2 # SPDX-License-Identifier: GPL-2.0+
4 # Copyright (C) 2017 Google, Inc
5 # Written by Simon Glass <sjg@chromium.org>
8 """Device tree to platform data class
10 This supports converting device tree data to C structures definitions and
21 # When we see these properties we ignore them - i.e. do not create a structure member
30 'u-boot,dm-pre-reloc',
35 # C type declarations for the tyues we support
37 fdt.TYPE_INT: 'fdt32_t',
38 fdt.TYPE_BYTE: 'unsigned char',
39 fdt.TYPE_STRING: 'const char *',
40 fdt.TYPE_BOOL: 'bool',
41 fdt.TYPE_INT64: 'fdt64_t',
44 STRUCT_PREFIX = 'dtd_'
47 # This holds information about a property which includes phandles.
49 # max_args: integer: Maximum number or arguments that any phandle uses (int).
50 # args: Number of args for each phandle in the property. The total number of
51 # phandles is len(args). This is a list of integers.
52 PhandleInfo = collections.namedtuple('PhandleInfo', ['max_args', 'args'])
55 def conv_name_to_c(name):
56 """Convert a device-tree name to a C identifier
58 This uses multiple replace() calls instead of re.sub() since it is faster
59 (400ms for 1m calls versus 1000ms for the 're' version).
64 String containing the C version of this name
66 new = name.replace('@', '_at_')
67 new = new.replace('-', '_')
68 new = new.replace(',', '_')
69 new = new.replace('.', '_')
72 def tab_to(num_tabs, line):
73 """Append tabs to a line of text to reach a tab stop.
76 num_tabs: Tab stop to obtain (0 = column 0, 1 = column 8, etc.)
77 line: Line of text to append to
80 line with the correct number of tabs appeneded. If the line already
81 extends past that tab stop then a single space is appended.
83 if len(line) >= num_tabs * 8:
85 return line + '\t' * (num_tabs - len(line) // 8)
87 def get_value(ftype, value):
88 """Get a value as a C expression
90 For integers this returns a byte-swapped (little-endian) hex string
91 For bytes this returns a hex string, e.g. 0x12
92 For strings this returns a literal string enclosed in quotes
93 For booleans this return 'true'
96 type: Data type (fdt_util)
97 value: Data value, as a string of bytes
99 if ftype == fdt.TYPE_INT:
100 return '%#x' % fdt_util.fdt32_to_cpu(value)
101 elif ftype == fdt.TYPE_BYTE:
102 return '%#x' % ord(value[0])
103 elif ftype == fdt.TYPE_STRING:
104 return '"%s"' % value
105 elif ftype == fdt.TYPE_BOOL:
107 elif ftype == fdt.TYPE_INT64:
110 def get_compat_name(node):
111 """Get a node's first compatible string as a C identifier
114 node: Node object to check
117 C identifier for the first compatible string
118 List of C identifiers for all the other compatible strings
121 compat = node.props['compatible'].value
123 if isinstance(compat, list):
124 compat, aliases = compat[0], compat[1:]
125 return conv_name_to_c(compat), [conv_name_to_c(a) for a in aliases]
128 class DtbPlatdata(object):
129 """Provide a means to convert device tree binary data to platform data
131 The output of this process is C structures which can be used in space-
132 constrained encvironments where the ~3KB code overhead of device tree
133 code is not affordable.
136 _fdt: Fdt object, referencing the device tree
137 _dtb_fname: Filename of the input device tree binary file
138 _valid_nodes: A list of Node object with compatible strings
139 _include_disabled: true to include nodes marked status = "disabled"
140 _outfile: The current output file (sys.stdout or a real file)
141 _lines: Stashed list of output lines for outputting in the future
143 def __init__(self, dtb_fname, include_disabled):
145 self._dtb_fname = dtb_fname
146 self._valid_nodes = None
147 self._include_disabled = include_disabled
152 def setup_output(self, fname):
153 """Set up the output destination
155 Once this is done, future calls to self.out() will output to this
159 fname: Filename to send output to, or '-' for stdout
162 self._outfile = sys.stdout
164 self._outfile = open(fname, 'w')
167 """Output a string to the output file
170 line: String to output
172 self._outfile.write(line)
175 """Buffer up a string to send later
178 line: String to add to our 'buffer' list
180 self._lines.append(line)
183 """Get the contents of the output buffer, and clear it
186 The output buffer, which is then cleared for future use
192 def out_header(self):
193 """Output a message indicating that this is an auto-generated file"""
197 * This file was generated by dtoc from a .dtb (device tree binary) file.
202 def get_phandle_argc(self, prop, node_name):
203 """Check if a node contains phandles
205 We have no reliable way of detecting whether a node uses a phandle
206 or not. As an interim measure, use a list of known property names.
