#!/usr/bin/python
# SPDX-License-Identifier: GPL-2.0+
#
# Copyright (C) 2017 Google, Inc
# Written by Simon Glass <sjg@chromium.org>
#
"""Device tree to platform data class
This supports converting device tree data to C structures definitions and
static data.
See doc/driver-model/of-plat.rst for more informaiton
"""
import collections
import copy
from enum import IntEnum
import os
import re
import sys
from dtoc import fdt
from dtoc import fdt_util
from dtoc import src_scan
from dtoc.src_scan import conv_name_to_c
# 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',
'u-boot,dm-tpl',
'u-boot,dm-spl',
]
# C type declarations for the types we support
TYPE_NAMES = {
fdt.Type.INT: 'fdt32_t',
fdt.Type.BYTE: 'unsigned char',
fdt.Type.STRING: 'const char *',
fdt.Type.BOOL: 'bool',
fdt.Type.INT64: 'fdt64_t',
}
STRUCT_PREFIX = 'dtd_'
VAL_PREFIX = 'dtv_'
class Ftype(IntEnum):
SOURCE, HEADER = range(2)
# This holds information about each type of output file dtoc can create
# type: Type of file (Ftype)
# fname: Filename excluding directory, e.g. 'dt-plat.c'
# hdr_comment: Comment explaining the purpose of the file
OutputFile = collections.namedtuple('OutputFile',
['ftype', 'fname', 'method', 'hdr_comment'])
# This holds information about a property which includes phandles.
#
# max_args: integer: Maximum number or arguments that any phandle uses (int).
# args: Number of args for each phandle in the property. The total number of
# phandles is len(args). This is a list of integers.
PhandleInfo = collections.namedtuple('PhandleInfo', ['max_args', 'args'])
# Holds a single phandle link, allowing a C struct value to be assigned to point
# to a device
#
# var_node: C variable to assign (e.g. 'dtv_mmc.clocks[0].node')
# dev_name: Name of device to assign to (e.g. 'clock')
PhandleLink = collections.namedtuple('PhandleLink', ['var_node', 'dev_name'])
def tab_to(num_tabs, line):
"""Append tabs to a line of text to reach a tab stop.
Args:
num_tabs (int): Tab stop to obtain (0 = column 0, 1 = column 8, etc.)
line (str): Line of text to append to
Returns:
str: line with the correct number of tabs appeneded. If the line already
extends past that tab stop then a single space is appended.
"""
if len(line) >= num_tabs * 8:
return line + ' '
return line + '\t' * (num_tabs - len(line) // 8)
def get_value(ftype, 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:
ftype (fdt.Type): Data type (fdt_util)
value (bytes): Data value, as a string of bytes
Returns:
str: String representation of the value
"""
if ftype == fdt.Type.INT:
val = '%#x' % fdt_util.fdt32_to_cpu(value)
elif ftype == fdt.Type.BYTE:
char = value[0]
val = '%#x' % (ord(char) if isinstance(char, str) else char)
elif ftype == fdt.Type.STRING:
# Handle evil ACPI backslashes by adding another backslash before them.
# So "\\_SB.GPO0" in the device tree effectively stays like that in C
val = '"%s"' % value.replace('\\', '\\\\')
elif ftype == fdt.Type.BOOL:
val = 'true'
else: # ftype == fdt.Type.INT64:
val = '%#x' % value
return val
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:
_scan: Scan object, for scanning and reporting on useful information
from the U-Boot source code
_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. The list
is ordered by conv_name_to_c(node.name)
_include_disabled: true to include nodes marked status = "disabled"
_outfile: The current output file (sys.stdout or a real file)
_lines: Stashed list of output lines for outputting in the future
_dirname: Directory to hold output files, or None for none (all files
go to stdout)
_struct_data (dict): OrderedDict of dtplat structures to output
key (str): Node name, as a C identifier
value: dict containing structure fields:
key (str): Field name
value: Prop object with field information
_basedir (str): Base directory of source tree
"""
def __init__(self, scan, dtb_fname, include_disabled):
self._scan = scan
self._fdt = None
self._dtb_fname = dtb_fname
self._valid_nodes = None
self._include_disabled = include_disabled
self._outfile = None
self._lines = []
self._dirnames = [None] * len(Ftype)
self._struct_data = collections.OrderedDict()
self._basedir = None
def setup_output_dirs(self, output_dirs):
"""Set up the output directories
This should be done before setup_output() is called
Args:
output_dirs (tuple of str):
Directory to use for C output files.
