u-boot-brain/tools/dtoc/dtb_platdata.py
Simon Glass bf776679a7 patman: Move to absolute imports
At present patman sets the python path on startup so that it can access
the libraries it needs. If we convert to use absolute imports this is not
necessary.

Move patman to use absolute imports. This requires changes in tools which
use the patman libraries (which is most of them).

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-04-26 14:25:21 -06:00

580 lines
20 KiB
Python

#!/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.
"""
import collections
import copy
import sys
from dtoc import fdt
from dtoc import fdt_util
from patman import tools
# 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 tyues 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'])
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: Name to convert
Return:
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: Tab stop to obtain (0 = column 0, 1 = column 8, etc.)
line: Line of text to append to
Returns:
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:
type: Data type (fdt_util)
value: Data value, as a string of bytes
"""
if ftype == fdt.TYPE_INT:
return '%#x' % fdt_util.fdt32_to_cpu(value)
elif ftype == fdt.TYPE_BYTE:
return '%#x' % tools.ToByte(value[0])
elif ftype == fdt.TYPE_STRING:
return '"%s"' % value
elif ftype == fdt.TYPE_BOOL:
return 'true'
elif ftype == fdt.TYPE_INT64:
return '%#x' % value
def get_compat_name(node):
"""Get a node's first compatible string as a C identifier
Args:
node: Node object to check
Return:
Tuple:
C identifier for the first compatible string
List of C identifiers for all the other compatible strings
(possibly empty)
"""
compat = node.props['compatible'].value
aliases = []
if isinstance(compat, list):
compat, aliases = compat[0], compat[1:]
return conv_name_to_c(compat), [conv_name_to_c(a) for a in aliases]
class DtbPlatdata(object):
"""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
_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
"""
def __init__(self, dtb_fname, include_disabled):
self._fdt = None
self._dtb_fname = dtb_fname
self._valid_nodes = None
self._include_disabled = include_disabled
self._outfile = None
self._lines = []
self._aliases = {}
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: 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: String to output
"""
self._outfile.write(line)
def buf(self, line):
"""Buffer up a string to send later
Args:
line: 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:
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: Prop object to check
Return:
Number of argument cells is this is a phandle, else None
"""
if prop.name in ['clocks']:
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))
prop_name = '#clock-cells'
cells = target.props.get(prop_name)
if not cells:
raise ValueError("Node '%s' has no '%s' property" %
(target.name, prop_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):
"""Scan a node and subnodes to build a tree of node and phandle info
This adds each node to self._valid_nodes.
Args:
root: Root node for scan
"""
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'):
self._valid_nodes.append(node)
# recurse to handle any subnodes
self.scan_node(node)
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
"""
self._valid_nodes = []
return self.scan_node(self._fdt.GetRoot())
@staticmethod
def get_num_cells(node):
"""Get the number of cells in addresses and sizes for this node
Args:
node: Node to check
Returns:
Tuple:
Number of address cells for this node
Number of size cells for this node
"""
parent = node.parent
na, ns = 2, 2
if parent:
na_prop = parent.props.get('#address-cells')
ns_prop = parent.props.get('#size-cells')
if na_prop:
na = fdt_util.fdt32_to_cpu(na_prop.value)
if ns_prop:
ns = fdt_util.fdt32_to_cpu(ns_prop.value)
return na, ns
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
na, ns = self.get_num_cells(node)
total = na + ns
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), na, ns))
reg.na = na
reg.ns = ns
if na != 1 or ns != 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.na)
i += na
size = fdt_util.fdt_cells_to_cpu(val[i:], reg.ns)
i += ns
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.
"""
structs = {}
for node in self._valid_nodes:
node_name, _ = get_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
upto = 0
for node in self._valid_nodes:
node_name, _ = get_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])
upto += 1
struct_name, aliases = get_compat_name(node)
for alias in aliases:
self._aliases[alias] = 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.
"""
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')
for alias, struct_name in self._aliases.items():
if alias not in sorted(structs):
self.out('#define %s%s %s%s\n'% (STRUCT_PREFIX, alias,
STRUCT_PREFIX, struct_name))
def output_node(self, node):
"""Output the C code for a node
Args:
node: node to output
"""
struct_name, _ = get_compat_name(node)
var_name = conv_name_to_c(node.name)
self.buf('static const struct %s%s %s%s = {\n' %
(STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
for pname in sorted(node.props):
prop = node.props[pname]
if pname in PROP_IGNORE_LIST or pname[0] == '#':
continue
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.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]
name = conv_name_to_c(target_node.name)
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{&%s%s, {%s}}' % (VAL_PREFIX, name,
', '.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('}')
else:
self.buf(get_value(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')
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('#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)
def run_steps(args, dtb_file, include_disabled, output):
"""Run all the steps of the dtoc tool
Args:
args: List of non-option arguments provided to the problem
dtb_file: Filename of dtb file to process
include_disabled: True to include disabled nodes
output: Name of output file
"""
if not args:
raise ValueError('Please specify a command: struct, platdata')
plat = DtbPlatdata(dtb_file, include_disabled)
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)