xref: /freebsd/sys/dev/uart/uart_dev_z8530.c (revision 875f70dba4ac5331af98ce31da9e3f02bdf2af21)
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_z8530.h>
40 
41 #include "uart_if.h"
42 
43 #define	DEFAULT_RCLK	307200
44 
45 /* Multiplexed I/O. */
46 static __inline void
47 uart_setmreg(struct uart_bas *bas, int reg, int val)
48 {
49 
50 	uart_setreg(bas, REG_CTRL, reg);
51 	uart_barrier(bas);
52 	uart_setreg(bas, REG_CTRL, val);
53 }
54 
55 static __inline uint8_t
56 uart_getmreg(struct uart_bas *bas, int reg)
57 {
58 
59 	uart_setreg(bas, REG_CTRL, reg);
60 	uart_barrier(bas);
61 	return (uart_getreg(bas, REG_CTRL));
62 }
63 
64 static int
65 z8530_divisor(int rclk, int baudrate)
66 {
67 	int act_baud, divisor, error;
68 
69 	if (baudrate == 0)
70 		return (0);
71 
72 	divisor = (rclk + baudrate) / (baudrate << 1) - 2;
73 	if (divisor >= 65536)
74 		return (0);
75 	act_baud = rclk / 2 / (divisor + 2);
76 
77 	/* 10 times error in percent: */
78 	error = ((act_baud - baudrate) * 2000 / baudrate + 1) >> 1;
79 
80 	/* 3.0% maximum error tolerance: */
81 	if (error < -30 || error > 30)
82 		return (0);
83 
84 	return (divisor);
85 }
86 
87 static int
88 z8530_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
89     int parity, uint8_t *tpcp)
90 {
91 	int divisor;
92 	uint8_t mpm, rpc, tpc;
93 
94 	rpc = RPC_RXE;
95 	mpm = MPM_CM16;
96 	tpc = TPC_TXE | (*tpcp & (TPC_DTR | TPC_RTS));
97 
98 	if (databits >= 8) {
99 		rpc |= RPC_RB8;
100 		tpc |= TPC_TB8;
101 	} else if (databits == 7) {
102 		rpc |= RPC_RB7;
103 		tpc |= TPC_TB7;
104 	} else if (databits == 6) {
105 		rpc |= RPC_RB6;
106 		tpc |= TPC_TB6;
107 	} else {
108 		rpc |= RPC_RB5;
109 		tpc |= TPC_TB5;
110 	}
111 	mpm |= (stopbits > 1) ? MPM_SB2 : MPM_SB1;
112 	switch (parity) {
113 	case UART_PARITY_EVEN:	mpm |= MPM_PE | MPM_EVEN; break;
114 	case UART_PARITY_NONE:	break;
115 	case UART_PARITY_ODD:	mpm |= MPM_PE; break;
116 	default:		return (EINVAL);
117 	}
118 
119 	/* Set baudrate. */
120 	if (baudrate > 0) {
121 		divisor = z8530_divisor(bas->rclk, baudrate);
122 		if (divisor == 0)
123 			return (EINVAL);
124 		uart_setmreg(bas, WR_TCL, divisor & 0xff);
125 		uart_barrier(bas);
126 		uart_setmreg(bas, WR_TCH, (divisor >> 8) & 0xff);
127 		uart_barrier(bas);
128 	}
129 
130 	uart_setmreg(bas, WR_RPC, rpc);
131 	uart_barrier(bas);
132 	uart_setmreg(bas, WR_MPM, mpm);
133 	uart_barrier(bas);
134 	uart_setmreg(bas, WR_TPC, tpc);
135 	uart_barrier(bas);
136 	*tpcp = tpc;
