Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 963 insertions, 0 deletions

diff --git a/tools/gpio/.gitignore b/tools/gpio/.gitignore
new file mode 100644
index 000000000..9e9dd4b68
--- /dev/null
+++ b/tools/gpio/.gitignore
@@ -0,0 +1,4 @@
+gpio-event-mon
+gpio-hammer
+lsgpio
+
diff --git a/tools/gpio/Build b/tools/gpio/Build
new file mode 100644
index 000000000..4141f3583
--- /dev/null
+++ b/tools/gpio/Build
@@ -0,0 +1,4 @@
+gpio-utils-y += gpio-utils.o
+lsgpio-y += lsgpio.o gpio-utils.o
+gpio-hammer-y += gpio-hammer.o gpio-utils.o
+gpio-event-mon-y += gpio-event-mon.o gpio-utils.o
diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile
new file mode 100644
index 000000000..3dbf7e8b0
--- /dev/null
+++ b/tools/gpio/Makefile
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: GPL-2.0
+include ../scripts/Makefile.include
+
+bindir ?= /usr/bin
+
+# This will work when gpio is built in tools env. where srctree
+# isn't set and when invoked from selftests build, where srctree
+# is set to ".". building_out_of_srctree is undefined for in srctree
+# builds
+ifndef building_out_of_srctree
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
+# Do not use make's built-in rules
+# (this improves performance and avoids hard-to-debug behaviour);
+MAKEFLAGS += -r
+
+CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
+
+ALL_TARGETS := lsgpio gpio-hammer gpio-event-mon
+ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
+
+all: $(ALL_PROGRAMS)
+
+export srctree OUTPUT CC LD CFLAGS
+include $(srctree)/tools/build/Makefile.include
+
+#
+# We need the following to be outside of kernel tree
+#
+$(OUTPUT)include/linux/gpio.h: ../../include/uapi/linux/gpio.h
+	mkdir -p $(OUTPUT)include/linux 2>&1 || true
+	ln -sf $(CURDIR)/../../include/uapi/linux/gpio.h $@
+
+prepare: $(OUTPUT)include/linux/gpio.h
+
+GPIO_UTILS_IN := $(OUTPUT)gpio-utils-in.o
+$(GPIO_UTILS_IN): prepare FORCE
+	$(Q)$(MAKE) $(build)=gpio-utils
+
+#
+# lsgpio
+#
+LSGPIO_IN := $(OUTPUT)lsgpio-in.o
+$(LSGPIO_IN): prepare FORCE $(OUTPUT)gpio-utils-in.o
+	$(Q)$(MAKE) $(build)=lsgpio
+$(OUTPUT)lsgpio: $(LSGPIO_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+#
+# gpio-hammer
+#
+GPIO_HAMMER_IN := $(OUTPUT)gpio-hammer-in.o
+$(GPIO_HAMMER_IN): prepare FORCE $(OUTPUT)gpio-utils-in.o
+	$(Q)$(MAKE) $(build)=gpio-hammer
+$(OUTPUT)gpio-hammer: $(GPIO_HAMMER_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+#
+# gpio-event-mon
+#
+GPIO_EVENT_MON_IN := $(OUTPUT)gpio-event-mon-in.o
+$(GPIO_EVENT_MON_IN): prepare FORCE $(OUTPUT)gpio-utils-in.o
+	$(Q)$(MAKE) $(build)=gpio-event-mon
+$(OUTPUT)gpio-event-mon: $(GPIO_EVENT_MON_IN)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
+
+clean:
+	rm -f $(ALL_PROGRAMS)
+	rm -f $(OUTPUT)include/linux/gpio.h
+	find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete
+
+install: $(ALL_PROGRAMS)
+	install -d -m 755 $(DESTDIR)$(bindir);		\
+	for program in $(ALL_PROGRAMS); do		\
+		install $$program $(DESTDIR)$(bindir);	\
+	done
+
+FORCE:
+
+.PHONY: all install clean FORCE prepare
diff --git a/tools/gpio/gpio-event-mon.c b/tools/gpio/gpio-event-mon.c
new file mode 100644
index 000000000..c864544ef
--- /dev/null
+++ b/tools/gpio/gpio-event-mon.c
@@ -0,0 +1,194 @@
+/*
+ * gpio-event-mon - monitor GPIO line events from userspace
+ *
+ * Copyright (C) 2016 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:
+ *	gpio-event-mon -n <device-name> -o <offset>
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <dirent.h>
+#include <errno.h>
+#include <string.h>
+#include <poll.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <linux/gpio.h>
+
+int monitor_device(const char *device_name,
+		   unsigned int line,
+		   uint32_t handleflags,
+		   uint32_t eventflags,
+		   unsigned int loops)
+{
+	struct gpioevent_request req;
+	struct gpiohandle_data data;
+	char *chrdev_name;
+	int fd;
+	int ret;
+	int i = 0;
+
+	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;
