xref: /freebsd-14.2/sys/dev/puc/puc.c (revision 5eb2dd94)
1 /*	$NetBSD: puc.c,v 1.7 2000/07/29 17:43:38 jlam Exp $	*/
2 #ifndef PUC_FASTINTR
3 #define PUC_FASTINTR
4 #endif
5 
6 /*-
7  * Copyright (c) 2002 JF Hay.  All rights reserved.
8  * Copyright (c) 2000 M. Warner Losh.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*-
33  * Copyright (c) 1996, 1998, 1999
34  *	Christopher G. Demetriou.  All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgement:
46  *      This product includes software developed by Christopher G. Demetriou
47  *	for the NetBSD Project.
48  * 4. The name of the author may not be used to endorse or promote products
49  *    derived from this software without specific prior written permission
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61  */
62 
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
65 
66 /*
67  * PCI "universal" communication card device driver, glues com, lpt,
68  * and similar ports to PCI via bridge chip often much larger than
69  * the devices being glued.
70  *
71  * Author: Christopher G. Demetriou, May 14, 1998 (derived from NetBSD
72  * sys/dev/pci/pciide.c, revision 1.6).
73  *
74  * These devices could be (and some times are) described as
75  * communications/{serial,parallel}, etc. devices with known
76  * programming interfaces, but those programming interfaces (in
77  * particular the BAR assignments for devices, etc.) in fact are not
78  * particularly well defined.
79  *
80  * After I/we have seen more of these devices, it may be possible
81  * to generalize some of these bits.  In particular, devices which
82  * describe themselves as communications/serial/16[45]50, and
83  * communications/parallel/??? might be attached via direct
84  * 'com' and 'lpt' attachments to pci.
85  */
86 
87 #include "opt_puc.h"
88 #include <sys/param.h>
89 #include <sys/systm.h>
90 #include <sys/kernel.h>
91 #include <sys/bus.h>
92 #include <sys/conf.h>
93 #include <sys/malloc.h>
94 
95 #include <machine/bus.h>
96 #include <machine/resource.h>
97 #include <sys/rman.h>
98 
99 #include <dev/pci/pcireg.h>
100 #include <dev/pci/pcivar.h>
101 
102 #define PUC_ENTRAILS	1
103 #include <dev/puc/pucvar.h>
104 
105 struct puc_device {
106 	struct resource_list resources;
107 	int	port;
108 	int	regshft;
109 	u_int	serialfreq;
110 	u_int	subtype;
111 };
112 
113 static void puc_intr(void *arg);
114 
115 static int puc_find_free_unit(char *);
116 #ifdef PUC_DEBUG
117 static void puc_print_resource_list(struct resource_list *);
118 #endif
119 
120 devclass_t puc_devclass;
121 
122 static int
123 puc_port_bar_index(struct puc_softc *sc, int bar)
124 {
125 	int i;
126 
127 	for (i = 0; i < PUC_MAX_BAR; i += 1) {
128 		if (!sc->sc_bar_mappings[i].used)
129 			break;
130 		if (sc->sc_bar_mappings[i].bar == bar)
131 			return (i);
132 	}
133 	if (i == PUC_MAX_BAR) {
134 		printf("%s: out of bars!\n", __func__);
135 		return (-1);
136 	}
137 	sc->sc_bar_mappings[i].bar = bar;
138 	sc->sc_bar_mappings[i].used = 1;
139 	return (i);
140 }
141 
142 static int
143 puc_probe_ilr(struct puc_softc *sc, struct resource *res)
144 {
145 	u_char t1, t2;
146 	int i;
147 
148 	switch (sc->sc_desc.ilr_type) {
149 	case PUC_ILR_TYPE_DIGI:
150 		sc->ilr_st = rman_get_bustag(res);
151 		sc->ilr_sh = rman_get_bushandle(res);
