xref: /freebsd/sys/dev/gpio/gpiopower.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 #include <sys/cdefs.h>
28 
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/eventhandler.h>
35 #include <sys/gpio.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/reboot.h>
39 
40 #include <dev/ofw/ofw_bus.h>
41 
42 #include <dev/gpio/gpiobusvar.h>
43 
44 struct gpiopower_softc {
45 	gpio_pin_t	sc_pin;
46 	int		sc_rbmask;
47 };
48 
49 static void gpiopower_assert(device_t dev, int howto);
50 
51 static int
52 gpiopower_probe(device_t dev)
53 {
54 
55 	if (ofw_bus_is_compatible(dev, "gpio-poweroff")) {
56 		device_set_desc(dev, "GPIO poweroff control");
57 		return (0);
58 	} else if (ofw_bus_is_compatible(dev, "gpio-restart")) {
59 		device_set_desc(dev, "GPIO restart control");
60 		return (0);
61 	}
62 
63 	return (ENXIO);
64 }
65 
66 static int
67 gpiopower_attach(device_t dev)
68 {
69 	struct gpiopower_softc *sc;
70 	phandle_t node;
71 
72 	sc = device_get_softc(dev);
73 
74 	if ((node = ofw_bus_get_node(dev)) == -1)
75 		return (ENXIO);
76 
77 	if (ofw_gpiobus_parse_gpios(dev, "gpios", &sc->sc_pin) <= 0) {
78 		device_printf(dev, "failed to map GPIO pin\n");
79 		return (ENXIO);
80 	}
81 
82 	if (ofw_bus_is_compatible(dev, "gpio-poweroff"))
83 		sc->sc_rbmask = RB_HALT | RB_POWEROFF;
84 	else
85 		sc->sc_rbmask = 0;
86 	EVENTHANDLER_REGISTER(shutdown_final, gpiopower_assert, dev,
87 	    SHUTDOWN_PRI_LAST);
88 	gpio_pin_setflags(sc->sc_pin, GPIO_PIN_OUTPUT);
89 
90 	return (0);
91 }
92 
93 static void
94 gpiopower_assert(device_t dev, int howto)
95 {
96 	struct gpiopower_softc *sc;
97 	int do_assert;
98 
99 	sc = device_get_softc(dev);
100 	do_assert = sc->sc_rbmask ? (sc->sc_rbmask & howto) :
101 	    ((howto & RB_HALT) == 0);
102 
103 	if (!do_assert)
104 		return;
105 
106 	if (howto & RB_POWEROFF)
107 		device_printf(dev, "powering system off\n");
108 	else if ((howto & RB_HALT) == 0)
109 		device_printf(dev, "resetting system\n");
110 	else
111 		return;
112 
113 	gpio_pin_set_active(sc->sc_pin, true);
114 
115 	/* Wait a second for it to trip */
116 	DELAY(10000000);
117 }
118 
119 static device_method_t gpiopower_methods[] = {
120 	/* Device interface */
121 	DEVMETHOD(device_probe,		gpiopower_probe),
122 	DEVMETHOD(device_attach,	gpiopower_attach),
123 
124 	DEVMETHOD_END
125 };
126 
127 static driver_t gpiopower_driver = {
128 	"gpiopower",
129 	gpiopower_methods,
130 	sizeof(struct gpiopower_softc)
131 };
132 
133 DRIVER_MODULE(gpiopower, simplebus, gpiopower_driver, 0, 0);
134 MODULE_DEPEND(gpiopower, gpiobus, 1, 1, 1);
135