device: iterable supported devices

Add supported device information to the device `handles` array. This
enables API's to iterate over supported devices for power management
purposes.

Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>

include/device.h

@@ -683,6 +683,26 @@ static inline bool device_is_ready(const struct device *dev)
  * in a distinct pass1 section (which will be replaced by
  * postprocessing).
  *
+ * Before processing in gen_handles.py, the array format is:
+ * {
+ *     DEVICE_ORDINAL (or DEVICE_HANDLE_NULL if not a devicetree node),
+ *     List of devicetree dependency ordinals (if any),
+ *     DEVICE_HANDLE_SEP,
+ *     List of injected dependency ordinals (if any),
+ *     DEVICE_HANDLE_SEP,
+ *     List of devicetree supporting ordinals (if any),
+ * }
+ *
+ * After processing in gen_handles.py, the format is updated to:
+ * {
+ *     List of existing devicetree dependency handles (if any),
+ *     DEVICE_HANDLE_SEP,
+ *     List of injected dependency ordinals (if any),
+ *     DEVICE_HANDLE_SEP,
+ *     List of existing devicetree support handles (if any),
+ *     DEVICE_HANDLE_NULL
+ * }
+ *
  * It is also (experimentally) necessary to provide explicit alignment
  * on each object. Otherwise x86-64 builds will introduce padding
  * between objects in the same input section in individual object
@@ -711,6 +731,9 @@ BUILD_ASSERT(sizeof(device_handle_t) == 2, "fix the linker scripts");
 		))							\
 			DEVICE_HANDLE_SEP,				\
 			Z_DEVICE_EXTRA_HANDLES(__VA_ARGS__)		\
+			DEVICE_HANDLE_SEP,				\
+	COND_CODE_1(DT_NODE_EXISTS(node_id),				\
+			(DT_SUPPORTS_DEP_ORDS(node_id)), ())		\
 		};
 
 #define Z_DEVICE_DEFINE_INIT(node_id, dev_name)				\

scripts/gen_handles.py

@@ -246,15 +246,19 @@ def main():
         hvi = 1
         handle.dev_deps = []
         handle.ext_deps = []
-        deps = handle.dev_deps
+        handle.dev_sups = []
+        hdls = handle.dev_deps
         while hvi < len(hv):
             h = hv[hvi]
             if h == DEVICE_HANDLE_ENDS:
                 break
             if h == DEVICE_HANDLE_SEP:
-                deps = handle.ext_deps
+                if hdls == handle.dev_deps:
+                    hdls = handle.ext_deps
+                else:
+                    hdls = handle.dev_sups
             else:
-                deps.append(h)
+                hdls.append(h)
                 n = edt
             hvi += 1
 
@@ -264,22 +268,36 @@ def main():
     root = edt.dep_ord2node[0]
     assert root not in used_nodes
 
-    for sn in used_nodes:
+    for n in used_nodes:
         # Where we're storing the final set of nodes: these are all used
-        sn.__depends = set()
+        n.__depends = set()
+        n.__supports = set()
 
-        deps = set(sn.depends_on)
+        deps = set(n.depends_on)
-        debug("\nNode: %s\nOrig deps:\n\t%s" % (sn.path, "\n\t".join([dn.path for dn in deps])))
+        debug("\nNode: %s\nOrig deps:\n\t%s" % (n.path, "\n\t".join([dn.path for dn in deps])))
         while len(deps) > 0:
             dn = deps.pop()
             if dn in used_nodes:
                 # this is used
-                sn.__depends.add(dn)
+                n.__depends.add(dn)
             elif dn != root:
                 # forward the dependency up one level
                 for ddn in dn.depends_on:
                     deps.add(ddn)
-        debug("final deps:\n\t%s\n" % ("\n\t".join([ _dn.path for _dn in sn.__depends])))
+        debug("Final deps:\n\t%s\n" % ("\n\t".join([ _dn.path for _dn in n.__depends])))
+
+        sups = set(n.required_by)
+        debug("\nOrig sups:\n\t%s" % ("\n\t".join([dn.path for dn in sups])))
+        while len(sups) > 0:
+            sn = sups.pop()
+            if sn in used_nodes:
+                # this is used
+                n.__supports.add(sn)
+            else:
+                # forward the support down one level
+                for ssn in sn.required_by:
+                    sups.add(ssn)
+        debug("\nFinal sups:\n\t%s" % ("\n\t".join([_sn.path for _sn in n.__supports])))
 
     with open(args.output_source, "w") as fp:
         fp.write('#include <device.h>\n')
@@ -290,6 +308,7 @@ def main():
             assert hs, "no hs for %s" % (dev.sym.name,)
             dep_paths = []
             ext_paths = []
+            sup_paths = []
             hdls = []
 
             sn = hs.node
@@ -300,12 +319,24 @@ def main():
                         dep_paths.append(dn.path)
                     else:
                         dep_paths.append('(%s)' % dn.path)
+            # Force separator to signal start of injected dependencies
+            hdls.append(DEVICE_HANDLE_SEP)
             if len(hs.ext_deps) > 0:
                 # TODO: map these to something smaller?
                 ext_paths.extend(map(str, hs.ext_deps))
                 hdls.append(DEVICE_HANDLE_SEP)
                 hdls.extend(hs.ext_deps)
 
+            # Force separator to signal start of supported devices
+            hdls.append(DEVICE_HANDLE_SEP)
+            if len(hs.dev_sups) > 0:
+                for dn in sn.required_by:
+                    if dn in sn.__supports:
+                        sup_paths.append(dn.path)
+                    else:
+                        sup_paths.append('(%s)' % dn.path)
+                hdls.extend(dn.__device.dev_handle for dn in sn.__supports)
+
             # Terminate the array with the end symbol
             hdls.append(DEVICE_HANDLE_ENDS)
 
@@ -315,9 +346,14 @@ def main():
             ]
 
             if len(dep_paths) > 0:
-                lines.append(' * - %s' % ('\n * - '.join(dep_paths)))
+                lines.append(' * Direct Dependencies:')
+                lines.append(' *   - %s' % ('\n *   - '.join(dep_paths)))
             if len(ext_paths) > 0:
-                lines.append(' * + %s' % ('\n * + '.join(ext_paths)))
+                lines.append(' * Injected Dependencies:')
+                lines.append(' *   - %s' % ('\n *   - '.join(ext_paths)))
+            if len(sup_paths) > 0:
+                lines.append(' * Supported:')
+                lines.append(' *   - %s' % ('\n *   - '.join(sup_paths)))
 
             lines.extend([
                 ' */',