Initial firmware commit.

firmware/baseband/rssi_dma.cpp

@@ -0,0 +1,182 @@
+/*
+ * 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 "rssi_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"
+
+namespace rf {
+namespace rssi {
+namespace dma {
+
+/* TODO: SO MUCH REPEATED CODE IN touch_dma.cpp!!! */
+
+static constexpr auto& gpdma_channel = gpdma::channels[portapack::adc1_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_peripheral = 0xe;
+constexpr uint32_t gpdma_src_peripheral = gpdma_peripheral;
+constexpr uint32_t gpdma_dest_peripheral = gpdma_peripheral;
+
+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 = 0,  /* Burst size: 1 transfer */
+		.dbsize = 0,  /* Burst size: 1 transfer */
+		.swidth = 0,  /* Source transfer width: byte (8 bits) */
+		.dwidth = 2,  /* Destination transfer width: word (32 bits) */
+		.s = gpdma_ahb_master_peripheral,
+		.d = gpdma_ahb_master_memory,
+		.si = 0,
+		.di = 1,
+		.prot1 = 0,
+		.prot2 = 0,
+		.prot3 = 0,
+		.i = 1,
+	};
+}
+
+constexpr gpdma::channel::Config config() {
+	return {
+		.e = 0,
+		.srcperipheral = gpdma_src_peripheral,
+		.destperipheral = gpdma_dest_peripheral,
+		.flowcntrl = gpdma::FlowControl::PeripheralToMemory_DMAControl,
+		.ie = 1,
+		.itc = 1,
+		.l = 0,
+		.a = 0,
+		.h = 0,
+	};
+}
+
+struct buffers_config_t {
+	size_t count;
+	size_t items_per_buffer;
+};
+
+static buffers_config_t			buffers_config;
+
+static sample_t				*samples	{ nullptr };
+static gpdma::channel::LLI	*lli		{ nullptr };
+
+static Semaphore semaphore;
+static volatile const gpdma::channel::LLI* next_lli = nullptr;
+
+static void transfer_complete() {
+	next_lli = gpdma_channel.next_lli();
+	chSemSignalI(&semaphore);
+}
+
+static void dma_error() {
+	disable();
+}
+
+void init() {
+	chSemInit(&semaphore, 0);
+	gpdma_channel.set_handlers(transfer_complete, dma_error);
+
+	// LPC_GPDMA->SYNC |= (1 << gpdma_peripheral);
+}
+
+void allocate(size_t buffer_count, size_t items_per_buffer) {
+	buffers_config = {
+		.count = buffer_count,
+		.items_per_buffer = items_per_buffer,
+	};
+
+	const auto peripheral = reinterpret_cast<uint32_t>(&LPC_ADC1->DR[portapack::adc1_rssi_input]) + 1;
+	const auto control_value = control(gpdma::buffer_words(buffers_config.items_per_buffer, 1));
+
+	samples = new sample_t[buffers_config.count * buffers_config.items_per_buffer];
+	lli = new gpdma::channel::LLI[buffers_config.count];
+
+	for(size_t i=0; i<buffers_config.count; i++) {
+		const auto memory = reinterpret_cast<uint32_t>(&samples[i * buffers_config.items_per_buffer]);
+		lli[i].srcaddr = peripheral;
+		lli[i].destaddr = memory;
+		lli[i].lli = lli_pointer(&lli[(i + 1) % buffers_config.count]);
+		lli[i].control = control_value;
+	}
+}
+
+void free() {
+	delete samples;
+	delete lli;
+}
+
+void enable() {
+	const auto gpdma_config = config();
+	gpdma_channel.configure(lli[0], gpdma_config);
+
+	chSemReset(&semaphore, 0);
+	gpdma_channel.enable();
+}
+
+bool is_enabled() {
+	return gpdma_channel.is_enabled();
+}
+
+void disable() {
+	gpdma_channel.disable_force();
+}
+
+rf::rssi::buffer_t wait_for_buffer() {
+	const auto status = chSemWait(&semaphore);
+	if( status == RDY_OK ) {
+		const auto next = next_lli;
+		if( next ) {
+			const size_t next_index = next - &lli[0];
+			const size_t free_index = (next_index + buffers_config.count - 2) % buffers_config.count;
+			return { reinterpret_cast<sample_t*>(lli[free_index].destaddr), buffers_config.items_per_buffer };
+		} else {
+			return { nullptr, 0 };
+		}
+	} else {
+		// TODO: Should I return here, or loop if RDY_RESET?
+		return { nullptr, 0 };
+	}
+}
+
+} /* namespace dma */
+} /* namespace rssi */
+} /* namespace rf */