xref: /freebsd/sys/dev/ppbus/lpt.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
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/buf.h>
72 #include <sys/kernel.h>
73 #include <sys/uio.h>
74 #include <sys/syslog.h>
75 
76 #include <machine/clock.h>
77 #include <machine/bus.h>
78 #include <machine/resource.h>
79 #include <sys/rman.h>
80 
81 #include <machine/lpt.h>
82 
83 #include <dev/ppbus/ppbconf.h>
84 #include <dev/ppbus/ppb_1284.h>
85 #include <dev/ppbus/lpt.h>
86 #include "ppbus_if.h"
87 #include <dev/ppbus/ppbio.h>
88 
89 #ifndef LPT_DEBUG
90 #define lprintf(args)
91 #else
92 #define lprintf(args)						\
93 		do {						\
94 			if (lptflag)				\
95 				printf args;			\
96 		} while (0)
97 static int volatile lptflag = 1;
98 #endif
99 
100 #define	LPINITRDY	4	/* wait up to 4 seconds for a ready */
101 #define	LPTOUTINITIAL	10	/* initial timeout to wait for ready 1/10 s */
102 #define	LPTOUTMAX	1	/* maximal timeout 1 s */
103 #define	LPPRI		(PZERO+8)
104 #define	BUFSIZE		1024
105 #define	BUFSTATSIZE	32
106 
107 #define	LPTUNIT(s)	((s)&0x03)
108 #define	LPTFLAGS(s)	((s)&0xfc)
109 
110 struct lpt_data {
111 
112 	short	sc_state;
113 	/* default case: negative prime, negative ack, handshake strobe,
114 	   prime once */
115 	u_char	sc_control;
116 	char	sc_flags;
117 #define LP_POS_INIT	0x04	/* if we are a postive init signal */
118 #define LP_POS_ACK	0x08	/* if we are a positive going ack */
119 #define LP_NO_PRIME	0x10	/* don't prime the printer at all */
120 #define LP_PRIMEOPEN	0x20	/* prime on every open */
121 #define LP_AUTOLF	0x40	/* tell printer to do an automatic lf */
122 #define LP_BYPASS	0x80	/* bypass  printer ready checks */
123 	struct	buf *sc_inbuf;
124 	struct	buf *sc_statbuf;
125 	short	sc_xfercnt ;
126 	char	sc_primed;
127 	char	*sc_cp ;
128 	u_short	sc_irq ;	/* IRQ status of port */
129 #define LP_HAS_IRQ	0x01	/* we have an irq available */
130 #define LP_USE_IRQ	0x02	/* we are using our irq */
131 #define LP_ENABLE_IRQ	0x04	/* enable IRQ on open */
132 #define LP_ENABLE_EXT	0x10	/* we shall use advanced mode when possible */
133 	u_char	sc_backoff ;	/* time to call lptout() again */
134 
135 	struct resource *intr_resource;	/* interrupt resource */
136 	void *intr_cookie;		/* interrupt registration cookie */
137 
138 };
139 
140 #define LPT_NAME	"lpt"		/* our official name */
141 
142 static timeout_t lptout;
143 static int	lpt_port_test(device_t dev, u_char data, u_char mask);
144 static int	lpt_detect(device_t dev);
145 
146 #define DEVTOSOFTC(dev) \
147 	((struct lpt_data *)device_get_softc(dev))
148 #define UNITOSOFTC(unit) \
149 	((struct lpt_data *)devclass_get_softc(lpt_devclass, (unit)))
150 #define UNITODEVICE(unit) \
151 	(devclass_get_device(lpt_devclass, (unit)))
152 
153 static void lptintr(device_t dev);
154 static void lpt_intr(void *arg);	/* without spls */
155 
156 static devclass_t lpt_devclass;
157 
158 
159 /* bits for state */
160 #define	OPEN		(1<<0)	/* device is open */
161 #define	ASLP		(1<<1)	/* awaiting draining of printer */
162 #define	EERROR		(1<<2)	/* error was received from printer */
163 #define	OBUSY		(1<<3)	/* printer is busy doing output */
164 #define LPTOUT		(1<<4)	/* timeout while not selected */
