Tom Rini | 8b0c8a1 | 2018-05-06 18:27:01 -0400 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause */ |
Simon Glass | a13d902 | 2017-05-27 07:38:11 -0600 | [diff] [blame] | 2 | /* |
| 3 | * pylibfdt - Flat Device Tree manipulation in Python |
| 4 | * Copyright (C) 2017 Google, Inc. |
| 5 | * Written by Simon Glass <sjg@chromium.org> |
Simon Glass | a13d902 | 2017-05-27 07:38:11 -0600 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | %module libfdt |
| 9 | |
Simon Glass | 1c87931 | 2017-08-13 16:02:54 -0600 | [diff] [blame] | 10 | %include <stdint.i> |
| 11 | |
Simon Glass | a13d902 | 2017-05-27 07:38:11 -0600 | [diff] [blame] | 12 | %{ |
| 13 | #define SWIG_FILE_WITH_INIT |
| 14 | #include "libfdt.h" |
| 15 | %} |
| 16 | |
| 17 | %pythoncode %{ |
| 18 | |
| 19 | import struct |
| 20 | |
| 21 | # Error codes, corresponding to FDT_ERR_... in libfdt.h |
| 22 | (NOTFOUND, |
| 23 | EXISTS, |
| 24 | NOSPACE, |
| 25 | BADOFFSET, |
| 26 | BADPATH, |
| 27 | BADPHANDLE, |
| 28 | BADSTATE, |
| 29 | TRUNCATED, |
| 30 | BADMAGIC, |
| 31 | BADVERSION, |
| 32 | BADSTRUCTURE, |
| 33 | BADLAYOUT, |
| 34 | INTERNAL, |
| 35 | BADNCELLS, |
| 36 | BADVALUE, |
| 37 | BADOVERLAY, |
| 38 | NOPHANDLES) = QUIET_ALL = range(1, 18) |
| 39 | # QUIET_ALL can be passed as the 'quiet' parameter to avoid exceptions |
| 40 | # altogether. All # functions passed this value will return an error instead |
| 41 | # of raising an exception. |
| 42 | |
| 43 | # Pass this as the 'quiet' parameter to return -ENOTFOUND on NOTFOUND errors, |
| 44 | # instead of raising an exception. |
| 45 | QUIET_NOTFOUND = (NOTFOUND,) |
| 46 | |
| 47 | |
| 48 | class FdtException(Exception): |
| 49 | """An exception caused by an error such as one of the codes above""" |
| 50 | def __init__(self, err): |
| 51 | self.err = err |
| 52 | |
| 53 | def __str__(self): |
| 54 | return 'pylibfdt error %d: %s' % (self.err, fdt_strerror(self.err)) |
| 55 | |
| 56 | def strerror(fdt_err): |
| 57 | """Get the string for an error number |
| 58 | |
| 59 | Args: |
| 60 | fdt_err: Error number (-ve) |
| 61 | |
| 62 | Returns: |
| 63 | String containing the associated error |
| 64 | """ |
| 65 | return fdt_strerror(fdt_err) |
| 66 | |
| 67 | def check_err(val, quiet=()): |
| 68 | """Raise an error if the return value is -ve |
| 69 | |
| 70 | This is used to check for errors returned by libfdt C functions. |
| 71 | |
| 72 | Args: |
| 73 | val: Return value from a libfdt function |
| 74 | quiet: Errors to ignore (empty to raise on all errors) |
| 75 | |
| 76 | Returns: |
| 77 | val if val >= 0 |
| 78 | |
| 79 | Raises |
| 80 | FdtException if val < 0 |
| 81 | """ |
| 82 | if val < 0: |
| 83 | if -val not in quiet: |
| 84 | raise FdtException(val) |
| 85 | return val |
| 86 | |
| 87 | def check_err_null(val, quiet=()): |
| 88 | """Raise an error if the return value is NULL |
| 89 | |
| 90 | This is used to check for a NULL return value from certain libfdt C |
| 91 | functions |
| 92 | |
| 93 | Args: |
| 94 | val: Return value from a libfdt function |
| 95 | quiet: Errors to ignore (empty to raise on all errors) |
| 96 | |
| 97 | Returns: |