137 	return (0);
138 }
139 
140 static int
141 z8530_setup(struct uart_bas *bas, int baudrate, int databits, int stopbits,
142     int parity)
143 {
144 	uint8_t mic, tpc;
145 
146 	if (bas->rclk == 0)
147 		bas->rclk = DEFAULT_RCLK;
148 
149 	/* Assume we don't need to perform a full hardware reset. */
150 	mic = MIC_MIE | MIC_NV;
151 	switch (bas->chan) {
152 	case 1:
153 		mic |= MIC_CRA;
154 		break;
155 	case 2:
156 		mic |= MIC_CRB;
157 		break;
158 	}
159 	uart_setmreg(bas, WR_MIC, mic);
160 	uart_barrier(bas);
161 	/* Set clock sources and enable BRG. */
162 	uart_setmreg(bas, WR_CMC, CMC_RC_BRG | CMC_TC_BRG);
163 	uart_setmreg(bas, WR_MCB2, MCB2_PCLK | MCB2_BRGE);
164 	uart_barrier(bas);
165 	/* Set data encoding. */
166 	uart_setmreg(bas, WR_MCB1, MCB1_NRZ);
167 	uart_barrier(bas);
168 
169 	tpc = TPC_DTR | TPC_RTS;
170 	z8530_param(bas, baudrate, databits, stopbits, parity, &tpc);
171 	return (int)tpc;
172 }
173 
174 /*
175  * Low-level UART interface.
176  */
177 static int z8530_probe(struct uart_bas *bas);
178 static void z8530_init(struct uart_bas *bas, int, int, int, int);
179 static void z8530_term(struct uart_bas *bas);
180 static void z8530_putc(struct uart_bas *bas, int);
181 static int z8530_poll(struct uart_bas *bas);
182 static int z8530_getc(struct uart_bas *bas);
183 
184 struct uart_ops uart_z8530_ops = {
185 	.probe = z8530_probe,
186 	.init = z8530_init,
187 	.term = z8530_term,
188 	.putc = z8530_putc,
189 	.poll = z8530_poll,
190 	.getc = z8530_getc,
191 };
192 
193 static int
194 z8530_probe(struct uart_bas *bas)
195 {
196 
197 	return (0);
198 }
199 
200 static void
201 z8530_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
202     int parity)
203 {
204 
205 	z8530_setup(bas, baudrate, databits, stopbits, parity);
206 }
207 
208 static void
209 z8530_term(struct uart_bas *bas)
210 {
211 }
212 
213 static void
214 z8530_putc(struct uart_bas *bas, int c)
215 {
216 
217 	while (!(uart_getmreg(bas, RR_BES) & BES_TXE))
218 		;
219 	uart_setreg(bas, REG_DATA, c);
220 	uart_barrier(bas);
221 }
222 
223 static int
224 z8530_poll(struct uart_bas *bas)
225 {
226 
227 	if (!(uart_getmreg(bas, RR_BES) & BES_RXA))
228 		return (-1);
229 	return (uart_getreg(bas, REG_DATA));
230 }
231 
232 static int
233 z8530_getc(struct uart_bas *bas)
234 {
235 
236 	while (!(uart_getmreg(bas, RR_BES) & BES_RXA))
237 		;
238 	return (uart_getreg(bas, REG_DATA));
239 }
240 
241 /*
242  * High-level UART interface.
