1 /*
2  * Copyright (c) 2003 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <machine/bus.h>
35 
36 #include <dev/uart/uart.h>
37 #include <dev/uart/uart_cpu.h>
38 #include <dev/uart/uart_bus.h>
39 #include <dev/uart/uart_dev_sab82532.h>
40 
41 #include "uart_if.h"
42 
43 #define	DEFAULT_RCLK	29491200
44 
45 /*
46  * NOTE: To allow us to read the baudrate divisor from the chip, we
47  * copy the value written to the write-only BGR register to an unused
48  * read-write register. We use TCR for that.
49  */
50 
51 static int
52 sab82532_delay(struct uart_bas *bas)
53 {
54 	int divisor, m, n;
55 	uint8_t bgr, ccr2;
56 
57 	bgr = uart_getreg(bas, SAB_TCR);
58 	ccr2 = uart_getreg(bas, SAB_CCR2);
59 	n = (bgr & 0x3f) + 1;
60 	m = (bgr >> 6) | ((ccr2 >> 4) & 0xC);
61 	divisor = n * (1<<m);
62 
63 	/* 1/10th the time to transmit 1 character (estimate). */
64 	return (16000000 * divisor / bas->rclk);
65 }
66 
67 static int
68 sab82532_divisor(int rclk, int baudrate)
69 {
70 	int act_baud, act_div, divisor;
71 	int error, m, n;
72 
73 	if (baudrate == 0)
74 		return (0);
75 
76 	divisor = (rclk / (baudrate << 3) + 1) >> 1;
77 	if (divisor < 2 || divisor >= 1048576)
78 		return (0);
79 
80 	/* Find the best (N+1,M) pair. */
81 	for (m = 1; m < 15; m++) {
82 		n = divisor / (1<<m);
83 		if (n < 1 || n > 63)
84 			continue;
85 		act_div = n * (1<<m);
86 		act_baud = rclk / (act_div << 4);
87 
88 		/* 10 times error in percent: */
89 		error = ((act_baud - baudrate) * 2000 / baudrate + 1) >> 1;
90 
91 		/* 3.0% maximum error tolerance: */
92 		if (error < -30 || error > 30)
93 			continue;
94 
95 		/* Got it. */
96 		return ((n - 1) | (m << 6));
97 	}
98 
99 	return (0);
100 }
101 
102 static void
103 sab82532_flush(struct uart_bas *bas, int what)
104 {
105 
106 	if (what & UART_FLUSH_TRANSMITTER) {
107 		while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
108 			;
109 		uart_setreg(bas, SAB_CMDR, SAB_CMDR_XRES);
110 		uart_barrier(bas);
111 	}
112 	if (what & UART_FLUSH_RECEIVER) {
113 		while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
114 			;
115 		uart_setreg(bas, SAB_CMDR, SAB_CMDR_RRES);
116 		uart_barrier(bas);
117 	}
118 }
119 
120 static int
121 sab82532_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
122     int parity)
123 {
124 	int divisor;
125 	uint8_t ccr2, dafo;
126 
127 	if (databits >= 8)
128 		dafo = SAB_DAFO_CHL_CS8;
129 	else if (databits == 7)
130 		dafo = SAB_DAFO_CHL_CS7;
131 	else if (databits == 6)
132 		dafo = SAB_DAFO_CHL_CS6;
133 	else
134 		dafo = SAB_DAFO_CHL_CS5;
135 	if (stopbits > 1)
136 		dafo |= SAB_DAFO_STOP;
137 	switch (parity) {
138 	case UART_PARITY_EVEN:	dafo |= SAB_DAFO_PAR_EVEN; break;
139 	case UART_PARITY_MARK:	dafo |= SAB_DAFO_PAR_MARK; break;
140 	case UART_PARITY_NONE:	dafo |= SAB_DAFO_PAR_NONE; break;
