2015-10-21 13:45:54 +00:00
|
|
|
/*
|
|
|
|
* lsgpio - example on how to list the GPIO lines on a system
|
|
|
|
*
|
|
|
|
* Copyright (C) 2015 Linus Walleij
|
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
|
|
* under the terms of the GNU General Public License version 2 as published by
|
|
|
|
* the Free Software Foundation.
|
|
|
|
*
|
|
|
|
* Usage:
|
|
|
|
* lsgpio <-n device-name>
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <unistd.h>
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include <stdbool.h>
|
|
|
|
#include <stdio.h>
|
|
|
|
#include <dirent.h>
|
|
|
|
#include <errno.h>
|
|
|
|
#include <string.h>
|
|
|
|
#include <poll.h>
|
|
|
|
#include <fcntl.h>
|
|
|
|
#include <getopt.h>
|
|
|
|
#include <sys/ioctl.h>
|
|
|
|
#include <linux/gpio.h>
|
|
|
|
|
|
|
|
#include "gpio-utils.h"
|
|
|
|
|
|
|
|
int list_device(const char *device_name)
|
|
|
|
{
|
|
|
|
struct gpiochip_info cinfo;
|
|
|
|
char *chrdev_name;
|
|
|
|
int fd;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = asprintf(&chrdev_name, "/dev/%s", device_name);
|
|
|
|
if (ret < 0)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
fd = open(chrdev_name, 0);
|
|
|
|
if (fd == -1) {
|
|
|
|
ret = -errno;
|
|
|
|
fprintf(stderr, "Failed to open %s\n", chrdev_name);
|
|
|
|
goto free_chrdev_name;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Inspect this GPIO chip */
|
|
|
|
ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo);
|
|
|
|
if (ret == -1) {
|
|
|
|
ret = -errno;
|
|
|
|
fprintf(stderr, "Failed to retrieve GPIO fd\n");
|
|
|
|
if (close(fd) == -1)
|
|
|
|
perror("Failed to close GPIO character device file");
|
|
|
|
|
|
|
|
goto free_chrdev_name;
|
|
|
|
}
|
2016-02-12 13:48:23 +00:00
|
|
|
fprintf(stdout, "GPIO chip: %s, \"%s\", %u GPIO lines\n",
|
|
|
|
cinfo.name, cinfo.label, cinfo.lines);
|
2015-10-21 13:45:54 +00:00
|
|
|
|
|
|
|
if (close(fd) == -1) {
|
|
|
|
ret = -errno;
|
|
|
|
goto free_chrdev_name;
|
|
|
|
}
|
|
|
|
|
|
|
|
free_chrdev_name:
|
|
|
|
free(chrdev_name);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
void print_usage(void)
|
|
|
|
{
|
|
|
|
fprintf(stderr, "Usage: lsgpio [options]...\n"
|
|
|
|
"List GPIO chips, lines and states\n"
|
|
|
|
" -n <name> List GPIOs on a named device\n"
|
|
|
|
" -? This helptext\n"
|
|
|
|
);
|
|
|
|
}
|
|
|
|
|
|
|
|
int main(int argc, char **argv)
|
|
|
|
{
|
|
|
|
const char *device_name;
|
|
|
|
int ret;
|
|
|
|
int c;
|
|
|
|
|
|
|
|
while ((c = getopt(argc, argv, "n:")) != -1) {
|
|
|
|
switch (c) {
|
|
|
|
case 'n':
|
|
|
|
device_name = optarg;
|
|
|
|
break;
|
|
|
|
case '?':
|
|
|
|
print_usage();
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (device_name)
|
|
|
|
ret = list_device(device_name);
|
|
|
|
else {
|
|
|
|
const struct dirent *ent;
|
|
|
|
DIR *dp;
|
|
|
|
|
|
|
|
/* List all GPIO devices one at a time */
|
|
|
|
dp = opendir("/dev");
|
|
|
|
if (!dp) {
|
|
|
|
ret = -errno;
|
|
|
|
goto error_out;
|
|
|
|
}
|
|
|
|
|
|
|
|
ret = -ENOENT;
|
|
|
|
while (ent = readdir(dp), ent) {
|
|
|
|
if (check_prefix(ent->d_name, "gpiochip")) {
|
|
|
|
ret = list_device(ent->d_name);
|
|
|
|
if (ret)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
ret = 0;
|
|
|
|
if (closedir(dp) == -1) {
|
|
|
|
perror("scanning devices: Failed to close directory");
|
|
|
|
ret = -errno;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
error_out:
|
|
|
|
return ret;
|
|
|
|
}
|