xref: /netbsd-src/sys/arch/mac68k/nubus/cpi_nubus.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: cpi_nubus.c,v 1.8 2014/03/16 05:20:25 dholland Exp $	*/
2 
3 /*-
4  * Copyright (c) 2008 Hauke Fath
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
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 __KERNEL_RCSID(0, "$NetBSD: cpi_nubus.c,v 1.8 2014/03/16 05:20:25 dholland Exp $");
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/proc.h>
32 #include <sys/device.h>
33 #include <sys/malloc.h>
34 #include <sys/event.h>
35 #include <sys/callout.h>
36 #include <sys/conf.h>
37 #include <sys/file.h>
38 #include <sys/uio.h>
39 #include <sys/ioctl.h>
40 #include <sys/tty.h>
41 #include <sys/time.h>
42 #include <sys/timetc.h>
43 #include <sys/kernel.h>
44 #include <sys/syslog.h>
45 #include <sys/errno.h>
46 
47 #include <machine/intr.h>
48 #include <machine/bus.h>
49 #include <machine/viareg.h>
50 
51 #include <dev/ic/z8536reg.h>
52 #include <mac68k/nubus/nubus.h>
53 #include <mac68k/nubus/cpi_nubusvar.h>
54 
55 #include "ioconf.h"
56 
57 #ifdef DEBUG
58 #define CPI_DEBUG
59 #endif
60 
61 /*
62  * Stuff taken from Egan/Teixeira ch 8: 'if(TRACE_FOO)' debug output
63  * statements don't break indentation, and when DEBUG is not defined,
64  * the compiler code optimizer drops them as dead code.
65  */
66 #ifdef CPI_DEBUG
67 #define M_TRACE_CONFIG	0x0001
68 #define M_TRACE_OPEN	0x0002
69 #define M_TRACE_CLOSE	0x0004
70 #define M_TRACE_READ	0x0008
71 #define M_TRACE_WRITE	0x0010
72 #define M_TRACE_IOCTL	0x0020
73 #define M_TRACE_STATUS	0x0040
74 #define M_TRACE_TCNTR	0x0080
75 #define M_TRACE_ALL	0xFFFF
76 #define M_TRACE_NONE	0x0000
77 
78 #define TRACE_CONFIG	(cpi_debug_mask & M_TRACE_CONFIG)
79 #define TRACE_OPEN	(cpi_debug_mask & M_TRACE_OPEN)
80 #define TRACE_CLOSE	(cpi_debug_mask & M_TRACE_CLOSE)
81 #define TRACE_READ	(cpi_debug_mask & M_TRACE_READ)
82 #define TRACE_WRITE	(cpi_debug_mask & M_TRACE_WRITE)
83 #define TRACE_IOCTL	(cpi_debug_mask & M_TRACE_IOCTL)
84 #define TRACE_STATUS	(cpi_debug_mask & M_TRACE_STATUS)
85 #define TRACE_TCNTR	(cpi_debug_mask & M_TRACE_TCNTR)
86 #define TRACE_ALL	(cpi_debug_mask & M_TRACE_ALL)
87 #define TRACE_NONE	(cpi_debug_mask & M_TRACE_NONE)
88 
89 uint32_t cpi_debug_mask = M_TRACE_NONE /* | M_TRACE_TCNTR | M_TRACE_WRITE */ ;
90 #else /* CPI_DEBUG */
91 #define TRACE_CONFIG	0
92 #define TRACE_OPEN	0
93 #define TRACE_CLOSE	0
94 #define TRACE_READ	0
95 #define TRACE_WRITE	0
96 #define TRACE_IOCTL	0
97 #define TRACE_STATUS	0
98 #define TRACE_TCNTR	0
99 #define TRACE_ALL	0
100 #define TRACE_NONE	0
101 #endif /* CPI_DEBUG */
102 
103 /* autoconf interface */
104 int cpi_nubus_match(device_t, cfdata_t, void *);
105 void cpi_nubus_attach(device_t, device_t, void *);
106 void cpi_nubus_intr(void *);
107 
108 CFATTACH_DECL_NEW(cpi, sizeof(struct cpi_softc),
