xref: /freebsd-11-stable/sys/dev/gpio/ofw_gpiobus.c (revision 95dcd4fefc810d2e2dcad66859acc35e1949f65d)
1 /*-
2  * Copyright (c) 2009, Nathan Whitehorn <nwhitehorn@FreeBSD.org>
3  * Copyright (c) 2013, Luiz Otavio O Souza <loos@FreeBSD.org>
4  * Copyright (c) 2013 The FreeBSD Foundation
5  * 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 unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 
39 #include <dev/gpio/gpiobusvar.h>
40 #include <dev/ofw/ofw_bus.h>
41 
42 #include "gpiobus_if.h"
43 
44 static struct ofw_gpiobus_devinfo *ofw_gpiobus_setup_devinfo(device_t,
45 	device_t, phandle_t);
46 static void ofw_gpiobus_destroy_devinfo(device_t, struct ofw_gpiobus_devinfo *);
47 static int ofw_gpiobus_parse_gpios_impl(device_t, phandle_t, char *,
48 	struct gpiobus_softc *, struct gpiobus_pin **);
49 
50 /*
51  * Utility functions for easier handling of OFW GPIO pins.
52  *
53  * !!! BEWARE !!!
54  * GPIOBUS uses children's IVARs, so we cannot use this interface for cross
55  * tree consumers.
56  *
57  */
58 int
gpio_pin_get_by_ofw_propidx(device_t consumer,phandle_t cnode,char * prop_name,int idx,gpio_pin_t * out_pin)59 gpio_pin_get_by_ofw_propidx(device_t consumer, phandle_t cnode,
60     char *prop_name, int idx, gpio_pin_t *out_pin)
61 {
62 	phandle_t xref;
63 	pcell_t *cells;
64 	device_t busdev;
65 	struct gpiobus_pin pin;
66 	int ncells, rv;
67 
68 	KASSERT(consumer != NULL && cnode > 0,
69 	    ("both consumer and cnode required"));
70 
71 	rv = ofw_bus_parse_xref_list_alloc(cnode, prop_name, "#gpio-cells",
72 	    idx, &xref, &ncells, &cells);
73 	if (rv != 0)
74 		return (rv);
75 
76 	/* Translate provider to device. */
77 	pin.dev = OF_device_from_xref(xref);
78 	if (pin.dev == NULL) {
79 		OF_prop_free(cells);
80 		return (ENODEV);
81 	}
82 
83 	/* Test if GPIO bus already exist. */
84 	busdev = GPIO_GET_BUS(pin.dev);
85 	if (busdev == NULL) {
86 		OF_prop_free(cells);
87 		return (ENODEV);
88 	}
89 
90 	/* Map GPIO pin. */
91 	rv = gpio_map_gpios(pin.dev, cnode, OF_node_from_xref(xref), ncells,
92 	    cells, &pin.pin, &pin.flags);
93 	OF_prop_free(cells);
94 	if (rv != 0)
95 		return (ENXIO);
96 
97 	/* Reserve GPIO pin. */
98 	rv = gpiobus_acquire_pin(busdev, pin.pin);
99 	if (rv != 0)
100 		return (EBUSY);
101 
102 	*out_pin = malloc(sizeof(struct gpiobus_pin), M_DEVBUF,
103 	    M_WAITOK | M_ZERO);
104 	**out_pin = pin;
105 	return (0);
106 }
107 
108 int
gpio_pin_get_by_ofw_idx(device_t consumer,phandle_t node,int idx,gpio_pin_t * pin)109 gpio_pin_get_by_ofw_idx(device_t consumer, phandle_t node,
110     int idx, gpio_pin_t *pin)
111 {
112 
113 	return (gpio_pin_get_by_ofw_propidx(consumer, node, "gpios", idx, pin));
114 }
115 
116 int
gpio_pin_get_by_ofw_property(device_t consumer,phandle_t node,char * name,gpio_pin_t * pin)117 gpio_pin_get_by_ofw_property(device_t consumer, phandle_t node,
118     char *name, gpio_pin_t *pin)
119 {
120 
121 	return (gpio_pin_get_by_ofw_propidx(consumer, node, name, 0, pin));
