lptvar.h revision 1.9 1 1.1 cgd /*
2 1.1 cgd * Copyright (c) 1990 William F. Jolitz, TeleMuse
3 1.1 cgd * All rights reserved.
4 1.1 cgd *
5 1.1 cgd * Redistribution and use in source and binary forms, with or without
6 1.1 cgd * modification, are permitted provided that the following conditions
7 1.1 cgd * are met:
8 1.1 cgd * 1. Redistributions of source code must retain the above copyright
9 1.1 cgd * notice, this list of conditions and the following disclaimer.
10 1.1 cgd * 2. Redistributions in binary form must reproduce the above copyright
11 1.1 cgd * notice, this list of conditions and the following disclaimer in the
12 1.1 cgd * documentation and/or other materials provided with the distribution.
13 1.1 cgd * 3. All advertising materials mentioning features or use of this software
14 1.1 cgd * must display the following acknowledgement:
15 1.1 cgd * This software is a component of "386BSD" developed by
16 1.1 cgd * William F. Jolitz, TeleMuse.
17 1.1 cgd * 4. Neither the name of the developer nor the name "386BSD"
18 1.1 cgd * may be used to endorse or promote products derived from this software
19 1.1 cgd * without specific prior written permission.
20 1.1 cgd *
21 1.1 cgd * THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ
22 1.1 cgd * AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS
23 1.1 cgd * SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
24 1.1 cgd * THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
25 1.1 cgd * NOT MAKE USE OF THIS WORK.
26 1.1 cgd *
27 1.1 cgd * FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
28 1.1 cgd * BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN
29 1.1 cgd * REFERENCES SUCH AS THE "PORTING UNIX TO THE 386" SERIES
30 1.1 cgd * (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING
31 1.1 cgd * JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND
32 1.1 cgd * LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE
33 1.1 cgd * ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS
34 1.1 cgd * OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
35 1.1 cgd *
36 1.1 cgd * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
37 1.1 cgd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 1.1 cgd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39 1.1 cgd * ARE DISCLAIMED. IN NO EVENT SHALL THE DEVELOPER BE LIABLE
40 1.1 cgd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41 1.1 cgd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42 1.1 cgd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43 1.1 cgd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44 1.1 cgd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45 1.1 cgd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46 1.1 cgd * SUCH DAMAGE.
47 1.1 cgd *
48 1.9 mycroft * $Id: lptvar.h,v 1.9 1993/12/20 09:06:23 mycroft Exp $
49 1.1 cgd */
50 1.1 cgd
51 1.1 cgd /*
52 1.1 cgd * Device Driver for AT parallel printer port
53 1.1 cgd * Written by William Jolitz 12/18/90
54 1.3 cgd *
55 1.3 cgd * Hacked heavily by Rod Grimes and Eric Haug...
56 1.1 cgd */
57 1.1 cgd
58 1.1 cgd #include "lpt.h"
59 1.1 cgd #if NLPT > 0
60 1.1 cgd
61 1.9 mycroft #include <sys/param.h>
62 1.9 mycroft #include <sys/systm.h>
63 1.9 mycroft #include <sys/proc.h>
64 1.9 mycroft #include <sys/user.h>
65 1.9 mycroft #include <sys/buf.h>
66 1.9 mycroft #include <sys/kernel.h>