109     cpi_nubus_match, cpi_nubus_attach, NULL, NULL);
110 
111 dev_type_open(cpi_open);
112 dev_type_close(cpi_close);
113 dev_type_read(cpi_read);
114 dev_type_write(cpi_write);
115 dev_type_ioctl(cpi_ioctl);
116 
117 const struct cdevsw cpi_cdevsw = {
118 	.d_open = cpi_open,
119 	.d_close = cpi_close,
120 	.d_read = noread,
121 	.d_write = cpi_write,
122 	.d_ioctl = cpi_ioctl,
123 	.d_stop = nostop,
124 	.d_tty = notty,
125 	.d_poll = nopoll,
126 	.d_mmap = nommap,
127 	.d_kqfilter = nokqfilter,
128 	.d_flag = D_OTHER
129 };
130 
131 /* prototypes */
132 static void cpi_lpreset(struct cpi_softc *);
133 static int cpi_notready(struct cpi_softc *);
134 static void cpi_wakeup(void *);
135 static int cpi_flush(struct cpi_softc *);
136 static void cpi_intr(void *);
137 
138 static void cpi_tc_initclock(struct cpi_softc *);
139 static uint cpi_get_timecount(struct timecounter *);
140 static uint z8536_read_counter1(bus_space_tag_t, bus_space_handle_t);
141 static uint z8536_read_counter2(bus_space_tag_t, bus_space_handle_t);
142 static void z8536_reg_set(bus_space_tag_t, bus_space_handle_t,
143     uint8_t, uint8_t);
144 static uint8_t z8536_reg_get(bus_space_tag_t, bus_space_handle_t,
145     uint8_t);
146 
147 
148 const uint8_t cio_reset[] = {
149 	/* register	value */
150 	Z8536_MICR, 	0x00,
151 	Z8536_MICR, 	MICR_RESET,
152 	Z8536_MICR, 	0x00
153 };
154 
155 const uint8_t cio_init[] = {
156 	/* register	value */
157 
158 	/* Interrupt vectors - clear all */
159 	Z8536_IVRA, 	0x00,
160 	Z8536_IVRB, 	0x00,
161 	Z8536_IVRCT, 	0x20 /* ??? Do we use this? */,
162 
163 	/*
164 	 * Port A specification - bit port, single buffered,
165 	 * latched output, pulsed handshake, all bits non-inverting
166 	 * non-special I/O
167 	 */
168 	Z8536_PMSRA, 	PMSR_PTS_OUT | PMSR_LPM,
169 	Z8536_PHSRA, 	PHSR_HTS_PUL,
170 	Z8536_DPPRA, 	0x00,
171 	Z8536_DDRA, 	0x00,
172 	Z8536_SIOCRA, 	0x00,
173 
174 	/*
175 	 * Port B specification - bit port, transparent output,
176 	 * pulsed handshake, all bits non-inverting
177 	 * bits 0, 4 output; bits 1-3, 5-8 input,
178 	 * non-special I/O
179 	 * Pattern matching: Bit 6 (BUSY) matching "1"
180 	 * Alternatively: Bit 3 (/ACK) matching "0"
181 	 */
182 	Z8536_PMSRB, 	PMSR_PMS_OR_PEV,
183 	Z8536_PHSRB, 	0x00,
184 	Z8536_DPPRB, 	0x00,
185 	Z8536_DDRB, 	0xee /*11101110b*/,
186 	Z8536_SIOCRB, 	0x00,
187 	Z8536_PPRB, 	0x00,
188 	Z8536_PTRB, 	0x00,
189 	Z8536_PMRB, 	0x40 /*01000000b = PB6 */,
190 
191 	Z8536_PDRB, 	0xFE,	/* Assign printer -RESET */
192 	Z8536_PCSRA, 	0x00,	/* Clear port A interrupt bits */
193 
194 	/*
195 	 * Port C specification - bit 3 out, bits 0-2 in,
196 	 * all 4 non-inverting, non-special I/O
197 	 */
198 	Z8536_DDRC, 	0x07 /*00000111b*/,
199 	Z8536_DPPRC, 	0x00,
200 	Z8536_SIOCRC, 	0x00,
201 
202 	/*
203 	 * We need Timer 3 for running port A in strobed mode.
