dts: edtlib: Turn Node.instance_no into EDT.compat2enabled

Add an EDT.compat2enabled attribute that maps compatibles to enabled
devicetree nodes that implement them. For example,
EDT.compat2enabled["foo"] is a list of all enabled nodes with "foo" in
the 'compatible' property.

The old Node.instance_no functionality can be implemented in terms of
EDT.compat2enabled, so remove Node.instance_no. EDT.compat2enabled is
more flexible and easier to understand.

Simplify main() in gen_defines.py by using EDT.compat2enabled to
generate the DT_COMPAT_<compatible> existence macros. The behavior is
slightly different now, as DT_COMPAT_<compatible> is generated for
enabled nodes that don't have a binding as well, but that might be an
improvement overall. It probably doesn't hurt at least.

EDT.compat2enabled simplifies the implementation of the new
$(dt_compat_get_str) preprocessor function in
https://github.com/zephyrproject-rtos/zephyr/pull/21560. That was the
original motivation.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>

scripts/dts/edtlib.py

@@ -65,7 +65,7 @@ a .dts file to parse and a list of paths to directories containing bindings.
 # - Please use ""-quoted strings instead of ''-quoted strings, just to make
 #   things consistent (''-quoting is more common otherwise in Python)
 
-from collections import OrderedDict
+from collections import OrderedDict, defaultdict
 import os
 import re
 import sys
@@ -96,6 +96,25 @@ class EDT:
     nodes:
       A list of Node objects for the nodes that appear in the devicetree
 
+    compat2enabled:
+      A collections.defaultdict that maps each 'compatible' string that appears
+      on some enabled Node to a list of enabled Nodes.
+
+      For example, edt.compat2enabled["bar"] would include the 'foo' and 'bar'
+      nodes below.
+
+        foo {
+                compatible = "bar";
+                status = "okay";
+                ...
+        };
+        bar {
+                compatible = "foo", "bar", "baz";
+                status = "okay";
+                ...
+        };
+
+
     dts_path:
       The .dts path passed to __init__()
 
@@ -128,6 +147,7 @@ class EDT:
 
         self._init_compat2binding(bindings_dirs)
         self._init_nodes()
+        self._init_compat2enabled()
 
         self._define_order()
 
@@ -443,7 +463,6 @@ class EDT:
             node.bus_node = node._bus_node()
             node._init_binding()
             node._init_regs()
-            node._set_instance_no()
 
             self.nodes.append(node)
             self._node2enode[dt_node] = node
@@ -456,6 +475,15 @@ class EDT:
             node._init_interrupts()
             node._init_pinctrls()
 
+    def _init_compat2enabled(self):
+        # Creates self.compat2enabled
+
+        self.compat2enabled = defaultdict(list)
+        for node in self.nodes:
+            if node.enabled:
+                for compat in node.compats:
+                    self.compat2enabled[compat].append(node)
+
     def _check_binding(self, binding, binding_path):
         # Does sanity checking on 'binding'. Only takes 'self' for the sake of
         # self._warn().
@@ -689,16 +717,6 @@ class Node:
     read_only:
       True if the node has a 'read-only' property, and False otherwise
 
-    instance_no:
-      Dictionary that maps each 'compatible' string for the node to a unique
-      index among all nodes that have that 'compatible' string.
-
-      As an example, 'instance_no["foo,led"] == 3' can be read as "this is the
-      fourth foo,led node".
-
-      Only enabled nodes (status != "disabled") are counted. 'instance_no' is
-      meaningless for disabled nodes.
-
     matching_compat:
       The 'compatible' string for the binding that matched the node, or None if
       the node has no binding
@@ -1297,17 +1315,6 @@ class Node:
 
         return OrderedDict(zip(cell_names, data_list))
 
-    def _set_instance_no(self):
-        # Initializes self.instance_no
-
-        self.instance_no = {}
-
-        for compat in self.compats:
-            self.instance_no[compat] = 0
-            for other_node in self.edt.nodes:
-                if compat in other_node.compats and other_node.enabled:
-                    self.instance_no[compat] += 1
-
 
 class Register:
     """

scripts/dts/gen_defines.py

@@ -42,8 +42,6 @@ def main():
 
     write_top_comment(edt)
 