67 1.9 mycroft #include <sys/ioctl.h>
68 1.9 mycroft #include <sys/tty.h>
69 1.9 mycroft #include <sys/uio.h>
70 1.1 cgd
71 1.9 mycroft #include <machine/pio.h>
72 1.9 mycroft
73 1.9 mycroft #include <i386/isa/isa.h>
74 1.9 mycroft #include <i386/isa/isa_device.h>
75 1.9 mycroft #include <i386/isa/lptreg.h>
76 1.1 cgd
77 1.1 cgd #define LPINITRDY 4 /* wait up to 4 seconds for a ready */
78 1.1 cgd #define LPTOUTTIME 4 /* wait up to 4 seconds for a ready */
79 1.1 cgd #define LPPRI (PZERO+8)
80 1.1 cgd #define BUFSIZE 1024
81 1.1 cgd
82 1.1 cgd #ifndef DEBUG
83 1.1 cgd #define lprintf
84 1.1 cgd #else
85 1.5 cgd #define lprintf if (lptflag) printf
86 1.5 cgd int lptflag = 1;
87 1.1 cgd #endif
88 1.1 cgd
89 1.1 cgd int lptout();
90 1.1 cgd #ifdef DEBUG
91 1.5 cgd int lptflag = 1;
92 1.1 cgd #endif
93 1.1 cgd
94 1.1 cgd int lptprobe(), lptattach(), lptintr();
95 1.1 cgd
96 1.1 cgd struct isa_driver lptdriver = {
97 1.1 cgd lptprobe, lptattach, "lpt"
98 1.1 cgd };
99 1.1 cgd
100 1.1 cgd #define LPTUNIT(s) (((s)>>6)&0x3)
101 1.1 cgd #define LPTFLAGS(s) ((s)&0x3f)
102 1.1 cgd
103 1.1 cgd struct lpt_softc {
104 1.1 cgd short sc_port;
105 1.1 cgd short sc_state;
106 1.1 cgd /* default case: negative prime, negative ack, handshake strobe,
107 1.1 cgd prime once */
108 1.1 cgd u_char sc_control;
109 1.1 cgd char sc_flags;
110 1.1 cgd #define LP_POS_INIT 0x01 /* if we are a postive init signal */
111 1.1 cgd #define LP_POS_ACK 0x02 /* if we are a positive going ack */
112 1.1 cgd #define LP_NO_PRIME 0x04 /* don't prime the printer at all */
113 1.1 cgd #define LP_PRIMEOPEN 0x08 /* prime on every open */
114 1.1 cgd #define LP_AUTOLF 0x10 /* tell printer to do an automatic lf */
115 1.1 cgd #define LP_BYPASS 0x20 /* bypass printer ready checks */
116 1.1 cgd struct buf *sc_inbuf;
117 1.1 cgd short sc_xfercnt ;
118 1.1 cgd char sc_primed;
119 1.1 cgd char *sc_cp ;
120 1.1 cgd } lpt_sc[NLPT] ;
121 1.1 cgd
122 1.1 cgd /* bits for state */
123 1.1 cgd #define OPEN (1<<0) /* device is open */
124 1.1 cgd #define ASLP (1<<1) /* awaiting draining of printer */
125 1.1 cgd #define ERROR (1<<2) /* error was received from printer */
126 1.1 cgd #define OBUSY (1<<3) /* printer is busy doing output */
127 1.1 cgd #define LPTOUT (1<<4) /* timeout while not selected */
128 1.1 cgd #define TOUT (1<<5) /* timeout while not selected */
129 1.1 cgd #define INIT (1<<6) /* waiting to initialize for open */
130 1.1 cgd
131 1.2 cgd /*
132 1.2 cgd * Internal routine to lptprobe to do port tests of one byte value
133 1.2 cgd */
134 1.2 cgd int
135 1.2 cgd lpt_port_test(short port, u_char data, u_char mask)
136 1.2 cgd {
137 1.5 cgd int temp, timeout;
138 1.2 cgd
139 1.2 cgd data = data & mask;
140 1.2 cgd outb(port, data);
141 1.5 cgd timeout = 100;
142 1.5 cgd do
143 1.5 cgd temp = inb(port) & mask;
144 1.5 cgd while (temp != data && --timeout);
145 1.2 cgd lprintf("Port 0x%x\tout=%x\tin=%x\n", port, data, temp);
146 1.2 cgd return (temp == data);
147 1.2 cgd }
148 1.2 cgd
149 1.2 cgd /*
150 1.2 cgd * New lptprobe routine written by Rodney W. Grimes, 3/25/1993
151 1.2 cgd *
152 1.2 cgd * Logic:
153 1.2 cgd * 1) You should be able to write to and read back the same value
154 1.2 cgd * to the data port. Do an alternating zeros, alternating ones,
155 1.2 cgd * walking zero, and walking one test to check for stuck bits.
