lib/libgpio/gpio.c

   1 /*-
   2  * Copyright (c) 2013-2014 Rui Paulo <rpaulo@FreeBSD.org>
   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
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  17  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  20  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  23  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  24  * POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD$
  27  */
  28 #include <stdio.h>
  29 #include <fcntl.h>
  30 #include <unistd.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <errno.h>
  34
  35 #include <sys/ioctl.h>
  36 #include <sys/types.h>
  37
  38 #include <libgpio.h>
  39
  40 gpio_handle_t
  41 gpio_open(unsigned int unit)
  42 {
  43         char device[16];
  44
  45         snprintf(device, sizeof(device), "/dev/gpioc%u", unit);
  46
  47         return (gpio_open_device(device));
  48 }
  49
  50 gpio_handle_t
  51 gpio_open_device(const char *device)
  52 {
  53         int fd, maxpins;
  54         int serr;
  55
  56         fd = open(device, O_RDONLY);
  57         if (fd < 0)
  58                 return (GPIO_INVALID_HANDLE);
  59         /*
  60          * Check whether a simple ioctl works.
  61          */
  62         if (ioctl(fd, GPIOMAXPIN, &maxpins) < 0) {
  63                 serr = errno;
  64                 close(fd);
  65                 errno = serr;
  66                 return (GPIO_INVALID_HANDLE);
  67         }
  68
  69         return (fd);
  70 }
  71
  72 void
  73 gpio_close(gpio_handle_t handle)
  74 {
  75         close(handle);
  76 }
  77
  78 int
  79 gpio_pin_list(gpio_handle_t handle, gpio_config_t **pcfgs)
  80 {
  81         int maxpins, i;
  82         gpio_config_t *cfgs;
  83
  84         *pcfgs = NULL;
  85         if (ioctl(handle, GPIOMAXPIN, &maxpins) < 0)
  86                 return (-1);
  87         /* Reasonable values. */
  88         if (maxpins < 0 || maxpins > 4096) {
  89                 errno = EINVAL;
  90                 return (-1);
  91         }
  92         cfgs = calloc(maxpins + 1, sizeof(*cfgs));
  93         if (cfgs == NULL)
  94                 return (-1);
  95         for (i = 0; i <= maxpins; i++) {
  96                 cfgs[i].g_pin = i;
  97                 gpio_pin_config(handle, &cfgs[i]);
  98         }
  99         *pcfgs = cfgs;
 100
 101         return (maxpins);
 102 }
 103
 104 int
 105 gpio_pin_config(gpio_handle_t handle, gpio_config_t *cfg)
 106 {
 107         struct gpio_pin gppin;
 108
 109         if (cfg == NULL)
 110                 return (-1);
 111         gppin.gp_pin = cfg->g_pin;
 112         if (ioctl(handle, GPIOGETCONFIG, &gppin) < 0)
 113                 return (-1);
 114         strlcpy(cfg->g_name, gppin.gp_name, GPIOMAXNAME);
 115         cfg->g_caps = gppin.gp_caps;
 116         cfg->g_flags = gppin.gp_flags;
 117
 118         return (0);
 119 }
 120
 121 int
 122 gpio_pin_set_name(gpio_handle_t handle, gpio_pin_t pin, char *name)
 123 {
 124         struct gpio_pin gppin;
 125
 126         if (name == NULL)
 127                 return (-1);
 128         bzero(&gppin, sizeof(gppin));
 129         gppin.gp_pin = pin;
 130         strlcpy(gppin.gp_name, name, GPIOMAXNAME);
 131         if (ioctl(handle, GPIOSETNAME, &gppin) < 0)
 132                 return (-1);
 133
 134         return (0);
 135 }
 136
 137 int
 138 gpio_pin_set_flags(gpio_handle_t handle, gpio_config_t *cfg)
 139 {
 140         struct gpio_pin gppin;
 141
 142         if (cfg == NULL)
 143                 return (-1);
 144         gppin.gp_pin = cfg->g_pin;
 145         gppin.gp_flags = cfg->g_flags;