Use None to write files relative current directory
Directory to use for H output files.
Defaults to the C output dir
"""
def process_dir(ftype, dirname):
if dirname:
os.makedirs(dirname, exist_ok=True)
self._dirnames[ftype] = dirname
if output_dirs:
c_dirname = output_dirs[0]
h_dirname = output_dirs[1] if len(output_dirs) > 1 else c_dirname
process_dir(Ftype.SOURCE, c_dirname)
process_dir(Ftype.HEADER, h_dirname)
def setup_output(self, ftype, fname):
"""Set up the output destination
Once this is done, future calls to self.out() will output to this
file. The file used is as follows:
self._dirnames[ftype] is None: output to fname, or stdout if None
self._dirnames[ftype] is not None: output to fname in that directory
Calling this function multiple times will close the old file and open
the new one. If they are the same file, nothing happens and output will
continue to the same file.
Args:
ftype (str): Type of file to create ('c' or 'h')
fname (str): Filename to send output to. If there is a directory in
self._dirnames for this file type, it will be put in that
directory
"""
dirname = self._dirnames[ftype]
if dirname:
pathname = os.path.join(dirname, fname)
if self._outfile:
self._outfile.close()
self._outfile = open(pathname, 'w')
elif fname:
if not self._outfile:
self._outfile = open(fname, 'w')
else:
self._outfile = sys.stdout
def finish_output(self):
"""Finish outputing to a file
This closes the output file, if one is in use
"""
if self._outfile != sys.stdout:
self._outfile.close()
def out(self, line):
"""Output a string to the output file
Args:
line (str): String to output
"""
self._outfile.write(line)
def buf(self, line):
"""Buffer up a string to send later
Args:
line (str): String to add to our 'buffer' list
"""
self._lines.append(line)
def get_buf(self):
"""Get the contents of the output buffer, and clear it
Returns:
list(str): The output buffer, which is then cleared for future use
"""
lines = self._lines
self._lines = []
return lines
def out_header(self, outfile):
"""Output a message indicating that this is an auto-generated file
Args:
outfile: OutputFile describing the file being generated
"""
self.out('''/*
* DO NOT MODIFY
*
* %s.
* This was generated by dtoc from a .dtb (device tree binary) file.
*/
''' % outfile.hdr_comment)
def get_phandle_argc(self, prop, node_name):
"""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 (fdt.Prop): Prop object to check
node_name (str): Node name, only used for raising an error
Returns:
int or None: Number of argument cells is this is a phandle,
else None
Raises:
ValueError: if the phandle cannot be parsed or the required property
is not present
"""
if prop.name in ['clocks', 'cd-gpios']:
if not isinstance(prop.value, list):
prop.value = [prop.value]
val = prop.value
i = 0
max_args = 0
args = []
while i < len(val):
phandle = fdt_util.fdt32_to_cpu(val[i])
# If we get to the end of the list, stop. This can happen
# since some nodes have more phandles in the list than others,
# but we allocate enough space for the largest list. So those
# nodes with shorter lists end up with zeroes at the end.
if not phandle:
break
target = self._fdt.phandle_to_node.get(phandle)
if not target:
raise ValueError("Cannot parse '%s' in node '%s'" %
(prop.name, node_name))
cells = None
for prop_name in ['#clock-cells', '#gpio-cells']:
cells = target.props.get(prop_name)
if cells:
break
if not cells:
raise ValueError("Node '%s' has no cells property" %
(target.name))
num_args = fdt_util.fdt32_to_cpu(cells.value)
max_args = max(max_args, num_args)
args.append(num_args)
i += 1 + num_args
return PhandleInfo(max_args, args)
return None
def scan_dtb(self):
"""Scan the device tree to obtain a tree of nodes 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.FdtScan(self._dtb_fname)
def scan_node(self, root, valid_nodes):
"""Scan a node and subnodes to build a tree of node and phandle info
This adds each node to self._valid_nodes.
