162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * GPIO character device helper for reading chip information. 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-chip-info <chip path> [name|label|num-lines]\n"); 2062306a36Sopenharmony_ci} 2162306a36Sopenharmony_ci 2262306a36Sopenharmony_ciint main(int argc, char **argv) 2362306a36Sopenharmony_ci{ 2462306a36Sopenharmony_ci struct gpiochip_info info; 2562306a36Sopenharmony_ci int fd, ret; 2662306a36Sopenharmony_ci 2762306a36Sopenharmony_ci if (argc != 3) { 2862306a36Sopenharmony_ci print_usage(); 2962306a36Sopenharmony_ci return EXIT_FAILURE; 3062306a36Sopenharmony_ci } 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci fd = open(argv[1], O_RDWR); 3362306a36Sopenharmony_ci if (fd < 0) { 3462306a36Sopenharmony_ci perror("unable to open the GPIO chip"); 3562306a36Sopenharmony_ci return EXIT_FAILURE; 3662306a36Sopenharmony_ci } 3762306a36Sopenharmony_ci 3862306a36Sopenharmony_ci memset(&info, 0, sizeof(info)); 3962306a36Sopenharmony_ci ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &info); 4062306a36Sopenharmony_ci if (ret) { 4162306a36Sopenharmony_ci perror("chip info ioctl failed"); 4262306a36Sopenharmony_ci return EXIT_FAILURE; 4362306a36Sopenharmony_ci } 4462306a36Sopenharmony_ci 4562306a36Sopenharmony_ci if (strcmp(argv[2], "name") == 0) { 4662306a36Sopenharmony_ci printf("%s\n", info.name); 4762306a36Sopenharmony_ci } else if (strcmp(argv[2], "label") == 0) { 4862306a36Sopenharmony_ci printf("%s\n", info.label); 4962306a36Sopenharmony_ci } else if (strcmp(argv[2], "num-lines") == 0) { 5062306a36Sopenharmony_ci printf("%u\n", info.lines); 5162306a36Sopenharmony_ci } else { 5262306a36Sopenharmony_ci fprintf(stderr, "unknown command: %s\n", argv[2]); 5362306a36Sopenharmony_ci return EXIT_FAILURE; 5462306a36Sopenharmony_ci } 5562306a36Sopenharmony_ci 5662306a36Sopenharmony_ci return EXIT_SUCCESS; 5762306a36Sopenharmony_ci} 58