sys/dev/gpio/gpiolock.c

   1 /* $NetBSD: gpiolock.c,v 1.2 2009/08/15 09:43:59 mbalmer 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 #define GPIOLOCK_MAXPINS        4
  42 #define GPIOLOCK_MINPINS        2
  43
  44 struct gpiolock_softc {
  45         void *                  sc_gpio;
  46         struct gpio_pinmap      sc_map;
  47         int                     _map[GPIOLOCK_MAXPINS];
  48
  49         int                     sc_npins;
  50         int                     sc_data;
  51         int                     sc_dying;
  52 };
  53
  54 int gpiolock_match(device_t, cfdata_t, void *);
  55 void gpiolock_attach(device_t, device_t, void *);
  56 int gpiolock_detach(device_t, int);
  57 int gpiolock_activate(device_t, enum devact);
  58 int gpiolock_position(void *);
  59
  60 CFATTACH_DECL_NEW(gpiolock, sizeof(struct gpiolock_softc),
  61         gpiolock_match, gpiolock_attach, gpiolock_detach, gpiolock_activate);
  62
  63 extern struct cfdriver gpiolock_cd;
  64
  65 int
  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
  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         pmf_device_register(self, NULL, NULL);
 127
 128         aprint_normal("\n");
 129         return;
 130
 131 fail:
 132         gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
 133 }
 134
 135 int
 136 gpiolock_detach(device_t self, int flags)
 137 {
 138         struct gpiolock_softc *sc = device_private(self);
 139
 140         pmf_device_deregister(self);
 141 #ifdef KEYLOCK
 142         keylock_unregister(self, gpiolock_position);
 143 #endif
 144         gpio_pin_unmap(sc->sc_gpio, &sc->sc_map);
 145
 146         return 0;
 147 }
 148
 149 int
 150 gpiolock_activate(device_t self, enum devact act)
 151 {
 152         struct gpiolock_softc *sc = device_private(self);
 153
 154         switch (act) {
 155         case DVACT_DEACTIVATE:
 156                 sc->sc_dying = 1;
 157                 return 0;
 158         default:
 159                 return EOPNOTSUPP;
 160         }
 161
 162 }
 163
 164 int
 165 gpiolock_position(void *arg)
 166 {
 167         struct gpiolock_softc *sc = device_private((device_t)arg);
 168         int pos, pin;
 169
 170         for (pos = pin = 0; pin < sc->sc_npins; pin++) {
 171                 if (gpio_pin_read(sc->sc_gpio, &sc->sc_map, pin) ==
 172                     GPIO_PIN_HIGH)
 173                         pos = pin + 1;
 174         }
 175         return pos;
 176 }
 177