xref: /freebsd/sys/dev/ppbus/lpt.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
1 /*
2  * Copyright (c) 1990 William F. Jolitz, TeleMuse
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  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This software is a component of "386BSD" developed by
16  *	William F. Jolitz, TeleMuse.
17  * 4. Neither the name of the developer nor the name "386BSD"
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ
22  * AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS
23  * SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
24  * THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
25  * NOT MAKE USE OF THIS WORK.
26  *
27  * FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
28  * BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN
29  * REFERENCES SUCH AS THE  "PORTING UNIX TO THE 386" SERIES
30  * (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING
31  * JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND
32  * LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE
33  * ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS
34  * OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE DEVELOPER BE LIABLE
40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46  * SUCH DAMAGE.
47  *
48  *	from: unknown origin, 386BSD 0.1
49  *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
50  *	From Id: nlpt.c,v 1.14 1999/02/08 13:55:43 des Exp
51  * $FreeBSD$
52  */
53 
54 /*
55  * Device Driver for AT parallel printer port
56  * Written by William Jolitz 12/18/90
57  */
58 
59 /*
60  * Updated for ppbus by Nicolas Souchu
61  * [Mon Jul 28 1997]
62  */
63 
64 #include "opt_lpt.h"
65 
66 #include <sys/param.h>
67 #include <sys/systm.h>
68 #include <sys/module.h>
69 #include <sys/bus.h>
70 #include <sys/conf.h>
71 #include <sys/kernel.h>
72 #include <sys/uio.h>
73 #include <sys/syslog.h>
74 #include <sys/malloc.h>
75 
76 #include <machine/bus.h>
77 #include <machine/resource.h>
78 #include <sys/rman.h>
79 
80 #include <dev/ppbus/lptio.h>
81 #include <dev/ppbus/ppbconf.h>
82 #include <dev/ppbus/ppb_1284.h>
83 #include <dev/ppbus/lpt.h>
84 #include "ppbus_if.h"
85 #include <dev/ppbus/ppbio.h>
86 
87 #ifndef LPT_DEBUG
88 #define lprintf(args)
89 #else
90 #define lprintf(args)						\
91 		do {						\
92 			if (lptflag)				\
93 				printf args;			\
94 		} while (0)
95 static int volatile lptflag = 1;
96 #endif
97 
98 #define	LPINITRDY	4	/* wait up to 4 seconds for a ready */
99 #define	LPTOUTINITIAL	10	/* initial timeout to wait for ready 1/10 s */
100 #define	LPTOUTMAX	1	/* maximal timeout 1 s */
101 #define	LPPRI		(PZERO+8)
102 #define	BUFSIZE		1024
103 #define	BUFSTATSIZE	32
104 
105 #define	LPTUNIT(s)	((s)&0x03)
106 #define	LPTFLAGS(s)	((s)&0xfc)
107 
108 struct lpt_data {
109 
110 	short	sc_state;
111 	/* default case: negative prime, negative ack, handshake strobe,
112 	   prime once */
113 	u_char	sc_control;
114 	char	sc_flags;
115 #define LP_POS_INIT	0x04	/* if we are a postive init signal */
116 #define LP_POS_ACK	0x08	/* if we are a positive going ack */
117 #define LP_NO_PRIME	0x10	/* don't prime the printer at all */
118 #define LP_PRIMEOPEN	0x20	/* prime on every open */
119 #define LP_AUTOLF	0x40	/* tell printer to do an automatic lf */
120 #define LP_BYPASS	0x80	/* bypass  printer ready checks */
121 	void	*sc_inbuf;
122 	void	*sc_statbuf;
123 	short	sc_xfercnt ;
124 	char	sc_primed;
125 	char	*sc_cp ;
126 	u_short	sc_irq ;	/* IRQ status of port */
127 #define LP_HAS_IRQ	0x01	/* we have an irq available */
128 #define LP_USE_IRQ	0x02	/* we are using our irq */
129 #define LP_ENABLE_IRQ	0x04	/* enable IRQ on open */
130 #define LP_ENABLE_EXT	0x10	/* we shall use advanced mode when possible */
131 	u_char	sc_backoff ;	/* time to call lptout() again */
132 
133 	struct resource *intr_resource;	/* interrupt resource */
