Merge git://git.denx.de/u-boot-dm

7 files changed, 883 insertions, 0 deletions

diff --git a/tools/Makefile b/tools/Makefile
index f72294a..421414b 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -107,6 +107,20 @@ mkimage-objs   := $(dumpimage-mkimage-objs) mkimage.o
 fit_info-objs   := $(dumpimage-mkimage-objs) fit_info.o
 fit_check_sign-objs   := $(dumpimage-mkimage-objs) fit_check_sign.o
 
+# Build a libfdt Python module if swig is available
+# Use 'sudo apt-get install swig libpython-dev' to enable this
+hostprogs-$(CONFIG_SPL_OF_PLATDATA) += \
+	$(if $(shell which swig),_libfdt.so)
+_libfdt.so-sharedobjs += $(LIBFDT_OBJS)
+libfdt:
+
+tools/_libfdt.so: $(patsubst %.o,%.c,$(LIBFDT_OBJS)) tools/libfdt_wrap.c
+	python $(srctree)/lib/libfdt/setup.py "$(_hostc_flags)" $^
+	mv _libfdt.so $@
+
+tools/libfdt_wrap.c: $(srctree)/lib/libfdt/libfdt.swig
+	swig -python -o $@ $<
+
 # TODO(sjg@chromium.org): Is this correct on Mac OS?
 
 ifneq ($(CONFIG_MX23)$(CONFIG_MX28),)
diff --git a/tools/dtoc/.gitignore b/tools/dtoc/.gitignore
new file mode 100644
index 0000000..0d20b64
--- /dev/null
+++ b/tools/dtoc/.gitignore
@@ -0,0 +1 @@
+*.pyc
diff --git a/tools/dtoc/dtoc b/tools/dtoc/dtoc
new file mode 120000
index 0000000..896ca44
--- /dev/null
+++ b/tools/dtoc/dtoc
@@ -0,0 +1 @@
+dtoc.py
\ No newline at end of file
diff --git a/tools/dtoc/dtoc.py b/tools/dtoc/dtoc.py
new file mode 100755
index 0000000..ec80abe
--- /dev/null
+++ b/tools/dtoc/dtoc.py
@@ -0,0 +1,394 @@
+#!/usr/bin/python
+#
+# Copyright (C) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+import copy
+from optparse import OptionError, OptionParser
+import os
+import sys
+
+import fdt_util
+
+# Bring in the patman libraries
+our_path = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(our_path, '../patman'))
+
+# Bring in either the normal fdt library (which relies on libfdt) or the
+# fallback one (which uses fdtget and is slower). Both provide the same
+# interfface for this file to use.
+try:
+    from fdt import Fdt
+    import fdt
+    have_libfdt = True
+except ImportError:
+    have_libfdt = False
+    from fdt_fallback import Fdt
+    import fdt_fallback as fdt
+
+import struct
+
+# When we see these properties we ignore them - i.e. do not create a structure member
+PROP_IGNORE_LIST = [
+    '#address-cells',
+    '#gpio-cells',
+    '#size-cells',
+    'compatible',
+    'linux,phandle',
+    "status",
+    'phandle',
+    'u-boot,dm-pre-reloc',
+]
+
+# C type declarations for the tyues we support
+TYPE_NAMES = {
+    fdt_util.TYPE_INT: 'fdt32_t',
+    fdt_util.TYPE_BYTE: 'unsigned char',
+    fdt_util.TYPE_STRING: 'const char *',
+    fdt_util.TYPE_BOOL: 'bool',
+};
+
+STRUCT_PREFIX = 'dtd_'
+VAL_PREFIX = 'dtv_'
+
+def Conv_name_to_c(name):
+    """Convert a device-tree name to a C identifier
+
+    Args:
+        name:   Name to convert
+    Return:
+        String containing the C version of this name
+    """
+    str = name.replace('@', '_at_')
+    str = str.replace('-', '_')
+    str = str.replace(',', '_')
+    str = str.replace('/', '__')
+    return str
+
+def TabTo(num_tabs, str):
+    if len(str) >= num_tabs * 8:
+        return str + ' '
+    return str + '\t' * (num_tabs - len(str) / 8)
+
+class DtbPlatdata:
+    """Provide a means to convert device tree binary data to platform data
+
+    The output of this process is C structures which can be used in space-
+    constrained encvironments where the ~3KB code overhead of device tree
+    code is not affordable.
