods = 0;
2013 	sc->sc_errors = 0;
2014 	mutex_spin_exit(&sc->sc_lock);
2015 
2016 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
2017 	    device_xname(sc->sc_dev),
2018 	    overflows, overflows == 1 ? "" : "s",
2019 	    floods, floods == 1 ? "" : "s");
2020 }
2021 
2022 static inline void
2023 com_rxsoft(struct com_softc *sc, struct tty *tp)
2024 {
2025 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
2026 	u_char *get, *end;
2027 	u_int cc, scc;
2028 	u_char lsr;
2029 	int code;
2030 
2031 	end = sc->sc_ebuf;
2032 	get = sc->sc_rbget;
2033 	scc = cc = com_rbuf_size - sc->sc_rbavail;
2034 
2035 	if (cc == com_rbuf_size) {
2036 		sc->sc_floods++;
2037 		if (sc->sc_errors++ == 0)
2038 			callout_reset(&sc->sc_diag_callout, 60 * hz,
2039 			    comdiag, sc);
2040 	}
2041 
2042 	/* If not yet open, drop the entire buffer content here */
2043 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
2044 		get += cc << 1;
2045 		if (get >= end)
2046 			get -= com_rbuf_size << 1;
2047 		cc = 0;
2048 	}
2049 	while (cc) {
2050 		code = get[0];
2051 		lsr = get[1];
2052 		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
2053 			if (ISSET(lsr, LSR_OE)) {
2054 				sc->sc_overflows++;
2055 				if (sc->sc_errors++ == 0)
2056 					callout_reset(&sc->sc_diag_callout,
2057 					    60 * hz, comdiag, sc);
2058 			}
2059 			if (ISSET(lsr, LSR_BI | LSR_FE))
2060 				SET(code, TTY_FE);
2061 			if (ISSET(lsr, LSR_PE))
2062 				SET(code, TTY_PE);
2063 		}
2064 		if ((*rint)(code, tp) == -1) {
2065 			/*
2066 			 * The line discipline's buffer is out of space.
2067 			 */
2068 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
2069 				/*
2070 				 * We're either not using flow control, or the
2071 				 * line discipline didn't tell us to block for
2072 				 * some reason.  Either way, we have no way to
2073 				 * know when there's more space available, so
2074 				 * just drop the rest of the data.
2075 				 */
2076 				get += cc << 1;
2077 				if (get >= end)
2078 					get -= com_rbuf_size << 1;
2079 				cc = 0;
2080 			} else {
2081 				/*
2082 				 * Don't schedule any more receive processing
2083 				 * until the line discipline tells us there's
2084 				 * space available (through comhwiflow()).
2085 				 * Leave the rest of the data in the input
2086 				 * buffer.
2087 				 */
2088 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
2089 			}
2090 			break;
2091 		}
2092 		get += 2;
2093 		if (get >= end)
2094 			get = sc->sc_rbuf;
2095 		cc--;
2096 	}
2097 
2098 	if (cc != scc) {
2099 		sc->sc_rbget = get;
2100 		mutex_spin_enter(&sc->sc_lock);
2101 
2102 		cc = sc->sc_rbavail += scc - cc;
2103 		/* Buffers should be ok again, release possible block. */
2104 		if (cc >= sc->sc_r_lowat) {
2105 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2106 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2107 				SET(sc->sc_ier, IER_ERXRDY);
2108 				if (sc->sc_type == COM_TYPE_PXA2x0)
2109 					SET(sc->sc_ier, IER_ERXTOUT);
2110 				if (sc->sc_type == COM_TYPE_INGENIC ||
2111 				    sc->sc_type == COM_TYPE_TEGRA)
2112 					SET(sc->sc_ier, IER_ERXTOUT);
2113 
2114 				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER,
2115 				    sc->sc_ier);
2116 			}
2117 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
2118 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2119 				com_hwiflow(sc);
2120 			}
2121 		}
2122 		mutex_spin_exit(&sc->sc_lock);
2123 	}
2124 }
2125 
2126 static inline void
2127 com_txsoft(struct com_softc *sc, struct tty *tp)
2128 {
2129 
2130 	CLR(tp->t_state, TS_BUSY);
2131 	if (ISSET(tp->t_state, TS_FLUSH))
2132 		CLR(tp->t_state, TS_FLUSH);
2133 	else
2134 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
2135 	(*tp->t_linesw->l_start)(tp);
2136 }
2137 
2138 static inline void
2139 com_stsoft(struct com_softc *sc, struct tty *tp)
2140 {
2141 	u_char msr, delta;
2142 
2143 	mutex_spin_enter(&sc->sc_lock);
2144 	msr = sc->sc_msr;
2145 	delta = sc->sc_msr_delta;
2146 	sc->sc_msr_delta = 0;
2147 	mutex_spin_exit(&sc->sc_lock);
2148 
2149 	if (ISSET(delta, sc->sc_msr_dcd)) {
2150 		/*
2151 		 * Inform the tty layer that carrier detect changed.
