xref: /netbsd-src/sys/arch/arm/at91/at91dbgu.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$Id: at91dbgu.c,v 1.15 2015/09/21 13:31:30 skrll Exp $	*/
2 /*	$NetBSD: at91dbgu.c,v 1.15 2015/09/21 13:31:30 skrll Exp $ */
3 
4 /*
5  *
6  * Copyright (c) 1998, 1999, 2001, 2002, 2004 The NetBSD Foundation, Inc.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by Jesse Off
11  *
12  * This code is derived from software contributed to The NetBSD Foundation
13  * by Ichiro FUKUHARA and Naoto Shimazaki.
14  *
15  * This code is derived from software contributed to The NetBSD Foundation
16  * by IWAMOTO Toshihiro.
17  *
18  * This code is derived from software contributed to The NetBSD Foundation
19  * by Charles M. Hannum.
20  *
21  * Redistribution and use in source and binary forms, with or without
22  * modification, are permitted provided that the following conditions
23  * are met:
24  * 1. Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  * 2. Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in the
28  *    documentation and/or other materials provided with the distribution.
29  * 3. All advertising materials mentioning features or use of this software
30  *    must display the following acknowledgement:
31  *        This product includes software developed by the NetBSD
32  *        Foundation, Inc. and its contributors.
33  * 4. Neither the name of The NetBSD Foundation nor the names of its
34  *    contributors may be used to endorse or promote products derived
35  *    from this software without specific prior written permission.
36  *
37  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
38  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
39  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
40  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
41  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
42  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
43  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
44  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
45  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
47  * POSSIBILITY OF SUCH DAMAGE.
48  */
49 
50 /*
51  * Copyright (c) 1991 The Regents of the University of California.
52  * All rights reserved.
53  *
54  * Redistribution and use in source and binary forms, with or without
55  * modification, are permitted provided that the following conditions
56  * are met:
57  * 1. Redistributions of source code must retain the above copyright
58  *    notice, this list of conditions and the following disclaimer.
59  * 2. Redistributions in binary form must reproduce the above copyright
60  *    notice, this list of conditions and the following disclaimer in the
61  *    documentation and/or other materials provided with the distribution.
62  * 3. Neither the name of the University nor the names of its contributors
63  *    may be used to endorse or promote products derived from this software
64  *    without specific prior written permission.
65  *
66  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
67  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
68  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
69  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
70  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
71  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
72  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
73  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
74  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
75  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
76  * SUCH DAMAGE.
77  *
78  *      @(#)com.c       7.5 (Berkeley) 5/16/91
79  */
80 
81 /*
82  * TODO: hardware flow control
83  */
84 
85 #include <sys/cdefs.h>
86 __KERNEL_RCSID(0, "$NetBSD: at91dbgu.c,v 1.15 2015/09/21 13:31:30 skrll Exp $");
87 
88 #include "opt_ddb.h"
89 #include "opt_kgdb.h"
90 
91 #include "rnd.h"
92 #ifdef RND_COM
93 #include <sys/rndsource.h>
94 #endif
95 
96 /*
97  * Override cnmagic(9) macro before including <sys/systm.h>.
98  * We need to know if cn_check_magic triggered debugger, so set a flag.
99  * Callers of cn_check_magic must declare int cn_trapped = 0;
100  * XXX: this is *ugly*!
101  */
102 #define cn_trap()				\
103 	do {					\
104 		console_debugger();		\
105 		cn_trapped = 1;			\
106 	} while (/* CONSTCOND */ 0)
107 
108 
109 #include <sys/param.h>
110 #include <sys/systm.h>
111 #include <sys/types.h>
112 #include <sys/conf.h>
113 #include <sys/file.h>