204 	 *
205 	 * Counter/Timer 3 specification -- clear IP & IUS, trigger +
206 	 * gate command bit, one-shot operation
207 	 */
208 	Z8536_CTCSR3, 	CTCS_CLR_IP_IUS | CTCS_GCB | CTCS_TCB,
209 	Z8536_CTMSR3, 	CTMS_DCS_ONESHOT,
210 	Z8536_CTTCR3_MSB, 0x00,
211 	Z8536_CTTCR3_LSB, 0x03,
212 
213 	/* Enable ports A+B+C+CT3 */
214 	Z8536_MCCR,	MCCR_PAE | MCCR_PBE | MCCR_PC_CT3E,
215 
216 	/* Master Interrupt Enable, Disable Lower Chain,
217 	 * No Interrupt Vector, port A+B+CT vectors include status */
218 	Z8536_MICR,  	MICR_MIE | MICR_DLC | MICR_NV | MICR_PAVIS |
219 	MICR_PBVIS | MICR_CTVIS,
220 	Z8536_PDRB, 	0xFE,	/* Clear printer -RESET */
221 };
222 
223 /* CPI default options */
224 /* int	cpi_options = 0 | CPI_CTC12_IS_TIMECOUNTER; */
225 
226 
227 /*
228  * Look for Creative Systems Inc. "Hurdler Centronics Parallel Interface"
229  */
230 int
231 cpi_nubus_match(device_t parent, cfdata_t cf, void *aux)
232 {
233 	struct nubus_attach_args *na;
234 
235 	na = aux;
236 	if ((na->category == NUBUS_CATEGORY_COMMUNICATIONS) &&
237 	    (na->type == NUBUS_TYPE_CENTRONICS) &&
238 	    (na->drsw == NUBUS_DRSW_CPI) &&
239 	    (na->drhw == NUBUS_DRHW_CPI))
240 		return 1;
241 	else
242 		return 0;
243 }
244 
245 void
246 cpi_nubus_attach(device_t parent, device_t self, void *aux)
247 {
248 	struct cpi_softc *sc;
249 	struct nubus_attach_args *na;
250 	int err, ii;
251 
252 	sc = device_private(self);
253 	sc->sc_options = (device_cfdata(self)->cf_flags & CPI_OPTIONS_MASK);
254 
255 	na = aux;
256 	sc->sc_bst = na->na_tag;
257 	memcpy(&sc->sc_slot, na->fmt, sizeof(nubus_slot));
258 	sc->sc_basepa = (bus_addr_t)NUBUS_SLOT2PA(na->slot);
259 
260 	/*
261 	 * The CIO sits eight bit wide on the top byte lane of
262 	 * Nubus, so map 16 byte.
263 	 */
264 	if (TRACE_CONFIG) {
265 		printf("\n");
266 		printf("\tcpi_nubus_attach() mapping 8536 CIO at 0x%lx.\n",
267 		    sc->sc_basepa + CIO_BASE_OFFSET);
268 	}
269 
270 	err = bus_space_map(sc->sc_bst, sc->sc_basepa + CIO_BASE_OFFSET,
271 	    (Z8536_IOSIZE << 4), 0, &sc->sc_bsh);
272 	if (err) {
273 		aprint_normal(": failed to map memory space.\n");
274 		return;
275 	}
276 
277 	sc->sc_lpstate = LP_INITIAL;
278 	sc->sc_intcount = 0;
279 	sc->sc_bytestoport = 0;
280 
281 	if (TRACE_CONFIG)
282 		printf("\tcpi_nubus_attach() about to set up 8536 CIO.\n");
283 
284 	for (ii = 0; ii < sizeof(cio_reset); ii += 2)
285 		z8536_reg_set(sc->sc_bst, sc->sc_bsh, cio_reset[ii],
286 		    cio_reset[ii + 1]);
287 
288 	delay(1000);		/* Give the CIO time to set itself up */
289 	for (ii = 0; ii < sizeof(cio_init); ii += 2) {
290 		z8536_reg_set(sc->sc_bst, sc->sc_bsh, cio_init[ii],
291 		    cio_init[ii + 1]);
292 	}
293 
294 	if (TRACE_CONFIG)
295 		printf("\tcpi_nubus_attach() done with 8536 CIO setup.\n");
296 
297 	/* XXX Get information strings from the card ROM */
298 	aprint_normal(": CSI Hurdler II Centronics\n");
299 
300 	/* Attach CIO timers 1+2 as timecounter */
301 	if (sc->sc_options & CPI_CTC12_IS_TIMECOUNTER) {
302 		cpi_tc_initclock(sc);
303 	}
304 
305 	callout_init(&sc->sc_wakeupchan, 0);	/* XXX */
306 
307 	/* make sure interrupts are vectored to us */
308 	add_nubus_intr(na->slot, cpi_nubus_intr, sc);
309 }
310 
311 void
312 cpi_nubus_intr(void *arg)
313 {