141 	case UART_PARITY_ODD:	dafo |= SAB_DAFO_PAR_ODD; break;
142 	case UART_PARITY_SPACE:	dafo |= SAB_DAFO_PAR_SPACE; break;
143 	default:		return (EINVAL);
144 	}
145 
146 	/* Set baudrate. */
147 	if (baudrate > 0) {
148 		divisor = sab82532_divisor(bas->rclk, baudrate);
149 		if (divisor == 0)
150 			return (EINVAL);
151 		uart_setreg(bas, SAB_BGR, divisor & 0xff);
152 		uart_barrier(bas);
153 		/* Allow reading the (n-1,m) tuple from the chip. */
154 		uart_setreg(bas, SAB_TCR, divisor & 0xff);
155 		uart_barrier(bas);
156 		ccr2 = uart_getreg(bas, SAB_CCR2);
157 		ccr2 &= ~(SAB_CCR2_BR9 | SAB_CCR2_BR8);
158 		ccr2 |= (divisor >> 2) & (SAB_CCR2_BR9 | SAB_CCR2_BR8);
159 		uart_setreg(bas, SAB_CCR2, ccr2);
160 		uart_barrier(bas);
161 	}
162 
163 	uart_setreg(bas, SAB_DAFO, dafo);
164 	uart_barrier(bas);
165 	return (0);
166 }
167 
168 /*
169  * Low-level UART interface.
170  */
171 static int sab82532_probe(struct uart_bas *bas);
172 static void sab82532_init(struct uart_bas *bas, int, int, int, int);
173 static void sab82532_term(struct uart_bas *bas);
174 static void sab82532_putc(struct uart_bas *bas, int);
175 static int sab82532_poll(struct uart_bas *bas);
176 static int sab82532_getc(struct uart_bas *bas);
177 
178 struct uart_ops uart_sab82532_ops = {
179 	.probe = sab82532_probe,
180 	.init = sab82532_init,
181 	.term = sab82532_term,
182 	.putc = sab82532_putc,
183 	.poll = sab82532_poll,
184 	.getc = sab82532_getc,
185 };
186 
187 static int
188 sab82532_probe(struct uart_bas *bas)
189 {
190 
191 	return (0);
192 }
193 
194 static void
195 sab82532_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
196     int parity)
197 {
198 	uint8_t ccr0, pvr;
199 
200 	if (bas->rclk == 0)
201 		bas->rclk = DEFAULT_RCLK;
202 
203 	/*
204 	 * Set all pins, except the DTR pins (pin 1 and 2) to be inputs.
205 	 * Pin 4 is magical, meaning that I don't know what it does, but
206 	 * it too has to be set to output.
207 	 */
208 	uart_setreg(bas, SAB_PCR,
209 	    ~(SAB_PVR_DTR_A|SAB_PVR_DTR_B|SAB_PVR_MAGIC));
210 	uart_barrier(bas);
211 	/* Disable port interrupts. */
212 	uart_setreg(bas, SAB_PIM, 0xff);
213 	uart_barrier(bas);
214 	/* Interrupts are active low. */
215 	uart_setreg(bas, SAB_IPC, SAB_IPC_ICPL);
216 	uart_barrier(bas);
217 	/* Set DTR. */
218 	pvr = uart_getreg(bas, SAB_PVR);
219 	switch (bas->chan) {
220 	case 1:
221 		pvr &= ~SAB_PVR_DTR_A;
222 		break;
223 	case 2:
224 		pvr &= ~SAB_PVR_DTR_B;
225 		break;
226 	}
227 	uart_setreg(bas, SAB_PVR, pvr | SAB_PVR_MAGIC);
228 	uart_barrier(bas);
229 
230 	/* power down */
231 	uart_setreg(bas, SAB_CCR0, 0);
232 	uart_barrier(bas);
233 
234 	/* set basic configuration */
235 	ccr0 = SAB_CCR0_MCE|SAB_CCR0_SC_NRZ|SAB_CCR0_SM_ASYNC;
236 	uart_setreg(bas, SAB_CCR0, ccr0);
237 	uart_barrier(bas);
