Add a GPIO poweroff and reset driver.

Summary:
This implements part of the gpio-poweroff and gpio-restart device tree
bindings.  Optional properties are not handled currently.  It also currently
only supports level-triggered reset.

Reviewed By: gonzo
Differential Revision: https://reviews.freebsd.org/D8521

sys/conf/files

@@ -1661,6 +1661,7 @@ dev/gpio/gpioc.c		optional gpio				\
 dev/gpio/gpioiic.c		optional gpioiic
 dev/gpio/gpioled.c		optional gpioled !fdt
 dev/gpio/gpioled_fdt.c		optional gpioled fdt
+dev/gpio/gpiopower.c		optional gpiopower fdt
 dev/gpio/gpioregulator.c	optional gpioregulator fdt ext_resources
 dev/gpio/gpiospi.c		optional gpiospi
 dev/gpio/gpio_if.m		optional gpio

sys/dev/gpio/gpiopower.c

@@ -0,0 +1,137 @@
+/*-
+ * Copyright (c) 2016 Justin Hibbits
+ * 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 ``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 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/eventhandler.h>
+#include <sys/gpio.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/reboot.h>
+
+#include <dev/ofw/ofw_bus.h>
+
+#include <dev/gpio/gpiobusvar.h>
+
+struct gpiopower_softc {
+	gpio_pin_t	sc_pin;
+	int		sc_rbmask;
+};
+
+static void gpiopower_assert(device_t dev, int howto);
+
+static int
+gpiopower_probe(device_t dev)
+{
+
+	if (ofw_bus_is_compatible(dev, "gpio-poweroff")) {
+		device_set_desc(dev, "GPIO poweroff control");
+		return (0);
+	} else if (ofw_bus_is_compatible(dev, "gpio-restart")) {
+		device_set_desc(dev, "GPIO restart control");
+		return (0);
+	}
+
+	return (ENXIO);
+}
+
+static int
+gpiopower_attach(device_t dev)
+{
+	struct gpiopower_softc *sc;
+	phandle_t node;
+
+	sc = device_get_softc(dev);
+
+	if ((node = ofw_bus_get_node(dev)) == -1)
+		return (ENXIO);
+
+	ofw_gpiobus_parse_gpios(dev, "gpios", &sc->sc_pin);
+	if (sc->sc_pin == NULL) {
+		device_printf(dev, "failed to map GPIO pin\n");
+		return (ENXIO);
+	}
+
+	if (ofw_bus_is_compatible(dev, "gpio-poweroff"))
+		sc->sc_rbmask = RB_HALT | RB_POWEROFF;
+	else
+		sc->sc_rbmask = 0;
+	EVENTHANDLER_REGISTER(shutdown_final, gpiopower_assert, dev,
+	    SHUTDOWN_PRI_LAST);
+	gpio_pin_setflags(sc->sc_pin, GPIO_PIN_OUTPUT);
+
+	return (0);
+}
+
+static void
+gpiopower_assert(device_t dev, int howto)
+{
+	struct gpiopower_softc *sc;
+	int do_assert;
+
+	sc = device_get_softc(dev);
+	do_assert = sc->sc_rbmask ? (sc->sc_rbmask & howto) :
+	    ((howto & RB_HALT) == 0);
+
+	if (!do_assert)
+		return;
+
+	if (howto & RB_POWEROFF)
+		device_printf(dev, "powering system off\n");
+	else if ((howto & RB_HALT) == 0)
+		device_printf(dev, "resetting system\n");
+	else
+		return;
+
+	gpio_pin_set_active(sc->sc_pin, true);
+
+	/* Wait a second for it to trip */
+	DELAY(10000000);
+}
+
+static devclass_t gpiopower_devclass;
+
+static device_method_t gpiopower_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_probe,		gpiopower_probe),
+	DEVMETHOD(device_attach,	gpiopower_attach),
+
+	DEVMETHOD_END
+};
+
+static driver_t gpiopower_driver = {
+	"gpiopower",
+	gpiopower_methods,
+	sizeof(struct gpiopower_softc)
+};
+
+DRIVER_MODULE(gpiopower, simplebus, gpiopower_driver, gpiopower_devclass, 0, 0);
+MODULE_DEPEND(gpiopower, gpiobus, 1, 1, 1);

sys/powerpc/conf/MPC85XX

@@ -75,6 +75,7 @@ device		alc
 device		ether
 device		fxp
 device  	gpio
+device  	gpiopower
 device		iic
 device		iicbus
 #device		isa

sys/powerpc/conf/MPC85XXSPE

@@ -75,6 +75,7 @@ device		alc
 device		ether
 device		fxp
 device  	gpio
+device  	gpiopower
 device		iic
 device		iicbus
 #device		isa