xref: /freebsd/sys/dev/gpio/gpiobus.c (revision 6b129086dcee14496517fae085b448e3edc69bc7)
1 /*-
2  * Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org>
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  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/gpio.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 
38 #include <dev/gpio/gpiobusvar.h>
39 
40 #include "gpiobus_if.h"
41 
42 #undef GPIOBUS_DEBUG
43 #ifdef GPIOBUS_DEBUG
44 #define	dprintf printf
45 #else
46 #define	dprintf(x, arg...)
47 #endif
48 
49 static void gpiobus_print_pins(struct gpiobus_ivar *, char *, size_t);
50 static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
51 static int gpiobus_probe(device_t);
52 static int gpiobus_attach(device_t);
53 static int gpiobus_detach(device_t);
54 static int gpiobus_suspend(device_t);
55 static int gpiobus_resume(device_t);
56 static int gpiobus_print_child(device_t, device_t);
57 static int gpiobus_child_location_str(device_t, device_t, char *, size_t);
58 static int gpiobus_child_pnpinfo_str(device_t, device_t, char *, size_t);
59 static device_t gpiobus_add_child(device_t, u_int, const char *, int);
60 static void gpiobus_hinted_child(device_t, const char *, int);
61 
62 /*
63  * GPIOBUS interface
64  */
65 static int gpiobus_acquire_bus(device_t, device_t, int);
66 static void gpiobus_release_bus(device_t, device_t);
67 static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
68 static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
69 static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
70 static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
71 static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
72 static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
73 
74 int
75 gpio_check_flags(uint32_t caps, uint32_t flags)
76 {
77 
78 	/* Check for unwanted flags. */
79 	if ((flags & caps) == 0 || (flags & caps) != flags)
80 		return (EINVAL);
81 	/* Cannot mix input/output together. */
82 	if (flags & GPIO_PIN_INPUT && flags & GPIO_PIN_OUTPUT)
83 		return (EINVAL);
84 	/* Cannot mix pull-up/pull-down together. */
85 	if (flags & GPIO_PIN_PULLUP && flags & GPIO_PIN_PULLDOWN)
86 		return (EINVAL);
87 
88 	return (0);
89 }
90 
91 static void
92 gpiobus_print_pins(struct gpiobus_ivar *devi, char *buf, size_t buflen)
93 {
94 	char tmp[128];
95 	int i, range_start, range_stop, need_coma;
96 
97 	if (devi->npins == 0)
98 		return;
99 
100 	need_coma = 0;
101 	range_start = range_stop = devi->pins[0];
102 	for (i = 1; i < devi->npins; i++) {
103 		if (devi->pins[i] != (range_stop + 1)) {
104 			if (need_coma)
105 				strlcat(buf, ",", buflen);
106 			memset(tmp, 0, sizeof(tmp));
107 			if (range_start != range_stop)
108 				snprintf(tmp, sizeof(tmp) - 1, "%d-%d",
109 				    range_start, range_stop);
110 			else
111 				snprintf(tmp, sizeof(tmp) - 1, "%d",
112 				    range_start);
113 			strlcat(buf, tmp, buflen);
114 
115 			range_start = range_stop = devi->pins[i];
116 			need_coma = 1;
117 		}
118 		else
119 			range_stop++;
120 	}
121 
122 	if (need_coma)