238 	uart_setreg(bas, SAB_CCR1, SAB_CCR1_ODS|SAB_CCR1_BCR|SAB_CCR1_CM_7);
239 	uart_barrier(bas);
240 	uart_setreg(bas, SAB_CCR2, SAB_CCR2_BDF|SAB_CCR2_SSEL|SAB_CCR2_TOE);
241 	uart_barrier(bas);
242 	uart_setreg(bas, SAB_CCR3, 0);
243 	uart_barrier(bas);
244 	uart_setreg(bas, SAB_CCR4, SAB_CCR4_MCK4|SAB_CCR4_EBRG|SAB_CCR4_ICD);
245 	uart_barrier(bas);
246 	uart_setreg(bas, SAB_MODE, SAB_MODE_FCTS|SAB_MODE_RTS|SAB_MODE_RAC);
247 	uart_barrier(bas);
248 	uart_setreg(bas, SAB_RFC, SAB_RFC_DPS|SAB_RFC_RFDF|
249 	    SAB_RFC_RFTH_32CHAR);
250 	uart_barrier(bas);
251 
252 	sab82532_param(bas, baudrate, databits, stopbits, parity);
253 
254 	/* Clear interrupts. */
255 	uart_setreg(bas, SAB_IMR0, 0xff);
256 	uart_setreg(bas, SAB_IMR1, 0xff);
257 	uart_barrier(bas);
258 	uart_getreg(bas, SAB_ISR0);
259 	uart_getreg(bas, SAB_ISR1);
260 	uart_barrier(bas);
261 
262 	sab82532_flush(bas, UART_FLUSH_TRANSMITTER|UART_FLUSH_RECEIVER);
263 
264 	/* Power up. */
265 	uart_setreg(bas, SAB_CCR0, ccr0|SAB_CCR0_PU);
266 	uart_barrier(bas);
267 }
268 
269 static void
270 sab82532_term(struct uart_bas *bas)
271 {
272 	uint8_t pvr;
273 
274 	pvr = uart_getreg(bas, SAB_PVR);
275 	switch (bas->chan) {
276 	case 1:
277 		pvr |= SAB_PVR_DTR_A;
278 		break;
279 	case 2:
280 		pvr |= SAB_PVR_DTR_B;
281 		break;
282 	}
283 	uart_setreg(bas, SAB_PVR, pvr);
284 	uart_barrier(bas);
285 }
286 
287 static void
288 sab82532_putc(struct uart_bas *bas, int c)
289 {
290 	int delay, limit;
291 
292 	/* 1/10th the time to transmit 1 character (estimate). */
293 	delay = sab82532_delay(bas);
294 
295 	limit = 20;
296 	while ((uart_getreg(bas, SAB_STAR) & SAB_STAR_TEC) && --limit)
297 		DELAY(delay);
298 	uart_setreg(bas, SAB_TIC, c);
299 	limit = 20;
300 	while ((uart_getreg(bas, SAB_STAR) & SAB_STAR_TEC) && --limit)
301 		DELAY(delay);
302 }
303 
304 static int
305 sab82532_poll(struct uart_bas *bas)
306 {
307 
308 	if (uart_getreg(bas, SAB_STAR) & SAB_STAR_RFNE)
309 		return (sab82532_getc(bas));
310 	return (-1);
311 }
312 
313 static int
314 sab82532_getc(struct uart_bas *bas)
315 {
316 	int c, delay;
317 
318 	/* 1/10th the time to transmit 1 character (estimate). */
319 	delay = sab82532_delay(bas);
320 
321 	while (!(uart_getreg(bas, SAB_STAR) & SAB_STAR_RFNE))
322 		DELAY(delay);
323 
324 	while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
325 		;
326 	uart_setreg(bas, SAB_CMDR, SAB_CMDR_RFRD);
327 	uart_barrier(bas);
328 
329 	while (!(uart_getreg(bas, SAB_ISR0) & SAB_ISR0_TCD))
330 		DELAY(delay);
331 
332 	c = uart_getreg(bas, SAB_RFIFO);
333 	uart_barrier(bas);
334 
335 	/* Blow away everything left in the FIFO... */
336 	while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
337 		;
338 	uart_setreg(bas, SAB_CMDR, SAB_CMDR_RMC);
339 	uart_barrier(bas);
340 	return (c);
341 }
342 
343 /*
344  * High-level UART interface.