165 #define TOUT		(1<<5)	/* timeout while not selected */
166 #define LPTINIT		(1<<6)	/* waiting to initialize for open */
167 #define INTERRUPTED	(1<<7)	/* write call was interrupted */
168 
169 #define HAVEBUS		(1<<8)	/* the driver owns the bus */
170 
171 
172 /* status masks to interrogate printer status */
173 #define RDY_MASK	(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)	/* ready ? */
174 #define LP_READY	(LPS_SEL|LPS_NBSY|LPS_NERR)
175 
176 /* Printer Ready condition  - from lpa.c */
177 /* Only used in polling code */
178 #define	LPS_INVERT	(LPS_NBSY | LPS_NACK |           LPS_SEL | LPS_NERR)
179 #define	LPS_MASK	(LPS_NBSY | LPS_NACK | LPS_OUT | LPS_SEL | LPS_NERR)
180 #define	NOT_READY(ppbus) ((ppb_rstr(ppbus)^LPS_INVERT)&LPS_MASK)
181 
182 #define	MAX_SLEEP	(hz*5)	/* Timeout while waiting for device ready */
183 #define	MAX_SPIN	20	/* Max delay for device ready in usecs */
184 
185 
186 static	d_open_t	lptopen;
187 static	d_close_t	lptclose;
188 static	d_write_t	lptwrite;
189 static	d_read_t	lptread;
190 static	d_ioctl_t	lptioctl;
191 
192 #define CDEV_MAJOR 16
193 static struct cdevsw lpt_cdevsw = {
194 	/* open */	lptopen,
195 	/* close */	lptclose,
196 	/* read */	lptread,
197 	/* write */	lptwrite,
198 	/* ioctl */	lptioctl,
199 	/* poll */	nopoll,
200 	/* mmap */	nommap,
201 	/* strategy */	nostrategy,
202 	/* name */	LPT_NAME,
203 	/* maj */	CDEV_MAJOR,
204 	/* dump */	nodump,
205 	/* psize */	nopsize,
206 	/* flags */	0,
207 	/* bmaj */	-1
208 };
209 
210 static int
211 lpt_request_ppbus(device_t dev, int how)
212 {
213 	device_t ppbus = device_get_parent(dev);
214 	struct lpt_data *sc = DEVTOSOFTC(dev);
215 	int error;
216 
217 	if (sc->sc_state & HAVEBUS)
218 		return (0);
219 
220 	/* we have the bus only if the request succeded */
221 	if ((error = ppb_request_bus(ppbus, dev, how)) == 0)
222 		sc->sc_state |= HAVEBUS;
223 
224 	return (error);
225 }
226 
227 static int
228 lpt_release_ppbus(device_t dev)
229 {
230 	device_t ppbus = device_get_parent(dev);
231 	struct lpt_data *sc = DEVTOSOFTC(dev);
232 	int error = 0;
233 
234 	if ((error = ppb_release_bus(ppbus, dev)) == 0)
235 		sc->sc_state &= ~HAVEBUS;
236 
237 	return (error);
238 }
239 
240 /*
241  * Internal routine to lptprobe to do port tests of one byte value
242  */
243 static int
244 lpt_port_test(device_t ppbus, u_char data, u_char mask)
245 {
246 	int	temp, timeout;
247 
248 	data = data & mask;
249 	ppb_wdtr(ppbus, data);
250 	timeout = 10000;
251 	do {
252 		DELAY(10);
253 		temp = ppb_rdtr(ppbus) & mask;
254 	}
255 	while (temp != data && --timeout);
256 	lprintf(("out=%x\tin=%x\ttout=%d\n", data, temp, timeout));
257 	return (temp == data);
258 }
259 
260 /*
261  * Probe simplified by replacing multiple loops with a hardcoded
262  * test pattern - 1999/02/08 des@freebsd.org
263  *
264  * New lpt port probe Geoff Rehmet - Rhodes University - 14/2/94
265  * Based partially on Rod Grimes' printer probe
266  *
267  * Logic:
268  *	1) If no port address was given, use the bios detected ports
269  *	   and autodetect what ports the printers are on.
270  *	2) Otherwise, probe the data port at the address given,
271  *	   using the method in Rod Grimes' port probe.
272  *	   (Much code ripped off directly from Rod's probe.)
