ppi.c revision 1.11 1 1.11 thorpej /* $NetBSD: ppi.c,v 1.11 1997/01/30 09:14:16 thorpej Exp $ */
2 1.6 cgd
3 1.1 cgd /*
4 1.11 thorpej * Copyright (c) 1996, 1997 Jason R. Thorpe. All rights reserved.
5 1.5 mycroft * Copyright (c) 1982, 1990, 1993
6 1.5 mycroft * The Regents of the University of California. All rights reserved.
7 1.1 cgd *
8 1.1 cgd * Redistribution and use in source and binary forms, with or without
9 1.1 cgd * modification, are permitted provided that the following conditions
10 1.1 cgd * are met:
11 1.1 cgd * 1. Redistributions of source code must retain the above copyright
12 1.1 cgd * notice, this list of conditions and the following disclaimer.
13 1.1 cgd * 2. Redistributions in binary form must reproduce the above copyright
14 1.1 cgd * notice, this list of conditions and the following disclaimer in the
15 1.1 cgd * documentation and/or other materials provided with the distribution.
16 1.1 cgd * 3. All advertising materials mentioning features or use of this software
17 1.1 cgd * must display the following acknowledgement:
18 1.1 cgd * This product includes software developed by the University of
19 1.1 cgd * California, Berkeley and its contributors.
20 1.1 cgd * 4. Neither the name of the University nor the names of its contributors
21 1.1 cgd * may be used to endorse or promote products derived from this software
22 1.1 cgd * without specific prior written permission.
23 1.1 cgd *
24 1.1 cgd * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 1.1 cgd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 1.1 cgd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 1.1 cgd * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 1.1 cgd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 1.1 cgd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 1.1 cgd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 1.1 cgd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 1.1 cgd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 1.1 cgd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 1.1 cgd * SUCH DAMAGE.
35 1.1 cgd *
36 1.6 cgd * @(#)ppi.c 8.1 (Berkeley) 6/16/93
37 1.1 cgd */
38 1.1 cgd
39 1.1 cgd /*
40 1.1 cgd * Printer/Plotter HPIB interface
41 1.1 cgd */
42 1.1 cgd
43 1.3 mycroft #include <sys/param.h>
44 1.3 mycroft #include <sys/systm.h>
45 1.3 mycroft #include <sys/errno.h>
46 1.3 mycroft #include <sys/uio.h>
47 1.3 mycroft #include <sys/malloc.h>
48 1.11 thorpej #include <sys/device.h>
49 1.11 thorpej #include <sys/conf.h>
50 1.11 thorpej
51 1.11 thorpej #include <hp300/dev/hpibvar.h>
52 1.1 cgd
53 1.3 mycroft #include <hp300/dev/ppiioctl.h>
54 1.1 cgd
55 1.1 cgd struct ppi_softc {