314         struct cpi_softc *sc;
315 	int s;
316 
317 	sc = (struct cpi_softc *)arg;
318 
319 	s = spltty();
320 
321 	sc->sc_intcount++;
322 
323 	/* Check for interrupt source, and clear interrupt */
324 
325 	/*
326 	 * Clear port A interrupt
327 	 * Interrupt from register A, clear "pending"
328 	 * and set "under service"
329 	 */
330 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_CLR_IE);
331 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_CLR_IP);
332 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_SET_IUS);
333 
334 	cpi_intr(sc);
335 
336 	/* Interrupt from register A, mark serviced */
337 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_CLR_IUS);
338 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_SET_IE);
339 
340 	splx(s);
341 }
342 
343 
344 /* cpi nuts and bolts */
345 
346 int
347 cpi_open(dev_t device, int flag, int mode, struct lwp *l)
348 {
349 	int err, ii, s;
350         struct cpi_softc *sc;
351 
352 	if (TRACE_OPEN)
353 		printf("\tcpi_open() called...\n");
354 
355 	/* Consistency checks: Valid unit number, softc, device state */
356 	sc = device_lookup_private(&cpi_cd, CPI_UNIT(device));
357 	if (NULL == sc) {
358 		if (TRACE_OPEN)
359 			printf("Tried to cpi_open() with NULL softc\n");
360 		return ENXIO;
361 	}
362 	if (sc->sc_lpstate != LP_INITIAL) {
363 		if (TRACE_OPEN)
364 			printf("Not in initial state (%x).\n",
365 			    sc->sc_lpstate);
366 		return EBUSY;
367 	}
368 	sc->sc_lpstate = LP_OPENING;
369 
370 	if (TRACE_OPEN)
371 		printf("\tcpi_open() resetting the printer...\n");
372 	cpi_lpreset(sc);
373 
374 	if (TRACE_OPEN)
375 		printf("\tcpi_open() waiting for printer ready...\n");
376 
377 	/* Wait max 15 sec for printer to get ready */
378 	for (ii = 15; cpi_notready(sc); ii--) {
379 		if (0 == ii) {
380 			sc->sc_lpstate = LP_INITIAL;
381 			return EBUSY;
382 		}
383 		/* sleep for a second, unless we get a signal */
384 		err = tsleep(sc, PZERO | PCATCH, "cpi_open", hz);
385 		if (err != EWOULDBLOCK) {
386 			sc->sc_lpstate = LP_INITIAL;
387 			return err;
388 		}
389 	}
390 	if (TRACE_OPEN)
391 		printf("\tcpi_open() allocating printer buffer...\n");
392 
393 	/* Allocate the driver's line buffer */
394 	sc->sc_printbuf = malloc(CPI_BUFSIZE, M_DEVBUF, M_WAITOK);
395 	sc->sc_bufbytes = 0;
396 	sc->sc_lpstate = LP_OPEN;
397 
398 	/* Statistics */
399 	sc->sc_intcount = 0;
400 	sc->sc_bytestoport = 0;
401 
402 	/* Kick off transfer */
403 	cpi_wakeup(sc);
404 
405 	/*
406 	 * Reset "interrupt {pending, under service}" bits, then
407 	 * enable Port A interrupts
408 	 */
409 	s = spltty();
410 
411 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_CLR_IP_IUS);
412 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_SET_IE);
413 	splx(s);
414 
415 	if (TRACE_OPEN)
416 		printf("\tcpi_open() done...\n");
417 
418 	return 0;
419 }
420 
421 int
422 cpi_close(dev_t device, int flag, int mode, struct lwp *l)
423 {
424         struct cpi_softc *sc;
425 
426 	sc = device_lookup_private(&cpi_cd, CPI_UNIT(device));
427 
428 	if (TRACE_CLOSE)
429 		printf("\tcpi_close() called (%lu hard, %lu bytes to port)\n",
430 		    sc->sc_intcount, sc->sc_bytestoport);
431 
432 	/* Flush the remaining buffer content, ignoring any errors */
433 	if (0 < sc->sc_bufbytes)