123 		strlcat(buf, ",", buflen);
124 	memset(tmp, 0, sizeof(tmp));
125 	if (range_start != range_stop)
126 		snprintf(tmp, sizeof(tmp) - 1, "%d-%d",
127 		    range_start, range_stop);
128 	else
129 		snprintf(tmp, sizeof(tmp) - 1, "%d",
130 		    range_start);
131 	strlcat(buf, tmp, buflen);
132 }
133 
134 int
135 gpiobus_init_softc(device_t dev)
136 {
137 	struct gpiobus_softc *sc;
138 
139 	sc = GPIOBUS_SOFTC(dev);
140 	sc->sc_busdev = dev;
141 	sc->sc_dev = device_get_parent(dev);
142 	sc->sc_intr_rman.rm_type = RMAN_ARRAY;
143 	sc->sc_intr_rman.rm_descr = "GPIO Interrupts";
144 	if (rman_init(&sc->sc_intr_rman) != 0 ||
145 	    rman_manage_region(&sc->sc_intr_rman, 0, ~0) != 0)
146 		panic("%s: failed to set up rman.", __func__);
147 
148 	if (GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins) != 0)
149 		return (ENXIO);
150 
151 	KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
152 
153 	/* Pins = GPIO_PIN_MAX() + 1 */
154 	sc->sc_npins++;
155 
156 	sc->sc_pins_mapped = malloc(sizeof(int) * sc->sc_npins, M_DEVBUF,
157 	    M_NOWAIT | M_ZERO);
158 	if (sc->sc_pins_mapped == NULL)
159 		return (ENOMEM);
160 
161 	/* Initialize the bus lock. */
162 	GPIOBUS_LOCK_INIT(sc);
163 
164 	return (0);
165 }
166 
167 static int
168 gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
169 {
170 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
171 	int i, npins;
172 
173 	npins = 0;
174 	for (i = 0; i < 32; i++) {
175 		if (mask & (1 << i))
176 			npins++;
177 	}
178 
179 	if (npins == 0) {
180 		device_printf(child, "empty pin mask\n");
181 		return (EINVAL);
182 	}
183 
184 	devi->npins = npins;
185 	devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
186 	    M_NOWAIT | M_ZERO);
187 
188 	if (!devi->pins)
189 		return (ENOMEM);
190 
191 	npins = 0;
192 	for (i = 0; i < 32; i++) {
193 
194 		if ((mask & (1 << i)) == 0)
195 			continue;
196 
197 		if (i >= sc->sc_npins) {
198 			device_printf(child,
199 			    "invalid pin %d, max: %d\n", i, sc->sc_npins - 1);
200 			free(devi->pins, M_DEVBUF);
201 			return (EINVAL);
202 		}
203 
204 		devi->pins[npins++] = i;
205 		/*
206 		 * Mark pin as mapped and give warning if it's already mapped
207 		 */
208 		if (sc->sc_pins_mapped[i]) {
209 			device_printf(child,
210 			    "warning: pin %d is already mapped\n", i);
211 			free(devi->pins, M_DEVBUF);
212 			return (EINVAL);
213 		}
214 		sc->sc_pins_mapped[i] = 1;
215 	}
216 
217 	return (0);
218 }
219 
220 static int
221 gpiobus_probe(device_t dev)
222 {
223 	device_set_desc(dev, "GPIO bus");
224 
225 	return (BUS_PROBE_GENERIC);
226 }
227 
228 static int
229 gpiobus_attach(device_t dev)
230 {
231 	int err;
232 
233 	err = gpiobus_init_softc(dev);
234 	if (err != 0)
235 		return (err);
236 
237 	/*
238 	 * Get parent's pins and mark them as unmapped
239 	 */
240 	bus_generic_probe(dev);
241 	bus_enumerate_hinted_children(dev);
242 
243 	return (bus_generic_attach(dev));
244 }
245 
246 /*
247  * Since this is not a self-enumerating bus, and since we always add
248  * children in attach, we have to always delete children here.
