freebsd-dev/sys/dev/gpio/gpiobacklight.c

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/*-
* Copyright (c) 2015-2016 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 "opt_platform.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/gpio/gpiobusvar.h>
struct gpiobacklight_softc
{
gpio_pin_t sc_pin;
struct sysctl_oid *sc_oid;
bool sc_brightness;
};
static int gpiobacklight_sysctl(SYSCTL_HANDLER_ARGS);
static void gpiobacklight_update_brightness(struct gpiobacklight_softc *);
static int gpiobacklight_probe(device_t);
static int gpiobacklight_attach(device_t);
static int gpiobacklight_detach(device_t);
static void
gpiobacklight_update_brightness(struct gpiobacklight_softc *sc)
{
if (sc->sc_pin)
gpio_pin_set_active(sc->sc_pin, sc->sc_brightness);
}
static int
gpiobacklight_sysctl(SYSCTL_HANDLER_ARGS)
{
struct gpiobacklight_softc *sc;
int error;
int brightness;
sc = (struct gpiobacklight_softc*)arg1;
brightness = sc->sc_brightness;
error = sysctl_handle_int(oidp, &brightness, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
sc->sc_brightness = (brightness > 0);
gpiobacklight_update_brightness(sc);
return (0);
}
static int
gpiobacklight_probe(device_t dev)
{
if (!ofw_bus_is_compatible(dev, "gpio-backlight"))
return (ENXIO);
device_set_desc(dev, "GPIO backlight");
return (0);
}
static int
gpiobacklight_attach(device_t dev)
{
struct gpiobacklight_softc *sc;
struct sysctl_ctx_list *ctx;
struct sysctl_oid *tree;
phandle_t node;
sc = device_get_softc(dev);
if ((node = ofw_bus_get_node(dev)) == -1)
return (ENXIO);
if (OF_hasprop(node, "default-on"))
sc->sc_brightness = true;
else
sc->sc_brightness = false;
gpio_pin_get_by_ofw_idx(dev, node, 0, &sc->sc_pin);
if (sc->sc_pin == NULL) {
device_printf(dev, "failed to map GPIO pin\n");
return (ENXIO);
}
gpio_pin_setflags(sc->sc_pin, GPIO_PIN_OUTPUT);
gpiobacklight_update_brightness(sc);
/* Init backlight interface */
ctx = device_get_sysctl_ctx(dev);
tree = device_get_sysctl_tree(dev);
sc->sc_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"brightness", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
gpiobacklight_sysctl, "I", "backlight brightness");
return (0);
}
static int
gpiobacklight_detach(device_t dev)
{
struct gpiobacklight_softc *sc;
sc = device_get_softc(dev);
if (sc->sc_pin)
gpio_pin_release(sc->sc_pin);
return (0);
}
static devclass_t gpiobacklight_devclass;
static device_method_t gpiobacklight_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, gpiobacklight_probe),
DEVMETHOD(device_attach, gpiobacklight_attach),
DEVMETHOD(device_detach, gpiobacklight_detach),
DEVMETHOD_END
};
static driver_t gpiobacklight_driver = {
"gpiobacklight",
gpiobacklight_methods,
sizeof(struct gpiobacklight_softc),
};
DRIVER_MODULE(gpiobacklight, simplebus, gpiobacklight_driver,
gpiobacklight_devclass, 0, 0);
MODULE_DEPEND(gpiobacklight, gpiobus, 1, 1, 1);