uhd

//

// 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 "usrp2_impl.hpp"

#include "usrp2_regs.hpp"

#include <uhd/usrp/dsp_props.hpp>

#include <uhd/utils/assert.hpp>

#include <boost/format.hpp>

#include <boost/bind.hpp>

#include <boost/assign/list_of.hpp>

#include <boost/math/special_functions/round.hpp>

using namespace uhd;

using namespace uhd::usrp;

static const size_t default_decim = 16;

static const size_t default_interp = 16;

#define rint boost::math::iround

template <class T> T log2(T num){

    return std::log(num)/std::log(T(2));

}

/***********************************************************************

 * DDC Helper Methods

 **********************************************************************/

static boost::uint32_t calculate_freq_word_and_update_actual_freq(double &freq, double clock_freq){

    double scale_factor = std::pow(2.0, 32);

    //calculate the freq register word

    boost::uint32_t freq_word = rint((freq / clock_freq) * scale_factor);

    //update the actual frequency

    freq = (double(freq_word) / scale_factor) * clock_freq;

    return freq_word;

}

static boost::uint32_t calculate_iq_scale_word(boost::int16_t i, boost::int16_t q){

    return (boost::uint16_t(i) << 16) | (boost::uint16_t(q) << 0);

}

template <class rate_t> static rate_t

pick_closest_rate(double exact_rate, const std::vector<rate_t> &rates){

    rate_t closest_match = rates.at(0);

    BOOST_FOREACH(rate_t possible_rate, rates){

        if(std::abs(exact_rate - possible_rate) < std::abs(exact_rate - closest_match))

            closest_match = possible_rate;

    }

    return closest_match;

}

void usrp2_impl::init_ddc_config(void){

    //create the ddc in the rx dsp dict

    _rx_dsp_proxy = wax_obj_proxy::make(

        boost::bind(&usrp2_impl::ddc_get, this, _1, _2),

        boost::bind(&usrp2_impl::ddc_set, this, _1, _2)

    );

    //initial config and update

    _ddc_decim = default_decim;

    _ddc_freq = 0;

    update_ddc_config();

    //initial command that kills streaming (in case if was left on)

    issue_ddc_stream_cmd(stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);

}

void usrp2_impl::update_ddc_config(void){

    //set the decimation

    _iface->poke32(FR_DSP_RX_DECIM_RATE, _ddc_decim);

    //set the scaling

    static const boost::int16_t default_rx_scale_iq = 1024;

    _iface->poke32(FR_DSP_RX_SCALE_IQ,

        calculate_iq_scale_word(default_rx_scale_iq, default_rx_scale_iq)

    );

}

/***********************************************************************

 * DDC Properties

 **********************************************************************/

void usrp2_impl::ddc_get(const wax::obj &key, wax::obj &val){

    switch(key.as<dsp_prop_t>()){

    case DSP_PROP_NAME:

        val = std::string("usrp2 ddc0");

        return;

    case DSP_PROP_OTHERS:

        val = prop_names_t(); //empty

        return;

    case DSP_PROP_FREQ_SHIFT:

        val = _ddc_freq;

        return;

    case DSP_PROP_CODEC_RATE:

        val = get_master_clock_freq();

        return;

    case DSP_PROP_HOST_RATE:

        val = get_master_clock_freq()/_ddc_decim;

        return;

    }

}

void usrp2_impl::ddc_set(const wax::obj &key, const wax::obj &val){

    switch(key.as<dsp_prop_t>()){

    case DSP_PROP_FREQ_SHIFT:{

            double new_freq = val.as<double>();

            ASSERT_THROW(new_freq <= get_master_clock_freq()/2.0);

            ASSERT_THROW(new_freq >= -get_master_clock_freq()/2.0);

            _ddc_freq = new_freq; //shadow

            _iface->poke32(FR_DSP_RX_FREQ,

                calculate_freq_word_and_update_actual_freq(_ddc_freq, get_master_clock_freq())

            );

        }

        return;

    case DSP_PROP_HOST_RATE:{

            double extact_rate = get_master_clock_freq()/val.as<double>();

            _ddc_decim = pick_closest_rate(extact_rate, _allowed_decim_and_interp_rates);

            update_ddc_config();

        }

        return;

    default:

        throw std::runtime_error("Error: trying to set read-only property on usrp2 ddc0");

    }

}

/***********************************************************************

 * DUC Helper Methods

 **********************************************************************/

void usrp2_impl::init_duc_config(void){

    //create the duc in the tx dsp dict

    _tx_dsp_proxy = wax_obj_proxy::make(

        boost::bind(&usrp2_impl::duc_get, this, _1, _2),

        boost::bind(&usrp2_impl::duc_set, this, _1, _2)

    );

    //initial config and update

    _duc_interp = default_interp;

    _duc_freq = 0;

    update_duc_config();

}

void usrp2_impl::update_duc_config(void){

    // Calculate CIC interpolation (i.e., without halfband interpolators)

    size_t tmp_interp = _duc_interp;

    while(tmp_interp > 128) tmp_interp /= 2;

    // Calculate closest multiplier constant to reverse gain absent scale multipliers

    double interp_cubed = std::pow(double(tmp_interp), 3);

    boost::int16_t scale = rint((4096*std::pow(2, ceil(log2(interp_cubed))))/(1.65*interp_cubed));

    //set the interpolation

    _iface->poke32(FR_DSP_TX_INTERP_RATE, _ddc_decim);

    //set the scaling

    _iface->poke32(FR_DSP_TX_SCALE_IQ, calculate_iq_scale_word(scale, scale));

}

/***********************************************************************

 * DUC Properties

 **********************************************************************/

void usrp2_impl::duc_get(const wax::obj &key, wax::obj &val){

    switch(key.as<dsp_prop_t>()){

    case DSP_PROP_NAME:

        val = std::string("usrp2 duc0");

        return;

    case DSP_PROP_OTHERS:

        val = prop_names_t(); //empty

        return;

    case DSP_PROP_FREQ_SHIFT:

        val = _duc_freq;

        return;

    case DSP_PROP_CODEC_RATE:

        val = get_master_clock_freq();

        return;

    case DSP_PROP_HOST_RATE:

        val = get_master_clock_freq()/_duc_interp;

        return;

    }

}

void usrp2_impl::duc_set(const wax::obj &key, const wax::obj &val){

    switch(key.as<dsp_prop_t>()){

    case DSP_PROP_FREQ_SHIFT:{

            double new_freq = val.as<double>();

            ASSERT_THROW(new_freq <= get_master_clock_freq()/2.0);

            ASSERT_THROW(new_freq >= -get_master_clock_freq()/2.0);

            _duc_freq = new_freq; //shadow

            _iface->poke32(FR_DSP_TX_FREQ,

                calculate_freq_word_and_update_actual_freq(_duc_freq, get_master_clock_freq())

            );

        }

        return;

    case DSP_PROP_HOST_RATE:{

            double extact_rate = get_master_clock_freq()/val.as<double>();

            _duc_interp = pick_closest_rate(extact_rate, _allowed_decim_and_interp_rates);

            update_duc_config();

        }

        return;

    default:

        throw std::runtime_error("Error: trying to set read-only property on usrp2 duc0");

    }

}