1 /* 2 * Copyright (c) 2011 The Chromium OS Authors. 3 * SPDX-License-Identifier: GPL-2.0+ 4 */ 5 6 #ifndef __fdtdec_h 7 #define __fdtdec_h 8 9 /* 10 * This file contains convenience functions for decoding useful and 11 * enlightening information from FDTs. It is intended to be used by device 12 * drivers and board-specific code within U-Boot. It aims to reduce the 13 * amount of FDT munging required within U-Boot itself, so that driver code 14 * changes to support FDT are minimized. 15 */ 16 17 #include <libfdt.h> 18 19 /* 20 * A typedef for a physical address. Note that fdt data is always big 21 * endian even on a litle endian machine. 22 */ 23 #ifdef CONFIG_PHYS_64BIT 24 typedef u64 fdt_addr_t; 25 typedef u64 fdt_size_t; 26 #define FDT_ADDR_T_NONE (-1ULL) 27 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg) 28 #define fdt_size_to_cpu(reg) be64_to_cpu(reg) 29 #else 30 typedef u32 fdt_addr_t; 31 typedef u32 fdt_size_t; 32 #define FDT_ADDR_T_NONE (-1U) 33 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg) 34 #define fdt_size_to_cpu(reg) be32_to_cpu(reg) 35 #endif 36 37 /* Information obtained about memory from the FDT */ 38 struct fdt_memory { 39 fdt_addr_t start; 40 fdt_addr_t end; 41 }; 42 43 /** 44 * Compat types that we know about and for which we might have drivers. 45 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory 46 * within drivers. 47 */ 48 enum fdt_compat_id { 49 COMPAT_UNKNOWN, 50 COMPAT_NVIDIA_TEGRA20_USB, /* Tegra20 USB port */ 51 COMPAT_NVIDIA_TEGRA30_USB, /* Tegra30 USB port */ 52 COMPAT_NVIDIA_TEGRA114_USB, /* Tegra114 USB port */ 53 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */ 54 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */ 55 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */ 56 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */ 57 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */ 58 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */ 59 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */ 60 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */ 61 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */ 62 COMPAT_NVIDIA_TEGRA124_SDMMC, /* Tegra124 SDMMC controller */ 63 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */ 64 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */ 65 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */ 66 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */ 67 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */ 68 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 69 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 70 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 71 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 72 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 73 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 74 COMPAT_GOOGLE_CROS_EC, /* Google CROS_EC Protocol */ 75 COMPAT_GOOGLE_CROS_EC_KEYB, /* Google CROS_EC Keyboard */ 76 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 77 COMPAT_SAMSUNG_EXYNOS5_XHCI, /* Exynos5 XHCI controller */ 78 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 79 COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */ 80 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */ 81 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */ 82 COMPAT_SAMSUNG_EXYNOS_MIPI_DSI, /* Exynos mipi dsi */ 83 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */ 84 COMPAT_SAMSUNG_EXYNOS_DWMMC, /* Exynos DWMMC controller */ 85 COMPAT_SAMSUNG_EXYNOS_MMC, /* Exynos MMC controller */ 86 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */ 87 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 88 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 89 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 90 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 91 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */ 92 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */ 93 COMPAT_SANDBOX_HOST_EMULATION, /* Sandbox emulation of a function */ 94 COMPAT_SANDBOX_LCD_SDL, /* Sandbox LCD emulation with SDL */ 95 COMPAT_TI_TPS65090, /* Texas Instrument TPS65090 */ 96 COMPAT_NXP_PTN3460, /* NXP PTN3460 DP/LVDS bridge */ 97 COMPAT_SAMSUNG_EXYNOS_SYSMMU, /* Exynos sysmmu */ 98 99 COMPAT_COUNT, 100 }; 101 102 /* GPIOs are numbered from 0 */ 103 enum { 104 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 105 106 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 107 }; 108 109 /* This is the state of a GPIO pin as defined by the fdt */ 110 struct fdt_gpio_state { 111 const char *name; /* name of the fdt property defining this */ 112 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 113 u8 flags; /* FDT_GPIO_... flags */ 114 }; 115 116 /* This tells us whether a fdt_gpio_state record is valid or not */ 117 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 118 119 /** 120 * Read the GPIO taking into account