56 1.11 thorpej struct device sc_dev;
57 1.1 cgd int sc_flags;
58 1.11 thorpej struct hpibqueue sc_hq; /* HP-IB job queue entry */
59 1.1 cgd struct ppiparam sc_param;
60 1.1 cgd #define sc_burst sc_param.burst
61 1.1 cgd #define sc_timo sc_param.timo
62 1.1 cgd #define sc_delay sc_param.delay
63 1.1 cgd int sc_sec;
64 1.11 thorpej int sc_slave; /* HP-IB slave address */
65 1.11 thorpej };
66 1.1 cgd
67 1.1 cgd /* sc_flags values */
68 1.1 cgd #define PPIF_ALIVE 0x01
69 1.1 cgd #define PPIF_OPEN 0x02
70 1.1 cgd #define PPIF_UIO 0x04
71 1.1 cgd #define PPIF_TIMO 0x08
72 1.1 cgd #define PPIF_DELAY 0x10
73 1.1 cgd
74 1.11 thorpej int ppimatch __P((struct device *, struct cfdata *, void *));
75 1.11 thorpej void ppiattach __P((struct device *, struct device *, void *));
76 1.11 thorpej
77 1.11 thorpej struct cfattach ppi_ca = {
78 1.11 thorpej sizeof(struct ppi_softc), ppimatch, ppiattach
79 1.11 thorpej };
80 1.11 thorpej
81 1.11 thorpej struct cfdriver ppi_cd = {
82 1.11 thorpej NULL, "ppi", DV_DULL
83 1.11 thorpej };
84 1.11 thorpej
85 1.11 thorpej void ppistart __P((void *));
86 1.11 thorpej void ppinoop __P((void *));
87 1.11 thorpej
88 1.11 thorpej void ppitimo __P((void *));
89 1.11 thorpej int ppirw __P((dev_t, struct uio *));
90 1.11 thorpej int ppihztoms __P((int));
91 1.11 thorpej int ppimstohz __P((int));
92 1.11 thorpej
93 1.11 thorpej bdev_decl(ppi);
94 1.11 thorpej cdev_decl(ppi);
95 1.11 thorpej
96 1.1 cgd #define UNIT(x) minor(x)
97 1.1 cgd
98 1.1 cgd #ifdef DEBUG
99 1.1 cgd int ppidebug = 0x80;
100 1.1 cgd #define PDB_FOLLOW 0x01
101 1.1 cgd #define PDB_IO 0x02
102 1.1 cgd #define PDB_NOCHECK 0x80
103 1.1 cgd #endif
104 1.1 cgd
105 1.7 thorpej int
106 1.11 thorpej ppimatch(parent, match, aux)
107 1.11 thorpej struct device *parent;
108 1.11 thorpej struct cfdata *match;
109 1.11 thorpej void *aux;
110 1.1 cgd {
111 1.11 thorpej struct hpibbus_attach_args *ha = aux;
112 1.11 thorpej
113 1.11 thorpej /*
114 1.11 thorpej * The printer/plotter doesn't return an ID tag.
115 1.11 thorpej * The check below prevents us from matching a CS80
116 1.11 thorpej * device by mistake.
117 1.11 thorpej */
118 1.11 thorpej if (ha->ha_id & 0x200)
119 1.11 thorpej return (0);
120 1.1 cgd
121 1.1 cgd /*
122 1.11 thorpej * To prevent matching all unused slots on the bus, we
123 1.11 thorpej * don't allow wildcarded locators.
124 1.1 cgd */
125 1.11 thorpej if (match->hpibbuscf_slave == HPIBBUS_SLAVE_UNK ||
126 1.11 thorpej match->hpibbuscf_punit == HPIBBUS_PUNIT_UNK)
127 1.7 thorpej return (0);
128 1.7 thorpej
129 1.7 thorpej return (1);
130 1.7 thorpej }
131 1.7 thorpej
132 1.7 thorpej void
133 1.11 thorpej ppiattach(parent, self, aux)
