xref: /netbsd-src/sys/dev/gpio/gpiolock.c (revision 82b8caba92d0ece070500659c43d13d9ecc6921e)
1 /* $NetBSD: gpiolock.c,v 1.5 2017/10/28 04:53:56 riastradh Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Marc Balmer <marc@msys.ch>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 /*
29  * Driver for multi-position keylocks on GPIO pins
30  */
31 
32 #include "opt_keylock.h"
33 
34 #include <sys/param.h>
35 #include <sys/device.h>
36 #include <sys/gpio.h>
37 
38 #include <dev/gpio/gpiovar.h>
39 #include <dev/keylock.h>
40 
41 #include "ioconf.h"
42 
43 #define GPIOLOCK_MAXPINS	4
44 #define GPIOLOCK_MINPINS	2
45 
46 struct gpiolock_softc {
47 	void *			sc_gpio;
48 	struct gpio_pinmap	sc_map;
49 	int			_map[GPIOLOCK_MAXPINS];
50 
51 	int			sc_npins;
52 	int			sc_data;
53 	int			sc_dying;
54 };
55 
56 int gpiolock_match(device_t, cfdata_t, void *);
57 void gpiolock_attach(device_t, device_t, void *);
58 int gpiolock_detach(device_t, int);
59 int gpiolock_activate(device_t, enum devact);
60 int gpiolock_position(void *);
61 
62 CFATTACH_DECL_NEW(gpiolock, sizeof(struct gpiolock_softc),
63 	gpiolock_match, gpiolock_attach, gpiolock_detach, gpiolock_activate);
64 
65 int
gpiolock_match(device_t parent,cfdata_t cf,void * aux)66 gpiolock_match(device_t parent, cfdata_t cf,
67     void *aux)
68 {
69 	struct gpio_attach_args *ga = aux;
70 	int npins;
71 
72 	if (strcmp(ga->ga_dvname, cf->cf_name))
73 		return 0;
74 
75 	if (ga->ga_offset == -1)
76 		return 0;
77 
78 	/* Check number of pins */
79 	npins = gpio_npins(ga->ga_mask);
80 	if (npins < GPIOLOCK_MINPINS || npins > GPIOLOCK_MAXPINS) {
81 		aprint_debug("%s: invalid pin mask 0x%02x\n", cf->cf_name,
82 		    ga->ga_mask);
83 		return 0;
84 	}
85 
86 	return 1;
87 }
88 
89 void
gpiolock_attach(device_t parent,device_t self,void * aux)90 gpiolock_attach(device_t parent, device_t self, void *aux)
91 {
92 	struct gpiolock_softc *sc = device_private(self);
93 	struct gpio_attach_args *ga = aux;
94 	int pin, caps;
95 
96 	sc->sc_npins = gpio_npins(ga->ga_mask);
97 
98 	/* Map pins */
99 	sc->sc_gpio = ga->ga_gpio;
100 	sc->sc_map.pm_map = sc->_map;
101 	if (gpio_pin_map(sc->sc_gpio, ga->ga_offset, ga->ga_mask,
102 	    &sc->sc_map)) {
103 		aprint_error(": can't map pins\n");
104 		return;
105 	}
106 
107 	/* Configure data pins */
108 	for (pin = 0; pin < sc->sc_npins; pin++) {
109 		caps = gpio_pin_caps(sc->sc_gpio, &sc->sc_map, pin);
110 		if (!(caps & GPIO_PIN_INPUT)) {
111 			aprint_error(": data pin is unable to read input\n");
112 			goto fail;
113 		}
114 		aprint_normal(" [%d]", sc->sc_map.pm_map[pin]);
115 		sc->sc_data = GPIO_PIN_INPUT;
116 		gpio_pin_ctl(sc->sc_gpio, &sc->sc_map, pin, sc->sc_data);
117 	}
118 
119 #ifdef KEYLOCK
120 	/* Register keylock */
121 	if (keylock_register(self, sc->sc_npins, gpiolock_position)) {
122 		aprint_error(": can't register keylock\n");
123 		goto fail;
124 	}
125 #endif
126 	if (!pmf_device_register(self, NULL, NULL))
127 		aprint_error_dev(self, "couldn't establish power handler\n");
128 
129 	aprint_normal("\n");
130 	return;
131 
132 fail:
133 	gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
134 }
135 
136 int
gpiolock_detach(device_t self,int flags)137 gpiolock_detach(device_t self, int flags)
138 {
139 	struct gpiolock_softc *sc = device_private(self);
140 
141 	pmf_device_deregister(self);
142 #ifdef KEYLOCK
143 	keylock_unregister(self, gpiolock_position);
144 #endif
145 	gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
146 
147 	return 0;
148 }
149 
150 int
gpiolock_activate(device_t self,enum devact act)151 gpiolock_activate(device_t self, enum devact act)
152 {
153 	struct gpiolock_softc *sc = device_private(self);
154 
155 	switch (act) {
156 	case DVACT_DEACTIVATE:
157 		sc->sc_dying = 1;
158 		return 0;
159 	default:
160 		return EOPNOTSUPP;
161 	}
162 
163 }
164 
165 int
gpiolock_position(void * arg)166 gpiolock_position(void *arg)
167 {
168 	struct gpiolock_softc *sc = device_private((device_t)arg);
169 	int pos, pin;
170 
171 	for (pos = pin = 0; pin < sc->sc_npins; pin++) {
172 		if (gpio_pin_read(sc->sc_gpio, &sc->sc_map, pin) ==
173 		    GPIO_PIN_HIGH)
174 			pos = pin + 1;
175 	}
176 	return pos;
177 }
178 
179