1/* $NetBSD: com.c,v 1.384 2023/04/11 13:01:41 riastradh 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 *	ttylock (IPL_VM)
69 *	-> sc->sc_lock (IPL_HIGH)
70 *	-> timecounter_lock (IPL_HIGH)
71 */
72
73#include <sys/cdefs.h>
74__KERNEL_RCSID(0, "$NetBSD: com.c,v 1.384 2023/04/11 13:01:41 riastradh Exp $");
75
76#include "opt_com.h"
77#include "opt_ddb.h"
78#include "opt_kgdb.h"
79#include "opt_lockdebug.h"
80#include "opt_multiprocessor.h"
81#include "opt_ntp.h"
82
83/* The COM16650 option was renamed to COM_16650. */
84#ifdef COM16650
85#error Obsolete COM16650 option; use COM_16650 instead.
86#endif
87
88/*
89 * Override cnmagic(9) macro before including <sys/systm.h>.
90 * We need to know if cn_check_magic triggered debugger, so set a flag.
91 * Callers of cn_check_magic must declare int cn_trapped = 0;
92 * XXX: this is *ugly*!
93 */
94#define cn_trap()				\
95	do {					\
96		console_debugger();		\
97		cn_trapped = 1;			\
98		(void)cn_trapped;		\
99	} while (/* CONSTCOND */ 0)
100
101#include <sys/param.h>
102#include <sys/systm.h>
103#include <sys/ioctl.h>
104#include <sys/select.h>
105#include <sys/poll.h>
106#include <sys/tty.h>
107#include <sys/proc.h>
108#include <sys/conf.h>
109#include <sys/file.h>
110#include <sys/uio.h>
111#include <sys/kernel.h>
112#include <sys/syslog.h>
113#include <sys/device.h>
114#include <sys/malloc.h>
115#include <sys/timepps.h>
116#include <sys/vnode.h>
117#include <sys/kauth.h>
118#include <sys/intr.h>
119#ifdef RND_COM
120#include <sys/rndsource.h>
121#endif
122
123#include <sys/bus.h>
124
125#include <ddb/db_active.h>
126
127#include <dev/ic/comreg.h>
128#include <dev/ic/comvar.h>
129#include <dev/ic/ns16550reg.h>
130#include <dev/ic/st16650reg.h>
131#include <dev/ic/hayespreg.h>
132#define	com_lcr	com_cfcr
133#include <dev/cons.h>
134
135#include "ioconf.h"
136
137#define	CSR_READ_1(r, o)	\
138	(r)->cr_read((r), (r)->cr_map[o])
139#define	CSR_WRITE_1(r, o, v)	\
140	(r)->cr_write((r), (r)->cr_map[o], (v))
141#define	CSR_WRITE_MULTI(r, o, p, n)	\
142	(r)->cr_write_multi((r), (r)->cr_map[o], (p), (n))
143
144/*
145 * XXX COM_TYPE_AU1x00 specific
146 */
147#define	CSR_WRITE_2(r, o, v)	\
148	bus_space_write_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o], v)
149#define	CSR_READ_2(r, o)	\
150	bus_space_read_2((r)->cr_iot, (r)->cr_ioh, (r)->cr_map[o])
151
152static void com_enable_debugport(struct com_softc *);
153
154void	com_config(struct com_softc *);
155void	com_shutdown(struct com_softc *);
156int	comspeed(long, long, int);
157static	u_char	cflag2lcr(tcflag_t);
158int	comparam(struct tty *, struct termios *);
159void	comstart(struct tty *);
160int	comhwiflow(struct tty *, int);
161
162void	com_loadchannelregs(struct com_softc *);
163void	com_hwiflow(struct com_softc *);
164void	com_break(struct com_softc *, int);
165void	com_modem(struct com_softc *, int);
166void	tiocm_to_com(struct com_softc *, u_long, int);
167int	com_to_tiocm(struct com_softc *);
168void	com_iflush(struct com_softc *);
169
170int	com_common_getc(dev_t, struct com_regs *);
171static void	com_common_putc(dev_t, struct com_regs *, int, int);
172
173int	cominit(struct com_regs *, int, int, int, tcflag_t);
174
175static int comcnreattach(void);
176
177int	comcngetc(dev_t);
178void	comcnputc(dev_t, int);
179void	comcnpollc(dev_t, int);
180
181void	comsoft(void *);
182static inline void com_rxsoft(struct com_softc *, struct tty *);
183static inline void com_txsoft(struct com_softc *, struct tty *);
184static inline void com_stsoft(struct com_softc *, struct tty *);
185static inline void com_schedrx(struct com_softc *);
186void	comdiag(void *);
187
188dev_type_open(comopen);
189dev_type_close(comclose);
190dev_type_read(comread);
191dev_type_write(comwrite);
192dev_type_ioctl(comioctl);
193dev_type_stop(comstop);
194dev_type_tty(comtty);
195dev_type_poll(compoll);
196
197static struct comcons_info comcons_info;
198
199/*
200 * Following are all routines needed for COM to act as console
201 */
202static struct consdev comcons = {
203	.cn_getc = comcngetc,
204	.cn_putc = comcnputc,
205	.cn_pollc = comcnpollc,
206	.cn_dev = NODEV,
207	.cn_pri = CN_NORMAL
208};
209
210
211const struct cdevsw com_cdevsw = {
212	.d_open = comopen,
213	.d_close = comclose,
214	.d_read = comread,
215	.d_write = comwrite,
216	.d_ioctl = comioctl,
217	.d_stop = comstop,
218	.d_tty = comtty,
219	.d_poll = compoll,
220	.d_mmap = nommap,
221	.d_kqfilter = ttykqfilter,
222	.d_discard = nodiscard,
223	.d_flag = D_TTY
224};
225
226/*
227 * Make this an option variable one can patch.
228 * But be warned:  this must be a power of 2!
229 */
230u_int com_rbuf_size = COM_RING_SIZE;
231
232/* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
233u_int com_rbuf_hiwat = (COM_RING_SIZE * 1) / 4;
234u_int com_rbuf_lowat = (COM_RING_SIZE * 3) / 4;
235
236static int comconsattached;
237static struct cnm_state com_cnm_state;
238
239#ifdef KGDB
240#include <sys/kgdb.h>
241
242static struct com_regs comkgdbregs;
243static int com_kgdb_attached;
244
245int	com_kgdb_getc(void *);
246void	com_kgdb_putc(void *, int);
247#endif /* KGDB */
248
249/* initializer for typical 16550-ish hardware */
250static const bus_size_t com_std_map[COM_REGMAP_NENTRIES] = {
251	[COM_REG_RXDATA]	=	com_data,
252	[COM_REG_TXDATA]	=	com_data,
253	[COM_REG_DLBL]		=	com_dlbl,
254	[COM_REG_DLBH]		=	com_dlbh,
255	[COM_REG_IER]		=	com_ier,
256	[COM_REG_IIR]		=	com_iir,
257	[COM_REG_FIFO]		=	com_fifo,
258	[COM_REG_TCR]		=	com_fifo,
259	[COM_REG_EFR]		=	com_efr,
260	[COM_REG_TLR]		=	com_efr,
261	[COM_REG_LCR]		=	com_lcr,
262	[COM_REG_MCR]		=	com_mcr,
263	[COM_REG_LSR]		=	com_lsr,
264	[COM_REG_MSR]		=	com_msr,
265	[COM_REG_USR]		=	com_usr,
266	[COM_REG_TFL]		=	com_tfl,
267	[COM_REG_RFL]		=	com_rfl,
268	[COM_REG_HALT]		=	com_halt,
269	[COM_REG_MDR1]		=	com_mdr1,
270};
271
272#define	COMDIALOUT_MASK	TTDIALOUT_MASK
273
274#define	COMUNIT(x)	TTUNIT(x)
275#define	COMDIALOUT(x)	TTDIALOUT(x)
276
277#define	COM_ISALIVE(sc)	((sc)->enabled != 0 && \
278			 device_is_active((sc)->sc_dev))
279
280#define	BR	BUS_SPACE_BARRIER_READ
281#define	BW	BUS_SPACE_BARRIER_WRITE
282#define COM_BARRIER(r, f) \
283	bus_space_barrier((r)->cr_iot, (r)->cr_ioh, 0, (r)->cr_nports, (f))
284
285/*
286 * com_read_1 --
287 *	Default register read callback using single byte accesses.
288 */
289static uint8_t
290com_read_1(struct com_regs *regs, u_int reg)
291{
292	return bus_space_read_1(regs->cr_iot, regs->cr_ioh, reg);
293}
294
295/*
296 * com_write_1 --
297 *	Default register write callback using single byte accesses.
298 */
299static void
300com_write_1(struct com_regs *regs, u_int reg, uint8_t val)
301{
302	bus_space_write_1(regs->cr_iot, regs->cr_ioh, reg, val);
303}
304
305/*
306 * com_write_multi_1 --
307 *	Default register multi write callback using single byte accesses.
308 */
309static void
310com_write_multi_1(struct com_regs *regs, u_int reg, const uint8_t *datap,
311    bus_size_t count)
312{
313	bus_space_write_multi_1(regs->cr_iot, regs->cr_ioh, reg, datap, count);
314}
315
316/*
317 * com_read_4 --
318 *	Default register read callback using dword accesses.
319 */
320static uint8_t
321com_read_4(struct com_regs *regs, u_int reg)
322{
323	return bus_space_read_4(regs->cr_iot, regs->cr_ioh, reg) & 0xff;
324}
325
326/*
327 * com_write_4 --
328 *	Default register write callback using dword accesses.
329 */
330static void
331com_write_4(struct com_regs *regs, u_int reg, uint8_t val)
332{
333	bus_space_write_4(regs->cr_iot, regs->cr_ioh, reg, val);
334}
335
336/*
337 * com_write_multi_4 --
338 *	Default register multi write callback using dword accesses.
339 */
340static void
341com_write_multi_4(struct com_regs *regs, u_int reg, const uint8_t *datap,
342    bus_size_t count)
343{
344	while (count-- > 0) {
345		bus_space_write_4(regs->cr_iot, regs->cr_ioh, reg, *datap++);
346	}
347}
348
349/*
350 * com_init_regs --
351 *	Driver front-ends use this to initialize our register map
352 *	in the standard fashion.  They may then tailor the map to
353 *	their own particular requirements.
354 */
355void
356com_init_regs(struct com_regs *regs, bus_space_tag_t st, bus_space_handle_t sh,
357	      bus_addr_t addr)
358{
359
360	memset(regs, 0, sizeof(*regs));
361	regs->cr_iot = st;
362	regs->cr_ioh = sh;
363	regs->cr_iobase = addr;
364	regs->cr_nports = COM_NPORTS;
365	regs->cr_read = com_read_1;
366	regs->cr_write = com_write_1;
367	regs->cr_write_multi = com_write_multi_1;
368	memcpy(regs->cr_map, com_std_map, sizeof(regs->cr_map));
369}
370
371/*
372 * com_init_regs_stride --
373 *	Convenience function for front-ends that have a stride between
374 *	registers.
375 */
376void
377com_init_regs_stride(struct com_regs *regs, bus_space_tag_t st,
378		     bus_space_handle_t sh, bus_addr_t addr, u_int regshift)
379{
380
381	com_init_regs(regs, st, sh, addr);
382	for (size_t i = 0; i < __arraycount(regs->cr_map); i++) {
383		regs->cr_map[i] <<= regshift;
384	}
385	regs->cr_nports <<= regshift;
386}
387
388/*
389 * com_init_regs_stride_width --
390 *	Convenience function for front-ends that have a stride between
391 *	registers and specific I/O width requirements.
