dev-arm: Use FdtState to generate GIC properites

Rather than hardcoding property values, we use a FdtState variable, so
that it is possible to retrieve them from an external object.

Change-Id: Ifd90814b03c68a7f55ef3be6123dcfee5e1de568
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/20051
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/dev/arm/Gic.py b/src/dev/arm/Gic.py
index d31a582..b431a6e 100644
--- a/src/dev/arm/Gic.py
+++ b/src/dev/arm/Gic.py
@@ -48,6 +48,9 @@
     abstract = True
     cxx_header = "dev/arm/base_gic.hh"
 
+    # Used for DTB autogeneration
+    _state = FdtState(addr_cells=0, interrupt_cells=3)
+
     platform = Param.Platform(Parent.any, "Platform this device is part of.")
 
     gicd_iidr = Param.UInt32(0,
@@ -59,6 +62,16 @@
     gicv_iidr = Param.UInt32(0,
         "VM CPU Interface Identification Register")
 
+    def interruptCells(self, int_type, int_num, int_flag):
+        """
+        Interupt cells generation helper:
+        Following specifications described in
+
+        Documentation/devicetree/bindings/interrupt-controller/arm,gic.txt
+        """
+        assert self._state.interrupt_cells == 3
+        return [ int_type, int_num, int_flag ]
+
 class ArmInterruptPin(SimObject):
     type = 'ArmInterruptPin'
     cxx_header = "dev/arm/base_gic.hh"
@@ -140,8 +153,8 @@
         node = FdtNode("interrupt-controller")
         node.appendCompatible(["gem5,gic", "arm,cortex-a15-gic",
                                "arm,cortex-a9-gic"])
-        node.append(FdtPropertyWords("#interrupt-cells", [3]))
-        node.append(FdtPropertyWords("#address-cells", [0]))
+        node.append(gic._state.interruptCellsProperty())
+        node.append(gic._state.addrCellsProperty())
         node.append(FdtProperty("interrupt-controller"))
 
         regs = (
@@ -178,6 +191,9 @@
     type = 'Gicv3'
     cxx_header = "dev/arm/gic_v3.hh"
 
+    # Used for DTB autogeneration
+    _state = FdtState(addr_cells=2, interrupt_cells=3)
+
     its = Param.Gicv3Its(Gicv3Its(), "GICv3 Interrupt Translation Service")
 
     dist_addr = Param.Addr("Address for distributor")