fdt: Use an Enum for the data type
Use an Enum instead of the current ad-hoc constants, so that there is a
data type associated with each 'type' value.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
index 03b8677..cb365ca 100644
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -5,6 +5,7 @@
# Written by Simon Glass <sjg@chromium.org>
#
+from enum import IntEnum
import struct
import sys
@@ -22,7 +23,25 @@
# so it is fairly efficient.
# A list of types we support
-(TYPE_BYTE, TYPE_INT, TYPE_STRING, TYPE_BOOL, TYPE_INT64) = range(5)
+class Type(IntEnum):
+ (BYTE, INT, STRING, BOOL, INT64) = range(5)
+
+ def is_wider_than(self, other):
+ """Check if another type is 'wider' than this one
+
+ A wider type is one that holds more information than an earlier one,
+ similar to the concept of type-widening in C.
+
+ This uses a simple arithmetic comparison, since type values are in order
+ from narrowest (BYTE) to widest (INT64).
+
+ Args:
+ other: Other type to compare against
+
+ Return:
+ True if the other type is wider
+ """
+ return self.value > other.value
def CheckErr(errnum, msg):
if errnum:
@@ -41,9 +60,9 @@
Type of data
Data, either a single element or a list of elements. Each element
is one of:
- TYPE_STRING: str/bytes value from the property
- TYPE_INT: a byte-swapped integer stored as a 4-byte str/bytes
- TYPE_BYTE: a byte stored as a single-byte str/bytes
+ Type.STRING: str/bytes value from the property
+ Type.INT: a byte-swapped integer stored as a 4-byte str/bytes
+ Type.BYTE: a byte stored as a single-byte str/bytes
"""
data = bytes(data)
size = len(data)
@@ -63,21 +82,21 @@
is_string = False
if is_string:
if count == 1:
- return TYPE_STRING, strings[0].decode()
+ return Type.STRING, strings[0].decode()
else:
- return TYPE_STRING, [s.decode() for s in strings[:-1]]
+ return Type.STRING, [s.decode() for s in strings[:-1]]
if size % 4:
if size == 1:
- return TYPE_BYTE, tools.ToChar(data[0])
+ return Type.BYTE, tools.ToChar(data[0])
else:
- return TYPE_BYTE, [tools.ToChar(ch) for ch in list(data)]
+ return Type.BYTE, [tools.ToChar(ch) for ch in list(data)]
val = []
for i in range(0, size, 4):
val.append(data[i:i + 4])
if size == 4:
- return TYPE_INT, val[0]
+ return Type.INT, val[0]
else:
- return TYPE_INT, val
+ return Type.INT, val
class Prop:
@@ -97,7 +116,7 @@
self.bytes = bytes(data)
self.dirty = False
if not data:
- self.type = TYPE_BOOL
+ self.type = Type.BOOL
self.value = True
return
self.type, self.value = BytesToValue(bytes(data))
@@ -128,9 +147,8 @@
update the current property to be like the second, since it is less
specific.
"""
- if newprop.type < self.type:
- # Special handling to convert an int into bytes
- if self.type == TYPE_INT and newprop.type == TYPE_BYTE:
+ if self.type.is_wider_than(newprop.type):
+ if self.type == Type.INT and newprop.type == Type.BYTE:
if type(self.value) == list:
new_value = []
for val in self.value:
@@ -155,11 +173,11 @@
Returns:
A single value of the given type
"""
- if type == TYPE_BYTE:
+ if type == Type.BYTE:
return chr(0)
- elif type == TYPE_INT:
+ elif type == Type.INT:
return struct.pack('>I', 0);
- elif type == TYPE_STRING:
+ elif type == Type.STRING:
return ''
else:
return True
@@ -184,7 +202,7 @@
"""
self.bytes = struct.pack('>I', val);
self.value = self.bytes
- self.type = TYPE_INT
+ self.type = Type.INT
self.dirty = True
def SetData(self, bytes):