209 prop: Prop object to check
211 Number of argument cells is this is a phandle, else None
213 if prop.name in ['clocks']:
215 if not isinstance(val, list):
222 phandle = fdt_util.fdt32_to_cpu(val[i])
223 target = self._fdt.phandle_to_node.get(phandle)
225 raise ValueError("Cannot parse '%s' in node '%s'" %
226 (prop.name, node_name))
227 prop_name = '#clock-cells'
228 cells = target.props.get(prop_name)
230 raise ValueError("Node '%s' has no '%s' property" %
231 (target.name, prop_name))
232 num_args = fdt_util.fdt32_to_cpu(cells.value)
233 max_args = max(max_args, num_args)
234 args.append(num_args)
236 return PhandleInfo(max_args, args)
240 """Scan the device tree to obtain a tree of nodes and properties
242 Once this is done, self._fdt.GetRoot() can be called to obtain the
243 device tree root node, and progress from there.
245 self._fdt = fdt.FdtScan(self._dtb_fname)
247 def scan_node(self, root):
248 """Scan a node and subnodes to build a tree of node and phandle info
250 This adds each node to self._valid_nodes.
253 root: Root node for scan
255 for node in root.subnodes:
256 if 'compatible' in node.props:
257 status = node.props.get('status')
258 if (not self._include_disabled and not status or
259 status.value != 'disabled'):
260 self._valid_nodes.append(node)
262 # recurse to handle any subnodes
266 """Scan the device tree for useful information
268 This fills in the following properties:
269 _valid_nodes: A list of nodes we wish to consider include in the
272 self._valid_nodes = []
273 return self.scan_node(self._fdt.GetRoot())
276 def get_num_cells(node):
277 """Get the number of cells in addresses and sizes for this node
284 Number of address cells for this node
285 Number of size cells for this node
290 na_prop = parent.props.get('#address-cells')
291 ns_prop = parent.props.get('#size-cells')
293 na = fdt_util.fdt32_to_cpu(na_prop.value)
295 ns = fdt_util.fdt32_to_cpu(ns_prop.value)
298 def scan_reg_sizes(self):
299 """Scan for 64-bit 'reg' properties and update the values
301 This finds 'reg' properties with 64-bit data and converts the value to
302 an array of 64-values. This allows it to be output in a way that the
305 for node in self._valid_nodes:
306 reg = node.props.get('reg')
309 na, ns = self.get_num_cells(node)
312 if reg.type != fdt.TYPE_INT:
313 raise ValueError("Node '%s' reg property is not an int")
314 if len(reg.value) % total:
315 raise ValueError("Node '%s' reg property has %d cells "
316 'which is not a multiple of na + ns = %d + %d)' %
317 (node.name, len(reg.value), na, ns))
320 if na != 1 or ns != 1:
321 reg.type = fdt.TYPE_INT64
325 if not isinstance(val, list):
328 addr = fdt_util.fdt_cells_to_cpu(val[i:], reg.na)
330 size = fdt_util.fdt_cells_to_cpu(val[i:], reg.ns)
332 new_value += [addr, size]
333 reg.value = new_value
335 def scan_structs(self):
336 """Scan the device tree building up the C structures we will use.
338 Build a dict keyed by C struct name containing a dict of Prop
339 object for each struct field (keyed by property name). Where the
340 same struct appears multiple times, try to use the 'widest'
341 property, i.e. the one with a type which can express all others.
343 Once the widest property is determined, all other properties are
344 updated to match that width.
347 for node in self._valid_nodes:
348 node_name, _ = get_compat_name(node)
351 # Get a list of all the valid properties in this node.
352 for name, prop in node.props.items():
353 if name not in PROP_IGNORE_LIST and name[0] != '#':
354 fields[name] = copy.deepcopy(prop)
356 # If we've seen this node_name before, update the existing struct.
357 if node_name in structs:
358 struct = structs[node_name]
359 for name, prop in fields.items():
360 oldprop = struct.get(name)
366 # Otherwise store this as a new struct.
368 structs[node_name] = fields
371 for node in self._valid_nodes:
372 node_name, _ = get_compat_name(node)
373 struct = structs[node_name]
374 for name, prop in node.props.items():
375 if name not in PROP_IGNORE_LIST and name[0] != '#':
376 prop.Widen(struct[name])
379 struct_name, aliases = get_compat_name(node)
380 for alias in aliases:
381 self._aliases[alias] = struct_name
385 def scan_phandles(self):
386 """Figure out what phandles each node uses
388 We need to be careful when outputing nodes that use phandles since
389 they must come after the declaration of the phandles in the C file.
390 Otherwise we get a compiler error since the phandle struct is not yet
393 This function adds to each node a list of phandle nodes that the node
394 depends on. This allows us to output things in the right order.
