mayhem-firmware/firmware/application/rf_path.cpp

/*
 * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
 *
 * This file is part of PortaPack.
 *
 * 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 2, 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; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "rf_path.hpp"
#include "platform.hpp"
#include "utility.hpp"
#include "gpio.hpp"
using namespace gpio_control;

namespace rf {
namespace path {

void Path::init() {
    /* Set safe initial default states */
    direction = Direction::Receive;
    rf_amp_en = false;
    ant_bias_en = false;

#ifdef PRALINE
    band = Band::Low;
#else
    band = Band::Mid;
#endif

    update();
}

void Path::set_direction(const Direction new_direction) {
    direction = new_direction;
    update();
}

void Path::set_band(const Band new_band) {
    band = new_band;
    update();
}

void Path::set_rf_amp(const bool new_rf_amp) {
    rf_amp_en = new_rf_amp;
    update();
}

void Path::set_ant_bias(const bool new_ant_bias) {
    ant_bias_en = new_ant_bias;
    update();
}

bool Path::get_ant_bias() const {
    return ant_bias_en;
}

void Path::update() {
    const bool is_tx = (direction == Direction::Transmit);

#ifdef PRALINE
    // PRALINE specific RF path control directly applied to pins.
    // Active-low pin inversion is handled internally inside setState().

    tx_enable.setState(is_tx);

    // On the PRALINE board the RFFC5072 mixer is used on BOTH the Low band
    // (<2320 MHz, low-side image reject, LPF) and the High band (>2580 MHz,
    // high-side image reject, LPF off). It is bypassed only in the Mid window
    // (2320-2580 MHz) where the MAX2831 tunes the RF directly. This mirrors the
    // reference firmware (hackrf rf_path.c rf_path_set_filter(): LOW_PASS and
    // HIGH_PASS both call mixer_enable(); only BYPASS disables it).
    //
    // setState() handles the active-low MIX_ENABLE_N inversion, so 'true' means
    // "mixer enabled". Bypassing the mixer on the High band leaves the MAX2831
    // IF (~2.3-2.7 GHz) at the antenna port instead of the requested RF, which
    // made TX (and RX) above 2580 MHz effectively not work.

    mix_bypass.setState(band != Band::Mid);

    lpf.setState(band == Band::Low);
    rf_amp_enable.setState(rf_amp_en);
    ant_bias.setState(ant_bias_en);

#else

    const bool is_rx = (direction == Direction::Receive);

    // HackRF One (OG & R9) RF path control
    const bool mix_bypass_en = (band == Band::Mid);
    const bool amplify = rf_amp_en;

    // Primary TX/RX routing switches
    if (!hackrf_r9) {
        og_tx.setState(is_tx);
    }

    if (hackrf_r9) {
        r9_rx.setState(is_rx);  // Single pin handles directional switching on R9
    } else {
        og_rx.setState(is_rx);
    }

    // RF path switch configuration matrix
    rx_mix_bypass.setState(mix_bypass_en);
    tx_mix_bp.setState(is_tx && mix_bypass_en);
    rx_mix_bp.setState(is_rx && mix_bypass_en);

    hpf.setState(band == Band::High);
    lpf.setState(band == Band::Low);

    amp_bypass.setState(!amplify);
    tx_amp.setState(is_tx && amplify);
    rx_amp.setState(is_rx && amplify);

    tx_mix_bypass.setState(mix_bypass_en);
    tx_amp_pwr.setState(is_tx && amplify);
    rx_amp_pwr.setState(is_rx && amplify);

    if (hackrf_r9) {
        ant_bias.setState(ant_bias_en);
    }
#endif
}

}  // namespace path
}  // namespace rf