162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * GPIO character device helper for reading line names. 462306a36Sopenharmony_ci * 562306a36Sopenharmony_ci * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl> 662306a36Sopenharmony_ci */ 762306a36Sopenharmony_ci 862306a36Sopenharmony_ci#include <fcntl.h> 962306a36Sopenharmony_ci#include <linux/gpio.h> 1062306a36Sopenharmony_ci#include <stdio.h> 1162306a36Sopenharmony_ci#include <stdlib.h> 1262306a36Sopenharmony_ci#include <string.h> 1362306a36Sopenharmony_ci#include <sys/ioctl.h> 1462306a36Sopenharmony_ci#include <sys/types.h> 1562306a36Sopenharmony_ci 1662306a36Sopenharmony_cistatic void print_usage(void) 1762306a36Sopenharmony_ci{ 1862306a36Sopenharmony_ci printf("usage:\n"); 1962306a36Sopenharmony_ci printf(" gpio-line-name <chip path> <line offset>\n"); 2062306a36Sopenharmony_ci} 2162306a36Sopenharmony_ci 2262306a36Sopenharmony_ciint main(int argc, char **argv) 2362306a36Sopenharmony_ci{ 2462306a36Sopenharmony_ci struct gpio_v2_line_info info; 2562306a36Sopenharmony_ci int fd, ret; 2662306a36Sopenharmony_ci char *endp; 2762306a36Sopenharmony_ci 2862306a36Sopenharmony_ci if (argc != 3) { 2962306a36Sopenharmony_ci print_usage(); 3062306a36Sopenharmony_ci return EXIT_FAILURE; 3162306a36Sopenharmony_ci } 3262306a36Sopenharmony_ci 3362306a36Sopenharmony_ci fd = open(argv[1], O_RDWR); 3462306a36Sopenharmony_ci if (fd < 0) { 3562306a36Sopenharmony_ci perror("unable to open the GPIO chip"); 3662306a36Sopenharmony_ci return EXIT_FAILURE; 3762306a36Sopenharmony_ci } 3862306a36Sopenharmony_ci 3962306a36Sopenharmony_ci memset(&info, 0, sizeof(info)); 4062306a36Sopenharmony_ci info.offset = strtoul(argv[2], &endp, 10); 4162306a36Sopenharmony_ci if (*endp != '\0') { 4262306a36Sopenharmony_ci print_usage(); 4362306a36Sopenharmony_ci return EXIT_FAILURE; 4462306a36Sopenharmony_ci } 4562306a36Sopenharmony_ci 4662306a36Sopenharmony_ci ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &info); 4762306a36Sopenharmony_ci if (ret) { 4862306a36Sopenharmony_ci perror("line info ioctl failed"); 4962306a36Sopenharmony_ci return EXIT_FAILURE; 5062306a36Sopenharmony_ci } 5162306a36Sopenharmony_ci 5262306a36Sopenharmony_ci printf("%s\n", info.name); 5362306a36Sopenharmony_ci 5462306a36Sopenharmony_ci return EXIT_SUCCESS; 5562306a36Sopenharmony_ci} 56