xref: /freebsd/sys/dev/puc/puc.c (revision b6de9e91bd2c47efaeec72a08642f8fd99cc7b20)
1 /*	$NetBSD: puc.c,v 1.7 2000/07/29 17:43:38 jlam Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002 JF Hay.  All rights reserved.
5  * Copyright (c) 2000 M. Warner Losh.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*-
30  * Copyright (c) 1996, 1998, 1999
31  *	Christopher G. Demetriou.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. All advertising materials mentioning features or use of this software
42  *    must display the following acknowledgement:
43  *      This product includes software developed by Christopher G. Demetriou
44  *	for the NetBSD Project.
45  * 4. The name of the author may not be used to endorse or promote products
46  *    derived from this software without specific prior written permission
47  *
48  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
49  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
50  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
51  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
52  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
53  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
54  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
55  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
56  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
57  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
58  */
59 
60 #include <sys/cdefs.h>
61 __FBSDID("$FreeBSD$");
62 
63 /*
64  * PCI "universal" communication card device driver, glues com, lpt,
65  * and similar ports to PCI via bridge chip often much larger than
66  * the devices being glued.
67  *
68  * Author: Christopher G. Demetriou, May 14, 1998 (derived from NetBSD
69  * sys/dev/pci/pciide.c, revision 1.6).
70  *
71  * These devices could be (and some times are) described as
72  * communications/{serial,parallel}, etc. devices with known
73  * programming interfaces, but those programming interfaces (in
74  * particular the BAR assignments for devices, etc.) in fact are not
75  * particularly well defined.
76  *
77  * After I/we have seen more of these devices, it may be possible
78  * to generalize some of these bits.  In particular, devices which
79  * describe themselves as communications/serial/16[45]50, and
80  * communications/parallel/??? might be attached via direct
81  * 'com' and 'lpt' attachments to pci.
82  */
83 
84 #include "opt_puc.h"
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/kernel.h>
88 #include <sys/bus.h>
89 #include <sys/conf.h>
90 #include <sys/malloc.h>
91 
92 #include <machine/bus.h>
93 #include <machine/resource.h>
94 #include <sys/rman.h>
95 
96 #include <dev/pci/pcireg.h>
97 #include <dev/pci/pcivar.h>
98 
99 #define PUC_ENTRAILS	1
100 #include <dev/puc/pucvar.h>
101 
102 struct puc_device {
103 	struct resource_list resources;
104 	int	port;
105 	int	regshft;
106 	u_int	serialfreq;
107 	u_int	subtype;
108 };
109 
110 static void puc_intr(void *arg);
111 
112 static int puc_find_free_unit(char *);
113 #ifdef PUC_DEBUG
114 static void puc_print_resource_list(struct resource_list *);
115 #endif
116 
117 devclass_t puc_devclass;
118 
119 static int
120 puc_port_bar_index(struct puc_softc *sc, int bar)
121 {
122 	int i;
123 
124 	for (i = 0; i < PUC_MAX_BAR; i += 1) {
125 		if (!sc->sc_bar_mappings[i].used)
126 			break;
127 		if (sc->sc_bar_mappings[i].bar == bar)
128 			return (i);
129 	}
130 	if (i == PUC_MAX_BAR) {