2152 		 */
2153 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
2154 	}
2155 
2156 	if (ISSET(delta, sc->sc_msr_cts)) {
2157 		/* Block or unblock output according to flow control. */
2158 		if (ISSET(msr, sc->sc_msr_cts)) {
2159 			sc->sc_tx_stopped = 0;
2160 			(*tp->t_linesw->l_start)(tp);
2161 		} else {
2162 			sc->sc_tx_stopped = 1;
2163 		}
2164 	}
2165 
2166 #ifdef COM_DEBUG
2167 	if (com_debug)
2168 		comstatus(sc, "com_stsoft");
2169 #endif
2170 }
2171 
2172 void
2173 comsoft(void *arg)
2174 {
2175 	struct com_softc *sc = arg;
2176 	struct tty *tp;
2177 
2178 	if (COM_ISALIVE(sc) == 0)
2179 		return;
2180 
2181 	tp = sc->sc_tty;
2182 
2183 	if (sc->sc_rx_ready) {
2184 		sc->sc_rx_ready = 0;
2185 		com_rxsoft(sc, tp);
2186 	}
2187 
2188 	if (sc->sc_st_check) {
2189 		sc->sc_st_check = 0;
2190 		com_stsoft(sc, tp);
2191 	}
2192 
2193 	if (sc->sc_tx_done) {
2194 		sc->sc_tx_done = 0;
2195 		com_txsoft(sc, tp);
2196 	}
2197 }
2198 
2199 int
2200 comintr(void *arg)
2201 {
2202 	struct com_softc *sc = arg;
2203 	struct com_regs *regsp = &sc->sc_regs;
2204 
2205 	u_char *put, *end;
2206 	u_int cc;
2207 	u_char lsr, iir;
2208 
2209 	if (COM_ISALIVE(sc) == 0)
2210 		return (0);
2211 
2212 	KASSERT(regsp != NULL);
2213 
2214 	mutex_spin_enter(&sc->sc_lock);
2215 	iir = CSR_READ_1(regsp, COM_REG_IIR);
2216 
2217 	/* Handle ns16750-specific busy interrupt. */
2218 	if (sc->sc_type == COM_TYPE_16750 &&
2219 	    (iir & IIR_BUSY) == IIR_BUSY) {
2220 		for (int timeout = 10000;
2221 		    (CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0; timeout--)
2222 			if (timeout <= 0) {
2223 				aprint_error_dev(sc->sc_dev,
2224 				    "timeout while waiting for BUSY interrupt "
2225 				    "acknowledge\n");
2226 				mutex_spin_exit(&sc->sc_lock);
2227 				return (0);
2228 			}
2229 
2230 		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2231 		iir = CSR_READ_1(regsp, COM_REG_IIR);
2232 	}
2233 
2234 	/* DesignWare APB UART BUSY interrupt */
2235 	if (sc->sc_type == COM_TYPE_DW_APB &&
2236 	    (iir & IIR_BUSY) == IIR_BUSY) {
2237 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
2238 			(void)CSR_READ_1(regsp, COM_REG_USR);
2239 		} else if ((CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0) {
2240 			CSR_WRITE_1(regsp, COM_REG_HALT, HALT_CHCFG_EN);
2241 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2242 			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2243 			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2244 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2245 			CSR_WRITE_1(regsp, COM_REG_HALT,
2246 			    HALT_CHCFG_EN | HALT_CHCFG_UD);
2247 			for (int timeout = 10000000;
2248 			    (CSR_READ_1(regsp, COM_REG_HALT) & HALT_CHCFG_UD) != 0;