243  */
244 struct z8530_softc {
245 	struct uart_softc base;
246 	uint8_t	tpc;
247 };
248 
249 static int z8530_bus_attach(struct uart_softc *);
250 static int z8530_bus_detach(struct uart_softc *);
251 static int z8530_bus_flush(struct uart_softc *, int);
252 static int z8530_bus_getsig(struct uart_softc *);
253 static int z8530_bus_ioctl(struct uart_softc *, int, intptr_t);
254 static int z8530_bus_ipend(struct uart_softc *);
255 static int z8530_bus_param(struct uart_softc *, int, int, int, int);
256 static int z8530_bus_probe(struct uart_softc *);
257 static int z8530_bus_receive(struct uart_softc *);
258 static int z8530_bus_setsig(struct uart_softc *, int);
259 static int z8530_bus_transmit(struct uart_softc *);
260 
261 static kobj_method_t z8530_methods[] = {
262 	KOBJMETHOD(uart_attach,		z8530_bus_attach),
263 	KOBJMETHOD(uart_detach,		z8530_bus_detach),
264 	KOBJMETHOD(uart_flush,		z8530_bus_flush),
265 	KOBJMETHOD(uart_getsig,		z8530_bus_getsig),
266 	KOBJMETHOD(uart_ioctl,		z8530_bus_ioctl),
267 	KOBJMETHOD(uart_ipend,		z8530_bus_ipend),
268 	KOBJMETHOD(uart_param,		z8530_bus_param),
269 	KOBJMETHOD(uart_probe,		z8530_bus_probe),
270 	KOBJMETHOD(uart_receive,	z8530_bus_receive),
271 	KOBJMETHOD(uart_setsig,		z8530_bus_setsig),
272 	KOBJMETHOD(uart_transmit,	z8530_bus_transmit),
273 	{ 0, 0 }
274 };
275 
276 struct uart_class uart_z8530_class = {
277 	"z8530 class",
278 	z8530_methods,
279 	sizeof(struct z8530_softc),
280 	.uc_range = 2,
281 	.uc_rclk = DEFAULT_RCLK
282 };
283 
284 #define	SIGCHG(c, i, s, d)				\
285 	if (c) {					\
286 		i |= (i & s) ? s : s | d;		\
287 	} else {					\
288 		i = (i & s) ? (i & ~s) | d : i;		\
289 	}
290 
291 static int
292 z8530_bus_attach(struct uart_softc *sc)
293 {
294 	struct z8530_softc *z8530 = (struct z8530_softc*)sc;
295 	struct uart_bas *bas;
296 	struct uart_devinfo *di;
297 
298 	bas = &sc->sc_bas;
299 	if (sc->sc_sysdev != NULL) {
300 		di = sc->sc_sysdev;
301 		z8530->tpc = TPC_DTR|TPC_RTS;
302 		z8530_param(bas, di->baudrate, di->databits, di->stopbits,
303 		    di->parity, &z8530->tpc);
304 	} else {
305 		z8530->tpc = z8530_setup(bas, 9600, 8, 1, UART_PARITY_NONE);
306 		z8530->tpc &= ~(TPC_DTR|TPC_RTS);
307 	}
308 
309 	sc->sc_rxfifosz = 3;
310 	sc->sc_txfifosz = 1;
311 
312 	(void)z8530_bus_getsig(sc);
313 
314 	uart_setmreg(bas, WR_IC, IC_BRK | IC_CTS | IC_DCD);
315 	uart_barrier(bas);
316 	uart_setmreg(bas, WR_IDT, IDT_TIE | IDT_RIA);
317 	uart_barrier(bas);
318 	uart_setmreg(bas, WR_IV, 0);
319 	uart_barrier(bas);
320 	uart_setmreg(bas, WR_TPC, z8530->tpc);
321 	uart_barrier(bas);
322 	return (0);
323 }
324 
325 static int
326 z8530_bus_detach(struct uart_softc *sc)
327 {
328 
329 	return (0);
330 }
331 
332 static int