the polarity of the pin. 121 * 122 * @param gpio pointer to the decoded gpio 123 * @return value of the gpio if successful, < 0 if unsuccessful 124 */ 125 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 126 127 /** 128 * Write the GPIO taking into account the polarity of the pin. 129 * 130 * @param gpio pointer to the decoded gpio 131 * @return 0 if successful 132 */ 133 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 134 135 /** 136 * Find the next numbered alias for a peripheral. This is used to enumerate 137 * all the peripherals of a certain type. 138 * 139 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 140 * this function will return a pointer to the node the alias points to, and 141 * then update *upto to 1. Next time you call this function, the next node 142 * will be returned. 143 * 144 * All nodes returned will match the compatible ID, as it is assumed that 145 * all peripherals use the same driver. 146 * 147 * @param blob FDT blob to use 148 * @param name Root name of alias to search for 149 * @param id Compatible ID to look for 150 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 151 */ 152 int fdtdec_next_alias(const void *blob, const char *name, 153 enum fdt_compat_id id, int *upto); 154 155 /** 156 * Find the compatible ID for a given node. 157 * 158 * Generally each node has at least one compatible string attached to it. 159 * This function looks through our list of known compatible strings and 160 * returns the corresponding ID which matches the compatible string. 161 * 162 * @param blob FDT blob to use 163 * @param node Node containing compatible string to find 164 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 165 */ 166 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 167 168 /** 169 * Find the next compatible node for a peripheral. 170 * 171 * Do the first call with node = 0. This function will return a pointer to 172 * the next compatible node. Next time you call this function, pass the 173 * value returned, and the next node will be provided. 174 * 175 * @param blob FDT blob to use 176 * @param node Start node for search 177 * @param id Compatible ID to look for (enum fdt_compat_id) 178 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 179 */ 180 int fdtdec_next_compatible(const void *blob, int node, 181 enum fdt_compat_id id); 182 183 /** 184 * Find the next compatible subnode for a peripheral. 185 * 186 * Do the first call with node set to the parent and depth = 0. This 187 * function will return the offset of the next compatible node. Next time 188 * you call this function, pass the node value returned last time, with 189 * depth unchanged, and the next node will be provided. 190 * 191 * @param blob FDT blob to use 192 * @param node Start node for search 193 * @param id Compatible ID to look for (enum fdt_compat_id) 194 * @param depthp Current depth (set to 0 before first call) 195 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 196 */ 197 int fdtdec_next_compatible_subnode(const void *blob, int node, 198 enum fdt_compat_id id, int *depthp); 199 200 /** 201 * Look up an address property in a node and return it as an address. 202 * The property must hold either one address with no trailing data or 203 * one address with a length. This is only tested on 32-bit machines. 204 * 205 * @param blob FDT blob 206 * @param node node to examine 207 * @param prop_name name of property to find 208 * @return address, if found, or FDT_ADDR_T_NONE if not 209 */ 210 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 211 const char *prop_name); 212 213 /** 214 * Look up an address property in a node and return it as an address. 215 * The property must hold one address with a length. This is only tested 216 * on 32-bit machines. 217 * 218 * @param blob FDT blob 219 * @param node node to examine 220 * @param prop_name name of property to find 221 * @return address, if found, or FDT_ADDR_T_NONE if not 222 */ 223 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 224 const char *prop_name, fdt_size_t *sizep); 225 226 /** 227 * Look up a 32-bit integer property in a node and return it. The property 228 * must have at least 4 bytes of data. The value of the first cell is 229 * returned. 230 * 231 * @param blob FDT blob 232 * @param node node to examine 233 * @param prop_name name of property to find 234 * @param default_val default value to return if the property is not found 235 * @return integer value, if found, or default_val if not 236 */ 237 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 238 s32 default_val); 239 240 /** 241 * Look up a 64-bit integer property in a node and return it. The property 242 * must have at least 8 bytes of data (2 cells). The first two cells are 243 * concatenated to form a 8 bytes value, where the first cell is top half and 244 * the second cell is bottom half. 245 * 246 * @param blob FDT blob 247 * @param node node to examine 248 * @param prop_name name of property to find 249 * @param default_val default value to return if the property is not found 250 * @return integer value, if found, or default_val if not 251 */ 252 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 253 uint64_t default_val); 254 255 /** 256 * Checks whether a node is enabled. 