+
+    Properties:
+        fdt: Fdt object, referencing the device tree
+        _dtb_fname: Filename of the input device tree binary file
+        _valid_nodes: A list of Node object with compatible strings
+        _options: Command-line options
+        _phandle_node: A dict of nodes indexed by phandle number (1, 2...)
+        _outfile: The current output file (sys.stdout or a real file)
+        _lines: Stashed list of output lines for outputting in the future
+        _phandle_node: A dict of Nodes indexed by phandle (an integer)
+    """
+    def __init__(self, dtb_fname, options):
+        self._dtb_fname = dtb_fname
+        self._valid_nodes = None
+        self._options = options
+        self._phandle_node = {}
+        self._outfile = None
+        self._lines = []
+
+    def SetupOutput(self, fname):
+        """Set up the output destination
+
+        Once this is done, future calls to self.Out() will output to this
+        file.
+
+        Args:
+            fname: Filename to send output to, or '-' for stdout
+        """
+        if fname == '-':
+            self._outfile = sys.stdout
+        else:
+            self._outfile = open(fname, 'w')
+
+    def Out(self, str):
+        """Output a string to the output file
+
+        Args:
+            str: String to output
+        """
+        self._outfile.write(str)
+
+    def Buf(self, str):
+        """Buffer up a string to send later
+
+        Args:
+            str: String to add to our 'buffer' list
+        """
+        self._lines.append(str)
+
+    def GetBuf(self):
+        """Get the contents of the output buffer, and clear it
+
+        Returns:
+            The output buffer, which is then cleared for future use
+        """
+        lines = self._lines
+        self._lines = []
+        return lines
+
+    def GetValue(self, type, value):
+        """Get a value as a C expression
+
+        For integers this returns a byte-swapped (little-endian) hex string
+        For bytes this returns a hex string, e.g. 0x12
+        For strings this returns a literal string enclosed in quotes
+        For booleans this return 'true'
+
+        Args:
+            type: Data type (fdt_util)
+            value: Data value, as a string of bytes
+        """
+        if type == fdt_util.TYPE_INT:
+            return '%#x' % fdt_util.fdt32_to_cpu(value)
+        elif type == fdt_util.TYPE_BYTE:
+            return '%#x' % ord(value[0])
+        elif type == fdt_util.TYPE_STRING:
+            return '"%s"' % value
+        elif type == fdt_util.TYPE_BOOL:
+            return 'true'
+
+    def GetCompatName(self, node):
+        """Get a node's first compatible string as a C identifier
+
+        Args:
+            node: Node object to check
+        Return:
+            C identifier for the first compatible string
+        """
+        compat = node.props['compatible'].value
+        if type(compat) == list:
+            compat = compat[0]
+        return Conv_name_to_c(compat)
+
+    def ScanDtb(self):
+        """Scan the device tree to obtain a tree of notes and properties
+
+        Once this is done, self.fdt.GetRoot() can be called to obtain the
+        device tree root node, and progress from there.