Args:
root (Node): Root node for scan
valid_nodes (list of Node): List of Node objects to add to
"""
for node in root.subnodes:
if 'compatible' in node.props:
status = node.props.get('status')
if (not self._include_disabled and not status or
status.value != 'disabled'):
valid_nodes.append(node)
# recurse to handle any subnodes
self.scan_node(node, valid_nodes)
def scan_tree(self):
"""Scan the device tree for useful information
This fills in the following properties:
_valid_nodes: A list of nodes we wish to consider include in the
platform data
"""
valid_nodes = []
self.scan_node(self._fdt.GetRoot(), valid_nodes)
self._valid_nodes = sorted(valid_nodes,
key=lambda x: conv_name_to_c(x.name))
for idx, node in enumerate(self._valid_nodes):
node.idx = idx
@staticmethod
def get_num_cells(node):
"""Get the number of cells in addresses and sizes for this node
Args:
node (fdt.None): Node to check
Returns:
Tuple:
Number of address cells for this node
Number of size cells for this node
"""
parent = node.parent
num_addr, num_size = 2, 2
if parent:
addr_prop = parent.props.get('#address-cells')
size_prop = parent.props.get('#size-cells')
if addr_prop:
num_addr = fdt_util.fdt32_to_cpu(addr_prop.value)
if size_prop:
num_size = fdt_util.fdt32_to_cpu(size_prop.value)
return num_addr, num_size
def scan_reg_sizes(self):
"""Scan for 64-bit 'reg' properties and update the values
This finds 'reg' properties with 64-bit data and converts the value to
an array of 64-values. This allows it to be output in a way that the
C code can read.
"""
for node in self._valid_nodes:
reg = node.props.get('reg')
if not reg:
continue
num_addr, num_size = self.get_num_cells(node)
total = num_addr + num_size
if reg.type != fdt.Type.INT:
raise ValueError("Node '%s' reg property is not an int" %
node.name)
if len(reg.value) % total:
raise ValueError(
"Node '%s' reg property has %d cells "
'which is not a multiple of na + ns = %d + %d)' %
(node.name, len(reg.value), num_addr, num_size))
reg.num_addr = num_addr
reg.num_size = num_size
if num_addr != 1 or num_size != 1:
reg.type = fdt.Type.INT64
i = 0
new_value = []
val = reg.value
if not isinstance(val, list):
val = [val]
while i < len(val):
addr = fdt_util.fdt_cells_to_cpu(val[i:], reg.num_addr)
i += num_addr
size = fdt_util.fdt_cells_to_cpu(val[i:], reg.num_size)
i += num_size
new_value += [addr, size]
reg.value = new_value
def scan_structs(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.
The results are written to self._struct_data
"""
structs = self._struct_data
for node in self._valid_nodes:
node_name, _ = self._scan.get_normalized_compat_name(node)
fields = {}
# Get a list of all the valid properties in this node.
for name, prop in node.props.items():
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.items():
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
for node in self._valid_nodes:
node_name, _ = self._scan.get_normalized_compat_name(node)
struct = structs[node_name]
for name, prop in node.props.items():
if name not in PROP_IGNORE_LIST and name[0] != '#':
prop.Widen(struct[name])
def scan_phandles(self):
"""Figure out what phandles each node uses
We need to be careful when outputing nodes that use phandles since
they must come after the declaration of the phandles in the C file.
Otherwise we get a compiler error since the phandle struct is not yet
declared.
This function adds to each node a list of phandle nodes that the node
depends on. This allows us to output things in the right order.
