xref: /netbsd-src/sys/arch/arm/imx/imxuart.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /* $NetBSD: imxuart.c,v 1.27 2021/03/08 06:23:31 mlelstv Exp $ */
2 
3 /*
4  * Copyright (c) 2009, 2010  Genetec Corporation.  All rights reserved.
5  * Written by Hiroyuki Bessho for Genetec Corporation.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY GENETEC CORPORATION ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GENETEC CORPORATION
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  *
28  */
29 
30 /*
31  * derived from sys/dev/ic/com.c
32  */
33 
34 /*-
35  * Copyright (c) 1998, 1999, 2004, 2008 The NetBSD Foundation, Inc.
36  * All rights reserved.
37  *
38  * This code is derived from software contributed to The NetBSD Foundation
39  * by Charles M. Hannum.
40  *
41  * Redistribution and use in source and binary forms, with or without
42  * modification, are permitted provided that the following conditions
43  * are met:
44  * 1. Redistributions of source code must retain the above copyright
45  *    notice, this list of conditions and the following disclaimer.
46  * 2. Redistributions in binary form must reproduce the above copyright
47  *    notice, this list of conditions and the following disclaimer in the
48  *    documentation and/or other materials provided with the distribution.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
51  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
52  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
53  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
54  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
55  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
56  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
57  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
58  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
59  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
60  * POSSIBILITY OF SUCH DAMAGE.
61  */
62 
63 /*
64  * Copyright (c) 1991 The Regents of the University of California.
65  * All rights reserved.
66  *
67  * Redistribution and use in source and binary forms, with or without
68  * modification, are permitted provided that the following conditions
69  * are met:
70  * 1. Redistributions of source code must retain the above copyright
71  *    notice, this list of conditions and the following disclaimer.
72  * 2. Redistributions in binary form must reproduce the above copyright
73  *    notice, this list of conditions and the following disclaimer in the
74  *    documentation and/or other materials provided with the distribution.
75  * 3. Neither the name of the University nor the names of its contributors
76  *    may be used to endorse or promote products derived from this software
77  *    without specific prior written permission.
78  *
79  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
80  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
81  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
82  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
83  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
84  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
85  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
86  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
87  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
88  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
89  * SUCH DAMAGE.
90  *
91  *	@(#)com.c	7.5 (Berkeley) 5/16/91
92  */
93 
94 /*
95  * driver for UART in i.MX SoC.
96  */
97 
98 #include <sys/cdefs.h>
99 __KERNEL_RCSID(0, "$NetBSD: imxuart.c,v 1.27 2021/03/08 06:23:31 mlelstv Exp $");
100 
101 #include "opt_imxuart.h"
102 #include "opt_ddb.h"
103 #include "opt_ddbparam.h"
104 #include "opt_kgdb.h"
105 #include "opt_lockdebug.h"
106 #include "opt_multiprocessor.h"
107 #include "opt_ntp.h"
108 #include "opt_imxuart.h"
109 
110 #ifdef RND_COM
111 #include <sys/rndsource.h>
112 #endif
113 
114 #ifndef	IMXUART_TOLERANCE
115 #define	IMXUART_TOLERANCE	30	/* baud rate tolerance, in 0.1% units */
116 #endif
117 
118 #ifndef	IMXUART_FREQDIV
119 #define	IMXUART_FREQDIV		2	/* XXX */
120 #endif
121 
122 #ifndef	IMXUART_FREQ
123 #define	IMXUART_FREQ	(56900000)
124 #endif
125 
126 /*
127  * Override cnmagic(9) macro before including <sys/systm.h>.
128  * We need to know if cn_check_magic triggered debugger, so set a flag.
129  * Callers of cn_check_magic must declare int cn_trapped = 0;
130  * XXX: this is *ugly*!
131  */
132 #define	cn_trap()				\
133 	do {					\
134 		console_debugger();		\
135 		cn_trapped = 1;			\
136 	} while (/* CONSTCOND */ 0)
137 
138 #include <sys/param.h>
139 #include <sys/systm.h>
140 #include <sys/ioctl.h>
141 #include <sys/select.h>
142 #include <sys/poll.h>
143 #include <sys/tty.h>
144 #include <sys/proc.h>
145 #include <sys/conf.h>
146 #include <sys/file.h>
147 #include <sys/uio.h>
148 #include <sys/kernel.h>
149 #include <sys/syslog.h>
150 #include <sys/device.h>
151 #include <sys/kmem.h>
152 #include <sys/timepps.h>
153 #include <sys/vnode.h>
154 #include <sys/kauth.h>
155 #include <sys/intr.h>
156 
157 #include <sys/bus.h>
158 
159 #include <arm/imx/imxuartreg.h>
160 #include <arm/imx/imxuartvar.h>
161 #include <dev/cons.h>
162 
163 #ifndef	IMXUART_RING_SIZE
164 #define	IMXUART_RING_SIZE	2048
165 #endif
166 
167 int	imxuspeed(long, struct imxuart_baudrate_ratio *);
168 int	imxuparam(struct tty *, struct termios *);
169 void	imxustart(struct tty *);
170 int	imxuhwiflow(struct tty *, int);
171 
172 void	imxuart_shutdown(struct imxuart_softc *);
173 void	imxuart_loadchannelregs(struct imxuart_softc *);
174 void	imxuart_hwiflow(struct imxuart_softc *);
175 void	imxuart_break(struct imxuart_softc *, bool);
176 void	imxuart_modem(struct imxuart_softc *, int);
177 void	tiocm_to_imxu(struct imxuart_softc *, u_long, int);
178 int	imxuart_to_tiocm(struct imxuart_softc *);
179 void	imxuart_iflush(struct imxuart_softc *);
180 int	imxuintr(void *);
181 
182 int	imxuart_common_getc(dev_t, struct imxuart_regs *);
183 void	imxuart_common_putc(dev_t, struct imxuart_regs *, int);
184 
185 
186 int	imxuart_init(struct imxuart_regs *, int, tcflag_t, int);
187 
188 int	imxucngetc(dev_t);
189 void	imxucnputc(dev_t, int);
190 void	imxucnpollc(dev_t, int);
191 
192 static void imxuintr_read(struct imxuart_softc *);
193 static void imxuintr_send(struct imxuart_softc *);
194 
195 static void imxuart_enable_debugport(struct imxuart_softc *);
196 static void imxuart_disable_all_interrupts(struct imxuart_softc *);
197 static void imxuart_control_rxint(struct imxuart_softc *, bool);
198 static void imxuart_control_txint(struct imxuart_softc *, bool);
199 static u_int imxuart_txfifo_space(struct imxuart_softc *sc);
200 
201 static	uint32_t	cflag_to_ucr2(tcflag_t, uint32_t);
202 
203 #define	integrate	static inline
204 void 	imxusoft(void *);
205 integrate void imxuart_rxsoft(struct imxuart_softc *, struct tty *);
206 integrate void imxuart_txsoft(struct imxuart_softc *, struct tty *);
207 integrate void imxuart_stsoft(struct imxuart_softc *, struct tty *);
208 integrate void imxuart_schedrx(struct imxuart_softc *);
209 void	imxudiag(void *);
210 static void imxuart_load_speed(struct imxuart_softc *);
211 static void imxuart_load_params(struct imxuart_softc *);
212 integrate void imxuart_load_pendings(struct imxuart_softc *);
213 
214 
215 extern struct cfdriver imxuart_cd;
216 
217 dev_type_open(imxuopen);
218 dev_type_close(imxuclose);
219 dev_type_read(imxuread);
220 dev_type_write(imxuwrite);
221 dev_type_ioctl(imxuioctl);
222 dev_type_stop(imxustop);
223 dev_type_tty(imxutty);
224 dev_type_poll(imxupoll);
225 
226 const struct cdevsw imxcom_cdevsw = {
227 	.d_open = imxuopen,
228 	.d_close = imxuclose,
229 	.d_read = imxuread,
230 	.d_write = imxuwrite,
231 	.d_ioctl = imxuioctl,
232 	.d_stop = imxustop,
233 	.d_tty = imxutty,
234 	.d_poll = imxupoll,
235 	.d_mmap = nommap,
236 	.d_kqfilter = ttykqfilter,
237 	.d_discard = nodiscard,
238 	.d_flag = D_TTY
239 };
240 
241 /*
242  * Make this an option variable one can patch.
243  * But be warned:  this must be a power of 2!
244  */
245 u_int imxuart_rbuf_size = IMXUART_RING_SIZE;
246 
247 /* Stop input when 3/4 of the ring is full; restart when only 1/4 is full. */
248 u_int imxuart_rbuf_hiwat = (IMXUART_RING_SIZE * 1) / 4;
249 u_int imxuart_rbuf_lowat = (IMXUART_RING_SIZE * 3) / 4;
250 
251 static struct imxuart_regs imxuconsregs;
252 static int imxuconsattached;
253 static int imxuconsrate;
254 static tcflag_t imxuconscflag;
255 static struct cnm_state imxuart_cnm_state;
256 
257 u_int imxuart_freq = IMXUART_FREQ;
258 u_int imxuart_freqdiv = IMXUART_FREQDIV;
259 
260 #ifdef KGDB
261 #include <sys/kgdb.h>
262 
263 static struct imxuart_regs imxu_kgdb_regs;
264 static int imxu_kgdb_attached;
265 
266 int	imxuart_kgdb_getc(void *);
267 void	imxuart_kgdb_putc(void *, int);
268 #endif /* KGDB */
269 
270 #define	IMXUART_DIALOUT_MASK	TTDIALOUT_MASK
271 
272 #define	IMXUART_UNIT(x)		TTUNIT(x)
273 #define	IMXUART_DIALOUT(x)	TTDIALOUT(x)
274 
275 #define	IMXUART_ISALIVE(sc)	((sc)->enabled != 0 && \
276 			 device_is_active((sc)->sc_dev))
277 
278 #define	BR	BUS_SPACE_BARRIER_READ
279 #define	BW	BUS_SPACE_BARRIER_WRITE
280 #define	IMXUART_BARRIER(r, f) \
281 	bus_space_barrier((r)->ur_iot, (r)->ur_ioh, 0, IMX_UART_SIZE, (f))
282 
283 
284 void
285 imxuart_attach_common(device_t parent, device_t self,
286     bus_space_tag_t iot, paddr_t iobase, size_t size, int intr, int flags)
287 {
288 	struct imxuart_softc *sc = device_private(self);
289 	struct imxuart_regs *regsp = &sc->sc_regs;
290 	bus_space_handle_t ioh;
291 
292 	aprint_naive("\n");
293 	aprint_normal("\n");
294 
295 	sc->sc_dev = self;
296 
297 	if (size <= 0)
298 		size = IMX_UART_SIZE;
299 
300 	sc->sc_intr = intr;
301 	regsp->ur_iot = iot;
302 	regsp->ur_iobase = iobase;
303 
304 	if (bus_space_map(iot, regsp->ur_iobase, size, 0, &ioh)) {
305 		return;
306 	}
307 	regsp->ur_ioh = ioh;
308 
309 	sc->sc_ih = intr_establish(sc->sc_intr, IPL_SERIAL, IST_LEVEL,
310 	    imxuintr, sc);
311 	if (sc->sc_ih == NULL) {
312 		aprint_error_dev(sc->sc_dev, "intr_establish failed\n");
313 		return;
314 	}
315 
316 	imxuart_attach_subr(sc);
317 }
318 
319 void
320 imxuart_attach_subr(struct imxuart_softc *sc)
321 {
322 	struct imxuart_regs *regsp = &sc->sc_regs;
323 	bus_space_tag_t iot = regsp->ur_iot;
324 	bus_space_handle_t ioh = regsp->ur_ioh;
325 	struct tty *tp;
326 
327 	callout_init(&sc->sc_diag_callout, 0);
328 	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_HIGH);
329 
330 	if (regsp->ur_iobase != imxuconsregs.ur_iobase)
331 		imxuart_init(&sc->sc_regs, TTYDEF_SPEED, TTYDEF_CFLAG, false);
332 
333 	bus_space_read_region_4(iot, ioh, IMX_UCR1, sc->sc_ucr, 4);
334 	sc->sc_ucr2_d = sc->sc_ucr2;
335 
336 	/* Disable interrupts before configuring the device. */
337 	imxuart_disable_all_interrupts(sc);
338 
339 	if (regsp->ur_iobase == imxuconsregs.ur_iobase) {
340 		imxuconsattached = 1;
341 
342 		/* Make sure the console is always "hardwired". */
343 #if 0
344 		delay(10000);			/* wait for output to finish */
345 #endif
346 		SET(sc->sc_hwflags, IMXUART_HW_CONSOLE);
347 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
348 	}
349 
350 
351 	tp = tty_alloc();
352 	tp->t_oproc = imxustart;
353 	tp->t_param = imxuparam;
354 	tp->t_hwiflow = imxuhwiflow;
355 
356 	sc->sc_tty = tp;
357 	sc->sc_rbuf = kmem_alloc(sizeof (*sc->sc_rbuf) * imxuart_rbuf_size,
358 	    KM_SLEEP);
359 	sc->sc_rbuf_size = imxuart_rbuf_size;
360 	sc->sc_rbuf_in = sc->sc_rbuf_out = 0;
361 	sc->sc_txfifo_len = 32;
362 	sc->sc_txfifo_thresh = 16;	/* when USR1.TRDY, fifo has space
363 					 * for this many characters */
364 
365 	tty_attach(tp);
366 
367 	if (ISSET(sc->sc_hwflags, IMXUART_HW_CONSOLE)) {
368 		int maj;
369 
370 		/* locate the major number */
371 		maj = cdevsw_lookup_major(&imxcom_cdevsw);
372 
373 		if (maj != NODEVMAJOR) {
374 			tp->t_dev = cn_tab->cn_dev = makedev(maj,
375 			    device_unit(sc->sc_dev));
376 
377 			aprint_normal_dev(sc->sc_dev, "console\n");
378 		}
379 	}
380 
381 #ifdef KGDB
382 	/*
383 	 * Allow kgdb to "take over" this port.  If this is
384 	 * not the console and is the kgdb device, it has
385 	 * exclusive use.  If it's the console _and_ the
386 	 * kgdb device, it doesn't.