2249 			    timeout--) {
2250 				if (timeout <= 0) {
2251 					aprint_error_dev(sc->sc_dev,
2252 					    "timeout while waiting for HALT "
2253 					    "update acknowledge 0x%x 0x%x\n",
2254 					    CSR_READ_1(regsp, COM_REG_HALT),
2255 					    CSR_READ_1(regsp, COM_REG_USR));
2256 					break;
2257 				}
2258 			}
2259 			CSR_WRITE_1(regsp, COM_REG_HALT, 0);
2260 			(void)CSR_READ_1(regsp, COM_REG_USR);
2261 		} else {
2262 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2263 			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2264 			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2265 			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2266 		}
2267 	}
2268 
2269 	end = sc->sc_ebuf;
2270 	put = sc->sc_rbput;
2271 	cc = sc->sc_rbavail;
2272 
2273 	if (ISSET(iir, IIR_NOPEND)) {
2274 		if (ISSET(sc->sc_hwflags, COM_HW_BROKEN_ETXRDY))
2275 			goto do_tx;
2276 		mutex_spin_exit(&sc->sc_lock);
2277 		return (0);
2278 	}
2279 
2280 again:	do {
2281 		u_char	msr, delta;
2282 
2283 		lsr = CSR_READ_1(regsp, COM_REG_LSR);
2284 		if (ISSET(lsr, LSR_BI)) {
2285 			int cn_trapped = 0; /* see above: cn_trap() */
2286 
2287 			cn_check_magic(sc->sc_tty->t_dev,
2288 				       CNC_BREAK, com_cnm_state);
2289 			if (cn_trapped)
2290 				continue;
2291 #if defined(KGDB) && !defined(DDB)
2292 			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2293 				kgdb_connect(1);
2294 				continue;
2295 			}
2296 #endif
2297 		}
2298 
2299 		if (sc->sc_type == COM_TYPE_BCMAUXUART && ISSET(iir, IIR_RXRDY))
2300 			lsr |= LSR_RXRDY;
2301 
2302 		if (ISSET(lsr, LSR_RCV_MASK) &&
2303 		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2304 			while (cc > 0) {
2305 				int cn_trapped = 0;
2306 				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
2307 				put[1] = lsr;
2308 				cn_check_magic(sc->sc_tty->t_dev,
2309 					       put[0], com_cnm_state);
2310 				if (cn_trapped)
2311 					goto next;
2312 				put += 2;
2313 				if (put >= end)
2314 					put = sc->sc_rbuf;
2315 				cc--;
2316 			next:
2317 				lsr = CSR_READ_1(regsp, COM_REG_LSR);
2318 				if (!ISSET(lsr, LSR_RCV_MASK))
2319 					break;
2320 			}
2321 
2322 			/*
2323 			 * Current string of incoming characters ended because
2324 			 * no more data was available or we ran out of space.
2325 			 * Schedule a receive event if any data was received.
2326 			 * If we're out of space, turn off receive interrupts.
2327 			 */
2328 			sc->sc_rbput = put;
2329 			sc->sc_rbavail = cc;
2330 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2331 				sc->sc_rx_ready = 1;
2332 
2333 			/*
2334 			 * See if we are in danger of overflowing a buffer. If
2335 			 * so, use hardware flow control to ease the pressure.