| 98 | val if val is a list, None if not |
| 99 | |
| 100 | Raises |
| 101 | FdtException if val indicates an error was reported and the error |
| 102 | is not in @quiet. |
| 103 | """ |
| 104 | # Normally a list is returned which contains the data and its length. |
| 105 | # If we get just an integer error code, it means the function failed. |
| 106 | if not isinstance(val, list): |
| 107 | if -val not in quiet: |
| 108 | raise FdtException(val) |
| 109 | return val |
| 110 | |
| 111 | class Fdt: |
| 112 | """Device tree class, supporting all operations |
| 113 | |
| 114 | The Fdt object is created is created from a device tree binary file, |
| 115 | e.g. with something like: |
| 116 | |
| 117 | fdt = Fdt(open("filename.dtb").read()) |
| 118 | |
| 119 | Operations can then be performed using the methods in this class. Each |
| 120 | method xxx(args...) corresponds to a libfdt function fdt_xxx(fdt, args...). |
| 121 | |
| 122 | All methods raise an FdtException if an error occurs. To avoid this |
| 123 | behaviour a 'quiet' parameter is provided for some functions. This |
| 124 | defaults to empty, but you can pass a list of errors that you expect. |
| 125 | If one of these errors occurs, the function will return an error number |
| 126 | (e.g. -NOTFOUND). |
| 127 | """ |
| 128 | def __init__(self, data): |
| 129 | self._fdt = bytearray(data) |
| 130 | check_err(fdt_check_header(self._fdt)); |
| 131 | |
Simon Glass | 460b252 | 2017-08-29 14:15:46 -0600 | [diff] [blame] | 132 | def subnode_offset(self, parentoffset, name, quiet=()): |
| 133 | """Get the offset of a named subnode |
| 134 | |
| 135 | Args: |
| 136 | parentoffset: Offset of the parent node to check |
| 137 | name: Name of the required subnode, e.g. 'subnode@1' |
| 138 | quiet: Errors to ignore (empty to raise on all errors) |
| 139 | |
| 140 | Returns: |
| 141 | The node offset of the found node, if any |
| 142 | |
| 143 | Raises |
| 144 | FdtException if there is no node with that name, or other error |
| 145 | """ |
| 146 | return check_err(fdt_subnode_offset(self._fdt, parentoffset, name), |
| 147 | quiet) |
| 148 | |
Simon Glass | a13d902 | 2017-05-27 07:38:11 -0600 | [diff] [blame] | 149 | def path_offset(self, path, quiet=()): |
| 150 | """Get the offset for a given path |
| 151 | |
| 152 | Args: |
| 153 | path: Path to the required node, e.g. '/node@3/subnode@1' |
| 154 | quiet: Errors to ignore (empty to raise on all errors) |
| 155 | |
| 156 | Returns: |
| 157 | Node offset |
| 158 | |
| 159 | Raises |
| 160 | FdtException if the path is not valid or not found |
| 161 | """ |
| 162 | return check_err(fdt_path_offset(self._fdt, path), quiet) |
| 163 | |
| 164 | def first_property_offset(self, nodeoffset, quiet=()): |
| 165 | """Get the offset of the first property in a node offset |
| 166 | |
| 167 | Args: |
| 168 | nodeoffset: Offset to the node to check |
| 169 | quiet: Errors to ignore (empty to raise on all errors) |
| 170 | |
| 171 | Returns: |
| 172 | Offset of the first property |
| 173 | |
| 174 | Raises |
| 175 | FdtException if the associated node has no properties, or some |
| 176 | other error occurred |
| 177 | """ |
