58 lines
1.2 KiB
C
58 lines
1.2 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* GPIO character device helper for reading chip information.
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*
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* Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl>
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*/
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#include <fcntl.h>
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#include <linux/gpio.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <sys/types.h>
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static void print_usage(void)
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{
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printf("usage:\n");
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printf(" gpio-chip-info <chip path> [name|label|num-lines]\n");
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}
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int main(int argc, char **argv)
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{
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struct gpiochip_info info;
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int fd, ret;
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if (argc != 3) {
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print_usage();
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return EXIT_FAILURE;
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}
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fd = open(argv[1], O_RDWR);
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if (fd < 0) {
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perror("unable to open the GPIO chip");
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return EXIT_FAILURE;
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}
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memset(&info, 0, sizeof(info));
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ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &info);
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if (ret) {
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perror("chip info ioctl failed");
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return EXIT_FAILURE;
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}
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if (strcmp(argv[2], "name") == 0) {
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printf("%s\n", info.name);
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} else if (strcmp(argv[2], "label") == 0) {
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printf("%s\n", info.label);
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} else if (strcmp(argv[2], "num-lines") == 0) {
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printf("%u\n", info.lines);
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} else {
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fprintf(stderr, "unknown command: %s\n", argv[2]);
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return EXIT_FAILURE;
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}
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return EXIT_SUCCESS;
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}
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