273  *
274  * Comments from Rod's probe:
275  * Logic:
276  *	1) You should be able to write to and read back the same value
277  *	   to the data port.  Do an alternating zeros, alternating ones,
278  *	   walking zero, and walking one test to check for stuck bits.
279  *
280  *	2) You should be able to write to and read back the same value
281  *	   to the control port lower 5 bits, the upper 3 bits are reserved
282  *	   per the IBM PC technical reference manauls and different boards
283  *	   do different things with them.  Do an alternating zeros, alternating
284  *	   ones, walking zero, and walking one test to check for stuck bits.
285  *
286  *	   Some printers drag the strobe line down when the are powered off
287  * 	   so this bit has been masked out of the control port test.
288  *
289  *	   XXX Some printers may not like a fast pulse on init or strobe, I
290  *	   don't know at this point, if that becomes a problem these bits
291  *	   should be turned off in the mask byte for the control port test.
292  *
293  *	   We are finally left with a mask of 0x14, due to some printers
294  *	   being adamant about holding other bits high ........
295  *
296  *	   Before probing the control port, we write a 0 to the data port -
297  *	   If not, some printers chuck out garbage when the strobe line
298  *	   gets toggled.
299  *
300  *	3) Set the data and control ports to a value of 0
301  *
302  *	This probe routine has been tested on Epson Lx-800, HP LJ3P,
303  *	Epson FX-1170 and C.Itoh 8510RM
304  *	printers.
305  *	Quick exit on fail added.
306  */
307 static int
308 lpt_detect(device_t dev)
309 {
310 	device_t ppbus = device_get_parent(dev);
311 
312 	static u_char	testbyte[18] = {
313 		0x55,			/* alternating zeros */
314 		0xaa,			/* alternating ones */
315 		0xfe, 0xfd, 0xfb, 0xf7,
316 		0xef, 0xdf, 0xbf, 0x7f,	/* walking zero */
317 		0x01, 0x02, 0x04, 0x08,
318 		0x10, 0x20, 0x40, 0x80	/* walking one */
319 	};
320 	int		i, error, status;
321 
322 	status = 1;				/* assume success */
323 
324 	if ((error = lpt_request_ppbus(dev, PPB_DONTWAIT))) {
325 		printf(LPT_NAME ": cannot alloc ppbus (%d)!\n", error);
326 		status = 0;
327 		goto end_probe;
328 	}
329 
330 	for (i = 0; i < 18 && status; i++)
331 		if (!lpt_port_test(ppbus, testbyte[i], 0xff)) {
332 			status = 0;
333 			goto end_probe;
334 		}
335 
336 end_probe:
337 	/* write 0's to control and data ports */
338 	ppb_wdtr(ppbus, 0);
339 	ppb_wctr(ppbus, 0);
340 
341 	lpt_release_ppbus(dev);
342 
343 	return (status);
344 }
345 
346 static void
347 lpt_identify(driver_t *driver, device_t parent)
348 {
349 
350 	BUS_ADD_CHILD(parent, 0, LPT_NAME, 0);
351 }
352 
353 /*
354  * lpt_probe()
355  */
356 static int
357 lpt_probe(device_t dev)
358 {
359 	struct lpt_data *sc;
360 
361 	sc = DEVTOSOFTC(dev);
362 	bzero(sc, sizeof(struct lpt_data));
363 
364 	/*
365 	 * Now, try to detect the printer.