2336 			 */
2337 			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2338 			    cc < sc->sc_r_hiwat) {
2339 				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2340 				com_hwiflow(sc);
2341 			}
2342 
2343 			/*
2344 			 * If we're out of space, disable receive interrupts
2345 			 * until the queue has drained a bit.
2346 			 */
2347 			if (!cc) {
2348 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2349 				switch (sc->sc_type) {
2350 				case COM_TYPE_PXA2x0:
2351 					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
2352 					break;
2353 				case COM_TYPE_INGENIC:
2354 				case COM_TYPE_TEGRA:
2355 					CLR(sc->sc_ier,
2356 					    IER_ERXRDY | IER_ERXTOUT);
2357 					break;
2358 				default:
2359 					CLR(sc->sc_ier, IER_ERXRDY);
2360 					break;
2361 				}
2362 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2363 			}
2364 		} else {
2365 			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
2366 				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
2367 				continue;
2368 			}
2369 		}
2370 
2371 		msr = CSR_READ_1(regsp, COM_REG_MSR);
2372 		delta = msr ^ sc->sc_msr;
2373 		sc->sc_msr = msr;
2374 		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
2375 		    (delta & MSR_DCD)) {
2376 			mutex_spin_enter(&timecounter_lock);
2377 			pps_capture(&sc->sc_pps_state);
2378 			pps_event(&sc->sc_pps_state,
2379 			    (msr & MSR_DCD) ?
2380 			    PPS_CAPTUREASSERT :
2381 			    PPS_CAPTURECLEAR);
2382 			mutex_spin_exit(&timecounter_lock);
2383 		}
2384 
2385 		/*
2386 		 * Process normal status changes
2387 		 */
2388 		if (ISSET(delta, sc->sc_msr_mask)) {
2389 			SET(sc->sc_msr_delta, delta);
2390 
2391 			/*
2392 			 * Stop output immediately if we lose the output
2393 			 * flow control signal or carrier detect.
2394 			 */
2395 			if (ISSET(~msr, sc->sc_msr_mask)) {
2396 				sc->sc_tbc = 0;
2397 				sc->sc_heldtbc = 0;
2398 #ifdef COM_DEBUG
2399 				if (com_debug)
2400 					comstatus(sc, "comintr  ");
2401 #endif
2402 			}
2403 
2404 			sc->sc_st_check = 1;
2405 		}
2406 	} while (!ISSET((iir =
2407 	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
2408 	    /*
2409 	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
2410 	     * by IIR read, so we can't do this way: `process all interrupts,
2411 	     * then do TX if possible'.
2412 	     */
2413 	    (iir & IIR_IMASK) != IIR_TXRDY);
2414 
2415 do_tx:
2416 	/*
2417 	 * Read LSR again, since there may be an interrupt between
2418 	 * the last LSR read and IIR read above.
2419 	 */
2420 	lsr = CSR_READ_1(regsp, COM_REG_LSR);
2421 
2422 	/*
2423 	 * See if data can be transmitted as well.
2424 	 * Schedule tx done event if no data left
2425 	 * and tty was marked busy.
2426 	 */
2427 	if (ISSET(lsr, LSR_TXRDY)) {
2428 		/*
2429 		 * If we've delayed a parameter change, do it now, and restart
2430 		 * output.