434 		(void)cpi_flush(sc);
435 
436 	callout_stop(&sc->sc_wakeupchan);
437 
438 	/* Disable Port A interrupts */
439 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_CLR_IE);
440 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PCSRA, PCSR_CLR_IP_IUS);
441 
442 	sc->sc_lpstate = LP_INITIAL;
443 	free(sc->sc_printbuf, M_DEVBUF);
444 
445 	return 0;
446 }
447 
448 int
449 cpi_write(dev_t device, struct uio *uio, int flags)
450 {
451 	int err;
452 	size_t numbytes;
453         struct cpi_softc *sc;
454 
455 	err = 0;
456 
457 	if (TRACE_WRITE)
458 		printf("\tcpi_write() called for %u bytes\n", uio->uio_resid);
459 
460 	sc = device_lookup_private(&cpi_cd, CPI_UNIT(device));
461 
462 	/* Send data to printer, a line buffer full at a time */
463 	while (uio->uio_resid > 0) {
464 		numbytes = min(CPI_BUFSIZE, uio->uio_resid);
465 		sc->sc_cp = sc->sc_printbuf;
466 		uiomove(sc->sc_cp, numbytes, uio);
467 		sc->sc_bufbytes = numbytes;
468 
469 		if (TRACE_WRITE)
470 			printf("\tQueuing %u bytes\n", numbytes);
471 		err = cpi_flush(sc);
472 		if (err) {
473 			/* Failure; adjust residual counter */
474 			if (TRACE_WRITE)
475 				printf("\tQueuing failed with %d\n", err);
476 			uio->uio_resid += sc->sc_bufbytes;
477 			sc->sc_bufbytes = 0;
478 			break;
479 		}
480 	}
481 	return err;
482 }
483 
484 int
485 cpi_ioctl(dev_t device, unsigned long cmd, void *data,
486     int flag, struct lwp *l)
487 {
488 	int err;
489 
490 	err = 0;
491 
492 	if (TRACE_IOCTL)
493 		printf("\tcpi_ioctl() called with %ld...\n", cmd);
494 
495 	switch (cmd) {
496 	default:
497 		if (TRACE_IOCTL)
498 			printf("\tcpi_ioctl() unknown ioctl %ld\n", cmd);
499 		err = ENODEV;
500 		break;
501 	}
502 	return err;
503 }
504 
505 /*
506  * Flush the print buffer that our top half uses to provide data to
507  * our bottom, interrupt-driven half.
508  */
509 static int
510 cpi_flush(struct cpi_softc *sc)
511 {
512 	int err, s;
513 
514 	err = 0;
515 	while (0 < sc->sc_bufbytes) {
516 		/* Feed the printer a char, if it's ready */
517 		if ( !cpi_notready(sc)) {
518 			if (TRACE_WRITE)
519 				printf("\tcpi_flush() writes %u bytes "
520 				    "(%lu hard, %lu bytes to port)\n",
521 				    sc->sc_bufbytes, sc->sc_intcount,
522 				    sc->sc_bytestoport);
523 			s = spltty();
524 			cpi_intr(sc);
525 			splx(s);
526 		}
527 		/* XXX Sure we want to wait forever for the printer? */
528 		err = tsleep((void *)sc, PZERO | PCATCH,
529 		    "cpi_flush", (60 * hz));
530 	}
531 	return err;
532 }
533 
534 
535 static void
536 cpi_wakeup(void *param)
537 {
538 	struct cpi_softc *sc;
539 	int s;
540 
541 	sc = param;
542 
543 	s = spltty();
544 	cpi_intr(sc);
545 	splx(s);
546 
547 	callout_reset(&sc->sc_wakeupchan, hz, cpi_wakeup, sc);
548 }
549 
550 
551 static void
552 cpi_lpreset(struct cpi_softc *sc)
553 {
554 	uint8_t portb;		/* Centronics -RESET is on port B, bit 0 */
555 
556 	portb = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_PDRB);
557 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PDRB, portb & ~CPI_RESET);
558 	delay(100);
559 	portb = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_PDRB);
560 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_PDRB, portb | CPI_RESET);
561 }
562 
563 
564 /*
