ngscopeclient · Jun 3, 2020 · Jun 3, 2020
Showing with 296 additions and 0 deletions.

+1 −0 scopehal/CMakeLists.txt

+216 −0 scopehal/SCPITMCTransport.cpp

+77 −0 scopehal/SCPITMCTransport.h

+1 −0 scopehal/scopehal.cpp

+1 −0 scopehal/scopehal.h
diff --git a/scopehal/CMakeLists.txt b/scopehal/CMakeLists.txt
@@ -13,6 +13,7 @@ set(SCOPEHAL_SOURCES
 	SCPISocketTransport.cpp
 	VICPSocketTransport.cpp
 	SCPILxiTransport.cpp
+	SCPITMCTransport.cpp
 	SCPIDevice.cpp
 
 	Instrument.cpp

diff --git a/scopehal/SCPITMCTransport.cpp b/scopehal/SCPITMCTransport.cpp
@@ -0,0 +1,216 @@
+/***********************************************************************************************************************
+*                                                                                                                      *
+* ANTIKERNEL v0.1                                                                                                      *
+*                                                                                                                      *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
+* All rights reserved.                                                                                                 *
+*                                                                                                                      *
+* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
+* following conditions are met:                                                                                        *
+*                                                                                                                      *
+*    * Redistributions of source code must retain the above copyright notice, this list of conditions, and the         *
+*      following disclaimer.                                                                                           *
+*                                                                                                                      *
+*    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the       *
+*      following disclaimer in the documentation and/or other materials provided with the distribution.                *
+*                                                                                                                      *
+*    * Neither the name of the author nor the names of any contributors may be used to endorse or promote products     *
+*      derived from this software without specific prior written permission.                                           *
+*                                                                                                                      *
+* THIS SOFTWARE IS PROVIDED BY THE AUTHORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   *
+* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL *
+* THE AUTHORS BE HELD LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES        *
+* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR       *
+* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT *
+* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE       *
+* POSSIBILITY OF SUCH DAMAGE.                                                                                          *
+*                                                                                                                      *
+***********************************************************************************************************************/
+
+/**
+	@file
+	@author Andrew D. Zonenberg
+	@brief Implementation of SCPITMCTransport
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "scopehal.h"
+
+using namespace std;
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Construction / destruction
+
+SCPITMCTransport::SCPITMCTransport(string args)
+{
+	// TODO: add configuration options:
+	// - set the maximum request size of usbtmc read requests (currently 2032)
+	// - set timeout value (when using kernel that has usbtmc v2 version)
+	// - set size of staging buffer (or get rid of it entirely?)
+	m_devicePath = args;
+
+	// FIXME: currently not used
+	m_timeout = 1000;
+
+	LogDebug("Connecting to SCPI oscilloscope over USBTMC through %s\n", m_devicePath.c_str());
+
+	m_handle = open(m_devicePath.c_str(), O_RDWR);
+	if (m_handle <= 0)
+	{
+		LogError("Couldn't open %s\n", m_devicePath.c_str());
+		return;
+	}
+
+	// Right now, I'm using an internal staging buffer because this code has been copied from the lxi transport driver.
+	// It's not strictly needed...
+	m_staging_buf_size = 150000000;
+	m_staging_buf = new unsigned char[m_staging_buf_size];
+	if (m_staging_buf == NULL)
+		return;
+	m_data_in_staging_buf = 0;
+	m_data_offset = 0;
+	m_data_depleted = false;
+}
+
+SCPITMCTransport::~SCPITMCTransport()
+{
+	if (IsConnected())
+		close(m_handle);
+
+	delete[] m_staging_buf;
+}
+
+bool SCPITMCTransport::IsConnected()
+{
+	return (m_handle > 0);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Actual transport code
+
+string SCPITMCTransport::GetTransportName()
+{
+	return "usbtmc";
+}
+
+string SCPITMCTransport::GetConnectionString()
+{
+	return m_devicePath;
+}
+
+bool SCPITMCTransport::SendCommand(string cmd)
+{
+	if (!IsConnected())
+		return false;
+
+	LogTrace("Sending %s\n", cmd.c_str());
+
+	int result = write(m_handle, cmd.c_str(), cmd.length());
+
+	m_data_in_staging_buf = 0;
+	m_data_offset = 0;
+	m_data_depleted = false;
+
+	return (result == (int)cmd.length());
+}
+
+string SCPITMCTransport::ReadReply()
+{
+	string ret;
+
+	if (!m_staging_buf || !IsConnected())
+		return ret;
+
+	//FIXME: there *has* to be a more efficient way to do this...
+	char tmp = ' ';
+	while(true)
+	{
+		if (m_data_depleted)
+			break;
+		ReadRawData(1, (unsigned char *)&tmp);
+		if( (tmp == '\n') || (tmp == ';') )
+			break;
+		else
+			ret += tmp;
+	}
+	LogTrace("Got %s\n", ret.c_str());
+	return ret;
+}
+
+void SCPITMCTransport::SendRawData(size_t len, const unsigned char* buf)
+{
+	// XXX: Should this reset m_data_depleted just like SendCommmand?
+	write(m_handle, (const char *)buf, len);
+}
+
+void SCPITMCTransport::ReadRawData(size_t len, unsigned char* buf)
+{
+	// Data in the staging buffer is assumed to always be a consequence of a SendCommand request.
+	// Since we fetch all the reply data in one go, once all this data has been fetched, we mark