114 #include <sys/device.h>
115 #include <sys/kernel.h>
116 #include <sys/malloc.h>
117 #include <sys/tty.h>
118 #include <sys/uio.h>
119 #include <sys/vnode.h>
120 #include <sys/kauth.h>
121 
122 #include <machine/intr.h>
123 #include <sys/bus.h>
124 
125 #include <arm/at91/at91reg.h>
126 #include <arm/at91/at91var.h>
127 #include <arm/at91/at91dbguvar.h>
128 #include <arm/at91/at91dbgureg.h>
129 
130 #include <dev/cons.h>
131 
132 static int	at91dbgu_match(device_t, cfdata_t, void *);
133 static void	at91dbgu_attach(device_t, device_t, void *);
134 
135 static int	at91dbgu_param(struct tty *, struct termios *);
136 static void	at91dbgu_start(struct tty *);
137 static int	at91dbgu_hwiflow(struct tty *, int);
138 
139 #if 0
140 static u_int	cflag2lcrhi(tcflag_t);
141 #endif
142 static void	at91dbgu_iflush(struct at91dbgu_softc *);
143 static void	at91dbgu_set(struct at91dbgu_softc *);
144 
145 int             at91dbgu_cn_getc(dev_t);
146 void            at91dbgu_cn_putc(dev_t, int);
147 void            at91dbgu_cn_pollc(dev_t, int);
148 
149 static void	at91dbgu_soft(void* arg);
150 inline static void	at91dbgu_txsoft(struct at91dbgu_softc *, struct tty *);
151 inline static void	at91dbgu_rxsoft(struct at91dbgu_softc *, struct tty *);
152 
153 void            at91dbgu_cn_probe(struct consdev *);
154 void            at91dbgu_cn_init(struct consdev *);
155 
156 static struct at91dbgu_cons_softc {
157 	bus_space_tag_t		sc_iot;
158 	bus_space_handle_t	sc_ioh;
159 	bus_addr_t		sc_hwbase;
160 	int			sc_ospeed;
161 	tcflag_t		sc_cflag;
162 	int			sc_attached;
163 
164 	uint8_t			*sc_rx_ptr;
165 	uint8_t			sc_rx_fifo[64];
166 } dbgu_cn_sc;
167 
168 static struct cnm_state at91dbgu_cnm_state;
169 
170 CFATTACH_DECL_NEW(at91dbgu, sizeof(struct at91dbgu_softc),
171 	      at91dbgu_match, at91dbgu_attach, NULL, NULL);
172 
173 extern struct cfdriver at91dbgu_cd;
174 
175 dev_type_open(at91dbgu_open);
176 dev_type_close(at91dbgu_close);
177 dev_type_read(at91dbgu_read);
178 dev_type_write(at91dbgu_write);
179 dev_type_ioctl(at91dbgu_ioctl);
180 dev_type_stop(at91dbgu_stop);
181 dev_type_tty(at91dbgu_tty);
182 dev_type_poll(at91dbgu_poll);
183 
184 const struct cdevsw at91dbgu_cdevsw = {
185 	.d_open = at91dbgu_open,
186 	.d_close = at91dbgu_close,
187 	.d_read = at91dbgu_read,
188 	.d_write = at91dbgu_write,
189 	.d_ioctl = at91dbgu_ioctl,
190 	.d_stop = at91dbgu_stop,
191 	.d_tty = at91dbgu_tty,
192 	.d_poll = at91dbgu_poll,
193 	.d_mmap = nommap,
194 	.d_kqfilter = ttykqfilter,
195 	.d_discard = nodiscard,
196 	.d_flag = D_TTY
197 };
198 
199 struct consdev at91dbgu_cons = {
200 	at91dbgu_cn_probe, NULL, at91dbgu_cn_getc, at91dbgu_cn_putc, at91dbgu_cn_pollc, NULL,
201 	NULL, NULL, NODEV, CN_REMOTE
202 };
203 
204 #ifndef DEFAULT_COMSPEED
205 #define DEFAULT_COMSPEED 115200
206 #endif
207 
208 #define COMUNIT(x)	TTUNIT(x)
209 #define COMDIALOUT(x)	TTDIALOUT(x)
210 
211 #define COM_ISALIVE(sc)	((sc)->enabled != 0 && device_is_active((sc)->sc_dev))
212 
213 static int
214 at91dbgu_match(device_t parent, cfdata_t match, void *aux)
215 {
216 	if (strcmp(match->cf_name, "at91dbgu") == 0)
217 		return 2;
218 	return 0;
219 }
220 
221 static int
222 dbgu_intr(void* arg);
223 
224 static void
225 at91dbgu_attach(device_t parent, device_t self, void *aux)
226 {
227 	struct at91dbgu_softc *sc = device_private(self);
228 	struct at91bus_attach_args *sa = aux;
229 	struct tty *tp;
230 
231 	printf("\n");
232 
233 	sc->sc_dev = self;
234 	bus_space_map(sa->sa_iot, sa->sa_addr, sa->sa_size, 0, &sc->sc_ioh);
235 	sc->sc_iot = sa->sa_iot;
236 	sc->sc_hwbase = sa->sa_addr;
237 
238 	DBGUREG(DBGU_IDR) = -1;
239 	at91_intr_establish(sa->sa_pid, IPL_SERIAL, INTR_HIGH_LEVEL, dbgu_intr, sc);
240 	DBGU_INIT(AT91_MSTCLK, 115200U);
241 
242 	if (sc->sc_iot == dbgu_cn_sc.sc_iot
243 	    && sc->sc_hwbase == dbgu_cn_sc.sc_hwbase) {
244 		dbgu_cn_sc.sc_attached = 1;
245 		/* Make sure the console is always "hardwired". */
246 		delay(10000);	/* wait for output to finish */
247 		SET(sc->sc_hwflags, COM_HW_CONSOLE);
248 		SET(sc->sc_swflags, TIOCFLAG_SOFTCAR);
249 		SET(sc->sc_ier, DBGU_INT_RXRDY);
250 		DBGUREG(DBGU_IER) = DBGU_INT_RXRDY; // @@@@@
251 	}
252 
253 	tp = tty_alloc();
254 	tp->t_oproc = at91dbgu_start;
255 	tp->t_param = at91dbgu_param;
256 	tp->t_hwiflow = at91dbgu_hwiflow;
257 
258 	sc->sc_tty = tp;
259 	sc->sc_rbuf = malloc(AT91DBGU_RING_SIZE << 1, M_DEVBUF, M_NOWAIT);
260 	sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