134 	void *intr_cookie;		/* interrupt registration cookie */
135 
136 };
137 
138 #define LPT_NAME	"lpt"		/* our official name */
139 
140 static timeout_t lptout;
141 static int	lpt_port_test(device_t dev, u_char data, u_char mask);
142 static int	lpt_detect(device_t dev);
143 
144 #define DEVTOSOFTC(dev) \
145 	((struct lpt_data *)device_get_softc(dev))
146 #define UNITOSOFTC(unit) \
147 	((struct lpt_data *)devclass_get_softc(lpt_devclass, (unit)))
148 #define UNITODEVICE(unit) \
149 	(devclass_get_device(lpt_devclass, (unit)))
150 
151 static void lptintr(device_t dev);
152 static void lpt_intr(void *arg);	/* without spls */
153 
154 static devclass_t lpt_devclass;
155 
156 
157 /* bits for state */
158 #define	OPEN		(1<<0)	/* device is open */
159 #define	ASLP		(1<<1)	/* awaiting draining of printer */
160 #define	EERROR		(1<<2)	/* error was received from printer */
161 #define	OBUSY		(1<<3)	/* printer is busy doing output */
162 #define LPTOUT		(1<<4)	/* timeout while not selected */
163 #define TOUT		(1<<5)	/* timeout while not selected */
164 #define LPTINIT		(1<<6)	/* waiting to initialize for open */
165 #define INTERRUPTED	(1<<7)	/* write call was interrupted */
166 
167 #define HAVEBUS		(1<<8)	/* the driver owns the bus */
168 
169 
170 /* status masks to interrogate printer status */
171 #define RDY_MASK	(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)	/* ready ? */
172 #define LP_READY	(LPS_SEL|LPS_NBSY|LPS_NERR)
173 
174 /* Printer Ready condition  - from lpa.c */
175 /* Only used in polling code */
176 #define	LPS_INVERT	(LPS_NBSY | LPS_NACK |           LPS_SEL | LPS_NERR)
177 #define	LPS_MASK	(LPS_NBSY | LPS_NACK | LPS_OUT | LPS_SEL | LPS_NERR)
178 #define	NOT_READY(ppbus) ((ppb_rstr(ppbus)^LPS_INVERT)&LPS_MASK)
179 
180 #define	MAX_SLEEP	(hz*5)	/* Timeout while waiting for device ready */
181 #define	MAX_SPIN	20	/* Max delay for device ready in usecs */
182 
183 
184 static	d_open_t	lptopen;
185 static	d_close_t	lptclose;
186 static	d_write_t	lptwrite;
187 static	d_read_t	lptread;
188 static	d_ioctl_t	lptioctl;
189 
190 #define CDEV_MAJOR 16
191 static struct cdevsw lpt_cdevsw = {
192 	.d_open =	lptopen,
193 	.d_close =	lptclose,
194 	.d_read =	lptread,
195 	.d_write =	lptwrite,
196 	.d_ioctl =	lptioctl,
197 	.d_name =	LPT_NAME,
198 	.d_maj =	CDEV_MAJOR,
199 };
200 
201 static int
202 lpt_request_ppbus(device_t dev, int how)
203 {
204 	device_t ppbus = device_get_parent(dev);
205 	struct lpt_data *sc = DEVTOSOFTC(dev);
206 	int error;
207 
208 	if (sc->sc_state & HAVEBUS)
209 		return (0);
210 
211 	/* we have the bus only if the request succeded */
212 	if ((error = ppb_request_bus(ppbus, dev, how)) == 0)
213 		sc->sc_state |= HAVEBUS;
214 
215 	return (error);
216 }
217 
218 static int
219 lpt_release_ppbus(device_t dev)
220 {
221 	device_t ppbus = device_get_parent(dev);
222 	struct lpt_data *sc = DEVTOSOFTC(dev);
223 	int error = 0;
224 
225 	if ((error = ppb_release_bus(ppbus, dev)) == 0)
226 		sc->sc_state &= ~HAVEBUS;
227 
228 	return (error);
229 }
230 
231 /*
232  * Internal routine to lptprobe to do port tests of one byte value
233  */
234 static int
235 lpt_port_test(device_t ppbus, u_char data, u_char mask)
236 {
237 	int	temp, timeout;
238 
239 	data = data & mask;
240 	ppb_wdtr(ppbus, data);
241 	timeout = 10000;
242 	do {
243 		DELAY(10);
244 		temp = ppb_rdtr(ppbus) & mask;
245 	}
246 	while (temp != data && --timeout);
247 	lprintf(("out=%x\tin=%x\ttout=%d\n", data, temp, timeout));
248 	return (temp == data);
249 }
250 
251 /*
252  * Probe simplified by replacing multiple loops with a hardcoded
253  * test pattern - 1999/02/08 des@freebsd.org
254  *
255  * New lpt port probe Geoff Rehmet - Rhodes University - 14/2/94
256  * Based partially on Rod Grimes' printer probe
257  *
258  * Logic:
259  *	1) If no port address was given, use the bios detected ports
260  *	   and autodetect what ports the printers are on.