396 for node in self._valid_nodes:
397 node.phandles = set()
398 for pname, prop in node.props.items():
399 if pname in PROP_IGNORE_LIST or pname[0] == '#':
401 info = self.get_phandle_argc(prop, node.name)
403 if not isinstance(prop.value, list):
404 prop.value = [prop.value]
405 # Process the list as pairs of (phandle, id)
407 for args in info.args:
408 phandle_cell = prop.value[pos]
409 phandle = fdt_util.fdt32_to_cpu(phandle_cell)
410 target_node = self._fdt.phandle_to_node[phandle]
411 node.phandles.add(target_node)
415 def generate_structs(self, structs):
416 """Generate struct defintions for the platform data
418 This writes out the body of a header file consisting of structure
419 definitions for node in self._valid_nodes. See the documentation in
420 README.of-plat for more information.
423 self.out('#include <stdbool.h>\n')
424 self.out('#include <linux/libfdt.h>\n')
426 # Output the struct definition
427 for name in sorted(structs):
428 self.out('struct %s%s {\n' % (STRUCT_PREFIX, name))
429 for pname in sorted(structs[name]):
430 prop = structs[name][pname]
431 info = self.get_phandle_argc(prop, structs[name])
433 # For phandles, include a reference to the target
434 struct_name = 'struct phandle_%d_arg' % info.max_args
435 self.out('\t%s%s[%d]' % (tab_to(2, struct_name),
436 conv_name_to_c(prop.name),
439 ptype = TYPE_NAMES[prop.type]
440 self.out('\t%s%s' % (tab_to(2, ptype),
441 conv_name_to_c(prop.name)))
442 if isinstance(prop.value, list):
443 self.out('[%d]' % len(prop.value))
447 for alias, struct_name in self._aliases.iteritems():
448 self.out('#define %s%s %s%s\n'% (STRUCT_PREFIX, alias,
449 STRUCT_PREFIX, struct_name))
451 def output_node(self, node):
452 """Output the C code for a node
457 struct_name, _ = get_compat_name(node)
458 var_name = conv_name_to_c(node.name)
459 self.buf('static struct %s%s %s%s = {\n' %
460 (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name))
461 for pname, prop in node.props.items():
462 if pname in PROP_IGNORE_LIST or pname[0] == '#':
464 member_name = conv_name_to_c(prop.name)
465 self.buf('\t%s= ' % tab_to(3, '.' + member_name))
467 # Special handling for lists
468 if isinstance(prop.value, list):
471 # For phandles, output a reference to the platform data
472 # of the target node.
473 info = self.get_phandle_argc(prop, node.name)
475 # Process the list as pairs of (phandle, id)
477 for args in info.args:
478 phandle_cell = prop.value[pos]
479 phandle = fdt_util.fdt32_to_cpu(phandle_cell)
480 target_node = self._fdt.phandle_to_node[phandle]
481 name = conv_name_to_c(target_node.name)
483 for i in range(args):
484 arg_values.append(str(fdt_util.fdt32_to_cpu(prop.value[pos + 1 + i])))
486 vals.append('\t{&%s%s, {%s}}' % (VAL_PREFIX, name,
487 ', '.join(arg_values)))
489 self.buf('\n\t\t%s,' % val)
491 for val in prop.value:
492 vals.append(get_value(prop.type, val))
494 # Put 8 values per line to avoid very long lines.
495 for i in xrange(0, len(vals), 8):
498 self.buf(', '.join(vals[i:i + 8]))
501 self.buf(get_value(prop.type, prop.value))
505 # Add a device declaration
506 self.buf('U_BOOT_DEVICE(%s) = {\n' % var_name)
507 self.buf('\t.name\t\t= "%s",\n' % struct_name)
508 self.buf('\t.platdata\t= &%s%s,\n' % (VAL_PREFIX, var_name))
509 self.buf('\t.platdata_size\t= sizeof(%s%s),\n' % (VAL_PREFIX, var_name))
513 self.out(''.join(self.get_buf()))
515 def generate_tables(self):
516 """Generate device defintions for the platform data
518 This writes out C platform data initialisation data and
519 U_BOOT_DEVICE() declarations for each valid node. Where a node has
520 multiple compatible strings, a #define is used to make them equivalent.
522 See the documentation in doc/driver-model/of-plat.txt for more
526 self.out('#include <common.h>\n')
527 self.out('#include <dm.h>\n')
528 self.out('#include <dt-structs.h>\n')
530 nodes_to_output = list(self._valid_nodes)
532 # Keep outputing nodes until there is none left
533 while nodes_to_output:
534 node = nodes_to_output[0]
535 # Output all the node's dependencies first
536 for req_node in node.phandles:
537 if req_node in nodes_to_output:
538 self.output_node(req_node)
539 nodes_to_output.remove(req_node)
540 self.output_node(node)
541 nodes_to_output.remove(node)
544 def run_steps(args, dtb_file, include_disabled, output):
545 """Run all the steps of the dtoc tool
548 args: List of non-option arguments provided to the problem
549 dtb_file: Filename of dtb file to process
550 include_disabled: True to include disabled nodes
551 output: Name of output file
554 raise ValueError('Please specify a command: struct, platdata')
556 plat = DtbPlatdata(dtb_file, include_disabled)
559 plat.scan_reg_sizes()
560 plat.setup_output(output)
561 structs = plat.scan_structs()
564 for cmd in args[0].split(','):
566 plat.generate_structs(structs)
567 elif cmd == 'platdata':
568 plat.generate_tables()
570 raise ValueError("Unknown command '%s': (use: struct, platdata)" %