131 		printf("%s: out of bars!\n", __func__);
132 		return (-1);
133 	}
134 	sc->sc_bar_mappings[i].bar = bar;
135 	sc->sc_bar_mappings[i].used = 1;
136 	return (i);
137 }
138 
139 static int
140 puc_probe_ilr(struct puc_softc *sc, struct resource *res)
141 {
142 	u_char t1, t2;
143 	int i;
144 
145 	switch (sc->sc_desc.ilr_type) {
146 	case PUC_ILR_TYPE_DIGI:
147 		sc->ilr_st = rman_get_bustag(res);
148 		sc->ilr_sh = rman_get_bushandle(res);
149 		for (i = 0; i < 2 && sc->sc_desc.ilr_offset[i] != 0; i++) {
150 			t1 = bus_space_read_1(sc->ilr_st, sc->ilr_sh,
151 			    sc->sc_desc.ilr_offset[i]);
152 			t1 = ~t1;
153 			bus_space_write_1(sc->ilr_st, sc->ilr_sh,
154 			    sc->sc_desc.ilr_offset[i], t1);
155 			t2 = bus_space_read_1(sc->ilr_st, sc->ilr_sh,
156 			    sc->sc_desc.ilr_offset[i]);
157 			if (t2 == t1)
158 				return (0);
159 		}
160 		return (1);
161 
162 	default:
163 		break;
164 	}
165 	return (0);
166 }
167 
168 int
169 puc_attach(device_t dev, const struct puc_device_description *desc)
170 {
171 	char *typestr;
172 	int bidx, childunit, i, irq_setup, ressz, rid, type;
173 	struct puc_softc *sc;
174 	struct puc_device *pdev;
175 	struct resource *res;
176 	struct resource_list_entry *rle;
177 	bus_space_handle_t bh;
178 
179 	if (desc == NULL)
180 		return (ENXIO);
181 
182 	sc = (struct puc_softc *)device_get_softc(dev);
183 	bzero(sc, sizeof(*sc));
184 	sc->sc_desc = *desc;
185 
186 #ifdef PUC_DEBUG
187 	bootverbose = 1;
188 
189 	printf("puc: name: %s\n", sc->sc_desc.name);
190 #endif
191 	rid = 0;
192 	res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
193 	    RF_ACTIVE | RF_SHAREABLE);
194 	if (!res)
195 		return (ENXIO);
196 
197 	sc->irqres = res;
198 	sc->irqrid = rid;
199 #ifdef PUC_FASTINTR
200 	irq_setup = BUS_SETUP_INTR(device_get_parent(dev), dev, res,
201 	    INTR_TYPE_TTY | INTR_FAST, puc_intr, sc, &sc->intr_cookie);
202 	if (irq_setup == 0)
203 		sc->fastintr = INTR_FAST;
204 	else
205 		irq_setup = BUS_SETUP_INTR(device_get_parent(dev), dev, res,
206 		    INTR_TYPE_TTY, puc_intr, sc, &sc->intr_cookie);
207 #else
208 	irq_setup = BUS_SETUP_INTR(device_get_parent(dev), dev, res,
209 	    INTR_TYPE_TTY, puc_intr, sc, &sc->intr_cookie);
210 #endif
211 	if (irq_setup != 0)
212 		return (ENXIO);
213 
214 	rid = 0;
215 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
216 		if (i > 0 && rid == sc->sc_desc.ports[i].bar)
217 			sc->barmuxed = 1;
218 		rid = sc->sc_desc.ports[i].bar;
219 		bidx = puc_port_bar_index(sc, rid);
220 
221 		if (bidx < 0 || sc->sc_bar_mappings[bidx].res != NULL)
222 			continue;
223 
224 		type = (sc->sc_desc.ports[i].flags & PUC_FLAGS_MEMORY)
225 		    ? SYS_RES_MEMORY : SYS_RES_IOPORT;
226 
227 		res = bus_alloc_resource_any(dev, type, &rid,
228 		    RF_ACTIVE);
229 		if (res == NULL &&
230 		    sc->sc_desc.ports[i].flags & PUC_FLAGS_ALTRES) {
231 			type = (type == SYS_RES_IOPORT)
232 			    ? SYS_RES_MEMORY : SYS_RES_IOPORT;
233 			res = bus_alloc_resource_any(dev, type, &rid,
234 			    RF_ACTIVE);
235 		}
236 		if (res == NULL) {
237 			device_printf(dev, "could not get resource\n");
238 			continue;
239 		}
240 		sc->sc_bar_mappings[bidx].type = type;
241 		sc->sc_bar_mappings[bidx].res = res;
242 
243 		if (sc->sc_desc.ilr_type != PUC_ILR_TYPE_NONE) {
244 			sc->ilr_enabled = puc_probe_ilr(sc, res);
245 			if (sc->ilr_enabled)
246 				device_printf(dev, "ILR enabled\n");
247 			else
248 				device_printf(dev, "ILR disabled\n");
