xref: /freebsd/sys/dev/gpio/gpiopower.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * Copyright (c) 2016 Justin Hibbits
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
21  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/bus.h>
31 #include <sys/eventhandler.h>
32 #include <sys/gpio.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/reboot.h>
36 
37 #include <dev/ofw/ofw_bus.h>
38 
39 #include <dev/gpio/gpiobusvar.h>
40 
41 struct gpiopower_softc {
42 	gpio_pin_t	sc_pin;
43 	int		sc_rbmask;
44 };
45 
46 static void gpiopower_assert(device_t dev, int howto);
47 
48 static int
49 gpiopower_probe(device_t dev)
50 {
51 
52 	if (ofw_bus_is_compatible(dev, "gpio-poweroff")) {
53 		device_set_desc(dev, "GPIO poweroff control");
54 		return (0);
55 	} else if (ofw_bus_is_compatible(dev, "gpio-restart")) {
56 		device_set_desc(dev, "GPIO restart control");
57 		return (0);
58 	}
59 
60 	return (ENXIO);
61 }
62 
63 static int
64 gpiopower_attach(device_t dev)
65 {
66 	struct gpiopower_softc *sc;
67 	phandle_t node;
68 
69 	sc = device_get_softc(dev);
70 
71 	if ((node = ofw_bus_get_node(dev)) == -1)
72 		return (ENXIO);
73 
74 	if (ofw_gpiobus_parse_gpios(dev, "gpios", &sc->sc_pin) <= 0) {
75 		device_printf(dev, "failed to map GPIO pin\n");
76 		return (ENXIO);
77 	}
78 
79 	if (ofw_bus_is_compatible(dev, "gpio-poweroff"))
80 		sc->sc_rbmask = RB_HALT | RB_POWEROFF;
81 	else
82 		sc->sc_rbmask = 0;
83 	EVENTHANDLER_REGISTER(shutdown_final, gpiopower_assert, dev,
84 	    SHUTDOWN_PRI_LAST);
85 	gpio_pin_setflags(sc->sc_pin, GPIO_PIN_OUTPUT);
86 
87 	return (0);
88 }
89 
90 static void
91 gpiopower_assert(device_t dev, int howto)
92 {
93 	struct gpiopower_softc *sc;
94 	int do_assert;
95 
96 	sc = device_get_softc(dev);
97 	do_assert = sc->sc_rbmask ? (sc->sc_rbmask & howto) :
98 	    ((howto & RB_HALT) == 0);
99 
100 	if (!do_assert)
101 		return;
102 
103 	if (howto & RB_POWEROFF)
104 		device_printf(dev, "powering system off\n");
105 	else if ((howto & RB_HALT) == 0)
106 		device_printf(dev, "resetting system\n");
107 	else
108 		return;
109 
110 	gpio_pin_set_active(sc->sc_pin, true);
111 
112 	/* Wait a second for it to trip */
113 	DELAY(10000000);
114 }
115 
116 static device_method_t gpiopower_methods[] = {
117 	/* Device interface */
118 	DEVMETHOD(device_probe,		gpiopower_probe),
119 	DEVMETHOD(device_attach,	gpiopower_attach),
120 
121 	DEVMETHOD_END
122 };
123 
124 static driver_t gpiopower_driver = {
125 	"gpiopower",
126 	gpiopower_methods,
127 	sizeof(struct gpiopower_softc)
128 };
129 
130 DRIVER_MODULE(gpiopower, simplebus, gpiopower_driver, 0, 0);
131 MODULE_DEPEND(gpiopower, gpiobus, 1, 1, 1);
132