261  *	2) Otherwise, probe the data port at the address given,
262  *	   using the method in Rod Grimes' port probe.
263  *	   (Much code ripped off directly from Rod's probe.)
264  *
265  * Comments from Rod's probe:
266  * Logic:
267  *	1) You should be able to write to and read back the same value
268  *	   to the data port.  Do an alternating zeros, alternating ones,
269  *	   walking zero, and walking one test to check for stuck bits.
270  *
271  *	2) You should be able to write to and read back the same value
272  *	   to the control port lower 5 bits, the upper 3 bits are reserved
273  *	   per the IBM PC technical reference manauls and different boards
274  *	   do different things with them.  Do an alternating zeros, alternating
275  *	   ones, walking zero, and walking one test to check for stuck bits.
276  *
277  *	   Some printers drag the strobe line down when the are powered off
278  * 	   so this bit has been masked out of the control port test.
279  *
280  *	   XXX Some printers may not like a fast pulse on init or strobe, I
281  *	   don't know at this point, if that becomes a problem these bits
282  *	   should be turned off in the mask byte for the control port test.
283  *
284  *	   We are finally left with a mask of 0x14, due to some printers
285  *	   being adamant about holding other bits high ........
286  *
287  *	   Before probing the control port, we write a 0 to the data port -
288  *	   If not, some printers chuck out garbage when the strobe line
289  *	   gets toggled.
290  *
291  *	3) Set the data and control ports to a value of 0
292  *
293  *	This probe routine has been tested on Epson Lx-800, HP LJ3P,
294  *	Epson FX-1170 and C.Itoh 8510RM
295  *	printers.
296  *	Quick exit on fail added.
297  */
298 static int
299 lpt_detect(device_t dev)
300 {
301 	device_t ppbus = device_get_parent(dev);
302 
303 	static u_char	testbyte[18] = {
304 		0x55,			/* alternating zeros */
305 		0xaa,			/* alternating ones */
306 		0xfe, 0xfd, 0xfb, 0xf7,
307 		0xef, 0xdf, 0xbf, 0x7f,	/* walking zero */
308 		0x01, 0x02, 0x04, 0x08,
309 		0x10, 0x20, 0x40, 0x80	/* walking one */
310 	};
311 	int		i, error, status;
312 
313 	status = 1;				/* assume success */
314 
315 	if ((error = lpt_request_ppbus(dev, PPB_DONTWAIT))) {
316 		printf(LPT_NAME ": cannot alloc ppbus (%d)!\n", error);
317 		status = 0;
318 		goto end_probe;
319 	}
320 
321 	for (i = 0; i < 18 && status; i++)
322 		if (!lpt_port_test(ppbus, testbyte[i], 0xff)) {
323 			status = 0;
324 			goto end_probe;
325 		}
326 
327 end_probe:
328 	/* write 0's to control and data ports */
329 	ppb_wdtr(ppbus, 0);
330 	ppb_wctr(ppbus, 0);
331 
332 	lpt_release_ppbus(dev);
333 
334 	return (status);
335 }
336 
337 static void
338 lpt_identify(driver_t *driver, device_t parent)
339 {
340 
341 	BUS_ADD_CHILD(parent, 0, LPT_NAME, -1);
342 }
343 
344 /*
345  * lpt_probe()
346  */
347 static int
348 lpt_probe(device_t dev)
349 {
350 	struct lpt_data *sc;
351 
352 	sc = DEVTOSOFTC(dev);
353 	bzero(sc, sizeof(struct lpt_data));
354 
355 	/*
356 	 * Now, try to detect the printer.
