Add new "single" attribut for FTDI devices.

FTDI devices could be selected with a module index (read value of
some pins) or a serial. In some setups there is only one module
present which can be identified with the VID and PID only. The
new attribute "single" checks for exactly one device with the
VID and PID. It throws an error if 0 or more than 1 devices with
this VID and PID are found.

Example for the syntax:
                <FTDI vendor="0x0403" product="0x6010">
                       <Device single="true"/>
                </FTDI>

iomatrix/templates/io_matrix/ftdi.lua

@@ -150,31 +150,43 @@ function IoMatrix_FTDI:__find_ftdi_devices(atAllDevices, atDeviceAttr)
     if aucPinMask~=nil then
       self.tLog.debug('Pin mask: %s', table.concat(aucPinMask, ', '))
     end
+    local fSingle = tDeviceAttr.single
 
     -- Search the complete list of devices.
     local tFoundDevice
-    for _, tDevice in pairs(atAllDevices) do
-      -- Is the device already part of the identified devices?
-      for _, tIdentDev in pairs(self.atDeviceAttrs) do
-        if tIdentDev.strPortNumbers==tDevice.strPortNumbers then
-          self.tLog.debug('Not considering device at port [%s] again.', tIdentDev.strPrettyPortNumbers)
-          tDevice = nil
-          break
-        end 
+    if fSingle==true then
+      local sizAllDevices = #atAllDevices
+      if sizAllDevices==1 then
+        tFoundDevice = atAllDevices[1]
+      elseif sizAllDevices==0 then
+        self.tLog.debug('No device found.')
+      else
+        self.tLog.debug('With the "single" attribute there must be exactly one device, but here are %d of them.', sizAllDevices)
       end
-      if tDevice~=nil then
-        -- Should a port number be checked and does it differ?
-        if strPN~=nil and tDevice.strPortNumbers~=strPN then
-          -- Do not use this device.
-          self.tLog.debug('The port of device [%s] does not match.', tDevice.strPrettyPortNumbers)
-        elseif strSerial~=nil and tDevice.strFtdiSerial~=strSerial then
-          self.tLog.debug('The serial of device [%s] does not match.', tDevice.strPrettyPortNumbers)
-        elseif ulModuleIndex~=nil and tDevice.ulModuleIndex~=ulModuleIndex then
-          self.tLog.debug('The module index of device [%s] does not match.', tDevice.strPrettyPortNumbers)
-        else
-          self.tLog.debug('Device [%s] matches.', tDevice.strPrettyPortNumbers)
-          tFoundDevice = tDevice
-          break
+    else
+      for _, tDevice in pairs(atAllDevices) do
+        -- Is the device already part of the identified devices?
+        for _, tIdentDev in pairs(self.atDeviceAttrs) do
+          if tIdentDev.strPortNumbers==tDevice.strPortNumbers then
+            self.tLog.debug('Not considering device at port [%s] again.', tIdentDev.strPrettyPortNumbers)
+            tDevice = nil
+            break
+          end
+        end
+        if tDevice~=nil then
+          -- Should a port number be checked and does it differ?
+          if strPN~=nil and tDevice.strPortNumbers~=strPN then
+            -- Do not use this device.
+            self.tLog.debug('The port of device [%s] does not match.', tDevice.strPrettyPortNumbers)
+          elseif strSerial~=nil and tDevice.strFtdiSerial~=strSerial then
+            self.tLog.debug('The serial of device [%s] does not match.', tDevice.strPrettyPortNumbers)
+          elseif ulModuleIndex~=nil and tDevice.ulModuleIndex~=ulModuleIndex then
+            self.tLog.debug('The module index of device [%s] does not match.', tDevice.strPrettyPortNumbers)
+          else
+            self.tLog.debug('Device [%s] matches.', tDevice.strPrettyPortNumbers)
+            tFoundDevice = tDevice
+            break
+          end
         end
       end
     end

lua/test_class_iomatrix.lua

@@ -209,17 +209,27 @@ function TestClassIoMatrix.parseCfg_StartElement(tParser, strName, atAttributes)
       end
     end
 
+    local fSingle
+    local strSingle = atAttributes['single']
+    if strSingle~=nil then
+      strSingle = string.lower(strSingle)
+      if strSingle=='true' or strSingle=='yes' or strSingle=='1' then
+        fSingle = true
+      end
+    end
+
     if fOk~=true then
       aLxpAttr.tResult = nil
-    elseif auiPort==nil and strSerial==nil and uiModuleIndex==nil then
+    elseif auiPort==nil and strSerial==nil and uiModuleIndex==nil and fSingle==nil then
       aLxpAttr.tResult = nil
       aLxpAttr.tLog.error('Error in line %d, col %d: No way to identify device as no port, serial or moduleIndex specified.', iPosLine, iPosColumn)
     else
       local atDevice = {
         port = auiPort,
         serial = strSerial,
         moduleidx = uiModuleIndex,
-        pinmask = aucPinMask
+        pinmask = aucPinMask,
+        single = fSingle
       }
       table.insert(aLxpAttr.tCurrentFTDIDevice, atDevice)
     end