xref: /netbsd-src/sys/arch/mvme68k/dev/zs.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: zs.c,v 1.37 2007/12/03 15:33:59 ad 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/cdefs.h>
49 __KERNEL_RCSID(0, "$NetBSD: zs.c,v 1.37 2007/12/03 15:33:59 ad Exp $");
50 
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/conf.h>
54 #include <sys/device.h>
55 #include <sys/file.h>
56 #include <sys/ioctl.h>
57 #include <sys/kernel.h>
58 #include <sys/proc.h>
59 #include <sys/tty.h>
60 #include <sys/time.h>
61 #include <sys/syslog.h>
62 #include <sys/cpu.h>
63 #include <sys/bus.h>
64 #include <sys/intr.h>
65 
66 #include <dev/cons.h>
67 #include <dev/ic/z8530reg.h>
68 #include <machine/z8530var.h>
69 
70 #include <mvme68k/dev/zsvar.h>
71 
72 /*
73  * Some warts needed by z8530tty.c -
74  * The default parity REALLY needs to be the same as the PROM uses,
75  * or you can not see messages done with printf during boot-up...
76  */
77 int zs_def_cflag = (CREAD | CS8 | HUPCL);
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 	0,			/*12: BAUDLO (default=9600) */
107 	0,			/*13: BAUDHI (default=9600) */
108 	ZSWR14_BAUD_ENA | ZSWR14_BAUD_FROM_PCLK,
109 	ZSWR15_BREAK_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 int	zs_getc __P((void *));
120 void	zs_putc __P((void *, int));
121 
122 #if 0
123 static int zs_get_speed __P((struct zs_chanstate *));
124 #endif
125 
126 extern struct cfdriver zsc_cd;
127 
128 cons_decl(zsc_pcc);
129 
130 
131 /*
132  * Configure children of an SCC.
133  */
134 void
135 zs_config(zsc, zs, vector, pclk)
136 	struct zsc_softc *zsc;
137 	struct zsdevice *zs;
138 	int vector, pclk;
139 {
140 	struct zsc_attach_args zsc_args;
141 	volatile struct zschan *zc;
142 	struct zs_chanstate *cs;
143 	int zsc_unit, channel, s;
144 
145 	zsc_unit = device_unit(&zsc->zsc_dev);
146 	printf(": Zilog 8530 SCC at vector 0x%x\n", vector);
147 
148 	/*
149 	 * Initialize software state for each channel.
150 	 */
151 	for (channel = 0; channel < 2; channel++) {
152 		zsc_args.channel = channel;
153 		zsc_args.hwflags = zs_hwflags[zsc_unit][channel];
154 		cs = &zsc->zsc_cs_store[channel];
155 		zsc->zsc_cs[channel] = cs;
156 		zs_lock_init(cs);
157 
158 		/*
159 		 * If we're the console, copy the channel state, and
160 		 * adjust the console channel pointer.
161 		 */
162 		if (zsc_args.hwflags & ZS_HWFLAG_CONSOLE) {
163 			memcpy(cs, zs_conschan, sizeof(struct zs_chanstate));
164 			zs_conschan = cs;
165 		} else {
166 			zc = (channel == 0) ? &zs->zs_chan_a : &zs->zs_chan_b;
167 			cs->cs_reg_csr  = zc->zc_csr;
168 			cs->cs_reg_data = zc->zc_data;
169 			memcpy(cs->cs_creg, zs_init_reg, 16);
170 			memcpy(cs->cs_preg, zs_init_reg, 16);
171 			cs->cs_defspeed = zs_defspeed[zsc_unit][channel];
172 		}
173 
174 		cs->cs_brg_clk = pclk / 16;
175 		cs->cs_creg[2] = cs->cs_preg[2] = vector;
176 		zs_set_speed(cs, cs->cs_defspeed);
177 		cs->cs_creg[12] = cs->cs_preg[12];
178 		cs->cs_creg[13] = cs->cs_preg[13];
179 		cs->cs_defcflag = zs_def_cflag;
180 
181 		/* Make these correspond to cs_defcflag (-crtscts) */
182 		cs->cs_rr0_dcd = ZSRR0_DCD;
183 		cs->cs_rr0_cts = 0;
184 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
185 		cs->cs_wr5_rts = 0;
186 
187 		cs->cs_channel = channel;
188 		cs->cs_private = NULL;
189 		cs->cs_ops = &zsops_null;
190 
191 		/*
192 		 * Clear the master interrupt enable.
