freebsd-skq/sys/dev/gpio/gpiobus.c
loos 04b6b93c32 Add a new ioctl to allow the setting of GPIO pin names.
When a gpiobus child is added, use its name to identify the mapped pin
names.

Make the respective changes to libgpio.

Add a new '-n' flag to gpioctl(8) to set the pin name.

Differential Revision:	https://reviews.freebsd.org/D2002
Reviewed by:	rpaulo
Requested by:	many
2015-03-08 00:47:50 +00:00

762 lines
19 KiB
C

/*-
* Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <dev/gpio/gpiobusvar.h>
#include "gpiobus_if.h"
#undef GPIOBUS_DEBUG
#ifdef GPIOBUS_DEBUG
#define dprintf printf
#else
#define dprintf(x, arg...)
#endif
static void gpiobus_print_pins(struct gpiobus_ivar *, char *, size_t);
static int gpiobus_parse_pins(struct gpiobus_softc *, device_t, int);
static int gpiobus_probe(device_t);
static int gpiobus_attach(device_t);
static int gpiobus_detach(device_t);
static int gpiobus_suspend(device_t);
static int gpiobus_resume(device_t);
static void gpiobus_probe_nomatch(device_t, device_t);
static int gpiobus_print_child(device_t, device_t);
static int gpiobus_child_location_str(device_t, device_t, char *, size_t);
static int gpiobus_child_pnpinfo_str(device_t, device_t, char *, size_t);
static device_t gpiobus_add_child(device_t, u_int, const char *, int);
static void gpiobus_hinted_child(device_t, const char *, int);
/*
* GPIOBUS interface
*/
static int gpiobus_acquire_bus(device_t, device_t, int);
static void gpiobus_release_bus(device_t, device_t);
static int gpiobus_pin_setflags(device_t, device_t, uint32_t, uint32_t);
static int gpiobus_pin_getflags(device_t, device_t, uint32_t, uint32_t*);
static int gpiobus_pin_getcaps(device_t, device_t, uint32_t, uint32_t*);
static int gpiobus_pin_set(device_t, device_t, uint32_t, unsigned int);
static int gpiobus_pin_get(device_t, device_t, uint32_t, unsigned int*);
static int gpiobus_pin_toggle(device_t, device_t, uint32_t);
int
gpio_check_flags(uint32_t caps, uint32_t flags)
{
/* Check for unwanted flags. */
if ((flags & caps) == 0 || (flags & caps) != flags)
return (EINVAL);
/* Cannot mix input/output together. */
if (flags & GPIO_PIN_INPUT && flags & GPIO_PIN_OUTPUT)
return (EINVAL);
/* Cannot mix pull-up/pull-down together. */
if (flags & GPIO_PIN_PULLUP && flags & GPIO_PIN_PULLDOWN)
return (EINVAL);
return (0);
}
static void
gpiobus_print_pins(struct gpiobus_ivar *devi, char *buf, size_t buflen)
{
char tmp[128];
int i, range_start, range_stop, need_coma;
if (devi->npins == 0)
return;
need_coma = 0;
range_start = range_stop = devi->pins[0];
for (i = 1; i < devi->npins; i++) {
if (devi->pins[i] != (range_stop + 1)) {
if (need_coma)
strlcat(buf, ",", buflen);
memset(tmp, 0, sizeof(tmp));
if (range_start != range_stop)
snprintf(tmp, sizeof(tmp) - 1, "%d-%d",
range_start, range_stop);
else
snprintf(tmp, sizeof(tmp) - 1, "%d",
range_start);
strlcat(buf, tmp, buflen);
range_start = range_stop = devi->pins[i];
need_coma = 1;
}
else
range_stop++;
}
if (need_coma)
strlcat(buf, ",", buflen);
memset(tmp, 0, sizeof(tmp));
if (range_start != range_stop)
snprintf(tmp, sizeof(tmp) - 1, "%d-%d",
range_start, range_stop);
else
snprintf(tmp, sizeof(tmp) - 1, "%d",
range_start);
strlcat(buf, tmp, buflen);
}
device_t
gpiobus_attach_bus(device_t dev)
{
device_t busdev;
busdev = device_add_child(dev, "gpiobus", -1);
if (busdev == NULL)
return (NULL);
