From be68ecfc72973114e62e038db29a1cdea98dc8ff Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Sat, 17 Nov 2012 19:55:33 +0100
Subject: [PATCH] uio: add simulation I/O object

---
 migen/uio/ioo.py | 60 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/migen/uio/ioo.py b/migen/uio/ioo.py
index 934cbf32e..72dbb391e 100644
--- a/migen/uio/ioo.py
+++ b/migen/uio/ioo.py
@@ -7,3 +7,63 @@ class UnifiedIOObject(Actor):
 		if dataflow is not None:
 			super().__init__(*dataflow)
 		self.buses = buses
+
+(_WAIT_COMPLETE, _WAIT_POLL) = range(2)
+
+class UnifiedIOSimulation(UnifiedIOObject):
+	def __init__(self, generator, dataflow=None, buses={}):
+		self.generator = generator
+		super().__init__(dataflow, buses)
+		
+		self.callers = []
+		self.busname_to_caller_id = {}
+		if dataflow is not None:
+			self.callers.append(TokenExchanger(self.demux_g(0), self))
+		for k, v in self.buses.items():
+			caller_id = len(self.callers)
+			self.busname_to_caller_id[k] = caller_id
+			g = self.demux_g(caller_id)
+			if isinstance(v, wishbone.Interface):
+				caller = wishbone.Initiator(g, v)
+			else:
+				raise NotImplementedError
+			self.callers.append(caller)
+		
+		self.dispatch_state = _WAIT_COMPLETE
+		self.dispatch_caller = 0
+		self.pending_transaction = None
+	
+	def identify_transaction(self, t):
+		if isinstance(t, Token):
+			return 0
+		elif isinstance(t, TRead) or isinstance(t, TWrite):
+			if t.busname is None:
+				if len(self.busname_to_caller_id) != 1:
+					raise TypeError
+				else:
+					return list(self.busname_to_caller_id.values())[0]
+			else:
+				return self.busname_to_caller_id[t.busname]
+		else:
+			raise TypeError
+	
+	def dispatch_g(self, caller_id):
+		while True:
+			if self.dispatch_state == _WAIT_COMPLETE and self.dispatch_caller == caller_id:
+				transaction = next(self.generator)
+				tr_cid = self.identify_transaction(transaction)
+				self.dispatch_caller = tr_cid
+				if tr_cid == caller_id:
+					yield transaction
+				else:
+					self.pending_transaction = transaction
+					self.dispatch_state = _WAIT_POLL
+					yield None
+			elif self.dispatch_state == _WAIT_POLL and self.dispatch_caller == caller_id:
+				self.dispatch_state = _WAIT_COMPLETE
+				yield self.pending_transaction
+			else:
+				yield None
+	
+	def get_fragment(self):
+		return sum([c.get_fragment() for c in self.callers], Fragment())