| 178 | return check_err(fdt_first_property_offset(self._fdt, nodeoffset), |
| 179 | quiet) |
| 180 | |
| 181 | def next_property_offset(self, prop_offset, quiet=()): |
| 182 | """Get the next property in a node |
| 183 | |
| 184 | Args: |
| 185 | prop_offset: Offset of the previous property |
| 186 | quiet: Errors to ignore (empty to raise on all errors) |
| 187 | |
| 188 | Returns: |
| 189 | Offset of the next property |
| 190 | |
| 191 | Raises: |
| 192 | FdtException if the associated node has no more properties, or |
| 193 | some other error occurred |
| 194 | """ |
| 195 | return check_err(fdt_next_property_offset(self._fdt, prop_offset), |
| 196 | quiet) |
| 197 | |
| 198 | def get_name(self, nodeoffset): |
| 199 | """Get the name of a node |
| 200 | |
| 201 | Args: |
| 202 | nodeoffset: Offset of node to check |
| 203 | |
| 204 | Returns: |
| 205 | Node name |
| 206 | |
| 207 | Raises: |
| 208 | FdtException on error (e.g. nodeoffset is invalid) |
| 209 | """ |
| 210 | return check_err_null(fdt_get_name(self._fdt, nodeoffset))[0] |
| 211 | |
| 212 | def get_property_by_offset(self, prop_offset, quiet=()): |
| 213 | """Obtains a property that can be examined |
| 214 | |
| 215 | Args: |
| 216 | prop_offset: Offset of property (e.g. from first_property_offset()) |
| 217 | quiet: Errors to ignore (empty to raise on all errors) |
| 218 | |
| 219 | Returns: |
| 220 | Property object, or None if not found |
| 221 | |
| 222 | Raises: |
| 223 | FdtException on error (e.g. invalid prop_offset or device |
| 224 | tree format) |
| 225 | """ |
| 226 | pdata = check_err_null( |
| 227 | fdt_get_property_by_offset(self._fdt, prop_offset), quiet) |
| 228 | if isinstance(pdata, (int)): |
| 229 | return pdata |
| 230 | return Property(pdata[0], pdata[1]) |
| 231 | |
| 232 | def first_subnode(self, nodeoffset, quiet=()): |
| 233 | """Find the first subnode of a parent node |
| 234 | |
| 235 | Args: |
| 236 | nodeoffset: Node offset of parent node |
| 237 | quiet: Errors to ignore (empty to raise on all errors) |
| 238 | |
| 239 | Returns: |
| 240 | The offset of the first subnode, if any |
| 241 | |
| 242 | Raises: |
| 243 | FdtException if no subnode found or other error occurs |
| 244 | """ |
| 245 | return check_err(fdt_first_subnode(self._fdt, nodeoffset), quiet) |
| 246 | |
| 247 | def next_subnode(self, nodeoffset, quiet=()): |
| 248 | """Find the next subnode |
| 249 | |
| 250 | Args: |
| 251 | nodeoffset: Node offset of previous subnode |
| 252 | quiet: Errors to ignore (empty to raise on all errors) |
| 253 | |
| 254 | Returns: |
| 255 | The offset of the next subnode, if any |
| 256 | |
| 257 | Raises: |
| 258 | FdtException if no more subnode found or other error occurs |
| 259 | """ |
| 260 | return check_err(fdt_next_subnode(self._fdt, nodeoffset), quiet) |
| 261 | |
| 262 | def totalsize(self): |
| 263 | """Return the total size of the device tree |
| 264 | |
| 265 | Returns: |
| 266 | Total tree size in bytes |
| 267 | """ |
| 268 | return check_err(fdt_totalsize(self._fdt)) |
| 269 | |
| 270 | def off_dt_struct(self): |
| 271 | """Return the start of the device tree struct area |
| 272 | |