152 		for (i = 0; i < 2 && sc->sc_desc.ilr_offset[i] != 0; i++) {
153 			t1 = bus_space_read_1(sc->ilr_st, sc->ilr_sh,
154 			    sc->sc_desc.ilr_offset[i]);
155 			t1 = ~t1;
156 			bus_space_write_1(sc->ilr_st, sc->ilr_sh,
157 			    sc->sc_desc.ilr_offset[i], t1);
158 			t2 = bus_space_read_1(sc->ilr_st, sc->ilr_sh,
159 			    sc->sc_desc.ilr_offset[i]);
160 			if (t2 == t1)
161 				return (0);
162 		}
163 		return (1);
164 
165 	default:
166 		break;
167 	}
168 	return (0);
169 }
170 
171 int
172 puc_attach(device_t dev, const struct puc_device_description *desc)
173 {
174 	char *typestr;
175 	int bidx, childunit, i, irq_setup, ressz, rid, type;
176 	struct puc_softc *sc;
177 	struct puc_device *pdev;
178 	struct resource *res;
179 	struct resource_list_entry *rle;
180 	bus_space_handle_t bh;
181 
182 	if (desc == NULL)
183 		return (ENXIO);
184 
185 	sc = (struct puc_softc *)device_get_softc(dev);
186 	bzero(sc, sizeof(*sc));
187 	sc->sc_desc = *desc;
188 
189 #ifdef PUC_DEBUG
190 	bootverbose = 1;
191 
192 	printf("puc: name: %s\n", sc->sc_desc.name);
193 #endif
194 	rid = 0;
195 	res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
196 	    RF_ACTIVE | RF_SHAREABLE);
197 	if (!res)
198 		return (ENXIO);
199 
200 	sc->irqres = res;
201 	sc->irqrid = rid;
202 #ifdef PUC_FASTINTR
203 	irq_setup = BUS_SETUP_INTR(device_get_parent(dev), dev, res,
204 	    INTR_TYPE_TTY | INTR_FAST, puc_intr, sc, &sc->intr_cookie);
205 	if (irq_setup == 0)
206 		sc->fastintr = INTR_FAST;
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 #else
211 	irq_setup = BUS_SETUP_INTR(device_get_parent(dev), dev, res,
212 	    INTR_TYPE_TTY, puc_intr, sc, &sc->intr_cookie);
213 #endif
214 	if (irq_setup != 0)
215 		return (ENXIO);
216 
217 	rid = 0;
218 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
219 		if (i > 0 && rid == sc->sc_desc.ports[i].bar)
220 			sc->barmuxed = 1;
221 		rid = sc->sc_desc.ports[i].bar;
222 		bidx = puc_port_bar_index(sc, rid);
223 
224 		if (bidx < 0 || sc->sc_bar_mappings[bidx].res != NULL)
225 			continue;
226 
227 		type = (sc->sc_desc.ports[i].flags & PUC_FLAGS_MEMORY)
228 		    ? SYS_RES_MEMORY : SYS_RES_IOPORT;
229 
230 		res = bus_alloc_resource_any(dev, type, &rid,
231 		    RF_ACTIVE);
232 		if (res == NULL &&
233 		    sc->sc_desc.ports[i].flags & PUC_FLAGS_ALTRES) {
234 			type = (type == SYS_RES_IOPORT)
235 			    ? SYS_RES_MEMORY : SYS_RES_IOPORT;
236 			res = bus_alloc_resource_any(dev, type, &rid,
237 			    RF_ACTIVE);
238 		}
239 		if (res == NULL) {
240 			device_printf(dev, "could not get resource\n");
241 			continue;
242 		}
243 		sc->sc_bar_mappings[bidx].type = type;
244 		sc->sc_bar_mappings[bidx].res = res;
245 
246 		if (sc->sc_desc.ilr_type != PUC_ILR_TYPE_NONE) {
247 			sc->ilr_enabled = puc_probe_ilr(sc, res);
248 			if (sc->ilr_enabled)
249 				device_printf(dev, "ILR enabled\n");
250 			else
251 				device_printf(dev, "ILR disabled\n");
252 		}
253 #ifdef PUC_DEBUG
254 		printf("%s rid %d bst %lx, start %lx, end %lx\n",
255 		    (type == SYS_RES_MEMORY) ? "memory" : "port", rid,
256 		    (u_long)rman_get_bustag(res), (u_long)rman_get_start(res),
257 		    (u_long)rman_get_end(res));
258 #endif
259 	}
260 
261 	if (desc->init != NULL) {
262 		i = desc->init(sc);
263 		if (i != 0)
264 			return (i);
265 	}
266 