if (device_add_child(dev, "gpioc", -1) == NULL) {
device_delete_child(dev, busdev);
return (NULL);
}
#ifdef FDT
ofw_gpiobus_register_provider(dev);
#endif
bus_generic_attach(dev);
return (busdev);
}
int
gpiobus_detach_bus(device_t dev)
{
#ifdef FDT
ofw_gpiobus_unregister_provider(dev);
#endif
return (bus_generic_detach(dev));
}
int
gpiobus_init_softc(device_t dev)
{
struct gpiobus_softc *sc;
sc = GPIOBUS_SOFTC(dev);
sc->sc_busdev = dev;
sc->sc_dev = device_get_parent(dev);
sc->sc_intr_rman.rm_type = RMAN_ARRAY;
sc->sc_intr_rman.rm_descr = "GPIO Interrupts";
if (rman_init(&sc->sc_intr_rman) != 0 ||
rman_manage_region(&sc->sc_intr_rman, 0, ~0) != 0)
panic("%s: failed to set up rman.", __func__);
if (GPIO_PIN_MAX(sc->sc_dev, &sc->sc_npins) != 0)
return (ENXIO);
KASSERT(sc->sc_npins != 0, ("GPIO device with no pins"));
/* Pins = GPIO_PIN_MAX() + 1 */
sc->sc_npins++;
sc->sc_pins = malloc(sizeof(*sc->sc_pins) * sc->sc_npins, M_DEVBUF,
M_NOWAIT | M_ZERO);
if (sc->sc_pins == NULL)
return (ENOMEM);
/* Initialize the bus lock. */
GPIOBUS_LOCK_INIT(sc);
return (0);
}
int
gpiobus_alloc_ivars(struct gpiobus_ivar *devi)
{
/* Allocate pins and flags memory. */
devi->pins = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
M_NOWAIT | M_ZERO);
if (devi->pins == NULL)
return (ENOMEM);
devi->flags = malloc(sizeof(uint32_t) * devi->npins, M_DEVBUF,
M_NOWAIT | M_ZERO);
if (devi->flags == NULL) {
free(devi->pins, M_DEVBUF);
return (ENOMEM);
}
return (0);
}
void
gpiobus_free_ivars(struct gpiobus_ivar *devi)
{
if (devi->flags) {
free(devi->flags, M_DEVBUF);
devi->flags = NULL;
}
if (devi->pins) {
free(devi->pins, M_DEVBUF);
devi->pins = NULL;
}
}
int
gpiobus_map_pin(device_t bus, uint32_t pin)
{
struct gpiobus_softc *sc;
sc = device_get_softc(bus);
/* Consistency check. */
if (pin >= sc->sc_npins) {
device_printf(bus,
"invalid pin %d, max: %d\n", pin, sc->sc_npins - 1);
return (-1);
}
/* Mark pin as mapped and give warning if it's already mapped. */
if (sc->sc_pins[pin].mapped) {
device_printf(bus, "warning: pin %d is already mapped\n", pin);
return (-1);
}
sc->sc_pins[pin].mapped = 1;
return (0);
}
static int
gpiobus_parse_pins(struct gpiobus_softc *sc, device_t child, int mask)
{
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
int i, npins;
npins = 0;
for (i = 0; i < 32; i++) {
if (mask & (1 << i))
npins++;
}
if (npins == 0) {
device_printf(child, "empty pin mask\n");
return (EINVAL);
}
devi->npins = npins;
if (gpiobus_alloc_ivars(devi) != 0) {
device_printf(child, "cannot allocate device ivars\n");
return (EINVAL);
}
npins = 0;
for (i = 0; i < 32; i++) {
if ((mask & (1 << i)) == 0)
continue;
/* Reserve the GPIO pin. */
if (gpiobus_map_pin(sc->sc_busdev, i) != 0) {
gpiobus_free_ivars(devi);
return (EINVAL);
}
devi->pins[npins++] = i;
/* Use the child name as pin name. */
GPIOBUS_PIN_SETNAME(sc->sc_busdev, i,
device_get_nameunit(child));
}
return (0);
}
static int
gpiobus_probe(device_t dev)
{
device_set_desc(dev, "GPIO bus");
return (BUS_PROBE_GENERIC);
}
static int
gpiobus_attach(device_t dev)
{
int err;
err = gpiobus_init_softc(dev);
if (err != 0)
return (err);
/*
* Get parent's pins and mark them as unmapped
*/
bus_generic_probe(dev);
bus_enumerate_hinted_children(dev);
return (bus_generic_attach(dev));
}
/*
* Since this is not a self-enumerating bus, and since we always add
* children in attach, we have to always delete children here.