2431 		 */
2432 		if (sc->sc_heldchange) {
2433 			com_loadchannelregs(sc);
2434 			sc->sc_heldchange = 0;
2435 			sc->sc_tbc = sc->sc_heldtbc;
2436 			sc->sc_heldtbc = 0;
2437 		}
2438 
2439 		/* Output the next chunk of the contiguous buffer, if any. */
2440 		if (sc->sc_tbc > 0) {
2441 			u_int n;
2442 
2443 			n = sc->sc_tbc;
2444 			if (n > sc->sc_fifolen)
2445 				n = sc->sc_fifolen;
2446 			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
2447 			sc->sc_tbc -= n;
2448 			sc->sc_tba += n;
2449 		} else {
2450 			/* Disable transmit completion interrupts if necessary. */
2451 			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2452 				CLR(sc->sc_ier, IER_ETXRDY);
2453 				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2454 			}
2455 			if (sc->sc_tx_busy) {
2456 				sc->sc_tx_busy = 0;
2457 				sc->sc_tx_done = 1;
2458 			}
2459 		}
2460 	}
2461 
2462 	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
2463 		goto again;
2464 
2465 	mutex_spin_exit(&sc->sc_lock);
2466 
2467 	/* Wake up the poller. */
2468 	if ((sc->sc_rx_ready | sc->sc_st_check | sc->sc_tx_done) != 0)
2469 		softint_schedule(sc->sc_si);
2470 
2471 #ifdef RND_COM
2472 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2473 #endif
2474 
2475 	return (1);
2476 }
2477 
2478 /*
2479  * The following functions are polled getc and putc routines, shared
2480  * by the console and kgdb glue.
2481  *
2482  * The read-ahead code is so that you can detect pending in-band
2483  * cn_magic in polled mode while doing output rather than having to
2484  * wait until the kernel decides it needs input.
2485  */
2486 
2487 #define MAX_READAHEAD	20
2488 static int com_readahead[MAX_READAHEAD];
2489 static int com_readaheadcount = 0;
2490 
2491 int
2492 com_common_getc(dev_t dev, struct com_regs *regsp)
2493 {
2494 	int s = splserial();
2495 	u_char stat, c;
2496 
2497 	/* got a character from reading things earlier */
2498 	if (com_readaheadcount > 0) {
2499 		int i;
2500 
2501 		c = com_readahead[0];
2502 		for (i = 1; i < com_readaheadcount; i++) {
2503 			com_readahead[i-1] = com_readahead[i];
2504 		}
2505 		com_readaheadcount--;
2506 		splx(s);
2507 		return (c);
2508 	}
2509 
2510 	/* don't block until a character becomes available */
2511 	if (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2512 		splx(s);
2513 		return -1;
2514 	}
2515 
2516 	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2517 	stat = CSR_READ_1(regsp, COM_REG_IIR);
2518 	{
2519 		int cn_trapped = 0;	/* required by cn_trap, see above */
2520 		if (!db_active)
2521 			cn_check_magic(dev, c, com_cnm_state);
2522 	}
2523 	splx(s);
2524 	return (c);
2525 }
2526 
2527 static void
2528 com_common_putc(dev_t dev, struct com_regs *regsp, int c, int with_readahead)
2529 {
2530 	int s = splserial();
2531 	int cin, stat, timo;
2532 
2533 	if (with_readahead && com_readaheadcount < MAX_READAHEAD
2534 	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2535 		int cn_trapped = 0;
2536 		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2537 		stat = CSR_READ_1(regsp, COM_REG_IIR);
2538 		cn_check_magic(dev, cin, com_cnm_state);
2539 		com_readahead[com_readaheadcount++] = cin;
2540 	}
2541 
2542 	/* wait for any pending transmission to finish */
2543 	timo = 150000;
2544 	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2545 		continue;
2546 
2547 	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2548 	COM_BARRIER(regsp, BR | BW);
2549 
2550 	splx(s);
2551 }
2552 
2553 /*
2554  * Initialize UART for use as console or KGDB line.
