#!/usr/bin/python
+# SPDX-License-Identifier: GPL-2.0+
#
# Copyright (C) 2016 Google, Inc
# Written by Simon Glass <sjg@chromium.org>
#
-# SPDX-License-Identifier: GPL-2.0+
-#
+# Utility functions for reading from a device tree. Once the upstream pylibfdt
+# implementation advances far enough, we should be able to drop these.
+
+import os
import struct
+import sys
+import tempfile
-# A list of types we support
-(TYPE_BYTE, TYPE_INT, TYPE_STRING, TYPE_BOOL) = range(4)
+import command
+import tools
-def BytesToValue(bytes):
- """Converts a string of bytes into a type and value
+def fdt32_to_cpu(val):
+ """Convert a device tree cell to an integer
Args:
- A string containing bytes
+ Value to convert (4-character string representing the cell value)
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
+ A native-endian integer value
"""
- 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
+ return struct.unpack('>I', val)[0]
+
+def fdt_cells_to_cpu(val, cells):
+ """Convert one or two cells to a long integer
+
+ Args:
+ Value to convert (array of one or more 4-character strings)
+
+ Return:
+ A native-endian integer value
+ """
+ if not cells:
+ return 0
+ out = int(fdt32_to_cpu(val[0]))
+ if cells == 2:
+ out = out << 32 | fdt32_to_cpu(val[1])
+ return out
-def GetEmpty(type):
- """Get an empty / zero value of the given type
+def EnsureCompiled(fname, tmpdir=None, capture_stderr=False):
+ """Compile an fdt .dts source file into a .dtb binary blob if needed.
+
+ Args:
+ fname: Filename (if .dts it will be compiled). It not it will be
+ left alone
+ tmpdir: Temporary directory for output files, or None to use the
+ tools-module output directory
Returns:
- A single value of the given type
+ Filename of resulting .dtb file
"""
- if type == TYPE_BYTE:
- return chr(0)
- elif type == TYPE_INT:
- return struct.pack('<I', 0);
- elif type == TYPE_STRING:
- return ''
+ _, ext = os.path.splitext(fname)
+ if ext != '.dts':
+ return fname
+
+ if tmpdir:
+ dts_input = os.path.join(tmpdir, 'source.dts')
+ dtb_output = os.path.join(tmpdir, 'source.dtb')
else:
+ dts_input = tools.GetOutputFilename('source.dts')
+ dtb_output = tools.GetOutputFilename('source.dtb')
+
+ search_paths = [os.path.join(os.getcwd(), 'include')]
+ root, _ = os.path.splitext(fname)
+ args = ['-E', '-P', '-x', 'assembler-with-cpp', '-D__ASSEMBLY__']
+ args += ['-Ulinux']
+ for path in search_paths:
+ args.extend(['-I', path])
+ args += ['-o', dts_input, fname]
+ command.Run('cc', *args)
+
+ # If we don't have a directory, put it in the tools tempdir
+ search_list = []
+ for path in search_paths:
+ search_list.extend(['-i', path])
+ args = ['-I', 'dts', '-o', dtb_output, '-O', 'dtb',
+ '-W', 'no-unit_address_vs_reg']
+ args.extend(search_list)
+ args.append(dts_input)
+ dtc = os.environ.get('DTC') or 'dtc'
+ command.Run(dtc, *args, capture_stderr=capture_stderr)
+ return dtb_output
+
+def GetInt(node, propname, default=None):
+ """Get an integer from a property
+
+ Args:
+ node: Node object to read from
+ propname: property name to read
+ default: Default value to use if the node/property do not exist
+
+ Returns:
+ Integer value read, or default if none
+ """
+ prop = node.props.get(propname)
+ if not prop:
+ return default
+ if isinstance(prop.value, list):
+ raise ValueError("Node '%s' property '%s' has list value: expecting "
+ "a single integer" % (node.name, propname))
+ value = fdt32_to_cpu(prop.value)
+ return value
+
+def GetString(node, propname, default=None):
+ """Get a string from a property
+
+ Args:
+ node: Node object to read from
+ propname: property name to read
+ default: Default value to use if the node/property do not exist
+
+ Returns:
+ String value read, or default if none
+ """
+ prop = node.props.get(propname)
+ if not prop:
+ return default
+ value = prop.value
+ if isinstance(value, list):
+ raise ValueError("Node '%s' property '%s' has list value: expecting "
+ "a single string" % (node.name, propname))
+ return value
+
+def GetBool(node, propname, default=False):
+ """Get an boolean from a property
+
+ Args:
+ node: Node object to read from
+ propname: property name to read
+ default: Default value to use if the node/property do not exist
+
+ Returns:
+ Boolean value read, or default if none (if you set this to True the
+ function will always return True)
+ """
+ if propname in node.props:
return True
+ return default
-def fdt32_to_cpu(val):
- """Convert a device tree cell to an integer
+def GetByte(node, propname, default=None):
+ """Get an byte from a property
Args:
- Value to convert (4-character string representing the cell value)
+ node: Node object to read from
+ propname: property name to read
+ default: Default value to use if the node/property do not exist
- Return:
- A native-endian integer value
+ Returns:
+ Byte value read, or default if none
+ """
+ prop = node.props.get(propname)
+ if not prop:
+ return default
+ value = prop.value
+ if isinstance(value, list):
+ raise ValueError("Node '%s' property '%s' has list value: expecting "
+ "a single byte" % (node.name, propname))
+ if len(value) != 1:
+ raise ValueError("Node '%s' property '%s' has length %d, expecting %d" %
+ (node.name, propname, len(value), 1))
+ return ord(value[0])
+
+def GetPhandleList(node, propname):
+ """Get a list of phandles from a property
+
+ Args:
+ node: Node object to read from
+ propname: property name to read
+
+ Returns:
+ List of phandles read, each an integer
+ """
+ prop = node.props.get(propname)
+ if not prop:
+ return None
+ value = prop.value
+ if not isinstance(value, list):
+ value = [value]
+ return [fdt32_to_cpu(v) for v in value]
+
+def GetDatatype(node, propname, datatype):
+ """Get a value of a given type from a property
+
+ Args:
+ node: Node object to read from
+ propname: property name to read
+ datatype: Type to read (str or int)
+
+ Returns:
+ value read, or None if none
+
+ Raises:
+ ValueError if datatype is not str or int
"""
- return struct.unpack(">I", val)[0]
+ if datatype == str:
+ return GetString(node, propname)
+ elif datatype == int:
+ return GetInt(node, propname)
+ raise ValueError("fdt_util internal error: Unknown data type '%s'" %
+ datatype)
projects / oweals / u-boot.git / blobdiff