357 	 */
358 	if (!lpt_detect(dev))
359 		return (ENXIO);
360 
361 	device_set_desc(dev, "Printer");
362 
363 	return (0);
364 }
365 
366 static int
367 lpt_attach(device_t dev)
368 {
369 	device_t ppbus = device_get_parent(dev);
370 	struct lpt_data *sc = DEVTOSOFTC(dev);
371 	int zero = 0, unit = device_get_unit(dev);
372 	int error;
373 	intptr_t irq;
374 
375 	sc->sc_primed = 0;	/* not primed yet */
376 
377 	if ((error = lpt_request_ppbus(dev, PPB_DONTWAIT))) {
378 		printf(LPT_NAME ": cannot alloc ppbus (%d)!\n", error);
379 		return (0);
380 	}
381 
382 	ppb_wctr(ppbus, LPC_NINIT);
383 
384 	/* check if we can use interrupt, should be done by ppc stuff */
385 	lprintf(("oldirq %x\n", sc->sc_irq));
386 
387 	/* retrieve the ppbus irq */
388 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
389 
390 	if (irq > 0) {
391 		/* declare our interrupt handler */
392 		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
393 						       &zero, irq, irq, 1, RF_SHAREABLE);
394 	}
395 	if (sc->intr_resource) {
396 		sc->sc_irq = LP_HAS_IRQ | LP_USE_IRQ | LP_ENABLE_IRQ;
397 		device_printf(dev, "Interrupt-driven port\n");
398 	} else {
399 		sc->sc_irq = 0;
400 		device_printf(dev, "Polled port\n");
401 	}
402 	lprintf(("irq %x %x\n", (int)irq, sc->sc_irq));
403 
404 	lpt_release_ppbus(dev);
405 
406 	make_dev(&lpt_cdevsw, unit,
407 	    UID_ROOT, GID_WHEEL, 0600, LPT_NAME "%d", unit);
408 	make_dev(&lpt_cdevsw, unit | LP_BYPASS,
409 	    UID_ROOT, GID_WHEEL, 0600, LPT_NAME "%d.ctl", unit);
410 	return (0);
411 }
412 
413 static void
414 lptout(void *arg)
415 {
416 	device_t dev = (device_t)arg;
417 	struct lpt_data *sc = DEVTOSOFTC(dev);
418 #ifdef LPT_DEBUG
419 	device_t ppbus = device_get_parent(dev);
420 #endif
421 
422 	lprintf(("T %x ", ppb_rstr(ppbus)));
423 	if (sc->sc_state & OPEN) {
424 		sc->sc_backoff++;
425 		if (sc->sc_backoff > hz/LPTOUTMAX)
426 			sc->sc_backoff = sc->sc_backoff > hz/LPTOUTMAX;
427 		timeout(lptout, (caddr_t)dev, sc->sc_backoff);
428 	} else
429 		sc->sc_state &= ~TOUT;
430 
431 	if (sc->sc_state & EERROR)
432 		sc->sc_state &= ~EERROR;
433 
434 	/*
435 	 * Avoid possible hangs due to missed interrupts
436 	 */
437 	if (sc->sc_xfercnt) {
438 		lptintr(dev);
439 	} else {
440 		sc->sc_state &= ~OBUSY;
441 		wakeup(dev);
442 	}
443 }
444 
445 /*
446  * lptopen -- reset the printer, then wait until it's selected and not busy.
447  *	If LP_BYPASS flag is selected, then we do not try to select the
448  *	printer -- this is just used for passing ioctls.
