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authorLinus Walleij <linus.walleij@linaro.org>2015-10-21 15:45:54 +0200
committerLinus Walleij <linus.walleij@linaro.org>2016-02-09 11:09:48 +0100
commit6d591c46bce037696d173bd5c8461b2b4bb680ad (patch)
tree5b7d5e0004de27d1451f38e3e1ddf99837e5d615 /tools/gpio
parent3c702e9987e261042a07e43460a8148be254412e (diff)
downloadlinux-linaro-stable-6d591c46bce037696d173bd5c8461b2b4bb680ad.tar.gz
tools/gpio: create GPIO tools
This creates GPIO tools under tools/gpio/* and adds a single example program to list the GPIOs on a system. When proper devices are created it provides this minimal output: Cc: Johan Hovold <johan@kernel.org> Cc: Michael Welling <mwelling@ieee.org> Cc: Markus Pargmann <mpa@pengutronix.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'tools/gpio')
-rw-r--r--tools/gpio/Makefile12
-rw-r--r--tools/gpio/gpio-utils.c11
-rw-r--r--tools/gpio/gpio-utils.h25
-rw-r--r--tools/gpio/lsgpio.c128
4 files changed, 176 insertions, 0 deletions
diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile
new file mode 100644
index 000000000000..4d198d5c4203
--- /dev/null
+++ b/tools/gpio/Makefile
@@ -0,0 +1,12 @@
+CC = $(CROSS_COMPILE)gcc
+CFLAGS += -Wall -g -D_GNU_SOURCE
+
+all: lsgpio
+
+lsgpio: lsgpio.o gpio-utils.o
+
+%.o: %.c gpio-utils.h
+
+.PHONY: clean
+clean:
+ rm -f *.o lsgpio
diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c
new file mode 100644
index 000000000000..8208718f2c99
--- /dev/null
+++ b/tools/gpio/gpio-utils.c
@@ -0,0 +1,11 @@
+/*
+ * GPIO tools - helpers library for the GPIO tools
+ *
+ * Copyright (C) 2015 Linus Walleij
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include "gpio-utils.h"
diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h
new file mode 100644
index 000000000000..b18209a45ad3
--- /dev/null
+++ b/tools/gpio/gpio-utils.h
@@ -0,0 +1,25 @@
+/*
+ * GPIO tools - utility helpers library for the GPIO tools
+ *
+ * Copyright (C) 2015 Linus Walleij
+ *
+ * Portions copied from iio_utils and lssio:
+ * Copyright (c) 2010 Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
+ * Copyright (c) 2008 Jonathan Cameron
+ * *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#ifndef _GPIO_UTILS_H_
+#define _GPIO_UTILS_H_
+
+#include <string.h>
+
+static inline int check_prefix(const char *str, const char *prefix)
+{
+ return strlen(str) > strlen(prefix) &&
+ strncmp(str, prefix, strlen(prefix)) == 0;
+}
+
+#endif /* _GPIO_UTILS_H_ */
diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c
new file mode 100644
index 000000000000..4cfe29da279b
--- /dev/null
+++ b/tools/gpio/lsgpio.c
@@ -0,0 +1,128 @@
+/*
+ * lsgpio - example on how to list the GPIO lines on a system
+ *
+ * Copyright (C) 2015 Linus Walleij
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * Usage:
+ * lsgpio <-n device-name>
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <dirent.h>
+#include <errno.h>
+#include <string.h>
+#include <poll.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <sys/ioctl.h>
+#include <linux/gpio.h>
+
+#include "gpio-utils.h"
+
+int list_device(const char *device_name)
+{
+ struct gpiochip_info cinfo;
+ char *chrdev_name;
+ int fd;
+ int ret;
+
+ ret = asprintf(&chrdev_name, "/dev/%s", device_name);
+ if (ret < 0)
+ return -ENOMEM;
+
+ fd = open(chrdev_name, 0);
+ if (fd == -1) {
+ ret = -errno;
+ fprintf(stderr, "Failed to open %s\n", chrdev_name);
+ goto free_chrdev_name;
+ }
+
+ /* Inspect this GPIO chip */
+ ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo);
+ if (ret == -1) {
+ ret = -errno;
+ fprintf(stderr, "Failed to retrieve GPIO fd\n");
+ if (close(fd) == -1)
+ perror("Failed to close GPIO character device file");
+
+ goto free_chrdev_name;
+ }
+ fprintf(stdout, "GPIO chip: %s, %u GPIO lines\n",
+ cinfo.name, cinfo.lines);
+
+ if (close(fd) == -1) {
+ ret = -errno;
+ goto free_chrdev_name;
+ }
+
+free_chrdev_name:
+ free(chrdev_name);
+
+ return ret;
+
+}
+
+void print_usage(void)
+{
+ fprintf(stderr, "Usage: lsgpio [options]...\n"
+ "List GPIO chips, lines and states\n"
+ " -n <name> List GPIOs on a named device\n"
+ " -? This helptext\n"
+ );
+}
+
+int main(int argc, char **argv)
+{
+ const char *device_name;
+ int ret;
+ int c;
+
+ while ((c = getopt(argc, argv, "n:")) != -1) {
+ switch (c) {
+ case 'n':
+ device_name = optarg;
+ break;
+ case '?':
+ print_usage();
+ return -1;
+ }
+ }
+
+ if (device_name)
+ ret = list_device(device_name);
+ else {
+ const struct dirent *ent;
+ DIR *dp;
+
+ /* List all GPIO devices one at a time */
+ dp = opendir("/dev");
+ if (!dp) {
+ ret = -errno;
+ goto error_out;
+ }
+
+ ret = -ENOENT;
+ while (ent = readdir(dp), ent) {
+ if (check_prefix(ent->d_name, "gpiochip")) {
+ ret = list_device(ent->d_name);
+ if (ret)
+ break;
+ }
+ }
+
+ ret = 0;
+ if (closedir(dp) == -1) {
+ perror("scanning devices: Failed to close directory");
+ ret = -errno;
+ }
+ }
+error_out:
+ return ret;
+}