392 */
393void
394com_init_regs_stride_width(struct com_regs *regs, bus_space_tag_t st,
395			   bus_space_handle_t sh, bus_addr_t addr,
396			   u_int regshift, u_int width)
397{
398
399	com_init_regs(regs, st, sh, addr);
400	for (size_t i = 0; i < __arraycount(regs->cr_map); i++) {
401		regs->cr_map[i] <<= regshift;
402	}
403	regs->cr_nports <<= regshift;
404
405	switch (width) {
406	case 1:
407		/* Already set by com_init_regs */
408		break;
409	case 4:
410		regs->cr_read = com_read_4;
411		regs->cr_write = com_write_4;
412		regs->cr_write_multi = com_write_multi_4;
413		break;
414	default:
415		panic("com: unsupported I/O width %d", width);
416	}
417}
418
419/*ARGSUSED*/
420int
421comspeed(long speed, long frequency, int type)
422{
423#define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
424
425	int x, err;
426	int divisor = 16;
427
428	if ((type == COM_TYPE_OMAP) && (speed > 230400)) {
429	    divisor = 13;
430	}
431
432	if (speed == 0)
433		return (0);
434	if (speed < 0)
435		return (-1);
436	x = divrnd(frequency / divisor, speed);
437	if (x <= 0)
438		return (-1);
439	err = divrnd(((quad_t)frequency) * 1000 / divisor, speed * x) - 1000;
440	if (err < 0)
441		err = -err;
442	if (err > COM_TOLERANCE)
443		return (-1);
444	return (x);
445
446#undef	divrnd
447}
448
449#ifdef COM_DEBUG
450int	com_debug = 0;
451
452void comstatus(struct com_softc *, const char *);
453void
454comstatus(struct com_softc *sc, const char *str)
455{
456	struct tty *tp = sc->sc_tty;
457
458	aprint_normal_dev(sc->sc_dev,
459	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
460	    str,
461	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
462	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
463	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
464	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
465	    sc->sc_tx_stopped ? '+' : '-');
466
467	aprint_normal_dev(sc->sc_dev,
468	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
469	    str,
470	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
471	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
472	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
473	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
474	    sc->sc_rx_flags);
475}
476#endif
477
478int
479com_probe_subr(struct com_regs *regs)
480{
481
482	/* force access to id reg */
483	CSR_WRITE_1(regs, COM_REG_LCR, LCR_8BITS);
484	CSR_WRITE_1(regs, COM_REG_IIR, 0);
485	if ((CSR_READ_1(regs, COM_REG_LCR) != LCR_8BITS) ||
486	    (CSR_READ_1(regs, COM_REG_IIR) & 0x38))
487		return (0);
488
489	return (1);
490}
491
492int
493comprobe1(bus_space_tag_t iot, bus_space_handle_t ioh)
494{
495	struct com_regs	regs;
496
497	com_init_regs(&regs, iot, ioh, 0/*XXX*/);
498
499	return com_probe_subr(&regs);
500}
501
502/*
503 * No locking in this routine; it is only called during attach,
504 * or with the port already locked.
505 */
506static void
507com_enable_debugport(struct com_softc *sc)
508{
509
510	/* Turn on line break interrupt, set carrier. */
511	sc->sc_ier = IER_ERLS;
512	if (sc->sc_type == COM_TYPE_PXA2x0)
513		sc->sc_ier |= IER_EUART | IER_ERXTOUT;
514	if (sc->sc_type == COM_TYPE_INGENIC ||
515	    sc->sc_type == COM_TYPE_TEGRA)
516		sc->sc_ier |= IER_ERXTOUT;
517	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
518	SET(sc->sc_mcr, MCR_DTR | MCR_RTS);
519	CSR_WRITE_1(&sc->sc_regs, COM_REG_MCR, sc->sc_mcr);
520}
521
522static void
523com_intr_poll(void *arg)
524{
525	struct com_softc * const sc = arg;
526
527	comintr(sc);
528
529	callout_schedule(&sc->sc_poll_callout, sc->sc_poll_ticks);
530}
531
532void
533com_attach_subr(struct com_softc *sc)
534{
535	struct com_regs *regsp = &sc->sc_regs;
536	struct tty *tp;
537	uint32_t cpr;
538	uint8_t lcr;
539	const char *fifo_msg = NULL;
540	prop_dictionary_t dict;
541	bool is_console = true;
542	bool force_console = false;
543
544	aprint_naive("\n");
545
546	dict = device_properties(sc->sc_dev);
547	prop_dictionary_get_bool(dict, "is_console", &is_console);
548	prop_dictionary_get_bool(dict, "force_console", &force_console);
549	callout_init(&sc->sc_diag_callout, 0);
550	callout_init(&sc->sc_poll_callout, 0);
551	callout_setfunc(&sc->sc_poll_callout, com_intr_poll, sc);
552	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
553
554#if defined(COM_16650)
555	sc->sc_type = COM_TYPE_16650;
556#elif defined(COM_16750)
557	sc->sc_type = COM_TYPE_16750;
558#elif defined(COM_HAYESP)
559	sc->sc_type = COM_TYPE_HAYESP;
560#elif defined(COM_PXA2X0)
561	sc->sc_type = COM_TYPE_PXA2x0;
562#endif
563
564	/* Disable interrupts before configuring the device. */
565	if (sc->sc_type == COM_TYPE_PXA2x0)
566		sc->sc_ier = IER_EUART;
567	else
568		sc->sc_ier = 0;
569
570	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
571
572	if ((bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
573	    regsp->cr_iobase == comcons_info.regs.cr_iobase) || force_console) {
574		comconsattached = 1;
575
576		if (force_console)
577			memcpy(regsp, &comcons_info.regs, sizeof(*regsp));
578
579		if (cn_tab == NULL && comcnreattach() != 0) {
580			printf("can't re-init serial console @%lx\n",
581			    (u_long)comcons_info.regs.cr_iobase);
582		}
583
584		switch (sc->sc_type) {
585		case COM_TYPE_16750:
586		case COM_TYPE_DW_APB:
587			/* Use in comintr(). */
588 			sc->sc_lcr = cflag2lcr(comcons_info.cflag);
589			break;
590		}
591
592		/* Make sure the console is always "hardwired". */
593		delay(10000);			/* wait for output to finish */
594		if (is_console) {
595			SET(sc->sc_hwflags, COM_HW_CONSOLE);
596		}
597
598		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
599	}
600
601	/* Probe for FIFO */
602	switch (sc->sc_type) {
603	case COM_TYPE_HAYESP:
604		goto fifodone;
605
606	case COM_TYPE_AU1x00:
607		sc->sc_fifolen = 16;
608		fifo_msg = "Au1X00 UART";
609		SET(sc->sc_hwflags, COM_HW_FIFO);
610		goto fifodelay;
611
612	case COM_TYPE_16550_NOERS:
613		sc->sc_fifolen = 16;
614		fifo_msg = "ns16650, no ERS";
615		SET(sc->sc_hwflags, COM_HW_FIFO);
616		goto fifodelay;
617
618	case COM_TYPE_OMAP:
619		sc->sc_fifolen = 64;
620		fifo_msg = "OMAP UART";
621		SET(sc->sc_hwflags, COM_HW_FIFO);
622		goto fifodelay;
623
624	case COM_TYPE_INGENIC:
625		sc->sc_fifolen = 16;
626		fifo_msg = "Ingenic UART";
627		SET(sc->sc_hwflags, COM_HW_FIFO);
628		SET(sc->sc_hwflags, COM_HW_NOIEN);
629		goto fifodelay;
630
631	case COM_TYPE_TEGRA:
632		sc->sc_fifolen = 8;
633		fifo_msg = "Tegra UART";
634		SET(sc->sc_hwflags, COM_HW_FIFO);
635		CSR_WRITE_1(regsp, COM_REG_FIFO,
636		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
637		goto fifodelay;
638
639	case COM_TYPE_BCMAUXUART:
640		sc->sc_fifolen = 1;
641		fifo_msg = "BCM AUX UART";
642		SET(sc->sc_hwflags, COM_HW_FIFO);
643		CSR_WRITE_1(regsp, COM_REG_FIFO,
644		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
645		goto fifodelay;
646
647	case COM_TYPE_DW_APB:
648		if (!prop_dictionary_get_uint(dict, "fifolen", &sc->sc_fifolen)) {
649			cpr = bus_space_read_4(sc->sc_regs.cr_iot,
650			    sc->sc_regs.cr_ioh, DW_APB_UART_CPR);
651			sc->sc_fifolen = __SHIFTOUT(cpr, UART_CPR_FIFO_MODE) * 16;
652		}
653		if (sc->sc_fifolen == 0) {
654			sc->sc_fifolen = 1;
655			fifo_msg = "DesignWare APB UART, no fifo";
656			CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
657		} else {
658			fifo_msg = "DesignWare APB UART";
659			SET(sc->sc_hwflags, COM_HW_FIFO);
660			CSR_WRITE_1(regsp, COM_REG_FIFO,
661			    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_1);
662		}
663		goto fifodelay;
664	}
665
666	sc->sc_fifolen = 1;
667	/* look for a NS 16550AF UART with FIFOs */
668	if (sc->sc_type == COM_TYPE_INGENIC) {
669		CSR_WRITE_1(regsp, COM_REG_FIFO,
670		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
671		    FIFO_TRIGGER_14 | FIFO_UART_ON);
672	} else
673		CSR_WRITE_1(regsp, COM_REG_FIFO,
674		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST | FIFO_TRIGGER_14);
675	delay(100);
676	if (ISSET(CSR_READ_1(regsp, COM_REG_IIR), IIR_FIFO_MASK)
677	    == IIR_FIFO_MASK)
678		if (ISSET(CSR_READ_1(regsp, COM_REG_FIFO), FIFO_TRIGGER_14)
679		    == FIFO_TRIGGER_14) {
680			SET(sc->sc_hwflags, COM_HW_FIFO);
681
682			fifo_msg = "ns16550a";
683			sc->sc_fifolen = 16;
684
685			/*
686			 * IIR changes into the EFR if LCR is set to LCR_EERS
687			 * on 16650s. We also know IIR != 0 at this point.
688			 * Write 0 into the EFR, and read it. If the result
689			 * is 0, we have a 16650.
690			 *
691			 * Older 16650s were broken; the test to detect them
692			 * is taken from the Linux driver. Apparently
693			 * setting DLAB enable gives access to the EFR on
694			 * these chips.
695			 */
696			if (sc->sc_type == COM_TYPE_16650) {
697				lcr = CSR_READ_1(regsp, COM_REG_LCR);
698				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
699				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
700				if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
701					CSR_WRITE_1(regsp, COM_REG_LCR,
702					    lcr | LCR_DLAB);
703					if (CSR_READ_1(regsp, COM_REG_EFR) == 0) {
704						CLR(sc->sc_hwflags, COM_HW_FIFO);
705						sc->sc_fifolen = 0;
706					} else {
707						SET(sc->sc_hwflags, COM_HW_FLOW);
708						sc->sc_fifolen = 32;
709					}
710				} else
711					sc->sc_fifolen = 16;
712
713				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
714				if (sc->sc_fifolen == 0)
715					fifo_msg = "st16650, broken fifo";
716				else if (sc->sc_fifolen == 32)
717					fifo_msg = "st16650a";
718				else
719					fifo_msg = "ns16550a";
720			}
721
722			/*
723			 * TL16C750 can enable 64byte FIFO, only when DLAB
724			 * is 1.  However, some 16750 may always enable.  For
725			 * example, restrictions according to DLAB in a data
726			 * sheet for SC16C750 were not described.
727			 * Please enable 'options COM_16650', supposing you
728			 * use SC16C750.  Probably 32 bytes of FIFO and HW FLOW
729			 * should become effective.
