Support Analog in DataView (#2782) (#2828)

Co-authored-by: Megan Wachs <megan@sifive.com>
(cherry picked from commit 26100a875c69bf56f7442fac82ca9c74ad3596eb)

Co-authored-by: Jack Koenig <koenig@sifive.com>

2 files changed, 47 insertions, 1 deletions

diff --git a/core/src/main/scala/chisel3/experimental/Analog.scala b/core/src/main/scala/chisel3/experimental/Analog.scala
index a366f0c3..7d89025c 100644
--- a/core/src/main/scala/chisel3/experimental/Analog.scala
+++ b/core/src/main/scala/chisel3/experimental/Analog.scala
@@ -69,7 +69,8 @@ final class Analog private (private[chisel3] val width: Width) extends Element {
     }
 
     targetTopBinding match {
-      case _: WireBinding | _: PortBinding => direction = ActualDirection.Bidirectional(ActualDirection.Default)
+      case _: WireBinding | _: PortBinding | _: ViewBinding | _: AggregateViewBinding =>
+        direction = ActualDirection.Bidirectional(ActualDirection.Default)
       case x => throwException(s"Analog can only be Ports and Wires, not '$x'")
     }
     binding = target
diff --git a/core/src/main/scala/chisel3/experimental/Attach.scala b/core/src/main/scala/chisel3/experimental/Attach.scala
new file mode 100644
index 00000000..5c9cfe53
--- /dev/null
+++ b/core/src/main/scala/chisel3/experimental/Attach.scala
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package chisel3.experimental
+
+import chisel3.RawModule
+import chisel3.internal._
+import chisel3.internal.Builder.pushCommand
+import chisel3.internal.firrtl._
+import chisel3.internal.sourceinfo.SourceInfo
+
+object attach {
+  // Exceptions that can be generated by attach
+  case class AttachException(message: String) extends ChiselException(message)
+  def ConditionalAttachException: AttachException =
+    AttachException(": Conditional attach is not allowed!")
+
+  // Actual implementation
+  private[chisel3] def impl(elts: Seq[Analog], contextModule: RawModule)(implicit sourceInfo: SourceInfo): Unit = {
+    if (Builder.whenDepth != 0) throw ConditionalAttachException
+
+    // TODO Check that references are valid and can be attached
+
+    pushCommand(Attach(sourceInfo, elts.map(_.lref)))
+  }
+
+  /** Create an electrical connection between [[Analog]] components
+    *
+    * @param elts The components to attach
+    *
+    * @example
+    * {{{
+    * val a1 = Wire(Analog(32.W))
+    * val a2 = Wire(Analog(32.W))
+    * attach(a1, a2)
+    * }}}
+    */
+  def apply(elts: Analog*)(implicit sourceInfo: SourceInfo): Unit = {
+    try {
+      impl(elts, Builder.forcedUserModule)
+    } catch {
+      case AttachException(message) =>
+        throwException(elts.mkString("Attaching (", ", ", s") failed @$message"))
+    }
+  }
+}