366 	 */
367 	if (!lpt_detect(dev))
368 		return (ENXIO);
369 
370 	device_set_desc(dev, "Printer");
371 
372 	return (0);
373 }
374 
375 static int
376 lpt_attach(device_t dev)
377 {
378 	device_t ppbus = device_get_parent(dev);
379 	struct lpt_data *sc = DEVTOSOFTC(dev);
380 	int zero = 0, unit = device_get_unit(dev);
381 	int error;
382 	uintptr_t irq;
383 
384 	sc->sc_primed = 0;	/* not primed yet */
385 
386 	if ((error = lpt_request_ppbus(dev, PPB_DONTWAIT))) {
387 		printf(LPT_NAME ": cannot alloc ppbus (%d)!\n", error);
388 		return (0);
389 	}
390 
391 	ppb_wctr(ppbus, LPC_NINIT);
392 
393 	/* check if we can use interrupt, should be done by ppc stuff */
394 	lprintf(("oldirq %x\n", sc->sc_irq));
395 
396 	/* retrieve the ppbus irq */
397 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
398 
399 	if (irq > 0) {
400 		/* declare our interrupt handler */
401 		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
402 						       &zero, irq, irq, 1, RF_SHAREABLE);
403 	}
404 	if (sc->intr_resource) {
405 		sc->sc_irq = LP_HAS_IRQ | LP_USE_IRQ | LP_ENABLE_IRQ;
406 		device_printf(dev, "Interrupt-driven port\n");
407 	} else {
408 		sc->sc_irq = 0;
409 		device_printf(dev, "Polled port\n");
410 	}
411 	lprintf(("irq %x %x\n", irq, sc->sc_irq));
412 
413 	lpt_release_ppbus(dev);
414 
415 	make_dev(&lpt_cdevsw, unit,
416 	    UID_ROOT, GID_WHEEL, 0600, LPT_NAME "%d", unit);
417 	make_dev(&lpt_cdevsw, unit | LP_BYPASS,
418 	    UID_ROOT, GID_WHEEL, 0600, LPT_NAME "%d.ctl", unit);
419 	return (0);
420 }
421 
422 static void
423 lptout(void *arg)
424 {
425 	device_t dev = (device_t)arg;
426 	struct lpt_data *sc = DEVTOSOFTC(dev);
427 #ifdef LPT_DEBUG
428 	device_t ppbus = device_get_parent(dev);
429 #endif
430 
431 	lprintf(("T %x ", ppb_rstr(ppbus)));
432 	if (sc->sc_state & OPEN) {
433 		sc->sc_backoff++;
434 		if (sc->sc_backoff > hz/LPTOUTMAX)
435 			sc->sc_backoff = sc->sc_backoff > hz/LPTOUTMAX;
436 		timeout(lptout, (caddr_t)dev, sc->sc_backoff);
437 	} else
438 		sc->sc_state &= ~TOUT;
439 
440 	if (sc->sc_state & EERROR)
441 		sc->sc_state &= ~EERROR;
442 
443 	/*
444 	 * Avoid possible hangs due to missed interrupts
445 	 */
446 	if (sc->sc_xfercnt) {
447 		lptintr(dev);
448 	} else {
449 		sc->sc_state &= ~OBUSY;
450 		wakeup((caddr_t)dev);
451 	}
452 }
453 
454 /*
455  * lptopen -- reset the printer, then wait until it's selected and not busy.
456  *	If LP_BYPASS flag is selected, then we do not try to select the
457  *	printer -- this is just used for passing ioctls.
458  */
459 
460 static	int
461 lptopen(dev_t dev, int flags, int fmt, struct proc *p)
462 {
463 	int s;
464 	int trys, err;
465 	u_int unit = LPTUNIT(minor(dev));
466 	struct lpt_data *sc = UNITOSOFTC(unit);
467 	device_t lptdev = UNITODEVICE(unit);
468 	device_t ppbus = device_get_parent(lptdev);
469 
470 	if (!sc)
471 		return (ENXIO);
472 
473 	if (sc->sc_state) {
474 		lprintf((LPT_NAME ": still open %x\n", sc->sc_state));
475 		return(EBUSY);
476 	} else
477 		sc->sc_state |= LPTINIT;
478 
479 	sc->sc_flags = LPTFLAGS(minor(dev));
480 
481 	/* Check for open with BYPASS flag set. */
482 	if (sc->sc_flags & LP_BYPASS) {
483 		sc->sc_state = OPEN;
484 		return(0);
485 	}
486 
487 	/* request the ppbus only if we don't have it already */
488 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0) {
489 		/* give it a chance to try later */
490 		sc->sc_state = 0;
491 		return (err);
492 	}
493 
494 	s = spltty();
495 	lprintf((LPT_NAME " flags 0x%x\n", sc->sc_flags));
496 
497 	/* set IRQ status according to ENABLE_IRQ flag