730			 */
731			if (sc->sc_type == COM_TYPE_16750) {
732				uint8_t iir1, iir2;
733				uint8_t fcr = FIFO_ENABLE | FIFO_TRIGGER_14;
734
735				lcr = CSR_READ_1(regsp, COM_REG_LCR);
736				CSR_WRITE_1(regsp, COM_REG_LCR,
737				    lcr & ~LCR_DLAB);
738				CSR_WRITE_1(regsp, COM_REG_FIFO,
739				    fcr | FIFO_64B_ENABLE);
740				iir1 = CSR_READ_1(regsp, COM_REG_IIR);
741				CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
742				CSR_WRITE_1(regsp, COM_REG_LCR, lcr | LCR_DLAB);
743				CSR_WRITE_1(regsp, COM_REG_FIFO,
744				    fcr | FIFO_64B_ENABLE);
745				iir2 = CSR_READ_1(regsp, COM_REG_IIR);
746
747				CSR_WRITE_1(regsp, COM_REG_LCR, lcr);
748
749				if (!ISSET(iir1, IIR_64B_FIFO) &&
750				    ISSET(iir2, IIR_64B_FIFO)) {
751					/* It is TL16C750. */
752					sc->sc_fifolen = 64;
753					SET(sc->sc_hwflags, COM_HW_AFE);
754				} else
755					CSR_WRITE_1(regsp, COM_REG_FIFO, fcr);
756
757				if (sc->sc_fifolen == 64)
758					fifo_msg = "tl16c750";
759				else
760					fifo_msg = "ns16750";
761			}
762		} else
763			fifo_msg = "ns16550, broken fifo";
764	else
765		fifo_msg = "ns8250 or ns16450, no fifo";
766	CSR_WRITE_1(regsp, COM_REG_FIFO, 0);
767
768fifodelay:
769	/*
770	 * Some chips will clear down both Tx and Rx FIFOs when zero is
771	 * written to com_fifo. If this chip is the console, writing zero
772	 * results in some of the chip/FIFO description being lost, so delay
773	 * printing it until now.
774	 */
775	delay(10);
776	if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
777		aprint_normal(": %s, %d-byte FIFO\n", fifo_msg, sc->sc_fifolen);
778	} else {
779		aprint_normal(": %s\n", fifo_msg);
780	}
781	if (ISSET(sc->sc_hwflags, COM_HW_TXFIFO_DISABLE)) {
782		sc->sc_fifolen = 1;
783		aprint_normal_dev(sc->sc_dev, "txfifo disabled\n");
784	}
785
786fifodone:
787
788	tp = tty_alloc();
789	tp->t_oproc = comstart;
790	tp->t_param = comparam;
791	tp->t_hwiflow = comhwiflow;
792	tp->t_softc = sc;
793
794	sc->sc_tty = tp;
795	sc->sc_rbuf = malloc(com_rbuf_size << 1, M_DEVBUF, M_WAITOK);
796	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
797	sc->sc_rbavail = com_rbuf_size;
798	sc->sc_ebuf = sc->sc_rbuf + (com_rbuf_size << 1);
799
800	tty_attach(tp);
801
802	if (!ISSET(sc->sc_hwflags, COM_HW_NOIEN))
803		SET(sc->sc_mcr, MCR_IENABLE);
804
805	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
806		int maj;
807
808		/* locate the major number */
809		maj = cdevsw_lookup_major(&com_cdevsw);
810
811		tp->t_dev = cn_tab->cn_dev = makedev(maj,
812						     device_unit(sc->sc_dev));
813
814		aprint_normal_dev(sc->sc_dev, "console\n");
815	}
816
817#ifdef KGDB
818	/*
819	 * Allow kgdb to "take over" this port.  If this is
820	 * not the console and is the kgdb device, it has
821	 * exclusive use.  If it's the console _and_ the
822	 * kgdb device, it doesn't.
823	 */
824	if (bus_space_is_equal(regsp->cr_iot, comkgdbregs.cr_iot) &&
825	    regsp->cr_iobase == comkgdbregs.cr_iobase) {
826		if (!ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
827			com_kgdb_attached = 1;
828
829			SET(sc->sc_hwflags, COM_HW_KGDB);
830		}
831		aprint_normal_dev(sc->sc_dev, "kgdb\n");
832	}
833#endif
834
835	sc->sc_si = softint_establish(SOFTINT_SERIAL, comsoft, sc);
836
837#ifdef RND_COM
838	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
839			  RND_TYPE_TTY, RND_FLAG_DEFAULT);
840#endif
841
842	/* if there are no enable/disable functions, assume the device
843	   is always enabled */
844	if (!sc->enable)
845		sc->enabled = 1;
846
847	com_config(sc);
848
849	SET(sc->sc_hwflags, COM_HW_DEV_OK);
850
851	if (sc->sc_poll_ticks != 0)
852		callout_schedule(&sc->sc_poll_callout, sc->sc_poll_ticks);
853}
854
855void
856com_config(struct com_softc *sc)
857{
858	struct com_regs *regsp = &sc->sc_regs;
859
860	/* Disable interrupts before configuring the device. */
861	if (sc->sc_type == COM_TYPE_PXA2x0)
862		sc->sc_ier = IER_EUART;
863	else
864		sc->sc_ier = 0;
865	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
866	(void) CSR_READ_1(regsp, COM_REG_IIR);
867
868	/* Look for a Hayes ESP board. */
869	if (sc->sc_type == COM_TYPE_HAYESP) {
870
871		/* Set 16550 compatibility mode */
872		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
873				  HAYESP_SETMODE);
874		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
875				  HAYESP_MODE_FIFO|HAYESP_MODE_RTS|
876				  HAYESP_MODE_SCALE);
877
878		/* Set RTS/CTS flow control */
879		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
880				  HAYESP_SETFLOWTYPE);
881		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
882				  HAYESP_FLOW_RTS);
883		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
884				  HAYESP_FLOW_CTS);
885
886		/* Set flow control levels */
887		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
888				  HAYESP_SETRXFLOW);
889		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
890				  HAYESP_HIBYTE(HAYESP_RXHIWMARK));
891		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
892				  HAYESP_LOBYTE(HAYESP_RXHIWMARK));
893		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
894				  HAYESP_HIBYTE(HAYESP_RXLOWMARK));
895		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
896				  HAYESP_LOBYTE(HAYESP_RXLOWMARK));
897	}
898
899	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE|COM_HW_KGDB))
900		com_enable_debugport(sc);
901}
902
903int
904com_detach(device_t self, int flags)
905{
906	struct com_softc *sc = device_private(self);
907	int maj, mn;
908
909	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
910		return EBUSY;
911
912	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE) &&
913	    (flags & DETACH_SHUTDOWN) != 0)
914		return EBUSY;
915
916	if (sc->disable != NULL && sc->enabled != 0) {
917		(*sc->disable)(sc);
918		sc->enabled = 0;
919	}
920
921	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
922		comconsattached = 0;
923		cn_tab = NULL;
924	}
925
926	/* locate the major number */
927	maj = cdevsw_lookup_major(&com_cdevsw);
928
929	/* Nuke the vnodes for any open instances. */
930	mn = device_unit(self);
931	vdevgone(maj, mn, mn, VCHR);
932
933	mn |= COMDIALOUT_MASK;
934	vdevgone(maj, mn, mn, VCHR);
935
936	if (sc->sc_rbuf == NULL) {
937		/*
938		 * Ring buffer allocation failed in the com_attach_subr,
939		 * only the tty is allocated, and nothing else.
940		 */
941		tty_free(sc->sc_tty);
942		return 0;
943	}
944
945	/* Free the receive buffer. */
946	free(sc->sc_rbuf, M_DEVBUF);
947
948	/* Detach and free the tty. */
949	tty_detach(sc->sc_tty);
950	tty_free(sc->sc_tty);
951
952	/* Unhook the soft interrupt handler. */
953	softint_disestablish(sc->sc_si);
954
955#ifdef RND_COM
956	/* Unhook the entropy source. */
957	rnd_detach_source(&sc->rnd_source);
958#endif
959	callout_destroy(&sc->sc_diag_callout);
960
961	/* Destroy the lock. */
962	mutex_destroy(&sc->sc_lock);
963
964	return (0);
965}
966
967void
968com_shutdown(struct com_softc *sc)
969{
970	struct tty *tp = sc->sc_tty;
971
972	mutex_spin_enter(&sc->sc_lock);
973
974	/* If we were asserting flow control, then deassert it. */
975	SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
976	com_hwiflow(sc);
977
978	/* Clear any break condition set with TIOCSBRK. */
979	com_break(sc, 0);
980
981	/*
982	 * Hang up if necessary.  Record when we hung up, so if we
983	 * immediately open the port again, we will wait a bit until
984	 * the other side has had time to notice that we hung up.
985	 */
986	if (ISSET(tp->t_cflag, HUPCL)) {
987		com_modem(sc, 0);
988		microuptime(&sc->sc_hup_pending);
989		sc->sc_hup_pending.tv_sec++;
990	}
991
992	/* Turn off interrupts. */
993	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
994		sc->sc_ier = IER_ERLS; /* interrupt on line break */
995		if ((sc->sc_type == COM_TYPE_PXA2x0) ||
996		    (sc->sc_type == COM_TYPE_INGENIC) ||
997		    (sc->sc_type == COM_TYPE_TEGRA))
998			sc->sc_ier |= IER_ERXTOUT;
999	} else
1000		sc->sc_ier = 0;
1001
1002	if (sc->sc_type == COM_TYPE_PXA2x0)
1003		sc->sc_ier |= IER_EUART;
1004
1005	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1006
1007	mutex_spin_exit(&sc->sc_lock);
1008
1009	if (sc->disable) {
1010#ifdef DIAGNOSTIC
1011		if (!sc->enabled)
1012			panic("com_shutdown: not enabled?");
1013#endif
1014		(*sc->disable)(sc);
1015		sc->enabled = 0;
1016	}
1017}
1018
1019int
1020comopen(dev_t dev, int flag, int mode, struct lwp *l)
1021{
1022	struct com_softc *sc;
1023	struct tty *tp;
1024	int s;
1025	int error;
1026
1027	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1028	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
1029		sc->sc_rbuf == NULL)
1030		return (ENXIO);
1031
1032	if (!device_is_active(sc->sc_dev))
1033		return (ENXIO);
1034
1035#ifdef KGDB
1036	/*
1037	 * If this is the kgdb port, no other use is permitted.
1038	 */
1039	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
1040		return (EBUSY);
1041#endif
1042
1043	tp = sc->sc_tty;
1044
1045	/*
1046	 * If the device is exclusively for kernel use, deny userland
1047	 * open.
1048	 */
1049	if (ISSET(tp->t_state, TS_KERN_ONLY))
1050		return (EBUSY);
1051
1052	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
1053		return (EBUSY);
1054
1055	s = spltty();
1056
1057	/*
1058	 * Do the following iff this is a first open.
