1 files changed, 130 insertions, 0 deletions
diff --git a/host/lib/usrp/tune_helper.cpp b/host/lib/usrp/tune_helper.cpp
new file mode 100644
index 000000000..e516477d3
--- /dev/null
+++ b/host/lib/usrp/tune_helper.cpp
@@ -0,0 +1,130 @@
+//
+// 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/usrp/tune_helper.hpp>
+#include <uhd/usrp/subdev_props.hpp>
+#include <uhd/usrp/dsp_props.hpp>
+#include <uhd/usrp/dboard_iface.hpp> //unit_t
+#include <boost/math/special_functions/sign.hpp>
+#include <cmath>
+
+using namespace uhd;
+using namespace uhd::usrp;
+
+/***********************************************************************
+ * Tune Helper Functions
+ **********************************************************************/
+static tune_result_t tune_xx_subdev_and_dxc(
+    dboard_iface::unit_t unit,
+    wax::obj subdev, wax::obj dxc,
+    double target_freq, double lo_offset
+){
+    wax::obj subdev_freq_proxy = subdev[SUBDEV_PROP_FREQ];
+    wax::obj dxc_freq_proxy = dxc[DSP_PROP_FREQ_SHIFT];
+    double dxc_sample_rate = dxc[DSP_PROP_CODEC_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>();
+
+    //perform the correction correction for dxc rates outside of nyquist
+    double delta_freq = std::fmod(target_freq - actual_inter_freq, dxc_sample_rate);
+    bool outside_of_nyquist = std::abs(delta_freq) > dxc_sample_rate/2.0;
+    double target_dxc_freq = (outside_of_nyquist)?
+        boost::math::sign(delta_freq)*dxc_sample_rate - delta_freq : -delta_freq;
+
+    //invert the sign on the dxc freq given the following conditions
+    if (unit == dboard_iface::UNIT_TX) target_dxc_freq *= -1.0;
+
+    dxc_freq_proxy = target_dxc_freq;
+    double actual_dxc_freq = dxc_freq_proxy.as<double>();
+
+    //load and return the tune result
+    tune_result_t tune_result;
+    tune_result.target_inter_freq = target_inter_freq;
+    tune_result.actual_inter_freq = actual_inter_freq;
+    tune_result.target_dsp_freq = target_dxc_freq;
+    tune_result.actual_dsp_freq = actual_dxc_freq;
+    return tune_result;
+}
+
+static double derive_freq_from_xx_subdev_and_dxc(
+    dboard_iface::unit_t unit,
+    wax::obj subdev, wax::obj dxc
+){
+    //extract actual dsp and IF frequencies
+    double actual_inter_freq = subdev[SUBDEV_PROP_FREQ].as<double>();
+    double actual_dxc_freq = dxc[DSP_PROP_FREQ_SHIFT].as<double>();
+
+    //invert the sign on the dxc freq given the following conditions
+    if (unit == dboard_iface::UNIT_TX) actual_dxc_freq *= -1.0;
+
+    return actual_inter_freq - actual_dxc_freq;
+}
+
+/***********************************************************************
+ * RX Tune
+ **********************************************************************/
+tune_result_t usrp::tune_rx_subdev_and_dsp(
+    wax::obj subdev, wax::obj ddc,
+    double target_freq, double lo_offset
+){
+    return tune_xx_subdev_and_dxc(dboard_iface::UNIT_RX, subdev, ddc, target_freq, lo_offset);
+}
+
+tune_result_t usrp::tune_rx_subdev_and_dsp(
+    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_USE_LO_OFFSET].as<bool>()){
+        lo_offset = 2.0*ddc[DSP_PROP_HOST_RATE].as<double>();
+    }
+    return tune_rx_subdev_and_dsp(subdev, ddc, target_freq, lo_offset);
+}
+
+double usrp::derive_freq_from_rx_subdev_and_dsp(wax::obj subdev, wax::obj ddc){
+    return derive_freq_from_xx_subdev_and_dxc(dboard_iface::UNIT_RX, subdev, ddc);
+}
+
+/***********************************************************************
+ * TX Tune
+ **********************************************************************/
+tune_result_t usrp::tune_tx_subdev_and_dsp(
+    wax::obj subdev, wax::obj duc,
+    double target_freq, double lo_offset
+){
+    return tune_xx_subdev_and_dxc(dboard_iface::UNIT_TX, subdev, duc, target_freq, lo_offset);
+}
+
+tune_result_t usrp::tune_tx_subdev_and_dsp(
+    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_USE_LO_OFFSET].as<bool>()){
+        lo_offset = 2.0*duc[DSP_PROP_HOST_RATE].as<double>();
+    }
+    return tune_tx_subdev_and_dsp(subdev, duc, target_freq, lo_offset);
+}
+
+double usrp::derive_freq_from_tx_subdev_and_dsp(wax::obj subdev, wax::obj duc){
+    return derive_freq_from_xx_subdev_and_dxc(dboard_iface::UNIT_TX, subdev, duc);
+}