449  */
450 
451 static	int
452 lptopen(dev_t dev, int flags, int fmt, struct thread *td)
453 {
454 	int s;
455 	int trys, err;
456 	u_int unit = LPTUNIT(minor(dev));
457 	struct lpt_data *sc = UNITOSOFTC(unit);
458 	device_t lptdev = UNITODEVICE(unit);
459 	device_t ppbus = device_get_parent(lptdev);
460 
461 	if (!sc)
462 		return (ENXIO);
463 
464 	if (sc->sc_state) {
465 		lprintf((LPT_NAME ": still open %x\n", sc->sc_state));
466 		return(EBUSY);
467 	} else
468 		sc->sc_state |= LPTINIT;
469 
470 	sc->sc_flags = LPTFLAGS(minor(dev));
471 
472 	/* Check for open with BYPASS flag set. */
473 	if (sc->sc_flags & LP_BYPASS) {
474 		sc->sc_state = OPEN;
475 		return(0);
476 	}
477 
478 	/* request the ppbus only if we don't have it already */
479 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0) {
480 		/* give it a chance to try later */
481 		sc->sc_state = 0;
482 		return (err);
483 	}
484 
485 	s = spltty();
486 	lprintf((LPT_NAME " flags 0x%x\n", sc->sc_flags));
487 
488 	/* set IRQ status according to ENABLE_IRQ flag
489 	 */
490 	if (sc->sc_irq & LP_ENABLE_IRQ)
491 		sc->sc_irq |= LP_USE_IRQ;
492 	else
493 		sc->sc_irq &= ~LP_USE_IRQ;
494 
495 	/* init printer */
496 	if ((sc->sc_flags & LP_NO_PRIME) == 0) {
497 		if((sc->sc_flags & LP_PRIMEOPEN) || sc->sc_primed == 0) {
498 			ppb_wctr(ppbus, 0);
499 			sc->sc_primed++;
500 			DELAY(500);
501 		}
502 	}
503 
504 	ppb_wctr(ppbus, LPC_SEL|LPC_NINIT);
505 
506 	/* wait till ready (printer running diagnostics) */
507 	trys = 0;
508 	do {
509 		/* ran out of waiting for the printer */
510 		if (trys++ >= LPINITRDY*4) {
511 			splx(s);
512 			sc->sc_state = 0;
513 			lprintf(("status %x\n", ppb_rstr(ppbus)));
514 
515 			lpt_release_ppbus(lptdev);
516 			return (EBUSY);
517 		}
518 
519 		/* wait 1/4 second, give up if we get a signal */
520 		if (tsleep(lptdev, LPPRI|PCATCH, "lptinit", hz/4) !=
521 		    EWOULDBLOCK) {
522 			sc->sc_state = 0;
523 			splx(s);
524 
525 			lpt_release_ppbus(lptdev);
526 			return (EBUSY);
527 		}
528 
529 		/* is printer online and ready for output */
530 	} while ((ppb_rstr(ppbus) &
531 			(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
532 					(LPS_SEL|LPS_NBSY|LPS_NERR));
533 
534 	sc->sc_control = LPC_SEL|LPC_NINIT;
535 	if (sc->sc_flags & LP_AUTOLF)
536 		sc->sc_control |= LPC_AUTOL;
537 
538 	/* enable interrupt if interrupt-driven */
539 	if (sc->sc_irq & LP_USE_IRQ)
540 		sc->sc_control |= LPC_ENA;
541 
542 	ppb_wctr(ppbus, sc->sc_control);
543 
544 	sc->sc_state = OPEN;
545 	sc->sc_inbuf = malloc(BUFSIZE, M_DEVBUF, M_WAITOK);
546 	sc->sc_statbuf = malloc(BUFSTATSIZE, M_DEVBUF, M_WAITOK);
547 	sc->sc_xfercnt = 0;
548 	splx(s);
549 
550 	/* release the ppbus */
551 	lpt_release_ppbus(lptdev);
552 
553 	/* only use timeout if using interrupt */
554 	lprintf(("irq %x\n", sc->sc_irq));
555 	if (sc->sc_irq & LP_USE_IRQ) {
556 		sc->sc_state |= TOUT;
557 		timeout(lptout, (caddr_t)lptdev,
558 			 (sc->sc_backoff = hz/LPTOUTINITIAL));
559 	}
560 
561 	lprintf(("opened.\n"));
562 	return(0);
563 }
564 
565 /*
566  * lptclose -- close the device, free the local line buffer.
567  *
568  * Check for interrupted write call added.
569  */
570 
571 static	int
572 lptclose(dev_t dev, int flags, int fmt, struct thread *td)
573 {
574 	u_int unit = LPTUNIT(minor(dev));
575 	struct lpt_data *sc = UNITOSOFTC(unit);
576 	device_t lptdev = UNITODEVICE(unit);
577         device_t ppbus = device_get_parent(lptdev);
578 	int err;
579 
580 	if(sc->sc_flags & LP_BYPASS)
581 		goto end_close;
582 
583 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0)
584 		return (err);
585 
586 	sc->sc_state &= ~OPEN;
587 
588 	/* if the last write was interrupted, don't complete it */
589 	if((!(sc->sc_state  & INTERRUPTED)) && (sc->sc_irq & LP_USE_IRQ))
590 		while ((ppb_rstr(ppbus) &
591 			(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
592 			(LPS_SEL|LPS_NBSY|LPS_NERR) || sc->sc_xfercnt)
593 			/* wait 1/4 second, give up if we get a signal */
594 			if (tsleep(lptdev, LPPRI|PCATCH,
595 				"lpclose", hz) != EWOULDBLOCK)
596 				break;
597 
598 	ppb_wctr(ppbus, LPC_NINIT);
599 	free(sc->sc_inbuf, M_DEVBUF);
600 	free(sc->sc_statbuf, M_DEVBUF);
601 
602 end_close:
603 	/* release the bus anyway
604 	 * unregistration of interrupt forced by release
605 	 */
606 	lpt_release_ppbus(lptdev);
607 
608 	sc->sc_state = 0;
609 	sc->sc_xfercnt = 0;
610 	lprintf(("closed.\n"));
611 	return(0);
612 }
613 
614 /*
615  * lpt_pushbytes()
616  *	Workhorse for actually spinning and writing bytes to printer
617  *	Derived from lpa.c
618  *	Originally by ?