122 }
123 
124 int
gpio_pin_get_by_ofw_name(device_t consumer,phandle_t node,char * name,gpio_pin_t * pin)125 gpio_pin_get_by_ofw_name(device_t consumer, phandle_t node,
126     char *name, gpio_pin_t *pin)
127 {
128 	int rv, idx;
129 
130 	KASSERT(consumer != NULL && node > 0,
131 	    ("both consumer and node required"));
132 
133 	rv = ofw_bus_find_string_index(node, "gpio-names", name, &idx);
134 	if (rv != 0)
135 		return (rv);
136 	return (gpio_pin_get_by_ofw_idx(consumer, node, idx, pin));
137 }
138 
139 void
gpio_pin_release(gpio_pin_t gpio)140 gpio_pin_release(gpio_pin_t gpio)
141 {
142 	device_t busdev;
143 
144 	if (gpio == NULL)
145 		return;
146 
147 	KASSERT(gpio->dev != NULL, ("invalid pin state"));
148 
149 	busdev = GPIO_GET_BUS(gpio->dev);
150 	if (busdev != NULL)
151 		gpiobus_release_pin(busdev, gpio->pin);
152 
153 	/* XXXX Unreserve pin. */
154 	free(gpio, M_DEVBUF);
155 }
156 
157 int
gpio_pin_getcaps(gpio_pin_t pin,uint32_t * caps)158 gpio_pin_getcaps(gpio_pin_t pin, uint32_t *caps)
159 {
160 
161 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
162 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
163 	return (GPIO_PIN_GETCAPS(pin->dev, pin->pin, caps));
164 }
165 
166 int
gpio_pin_is_active(gpio_pin_t pin,bool * active)167 gpio_pin_is_active(gpio_pin_t pin, bool *active)
168 {
169 	int rv;
170 	uint32_t tmp;
171 
172 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
173 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
174 	rv = GPIO_PIN_GET(pin->dev, pin->pin, &tmp);
175 	if (rv  != 0) {
176 		return (rv);
177 	}
178 
179 	if (pin->flags & GPIO_ACTIVE_LOW)
180 		*active = tmp == 0;
181 	else
182 		*active = tmp != 0;
183 	return (0);
184 }
185 
186 int
gpio_pin_set_active(gpio_pin_t pin,bool active)187 gpio_pin_set_active(gpio_pin_t pin, bool active)
188 {
189 	int rv;
190 	uint32_t tmp;
191 
192 	if (pin->flags & GPIO_ACTIVE_LOW)
193 		tmp = active ? 0 : 1;
194 	else
195 		tmp = active ? 1 : 0;
196 
197 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
198 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
199 	rv = GPIO_PIN_SET(pin->dev, pin->pin, tmp);
200 	return (rv);
201 }
202 
203 int
gpio_pin_setflags(gpio_pin_t pin,uint32_t flags)204 gpio_pin_setflags(gpio_pin_t pin, uint32_t flags)
205 {
206 	int rv;
207 
208 	KASSERT(pin != NULL, ("GPIO pin is NULL."));
209 	KASSERT(pin->dev != NULL, ("GPIO pin device is NULL."));
210 
211 	rv = GPIO_PIN_SETFLAGS(pin->dev, pin->pin, flags);
212 	return (rv);
213 }
214 
215 /*
216  * OFW_GPIOBUS driver.
217  */
218 device_t
ofw_gpiobus_add_fdt_child(device_t bus,const char * drvname,phandle_t child)219 ofw_gpiobus_add_fdt_child(device_t bus, const char *drvname, phandle_t child)
220 {
221 	device_t childdev;
222 	int i;
223 	struct gpiobus_ivar *devi;
224 	struct ofw_gpiobus_devinfo *dinfo;
225 
226 	/*
227 	 * Check to see if we already have a child for @p child, and if so
228 	 * return it.
