soapy: provide default gain range step

The soapysdr range type does not provide a step size,
however apps like the osmocom siggen use this size for a slider,
and a value of zero will cause a divide by zero error.

Although many ranges are not actually linear,
the idea to provide some default step to avoid crashes.
A future addition to the API may include providing a step.

2 files changed, 4 insertions, 4 deletions

diff --git a/lib/soapy/soapy_sink_c.cc b/lib/soapy/soapy_sink_c.cc
index c1f6fc1..b4dd219 100644
--- a/lib/soapy/soapy_sink_c.cc
+++ b/lib/soapy/soapy_sink_c.cc
@@ -184,14 +184,14 @@ std::vector<std::string> soapy_sink_c::get_gain_names( size_t chan)
 osmosdr::gain_range_t soapy_sink_c::get_gain_range( size_t chan)
 {
     SoapySDR::Range r = _device->getGainRange(SOAPY_SDR_TX, chan);
-    return osmosdr::gain_range_t(r.minimum(), r.maximum());
+    return osmosdr::gain_range_t(r.minimum(), r.maximum(), 1.0);
 }
 
 osmosdr::gain_range_t soapy_sink_c::get_gain_range( const std::string & name,
                                                 size_t chan)
 {
     SoapySDR::Range r = _device->getGainRange(SOAPY_SDR_TX, chan, name);
-    return osmosdr::gain_range_t(r.minimum(), r.maximum());
+    return osmosdr::gain_range_t(r.minimum(), r.maximum(), 1.0);
 }
 
 bool soapy_sink_c::set_gain_mode( bool automatic, size_t chan)
diff --git a/lib/soapy/soapy_source_c.cc b/lib/soapy/soapy_source_c.cc
index e64f34a..5fc0dbc 100644
--- a/lib/soapy/soapy_source_c.cc
+++ b/lib/soapy/soapy_source_c.cc
@@ -181,14 +181,14 @@ std::vector<std::string> soapy_source_c::get_gain_names( size_t chan )
 osmosdr::gain_range_t soapy_source_c::get_gain_range( size_t chan )
 {
     SoapySDR::Range r = _device->getGainRange(SOAPY_SDR_RX, chan);
-    return osmosdr::gain_range_t(r.minimum(), r.maximum());
+    return osmosdr::gain_range_t(r.minimum(), r.maximum(), 1.0);
 }
 
 osmosdr::gain_range_t soapy_source_c::get_gain_range( const std::string & name,
                                                 size_t chan )
 {
     SoapySDR::Range r = _device->getGainRange(SOAPY_SDR_RX, chan, name);
-    return osmosdr::gain_range_t(r.minimum(), r.maximum());
+    return osmosdr::gain_range_t(r.minimum(), r.maximum(), 1.0);
 }
 
 bool soapy_source_c::set_gain_mode( bool automatic, size_t chan )