565  * Centronics BUSY 		is on port B, bit 6
566  *	      SELECT		is on Port B, bit 5
567  *	      /FAULT		is on Port B, bit 1
568  *            PAPER EMPTY	is on Port C, bit 1
569  */
570 static int
571 cpi_notready(struct cpi_softc *sc)
572 {
573 	uint8_t portb, portc;
574 	int is_busy, is_select, is_fault, is_paper_empty;
575 
576 	if (TRACE_STATUS)
577 		printf("\tcpi_notready() checking printer status...\n");
578 
579 	portb = bus_space_read_1(sc->sc_bst, sc->sc_bsh, CIO_PORTB);
580 	if (TRACE_STATUS)
581 		printf("\tPort B has 0x0%X\n", portb);
582 
583 	is_busy = CPI_BUSY & portb;
584 	if (TRACE_STATUS)
585 		printf("\t\tBUSY = %d\n", is_busy);
586 
587 	is_select = CPI_SELECT & portb;
588 	if (TRACE_STATUS)
589 		printf("\t\tSELECT = %d\n", is_select);
590 
591 	is_fault = CPI_FAULT & portb;
592 	if (TRACE_STATUS)
593 		printf("\t\t/FAULT = %d\n", is_fault);
594 
595 	portc = bus_space_read_1(sc->sc_bst, sc->sc_bsh, CIO_PORTC);
596 	if (TRACE_STATUS)
597 		printf("\tPort C has 0x0%X\n", portc);
598 
599 	is_paper_empty = CPI_PAPER_EMPTY & portc;
600 	if (TRACE_STATUS)
601 		printf("\t\tPAPER EMPTY = %d\n", is_paper_empty);
602 
603 	return (is_busy || !is_select || !is_fault || is_paper_empty);
604 }
605 
606 static void
607 cpi_intr(void *arg)
608 {
609 	struct cpi_softc *sc;
610 
611 	sc = arg;
612 
613 	/* Printer ready for output? */
614 	if (cpi_notready(sc))
615 		return;
616 
617 	if (0 && TRACE_WRITE)
618 		printf("\tcpi_soft_intr() has %u bytes.\n", sc->sc_bufbytes);
619 
620 	/* Anything to print? */
621 	if (sc->sc_bufbytes) {
622 		/* Data byte */
623 		bus_space_write_1(sc->sc_bst, sc->sc_bsh,
624 		    CIO_PORTA, *sc->sc_cp++);
625 		sc->sc_bufbytes--;
626 		sc->sc_bytestoport++;
627 	}
628 	if (0 == sc->sc_bufbytes)
629 		/* line buffer empty, wake up our top half */
630 		wakeup((void *)sc);
631 }
632 
633 static void
634 cpi_tc_initclock(struct cpi_softc *sc)
635 {
636 	uint8_t reg;
637 
638 	/*
639 	 * Set up c/t 1 and 2 as a single, free-running 32 bit counter
640 	 */
641 
642 	/* Disable counters 1 and 2 */
643 	reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_MCCR);
644 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_MCCR,
645 	    reg & ~(MCCR_CT1E | MCCR_CT2E));
646 
647 	/* Make sure interrupt enable bits are cleared */
648 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR1, CTCS_CLR_IE);
649 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR2, CTCS_CLR_IE);
650 
651 	/* Initialise counter start values, and set to continuous cycle */
652 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTMSR1,
653 	    CTMS_CSC | CTMS_DCS_PULSE);
654 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTTCR1_MSB, 0x00);
655 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTTCR1_LSB, 0x00);
656 
657 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTMSR2,
658 	    CTMS_CSC | CTMS_DCS_PULSE);
659 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTTCR2_MSB, 0x00);
660 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTTCR2_LSB, 0x00);
661 
662 	/* Link counters 1 and 2 */
663 	reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_MCCR);
664 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_MCCR, reg | MCCR_CT1CT2);
665 
666 	/* Enable and counter pair */