229 	 */
230 	childdev = ofw_bus_find_child_device_by_phandle(bus, child);
231 	if (childdev != NULL)
232 		return (childdev);
233 
234 	/*
235 	 * Set up the GPIO child and OFW bus layer devinfo and add it to bus.
236 	 */
237 	childdev = device_add_child(bus, drvname, -1);
238 	if (childdev == NULL)
239 		return (NULL);
240 	dinfo = ofw_gpiobus_setup_devinfo(bus, childdev, child);
241 	if (dinfo == NULL) {
242 		device_delete_child(bus, childdev);
243 		return (NULL);
244 	}
245 	if (device_probe_and_attach(childdev) != 0) {
246 		ofw_gpiobus_destroy_devinfo(bus, dinfo);
247 		device_delete_child(bus, childdev);
248 		return (NULL);
249 	}
250 	/* Use the child name as pin name. */
251 	devi = &dinfo->opd_dinfo;
252 	for (i = 0; i < devi->npins; i++)
253 		GPIOBUS_PIN_SETNAME(bus, devi->pins[i],
254 		    device_get_nameunit(childdev));
255 
256 	return (childdev);
257 }
258 
259 int
ofw_gpiobus_parse_gpios(device_t consumer,char * pname,struct gpiobus_pin ** pins)260 ofw_gpiobus_parse_gpios(device_t consumer, char *pname,
261 	struct gpiobus_pin **pins)
262 {
263 
264 	return (ofw_gpiobus_parse_gpios_impl(consumer,
265 	    ofw_bus_get_node(consumer), pname, NULL, pins));
266 }
267 
268 void
ofw_gpiobus_register_provider(device_t provider)269 ofw_gpiobus_register_provider(device_t provider)
270 {
271 	phandle_t node;
272 
273 	node = ofw_bus_get_node(provider);
274 	OF_device_register_xref(OF_xref_from_node(node), provider);
275 }
276 
277 void
ofw_gpiobus_unregister_provider(device_t provider)278 ofw_gpiobus_unregister_provider(device_t provider)
279 {
280 	phandle_t node;
281 
282 	node = ofw_bus_get_node(provider);
283 	OF_device_register_xref(OF_xref_from_node(node), NULL);
284 }
285 
286 static struct ofw_gpiobus_devinfo *
ofw_gpiobus_setup_devinfo(device_t bus,device_t child,phandle_t node)287 ofw_gpiobus_setup_devinfo(device_t bus, device_t child, phandle_t node)
288 {
289 	int i, npins;
290 	struct gpiobus_ivar *devi;
291 	struct gpiobus_pin *pins;
292 	struct gpiobus_softc *sc;
293 	struct ofw_gpiobus_devinfo *dinfo;
294 
295 	sc = device_get_softc(bus);
296 	dinfo = malloc(sizeof(*dinfo), M_DEVBUF, M_NOWAIT | M_ZERO);
297 	if (dinfo == NULL)
298 		return (NULL);
299 	if (ofw_bus_gen_setup_devinfo(&dinfo->opd_obdinfo, node) != 0) {
300 		free(dinfo, M_DEVBUF);
301 		return (NULL);
302 	}
303 	/* Parse the gpios property for the child. */
304 	npins = ofw_gpiobus_parse_gpios_impl(child, node, "gpios", sc, &pins);
305 	if (npins <= 0) {
306 		ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
307 		free(dinfo, M_DEVBUF);
308 		return (NULL);
309 	}
310 	/* Initialize the irq resource list. */
311 	resource_list_init(&dinfo->opd_dinfo.rl);
