Commit 16c138f3 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

selftests: gpio: provide a helper for reading chip info 



Add a simple program that allows to retrieve chip properties from the
GPIO character device. This will be used in gpio-sim selftests.

Signed-off-by: default avatarBartosz Golaszewski <brgl@bgdev.pl>
parent cb8c474e

tools/testing/selftests/gpio/.gitignore

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# SPDX-License-Identifier: GPL-2.0-only

gpio-mockup-cdev

gpio-chip-info

tools/testing/selftests/gpio/Makefile

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@@ -2,6 +2,6 @@ 


TEST_PROGS := gpio-mockup.sh

TEST_FILES := gpio-mockup-sysfs.sh

TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev

TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info



include ../lib.mk

tools/testing/selftests/gpio/gpio-chip-info.c

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// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * GPIO character device helper for reading chip information.

 *

 * 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-chip-info <chip path> [name|label|num-lines]\n");

}



int main(int argc, char **argv)

{

	struct gpiochip_info info;

	int fd, ret;



	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));

	ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &info);

	if (ret) {

		perror("chip info ioctl failed");

		return EXIT_FAILURE;

	}



	if (strcmp(argv[2], "name") == 0) {

		printf("%s\n", info.name);

	} else if (strcmp(argv[2], "label") == 0) {

		printf("%s\n", info.label);

	} else if (strcmp(argv[2], "num-lines") == 0) {

		printf("%u\n", info.lines);

	} else {

		fprintf(stderr, "unknown command: %s\n", argv[2]);

		return EXIT_FAILURE;

	}



	return EXIT_SUCCESS;

}