333 z8530_bus_flush(struct uart_softc *sc, int what)
334 {
335 
336 	return (0);
337 }
338 
339 static int
340 z8530_bus_getsig(struct uart_softc *sc)
341 {
342 	uint32_t new, old, sig;
343 	uint8_t bes;
344 
345 	do {
346 		old = sc->sc_hwsig;
347 		sig = old;
348 		mtx_lock_spin(&sc->sc_hwmtx);
349 		bes = uart_getmreg(&sc->sc_bas, RR_BES);
350 		mtx_unlock_spin(&sc->sc_hwmtx);
351 		SIGCHG(bes & BES_CTS, sig, UART_SIG_CTS, UART_SIG_DCTS);
352 		SIGCHG(bes & BES_DCD, sig, UART_SIG_DCD, UART_SIG_DDCD);
353 		new = sig & ~UART_SIGMASK_DELTA;
354 	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
355 	return (sig);
356 }
357 
358 static int
359 z8530_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
360 {
361 	struct z8530_softc *z8530 = (struct z8530_softc*)sc;
362 	struct uart_bas *bas;
363 	int error;
364 
365 	bas = &sc->sc_bas;
366 	error = 0;
367 	mtx_lock_spin(&sc->sc_hwmtx);
368 	switch (request) {
369 	case UART_IOCTL_BREAK:
370 		if (data)
371 			z8530->tpc |= TPC_BRK;
372 		else
373 			z8530->tpc &= ~TPC_BRK;
374 		uart_setmreg(bas, WR_TPC, z8530->tpc);
375 		uart_barrier(bas);
376 		break;
377 	default:
378 		error = EINVAL;
379 		break;
380 	}
381 	mtx_unlock_spin(&sc->sc_hwmtx);
382 	return (error);
383 }
384 
385 static int
386 z8530_bus_ipend(struct uart_softc *sc)
387 {
388 	struct uart_bas *bas;
389 	int ipend;
390 	uint32_t sig;
391 	uint8_t bes, src;
392 
393 	bas = &sc->sc_bas;
394 	ipend = 0;
395 	mtx_lock_spin(&sc->sc_hwmtx);
396 	uart_setreg(bas, REG_CTRL, CR_RSTIUS);
397 	uart_barrier(bas);
398 	bes = uart_getmreg(bas, RR_BES);
399 	if (bes & BES_BRK) {
400 		uart_setreg(bas, REG_CTRL, CR_RSTXSI);
401 		ipend |= UART_IPEND_BREAK;
402 	}
403 	if (bes & BES_TXE) {
404 		uart_setreg(bas, REG_CTRL, CR_RSTTXI);
405 		ipend |= UART_IPEND_TXIDLE;
406 	}
407 	if (bes & BES_RXA)
408 		ipend |= UART_IPEND_RXREADY;
409 	sig = sc->sc_hwsig;
410 	SIGCHG(bes & BES_CTS, sig, UART_SIG_CTS, UART_SIG_DCTS);
411 	SIGCHG(bes & BES_DCD, sig, UART_SIG_DCD, UART_SIG_DDCD);
412 	if (sig & UART_SIGMASK_DELTA)
413 		ipend |= UART_IPEND_SIGCHG;
414 	src = uart_getmreg(bas, RR_SRC);
415 	if (src & SRC_OVR) {
416 		uart_setreg(bas, REG_CTRL, CR_RSTERR);
417 		ipend |= UART_IPEND_OVERRUN;
418 	}
419 	mtx_unlock_spin(&sc->sc_hwmtx);
420 	return (ipend);
421 }
422 
423 static int
424 z8530_bus_param(struct uart_softc *sc, int baudrate, int databits,
425     int stopbits, int parity)
426 {
427 	struct z8530_softc *z8530 = (struct z8530_softc*)sc;
428 	int error;
429 
430 	mtx_lock_spin(&sc->sc_hwmtx);
431 	error = z8530_param(&sc->sc_bas, baudrate, databits, stopbits, parity,
432 	    &z8530->tpc);
433 	mtx_unlock_spin(&sc->sc_hwmtx);
434 	return (error);
435 }
436 
437 static int
438 z8530_bus_probe(struct uart_softc *sc)
439 {
