diff options
Diffstat (limited to 'tools/leds/uledmon.c')
-rw-r--r-- | tools/leds/uledmon.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/tools/leds/uledmon.c b/tools/leds/uledmon.c new file mode 100644 index 0000000..25cbc7a --- /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; +} |