267 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
268 		rid = sc->sc_desc.ports[i].bar;
269 		bidx = puc_port_bar_index(sc, rid);
270 		if (bidx < 0 || sc->sc_bar_mappings[bidx].res == NULL)
271 			continue;
272 
273 		switch (sc->sc_desc.ports[i].type & ~PUC_PORT_SUBTYPE_MASK) {
274 		case PUC_PORT_TYPE_COM:
275 			typestr = "sio";
276 			break;
277 		case PUC_PORT_TYPE_LPT:
278 			typestr = "ppc";
279 			break;
280 		case PUC_PORT_TYPE_UART:
281 			typestr = "uart";
282 			break;
283 		default:
284 			continue;
285 		}
286 		switch (sc->sc_desc.ports[i].type & PUC_PORT_SUBTYPE_MASK) {
287 		case PUC_PORT_UART_SAB82532:
288 			ressz = 64;
289 			break;
290 		case PUC_PORT_UART_Z8530:
291 			ressz = 2;
292 			break;
293 		default:
294 			ressz = 8;
295 			break;
296 		}
297 		pdev = malloc(sizeof(struct puc_device), M_DEVBUF,
298 		    M_NOWAIT | M_ZERO);
299 		if (!pdev)
300 			continue;
301 		resource_list_init(&pdev->resources);
302 
303 		/* First fake up an IRQ resource. */
304 		resource_list_add(&pdev->resources, SYS_RES_IRQ, 0,
305 		    rman_get_start(sc->irqres), rman_get_end(sc->irqres),
306 		    rman_get_end(sc->irqres) - rman_get_start(sc->irqres) + 1);
307 		rle = resource_list_find(&pdev->resources, SYS_RES_IRQ, 0);
308 		rle->res = sc->irqres;
309 
310 		/* Now fake an IOPORT or MEMORY resource */
311 		res = sc->sc_bar_mappings[bidx].res;
312 		type = sc->sc_bar_mappings[bidx].type;
313 		resource_list_add(&pdev->resources, type, 0,
314 		    rman_get_start(res) + sc->sc_desc.ports[i].offset,
315 		    rman_get_start(res) + sc->sc_desc.ports[i].offset
316 		    + ressz - 1, ressz);
317 		rle = resource_list_find(&pdev->resources, type, 0);
318 
319 		if (sc->barmuxed == 0) {
320 			rle->res = sc->sc_bar_mappings[bidx].res;
321 		} else {
322 			rle->res = rman_secret_puc_alloc_resource(M_WAITOK);
323 			if (rle->res == NULL) {
324 				free(pdev, M_DEVBUF);
325 				return (ENOMEM);
326 			}
327 
328 			rman_set_start(rle->res, rman_get_start(res) +
329 			    sc->sc_desc.ports[i].offset);
330 			rman_set_end(rle->res, rman_get_start(rle->res) +
331 			    ressz - 1);
332 			rman_set_bustag(rle->res, rman_get_bustag(res));
333 			bus_space_subregion(rman_get_bustag(rle->res),
334 			    rman_get_bushandle(res),
335 			    sc->sc_desc.ports[i].offset, ressz,
336 			    &bh);
337 			rman_set_bushandle(rle->res, bh);
338 		}
339 
340 		pdev->port = i + 1;
341 		pdev->serialfreq = sc->sc_desc.ports[i].serialfreq;
342 		pdev->subtype = sc->sc_desc.ports[i].type &
343 		    PUC_PORT_SUBTYPE_MASK;
344 		pdev->regshft = sc->sc_desc.ports[i].regshft;
345 
346 		childunit = puc_find_free_unit(typestr);
347 		if (childunit < 0 && strcmp(typestr, "uart") != 0) {
348 			typestr = "uart";
349 			childunit = puc_find_free_unit(typestr);
350 		}
351 		sc->sc_ports[i].dev = device_add_child(dev, typestr,
352 		    childunit);
353 		if (sc->sc_ports[i].dev == NULL) {
354 			if (sc->barmuxed) {
355 				bus_space_unmap(rman_get_bustag(rle->res),
356 				    rman_get_bushandle(rle->res), ressz);
357 				rman_secret_puc_free_resource(rle->res);
358 				free(pdev, M_DEVBUF);
359 			}
360 			continue;
361 		}
362 		device_set_ivars(sc->sc_ports[i].dev, pdev);
363 		device_set_desc(sc->sc_ports[i].dev, sc->sc_desc.name);
364 #ifdef PUC_DEBUG
365 		printf("puc: type %d, bar %x, offset %x\n",