134 1.11 thorpej struct device *parent, *self;
135 1.11 thorpej void *aux;
136 1.7 thorpej {
137 1.11 thorpej struct ppi_softc *sc = (struct ppi_softc *)self;
138 1.11 thorpej struct hpibbus_attach_args *ha = aux;
139 1.7 thorpej
140 1.10 christos printf("\n");
141 1.7 thorpej
142 1.11 thorpej sc->sc_slave = ha->ha_slave;
143 1.11 thorpej
144 1.11 thorpej /* Initialize the hpib queue entry. */
145 1.11 thorpej sc->sc_hq.hq_softc = sc;
146 1.11 thorpej sc->sc_hq.hq_slave = sc->sc_slave;
147 1.11 thorpej sc->sc_hq.hq_start = ppistart;
148 1.11 thorpej sc->sc_hq.hq_go = ppinoop;
149 1.11 thorpej sc->sc_hq.hq_intr = ppinoop;
150 1.11 thorpej
151 1.1 cgd sc->sc_flags = PPIF_ALIVE;
152 1.1 cgd }
153 1.1 cgd
154 1.11 thorpej void
155 1.11 thorpej ppinoop(arg)
156 1.11 thorpej void *arg;
157 1.11 thorpej {
158 1.11 thorpej /* Noop! */
159 1.11 thorpej }
160 1.11 thorpej
161 1.11 thorpej int
162 1.11 thorpej ppiopen(dev, flags, fmt, p)
163 1.1 cgd dev_t dev;
164 1.11 thorpej int flags, fmt;
165 1.11 thorpej struct proc *p;
166 1.1 cgd {
167 1.1 cgd register int unit = UNIT(dev);
168 1.11 thorpej struct ppi_softc *sc;
169 1.11 thorpej
170 1.11 thorpej if (unit >= ppi_cd.cd_ndevs ||
171 1.11 thorpej (sc = ppi_cd.cd_devs[unit]) == NULL ||
172 1.11 thorpej (sc->sc_flags & PPIF_ALIVE) == 0)
173 1.11 thorpej return (ENXIO);
174 1.1 cgd
175 1.1 cgd #ifdef DEBUG
176 1.1 cgd if (ppidebug & PDB_FOLLOW)
177 1.10 christos printf("ppiopen(%x, %x): flags %x\n",
178 1.1 cgd dev, flags, sc->sc_flags);
179 1.1 cgd #endif
180 1.1 cgd if (sc->sc_flags & PPIF_OPEN)
181 1.11 thorpej return (EBUSY);
182 1.1 cgd sc->sc_flags |= PPIF_OPEN;
183 1.1 cgd sc->sc_burst = PPI_BURST;
184 1.1 cgd sc->sc_timo = ppimstohz(PPI_TIMO);
185 1.1 cgd sc->sc_delay = ppimstohz(PPI_DELAY);
186 1.1 cgd sc->sc_sec = -1;
187 1.1 cgd return(0);
188 1.1 cgd }
189 1.1 cgd
190 1.11 thorpej int
191 1.11 thorpej ppiclose(dev, flags, fmt, p)
192 1.1 cgd dev_t dev;
193 1.11 thorpej int flags, fmt;
194 1.11 thorpej struct proc *p;
195 1.1 cgd {
196 1.1 cgd register int unit = UNIT(dev);
197 1.11 thorpej struct ppi_softc *sc = ppi_cd.cd_devs[unit];
198 1.1 cgd
199 1.1 cgd #ifdef DEBUG
200 1.1 cgd if (ppidebug & PDB_FOLLOW)
201 1.10 christos printf("ppiclose(%x, %x): flags %x\n",
202 1.1 cgd dev, flags, sc->sc_flags);
203 1.1 cgd #endif
204 1.1 cgd sc->sc_flags &= ~PPIF_OPEN;
205 1.1 cgd return(0);
206 1.1 cgd }
207 1.1 cgd
208 1.11 thorpej void
209 1.11 thorpej ppistart(arg)
210 1.11 thorpej void *arg;
211 1.1 cgd {
212 1.11 thorpej struct ppi_softc *sc = arg;
213 1.11 thorpej
214 1.1 cgd #ifdef DEBUG
215 1.1 cgd if (ppidebug & PDB_FOLLOW)
216 1.10 christos printf("ppistart(%x)\n", unit);