498 	 */
499 	if (sc->sc_irq & LP_ENABLE_IRQ)
500 		sc->sc_irq |= LP_USE_IRQ;
501 	else
502 		sc->sc_irq &= ~LP_USE_IRQ;
503 
504 	/* init printer */
505 	if ((sc->sc_flags & LP_NO_PRIME) == 0) {
506 		if((sc->sc_flags & LP_PRIMEOPEN) || sc->sc_primed == 0) {
507 			ppb_wctr(ppbus, 0);
508 			sc->sc_primed++;
509 			DELAY(500);
510 		}
511 	}
512 
513 	ppb_wctr(ppbus, LPC_SEL|LPC_NINIT);
514 
515 	/* wait till ready (printer running diagnostics) */
516 	trys = 0;
517 	do {
518 		/* ran out of waiting for the printer */
519 		if (trys++ >= LPINITRDY*4) {
520 			splx(s);
521 			sc->sc_state = 0;
522 			lprintf(("status %x\n", ppb_rstr(ppbus)));
523 
524 			lpt_release_ppbus(lptdev);
525 			return (EBUSY);
526 		}
527 
528 		/* wait 1/4 second, give up if we get a signal */
529 		if (tsleep((caddr_t)lptdev, LPPRI|PCATCH, "lptinit", hz/4) !=
530 		    EWOULDBLOCK) {
531 			sc->sc_state = 0;
532 			splx(s);
533 
534 			lpt_release_ppbus(lptdev);
535 			return (EBUSY);
536 		}
537 
538 		/* is printer online and ready for output */
539 	} while ((ppb_rstr(ppbus) &
540 			(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
541 					(LPS_SEL|LPS_NBSY|LPS_NERR));
542 
543 	sc->sc_control = LPC_SEL|LPC_NINIT;
544 	if (sc->sc_flags & LP_AUTOLF)
545 		sc->sc_control |= LPC_AUTOL;
546 
547 	/* enable interrupt if interrupt-driven */
548 	if (sc->sc_irq & LP_USE_IRQ)
549 		sc->sc_control |= LPC_ENA;
550 
551 	ppb_wctr(ppbus, sc->sc_control);
552 
553 	sc->sc_state = OPEN;
554 	sc->sc_inbuf = geteblk(BUFSIZE);
555 	sc->sc_statbuf = geteblk(BUFSTATSIZE);
556 	sc->sc_xfercnt = 0;
557 	splx(s);
558 
559 	/* release the ppbus */
560 	lpt_release_ppbus(lptdev);
561 
562 	/* only use timeout if using interrupt */
563 	lprintf(("irq %x\n", sc->sc_irq));
564 	if (sc->sc_irq & LP_USE_IRQ) {
565 		sc->sc_state |= TOUT;
566 		timeout(lptout, (caddr_t)lptdev,
567 			 (sc->sc_backoff = hz/LPTOUTINITIAL));
568 	}
569 
570 	lprintf(("opened.\n"));
571 	return(0);
572 }
573 
574 /*
575  * lptclose -- close the device, free the local line buffer.
576  *
577  * Check for interrupted write call added.
578  */
579 
580 static	int
581 lptclose(dev_t dev, int flags, int fmt, struct proc *p)
582 {
583 	u_int unit = LPTUNIT(minor(dev));
584 	struct lpt_data *sc = UNITOSOFTC(unit);
585 	device_t lptdev = UNITODEVICE(unit);
586         device_t ppbus = device_get_parent(lptdev);
587 	int err;
588 
589 	if(sc->sc_flags & LP_BYPASS)
590 		goto end_close;
591 
592 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0)
593 		return (err);
594 
595 	sc->sc_state &= ~OPEN;
596 
597 	/* if the last write was interrupted, don't complete it */
598 	if((!(sc->sc_state  & INTERRUPTED)) && (sc->sc_irq & LP_USE_IRQ))
599 		while ((ppb_rstr(ppbus) &
600 			(LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
601 			(LPS_SEL|LPS_NBSY|LPS_NERR) || sc->sc_xfercnt)
602 			/* wait 1/4 second, give up if we get a signal */
603 			if (tsleep((caddr_t)lptdev, LPPRI|PCATCH,
604 				"lpclose", hz) != EWOULDBLOCK)
605 				break;
606 
607 	ppb_wctr(ppbus, LPC_NINIT);
608 	brelse(sc->sc_inbuf);
609 	brelse(sc->sc_statbuf);
610 
611 end_close:
612 	/* release the bus anyway
613 	 * unregistration of interrupt forced by release
614 	 */
615 	lpt_release_ppbus(lptdev);
616 
617 	sc->sc_state = 0;
618 	sc->sc_xfercnt = 0;
619 	lprintf(("closed.\n"));
620 	return(0);
621 }
622 
623 /*
624  * lpt_pushbytes()
625  *	Workhorse for actually spinning and writing bytes to printer
626  *	Derived from lpa.c
627  *	Originally by ?