1059	 */
1060	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1061		struct termios t;
1062		struct timeval now, diff;
1063
1064		tp->t_dev = dev;
1065
1066		if (sc->enable) {
1067			if ((*sc->enable)(sc)) {
1068				splx(s);
1069				aprint_error_dev(sc->sc_dev,
1070				    "device enable failed\n");
1071				return (EIO);
1072			}
1073			mutex_spin_enter(&sc->sc_lock);
1074			sc->enabled = 1;
1075			com_config(sc);
1076		} else {
1077			mutex_spin_enter(&sc->sc_lock);
1078		}
1079
1080		if (timerisset(&sc->sc_hup_pending)) {
1081			microuptime(&now);
1082			while (timercmp(&now, &sc->sc_hup_pending, <)) {
1083				timersub(&sc->sc_hup_pending, &now, &diff);
1084				const int ms = diff.tv_sec * 1000 +
1085				    diff.tv_usec / 1000;
1086				kpause(ttclos, false, uimax(mstohz(ms), 1),
1087				    &sc->sc_lock);
1088				microuptime(&now);
1089			}
1090			timerclear(&sc->sc_hup_pending);
1091		}
1092
1093		/* Turn on interrupts. */
1094		sc->sc_ier = IER_ERXRDY | IER_ERLS;
1095		if (!ISSET(tp->t_cflag, CLOCAL))
1096			sc->sc_ier |= IER_EMSC;
1097
1098		if (sc->sc_type == COM_TYPE_PXA2x0)
1099			sc->sc_ier |= IER_EUART | IER_ERXTOUT;
1100		else if (sc->sc_type == COM_TYPE_INGENIC ||
1101			 sc->sc_type == COM_TYPE_TEGRA)
1102			sc->sc_ier |= IER_ERXTOUT;
1103		CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, sc->sc_ier);
1104
1105		/* Fetch the current modem control status, needed later. */
1106		sc->sc_msr = CSR_READ_1(&sc->sc_regs, COM_REG_MSR);
1107
1108		/* Clear PPS capture state on first open. */
1109		mutex_spin_enter(&timecounter_lock);
1110		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
1111		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
1112		pps_init(&sc->sc_pps_state);
1113		mutex_spin_exit(&timecounter_lock);
1114
1115		mutex_spin_exit(&sc->sc_lock);
1116
1117		/*
1118		 * Initialize the termios status to the defaults.  Add in the
1119		 * sticky bits from TIOCSFLAGS.
1120		 */
1121		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1122			t.c_ospeed = comcons_info.rate;
1123			t.c_cflag = comcons_info.cflag;
1124		} else {
1125			t.c_ospeed = TTYDEF_SPEED;
1126			t.c_cflag = TTYDEF_CFLAG;
1127		}
1128		t.c_ispeed = t.c_ospeed;
1129		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
1130			SET(t.c_cflag, CLOCAL);
1131		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
1132			SET(t.c_cflag, CRTSCTS);
1133		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
1134			SET(t.c_cflag, MDMBUF);
1135		/* Make sure comparam() will do something. */
1136		tp->t_ospeed = 0;
1137		(void) comparam(tp, &t);
1138		tp->t_iflag = TTYDEF_IFLAG;
1139		tp->t_oflag = TTYDEF_OFLAG;
1140		tp->t_lflag = TTYDEF_LFLAG;
1141		ttychars(tp);
1142		ttsetwater(tp);
1143
1144		mutex_spin_enter(&sc->sc_lock);
1145
1146		/*
1147		 * Turn on DTR.  We must always do this, even if carrier is not
1148		 * present, because otherwise we'd have to use TIOCSDTR
1149		 * immediately after setting CLOCAL, which applications do not
1150		 * expect.  We always assert DTR while the device is open
1151		 * unless explicitly requested to deassert it.
1152		 */
1153		com_modem(sc, 1);
1154
1155		/* Clear the input ring, and unblock. */
1156		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
1157		sc->sc_rbavail = com_rbuf_size;
1158		com_iflush(sc);
1159		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
1160		com_hwiflow(sc);
1161
1162#ifdef COM_DEBUG
1163		if (com_debug)
1164			comstatus(sc, "comopen  ");
1165#endif
1166
1167		mutex_spin_exit(&sc->sc_lock);
1168	}
1169
1170	splx(s);
1171
1172	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
1173	if (error)
1174		goto bad;
1175
1176	error = (*tp->t_linesw->l_open)(dev, tp);
1177	if (error)
1178		goto bad;
1179
1180	return (0);
1181
1182bad:
1183	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1184		/*
1185		 * We failed to open the device, and nobody else had it opened.
1186		 * Clean up the state as appropriate.
1187		 */
1188		com_shutdown(sc);
1189	}
1190
1191	return (error);
1192}
1193
1194int
1195comclose(dev_t dev, int flag, int mode, struct lwp *l)
1196{
1197	struct com_softc *sc =
1198	    device_lookup_private(&com_cd, COMUNIT(dev));
1199	struct tty *tp = sc->sc_tty;
1200
1201	/* XXX This is for cons.c. */
1202	if (!ISSET(tp->t_state, TS_ISOPEN))
1203		return (0);
1204	/*
1205	 * If the device is exclusively for kernel use, deny userland
1206	 * close.
1207	 */
1208	if (ISSET(tp->t_state, TS_KERN_ONLY))
1209		return (0);
1210
1211	(*tp->t_linesw->l_close)(tp, flag);
1212	ttyclose(tp);
1213
1214	if (COM_ISALIVE(sc) == 0)
1215		return (0);
1216
1217	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
1218		/*
1219		 * Although we got a last close, the device may still be in
1220		 * use; e.g. if this was the dialout node, and there are still
1221		 * processes waiting for carrier on the non-dialout node.
1222		 */
1223		com_shutdown(sc);
1224	}
1225
1226	return (0);
1227}
1228
1229int
1230comread(dev_t dev, struct uio *uio, int flag)
1231{
1232	struct com_softc *sc =
1233	    device_lookup_private(&com_cd, COMUNIT(dev));
1234	struct tty *tp = sc->sc_tty;
1235
1236	if (COM_ISALIVE(sc) == 0)
1237		return (EIO);
1238
1239	return ((*tp->t_linesw->l_read)(tp, uio, flag));
1240}
1241
1242int
1243comwrite(dev_t dev, struct uio *uio, int flag)
1244{
1245	struct com_softc *sc =
1246	    device_lookup_private(&com_cd, COMUNIT(dev));
1247	struct tty *tp = sc->sc_tty;
1248
1249	if (COM_ISALIVE(sc) == 0)
1250		return (EIO);
1251
1252	return ((*tp->t_linesw->l_write)(tp, uio, flag));
1253}
1254
1255int
1256compoll(dev_t dev, int events, struct lwp *l)
1257{
1258	struct com_softc *sc =
1259	    device_lookup_private(&com_cd, COMUNIT(dev));
1260	struct tty *tp = sc->sc_tty;
1261
1262	if (COM_ISALIVE(sc) == 0)
1263		return (POLLHUP);
1264
1265	return ((*tp->t_linesw->l_poll)(tp, events, l));
1266}
1267
1268struct tty *
1269comtty(dev_t dev)
1270{
1271	struct com_softc *sc =
1272	    device_lookup_private(&com_cd, COMUNIT(dev));
1273	struct tty *tp = sc->sc_tty;
1274
1275	return (tp);
1276}
1277
1278int
1279comioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1280{
1281	struct com_softc *sc;
1282	struct tty *tp;
1283	int error;
1284
1285	sc = device_lookup_private(&com_cd, COMUNIT(dev));
1286	if (sc == NULL)
1287		return ENXIO;
1288	if (COM_ISALIVE(sc) == 0)
1289		return (EIO);
1290
1291	tp = sc->sc_tty;
1292
1293	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1294	if (error != EPASSTHROUGH)
1295		return (error);
1296
1297	error = ttioctl(tp, cmd, data, flag, l);
1298	if (error != EPASSTHROUGH)
1299		return (error);
1300
1301	error = 0;
1302	switch (cmd) {
1303	case TIOCSFLAGS:
1304		error = kauth_authorize_device_tty(l->l_cred,
1305		    KAUTH_DEVICE_TTY_PRIVSET, tp);
1306		break;
1307	default:
1308		/* nothing */
1309		break;
1310	}
1311	if (error) {
1312		return error;
1313	}
1314
1315	mutex_spin_enter(&sc->sc_lock);
1316
1317	switch (cmd) {
1318	case TIOCSBRK:
1319		com_break(sc, 1);
1320		break;
1321
1322	case TIOCCBRK:
1323		com_break(sc, 0);
1324		break;
1325
1326	case TIOCSDTR:
1327		com_modem(sc, 1);
1328		break;
1329
1330	case TIOCCDTR:
1331		com_modem(sc, 0);
1332		break;
1333
1334	case TIOCGFLAGS:
1335		*(int *)data = sc->sc_swflags;
1336		break;
1337
1338	case TIOCSFLAGS:
1339		sc->sc_swflags = *(int *)data;
1340		break;
1341
1342	case TIOCMSET:
1343	case TIOCMBIS:
1344	case TIOCMBIC:
1345		tiocm_to_com(sc, cmd, *(int *)data);
1346		break;
1347
1348	case TIOCMGET:
1349		*(int *)data = com_to_tiocm(sc);
1350		break;
1351
1352	case PPS_IOC_CREATE:
1353	case PPS_IOC_DESTROY:
1354	case PPS_IOC_GETPARAMS:
1355	case PPS_IOC_SETPARAMS:
1356	case PPS_IOC_GETCAP:
1357	case PPS_IOC_FETCH:
1358#ifdef PPS_SYNC
1359	case PPS_IOC_KCBIND:
1360#endif
1361		mutex_spin_enter(&timecounter_lock);
1362		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
1363		mutex_spin_exit(&timecounter_lock);
1364		break;
1365
1366	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
1367		mutex_spin_enter(&timecounter_lock);
1368#ifndef PPS_TRAILING_EDGE
1369		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1370		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
1371#else
1372		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
1373		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
1374#endif
1375		mutex_spin_exit(&timecounter_lock);
1376		break;
1377
1378	default:
1379		error = EPASSTHROUGH;
1380		break;
1381	}
1382
1383	mutex_spin_exit(&sc->sc_lock);
1384
1385#ifdef COM_DEBUG
1386	if (com_debug)
1387		comstatus(sc, "comioctl ");
1388#endif
1389
1390	return (error);
1391}
1392
1393static inline void
1394com_schedrx(struct com_softc *sc)
1395{
1396
1397	sc->sc_rx_ready = 1;
1398
1399	/* Wake up the poller. */
1400	softint_schedule(sc->sc_si);
1401}
1402
1403void
1404com_break(struct com_softc *sc, int onoff)
1405{
1406
1407	if (onoff)
1408		SET(sc->sc_lcr, LCR_SBREAK);
1409	else
1410		CLR(sc->sc_lcr, LCR_SBREAK);
1411
1412	if (!sc->sc_heldchange) {
1413		if (sc->sc_tx_busy) {
1414			sc->sc_heldtbc = sc->sc_tbc;
1415			sc->sc_tbc = 0;
1416			sc->sc_heldchange = 1;
1417		} else
1418			com_loadchannelregs(sc);
1419	}
1420}
1421
1422void
1423com_modem(struct com_softc *sc, int onoff)
1424{
1425
1426	if (sc->sc_mcr_dtr == 0)
1427		return;
1428
1429	if (onoff)
1430		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1431	else
1432		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1433
1434	if (!sc->sc_heldchange) {
1435		if (sc->sc_tx_busy) {
1436			sc->sc_heldtbc = sc->sc_tbc;
1437			sc->sc_tbc = 0;
1438			sc->sc_heldchange = 1;
1439		} else
1440			com_loadchannelregs(sc);
1441	}
1442}
1443
1444void
1445tiocm_to_com(struct com_softc *sc, u_long how, int ttybits)
1446{
1447	u_char combits;
1448
1449	combits = 0;
1450	if (ISSET(ttybits, TIOCM_DTR))
1451		SET(combits, MCR_DTR);
1452	if (ISSET(ttybits, TIOCM_RTS))
1453		SET(combits, MCR_RTS);
1454
1455	switch (how) {
1456	case TIOCMBIC:
1457		CLR(sc->sc_mcr, combits);
1458		break;
1459
1460	case TIOCMBIS:
1461		SET(sc->sc_mcr, combits);
1462		break;
1463
1464	case TIOCMSET:
1465		CLR(sc->sc_mcr, MCR_DTR | MCR_RTS);
1466		SET(sc->sc_mcr, combits);
1467		break;
1468	}
1469
1470	if (!sc->sc_heldchange) {
1471		if (sc->sc_tx_busy) {
1472			sc->sc_heldtbc = sc->sc_tbc;
1473			sc->sc_tbc = 0;
1474			sc->sc_heldchange = 1;
1475		} else
1476			com_loadchannelregs(sc);
1477	}
1478}
1479
1480int
1481com_to_tiocm(struct com_softc *sc)
1482{
1483	u_char combits;
1484	int ttybits = 0;
1485
1486	combits = sc->sc_mcr;
1487	if (ISSET(combits, MCR_DTR))
1488		SET(ttybits, TIOCM_DTR);
1489	if (ISSET(combits, MCR_RTS))
1490		SET(ttybits, TIOCM_RTS);
1491
1492	combits = sc->sc_msr;
1493	if (sc->sc_type == COM_TYPE_INGENIC) {
1494		SET(ttybits, TIOCM_CD);
1495	} else {
1496		if (ISSET(combits, MSR_DCD))
1497			SET(ttybits, TIOCM_CD);
1498	}
1499	if (ISSET(combits, MSR_CTS))
1500		SET(ttybits, TIOCM_CTS);
1501	if (ISSET(combits, MSR_DSR))
1502		SET(ttybits, TIOCM_DSR);
1503	if (ISSET(combits, MSR_RI | MSR_TERI))
1504		SET(ttybits, TIOCM_RI);
1505
1506	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1507		SET(ttybits, TIOCM_LE);
1508
1509	return (ttybits);
1510}
1511
1512static u_char
1513cflag2lcr(tcflag_t cflag)
1514{
1515	u_char lcr = 0;
1516
1517	switch (ISSET(cflag, CSIZE)) {
1518	case CS5:
1519		SET(lcr, LCR_5BITS);
1520		break;
1521	case CS6:
1522		SET(lcr, LCR_6BITS);
1523		break;
1524	case CS7:
1525		SET(lcr, LCR_7BITS);
1526		break;
1527	case CS8:
1528		SET(lcr, LCR_8BITS);
1529		break;
1530	}
1531	if (ISSET(cflag, PARENB)) {
1532		SET(lcr, LCR_PENAB);
1533		if (!ISSET(cflag, PARODD))
1534			SET(lcr, LCR_PEVEN);
1535	}
1536	if (ISSET(cflag, CSTOPB))
1537		SET(lcr, LCR_STOPB);
1538
1539	return (lcr);
1540}
1541
1542int
1543comparam(struct tty *tp, struct termios *t)
1544{
1545	struct com_softc *sc =
1546	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1547	int ospeed;
1548	u_char lcr;
1549
1550	if (COM_ISALIVE(sc) == 0)
1551		return (EIO);
1552
1553	if (sc->sc_type == COM_TYPE_HAYESP) {
1554		int prescaler, speed;
1555
1556		/*
1557		 * Calculate UART clock prescaler.  It should be in
1558		 * range of 0 .. 3.