217 1.1 cgd #endif
218 1.11 thorpej sc->sc_flags &= ~PPIF_DELAY;
219 1.11 thorpej wakeup(sc);
220 1.1 cgd }
221 1.1 cgd
222 1.5 mycroft void
223 1.11 thorpej ppitimo(arg)
224 1.11 thorpej void *arg;
225 1.1 cgd {
226 1.11 thorpej struct ppi_softc *sc = arg;
227 1.11 thorpej
228 1.1 cgd #ifdef DEBUG
229 1.1 cgd if (ppidebug & PDB_FOLLOW)
230 1.11 thorpej printf("ppitimo(%x)\n", sc->sc_dev.dv_unit);
231 1.1 cgd #endif
232 1.11 thorpej sc->sc_flags &= ~(PPIF_UIO|PPIF_TIMO);
233 1.11 thorpej wakeup(sc);
234 1.1 cgd }
235 1.1 cgd
236 1.11 thorpej int
237 1.11 thorpej ppiread(dev, uio, flags)
238 1.1 cgd dev_t dev;
239 1.1 cgd struct uio *uio;
240 1.11 thorpej int flags;
241 1.1 cgd {
242 1.1 cgd
243 1.1 cgd #ifdef DEBUG
244 1.1 cgd if (ppidebug & PDB_FOLLOW)
245 1.10 christos printf("ppiread(%x, %x)\n", dev, uio);
246 1.1 cgd #endif
247 1.1 cgd return (ppirw(dev, uio));
248 1.1 cgd }
249 1.1 cgd
250 1.11 thorpej int
251 1.11 thorpej ppiwrite(dev, uio, flags)
252 1.1 cgd dev_t dev;
253 1.1 cgd struct uio *uio;
254 1.11 thorpej int flags;
255 1.1 cgd {
256 1.1 cgd
257 1.1 cgd #ifdef DEBUG
258 1.1 cgd if (ppidebug & PDB_FOLLOW)
259 1.10 christos printf("ppiwrite(%x, %x)\n", dev, uio);
260 1.1 cgd #endif
261 1.1 cgd return (ppirw(dev, uio));
262 1.1 cgd }
263 1.1 cgd
264 1.11 thorpej int
265 1.1 cgd ppirw(dev, uio)
266 1.1 cgd dev_t dev;
267 1.1 cgd register struct uio *uio;
268 1.1 cgd {
269 1.1 cgd int unit = UNIT(dev);
270 1.11 thorpej struct ppi_softc *sc = ppi_cd.cd_devs[unit];
271 1.1 cgd register int s, len, cnt;
272 1.1 cgd register char *cp;
273 1.1 cgd int error = 0, gotdata = 0;
274 1.11 thorpej int buflen, ctlr, slave;
275 1.1 cgd char *buf;
276 1.1 cgd
277 1.1 cgd if (uio->uio_resid == 0)
278 1.1 cgd return(0);
279 1.1 cgd
280 1.11 thorpej ctlr = sc->sc_dev.dv_parent->dv_unit;
281 1.11 thorpej slave = sc->sc_slave;
282 1.11 thorpej
283 1.1 cgd #ifdef DEBUG
284 1.1 cgd if (ppidebug & (PDB_FOLLOW|PDB_IO))
285 1.10 christos printf("ppirw(%x, %x, %c): burst %d, timo %d, resid %x\n",
286 1.1 cgd dev, uio, uio->uio_rw == UIO_READ ? 'R' : 'W',
287 1.1 cgd sc->sc_burst, sc->sc_timo, uio->uio_resid);
288 1.1 cgd #endif
289 1.5 mycroft buflen = min(sc->sc_burst, uio->uio_resid);
290 1.1 cgd buf = (char *)malloc(buflen, M_DEVBUF, M_WAITOK);
291 1.1 cgd sc->sc_flags |= PPIF_UIO;
292 1.1 cgd if (sc->sc_timo > 0) {
293 1.1 cgd sc->sc_flags |= PPIF_TIMO;
294 1.11 thorpej timeout(ppitimo, sc, sc->sc_timo);
295 1.1 cgd }
296 1.1 cgd while (uio->uio_resid > 0) {
297 1.5 mycroft len = min(buflen, uio->uio_resid);
298 1.1 cgd cp = buf;
299 1.1 cgd if (uio->uio_rw == UIO_WRITE) {
300 1.1 cgd error = uiomove(cp, len, uio);