628  *
629  *	This code is only used when we are polling the port
630  */
631 static int
632 lpt_pushbytes(device_t dev)
633 {
634 	struct lpt_data *sc = DEVTOSOFTC(dev);
635 	device_t ppbus = device_get_parent(dev);
636 	int spin, err, tic;
637 	char ch;
638 
639 	lprintf(("p"));
640 	/* loop for every character .. */
641 	while (sc->sc_xfercnt > 0) {
642 		/* printer data */
643 		ch = *(sc->sc_cp);
644 		sc->sc_cp++;
645 		sc->sc_xfercnt--;
646 
647 		/*
648 		 * Wait for printer ready.
649 		 * Loop 20 usecs testing BUSY bit, then sleep
650 		 * for exponentially increasing timeout. (vak)
651 		 */
652 		for (spin = 0; NOT_READY(ppbus) && spin < MAX_SPIN; ++spin)
653 			DELAY(1);	/* XXX delay is NOT this accurate! */
654 		if (spin >= MAX_SPIN) {
655 			tic = 0;
656 			while (NOT_READY(ppbus)) {
657 				/*
658 				 * Now sleep, every cycle a
659 				 * little longer ..
660 				 */
661 				tic = tic + tic + 1;
662 				/*
663 				 * But no more than 10 seconds. (vak)
664 				 */
665 				if (tic > MAX_SLEEP)
666 					tic = MAX_SLEEP;
667 				err = tsleep((caddr_t)dev, LPPRI,
668 					LPT_NAME "poll", tic);
669 				if (err != EWOULDBLOCK) {
670 					return (err);
671 				}
672 			}
673 		}
674 
675 		/* output data */
676 		ppb_wdtr(ppbus, ch);
677 		/* strobe */
678 		ppb_wctr(ppbus, sc->sc_control|LPC_STB);
679 		ppb_wctr(ppbus, sc->sc_control);
680 
681 	}
682 	return(0);
683 }
684 
685 /*
686  * lptread --retrieve printer status in IEEE1284 NIBBLE mode
687  */
688 
689 static int
690 lptread(dev_t dev, struct uio *uio, int ioflag)
691 {
692         u_int	unit = LPTUNIT(minor(dev));
693 	struct lpt_data *sc = UNITOSOFTC(unit);
694 	device_t lptdev = UNITODEVICE(unit);
695         device_t ppbus = device_get_parent(lptdev);
696 	int error = 0, len;
697 
698 	if ((error = ppb_1284_negociate(ppbus, PPB_NIBBLE, 0)))
699 		return (error);
700 
701 	/* read data in an other buffer, read/write may be simultaneous */
702 	len = 0;
703 	while (uio->uio_resid) {
704 		if ((error = ppb_1284_read(ppbus, PPB_NIBBLE,
705 				sc->sc_statbuf->b_data, min(BUFSTATSIZE,
706 				uio->uio_resid), &len))) {
707 			goto error;
708 		}
709 
710 		if (!len)
711 			goto error;		/* no more data */
712 
713 		if ((error = uiomove(sc->sc_statbuf->b_data, len, uio)))
714 			goto error;
715 	}
716 
717 error:
718 	ppb_1284_terminate(ppbus);
719 	return (error);
720 }
721 
722 /*
723  * lptwrite --copy a line from user space to a local buffer, then call
724  * putc to get the chars moved to the output queue.
725  *
726  * Flagging of interrupted write added.