*/
static int
gpiobus_detach(device_t dev)
{
struct gpiobus_softc *sc;
struct gpiobus_ivar *devi;
device_t *devlist;
int i, err, ndevs;
sc = GPIOBUS_SOFTC(dev);
KASSERT(mtx_initialized(&sc->sc_mtx),
("gpiobus mutex not initialized"));
GPIOBUS_LOCK_DESTROY(sc);
if ((err = bus_generic_detach(dev)) != 0)
return (err);
if ((err = device_get_children(dev, &devlist, &ndevs)) != 0)
return (err);
for (i = 0; i < ndevs; i++) {
device_delete_child(dev, devlist[i]);
devi = GPIOBUS_IVAR(devlist[i]);
gpiobus_free_ivars(devi);
}
free(devlist, M_TEMP);
if (sc->sc_pins) {
for (i = 0; i < sc->sc_npins; i++) {
if (sc->sc_pins[i].name != NULL)
free(sc->sc_pins[i].name, M_DEVBUF);
sc->sc_pins[i].name = NULL;
}
free(sc->sc_pins, M_DEVBUF);
sc->sc_pins = NULL;
}
return (0);
}
static int
gpiobus_suspend(device_t dev)
{
return (bus_generic_suspend(dev));
}
static int
gpiobus_resume(device_t dev)
{
return (bus_generic_resume(dev));
}
static void
gpiobus_probe_nomatch(device_t dev, device_t child)
{
char pins[128];
struct gpiobus_ivar *devi;
devi = GPIOBUS_IVAR(child);
memset(pins, 0, sizeof(pins));
gpiobus_print_pins(devi, pins, sizeof(pins));
device_printf(dev, "<unknown device> at pin(s) %s", pins);
resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%ld");
printf("\n");
}
static int
gpiobus_print_child(device_t dev, device_t child)
{
char pins[128];
int retval = 0;
struct gpiobus_ivar *devi;
devi = GPIOBUS_IVAR(child);
memset(pins, 0, sizeof(pins));
retval += bus_print_child_header(dev, child);
retval += printf(" at pin(s) ");
gpiobus_print_pins(devi, pins, sizeof(pins));
retval += printf("%s", pins);
resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%ld");
retval += bus_print_child_footer(dev, child);
return (retval);
}
static int
gpiobus_child_location_str(device_t bus, device_t child, char *buf,
size_t buflen)
{
struct gpiobus_ivar *devi;
devi = GPIOBUS_IVAR(child);
strlcpy(buf, "pin(s)=", buflen);
gpiobus_print_pins(devi, buf, buflen);
return (0);
}
static int
gpiobus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
size_t buflen)
{
*buf = '\0';
return (0);
}
static device_t
gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
{
device_t child;
struct gpiobus_ivar *devi;
child = device_add_child_ordered(dev, order, name, unit);
if (child == NULL)
return (child);
devi = malloc(sizeof(struct gpiobus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
if (devi == NULL) {
device_delete_child(dev, child);
return (0);
}
resource_list_init(&devi->rl);
device_set_ivars(child, devi);
return (child);
}
static void
gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
{
struct gpiobus_softc *sc = GPIOBUS_SOFTC(bus);
struct gpiobus_ivar *devi;
device_t child;
int irq, pins;
child = BUS_ADD_CHILD(bus, 0, dname, dunit);
devi = GPIOBUS_IVAR(child);
resource_int_value(dname, dunit, "pins", &pins);
if (gpiobus_parse_pins(sc, child, pins))
device_delete_child(bus, child);
if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
device_printf(bus,
"warning: bus_set_resource() failed\n");
}
}
static int
gpiobus_set_resource(device_t dev, device_t child, int type, int rid,
u_long start, u_long count)
{
struct gpiobus_ivar *devi;
struct resource_list_entry *rle;
dprintf("%s: entry (%p, %p, %d, %d, %p, %ld)\n",
__func__, dev, child, type, rid, (void *)(intptr_t)start, count);
devi = GPIOBUS_IVAR(child);