345  */
346 struct sab82532_softc {
347 	struct uart_softc base;
348 };
349 
350 static int sab82532_bus_attach(struct uart_softc *);
351 static int sab82532_bus_detach(struct uart_softc *);
352 static int sab82532_bus_flush(struct uart_softc *, int);
353 static int sab82532_bus_getsig(struct uart_softc *);
354 static int sab82532_bus_ioctl(struct uart_softc *, int, intptr_t);
355 static int sab82532_bus_ipend(struct uart_softc *);
356 static int sab82532_bus_param(struct uart_softc *, int, int, int, int);
357 static int sab82532_bus_probe(struct uart_softc *);
358 static int sab82532_bus_receive(struct uart_softc *);
359 static int sab82532_bus_setsig(struct uart_softc *, int);
360 static int sab82532_bus_transmit(struct uart_softc *);
361 
362 static kobj_method_t sab82532_methods[] = {
363 	KOBJMETHOD(uart_attach,		sab82532_bus_attach),
364 	KOBJMETHOD(uart_detach,		sab82532_bus_detach),
365 	KOBJMETHOD(uart_flush,		sab82532_bus_flush),
366 	KOBJMETHOD(uart_getsig,		sab82532_bus_getsig),
367 	KOBJMETHOD(uart_ioctl,		sab82532_bus_ioctl),
368 	KOBJMETHOD(uart_ipend,		sab82532_bus_ipend),
369 	KOBJMETHOD(uart_param,		sab82532_bus_param),
370 	KOBJMETHOD(uart_probe,		sab82532_bus_probe),
371 	KOBJMETHOD(uart_receive,	sab82532_bus_receive),
372 	KOBJMETHOD(uart_setsig,		sab82532_bus_setsig),
373 	KOBJMETHOD(uart_transmit,	sab82532_bus_transmit),
374 	{ 0, 0 }
375 };
376 
377 struct uart_class uart_sab82532_class = {
378 	"sab82532 class",
379 	sab82532_methods,
380 	sizeof(struct sab82532_softc),
381 	.uc_range = 64,
382 	.uc_rclk = DEFAULT_RCLK
383 };
384 
385 #define	SIGCHG(c, i, s, d)				\
386 	if (c) {					\
387 		i |= (i & s) ? s : s | d;		\
388 	} else {					\
389 		i = (i & s) ? (i & ~s) | d : i;		\
390 	}
391 
392 static int
393 sab82532_bus_attach(struct uart_softc *sc)
394 {
395 	struct uart_bas *bas;
396 	uint8_t imr0, imr1;
397 
398 	bas = &sc->sc_bas;
399 	if (sc->sc_sysdev == NULL)
400 		sab82532_init(bas, 9600, 8, 1, UART_PARITY_NONE);
401 
402 	sc->sc_rxfifosz = 32;
403 	sc->sc_txfifosz = 32;
404 
405 	imr0 = SAB_IMR0_TCD|SAB_IMR0_TIME|SAB_IMR0_CDSC|SAB_IMR0_RFO|
406 	    SAB_IMR0_RPF;
407 	uart_setreg(bas, SAB_IMR0, 0xff & ~imr0);
408 	imr1 = SAB_IMR1_BRKT|SAB_IMR1_ALLS|SAB_IMR1_CSC;
409 	uart_setreg(bas, SAB_IMR1, 0xff & ~imr1);
410 	uart_barrier(bas);
411 
412 	if (sc->sc_sysdev == NULL)
413 		sab82532_bus_setsig(sc, UART_SIG_DDTR|UART_SIG_DRTS);
414 	(void)sab82532_bus_getsig(sc);
415 	return (0);
416 }
417 
418 static int
419 sab82532_bus_detach(struct uart_softc *sc)
