xref: /netbsd-src/sys/arch/mvme68k/dev/zs.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
1 /*	$NetBSD: zs.c,v 1.15 1998/08/22 10:55:33 scw Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Gordon W. Ross.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Zilog Z8530 Dual UART driver (machine-dependent part)
41  *
42  * Runs two serial lines per chip using slave drivers.
43  * Plain tty/async lines use the zs_async slave.
44  *
45  * Modified for NetBSD/mvme68k by Jason R. Thorpe <thorpej@NetBSD.ORG>
46  */
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/conf.h>
51 #include <sys/device.h>
52 #include <sys/file.h>
53 #include <sys/ioctl.h>
54 #include <sys/kernel.h>
55 #include <sys/proc.h>
56 #include <sys/tty.h>
57 #include <sys/time.h>
58 #include <sys/syslog.h>
59 
60 #include <dev/cons.h>
61 #include <dev/ic/z8530reg.h>
62 #include <machine/z8530var.h>
63 
64 #include <machine/cpu.h>
65 
66 #include <mvme68k/dev/zsvar.h>
67 
68 /*
69  * Some warts needed by z8530tty.c -
70  * The default parity REALLY needs to be the same as the PROM uses,
71  * or you can not see messages done with printf during boot-up...
72  */
73 int zs_def_cflag = (CREAD | CS8 | HUPCL);
74 /* XXX Shouldn't hardcode the minor number... */
75 int zs_major = 12;
76 
77 static u_long zs_sir;	/* software interrupt cookie */
78 
79 /* Flags from zscnprobe() */
80 static int zs_hwflags[NZSC][2];
81 
82 /* Default speed for each channel */
83 static int zs_defspeed[NZSC][2] = {
84 	{ 9600, 	/* port 1 */
85 	  9600 },	/* port 2 */
86 	{ 9600, 	/* port 3 */
87 	  9600 },	/* port 4 */
88 };
89 
90 static struct zs_chanstate zs_conschan_store;
91 static struct zs_chanstate *zs_conschan;
92 
93 u_char zs_init_reg[16] = {
94 	0,	/* 0: CMD (reset, etc.) */
95 	0,	/* 1: No interrupts yet. */
96 	0x18 + ZSHARD_PRI,	/* IVECT */
97 	ZSWR3_RX_8 | ZSWR3_RX_ENABLE,
98 	ZSWR4_CLK_X16 | ZSWR4_ONESB | ZSWR4_EVENP,
99 	ZSWR5_TX_8 | ZSWR5_TX_ENABLE,
100 	0,	/* 6: TXSYNC/SYNCLO */
101 	0,	/* 7: RXSYNC/SYNCHI */
102 	0,	/* 8: alias for data port */
103 	ZSWR9_MASTER_IE,
104 	0,	/*10: Misc. TX/RX control bits */
105 	ZSWR11_TXCLK_BAUD | ZSWR11_RXCLK_BAUD,
106 	14,	/*12: BAUDLO (default=9600) */
107 	0,	/*13: BAUDHI (default=9600) */
108 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
109 	ZSWR15_BREAK_IE | ZSWR15_DCD_IE,
110 };
111 
112 
113 /****************************************************************
114  * Autoconfig
115  ****************************************************************/
116 
117 /* Definition of the driver for autoconfig. */
118 static int	zsc_print __P((void *, const char *name));
119 
120 static int zs_get_speed __P((struct zs_chanstate *));
121 
122 extern struct cfdriver zsc_cd;
123 
124 /*
125  * Configure children of an SCC.
126  */
127 void
128 zs_config(zsc, chan_addr)
129 	struct zsc_softc *zsc;
130 	struct zschan *(*chan_addr) __P((int, int));
131 {
132 	struct zsc_attach_args zsc_args;
133 	volatile struct zschan *zc;
134 	struct zs_chanstate *cs;
135 	int zsc_unit, channel, s;
136 
137 	zsc_unit = zsc->zsc_dev.dv_unit;
138 	printf(": Zilog 8530 SCC\n");
139 
140 	/*
141 	 * Initialize software state for each channel.
142 	 */
143 	for (channel = 0; channel < 2; channel++) {
144 		zsc_args.channel = channel;
145 		zsc_args.hwflags = zs_hwflags[zsc_unit][channel];
146 		cs = &zsc->zsc_cs_store[channel];
147 		zsc->zsc_cs[channel] = cs;
148 
149 		/*
150 		 * If we're the console, copy the channel state, and
151 		 * adjust the console channel pointer.