312 	/* Allocate the child ivars and copy the parsed pin data. */
313 	devi = &dinfo->opd_dinfo;
314 	devi->npins = (uint32_t)npins;
315 	if (gpiobus_alloc_ivars(devi) != 0) {
316 		free(pins, M_DEVBUF);
317 		ofw_gpiobus_destroy_devinfo(bus, dinfo);
318 		return (NULL);
319 	}
320 	for (i = 0; i < devi->npins; i++)
321 		devi->pins[i] = pins[i].pin;
322 	free(pins, M_DEVBUF);
323 	/* Parse the interrupt resources. */
324 	if (ofw_bus_intr_to_rl(bus, node, &dinfo->opd_dinfo.rl, NULL) != 0) {
325 		ofw_gpiobus_destroy_devinfo(bus, dinfo);
326 		return (NULL);
327 	}
328 	device_set_ivars(child, dinfo);
329 
330 	return (dinfo);
331 }
332 
333 static void
ofw_gpiobus_destroy_devinfo(device_t bus,struct ofw_gpiobus_devinfo * dinfo)334 ofw_gpiobus_destroy_devinfo(device_t bus, struct ofw_gpiobus_devinfo *dinfo)
335 {
336 	int i;
337 	struct gpiobus_ivar *devi;
338 	struct gpiobus_softc *sc;
339 
340 	sc = device_get_softc(bus);
341 	devi = &dinfo->opd_dinfo;
342 	for (i = 0; i < devi->npins; i++) {
343 		if (devi->pins[i] > sc->sc_npins)
344 			continue;
345 		sc->sc_pins[devi->pins[i]].mapped = 0;
346 	}
347 	gpiobus_free_ivars(devi);
348 	resource_list_free(&dinfo->opd_dinfo.rl);
349 	ofw_bus_gen_destroy_devinfo(&dinfo->opd_obdinfo);
350 	free(dinfo, M_DEVBUF);
351 }
352 
353 static int
ofw_gpiobus_parse_gpios_impl(device_t consumer,phandle_t cnode,char * pname,struct gpiobus_softc * bussc,struct gpiobus_pin ** pins)354 ofw_gpiobus_parse_gpios_impl(device_t consumer, phandle_t cnode, char *pname,
355 	struct gpiobus_softc *bussc, struct gpiobus_pin **pins)
356 {
357 	int gpiocells, i, j, ncells, npins;
358 	pcell_t *gpios;
359 	phandle_t gpio;
360 
361 	ncells = OF_getencprop_alloc(cnode, pname, sizeof(*gpios),
362             (void **)&gpios);
363 	if (ncells == -1) {
364 		device_printf(consumer,
365 		    "Warning: No %s specified in fdt data; "
366 		    "device may not function.\n", pname);
367 		return (-1);
368 	}
369 	/*
370 	 * The gpio-specifier is controller independent, the first pcell has
371 	 * the reference to the GPIO controller phandler.
372 	 * Count the number of encoded gpio-specifiers on the first pass.
373 	 */
374 	i = 0;
375 	npins = 0;
376 	while (i < ncells) {
377 		/* Allow NULL specifiers. */
378 		if (gpios[i] == 0) {
379 			npins++;
380 			i++;
381 			continue;
382 		}
383 		gpio = OF_node_from_xref(gpios[i]);
384 		/* If we have bussc, ignore devices from other gpios. */
385 		if (bussc != NULL)
386 			if (ofw_bus_get_node(bussc->sc_dev) != gpio)
387 				return (0);
388 		/*
389 		 * Check for gpio-controller property and read the #gpio-cells
390 		 * for this GPIO controller.