619  *
620  *	This code is only used when we are polling the port
621  */
622 static int
623 lpt_pushbytes(device_t dev)
624 {
625 	struct lpt_data *sc = DEVTOSOFTC(dev);
626 	device_t ppbus = device_get_parent(dev);
627 	int spin, err, tic;
628 	char ch;
629 
630 	lprintf(("p"));
631 	/* loop for every character .. */
632 	while (sc->sc_xfercnt > 0) {
633 		/* printer data */
634 		ch = *(sc->sc_cp);
635 		sc->sc_cp++;
636 		sc->sc_xfercnt--;
637 
638 		/*
639 		 * Wait for printer ready.
640 		 * Loop 20 usecs testing BUSY bit, then sleep
641 		 * for exponentially increasing timeout. (vak)
642 		 */
643 		for (spin = 0; NOT_READY(ppbus) && spin < MAX_SPIN; ++spin)
644 			DELAY(1);	/* XXX delay is NOT this accurate! */
645 		if (spin >= MAX_SPIN) {
646 			tic = 0;
647 			while (NOT_READY(ppbus)) {
648 				/*
649 				 * Now sleep, every cycle a
650 				 * little longer ..
651 				 */
652 				tic = tic + tic + 1;
653 				/*
654 				 * But no more than 10 seconds. (vak)
655 				 */
656 				if (tic > MAX_SLEEP)
657 					tic = MAX_SLEEP;
658 				err = tsleep(dev, LPPRI,
659 					LPT_NAME "poll", tic);
660 				if (err != EWOULDBLOCK) {
661 					return (err);
662 				}
663 			}
664 		}
665 
666 		/* output data */
667 		ppb_wdtr(ppbus, ch);
668 		/* strobe */
669 		ppb_wctr(ppbus, sc->sc_control|LPC_STB);
670 		ppb_wctr(ppbus, sc->sc_control);
671 
672 	}
673 	return(0);
674 }
675 
676 /*
677  * lptread --retrieve printer status in IEEE1284 NIBBLE mode
678  */
679 
680 static int
681 lptread(dev_t dev, struct uio *uio, int ioflag)
682 {
683         u_int	unit = LPTUNIT(minor(dev));
684 	struct lpt_data *sc = UNITOSOFTC(unit);
685 	device_t lptdev = UNITODEVICE(unit);
686         device_t ppbus = device_get_parent(lptdev);
687 	int error = 0, len;
688 
689 	if (sc->sc_flags & LP_BYPASS) {
690 		/* we can't do reads in bypass mode */
691 		return (EPERM);
692 	}
693 
694 	if ((error = ppb_1284_negociate(ppbus, PPB_NIBBLE, 0)))
695 		return (error);
696 
697 	/* read data in an other buffer, read/write may be simultaneous */
698 	len = 0;
699 	while (uio->uio_resid) {
700 		if ((error = ppb_1284_read(ppbus, PPB_NIBBLE,
701 				sc->sc_statbuf, min(BUFSTATSIZE,
702 				uio->uio_resid), &len))) {
703 			goto error;
704 		}
705 
706 		if (!len)
707 			goto error;		/* no more data */
708 
709 		if ((error = uiomove(sc->sc_statbuf, len, uio)))
710 			goto error;
711 	}
712 
713 error:
714 	ppb_1284_terminate(ppbus);
715 	return (error);
716 }
717 
718 /*
719  * lptwrite --copy a line from user space to a local buffer, then call
720  * putc to get the chars moved to the output queue.
721  *
722  * Flagging of interrupted write added.
