a simple tool to poke the new device

helloctl/hellctl.c

@@ -0,0 +1,27 @@
+#include <stdio.h> 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <string.h>
+#include <unistd.h>
+
+#define HELLOCTL "/dev/helloctl"
+
+int main(int argc, char ** argv) {
+	int fd = -1;
+	fd = open(HELLOCTL, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "Could not open %s\n", HELLOCTL);
+		_exit(1);
+	}
+
+	int ret;
+	if (ret = ioctl(fd, 1, 1) < 0) {
+		fprintf(stderr, "ioctl failed with: %s\n", strerror(ret));
+		goto done;
+	}
+done:
+	close(fd);
+}