portapack-mayhem/firmware/baseband/touch_dma.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 "touch_dma.hpp"

#include <cstdint>
#include <cstddef>
#include <array>

#include "hal.h"
#include "gpdma.hpp"
using namespace lpc43xx;

#include "portapack_dma.hpp"
#include "portapack_adc.hpp"
#include "portapack_shared_memory.hpp"

namespace touch {
namespace dma {

/* TODO: SO MUCH REPEATED CODE FROM rssi_dma.cpp!!! */

static constexpr auto& gpdma_channel = gpdma::channels[portapack::adc0_gpdma_channel_number];

constexpr uint32_t gpdma_ahb_master_peripheral = 1;
constexpr uint32_t gpdma_ahb_master_memory = 0;
constexpr uint32_t gpdma_ahb_master_lli_fetch = 0;

constexpr uint32_t gpdma_src_peripheral = 0xd;
constexpr uint32_t gpdma_dest_peripheral = 0xd;

constexpr gpdma::channel::LLIPointer lli_pointer(const void* lli) {
    return {
        .lm = gpdma_ahb_master_lli_fetch,
        .r = 0,
        .lli = reinterpret_cast<uint32_t>(lli),
    };
}

constexpr gpdma::channel::Control control(const size_t number_of_transfers) {
    return {
        .transfersize = number_of_transfers,
        .sbsize = 2, /* Burst size: 8 transfers */
        .dbsize = 2, /* Burst size: 8 transfers */
        .swidth = 2, /* Source transfer width: word (32 bits) */
        .dwidth = 2, /* Destination transfer width: word (32 bits) */
        .s = gpdma_ahb_master_peripheral,
        .d = gpdma_ahb_master_memory,
        .si = 1,
        .di = 1,
        .prot1 = 0,
        .prot2 = 0,
        .prot3 = 0,
        .i = 0,
    };
}

constexpr gpdma::channel::Config config() {
    return {
        .e = 0,
        .srcperipheral = gpdma_src_peripheral,
        .destperipheral = gpdma_dest_peripheral,
        .flowcntrl = gpdma::FlowControl::PeripheralToMemory_DMAControl,
        .ie = 0,
        .itc = 0,
        .l = 0,
        .a = 0,
        .h = 0,
    };
}

static gpdma::channel::LLI lli;

constexpr size_t channels_per_sample = 8;
// constexpr size_t samples_per_frame = 40;
// constexpr size_t channel_samples_per_frame = channels_per_sample * samples_per_frame;

void init() {
}

void allocate() {
    lli.srcaddr = reinterpret_cast<uint32_t>(&LPC_ADC0->DR[0]);
    lli.destaddr = reinterpret_cast<uint32_t>(&shared_memory.touch_adc_frame.dr[0]);
    lli.lli = lli_pointer(&lli);
    lli.control = control(channels_per_sample);
}

void free() {
}

void enable() {
    const auto gpdma_config = config();
    gpdma_channel.configure(lli, gpdma_config);
    gpdma_channel.enable();
}

bool is_enabled() {
    return gpdma_channel.is_enabled();
}

void disable() {
    gpdma_channel.disable();
}

} /* namespace dma */
} /* namespace touch */