193 		 * The INTENA is common to both channels,
194 		 * so just do it on the A channel.
195 		 * Write the interrupt vector while we're at it.
196 		 */
197 		if (channel == 0) {
198 			zs_write_reg(cs, 9, 0);
199 			zs_write_reg(cs, 2, vector);
200 		}
201 
202 		/*
203 		 * Look for a child driver for this channel.
204 		 * The child attach will setup the hardware.
205 		 */
206 		if (!config_found(&zsc->zsc_dev, (void *)&zsc_args, zsc_print)) {
207 			/* No sub-driver.  Just reset it. */
208 			u_char reset = (channel == 0) ?
209 				ZSWR9_A_RESET : ZSWR9_B_RESET;
210 			s = splzs();
211 			zs_write_reg(cs,  9, reset);
212 			splx(s);
213 		}
214 	}
215 
216 	/*
217 	 * Allocate a software interrupt cookie.
218 	 */
219 	zsc->zsc_softintr_cookie = softint_establish(SOFTINT_SERIAL,
220 	    (void (*)(void *)) zsc_intr_soft, zsc);
221 #ifdef DEBUG
222 	assert(zsc->zsc_softintr_cookie);
223 #endif
224 }
225 
226 static int
227 zsc_print(aux, name)
228 	void *aux;
229 	const char *name;
230 {
231 	struct zsc_attach_args *args = aux;
232 
233 	if (name != NULL)
234 		aprint_normal("%s: ", name);
235 
236 	if (args->channel != -1)
237 		aprint_normal(" channel %d", args->channel);
238 
239 	return UNCONF;
240 }
241 
242 #if defined(MVME162) || defined(MVME172)
243 /*
244  * Our ZS chips each have their own interrupt vector.
245  */
246 int
247 zshard_unshared(arg)
248 	void *arg;
249 {
250 	struct zsc_softc *zsc = arg;
251 	int rval;
252 
253 	rval = zsc_intr_hard(zsc);
254 
255 	if (rval) {
256 		if ((zsc->zsc_cs[0]->cs_softreq) ||
257 		    (zsc->zsc_cs[1]->cs_softreq))
258 			softint_schedule(zsc->zsc_softintr_cookie);
259 		zsc->zsc_evcnt.ev_count++;
260 	}
261 
262 	return (rval);
263 }
264 #endif
265 
266 #ifdef MVME147
267 /*
268  * Our ZS chips all share a common, PCC-vectored interrupt,
269  * so we have to look at all of them on each interrupt.
270  */
271 int
272 zshard_shared(arg)
273 	void *arg;
274 {
275 	struct zsc_softc *zsc;
276 	int unit, rval;
277 
278 	rval = 0;
279 	for (unit = 0; unit < zsc_cd.cd_ndevs; unit++) {
280 		zsc = zsc_cd.cd_devs[unit];
281 		if (zsc != NULL && zsc_intr_hard(zsc)) {
282 			if ((zsc->zsc_cs[0]->cs_softreq) ||
283 			    (zsc->zsc_cs[1]->cs_softreq))
284 				softint_schedule(zsc->zsc_softintr_cookie);
285 			zsc->zsc_evcnt.ev_count++;
286 			rval++;
287 		}
288 	}
289 	return (rval);
290 }
291 #endif
292 
293 
294 #if 0
295 /*
296  * Compute the current baud rate given a ZSCC channel.
297  */
298 static int
299 zs_get_speed(cs)
300 	struct zs_chanstate *cs;
301 {
302 	int tconst;
303 
304 	tconst = zs_read_reg(cs, 12);
305 	tconst |= zs_read_reg(cs, 13) << 8;
306 	return (TCONST_TO_BPS(cs->cs_brg_clk, tconst));
307 }
308 #endif
309 
310 /*
311  * MD functions for setting the baud rate and control modes.
