[RFC 1/6] dtoc: add support to scan drivers

[Walter Lozano]

Currently dtoc scans dtbs to convert them to struct platdata and
to generate U_BOOT_DEVICE entries. These entries need to be filled
with the driver name, but at this moment the information used is the
compatible name present in the dtb. This causes that only nodes with
a compatible name that matches a driver name generate a working
entry.

In order to improve this behaviour, this patch adds to dtoc the
capability of scan drivers source code to generate a list of valid driver
names. This allows to rise a warning in the case that an U_BOOT_DEVICE
entry will try to use a name not valid.

Additionally, in order to add more flexibility to the solution, adds the
U_BOOT_DRIVER_ALIAS macro, which generates no code at all, but allows an
easy way to declare driver name aliases. Thanks to this, dtoc can look
for the driver name based on its alias when it populates the U_BOOT_DEVICE entry.

Signed-off-by: Walter Lozano <walter.lozano at collabora.com>
---
 include/dm/device.h        |  6 +++++
 tools/dtoc/dtb_platdata.py | 53 +++++++++++++++++++++++++++++++++++---
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/include/dm/device.h b/include/dm/device.h
index 975eec5d0e..d5b3e732c3 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -282,6 +282,12 @@ struct driver {
 #define DM_GET_DRIVER(__name)						\
 	ll_entry_get(struct driver, __name, driver)
 
+/* Declare a macro to state a alias for a driver name. This macro will
+ * produce no code but its information will be parsed by tools like
+ * dtoc
+ */
+#define U_BOOT_DRIVER_ALIAS(__name, __alias)
+
 /**
  * dev_get_platdata() - Get the platform data for a device
  *
diff --git a/tools/dtoc/dtb_platdata.py b/tools/dtoc/dtb_platdata.py
index ecfe0624d1..3f899a8bac 100644
--- a/tools/dtoc/dtb_platdata.py
+++ b/tools/dtoc/dtb_platdata.py
@@ -14,6 +14,8 @@ static data.
 import collections
 import copy
 import sys
+import os
+import re
 
 from dtoc import fdt
 from dtoc import fdt_util
@@ -149,6 +151,20 @@ class DtbPlatdata(object):
         self._outfile = None
         self._lines = []
         self._aliases = {}
+        self._drivers = []
+        self._driver_aliases = {}
+
+    def get_normalized_compat_name(self, node):
+        compat_c, aliases_c = get_compat_name(node)
+        if compat_c not in self._drivers:
+            try: # pragma: no cover
+                compat_c_old = compat_c
+                compat_c = self._driver_aliases[compat_c]
+                aliases_c = [compat_c_old] + aliases
+            except:
+                print('WARNING: the driver %s was not found in the driver list' % (compat_c))
+
+        return compat_c, aliases_c
 
     def setup_output(self, fname):
         """Set up the output destination
@@ -243,6 +259,34 @@ class DtbPlatdata(object):
             return PhandleInfo(max_args, args)
         return None
 
+    def scan_driver(self, fn):
+        f = open(fn)
+
+        b = f.read()
+
+        drivers = re.findall('U_BOOT_DRIVER\((.*)\)', b)
+
+        for d in drivers:
+            self._drivers.append(d)
+
+        driver_aliases = re.findall('U_BOOT_DRIVER_ALIAS\(\s*(\w+)\s*,\s*(\w+)\s*\)', b)
+
+        for a in driver_aliases: # pragma: no cover
+            try:
+                self._driver_aliases[a[1]] = a[0]
+            except:
+                pass
+
+    def scan_drivers(self):
+        """Scan the driver folders to build a list of driver names and possible
+        aliases
+        """
+        for (dirpath, dirnames, filenames) in os.walk('./'):
+            for fn in filenames:
+                if not fn.endswith('.c'):
+                    continue
+                self.scan_driver(dirpath + '/' + fn)
+
     def scan_dtb(self):
         """Scan the device tree to obtain a tree of nodes and properties
 
@@ -353,7 +397,7 @@ class DtbPlatdata(object):
         """
         structs = {}
         for node in self._valid_nodes:
-            node_name, _ = get_compat_name(node)
+            node_name, _ = self.get_normalized_compat_name(node)
             fields = {}
 
             # Get a list of all the valid properties in this node.
@@ -377,14 +421,14 @@ class DtbPlatdata(object):
 
         upto = 0
         for node in self._valid_nodes:
-            node_name, _ = get_compat_name(node)
+            node_name, _ = self.get_normalized_compat_name(node)
             struct = structs[node_name]
             for name, prop in node.props.items():
                 if name not in PROP_IGNORE_LIST and name[0] != '#':
                     prop.Widen(struct[name])
             upto += 1
 
-            struct_name, aliases = get_compat_name(node)
+            struct_name, aliases = self.get_normalized_compat_name(node)
             for alias in aliases:
                 self._aliases[alias] = struct_name
 
@@ -461,7 +505,7 @@ class DtbPlatdata(object):
         Args:
             node: node to output
         """
-        struct_name, _ = get_compat_name(node)
+        struct_name, _ = self.get_normalized_compat_name(node)
         var_name = conv_name_to_c(node.name)
         self.buf('static const struct %s%s %s%s = {\n' %
                  (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
@@ -562,6 +606,7 @@ def run_steps(args, dtb_file, include_disabled, output):
         raise ValueError('Please specify a command: struct, platdata')
 
     plat = DtbPlatdata(dtb_file, include_disabled)
+    plat.scan_drivers()
     plat.scan_dtb()
     plat.scan_tree()
     plat.scan_reg_sizes()
-- 
2.20.1