261 	sc->sc_rbavail = AT91DBGU_RING_SIZE;
262 	if (sc->sc_rbuf == NULL) {
263 		printf("%s: unable to allocate ring buffer\n",
264 		    device_xname(sc->sc_dev));
265 		return;
266 	}
267 	sc->sc_ebuf = sc->sc_rbuf + (AT91DBGU_RING_SIZE << 1);
268 	sc->sc_tbc = 0;
269 
270 	tty_attach(tp);
271 
272 	if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
273 		int maj;
274 
275 		/* locate the major number */
276 		maj = cdevsw_lookup_major(&at91dbgu_cdevsw);
277 
278 		cn_tab->cn_dev = makedev(maj, device_unit(sc->sc_dev));
279 
280 		aprint_normal("%s: console (maj %u min %u cn_dev %#"PRIx64")\n",
281 		    device_xname(sc->sc_dev), maj, device_unit(sc->sc_dev),
282 		    cn_tab->cn_dev);
283 	}
284 
285 	sc->sc_si = softint_establish(SOFTINT_SERIAL, at91dbgu_soft, sc);
286 
287 #ifdef RND_COM
288 	rnd_attach_source(&sc->rnd_source, device_xname(sc->sc_dev),
289 			  RND_TYPE_TTY, RND_FLAG_DEFAULT);
290 #endif
291 
292 	/* if there are no enable/disable functions, assume the device
293 	   is always enabled */
294 	if (!sc->enable)
295 		sc->enabled = 1;
296 
297 	/* XXX configure register */
298 	/* xxx_config(sc) */
299 
300 	SET(sc->sc_hwflags, COM_HW_DEV_OK);
301 }
302 
303 static int
304 at91dbgu_param(struct tty *tp, struct termios *t)
305 {
306 	struct at91dbgu_softc *sc
307 		= device_lookup_private(&at91dbgu_cd, COMUNIT(tp->t_dev));
308 	int s;
309 
310 	if (COM_ISALIVE(sc) == 0)
311 		return (EIO);
312 
313 	if (t->c_ispeed && t->c_ispeed != t->c_ospeed)
314 		return (EINVAL);
315 
316 	/*
317 	 * For the console, always force CLOCAL and !HUPCL, so that the port
318 	 * is always active.
319 	 */
320 	if (ISSET(sc->sc_swflags, TIOCFLAG_SOFTCAR) ||
321 	    ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
322 		SET(t->c_cflag, CLOCAL);
323 		CLR(t->c_cflag, HUPCL);
324 	}
325 
326 	/*
327 	 * If there were no changes, don't do anything.  This avoids dropping
328 	 * input and improves performance when all we did was frob things like
329 	 * VMIN and VTIME.
330 	 */
331 	if (tp->t_ospeed == t->c_ospeed &&
332 	    tp->t_cflag == t->c_cflag)
333 		return (0);
334 
335 	s = splserial();
336 
337 	sc->sc_brgr = (AT91_MSTCLK / 16 + t->c_ospeed / 2) / t->c_ospeed;
338 
339 	/* And copy to tty. */
340 	tp->t_ispeed = 0;
341 	tp->t_ospeed = t->c_ospeed;
342 	tp->t_cflag = t->c_cflag;
343 	at91dbgu_set(sc);
344 
345 	splx(s);
346 
347 	/*
348 	 * Update the tty layer's idea of the carrier bit.
349 	 * We tell tty the carrier is always on.
350 	 */
351 	(void) (*tp->t_linesw->l_modem)(tp, 1);
352 
353 #ifdef COM_DEBUG
354 	if (com_debug)
355 		comstatus(sc, "comparam ");
356 #endif
357 
358 	if (!ISSET(t->c_cflag, CHWFLOW)) {
359 		if (sc->sc_tx_stopped) {
360 			sc->sc_tx_stopped = 0;
361 			at91dbgu_start(tp);
362 		}
363 	}
364 
365 	return (0);
366 }
367 
368 static int
369 at91dbgu_hwiflow(struct tty *tp, int block)
370 {
371 	return (0);
372 }
373 
374 static void
375 at91dbgu_filltx(struct at91dbgu_softc *sc)
376 {
377 #if 0
378 	bus_space_tag_t iot = sc->sc_iot;
379 	bus_space_handle_t ioh = sc->sc_ioh;
380 #endif
381 	int n;
382 
383 	n = 0;
384         while (DBGUREG(DBGU_SR) & DBGU_SR_TXRDY) {
385 		if (n >= sc->sc_tbc)
386 			break;
387 		DBGUREG(DBGU_THR) = *(sc->sc_tba + n) & 0xff;
388 		n++;
389         }
390         sc->sc_tbc -= n;
391         sc->sc_tba += n;
392 }
393 
394 static void
395 at91dbgu_start(struct tty *tp)
396 {
397 	struct at91dbgu_softc *sc
398 		= device_lookup_private(&at91dbgu_cd, COMUNIT(tp->t_dev));
399 	int s;
400 
401 	if (COM_ISALIVE(sc) == 0)
402 		return;
403 
404 	s = spltty();
405 	if (ISSET(tp->t_state, TS_BUSY | TS_TIMEOUT | TS_TTSTOP))
406 		goto out;
407 	if (sc->sc_tx_stopped)
408 		goto out;
409 	if (!ttypull(tp))
410 		goto out;
411 
412 	/* Grab the first contiguous region of buffer space. */
413 	{
414 		u_char *tba;
415 		int tbc;
416 
417 		tba = tp->t_outq.c_cf;
418 		tbc = ndqb(&tp->t_outq, 0);
419 
420 		(void)splserial();
421 
422 		sc->sc_tba = tba;
423 		sc->sc_tbc = tbc;
424 	}
425 
426 	SET(tp->t_state, TS_BUSY);
427 	sc->sc_tx_busy = 1;
428 
429 	/* Output the first chunk of the contiguous buffer. */
430 	at91dbgu_filltx(sc);
431 
432 	SET(sc->sc_ier, DBGU_INT_TXRDY);
433 	DBGUREG(DBGU_IER) = DBGU_INT_TXRDY;
434 
435 out:
436 	splx(s);
437 	return;
438 }
439 
440 static void
441 at91dbgu_break(struct at91dbgu_softc *sc, int onoff)
442 {
443 	// @@@ we must disconnect the TX pin from the DBGU and control
444 	// @@@ the pin directly to support this...
