[bench] USBPlugged command

ion/src/device/bench/Makefile

@@ -27,5 +27,6 @@ ion_target_device_bench_src += $(addprefix ion/src/device/bench/command/, \
   sleep.cpp \
   stop.cpp \
   standby.cpp \
+  usb_plugged.cpp \
   vblank.cpp \
 )

ion/src/device/bench/bench.cpp

@@ -29,6 +29,7 @@ constexpr CommandHandler handles[] = {
   CommandHandler("SLEEP", Command::Sleep),
   CommandHandler("STOP", Command::Stop),
   CommandHandler("STANDBY", Command::Standby),
+  CommandHandler("USB_PLUGGED", Command::USBPlugged),
   CommandHandler("VBLANK", Command::VBlank),
   CommandHandler(nullptr, nullptr)
 };

ion/src/device/bench/command/command.h

@@ -30,6 +30,7 @@ void ScreenID(const char * input);
 void Sleep(const char * input);
 void Stop(const char * input);
 void Standby(const char * input);
+void USBPlugged(const char * input);
 void VBlank(const char * input);
 
 extern const char * const sOK;

ion/src/device/bench/command/usb_plugged.cpp

@@ -0,0 +1,24 @@
+#include "command.h"
+#include <ion/usb.h>
+
+namespace Ion {
+namespace Device {
+namespace Bench {
+namespace Command {
+
+void USBPlugged(const char * input) {
+  if (input != nullptr) {
+    reply(sSyntaxError);
+    return;
+  }
+  if (Ion::USB::isPlugged()) {
+    reply(sON);
+  } else {
+    reply(sOFF);
+  }
+}
+
+}
+}
+}
+}