387 	 */
388 	if (regsp->ur_iobase == imxu_kgdb_regs.ur_iobase) {
389 		if (!ISSET(sc->sc_hwflags, IMXUART_HW_CONSOLE)) {
390 			imxu_kgdb_attached = 1;
391 
392 			SET(sc->sc_hwflags, IMXUART_HW_KGDB);
393 		}
394 		aprint_normal_dev(sc->sc_dev, "kgdb\n");
395 	}
396 #endif
397 
398 	sc->sc_si = softint_establish(SOFTINT_SERIAL, imxusoft, sc);
399 
400 #ifdef RND_COM
401 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
402 			  RND_TYPE_TTY, RND_FLAG_COLLECT_TIME |
403 					RND_FLAG_ESTIMATE_TIME);
404 #endif
405 
406 	/* if there are no enable/disable functions, assume the device
407 	   is always enabled */
408 	if (!sc->enable)
409 		sc->enabled = 1;
410 
411 	imxuart_enable_debugport(sc);
412 
413 	SET(sc->sc_hwflags, IMXUART_HW_DEV_OK);
414 
415 	//shutdownhook_establish(imxuart_shutdownhook, sc);
416 
417 
418 #if 0
419 	{
420 		uint32_t reg;
421 		reg = bus_space_read_4(iot, ioh, IMX_UCR1);
422 		reg |= IMX_UCR1_TXDMAEN | IMX_UCR1_RXDMAEN;
423 		bus_space_write_4(iot, ioh, IMX_UCR1, reg);
424 	}
425 #endif
426 }
427 
428 /*
429  * baudrate = RefFreq / (16 * (UMBR + 1)/(UBIR + 1))
430  *
431  * (UBIR + 1) / (UBMR + 1) = (16 * BaurdRate) / RefFreq
432  */
433 
434 static long
435 gcd(long m, long n)
436 {
437 
438 	if (m < n)
439 		return gcd(n, m);
440 
441 	if (n <= 0)
442 		return m;
443 	return gcd(n, m % n);
444 }
445 
446 int
447 imxuspeed(long speed, struct imxuart_baudrate_ratio *ratio)
448 {
449 #define	divrnd(n, q)	(((n)*2/(q)+1)/2)	/* divide and round off */
450 	long b = 16 * speed;
451 	long f = imxuart_freq / imxuart_freqdiv;
452 	long d;
453 	int err = 0;
454 
455 	/* reduce b/f */
456 	while ((f > (1<<16) || b > (1<<16)) && (d = gcd(f, b)) > 1) {
457 		f /= d;
458 		b /= d;
459 	}
460 
461 
462 	while (f > (1<<16) || b > (1<<16)) {
463 		f /= 2;
464 		b /= 2;
465 	}
466 	if (f <= 0 || b <= 0)
467 		return -1;
468 
469 #ifdef	DIAGNOSTIC
470 	err = divrnd(((uint64_t)imxuart_freq) * 1000 / imxuart_freqdiv,
471 		     (uint64_t)speed * 16 * f / b) - 1000;
472 	if (err < 0)
473 		err = -err;
474 #endif
475 
476 	ratio->numerator = b-1;
477 	ratio->modulator = f-1;
478 
479 	if (err > IMXUART_TOLERANCE)
480 		return -1;
481 
482 	return 0;
483 #undef	divrnd
484 }
485 
486 #ifdef IMXUART_DEBUG
487 int	imxuart_debug = 0;
488 
489 void imxustatus(struct imxuart_softc *, const char *);
490 void
491 imxustatus(struct imxuart_softc *sc, const char *str)
492 {
493 	struct tty *tp = sc->sc_tty;
494 
495 	aprint_normal_dev(sc->sc_dev,
496 	    "%s %cclocal  %cdcd %cts_carr_on %cdtr %ctx_stopped\n",
497 	    str,
498 	    ISSET(tp->t_cflag, CLOCAL) ? '+' : '-',
499 	    ISSET(sc->sc_msr, MSR_DCD) ? '+' : '-',
500 	    ISSET(tp->t_state, TS_CARR_ON) ? '+' : '-',
501 	    ISSET(sc->sc_mcr, MCR_DTR) ? '+' : '-',
502 	    sc->sc_tx_stopped ? '+' : '-');
503 
504 	aprint_normal_dev(sc->sc_dev,
505 	    "%s %ccrtscts %ccts %cts_ttstop  %crts rx_flags=0x%x\n",
506 	    str,
507 	    ISSET(tp->t_cflag, CRTSCTS) ? '+' : '-',
508 	    ISSET(sc->sc_msr, MSR_CTS) ? '+' : '-',
509 	    ISSET(tp->t_state, TS_TTSTOP) ? '+' : '-',
510 	    ISSET(sc->sc_mcr, MCR_RTS) ? '+' : '-',
511 	    sc->sc_rx_flags);
512 }
513 #endif
514 
515 #if 0
516 int
517 imxuart_detach(device_t self, int flags)
518 {
519 	struct imxuart_softc *sc = device_private(self);
520 	int maj, mn;
521 
522         if (ISSET(sc->sc_hwflags, IMXUART_HW_CONSOLE))
523 		return EBUSY;
524 
525 	/* locate the major number */
526 	maj = cdevsw_lookup_major(&imxcom_cdevsw);
527 
528 	/* Nuke the vnodes for any open instances. */
529 	mn = device_unit(self);
530 	vdevgone(maj, mn, mn, VCHR);
531 
532 	mn |= IMXUART_DIALOUT_MASK;
533 	vdevgone(maj, mn, mn, VCHR);
534 
535 	if (sc->sc_rbuf == NULL) {
536 		/*
537 		 * Ring buffer allocation failed in the imxuart_attach_subr,
538 		 * only the tty is allocated, and nothing else.
539 		 */
540 		tty_free(sc->sc_tty);
541 		return 0;
542 	}
543 
544 	/* Free the receive buffer. */
545 	kmem_free(sc->sc_rbuf, sizeof(*sc->sc_rbuf) * sc->sc_rbuf_size);
546 
547 	/* Detach and free the tty. */
548 	tty_detach(sc->sc_tty);
549 	tty_free(sc->sc_tty);
550 
551 	/* Unhook the soft interrupt handler. */
552 	softint_disestablish(sc->sc_si);
553 
554 #ifdef RND_COM
555 	/* Unhook the entropy source. */
556 	rnd_detach_source(&sc->rnd_source);
557 #endif
558 	callout_destroy(&sc->sc_diag_callout);
559 
560 	/* Destroy the lock. */
561 	mutex_destroy(&sc->sc_lock);
562 
563 	return (0);
564 }
565 #endif
566 
567 #ifdef notyet
568 int
569 imxuart_activate(device_t self, enum devact act)
570 {
571 	struct imxuart_softc *sc = device_private(self);
572 	int rv = 0;
573 
574 	switch (act) {
575 	case DVACT_ACTIVATE:
576 		rv = EOPNOTSUPP;
577 		break;
578 
579 	case DVACT_DEACTIVATE:
580 		if (sc->sc_hwflags & (IMXUART_HW_CONSOLE|IMXUART_HW_KGDB)) {
581 			rv = EBUSY;
582 			break;
583 		}
584 
585 		if (sc->disable != NULL && sc->enabled != 0) {
586 			(*sc->disable)(sc);
587 			sc->enabled = 0;
588 		}
589 		break;
590 	}
591 
592 	return (rv);
593 }
594 #endif
595 
596 void
597 imxuart_shutdown(struct imxuart_softc *sc)
598 {
599 	struct tty *tp = sc->sc_tty;
600 
601 	mutex_spin_enter(&sc->sc_lock);
602 
603 	/* If we were asserting flow control, then deassert it. */
604 	SET(sc->sc_rx_flags, IMXUART_RX_IBUF_BLOCKED);
605 	imxuart_hwiflow(sc);
606 
607 	/* Clear any break condition set with TIOCSBRK. */
608 	imxuart_break(sc, false);
609 
610 	/*
611 	 * Hang up if necessary.  Wait a bit, so the other side has time to
612 	 * notice even if we immediately open the port again.
613 	 * Avoid tsleeping above splhigh().