+	}
+
+	req.lineoffset = line;
+	req.handleflags = handleflags;
+	req.eventflags = eventflags;
+	strcpy(req.consumer_label, "gpio-event-mon");
+
+	ret = ioctl(fd, GPIO_GET_LINEEVENT_IOCTL, &req);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue GET EVENT "
+			"IOCTL (%d)\n",
+			ret);
+		goto exit_close_error;
+	}
+
+	/* Read initial states */
+	ret = ioctl(req.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue GPIOHANDLE GET LINE "
+			"VALUES IOCTL (%d)\n",
+			ret);
+		goto exit_close_error;
+	}
+
+	fprintf(stdout, "Monitoring line %d on %s\n", line, device_name);
+	fprintf(stdout, "Initial line value: %d\n", data.values[0]);
+
+	while (1) {
+		struct gpioevent_data event;
+
+		ret = read(req.fd, &event, sizeof(event));
+		if (ret == -1) {
+			if (errno == -EAGAIN) {
+				fprintf(stderr, "nothing available\n");
+				continue;
+			} else {
+				ret = -errno;
+				fprintf(stderr, "Failed to read event (%d)\n",
+					ret);
+				break;
+			}
+		}
+
+		if (ret != sizeof(event)) {
+			fprintf(stderr, "Reading event failed\n");
+			ret = -EIO;
+			break;
+		}
+		fprintf(stdout, "GPIO EVENT %llu: ", event.timestamp);
+		switch (event.id) {
+		case GPIOEVENT_EVENT_RISING_EDGE:
+			fprintf(stdout, "rising edge");
+			break;
+		case GPIOEVENT_EVENT_FALLING_EDGE:
+			fprintf(stdout, "falling edge");
+			break;
+		default:
+			fprintf(stdout, "unknown event");
+		}
+		fprintf(stdout, "\n");
+
+		i++;
+		if (i == loops)
+			break;
+	}
+
+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: gpio-event-mon [options]...\n"
+		"Listen to events on GPIO lines, 0->1 1->0\n"
+		"  -n <name>  Listen on GPIOs on a named device (must be stated)\n"
+		"  -o <n>     Offset to monitor\n"
+		"  -d         Set line as open drain\n"
+		"  -s         Set line as open source\n"
+		"  -r         Listen for rising edges\n"
+		"  -f         Listen for falling edges\n"
+		" [-c <n>]    Do <n> loops (optional, infinite loop if not stated)\n"
+		"  -?         This helptext\n"
+		"\n"
+		"Example:\n"
+		"gpio-event-mon -n gpiochip0 -o 4 -r -f\n"
+	);
+}
+
+int main(int argc, char **argv)
+{
+	const char *device_name = NULL;
+	unsigned int line = -1;
+	unsigned int loops = 0;
+	uint32_t handleflags = GPIOHANDLE_REQUEST_INPUT;
+	uint32_t eventflags = 0;
+	int c;
+
+	while ((c = getopt(argc, argv, "c:n:o:dsrf?")) != -1) {
+		switch (c) {
+		case 'c':
+			loops = strtoul(optarg, NULL, 10);
+			break;
+		case 'n':
+			device_name = optarg;
+			break;
+		case 'o':
+			line = strtoul(optarg, NULL, 10);
+			break;
+		case 'd':
+			handleflags |= GPIOHANDLE_REQUEST_OPEN_DRAIN;
+			break;
+		case 's':
+			handleflags |= GPIOHANDLE_REQUEST_OPEN_SOURCE;
+			break;
+		case 'r':
+			eventflags |= GPIOEVENT_REQUEST_RISING_EDGE;
+			break;
+		case 'f':
+			eventflags |= GPIOEVENT_REQUEST_FALLING_EDGE;
+			break;
+		case '?':
+			print_usage();
+			return -1;
+		}
+	}
+
+	if (!device_name || line == -1) {
+		print_usage();
+		return -1;
+	}
+	if (!eventflags) {
+		printf("No flags specified, listening on both rising and "
+		       "falling edges\n");
+		eventflags = GPIOEVENT_REQUEST_BOTH_EDGES;
+	}
+	return monitor_device(device_name, line, handleflags,
+			      eventflags, loops);
+}
diff --git a/tools/gpio/gpio-hammer.c b/tools/gpio/gpio-hammer.c
new file mode 100644
index 000000000..3da5462a0
--- /dev/null
+++ b/tools/gpio/gpio-hammer.c
@@ -0,0 +1,171 @@
+/*
+ * gpio-hammer - example swiss army knife to shake GPIO lines on a system
+ *
+ * Copyright (C) 2016 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:
+ *	gpio-hammer -n <device-name> -o <offset1> -o <offset2>
+ */
+
+#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 hammer_device(const char *device_name, unsigned int *lines, int nlines,
+		  unsigned int loops)
+{
+	struct gpiohandle_data data;
+	char swirr[] = "-\\|/";
+	int fd;
+	int ret;
+	int i, j;
+	unsigned int iteration = 0;
+
