[PATCH v3 10/11] selftests: gpio: add a helper for reading GPIO line names

Bartosz Golaszewski
2021-03-09T21:00:46Z

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 <bgolaszewski@baylibre.com>
---
tools/testing/selftests/gpio/.gitignore | 1 +
tools/testing/selftests/gpio/Makefile | 2 +-
tools/testing/selftests/gpio/gpio-line-name.c | 55 +++++++++++++++++++
3 files changed, 57 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/gpio/gpio-line-name.c

diff --git a/tools/testing/selftests/gpio/.gitignore b/tools/testing/selftests/gpio/.gitignore
index 4ea4f58dab1a..ededb077a3a6 100644
--- a/tools/testing/selftests/gpio/.gitignore
+++ b/tools/testing/selftests/gpio/.gitignore
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
gpio-mockup-cdev
gpio-chip-info
+gpio-line-name
diff --git a/tools/testing/selftests/gpio/Makefile b/tools/testing/selftests/gpio/Makefile
index 84b48547f94c..d7d8f1985d99 100644
--- a/tools/testing/selftests/gpio/Makefile
+++ b/tools/testing/selftests/gpio/Makefile
@@ -2,6 +2,6 @@

TEST_PROGS := gpio-mockup.sh
TEST_FILES := gpio-mockup-sysfs.sh
-TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info
+TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info gpio-line-name

include ../lib.mk
diff --git a/tools/testing/selftests/gpio/gpio-line-name.c b/tools/testing/selftests/gpio/gpio-line-name.c
new file mode 100644
index 000000000000..a52e75bc37ba
--- /dev/null
+++ b/tools/testing/selftests/gpio/gpio-line-name.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * GPIO character device helper for reading line names.
+ *
+ * Copyright (C) 2021 Bartosz Golaszewski <bgolaszewski@baylibre.com>
+ */
+
+#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-line-name <chip path> <line offset>\n");
+}
+
+int main(int argc, char **argv)
+{
+ struct gpio_v2_line_info info;
+ int fd, ret;
+ char *endp;
+
+ 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));
+ info.offset = strtoul(argv[2], &endp, 10);
+ if (*endp != '\0') {
+ print_usage();
+ return EXIT_FAILURE;
+ }
+
+ ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &info);
+ if (ret) {
+ perror("line info ioctl failed");
+ return EXIT_FAILURE;
+ }
+
+ printf("%s\n", info.name);
+
+ return EXIT_SUCCESS;
+}
--
2.30.1