"""
for node in self._valid_nodes:
node.phandles = set()
for pname, prop in node.props.items():
if pname in PROP_IGNORE_LIST or pname[0] == '#':
continue
info = self.get_phandle_argc(prop, node.name)
if info:
# Process the list as pairs of (phandle, id)
pos = 0
for args in info.args:
phandle_cell = prop.value[pos]
phandle = fdt_util.fdt32_to_cpu(phandle_cell)
target_node = self._fdt.phandle_to_node[phandle]
node.phandles.add(target_node)
pos += 1 + args
def generate_structs(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
doc/driver-model/of-plat.rst for more information.
"""
structs = self._struct_data
self.out('#include <stdbool.h>\n')
self.out('#include <linux/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]
info = self.get_phandle_argc(prop, structs[name])
if info:
# For phandles, include a reference to the target
struct_name = 'struct phandle_%d_arg' % info.max_args
self.out('\t%s%s[%d]' % (tab_to(2, struct_name),
conv_name_to_c(prop.name),
len(info.args)))
else:
ptype = TYPE_NAMES[prop.type]
self.out('\t%s%s' % (tab_to(2, ptype),
conv_name_to_c(prop.name)))
if isinstance(prop.value, list):
self.out('[%d]' % len(prop.value))
self.out(';\n')
self.out('};\n')
def _output_list(self, node, prop):
"""Output the C code for a devicetree property that holds a list
Args:
node (fdt.Node): Node to output
prop (fdt.Prop): Prop to output
"""
self.buf('{')
vals = []
# For phandles, output a reference to the platform data
# of the target node.
info = self.get_phandle_argc(prop, node.name)
if info:
# Process the list as pairs of (phandle, id)
pos = 0
for args in info.args:
phandle_cell = prop.value[pos]
phandle = fdt_util.fdt32_to_cpu(phandle_cell)
target_node = self._fdt.phandle_to_node[phandle]
arg_values = []
for i in range(args):
arg_values.append(
str(fdt_util.fdt32_to_cpu(prop.value[pos + 1 + i])))
pos += 1 + args
vals.append('\t{%d, {%s}}' % (target_node.idx,
', '.join(arg_values)))
for val in vals:
self.buf('\n\t\t%s,' % val)
else:
for val in prop.value:
vals.append(get_value(prop.type, val))
# Put 8 values per line to avoid very long lines.
for i in range(0, len(vals), 8):
if i:
self.buf(',\n\t\t')
self.buf(', '.join(vals[i:i + 8]))
self.buf('}')
def _declare_device(self, var_name, struct_name, node_parent):
"""Add a device declaration to the output
This declares a U_BOOT_DRVINFO() for the device being processed
Args:
var_name (str): C name for the node
struct_name (str): Name for the dt struct associated with the node
node_parent (Node): Parent of the node (or None if none)
"""
self.buf('U_BOOT_DRVINFO(%s) = {\n' % var_name)
self.buf('\t.name\t\t= "%s",\n' % struct_name)
self.buf('\t.plat\t= &%s%s,\n' % (VAL_PREFIX, var_name))
self.buf('\t.plat_size\t= sizeof(%s%s),\n' % (VAL_PREFIX, var_name))
idx = -1
if node_parent and node_parent in self._valid_nodes:
idx = node_parent.idx
self.buf('\t.parent_idx\t= %d,\n' % idx)
self.buf('};\n')
self.buf('\n')
def _output_prop(self, node, prop):
"""Output a line containing the value of a struct member
Args:
node (Node): Node being output
prop (Prop): Prop object to output
"""
if prop.name in PROP_IGNORE_LIST or prop.name[0] == '#':
return
member_name = conv_name_to_c(prop.name)
self.buf('\t%s= ' % tab_to(3, '.' + member_name))
# Special handling for lists
if isinstance(prop.value, list):
self._output_list(node, prop)
else:
self.buf(get_value(prop.type, prop.value))
self.buf(',\n')
def _output_values(self, var_name, struct_name, node):
"""Output the definition of a device's struct values
Args:
var_name (str): C name for the node
struct_name (str): Name for the dt struct associated with the node
node (Node): Node being output
"""
self.buf('static struct %s%s %s%s = {\n' %
(STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
for pname in sorted(node.props):
self._output_prop(node, node.props[pname])
self.buf('};\n')
def output_node(self, node):
"""Output the C code for a node
Args:
node (fdt.Node): node to output
"""
struct_name, _ = self._scan.get_normalized_compat_name(node)
var_name = conv_name_to_c(node.name)
self.buf('/* Node %s index %d */\n' % (node.path, node.idx))
self._output_values(var_name, struct_name, node)
self._declare_device(var_name, struct_name, node.parent)
self.out(''.join(self.get_buf()))
def generate_plat(self):
"""Generate device defintions for the platform data
This writes out C platform data initialisation data and
U_BOOT_DRVINFO() declarations for each valid node. Where a node has
multiple compatible strings, a #define is used to make them equivalent.
