linux/tools/testing/selftests/gpio/gpio-line-name.c
Bartosz Golaszewski b2bb90c80a selftests: gpio: add a helper for reading GPIO line names
Add a simple program that allows to read GPIO line names from the
character device. This will be used in gpio-sim selftests.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
2021-12-17 12:26:13 +01:00

56 lines
1.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* GPIO character device helper for reading line names.
*
* Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
*/
#include <fcntl.h>
#include <linux/gpio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/types.h>
static void print_usage(void)
{
printf("usage:\n");
printf(" gpio-line-name <chip path> <line offset>\n");
}
int main(int argc, char **argv)
{
struct gpio_v2_line_info info;
int fd, ret;
char *endp;
if (argc != 3) {
print_usage();
return EXIT_FAILURE;
}
fd = open(argv[1], O_RDWR);
if (fd < 0) {
perror("unable to open the GPIO chip");
return EXIT_FAILURE;
}
memset(&info, 0, sizeof(info));
info.offset = strtoul(argv[2], &endp, 10);
if (*endp != '\0') {
print_usage();
return EXIT_FAILURE;
}
ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &info);
if (ret) {
perror("line info ioctl failed");
return EXIT_FAILURE;
}
printf("%s\n", info.name);
return EXIT_SUCCESS;
}