249  */
250 static int
251 gpiobus_detach(device_t dev)
252 {
253 	struct gpiobus_softc *sc;
254 	struct gpiobus_ivar *devi;
255 	device_t *devlist;
256 	int i, err, ndevs;
257 
258 	sc = GPIOBUS_SOFTC(dev);
259 	KASSERT(mtx_initialized(&sc->sc_mtx),
260 	    ("gpiobus mutex not initialized"));
261 	GPIOBUS_LOCK_DESTROY(sc);
262 
263 	if ((err = bus_generic_detach(dev)) != 0)
264 		return (err);
265 
266 	if ((err = device_get_children(dev, &devlist, &ndevs)) != 0)
267 		return (err);
268 	for (i = 0; i < ndevs; i++) {
269 		device_delete_child(dev, devlist[i]);
270 		devi = GPIOBUS_IVAR(devlist[i]);
271 		if (devi->pins) {
272 			free(devi->pins, M_DEVBUF);
273 			devi->pins = NULL;
274 		}
275 	}
276 	free(devlist, M_TEMP);
277 
278 	if (sc->sc_pins_mapped) {
279 		free(sc->sc_pins_mapped, M_DEVBUF);
280 		sc->sc_pins_mapped = NULL;
281 	}
282 
283 	return (0);
284 }
285 
286 static int
287 gpiobus_suspend(device_t dev)
288 {
289 
290 	return (bus_generic_suspend(dev));
291 }
292 
293 static int
294 gpiobus_resume(device_t dev)
295 {
296 
297 	return (bus_generic_resume(dev));
298 }
299 
300 static int
301 gpiobus_print_child(device_t dev, device_t child)
302 {
303 	char pins[128];
304 	int retval = 0;
305 	struct gpiobus_ivar *devi;
306 
307 	devi = GPIOBUS_IVAR(child);
308 	memset(pins, 0, sizeof(pins));
309 	retval += bus_print_child_header(dev, child);
310 	retval += printf(" at pin(s) ");
311 	gpiobus_print_pins(devi, pins, sizeof(pins));
312 	retval += printf("%s", pins);
313 	resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%ld");
314 	retval += bus_print_child_footer(dev, child);
315 
316 	return (retval);
317 }
318 
319 static int
320 gpiobus_child_location_str(device_t bus, device_t child, char *buf,
321     size_t buflen)
322 {
323 	struct gpiobus_ivar *devi;
324 
325 	devi = GPIOBUS_IVAR(child);
326 	strlcpy(buf, "pin(s)=", buflen);
327 	gpiobus_print_pins(devi, buf, buflen);
328 
329 	return (0);
330 }
331 
332 static int
333 gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
334     size_t buflen)
335 {
336 
337 	*buf = '\0';
338 	return (0);
339 }
340 
341 static device_t
342 gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
343 {
344 	device_t child;
345 	struct gpiobus_ivar *devi;
346 
347 	child = device_add_child_ordered(dev, order, name, unit);
348 	if (child == NULL)
349 		return (child);
350 	devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
351 	if (devi == NULL) {
352 		device_delete_child(dev, child);
353 		return (0);
354 	}
355 	resource_list_init(&devi->rl);
356 	device_set_ivars(child, devi);
357 
358 	return (child);
359 }
360 
361 static void
362 gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
363 {
364 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
365 	struct gpiobus_ivar *devi;
366 	device_t child;
367 	int irq, pins;
368 
369 	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
370 	devi = GPIOBUS_IVAR(child);
371 	resource_int_value(dname, dunit, "pins", &pins);
372 	if (gpiobus_parse_pins(sc, child, pins))
373 		device_delete_child(bus, child);
374 	if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
375 		if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
376 			device_printf(bus,
377 			    "warning: bus_set_resource() failed\n");
378 	}
379 }
380 
381 static int
382 gpiobus_set_resource(device_t dev, device_t child, int type, int rid,
383     u_long start, u_long count)
384 {
385 	struct gpiobus_ivar *devi;
386 	struct resource_list_entry *rle;
387 
388 	dprintf("%s: entry (%p, %p, %d, %d, %p, %ld)\n",
389 	    __func__, dev, child, type, rid, (void *)(intptr_t)start, count);
390 	devi = GPIOBUS_IVAR(child);