614 	 */
615 	if (ISSET(tp->t_cflag, HUPCL)) {
616 		imxuart_modem(sc, 0);
617 		mutex_spin_exit(&sc->sc_lock);
618 		/* XXX will only timeout */
619 		(void) kpause(ttclos, false, hz, NULL);
620 		mutex_spin_enter(&sc->sc_lock);
621 	}
622 
623 	/* Turn off interrupts. */
624 	imxuart_disable_all_interrupts(sc);
625 	/* re-enable recv interrupt for console or kgdb port */
626 	imxuart_enable_debugport(sc);
627 
628 	mutex_spin_exit(&sc->sc_lock);
629 
630 #ifdef	notyet
631 	if (sc->disable) {
632 #ifdef DIAGNOSTIC
633 		if (!sc->enabled)
634 			panic("imxuart_shutdown: not enabled?");
635 #endif
636 		(*sc->disable)(sc);
637 		sc->enabled = 0;
638 	}
639 #endif
640 }
641 
642 int
643 imxuopen(dev_t dev, int flag, int mode, struct lwp *l)
644 {
645 	struct imxuart_softc *sc;
646 	struct tty *tp;
647 	int s;
648 	int error;
649 
650 	sc = device_lookup_private(&imxuart_cd, IMXUART_UNIT(dev));
651 	if (sc == NULL || !ISSET(sc->sc_hwflags, IMXUART_HW_DEV_OK) ||
652 		sc->sc_rbuf == NULL)
653 		return (ENXIO);
654 
655 	if (!device_is_active(sc->sc_dev))
656 		return (ENXIO);
657 
658 #ifdef KGDB
659 	/*
660 	 * If this is the kgdb port, no other use is permitted.
661 	 */
662 	if (ISSET(sc->sc_hwflags, IMXUART_HW_KGDB))
663 		return (EBUSY);
664 #endif
665 
666 	tp = sc->sc_tty;
667 
668 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
669 		return (EBUSY);
670 
671 	s = spltty();
672 
673 	/*
674 	 * Do the following iff this is a first open.
675 	 */
676 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
677 		struct termios t;
678 
679 		tp->t_dev = dev;
680 
681 
682 #ifdef notyet
683 		if (sc->enable) {
684 			if ((*sc->enable)(sc)) {
685 				splx(s);
686 				aprint_error_dev(sc->sc_dev,
687 				    "device enable failed\n");
688 				return (EIO);
689 			}
690 			sc->enabled = 1;
691 		}
692 #endif
693 
694 		mutex_spin_enter(&sc->sc_lock);
695 
696 		imxuart_disable_all_interrupts(sc);
697 
698 		/* Fetch the current modem control status, needed later. */
699 
700 #ifdef	IMXUART_PPS
701 		/* Clear PPS capture state on first open. */
702 		mutex_spin_enter(&timecounter_lock);
703 		memset(&sc->sc_pps_state, 0, sizeof(sc->sc_pps_state));
704 		sc->sc_pps_state.ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
705 		pps_init(&sc->sc_pps_state);
706 		mutex_spin_exit(&timecounter_lock);
707 #endif
708 
709 		mutex_spin_exit(&sc->sc_lock);
710 
711 		/*
712 		 * Initialize the termios status to the defaults.  Add in the
713 		 * sticky bits from TIOCSFLAGS.
714 		 */
715 		if (ISSET(sc->sc_hwflags, IMXUART_HW_CONSOLE)) {
716 			t.c_ospeed = imxuconsrate;
717 			t.c_cflag = imxuconscflag;
718 		} else {
719 			t.c_ospeed = TTYDEF_SPEED;
720 			t.c_cflag = TTYDEF_CFLAG;
721 		}
722 		t.c_ispeed = t.c_ospeed;
723 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
724 			SET(t.c_cflag, CLOCAL);
725 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
726 			SET(t.c_cflag, CRTSCTS);
727 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
728 			SET(t.c_cflag, MDMBUF);
729 		/* Make sure imxuparam() will do something. */
730 		tp->t_ospeed = 0;
731 		(void) imxuparam(tp, &t);
732 		tp->t_iflag = TTYDEF_IFLAG;
733 		tp->t_oflag = TTYDEF_OFLAG;
734 		tp->t_lflag = TTYDEF_LFLAG;
735 		ttychars(tp);
736 		ttsetwater(tp);
737 
738 		mutex_spin_enter(&sc->sc_lock);
739 
740 		/*
741 		 * Turn on DTR.  We must always do this, even if carrier is not
742 		 * present, because otherwise we'd have to use TIOCSDTR
743 		 * immediately after setting CLOCAL, which applications do not
744 		 * expect.  We always assert DTR while the device is open
745 		 * unless explicitly requested to deassert it.
746 		 */
747 		imxuart_modem(sc, 1);
748 
749 		/* Clear the input ring, and unblock. */
750 		sc->sc_rbuf_in = sc->sc_rbuf_out = 0;
751 		imxuart_iflush(sc);
752 		CLR(sc->sc_rx_flags, IMXUART_RX_ANY_BLOCK);
753 		imxuart_hwiflow(sc);
754 
755 		/* Turn on interrupts. */
756 		imxuart_control_rxint(sc, true);
757 
758 #ifdef IMXUART_DEBUG
759 		if (imxuart_debug)
760 			imxustatus(sc, "imxuopen  ");
761 #endif
762 
763 		mutex_spin_exit(&sc->sc_lock);
764 	}
765 
766 	splx(s);
767 
768 #if 0
769 	error = ttyopen(tp, IMXUART_DIALOUT(dev), ISSET(flag, O_NONBLOCK));
770 #else
771 	error = ttyopen(tp, 1, ISSET(flag, O_NONBLOCK));
772 #endif
773 	if (error)
774 		goto bad;
775 
776 	error = (*tp->t_linesw->l_open)(dev, tp);
777 	if (error)
778 		goto bad;
779 
780 	return (0);
781 
782 bad:
783 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
784 		/*
785 		 * We failed to open the device, and nobody else had it opened.
786 		 * Clean up the state as appropriate.
787 		 */
788 		imxuart_shutdown(sc);
789 	}
790 
791 	return (error);
792 }
793 
794 int
795 imxuclose(dev_t dev, int flag, int mode, struct lwp *l)
796 {
797 	struct imxuart_softc *sc =
798 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(dev));
799 	struct tty *tp = sc->sc_tty;
800 
801 	/* XXX This is for cons.c. */
802 	if (!ISSET(tp->t_state, TS_ISOPEN))
803 		return (0);
804 
805 	(*tp->t_linesw->l_close)(tp, flag);
806 	ttyclose(tp);
807 
808 	if (IMXUART_ISALIVE(sc) == 0)
809 		return (0);
810 
811 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
812 		/*
813 		 * Although we got a last close, the device may still be in
814 		 * use; e.g. if this was the dialout node, and there are still
815 		 * processes waiting for carrier on the non-dialout node.
816 		 */
817 		imxuart_shutdown(sc);
818 	}
819 
820 	return (0);
821 }
822 
823 int
824 imxuread(dev_t dev, struct uio *uio, int flag)
825 {
826 	struct imxuart_softc *sc =
827 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(dev));
828 	struct tty *tp = sc->sc_tty;
829 
830 	if (IMXUART_ISALIVE(sc) == 0)
831 		return (EIO);
832 
833 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
834 }
835 
836 int
837 imxuwrite(dev_t dev, struct uio *uio, int flag)
838 {
839 	struct imxuart_softc *sc =
840 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(dev));
841 	struct tty *tp = sc->sc_tty;
842 
843 	if (IMXUART_ISALIVE(sc) == 0)
844 		return (EIO);
845 
846 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
847 }
848 
849 int
850 imxupoll(dev_t dev, int events, struct lwp *l)
851 {
852 	struct imxuart_softc *sc =
853 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(dev));
854 	struct tty *tp = sc->sc_tty;
855 
856 	if (IMXUART_ISALIVE(sc) == 0)
857 		return (POLLHUP);
858 
859 	return ((*tp->t_linesw->l_poll)(tp, events, l));
860 }
861 
862 struct tty *
863 imxutty(dev_t dev)
864 {
865 	struct imxuart_softc *sc =
866 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(dev));
867 	struct tty *tp = sc->sc_tty;
868 
869 	return (tp);
870 }
871 
872 int
873 imxuioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
874 {
875 	struct imxuart_softc *sc;
876 	struct tty *tp;
877 	int error;
878 
879 	sc = device_lookup_private(&imxuart_cd, IMXUART_UNIT(dev));
880 	if (sc == NULL)
881 		return ENXIO;
882 	if (IMXUART_ISALIVE(sc) == 0)
883 		return (EIO);
884 
885 	tp = sc->sc_tty;
886 
887 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
888 	if (error != EPASSTHROUGH)
889 		return (error);
890 
891 	error = ttioctl(tp, cmd, data, flag, l);
892 	if (error != EPASSTHROUGH)
893 		return (error);
894 
895 	error = 0;
896 	switch (cmd) {
897 	case TIOCSFLAGS:
898 		error = kauth_authorize_device_tty(l->l_cred,
899 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
900 		break;
901 	default:
902 		/* nothing */
903 		break;
904 	}
905 	if (error) {
906 		return error;
907 	}
908 
909 	mutex_spin_enter(&sc->sc_lock);
910 
911 	switch (cmd) {
912 	case TIOCSBRK:
913 		imxuart_break(sc, true);
914 		break;
915 
916 	case TIOCCBRK:
917 		imxuart_break(sc, false);
918 		break;
919 
920 	case TIOCSDTR:
921 		imxuart_modem(sc, 1);
922 		break;
923 
924 	case TIOCCDTR:
925 		imxuart_modem(sc, 0);
926 		break;
927 
928 	case TIOCGFLAGS:
929 		*(int *)data = sc->sc_swflags;
930 		break;
931 
932 	case TIOCSFLAGS:
933 		sc->sc_swflags = *(int *)data;
934 		break;
935 
936 	case TIOCMSET:
937 	case TIOCMBIS:
938 	case TIOCMBIC:
939 		tiocm_to_imxu(sc, cmd, *(int *)data);
940 		break;
941 
942 	case TIOCMGET:
943 		*(int *)data = imxuart_to_tiocm(sc);
944 		break;
945 
946 #ifdef notyet
947 	case PPS_IOC_CREATE:
948 	case PPS_IOC_DESTROY:
949 	case PPS_IOC_GETPARAMS:
950 	case PPS_IOC_SETPARAMS:
951 	case PPS_IOC_GETCAP:
952 	case PPS_IOC_FETCH:
953 #ifdef PPS_SYNC
954 	case PPS_IOC_KCBIND:
955 #endif
956 		mutex_spin_enter(&timecounter_lock);
957 		error = pps_ioctl(cmd, data, &sc->sc_pps_state);
958 		mutex_spin_exit(&timecounter_lock);
959 		break;
960 
961 	case TIOCDCDTIMESTAMP:	/* XXX old, overloaded  API used by xntpd v3 */
962 		mutex_spin_enter(&timecounter_lock);
963 #ifndef PPS_TRAILING_EDGE
964 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
965 		    &sc->sc_pps_state.ppsinfo.assert_timestamp);
966 #else
967 		TIMESPEC_TO_TIMEVAL((struct timeval *)data,
968 		    &sc->sc_pps_state.ppsinfo.clear_timestamp);
969 #endif
970 		mutex_spin_exit(&timecounter_lock);
971 		break;
972 #endif
973 
974 	default:
975 		error = EPASSTHROUGH;
976 		break;
977 	}
978 
979 	mutex_spin_exit(&sc->sc_lock);
980 
981 #ifdef IMXUART_DEBUG
982 	if (imxuart_debug)
983 		imxustatus(sc, "imxuioctl ");
984 #endif
985 
986 	return (error);
987 }
988 
989 integrate void
990 imxuart_schedrx(struct imxuart_softc *sc)
991 {
992 	sc->sc_rx_ready = 1;
993 
994 	/* Wake up the poller. */
995 	softint_schedule(sc->sc_si);
996 }
997 
998 void
999 imxuart_break(struct imxuart_softc *sc, bool onoff)
1000 {
1001 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1002 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1003 
1004 	if (onoff)
1005 		SET(sc->sc_ucr1, IMX_UCR1_SNDBRK);
1006 	else
1007 		CLR(sc->sc_ucr1, IMX_UCR1_SNDBRK);
1008 
1009 	bus_space_write_4(iot, ioh, IMX_UCR1, sc->sc_ucr1);
1010 }
1011 
1012 void
1013 imxuart_modem(struct imxuart_softc *sc, int onoff)
1014 {
1015 #ifdef notyet
1016 	if (sc->sc_mcr_dtr == 0)
1017 		return;
1018 
1019 	if (onoff)
1020 		SET(sc->sc_mcr, sc->sc_mcr_dtr);
1021 	else
1022 		CLR(sc->sc_mcr, sc->sc_mcr_dtr);
1023 
1024 	if (!sc->sc_heldchange) {
1025 		if (sc->sc_tx_busy) {
1026 			sc->sc_heldtbc = sc->sc_tbc;
1027 			sc->sc_tbc = 0;
1028 			sc->sc_heldchange = 1;
1029 		} else
1030 			imxuart_loadchannelregs(sc);
1031 	}
1032 #endif
1033 }
1034 
1035 /*
1036  * RTS output is controlled by UCR2.CTS bit.