156 1.2 cgd *
157 1.2 cgd * 2) You should be able to write to and read back the same value
158 1.2 cgd * to the control port lower 5 bits, the upper 3 bits are reserved
159 1.2 cgd * per the IBM PC technical reference manauls and different boards
160 1.2 cgd * do different things with them. Do an alternating zeros, alternating
161 1.2 cgd * ones, walking zero, and walking one test to check for stuck bits.
162 1.2 cgd *
163 1.2 cgd * Some printers drag the strobe line down when the are powered off
164 1.2 cgd * so this bit has been masked out of the control port test.
165 1.2 cgd *
166 1.2 cgd * XXX Some printers may not like a fast pulse on init or strobe, I
167 1.2 cgd * don't know at this point, if that becomes a problem these bits
168 1.2 cgd * should be turned off in the mask byte for the control port test.
169 1.2 cgd *
170 1.2 cgd * 3) Set the data and control ports to a value of 0
171 1.2 cgd */
172 1.2 cgd
173 1.2 cgd int
174 1.2 cgd lptprobe(struct isa_device *dvp)
175 1.2 cgd {
176 1.2 cgd int status;
177 1.2 cgd short port;
178 1.2 cgd u_char data;
179 1.2 cgd u_char mask;
180 1.2 cgd int i;
181 1.2 cgd
182 1.2 cgd status = IO_LPTSIZE;
183 1.2 cgd
184 1.2 cgd port = dvp->id_iobase + lpt_data;
185 1.2 cgd mask = 0xff;
186 1.2 cgd while (mask != 0)
187 1.2 cgd {
188 1.2 cgd data = 0x55; /* Alternating zeros */
189 1.2 cgd if (!lpt_port_test(port, data, mask)) status = 0;
190 1.2 cgd
191 1.2 cgd data = 0xaa; /* Alternating ones */
192 1.2 cgd if (!lpt_port_test(port, data, mask)) status = 0;
193 1.2 cgd
194 1.2 cgd for (i = 0; i < 8; i++) /* Walking zero */
195 1.2 cgd {
196 1.2 cgd data = ~(1 << i);
197 1.2 cgd if (!lpt_port_test(port, data, mask)) status = 0;
198 1.2 cgd }
199 1.2 cgd
200 1.2 cgd for (i = 0; i < 8; i++) /* Walking one */
201 1.2 cgd {
202 1.2 cgd data = (1 << i);
203 1.2 cgd if (!lpt_port_test(port, data, mask)) status = 0;
204 1.2 cgd }
205 1.2 cgd
206 1.2 cgd if (port == dvp->id_iobase + lpt_data)
207 1.2 cgd {
208 1.2 cgd port = dvp->id_iobase + lpt_control;
209 1.2 cgd mask = 0x1e;
210 1.2 cgd }
211 1.2 cgd else
212 1.2 cgd mask = 0;
213 1.2 cgd }
214 1.2 cgd outb(dvp->id_iobase+lpt_data, 0);
215 1.2 cgd outb(dvp->id_iobase+lpt_control, 0);
216 1.2 cgd return (status);
217 1.1 cgd }
218 1.1 cgd
219 1.1 cgd lptattach(isdp)
220 1.1 cgd struct isa_device *isdp;
221 1.1 cgd {
222 1.1 cgd struct lpt_softc *sc;
223 1.1 cgd
224 1.1 cgd sc = lpt_sc + isdp->id_unit;
225 1.1 cgd sc->sc_port = isdp->id_iobase;
226 1.6 mycroft sc->sc_state = 0;
227 1.1 cgd outb(sc->sc_port+lpt_control, LPC_NINIT);
228 1.1 cgd return (1);
229 1.1 cgd }
230 1.1 cgd
231 1.1 cgd /*
232 1.1 cgd * lptopen -- reset the printer, then wait until it's selected and not busy.