2555  */
2556 int
2557 cominit(struct com_regs *regsp, int rate, int frequency, int type,
2558     tcflag_t cflag)
2559 {
2560 
2561 	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2562 		&regsp->cr_ioh))
2563 		return (ENOMEM); /* ??? */
2564 
2565 	if (type == COM_TYPE_OMAP) {
2566 		/* disable before changing settings */
2567 		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
2568 	}
2569 
2570 	rate = comspeed(rate, frequency, type);
2571 	if (rate != -1) {
2572 		if (type == COM_TYPE_AU1x00) {
2573 			/* no EFR on alchemy */
2574 			CSR_WRITE_2(regsp, COM_REG_DLBL, rate);
2575 		} else {
2576 			if ((type != COM_TYPE_16550_NOERS) &&
2577 			    (type != COM_TYPE_INGENIC)) {
2578 				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2579 				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2580 			}
2581 			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2582 			CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2583 			CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2584 		}
2585 	}
2586 	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2587 	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2588 
2589 	if (type == COM_TYPE_INGENIC) {
2590 		CSR_WRITE_1(regsp, COM_REG_FIFO,
2591 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2592 		    FIFO_TRIGGER_1 | FIFO_UART_ON);
2593 	} else {
2594 		CSR_WRITE_1(regsp, COM_REG_FIFO,
2595 		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2596 		    FIFO_TRIGGER_1);
2597 	}
2598 
2599 	if (type == COM_TYPE_OMAP) {
2600 		/* setup the fifos.  the FCR value is not used as long
2601 		   as SCR[6] and SCR[7] are 0, which they are at reset
2602 		   and we never touch the SCR register */
2603 		uint8_t rx_fifo_trig = 40;
2604 		uint8_t tx_fifo_trig = 60;
2605 		uint8_t rx_start = 8;
2606 		uint8_t rx_halt = 60;
2607 		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
2608 		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
2609 
2610 		/* enable access to TCR & TLR */
2611 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS | MCR_TCR_TLR);
2612 
2613 		/* write tcr and tlr values */
2614 		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
2615 		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
2616 
2617 		/* disable access to TCR & TLR */
2618 		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2619 
2620 		/* enable again, but mode is based on speed */
2621 		if (rate > 230400) {
2622 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
2623 		} else {
2624 			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
2625 		}
2626 	}
2627 
2628 	if (type == COM_TYPE_PXA2x0)
2629 		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2630 	else
2631 		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2632 
2633 	return (0);
2634 }
2635 
2636 int
2637 comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2638     tcflag_t cflag)
2639 {
2640 	int res;
2641 
2642 	comcons_info.regs = *regsp;
2643 
2644 	res = cominit(&comcons_info.regs, rate, frequency, type, cflag);
2645 	if (res)
2646 		return (res);
2647 
2648 	cn_tab = &comcons;
2649 	cn_init_magic(&com_cnm_state);
2650 	cn_set_magic("\047\001"); /* default magic is BREAK */
2651 
2652 	comcons_info.frequency = frequency;
2653 	comcons_info.type = type;
2654 	comcons_info.rate = rate;
2655 	comcons_info.cflag = cflag;
2656 
2657 	return (0);
2658 }
2659 
2660 int
2661 comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2662     int type, tcflag_t cflag)
2663 {
2664 	struct com_regs	regs;
2665 
2666 	/*XXX*/
2667 	bus_space_handle_t dummy_bsh;
2668 	memset(&dummy_bsh, 0, sizeof(dummy_bsh));
2669 
2670 	/*
2671 	 * dummy_bsh required because com_init_regs() wants it.  A
2672 	 * real bus_space_handle will be filled in by cominit() later.
2673 	 * XXXJRT Detangle this mess eventually, plz.
2674 	 */
2675 	com_init_regs(&regs, iot, dummy_bsh/*XXX*/, iobase);
2676 
2677 	return comcnattach1(&regs, rate, frequency, type, cflag);
2678 }
2679 
2680 static int
2681 comcnreattach(void)
2682 {
2683 	return comcnattach1(&comcons_info.regs, comcons_info.rate,
2684 	    comcons_info.frequency, comcons_info.type, comcons_info.cflag);
2685 }
2686 
2687 int
2688 comcngetc(dev_t dev)
2689 {
2690 
2691 	return (com_common_getc(dev, &comcons_info.regs));
2692 }
2693 
2694 /*
2695  * Console kernel output character routine.