rle = resource_list_add(&devi->rl, type, rid, start,
start + count - 1, count);
if (rle == NULL)
return (ENXIO);
return (0);
}
static struct resource *
gpiobus_alloc_resource(device_t bus, device_t child, int type, int *rid,
u_long start, u_long end, u_long count, u_int flags)
{
struct gpiobus_softc *sc;
struct resource *rv;
struct resource_list *rl;
struct resource_list_entry *rle;
int isdefault;
if (type != SYS_RES_IRQ)
return (NULL);
isdefault = (start == 0UL && end == ~0UL && count == 1);
rle = NULL;
if (isdefault) {
rl = BUS_GET_RESOURCE_LIST(bus, child);
if (rl == NULL)
return (NULL);
rle = resource_list_find(rl, type, *rid);
if (rle == NULL)
return (NULL);
if (rle->res != NULL)
panic("%s: resource entry is busy", __func__);
start = rle->start;
count = rle->count;
end = rle->end;
}
sc = device_get_softc(bus);
rv = rman_reserve_resource(&sc->sc_intr_rman, start, end, count, flags,
child);
if (rv == NULL)
return (NULL);
rman_set_rid(rv, *rid);
if ((flags & RF_ACTIVE) != 0 &&
bus_activate_resource(child, type, *rid, rv) != 0) {
rman_release_resource(rv);
return (NULL);
}
return (rv);
}
static int
gpiobus_release_resource(device_t bus __unused, device_t child, int type,
int rid, struct resource *r)
{
int error;
if (rman_get_flags(r) & RF_ACTIVE) {
error = bus_deactivate_resource(child, type, rid, r);
if (error)
return (error);
}
return (rman_release_resource(r));
}
static struct resource_list *
gpiobus_get_resource_list(device_t bus __unused, device_t child)
{
struct gpiobus_ivar *ivar;
ivar = GPIOBUS_IVAR(child);
return (&ivar->rl);
}
static int
gpiobus_acquire_bus(device_t busdev, device_t child, int how)
{
struct gpiobus_softc *sc;
sc = device_get_softc(busdev);
GPIOBUS_ASSERT_UNLOCKED(sc);
GPIOBUS_LOCK(sc);
if (sc->sc_owner != NULL) {
if (how == GPIOBUS_DONTWAIT) {
GPIOBUS_UNLOCK(sc);
return (EWOULDBLOCK);
}
while (sc->sc_owner != NULL)
mtx_sleep(sc, &sc->sc_mtx, 0, "gpiobuswait", 0);
}
sc->sc_owner = child;
GPIOBUS_UNLOCK(sc);
return (0);
}
static void
gpiobus_release_bus(device_t busdev, device_t child)
{
struct gpiobus_softc *sc;
sc = device_get_softc(busdev);
GPIOBUS_ASSERT_UNLOCKED(sc);
GPIOBUS_LOCK(sc);
if (sc->sc_owner == NULL)
panic("gpiobus: releasing unowned bus.");
if (sc->sc_owner != child)
panic("gpiobus: you don't own the bus. game over.");
sc->sc_owner = NULL;
wakeup(sc);
GPIOBUS_UNLOCK(sc);
}
static int
gpiobus_pin_setflags(device_t dev, device_t child, uint32_t pin,
uint32_t flags)
{
struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
uint32_t caps;
if (pin >= devi->npins)
return (EINVAL);
if (GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], &caps) != 0)
return (EINVAL);
if (gpio_check_flags(caps, flags) != 0)
return (EINVAL);
return (GPIO_PIN_SETFLAGS(sc->sc_dev, devi->pins[pin], flags));
}
static int
gpiobus_pin_getflags(device_t dev, device_t child, uint32_t pin,
uint32_t *flags)
{
struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
if (pin >= devi->npins)
return (EINVAL);
return GPIO_PIN_GETFLAGS(sc->sc_dev, devi->pins[pin], flags);
}
static int
gpiobus_pin_getcaps(device_t dev, device_t child, uint32_t pin,
uint32_t *caps)
{
struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
if (pin >= devi->npins)
return (EINVAL);
return GPIO_PIN_GETCAPS(sc->sc_dev, devi->pins[pin], caps);
}
static int
gpiobus_pin_set(device_t dev, device_t child, uint32_t pin,
unsigned int value)
