From a6b86168ce98ad17a844c1a5449ccb4b1ba07cb0 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Thu, 8 Dec 2011 18:47:32 +0100
Subject: [PATCH] Simple bus base class

---
 migen/bus/csr.py        | 29 ++++++++++++++---------------
 migen/bus/simple.py     | 17 +++++++++++++++++
 migen/fhdl/structure.py |  2 +-
 3 files changed, 32 insertions(+), 16 deletions(-)
 create mode 100644 migen/bus/simple.py

diff --git a/migen/bus/csr.py b/migen/bus/csr.py
index cd06436cd..f4fdcad0a 100644
--- a/migen/bus/csr.py
+++ b/migen/bus/csr.py
@@ -1,21 +1,20 @@
 from migen.fhdl import structure as f
-from functools import partial
+from .simple import Simple
 
-class Master:
-	def __init__(self):
-		d = partial(f.Declare, self)
-		d("a_o", f.BV(16))
-		d("we_o")
-		d("d_o", f.BV(32))
-		d("d_i", f.BV(32))
+_desc = [
+	(True,	"a",	16),
+	(True,	"we",	1),
+	(True,	"d",	32),
+	(False,	"d",	32)
+]
 
-class Slave:
+class Master(Simple):
 	def __init__(self):
-		d = partial(f.Declare, self)
-		d("a_i", f.BV(16))
-		d("we_i")
-		d("d_i", f.BV(32))
-		d("d_o", f.BV(32))
+		Simple.__init__(self, _desc, False)
+
+class Slave(Simple):
+	def __init__(self):
+		Simple.__init__(self, _desc, True)
 
 class Interconnect:
 	def __init__(self, master, slaves):
@@ -32,4 +31,4 @@ class Interconnect:
 			comb.append(a(slave.d_i, self.master.d_o))
 			rb = rb | slave.d_o
 		comb.append(a(master.d_i, rb))
-		return f.Fragment(comb)
\ No newline at end of file
+		return f.Fragment(comb)
diff --git a/migen/bus/simple.py b/migen/bus/simple.py
new file mode 100644
index 000000000..8ca279922
--- /dev/null
+++ b/migen/bus/simple.py
@@ -0,0 +1,17 @@
+from migen.fhdl import structure as f
+
+# desc is a list of tuples, each made up of:
+# 0) boolean: "master to slave"
+# 1) string: name
+# 2) int: width
+class Simple():
+	def __init__(self, desc, slave):
+		for signal in desc:
+			if signal[0] ^ slave:
+				suffix = "_o"
+			else:
+				suffix = "_i"
+			modules = self.__module__.split('.')
+			busname = modules[len(modules)-1]
+			signame = signal[1]+suffix
+			setattr(self, signame, f.Signal(f.BV(signal[2]), busname+"_"+signame))
diff --git a/migen/fhdl/structure.py b/migen/fhdl/structure.py
index f3ff20443..254667aa7 100644
--- a/migen/fhdl/structure.py
+++ b/migen/fhdl/structure.py
@@ -117,7 +117,7 @@ class Signal(Value):
 		return id(self)
 
 def Declare(parent, name, bv=BV(), variable=False, reset=0):
-	setattr(parent, name, Signal(bv, parent.__class__.__name__+"_"+name, variable, reset))
+	setattr(parent, name, Signal(bv, parent.__class__.__name__ + "_" + name, variable, reset))
 
 # statements