From cefca72c53f80dd483ac53a405b9e8870c1da10e Mon Sep 17 00:00:00 2001
From: David Lawrence <dlaw@dlaw.me>
Date: Sun, 3 Nov 2019 16:22:04 -0500
Subject: [PATCH] Override setGain and getGainRange to avoid changing RFGR.

SDRPlay's "RFGR" is actually a mode selector for the front-end LNA.
It does *not* have units of dB. (In fact, it is frequency-dependent.)
As a result, the default gain allocation algorithm does not apply and
only IFGR should be used for adjusting the overall system gain.
---
 Settings.cpp     | 18 ++++++++++++++++++
 SoapySDRPlay.hpp |  6 ++++++
 2 files changed, 24 insertions(+)

diff --git a/Settings.cpp b/Settings.cpp
index 8f6d5c6..0f929d1 100644
--- a/Settings.cpp
+++ b/Settings.cpp
@@ -653,6 +653,12 @@ void SoapySDRPlay::setGain(const int direction, const size_t channel, const std:
    }
 }
 
+void SoapySDRPlay::setGain(const int direction, const size_t channel, const double value)
+{
+   // Only IFGR should be used for adjusting the overall system gain.
+   this->setGain(direction, channel, "IFGR", value);
+}
+
 double SoapySDRPlay::getGain(const int direction, const size_t channel, const std::string &name) const
 {
     std::lock_guard <std::mutex> lock(_general_state_mutex);
@@ -669,6 +675,12 @@ double SoapySDRPlay::getGain(const int direction, const size_t channel, const st
    return 0;
 }
 
+double SoapySDRPlay::getGain(const int direction, const size_t channel) const
+{
+   // Only IFGR should be used for adjusting the overall system gain.
+   return this->getGain(direction, channel, "IFGR");
+}
+
 SoapySDR::Range SoapySDRPlay::getGainRange(const int direction, const size_t channel, const std::string &name) const
 {
    if (name == "IFGR")
@@ -698,6 +710,12 @@ SoapySDR::Range SoapySDRPlay::getGainRange(const int direction, const size_t cha
     return SoapySDR::Range(20, 59);
 }
 
+SoapySDR::Range SoapySDRPlay::getGainRange(const int direction, const size_t channel) const
+{
+   // Only IFGR should be used for adjusting the overall system gain.
+   return this->getGainRange(direction, channel, "IFGR");
+}
+
 /*******************************************************************
  * Frequency API
  ******************************************************************/
diff --git a/SoapySDRPlay.hpp b/SoapySDRPlay.hpp
index 086e73e..5009356 100644
--- a/SoapySDRPlay.hpp
+++ b/SoapySDRPlay.hpp
@@ -146,10 +146,16 @@ class SoapySDRPlay: public SoapySDR::Device
 
     void setGain(const int direction, const size_t channel, const std::string &name, const double value);
 
+    void setGain(const int direction, const size_t channel, const double value);
+
     double getGain(const int direction, const size_t channel, const std::string &name) const;
 
+    double getGain(const int direction, const size_t channel) const;
+
     SoapySDR::Range getGainRange(const int direction, const size_t channel, const std::string &name) const;
 
+    SoapySDR::Range getGainRange(const int direction, const size_t channel) const;
+
     /*******************************************************************
      * Frequency API
      ******************************************************************/