445 }
446 
447 static void
448 at91dbgu_shutdown(struct at91dbgu_softc *sc)
449 {
450 	int s;
451 
452 	s = splserial();
453 
454 	/* Turn off interrupts. */
455 	DBGUREG(DBGU_IDR) = -1;
456 
457 	/* Clear any break condition set with TIOCSBRK. */
458 	at91dbgu_break(sc, 0);
459 	at91dbgu_set(sc);
460 
461 	if (sc->disable) {
462 #ifdef DIAGNOSTIC
463 		if (!sc->enabled)
464 			panic("at91dbgu_shutdown: not enabled?");
465 #endif
466 		(*sc->disable)(sc);
467 		sc->enabled = 0;
468 	}
469 	splx(s);
470 }
471 
472 int
473 at91dbgu_open(dev_t dev, int flag, int mode, struct lwp *l)
474 {
475 	struct at91dbgu_softc *sc;
476 	struct tty *tp;
477 	int s, s2;
478 	int error;
479 
480 	sc = device_lookup_private(&at91dbgu_cd, COMUNIT(dev));
481 	if (sc == NULL || !ISSET(sc->sc_hwflags, COM_HW_DEV_OK) ||
482 		sc->sc_rbuf == NULL)
483 		return (ENXIO);
484 
485 	if (!device_is_active(sc->sc_dev))
486 		return (ENXIO);
487 
488 #ifdef KGDB
489 	/*
490 	 * If this is the kgdb port, no other use is permitted.
491 	 */
492 	if (ISSET(sc->sc_hwflags, COM_HW_KGDB))
493 		return (EBUSY);
494 #endif
495 
496 	tp = sc->sc_tty;
497 
498 	if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN, tp))
499 		return (EBUSY);
500 
501 	s = spltty();
502 
503 	/*
504 	 * Do the following iff this is a first open.
505 	 */
506 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
507 		struct termios t;
508 
509 		tp->t_dev = dev;
510 
511 		s2 = splserial();
512 
513 		if (sc->enable) {
514 			if ((*sc->enable)(sc)) {
515 				splx(s2);
516 				splx(s);
517 				printf("%s: device enable failed\n",
518 				       device_xname(sc->sc_dev));
519 				return (EIO);
520 			}
521 			sc->enabled = 1;
522 #if 0
523 /* XXXXXXXXXXXXXXX */
524 			com_config(sc);
525 #endif
526 		}
527 
528 		/* Turn on interrupts. */
529 		sc->sc_ier |= DBGU_INT_RXRDY;
530 		DBGUREG(DBGU_IER) = DBGU_INT_RXRDY;
531 
532 #if 0
533 		/* Fetch the current modem control status, needed later. */
534 		sc->sc_msr = bus_space_read_1(sc->sc_iot, sc->sc_ioh, com_msr);
535 
536 		/* Clear PPS capture state on first open. */
537 		sc->sc_ppsmask = 0;
538 		sc->ppsparam.mode = 0;
539 #endif
540 
541 		splx(s2);
542 
543 		/*
544 		 * Initialize the termios status to the defaults.  Add in the
545 		 * sticky bits from TIOCSFLAGS.
546 		 */
547 		t.c_ispeed = 0;
548 		if (ISSET(sc->sc_hwflags, COM_HW_CONSOLE)) {
549 			t.c_ospeed = dbgu_cn_sc.sc_ospeed;
550 			t.c_cflag = dbgu_cn_sc.sc_cflag;
551 		} else {
552 			t.c_ospeed = TTYDEF_SPEED;
553 			t.c_cflag = TTYDEF_CFLAG;
554 		}
555 		if (ISSET(sc->sc_swflags, TIOCFLAG_CLOCAL))
556 			SET(t.c_cflag, CLOCAL);
557 		if (ISSET(sc->sc_swflags, TIOCFLAG_CRTSCTS))
558 			SET(t.c_cflag, CRTSCTS);
559 		if (ISSET(sc->sc_swflags, TIOCFLAG_MDMBUF))
560 			SET(t.c_cflag, MDMBUF);
561 		/* Make sure at91dbgu_param() will do something. */
562 		tp->t_ospeed = 0;
563 		(void) at91dbgu_param(tp, &t);
564 		tp->t_iflag = TTYDEF_IFLAG;
565 		tp->t_oflag = TTYDEF_OFLAG;
566 		tp->t_lflag = TTYDEF_LFLAG;
567 		ttychars(tp);
568 		ttsetwater(tp);
569 
570 		s2 = splserial();
571 
572 		/* Clear the input ring, and unblock. */
573 		sc->sc_rbput = sc->sc_rbget = sc->sc_rbuf;
574 		sc->sc_rbavail = AT91DBGU_RING_SIZE;
575 		at91dbgu_iflush(sc);
576 		CLR(sc->sc_rx_flags, RX_ANY_BLOCK);
577 
578 #ifdef COM_DEBUG
579 		if (at91dbgu_debug)
580 			comstatus(sc, "at91dbgu_open  ");
581 #endif
582 
583 		splx(s2);
584 	}
585 
586 	splx(s);
587 
588 	error = ttyopen(tp, COMDIALOUT(dev), ISSET(flag, O_NONBLOCK));
589 	if (error)
590 		goto bad;
591 
592 	error = (*tp->t_linesw->l_open)(dev, tp);
593 	if (error)
594 		goto bad;
595 
596 	return (0);
597 
598 bad:
599 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
600 		/*
601 		 * We failed to open the device, and nobody else had it opened.