391 		 */
392 		if (!OF_hasprop(gpio, "gpio-controller") ||
393 		    OF_getencprop(gpio, "#gpio-cells", &gpiocells,
394 		    sizeof(gpiocells)) < 0) {
395 			device_printf(consumer,
396 			    "gpio reference is not a gpio-controller.\n");
397 			OF_prop_free(gpios);
398 			return (-1);
399 		}
400 		if (ncells - i < gpiocells + 1) {
401 			device_printf(consumer,
402 			    "%s cells doesn't match #gpio-cells.\n", pname);
403 			return (-1);
404 		}
405 		npins++;
406 		i += gpiocells + 1;
407 	}
408 	if (npins == 0 || pins == NULL) {
409 		if (npins == 0)
410 			device_printf(consumer, "no pin specified in %s.\n",
411 			    pname);
412 		OF_prop_free(gpios);
413 		return (npins);
414 	}
415 	*pins = malloc(sizeof(struct gpiobus_pin) * npins, M_DEVBUF,
416 	    M_NOWAIT | M_ZERO);
417 	if (*pins == NULL) {
418 		OF_prop_free(gpios);
419 		return (-1);
420 	}
421 	/* Decode the gpio specifier on the second pass. */
422 	i = 0;
423 	j = 0;
424 	while (i < ncells) {
425 		/* Allow NULL specifiers. */
426 		if (gpios[i] == 0) {
427 			j++;
428 			i++;
429 			continue;
430 		}
431 		gpio = OF_node_from_xref(gpios[i]);
432 		/* Read gpio-cells property for this GPIO controller. */
433 		if (OF_getencprop(gpio, "#gpio-cells", &gpiocells,
434 		    sizeof(gpiocells)) < 0) {
435 			device_printf(consumer,
436 			    "gpio does not have the #gpio-cells property.\n");
437 			goto fail;
438 		}
439 		/* Return the device reference for the GPIO controller. */
440 		(*pins)[j].dev = OF_device_from_xref(gpios[i]);
441 		if ((*pins)[j].dev == NULL) {
442 			device_printf(consumer,
443 			    "no device registered for the gpio controller.\n");
444 			goto fail;
445 		}
446 		/*
447 		 * If the gpiobus softc is NULL we use the GPIO_GET_BUS() to
448 		 * retrieve it.  The GPIO_GET_BUS() method is only valid after
449 		 * the child is probed and attached.
450 		 */
451 		if (bussc == NULL) {
452 			if (GPIO_GET_BUS((*pins)[j].dev) == NULL) {
453 				device_printf(consumer,
454 				    "no gpiobus reference for %s.\n",
455 				    device_get_nameunit((*pins)[j].dev));
456 				goto fail;
457 			}
458 			bussc = device_get_softc(GPIO_GET_BUS((*pins)[j].dev));
459 		}
460 		/* Get the GPIO pin number and flags. */
461 		if (gpio_map_gpios((*pins)[j].dev, cnode, gpio, gpiocells,
462 		    &gpios[i + 1], &(*pins)[j].pin, &(*pins)[j].flags) != 0) {
463 			device_printf(consumer,
464 			    "cannot map the gpios specifier.\n");
465 			goto fail;
466 		}
467 		/* Reserve the GPIO pin. */
468 		if (gpiobus_acquire_pin(bussc->sc_busdev, (*pins)[j].pin) != 0)
469 			goto fail;
470 		j++;
471 		i += gpiocells + 1;
472 	}
473 	OF_prop_free(gpios);
474 
475 	return (npins);
476 
477 fail:
478 	OF_prop_free(gpios);
479 	free(*pins, M_DEVBUF);
480 	return (-1);
481 }
482 
483 static int
ofw_gpiobus_probe(device_t dev)484 ofw_gpiobus_probe(device_t dev)
485 {
486 
487 	if (ofw_bus_get_node(dev) == -1)
488 		return (ENXIO);
489 	device_set_desc(dev, "OFW GPIO bus");
490 
491 	return (0);
492 }
493 
494 static int
ofw_gpiobus_attach(device_t dev)495 ofw_gpiobus_attach(device_t dev)
496 {
497 	int err;
498 	phandle_t child;
499 
500 	err = gpiobus_init_softc(dev);
501 	if (err != 0)
502 		return (err);
503 	bus_generic_probe(dev);
504 	bus_enumerate_hinted_children(dev);
505 	/*
506 	 * Attach the children represented in the device tree.