233 1.1 cgd */
234 1.1 cgd
235 1.1 cgd lptopen(dev, flag)
236 1.1 cgd dev_t dev;
237 1.1 cgd int flag;
238 1.1 cgd {
239 1.1 cgd struct lpt_softc *sc = lpt_sc + LPTUNIT(minor(dev));
240 1.1 cgd int s;
241 1.1 cgd int trys, port;
242 1.1 cgd
243 1.1 cgd if (sc->sc_state) {
244 1.8 cgd lprintf("lp: still open %x\n", sc->sc_state);
245 1.1 cgd return(EBUSY);
246 1.1 cgd } else sc->sc_state |= INIT;
247 1.1 cgd
248 1.1 cgd s = spltty();
249 1.1 cgd sc->sc_flags = LPTFLAGS(minor(dev));
250 1.1 cgd lprintf("lp flags 0x%x\n", sc->sc_flags);
251 1.1 cgd port = sc->sc_port;
252 1.1 cgd
253 1.1 cgd /* init printer */
254 1.1 cgd if((sc->sc_flags & LP_NO_PRIME) == 0) {
255 1.1 cgd if((sc->sc_flags & LP_PRIMEOPEN) || sc->sc_primed == 0) {
256 1.1 cgd outb(port+lpt_control, 0);
257 1.1 cgd sc->sc_primed++;
258 1.1 cgd DELAY(500);
259 1.1 cgd }
260 1.1 cgd }
261 1.1 cgd outb(port+lpt_control, LPC_SEL|LPC_NINIT);
262 1.1 cgd
263 1.1 cgd /* wait till ready (printer running diagnostics) */
264 1.1 cgd trys = 0;
265 1.1 cgd do {
266 1.1 cgd /* ran out of waiting for the printer */
267 1.1 cgd if (trys++ >= LPINITRDY*4) {
268 1.1 cgd splx(s);
269 1.1 cgd sc->sc_state = 0;
270 1.8 cgd lprintf ("status %x\n", inb(port+lpt_status) );
271 1.1 cgd return (EBUSY);
272 1.1 cgd }
273 1.1 cgd
274 1.1 cgd /* wait 1/4 second, give up if we get a signal */
275 1.7 mycroft if (tsleep((caddr_t)sc,
276 1.7 mycroft LPPRI|PCATCH, "lptinit", hz/4) != EWOULDBLOCK) {
277 1.1 cgd sc->sc_state = 0;
278 1.1 cgd splx(s);
279 1.1 cgd return (EBUSY);
280 1.1 cgd }
281 1.1 cgd
282 1.1 cgd /* is printer online and ready for output */
283 1.1 cgd } while ((inb(port+lpt_status) & (LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
284 1.1 cgd (LPS_SEL|LPS_NBSY|LPS_NERR));
285 1.1 cgd
286 1.1 cgd if(sc->sc_flags&LP_AUTOLF) {
287 1.1 cgd outb(port+lpt_control, LPC_SEL|LPC_NINIT|LPC_ENA|LPC_AUTOL);
288 1.1 cgd sc->sc_control = LPC_SEL|LPC_NINIT|LPC_ENA|LPC_AUTOL;
289 1.1 cgd } else {
290 1.1 cgd outb(port+lpt_control, LPC_SEL|LPC_NINIT|LPC_ENA);
291 1.1 cgd sc->sc_control = LPC_SEL|LPC_NINIT|LPC_ENA;
292 1.1 cgd }
293 1.1 cgd
294 1.1 cgd sc->sc_state = OPEN | TOUT;
295 1.1 cgd sc->sc_inbuf = geteblk(BUFSIZE);
296 1.1 cgd sc->sc_xfercnt = 0;
297 1.1 cgd splx(s);
298 1.7 mycroft timeout((timeout_t)lptout, (caddr_t)sc, hz/2);
299 1.1 cgd lprintf("opened.\n");
300 1.1 cgd return(0);
301 1.1 cgd }
302 1.1 cgd
303 1.1 cgd lptout (sc)
304 1.1 cgd struct lpt_softc *sc;
305 1.1 cgd { int pl;
306 1.1 cgd
307 1.1 cgd lprintf ("T %x ", inb(sc->sc_port+lpt_status));
308 1.1 cgd if (sc->sc_state&OPEN)
309 1.7 mycroft timeout((timeout_t)lptout, (caddr_t)sc, hz/2);