420 {
421 	struct uart_bas *bas;
422 
423 	bas = &sc->sc_bas;
424 	uart_setreg(bas, SAB_IMR0, 0xff);
425 	uart_setreg(bas, SAB_IMR1, 0xff);
426 	uart_barrier(bas);
427 	uart_getreg(bas, SAB_ISR0);
428 	uart_getreg(bas, SAB_ISR1);
429 	uart_barrier(bas);
430 	uart_setreg(bas, SAB_CCR0, 0);
431 	uart_barrier(bas);
432 	return (0);
433 }
434 
435 static int
436 sab82532_bus_flush(struct uart_softc *sc, int what)
437 {
438 
439 	mtx_lock_spin(&sc->sc_hwmtx);
440 	sab82532_flush(&sc->sc_bas, what);
441 	mtx_unlock_spin(&sc->sc_hwmtx);
442 	return (0);
443 }
444 
445 static int
446 sab82532_bus_getsig(struct uart_softc *sc)
447 {
448 	struct uart_bas *bas;
449 	uint32_t new, old, sig;
450 	uint8_t pvr, star, vstr;
451 
452 	bas = &sc->sc_bas;
453 	do {
454 		old = sc->sc_hwsig;
455 		sig = old;
456 		mtx_lock_spin(&sc->sc_hwmtx);
457 		star = uart_getreg(bas, SAB_STAR);
458 		SIGCHG(star & SAB_STAR_CTS, sig, UART_SIG_CTS, UART_SIG_DCTS);
459 		vstr = uart_getreg(bas, SAB_VSTR);
460 		SIGCHG(vstr & SAB_VSTR_CD, sig, UART_SIG_DCD, UART_SIG_DDCD);
461 		pvr = uart_getreg(bas, SAB_PVR);
462 		switch (bas->chan) {
463 		case 1:
464 			pvr &= SAB_PVR_DSR_A;
465 			break;
466 		case 2:
467 			pvr &= SAB_PVR_DSR_B;
468 			break;
469 		}
470 		SIGCHG(~pvr, sig, UART_SIG_DSR, UART_SIG_DDSR);
471 		mtx_unlock_spin(&sc->sc_hwmtx);
472 		new = sig & ~UART_SIGMASK_DELTA;
473 	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
474 	return (sig);
475 }
476 
477 static int
478 sab82532_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
479 {
480 	struct uart_bas *bas;
481 	uint8_t dafo, mode;
482 	int error;
483 
484 	bas = &sc->sc_bas;
485 	error = 0;
486 	mtx_lock_spin(&sc->sc_hwmtx);
487 	switch (request) {
488 	case UART_IOCTL_BREAK:
489 		dafo = uart_getreg(bas, SAB_DAFO);
490 		if (data)
491 			dafo |= SAB_DAFO_XBRK;
492 		else
493 			dafo &= ~SAB_DAFO_XBRK;
494 		uart_setreg(bas, SAB_DAFO, dafo);
495 		uart_barrier(bas);
496 		break;
497 	case UART_IOCTL_IFLOW:
498 		mode = uart_getreg(bas, SAB_MODE);
499 		if (data) {
500 			mode &= ~SAB_MODE_RTS;
501 			mode |= SAB_MODE_FRTS;
502 		} else {
503 			mode |= SAB_MODE_RTS;
504 			mode &= ~SAB_MODE_FRTS;
505 		}
506 		uart_setreg(bas, SAB_MODE, mode);
507 		uart_barrier(bas);
508 		break;
509 	case UART_IOCTL_OFLOW:
510 		mode = uart_getreg(bas, SAB_MODE);
511 		if (data)
512 			mode &= ~SAB_MODE_FCTS;
513 		else
514 			mode |= SAB_MODE_FCTS;
515 		uart_setreg(bas, SAB_MODE, mode);
516 		uart_barrier(bas);
517 		break;
