From 641a4d577af5b8c0bcaf88d7f446316851dc71ee Mon Sep 17 00:00:00 2001
From: "Wesley W. Terpstra" <wesley@sifive.com>
Date: Thu, 20 Apr 2017 11:49:07 -0700
Subject: [PATCH] tilelink2: Error device for returning errors on demand

---
 src/main/scala/uncore/tilelink2/Error.scala | 56 +++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 src/main/scala/uncore/tilelink2/Error.scala

diff --git a/src/main/scala/uncore/tilelink2/Error.scala b/src/main/scala/uncore/tilelink2/Error.scala
new file mode 100644
index 00000000..38ebf646
--- /dev/null
+++ b/src/main/scala/uncore/tilelink2/Error.scala
@@ -0,0 +1,56 @@
+// See LICENSE.SiFive for license details.
+
+package uncore.tilelink2
+
+import Chisel._
+import config._
+import diplomacy._
+import util._
+
+class TLError(address: Seq[AddressSet], beatBytes: Int = 4)(implicit p: Parameters) extends LazyModule
+{
+  val device = new SimpleDevice("error-device", Seq("sifive,error0"))
+
+  val node = TLManagerNode(Seq(TLManagerPortParameters(
+    Seq(TLManagerParameters(
+      address            = address,
+      resources          = device.reg,
+      supportsGet        = TransferSizes(1, beatBytes),
+      supportsPutPartial = TransferSizes(1, beatBytes),
+      supportsPutFull    = TransferSizes(1, beatBytes),
+      supportsArithmetic = TransferSizes(1, beatBytes),
+      supportsLogical    = TransferSizes(1, beatBytes),
+      supportsHint       = TransferSizes(1, beatBytes),
+      fifoId             = Some(0))), // requests are handled in order
+    beatBytes  = beatBytes,
+    minLatency = 1))) // no bypass needed for this device
+
+  lazy val module = new LazyModuleImp(this) {
+    val io = new Bundle {
+      val in = node.bundleIn
+    }
+
+    import TLMessages._
+    val opcodes = Vec(AccessAck, AccessAck, AccessAckData, AccessAckData, AccessAckData, HintAck)
+
+    val in = io.in(0)
+    val a = Queue(in.a, 1)
+    val d = in.d
+
+    a.ready := d.ready
+    d.valid := a.valid
+    d.bits.opcode  := opcodes(a.bits.opcode)
+    d.bits.param   := UInt(0)
+    d.bits.size    := a.bits.size
+    d.bits.source  := a.bits.source
+    d.bits.sink    := UInt(0)
+    d.bits.addr_lo := a.bits.address
+    d.bits.data    := UInt(0)
+    d.bits.error   := a.bits.opcode =/= Hint // Hints may not error
+
+    // Tie off unused channels
+    in.b.valid := Bool(false)
+    in.c.ready := Bool(true)
+    in.e.ready := Bool(true)
+  }
+}