310 1.1 cgd else sc->sc_state &= ~TOUT;
311 1.1 cgd
312 1.1 cgd if (sc->sc_state & ERROR)
313 1.1 cgd sc->sc_state &= ~ERROR;
314 1.1 cgd
315 1.1 cgd /*
316 1.1 cgd * Avoid possible hangs do to missed interrupts
317 1.1 cgd */
318 1.1 cgd if (sc->sc_xfercnt) {
319 1.1 cgd pl = spltty();
320 1.1 cgd lptintr(sc - lpt_sc);
321 1.1 cgd splx(pl);
322 1.1 cgd } else {
323 1.1 cgd sc->sc_state &= ~OBUSY;
324 1.1 cgd wakeup((caddr_t)sc);
325 1.1 cgd }
326 1.1 cgd }
327 1.1 cgd
328 1.1 cgd /*
329 1.1 cgd * lptclose -- close the device, free the local line buffer.
330 1.1 cgd */
331 1.1 cgd
332 1.1 cgd lptclose(dev, flag)
333 1.1 cgd int flag;
334 1.1 cgd {
335 1.1 cgd struct lpt_softc *sc = lpt_sc + LPTUNIT(minor(dev));
336 1.1 cgd int port = sc->sc_port;
337 1.1 cgd
338 1.1 cgd sc->sc_state &= ~OPEN;
339 1.1 cgd while ((inb(port+lpt_status) & (LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR)) !=
340 1.1 cgd (LPS_SEL|LPS_NBSY|LPS_NERR) || sc->sc_xfercnt)
341 1.1 cgd /* wait 1/4 second, give up if we get a signal */
342 1.7 mycroft if (tsleep((caddr_t)sc,
343 1.7 mycroft LPPRI|PCATCH, "lpclose", hz) != EWOULDBLOCK)
344 1.1 cgd break;
345 1.1 cgd
346 1.1 cgd sc->sc_state = 0;
347 1.1 cgd sc->sc_xfercnt = 0;
348 1.1 cgd outb(sc->sc_port+lpt_control, LPC_NINIT);
349 1.1 cgd brelse(sc->sc_inbuf);
350 1.1 cgd lprintf("closed.\n");
351 1.1 cgd return(0);
352 1.1 cgd }
353 1.1 cgd
354 1.1 cgd /*
355 1.1 cgd * lptwrite --copy a line from user space to a local buffer, then call
356 1.1 cgd * putc to get the chars moved to the output queue.
357 1.1 cgd */
358 1.1 cgd
359 1.1 cgd lptwrite(dev, uio)
360 1.1 cgd dev_t dev;
361 1.1 cgd struct uio *uio;
362 1.1 cgd {
363 1.1 cgd register unsigned n;
364 1.1 cgd int pl, err;
365 1.1 cgd struct lpt_softc *sc = lpt_sc + LPTUNIT(minor(dev));
366 1.1 cgd
367 1.1 cgd while (n = MIN(BUFSIZE, uio->uio_resid)) {
368 1.1 cgd sc->sc_cp = sc->sc_inbuf->b_un.b_addr ;
369 1.1 cgd uiomove(sc->sc_cp, n, uio);
370 1.1 cgd sc->sc_xfercnt = n ;
371 1.1 cgd while (sc->sc_xfercnt > 0) {
372 1.1 cgd /* if the printer is ready for a char, give it one */
373 1.1 cgd if ((sc->sc_state & OBUSY) == 0){
374 1.1 cgd lprintf("\nC %d. ", sc->sc_xfercnt);
375 1.1 cgd pl = spltty();
376 1.1 cgd lptintr(sc - lpt_sc);
377 1.1 cgd (void) splx(pl);
378 1.1 cgd }
379 1.1 cgd lprintf("W ");
380 1.7 mycroft if (err = tsleep((caddr_t)sc,
381 1.7 mycroft LPPRI|PCATCH, "lpwrite", 0))
382 1.1 cgd return(err);
383 1.1 cgd }
384 1.1 cgd }
385 1.1 cgd return(0);
386 1.1 cgd }
387 1.1 cgd
388 1.1 cgd /*
389 1.1 cgd * lptintr -- handle printer interrupts which occur when the printer is
390 1.1 cgd * ready to accept another char.