+        """
+        self.fdt = Fdt(self._dtb_fname)
+        self.fdt.Scan()
+
+    def ScanTree(self):
+        """Scan the device tree for useful information
+
+        This fills in the following properties:
+            _phandle_node: A dict of Nodes indexed by phandle (an integer)
+            _valid_nodes: A list of nodes we wish to consider include in the
+                platform data
+        """
+        node_list = []
+        self._phandle_node = {}
+        for node in self.fdt.GetRoot().subnodes:
+            if 'compatible' in node.props:
+                status = node.props.get('status')
+                if (not options.include_disabled and not status or
+                    status.value != 'disabled'):
+                    node_list.append(node)
+                    phandle_prop = node.props.get('phandle')
+                    if phandle_prop:
+                        phandle = phandle_prop.GetPhandle()
+                        self._phandle_node[phandle] = node
+
+        self._valid_nodes = node_list
+
+    def IsPhandle(self, prop):
+        """Check if a node contains phandles
+
+        We have no reliable way of detecting whether a node uses a phandle
+        or not. As an interim measure, use a list of known property names.
+
+        Args:
+            prop: Prop object to check
+        Return:
+            True if the object value contains phandles, else False
+        """
+        if prop.name in ['clocks']:
+            return True
+        return False
+
+    def ScanStructs(self):
+        """Scan the device tree building up the C structures we will use.
+
+        Build a dict keyed by C struct name containing a dict of Prop
+        object for each struct field (keyed by property name). Where the
+        same struct appears multiple times, try to use the 'widest'
+        property, i.e. the one with a type which can express all others.
+
+        Once the widest property is determined, all other properties are
+        updated to match that width.
+        """
+        structs = {}
+        for node in self._valid_nodes:
+            node_name = self.GetCompatName(node)
+            fields = {}
+
+            # Get a list of all the valid properties in this node.
+            for name, prop in node.props.iteritems():
+                if name not in PROP_IGNORE_LIST and name[0] != '#':
+                    fields[name] = copy.deepcopy(prop)
+
+            # If we've seen this node_name before, update the existing struct.
+            if node_name in structs:
+                struct = structs[node_name]
+                for name, prop in fields.iteritems():
+                    oldprop = struct.get(name)
+                    if oldprop:
+                        oldprop.Widen(prop)
+                    else:
+                        struct[name] = prop
+
+            # Otherwise store this as a new struct.
+            else:
+                structs[node_name] = fields
+
+        upto = 0
+        for node in self._valid_nodes:
+            node_name = self.GetCompatName(node)
+            struct = structs[node_name]
+            for name, prop in node.props.iteritems():
+                if name not in PROP_IGNORE_LIST and name[0] != '#':
+                    prop.Widen(struct[name])
+            upto += 1
+        return structs
+
+    def GenerateStructs(self, structs):
+        """Generate struct defintions for the platform data
+
+        This writes out the body of a header file consisting of structure
+        definitions for node in self._valid_nodes. See the documentation in
+        README.of-plat for more information.
+        """
+        self.Out('#include <stdbool.h>\n')
+        self.Out('#include <libfdt.h>\n')
+
+        # Output the struct definition
+        for name in sorted(structs):
+            self.Out('struct %s%s {\n' % (STRUCT_PREFIX, name));
+            for pname in sorted(structs[name]):
+                prop = structs[name][pname]
+                if self.IsPhandle(prop):
+                    # For phandles, include a reference to the target
+                    self.Out('\t%s%s[%d]' % (TabTo(2, 'struct phandle_2_cell'),
+                                             Conv_name_to_c(prop.name),
+                                             len(prop.value) / 2))
+                else:
+                    ptype = TYPE_NAMES[prop.type]
+                    self.Out('\t%s%s' % (TabTo(2, ptype),
+                                         Conv_name_to_c(prop.name)))
+                    if type(prop.value) == list:
+                        self.Out('[%d]' % len(prop.value))
+                self.Out(';\n')
+            self.Out('};\n')
+
+    def GenerateTables(self):
+        """Generate device defintions for the platform data
+
+        This writes out C platform data initialisation data and
+        U_BOOT_DEVICE() declarations for each valid node. See the
+        documentation in README.of-plat for more information.