+	memset(&data.values, 0, sizeof(data.values));
+	ret = gpiotools_request_linehandle(device_name, lines, nlines,
+					   GPIOHANDLE_REQUEST_OUTPUT, &data,
+					   "gpio-hammer");
+	if (ret < 0)
+		goto exit_error;
+	else
+		fd = ret;
+
+	ret = gpiotools_get_values(fd, &data);
+	if (ret < 0)
+		goto exit_close_error;
+
+	fprintf(stdout, "Hammer lines [");
+	for (i = 0; i < nlines; i++) {
+		fprintf(stdout, "%d", lines[i]);
+		if (i != (nlines - 1))
+			fprintf(stdout, ", ");
+	}
+	fprintf(stdout, "] on %s, initial states: [", device_name);
+	for (i = 0; i < nlines; i++) {
+		fprintf(stdout, "%d", data.values[i]);
+		if (i != (nlines - 1))
+			fprintf(stdout, ", ");
+	}
+	fprintf(stdout, "]\n");
+
+	/* Hammertime! */
+	j = 0;
+	while (1) {
+		/* Invert all lines so we blink */
+		for (i = 0; i < nlines; i++)
+			data.values[i] = !data.values[i];
+
+		ret = gpiotools_set_values(fd, &data);
+		if (ret < 0)
+			goto exit_close_error;
+
+		/* Re-read values to get status */
+		ret = gpiotools_get_values(fd, &data);
+		if (ret < 0)
+			goto exit_close_error;
+
+		fprintf(stdout, "[%c] ", swirr[j]);
+		j++;
+		if (j == sizeof(swirr)-1)
+			j = 0;
+
+		fprintf(stdout, "[");
+		for (i = 0; i < nlines; i++) {
+			fprintf(stdout, "%d: %d", lines[i], data.values[i]);
+			if (i != (nlines - 1))
+				fprintf(stdout, ", ");
+		}
+		fprintf(stdout, "]\r");
+		fflush(stdout);
+		sleep(1);
+		iteration++;
+		if (loops && iteration == loops)
+			break;
+	}
+	fprintf(stdout, "\n");
+	ret = 0;
+
+exit_close_error:
+	gpiotools_release_linehandle(fd);
+exit_error:
+	return ret;
+}
+
+void print_usage(void)
+{
+	fprintf(stderr, "Usage: gpio-hammer [options]...\n"
+		"Hammer GPIO lines, 0->1->0->1...\n"
+		"  -n <name>  Hammer GPIOs on a named device (must be stated)\n"
+		"  -o <n>     Offset[s] to hammer, at least one, several can be stated\n"
+		" [-c <n>]    Do <n> loops (optional, infinite loop if not stated)\n"
+		"  -?         This helptext\n"
+		"\n"
+		"Example:\n"
+		"gpio-hammer -n gpiochip0 -o 4\n"
+	);
+}
+
+int main(int argc, char **argv)
+{
+	const char *device_name = NULL;
+	unsigned int lines[GPIOHANDLES_MAX];
+	unsigned int loops = 0;
+	int nlines;
+	int c;
+	int i;
+
+	i = 0;
+	while ((c = getopt(argc, argv, "c:n:o:?")) != -1) {
+		switch (c) {
+		case 'c':
+			loops = strtoul(optarg, NULL, 10);
+			break;
+		case 'n':
+			device_name = optarg;
+			break;
+		case 'o':
+			/*
+			 * Avoid overflow. Do not immediately error, we want to
+			 * be able to accurately report on the amount of times
+			 * '-o' was given to give an accurate error message
+			 */
+			if (i < GPIOHANDLES_MAX)
+				lines[i] = strtoul(optarg, NULL, 10);
+
+			i++;
+			break;
+		case '?':
+			print_usage();
+			return -1;
+		}
+	}
+
+	if (i >= GPIOHANDLES_MAX) {
+		fprintf(stderr,
+			"Only %d occurences of '-o' are allowed, %d were found\n",
+			GPIOHANDLES_MAX, i + 1);
+		return -1;
+	}
+
+	nlines = i;
+
+	if (!device_name || !nlines) {
+		print_usage();
+		return -1;
+	}
+	return hammer_device(device_name, lines, nlines, loops);
+}
diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c
new file mode 100644
index 000000000..cf7e2f341
--- /dev/null
+++ b/tools/gpio/gpio-utils.c
@@ -0,0 +1,270 @@
+/*
+ * GPIO tools - helpers library for the GPIO tools
+ *
+ * Copyright (C) 2015 Linus Walleij
+ * Copyright (C) 2016 Bamvor Jian Zhang
+ *
+ * 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 <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <sys/ioctl.h>
+#include <linux/gpio.h>
+#include "gpio-utils.h"
+
+#define COMSUMER "gpio-utils"
+
+/**
+ * doc: Operation of gpio
+ *
+ * Provide the api of gpiochip for chardev interface. There are two
+ * types of api.  The first one provide as same function as each
+ * ioctl, including request and release for lines of gpio, read/write
+ * the value of gpio. If the user want to do lots of read and write of
+ * lines of gpio, user should use this type of api.