727  */
728 
729 static	int
730 lptwrite(dev_t dev, struct uio *uio, int ioflag)
731 {
732 	register unsigned n;
733 	int err;
734         u_int	unit = LPTUNIT(minor(dev));
735 	struct lpt_data *sc = UNITOSOFTC(unit);
736 	device_t lptdev = UNITODEVICE(unit);
737         device_t ppbus = device_get_parent(lptdev);
738 
739 	if(sc->sc_flags & LP_BYPASS) {
740 		/* we can't do writes in bypass mode */
741 		return(EPERM);
742 	}
743 
744 	/* request the ppbus only if we don't have it already */
745 	/* XXX interrupt registration?! */
746 	if ((err = lpt_request_ppbus(lptdev, PPB_WAIT|PPB_INTR)) != 0)
747 		return (err);
748 
749 	/* if interrupts are working, register the handler */
750 	if (sc->sc_irq & LP_USE_IRQ) {
751 		/* register our interrupt handler */
752 		err = BUS_SETUP_INTR(ppbus, lptdev, sc->intr_resource,
753 			       INTR_TYPE_TTY, lpt_intr, lptdev,
754 			       &sc->intr_cookie);
755 		if (err) {
756 			device_printf(lptdev, "handler registration failed, polled mode.\n");
757 			sc->sc_irq &= ~LP_USE_IRQ;
758 		}
759 	}
760 
761 	sc->sc_state &= ~INTERRUPTED;
762 	while ((n = min(BUFSIZE, uio->uio_resid)) != 0) {
763 		sc->sc_cp = sc->sc_inbuf->b_data ;
764 		uiomove(sc->sc_cp, n, uio);
765 		sc->sc_xfercnt = n ;
766 
767 		if (sc->sc_irq & LP_ENABLE_EXT) {
768 			/* try any extended mode */
769 			err = ppb_write(ppbus, sc->sc_cp,
770 					sc->sc_xfercnt, 0);
771 			switch (err) {
772 			case 0:
773 				/* if not all data was sent, we could rely
774 				 * on polling for the last bytes */
775 				sc->sc_xfercnt = 0;
776 				break;
777 			case EINTR:
778 				sc->sc_state |= INTERRUPTED;
779 				return(err);
780 			case EINVAL:
781 				/* advanced mode not avail */
782 				log(LOG_NOTICE, LPT_NAME "%d: advanced mode not avail, polling\n", unit);
783 				break;
784 			default:
785 				return(err);
786 			}
787 		} else while ((sc->sc_xfercnt > 0)&&(sc->sc_irq & LP_USE_IRQ)) {
788 			lprintf(("i"));
789 			/* if the printer is ready for a char, */
790 			/* give it one */
791 			if ((sc->sc_state & OBUSY) == 0){
792 				lprintf(("\nC %d. ", sc->sc_xfercnt));
793 				lptintr(lptdev);
794 			}
795 			lprintf(("W "));
796 			if (sc->sc_state & OBUSY)
797 				if ((err = tsleep((caddr_t)lptdev,
798 					 LPPRI|PCATCH, LPT_NAME "write", 0))) {
799 					sc->sc_state |= INTERRUPTED;
800 					return(err);
801 				}
802 		}
803 
804 		/* check to see if we must do a polled write */
805 		if(!(sc->sc_irq & LP_USE_IRQ) && (sc->sc_xfercnt)) {
806 			lprintf(("p"));
807 
808 			err = lpt_pushbytes(lptdev);
809 
810 			if (err)
811 				return(err);
812 		}
813 	}
814 
815 	/* we have not been interrupted, release the ppbus */
816 	lpt_release_ppbus(lptdev);
817 
818 	return(0);
819 }
820 
821 /*
822  * lpt_intr -- handle printer interrupts which occur when the printer is
823  * ready to accept another char.
824  *
825  * do checking for interrupted write call.
826  */
827 
828 static void
829 lpt_intr(void *arg)
830 {
831 	device_t lptdev = (device_t)arg;
832         device_t ppbus = device_get_parent(lptdev);
833 	struct lpt_data *sc = DEVTOSOFTC(lptdev);
834 	int sts = 0;
835 	int i;
836 
837 	/* we must own the bus to use it */
838 	if ((sc->sc_state & HAVEBUS) == 0)
839 		return;
840 
841 	/*
842 	 * Is printer online and ready for output?
843 	 *
844 	 * Avoid falling back to lptout() too quickly.  First spin-loop
845 	 * to see if the printer will become ready ``really soon now''.