440 	char buf[80];
441 	int error;
442 	char ch;
443 
444 	error = z8530_probe(&sc->sc_bas);
445 	if (error)
446 		return (error);
447 
448 	ch = sc->sc_bas.chan - 1 + 'A';
449 
450 	snprintf(buf, sizeof(buf), "z8530, channel %c", ch);
451 	device_set_desc_copy(sc->sc_dev, buf);
452 	return (0);
453 }
454 
455 static int
456 z8530_bus_receive(struct uart_softc *sc)
457 {
458 	struct uart_bas *bas;
459 	int xc;
460 	uint8_t bes, src;
461 
462 	bas = &sc->sc_bas;
463 	mtx_lock_spin(&sc->sc_hwmtx);
464 	bes = uart_getmreg(bas, RR_BES);
465 	while (bes & BES_RXA) {
466 		if (uart_rx_full(sc)) {
467 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
468 			break;
469 		}
470 		src = uart_getmreg(bas, RR_SRC);
471 		xc = uart_getreg(bas, REG_DATA);
472 		if (src & SRC_FE)
473 			xc |= UART_STAT_FRAMERR;
474 		if (src & SRC_PE)
475 			xc |= UART_STAT_PARERR;
476 		uart_rx_put(sc, xc);
477 		if (src & (SRC_FE | SRC_PE)) {
478 			uart_setreg(bas, REG_CTRL, CR_RSTERR);
479 			uart_barrier(bas);
480 		}
481 		bes = uart_getmreg(bas, RR_BES);
482 	}
483 	/* Discard everything left in the Rx FIFO. */
484 	while (bes & BES_RXA) {
485 		src = uart_getmreg(bas, RR_SRC);
486 		(void)uart_getreg(bas, REG_DATA);
487 		if (src & (SRC_FE | SRC_PE)) {
488 			uart_setreg(bas, REG_CTRL, CR_RSTERR);
489 			uart_barrier(bas);
490 		}
491 		bes = uart_getmreg(bas, RR_BES);
492 	}
493 	mtx_unlock_spin(&sc->sc_hwmtx);
494 	return (0);
495 }
496 
497 static int
498 z8530_bus_setsig(struct uart_softc *sc, int sig)
499 {
500 	struct z8530_softc *z8530 = (struct z8530_softc*)sc;
501 	struct uart_bas *bas;
502 	uint32_t new, old;
503 
504 	bas = &sc->sc_bas;
505 	do {
506 		old = sc->sc_hwsig;
507 		new = old;
508 		if (sig & UART_SIG_DDTR) {
509 			SIGCHG(sig & UART_SIG_DTR, new, UART_SIG_DTR,
510 			    UART_SIG_DDTR);
511 		}
512 		if (sig & UART_SIG_DRTS) {
513 			SIGCHG(sig & UART_SIG_RTS, new, UART_SIG_RTS,
514 			    UART_SIG_DRTS);
515 		}
516 	} while (!atomic_cmpset_32(&sc->sc_hwsig, old, new));
517 
518 	mtx_lock_spin(&sc->sc_hwmtx);
519 	if (new & UART_SIG_DTR)
520 		z8530->tpc |= TPC_DTR;
521 	else
522 		z8530->tpc &= ~TPC_DTR;
523 	if (new & UART_SIG_RTS)
524 		z8530->tpc |= TPC_RTS;
525 	else
526 		z8530->tpc &= ~TPC_RTS;
527 	uart_setmreg(bas, WR_TPC, z8530->tpc);
528 	uart_barrier(bas);
529 	mtx_unlock_spin(&sc->sc_hwmtx);
530 	return (0);
531 }
532 
533 static int
534 z8530_bus_transmit(struct uart_softc *sc)
535 {
536 	struct uart_bas *bas;
537 
538 	bas = &sc->sc_bas;
539 	mtx_lock_spin(&sc->sc_hwmtx);
540 	while (!(uart_getmreg(bas, RR_BES) & BES_TXE))
541 		;
542 	uart_setreg(bas, REG_DATA, sc->sc_txbuf[0]);
543 	uart_barrier(bas);
544 	sc->sc_txbusy = 1;
545 	mtx_unlock_spin(&sc->sc_hwmtx);
546 	return (0);
547 }
548