+ *
+ * The second one provide the easy to use api for user. Each of the
+ * following api will request gpio lines, do the operation and then
+ * release these lines.
+ */
+/**
+ * gpiotools_request_linehandle() - request gpio lines in a gpiochip
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0"
+ * @lines:		An array desired lines, specified by offset
+ *			index for the associated GPIO device.
+ * @nline:		The number of lines to request.
+ * @flag:		The new flag for requsted gpio. Reference
+ *			"linux/gpio.h" for the meaning of flag.
+ * @data:		Default value will be set to gpio when flag is
+ *			GPIOHANDLE_REQUEST_OUTPUT.
+ * @consumer_label:	The name of consumer, such as "sysfs",
+ *			"powerkey". This is useful for other users to
+ *			know who is using.
+ *
+ * Request gpio lines through the ioctl provided by chardev. User
+ * could call gpiotools_set_values() and gpiotools_get_values() to
+ * read and write respectively through the returned fd. Call
+ * gpiotools_release_linehandle() to release these lines after that.
+ *
+ * Return:		On success return the fd;
+ *			On failure return the errno.
+ */
+int gpiotools_request_linehandle(const char *device_name, unsigned int *lines,
+				 unsigned int nlines, unsigned int flag,
+				 struct gpiohandle_data *data,
+				 const char *consumer_label)
+{
+	struct gpiohandle_request req;
+	char *chrdev_name;
+	int fd;
+	int i;
+	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, %s\n",
+			chrdev_name, strerror(errno));
+		goto exit_close_error;
+	}
+
+	for (i = 0; i < nlines; i++)
+		req.lineoffsets[i] = lines[i];
+
+	req.flags = flag;
+	strcpy(req.consumer_label, consumer_label);
+	req.lines = nlines;
+	if (flag & GPIOHANDLE_REQUEST_OUTPUT)
+		memcpy(req.default_values, data, sizeof(req.default_values));
+
+	ret = ioctl(fd, GPIO_GET_LINEHANDLE_IOCTL, &req);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue %s (%d), %s\n",
+			"GPIO_GET_LINEHANDLE_IOCTL", ret, strerror(errno));
+	}
+
+exit_close_error:
+	if (close(fd) == -1)
+		perror("Failed to close GPIO character device file");
+	free(chrdev_name);
+	return ret < 0 ? ret : req.fd;
+}
+/**
+ * gpiotools_set_values(): Set the value of gpio(s)
+ * @fd:			The fd returned by
+ *			gpiotools_request_linehandle().
+ * @data:		The array of values want to set.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_set_values(const int fd, struct gpiohandle_data *data)
+{
+	int ret;
+
+	ret = ioctl(fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, data);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue %s (%d), %s\n",
+			"GPIOHANDLE_SET_LINE_VALUES_IOCTL", ret,
+			strerror(errno));
+	}
+
+	return ret;
+}
+
+/**
+ * gpiotools_get_values(): Get the value of gpio(s)
+ * @fd:			The fd returned by
+ *			gpiotools_request_linehandle().
+ * @data:		The array of values get from hardware.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_get_values(const int fd, struct gpiohandle_data *data)
+{
+	int ret;
+
+	ret = ioctl(fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, data);
+	if (ret == -1) {
+		ret = -errno;
+		fprintf(stderr, "Failed to issue %s (%d), %s\n",
+			"GPIOHANDLE_GET_LINE_VALUES_IOCTL", ret,
+			strerror(errno));
+	}
+
+	return ret;
+}
+
+/**
+ * gpiotools_release_linehandle(): Release the line(s) of gpiochip
+ * @fd:			The fd returned by
+ *			gpiotools_request_linehandle().
