soapy: support step size in gain ranges

* This change is backwards compatible and checks for API support for step size.
* Created soapy_common.cc/h to house common gain range functions
* Moved factory mutex declaration to common source files as well

1 files changed, 43 insertions, 0 deletions

diff --git a/lib/soapy/soapy_common.cc b/lib/soapy/soapy_common.cc
new file mode 100644
index 0000000..0e277e4
--- /dev/null
+++ b/lib/soapy/soapy_common.cc
@@ -0,0 +1,43 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2017 Josh Blum <josh@joshknows.com>
+ *
+ * GNU Radio 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 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "soapy_common.h"
+#include <SoapySDR/Version.hpp>
+
+osmosdr::gain_range_t soapy_range_to_gain_range(const SoapySDR::Range &r)
+{
+    //default step size when unspecified
+    double step = 1.0;
+
+    //support the step size in 0.6 API and above
+    //but do not allow unspecified steps
+    //to avoid device by zero in some applications
+    #ifdef SOAPY_SDR_API_HAS_RANGE_TYPE_STEP
+    if (r.step() != 0.0) step = r.step();
+    #endif
+
+    return osmosdr::gain_range_t(r.minimum(), r.maximum(), step);
+}
+
+boost::mutex &get_soapy_maker_mutex(void)
+{
+    static boost::mutex m;
+    return m;
+}