312  */
313 int
314 zs_set_speed(cs, bps)
315 	struct zs_chanstate *cs;
316 	int bps;	/* bits per second */
317 {
318 	int tconst, real_bps;
319 
320 	if (bps == 0)
321 		return (0);
322 
323 #ifdef	DIAGNOSTIC
324 	if (cs->cs_brg_clk == 0)
325 		panic("zs_set_speed");
326 #endif
327 
328 	tconst = BPS_TO_TCONST(cs->cs_brg_clk, bps);
329 	if (tconst < 0)
330 		return (EINVAL);
331 
332 	/* Convert back to make sure we can do it. */
333 	real_bps = TCONST_TO_BPS(cs->cs_brg_clk, tconst);
334 
335 	/* Allow 2% tolerance WRT the required bps */
336 	if (((abs(real_bps - bps) * 1000) / bps) > 20)
337 		return (EINVAL);
338 
339 	cs->cs_preg[12] = tconst;
340 	cs->cs_preg[13] = tconst >> 8;
341 
342 	/* Caller will stuff the pending registers. */
343 	return (0);
344 }
345 
346 int
347 zs_set_modes(cs, cflag)
348 	struct zs_chanstate *cs;
349 	int cflag;	/* bits per second */
350 {
351 	int s;
352 
353 	/*
354 	 * Output hardware flow control on the chip is horrendous:
355 	 * if carrier detect drops, the receiver is disabled, and if
356 	 * CTS drops, the transmitter is stoped IN MID CHARACTER!
357 	 * Therefore, NEVER set the HFC bit, and instead use the
358 	 * status interrupt to detect CTS changes.
359 	 */
360 	s = splzs();
361 	cs->cs_rr0_pps = 0;
362 	if ((cflag & (CLOCAL | MDMBUF)) != 0) {
363 		cs->cs_rr0_dcd = 0;
364 		if ((cflag & MDMBUF) == 0)
365 			cs->cs_rr0_pps = ZSRR0_DCD;
366 	} else
367 		cs->cs_rr0_dcd = ZSRR0_DCD;
368 	if ((cflag & CRTSCTS) != 0) {
369 		cs->cs_wr5_dtr = ZSWR5_DTR;
370 		cs->cs_wr5_rts = ZSWR5_RTS;
371 		cs->cs_rr0_cts = ZSRR0_CTS;
372 	} else if ((cflag & MDMBUF) != 0) {
373 		cs->cs_wr5_dtr = 0;
374 		cs->cs_wr5_rts = ZSWR5_DTR;
375 		cs->cs_rr0_cts = ZSRR0_DCD;
376 	} else {
377 		cs->cs_wr5_dtr = ZSWR5_DTR | ZSWR5_RTS;
378 		cs->cs_wr5_rts = 0;
379 		cs->cs_rr0_cts = 0;
380 	}
381 	splx(s);
382 
383 	/* Caller will stuff the pending registers. */
384 	return (0);
385 }
386 
387 
388 /*
389  * Read or write the chip with suitable delays.
390  */
391 
392 u_char
393 zs_read_reg(cs, reg)
394 	struct zs_chanstate *cs;
395 	u_char reg;
396 {
397 	u_char val;
398 
399 	*cs->cs_reg_csr = reg;
400 	ZS_DELAY();
401 	val = *cs->cs_reg_csr;
402 	ZS_DELAY();
403 	return val;
404 }
405 
406 void
407 zs_write_reg(cs, reg, val)
408 	struct zs_chanstate *cs;
409 	u_char reg, val;
410 {
411 	*cs->cs_reg_csr = reg;
412 	ZS_DELAY();
413 	*cs->cs_reg_csr = val;
414 	ZS_DELAY();
415 }
416 
417 u_char zs_read_csr(cs)
418 	struct zs_chanstate *cs;
419 {
420 	u_char val;
421 
422 	val = *cs->cs_reg_csr;
423 	ZS_DELAY();
424 	return val;
425 }
426 
427 void  zs_write_csr(cs, val)
428 	struct zs_chanstate *cs;
429 	u_char val;
430 {
431 	*cs->cs_reg_csr = val;
432 	ZS_DELAY();
433 }
434 
435 u_char zs_read_data(cs)
436 	struct zs_chanstate *cs;
437 {
438 	u_char val;
439 
440 	val = *cs->cs_reg_data;
441 	ZS_DELAY();
442 	return val;
443 }
444 
445 void  zs_write_data(cs, val)
446 	struct zs_chanstate *cs;
447 	u_char val;
448 {
449 	*cs->cs_reg_data = val;
450 	ZS_DELAY();
451 }
452 
453 /****************************************************************
454  * Console support functions (MVME specific!)
455  ****************************************************************/
456 
457 /*
458  * Polled input char.