366 		    sc->sc_desc.ports[i].type,
367 		    sc->sc_desc.ports[i].bar,
368 		    sc->sc_desc.ports[i].offset);
369 		puc_print_resource_list(&pdev->resources);
370 #endif
371 		device_set_flags(sc->sc_ports[i].dev,
372 		    sc->sc_desc.ports[i].flags);
373 		if (device_probe_and_attach(sc->sc_ports[i].dev) != 0) {
374 			if (sc->barmuxed) {
375 				bus_space_unmap(rman_get_bustag(rle->res),
376 				    rman_get_bushandle(rle->res), ressz);
377 				rman_secret_puc_free_resource(rle->res);
378 				free(pdev, M_DEVBUF);
379 			}
380 		}
381 	}
382 
383 #ifdef PUC_DEBUG
384 	bootverbose = 0;
385 #endif
386 	return (0);
387 }
388 
389 static u_int32_t
390 puc_ilr_read(struct puc_softc *sc)
391 {
392 	u_int32_t mask;
393 	int i;
394 
395 	mask = 0;
396 	switch (sc->sc_desc.ilr_type) {
397 	case PUC_ILR_TYPE_DIGI:
398 		for (i = 1; i >= 0 && sc->sc_desc.ilr_offset[i] != 0; i--) {
399 			mask = (mask << 8) | (bus_space_read_1(sc->ilr_st,
400 			    sc->ilr_sh, sc->sc_desc.ilr_offset[i]) & 0xff);
401 		}
402 		break;
403 
404 	default:
405 		mask = 0xffffffff;
406 		break;
407 	}
408 	return (mask);
409 }
410 
411 /*
412  * This is an interrupt handler. For boards that can't tell us which
413  * device generated the interrupt it just calls all the registered
414  * handlers sequencially, but for boards that can tell us which
415  * device(s) generated the interrupt it calls only handlers for devices
416  * that actually generated the interrupt.
417  */
418 static void
419 puc_intr(void *arg)
420 {
421 	int i;
422 	u_int32_t ilr_mask;
423 	struct puc_softc *sc;
424 
425 	sc = (struct puc_softc *)arg;
426 	ilr_mask = sc->ilr_enabled ? puc_ilr_read(sc) : 0xffffffff;
427 	for (i = 0; i < PUC_MAX_PORTS; i++)
428 		if (sc->sc_ports[i].ihand != NULL &&
429 		    ((ilr_mask >> i) & 0x00000001))
430 			(sc->sc_ports[i].ihand)(sc->sc_ports[i].ihandarg);
431 }
432 
433 static int
434 puc_find_free_unit(char *name)
435 {
436 	devclass_t dc;
437 	int start;
438 	int unit;
439 
440 	unit = 0;
441 	start = 0;
442 	while (resource_int_value(name, unit, "port", &start) == 0 &&
443 	    start > 0)
444 		unit++;
445 	dc = devclass_find(name);
446 	if (dc == NULL)
447 		return (-1);
448 	while (devclass_get_device(dc, unit))
449 		unit++;
450 #ifdef PUC_DEBUG
451 	printf("puc: Using %s%d\n", name, unit);
452 #endif
453 	return (unit);
454 }
455 
456 #ifdef PUC_DEBUG
457 static void
458 puc_print_resource_list(struct resource_list *rl)
459 {
460 #if 0
461 	struct resource_list_entry *rle;
462 
463 	printf("print_resource_list: rl %p\n", rl);
464 	SLIST_FOREACH(rle, rl, link)
465 		printf("  type %x, rid %x start %lx end %lx count %lx\n",
466 		    rle->type, rle->rid, rle->start, rle->end, rle->count);
467 	printf("print_resource_list: end.\n");
468 #endif
469 }
470 #endif
471 
472 struct resource *
473 puc_alloc_resource(device_t dev, device_t child, int type, int *rid,
474     u_long start, u_long end, u_long count, u_int flags)
475 {
476 	struct puc_device *pdev;
477 	struct resource *retval;
478 	struct resource_list *rl;
479 	struct resource_list_entry *rle;
480 	device_t my_child;
481 
482 	/*
483 	 * in the case of a child of child we need to find our immediate child
484 	 */
485 	for (my_child = child; device_get_parent(my_child) != dev;