| 273 | Returns: |
| 274 | Start offset of struct area |
| 275 | """ |
| 276 | return check_err(fdt_off_dt_struct(self._fdt)) |
| 277 | |
| 278 | def pack(self, quiet=()): |
| 279 | """Pack the device tree to remove unused space |
| 280 | |
| 281 | This adjusts the tree in place. |
| 282 | |
| 283 | Args: |
| 284 | quiet: Errors to ignore (empty to raise on all errors) |
| 285 | |
| 286 | Raises: |
| 287 | FdtException if any error occurs |
| 288 | """ |
| 289 | return check_err(fdt_pack(self._fdt), quiet) |
| 290 | |
| 291 | def delprop(self, nodeoffset, prop_name): |
| 292 | """Delete a property from a node |
| 293 | |
| 294 | Args: |
| 295 | nodeoffset: Node offset containing property to delete |
| 296 | prop_name: Name of property to delete |
| 297 | |
| 298 | Raises: |
| 299 | FdtError if the property does not exist, or another error occurs |
| 300 | """ |
| 301 | return check_err(fdt_delprop(self._fdt, nodeoffset, prop_name)) |
| 302 | |
| 303 | def getprop(self, nodeoffset, prop_name, quiet=()): |
| 304 | """Get a property from a node |
| 305 | |
| 306 | Args: |
| 307 | nodeoffset: Node offset containing property to get |
| 308 | prop_name: Name of property to get |
| 309 | quiet: Errors to ignore (empty to raise on all errors) |
| 310 | |
| 311 | Returns: |
| 312 | Value of property as a bytearray, or -ve error number |
| 313 | |
| 314 | Raises: |
| 315 | FdtError if any error occurs (e.g. the property is not found) |
| 316 | """ |
| 317 | pdata = check_err_null(fdt_getprop(self._fdt, nodeoffset, prop_name), |
| 318 | quiet) |
| 319 | if isinstance(pdata, (int)): |
| 320 | return pdata |
| 321 | return bytearray(pdata[0]) |
| 322 | |
Simon Glass | 460b252 | 2017-08-29 14:15:46 -0600 | [diff] [blame] | 323 | def get_phandle(self, nodeoffset): |
| 324 | """Get the phandle of a node |
| 325 | |
| 326 | Args: |
| 327 | nodeoffset: Node offset to check |
| 328 | |
| 329 | Returns: |
| 330 | phandle of node, or 0 if the node has no phandle or another error |
| 331 | occurs |
| 332 | """ |
| 333 | return fdt_get_phandle(self._fdt, nodeoffset) |
| 334 | |
| 335 | def parent_offset(self, nodeoffset, quiet=()): |
| 336 | """Get the offset of a node's parent |
| 337 | |
| 338 | Args: |
| 339 | nodeoffset: Node offset to check |
| 340 | quiet: Errors to ignore (empty to raise on all errors) |
| 341 | |
| 342 | Returns: |
| 343 | The offset of the parent node, if any |
| 344 | |
| 345 | Raises: |
| 346 | FdtException if no parent found or other error occurs |
| 347 | """ |
| 348 | return check_err(fdt_parent_offset(self._fdt, nodeoffset), quiet) |
| 349 | |
| 350 | def node_offset_by_phandle(self, phandle, quiet=()): |
| 351 | """Get the offset of a node with the given phandle |
| 352 | |
| 353 | Args: |
| 354 | phandle: Phandle to search for |
| 355 | quiet: Errors to ignore (empty to raise on all errors) |
| 356 | |
| 357 | Returns: |
| 358 | The offset of node with that phandle, if any |
| 359 | |
| 360 | Raises: |
| 361 | FdtException if no node found or other error occurs |
| 362 | """ |
| 363 | return check_err(fdt_node_offset_by_phandle(self._fdt, phandle), quiet) |
