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Linux kernel mirror (for testing)
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kernel
os
linux
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>
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tools/testing/selftests/gpio/.gitignore
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tools/testing/selftests/gpio/.gitignore
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tools/testing/selftests/gpio/Makefile
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tools/testing/selftests/gpio/Makefile
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tools/testing/selftests/gpio/gpio-line-name.c
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tools/testing/selftests/gpio/gpio-line-name.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 line names.
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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-line-name <chip path> <line offset>\n");
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}
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int main(int argc, char **argv)
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{
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struct gpio_v2_line_info info;
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int fd, ret;
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char *endp;
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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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info.offset = strtoul(argv[2], &endp, 10);
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if (*endp != '\0') {
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print_usage();
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return EXIT_FAILURE;
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}
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ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &info);
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if (ret) {
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perror("line info ioctl failed");
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return EXIT_FAILURE;
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}
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printf("%s\n", info.name);
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return EXIT_SUCCESS;
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}