507 	 */
508 	for (child = OF_child(ofw_bus_get_node(dev)); child != 0;
509 	    child = OF_peer(child)) {
510 		if (!OF_hasprop(child, "gpios"))
511 			continue;
512 		if (ofw_gpiobus_add_fdt_child(dev, NULL, child) == NULL)
513 			continue;
514 	}
515 
516 	return (bus_generic_attach(dev));
517 }
518 
519 static device_t
ofw_gpiobus_add_child(device_t dev,u_int order,const char * name,int unit)520 ofw_gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
521 {
522 	device_t child;
523 	struct ofw_gpiobus_devinfo *devi;
524 
525 	child = device_add_child_ordered(dev, order, name, unit);
526 	if (child == NULL)
527 		return (child);
528 	devi = malloc(sizeof(struct ofw_gpiobus_devinfo), M_DEVBUF,
529 	    M_NOWAIT | M_ZERO);
530 	if (devi == NULL) {
531 		device_delete_child(dev, child);
532 		return (0);
533 	}
534 
535 	/*
536 	 * NULL all the OFW-related parts of the ivars for non-OFW
537 	 * children.
538 	 */
539 	devi->opd_obdinfo.obd_node = -1;
540 	devi->opd_obdinfo.obd_name = NULL;
541 	devi->opd_obdinfo.obd_compat = NULL;
542 	devi->opd_obdinfo.obd_type = NULL;
543 	devi->opd_obdinfo.obd_model = NULL;
544 
545 	device_set_ivars(child, devi);
546 
547 	return (child);
548 }
549 
550 static const struct ofw_bus_devinfo *
ofw_gpiobus_get_devinfo(device_t bus,device_t dev)551 ofw_gpiobus_get_devinfo(device_t bus, device_t dev)
552 {
553 	struct ofw_gpiobus_devinfo *dinfo;
554 
555 	dinfo = device_get_ivars(dev);
556 
557 	return (&dinfo->opd_obdinfo);
558 }
559 
560 static device_method_t ofw_gpiobus_methods[] = {
561 	/* Device interface */
562 	DEVMETHOD(device_probe,		ofw_gpiobus_probe),
563 	DEVMETHOD(device_attach,	ofw_gpiobus_attach),
564 
565 	/* Bus interface */
566 	DEVMETHOD(bus_child_pnpinfo_str,	ofw_bus_gen_child_pnpinfo_str),
567 	DEVMETHOD(bus_add_child,	ofw_gpiobus_add_child),
568 
569 	/* ofw_bus interface */
570 	DEVMETHOD(ofw_bus_get_devinfo,	ofw_gpiobus_get_devinfo),
571 	DEVMETHOD(ofw_bus_get_compat,	ofw_bus_gen_get_compat),
572 	DEVMETHOD(ofw_bus_get_model,	ofw_bus_gen_get_model),
573 	DEVMETHOD(ofw_bus_get_name,	ofw_bus_gen_get_name),
574 	DEVMETHOD(ofw_bus_get_node,	ofw_bus_gen_get_node),
575 	DEVMETHOD(ofw_bus_get_type,	ofw_bus_gen_get_type),
576 
577 	DEVMETHOD_END
578 };
579 
580 devclass_t ofwgpiobus_devclass;
581 
582 DEFINE_CLASS_1(gpiobus, ofw_gpiobus_driver, ofw_gpiobus_methods,
583     sizeof(struct gpiobus_softc), gpiobus_driver);
584 EARLY_DRIVER_MODULE(ofw_gpiobus, gpio, ofw_gpiobus_driver, ofwgpiobus_devclass,
585     0, 0, BUS_PASS_BUS);
586 MODULE_VERSION(ofw_gpiobus, 1);
587 MODULE_DEPEND(ofw_gpiobus, gpiobus, 1, 1, 1);
588