[U-Boot] [PATCH 29/31] dm: Add a tool to generate C code from a device tree
Simon Glass
sjg at chromium.org
Wed Jun 8 04:48:07 CEST 2016
This tool can produce C struct definitions and C platform data tables.
This is used to support the of-platdata feature.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
tools/dtoc/dtoc | 1 +
tools/dtoc/dtoc.py | 365 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 366 insertions(+)
create mode 120000 tools/dtoc/dtoc
create mode 100755 tools/dtoc/dtoc.py
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..6a2f6ef
--- /dev/null
+++ b/tools/dtoc/dtoc.py
@@ -0,0 +1,365 @@
+#!/usr/bin/python
+#
+# Copyright (C) 2016 Google, Inc
+# Written by Simon Glass <sjg at chromium.org>
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+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',
+]
+
+# 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 GenerateStructs(self):
+ """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')
+
+ # 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.
+ structs = {}
+ for node in self._valid_nodes:
+ node_name = self.GetCompatName(node)
+ fields = {}
+ for name, prop in node.props.iteritems():
+ if name not in PROP_IGNORE_LIST and name[0] != '#':
+ fields[name] = prop
+ if node_name in structs:
+ struct = structs[node_name]
+ for name, prop in fields.iteritems():
+ oldprop = struct.get(name)
+ if oldprop:
+ struct[name].Widen(oldprop)
+ else:
+ struct[name] = prop
+ else:
+ structs[node_name] = fields
+
+ # 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('};\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)
+
+for cmd in args[0].split(','):
+ if cmd == 'struct':
+ plat.GenerateStructs()
+ elif cmd == 'platdata':
+ plat.GenerateTables()
+ else:
+ raise ValueError("Unknown command '%s': (use: struct, platdata)" % cmd)
--
2.8.0.rc3.226.g39d4020
More information about the U-Boot
mailing list