667 	reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_MCCR);
668 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_MCCR,
669 	    reg | (MCCR_CT1E | MCCR_CT2E));
670 
671 	/* Start c/t 1; c/t 2 gets started by c/t 1 pulse */
672 	reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR1);
673 	z8536_reg_set(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR1,
674 	    CTCSR_MASK(reg | CTCS_TCB | CTCS_GCB));
675 
676 	if (TRACE_TCNTR) {
677 		printf("Before tc_init():\n");
678 		reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR1);
679 		printf("Counter 1 CTCSR setup bits are 0x%03x\n", reg);
680 		printf("Counter 1 (LSW) is now 0x%05x\n",
681 		    z8536_read_counter1(sc->sc_bst, sc->sc_bsh));
682 		reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR2);
683 		printf("Counter 2 CTCSR setup bits are 0x%03x\n", reg);
684 		printf("Counter 2 (MSW) is now 0x%05x\n",
685 		    z8536_read_counter2(sc->sc_bst, sc->sc_bsh));
686 
687 		delay(1000);
688 	}
689 
690 	sc->sc_timecounter.tc_get_timecount = cpi_get_timecount;
691 	sc->sc_timecounter.tc_poll_pps      = 0;
692 	sc->sc_timecounter.tc_counter_mask  = ~0u;
693 	sc->sc_timecounter.tc_frequency     = CPI_CLK_FREQ;
694 	sc->sc_timecounter.tc_name          = "Nubus CPI";
695 	sc->sc_timecounter.tc_quality       = 1000;
696 	/*
697 	 * Squirrel away the device's sc so we can talk
698 	 * to the CIO later
699 	 */
700 	sc->sc_timecounter.tc_priv          = sc;
701 	sc->sc_timecounter.tc_next          = NULL;
702 
703         tc_init(&(sc->sc_timecounter));
704 
705 	if (TRACE_TCNTR) {
706 		delay(1000);
707 
708 		printf("After tc_init():\n");
709 		reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR1);
710 		printf("Counter 1 CTCSR setup bits are 0x%03x\n", reg);
711 		printf("Counter 1 (LSW) is now 0x%05x\n",
712 		    z8536_read_counter1(sc->sc_bst, sc->sc_bsh));
713 		reg = z8536_reg_get(sc->sc_bst, sc->sc_bsh, Z8536_CTCSR2);
714 		printf("Counter 2 CTCSR setup bits are 0x%03x\n", reg);
715 		printf("Counter 2 (MSW) is now 0x%05x\n",
716 		    z8536_read_counter2(sc->sc_bst, sc->sc_bsh));
717 	}
718 }
719 
720 static u_int
721 cpi_get_timecount(struct timecounter *tc)
722 {
723         int s;
724 	uint msw, msw2, lsw;
725 	uint8_t reg;
726 	bus_space_tag_t bst;
727 	bus_space_handle_t bsh;
728 
729 	bst = ((struct cpi_softc *)tc->tc_priv)->sc_bst;
730 	bsh = ((struct cpi_softc *)tc->tc_priv)->sc_bsh;
731 	/*
732 	 * We run CIO counters 1 and 2 in an internally coupled mode,
733 	 * where the output of counter 1 (LSW) clocks counter 2 (MSW).
734 	 * The counters are buffered, and the buffers have to be
735 	 * locked before we can read out a consistent counter
736 	 * value. Reading the LSB releases the buffer lock.
737 	 *
738 	 * Unfortunately, there is no such mechanism between MSW and
739 	 * LSW of the coupled counter. To ensure a consistent
740 	 * read-out, we read the MSW, then the LSW, then re-read the
741 	 * MSW and compare with the old value. If we find that the MSW
742 	 * has just been incremented, we re-read the LSW. This avoids
743 	 * a race that could leave us with a new (just wrapped) LSW
744 	 * and an old MSW value.
745 	 *
746 	 * For simplicity, we roll the procedure into a loop - the
747 	 * rollover case is rare.