1037  * DTR output is controlled by UCR3.DSR bit.
1038  * (i.MX reference manual uses names in DCE mode)
1039  *
1040  * note: if UCR2.CTSC == 1 for automatic HW flow control, UCR2.CTS is ignored.
1041  */
1042 void
1043 tiocm_to_imxu(struct imxuart_softc *sc, u_long how, int ttybits)
1044 {
1045 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1046 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1047 
1048 	uint32_t ucr2 = sc->sc_ucr2_d;
1049 	uint32_t ucr3 = sc->sc_ucr3;
1050 
1051 	uint32_t ucr2_mask = 0;
1052 	uint32_t ucr3_mask = 0;
1053 
1054 
1055 	if (ISSET(ttybits, TIOCM_DTR))
1056 		ucr3_mask = IMX_UCR3_DSR;
1057 	if (ISSET(ttybits, TIOCM_RTS))
1058 		ucr2_mask = IMX_UCR2_CTS;
1059 
1060 	switch (how) {
1061 	case TIOCMBIC:
1062 		CLR(ucr2, ucr2_mask);
1063 		CLR(ucr3, ucr3_mask);
1064 		break;
1065 
1066 	case TIOCMBIS:
1067 		SET(ucr2, ucr2_mask);
1068 		SET(ucr3, ucr3_mask);
1069 		break;
1070 
1071 	case TIOCMSET:
1072 		CLR(ucr2, ucr2_mask);
1073 		CLR(ucr3, ucr3_mask);
1074 		SET(ucr2, ucr2_mask);
1075 		SET(ucr3, ucr3_mask);
1076 		break;
1077 	}
1078 
1079 	if (ucr3 != sc->sc_ucr3) {
1080 		bus_space_write_4(iot, ioh, IMX_UCR3, ucr3);
1081 		sc->sc_ucr3 = ucr3;
1082 	}
1083 
1084 	if (ucr2 == sc->sc_ucr2_d)
1085 		return;
1086 
1087 	sc->sc_ucr2_d = ucr2;
1088 	/* update CTS bit only */
1089 	ucr2 = (sc->sc_ucr2 & ~IMX_UCR2_CTS) |
1090 	    (ucr2 & IMX_UCR2_CTS);
1091 
1092 	bus_space_write_4(iot, ioh, IMX_UCR2, ucr2);
1093 	sc->sc_ucr2 = ucr2;
1094 }
1095 
1096 int
1097 imxuart_to_tiocm(struct imxuart_softc *sc)
1098 {
1099 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1100 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1101 	int ttybits = 0;
1102 	uint32_t usr[2];
1103 
1104 	if (ISSET(sc->sc_ucr3, IMX_UCR3_DSR))
1105 		SET(ttybits, TIOCM_DTR);
1106 	if (ISSET(sc->sc_ucr2, IMX_UCR2_CTS))
1107 		SET(ttybits, TIOCM_RTS);
1108 
1109 	bus_space_read_region_4(iot, ioh, IMX_USR1, usr, 2);
1110 
1111 	if (ISSET(usr[0], IMX_USR1_RTSS))
1112 		SET(ttybits, TIOCM_CTS);
1113 
1114 	if (ISSET(usr[1], IMX_USR2_DCDIN))
1115 		SET(ttybits, TIOCM_CD);
1116 
1117 #if 0
1118 	/* XXXbsh: I couldn't find the way to read ipp_uart_dsr_dte_i signal,
1119 	   although there are bits in UART registers to detect delta of DSR.
1120 	*/
1121 	if (ISSET(imxubits, MSR_DSR))
1122 		SET(ttybits, TIOCM_DSR);
1123 #endif
1124 
1125 	if (ISSET(usr[1], IMX_USR2_RIIN))
1126 		SET(ttybits, TIOCM_RI);
1127 
1128 
1129 #ifdef	notyet
1130 	if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
1131 		SET(ttybits, TIOCM_LE);
1132 #endif
1133 
1134 	return (ttybits);
1135 }
1136 
1137 static uint32_t
1138 cflag_to_ucr2(tcflag_t cflag, uint32_t oldval)
1139 {
1140 	uint32_t val = oldval;
1141 
1142 	CLR(val,IMX_UCR2_WS|IMX_UCR2_PREN|IMX_UCR2_PROE|IMX_UCR2_STPB);
1143 
1144 	switch (cflag & CSIZE) {
1145 	case CS5:
1146 	case CS6:
1147 		/* not suppreted. use 7-bits */
1148 	case CS7:
1149 		break;
1150 	case CS8:
1151 		SET(val, IMX_UCR2_WS);
1152 		break;
1153 	}
1154 
1155 
1156 	if (ISSET(cflag, PARENB)) {
1157 		SET(val, IMX_UCR2_PREN);
1158 
1159 		/* odd parity */
1160 		if (!ISSET(cflag, PARODD))
1161 			SET(val, IMX_UCR2_PROE);
1162 	}
1163 
1164 	if (ISSET(cflag, CSTOPB))
1165 		SET(val, IMX_UCR2_STPB);
1166 
1167 	val |= IMX_UCR2_TXEN| IMX_UCR2_RXEN|IMX_UCR2_SRST;
1168 
1169 	return val;
1170 }
1171 
1172 int
1173 imxuparam(struct tty *tp, struct termios *t)
1174 {
1175 	struct imxuart_softc *sc =
1176 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(tp->t_dev));
1177 	struct imxuart_baudrate_ratio ratio;
1178 	uint32_t ucr2;
1179 	bool change_speed = tp->t_ospeed != t->c_ospeed;
1180 
1181 	if (IMXUART_ISALIVE(sc) == 0)
1182 		return (EIO);
1183 
1184 	/* Check requested parameters. */
1185 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
1186 		return (EINVAL);
1187 
1188 	/*
1189 	 * For the console, always force CLOCAL and !HUPCL, so that the port
1190 	 * is always active.
1191 	 */
1192 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
1193 	    ISSET(sc->sc_hwflags, IMXUART_HW_CONSOLE)) {
1194 		SET(t->c_cflag, CLOCAL);
1195 		CLR(t->c_cflag, HUPCL);
1196 	}
1197 
1198 	/*
1199 	 * If there were no changes, don't do anything.  This avoids dropping
1200 	 * input and improves performance when all we did was frob things like
1201 	 * VMIN and VTIME.
1202 	 */
1203 	if ( !change_speed && tp->t_cflag == t->c_cflag)
1204 		return (0);
1205 
1206 	if (change_speed) {
1207 		/* calculate baudrate modulator value */
1208 		if (imxuspeed(t->c_ospeed, &ratio) < 0)
1209 			return (EINVAL);
1210 		sc->sc_ratio = ratio;
1211 	}
1212 
1213 	ucr2 = cflag_to_ucr2(t->c_cflag, sc->sc_ucr2_d);
1214 
1215 	mutex_spin_enter(&sc->sc_lock);
1216 
1217 #if 0	/* flow control stuff.  not yet */
1218 	/*
1219 	 * If we're not in a mode that assumes a connection is present, then
1220 	 * ignore carrier changes.
1221 	 */
1222 	if (ISSET(t->c_cflag, CLOCAL | MDMBUF))
1223 		sc->sc_msr_dcd = 0;
1224 	else
1225 		sc->sc_msr_dcd = MSR_DCD;
1226 	/*
1227 	 * Set the flow control pins depending on the current flow control
1228 	 * mode.
1229 	 */
1230 	if (ISSET(t->c_cflag, CRTSCTS)) {
1231 		sc->sc_mcr_dtr = MCR_DTR;
1232 		sc->sc_mcr_rts = MCR_RTS;
1233 		sc->sc_msr_cts = MSR_CTS;
1234 		sc->sc_efr = EFR_AUTORTS | EFR_AUTOCTS;
1235 	} else if (ISSET(t->c_cflag, MDMBUF)) {
1236 		/*
1237 		 * For DTR/DCD flow control, make sure we don't toggle DTR for
1238 		 * carrier detection.
1239 		 */
1240 		sc->sc_mcr_dtr = 0;
1241 		sc->sc_mcr_rts = MCR_DTR;
1242 		sc->sc_msr_cts = MSR_DCD;
1243 		sc->sc_efr = 0;
1244 	} else {
1245 		/*
1246 		 * If no flow control, then always set RTS.  This will make
1247 		 * the other side happy if it mistakenly thinks we're doing
1248 		 * RTS/CTS flow control.