723  */
724 
725 static	int
726 lptwrite(dev_t dev, struct uio *uio, int ioflag)
727 {
728 	register unsigned n;
729 	int err;
730         u_int	unit = LPTUNIT(minor(dev));
731 	struct lpt_data *sc = UNITOSOFTC(unit);
732 	device_t lptdev = UNITODEVICE(unit);
733         device_t ppbus = device_get_parent(lptdev);
734 
735 	if(sc->sc_flags & LP_BYPASS) {
736 		/* we can't do writes in bypass mode */
737 		return(EPERM);
738 	}
739 
740 	/* request the ppbus only if we don't have it already */
741 	/* XXX interrupt registration?! */
742 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0)
743 		return (err);
744 
745 	/* if interrupts are working, register the handler */
746 	if (sc->sc_irq & LP_USE_IRQ) {
747 		/* register our interrupt handler */
748 		err = BUS_SETUP_INTR(ppbus, lptdev, sc->intr_resource,
749 			       INTR_TYPE_TTY, lpt_intr, lptdev,
750 			       &sc->intr_cookie);
751 		if (err) {
752 			device_printf(lptdev, "handler registration failed, polled mode.\n");
753 			sc->sc_irq &= ~LP_USE_IRQ;
754 		}
755 	}
756 
757 	sc->sc_state &= ~INTERRUPTED;
758 	while ((n = min(BUFSIZE, uio->uio_resid)) != 0) {
759 		sc->sc_cp = sc->sc_inbuf;
760 		uiomove(sc->sc_cp, n, uio);
761 		sc->sc_xfercnt = n ;
762 
763 		if (sc->sc_irq & LP_ENABLE_EXT) {
764 			/* try any extended mode */
765 			err = ppb_write(ppbus, sc->sc_cp,
766 					sc->sc_xfercnt, 0);
767 			switch (err) {
768 			case 0:
769 				/* if not all data was sent, we could rely
770 				 * on polling for the last bytes */
771 				sc->sc_xfercnt = 0;
772 				break;
773 			case EINTR:
774 				sc->sc_state |= INTERRUPTED;
775 				return(err);
776 			case EINVAL:
777 				/* advanced mode not avail */
778 				log(LOG_NOTICE, LPT_NAME "%d: advanced mode not avail, polling\n", unit);
779 				break;
780 			default:
781 				return(err);
782 			}
783 		} else while ((sc->sc_xfercnt > 0)&&(sc->sc_irq & LP_USE_IRQ)) {
784 			lprintf(("i"));
785 			/* if the printer is ready for a char, */
786 			/* give it one */
787 			if ((sc->sc_state & OBUSY) == 0){
788 				lprintf(("\nC %d. ", sc->sc_xfercnt));
789 				lptintr(lptdev);
790 			}
791 			lprintf(("W "));
792 			if (sc->sc_state & OBUSY)
793 				if ((err = tsleep(lptdev,
794 					 LPPRI|PCATCH, LPT_NAME "write", 0))) {
795 					sc->sc_state |= INTERRUPTED;
796 					return(err);
797 				}
798 		}
799 
800 		/* check to see if we must do a polled write */
801 		if(!(sc->sc_irq & LP_USE_IRQ) && (sc->sc_xfercnt)) {
802 			lprintf(("p"));
803 
804 			err = lpt_pushbytes(lptdev);
805 
806 			if (err)
807 				return(err);
808 		}
809 	}
810 
811 	/* we have not been interrupted, release the ppbus */
812 	lpt_release_ppbus(lptdev);
813 
814 	return(0);
815 }
816 
817 /*
818  * lpt_intr -- handle printer interrupts which occur when the printer is
819  * ready to accept another char.
820  *
821  * do checking for interrupted write call.
822  */
823 
824 static void
825 lpt_intr(void *arg)
826 {
827 	device_t lptdev = (device_t)arg;
828         device_t ppbus = device_get_parent(lptdev);
829 	struct lpt_data *sc = DEVTOSOFTC(lptdev);
830 	int sts = 0;
831 	int i;
832 
833 	/* we must own the bus to use it */
834 	if ((sc->sc_state & HAVEBUS) == 0)
835 		return;
836 
837 	/*
838 	 * Is printer online and ready for output?
839 	 *
840 	 * Avoid falling back to lptout() too quickly.  First spin-loop
841 	 * to see if the printer will become ready ``really soon now''.