See the documentation in doc/driver-model/of-plat.rst for more
information.
"""
self.out('/* Allow use of U_BOOT_DRVINFO() in this file */\n')
self.out('#define DT_PLAT_C\n')
self.out('\n')
self.out('#include <common.h>\n')
self.out('#include <dm.h>\n')
self.out('#include <dt-structs.h>\n')
self.out('\n')
for node in self._valid_nodes:
self.output_node(node)
self.out(''.join(self.get_buf()))
# Types of output file we understand
# key: Command used to generate this file
# value: OutputFile for this command
OUTPUT_FILES = {
'struct':
OutputFile(Ftype.HEADER, 'dt-structs-gen.h',
DtbPlatdata.generate_structs,
'Defines the structs used to hold devicetree data'),
'platdata':
OutputFile(Ftype.SOURCE, 'dt-plat.c', DtbPlatdata.generate_plat,
'Declares the U_BOOT_DRIVER() records and platform data'),
}
def run_steps(args, dtb_file, include_disabled, output, output_dirs,
warning_disabled=False, drivers_additional=None, basedir=None,
scan=None):
"""Run all the steps of the dtoc tool
Args:
args (list): List of non-option arguments provided to the problem
dtb_file (str): Filename of dtb file to process
include_disabled (bool): True to include disabled nodes
output (str): Name of output file (None for stdout)
output_dirs (tuple of str):
Directory to put C output files
Directory to put H output files
warning_disabled (bool): True to avoid showing warnings about missing
drivers
drivers_additional (list): List of additional drivers to use during
scanning
basedir (str): Base directory of U-Boot source code. Defaults to the
grandparent of this file's directory
scan (src_src.Scanner): Scanner from a previous run. This can help speed
up tests. Use None for normal operation
Raises:
ValueError: if args has no command, or an unknown command
"""
if not args:
raise ValueError('Please specify a command: struct, platdata, all')
if output and output_dirs and any(output_dirs):
raise ValueError('Must specify either output or output_dirs, not both')
if not scan:
scan = src_scan.Scanner(basedir, warning_disabled, drivers_additional)
scan.scan_drivers()
plat = DtbPlatdata(scan, dtb_file, include_disabled)
plat.scan_dtb()
plat.scan_tree()
plat.scan_reg_sizes()
plat.setup_output_dirs(output_dirs)
plat.scan_structs()
plat.scan_phandles()
cmds = args[0].split(',')
if 'all' in cmds:
cmds = sorted(OUTPUT_FILES.keys())
for cmd in cmds:
outfile = OUTPUT_FILES.get(cmd)
if not outfile:
raise ValueError("Unknown command '%s': (use: %s)" %
(cmd, ', '.join(sorted(OUTPUT_FILES.keys()))))
plat.setup_output(outfile.ftype,
outfile.fname if output_dirs else output)
plat.out_header(outfile)
outfile.method(plat)
plat.finish_output()