459  */
460 int
461 zs_getc(arg)
462 	void *arg;
463 {
464 	struct zs_chanstate *cs = arg;
465 	int s, c, rr0, stat;
466 
467 	s = splhigh();
468  top:
469 	/* Wait for a character to arrive. */
470 	do {
471 		rr0 = *cs->cs_reg_csr;
472 		ZS_DELAY();
473 	} while ((rr0 & ZSRR0_RX_READY) == 0);
474 
475 	/* Read error register. */
476 	stat = zs_read_reg(cs, 1) & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE);
477 	if (stat) {
478 		zs_write_csr(cs, ZSM_RESET_ERR);
479 		goto top;
480 	}
481 
482 	/* Read character. */
483 	c = *cs->cs_reg_data;
484 	ZS_DELAY();
485 	splx(s);
486 
487 	return (c);
488 }
489 
490 /*
491  * Polled output char.
492  */
493 void
494 zs_putc(arg, c)
495 	void *arg;
496 	int c;
497 {
498 	struct zs_chanstate *cs = arg;
499 	int s, rr0;
500 
501 	s = splhigh();
502 	/* Wait for transmitter to become ready. */
503 	do {
504 		rr0 = *cs->cs_reg_csr;
505 		ZS_DELAY();
506 	} while ((rr0 & ZSRR0_TX_READY) == 0);
507 
508 	*cs->cs_reg_data = c;
509 	ZS_DELAY();
510 	splx(s);
511 }
512 
513 /*
514  * Common parts of console init.
515  */
516 void
517 zs_cnconfig(zsc_unit, channel, zs, pclk)
518 	int zsc_unit, channel;
519 	struct zsdevice *zs;
520 	int pclk;
521 {
522 	struct zs_chanstate *cs;
523 	struct zschan *zc;
524 
525 	zc = (channel == 0) ? &zs->zs_chan_a : &zs->zs_chan_b;
526 
527 	/*
528 	 * Pointer to channel state.  Later, the console channel
529 	 * state is copied into the softc, and the console channel
530 	 * pointer adjusted to point to the new copy.
531 	 */
532 	zs_conschan = cs = &zs_conschan_store;
533 	zs_hwflags[zsc_unit][channel] = ZS_HWFLAG_CONSOLE;
534 
535 	/* Setup temporary chanstate. */
536 	cs->cs_brg_clk = pclk / 16;
537 	cs->cs_reg_csr  = zc->zc_csr;
538 	cs->cs_reg_data = zc->zc_data;
539 
540 	/* Initialize the pending registers. */
541 	memcpy(cs->cs_preg, zs_init_reg, 16);
542 	cs->cs_preg[5] |= (ZSWR5_DTR | ZSWR5_RTS);
543 
544 #if 0
545 	/* XXX: Preserve BAUD rate from boot loader. */
546 	/* XXX: Also, why reset the chip here? -gwr */
547 	cs->cs_defspeed = zs_get_speed(cs);
548 #else
549 	cs->cs_defspeed = 9600;	/* XXX */
550 #endif
551 	zs_set_speed(cs, cs->cs_defspeed);
552 	cs->cs_creg[12] = cs->cs_preg[12];
553 	cs->cs_creg[13] = cs->cs_preg[13];
554 
555 	/* Clear the master interrupt enable. */
556 	zs_write_reg(cs, 9, 0);
557 
558 	/* Reset the whole SCC chip. */
559 	zs_write_reg(cs, 9, ZSWR9_HARD_RESET);
560 
561 	/* Copy "pending" to "current" and H/W. */
562 	zs_loadchannelregs(cs);
563 }
564 
565 /*
566  * Polled console input putchar.
567  */
568 int
569 zsc_pcccngetc(dev)
570 	dev_t dev;
571 {
572 	struct zs_chanstate *cs = zs_conschan;
573 	int c;
574 
575 	c = zs_getc(cs);
576 	return (c);
577 }
578 
579 /*
580  * Polled console output putchar.
581  */
582 void
583 zsc_pcccnputc(dev, c)
584 	dev_t dev;
585 	int c;
586 {
587 	struct zs_chanstate *cs = zs_conschan;
588 
589 	zs_putc(cs, c);
590 }
591 
592 /*
593  * Handle user request to enter kernel debugger.
594  */
595 void
596 zs_abort(cs)
597 	struct zs_chanstate *cs;
598 {
599 	int rr0;
600 
601 	/* Wait for end of break to avoid PROM abort. */
602 	/* XXX - Limit the wait? */
603 	do {
604 		rr0 = *cs->cs_reg_csr;
605 		ZS_DELAY();
606 	} while (rr0 & ZSRR0_BREAK);
607 
608 	mvme68k_abort("SERIAL LINE ABORT");
609 }
610