257 * This looks for a 'status' property. If this exists, then returns 1 if 258 * the status is 'ok' and 0 otherwise. If there is no status property, 259 * it returns 1 on the assumption that anything mentioned should be enabled 260 * by default. 261 * 262 * @param blob FDT blob 263 * @param node node to examine 264 * @return integer value 0 (not enabled) or 1 (enabled) 265 */ 266 int fdtdec_get_is_enabled(const void *blob, int node); 267 268 /** 269 * Make sure we have a valid fdt available to control U-Boot. 270 * 271 * If not, a message is printed to the console if the console is ready. 272 * 273 * @return 0 if all ok, -1 if not 274 */ 275 int fdtdec_prepare_fdt(void); 276 277 /** 278 * Checks that we have a valid fdt available to control U-Boot. 279 280 * However, if not then for the moment nothing is done, since this function 281 * is called too early to panic(). 282 * 283 * @returns 0 284 */ 285 int fdtdec_check_fdt(void); 286 287 /** 288 * Find the nodes for a peripheral and return a list of them in the correct 289 * order. This is used to enumerate all the peripherals of a certain type. 290 * 291 * To use this, optionally set up a /aliases node with alias properties for 292 * a peripheral. For example, for usb you could have: 293 * 294 * aliases { 295 * usb0 = "/ehci@c5008000"; 296 * usb1 = "/ehci@c5000000"; 297 * }; 298 * 299 * Pass "usb" as the name to this function and will return a list of two 300 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 301 * 302 * All nodes returned will match the compatible ID, as it is assumed that 303 * all peripherals use the same driver. 304 * 305 * If no alias node is found, then the node list will be returned in the 306 * order found in the fdt. If the aliases mention a node which doesn't 307 * exist, then this will be ignored. If nodes are found with no aliases, 308 * they will be added in any order. 309 * 310 * If there is a gap in the aliases, then this function return a 0 node at 311 * that position. The return value will also count these gaps. 312 * 313 * This function checks node properties and will not return nodes which are 314 * marked disabled (status = "disabled"). 315 * 316 * @param blob FDT blob to use 317 * @param name Root name of alias to search for 318 * @param id Compatible ID to look for 319 * @param node_list Place to put list of found nodes 320 * @param maxcount Maximum number of nodes to find 321 * @return number of nodes found on success, FTD_ERR_... on error 322 */ 323 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 324 enum fdt_compat_id id, int *node_list, int maxcount); 325 326 /* 327 * This function is similar to fdtdec_find_aliases_for_id() except that it 328 * adds to the node_list that is passed in. Any 0 elements are considered 329 * available for allocation - others are considered already used and are 330 * skipped. 331 * 332 * You can use this by calling fdtdec_find_aliases_for_id() with an 333 * uninitialised array, then setting the elements that are returned to -1, 334 * say, then calling this function, perhaps with a different compat id. 335 * Any elements you get back that are >0 are new nodes added by the call 336 * to this function. 337 * 338 * Note that if you have some nodes with aliases and some without, you are 339 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 340 * one compat_id may fill in positions for which you have aliases defined 341 * for another compat_id. When you later call *this* function with the second 342 * compat_id, the alias positions may already be used. A debug warning may 343 * be generated in this case, but it is safest to define aliases for all 344 * nodes when you care about the ordering. 345 */ 346 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 347 enum fdt_compat_id id, int *node_list, int maxcount); 348 349 /** 350 * Get the alias sequence number of a node 351 * 352 * This works out whether a node is pointed to by an alias, and if so, the 353 * sequence number of that alias. Aliases are of the form <base><num> where 354 * <num> is the sequence number. For example spi2 would be sequence number 355 * 2. 356 * 357 * @param blob Device tree blob (if NULL, then error is returned) 358 * @param base Base name for alias (before the underscore) 359 * @param node Node to look up 360 * @param seqp This is set to the sequence number if one is found, 361 * but otherwise the value is left alone 362 * @return 0 if a sequence was found, -ve if not 363 */ 364 int fdtdec_get_alias_seq(const void *blob, const char *base, int node, 365 int *seqp); 366 367 /** 368 * Get the offset of the given alias node 369 * 370 * This looks up an alias in /aliases then finds the offset of that node. 371 * 372 * @param blob Device tree blob (if NULL, then error is returned) 373 * @param name Alias name, e.g. "console" 374 * @return Node offset referred to by that alias, or -ve FDT_ERR_... 