1249 		 */
1250 		sc->sc_mcr_dtr = MCR_DTR | MCR_RTS;
1251 		sc->sc_mcr_rts = 0;
1252 		sc->sc_msr_cts = 0;
1253 		sc->sc_efr = 0;
1254 		if (ISSET(sc->sc_mcr, MCR_DTR))
1255 			SET(sc->sc_mcr, MCR_RTS);
1256 		else
1257 			CLR(sc->sc_mcr, MCR_RTS);
1258 	}
1259 	sc->sc_msr_mask = sc->sc_msr_cts | sc->sc_msr_dcd;
1260 #endif
1261 
1262 	/* And copy to tty. */
1263 	tp->t_ispeed = t->c_ospeed;
1264 	tp->t_ospeed = t->c_ospeed;
1265 	tp->t_cflag = t->c_cflag;
1266 
1267 	if (!change_speed && ucr2 == sc->sc_ucr2_d) {
1268 		/* noop */
1269 	}
1270 	else if (!sc->sc_pending && !sc->sc_tx_busy) {
1271 		if (ucr2 != sc->sc_ucr2_d) {
1272 			sc->sc_ucr2_d = ucr2;
1273 			imxuart_load_params(sc);
1274 		}
1275 		if (change_speed)
1276 			imxuart_load_speed(sc);
1277 	}
1278 	else {
1279 		if (!sc->sc_pending) {
1280 			sc->sc_heldtbc = sc->sc_tbc;
1281 			sc->sc_tbc = 0;
1282 		}
1283 		sc->sc_pending |=
1284 		    (ucr2 == sc->sc_ucr2_d ? 0 : IMXUART_PEND_PARAM) |
1285 		    (change_speed ? 0 : IMXUART_PEND_SPEED);
1286 		sc->sc_ucr2_d = ucr2;
1287 	}
1288 
1289 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1290 		/* Disable the high water mark. */
1291 		sc->sc_r_hiwat = 0;
1292 		sc->sc_r_lowat = 0;
1293 		if (ISSET(sc->sc_rx_flags, IMXUART_RX_TTY_OVERFLOWED)) {
1294 			CLR(sc->sc_rx_flags, IMXUART_RX_TTY_OVERFLOWED);
1295 			imxuart_schedrx(sc);
1296 		}
1297 		if (ISSET(sc->sc_rx_flags,
1298 			IMXUART_RX_TTY_BLOCKED|IMXUART_RX_IBUF_BLOCKED)) {
1299 			CLR(sc->sc_rx_flags,
1300 			    IMXUART_RX_TTY_BLOCKED|IMXUART_RX_IBUF_BLOCKED);
1301 			imxuart_hwiflow(sc);
1302 		}
1303 	} else {
1304 		sc->sc_r_hiwat = imxuart_rbuf_hiwat;
1305 		sc->sc_r_lowat = imxuart_rbuf_lowat;
1306 	}
1307 
1308 	mutex_spin_exit(&sc->sc_lock);
1309 
1310 #if 0
1311 	/*
1312 	 * Update the tty layer's idea of the carrier bit, in case we changed
1313 	 * CLOCAL or MDMBUF.  We don't hang up here; we only do that by
1314 	 * explicit request.
1315 	 */
1316 	(void) (*tp->t_linesw->l_modem)(tp, ISSET(sc->sc_msr, MSR_DCD));
1317 #else
1318 	/* XXX: always report that we have DCD */
1319 	(void) (*tp->t_linesw->l_modem)(tp, 1);
1320 #endif
1321 
1322 #ifdef IMXUART_DEBUG
1323 	if (imxuart_debug)
1324 		imxustatus(sc, "imxuparam ");
1325 #endif
1326 
1327 	if (!ISSET(t->c_cflag, CHWFLOW)) {
1328 		if (sc->sc_tx_stopped) {
1329 			sc->sc_tx_stopped = 0;
1330 			imxustart(tp);
1331 		}
1332 	}
1333 
1334 	return (0);
1335 }
1336 
1337 void
1338 imxuart_iflush(struct imxuart_softc *sc)
1339 {
1340 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1341 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1342 #ifdef DIAGNOSTIC
1343 	uint32_t reg = 0xffff;
1344 #endif
1345 	int timo;
1346 
1347 	timo = 50000;
1348 	/* flush any pending I/O */
1349 	while (ISSET(bus_space_read_4(iot, ioh, IMX_USR2), IMX_USR2_RDR)
1350 	    && --timo)
1351 #ifdef DIAGNOSTIC
1352 		reg =
1353 #else
1354 		    (void)
1355 #endif
1356 		    bus_space_read_4(iot, ioh, IMX_URXD);
1357 #ifdef DIAGNOSTIC
1358 	if (!timo)
1359 		aprint_error_dev(sc->sc_dev, "imxuart_iflush timeout %02x\n", reg);
1360 #endif
1361 }
1362 
1363 int
1364 imxuhwiflow(struct tty *tp, int block)
1365 {
1366 	struct imxuart_softc *sc =
1367 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(tp->t_dev));
1368 
1369 	if (IMXUART_ISALIVE(sc) == 0)
1370 		return (0);
1371 
1372 #ifdef notyet
1373 	if (sc->sc_mcr_rts == 0)
1374 		return (0);
1375 #endif
1376 
1377 	mutex_spin_enter(&sc->sc_lock);
1378 
1379 	if (block) {
1380 		if (!ISSET(sc->sc_rx_flags, IMXUART_RX_TTY_BLOCKED)) {
1381 			SET(sc->sc_rx_flags, IMXUART_RX_TTY_BLOCKED);
1382 			imxuart_hwiflow(sc);
1383 		}
1384 	} else {
1385 		if (ISSET(sc->sc_rx_flags, IMXUART_RX_TTY_OVERFLOWED)) {
1386 			CLR(sc->sc_rx_flags, IMXUART_RX_TTY_OVERFLOWED);
1387 			imxuart_schedrx(sc);
1388 		}
1389 		if (ISSET(sc->sc_rx_flags, IMXUART_RX_TTY_BLOCKED)) {
1390 			CLR(sc->sc_rx_flags, IMXUART_RX_TTY_BLOCKED);
1391 			imxuart_hwiflow(sc);
1392 		}
1393 	}
1394 
1395 	mutex_spin_exit(&sc->sc_lock);
1396 	return (1);
1397 }
1398 
1399 /*
1400  * (un)block input via hw flowcontrol
1401  */
1402 void
1403 imxuart_hwiflow(struct imxuart_softc *sc)
1404 {
1405 #ifdef notyet
1406 	struct imxuart_regs *regsp= &sc->sc_regs;
1407 
1408 	if (sc->sc_mcr_rts == 0)
1409 		return;
1410 
1411 	if (ISSET(sc->sc_rx_flags, RX_ANY_BLOCK)) {
1412 		CLR(sc->sc_mcr, sc->sc_mcr_rts);
1413 		CLR(sc->sc_mcr_active, sc->sc_mcr_rts);
1414 	} else {
1415 		SET(sc->sc_mcr, sc->sc_mcr_rts);
1416 		SET(sc->sc_mcr_active, sc->sc_mcr_rts);
1417 	}
1418 	UR_WRITE_1(regsp, IMXUART_REG_MCR, sc->sc_mcr_active);
1419 #endif
1420 }
1421 
1422 
1423 void
1424 imxustart(struct tty *tp)
1425 {
1426 	struct imxuart_softc *sc =
1427 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(tp->t_dev));
1428 	int s;
1429 	u_char *tba;
1430 	int tbc;
1431 	u_int n;
1432 	u_int space;
1433 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1434 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1435 
1436 	if (IMXUART_ISALIVE(sc) == 0)
1437 		return;
1438 
1439 	s = spltty();
1440 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
1441 		goto out;
1442 	if (sc->sc_tx_stopped)
1443 		goto out;
1444 	if (!ttypull(tp))
1445 		goto out;
1446 
1447 	/* Grab the first contiguous region of buffer space. */
1448 	tba = tp->t_outq.c_cf;
1449 	tbc = ndqb(&tp->t_outq, 0);
1450 
1451 	mutex_spin_enter(&sc->sc_lock);
1452 
1453 	sc->sc_tba = tba;
1454 	sc->sc_tbc = tbc;
1455 
1456 	SET(tp->t_state, TS_BUSY);
1457 	sc->sc_tx_busy = 1;
1458 
1459 	space = imxuart_txfifo_space(sc);
1460 	n = MIN(sc->sc_tbc, space);
1461 
1462 	if (n > 0) {
1463 		bus_space_write_multi_1(iot, ioh, IMX_UTXD, sc->sc_tba, n);
1464 		sc->sc_tbc -= n;
1465 		sc->sc_tba += n;
1466 	}
1467 
1468 	/* Enable transmit completion interrupts */
1469 	imxuart_control_txint(sc, true);
1470 
1471 	mutex_spin_exit(&sc->sc_lock);
1472 out:
1473 	splx(s);
1474 	return;
1475 }
1476 
1477 /*
1478  * Stop output on a line.
1479  */
1480 void
1481 imxustop(struct tty *tp, int flag)
1482 {
1483 	struct imxuart_softc *sc =
1484 	    device_lookup_private(&imxuart_cd, IMXUART_UNIT(tp->t_dev));
1485 
1486 	mutex_spin_enter(&sc->sc_lock);
1487 	if (ISSET(tp->t_state, TS_BUSY)) {
1488 		/* Stop transmitting at the next chunk. */
1489 		sc->sc_tbc = 0;
1490 		sc->sc_heldtbc = 0;
1491 		if (!ISSET(tp->t_state, TS_TTSTOP))
1492 			SET(tp->t_state, TS_FLUSH);
1493 	}
1494 	mutex_spin_exit(&sc->sc_lock);
1495 }
1496 
1497 void
1498 imxudiag(void *arg)
1499 {
1500 #ifdef notyet
1501 	struct imxuart_softc *sc = arg;
1502 	int overflows, floods;
1503 
1504 	mutex_spin_enter(&sc->sc_lock);
1505 	overflows = sc->sc_overflows;
1506 	sc->sc_overflows = 0;
1507 	floods = sc->sc_floods;
1508 	sc->sc_floods = 0;
1509 	sc->sc_errors = 0;
1510 	mutex_spin_exit(&sc->sc_lock);
1511 
1512 	log(LOG_WARNING, "%s: %d silo overflow%s, %d ibuf flood%s\n",
1513 	    device_xname(sc->sc_dev),
1514 	    overflows, overflows == 1 ? "" : "s",
1515 	    floods, floods == 1 ? "" : "s");
1516 #endif
1517 }
1518 
1519 integrate void
1520 imxuart_rxsoft(struct imxuart_softc *sc, struct tty *tp)
1521 {
1522 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
1523 	u_int cc, scc, outp;
1524 	uint16_t data;
1525 	u_int code;
1526 
1527 	scc = cc = IMXUART_RBUF_AVAIL(sc);
1528 
1529 #if 0
1530 	if (cc == imxuart_rbuf_size-1) {
1531 		sc->sc_floods++;
1532 		if (sc->sc_errors++ == 0)
1533 			callout_reset(&sc->sc_diag_callout, 60 * hz,
1534 			    imxudiag, sc);
1535 	}
1536 #endif
1537 
1538 	/* If not yet open, drop the entire buffer content here */
1539 	if (!ISSET(tp->t_state, TS_ISOPEN)) {
1540 		sc->sc_rbuf_out = sc->sc_rbuf_in;
1541 		cc = 0;
1542 	}
1543 
1544 	outp = sc->sc_rbuf_out;
1545 
1546 #define	ERRBITS (IMX_URXD_PRERR|IMX_URXD_BRK|IMX_URXD_FRMERR|IMX_URXD_OVRRUN)
1547 
1548 	while (cc) {
1549 	        data = sc->sc_rbuf[outp];
1550 		code = data & IMX_URXD_RX_DATA;
1551 		if (ISSET(data, ERRBITS)) {
1552 			if (sc->sc_errors.err == 0)
1553 				callout_reset(&sc->sc_diag_callout,
1554 				    60 * hz, imxudiag, sc);
1555 			if (ISSET(data, IMX_URXD_OVRRUN))
1556 				sc->sc_errors.ovrrun++;
1557 			if (ISSET(data, IMX_URXD_BRK)) {
1558 				sc->sc_errors.brk++;
1559 				SET(code, TTY_FE);
1560 			}
1561 			if (ISSET(data, IMX_URXD_FRMERR)) {
1562 				sc->sc_errors.frmerr++;
1563 				SET(code, TTY_FE);
1564 			}
1565 			if (ISSET(data, IMX_URXD_PRERR)) {
1566 				sc->sc_errors.prerr++;
1567 				SET(code, TTY_PE);
1568 			}
1569 		}
1570 		if ((*rint)(code, tp) == -1) {
1571 			/*
1572 			 * The line discipline's buffer is out of space.