602 		 * Clean up the state as appropriate.
603 		 */
604 		at91dbgu_shutdown(sc);
605 	}
606 
607 	return (error);
608 }
609 
610 int
611 at91dbgu_close(dev_t dev, int flag, int mode, struct lwp *l)
612 {
613 	struct at91dbgu_softc *sc = device_lookup_private(&at91dbgu_cd, COMUNIT(dev));
614 	struct tty *tp = sc->sc_tty;
615 
616 	/* XXX This is for cons.c. */
617 	if (!ISSET(tp->t_state, TS_ISOPEN))
618 		return (0);
619 
620 	(*tp->t_linesw->l_close)(tp, flag);
621 	ttyclose(tp);
622 
623 	if (COM_ISALIVE(sc) == 0)
624 		return (0);
625 
626 	if (!ISSET(tp->t_state, TS_ISOPEN) && tp->t_wopen == 0) {
627 		/*
628 		 * Although we got a last close, the device may still be in
629 		 * use; e.g. if this was the dialout node, and there are still
630 		 * processes waiting for carrier on the non-dialout node.
631 		 */
632 		at91dbgu_shutdown(sc);
633 	}
634 
635 	return (0);
636 }
637 
638 int
639 at91dbgu_read(dev_t dev, struct uio *uio, int flag)
640 {
641 	struct at91dbgu_softc *sc = device_lookup_private(&at91dbgu_cd, COMUNIT(dev));
642 	struct tty *tp = sc->sc_tty;
643 
644 	if (COM_ISALIVE(sc) == 0)
645 		return (EIO);
646 
647 	return ((*tp->t_linesw->l_read)(tp, uio, flag));
648 }
649 
650 int
651 at91dbgu_write(dev_t dev, struct uio *uio, int flag)
652 {
653 	struct at91dbgu_softc *sc = device_lookup_private(&at91dbgu_cd, COMUNIT(dev));
654 	struct tty *tp = sc->sc_tty;
655 
656 	if (COM_ISALIVE(sc) == 0)
657 		return (EIO);
658 
659 	return ((*tp->t_linesw->l_write)(tp, uio, flag));
660 }
661 
662 int
663 at91dbgu_poll(dev_t dev, int events, struct lwp *l)
664 {
665 	struct at91dbgu_softc *sc = device_lookup_private(&at91dbgu_cd, COMUNIT(dev));
666 	struct tty *tp = sc->sc_tty;
667 
668 	if (COM_ISALIVE(sc) == 0)
669 		return (EIO);
670 
671 	return ((*tp->t_linesw->l_poll)(tp, events, l));
672 }
673 
674 struct tty *
675 at91dbgu_tty(dev_t dev)
676 {
677 	struct at91dbgu_softc *sc = device_lookup_private(&at91dbgu_cd, COMUNIT(dev));
678 	struct tty *tp = sc->sc_tty;
679 
680 	return (tp);
681 }
682 
683 int
684 at91dbgu_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
685 {
686 	struct at91dbgu_softc *sc = device_lookup_private(&at91dbgu_cd, COMUNIT(dev));
687 	struct tty *tp = sc->sc_tty;
688 	int error;
689 	int s;
690 
691 	if (COM_ISALIVE(sc) == 0)
692 		return (EIO);
693 
694 	error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
695 	if (error != EPASSTHROUGH)
696 		return (error);
697 
698 	error = ttioctl(tp, cmd, data, flag, l);
699 	if (error != EPASSTHROUGH)
700 		return (error);
701 
702 	error = 0;
703 
704 	s = splserial();
705 
706 	switch (cmd) {
707 	case TIOCSBRK:
708 		at91dbgu_break(sc, 1);
709 		break;
710 
711 	case TIOCCBRK:
712 		at91dbgu_break(sc, 0);
713 		break;
714 
715 	case TIOCGFLAGS:
716 		*(int *)data = sc->sc_swflags;
717 		break;
718 
719 	case TIOCSFLAGS:
720 		error = kauth_authorize_device_tty(l->l_cred,
721 		    KAUTH_DEVICE_TTY_PRIVSET, tp);
722 		if (error)
723 			break;
724 		sc->sc_swflags = *(int *)data;
725 		break;
726 
727 	default:
728 		error = EPASSTHROUGH;
729 		break;
730 	}
731 
732 	splx(s);
733 
734 	return (error);
735 }
736 
737 /*
738  * Stop output on a line.