+        """
+        self.Out('#include <common.h>\n')
+        self.Out('#include <dm.h>\n')
+        self.Out('#include <dt-structs.h>\n')
+        self.Out('\n')
+        node_txt_list = []
+        for node in self._valid_nodes:
+            struct_name = self.GetCompatName(node)
+            var_name = Conv_name_to_c(node.name)
+            self.Buf('static struct %s%s %s%s = {\n' %
+                (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
+            for pname, prop in node.props.iteritems():
+                if pname in PROP_IGNORE_LIST or pname[0] == '#':
+                    continue
+                ptype = TYPE_NAMES[prop.type]
+                member_name = Conv_name_to_c(prop.name)
+                self.Buf('\t%s= ' % TabTo(3, '.' + member_name))
+
+                # Special handling for lists
+                if type(prop.value) == list:
+                    self.Buf('{')
+                    vals = []
+                    # For phandles, output a reference to the platform data
+                    # of the target node.
+                    if self.IsPhandle(prop):
+                        # Process the list as pairs of (phandle, id)
+                        it = iter(prop.value)
+                        for phandle_cell, id_cell in zip(it, it):
+                            phandle = fdt_util.fdt32_to_cpu(phandle_cell)
+                            id = fdt_util.fdt32_to_cpu(id_cell)
+                            target_node = self._phandle_node[phandle]
+                            name = Conv_name_to_c(target_node.name)
+                            vals.append('{&%s%s, %d}' % (VAL_PREFIX, name, id))
+                    else:
+                        for val in prop.value:
+                            vals.append(self.GetValue(prop.type, val))
+                    self.Buf(', '.join(vals))
+                    self.Buf('}')
+                else:
+                    self.Buf(self.GetValue(prop.type, prop.value))
+                self.Buf(',\n')
+            self.Buf('};\n')
+
+            # Add a device declaration
+            self.Buf('U_BOOT_DEVICE(%s) = {\n' % var_name)
+            self.Buf('\t.name\t\t= "%s",\n' % struct_name)
+            self.Buf('\t.platdata\t= &%s%s,\n' % (VAL_PREFIX, var_name))
+            self.Buf('\t.platdata_size\t= sizeof(%s%s),\n' %
+                     (VAL_PREFIX, var_name))
+            self.Buf('};\n')
+            self.Buf('\n')
+
+            # Output phandle target nodes first, since they may be referenced
+            # by others
+            if 'phandle' in node.props:
+                self.Out(''.join(self.GetBuf()))
+            else:
+                node_txt_list.append(self.GetBuf())
+
+        # Output all the nodes which are not phandle targets themselves, but
+        # may reference them. This avoids the need for forward declarations.
+        for node_txt in node_txt_list:
+            self.Out(''.join(node_txt))
+
+
+if __name__ != "__main__":
+    pass
+
+parser = OptionParser()
+parser.add_option('-d', '--dtb-file', action='store',
+                  help='Specify the .dtb input file')
+parser.add_option('--include-disabled', action='store_true',
+                  help='Include disabled nodes')
+parser.add_option('-o', '--output', action='store', default='-',
+                  help='Select output filename')
+(options, args) = parser.parse_args()
+
+if not args:
+    raise ValueError('Please specify a command: struct, platdata')
+
+plat = DtbPlatdata(options.dtb_file, options)
+plat.ScanDtb()
+plat.ScanTree()
+plat.SetupOutput(options.output)
+structs = plat.ScanStructs()
+
+for cmd in args[0].split(','):
+    if cmd == 'struct':
+        plat.GenerateStructs(structs)
+    elif cmd == 'platdata':
+        plat.GenerateTables()
+    else:
+        raise ValueError("Unknown command '%s': (use: struct, platdata)" % cmd)
diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
new file mode 100644
index 0000000..1d913a9
--- /dev/null
+++ b/tools/dtoc/fdt.py
@@ -0,0 +1,180 @@
+#!/usr/bin/python
+#
+# Copyright (C) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+
+import fdt_util
+import libfdt
+import sys
+
+# This deals with a device tree, presenting it as a list of Node and Prop
+# objects, representing nodes and properties, respectively.