152 		 */
153 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE) {
154 			bcopy(zs_conschan, cs, sizeof(struct zs_chanstate));
155 			zs_conschan = cs;
156 		} else {
157 			zc = (*chan_addr)(zsc_unit, channel);
158 			cs->cs_reg_csr  = &zc->zc_csr;
159 			cs->cs_reg_data = &zc->zc_data;
160 			bcopy(zs_init_reg, cs->cs_creg, 16);
161 			bcopy(zs_init_reg, cs->cs_preg, 16);
162 			cs->cs_defspeed = zs_defspeed[zsc_unit][channel];
163 		}
164 		cs->cs_defcflag = zs_def_cflag;
165 
166 		/* Make these correspond to cs_defcflag (-crtscts) */
167 		cs->cs_rr0_dcd = ZSRR0_DCD;
168 		cs->cs_rr0_cts = 0;
169 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
170 		cs->cs_wr5_rts = 0;
171 
172 		cs->cs_channel = channel;
173 		cs->cs_private = NULL;
174 		cs->cs_ops = &zsops_null;
175 		cs->cs_brg_clk = PCLK / 16;
176 
177 		/*
178 		 * Clear the master interrupt enable.
179 		 * The INTENA is common to both channels,
180 		 * so just do it on the A channel.
181 		 */
182 		if (channel == 0) {
183 			zs_write_reg(cs, 9, 0);
184 		}
185 
186 		/*
187 		 * Look for a child driver for this channel.
188 		 * The child attach will setup the hardware.
189 		 */
190 		if (!config_found(&zsc->zsc_dev, (void *)&zsc_args, zsc_print)) {
191 			/* No sub-driver.  Just reset it. */
192 			u_char reset = (channel == 0) ?
193 				ZSWR9_A_RESET : ZSWR9_B_RESET;
194 			s = splzs();
195 			zs_write_reg(cs,  9, reset);
196 			splx(s);
197 		}
198 	}
199 
200 	/*
201 	 * Allocate a software interrupt cookie.  Note that the argument
202 	 * "zsc" is never actually used in the software interrupt
203 	 * handler.
204 	 */
205 	if (zs_sir == 0)
206 		zs_sir = allocate_sir(zssoft, zsc);
207 }
208 
209 static int
210 zsc_print(aux, name)
211 	void *aux;
212 	const char *name;
213 {
214 	struct zsc_attach_args *args = aux;
215 
216 	if (name != NULL)
217 		printf("%s: ", name);
218 
219 	if (args->channel != -1)
220 		printf(" channel %d", args->channel);
221 
222 	return UNCONF;
223 }
224 
225 static int zssoftpending;
226 
227 /*
228  * Our ZS chips all share a common, autovectored interrupt,
229  * so we have to look at all of them on each interrupt.
230  */
231 int
232 zshard(arg)
233 	void *arg;
234 {
235 	struct zsc_softc *zsc;
236 	int unit, rval;
237 
238 	rval = 0;
239 	for (unit = 0; unit < zsc_cd.cd_ndevs; unit++) {
240 		zsc = zsc_cd.cd_devs[unit];
241 		if (zsc == NULL)
242 			continue;
243 		rval |= zsc_intr_hard(zsc);
244 		if ((zsc->zsc_cs[0]->cs_softreq) ||
245 			(zsc->zsc_cs[1]->cs_softreq))
246 		{
247 			/* zsc_req_softint(zsc); */
248 			/* We are at splzs here, so no need to lock. */
249 			if (zssoftpending == 0) {
250 				zssoftpending = zs_sir;
251 				setsoftint(zs_sir);
252 			}
253 		}
254 	}
255 	return (rval);
256 }
257 
258 /*
259  * Similar scheme as for zshard (look at all of them)
260  */
261 int
262 zssoft(arg)
263 	void *arg;
264 {
265 	struct zsc_softc *zsc;
266 	int unit;
267 
268 	/* This is not the only ISR on this IPL. */
269 	if (zssoftpending == 0)
270 		return (0);
271 
272 	/*
273 	 * The soft intr. bit will be set by zshard only if
274 	 * the variable zssoftpending is zero.
275 	 */
276 	zssoftpending = 0;
277 
278 	for (unit = 0; unit < zsc_cd.cd_ndevs; ++unit) {
279 		zsc = zsc_cd.cd_devs[unit];
280 		if (zsc == NULL)
281 			continue;
282 		(void) zsc_intr_soft(zsc);
283 	}
284 	return (1);
285 }
286 
287 
288 /*
289  * Compute the current baud rate given a ZSCC channel.