739  */
740 void
741 at91dbgu_stop(struct tty *tp, int flag)
742 {
743 	struct at91dbgu_softc *sc
744 		= device_lookup_private(&at91dbgu_cd, COMUNIT(tp->t_dev));
745 	int s;
746 
747 	s = splserial();
748 	if (ISSET(tp->t_state, TS_BUSY)) {
749 		/* Stop transmitting at the next chunk. */
750 		sc->sc_tbc = 0;
751 		if (!ISSET(tp->t_state, TS_TTSTOP))
752 			SET(tp->t_state, TS_FLUSH);
753 	}
754 	splx(s);
755 }
756 
757 #if 0
758 static u_int
759 cflag2lcrhi(tcflag_t cflag)
760 {
761 	uint32_t	mr;
762 
763 	switch (cflag & CSIZE) {
764 	default:
765 		mr = 0x0;
766 		break;
767 	}
768 #if 0
769 	mr |= (cflag & PARENB) ? LinCtrlHigh_PEN : 0;
770 	mr |= (cflag & PARODD) ? 0 : LinCtrlHigh_EPS;
771 	mr |= (cflag & CSTOPB) ? LinCtrlHigh_STP2 : 0;
772 	mr |= LinCtrlHigh_FEN;  /* FIFO always enabled */
773 #endif
774 	mr |= DBGU_MR_PAR_NONE;
775 	return (mr);
776 }
777 #endif
778 
779 static void
780 at91dbgu_iflush(struct at91dbgu_softc *sc)
781 {
782 #if 0
783 	bus_space_tag_t iot = sc->sc_iot;
784 	bus_space_handle_t ioh = sc->sc_ioh;
785 #endif
786 #ifdef DIAGNOSTIC
787 	int reg;
788 #endif
789 	int timo;
790 
791 #ifdef DIAGNOSTIC
792 	reg = 0xffff;
793 #endif
794 	timo = 50000;
795 	/* flush any pending I/O */
796 	while (DBGUREG(DBGU_SR) & DBGU_SR_RXRDY
797 	       && --timo)
798 #ifdef DIAGNOSTIC
799 		reg =
800 #else
801 			(void)
802 #endif
803 			DBGUREG(DBGU_RHR);
804 #ifdef DIAGNOSTIC
805 	if (!timo)
806 		printf("%s: com_iflush timeout %02x\n", device_xname(sc->sc_dev),
807 		       reg);
808 #endif
809 }
810 
811 static void
812 at91dbgu_set(struct at91dbgu_softc *sc)
813 {
814 	DBGUREG(DBGU_MR) = DBGU_MR_PAR_NONE;
815 	DBGUREG(DBGU_BRGR) = sc->sc_brgr;
816 	DBGUREG(DBGU_CR) = DBGU_CR_TXEN | DBGU_CR_RXEN; // @@@ just in case
817 }
818 
819 void
820 at91dbgu_cn_attach(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t ioh,
821 		   int ospeed, tcflag_t cflag);
822 void
823 at91dbgu_cn_attach(bus_space_tag_t iot, bus_addr_t iobase, bus_space_handle_t ioh,
824 		   int ospeed, tcflag_t cflag)
825 {
826 	cn_tab = &at91dbgu_cons;
827 	cn_init_magic(&at91dbgu_cnm_state);
828 	cn_set_magic("\047\001");
829 
830 	dbgu_cn_sc.sc_iot = iot;
831 	dbgu_cn_sc.sc_ioh = ioh;
832 	dbgu_cn_sc.sc_hwbase = iobase;
833 	dbgu_cn_sc.sc_ospeed = ospeed;
834 	dbgu_cn_sc.sc_cflag = cflag;
835 
836 	DBGU_INIT(AT91_MSTCLK, ospeed);
837 }
838 
839 void at91dbgu_attach_cn(bus_space_tag_t iot, int ospeed, int cflag)
840 {
841 	bus_space_handle_t ioh;
842 	bus_space_map(iot, AT91DBGU_BASE, AT91DBGU_SIZE, 0, &ioh);
843 	at91dbgu_cn_attach(iot, AT91DBGU_BASE, ioh, ospeed, cflag);
844 }
845 
846 void
847 at91dbgu_cn_probe(struct consdev *cp)
848 {
849 	cp->cn_pri = CN_REMOTE;
850 }
851 
852 void
853 at91dbgu_cn_pollc(dev_t dev, int on)
854 {
855 	if (on) {
856 		// enable polling mode
857 		DBGUREG(DBGU_IDR) = DBGU_INT_RXRDY;
858 	} else {
859 		// disable polling mode
860 		DBGUREG(DBGU_IER) = DBGU_INT_RXRDY;
861 	}
862 }
863 
864 void
865 at91dbgu_cn_putc(dev_t dev, int c)
866 {
867 #if 0
868 	bus_space_tag_t		iot = dbgu_cn_sc.sc_iot;
869 	bus_space_handle_t	ioh = dbgu_cn_sc.sc_ioh;
870 #endif
871 	DBGU_PUTC(c);