1559		 */
1560		for (prescaler = 0, speed = t->c_ospeed; prescaler < 4;
1561		    prescaler++, speed /= 2)
1562			if ((ospeed = comspeed(speed, sc->sc_frequency,
1563					       sc->sc_type)) > 0)
1564				break;
1565
1566		if (prescaler == 4)
1567			return (EINVAL);
1568		sc->sc_prescaler = prescaler;
1569	} else
1570		ospeed = comspeed(t->c_ospeed, sc->sc_frequency, sc->sc_type);
1571
1572	/* Check requested parameters. */
1573	if (ospeed < 0)
1574		return (EINVAL);
1575	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1576		return (EINVAL);
1577
1578	/*
1579	 * For the console, always force CLOCAL and !HUPCL, so that the port
1580	 * is always active.
1581	 */
1582	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1583	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
1584		SET(t->c_cflag, CLOCAL);
1585		CLR(t->c_cflag, HUPCL);
1586	}
1587
1588	/*
1589	 * If there were no changes, don't do anything.  This avoids dropping
1590	 * input and improves performance when all we did was frob things like
1591	 * VMIN and VTIME.
1592	 */
1593	if (tp->t_ospeed == t->c_ospeed &&
1594	    tp->t_cflag == t->c_cflag)
1595		return (0);
1596
1597	lcr = ISSET(sc->sc_lcr, LCR_SBREAK) | cflag2lcr(t->c_cflag);
1598
1599	mutex_spin_enter(&sc->sc_lock);
1600
1601	sc->sc_lcr = lcr;
1602
1603	/*
1604	 * If we're not in a mode that assumes a connection is present, then
1605	 * ignore carrier changes.
1606	 */
1607	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1608		sc->sc_msr_dcd = 0;
1609	else
1610		sc->sc_msr_dcd = MSR_DCD;
1611	/*
1612	 * Set the flow control pins depending on the current flow control
1613	 * mode.
1614	 */
1615	if (ISSET(t->c_cflag, CRTSCTS)) {
1616		sc->sc_mcr_dtr = MCR_DTR;
1617		sc->sc_mcr_rts = MCR_RTS;
1618		sc->sc_msr_cts = MSR_CTS;
1619		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1620			SET(sc->sc_mcr, MCR_AFE);
1621		} else {
1622			sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1623		}
1624	} else if (ISSET(t->c_cflag, MDMBUF)) {
1625		/*
1626		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1627		 * carrier detection.
1628		 */
1629		sc->sc_mcr_dtr = 0;
1630		sc->sc_mcr_rts = MCR_DTR;
1631		sc->sc_msr_cts = MSR_DCD;
1632		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1633			CLR(sc->sc_mcr, MCR_AFE);
1634		} else {
1635			sc->sc_efr = 0;
1636		}
1637	} else {
1638		/*
1639		 * If no flow control, then always set RTS.  This will make
1640		 * the other side happy if it mistakenly thinks we're doing
1641		 * RTS/CTS flow control.
1642		 */
1643		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1644		sc->sc_mcr_rts = 0;
1645		sc->sc_msr_cts = 0;
1646		if (ISSET(sc->sc_hwflags, COM_HW_AFE)) {
1647			CLR(sc->sc_mcr, MCR_AFE);
1648		} else {
1649			sc->sc_efr = 0;
1650		}
1651		if (ISSET(sc->sc_mcr, MCR_DTR))
1652			SET(sc->sc_mcr, MCR_RTS);
1653		else
1654			CLR(sc->sc_mcr, MCR_RTS);
1655	}
1656	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1657
1658	if (t->c_ospeed == 0 && tp->t_ospeed != 0)
1659		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1660	else if (t->c_ospeed != 0 && tp->t_ospeed == 0)
1661		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1662
1663	sc->sc_dlbl = ospeed;
1664	sc->sc_dlbh = ospeed >> 8;
1665
1666	/*
1667	 * Set the FIFO threshold based on the receive speed.
1668	 *
1669	 *  * If it's a low speed, it's probably a mouse or some other
1670	 *    interactive device, so set the threshold low.
1671	 *  * If it's a high speed, trim the trigger level down to prevent
1672	 *    overflows.
1673	 *  * Otherwise set it a bit higher.
1674	 */
1675	if (sc->sc_type == COM_TYPE_HAYESP) {
1676		sc->sc_fifo = FIFO_DMA_MODE | FIFO_ENABLE | FIFO_TRIGGER_8;
1677	} else if (sc->sc_type == COM_TYPE_TEGRA) {
1678		sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1679	} else if (ISSET(sc->sc_hwflags, COM_HW_FIFO)) {
1680		if (t->c_ospeed <= 1200)
1681			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
1682		else if (t->c_ospeed <= 38400)
1683			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
1684		else
1685			sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
1686	} else {
1687		sc->sc_fifo = 0;
1688	}
1689
1690	if (sc->sc_type == COM_TYPE_INGENIC)
1691		sc->sc_fifo |= FIFO_UART_ON;
1692
1693	/* And copy to tty. */
1694	tp->t_ispeed = t->c_ospeed;
1695	tp->t_ospeed = t->c_ospeed;
1696	tp->t_cflag = t->c_cflag;
1697
1698	if (!sc->sc_heldchange) {
1699		if (sc->sc_tx_busy) {
1700			sc->sc_heldtbc = sc->sc_tbc;
1701			sc->sc_tbc = 0;
1702			sc->sc_heldchange = 1;
1703		} else
1704			com_loadchannelregs(sc);
1705	}
1706
1707	if (!ISSET(t->c_cflag, CHWFLOW)) {
1708		/* Disable the high water mark. */
1709		sc->sc_r_hiwat = 0;
1710		sc->sc_r_lowat = 0;
1711		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1712			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1713			com_schedrx(sc);
1714		}
1715		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED)) {
1716			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED|RX_IBUF_BLOCKED);
1717			com_hwiflow(sc);
1718		}
1719	} else {
1720		sc->sc_r_hiwat = com_rbuf_hiwat;
1721		sc->sc_r_lowat = com_rbuf_lowat;
1722	}
1723
1724	mutex_spin_exit(&sc->sc_lock);
1725
1726	/*
1727	 * Update the tty layer's idea of the carrier bit, in case we changed
1728	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1729	 * explicit request.
1730	 */
1731	if (sc->sc_type == COM_TYPE_INGENIC) {
1732		/* no DCD here */
1733		(void) (*tp->t_linesw->l_modem)(tp, 1);
1734	} else
1735		(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1736
1737#ifdef COM_DEBUG
1738	if (com_debug)
1739		comstatus(sc, "comparam ");
1740#endif
1741
1742	if (!ISSET(t->c_cflag, CHWFLOW)) {
1743		if (sc->sc_tx_stopped) {
1744			sc->sc_tx_stopped = 0;
1745			comstart(tp);
1746		}
1747	}
1748
1749	return (0);
1750}
1751
1752void
1753com_iflush(struct com_softc *sc)
1754{
1755	struct com_regs	*regsp = &sc->sc_regs;
1756	uint8_t fifo;
1757#ifdef DIAGNOSTIC
1758	int reg;
1759#endif
1760	int timo;
1761
1762#ifdef DIAGNOSTIC
1763	reg = 0xffff;
1764#endif
1765	timo = 50000;
1766	/* flush any pending I/O */
1767	while (ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)
1768	    && --timo)
1769#ifdef DIAGNOSTIC
1770		reg =
1771#else
1772		    (void)
1773#endif
1774		    CSR_READ_1(regsp, COM_REG_RXDATA);
1775#ifdef DIAGNOSTIC
1776	if (!timo)
1777		aprint_error_dev(sc->sc_dev, "com_iflush timeout %02x\n", reg);
1778#endif
1779
1780	switch (sc->sc_type) {
1781	case COM_TYPE_16750:
1782	case COM_TYPE_DW_APB:
1783		/*
1784		 * Reset all Rx/Tx FIFO, preserve current FIFO length.
1785		 * This should prevent triggering busy interrupt while
1786		 * manipulating divisors.