842 	 */
843 	for (i = 0; i < 100 &&
844 	     ((sts=ppb_rstr(ppbus)) & RDY_MASK) != LP_READY; i++) ;
845 
846 	if ((sts & RDY_MASK) == LP_READY) {
847 		sc->sc_state = (sc->sc_state | OBUSY) & ~EERROR;
848 		sc->sc_backoff = hz/LPTOUTINITIAL;
849 
850 		if (sc->sc_xfercnt) {
851 			/* send char */
852 			/*lprintf(("%x ", *sc->sc_cp)); */
853 			ppb_wdtr(ppbus, *sc->sc_cp++) ;
854 			ppb_wctr(ppbus, sc->sc_control|LPC_STB);
855 			/* DELAY(X) */
856 			ppb_wctr(ppbus, sc->sc_control);
857 
858 			/* any more data for printer */
859 			if(--(sc->sc_xfercnt) > 0) return;
860 		}
861 
862 		/*
863 		 * No more data waiting for printer.
864 		 * Wakeup is not done if write call was not interrupted.
865 		 */
866 		sc->sc_state &= ~OBUSY;
867 
868 		if(!(sc->sc_state & INTERRUPTED))
869 			wakeup(lptdev);
870 		lprintf(("w "));
871 		return;
872 	} else	{	/* check for error */
873 		if(((sts & (LPS_NERR | LPS_OUT) ) != LPS_NERR) &&
874 				(sc->sc_state & OPEN))
875 			sc->sc_state |= EERROR;
876 		/* lptout() will jump in and try to restart. */
877 	}
878 	lprintf(("sts %x ", sts));
879 }
880 
881 static void
882 lptintr(device_t dev)
883 {
884 	/* call the interrupt at required spl level */
885 	int s = spltty();
886 
887 	lpt_intr(dev);
888 
889 	splx(s);
890 	return;
891 }
892 
893 static	int
894 lptioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
895 {
896 	int	error = 0;
897         u_int	unit = LPTUNIT(minor(dev));
898         struct	lpt_data *sc = UNITOSOFTC(unit);
899 	u_char	old_sc_irq;	/* old printer IRQ status */
900 
901 	switch (cmd) {
902 	case LPT_IRQ :
903 		if(sc->sc_irq & LP_HAS_IRQ) {
904 			/*
905 			 * NOTE:
906 			 * If the IRQ status is changed,
907 			 * this will only be visible on the
908 			 * next open.
909 			 *
910 			 * If interrupt status changes,
911 			 * this gets syslog'd.
912 			 */
913 			old_sc_irq = sc->sc_irq;
914 			switch(*(int*)data) {
915 			case 0:
916 				sc->sc_irq &= (~LP_ENABLE_IRQ);
917 				break;
918 			case 1:
919 				sc->sc_irq &= (~LP_ENABLE_EXT);
920 				sc->sc_irq |= LP_ENABLE_IRQ;
921 				break;
922 			case 2:
923 				/* classic irq based transfer and advanced
924 				 * modes are in conflict
925 				 */
926 				sc->sc_irq &= (~LP_ENABLE_IRQ);
927 				sc->sc_irq |= LP_ENABLE_EXT;
928 				break;
929 			case 3:
930 				sc->sc_irq &= (~LP_ENABLE_EXT);
931 				break;
932 			default:
933 				break;
934 			}
935 
936 			if (old_sc_irq != sc->sc_irq )
937 				log(LOG_NOTICE, LPT_NAME "%d: switched to %s %s mode\n",
938 					unit,
939 					(sc->sc_irq & LP_ENABLE_IRQ)?
940 					"interrupt-driven":"polled",
941 					(sc->sc_irq & LP_ENABLE_EXT)?
942 					"extended":"standard");
943 		} else /* polled port */
944 			error = EOPNOTSUPP;
945 		break;
946 	default:
947 		error = ENODEV;
948 	}
949 
950 	return(error);
951 }
952 
953 static device_method_t lpt_methods[] = {
954 	/* device interface */
955 	DEVMETHOD(device_identify,	lpt_identify),
956 	DEVMETHOD(device_probe,		lpt_probe),
957 	DEVMETHOD(device_attach,	lpt_attach),
958 
959 	{ 0, 0 }
960 };
961 
962 static driver_t lpt_driver = {
963 	LPT_NAME,
964 	lpt_methods,
965 	sizeof(struct lpt_data),
966 };
967 
968 DRIVER_MODULE(lpt, ppbus, lpt_driver, lpt_devclass, 0, 0);
969