301 1.1 cgd if (error)
302 1.1 cgd break;
303 1.1 cgd }
304 1.1 cgd again:
305 1.1 cgd s = splbio();
306 1.11 thorpej if ((sc->sc_flags & PPIF_UIO) &&
307 1.11 thorpej hpibreq(sc->sc_dev.dv_parent, &sc->sc_hq) == 0)
308 1.1 cgd sleep(sc, PRIBIO+1);
309 1.1 cgd /*
310 1.1 cgd * Check if we timed out during sleep or uiomove
311 1.1 cgd */
312 1.1 cgd (void) splsoftclock();
313 1.1 cgd if ((sc->sc_flags & PPIF_UIO) == 0) {
314 1.1 cgd #ifdef DEBUG
315 1.1 cgd if (ppidebug & PDB_IO)
316 1.10 christos printf("ppirw: uiomove/sleep timo, flags %x\n",
317 1.1 cgd sc->sc_flags);
318 1.1 cgd #endif
319 1.1 cgd if (sc->sc_flags & PPIF_TIMO) {
320 1.11 thorpej untimeout(ppitimo, sc);
321 1.1 cgd sc->sc_flags &= ~PPIF_TIMO;
322 1.1 cgd }
323 1.1 cgd splx(s);
324 1.1 cgd break;
325 1.1 cgd }
326 1.1 cgd splx(s);
327 1.1 cgd /*
328 1.1 cgd * Perform the operation
329 1.1 cgd */
330 1.1 cgd if (uio->uio_rw == UIO_WRITE)
331 1.11 thorpej cnt = hpibsend(ctlr, slave, sc->sc_sec, cp, len);
332 1.1 cgd else
333 1.11 thorpej cnt = hpibrecv(ctlr, slave, sc->sc_sec, cp, len);
334 1.1 cgd s = splbio();
335 1.11 thorpej hpibfree(sc->sc_dev.dv_parent, &sc->sc_hq);
336 1.1 cgd #ifdef DEBUG
337 1.1 cgd if (ppidebug & PDB_IO)
338 1.10 christos printf("ppirw: %s(%d, %d, %x, %x, %d) -> %d\n",
339 1.1 cgd uio->uio_rw == UIO_READ ? "recv" : "send",
340 1.11 thorpej ctlr, slave, sc->sc_sec, cp, len, cnt);
341 1.1 cgd #endif
342 1.1 cgd splx(s);
343 1.1 cgd if (uio->uio_rw == UIO_READ) {
344 1.1 cgd if (cnt) {
345 1.1 cgd error = uiomove(cp, cnt, uio);
346 1.1 cgd if (error)
347 1.1 cgd break;
348 1.1 cgd gotdata++;
349 1.1 cgd }
350 1.1 cgd /*
351 1.1 cgd * Didn't get anything this time, but did in the past.
352 1.1 cgd * Consider us done.
353 1.1 cgd */
354 1.1 cgd else if (gotdata)
355 1.1 cgd break;
356 1.1 cgd }
357 1.1 cgd s = splsoftclock();
358 1.1 cgd /*
359 1.1 cgd * Operation timeout (or non-blocking), quit now.
360 1.1 cgd */
361 1.1 cgd if ((sc->sc_flags & PPIF_UIO) == 0) {
362 1.1 cgd #ifdef DEBUG
363 1.1 cgd if (ppidebug & PDB_IO)
364 1.10 christos printf("ppirw: timeout/done\n");
365 1.1 cgd #endif
366 1.1 cgd splx(s);
367 1.1 cgd break;
368 1.1 cgd }
369 1.1 cgd /*
370 1.1 cgd * Implement inter-read delay
371 1.1 cgd */
372 1.1 cgd if (sc->sc_delay > 0) {
373 1.1 cgd sc->sc_flags |= PPIF_DELAY;
374 1.11 thorpej timeout(ppistart, sc, sc->sc_delay);
375 1.1 cgd error = tsleep(sc, PCATCH|PZERO+1, "hpib", 0);
376 1.1 cgd if (error) {
377 1.1 cgd splx(s);
378 1.1 cgd break;
379 1.1 cgd }
380 1.1 cgd }
381 1.1 cgd splx(s);
382 1.1 cgd /*
383 1.1 cgd * Must not call uiomove again til we've used all data
384 1.1 cgd * that we already grabbed.