391 	rle = resource_list_add(&devi->rl, type, rid, start,
392 	    start + count - 1, count);
393 	if (rle == NULL)
394 		return (ENXIO);
395 
396 	return (0);
397 }
398 
399 static struct resource *
400 gpiobus_alloc_resource(device_t bus, device_t child, int type, int *rid,
401     u_long start, u_long end, u_long count, u_int flags)
402 {
403 	struct gpiobus_softc *sc;
404 	struct resource *rv;
405 	struct resource_list *rl;
406 	struct resource_list_entry *rle;
407 	int isdefault;
408 
409 	if (type != SYS_RES_IRQ)
410 		return (NULL);
411 	isdefault = (start == 0UL && end == ~0UL && count == 1);
412 	rle = NULL;
413 	if (isdefault) {
414 		rl = BUS_GET_RESOURCE_LIST(bus, child);
415 		if (rl == NULL)
416 			return (NULL);
417 		rle = resource_list_find(rl, type, *rid);
418 		if (rle == NULL)
419 			return (NULL);
420 		if (rle->res != NULL)
421 			panic("%s: resource entry is busy", __func__);
422 		start = rle->start;
423 		count = rle->count;
424 		end = rle->end;
425 	}
426 	sc = device_get_softc(bus);
427 	rv = rman_reserve_resource(&sc->sc_intr_rman, start, end, count, flags,
428 	    child);
429 	if (rv == NULL)
430 		return (NULL);
431 	rman_set_rid(rv, *rid);
432 	if ((flags & RF_ACTIVE) != 0 &&
433 	    bus_activate_resource(child, type, *rid, rv) != 0) {
434 		rman_release_resource(rv);
435 		return (NULL);
436 	}
437 
438 	return (rv);
439 }
440 
441 static int
442 gpiobus_release_resource(device_t bus __unused, device_t child, int type,
443     int rid, struct resource *r)
444 {
445 	int error;
446 
447 	if (rman_get_flags(r) & RF_ACTIVE) {
448 		error = bus_deactivate_resource(child, type, rid, r);
449 		if (error)
450 			return (error);
451 	}
452 
453 	return (rman_release_resource(r));
454 }
455 
456 static struct resource_list *
457 gpiobus_get_resource_list(device_t bus __unused, device_t child)
458 {
459 	struct gpiobus_ivar *ivar;
460 
461 	ivar = GPIOBUS_IVAR(child);
462 
463 	return (&ivar->rl);
464 }
465 
466 static int
467 gpiobus_acquire_bus(device_t busdev, device_t child, int how)
468 {
469 	struct gpiobus_softc *sc;
470 
471 	sc = device_get_softc(busdev);
472 	GPIOBUS_ASSERT_UNLOCKED(sc);
473 	GPIOBUS_LOCK(sc);
474 	if (sc->sc_owner != NULL) {
475 		if (how == GPIOBUS_DONTWAIT) {
476 			GPIOBUS_UNLOCK(sc);
477 			return (EWOULDBLOCK);
478 		}
479 		while (sc->sc_owner != NULL)
480 			mtx_sleep(sc, &sc->sc_mtx, 0, "gpiobuswait", 0);
481 	}
482 	sc->sc_owner = child;
483 	GPIOBUS_UNLOCK(sc);
484 
485 	return (0);
486 }
487 
488 static void
489 gpiobus_release_bus(device_t busdev, device_t child)
490 {
491 	struct gpiobus_softc *sc;
492 
493 	sc = device_get_softc(busdev);
494 	GPIOBUS_ASSERT_UNLOCKED(sc);
495 	GPIOBUS_LOCK(sc);
496 	if (sc->sc_owner == NULL)
497 		panic("gpiobus: releasing unowned bus.");
498 	if (sc->sc_owner != child)
499 		panic("gpiobus: you don't own the bus. game over.");
500 	sc->sc_owner = NULL;
501 	wakeup(sc);
502 	GPIOBUS_UNLOCK(sc);
503 }
504 
505 static int
506 gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
507     uint32_t flags)
508 {
509 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
510 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
511 	uint32_t caps;
512 
513 	if (pin >= devi->npins)
514 		return (EINVAL);
515 	if (GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], &caps) != 0)
516 		return (EINVAL);
517 	if (gpio_check_flags(caps, flags) != 0)
518 		return (EINVAL);
519 
520 	return (GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags));
521 }
522 
523 static int
524 gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
525     uint32_t *flags)
526 {
