#!/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
import os
import re
import sys
from dtoc import fdt
from dtoc import fdt_util
# 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_'
# 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'])
class Driver:
"""Information about a driver in U-Boot
Attributes:
name: Name of driver. For U_BOOT_DRIVER(x) this is 'x'
"""
def __init__(self, name):
self.name = name
def __eq__(self, other):
return self.name == other.name
def __repr__(self):
return "Driver(name='%s')" % self.name
def conv_name_to_c(name):
"""Convert a device-tree name to a C identifier
This uses multiple replace() calls instead of re.sub() since it is faster
(400ms for 1m calls versus 1000ms for the 're' version).
Args:
name (str): Name to convert
Return:
str: String containing the C version of this name
"""
new = name.replace('@', '_at_')
new = new.replace('-', '_')
new = new.replace(',', '_')
new = new.replace('.', '_')
return new
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
def get_compat_name(node):
"""Get the node's list of compatible string as a C identifiers
Args:
node (fdt.Node): Node object to check
Return:
list of str: List of C identifiers for all the compatible strings
"""
compat = node.props['compatible'].value
if not isinstance(compat, list):
compat = [compat]
return [conv_name_to_c(c) for c in compat]
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. 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)
_warning_disabled: true to disable warnings about driver names not found
_lines: Stashed list of output lines for outputting in the future
_drivers: Dict of valid driver names found in drivers/
key: Driver name
value: Driver for that driver
_driver_aliases: Dict that holds aliases for driver names
key: Driver alias declared with
U_BOOT_DRIVER_ALIAS(driver_alias, driver_name)
value: Driver name declared with U_BOOT_DRIVER(driver_name)
_drivers_additional: List of additional drivers to use during scanning
"""
def __init__(self, dtb_fname, include_disabled, warning_disabled,
drivers_additional=None):
self._fdt = None
self._dtb_fname = dtb_fname
self._valid_nodes = None
self._include_disabled = include_disabled
self._outfile = None
self._warning_disabled = warning_disabled
self._lines = []
self._drivers = {}
self._driver_aliases = {}
self._drivers_additional = drivers_additional or []
def get_normalized_compat_name(self, node):
"""Get a node's normalized compat name
Returns a valid driver name by retrieving node's list of compatible
string as a C identifier and performing a check against _drivers
and a lookup in driver_aliases printing a warning in case of failure.
Args:
node (Node): Node object to check
Return:
Tuple:
Driver name associated with the first compatible string
List of C identifiers for all the other compatible strings
(possibly empty)
In case of no match found, the return will be the same as
get_compat_name()
"""
compat_list_c = get_compat_name(node)
for compat_c in compat_list_c:
if not compat_c in self._drivers.keys():
compat_c = self._driver_aliases.get(compat_c)
if not compat_c:
continue
aliases_c = compat_list_c
if compat_c in aliases_c:
aliases_c.remove(compat_c)
return compat_c, aliases_c
if not self._warning_disabled:
print('WARNING: the driver %s was not found in the driver list'
% (compat_list_c[0]))
return compat_list_c[0], compat_list_c[1:]
def setup_output(self, fname):
"""Set up the output destination
Once this is done, future calls to self.out() will output to this
file.
Args:
fname (str): Filename to send output to, or '-' for stdout
"""
if fname == '-':
self._outfile = sys.stdout
else:
self._outfile = open(fname, 'w')
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):
"""Output a message indicating that this is an auto-generated file"""
self.out('''/*
* DO NOT MODIFY
*
* This file was generated by dtoc from a .dtb (device tree binary) file.
*/
''')
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_driver(self, fname):
"""Scan a driver file to build a list of driver names and aliases
This procedure will populate self._drivers and self._driver_aliases
Args
fname: Driver filename to scan
"""
with open(fname, encoding='utf-8') as inf:
try:
buff = inf.read()
except UnicodeDecodeError:
# This seems to happen on older Python versions
print("Skipping file '%s' due to unicode error" % fname)
return
# The following re will search for driver names declared as
# U_BOOT_DRIVER(driver_name)
drivers = re.findall(r'U_BOOT_DRIVER\((.*)\)', buff)
for driver in drivers:
self._drivers[driver] = Driver(driver)
# The following re will search for driver aliases declared as
# U_BOOT_DRIVER_ALIAS(alias, driver_name)
driver_aliases = re.findall(
r'U_BOOT_DRIVER_ALIAS\(\s*(\w+)\s*,\s*(\w+)\s*\)',
buff)
for alias in driver_aliases: # pragma: no cover
if len(alias) != 2:
continue
self._driver_aliases[alias[1]] = alias[0]
def scan_drivers(self):
"""Scan the driver folders to build a list of driver names and aliases
This procedure will populate self._drivers and self._driver_aliases
"""
basedir = sys.argv[0].replace('tools/dtoc/dtoc', '')
if basedir == '':
basedir = './'
for (dirpath, _, filenames) in os.walk(basedir):
for fname in filenames:
if not fname.endswith('.c'):
continue
self.scan_driver(dirpath + '/' + fname)
for fname in self._drivers_additional:
if not isinstance(fname, str) or len(fname) == 0:
continue
if fname[0] == '/':
self.scan_driver(fname)
else:
self.scan_driver(basedir + '/' + fname)
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.
Returns:
dict of dict: dict containing structures:
key (str): Node name, as a C identifier
value: dict containing structure fields:
key (str): Field name
value: Prop object with field information
"""
structs = collections.OrderedDict()
for node in self._valid_nodes:
node_name, _ = self.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.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])
return structs
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, 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
doc/driver-model/of-plat.rst for more information.
Args:
structs (dict): dict containing structures:
key (str): Node name, as a C identifier
value: dict containing structure fields:
key (str): Field name
value: Prop object with field information
"""
self.out_header()
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_DEVICE() 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_DEVICE(%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.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_tables(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. 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_header()
self.out('/* Allow use of U_BOOT_DEVICE() in this file */\n')
self.out('#define DT_PLATDATA_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')
nodes_to_output = list(self._valid_nodes)
# Keep outputing nodes until there is none left
while nodes_to_output:
node = nodes_to_output[0]
# Output all the node's dependencies first
for req_node in node.phandles:
if req_node in nodes_to_output:
self.output_node(req_node)
nodes_to_output.remove(req_node)
self.output_node(node)
nodes_to_output.remove(node)
# Define dm_populate_phandle_data() which will add the linking between
# nodes using DM_GET_DEVICE
# dtv_dmc_at_xxx.clocks[0].node = DM_GET_DEVICE(clock_controller_at_xxx)
self.buf('void dm_populate_phandle_data(void) {\n')
self.buf('}\n')
self.out(''.join(self.get_buf()))
def run_steps(args, dtb_file, include_disabled, output, warning_disabled=False,
drivers_additional=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
warning_disabled (bool): True to avoid showing warnings about missing
drivers
drivers_additional (list): List of additional drivers to use during
scanning
Raises:
ValueError: if args has no command, or an unknown command
"""
if not args:
raise ValueError('Please specify a command: struct, platdata')
plat = DtbPlatdata(dtb_file, include_disabled, warning_disabled,
drivers_additional)
plat.scan_drivers()
plat.scan_dtb()
plat.scan_tree()
plat.scan_reg_sizes()
plat.setup_output(output)
structs = plat.scan_structs()
plat.scan_phandles()
for cmd in args[0].split(','):
if cmd == 'struct':
plat.generate_structs(structs)
elif cmd == 'platdata':
plat.generate_tables()
else:
raise ValueError("Unknown command '%s': (use: struct, platdata)" %
cmd)