atrf-path: generalized sweep interface (for reuse)

- sweep.h (struct sweep ), atrf-path.c (sample, do_sweeps, main): pass
  sweep parameters via a struct
- sweep.h (do_sweep), atrf-path.c (do_sweep, do_sweeps): separated single
  sweep and made it public
- sweep.h (struct sample), atrf-path.c (sample, print_sweep, do_sweeps):
  made "sample" and do_sweep return the sample value/vector and moved
  output from "sample" to print_sweep

tools/atrf-path/sweep.h

@@ -0,0 +1,37 @@
+/*
+ * atrf-path/sweep.h - Measure path characteristics
+ *
+ * Written 2011 by Werner Almesberger
+ * Copyright 2011 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+#ifndef	SWEEP_H
+#define	SWEEP_H
+
+#include "atrf.h"
+
+
+struct sweep {
+	struct atrf_dsc *tx;
+	struct atrf_dsc *rx;
+	int trim_tx;
+	int trim_rx;
+	int power;
+	int samples;
+};
+
+struct sample {
+	double avg;
+	double min, max;
+};
+
+
+void do_sweep(const struct sweep *sweep, struct sample *res);
+
+#endif /* !SWEEP_H */