{
struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
if (pin >= devi->npins)
return (EINVAL);
return GPIO_PIN_SET(sc->sc_dev, devi->pins[pin], value);
}
static int
gpiobus_pin_get(device_t dev, device_t child, uint32_t pin,
unsigned int *value)
{
struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
if (pin >= devi->npins)
return (EINVAL);
return GPIO_PIN_GET(sc->sc_dev, devi->pins[pin], value);
}
static int
gpiobus_pin_toggle(device_t dev, device_t child, uint32_t pin)
{
struct gpiobus_softc *sc = GPIOBUS_SOFTC(dev);
struct gpiobus_ivar *devi = GPIOBUS_IVAR(child);
if (pin >= devi->npins)
return (EINVAL);
return GPIO_PIN_TOGGLE(sc->sc_dev, devi->pins[pin]);
}
static int
gpiobus_pin_getname(device_t dev, uint32_t pin, char *name)
{
struct gpiobus_softc *sc;
sc = GPIOBUS_SOFTC(dev);
if (pin > sc->sc_npins)
return (EINVAL);
/* Did we have a name for this pin ? */
if (sc->sc_pins[pin].name != NULL) {
memcpy(name, sc->sc_pins[pin].name, GPIOMAXNAME);
return (0);
}
/* Return the default pin name. */
return (GPIO_PIN_GETNAME(device_get_parent(dev), pin, name));
}
static int
gpiobus_pin_setname(device_t dev, uint32_t pin, const char *name)
{
struct gpiobus_softc *sc;
sc = GPIOBUS_SOFTC(dev);
if (pin > sc->sc_npins)
return (EINVAL);
if (name == NULL)
return (EINVAL);
/* Save the pin name. */
if (sc->sc_pins[pin].name == NULL)
sc->sc_pins[pin].name = malloc(GPIOMAXNAME, M_DEVBUF,
M_WAITOK | M_ZERO);
strlcpy(sc->sc_pins[pin].name, name, GPIOMAXNAME);
return (0);
}
static device_method_t gpiobus_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, gpiobus_probe),
DEVMETHOD(device_attach, gpiobus_attach),
DEVMETHOD(device_detach, gpiobus_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
DEVMETHOD(device_suspend, gpiobus_suspend),
DEVMETHOD(device_resume, gpiobus_resume),
/* Bus interface */
DEVMETHOD(bus_setup_intr, bus_generic_setup_intr),
DEVMETHOD(bus_config_intr, bus_generic_config_intr),
DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
DEVMETHOD(bus_set_resource, gpiobus_set_resource),
DEVMETHOD(bus_alloc_resource, gpiobus_alloc_resource),
DEVMETHOD(bus_release_resource, gpiobus_release_resource),
DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
DEVMETHOD(bus_get_resource_list, gpiobus_get_resource_list),
DEVMETHOD(bus_add_child, gpiobus_add_child),
DEVMETHOD(bus_probe_nomatch, gpiobus_probe_nomatch),
DEVMETHOD(bus_print_child, gpiobus_print_child),
DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),
DEVMETHOD(bus_child_location_str, gpiobus_child_location_str),
DEVMETHOD(bus_hinted_child, gpiobus_hinted_child),
/* GPIO protocol */
DEVMETHOD(gpiobus_acquire_bus, gpiobus_acquire_bus),
DEVMETHOD(gpiobus_release_bus, gpiobus_release_bus),
DEVMETHOD(gpiobus_pin_getflags, gpiobus_pin_getflags),
DEVMETHOD(gpiobus_pin_getcaps, gpiobus_pin_getcaps),
DEVMETHOD(gpiobus_pin_setflags, gpiobus_pin_setflags),
DEVMETHOD(gpiobus_pin_get, gpiobus_pin_get),
DEVMETHOD(gpiobus_pin_set, gpiobus_pin_set),
DEVMETHOD(gpiobus_pin_toggle, gpiobus_pin_toggle),
DEVMETHOD(gpiobus_pin_getname, gpiobus_pin_getname),
DEVMETHOD(gpiobus_pin_setname, gpiobus_pin_setname),
DEVMETHOD_END
};
driver_t gpiobus_driver = {
"gpiobus",
gpiobus_methods,
sizeof(struct gpiobus_softc)
};
devclass_t gpiobus_devclass;
DRIVER_MODULE(gpiobus, gpio, gpiobus_driver, gpiobus_devclass, 0, 0);
MODULE_VERSION(gpiobus, 1);