@@ -4647,6 +4647,7 @@ F: include/linux/gpio/
F: include/linux/gpio.h
F: include/asm-generic/gpio.h
F: include/uapi/linux/gpio.h
+F: tools/gpio/
GRE DEMULTIPLEXER DRIVER
M: Dmitry Kozlov <xeb@mail.ru>
@@ -12,6 +12,7 @@ help:
@echo ' cgroup - cgroup tools'
@echo ' cpupower - a tool for all things x86 CPU power'
@echo ' firewire - the userspace part of nosy, an IEEE-1394 traffic sniffer'
+ @echo ' gpio - GPIO tools'
@echo ' hv - tools used when in Hyper-V clients'
@echo ' iio - IIO tools'
@echo ' lguest - a minimal 32-bit x86 hypervisor'
@@ -48,7 +49,7 @@ acpi: FORCE
cpupower: FORCE
$(call descend,power/$@)
-cgroup firewire hv guest usb virtio vm net iio: FORCE
+cgroup firewire hv guest usb virtio vm net iio gpio: FORCE
$(call descend,$@)
liblockdep: FORCE
@@ -109,7 +110,7 @@ acpi_clean:
cpupower_clean:
$(call descend,power/cpupower,clean)
-cgroup_clean hv_clean firewire_clean lguest_clean usb_clean virtio_clean vm_clean net_clean iio_clean:
+cgroup_clean hv_clean firewire_clean lguest_clean usb_clean virtio_clean vm_clean net_clean iio_clean gpio_clean:
$(call descend,$(@:_clean=),clean)
liblockdep_clean:
@@ -136,6 +137,6 @@ freefall_clean:
clean: acpi_clean cgroup_clean cpupower_clean hv_clean firewire_clean lguest_clean \
perf_clean selftests_clean turbostat_clean usb_clean virtio_clean \
vm_clean net_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
- freefall_clean
+ freefall_clean gpio_clean
.PHONY: FORCE
new file mode 100644
@@ -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
new file mode 100644
@@ -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"
new file mode 100644
@@ -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_ */
new file mode 100644
@@ -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;
+}
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> --- MAINTAINERS | 1 + tools/Makefile | 7 +-- tools/gpio/Makefile | 12 +++++ tools/gpio/gpio-utils.c | 11 +++++ tools/gpio/gpio-utils.h | 25 ++++++++++ tools/gpio/lsgpio.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 181 insertions(+), 3 deletions(-) create mode 100644 tools/gpio/Makefile create mode 100644 tools/gpio/gpio-utils.c create mode 100644 tools/gpio/gpio-utils.h create mode 100644 tools/gpio/lsgpio.c