249 		}
250 #ifdef PUC_DEBUG
251 		printf("%s rid %d bst %lx, start %lx, end %lx\n",
252 		    (type == SYS_RES_MEMORY) ? "memory" : "port", rid,
253 		    (u_long)rman_get_bustag(res), (u_long)rman_get_start(res),
254 		    (u_long)rman_get_end(res));
255 #endif
256 	}
257 
258 	if (desc->init != NULL) {
259 		i = desc->init(sc);
260 		if (i != 0)
261 			return (i);
262 	}
263 
264 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
265 		rid = sc->sc_desc.ports[i].bar;
266 		bidx = puc_port_bar_index(sc, rid);
267 		if (bidx < 0 || sc->sc_bar_mappings[bidx].res == NULL)
268 			continue;
269 
270 		switch (sc->sc_desc.ports[i].type & ~PUC_PORT_SUBTYPE_MASK) {
271 		case PUC_PORT_TYPE_COM:
272 			typestr = "sio";
273 			break;
274 		case PUC_PORT_TYPE_LPT:
275 			typestr = "ppc";
276 			break;
277 		case PUC_PORT_TYPE_UART:
278 			typestr = "uart";
279 			break;
280 		default:
281 			continue;
282 		}
283 		switch (sc->sc_desc.ports[i].type & PUC_PORT_SUBTYPE_MASK) {
284 		case PUC_PORT_UART_SAB82532:
285 			ressz = 64;
286 			break;
287 		case PUC_PORT_UART_Z8530:
288 			ressz = 2;
289 			break;
290 		default:
291 			ressz = 8;
292 			break;
293 		}
294 		pdev = malloc(sizeof(struct puc_device), M_DEVBUF,
295 		    M_NOWAIT | M_ZERO);
296 		if (!pdev)
297 			continue;
298 		resource_list_init(&pdev->resources);
299 
300 		/* First fake up an IRQ resource. */
301 		resource_list_add(&pdev->resources, SYS_RES_IRQ, 0,
302 		    rman_get_start(sc->irqres), rman_get_end(sc->irqres),
303 		    rman_get_end(sc->irqres) - rman_get_start(sc->irqres) + 1);
304 		rle = resource_list_find(&pdev->resources, SYS_RES_IRQ, 0);
305 		rle->res = sc->irqres;
306 
307 		/* Now fake an IOPORT or MEMORY resource */
308 		res = sc->sc_bar_mappings[bidx].res;
309 		type = sc->sc_bar_mappings[bidx].type;
310 		resource_list_add(&pdev->resources, type, 0,
311 		    rman_get_start(res) + sc->sc_desc.ports[i].offset,
312 		    rman_get_start(res) + sc->sc_desc.ports[i].offset
313 		    + ressz - 1, ressz);
314 		rle = resource_list_find(&pdev->resources, type, 0);
315 
316 		if (sc->barmuxed == 0) {
317 			rle->res = sc->sc_bar_mappings[bidx].res;
318 		} else {
319 			rle->res = malloc(sizeof(struct resource), M_DEVBUF,
320 			    M_WAITOK | M_ZERO);
321 			if (rle->res == NULL) {
322 				free(pdev, M_DEVBUF);
323 				return (ENOMEM);
324 			}
325 
326 			rman_set_start(rle->res, rman_get_start(res) +
327 			    sc->sc_desc.ports[i].offset);
328 			rman_set_end(rle->res, rman_get_start(rle->res) +
329 			    ressz - 1);
330 			rman_set_bustag(rle->res, rman_get_bustag(res));
331 			bus_space_subregion(rman_get_bustag(rle->res),
332 			    rman_get_bushandle(res),
333 			    sc->sc_desc.ports[i].offset, ressz,
334 			    &bh);
335 			rman_set_bushandle(rle->res, bh);
336 		}
337 
338 		pdev->port = i + 1;
339 		pdev->serialfreq = sc->sc_desc.ports[i].serialfreq;
340 		pdev->subtype = sc->sc_desc.ports[i].type &
341 		    PUC_PORT_SUBTYPE_MASK;
342 		pdev->regshft = sc->sc_desc.ports[i].regshft;
343 
344 		childunit = puc_find_free_unit(typestr);
345 		if (childunit < 0 && strcmp(typestr, "uart") != 0) {
346 			typestr = "uart";
347 			childunit = puc_find_free_unit(typestr);
348 		}
349 		sc->sc_ports[i].dev = device_add_child(dev, typestr,
350 		    childunit);
351 		if (sc->sc_ports[i].dev == NULL) {
352 			if (sc->barmuxed) {
353 				bus_space_unmap(rman_get_bustag(rle->res),
