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* libscopeprotocols                                                                                                    *
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* Copyright (c) 2012-2023 Andrew D. Zonenberg and contributors                                                         *
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#include "../scopehal/scopehal.h"
#include "EthernetProtocolDecoder.h"
#include "EthernetRGMIIDecoder.h"
#include <algorithm>

using namespace std;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Construction / destruction

EthernetRGMIIDecoder::EthernetRGMIIDecoder(const string& color)
	: EthernetProtocolDecoder(color)
{
	//Digital inputs, so need to undo some stuff for the PHY layer decodes
	m_signalNames.clear();
	m_inputs.clear();

	//Add inputs. Make data be the first, because we normally want the overlay shown there.
	CreateInput("data");
	CreateInput("clk");
	CreateInput("ctl");
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Accessors

string EthernetRGMIIDecoder::GetProtocolName()
{
	return "Ethernet - RGMII";
}

bool EthernetRGMIIDecoder::ValidateChannel(size_t i, StreamDescriptor stream)
{
	auto chan = stream.m_channel;
	if(chan == NULL)
		return false;

	switch(i)
	{
		case 0:
			if(stream.GetType() != Stream::STREAM_TYPE_DIGITAL_BUS)
				return true;
			break;

		case 1:
		case 2:
			if(stream.GetType() != Stream::STREAM_TYPE_DIGITAL)
				return true;
			break;
	}

	return false;
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Actual decoder logic

void EthernetRGMIIDecoder::Refresh()
{
	ClearPackets();

	if(!VerifyAllInputsOK())
	{
		SetData(NULL, 0);
		return;
	}

	//Get the input data
	auto data = GetInputWaveform(0);
	auto clk = GetInputWaveform(1);
	auto ctl = GetInputWaveform(2);

	//Sample everything on the clock edges
	SparseDigitalWaveform dctl;
	SparseDigitalBusWaveform ddata;
	SampleOnAnyEdgesBase(ctl, clk, dctl);
	SampleOnAnyEdgesBase(data, clk, ddata);

	dctl.PrepareForCpuAccess();
	ddata.PrepareForCpuAccess();

	//Need a reasonable number of samples or there's no point in decoding.
	//Cut off the last few samples because we might be either DDR or SDR and need to seek past our current position.
	size_t len = min(dctl.size(), ddata.size());
	if(len < 100)
	{
		SetData(NULL, 0);
		return;
	}
	len -= 4;

	//Create the output capture
	auto cap = new EthernetWaveform;
	cap->m_timescale = 1;
	cap->m_startTimestamp = data->m_startTimestamp;
	cap->m_startFemtoseconds = data->m_startFemtoseconds;
	cap->PrepareForCpuAccess();

	//skip first 2 samples so we can get a full clock cycle before starting
	for(size_t i=2; i < len; i++)
	{
		//Not sending a frame. Decode in-band status
		if(!dctl.m_samples[i])
		{
			//Extract in-band status
			uint8_t status = 0;
			for(size_t j=0; j<4; j++)
			{
				if(ddata.m_samples[i][j])
					status |= (1 << j);
			}

			//Same status? Merge samples
			bool extend = false;
			size_t last = cap->size() - 1;
			if(!cap->m_samples.empty())
			{
				auto& sample = cap->m_samples[last];
				if( (sample.m_type == EthernetFrameSegment::TYPE_INBAND_STATUS) &&
					(sample.m_data[0] == status) )
				{
					extend = true;
				}
			}

			//Decode
			if(extend)
				cap->m_durations[last] = ddata.m_offsets[i] + ddata.m_durations[i] - cap->m_offsets[last];
			else
			{
				cap->m_offsets.push_back(ddata.m_offsets[i]);
				cap->m_durations.push_back(ddata.m_durations[i]);
				cap->m_samples.push_back(EthernetFrameSegment(EthernetFrameSegment::TYPE_INBAND_STATUS, status));
			}

			continue;
		}

		//We're processing a frame.
		//Figure out the clock period.
		//Need to do this cycle-by-cycle in case the link speed changes during a deep capture
		//TODO: alert if clock isn't close to one of the three legal frequencies
		int64_t clkperiod = dctl.m_offsets[i] - dctl.m_offsets[i-2];
		bool ddr = false;			//Default to 2.5/25 MHz SDR.
		if(clkperiod < 10000000)	//Faster than 100 MHz? assume it's 125 MHz DDR.
			ddr = true;

		//Set of recovered bytes and timestamps
		vector<uint8_t> bytes;
		vector<uint64_t> starts;
		vector<uint64_t> ends;

		//TODO: handle error signal (ignored for now)
		while( (i < len) && (dctl.m_samples[i]) )
		{
			//Start time
			starts.push_back(ddata.m_offsets[i]);

			if(ddr)
			{
				//Convert bits to bytes
				uint8_t dval = 0;
				for(size_t j=0; j<8; j++)
				{
					if(j < 4)
					{
						if(ddata.m_samples[i][j])
							dval |= (1 << j);
					}
					else if(ddata.m_samples[i+1][j-4])
						dval |= (1 << j);
				}
				bytes.push_back(dval);

				ends.push_back(ddata.m_offsets[i+1] + ddata.m_durations[i+1]);
				i += 2;
			}

			else
			{
				//Convert bits to bytes
				uint8_t dval = 0;
				for(size_t j=0; j<8; j++)
				{
					if(j < 4)
					{
						if(ddata.m_samples[i][j])
							dval |= (1 << j);
					}
					else if(ddata.m_samples[i+2][j-4])
						dval |= (1 << j);
				}
				bytes.push_back(dval);

				ends.push_back(ddata.m_offsets[i+3] + ddata.m_durations[i+3]);
				i += 4;
			}
		}
		//Crunch the data
		BytesToFrames(bytes, starts, ends, cap);
	}

	SetData(cap, 0);

	cap->MarkModifiedFromCpu();
}