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_release_linehandle(const int fd)
+{
+	int ret;
+
+	ret = close(fd);
+	if (ret == -1) {
+		perror("Failed to close GPIO LINEHANDLE device file");
+		ret = -errno;
+	}
+
+	return ret;
+}
+
+/**
+ * gpiotools_get(): Get value from specific line
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0"
+ * @line:		number of line, such as 2.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_get(const char *device_name, unsigned int line)
+{
+	struct gpiohandle_data data;
+	unsigned int lines[] = {line};
+
+	gpiotools_gets(device_name, lines, 1, &data);
+	return data.values[0];
+}
+
+
+/**
+ * gpiotools_gets(): Get values from specific lines.
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0".
+ * @lines:		An array desired lines, specified by offset
+ *			index for the associated GPIO device.
+ * @nline:		The number of lines to request.
+ * @data:		The array of values get from gpiochip.
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_gets(const char *device_name, unsigned int *lines,
+		   unsigned int nlines, struct gpiohandle_data *data)
+{
+	int fd;
+	int ret;
+	int ret_close;
+
+	ret = gpiotools_request_linehandle(device_name, lines, nlines,
+					   GPIOHANDLE_REQUEST_INPUT, data,
+					   COMSUMER);
+	if (ret < 0)
+		return ret;
+
+	fd = ret;
+	ret = gpiotools_get_values(fd, data);
+	ret_close = gpiotools_release_linehandle(fd);
+	return ret < 0 ? ret : ret_close;
+}
+
+/**
+ * gpiotools_set(): Set value to specific line
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0"
+ * @line:		number of line, such as 2.
+ * @value:		The value of gpio, must be 0(low) or 1(high).
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_set(const char *device_name, unsigned int line,
+		  unsigned int value)
+{
+	struct gpiohandle_data data;
+	unsigned int lines[] = {line};
+
+	data.values[0] = value;
+	return gpiotools_sets(device_name, lines, 1, &data);
+}
+
+/**
+ * gpiotools_sets(): Set values to specific lines.
+ * @device_name:	The name of gpiochip without prefix "/dev/",
+ *			such as "gpiochip0".
+ * @lines:		An array desired lines, specified by offset
+ *			index for the associated GPIO device.
+ * @nline:		The number of lines to request.
+ * @data:		The array of values set to gpiochip, must be
+ *			0(low) or 1(high).
+ *
+ * Return:		On success return 0;
+ *			On failure return the errno.
+ */
+int gpiotools_sets(const char *device_name, unsigned int *lines,
+		   unsigned int nlines, struct gpiohandle_data *data)
+{
+	int ret;
+
+	ret = gpiotools_request_linehandle(device_name, lines, nlines,
+					   GPIOHANDLE_REQUEST_OUTPUT, data,
+					   COMSUMER);
+	if (ret < 0)
+		return ret;
+
+	return gpiotools_release_linehandle(ret);
+}
diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h
new file mode 100644
index 000000000..344ea041f
--- /dev/null
+++ b/tools/gpio/gpio-utils.h
@@ -0,0 +1,43 @@
+/*
+ * 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>
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+static inline int check_prefix(const char *str, const char *prefix)
+{
+	return strlen(str) > strlen(prefix) &&
+		strncmp(str, prefix, strlen(prefix)) == 0;
+}
+
+int gpiotools_request_linehandle(const char *device_name, unsigned int *lines,
+				 unsigned int nlines, unsigned int flag,
+				 struct gpiohandle_data *data,
+				 const char *consumer_label);
+int gpiotools_set_values(const int fd, struct gpiohandle_data *data);
+int gpiotools_get_values(const int fd, struct gpiohandle_data *data);
+int gpiotools_release_linehandle(const int fd);
+
+int gpiotools_get(const char *device_name, unsigned int line);
+int gpiotools_gets(const char *device_name, unsigned int *lines,
+		   unsigned int nlines, struct gpiohandle_data *data);
+int gpiotools_set(const char *device_name, unsigned int line,
+		  unsigned int value);
+int gpiotools_sets(const char *device_name, unsigned int *lines,
+		   unsigned int nlines, struct gpiohandle_data *data);
+
+#endif /* _GPIO_UTILS_H_ */
diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c
new file mode 100644
index 000000000..eb3f56efd
--- /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 = NULL;
+	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;
+}