freebsd-dev/sys/dev/gpio/gpioled.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/bio.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>

#include <dev/led/led.h>
#include <sys/gpio.h>
#include "gpiobus_if.h"

/*
 * Only one pin for led
 */
#define	GPIOLED_PIN	0

#define GPIOLED_LOCK(_sc)		mtx_lock(&(_sc)->sc_mtx)
#define	GPIOLED_UNLOCK(_sc)		mtx_unlock(&(_sc)->sc_mtx)
#define GPIOLED_LOCK_INIT(_sc) \
	mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
	    "gpioled", MTX_DEF)
#define GPIOLED_LOCK_DESTROY(_sc)	mtx_destroy(&_sc->sc_mtx);

struct gpioled_softc 
{
	device_t	sc_dev;
	device_t	sc_busdev;
	struct mtx	sc_mtx;
	struct cdev	*sc_leddev;
};

static void gpioled_control(void *, int);
static int gpioled_probe(device_t);
static int gpioled_attach(device_t);
static int gpioled_detach(device_t);

static void 
gpioled_control(void *priv, int onoff)
{
	struct gpioled_softc *sc = priv;
	GPIOLED_LOCK(sc);
	GPIOBUS_LOCK_BUS(sc->sc_busdev);
	GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev);
	GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, GPIOLED_PIN, 
	    onoff ? GPIO_PIN_HIGH : GPIO_PIN_LOW);
	GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev);
	GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
	GPIOLED_UNLOCK(sc);
}

static int
gpioled_probe(device_t dev)
{
	device_set_desc(dev, "GPIO led");
	return (0);
}

static int
gpioled_attach(device_t dev)
{
	struct gpioled_softc *sc;
	const char *name;

	sc = device_get_softc(dev);
	sc->sc_dev = dev;
	sc->sc_busdev = device_get_parent(dev);
	GPIOLED_LOCK_INIT(sc);
	if (resource_string_value(device_get_name(dev), 
	    device_get_unit(dev), "name", &name))
		name = NULL;

	GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, GPIOLED_PIN,
	    GPIO_PIN_OUTPUT);

	sc->sc_leddev = led_create(gpioled_control, sc, name ? name :
	    device_get_nameunit(dev));

	return (0);
}

static int
gpioled_detach(device_t dev)
{
	struct gpioled_softc *sc;

	sc = device_get_softc(dev);
	if (sc->sc_leddev) {
		led_destroy(sc->sc_leddev);
		sc->sc_leddev = NULL;
	}
	GPIOLED_LOCK_DESTROY(sc);
	return (0);
}

static devclass_t gpioled_devclass;

static device_method_t gpioled_methods[] = {
	/* Device interface */
	DEVMETHOD(device_probe,		gpioled_probe),
	DEVMETHOD(device_attach,	gpioled_attach),
	DEVMETHOD(device_detach,	gpioled_detach),

	{ 0, 0 }
};

static driver_t gpioled_driver = {
	"gpioled",
	gpioled_methods,
	sizeof(struct gpioled_softc),
};

DRIVER_MODULE(gpioled, gpiobus, gpioled_driver, gpioled_devclass, 0, 0);