1573 			 */
1574 			if (!ISSET(sc->sc_rx_flags, IMXUART_RX_TTY_BLOCKED)) {
1575 				/*
1576 				 * We're either not using flow control, or the
1577 				 * line discipline didn't tell us to block for
1578 				 * some reason.  Either way, we have no way to
1579 				 * know when there's more space available, so
1580 				 * just drop the rest of the data.
1581 				 */
1582 				sc->sc_rbuf_out = sc->sc_rbuf_in;
1583 				cc = 0;
1584 			} else {
1585 				/*
1586 				 * Don't schedule any more receive processing
1587 				 * until the line discipline tells us there's
1588 				 * space available (through imxuhwiflow()).
1589 				 * Leave the rest of the data in the input
1590 				 * buffer.
1591 				 */
1592 				SET(sc->sc_rx_flags, IMXUART_RX_TTY_OVERFLOWED);
1593 			}
1594 			break;
1595 		}
1596 		outp = IMXUART_RBUF_INC(sc, outp, 1);
1597 		cc--;
1598 	}
1599 
1600 	if (cc != scc) {
1601 		sc->sc_rbuf_out = outp;
1602 		mutex_spin_enter(&sc->sc_lock);
1603 
1604 		cc = IMXUART_RBUF_SPACE(sc);
1605 
1606 		/* Buffers should be ok again, release possible block. */
1607 		if (cc >= sc->sc_r_lowat) {
1608 			if (ISSET(sc->sc_rx_flags, IMXUART_RX_IBUF_OVERFLOWED)) {
1609 				CLR(sc->sc_rx_flags, IMXUART_RX_IBUF_OVERFLOWED);
1610 				imxuart_control_rxint(sc, true);
1611 			}
1612 			if (ISSET(sc->sc_rx_flags, IMXUART_RX_IBUF_BLOCKED)) {
1613 				CLR(sc->sc_rx_flags, IMXUART_RX_IBUF_BLOCKED);
1614 				imxuart_hwiflow(sc);
1615 			}
1616 		}
1617 		mutex_spin_exit(&sc->sc_lock);
1618 	}
1619 }
1620 
1621 integrate void
1622 imxuart_txsoft(struct imxuart_softc *sc, struct tty *tp)
1623 {
1624 
1625 	CLR(tp->t_state, TS_BUSY);
1626 	if (ISSET(tp->t_state, TS_FLUSH))
1627 		CLR(tp->t_state, TS_FLUSH);
1628 	else
1629 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
1630 	(*tp->t_linesw->l_start)(tp);
1631 }
1632 
1633 integrate void
1634 imxuart_stsoft(struct imxuart_softc *sc, struct tty *tp)
1635 {
1636 #ifdef notyet
1637 	u_char msr, delta;
1638 
1639 	mutex_spin_enter(&sc->sc_lock);
1640 	msr = sc->sc_msr;
1641 	delta = sc->sc_msr_delta;
1642 	sc->sc_msr_delta = 0;
1643 	mutex_spin_exit(&sc->sc_lock);
1644 
1645 	if (ISSET(delta, sc->sc_msr_dcd)) {
1646 		/*
1647 		 * Inform the tty layer that carrier detect changed.
1648 		 */
1649 		(void) (*tp->t_linesw->l_modem)(tp, ISSET(msr, MSR_DCD));
1650 	}
1651 
1652 	if (ISSET(delta, sc->sc_msr_cts)) {
1653 		/* Block or unblock output according to flow control. */
1654 		if (ISSET(msr, sc->sc_msr_cts)) {
1655 			sc->sc_tx_stopped = 0;
1656 			(*tp->t_linesw->l_start)(tp);
1657 		} else {
1658 			sc->sc_tx_stopped = 1;
1659 		}
1660 	}
1661 
1662 #endif
1663 #ifdef IMXUART_DEBUG
1664 	if (imxuart_debug)
1665 		imxustatus(sc, "imxuart_stsoft");
1666 #endif
1667 }
1668 
1669 void
1670 imxusoft(void *arg)
1671 {
1672 	struct imxuart_softc *sc = arg;
1673 	struct tty *tp;
1674 
1675 	if (IMXUART_ISALIVE(sc) == 0)
1676 		return;
1677 
1678 	tp = sc->sc_tty;
1679 
1680 	if (sc->sc_rx_ready) {
1681 		sc->sc_rx_ready = 0;
1682 		imxuart_rxsoft(sc, tp);
1683 	}
1684 
1685 	if (sc->sc_st_check) {
1686 		sc->sc_st_check = 0;
1687 		imxuart_stsoft(sc, tp);
1688 	}
1689 
1690 	if (sc->sc_tx_done) {
1691 		sc->sc_tx_done = 0;
1692 		imxuart_txsoft(sc, tp);
1693 	}
1694 }
1695 
1696 int
1697 imxuintr(void *arg)
1698 {
1699 	struct imxuart_softc *sc = arg;
1700 	uint32_t usr1, usr2;
1701 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1702 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1703 
1704 
1705 	if (IMXUART_ISALIVE(sc) == 0)
1706 		return (0);
1707 
1708 	mutex_spin_enter(&sc->sc_lock);
1709 
1710 	usr2 = bus_space_read_4(iot, ioh, IMX_USR2);
1711 
1712 
1713 	do {
1714 		bus_space_write_4(iot, ioh, IMX_USR2,
1715 		    usr2 & (IMX_USR2_BRCD|IMX_USR2_ORE));
1716 		if (usr2 & IMX_USR2_BRCD) {
1717 			/* Break signal detected */
1718 			int cn_trapped = 0;
1719 
1720 			cn_check_magic(sc->sc_tty->t_dev,
1721 				       CNC_BREAK, imxuart_cnm_state);
1722 			if (cn_trapped)
1723 				goto next;
1724 #if defined(KGDB) && !defined(DDB)
1725 			if (ISSET(sc->sc_hwflags, IMXUART_HW_KGDB)) {
1726 				kgdb_connect(1);
1727 				goto next;
1728 			}
1729 #endif
1730 		}
1731 
1732 		if (usr2 & IMX_USR2_RDR)
1733 			imxuintr_read(sc);
1734 
1735 #ifdef	IMXUART_PPS
1736 		{
1737 			u_char	msr, delta;
1738 
1739 			msr = CSR_READ_1(regsp, IMXUART_REG_MSR);
1740 			delta = msr ^ sc->sc_msr;
1741 			sc->sc_msr = msr;
1742 			if ((sc->sc_pps_state.ppsparam.mode & PPS_CAPTUREBOTH) &&
1743 			    (delta & MSR_DCD)) {
1744 				mutex_spin_enter(&timecounter_lock);
1745 				pps_capture(&sc->sc_pps_state);
1746 				pps_event(&sc->sc_pps_state,
1747 				    (msr & MSR_DCD) ?
1748 				    PPS_CAPTUREASSERT :
1749 				    PPS_CAPTURECLEAR);
1750 				mutex_spin_exit(&timecounter_lock);
1751 			}
1752 		}
1753 #endif
1754 
1755 #ifdef notyet
1756 		/*
1757 		 * Process normal status changes
1758 		 */
1759 		if (ISSET(delta, sc->sc_msr_mask)) {
1760 			SET(sc->sc_msr_delta, delta);
1761 
1762 			/*
1763 			 * Stop output immediately if we lose the output
1764 			 * flow control signal or carrier detect.
1765 			 */
1766 			if (ISSET(~msr, sc->sc_msr_mask)) {
1767 				sc->sc_tbc = 0;
1768 				sc->sc_heldtbc = 0;
1769 #ifdef IMXUART_DEBUG
1770 				if (imxuart_debug)
1771 					imxustatus(sc, "imxuintr  ");
1772 #endif
1773 			}
1774 
1775 			sc->sc_st_check = 1;
1776 		}
1777 #endif
1778 
1779 next:
1780 		usr2 = bus_space_read_4(iot, ioh, IMX_USR2);
1781 	} while (usr2 & (IMX_USR2_RDR|IMX_USR2_BRCD));
1782 
1783 	usr1 = bus_space_read_4(iot, ioh, IMX_USR1);
1784 	if (usr1 & IMX_USR1_TRDY)
1785 		imxuintr_send(sc);
1786 
1787 	mutex_spin_exit(&sc->sc_lock);
1788 
1789 	/* Wake up the poller. */
1790 	softint_schedule(sc->sc_si);
1791 
1792 #ifdef RND_COM
1793 	rnd_add_uint32(&sc->rnd_source, iir | lsr);
1794 #endif
1795 
1796 	return (1);
1797 }
1798 
1799 
1800 /*
1801  * called when there is least one character in rxfifo
1802  *
1803  */
1804 
1805 static void
1806 imxuintr_read(struct imxuart_softc *sc)
1807 {
1808 	int cc;
1809 	uint16_t rd;
1810 	uint32_t usr2;
1811 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1812 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1813 
1814 	cc = IMXUART_RBUF_SPACE(sc);
1815 
1816 	/* clear aging timer interrupt */
1817 	bus_space_write_4(iot, ioh, IMX_USR1, IMX_USR1_AGTIM);
1818 
1819 	while (cc > 0) {
1820 		int cn_trapped = 0;
1821 
1822 
1823 		sc->sc_rbuf[sc->sc_rbuf_in] = rd =
1824 		    bus_space_read_4(iot, ioh, IMX_URXD);
1825 
1826 		cn_check_magic(sc->sc_tty->t_dev,
1827 		    rd & 0xff, imxuart_cnm_state);
1828 
1829 		if (!cn_trapped) {
1830 #if defined(DDB) && defined(DDB_KEYCODE)
1831 			/*
1832 			 * Temporary hack so that I can force the kernel into
1833 			 * the debugger via the serial port
1834 			 */
1835 			if ((rd & 0xff) == DDB_KEYCODE)
1836 				Debugger();
1837 #endif
1838 			sc->sc_rbuf_in = IMXUART_RBUF_INC(sc, sc->sc_rbuf_in, 1);
1839 			cc--;
1840 		}
1841 
1842 		usr2 = bus_space_read_4(iot, ioh, IMX_USR2);
1843 		if (!(usr2 & IMX_USR2_RDR))
1844 			break;
1845 	}
1846 
1847 	/*
1848 	 * Current string of incoming characters ended because
1849 	 * no more data was available or we ran out of space.
1850 	 * Schedule a receive event if any data was received.
1851 	 * If we're out of space, turn off receive interrupts.
1852 	 */
1853 	if (!ISSET(sc->sc_rx_flags, IMXUART_RX_TTY_OVERFLOWED))
1854 		sc->sc_rx_ready = 1;
1855 	/*
1856 	 * See if we are in danger of overflowing a buffer. If
1857 	 * so, use hardware flow control to ease the pressure.
1858 	 */
1859 	if (!ISSET(sc->sc_rx_flags, IMXUART_RX_IBUF_BLOCKED) &&
1860 	    cc < sc->sc_r_hiwat) {
1861 		sc->sc_rx_flags |= IMXUART_RX_IBUF_BLOCKED;
1862 		imxuart_hwiflow(sc);
1863 	}
1864 
1865 	/*
1866 	 * If we're out of space, disable receive interrupts
1867 	 * until the queue has drained a bit.