385 1.1 cgd */
386 1.1 cgd if (uio->uio_rw == UIO_WRITE && cnt != len) {
387 1.1 cgd cp += cnt;
388 1.1 cgd len -= cnt;
389 1.1 cgd cnt = 0;
390 1.1 cgd goto again;
391 1.1 cgd }
392 1.1 cgd }
393 1.1 cgd s = splsoftclock();
394 1.1 cgd if (sc->sc_flags & PPIF_TIMO) {
395 1.11 thorpej untimeout(ppitimo, sc);
396 1.1 cgd sc->sc_flags &= ~PPIF_TIMO;
397 1.1 cgd }
398 1.1 cgd if (sc->sc_flags & PPIF_DELAY) {
399 1.11 thorpej untimeout(ppistart, sc);
400 1.1 cgd sc->sc_flags &= ~PPIF_DELAY;
401 1.1 cgd }
402 1.1 cgd splx(s);
403 1.1 cgd /*
404 1.1 cgd * Adjust for those chars that we uiomove'ed but never wrote
405 1.1 cgd */
406 1.1 cgd if (uio->uio_rw == UIO_WRITE && cnt != len) {
407 1.1 cgd uio->uio_resid += (len - cnt);
408 1.1 cgd #ifdef DEBUG
409 1.1 cgd if (ppidebug & PDB_IO)
410 1.10 christos printf("ppirw: short write, adjust by %d\n",
411 1.1 cgd len-cnt);
412 1.1 cgd #endif
413 1.1 cgd }
414 1.1 cgd free(buf, M_DEVBUF);
415 1.1 cgd #ifdef DEBUG
416 1.1 cgd if (ppidebug & (PDB_FOLLOW|PDB_IO))
417 1.10 christos printf("ppirw: return %d, resid %d\n", error, uio->uio_resid);
418 1.1 cgd #endif
419 1.1 cgd return (error);
420 1.1 cgd }
421 1.1 cgd
422 1.11 thorpej int
423 1.3 mycroft ppiioctl(dev, cmd, data, flag, p)
424 1.1 cgd dev_t dev;
425 1.11 thorpej u_long cmd;
426 1.1 cgd caddr_t data;
427 1.1 cgd int flag;
428 1.3 mycroft struct proc *p;
429 1.1 cgd {
430 1.11 thorpej struct ppi_softc *sc = ppi_cd.cd_devs[UNIT(dev)];
431 1.1 cgd struct ppiparam *pp, *upp;
432 1.1 cgd int error = 0;
433 1.1 cgd
434 1.1 cgd switch (cmd) {
435 1.1 cgd case PPIIOCGPARAM:
436 1.1 cgd pp = &sc->sc_param;
437 1.1 cgd upp = (struct ppiparam *)data;
438 1.1 cgd upp->burst = pp->burst;
439 1.1 cgd upp->timo = ppihztoms(pp->timo);
440 1.1 cgd upp->delay = ppihztoms(pp->delay);
441 1.1 cgd break;
442 1.1 cgd case PPIIOCSPARAM:
443 1.1 cgd pp = &sc->sc_param;
444 1.1 cgd upp = (struct ppiparam *)data;
445 1.1 cgd if (upp->burst < PPI_BURST_MIN || upp->burst > PPI_BURST_MAX ||
446 1.1 cgd upp->delay < PPI_DELAY_MIN || upp->delay > PPI_DELAY_MAX)
447 1.1 cgd return(EINVAL);
448 1.1 cgd pp->burst = upp->burst;
449 1.1 cgd pp->timo = ppimstohz(upp->timo);
450 1.1 cgd pp->delay = ppimstohz(upp->delay);
451 1.1 cgd break;
452 1.1 cgd case PPIIOCSSEC:
453 1.1 cgd sc->sc_sec = *(int *)data;
454 1.1 cgd break;
455 1.1 cgd default:
456 1.1 cgd return(EINVAL);
457 1.1 cgd }
458 1.1 cgd return (error);
459 1.1 cgd }
460 1.1 cgd
461 1.11 thorpej int
462 1.1 cgd ppihztoms(h)
463 1.1 cgd int h;
464 1.1 cgd {
465 1.1 cgd extern int hz;
466 1.1 cgd register int m = h;
467 1.1 cgd
468 1.1 cgd if (m > 0)
469 1.1 cgd m = m * 1000 / hz;
470 1.1 cgd return(m);
471 1.1 cgd }
472 1.1 cgd
473 1.11 thorpej int
474 1.1 cgd ppimstohz(m)
475 1.1 cgd int m;
476 1.1 cgd {
477 1.1 cgd extern int hz;
478 1.1 cgd register int h = m;
479 1.1 cgd
480 1.1 cgd if (h > 0) {
481 1.1 cgd h = h * hz / 1000;
482 1.1 cgd if (h == 0)
483 1.1 cgd h = 1000 / hz;
484 1.1 cgd }
485 1.1 cgd return(h);
486 1.1 cgd }
487