 146         if (ioctl(handle, GPIOSETCONFIG, &gppin) < 0)
 147                 return (-1);
 148
 149         return (0);
 150 }
 151
 152 gpio_value_t
 153 gpio_pin_get(gpio_handle_t handle, gpio_pin_t pin)
 154 {
 155         struct gpio_req gpreq;
 156
 157         bzero(&gpreq, sizeof(gpreq));
 158         gpreq.gp_pin = pin;
 159         if (ioctl(handle, GPIOGET, &gpreq) < 0)
 160                 return (GPIO_VALUE_INVALID);
 161
 162         return (gpreq.gp_value);
 163 }
 164
 165 int
 166 gpio_pin_set(gpio_handle_t handle, gpio_pin_t pin, gpio_value_t value)
 167 {
 168         struct gpio_req gpreq;
 169
 170         if (value == GPIO_VALUE_INVALID)
 171                 return (-1);
 172         bzero(&gpreq, sizeof(gpreq));
 173         gpreq.gp_pin = pin;
 174         gpreq.gp_value = value;
 175         if (ioctl(handle, GPIOSET, &gpreq) < 0)
 176                 return (-1);
 177
 178         return (0);
 179 }
 180
 181 int
 182 gpio_pin_toggle(gpio_handle_t handle, gpio_pin_t pin)
 183 {
 184         struct gpio_req gpreq;
 185
 186         bzero(&gpreq, sizeof(gpreq));
 187         gpreq.gp_pin = pin;
 188         if (ioctl(handle, GPIOTOGGLE, &gpreq) < 0)
 189                 return (-1);
 190
 191         return (0);
 192 }
 193
 194 int
 195 gpio_pin_low(gpio_handle_t handle, gpio_pin_t pin)
 196 {
 197         return (gpio_pin_set(handle, pin, GPIO_VALUE_LOW));
 198 }
 199
 200 int
 201 gpio_pin_high(gpio_handle_t handle, gpio_pin_t pin)
 202 {
 203         return (gpio_pin_set(handle, pin, GPIO_VALUE_HIGH));
 204 }
 205
 206 static int
 207 gpio_pin_set_flag(gpio_handle_t handle, gpio_pin_t pin, uint32_t flag)
 208 {
 209         gpio_config_t cfg;
 210
 211         bzero(&cfg, sizeof(cfg));
 212         cfg.g_pin = pin;
 213         if (gpio_pin_config(handle, &cfg) < 0)
 214                 return (-1);
 215         cfg.g_flags = flag;
 216
 217         return (gpio_pin_set_flags(handle, &cfg));
 218 }
 219
 220 int
 221 gpio_pin_input(gpio_handle_t handle, gpio_pin_t pin)
 222 {
 223         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_INPUT));
 224 }
 225
 226 int
 227 gpio_pin_output(gpio_handle_t handle, gpio_pin_t pin)
 228 {
 229         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_OUTPUT));
 230 }
 231
 232 int
 233 gpio_pin_opendrain(gpio_handle_t handle, gpio_pin_t pin)
 234 {
 235         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_OPENDRAIN));
 236 }
 237
 238 int
 239 gpio_pin_pushpull(gpio_handle_t handle, gpio_pin_t pin)
 240 {
 241         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PUSHPULL));
 242 }
 243
 244 int
 245 gpio_pin_tristate(gpio_handle_t handle, gpio_pin_t pin)
 246 {
 247         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_TRISTATE));
 248 }
 249
 250 int
 251 gpio_pin_pullup(gpio_handle_t handle, gpio_pin_t pin)
 252 {
 253         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PULLUP));
 254 }
 255
 256 int
 257 gpio_pin_pulldown(gpio_handle_t handle, gpio_pin_t pin)
 258 {
 259         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PULLDOWN));
 260 }
 261
 262 int
 263 gpio_pin_invin(gpio_handle_t handle, gpio_pin_t pin)
 264 {
 265         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_INVIN));
 266 }
 267
 268 int
 269 gpio_pin_invout(gpio_handle_t handle, gpio_pin_t pin)
 270 {
 271         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_INVOUT));
 272 }
 273
 274 int
 275 gpio_pin_pulsate(gpio_handle_t handle, gpio_pin_t pin)
 276 {
 277         return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PULSATE));
 278 }