748 	 */
749 	do {
750 
751 #define delay(a)
752 
753 		/* Guard HW timer access */
754 		s = splhigh();
755 
756 		/* Lock counter 2 latch in preparation for read-out */
757 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR2);
758 		delay(1);
759 		reg = bus_space_read_1(bst, bsh, CIO_CTRL);
760 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR2);
761 		bus_space_write_1(bst, bsh, CIO_CTRL, CTCSR_MASK(reg | CTCS_RCC));
762 
763 		/* Read out counter 2 MSB,then LSB (releasing the latch) */
764 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR2_MSB);
765 		delay(1);
766 		msw = bus_space_read_1(bst, bsh, CIO_CTRL) << 8;
767 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR2_LSB);
768 		delay(1);
769 		msw |= bus_space_read_1(bst, bsh, CIO_CTRL);
770 
771 		/* Lock counter 1 latch in preparation for read-out */
772 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR1);
773 		delay(1);
774 		reg = bus_space_read_1(bst, bsh, CIO_CTRL);
775 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR1);
776 		bus_space_write_1(bst, bsh, CIO_CTRL, CTCSR_MASK(reg |CTCS_RCC));
777 
778 		/* Read out counter 1 MSB,then LSB (releasing the latch) */
779 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR1_MSB);
780 		delay(1);
781 		lsw = bus_space_read_1(bst, bsh, CIO_CTRL) << 8;
782 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR1_LSB);
783 		delay(1);
784 		lsw |= bus_space_read_1(bst, bsh, CIO_CTRL);
785 
786 		/* Lock counter 2 latch in preparation for read-out */
787 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR2);
788 		delay(1);
789 		reg = bus_space_read_1(bst, bsh, CIO_CTRL);
790 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR2);
791 		bus_space_write_1(bst, bsh, CIO_CTRL, CTCSR_MASK(reg | CTCS_RCC));
792 
793 		/* Read out counter 2 MSB,then LSB (releasing the latch) */
794 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR2_MSB);
795 		delay(1);
796 		msw2 = bus_space_read_1(bst, bsh, CIO_CTRL) << 8;
797 		bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR2_LSB);
798 		delay(1);
799 		msw2 |= bus_space_read_1(bst, bsh, CIO_CTRL);
800 
801 		splx(s);
802 
803 	} while (msw2 != msw);
804 
805 	/* timecounter expects an upward counter */
806 	return ~0u - ((msw << 16) | lsw);
807 }
808 
809 /*
810  * Z8536 CIO convenience atomic register getter/setter
811  */
812 
813 static uint
814 z8536_read_counter1(bus_space_tag_t bst, bus_space_handle_t bsh)
815 {
816 	uint8_t reg;
817 	uint32_t lsw;
818 	int s;
819 
820 	s = splhigh();
821 
822 	/* Lock counter 1 latch in preparation for read-out */
823 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR1);
824 	delay(1);
825 	reg = bus_space_read_1(bst, bsh, CIO_CTRL);
826 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR1);
827 	bus_space_write_1(bst, bsh, CIO_CTRL, CTCSR_MASK(reg | CTCS_RCC));
828 
829 	/* Read out counter 1 MSB,then LSB (releasing the latch) */
830 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR1_MSB);
831 	delay(1);
832 	lsw = bus_space_read_1(bst, bsh, CIO_CTRL) << 8;
833 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR1_LSB);
834 	delay(1);
835 	lsw |= bus_space_read_1(bst, bsh, CIO_CTRL);
836 
837 	splx(s);
838 
839 	return lsw;
840 }
841 
842 static uint
843 z8536_read_counter2(bus_space_tag_t bst, bus_space_handle_t bsh)
844 {
845 	uint8_t reg;
846 	uint32_t msw;
847 	int s;
848 
849 	s = splhigh();
850 
851 	/* Lock counter 2 latch in preparation for read-out */
852 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR2);
853 	delay(1);
854 	reg = bus_space_read_1(bst, bsh, CIO_CTRL);
855 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCSR2);
856 	bus_space_write_1(bst, bsh, CIO_CTRL, CTCSR_MASK(reg | CTCS_RCC));
857 
858 	/* Read out counter 2 MSB,then LSB (releasing the latch) */
859 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR2_MSB);
860 	delay(1);
861 	msw = bus_space_read_1(bst, bsh, CIO_CTRL) << 8;
862 	bus_space_write_1(bst, bsh, CIO_CTRL, Z8536_CTCCR2_LSB);
863 	delay(1);
864 	msw |= bus_space_read_1(bst, bsh, CIO_CTRL);
865 
866 	splx(s);
867 
868 	return msw;
869 }
870 
871 static void
872 z8536_reg_set(bus_space_tag_t bspace, bus_space_handle_t bhandle,
873     uint8_t reg, uint8_t val)
874 {
875 	int s;
876 
877 	s = splhigh();
878 	bus_space_write_1(bspace, bhandle, CIO_CTRL, reg);
879 	delay(1);
880 	bus_space_write_1(bspace, bhandle, CIO_CTRL, val);
881 	splx(s);
882 }
883 
884 static uint8_t
885 z8536_reg_get(bus_space_tag_t bspace, bus_space_handle_t bhandle, uint8_t reg)
886 {
887 	int s;
888 	uint8_t val;
889 
890 	s = splhigh();
891 	bus_space_write_1(bspace, bhandle, CIO_CTRL, reg);
892 	delay(1);
893 	val = bus_space_read_1(bspace, bhandle, CIO_CTRL);
894 	splx(s);
895 
896 	return val;
897 }
898