Simon Glass | a13d902 | 2017-05-27 07:38:11 -0600 | [diff] [blame] | 364 | |
| 365 | class Property: |
| 366 | """Holds a device tree property name and value. |
| 367 | |
| 368 | This holds a copy of a property taken from the device tree. It does not |
| 369 | reference the device tree, so if anything changes in the device tree, |
| 370 | a Property object will remain valid. |
| 371 | |
| 372 | Properties: |
| 373 | name: Property name |
| 374 | value: Proper value as a bytearray |
| 375 | """ |
| 376 | def __init__(self, name, value): |
| 377 | self.name = name |
| 378 | self.value = value |
| 379 | %} |
| 380 | |
| 381 | %rename(fdt_property) fdt_property_func; |
| 382 | |
| 383 | typedef int fdt32_t; |
| 384 | |
| 385 | %include "libfdt/fdt.h" |
| 386 | |
| 387 | %include "typemaps.i" |
| 388 | |
| 389 | /* Most functions don't change the device tree, so use a const void * */ |
| 390 | %typemap(in) (const void *)(const void *fdt) { |
| 391 | if (!PyByteArray_Check($input)) { |
| 392 | SWIG_exception_fail(SWIG_TypeError, "in method '" "$symname" |
| 393 | "', argument " "$argnum"" of type '" "$type""'"); |
| 394 | } |
| 395 | $1 = (void *)PyByteArray_AsString($input); |
| 396 | fdt = $1; |
| 397 | fdt = fdt; /* avoid unused variable warning */ |
| 398 | } |
| 399 | |
| 400 | /* Some functions do change the device tree, so use void * */ |
| 401 | %typemap(in) (void *)(const void *fdt) { |
| 402 | if (!PyByteArray_Check($input)) { |
| 403 | SWIG_exception_fail(SWIG_TypeError, "in method '" "$symname" |
| 404 | "', argument " "$argnum"" of type '" "$type""'"); |
| 405 | } |
| 406 | $1 = PyByteArray_AsString($input); |
| 407 | fdt = $1; |
| 408 | fdt = fdt; /* avoid unused variable warning */ |
| 409 | } |
| 410 | |
| 411 | %typemap(out) (struct fdt_property *) { |
| 412 | PyObject *buff; |
| 413 | |
| 414 | if ($1) { |
| 415 | resultobj = PyString_FromString( |
| 416 | fdt_string(fdt1, fdt32_to_cpu($1->nameoff))); |
| 417 | buff = PyByteArray_FromStringAndSize( |
| 418 | (const char *)($1 + 1), fdt32_to_cpu($1->len)); |
| 419 | resultobj = SWIG_Python_AppendOutput(resultobj, buff); |
| 420 | } |
| 421 | } |
| 422 | |
| 423 | %apply int *OUTPUT { int *lenp }; |
| 424 | |
| 425 | /* typemap used for fdt_getprop() */ |
| 426 | %typemap(out) (const void *) { |
| 427 | if (!$1) |
| 428 | $result = Py_None; |
| 429 | else |
| 430 | $result = Py_BuildValue("s#", $1, *arg4); |
| 431 | } |
| 432 | |
| 433 | /* We have both struct fdt_property and a function fdt_property() */ |
| 434 | %warnfilter(302) fdt_property; |
| 435 | |
| 436 | /* These are macros in the header so have to be redefined here */ |
| 437 | int fdt_magic(const void *fdt); |
| 438 | int fdt_totalsize(const void *fdt); |
| 439 | int fdt_off_dt_struct(const void *fdt); |
| 440 | int fdt_off_dt_strings(const void *fdt); |
| 441 | int fdt_off_mem_rsvmap(const void *fdt); |
| 442 | int fdt_version(const void *fdt); |
| 443 | int fdt_last_comp_version(const void *fdt); |
| 444 | int fdt_boot_cpuid_phys(const void *fdt); |
| 445 | int fdt_size_dt_strings(const void *fdt); |
| 446 | int fdt_size_dt_struct(const void *fdt); |
| 447 | |
| 448 | %include <../libfdt/libfdt.h> |