+#
+# This implementation uses a libfdt Python library to access the device tree,
+# so it is fairly efficient.
+
+class Prop:
+    """A device tree property
+
+    Properties:
+        name: Property name (as per the device tree)
+        value: Property value as a string of bytes, or a list of strings of
+            bytes
+        type: Value type
+    """
+    def __init__(self, name, bytes):
+        self.name = name
+        self.value = None
+        if not bytes:
+            self.type = fdt_util.TYPE_BOOL
+            self.value = True
+            return
+        self.type, self.value = fdt_util.BytesToValue(bytes)
+
+    def GetPhandle(self):
+        """Get a (single) phandle value from a property
+
+        Gets the phandle valuie from a property and returns it as an integer
+        """
+        return fdt_util.fdt32_to_cpu(self.value[:4])
+
+    def Widen(self, newprop):
+        """Figure out which property type is more general
+
+        Given a current property and a new property, this function returns the
+        one that is less specific as to type. The less specific property will
+        be ble to represent the data in the more specific property. This is
+        used for things like:
+
+            node1 {
+                compatible = "fred";
+                value = <1>;
+            };
+            node1 {
+                compatible = "fred";
+                value = <1 2>;
+            };
+
+        He we want to use an int array for 'value'. The first property
+        suggests that a single int is enough, but the second one shows that
+        it is not. Calling this function with these two propertes would
+        update the current property to be like the second, since it is less
+        specific.
+        """
+        if newprop.type < self.type:
+            self.type = newprop.type
+
+        if type(newprop.value) == list and type(self.value) != list:
+            self.value = [self.value]
+
+        if type(self.value) == list and len(newprop.value) > len(self.value):
+            val = fdt_util.GetEmpty(self.type)
+            while len(self.value) < len(newprop.value):
+                self.value.append(val)
+
+
+class Node:
+    """A device tree node
+
+    Properties:
+        offset: Integer offset in the device tree
+        name: Device tree node tname
+        path: Full path to node, along with the node name itself
+        _fdt: Device tree object
+        subnodes: A list of subnodes for this node, each a Node object
+        props: A dict of properties for this node, each a Prop object.
+            Keyed by property name
+    """
+    def __init__(self, fdt, offset, name, path):
+        self.offset = offset
+        self.name = name
+        self.path = path
+        self._fdt = fdt
+        self.subnodes = []
+        self.props = {}
+
+    def Scan(self):
+        """Scan a node's properties and subnodes
+
+        This fills in the props and subnodes properties, recursively
+        searching into subnodes so that the entire tree is built.
+        """
+        self.props = self._fdt.GetProps(self.path)
+
+        offset = libfdt.fdt_first_subnode(self._fdt.GetFdt(), self.offset)
+        while offset >= 0:
+            sep = '' if self.path[-1] == '/' else '/'
+            name = libfdt.Name(self._fdt.GetFdt(), offset)
+            path = self.path + sep + name
+            node = Node(self._fdt, offset, name, path)
+            self.subnodes.append(node)
+
+            node.Scan()
+            offset = libfdt.fdt_next_subnode(self._fdt.GetFdt(), offset)
+
+
+class Fdt:
+    """Provides simple access to a flat device tree blob.
+
+    Properties:
+      fname: Filename of fdt
+      _root: Root of device tree (a Node object)
+    """
+
+    def __init__(self, fname):
+        self.fname = fname
+        with open(fname) as fd:
+            self._fdt = fd.read()
+
+    def GetFdt(self):
+        """Get the contents of the FDT
+
+        Returns:
+            The FDT contents as a string of bytes
+        """
+        return self._fdt
+
+    def Scan(self):
+        """Scan a device tree, building up a tree of Node objects
+
+        This fills in the self._root property
+        """
+        self._root = Node(self, 0, '/', '/')
+        self._root.Scan()
+
+    def GetRoot(self):
+        """Get the root Node of the device tree
+
+        Returns:
+            The root Node object
+        """
+        return self._root
+
+    def GetProps(self, node):
+        """Get all properties from a node.
