package/gpioctl/src/main.c

   1 /*
   2 * This program is free software; you can redistribute it and/or modify
   3 * it under the terms of the GNU General Public License as published by
   4 * the Free Software Foundation; either version 2 of the License, or
   5 * (at your option) any later version.
   6 *
   7 * This program is distributed in the hope that it will be useful,
   8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  10 * GNU General Public License for more details.
  11 *
  12 * You should have received a copy of the GNU General Public License
  13 * along with this program; if not, write to the Free Software
  14 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307USA
  15 *
  16 * Feedback, Bugs...  blogic@openwrt.org
  17 *
  18 */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <fcntl.h>
  25 #include <linux/gpio_dev.h>
  26 #include <linux/ioctl.h>
  27
  28 void
  29 print_usage()
  30 {
  31         printf("gpioctl dirin|dirout|get|set|clear gpio\n");
  32         exit(0);
  33 }
  34
  35 int
  36 main(int argc, char **argv)
  37 {
  38         int gpio_pin;
  39         int fd;
  40         int result = 0;
  41
  42         if (argc != 3)
  43         {
  44                 print_usage();
  45         }
  46
  47         if ((fd = open("/dev/gpio", O_RDWR)) < 0)
  48         {
  49         printf("Error whilst opening /dev/gpio\n");
  50         return -1;
  51         }
  52
  53         gpio_pin = atoi(argv[2]);
  54
  55         printf("using gpio pin %d\n", gpio_pin);
  56
  57         if (!strcmp(argv[1], "dirin"))
  58         {
  59                 ioctl(fd, GPIO_DIR_IN, gpio_pin);
  60         } else if (!strcmp(argv[1], "dirout"))
  61         {
  62                 ioctl(fd, GPIO_DIR_OUT, gpio_pin);
  63         } else if (!strcmp(argv[1], "get"))
  64         {
  65                 result = ioctl(fd, GPIO_GET, gpio_pin);
  66                 printf("Pin %d is %s\n", gpio_pin, (result ? "HIGH" : "LOW"));
  67         } else if (!strcmp(argv[1], "set"))
  68         {
  69                 ioctl(fd, GPIO_SET, gpio_pin);
  70         } else if (!strcmp(argv[1], "clear"))
  71         {
  72                 ioctl(fd, GPIO_CLEAR, gpio_pin);
  73         } else print_usage();
  74
  75         return result;
  76 }