dtoc: Support processing the root node

The device for the root node is normally bound by driver model on init.
With devices being instantiated at build time, we must handle the root
device also.

Add support for processing the root node, which may not have a compatible
string.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/dtoc/dtb_platdata.py

@@ -350,16 +350,22 @@ class DtbPlatdata():
             # recurse to handle any subnodes
             self.scan_node(subnode, valid_nodes)
 
-    def scan_tree(self):
+    def scan_tree(self, add_root):
         """Scan the device tree for useful information
 
         This fills in the following properties:
             _valid_nodes_unsorted: A list of nodes we wish to consider include
                 in the platform data (in devicetree node order)
             _valid_nodes: Sorted version of _valid_nodes_unsorted
+
+        Args:
+            add_root: True to add the root node also (which wouldn't normally
+                be added as it may not have a compatible string)
         """
         root = self._fdt.GetRoot()
         valid_nodes = []
+        if add_root:
+            valid_nodes.append(root)
         self.scan_node(root, valid_nodes)
         self._valid_nodes_unsorted = valid_nodes
         self._valid_nodes = sorted(valid_nodes,
@@ -839,7 +845,7 @@ def run_steps(args, dtb_file, include_disabled, output, output_dirs, phase,
         do_process = False
     plat = DtbPlatdata(scan, dtb_file, include_disabled)
     plat.scan_dtb()
-    plat.scan_tree()
+    plat.scan_tree(add_root=False)
     plat.prepare_nodes()
     plat.scan_reg_sizes()
     plat.setup_output_dirs(output_dirs)

tools/dtoc/src_scan.py

@@ -33,6 +33,8 @@ def conv_name_to_c(name):
     new = new.replace('-', '_')
     new = new.replace(',', '_')
     new = new.replace('.', '_')
+    if new == '/':
+        return 'root'
     return new
 
 def get_compat_name(node):
@@ -250,6 +252,9 @@ class Scanner:
                 In case of no match found, the return will be the same as
                 get_compat_name()
         """
+        if not node.parent:
+            compat_list_c = ['root_driver']
+        else:
             compat_list_c = get_compat_name(node)
 
         for compat_c in compat_list_c:
@@ -509,7 +514,9 @@ class Scanner:
                 elif m_hdr:
                     driver.headers.append(m_hdr.group(1))
                 elif '};' in line:
-                    if driver.uclass_id and compat:
+                    is_root = driver.name == 'root_driver'
+                    if driver.uclass_id and (compat or is_root):
+                        if not is_root:
                             if compat not in of_match:
                                 raise ValueError(
                                     "%s: Unknown compatible var '%s' (found: %s)" %

tools/dtoc/test_dtoc.py

@@ -974,10 +974,10 @@ U_BOOT_DRVINFO(spl_test2) = {
         output = tools.GetOutputFilename('output')
 
         # Take a copy before messing with it
-        scan = copy.deepcopy(saved_scan)
+        scan = copy_scan()
         plat = dtb_platdata.DtbPlatdata(scan, dtb_file, False)
         plat.scan_dtb()
-        plat.scan_tree()
+        plat.scan_tree(False)
         plat.prepare_nodes()
         return plat, scan
 
@@ -1123,3 +1123,22 @@ U_BOOT_DRVINFO(spl_test2) = {
         self.assertEqual(4, i2c.seq)
         spl = plat._fdt.GetNode('/spl-test')
         self.assertEqual(0, spl.seq)
+
+    def test_process_root(self):
+        """Test assignment of sequence numnbers"""
+        dtb_file = get_dtb_file('dtoc_test_simple.dts')
+        output = tools.GetOutputFilename('output')
+
+        # Take a copy before messing with it
+        scan = copy_scan()
+        plat = dtb_platdata.DtbPlatdata(scan, dtb_file, False)
+        plat.scan_dtb()
+        root = plat._fdt.GetRoot()
+
+        plat.scan_tree(False)
+        self.assertNotIn(root, plat._valid_nodes)
+
+        plat.scan_tree(True)
+        self.assertIn(root, plat._valid_nodes)
+        self.assertEqual('root_driver',
+                         scan.get_normalized_compat_name(root)[0])

tools/dtoc/test_src_scan.py

@@ -161,6 +161,10 @@ class TestSrcScan(unittest.TestCase):
         prop.value = 'rockchip,rk3288-grf'
         node = FakeNode()
         node.props = {'compatible': prop}
+
+        # get_normalized_compat_name() uses this to check for root node
+        node.parent = FakeNode()
+
         scan = src_scan.Scanner(None, False, None)
         with test_util.capture_sys_output() as (stdout, _):
             name, aliases = scan.get_normalized_compat_name(node)
@@ -419,6 +423,9 @@ U_BOOT_DRIVER(%s) = {
         node.name = 'testing'
         node.props = {'compatible': prop}
 
+        # get_normalized_compat_name() uses this to check for root node
+        node.parent = FakeNode()
+
         return scan, drv1, driver2, node
 
     def test_dup_drivers(self):