391 1.1 cgd */
392 1.1 cgd
393 1.1 cgd lptintr(unit)
394 1.1 cgd {
395 1.1 cgd struct lpt_softc *sc = lpt_sc + unit;
396 1.1 cgd int port = sc->sc_port,sts;
397 1.1 cgd
398 1.6 mycroft sts = inb(port+lpt_status);
399 1.6 mycroft
400 1.6 mycroft if (!sc->sc_state) {
401 1.6 mycroft printf ("lpt%d: stray interrupt sts=0x%02x\n", unit, sts);
402 1.6 mycroft return;
403 1.6 mycroft }
404 1.6 mycroft
405 1.1 cgd /* is printer online and ready for output */
406 1.6 mycroft if ((sts & (LPS_SEL|LPS_OUT|LPS_NBSY|LPS_NERR/*|LPS_NACK*/)) ==
407 1.1 cgd (LPS_SEL|LPS_NBSY|LPS_NERR)) {
408 1.1 cgd /* is this a false interrupt ? */
409 1.1 cgd if ((sc->sc_state & OBUSY)
410 1.1 cgd && (sts & LPS_NACK) == 0) return;
411 1.1 cgd sc->sc_state |= OBUSY; sc->sc_state &= ~ERROR;
412 1.1 cgd
413 1.1 cgd if (sc->sc_xfercnt) {
414 1.1 cgd /* send char */
415 1.1 cgd /*lprintf("%x ", *sc->sc_cp); */
416 1.1 cgd outb(port+lpt_data, *sc->sc_cp++) ; sc->sc_xfercnt-- ;
417 1.1 cgd outb(port+lpt_control, sc->sc_control|LPC_STB);
418 1.1 cgd /* DELAY(X) */
419 1.1 cgd outb(port+lpt_control, sc->sc_control);
420 1.1 cgd }
421 1.1 cgd
422 1.1 cgd /* any more bytes for the printer? */
423 1.1 cgd if (sc->sc_xfercnt > 0) return;
424 1.1 cgd
425 1.1 cgd /* none, wake up the top half to get more */
426 1.1 cgd sc->sc_state &= ~OBUSY;
427 1.1 cgd wakeup((caddr_t)sc);
428 1.1 cgd lprintf("w ");
429 1.1 cgd return;
430 1.1 cgd } else sc->sc_state |= ERROR;
431 1.1 cgd lprintf("sts %x ", sts);
432 1.1 cgd }
433 1.1 cgd
434 1.2 cgd int
435 1.2 cgd lptioctl(dev_t dev, int cmd, caddr_t data, int flag)
436 1.2 cgd {
437 1.2 cgd int error;
438 1.2 cgd
439 1.2 cgd error = 0;
440 1.2 cgd switch (cmd) {
441 1.2 cgd #ifdef THISISASAMPLE
442 1.2 cgd case XXX:
443 1.2 cgd dothis; andthis; andthat;
444 1.2 cgd error=x;
445 1.2 cgd break;
446 1.2 cgd #endif /* THISISASAMPLE */
447 1.2 cgd default:
448 1.2 cgd error = ENODEV;
449 1.2 cgd }
450 1.2 cgd
451 1.2 cgd return(error);
452 1.2 cgd }
453 1.2 cgd
454 1.2 cgd #endif /* NLPT */
455