1868 	 */
1869 	if (!cc) {
1870 		sc->sc_rx_flags |= IMXUART_RX_IBUF_OVERFLOWED;
1871 		imxuart_control_rxint(sc, false);
1872 	}
1873 }
1874 
1875 
1876 
1877 /*
1878  * find how many chars we can put into tx-fifo
1879  */
1880 static u_int
1881 imxuart_txfifo_space(struct imxuart_softc *sc)
1882 {
1883 	uint32_t usr1, usr2;
1884 	u_int cc;
1885 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1886 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1887 
1888 	usr2 = bus_space_read_4(iot, ioh, IMX_USR2);
1889 	if (usr2 & IMX_USR2_TXFE)
1890 		cc = sc->sc_txfifo_len;
1891 	else {
1892 		usr1 = bus_space_read_4(iot, ioh, IMX_USR1);
1893 		if (usr1 & IMX_USR1_TRDY)
1894 			cc = sc->sc_txfifo_thresh;
1895 		else
1896 			cc = 0;
1897 	}
1898 
1899 	return cc;
1900 }
1901 
1902 void
1903 imxuintr_send(struct imxuart_softc *sc)
1904 {
1905 	uint32_t usr2;
1906 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1907 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1908 	int cc = 0;
1909 
1910 	usr2 = bus_space_read_4(iot, ioh, IMX_USR2);
1911 
1912 	if (sc->sc_pending) {
1913 		if (usr2 & IMX_USR2_TXFE) {
1914 			imxuart_load_pendings(sc);
1915 			sc->sc_tbc = sc->sc_heldtbc;
1916 			sc->sc_heldtbc = 0;
1917 		}
1918 		else {
1919 			/* wait for TX fifo empty */
1920 			imxuart_control_txint(sc, true);
1921 			return;
1922 		}
1923 	}
1924 
1925 	cc = imxuart_txfifo_space(sc);
1926 	cc = MIN(cc, sc->sc_tbc);
1927 
1928 	if (cc > 0) {
1929 		bus_space_write_multi_1(iot, ioh, IMX_UTXD, sc->sc_tba, cc);
1930 		sc->sc_tbc -= cc;
1931 		sc->sc_tba += cc;
1932 	}
1933 
1934 	if (sc->sc_tbc > 0)
1935 		imxuart_control_txint(sc, true);
1936 	else {
1937 		/* no more chars to send.
1938 		   we don't need tx interrupt any more. */
1939 		imxuart_control_txint(sc, false);
1940 		if (sc->sc_tx_busy) {
1941 			sc->sc_tx_busy = 0;
1942 			sc->sc_tx_done = 1;
1943 		}
1944 	}
1945 }
1946 
1947 static void
1948 imxuart_disable_all_interrupts(struct imxuart_softc *sc)
1949 {
1950 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1951 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1952 
1953 	sc->sc_ucr1 &= ~IMXUART_INTRS_UCR1;
1954 	sc->sc_ucr2 &= ~IMXUART_INTRS_UCR2;
1955 	sc->sc_ucr3 &= ~IMXUART_INTRS_UCR3;
1956 	sc->sc_ucr4 &= ~IMXUART_INTRS_UCR4;
1957 
1958 
1959 	bus_space_write_region_4(iot, ioh, IMX_UCR1, sc->sc_ucr, 4);
1960 }
1961 
1962 static void
1963 imxuart_control_rxint(struct imxuart_softc *sc, bool enable)
1964 {
1965 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1966 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1967 	uint32_t ucr1, ucr2;
1968 
1969 	ucr1 = sc->sc_ucr1;
1970 	ucr2 = sc->sc_ucr2;
1971 
1972 	if (enable) {
1973 		ucr1 |= IMX_UCR1_RRDYEN;
1974 		ucr2 |= IMX_UCR2_ATEN;
1975 	}
1976 	else {
1977 		ucr1 &= ~IMX_UCR1_RRDYEN;
1978 		ucr2 &= ~IMX_UCR2_ATEN;
1979 	}
1980 
1981 	if (ucr1 != sc->sc_ucr1 || ucr2 != sc->sc_ucr2) {
1982 		sc->sc_ucr1 = ucr1;
1983 		sc->sc_ucr2 = ucr2;
1984 		bus_space_write_region_4(iot, ioh, IMX_UCR1, sc->sc_ucr, 2);
1985 	}
1986 }
1987 
1988 static void
1989 imxuart_control_txint(struct imxuart_softc *sc, bool enable)
1990 {
1991 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
1992 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
1993 	uint32_t ucr1;
1994 	uint32_t mask;
1995 
1996 	/* if parameter change is pending, get interrupt when Tx fifo
1997 	   is completely empty.  otherwise, get interrupt when txfifo
1998 	   has less characters than threshold */
1999 	mask = sc->sc_pending ? IMX_UCR1_TXMPTYEN : IMX_UCR1_TRDYEN;
2000 
2001 	ucr1 = sc->sc_ucr1;
2002 
2003 	CLR(ucr1, IMX_UCR1_TXMPTYEN|IMX_UCR1_TRDYEN);
2004 	if (enable)
2005 		SET(ucr1, mask);
2006 
2007 	if (ucr1 != sc->sc_ucr1) {
2008 		bus_space_write_4(iot, ioh, IMX_UCR1, ucr1);
2009 		sc->sc_ucr1 = ucr1;
2010 	}
2011 }
2012 
2013 
2014 static void
2015 imxuart_load_params(struct imxuart_softc *sc)
2016 {
2017 	uint32_t ucr2;
2018 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
2019 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
2020 
2021 	ucr2 = (sc->sc_ucr2_d & ~IMX_UCR2_ATEN) |
2022 	    (sc->sc_ucr2 & IMX_UCR2_ATEN);
2023 
2024 	bus_space_write_4(iot, ioh, IMX_UCR2, ucr2);
2025 	sc->sc_ucr2 = ucr2;
2026 }
2027 
2028 static void
2029 imxuart_load_speed(struct imxuart_softc *sc)
2030 {
2031 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
2032 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
2033 	int n, rfdiv, ufcr;
2034 
2035 #ifdef notyet
2036 	/*
2037 	 * Set the FIFO threshold based on the receive speed.
2038 	 *
2039 	 *  * If it's a low speed, it's probably a mouse or some other
2040 	 *    interactive device, so set the threshold low.
2041 	 *  * If it's a high speed, trim the trigger level down to prevent
2042 	 *    overflows.
2043 	 *  * Otherwise set it a bit higher.
2044 	 */
2045 	if (t->c_ospeed <= 1200)
2046 		sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_1;
2047 	else if (t->c_ospeed <= 38400)
2048 		sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_8;
2049 	else
2050 		sc->sc_fifo = FIFO_ENABLE | FIFO_TRIGGER_4;
2051 #endif
2052 
2053 	n = 32 - sc->sc_txfifo_thresh;
2054 	n = MAX(2, n);
2055 
2056 	rfdiv = IMX_UFCR_DIVIDER_TO_RFDIV(imxuart_freqdiv);
2057 
2058 	ufcr = (n << IMX_UFCR_TXTL_SHIFT) |
2059 		(rfdiv << IMX_UFCR_RFDIV_SHIFT) |
2060 		(16 << IMX_UFCR_RXTL_SHIFT);
2061 
2062 	/* keep DCE/DTE bit */
2063 	ufcr |= bus_space_read_4(iot, ioh, IMX_UFCR) & IMX_UFCR_DCEDTE;
2064 
2065 	bus_space_write_4(iot, ioh, IMX_UFCR, ufcr);
2066 
2067 	/* UBIR must updated before UBMR */
2068 	bus_space_write_4(iot, ioh,
2069 	    IMX_UBIR, sc->sc_ratio.numerator);
2070 	bus_space_write_4(iot, ioh,
2071 	    IMX_UBMR, sc->sc_ratio.modulator);
2072 
2073 
2074 }
2075 
2076 
2077 static void
2078 imxuart_load_pendings(struct imxuart_softc *sc)
2079 {
2080 	if (sc->sc_pending & IMXUART_PEND_PARAM)
2081 		imxuart_load_params(sc);
2082 	if (sc->sc_pending & IMXUART_PEND_SPEED)
2083 		imxuart_load_speed(sc);
2084 	sc->sc_pending = 0;
2085 }
2086 
2087 /*
2088  * The following functions are polled getc and putc routines, shared
2089  * by the console and kgdb glue.
2090  *
2091  * The read-ahead code is so that you can detect pending in-band
2092  * cn_magic in polled mode while doing output rather than having to
2093  * wait until the kernel decides it needs input.