2696  */
2697 void
2698 comcnputc(dev_t dev, int c)
2699 {
2700 
2701 	com_common_putc(dev, &comcons_info.regs, c, cold);
2702 }
2703 
2704 void
2705 comcnpollc(dev_t dev, int on)
2706 {
2707 
2708 	com_readaheadcount = 0;
2709 }
2710 
2711 #ifdef KGDB
2712 int
2713 com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2714     tcflag_t cflag)
2715 {
2716 	int res;
2717 
2718 	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
2719 	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
2720 #if !defined(DDB)
2721 		return (EBUSY); /* cannot share with console */
2722 #else
2723 		comkgdbregs = *regsp;
2724 		comkgdbregs.cr_ioh = comcons_info.regs.cr_ioh;
2725 #endif
2726 	} else {
2727 		comkgdbregs = *regsp;
2728 		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2729 		if (res)
2730 			return (res);
2731 
2732 		/*
2733 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2734 		 * expects this to be initialized
2735 		 */
2736 		cn_init_magic(&com_cnm_state);
2737 		cn_set_magic("\047\001");
2738 	}
2739 
2740 	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2741 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2742 
2743 	return (0);
2744 }
2745 
2746 int
2747 com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2748     int frequency, int type, tcflag_t cflag)
2749 {
2750 	struct com_regs regs;
2751 
2752 	com_init_regs(&regs, iot, (bus_space_handle_t)0/*XXX*/, iobase);
2753 
2754 	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2755 }
2756 
2757 /* ARGSUSED */
2758 int
2759 com_kgdb_getc(void *arg)
2760 {
2761 
2762 	return (com_common_getc(NODEV, &comkgdbregs));
2763 }
2764 
2765 /* ARGSUSED */
2766 void
2767 com_kgdb_putc(void *arg, int c)
2768 {
2769 
2770 	com_common_putc(NODEV, &comkgdbregs, c, 0);
2771 }
2772 #endif /* KGDB */
2773 
2774 /*
2775  * helper function to identify the com ports used by
2776  * console or KGDB (and not yet autoconf attached)
2777  */
2778 int
2779 com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2780 {
2781 	bus_space_handle_t help;
2782 
2783 	if (!comconsattached &&
2784 	    bus_space_is_equal(iot, comcons_info.regs.cr_iot) &&
2785 	    iobase == comcons_info.regs.cr_iobase)
2786 		help = comcons_info.regs.cr_ioh;
2787 #ifdef KGDB
2788 	else if (!com_kgdb_attached &&
2789 	    bus_space_is_equal(iot, comkgdbregs.cr_iot) &&
2790 	    iobase == comkgdbregs.cr_iobase)
2791 		help = comkgdbregs.cr_ioh;
2792 #endif
2793 	else
2794 		return (0);
2795 
2796 	if (ioh)
2797 		*ioh = help;
2798 	return (1);
2799 }
2800 
2801 /*
2802  * this routine exists to serve as a shutdown hook for systems that
2803  * have firmware which doesn't interact properly with a com device in
2804  * FIFO mode.
2805  */
2806 bool
2807 com_cleanup(device_t self, int how)
2808 {
2809 	struct com_softc *sc = device_private(self);
2810 
2811 	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2812 		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2813 
2814 	return true;
2815 }
2816 
2817 bool
2818 com_suspend(device_t self, const pmf_qual_t *qual)
2819 {
2820 	struct com_softc *sc = device_private(self);
2821 
2822 	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2823 	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2824 
2825 	return true;
2826 }
2827 
2828 bool
2829 com_resume(device_t self, const pmf_qual_t *qual)
2830 {
2831 	struct com_softc *sc = device_private(self);
2832 
2833 	mutex_spin_enter(&sc->sc_lock);
2834 	com_loadchannelregs(sc);
2835 	mutex_spin_exit(&sc->sc_lock);
2836 
2837 	return true;
2838 }
2839