872 
873 #ifdef DEBUG
874 	if (c == '\r') {
875 		int s = splserial();
876 		while((DBGUREG(DBGU_SR) & DBGU_SR_TXEMPTY) == 0) {
877 			splx(s);
878 			s = splserial();
879 		}
880 		splx(s);
881 	}
882 #endif
883 
884 }
885 
886 int
887 at91dbgu_cn_getc(dev_t dev)
888 {
889 	int			c, sr;
890 	int			s;
891 #if 0
892 	bus_space_tag_t		iot = dbgu_cn_sc.sc_iot;
893 	bus_space_handle_t	ioh = dbgu_cn_sc.sc_ioh;
894 #endif
895 
896         s = splserial();
897 
898 	while ((c = DBGU_PEEKC()) == -1) {
899 	  splx(s);
900 	  s = splserial();
901 	}
902 		;
903 	sr = DBGUREG(DBGU_SR);
904 	if (ISSET(sr, DBGU_SR_FRAME) && c == 0) {
905 		DBGUREG(DBGU_CR) = DBGU_CR_RSTSTA;	// reset status bits
906 		c = CNC_BREAK;
907 	}
908 #ifdef DDB
909 	extern int db_active;
910 	if (!db_active)
911 #endif
912 	{
913 		int cn_trapped __unused = 0;
914 
915 		cn_check_magic(dev, c, at91dbgu_cnm_state);
916 	}
917 	splx(s);
918 
919 	c &= 0xff;
920 
921 	return (c);
922 }
923 
924 inline static void
925 at91dbgu_txsoft(struct at91dbgu_softc *sc, struct tty *tp)
926 {
927 	CLR(tp->t_state, TS_BUSY);
928 	if (ISSET(tp->t_state, TS_FLUSH))
929 		CLR(tp->t_state, TS_FLUSH);
930         else
931 		ndflush(&tp->t_outq, (int)(sc->sc_tba - tp->t_outq.c_cf));
932 	(*tp->t_linesw->l_start)(tp);
933 }
934 
935 inline static void
936 at91dbgu_rxsoft(struct at91dbgu_softc *sc, struct tty *tp)
937 {
938 	int (*rint)(int, struct tty *) = tp->t_linesw->l_rint;
939 	u_char *get, *end;
940 	u_int cc, scc;
941 	u_char sts;
942 	int code;
943 	int s;
944 
945 	end = sc->sc_ebuf;
946 	get = sc->sc_rbget;
947 	scc = cc = AT91DBGU_RING_SIZE - sc->sc_rbavail;
948 #if 0
949 	if (cc == AT91DBGU_RING_SIZE) {
950 		sc->sc_floods++;
951 		if (sc->sc_errors++ == 0)
952 			callout_reset(&sc->sc_diag_callout, 60 * hz,
953 			    comdiag, sc);
954 	}
955 #endif
956 	while (cc) {
957 		code = get[0];
958 		sts = get[1];
959 		if (ISSET(sts, DBGU_SR_PARE | DBGU_SR_FRAME | DBGU_SR_OVRE)) {
960 #if 0
961 			if (ISSET(lsr, DR_ROR)) {
962 				sc->sc_overflows++;
963 				if (sc->sc_errors++ == 0)
964 					callout_reset(&sc->sc_diag_callout,
965 					    60 * hz, comdiag, sc);
966 			}
967 #endif
968 			if (ISSET(sts, (DBGU_SR_FRAME | DBGU_SR_OVRE)))
969 				SET(code, TTY_FE);
970 			if (ISSET(sts, DBGU_SR_PARE))
971 				SET(code, TTY_PE);
972 		}
973 		if ((*rint)(code, tp) == -1) {
974 			/*
975 			 * The line discipline's buffer is out of space.
976 			 */
977 			if (!ISSET(sc->sc_rx_flags, RX_TTY_BLOCKED)) {
978 				/*
979 				 * We're either not using flow control, or the
980 				 * line discipline didn't tell us to block for
981 				 * some reason.  Either way, we have no way to
982 				 * know when there's more space available, so
983 				 * just drop the rest of the data.
984 				 */
985 				get += cc << 1;
986 				if (get >= end)
987 					get -= AT91DBGU_RING_SIZE << 1;
988 				cc = 0;
989 			} else {
990 				/*
991 				 * Don't schedule any more receive processing
992 				 * until the line discipline tells us there's
993 				 * space available (through comhwiflow()).
994 				 * Leave the rest of the data in the input
995 				 * buffer.