527 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
528 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
529 
530 	if (pin >= devi->npins)
531 		return (EINVAL);
532 
533 	return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
534 }
535 
536 static int
537 gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
538     uint32_t *caps)
539 {
540 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
541 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
542 
543 	if (pin >= devi->npins)
544 		return (EINVAL);
545 
546 	return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
547 }
548 
549 static int
550 gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
551     unsigned int value)
552 {
553 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
554 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
555 
556 	if (pin >= devi->npins)
557 		return (EINVAL);
558 
559 	return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
560 }
561 
562 static int
563 gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
564     unsigned int *value)
565 {
566 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
567 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
568 
569 	if (pin >= devi->npins)
570 		return (EINVAL);
571 
572 	return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
573 }
574 
575 static int
576 gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
577 {
578 	struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
579 	struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
580 
581 	if (pin >= devi->npins)
582 		return (EINVAL);
583 
584 	return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
585 }
586 
587 static device_method_t gpiobus_methods[] = {
588 	/* Device interface */
589 	DEVMETHOD(device_probe,		gpiobus_probe),
590 	DEVMETHOD(device_attach,	gpiobus_attach),
591 	DEVMETHOD(device_detach,	gpiobus_detach),
592 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
593 	DEVMETHOD(device_suspend,	gpiobus_suspend),
594 	DEVMETHOD(device_resume,	gpiobus_resume),
595 
596 	/* Bus interface */
597 	DEVMETHOD(bus_setup_intr,	bus_generic_setup_intr),
598 	DEVMETHOD(bus_config_intr,	bus_generic_config_intr),
599 	DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
600 	DEVMETHOD(bus_set_resource,	gpiobus_set_resource),
601 	DEVMETHOD(bus_alloc_resource,	gpiobus_alloc_resource),
602 	DEVMETHOD(bus_release_resource,	gpiobus_release_resource),
603 	DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
604 	DEVMETHOD(bus_deactivate_resource,	bus_generic_deactivate_resource),
605 	DEVMETHOD(bus_get_resource_list,	gpiobus_get_resource_list),
606 	DEVMETHOD(bus_add_child,	gpiobus_add_child),
607 	DEVMETHOD(bus_print_child,	gpiobus_print_child),
608 	DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
609 	DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
610 	DEVMETHOD(bus_hinted_child,	gpiobus_hinted_child),
611 
612 	/* GPIO protocol */
613 	DEVMETHOD(gpiobus_acquire_bus,	gpiobus_acquire_bus),
614 	DEVMETHOD(gpiobus_release_bus,	gpiobus_release_bus),
615 	DEVMETHOD(gpiobus_pin_getflags,	gpiobus_pin_getflags),
616 	DEVMETHOD(gpiobus_pin_getcaps,	gpiobus_pin_getcaps),
617 	DEVMETHOD(gpiobus_pin_setflags,	gpiobus_pin_setflags),
618 	DEVMETHOD(gpiobus_pin_get,	gpiobus_pin_get),
619 	DEVMETHOD(gpiobus_pin_set,	gpiobus_pin_set),
620 	DEVMETHOD(gpiobus_pin_toggle,	gpiobus_pin_toggle),
621 
622 	DEVMETHOD_END
623 };
624 
625 driver_t gpiobus_driver = {
626 	"gpiobus",
627 	gpiobus_methods,
628 	sizeof(struct gpiobus_softc)
629 };
630 
631 devclass_t	gpiobus_devclass;
632 
633 DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0);
634 MODULE_VERSION(gpiobus, 1);
635