dtoc: Move BytesToValue() and GetEmpty() into PropBase

These functions are currently in a separate fdt_util file. Since they are
only used from PropBase and subclasses, it makes sense for them to be in the
PropBase class.

Move these functions into fdt.py along with the list of types.

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

1 files changed, 66 insertions, 0 deletions

diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
index 413d45d..329d03c 100644
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -17,6 +17,9 @@ import fdt_util
 # implementation is in the FdtFallback and FdtNormal subclasses. See
 # fdt_select.py for how to create an Fdt object.
 
+# A list of types we support
+(TYPE_BYTE, TYPE_INT, TYPE_STRING, TYPE_BOOL) = range(4)
+
 def CheckErr(errnum, msg):
     if errnum:
         raise ValueError('Error %d: %s: %s' %
@@ -37,6 +40,69 @@ class PropBase:
         self.name = name
         self.value = None
 
+    def BytesToValue(self, bytes):
+        """Converts a string of bytes into a type and value
+
+        Args:
+            A string containing bytes
+
+        Return:
+            A tuple:
+                Type of data
+                Data, either a single element or a list of elements. Each element
+                is one of:
+                    TYPE_STRING: string value from the property
+                    TYPE_INT: a byte-swapped integer stored as a 4-byte string
+                    TYPE_BYTE: a byte stored as a single-byte string
+        """
+        size = len(bytes)
+        strings = bytes.split('\0')
+        is_string = True
+        count = len(strings) - 1
+        if count > 0 and not strings[-1]:
+            for string in strings[:-1]:
+                if not string:
+                    is_string = False
+                    break
+                for ch in string:
+                    if ch < ' ' or ch > '~':
+                        is_string = False
+                        break
+        else:
+            is_string = False
+        if is_string:
+            if count == 1:
+                return TYPE_STRING, strings[0]
+            else:
+                return TYPE_STRING, strings[:-1]
+        if size % 4:
+            if size == 1:
+                return TYPE_BYTE, bytes[0]
+            else:
+                return TYPE_BYTE, list(bytes)
+        val = []
+        for i in range(0, size, 4):
+            val.append(bytes[i:i + 4])
+        if size == 4:
+            return TYPE_INT, val[0]
+        else:
+            return TYPE_INT, val
+
+    def GetEmpty(self, type):
+        """Get an empty / zero value of the given type
+
+        Returns:
+            A single value of the given type
+        """
+        if type == TYPE_BYTE:
+            return chr(0)
+        elif type == TYPE_INT:
+            return struct.pack('<I', 0);
+        elif type == TYPE_STRING:
+            return ''
+        else:
+            return True
+
 class NodeBase:
     """A device tree node