846 	 */
847 	for (i = 0; i < 100 &&
848 	     ((sts=ppb_rstr(ppbus)) & RDY_MASK) != LP_READY; i++) ;
849 
850 	if ((sts & RDY_MASK) == LP_READY) {
851 		sc->sc_state = (sc->sc_state | OBUSY) & ~EERROR;
852 		sc->sc_backoff = hz/LPTOUTINITIAL;
853 
854 		if (sc->sc_xfercnt) {
855 			/* send char */
856 			/*lprintf(("%x ", *sc->sc_cp)); */
857 			ppb_wdtr(ppbus, *sc->sc_cp++) ;
858 			ppb_wctr(ppbus, sc->sc_control|LPC_STB);
859 			/* DELAY(X) */
860 			ppb_wctr(ppbus, sc->sc_control);
861 
862 			/* any more data for printer */
863 			if(--(sc->sc_xfercnt) > 0) return;
864 		}
865 
866 		/*
867 		 * No more data waiting for printer.
868 		 * Wakeup is not done if write call was not interrupted.
869 		 */
870 		sc->sc_state &= ~OBUSY;
871 
872 		if(!(sc->sc_state & INTERRUPTED))
873 			wakeup((caddr_t)lptdev);
874 		lprintf(("w "));
875 		return;
876 	} else	{	/* check for error */
877 		if(((sts & (LPS_NERR | LPS_OUT) ) != LPS_NERR) &&
878 				(sc->sc_state & OPEN))
879 			sc->sc_state |= EERROR;
880 		/* lptout() will jump in and try to restart. */
881 	}
882 	lprintf(("sts %x ", sts));
883 }
884 
885 static void
886 lptintr(device_t dev)
887 {
888 	/* call the interrupt at required spl level */
889 	int s = spltty();
890 
891 	lpt_intr(dev);
892 
893 	splx(s);
894 	return;
895 }
896 
897 static	int
898 lptioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
899 {
900 	int	error = 0;
901         u_int	unit = LPTUNIT(minor(dev));
902         struct	lpt_data *sc = UNITOSOFTC(unit);
903 	u_char	old_sc_irq;	/* old printer IRQ status */
904 
905 	switch (cmd) {
906 	case LPT_IRQ :
907 		if(sc->sc_irq & LP_HAS_IRQ) {
908 			/*
909 			 * NOTE:
910 			 * If the IRQ status is changed,
911 			 * this will only be visible on the
912 			 * next open.
913 			 *
914 			 * If interrupt status changes,
915 			 * this gets syslog'd.
916 			 */
917 			old_sc_irq = sc->sc_irq;
918 			switch(*(int*)data) {
919 			case 0:
920 				sc->sc_irq &= (~LP_ENABLE_IRQ);
921 				break;
922 			case 1:
923 				sc->sc_irq &= (~LP_ENABLE_EXT);
924 				sc->sc_irq |= LP_ENABLE_IRQ;
925 				break;
926 			case 2:
927 				/* classic irq based transfer and advanced
928 				 * modes are in conflict
929 				 */
930 				sc->sc_irq &= (~LP_ENABLE_IRQ);
931 				sc->sc_irq |= LP_ENABLE_EXT;
932 				break;
933 			case 3:
934 				sc->sc_irq &= (~LP_ENABLE_EXT);
935 				break;
936 			default:
937 				break;
938 			}
939 
940 			if (old_sc_irq != sc->sc_irq )
941 				log(LOG_NOTICE, LPT_NAME "%d: switched to %s %s mode\n",
942 					unit,
943 					(sc->sc_irq & LP_ENABLE_IRQ)?
944 					"interrupt-driven":"polled",
945 					(sc->sc_irq & LP_ENABLE_EXT)?
946 					"extended":"standard");
947 		} else /* polled port */
948 			error = EOPNOTSUPP;
949 		break;
950 	default:
951 		error = ENODEV;
952 	}
953 
954 	return(error);
955 }
956 
957 static device_method_t lpt_methods[] = {
958 	/* device interface */
959 	DEVMETHOD(device_identify,	lpt_identify),
960 	DEVMETHOD(device_probe,		lpt_probe),
961 	DEVMETHOD(device_attach,	lpt_attach),
962 
963 	{ 0, 0 }
964 };
965 
966 static driver_t lpt_driver = {
967 	LPT_NAME,
968 	lpt_methods,
969 	sizeof(struct lpt_data),
970 };
971 
972 DRIVER_MODULE(lpt, ppbus, lpt_driver, lpt_devclass, 0, 0);
973