summaryrefslogtreecommitdiffstats
path: root/tools/leds/uledmon.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/leds/uledmon.c')
-rw-r--r--tools/leds/uledmon.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/tools/leds/uledmon.c b/tools/leds/uledmon.c
new file mode 100644
index 000000000..c15a39c1f
--- /dev/null
+++ b/tools/leds/uledmon.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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;
+}