+
+        Args:
+            node: Full path to node name to look in.
+
+        Returns:
+            A dictionary containing all the properties, indexed by node name.
+            The entries are Prop objects.
+
+        Raises:
+            ValueError: if the node does not exist.
+        """
+        offset = libfdt.fdt_path_offset(self._fdt, node)
+        if offset < 0:
+            libfdt.Raise(offset)
+        props_dict = {}
+        poffset = libfdt.fdt_first_property_offset(self._fdt, offset)
+        while poffset >= 0:
+            dprop, plen = libfdt.fdt_get_property_by_offset(self._fdt, poffset)
+            prop = Prop(libfdt.String(self._fdt, dprop.nameoff), libfdt.Data(dprop))
+            props_dict[prop.name] = prop
+
+            poffset = libfdt.fdt_next_property_offset(self._fdt, poffset)
+        return props_dict
diff --git a/tools/dtoc/fdt_fallback.py b/tools/dtoc/fdt_fallback.py
new file mode 100644
index 0000000..14decf3
--- /dev/null
+++ b/tools/dtoc/fdt_fallback.py
@@ -0,0 +1,207 @@
+#!/usr/bin/python
+#
+# Copyright (C) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+
+import command
+import fdt_util
+import sys
+
+# This deals with a device tree, presenting it as a list of Node and Prop
+# objects, representing nodes and properties, respectively.
+#
+# This implementation uses the fdtget tool to access the device tree, so it
+# is not very efficient for larger trees. The tool is called once for each
+# node and property in the tree.
+
+class Prop:
+    """A device tree property
+
+    Properties:
+        name: Property name (as per the device tree)
+        value: Property value as a string of bytes, or a list of strings of
+            bytes
+        type: Value type
+    """
+    def __init__(self, name, byte_list_str):
+        self.name = name
+        self.value = None
+        if not byte_list_str.strip():
+            self.type = fdt_util.TYPE_BOOL
+            return
+        bytes = [chr(int(byte, 16)) for byte in byte_list_str.strip().split(' ')]
+        self.type, self.value = fdt_util.BytesToValue(''.join(bytes))
+
+    def GetPhandle(self):
+        """Get a (single) phandle value from a property
+
+        Gets the phandle valuie from a property and returns it as an integer
+        """
+        return fdt_util.fdt32_to_cpu(self.value[:4])
+
+    def Widen(self, newprop):
+        """Figure out which property type is more general
+
+        Given a current property and a new property, this function returns the
+        one that is less specific as to type. The less specific property will
+        be ble to represent the data in the more specific property. This is
+        used for things like:
+
+            node1 {
+                compatible = "fred";
+                value = <1>;
+            };
+            node1 {
+                compatible = "fred";
+                value = <1 2>;
+            };
+
+        He we want to use an int array for 'value'. The first property
+        suggests that a single int is enough, but the second one shows that
+        it is not. Calling this function with these two propertes would
+        update the current property to be like the second, since it is less
+        specific.
+        """
+        if newprop.type < self.type:
+            self.type = newprop.type
+
+        if type(newprop.value) == list and type(self.value) != list:
+            self.value = newprop.value
+
+class Node:
+    """A device tree node
+
+    Properties:
+        name: Device tree node tname
+        path: Full path to node, along with the node name itself
+        _fdt: Device tree object
+        subnodes: A list of subnodes for this node, each a Node object
+        props: A dict of properties for this node, each a Prop object.
+            Keyed by property name
+    """
+    def __init__(self, fdt, name, path):
+        self.name = name
+        self.path = path
+        self._fdt = fdt
+        self.subnodes = []
+        self.props = {}
+
+    def Scan(self):
+        """Scan a node's properties and subnodes
+
+        This fills in the props and subnodes properties, recursively
+        searching into subnodes so that the entire tree is built.