1787		 */
1788		fifo = CSR_READ_1(regsp, COM_REG_FIFO) & (FIFO_TRIGGER_1 |
1789		    FIFO_TRIGGER_4 | FIFO_TRIGGER_8 | FIFO_TRIGGER_14);
1790		CSR_WRITE_1(regsp, COM_REG_FIFO,
1791		    fifo | FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST);
1792		delay(100);
1793		break;
1794	}
1795}
1796
1797void
1798com_loadchannelregs(struct com_softc *sc)
1799{
1800	struct com_regs *regsp = &sc->sc_regs;
1801
1802	/* XXXXX necessary? */
1803	com_iflush(sc);
1804
1805	if (sc->sc_type == COM_TYPE_PXA2x0)
1806		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
1807	else
1808		CSR_WRITE_1(regsp, COM_REG_IER, 0);
1809
1810	if (sc->sc_type == COM_TYPE_OMAP) {
1811		/* disable before changing settings */
1812		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
1813	}
1814
1815	if (ISSET(sc->sc_hwflags, COM_HW_FLOW)) {
1816		KASSERT(sc->sc_type != COM_TYPE_AU1x00);
1817		KASSERT(sc->sc_type != COM_TYPE_16550_NOERS);
1818		/* no EFR on alchemy */
1819		CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
1820		CSR_WRITE_1(regsp, COM_REG_EFR, sc->sc_efr);
1821	}
1822	if (sc->sc_type == COM_TYPE_AU1x00) {
1823		/* alchemy has single separate 16-bit clock divisor register */
1824		CSR_WRITE_2(regsp, COM_REG_DLBL, sc->sc_dlbl +
1825		    (sc->sc_dlbh << 8));
1826	} else {
1827		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
1828		CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
1829		CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
1830	}
1831	CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
1832	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active = sc->sc_mcr);
1833	CSR_WRITE_1(regsp, COM_REG_FIFO, sc->sc_fifo);
1834	if (sc->sc_type == COM_TYPE_HAYESP) {
1835		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD1,
1836		    HAYESP_SETPRESCALER);
1837		bus_space_write_1(regsp->cr_iot, sc->sc_hayespioh, HAYESP_CMD2,
1838		    sc->sc_prescaler);
1839	}
1840	if (sc->sc_type == COM_TYPE_OMAP) {
1841		/* setup the fifos.  the FCR value is not used as long
1842		   as SCR[6] and SCR[7] are 0, which they are at reset
1843		   and we never touch the SCR register */
1844		uint8_t rx_fifo_trig = 40;
1845		uint8_t tx_fifo_trig = 60;
1846		uint8_t rx_start = 8;
1847		uint8_t rx_halt = 60;
1848		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
1849		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
1850
1851		/* enable access to TCR & TLR */
1852		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr | MCR_TCR_TLR);
1853
1854		/* write tcr and tlr values */
1855		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
1856		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
1857
1858		/* disable access to TCR & TLR */
1859		CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr);
1860
1861		/* enable again, but mode is based on speed */
1862		if (sc->sc_tty->t_termios.c_ospeed > 230400) {
1863			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
1864		} else {
1865			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
1866		}
1867	}
1868
1869	CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1870}
1871
1872int
1873comhwiflow(struct tty *tp, int block)
1874{
1875	struct com_softc *sc =
1876	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1877
1878	if (COM_ISALIVE(sc) == 0)
1879		return (0);
1880
1881	if (sc->sc_mcr_rts == 0)
1882		return (0);
1883
1884	mutex_spin_enter(&sc->sc_lock);
1885
1886	if (block) {
1887		if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1888			SET(sc->sc_rx_flags, RX_TTY_BLOCKED);
1889			com_hwiflow(sc);
1890		}
1891	} else {
1892		if (ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED)) {
1893			CLR(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
1894			com_schedrx(sc);
1895		}
1896		if (ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
1897			CLR(sc->sc_rx_flags, RX_TTY_BLOCKED);
1898			com_hwiflow(sc);
1899		}
1900	}
1901
1902	mutex_spin_exit(&sc->sc_lock);
1903	return (1);
1904}
1905
1906/*
1907 * (un)block input via hw flowcontrol
1908 */
1909void
1910com_hwiflow(struct com_softc *sc)
1911{
1912	struct com_regs *regsp= &sc->sc_regs;
1913
1914	if (sc->sc_mcr_rts == 0)
1915		return;
1916
1917	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1918		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1919		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1920	} else {
1921		SET(sc->sc_mcr, sc->sc_mcr_rts);
1922		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1923	}
1924	CSR_WRITE_1(regsp, COM_REG_MCR, sc->sc_mcr_active);
1925}
1926
1927
1928void
1929comstart(struct tty *tp)
1930{
1931	struct com_softc *sc =
1932	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1933	struct com_regs *regsp = &sc->sc_regs;
1934
1935	if (COM_ISALIVE(sc) == 0)
1936		return;
1937
1938	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1939		return;
1940	if (sc->sc_tx_stopped)
1941		return;
1942	if (!ttypull(tp))
1943		return;
1944
1945	/* Grab the first contiguous region of buffer space. */
1946	{
1947		u_char *tba;
1948		int tbc;
1949
1950		tba = tp->t_outq.c_cf;
1951		tbc = ndqb(&tp->t_outq, 0);
1952
1953		mutex_spin_enter(&sc->sc_lock);
1954
1955		sc->sc_tba = tba;
1956		sc->sc_tbc = tbc;
1957	}
1958
1959	SET(tp->t_state, TS_BUSY);
1960	sc->sc_tx_busy = 1;
1961
1962	/* Enable transmit completion interrupts if necessary. */
1963	if (!ISSET(sc->sc_ier, IER_ETXRDY)) {
1964		SET(sc->sc_ier, IER_ETXRDY);
1965		CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
1966	}
1967
1968	/* Output the first chunk of the contiguous buffer. */
1969	if (!ISSET(sc->sc_hwflags, COM_HW_NO_TXPRELOAD)) {
1970		u_int n;
1971
1972		n = sc->sc_tbc;
1973		if (n > sc->sc_fifolen)
1974			n = sc->sc_fifolen;
1975		CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
1976		sc->sc_tbc -= n;
1977		sc->sc_tba += n;
1978	}
1979
1980	mutex_spin_exit(&sc->sc_lock);
1981}
1982
1983/*
1984 * Stop output on a line.
1985 */
1986void
1987comstop(struct tty *tp, int flag)
1988{
1989	struct com_softc *sc =
1990	    device_lookup_private(&com_cd, COMUNIT(tp->t_dev));
1991
1992	mutex_spin_enter(&sc->sc_lock);
1993	if (ISSET(tp->t_state, TS_BUSY)) {
1994		/* Stop transmitting at the next chunk. */
1995		sc->sc_tbc = 0;
1996		sc->sc_heldtbc = 0;
1997		if (!ISSET(tp->t_state, TS_TTSTOP))
1998			SET(tp->t_state, TS_FLUSH);
1999	}
2000	mutex_spin_exit(&sc->sc_lock);
2001}
2002
2003void
2004comdiag(void *arg)
2005{
2006	struct com_softc *sc = arg;
2007	int overflows, floods;
2008
2009	mutex_spin_enter(&sc->sc_lock);
2010	overflows = sc->sc_overflows;
2011	sc->sc_overflows = 0;
2012	floods = sc->sc_floods;
2013	sc->sc_floods = 0;
2014	sc->sc_errors = 0;
2015	mutex_spin_exit(&sc->sc_lock);
2016
2017	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
2018	    device_xname(sc->sc_dev),
2019	    overflows, overflows == 1 ? "" : "s",
2020	    floods, floods == 1 ? "" : "s");
2021}
2022
2023static inline void
2024com_rxsoft(struct com_softc *sc, struct tty *tp)
2025{
2026	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
2027	u_char *get, *end;
2028	u_int cc, scc;
2029	u_char lsr;
2030	int code;
2031
2032	end = sc->sc_ebuf;
2033	get = sc->sc_rbget;
2034	scc = cc = com_rbuf_size - sc->sc_rbavail;
2035
2036	if (cc == com_rbuf_size) {
2037		sc->sc_floods++;
2038		if (sc->sc_errors++ == 0)
2039			callout_reset(&sc->sc_diag_callout, 60 * hz,
2040			    comdiag, sc);
2041	}
2042
2043	/* If not yet open, drop the entire buffer content here */
2044	if (!ISSET(tp->t_state, TS_ISOPEN)) {
2045		get += cc << 1;
2046		if (get >= end)
2047			get -= com_rbuf_size << 1;
2048		cc = 0;
2049	}
2050	while (cc) {
2051		code = get[0];
2052		lsr = get[1];
2053		if (ISSET(lsr, LSR_OE | LSR_BI | LSR_FE | LSR_PE)) {
2054			if (ISSET(lsr, LSR_OE)) {
2055				sc->sc_overflows++;
2056				if (sc->sc_errors++ == 0)
2057					callout_reset(&sc->sc_diag_callout,
2058					    60 * hz, comdiag, sc);
2059			}
2060			if (ISSET(lsr, LSR_BI | LSR_FE))
2061				SET(code, TTY_FE);
2062			if (ISSET(lsr, LSR_PE))
2063				SET(code, TTY_PE);
2064		}
2065		if ((*rint)(code, tp) == -1) {
2066			/*
2067			 * The line discipline's buffer is out of space.
2068			 */
2069			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
2070				/*
2071				 * We're either not using flow control, or the
2072				 * line discipline didn't tell us to block for
2073				 * some reason.  Either way, we have no way to
2074				 * know when there's more space available, so
2075				 * just drop the rest of the data.
2076				 */
2077				get += cc << 1;
2078				if (get >= end)
2079					get -= com_rbuf_size << 1;
2080				cc = 0;
2081			} else {
2082				/*
2083				 * Don't schedule any more receive processing
2084				 * until the line discipline tells us there's
2085				 * space available (through comhwiflow()).
2086				 * Leave the rest of the data in the input
2087				 * buffer.
2088				 */
2089				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
2090			}
2091			break;
2092		}
2093		get += 2;
2094		if (get >= end)
2095			get = sc->sc_rbuf;
2096		cc--;
2097	}
2098
2099	if (cc != scc) {
2100		sc->sc_rbget = get;
2101		mutex_spin_enter(&sc->sc_lock);
2102
2103		cc = sc->sc_rbavail += scc - cc;
2104		/* Buffers should be ok again, release possible block. */
2105		if (cc >= sc->sc_r_lowat) {
2106			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2107				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2108				SET(sc->sc_ier, IER_ERXRDY);
2109				if (sc->sc_type == COM_TYPE_PXA2x0)
2110					SET(sc->sc_ier, IER_ERXTOUT);
2111				if (sc->sc_type == COM_TYPE_INGENIC ||
2112				    sc->sc_type == COM_TYPE_TEGRA)
2113					SET(sc->sc_ier, IER_ERXTOUT);
2114
2115				CSR_WRITE_1(&sc->sc_regs, COM_REG_IER,
2116				    sc->sc_ier);
2117			}
2118			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
2119				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2120				com_hwiflow(sc);
2121			}
2122		}
2123		mutex_spin_exit(&sc->sc_lock);
2124	}
2125}
2126
2127static inline void
2128com_txsoft(struct com_softc *sc, struct tty *tp)
2129{
2130
2131	CLR(tp->t_state, TS_BUSY);
2132	if (ISSET(tp->t_state, TS_FLUSH))
2133		CLR(tp->t_state, TS_FLUSH);
2134	else
2135		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
2136	(*tp->t_linesw->l_start)(tp);
2137}
2138
2139static inline void
2140com_stsoft(struct com_softc *sc, struct tty *tp)
2141{
2142	u_char msr, delta;
2143
2144	mutex_spin_enter(&sc->sc_lock);
2145	msr = sc->sc_msr;
2146	delta = sc->sc_msr_delta;
2147	sc->sc_msr_delta = 0;
2148	mutex_spin_exit(&sc->sc_lock);
2149
2150	if (ISSET(delta, sc->sc_msr_dcd)) {
2151		/*
2152		 * Inform the tty layer that carrier detect changed.