354 				    rman_get_bushandle(rle->res), ressz);
355 				free(rle->res, M_DEVBUF);
356 				free(pdev, M_DEVBUF);
357 			}
358 			continue;
359 		}
360 		device_set_ivars(sc->sc_ports[i].dev, pdev);
361 		device_set_desc(sc->sc_ports[i].dev, sc->sc_desc.name);
362 #ifdef PUC_DEBUG
363 		printf("puc: type %d, bar %x, offset %x\n",
364 		    sc->sc_desc.ports[i].type,
365 		    sc->sc_desc.ports[i].bar,
366 		    sc->sc_desc.ports[i].offset);
367 		puc_print_resource_list(&pdev->resources);
368 #endif
369 		device_set_flags(sc->sc_ports[i].dev,
370 		    sc->sc_desc.ports[i].flags);
371 		if (device_probe_and_attach(sc->sc_ports[i].dev) != 0) {
372 			if (sc->barmuxed) {
373 				bus_space_unmap(rman_get_bustag(rle->res),
374 				    rman_get_bushandle(rle->res), ressz);
375 				free(rle->res, M_DEVBUF);
376 				free(pdev, M_DEVBUF);
377 			}
378 		}
379 	}
380 
381 #ifdef PUC_DEBUG
382 	bootverbose = 0;
383 #endif
384 	return (0);
385 }
386 
387 static u_int32_t
388 puc_ilr_read(struct puc_softc *sc)
389 {
390 	u_int32_t mask;
391 	int i;
392 
393 	mask = 0;
394 	switch (sc->sc_desc.ilr_type) {
395 	case PUC_ILR_TYPE_DIGI:
396 		for (i = 1; i >= 0 && sc->sc_desc.ilr_offset[i] != 0; i--) {
397 			mask = (mask << 8) | (bus_space_read_1(sc->ilr_st,
398 			    sc->ilr_sh, sc->sc_desc.ilr_offset[i]) & 0xff);
399 		}
400 		break;
401 
402 	default:
403 		mask = 0xffffffff;
404 		break;
405 	}
406 	return (mask);
407 }
408 
409 /*
410  * This is an interrupt handler. For boards that can't tell us which
411  * device generated the interrupt it just calls all the registered
412  * handlers sequencially, but for boards that can tell us which
413  * device(s) generated the interrupt it calls only handlers for devices
414  * that actually generated the interrupt.
415  */
416 static void
417 puc_intr(void *arg)
418 {
419 	int i;
420 	u_int32_t ilr_mask;
421 	struct puc_softc *sc;
422 
423 	sc = (struct puc_softc *)arg;
424 	ilr_mask = sc->ilr_enabled ? puc_ilr_read(sc) : 0xffffffff;
425 	for (i = 0; i < PUC_MAX_PORTS; i++)
426 		if (sc->sc_ports[i].ihand != NULL &&
427 		    ((ilr_mask >> i) & 0x00000001))
428 			(sc->sc_ports[i].ihand)(sc->sc_ports[i].ihandarg);
429 }
430 
431 static int
432 puc_find_free_unit(char *name)
433 {
434 	devclass_t dc;
435 	int start;
436 	int unit;
437 
438 	unit = 0;
439 	start = 0;
440 	while (resource_int_value(name, unit, "port", &start) == 0 &&
441 	    start > 0)
442 		unit++;
443 	dc = devclass_find(name);
444 	if (dc == NULL)
445 		return (-1);
446 	while (devclass_get_device(dc, unit))
447 		unit++;
448 #ifdef PUC_DEBUG
449 	printf("puc: Using %s%d\n", name, unit);
450 #endif
451 	return (unit);
452 }
453 
454 #ifdef PUC_DEBUG
455 static void
456 puc_print_resource_list(struct resource_list *rl)
457 {
458 #if 0
459 	struct resource_list_entry *rle;
460 
461 	printf("print_resource_list: rl %p\n", rl);
462 	SLIST_FOREACH(rle, rl, link)
463 		printf("  type %x, rid %x start %lx end %lx count %lx\n",
464 		    rle->type, rle->rid, rle->start, rle->end, rle->count);
465 	printf("print_resource_list: end.\n");
466 #endif
467 }
468 #endif
469 
470 struct resource *
471 puc_alloc_resource(device_t dev, device_t child, int type, int *rid,
472     u_long start, u_long end, u_long count, u_int flags)
473 {
474 	struct puc_device *pdev;
475 	struct resource *retval;
476 	struct resource_list *rl;
477 	struct resource_list_entry *rle;
478 	device_t my_child;
479 
480 	/*
