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authorDavid Lechner <david@lechnology.com>2016-09-16 22:16:50 +0300
committerJacek Anaszewski <j.anaszewski@samsung.com>2016-11-22 14:07:02 +0300
commitfa7f32422ea1ac276b45b96a540ed5981caaa61f (patch)
treea11d1dede38a7a7bf9eb45a81b6d4ab31a953e5c /tools/leds/uledmon.c
parenteb1ce7469940b4eb8a466d9ae4d032fb2c9969dc (diff)
downloadlinux-fa7f32422ea1ac276b45b96a540ed5981caaa61f.tar.xz
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>
Diffstat (limited to 'tools/leds/uledmon.c')
-rw-r--r--tools/leds/uledmon.c63
1 files changed, 63 insertions, 0 deletions
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;
+}