2153		 */
2154		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
2155	}
2156
2157	if (ISSET(delta, sc->sc_msr_cts)) {
2158		/* Block or unblock output according to flow control. */
2159		if (ISSET(msr, sc->sc_msr_cts)) {
2160			sc->sc_tx_stopped = 0;
2161			(*tp->t_linesw->l_start)(tp);
2162		} else {
2163			sc->sc_tx_stopped = 1;
2164		}
2165	}
2166
2167#ifdef COM_DEBUG
2168	if (com_debug)
2169		comstatus(sc, "com_stsoft");
2170#endif
2171}
2172
2173void
2174comsoft(void *arg)
2175{
2176	struct com_softc *sc = arg;
2177	struct tty *tp;
2178
2179	if (COM_ISALIVE(sc) == 0)
2180		return;
2181
2182	tp = sc->sc_tty;
2183
2184	if (sc->sc_rx_ready) {
2185		sc->sc_rx_ready = 0;
2186		com_rxsoft(sc, tp);
2187	}
2188
2189	if (sc->sc_st_check) {
2190		sc->sc_st_check = 0;
2191		com_stsoft(sc, tp);
2192	}
2193
2194	if (sc->sc_tx_done) {
2195		sc->sc_tx_done = 0;
2196		com_txsoft(sc, tp);
2197	}
2198}
2199
2200int
2201comintr(void *arg)
2202{
2203	struct com_softc *sc = arg;
2204	struct com_regs *regsp = &sc->sc_regs;
2205
2206	u_char *put, *end;
2207	u_int cc;
2208	u_char lsr, iir;
2209
2210	if (COM_ISALIVE(sc) == 0)
2211		return (0);
2212
2213	KASSERT(regsp != NULL);
2214
2215	mutex_spin_enter(&sc->sc_lock);
2216	iir = CSR_READ_1(regsp, COM_REG_IIR);
2217
2218	/* Handle ns16750-specific busy interrupt. */
2219	if (sc->sc_type == COM_TYPE_16750 &&
2220	    (iir & IIR_BUSY) == IIR_BUSY) {
2221		for (int timeout = 10000;
2222		    (CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0; timeout--)
2223			if (timeout <= 0) {
2224				aprint_error_dev(sc->sc_dev,
2225				    "timeout while waiting for BUSY interrupt "
2226				    "acknowledge\n");
2227				mutex_spin_exit(&sc->sc_lock);
2228				return (0);
2229			}
2230
2231		CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2232		iir = CSR_READ_1(regsp, COM_REG_IIR);
2233	}
2234
2235	/* DesignWare APB UART BUSY interrupt */
2236	if (sc->sc_type == COM_TYPE_DW_APB &&
2237	    (iir & IIR_BUSY) == IIR_BUSY) {
2238		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
2239			(void)CSR_READ_1(regsp, COM_REG_USR);
2240		} else if ((CSR_READ_1(regsp, COM_REG_USR) & 0x1) != 0) {
2241			CSR_WRITE_1(regsp, COM_REG_HALT, HALT_CHCFG_EN);
2242			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2243			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2244			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2245			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2246			CSR_WRITE_1(regsp, COM_REG_HALT,
2247			    HALT_CHCFG_EN | HALT_CHCFG_UD);
2248			for (int timeout = 10000000;
2249			    (CSR_READ_1(regsp, COM_REG_HALT) & HALT_CHCFG_UD) != 0;
2250			    timeout--) {
2251				if (timeout <= 0) {
2252					aprint_error_dev(sc->sc_dev,
2253					    "timeout while waiting for HALT "
2254					    "update acknowledge 0x%x 0x%x\n",
2255					    CSR_READ_1(regsp, COM_REG_HALT),
2256					    CSR_READ_1(regsp, COM_REG_USR));
2257					break;
2258				}
2259			}
2260			CSR_WRITE_1(regsp, COM_REG_HALT, 0);
2261			(void)CSR_READ_1(regsp, COM_REG_USR);
2262		} else {
2263			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr | LCR_DLAB);
2264			CSR_WRITE_1(regsp, COM_REG_DLBL, sc->sc_dlbl);
2265			CSR_WRITE_1(regsp, COM_REG_DLBH, sc->sc_dlbh);
2266			CSR_WRITE_1(regsp, COM_REG_LCR, sc->sc_lcr);
2267		}
2268	}
2269
2270	end = sc->sc_ebuf;
2271	put = sc->sc_rbput;
2272	cc = sc->sc_rbavail;
2273
2274	if (ISSET(iir, IIR_NOPEND)) {
2275		if (ISSET(sc->sc_hwflags, COM_HW_BROKEN_ETXRDY))
2276			goto do_tx;
2277		mutex_spin_exit(&sc->sc_lock);
2278		return (0);
2279	}
2280
2281again:	do {
2282		u_char	msr, delta;
2283
2284		lsr = CSR_READ_1(regsp, COM_REG_LSR);
2285		if (ISSET(lsr, LSR_BI)) {
2286			int cn_trapped = 0; /* see above: cn_trap() */
2287
2288			cn_check_magic(sc->sc_tty->t_dev,
2289				       CNC_BREAK, com_cnm_state);
2290			if (cn_trapped)
2291				continue;
2292#if defined(KGDB) && !defined(DDB)
2293			if (ISSET(sc->sc_hwflags, COM_HW_KGDB)) {
2294				kgdb_connect(1);
2295				continue;
2296			}
2297#endif
2298		}
2299
2300		if (sc->sc_type == COM_TYPE_BCMAUXUART && ISSET(iir, IIR_RXRDY))
2301			lsr |= LSR_RXRDY;
2302
2303		if (ISSET(lsr, LSR_RCV_MASK) &&
2304		    !ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
2305			while (cc > 0) {
2306				int cn_trapped = 0;
2307				put[0] = CSR_READ_1(regsp, COM_REG_RXDATA);
2308				put[1] = lsr;
2309				cn_check_magic(sc->sc_tty->t_dev,
2310					       put[0], com_cnm_state);
2311				if (cn_trapped)
2312					goto next;
2313				put += 2;
2314				if (put >= end)
2315					put = sc->sc_rbuf;
2316				cc--;
2317			next:
2318				lsr = CSR_READ_1(regsp, COM_REG_LSR);
2319				if (!ISSET(lsr, LSR_RCV_MASK))
2320					break;
2321			}
2322
2323			/*
2324			 * Current string of incoming characters ended because
2325			 * no more data was available or we ran out of space.
2326			 * Schedule a receive event if any data was received.
2327			 * If we're out of space, turn off receive interrupts.
2328			 */
2329			sc->sc_rbput = put;
2330			sc->sc_rbavail = cc;
2331			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
2332				sc->sc_rx_ready = 1;
2333
2334			/*
2335			 * See if we are in danger of overflowing a buffer. If
2336			 * so, use hardware flow control to ease the pressure.
2337			 */
2338			if (!ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED) &&
2339			    cc < sc->sc_r_hiwat) {
2340				SET(sc->sc_rx_flags, RX_IBUF_BLOCKED);
2341				com_hwiflow(sc);
2342			}
2343
2344			/*
2345			 * If we're out of space, disable receive interrupts
2346			 * until the queue has drained a bit.
2347			 */
2348			if (!cc) {
2349				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
2350				switch (sc->sc_type) {
2351				case COM_TYPE_PXA2x0:
2352					CLR(sc->sc_ier, IER_ERXRDY|IER_ERXTOUT);
2353					break;
2354				case COM_TYPE_INGENIC:
2355				case COM_TYPE_TEGRA:
2356					CLR(sc->sc_ier,
2357					    IER_ERXRDY | IER_ERXTOUT);
2358					break;
2359				default:
2360					CLR(sc->sc_ier, IER_ERXRDY);
2361					break;
2362				}
2363				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2364			}
2365		} else {
2366			if ((iir & (IIR_RXRDY|IIR_TXRDY)) == IIR_RXRDY) {
2367				(void) CSR_READ_1(regsp, COM_REG_RXDATA);
2368				continue;
2369			}
2370		}
2371
2372		msr = CSR_READ_1(regsp, COM_REG_MSR);
2373		delta = msr ^ sc->sc_msr;
2374		sc->sc_msr = msr;
2375		if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
2376		    (delta & MSR_DCD)) {
2377			mutex_spin_enter(&timecounter_lock);
2378			pps_capture(&sc->sc_pps_state);
2379			pps_event(&sc->sc_pps_state,
2380			    (msr & MSR_DCD) ?
2381			    PPS_CAPTUREASSERT :
2382			    PPS_CAPTURECLEAR);
2383			mutex_spin_exit(&timecounter_lock);
2384		}
2385
2386		/*
2387		 * Process normal status changes
2388		 */
2389		if (ISSET(delta, sc->sc_msr_mask)) {
2390			SET(sc->sc_msr_delta, delta);
2391
2392			/*
2393			 * Stop output immediately if we lose the output
2394			 * flow control signal or carrier detect.
2395			 */
2396			if (ISSET(~msr, sc->sc_msr_mask)) {
2397				sc->sc_tbc = 0;
2398				sc->sc_heldtbc = 0;
2399#ifdef COM_DEBUG
2400				if (com_debug)
2401					comstatus(sc, "comintr  ");
2402#endif
2403			}
2404
2405			sc->sc_st_check = 1;
2406		}
2407	} while (!ISSET((iir =
2408	    CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND) &&
2409	    /*
2410	     * Since some device (e.g., ST16C1550) doesn't clear IIR_TXRDY
2411	     * by IIR read, so we can't do this way: `process all interrupts,
2412	     * then do TX if possible'.
2413	     */
2414	    (iir & IIR_IMASK) != IIR_TXRDY);
2415
2416do_tx:
2417	/*
2418	 * Read LSR again, since there may be an interrupt between
2419	 * the last LSR read and IIR read above.
2420	 */
2421	lsr = CSR_READ_1(regsp, COM_REG_LSR);
2422
2423	/*
2424	 * See if data can be transmitted as well.
2425	 * Schedule tx done event if no data left
2426	 * and tty was marked busy.
2427	 */
2428	if (ISSET(lsr, LSR_TXRDY)) {
2429		/*
2430		 * If we've delayed a parameter change, do it now, and restart
2431		 * output.
2432		 */
2433		if (sc->sc_heldchange) {
2434			com_loadchannelregs(sc);
2435			sc->sc_heldchange = 0;
2436			sc->sc_tbc = sc->sc_heldtbc;
2437			sc->sc_heldtbc = 0;
2438		}
2439
2440		/* Output the next chunk of the contiguous buffer, if any. */
2441		if (sc->sc_tbc > 0) {
2442			u_int n;
2443
2444			n = sc->sc_tbc;
2445			if (n > sc->sc_fifolen)
2446				n = sc->sc_fifolen;
2447			CSR_WRITE_MULTI(regsp, COM_REG_TXDATA, sc->sc_tba, n);
2448			sc->sc_tbc -= n;
2449			sc->sc_tba += n;
2450		} else {
2451			/* Disable transmit completion interrupts if necessary. */
2452			if (ISSET(sc->sc_ier, IER_ETXRDY)) {
2453				CLR(sc->sc_ier, IER_ETXRDY);
2454				CSR_WRITE_1(regsp, COM_REG_IER, sc->sc_ier);
2455			}
2456			if (sc->sc_tx_busy) {
2457				sc->sc_tx_busy = 0;
2458				sc->sc_tx_done = 1;
2459			}
2460		}
2461	}
2462
2463	if (!ISSET((iir = CSR_READ_1(regsp, COM_REG_IIR)), IIR_NOPEND))
2464		goto again;
2465
2466	mutex_spin_exit(&sc->sc_lock);
2467
2468	/* Wake up the poller. */
2469	if ((sc->sc_rx_ready | sc->sc_st_check | sc->sc_tx_done) != 0)
2470		softint_schedule(sc->sc_si);
2471
2472#ifdef RND_COM
2473	rnd_add_uint32(&sc->rnd_source, iir | lsr);
2474#endif
2475
2476	return (1);
2477}
2478
2479/*
2480 * The following functions are polled getc and putc routines, shared
2481 * by the console and kgdb glue.
2482 *
2483 * The read-ahead code is so that you can detect pending in-band
2484 * cn_magic in polled mode while doing output rather than having to
2485 * wait until the kernel decides it needs input.
