From 135a2eb86899149d9877202600877577a6445983 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Sun, 18 Dec 2011 00:28:04 +0100
Subject: [PATCH] bank: support raw registers

---
 migen/bank/csrgen.py      | 66 ++++++++++++++++++++++-----------------
 migen/bank/description.py | 10 ++++--
 2 files changed, 46 insertions(+), 30 deletions(-)

diff --git a/migen/bank/csrgen.py b/migen/bank/csrgen.py
index e6d0f43b1..acd0d7dc9 100644
--- a/migen/bank/csrgen.py
+++ b/migen/bank/csrgen.py
@@ -22,14 +22,20 @@ class Bank:
 		bwcases = []
 		for i in range(nregs):
 			reg = self.description[i]
-			nfields = len(reg.fields)
-			bwra = [Constant(i, BV(nbits))]
-			for j in range(nfields):
-				field = reg.fields[j]
-				if field.access_bus == WRITE_ONLY or field.access_bus == READ_WRITE:
-					bwra.append(field.storage.eq(self.interface.d_i[j]))
-			if len(bwra) > 1:
-				bwcases.append(bwra)
+			if reg.raw is None:
+				bwra = [Constant(i, BV(nbits))]
+				nfields = len(reg.fields)
+				for j in range(nfields):
+					field = reg.fields[j]
+					if field.access_bus == WRITE_ONLY or field.access_bus == READ_WRITE:
+						bwra.append(field.storage.eq(self.interface.d_i[j]))
+				if len(bwra) > 1:
+					bwcases.append(bwra)
+			else:
+				comb.append(reg.dev_r.eq(self.interface.d_i[:reg.raw.width]))
+				comb.append(reg.dev_re.eq(self._sel & \
+					self.interface.we_i & \
+					(self.interface.a_i[:nbits] == Constant(i, BV(nbits)))))
 		if bwcases:
 			sync.append(If(self._sel & self.interface.we_i, Case(self.interface.a_i[:nbits], *bwcases)))
 		
@@ -37,21 +43,24 @@ class Bank:
 		brcases = []
 		for i in range(nregs):
 			reg = self.description[i]
-			nfields = len(reg.fields)
-			brs = []
-			reg_readable = False
-			for j in range(nfields):
-				field = reg.fields[j]
-				if field.access_bus == READ_ONLY or field.access_bus == READ_WRITE:
-					brs.append(field.storage)
-					reg_readable = True
-				else:
-					brs.append(Constant(0, BV(field.size)))
-			if reg_readable:
-				if len(brs) > 1:
-					brcases.append([Constant(i, BV(nbits)), self.interface.d_o.eq(f.Cat(*brs))])
-				else:
-					brcases.append([Constant(i, BV(nbits)), self.interface.d_o.eq(brs[0])])
+			if reg.raw is None:
+				nfields = len(reg.fields)
+				brs = []
+				reg_readable = False
+				for j in range(nfields):
+					field = reg.fields[j]
+					if field.access_bus == READ_ONLY or field.access_bus == READ_WRITE:
+						brs.append(field.storage)
+						reg_readable = True
+					else:
+						brs.append(Constant(0, BV(field.size)))
+				if reg_readable:
+					if len(brs) > 1:
+						brcases.append([Constant(i, BV(nbits)), self.interface.d_o.eq(f.Cat(*brs))])
+					else:
+						brcases.append([Constant(i, BV(nbits)), self.interface.d_o.eq(brs[0])])
+			else:
+				brcases.append([Constant(i, BV(nbits)), self.interface.d_o.eq(reg.dev_w)])
 		if brcases:
 			sync.append(self.interface.d_o.eq(Constant(0, BV(8))))
 			sync.append(If(self._sel, Case(self.interface.a_i[:nbits], *brcases)))
@@ -60,10 +69,11 @@ class Bank:
 		
 		# Device access
 		for reg in self.description:
-			for field in reg.fields:
-				if field.access_dev == READ_ONLY or field.access_dev == READ_WRITE:
-					comb.append(field.dev_r.eq(field.storage))
-				if field.access_dev == WRITE_ONLY or field.access_dev == READ_WRITE:
-					sync.append(If(field.dev_we, field.storage.eq(field.dev_w)))
+			if reg.raw is None:
+				for field in reg.fields:
+					if field.access_dev == READ_ONLY or field.access_dev == READ_WRITE:
+						comb.append(field.dev_r.eq(field.storage))
+					if field.access_dev == WRITE_ONLY or field.access_dev == READ_WRITE:
+						sync.append(If(field.dev_we, field.storage.eq(field.dev_w)))
 		
 		return Fragment(comb, sync)
diff --git a/migen/bank/description.py b/migen/bank/description.py
index d0115f7fb..102deff01 100644
--- a/migen/bank/description.py
+++ b/migen/bank/description.py
@@ -1,9 +1,15 @@
 from migen.fhdl.structure import *
 
 class Register:
-	def __init__(self, name):
+	def __init__(self, name, raw=None):
 		self.name = name
-		self.fields = []
+		self.raw = raw
+		if raw is not None:
+			self.dev_re = Signal(name=name + "_re")
+			self.dev_r = Signal(raw, name + "_r")
+			self.dev_w = Signal(raw, name + "_w")
+		else:
+			self.fields = []
 	
 	def add_field(self, f):
 		self.fields.append(f)