tools/leds: Add uledmon program for monitoring userspace LEDs

The uleds driver provides userspace LED devices. This tool is used to
create one of these devices and monitor the changes in brighness for
testing purposes.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

3 files changed, 77 insertions, 0 deletions

diff --git a/tools/leds/.gitignore b/tools/leds/.gitignore
new file mode 100644
index 000000000000..ac96d9f53dfc
--- /dev/null
+++ b/tools/leds/.gitignore
@@ -0,0 +1 @@
+uledmon
diff --git a/tools/leds/Makefile b/tools/leds/Makefile
new file mode 100644
index 000000000000..c03a79ebf9c8
--- /dev/null
+++ b/tools/leds/Makefile
@@ -0,0 +1,13 @@
+# Makefile for LEDs tools
+
+CC = $(CROSS_COMPILE)gcc
+CFLAGS = -Wall -Wextra -g -I../../include/uapi
+
+all: uledmon
+%: %.c
+	$(CC) $(CFLAGS) -o $@ $^
+
+clean:
+	$(RM) uledmon
+
+.PHONY: all clean
diff --git a/tools/leds/uledmon.c b/tools/leds/uledmon.c
new file mode 100644
index 000000000000..25cbc7acf50a
--- /dev/null
+++ b/tools/leds/uledmon.c
@@ -0,0 +1,63 @@
+/*
+ * uledmon.c
+ *
+ * This program creates a new userspace LED class device and monitors it. A
+ * timestamp and brightness value is printed each time the brightness changes.
+ *
+ * Usage: uledmon <device-name>
+ *
+ * <device-name> is the name of the LED class device to be created. Pressing
+ * CTRL+C will exit.
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <linux/uleds.h>
+
+int main(int argc, char const *argv[])
+{
+	struct uleds_user_dev uleds_dev;
+	int fd, ret;
+	int brightness;
+	struct timespec ts;
+
+	if (argc != 2) {
+		fprintf(stderr, "Requires <device-name> argument\n");
+		return 1;
+	}
+
+	strncpy(uleds_dev.name, argv[1], LED_MAX_NAME_SIZE);
+	uleds_dev.max_brightness = 100;
+
+	fd = open("/dev/uleds", O_RDWR);
+	if (fd == -1) {
+		perror("Failed to open /dev/uleds");
+		return 1;
+	}
+
+	ret = write(fd, &uleds_dev, sizeof(uleds_dev));
+	if (ret == -1) {
+		perror("Failed to write to /dev/uleds");
+		close(fd);
+		return 1;
+	}
+
+	while (1) {
+		ret = read(fd, &brightness, sizeof(brightness));
+		if (ret == -1) {
+			perror("Failed to read from /dev/uleds");
+			close(fd);
+			return 1;
+		}
+		clock_gettime(CLOCK_MONOTONIC, &ts);
+		printf("[%ld.%09ld] %u\n", ts.tv_sec, ts.tv_nsec, brightness);
+	}
+
+	close(fd);
+
+	return 0;
+}