2486 */
2487
2488#define MAX_READAHEAD	20
2489static int com_readahead[MAX_READAHEAD];
2490static int com_readaheadcount = 0;
2491
2492int
2493com_common_getc(dev_t dev, struct com_regs *regsp)
2494{
2495	int s = splserial();
2496	u_char stat, c;
2497
2498	/* got a character from reading things earlier */
2499	if (com_readaheadcount > 0) {
2500		int i;
2501
2502		c = com_readahead[0];
2503		for (i = 1; i < com_readaheadcount; i++) {
2504			com_readahead[i-1] = com_readahead[i];
2505		}
2506		com_readaheadcount--;
2507		splx(s);
2508		return (c);
2509	}
2510
2511	/* don't block until a character becomes available */
2512	if (!ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2513		splx(s);
2514		return -1;
2515	}
2516
2517	c = CSR_READ_1(regsp, COM_REG_RXDATA);
2518	stat = CSR_READ_1(regsp, COM_REG_IIR);
2519	{
2520		int cn_trapped = 0;	/* required by cn_trap, see above */
2521		if (!db_active)
2522			cn_check_magic(dev, c, com_cnm_state);
2523	}
2524	splx(s);
2525	return (c);
2526}
2527
2528static void
2529com_common_putc(dev_t dev, struct com_regs *regsp, int c, int with_readahead)
2530{
2531	int s = splserial();
2532	int cin, stat, timo;
2533
2534	if (with_readahead && com_readaheadcount < MAX_READAHEAD
2535	     && ISSET(stat = CSR_READ_1(regsp, COM_REG_LSR), LSR_RXRDY)) {
2536		int cn_trapped = 0;
2537		cin = CSR_READ_1(regsp, COM_REG_RXDATA);
2538		stat = CSR_READ_1(regsp, COM_REG_IIR);
2539		cn_check_magic(dev, cin, com_cnm_state);
2540		com_readahead[com_readaheadcount++] = cin;
2541	}
2542
2543	/* wait for any pending transmission to finish */
2544	timo = 150000;
2545	while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR), LSR_TXRDY) && --timo)
2546		continue;
2547
2548	CSR_WRITE_1(regsp, COM_REG_TXDATA, c);
2549	COM_BARRIER(regsp, BR | BW);
2550
2551	splx(s);
2552}
2553
2554/*
2555 * Initialize UART for use as console or KGDB line.
2556 */
2557int
2558cominit(struct com_regs *regsp, int rate, int frequency, int type,
2559    tcflag_t cflag)
2560{
2561
2562	if (bus_space_map(regsp->cr_iot, regsp->cr_iobase, regsp->cr_nports, 0,
2563		&regsp->cr_ioh))
2564		return (ENOMEM); /* ??? */
2565
2566	if (type == COM_TYPE_OMAP) {
2567		/* disable before changing settings */
2568		CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_DISABLE);
2569	}
2570
2571	rate = comspeed(rate, frequency, type);
2572	if (rate != -1) {
2573		if (type == COM_TYPE_AU1x00) {
2574			/* no EFR on alchemy */
2575			CSR_WRITE_2(regsp, COM_REG_DLBL, rate);
2576		} else {
2577			if ((type != COM_TYPE_16550_NOERS) &&
2578			    (type != COM_TYPE_INGENIC)) {
2579				CSR_WRITE_1(regsp, COM_REG_LCR, LCR_EERS);
2580				CSR_WRITE_1(regsp, COM_REG_EFR, 0);
2581			}
2582			CSR_WRITE_1(regsp, COM_REG_LCR, LCR_DLAB);
2583			CSR_WRITE_1(regsp, COM_REG_DLBL, rate & 0xff);
2584			CSR_WRITE_1(regsp, COM_REG_DLBH, rate >> 8);
2585		}
2586	}
2587	CSR_WRITE_1(regsp, COM_REG_LCR, cflag2lcr(cflag));
2588	CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2589
2590	if (type == COM_TYPE_INGENIC) {
2591		CSR_WRITE_1(regsp, COM_REG_FIFO,
2592		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2593		    FIFO_TRIGGER_1 | FIFO_UART_ON);
2594	} else {
2595		CSR_WRITE_1(regsp, COM_REG_FIFO,
2596		    FIFO_ENABLE | FIFO_RCV_RST | FIFO_XMT_RST |
2597		    FIFO_TRIGGER_1);
2598	}
2599
2600	if (type == COM_TYPE_OMAP) {
2601		/* setup the fifos.  the FCR value is not used as long
2602		   as SCR[6] and SCR[7] are 0, which they are at reset
2603		   and we never touch the SCR register */
2604		uint8_t rx_fifo_trig = 40;
2605		uint8_t tx_fifo_trig = 60;
2606		uint8_t rx_start = 8;
2607		uint8_t rx_halt = 60;
2608		uint8_t tlr_value = ((rx_fifo_trig>>2) << 4) | (tx_fifo_trig>>2);
2609		uint8_t tcr_value = ((rx_start>>2) << 4) | (rx_halt>>2);
2610
2611		/* enable access to TCR & TLR */
2612		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS | MCR_TCR_TLR);
2613
2614		/* write tcr and tlr values */
2615		CSR_WRITE_1(regsp, COM_REG_TLR, tlr_value);
2616		CSR_WRITE_1(regsp, COM_REG_TCR, tcr_value);
2617
2618		/* disable access to TCR & TLR */
2619		CSR_WRITE_1(regsp, COM_REG_MCR, MCR_DTR | MCR_RTS);
2620
2621		/* enable again, but mode is based on speed */
2622		if (rate > 230400) {
2623			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_13X);
2624		} else {
2625			CSR_WRITE_1(regsp, COM_REG_MDR1, MDR1_MODE_UART_16X);
2626		}
2627	}
2628
2629	if (type == COM_TYPE_PXA2x0)
2630		CSR_WRITE_1(regsp, COM_REG_IER, IER_EUART);
2631	else
2632		CSR_WRITE_1(regsp, COM_REG_IER, 0);
2633
2634	return (0);
2635}
2636
2637int
2638comcnattach1(struct com_regs *regsp, int rate, int frequency, int type,
2639    tcflag_t cflag)
2640{
2641	int res;
2642
2643	comcons_info.regs = *regsp;
2644
2645	res = cominit(&comcons_info.regs, rate, frequency, type, cflag);
2646	if (res)
2647		return (res);
2648
2649	cn_tab = &comcons;
2650	cn_init_magic(&com_cnm_state);
2651	cn_set_magic("\047\001"); /* default magic is BREAK */
2652
2653	comcons_info.frequency = frequency;
2654	comcons_info.type = type;
2655	comcons_info.rate = rate;
2656	comcons_info.cflag = cflag;
2657
2658	return (0);
2659}
2660
2661int
2662comcnattach(bus_space_tag_t iot, bus_addr_t iobase, int rate, int frequency,
2663    int type, tcflag_t cflag)
2664{
2665	struct com_regs	regs;
2666
2667	/*XXX*/
2668	bus_space_handle_t dummy_bsh;
2669	memset(&dummy_bsh, 0, sizeof(dummy_bsh));
2670
2671	/*
2672	 * dummy_bsh required because com_init_regs() wants it.  A
2673	 * real bus_space_handle will be filled in by cominit() later.
2674	 * XXXJRT Detangle this mess eventually, plz.
2675	 */
2676	com_init_regs(&regs, iot, dummy_bsh/*XXX*/, iobase);
2677
2678	return comcnattach1(&regs, rate, frequency, type, cflag);
2679}
2680
2681static int
2682comcnreattach(void)
2683{
2684	return comcnattach1(&comcons_info.regs, comcons_info.rate,
2685	    comcons_info.frequency, comcons_info.type, comcons_info.cflag);
2686}
2687
2688int
2689comcngetc(dev_t dev)
2690{
2691
2692	return (com_common_getc(dev, &comcons_info.regs));
2693}
2694
2695/*
2696 * Console kernel output character routine.
2697 */
2698void
2699comcnputc(dev_t dev, int c)
2700{
2701
2702	com_common_putc(dev, &comcons_info.regs, c, cold);
2703}
2704
2705void
2706comcnpollc(dev_t dev, int on)
2707{
2708
2709	com_readaheadcount = 0;
2710}
2711
2712#ifdef KGDB
2713int
2714com_kgdb_attach1(struct com_regs *regsp, int rate, int frequency, int type,
2715    tcflag_t cflag)
2716{
2717	int res;
2718
2719	if (bus_space_is_equal(regsp->cr_iot, comcons_info.regs.cr_iot) &&
2720	    regsp->cr_iobase == comcons_info.regs.cr_iobase) {
2721#if !defined(DDB)
2722		return (EBUSY); /* cannot share with console */
2723#else
2724		comkgdbregs = *regsp;
2725		comkgdbregs.cr_ioh = comcons_info.regs.cr_ioh;
2726#endif
2727	} else {
2728		comkgdbregs = *regsp;
2729		res = cominit(&comkgdbregs, rate, frequency, type, cflag);
2730		if (res)
2731			return (res);
2732
2733		/*
2734		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2735		 * expects this to be initialized
2736		 */
2737		cn_init_magic(&com_cnm_state);
2738		cn_set_magic("\047\001");
2739	}
2740
2741	kgdb_attach(com_kgdb_getc, com_kgdb_putc, NULL);
2742	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2743
2744	return (0);
2745}
2746
2747int
2748com_kgdb_attach(bus_space_tag_t iot, bus_addr_t iobase, int rate,
2749    int frequency, int type, tcflag_t cflag)
2750{
2751	struct com_regs regs;
2752
2753	com_init_regs(&regs, iot, (bus_space_handle_t)0/*XXX*/, iobase);
2754
2755	return com_kgdb_attach1(&regs, rate, frequency, type, cflag);
2756}
2757
2758/* ARGSUSED */
2759int
2760com_kgdb_getc(void *arg)
2761{
2762
2763	return (com_common_getc(NODEV, &comkgdbregs));
2764}
2765
2766/* ARGSUSED */
2767void
2768com_kgdb_putc(void *arg, int c)
2769{
2770
2771	com_common_putc(NODEV, &comkgdbregs, c, 0);
2772}
2773#endif /* KGDB */
2774
2775/*
2776 * helper function to identify the com ports used by
2777 * console or KGDB (and not yet autoconf attached)
2778 */
2779int
2780com_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2781{
2782	bus_space_handle_t help;
2783
2784	if (!comconsattached &&
2785	    bus_space_is_equal(iot, comcons_info.regs.cr_iot) &&
2786	    iobase == comcons_info.regs.cr_iobase)
2787		help = comcons_info.regs.cr_ioh;
2788#ifdef KGDB
2789	else if (!com_kgdb_attached &&
2790	    bus_space_is_equal(iot, comkgdbregs.cr_iot) &&
2791	    iobase == comkgdbregs.cr_iobase)
2792		help = comkgdbregs.cr_ioh;
2793#endif
2794	else
2795		return (0);
2796
2797	if (ioh)
2798		*ioh = help;
2799	return (1);
2800}
2801
2802/*
2803 * this routine exists to serve as a shutdown hook for systems that
2804 * have firmware which doesn't interact properly with a com device in
2805 * FIFO mode.
2806 */
2807bool
2808com_cleanup(device_t self, int how)
2809{
2810	struct com_softc *sc = device_private(self);
2811
2812	if (ISSET(sc->sc_hwflags, COM_HW_FIFO))
2813		CSR_WRITE_1(&sc->sc_regs, COM_REG_FIFO, 0);
2814
2815	return true;
2816}
2817
2818bool
2819com_suspend(device_t self, const pmf_qual_t *qual)
2820{
2821	struct com_softc *sc = device_private(self);
2822
2823	CSR_WRITE_1(&sc->sc_regs, COM_REG_IER, 0);
2824	(void)CSR_READ_1(&sc->sc_regs, COM_REG_IIR);
2825
2826	return true;
2827}
2828
2829bool
2830com_resume(device_t self, const pmf_qual_t *qual)
2831{
2832	struct com_softc *sc = device_private(self);
2833
2834	mutex_spin_enter(&sc->sc_lock);
2835	com_loadchannelregs(sc);
2836	mutex_spin_exit(&sc->sc_lock);
2837
2838	return true;
2839}
2840