Add GPIO backlight driver compatible with Linux FDT bindings.
Brightness is controlled through sysctl dev.gpiobacklight.X.brightness:
- any value greater than 0: backlight is on
- any value less than or equal to 0: backlight is off
FDT bindings docs in Linux tree:
Documentation/devicetree/bindings/video/backlight/gpio-backlight.txt
This commit is contained in:
Oleksandr Tymoshenko
parent
bc81f73771
commit
40ebf1626f
@ -1436,6 +1436,7 @@ dev/fxp/inphy.c optional fxp
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dev/gem/if_gem.c optional gem
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dev/gem/if_gem_pci.c optional gem pci
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dev/gem/if_gem_sbus.c optional gem sbus
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dev/gpio/gpiobacklight.c optional gpiobacklight fdt
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dev/gpio/gpiobus.c optional gpio \
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dependency "gpiobus_if.h"
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dev/gpio/gpioc.c optional gpio \
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211
sys/dev/gpio/gpiobacklight.c
Normal file
211
sys/dev/gpio/gpiobacklight.c
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@ -0,0 +1,211 @@
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/*-
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* Copyright (c) 2015 Oleksandr Tymoshenko <gonzo@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_platform.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bus.h>
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#include <sys/gpio.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#include <sys/sysctl.h>
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#include <dev/fdt/fdt_common.h>
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#include <dev/ofw/ofw_bus.h>
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#include <dev/gpio/gpiobusvar.h>
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#include "gpiobus_if.h"
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/*
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* Only one pin for led
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*/
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#define GPIOBL_PIN 0
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#define GPIOBL_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
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#define GPIOBL_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
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#define GPIOBL_LOCK_INIT(_sc) \
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mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
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"gpiobacklight", MTX_DEF)
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#define GPIOBL_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx);
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struct gpiobacklight_softc
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{
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device_t sc_dev;
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device_t sc_busdev;
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struct mtx sc_mtx;
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struct sysctl_oid *sc_oid;
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int sc_brightness;
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};
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static int gpiobacklight_sysctl(SYSCTL_HANDLER_ARGS);
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static void gpiobacklight_update_brightness(struct gpiobacklight_softc *);
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static int gpiobacklight_probe(device_t);
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static int gpiobacklight_attach(device_t);
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static int gpiobacklight_detach(device_t);
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static void
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gpiobacklight_update_brightness(struct gpiobacklight_softc *sc)
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{
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int error;
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GPIOBL_LOCK(sc);
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error = GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev,
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GPIOBUS_DONTWAIT);
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if (error != 0) {
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GPIOBL_UNLOCK(sc);
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return;
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}
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error = GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev,
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GPIOBL_PIN, GPIO_PIN_OUTPUT);
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if (error == 0)
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GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, GPIOBL_PIN,
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sc->sc_brightness ? GPIO_PIN_HIGH : GPIO_PIN_LOW);
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GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev);
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GPIOBL_UNLOCK(sc);
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}
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static int
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gpiobacklight_sysctl(SYSCTL_HANDLER_ARGS)
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{
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struct gpiobacklight_softc *sc;
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int error;
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int brightness;
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sc = (struct gpiobacklight_softc*)arg1;
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brightness = sc->sc_brightness;
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error = sysctl_handle_int(oidp, &brightness, 0, req);
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if (error != 0 || req->newptr == NULL)
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return (error);
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if (brightness <= 0)
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sc->sc_brightness = 0;
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else
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sc->sc_brightness = 1;
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gpiobacklight_update_brightness(sc);
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return (error);
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}
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static void
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gpiobacklight_identify(driver_t *driver, device_t bus)
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{
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phandle_t node, root;
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root = OF_finddevice("/");
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if (root == 0)
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return;
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for (node = OF_child(root); node != 0; node = OF_peer(node)) {
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if (!fdt_is_compatible_strict(node, "gpio-backlight"))
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continue;
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ofw_gpiobus_add_fdt_child(bus, driver->name, node);
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}
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}
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static int
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gpiobacklight_probe(device_t dev)
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{
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if (!ofw_bus_is_compatible(dev, "gpio-backlight"))
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return (ENXIO);
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device_set_desc(dev, "GPIO backlight");
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return (0);
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}
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static int
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gpiobacklight_attach(device_t dev)
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{
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struct gpiobacklight_softc *sc;
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struct sysctl_ctx_list *ctx;
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struct sysctl_oid *tree;
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phandle_t node;
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sc = device_get_softc(dev);
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sc->sc_dev = dev;
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sc->sc_busdev = device_get_parent(dev);
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if ((node = ofw_bus_get_node(dev)) == -1)
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return (ENXIO);
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GPIOBL_LOCK_INIT(sc);
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if (OF_hasprop(node, "default-on"))
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sc->sc_brightness = 1;
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else
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sc->sc_brightness = 0;
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/* Init backlight interface */
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ctx = device_get_sysctl_ctx(sc->sc_dev);
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tree = device_get_sysctl_tree(sc->sc_dev);
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sc->sc_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
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"brightness", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
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gpiobacklight_sysctl, "I", "backlight brightness");
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gpiobacklight_update_brightness(sc);
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return (0);
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}
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static int
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gpiobacklight_detach(device_t dev)
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{
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struct gpiobacklight_softc *sc;
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sc = device_get_softc(dev);
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GPIOBL_LOCK_DESTROY(sc);
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return (0);
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}
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static devclass_t gpiobacklight_devclass;
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static device_method_t gpiobacklight_methods[] = {
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/* Device interface */
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DEVMETHOD(device_identify, gpiobacklight_identify),
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DEVMETHOD(device_probe, gpiobacklight_probe),
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DEVMETHOD(device_attach, gpiobacklight_attach),
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DEVMETHOD(device_detach, gpiobacklight_detach),
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DEVMETHOD_END
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};
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static driver_t gpiobacklight_driver = {
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"gpiobacklight",
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gpiobacklight_methods,
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sizeof(struct gpiobacklight_softc),
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};
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DRIVER_MODULE(gpiobacklight, gpiobus, gpiobacklight_driver, gpiobacklight_devclass, 0, 0);
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