1 files changed, 125 insertions, 0 deletions
diff --git a/host/lib/tune_helper.cpp b/host/lib/tune_helper.cpp
new file mode 100644
index 000000000..1e5c4cd0d
--- /dev/null
+++ b/host/lib/tune_helper.cpp
@@ -0,0 +1,125 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// 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 3 of the License, or
+// (at your option) any later version.
+//
+// This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#include <uhd/utils/tune_helper.hpp>
+#include <uhd/utils/algorithm.hpp>
+#include <uhd/props.hpp>
+#include <cmath>
+
+using namespace uhd;
+
+/***********************************************************************
+ * Tune Helper Function
+ **********************************************************************/
+static tune_result_t tune_xx_subdev_and_dxc(
+    bool is_tx,
+    wax::obj subdev, wax::obj dxc,
+    double target_freq, double lo_offset
+){
+    wax::obj subdev_freq_proxy = subdev[SUBDEV_PROP_FREQ];
+    bool subdev_quadrature = subdev[SUBDEV_PROP_QUADRATURE].as<bool>();
+    bool subdev_spectrum_inverted = subdev[SUBDEV_PROP_SPECTRUM_INVERTED].as<bool>();
+    wax::obj dxc_freq_proxy = dxc[std::string("freq")];
+    double dxc_sample_rate = dxc[std::string("if_rate")].as<double>();
+
+    // Ask the d'board to tune as closely as it can to target_freq+lo_offset
+    double target_inter_freq = target_freq + lo_offset;
+    subdev_freq_proxy = target_inter_freq;
+    double actual_inter_freq = subdev_freq_proxy.as<double>();
+
+    // Calculate the DDC setting that will downconvert the baseband from the
+    // daughterboard to our target frequency.
+    double delta_freq = target_freq - actual_inter_freq;
+    double delta_sign = std::signum(delta_freq);
+    delta_freq *= delta_sign;
+    delta_freq = std::fmod(delta_freq, dxc_sample_rate);
+    bool inverted = delta_freq > dxc_sample_rate/2.0;
+    double target_dxc_freq = inverted? (delta_freq - dxc_sample_rate) : (-delta_freq);
+    target_dxc_freq *= delta_sign;
+
+    // If the spectrum is inverted, and the daughterboard doesn't do
+    // quadrature downconversion, we can fix the inversion by flipping the
+    // sign of the dxc_freq...  (This only happens using the basic_rx board)
+    if (subdev_spectrum_inverted){
+        inverted = not inverted;
+    }
+    if (inverted and not subdev_quadrature){
+        target_dxc_freq *= -1.0;
+        inverted = not inverted;
+    }
+    // down conversion versus up conversion, fight!
+    // your mother is ugly and your going down...
+    target_dxc_freq *= (is_tx)? -1.0 : +1.0;
+
+    dxc_freq_proxy = target_dxc_freq;
+    double actual_dxc_freq = dxc_freq_proxy.as<double>();
+
+    //return some kind of tune result tuple/struct
+    tune_result_t tune_result;
+    tune_result.target_inter_freq = target_inter_freq;
+    tune_result.actual_inter_freq = actual_inter_freq;
+    tune_result.target_dxc_freq = target_dxc_freq;
+    tune_result.actual_dxc_freq = actual_dxc_freq;
+    tune_result.spectrum_inverted = inverted;
+    return tune_result;
+}
+
+/***********************************************************************
+ * RX Tune
+ **********************************************************************/
+tune_result_t uhd::tune_rx_subdev_and_ddc(
+    wax::obj subdev, wax::obj ddc,
+    double target_freq, double lo_offset
+){
+    bool is_tx = false;
+    return tune_xx_subdev_and_dxc(is_tx, subdev, ddc, target_freq, lo_offset);
+}
+
+tune_result_t uhd::tune_rx_subdev_and_ddc(
+    wax::obj subdev, wax::obj ddc,
+    double target_freq
+){
+    double lo_offset = 0.0;
+    //if the local oscillator will be in the passband, use an offset
+    if (subdev[SUBDEV_PROP_LO_INTERFERES].as<bool>()){
+        lo_offset = 2.0*ddc[std::string("bb_rate")].as<double>();
+    }
+    return tune_rx_subdev_and_ddc(subdev, ddc, target_freq, lo_offset);
+}
+
+/***********************************************************************
+ * TX Tune
+ **********************************************************************/
+tune_result_t uhd::tune_tx_subdev_and_duc(
+    wax::obj subdev, wax::obj duc,
+    double target_freq, double lo_offset
+){
+    bool is_tx = true;
+    return tune_xx_subdev_and_dxc(is_tx, subdev, duc, target_freq, lo_offset);
+}
+
+tune_result_t uhd::tune_tx_subdev_and_duc(
+    wax::obj subdev, wax::obj duc,
+    double target_freq
+){
+    double lo_offset = 0.0;
+    //if the local oscillator will be in the passband, use an offset
+    if (subdev[SUBDEV_PROP_LO_INTERFERES].as<bool>()){
+        lo_offset = 2.0*duc[std::string("bb_rate")].as<double>();
+    }
+    return tune_tx_subdev_and_duc(subdev, duc, target_freq, lo_offset);
+}