-    active_compats = set()
-
     for node in edt.nodes:
         if node.enabled and node.matching_compat:
             # Skip 'fixed-partitions' devices since they are handled by
@@ -60,10 +58,8 @@ def main():
             write_bus(node)
             write_existence_flags(node)
 
-            active_compats.update(node.compats)
+    out_comment("Compatibles appearing on enabled nodes")
-
+    for compat in sorted(edt.compat2enabled):
-    out_comment("Active compatibles (mentioned in DTS + binding found)")
-    for compat in sorted(active_compats):
         #define DT_COMPAT_<COMPAT> 1
         out(f"COMPAT_{str2ident(compat)}", 1)
 
@@ -272,12 +268,13 @@ def write_bus(node):
 def write_existence_flags(node):
     # Generate #defines of the form
     #
-    #   #define DT_INST_<INSTANCE>_<COMPAT> 1
+    #   #define DT_INST_<instance no.>_<compatible string> 1
     #
-    # These are flags for which devices exist.
+    # for enabled nodes. These are flags for which devices exist.
 
     for compat in node.compats:
-        out(f"INST_{node.instance_no[compat]}_{str2ident(compat)}", 1)
+        instance_no = node.edt.compat2enabled[compat].index(node)
+        out(f"INST_{instance_no}_{str2ident(compat)}", 1)
 
 
 def node_ident(node):
@@ -337,8 +334,11 @@ def node_instance_aliases(node):
     # This is a list since a node can have multiple 'compatible' strings, each
     # with their own instance number.
 
-    return [f"INST_{node.instance_no[compat]}_{str2ident(compat)}"
+    res = []
-            for compat in node.compats]
+    for compat in node.compats:
+        instance_no = node.edt.compat2enabled[compat].index(node)
+        res.append(f"INST_{instance_no}_{str2ident(compat)}")
+    return res
 
 
 def write_addr_size(edt, prop_name, prefix):

scripts/dts/test.dts

@@ -294,6 +294,31 @@
 		default-not-used = <234>;
 	};
 
+	//
+	// For testing EDT.compat2enabled
+	//
+
+	compat2enabled {
+		foo-1 {
+			status = "okay";
+			compatible = "compat2enabled";
+		};
+		foo-disabled {
+			status = "disabled";
+			compatible = "compat2enabled";
+		};
+		foo-2 {
+			// No 'status', which is also treated as enabled
+			compatible = "compat2enabled";
+		};
+		// Should not create an entry in compat2enabled, since all nodes
+		// with the compatible are disabled
+		bar {
+			status = "disabled";
+			compatible = "compat2enabled-disabled";
+		};
+	};
+
 	//
 	// For testing 'bus:' and 'on-bus:'
 	//

scripts/dts/testedtlib.py

@@ -164,6 +164,15 @@ warning: "#cells:" in test-bindings/deprecated.yaml is deprecated and will be re
     verify_streq(edt.get_node("/deprecated/sub-node").props,
                  "OrderedDict([('foos', <Property, name: foos, type: phandle-array, value: [<ControllerAndData, controller: <Node /deprecated in 'test.dts', binding test-bindings/deprecated.yaml>, data: OrderedDict([('foo', 1), ('bar', 2)])>]>)])")
 
+    #
+    # Test EDT.compat2enabled
+    #
+
+    verify_streq(edt.compat2enabled["compat2enabled"], "[<Node /compat2enabled/foo-1 in 'test.dts', no binding>, <Node /compat2enabled/foo-2 in 'test.dts', no binding>]")
+
+    if "compat2enabled-disabled" in edt.compat2enabled:
+        fail("'compat2enabled-disabled' should not appear in edt.compat2enabled")
+
     #
     # Test Node.props (derived from DT and 'properties:' in the binding)
     #