TLBuffer: Create a wrapper module for TLBufferChain, to allow for more stable naming

src/main/scala/coreplex/FrontBus.scala

@@ -23,7 +23,8 @@ class FrontBus(params: FrontBusParams)(implicit p: Parameters) extends TLBusWrap
     fromSyncPorts(params, buffers, name)
 
   def fromSyncPorts(params: BufferParams =  BufferParams.default, buffers: Int = 1, name: Option[String] = None): TLInwardNode = {
-    val (in, out) = bufferChain(buffers, params, name)
+    require(params == BufferParams.default, "Only BufferParams.default supported for FrontBus at this time.")
+    val (in, out) = bufferChain(buffers, name)
     inwardNode :=* out
     in
   }

src/main/scala/coreplex/SystemBus.scala

@@ -38,7 +38,7 @@ class SystemBus(params: SystemBusParams)(implicit p: Parameters) extends TLBusWr
   def toSplitSlaves: TLOutwardNode = outwardSplitNode
 
   def toPeripheryBus(nBuffers: Int): TLOutwardNode = {
-    val (in, out) = bufferChain(nBuffers, name = Some("PeripheryBus"))
+    val (in, out) = bufferChain(nBuffers, name = Some("pbus"))
     in := pbus_fixer.node
     out
   }

src/main/scala/tilelink/Buffer.scala

@@ -77,3 +77,28 @@ object TLBuffer
     buffer.node
   }
 }
+
+class TLBufferChain(depth: Int)(implicit p: Parameters) extends LazyModule {
+
+  val nodeIn = TLInputNode()
+  val nodeOut = TLOutputNode()
+
+  val buf_chain = if (depth > 0) {
+    val chain = List.fill(depth)(LazyModule(new TLBuffer(BufferParams.default)))
+
+    (chain.init zip chain.tail) foreach { case(prev, next) => next.node :=* prev.node }
+    chain
+  } else {
+    List(LazyModule(new TLBuffer(BufferParams.none)))
+  }
+
+  buf_chain.head.node :=* nodeIn
+  nodeOut :=* buf_chain.last.node
+
+  lazy val module = new LazyModuleImp(this) {
+    val io = new Bundle {
+      val in  = nodeIn.bundleIn
+      val out = nodeOut.bundleOut
+    }
+  }
+}

src/main/scala/tilelink/Bus.scala

@@ -67,17 +67,10 @@ abstract class TLBusWrapper(params: TLBusParams, val busName: String)(implicit p
   protected def inwardNode: TLInwardNode = xbar.node
   protected def inwardBufNode: TLInwardNode = master_buffer.node
 
-  protected def bufferChain(depth: Int, params: BufferParams = BufferParams.default, name: Option[String] = None): (TLInwardNode, TLOutwardNode) = {
+  protected def bufferChain(depth: Int, name: Option[String] = None): (TLInwardNode, TLOutwardNode) = {
-    if (depth > 0) {
+    val chain = LazyModule(new TLBufferChain(depth))
-      val chain = List.fill(depth)(LazyModule(new TLBuffer(params)))
+    name.foreach { n => chain.suggestName(s"${busName}_${n}_TLBufferChain")}
-      name.foreach { n => chain.zipWithIndex foreach { case(b, i) => b.suggestName(s"${busName}_${n}_${i}_TLBuffer") } }
+    (chain.nodeIn, chain.nodeOut)
-      (chain.init zip chain.tail) foreach { case(prev, next) => next.node :=* prev.node }
-      (chain.head.node, chain.last.node)
-    } else {
-      val dummy = LazyModule(new TLBuffer(BufferParams.none))
-      name.foreach { n => dummy.suggestName(s"${busName}_${n}_empty_TLBuffer")}
-      (dummy.node, dummy.node)
-    }
   }
 
   def bufferFromMasters: TLInwardNode = inwardBufNode