996 				 */
997 				SET(sc->sc_rx_flags, RX_TTY_OVERFLOWED);
998 			}
999 			break;
1000 		}
1001 		get += 2;
1002 		if (get >= end)
1003 			get = sc->sc_rbuf;
1004 		cc--;
1005 	}
1006 
1007 	if (cc != scc) {
1008 		sc->sc_rbget = get;
1009 		s = splserial();
1010 
1011 		cc = sc->sc_rbavail += scc - cc;
1012 		/* Buffers should be ok again, release possible block. */
1013 		if (cc >= 1) {
1014 			if (ISSET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED)) {
1015 				CLR(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1016 				DBGUREG(DBGU_IER) = DBGU_INT_RXRDY;
1017 			}
1018 			if (ISSET(sc->sc_rx_flags, RX_IBUF_BLOCKED)) {
1019 				CLR(sc->sc_rx_flags, RX_IBUF_BLOCKED);
1020 #if 0
1021 				com_hwiflow(sc);
1022 #endif
1023 			}
1024 		}
1025 		splx(s);
1026 	}
1027 }
1028 
1029 static void
1030 at91dbgu_soft(void* arg)
1031 {
1032 	struct at91dbgu_softc *sc = arg;
1033 
1034 	if (COM_ISALIVE(sc) == 0)
1035 		return;
1036 
1037 	if (sc->sc_rx_ready) {
1038 		sc->sc_rx_ready = 0;
1039 		at91dbgu_rxsoft(sc, sc->sc_tty);
1040 	}
1041 	if (sc->sc_tx_done) {
1042 		sc->sc_tx_done = 0;
1043 		at91dbgu_txsoft(sc, sc->sc_tty);
1044 	}
1045 }
1046 
1047 
1048 static int
1049 dbgu_intr(void* arg)
1050 {
1051 	struct at91dbgu_softc *sc = arg;
1052 #if 0
1053 	bus_space_tag_t iot = sc->sc_iot;
1054 	bus_space_handle_t ioh = sc->sc_ioh;
1055 #endif
1056 	u_char *put, *end;
1057 	u_int cc;
1058 	uint32_t imr, sr;
1059 	int c = 0;
1060 	imr = DBGUREG(DBGU_IMR);
1061 #if 0
1062 	if (!imr)
1063 		return 0;
1064 #endif
1065 	sr = DBGUREG(DBGU_SR);
1066 	if (!(sr & imr)) {
1067 		if (sr & DBGU_SR_RXRDY) {
1068 //			printf("sr=0x%08x imr=0x%08x\n", sr, imr);
1069 		}
1070 		return 0;
1071 	}
1072 
1073 	end = sc->sc_ebuf;
1074 	put = sc->sc_rbput;
1075 	cc = sc->sc_rbavail;
1076 
1077 	// ok, we DO have some interrupts to serve!
1078 	if (sr & DBGU_SR_RXRDY) {
1079 		int cn_trapped = 0;
1080 
1081 		c = DBGUREG(DBGU_RHR);
1082 		if (ISSET(sr, (DBGU_SR_OVRE | DBGU_SR_FRAME | DBGU_SR_PARE)))
1083 			DBGUREG(DBGU_CR) = DBGU_CR_RSTSTA;
1084 		if (ISSET(sr, DBGU_SR_FRAME) && c == 0) {
1085 			c = CNC_BREAK;
1086 		}
1087 #ifdef DDB
1088 		extern int db_active;
1089 		if (!db_active)
1090 #endif
1091 			cn_check_magic(cn_tab->cn_dev, c, at91dbgu_cnm_state);
1092 		if (!cn_trapped && cc) {
1093 			put[0] = c & 0xff;
1094 			put[1] = sr & 0xff;
1095 			put += 2;
1096 			if (put >= end)
1097 				put = sc->sc_rbuf;
1098 			cc--;
1099 			/*
1100 			 * Current string of incoming characters ended because
1101 			 * no more data was available or we ran out of space.
1102 			 * Schedule a receive event if any data was received.
1103 			 * If we're out of space, turn off receive interrupts.
1104 			 */
1105 			sc->sc_rbput = put;
1106 			sc->sc_rbavail = cc;
1107 			if (!ISSET(sc->sc_rx_flags, RX_TTY_OVERFLOWED))
1108 				sc->sc_rx_ready = 1;
1109 
1110 			/*
1111 			 * See if we are in danger of overflowing a buffer. If
1112 			 * so, use hardware flow control to ease the pressure.
1113 			 */
1114 
1115 			/* but at91dbgu cannot (yet). X-( */
1116 
1117 			/*
1118 			 * If we're out of space, disable receive interrupts
1119 			 * until the queue has drained a bit.
1120 			 */
1121 			if (!cc) {
1122 				SET(sc->sc_rx_flags, RX_IBUF_OVERFLOWED);
1123 			}
1124 		}
1125 	}
1126 
1127 	/*
1128 	 * Done handling any receive interrupts. See if data can be
1129 	 * transmitted as well. Schedule tx done event if no data left
1130 	 * and tty was marked busy.
1131 	 */
1132 
1133 	if (ISSET(sr, DBGU_SR_TXRDY) && sc->sc_tbc > 0) {
1134 		/* Output the next chunk of the contiguous buffer, if any. */
1135 		at91dbgu_filltx(sc);
1136 	} else {
1137 		/* Disable transmit completion interrupts if necessary. */
1138 		DBGUREG(DBGU_IDR) = DBGU_INT_TXRDY;
1139 		if (sc->sc_tx_busy) {
1140 			sc->sc_tx_busy = 0;
1141 			sc->sc_tx_done = 1;
1142 		}
1143 	}
1144 
1145 	/* Wake up the poller. */
1146 	softint_schedule(sc->sc_si);
1147 #if 0
1148 #ifdef RND_COM
1149 	rnd_add_uint32(&sc->rnd_source, imr ^ sr ^ c);
1150 #endif
1151 #endif
1152 
1153 	return (1);
1154 }
1155