+	// the staging buffer as depleted and don't issue a new read until a new SendCommand
+	// is issued.
+
+	if (!m_staging_buf || !IsConnected())
+		return;
+
+	if (!m_data_depleted)
+	{
+		if (m_data_in_staging_buf == 0)
+		{
+
+#if 0
+			// This is what we'd use if we could be sure that the installed Linux kernel had
+			// usbtmc driver v2.
+			m_data_in_staging_buf = read(m_handle, (char *)m_staging_buf, m_staging_buf_size);
+#else			
+			// Split up one potentially large read into a bunch of smaller ones.
+			// The performance impact of this is pretty small.
+			const int max_bytes_per_req = 2032;
+			int i = 0;
+			int bytes_fetched, bytes_requested;
+
+			do
+			{
+				bytes_requested = (max_bytes_per_req < len) ? max_bytes_per_req : len;
+				bytes_fetched = read(m_handle, (char *)m_staging_buf + i, m_staging_buf_size);
+				i += bytes_fetched;
+			} while(bytes_fetched == bytes_requested);
+
+			m_data_in_staging_buf = i;
+#endif
+
+			if (m_data_in_staging_buf <= 0)
+				m_data_in_staging_buf = 0;
+			m_data_offset = 0;
+		}
+
+		unsigned int data_left = m_data_in_staging_buf - m_data_offset;
+		if (data_left > 0)
+		{
+			int nr_bytes = len > data_left ? data_left : len;
+
+			memcpy(buf, m_staging_buf + m_data_offset, nr_bytes);
+
+			m_data_offset += nr_bytes;
+		}
+
+		if (m_data_offset == m_data_in_staging_buf)
+			m_data_depleted = true;
+	}
+	else
+	{
+		// When this happens, the SCPIDevice is fetching more data from device than what
+		// could be expected from the SendCommand that was issued.
+		LogDebug("ReadRawData: data depleted.\n");
+	}
+}
+
+bool SCPITMCTransport::IsCommandBatchingSupported()
+{
+	return false;
+}
diff --git a/scopehal/SCPITMCTransport.h b/scopehal/SCPITMCTransport.h
@@ -0,0 +1,77 @@
+/***********************************************************************************************************************
+*                                                                                                                      *
+* ANTIKERNEL v0.1                                                                                                      *
+*                                                                                                                      *
+* Copyright (c) 2012-2020 Andrew D. Zonenberg                                                                          *
+* All rights reserved.                                                                                                 *
+*                                                                                                                      *
+* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the     *
+* following conditions are met:                                                                                        *
+*                                                                                                                      *
+*    * Redistributions of source code must retain the above copyright notice, this list of conditions, and the         *
+*      following disclaimer.                                                                                           *
+*                                                                                                                      *
+*    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the       *
+*      following disclaimer in the documentation and/or other materials provided with the distribution.                *
+*                                                                                                                      *
+*    * Neither the name of the author nor the names of any contributors may be used to endorse or promote products     *
+*      derived from this software without specific prior written permission.                                           *
+*                                                                                                                      *
+* THIS SOFTWARE IS PROVIDED BY THE AUTHORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   *
+* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL *
+* THE AUTHORS BE HELD LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES        *
+* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR       *
+* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT *
+* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE       *
+* POSSIBILITY OF SUCH DAMAGE.                                                                                          *
+*                                                                                                                      *
+***********************************************************************************************************************/
+
+/**
+	@file
+	@author Andrew D. Zonenberg
+	@brief Declaration of SCPITMCTransport
+ */
+
+#ifndef SCPITMCTransport_h
+#define SCPITMCTransport_h
+
+/**
+	@brief Abstraction of a transport layer for moving SCPI data between endpoints
+ */
+class SCPITMCTransport : public SCPITransport
+{
+public:
+	SCPITMCTransport(std::string args);
+	virtual ~SCPITMCTransport();
+
+	virtual std::string GetConnectionString();
+	static std::string GetTransportName();
+
+	virtual bool SendCommand(std::string cmd);
+	virtual std::string ReadReply();
+	virtual void ReadRawData(size_t len, unsigned char* buf);
+	virtual void SendRawData(size_t len, const unsigned char* buf);
+
+	virtual bool IsCommandBatchingSupported();
+	virtual bool IsConnected();
+
+	TRANSPORT_INITPROC(SCPITMCTransport)
+
+	std::string GetDevicePath()
+	{ return m_devicePath; }
+
+protected:
+	std::string m_devicePath;
+
+	int m_handle;
+	int m_timeout;
+
+	int m_staging_buf_size;
+	unsigned char *m_staging_buf;
+	int m_data_in_staging_buf;
+	int m_data_offset;
+	bool m_data_depleted;
+};
+
+#endif
diff --git a/scopehal/scopehal.cpp b/scopehal/scopehal.cpp
@@ -55,6 +55,7 @@ void TransportStaticInit()
 
 	AddTransportClass(SCPISocketTransport);
 	AddTransportClass(SCPILxiTransport);
+	AddTransportClass(SCPITMCTransport);
 	AddTransportClass(VICPSocketTransport);
 }
 

diff --git a/scopehal/scopehal.h b/scopehal/scopehal.h
@@ -61,6 +61,7 @@ extern "C"
 #include "SCPITransport.h"
 #include "SCPISocketTransport.h"
 #include "SCPILxiTransport.h"
+#include "SCPITMCTransport.h"
 #include "VICPSocketTransport.h"
 #include "SCPIDevice.h"