From 16e0e1f7ca0859367ee94884ed1ae463bdab4643 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beat=20K=C3=BCng?= <beat-kueng@gmx.net>
Date: Thu, 4 May 2017 16:42:41 +0200
Subject: [PATCH] perf: add documentation

---
 src/systemcmds/perf/perf.c | 34 ++++++++++++++--------------------
 1 file changed, 14 insertions(+), 20 deletions(-)

diff --git a/src/systemcmds/perf/perf.c b/src/systemcmds/perf/perf.c
index 49551aec93..b030ee8df1 100644
--- a/src/systemcmds/perf/perf.c
+++ b/src/systemcmds/perf/perf.c
@@ -31,36 +31,30 @@
  *
  ****************************************************************************/
 
-/****************************************************************************
- * Included Files
- ****************************************************************************/
 
 
 #include <px4_config.h>
+#include <px4_module.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <string.h>
 
 #include "systemlib/perf_counter.h"
 
-
-/****************************************************************************
- * Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Private Data
- ****************************************************************************/
-
-/****************************************************************************
- * Public Functions
- ****************************************************************************/
-
 __EXPORT int perf_main(int argc, char *argv[]);
 
-/****************************************************************************
- * user_start
- ****************************************************************************/
+
+static void print_usage(void)
+{
+	PRINT_MODULE_DESCRIPTION("Tool to print performance counters");
+
+	PRINT_MODULE_USAGE_NAME_SIMPLE("perf", "command");
+	PRINT_MODULE_USAGE_COMMAND_DESCR("reset", "Reset all counters");
+	PRINT_MODULE_USAGE_COMMAND_DESCR("latency", "Print HRT timer latency histogram");
+
+	PRINT_MODULE_USAGE_PARAM_COMMENT("Prints all performance counters if no arguments given");
+}
+
 
 int perf_main(int argc, char *argv[])
 {
@@ -75,7 +69,7 @@ int perf_main(int argc, char *argv[])
 			return 0;
 		}
 
-		printf("Usage: perf [reset | latency]\n");
+		print_usage();
 		return -1;
 	}