290  */
291 static int
292 zs_get_speed(cs)
293 	struct zs_chanstate *cs;
294 {
295 	int tconst;
296 
297 	tconst = zs_read_reg(cs, 12);
298 	tconst |= zs_read_reg(cs, 13) << 8;
299 	return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
300 }
301 
302 /*
303  * MD functions for setting the baud rate and control modes.
304  */
305 int
306 zs_set_speed(cs, bps)
307 	struct zs_chanstate *cs;
308 	int bps;	/* bits per second */
309 {
310 	int tconst, real_bps;
311 
312 	if (bps == 0)
313 		return (0);
314 
315 #ifdef	DIAGNOSTIC
316 	if (cs->cs_brg_clk == 0)
317 		panic("zs_set_speed");
318 #endif
319 
320 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
321 	if (tconst < 0)
322 		return (EINVAL);
323 
324 	/* Convert back to make sure we can do it. */
325 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
326 
327 	/* XXX - Allow some tolerance here? */
328 	if (real_bps != bps)
329 		return (EINVAL);
330 
331 	cs->cs_preg[12] = tconst;
332 	cs->cs_preg[13] = tconst >> 8;
333 
334 	/* Caller will stuff the pending registers. */
335 	return (0);
336 }
337 
338 int
339 zs_set_modes(cs, cflag)
340 	struct zs_chanstate *cs;
341 	int cflag;	/* bits per second */
342 {
343 	int s;
344 
345 	/*
346 	 * Output hardware flow control on the chip is horrendous:
347 	 * if carrier detect drops, the receiver is disabled, and if
348 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
349 	 * Therefore, NEVER set the HFC bit, and instead use the
350 	 * status interrupt to detect CTS changes.
351 	 */
352 	s = splzs();
353 	if ((cflag & (CLOCAL | MDMBUF)) != 0)
354 		cs->cs_rr0_dcd = 0;
355 	else
356 		cs->cs_rr0_dcd = ZSRR0_DCD;
357 	if ((cflag & CRTSCTS) != 0) {
358 		cs->cs_wr5_dtr = ZSWR5_DTR;
359 		cs->cs_wr5_rts = ZSWR5_RTS;
360 		cs->cs_rr0_cts = ZSRR0_CTS;
361 	} else if ((cflag & MDMBUF) != 0) {
362 		cs->cs_wr5_dtr = 0;
363 		cs->cs_wr5_rts = ZSWR5_DTR;
364 		cs->cs_rr0_cts = ZSRR0_DCD;
365 	} else {
366 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
367 		cs->cs_wr5_rts = 0;
368 		cs->cs_rr0_cts = 0;
369 	}
370 	splx(s);
371 
372 	/* Caller will stuff the pending registers. */
373 	return (0);
374 }
375 
376 
377 /*
378  * Read or write the chip with suitable delays.
379  */
380 
381 u_char
382 zs_read_reg(cs, reg)
383 	struct zs_chanstate *cs;
384 	u_char reg;
385 {
386 	u_char val;
387 
388 	*cs->cs_reg_csr = reg;
389 	ZS_DELAY();
390 	val = *cs->cs_reg_csr;
391 	ZS_DELAY();
392 	return val;
393 }
394 
395 void
396 zs_write_reg(cs, reg, val)
397 	struct zs_chanstate *cs;
398 	u_char reg, val;
399 {
400 	*cs->cs_reg_csr = reg;
401 	ZS_DELAY();
402 	*cs->cs_reg_csr = val;
403 	ZS_DELAY();
404 }
405 
406 u_char zs_read_csr(cs)
407 	struct zs_chanstate *cs;
408 {
409 	u_char val;
410 
411 	val = *cs->cs_reg_csr;
412 	ZS_DELAY();
413 	return val;
414 }
415 
416 void  zs_write_csr(cs, val)
417 	struct zs_chanstate *cs;
418 	u_char val;
419 {
420 	*cs->cs_reg_csr = val;
421 	ZS_DELAY();
422 }
423 
424 u_char zs_read_data(cs)
425 	struct zs_chanstate *cs;
426 {
427 	u_char val;
428 
429 	val = *cs->cs_reg_data;
430 	ZS_DELAY();
431 	return val;
432 }
433 
434 void  zs_write_data(cs, val)
435 	struct zs_chanstate *cs;
436 	u_char val;
437 {
438 	*cs->cs_reg_data = val;
439 	ZS_DELAY();
440 }
441 
442 /****************************************************************
443  * Console support functions (MVME specific!)