486 	     my_child = device_get_parent(my_child));
487 
488 	pdev = device_get_ivars(my_child);
489 	rl = &pdev->resources;
490 
491 #ifdef PUC_DEBUG
492 	printf("puc_alloc_resource: pdev %p, looking for t %x, r %x\n",
493 	    pdev, type, *rid);
494 	puc_print_resource_list(rl);
495 #endif
496 	retval = NULL;
497 	rle = resource_list_find(rl, type, *rid);
498 	if (rle) {
499 #ifdef PUC_DEBUG
500 		printf("found rle, %lx, %lx, %lx\n", rle->start, rle->end,
501 		    rle->count);
502 #endif
503 		retval = rle->res;
504 	}
505 #ifdef PUC_DEBUG
506 	else
507 		printf("oops rle is gone\n");
508 #endif
509 
510 	return (retval);
511 }
512 
513 int
514 puc_release_resource(device_t dev, device_t child, int type, int rid,
515     struct resource *res)
516 {
517 	return (0);
518 }
519 
520 int
521 puc_get_resource(device_t dev, device_t child, int type, int rid,
522     u_long *startp, u_long *countp)
523 {
524 	struct puc_device *pdev;
525 	struct resource_list *rl;
526 	struct resource_list_entry *rle;
527 
528 	pdev = device_get_ivars(child);
529 	rl = &pdev->resources;
530 
531 #ifdef PUC_DEBUG
532 	printf("puc_get_resource: pdev %p, looking for t %x, r %x\n", pdev,
533 	    type, rid);
534 	puc_print_resource_list(rl);
535 #endif
536 	rle = resource_list_find(rl, type, rid);
537 	if (rle) {
538 #ifdef PUC_DEBUG
539 		printf("found rle %p,", rle);
540 #endif
541 		if (startp != NULL)
542 			*startp = rle->start;
543 		if (countp != NULL)
544 			*countp = rle->count;
545 #ifdef PUC_DEBUG
546 		printf(" %lx, %lx\n", rle->start, rle->count);
547 #endif
548 		return (0);
549 	} else
550 		printf("oops rle is gone\n");
551 	return (ENXIO);
552 }
553 
554 int
555 puc_setup_intr(device_t dev, device_t child, struct resource *r, int flags,
556 	       void (*ihand)(void *), void *arg, void **cookiep)
557 {
558 	int i;
559 	struct puc_softc *sc;
560 
561 	sc = (struct puc_softc *)device_get_softc(dev);
562 	if ((flags & INTR_FAST) != sc->fastintr)
563 		return (ENXIO);
564 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
565 		if (sc->sc_ports[i].dev == child) {
566 			if (sc->sc_ports[i].ihand != 0)
567 				return (ENXIO);
568 			sc->sc_ports[i].ihand = ihand;
569 			sc->sc_ports[i].ihandarg = arg;
570 			*cookiep = arg;
571 			return (0);
572 		}
573 	}
574 	return (ENXIO);
575 }
576 
577 int
578 puc_teardown_intr(device_t dev, device_t child, struct resource *r,
579 		  void *cookie)
580 {
581 	int i;
582 	struct puc_softc *sc;
583 
584 	sc = (struct puc_softc *)device_get_softc(dev);
585 	for (i = 0; PUC_PORT_VALID(sc->sc_desc, i); i++) {
586 		if (sc->sc_ports[i].dev == child) {
587 			sc->sc_ports[i].ihand = NULL;
588 			sc->sc_ports[i].ihandarg = NULL;
589 			return (0);
590 		}
591 	}
592 	return (ENXIO);
593 }
594 
595 int
596 puc_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
597 {
598 	struct puc_device *pdev;
599 
600 	pdev = device_get_ivars(child);
601 	if (pdev == NULL)
602 		return (ENOENT);
603 
604 	switch(index) {
605 	case PUC_IVAR_FREQ:
606 		*result = pdev->serialfreq;
607 		break;
608 	case PUC_IVAR_PORT:
609 		*result = pdev->port;
610 		break;
611 	case PUC_IVAR_REGSHFT:
612 		*result = pdev->regshft;
613 		break;
614 	case PUC_IVAR_SUBTYPE:
615 		*result = pdev->subtype;
616 		break;
617 	default:
618 		return (ENOENT);
619 	}
620 	return (0);
621 }
622