portapack-mayhem/firmware/baseband/baseband_dma.cpp
Jared Boone 96da55d83a wait_for_buffer() now handles TX buffers.
Feels a bit awkward to read LLI src/dest to determine if RX or TX. But it works.
2016-08-10 10:34:14 -07:00

175 lines
5.6 KiB
C++

/*
* 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 "baseband_dma.hpp"
#include <cstdint>
#include <cstddef>
#include <array>
#include "hal.h"
#include "gpdma.hpp"
using namespace lpc43xx;
#include "portapack_dma.hpp"
#include "thread_wait.hpp"
namespace baseband {
namespace dma {
constexpr uint32_t gpdma_ahb_master_sgpio = 0;
constexpr uint32_t gpdma_ahb_master_memory = 1;
constexpr uint32_t gpdma_ahb_master_lli_fetch = 0;
constexpr uint32_t gpdma_src_peripheral = 0x0;
constexpr uint32_t gpdma_dest_peripheral = 0x0;
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 baseband::Direction direction, const size_t buffer_words) {
return {
.transfersize = buffer_words,
.sbsize = 0, /* Burst size: 1 */
.dbsize = 0, /* Burst size: 1 */
.swidth = 2, /* Source transfer width: word (32 bits) */
.dwidth = 2, /* Destination transfer width: word (32 bits) */
.s = (direction == baseband::Direction::Transmit) ? gpdma_ahb_master_memory : gpdma_ahb_master_sgpio,
.d = (direction == baseband::Direction::Transmit) ? gpdma_ahb_master_sgpio : gpdma_ahb_master_memory,
.si = (direction == baseband::Direction::Transmit) ? 1U : 0U,
.di = (direction == baseband::Direction::Transmit) ? 0U : 1U,
.prot1 = 0,
.prot2 = 0,
.prot3 = 0,
.i = 1,
};
}
constexpr gpdma::channel::Config config(const baseband::Direction direction) {
return {
.e = 0,
.srcperipheral = gpdma_src_peripheral,
.destperipheral = gpdma_dest_peripheral,
.flowcntrl = (direction == baseband::Direction::Transmit)
? gpdma::FlowControl::MemoryToPeripheral_DMAControl
: gpdma::FlowControl::PeripheralToMemory_DMAControl,
.ie = 1,
.itc = 1,
.l = 0,
.a = 0,
.h = 0,
};
}
constexpr size_t buffer_samples_log2n = 13;
constexpr size_t buffer_samples = (1 << buffer_samples_log2n);
constexpr size_t transfers_per_buffer_log2n = 2;
constexpr size_t transfers_per_buffer = (1 << transfers_per_buffer_log2n);
constexpr size_t transfer_samples = buffer_samples / transfers_per_buffer;
constexpr size_t transfers_mask = transfers_per_buffer - 1;
constexpr size_t buffer_bytes = buffer_samples * sizeof(baseband::sample_t);
constexpr size_t transfer_bytes = transfer_samples * sizeof(baseband::sample_t);
constexpr size_t msg_count = transfers_per_buffer - 1;
static std::array<gpdma::channel::LLI, transfers_per_buffer> lli_loop;
static constexpr auto& gpdma_channel_sgpio = gpdma::channels[portapack::sgpio_gpdma_channel_number];
static ThreadWait thread_wait;
static void transfer_complete() {
const auto next_lli_index = gpdma_channel_sgpio.next_lli() - &lli_loop[0];
thread_wait.wake_from_interrupt(next_lli_index);
}
static void dma_error() {
thread_wait.wake_from_interrupt(-1);
disable();
}
void init() {
gpdma_channel_sgpio.set_handlers(transfer_complete, dma_error);
#if defined(PORTAPACK_BASEBAND_DMA_NO_SYNC)
/* Disable synchronization logic to improve(?) DMA response time.
* SGPIO (peripheral) must be on same clock as GPDMA peripheral.
* SGPIO runs from BASE_PERIPH_CLK, which is set to PLL1 in normal
* operation, same as the M4 and M0 cores. Memory, of course, is
* running from the same clock as the cores.
*/
LPC_GPDMA->SYNC |= (1 << gpdma_src_peripheral);
LPC_GPDMA->SYNC |= (1 << gpdma_dest_peripheral);
#endif
}
void configure(
baseband::sample_t* const buffer_base,
const baseband::Direction direction
) {
const auto peripheral = reinterpret_cast<uint32_t>(&LPC_SGPIO->REG_SS[0]);
const auto control_value = control(direction, gpdma::buffer_words(transfer_bytes, 4));
for(size_t i=0; i<lli_loop.size(); i++) {
const auto memory = reinterpret_cast<uint32_t>(&buffer_base[i * transfer_samples]);
lli_loop[i].srcaddr = (direction == Direction::Transmit) ? memory : peripheral;
lli_loop[i].destaddr = (direction == Direction::Transmit) ? peripheral : memory;
lli_loop[i].lli = lli_pointer(&lli_loop[(i + 1) % lli_loop.size()]);
lli_loop[i].control = control_value;
}
}
void enable(const baseband::Direction direction) {
const auto gpdma_config = config(direction);
gpdma_channel_sgpio.configure(lli_loop[0], gpdma_config);
gpdma_channel_sgpio.enable();
}
bool is_enabled() {
return gpdma_channel_sgpio.is_enabled();
}
void disable() {
gpdma_channel_sgpio.disable();
}
baseband::buffer_t wait_for_buffer() {
const auto next_index = thread_wait.sleep();
if( next_index >= 0 ) {
const size_t free_index = (next_index + transfers_per_buffer - 2) & transfers_mask;
const auto src = lli_loop[free_index].srcaddr;
const auto dst = lli_loop[free_index].destaddr;
const auto p = (src == reinterpret_cast<uint32_t>(&LPC_SGPIO->REG_SS[0])) ? dst : src;
return { reinterpret_cast<sample_t*>(p), transfer_samples };
} else {
return { };
}
}
} /* namespace dma */
} /* namespace baseband */