summaryrefslogtreecommitdiff
path: root/tools/gpio/lsgpio.c
diff options
context:
space:
mode:
authorTony Lindgren <tony@atomide.com>2016-03-30 20:36:06 +0300
committerTony Lindgren <tony@atomide.com>2016-03-30 20:36:06 +0300
commit1809de7e7d37c585e01a1bcc583ea92b78fc759d (patch)
tree76c5b35c2b04eafce86a1a729c02ab705eba44bc /tools/gpio/lsgpio.c
parentebf24414809200915b9ddf7f109bba7c278c8210 (diff)
parent3ca4a238106dedc285193ee47f494a6584b6fd2f (diff)
downloadlinux-1809de7e7d37c585e01a1bcc583ea92b78fc759d.tar.xz
Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes
ARM: OMAP2+: first hwmod fix for v4.6-rc Fix a longstanding bug in the hwmod code that could cause hardware SYSCONFIG register values to not match the kernel's idea of what they should be, and that could result in lower performance during IP block idle entry. Basic build, boot, and PM test logs are available here: http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/
Diffstat (limited to 'tools/gpio/lsgpio.c')
-rw-r--r--tools/gpio/lsgpio.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c
new file mode 100644
index 000000000000..1124da375942
--- /dev/null
+++ b/tools/gpio/lsgpio.c
@@ -0,0 +1,195 @@
+/*
+ * 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"
+
+struct gpio_flag {
+ char *name;
+ unsigned long mask;
+};
+
+struct gpio_flag flagnames[] = {
+ {
+ .name = "kernel",
+ .mask = GPIOLINE_FLAG_KERNEL,
+ },
+ {
+ .name = "output",
+ .mask = GPIOLINE_FLAG_IS_OUT,
+ },
+ {
+ .name = "active-low",
+ .mask = GPIOLINE_FLAG_ACTIVE_LOW,
+ },
+ {
+ .name = "open-drain",
+ .mask = GPIOLINE_FLAG_OPEN_DRAIN,
+ },
+ {
+ .name = "open-source",
+ .mask = GPIOLINE_FLAG_OPEN_SOURCE,
+ },
+};
+
+void print_flags(unsigned long flags)
+{
+ int i;
+ int printed = 0;
+
+ for (i = 0; i < ARRAY_SIZE(flagnames); i++) {
+ if (flags & flagnames[i].mask) {
+ if (printed)
+ fprintf(stdout, " ");
+ fprintf(stdout, "%s", flagnames[i].name);
+ printed++;
+ }
+ }
+}
+
+int list_device(const char *device_name)
+{
+ struct gpiochip_info cinfo;
+ char *chrdev_name;
+ int fd;
+ int ret;
+ int i;
+
+ 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 exit_close_error;
+ }
+
+ /* Inspect this GPIO chip */
+ ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo);
+ if (ret == -1) {
+ ret = -errno;
+ perror("Failed to issue CHIPINFO IOCTL\n");
+ goto exit_close_error;
+ }
+ fprintf(stdout, "GPIO chip: %s, \"%s\", %u GPIO lines\n",
+ cinfo.name, cinfo.label, cinfo.lines);
+
+ /* Loop over the lines and print info */
+ for (i = 0; i < cinfo.lines; i++) {
+ struct gpioline_info linfo;
+
+ memset(&linfo, 0, sizeof(linfo));
+ linfo.line_offset = i;
+
+ ret = ioctl(fd, GPIO_GET_LINEINFO_IOCTL, &linfo);
+ if (ret == -1) {
+ ret = -errno;
+ perror("Failed to issue LINEINFO IOCTL\n");
+ goto exit_close_error;
+ }
+ fprintf(stdout, "\tline %2d:", linfo.line_offset);
+ if (linfo.name[0])
+ fprintf(stdout, " \"%s\"", linfo.name);
+ else
+ fprintf(stdout, " unnamed");
+ if (linfo.consumer[0])
+ fprintf(stdout, " \"%s\"", linfo.consumer);
+ else
+ fprintf(stdout, " unused");
+ if (linfo.flags) {
+ fprintf(stdout, " [");
+ print_flags(linfo.flags);
+ fprintf(stdout, "]");
+ }
+ fprintf(stdout, "\n");
+
+ }
+
+exit_close_error:
+ if (close(fd) == -1)
+ perror("Failed to close GPIO character device file");
+ 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;
+}