+        """
+        for name, byte_list_str in self._fdt.GetProps(self.path).iteritems():
+            prop = Prop(name, byte_list_str)
+            self.props[name] = prop
+
+        for name in self._fdt.GetSubNodes(self.path):
+            sep = '' if self.path[-1] == '/' else '/'
+            path = self.path + sep + name
+            node = Node(self._fdt, name, path)
+            self.subnodes.append(node)
+
+            node.Scan()
+
+
+class Fdt:
+    """Provides simple access to a flat device tree blob.
+
+    Properties:
+      fname: Filename of fdt
+      _root: Root of device tree (a Node object)
+    """
+
+    def __init__(self, fname):
+        self.fname = fname
+
+    def Scan(self):
+        """Scan a device tree, building up a tree of Node objects
+
+        This fills in the self._root property
+        """
+        self._root = Node(self, '/', '/')
+        self._root.Scan()
+
+    def GetRoot(self):
+        """Get the root Node of the device tree
+
+        Returns:
+            The root Node object
+        """
+        return self._root
+
+    def GetSubNodes(self, node):
+        """Returns a list of sub-nodes of a given node
+
+        Args:
+            node: Node name to return children from
+
+        Returns:
+            List of children in the node (each a string node name)
+
+        Raises:
+            CmdError: if the node does not exist.
+        """
+        out = command.Output('fdtget', self.fname, '-l', node)
+        return out.strip().splitlines()
+
+    def GetProps(self, node, convert_dashes=False):
+        """Get all properties from a node
+
+        Args:
+            node: full path to node name to look in
+            convert_dashes: True to convert - to _ in node names
+
+        Returns:
+            A dictionary containing all the properties, indexed by node name.
+            The entries are simply strings - no decoding of lists or numbers
+            is done.
+
+        Raises:
+            CmdError: if the node does not exist.
+        """
+        out = command.Output('fdtget', self.fname, node, '-p')
+        props = out.strip().splitlines()
+        props_dict = {}
+        for prop in props:
+            name = prop
+            if convert_dashes:
+                prop = re.sub('-', '_', prop)
+            props_dict[prop] = self.GetProp(node, name)
+        return props_dict
+
+    def GetProp(self, node, prop, default=None, typespec=None):
+        """Get a property from a device tree.
+
+        This looks up the given node and property, and returns the value as a
+        string,
+
+        If the node or property does not exist, this will return the default
+        value.
+
+        Args:
+            node: Full path to node to look up.
+            prop: Property name to look up.
+            default: Default value to return if nothing is present in the fdt,
+                or None to raise in this case. This will be converted to a
+                string.
+            typespec: Type character to use (None for default, 's' for string)
+
+        Returns:
+            string containing the property value.
+
+        Raises:
+            CmdError: if the property does not exist and no default is provided.
+        """
+        args = [self.fname, node, prop, '-t', 'bx']
+        if default is not None:
+          args += ['-d', str(default)]
+        if typespec is not None:
+          args += ['-t%s' % typespec]
+        out = command.Output('fdtget', *args)
+        return out.strip()
diff --git a/tools/dtoc/fdt_util.py b/tools/dtoc/fdt_util.py
new file mode 100644
index 0000000..929b524
--- /dev/null
+++ b/tools/dtoc/fdt_util.py
@@ -0,0 +1,86 @@
+#!/usr/bin/python
+#
+# Copyright (C) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+
+import struct
+
+# A list of types we support
+(TYPE_BYTE, TYPE_INT, TYPE_STRING, TYPE_BOOL) = range(4)
+
+def BytesToValue(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(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
+
+def fdt32_to_cpu(val):
+    """Convert a device tree cell to an integer
+
+    Args:
+        Value to convert (4-character string representing the cell value)
+
+    Return:
+        A native-endian integer value
+    """
+    return struct.unpack(">I", val)[0]