518 	default:
519 		error = EINVAL;
520 		break;
521 	}
522 	mtx_unlock_spin(&sc->sc_hwmtx);
523 	return (error);
524 }
525 
526 static int
527 sab82532_bus_ipend(struct uart_softc *sc)
528 {
529 	struct uart_bas *bas;
530 	int ipend;
531 	uint8_t isr0, isr1;
532 
533 	bas = &sc->sc_bas;
534 	mtx_lock_spin(&sc->sc_hwmtx);
535 	isr0 = uart_getreg(bas, SAB_ISR0);
536 	isr1 = uart_getreg(bas, SAB_ISR1);
537 	uart_barrier(bas);
538 	if (isr0 & SAB_ISR0_TIME) {
539 		while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
540 			;
541 		uart_setreg(bas, SAB_CMDR, SAB_CMDR_RFRD);
542 		uart_barrier(bas);
543 	}
544 	mtx_unlock_spin(&sc->sc_hwmtx);
545 
546 	ipend = 0;
547 	if (isr1 & SAB_ISR1_BRKT)
548 		ipend |= UART_IPEND_BREAK;
549 	if (isr0 & SAB_ISR0_RFO)
550 		ipend |= UART_IPEND_OVERRUN;
551 	if (isr0 & (SAB_ISR0_TCD|SAB_ISR0_RPF))
552 		ipend |= UART_IPEND_RXREADY;
553 	if ((isr0 & SAB_ISR0_CDSC) || (isr1 & SAB_ISR1_CSC))
554 		ipend |= UART_IPEND_SIGCHG;
555 	if (isr1 & SAB_ISR1_ALLS)
556 		ipend |= UART_IPEND_TXIDLE;
557 
558 	return (ipend);
559 }
560 
561 static int
562 sab82532_bus_param(struct uart_softc *sc, int baudrate, int databits,
563     int stopbits, int parity)
564 {
565 	struct uart_bas *bas;
566 	int error;
567 
568 	bas = &sc->sc_bas;
569 	mtx_lock_spin(&sc->sc_hwmtx);
570 	error = sab82532_param(bas, baudrate, databits, stopbits, parity);
571 	mtx_unlock_spin(&sc->sc_hwmtx);
572 	return (error);
573 }
574 
575 static int
576 sab82532_bus_probe(struct uart_softc *sc)
577 {
578 	char buf[80];
579 	const char *vstr;
580 	int error;
581 	char ch;
582 
583 	error = sab82532_probe(&sc->sc_bas);
584 	if (error)
585 		return (error);
586 
587 	ch = sc->sc_bas.chan - 1 + 'A';
588 
589 	switch (uart_getreg(&sc->sc_bas, SAB_VSTR) & SAB_VSTR_VMASK) {
590 	case SAB_VSTR_V_1:
591 		vstr = "v1";
592 		break;
593 	case SAB_VSTR_V_2:
594 		vstr = "v2";
595 		break;
596 	case SAB_VSTR_V_32:
597 		vstr = "v3.2";
598 		sc->sc_hwiflow = 0;	/* CTS doesn't work with RFC:RFDF. */
599 		sc->sc_hwoflow = 1;
600 		break;
601 	default:
602 		vstr = "v4?";
603 		break;
604 	}
605 
606 	snprintf(buf, sizeof(buf), "SAB 82532 %s, channel %c", vstr, ch);
607 	device_set_desc_copy(sc->sc_dev, buf);
608 	return (0);
609 }
610 
611 static int
612 sab82532_bus_receive(struct uart_softc *sc)
613 {
614 	struct uart_bas *bas;
615 	int i, rbcl, xc;
616 	uint8_t s;
617 
618 	bas = &sc->sc_bas;
619 	mtx_lock_spin(&sc->sc_hwmtx);
620 	if (uart_getreg(bas, SAB_STAR) & SAB_STAR_RFNE) {