444  ****************************************************************/
445 
446 /*
447  * Polled input char.
448  */
449 int
450 zs_getc(arg)
451 	void *arg;
452 {
453 	struct zs_chanstate *cs = arg;
454 	int s, c, rr0, stat;
455 
456 	s = splhigh();
457  top:
458 	/* Wait for a character to arrive. */
459 	do {
460 		rr0 = *cs->cs_reg_csr;
461 		ZS_DELAY();
462 	} while ((rr0 & ZSRR0_RX_READY) == 0);
463 
464 	/* Read error register. */
465 	stat = zs_read_reg(cs, 1) & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE);
466 	if (stat) {
467 		zs_write_csr(cs, ZSM_RESET_ERR);
468 		goto top;
469 	}
470 
471 	/* Read character. */
472 	c = *cs->cs_reg_data;
473 	ZS_DELAY();
474 	splx(s);
475 
476 	return (c);
477 }
478 
479 /*
480  * Polled output char.
481  */
482 void
483 zs_putc(arg, c)
484 	void *arg;
485 	int c;
486 {
487 	struct zs_chanstate *cs = arg;
488 	int s, rr0;
489 
490 	s = splhigh();
491 	/* Wait for transmitter to become ready. */
492 	do {
493 		rr0 = *cs->cs_reg_csr;
494 		ZS_DELAY();
495 	} while ((rr0 & ZSRR0_TX_READY) == 0);
496 
497 	*cs->cs_reg_data = c;
498 	ZS_DELAY();
499 	splx(s);
500 }
501 
502 /*
503  * Common parts of console init.
504  */
505 void
506 zs_cnconfig(zsc_unit, channel, zc)
507 	int zsc_unit, channel;
508 	struct zschan *zc;
509 {
510 	struct zs_chanstate *cs;
511 
512 	/*
513 	 * Pointer to channel state.  Later, the console channel
514 	 * state is copied into the softc, and the console channel
515 	 * pointer adjusted to point to the new copy.
516 	 */
517 	zs_conschan = cs = &zs_conschan_store;
518 	zs_hwflags[zsc_unit][channel] = ZS_HWFLAG_CONSOLE;
519 
520 	/* Setup temporary chanstate. */
521 	cs->cs_reg_csr  = &zc->zc_csr;
522 	cs->cs_reg_data = &zc->zc_data;
523 
524 	/* Initialize the pending registers. */
525 	bcopy(zs_init_reg, cs->cs_preg, 16);
526 	cs->cs_preg[5] |= (ZSWR5_DTR | ZSWR5_RTS);
527 
528 	/* XXX: Preserve BAUD rate from boot loader. */
529 	/* XXX: Also, why reset the chip here? -gwr */
530 	/* cs->cs_defspeed = zs_get_speed(cs); */
531 	cs->cs_defspeed = 9600;	/* XXX */
532 
533 	/* Clear the master interrupt enable. */
534 	zs_write_reg(cs, 9, 0);
535 
536 	/* Reset the whole SCC chip. */
537 	zs_write_reg(cs, 9, ZSWR9_HARD_RESET);
538 
539 	/* Copy "pending" to "current" and H/W. */
540 	zs_loadchannelregs(cs);
541 }
542 
543 /*
544  * Polled console input putchar.
545  */
546 int
547 zscngetc(dev)
548 	dev_t dev;
549 {
550 	struct zs_chanstate *cs = zs_conschan;
551 	int c;
552 
553 	c = zs_getc(cs);
554 	return (c);
555 }
556 
557 /*
558  * Polled console output putchar.
559  */
560 void
561 zscnputc(dev, c)
562 	dev_t dev;
563 	int c;
564 {
565 	struct zs_chanstate *cs = zs_conschan;
566 
567 	zs_putc(cs, c);
568 }
569 
570 /*
571  * Handle user request to enter kernel debugger.
572  */
573 void
574 zs_abort(cs)
575 	struct zs_chanstate *cs;
576 {
577 	int rr0;
578 
579 	/* Wait for end of break to avoid PROM abort. */
580 	/* XXX - Limit the wait? */
581 	do {
582 		rr0 = *cs->cs_reg_csr;
583 		ZS_DELAY();
584 	} while (rr0 & ZSRR0_BREAK);
585 
586 	mvme68k_abort("SERIAL LINE ABORT");
587 }
588