481 	 * in the case of a child of child we need to find our immediate child
482 	 */
483 	for (my_child = child; device_get_parent(my_child) != dev;
484 	     my_child = device_get_parent(my_child));
485 
486 	pdev = device_get_ivars(my_child);
487 	rl = &pdev->resources;
488 
489 #ifdef PUC_DEBUG
490 	printf("puc_alloc_resource: pdev %p, looking for t %x, r %x\n",
491 	    pdev, type, *rid);
492 	puc_print_resource_list(rl);
493 #endif
494 	retval = NULL;
495 	rle = resource_list_find(rl, type, *rid);
496 	if (rle) {
497 #ifdef PUC_DEBUG
498 		printf("found rle, %lx, %lx, %lx\n", rle->start, rle->end,
499 		    rle->count);
500 #endif
501 		retval = rle->res;
502 	}
503 #ifdef PUC_DEBUG
504 	else
505 		printf("oops rle is gone\n");
506 #endif
507 
508 	return (retval);
509 }
510 
511 int
512 puc_release_resource(device_t dev, device_t child, int type, int rid,
513     struct resource *res)
514 {
515 	return (0);
516 }
517 
518 int
519 puc_get_resource(device_t dev, device_t child, int type, int rid,
520     u_long *startp, u_long *countp)
521 {
522 	struct puc_device *pdev;
523 	struct resource_list *rl;
524 	struct resource_list_entry *rle;
525 
526 	pdev = device_get_ivars(child);
527 	rl = &pdev->resources;
528 
529 #ifdef PUC_DEBUG
530 	printf("puc_get_resource: pdev %p, looking for t %x, r %x\n", pdev,
531 	    type, rid);
532 	puc_print_resource_list(rl);
533 #endif
534 	rle = resource_list_find(rl, type, rid);
535 	if (rle) {
536 #ifdef PUC_DEBUG
537 		printf("found rle %p,", rle);
538 #endif
539 		if (startp != NULL)
540 			*startp = rle->start;
541 		if (countp != NULL)
542 			*countp = rle->count;
543 #ifdef PUC_DEBUG
544 		printf(" %lx, %lx\n", rle->start, rle->count);
545 #endif
546 		return (0);
547 	} else
548 		printf("oops rle is gone\n");
549 	return (ENXIO);
550 }
551 
552 int
553 puc_setup_intr(device_t dev, device_t child, struct resource *r, int flags,
554 	       void (*ihand)(void *), void *arg, void **cookiep)
555 {
556 	int i;
557 	struct puc_softc *sc;
558 
559 	sc = (struct puc_softc *)device_get_softc(dev);
560 	if ((flags & INTR_FAST) != sc->fastintr)
561 		return (ENXIO);
562 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
563 		if (sc->sc_ports[i].dev == child) {
564 			if (sc->sc_ports[i].ihand != 0)
565 				return (ENXIO);
566 			sc->sc_ports[i].ihand = ihand;
567 			sc->sc_ports[i].ihandarg = arg;
568 			*cookiep = arg;
569 			return (0);
570 		}
571 	}
572 	return (ENXIO);
573 }
574 
575 int
576 puc_teardown_intr(device_t dev, device_t child, struct resource *r,
577 		  void *cookie)
578 {
579 	int i;
580 	struct puc_softc *sc;
581 
582 	sc = (struct puc_softc *)device_get_softc(dev);
583 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
584 		if (sc->sc_ports[i].dev == child) {
585 			sc->sc_ports[i].ihand = NULL;
586 			sc->sc_ports[i].ihandarg = NULL;
587 			return (0);
588 		}
589 	}
590 	return (ENXIO);
591 }
592 
593 int
594 puc_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
595 {
596 	struct puc_device *pdev;
597 
598 	pdev = device_get_ivars(child);
599 	if (pdev == NULL)
600 		return (ENOENT);
601 
602 	switch(index) {
603 	case PUC_IVAR_FREQ:
604 		*result = pdev->serialfreq;
605 		break;
606 	case PUC_IVAR_PORT:
607 		*result = pdev->port;
608 		break;
609 	case PUC_IVAR_REGSHFT:
610 		*result = pdev->regshft;
611 		break;
612 	case PUC_IVAR_SUBTYPE:
613 		*result = pdev->subtype;
614 		break;
615 	default:
616 		return (ENOENT);
617 	}
618 	return (0);
619 }
620