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>

4 files changed, 59 insertions, 20 deletions

diff --git a/tools/dtoc/dtb_platdata.py b/tools/dtoc/dtb_platdata.py
index af21156659..e08b92cf8a 100644
--- a/tools/dtoc/dtb_platdata.py
+++ b/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)
diff --git a/tools/dtoc/src_scan.py b/tools/dtoc/src_scan.py
index 8619206a8d..114212cfe2 100644
--- a/tools/dtoc/src_scan.py
+++ b/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):
@@ -250,7 +252,10 @@ class Scanner:
                 In case of no match found, the return will be the same as
                 get_compat_name()
         """
-        compat_list_c = get_compat_name(node)
+        if not node.parent:
+            compat_list_c = ['root_driver']
+        else:
+            compat_list_c = get_compat_name(node)
 
         for compat_c in compat_list_c:
             if not compat_c in self._drivers.keys():
@@ -509,21 +514,23 @@ class Scanner:
                 elif m_hdr:
                     driver.headers.append(m_hdr.group(1))
                 elif '};' in line:
-                    if driver.uclass_id and compat:
-                        if compat not in of_match:
-                            raise ValueError(
-                                "%s: Unknown compatible var '%s' (found: %s)" %
-                                (fname, compat, ','.join(of_match.keys())))
-                        driver.compat = of_match[compat]
-
-                        # This needs to be deterministic, since a driver may
-                        # have multiple compatible strings pointing to it.
-                        # We record the one earliest in the alphabet so it
-                        # will produce the same result on all machines.
-                        for compat_id in of_match[compat]:
-                            old = self._compat_to_driver.get(compat_id)
-                            if not old or driver.name < old.name:
-                                self._compat_to_driver[compat_id] = driver
+                    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)" %
+                                    (fname, compat, ','.join(of_match.keys())))
+                            driver.compat = of_match[compat]
+
+                            # This needs to be deterministic, since a driver may
+                            # have multiple compatible strings pointing to it.
+                            # We record the one earliest in the alphabet so it
+                            # will produce the same result on all machines.
+                            for compat_id in of_match[compat]:
+                                old = self._compat_to_driver.get(compat_id)
+                                if not old or driver.name < old.name:
+                                    self._compat_to_driver[compat_id] = driver
                         drivers[driver.name] = driver
                     else:
                         # The driver does not have a uclass or compat string.
diff --git a/tools/dtoc/test_dtoc.py b/tools/dtoc/test_dtoc.py
index b077cf0e76..ed8c7e4788 100755
--- a/tools/dtoc/test_dtoc.py
+++ b/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])
diff --git a/tools/dtoc/test_src_scan.py b/tools/dtoc/test_src_scan.py
index d32aa58400..0af86dcf0c 100644
--- a/tools/dtoc/test_src_scan.py
+++ b/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):