621 		rbcl = uart_getreg(bas, SAB_RBCL) & 31;
622 		if (rbcl == 0)
623 			rbcl = 32;
624 		for (i = 0; i < rbcl; i += 2) {
625 			if (uart_rx_full(sc)) {
626 				sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
627 				break;
628 			}
629 			xc = uart_getreg(bas, SAB_RFIFO);
630 			s = uart_getreg(bas, SAB_RFIFO + 1);
631 			if (s & SAB_RSTAT_FE)
632 				xc |= UART_STAT_FRAMERR;
633 			if (s & SAB_RSTAT_PE)
634 				xc |= UART_STAT_PARERR;
635 			uart_rx_put(sc, xc);
636 		}
637 	}
638 
639 	while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
640 		;
641 	uart_setreg(bas, SAB_CMDR, SAB_CMDR_RMC);
642 	uart_barrier(bas);
643 	mtx_unlock_spin(&sc->sc_hwmtx);
644 	return (0);
645 }
646 
647 static int
648 sab82532_bus_setsig(struct uart_softc *sc, int sig)
649 {
650 	struct uart_bas *bas;
651 	uint32_t new, old;
652 	uint8_t mode, pvr;
653 
654 	bas = &sc->sc_bas;
655 	do {
656 		old = sc->sc_hwsig;
657 		new = old;
658 		if (sig & UART_SIG_DDTR) {
659 			SIGCHG(sig & UART_SIG_DTR, new, UART_SIG_DTR,
660 			    UART_SIG_DDTR);
661 		}
662 		if (sig & UART_SIG_DRTS) {
663 			SIGCHG(sig & UART_SIG_RTS, new, UART_SIG_RTS,
664 			    UART_SIG_DRTS);
665 		}
666 	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
667 
668 	mtx_lock_spin(&sc->sc_hwmtx);
669 	/* Set DTR pin. */
670 	pvr = uart_getreg(bas, SAB_PVR);
671 	switch (bas->chan) {
672 	case 1:
673 		if (new & UART_SIG_DTR)
674 			pvr &= ~SAB_PVR_DTR_A;
675 		else
676 			pvr |= SAB_PVR_DTR_A;
677 		break;
678 	case 2:
679 		if (new & UART_SIG_DTR)
680 			pvr &= ~SAB_PVR_DTR_B;
681 		else
682 			pvr |= SAB_PVR_DTR_B;
683 		break;
684 	}
685 	uart_setreg(bas, SAB_PVR, pvr);
686 
687 	/* Set RTS pin. */
688 	mode = uart_getreg(bas, SAB_MODE);
689 	if (new & UART_SIG_RTS)
690 		mode &= ~SAB_MODE_FRTS;
691 	else
692 		mode |= SAB_MODE_FRTS;
693 	uart_setreg(bas, SAB_MODE, mode);
694 	uart_barrier(bas);
695 	mtx_unlock_spin(&sc->sc_hwmtx);
696 	return (0);
697 }
698 
699 static int
700 sab82532_bus_transmit(struct uart_softc *sc)
701 {
702 	struct uart_bas *bas;
703 	int i;
704 
705 	bas = &sc->sc_bas;
706 	mtx_lock_spin(&sc->sc_hwmtx);
707 	while (!(uart_getreg(bas, SAB_STAR) & SAB_STAR_XFW))
708 		;
709 	for (i = 0; i < sc->sc_txdatasz; i++)
710 		uart_setreg(bas, SAB_XFIFO + i, sc->sc_txbuf[i]);
711 	uart_barrier(bas);
712 	while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
713 		;
714 	uart_setreg(bas, SAB_CMDR, SAB_CMDR_XF);
715 	sc->sc_txbusy = 1;
716 	mtx_unlock_spin(&sc->sc_hwmtx);
717 	return (0);
718 }
719