2094  */
2095 
2096 #define	READAHEAD_RING_LEN	16
2097 static int imxuart_readahead[READAHEAD_RING_LEN];
2098 static int imxuart_readahead_in = 0;
2099 static int imxuart_readahead_out = 0;
2100 #define	READAHEAD_IS_EMPTY()	(imxuart_readahead_in==imxuart_readahead_out)
2101 #define	READAHEAD_IS_FULL()	\
2102 	(((imxuart_readahead_in+1) & (READAHEAD_RING_LEN-1)) ==imxuart_readahead_out)
2103 
2104 int
2105 imxuart_common_getc(dev_t dev, struct imxuart_regs *regsp)
2106 {
2107 	int s = splserial();
2108 	u_char c;
2109 	bus_space_tag_t iot = regsp->ur_iot;
2110 	bus_space_handle_t ioh = regsp->ur_ioh;
2111 	uint32_t usr2;
2112 
2113 	/* got a character from reading things earlier */
2114 	if (imxuart_readahead_in != imxuart_readahead_out) {
2115 
2116 		c = imxuart_readahead[imxuart_readahead_out];
2117 		imxuart_readahead_out = (imxuart_readahead_out + 1) &
2118 		    (READAHEAD_RING_LEN-1);
2119 		splx(s);
2120 		return (c);
2121 	}
2122 
2123 	/* block until a character becomes available */
2124 	while (!((usr2 = bus_space_read_4(iot, ioh, IMX_USR2)) & IMX_USR2_RDR))
2125 		;
2126 
2127 	c = 0xff & bus_space_read_4(iot, ioh, IMX_URXD);
2128 
2129 	{
2130 		int __attribute__((__unused__))cn_trapped = 0; /* unused */
2131 #ifdef DDB
2132 		extern int db_active;
2133 		if (!db_active)
2134 #endif
2135 			cn_check_magic(dev, c, imxuart_cnm_state);
2136 	}
2137 	splx(s);
2138 	return (c);
2139 }
2140 
2141 void
2142 imxuart_common_putc(dev_t dev, struct imxuart_regs *regsp, int c)
2143 {
2144 	int s = splserial();
2145 	int cin, timo;
2146 	bus_space_tag_t iot = regsp->ur_iot;
2147 	bus_space_handle_t ioh = regsp->ur_ioh;
2148 	uint32_t usr2;
2149 
2150 	if (!READAHEAD_IS_FULL() &&
2151 	    ((usr2 = bus_space_read_4(iot, ioh, IMX_USR2)) & IMX_USR2_RDR)) {
2152 
2153 		int __attribute__((__unused__))cn_trapped = 0;
2154 		cin = bus_space_read_4(iot, ioh, IMX_URXD);
2155 		cn_check_magic(dev, cin & 0xff, imxuart_cnm_state);
2156 		imxuart_readahead_in = (imxuart_readahead_in + 1) &
2157 		    (READAHEAD_RING_LEN-1);
2158 	}
2159 
2160 	/* wait for any pending transmission to finish */
2161 	timo = 150000;
2162 	do {
2163 		if (bus_space_read_4(iot, ioh, IMX_USR1) & IMX_USR1_TRDY) {
2164 			bus_space_write_4(iot, ioh, IMX_UTXD, c);
2165 			break;
2166 		}
2167 	} while(--timo > 0);
2168 
2169 	IMXUART_BARRIER(regsp, BR | BW);
2170 
2171 	splx(s);
2172 }
2173 
2174 /*
2175  * Initialize UART
2176  */
2177 int
2178 imxuart_init(struct imxuart_regs *regsp, int rate, tcflag_t cflag, int domap)
2179 {
2180 	struct imxuart_baudrate_ratio ratio;
2181 	int rfdiv = IMX_UFCR_DIVIDER_TO_RFDIV(imxuart_freqdiv);
2182 	uint32_t ufcr;
2183 	int error;
2184 
2185 	if (domap && (error = bus_space_map(regsp->ur_iot, regsp->ur_iobase,
2186 	     IMX_UART_SIZE, 0, &regsp->ur_ioh)) != 0)
2187 		return error;
2188 
2189 	if (imxuart_freq != 0) {
2190 		if (imxuspeed(rate, &ratio) < 0)
2191 			return EINVAL;
2192 
2193 		/* UBIR must updated before UBMR */
2194 		bus_space_write_4(regsp->ur_iot, regsp->ur_ioh,
2195 		    IMX_UBIR, ratio.numerator);
2196 		bus_space_write_4(regsp->ur_iot, regsp->ur_ioh,
2197 		    IMX_UBMR, ratio.modulator);
2198 	}
2199 
2200 	/* XXX: DTREN, DPEC */
2201 	bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, IMX_UCR3,
2202 	    IMX_UCR3_DSR|IMX_UCR3_RXDMUXSEL);
2203 
2204 	ufcr = bus_space_read_4(regsp->ur_iot, regsp->ur_ioh, IMX_UFCR);
2205 	ufcr &= ~IMX_UFCR_TXTL;
2206 	ufcr |= (8 << IMX_UFCR_TXTL_SHIFT);
2207 	ufcr &= ~IMX_UFCR_RXTL;
2208 	ufcr |= (1 << IMX_UFCR_RXTL_SHIFT);
2209 	if (imxuart_freq != 0) {
2210 		ufcr &= ~IMX_UFCR_RFDIV;
2211 		ufcr |= (rfdiv << IMX_UFCR_RFDIV_SHIFT);
2212 	}
2213 	bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, IMX_UFCR, ufcr);
2214 
2215 	if (imxuart_freq != 0) {
2216 		bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, IMX_ONEMS,
2217 		    imxuart_freq / imxuart_freqdiv / 1000);
2218 	}
2219 
2220 	bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, IMX_UCR2,
2221 			  IMX_UCR2_IRTS|
2222 			  IMX_UCR2_CTSC|
2223 			  IMX_UCR2_WS|IMX_UCR2_TXEN|
2224 			  IMX_UCR2_RXEN|IMX_UCR2_SRST);
2225 	/* clear status registers */
2226 	bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, IMX_USR1, 0xffff);
2227 	bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, IMX_USR2, 0xffff);
2228 
2229 
2230 	bus_space_write_4(regsp->ur_iot, regsp->ur_ioh, IMX_UCR1,
2231 	    IMX_UCR1_UARTEN);
2232 
2233 	return (0);
2234 }
2235 
2236 
2237 /*
2238  * Following are all routines needed for UART to act as console
2239  */
2240 struct consdev imxucons = {
2241 	NULL, NULL, imxucngetc, imxucnputc, imxucnpollc, NULL, NULL, NULL,
2242 	NODEV, CN_NORMAL
2243 };
2244 
2245 
2246 int
2247 imxuart_cnattach(bus_space_tag_t iot, paddr_t iobase, u_int rate,
2248     tcflag_t cflag)
2249 {
2250 	struct imxuart_regs regs;
2251 	int res;
2252 
2253 	regs.ur_iot = iot;
2254 	regs.ur_iobase = iobase;
2255 
2256 	res = imxuart_init(&regs, rate, cflag, true);
2257 	if (res)
2258 		return (res);
2259 
2260 	cn_tab = &imxucons;
2261 	cn_init_magic(&imxuart_cnm_state);
2262 	cn_set_magic("\047\001"); /* default magic is BREAK */
2263 
2264 	imxuconsrate = rate;
2265 	imxuconscflag = cflag;
2266 
2267 	imxuconsregs = regs;
2268 
2269 	return 0;
2270 }
2271 
2272 int
2273 imxucngetc(dev_t dev)
2274 {
2275 	return (imxuart_common_getc(dev, &imxuconsregs));
2276 }
2277 
2278 /*
2279  * Console kernel output character routine.
2280  */
2281 void
2282 imxucnputc(dev_t dev, int c)
2283 {
2284 	imxuart_common_putc(dev, &imxuconsregs, c);
2285 }
2286 
2287 void
2288 imxucnpollc(dev_t dev, int on)
2289 {
2290 
2291 	imxuart_readahead_in = 0;
2292 	imxuart_readahead_out = 0;
2293 }
2294 
2295 #ifdef KGDB
2296 int
2297 imxuart_kgdb_attach(bus_space_tag_t iot, paddr_t iobase, u_int rate,
2298     tcflag_t cflag)
2299 {
2300 	int res;
2301 
2302 	if (iot == imxuconsregs.ur_iot &&
2303 	    iobase == imxuconsregs.ur_iobase) {
2304 #if !defined(DDB)
2305 		return (EBUSY); /* cannot share with console */
2306 #else
2307 		imxu_kgdb_regs.ur_iot = iot;
2308 		imxu_kgdb_regs.ur_ioh = imxuconsregs.ur_ioh;
2309 		imxu_kgdb_regs.ur_iobase = iobase;
2310 #endif
2311 	} else {
2312 		imxu_kgdb_regs.ur_iot = iot;
2313 		imxu_kgdb_regs.ur_iobase = iobase;
2314 
2315 		res = imxuart_init(&imxu_kgdb_regs, rate, cflag, true);
2316 		if (res)
2317 			return (res);
2318 
2319 		/*
2320 		 * XXXfvdl this shouldn't be needed, but the cn_magic goo
2321 		 * expects this to be initialized
2322 		 */
2323 		cn_init_magic(&imxuart_cnm_state);
2324 		cn_set_magic("\047\001");
2325 	}
2326 
2327 	kgdb_attach(imxuart_kgdb_getc, imxuart_kgdb_putc, &imxu_kgdb_regs);
2328 	kgdb_dev = 123; /* unneeded, only to satisfy some tests */
2329 
2330 	return (0);
2331 }
2332 
2333 /* ARGSUSED */
2334 int
2335 imxuart_kgdb_getc(void *arg)
2336 {
2337 	struct imxuart_regs *regs = arg;
2338 
2339 	return (imxuart_common_getc(NODEV, regs));
2340 }
2341 
2342 /* ARGSUSED */
2343 void
2344 imxuart_kgdb_putc(void *arg, int c)
2345 {
2346 	struct imxuart_regs *regs = arg;
2347 
2348 	imxuart_common_putc(NODEV, regs, c);
2349 }
2350 #endif /* KGDB */
2351 
2352 /* helper function to identify the imxu ports used by
2353  console or KGDB (and not yet autoconf attached) */
2354 int
2355 imxuart_is_console(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t *ioh)
2356 {
2357 	bus_space_handle_t help;
2358 
2359 	if (!imxuconsattached &&
2360 	    iot == imxuconsregs.ur_iot && iobase == imxuconsregs.ur_iobase)
2361 		help = imxuconsregs.ur_ioh;
2362 #ifdef KGDB
2363 	else if (!imxu_kgdb_attached &&
2364 	    iot == imxu_kgdb_regs.ur_iot && iobase == imxu_kgdb_regs.ur_iobase)
2365 		help = imxu_kgdb_regs.ur_ioh;
2366 #endif
2367 	else
2368 		return (0);
2369 
2370 	if (ioh)
2371 		*ioh = help;
2372 	return (1);
2373 }
2374 
2375 #ifdef notyet
2376 
2377 bool
2378 imxuart_cleanup(device_t self, int how)
2379 {
2380 /*
2381  * this routine exists to serve as a shutdown hook for systems that
2382  * have firmware which doesn't interact properly with a imxuart device in
2383  * FIFO mode.
2384  */
2385 	struct imxuart_softc *sc = device_private(self);
2386 
2387 	if (ISSET(sc->sc_hwflags, IMXUART_HW_FIFO))
2388 		UR_WRITE_1(&sc->sc_regs, IMXUART_REG_FIFO, 0);
2389 
2390 	return true;
2391 }
2392 #endif
2393 
2394 #ifdef notyet
2395 bool
2396 imxuart_suspend(device_t self PMF_FN_ARGS)
2397 {
2398 	struct imxuart_softc *sc = device_private(self);
2399 
2400 	UR_WRITE_1(&sc->sc_regs, IMXUART_REG_IER, 0);
2401 	(void)CSR_READ_1(&sc->sc_regs, IMXUART_REG_IIR);
2402 
2403 	return true;
2404 }
2405 #endif
2406 
2407 #ifdef notyet
2408 bool
2409 imxuart_resume(device_t self PMF_FN_ARGS)
2410 {
2411 	struct imxuart_softc *sc = device_private(self);
2412 
2413 	mutex_spin_enter(&sc->sc_lock);
2414 	imxuart_loadchannelregs(sc);
2415 	mutex_spin_exit(&sc->sc_lock);
2416 
2417 	return true;
2418 }
2419 #endif
2420 
2421 static void
2422 imxuart_enable_debugport(struct imxuart_softc *sc)
2423 {
2424 	bus_space_tag_t iot = sc->sc_regs.ur_iot;
2425 	bus_space_handle_t ioh = sc->sc_regs.ur_ioh;
2426 
2427 	if (sc->sc_hwflags & (IMXUART_HW_CONSOLE|IMXUART_HW_KGDB)) {
2428 
2429 		/* Turn on line break interrupt, set carrier. */
2430 
2431 		sc->sc_ucr3 |= IMX_UCR3_DSR;
2432 		bus_space_write_4(iot, ioh, IMX_UCR3, sc->sc_ucr3);
2433 
2434 		sc->sc_ucr4 |= IMX_UCR4_BKEN;
2435 		bus_space_write_4(iot, ioh, IMX_UCR4, sc->sc_ucr4);
2436 
2437 		sc->sc_ucr2 |= IMX_UCR2_TXEN|IMX_UCR2_RXEN|
2438 		    IMX_UCR2_CTS;
2439 		bus_space_write_4(iot, ioh, IMX_UCR2, sc->sc_ucr2);
2440 
2441 		sc->sc_ucr1 |= IMX_UCR1_UARTEN;
2442 		bus_space_write_4(iot, ioh, IMX_UCR1, sc->sc_ucr1);
2443 	}
2444 }
2445 
2446 
2447 void
2448 imxuart_set_frequency(u_int freq, u_int div)
2449 {
2450 	imxuart_freq = freq;
2451 	imxuart_freqdiv = div;
2452 }
2453