375 */ 376 int fdtdec_get_alias_node(const void *blob, const char *name); 377 378 /* 379 * Get the name for a compatible ID 380 * 381 * @param id Compatible ID to look for 382 * @return compatible string for that id 383 */ 384 const char *fdtdec_get_compatible(enum fdt_compat_id id); 385 386 /* Look up a phandle and follow it to its node. Then return the offset 387 * of that node. 388 * 389 * @param blob FDT blob 390 * @param node node to examine 391 * @param prop_name name of property to find 392 * @return node offset if found, -ve error code on error 393 */ 394 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 395 396 /** 397 * Look up a property in a node and return its contents in an integer 398 * array of given length. The property must have at least enough data for 399 * the array (4*count bytes). It may have more, but this will be ignored. 400 * 401 * @param blob FDT blob 402 * @param node node to examine 403 * @param prop_name name of property to find 404 * @param array array to fill with data 405 * @param count number of array elements 406 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 407 * or -FDT_ERR_BADLAYOUT if not enough data 408 */ 409 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 410 u32 *array, int count); 411 412 /** 413 * Look up a property in a node and return a pointer to its contents as a 414 * unsigned int array of given length. The property must have at least enough 415 * data for the array ('count' cells). It may have more, but this will be 416 * ignored. The data is not copied. 417 * 418 * Note that you must access elements of the array with fdt32_to_cpu(), 419 * since the elements will be big endian even on a little endian machine. 420 * 421 * @param blob FDT blob 422 * @param node node to examine 423 * @param prop_name name of property to find 424 * @param count number of array elements 425 * @return pointer to array if found, or NULL if the property is not 426 * found or there is not enough data 427 */ 428 const u32 *fdtdec_locate_array(const void *blob, int node, 429 const char *prop_name, int count); 430 431 /** 432 * Look up a boolean property in a node and return it. 433 * 434 * A boolean properly is true if present in the device tree and false if not 435 * present, regardless of its value. 436 * 437 * @param blob FDT blob 438 * @param node node to examine 439 * @param prop_name name of property to find 440 * @return 1 if the properly is present; 0 if it isn't present 441 */ 442 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 443 444 /** 445 * Decode a single GPIOs from an FDT. 446 * 447 * If the property is not found, then the GPIO structure will still be 448 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 449 * provide optional GPIOs. 450 * 451 * @param blob FDT blob to use 452 * @param node Node to look at 453 * @param prop_name Node property name 454 * @param gpio gpio elements to fill from FDT 455 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 456 */ 457 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 458 struct fdt_gpio_state *gpio); 459 460 /** 461 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 462 * terminating item. 463 * 464 * @param blob FDT blob to use 465 * @param node Node to look at 466 * @param prop_name Node property name 467 * @param gpio Array of gpio elements to fill from FDT. This will be 468 * untouched if either 0 or an error is returned 469 * @param max_count Maximum number of elements allowed 470 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 471 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 472 */ 473 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 474 struct fdt_gpio_state *gpio, int max_count); 475 476 /** 477 * Set up a GPIO pin according to the provided gpio information. At present this 478 * just requests the GPIO. 479 * 480 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 481 * deal with optional GPIOs. 482 * 483 * @param gpio GPIO info to use for set up 484 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 485 */ 486 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 487 488 /** 489 * Look in the FDT for a config item with the given name and return its value 490 * as a 32-bit integer. The property must have at least 4 bytes of data. The 491 * value of the first cell is returned. 492 * 493 * @param blob FDT blob to use 494 * @param prop_name Node property name 495 * @param default_val default value to return if the property is not found 496 * @return integer value, if found, or default_val if not 497 */ 498 int fdtdec_get_config_int(const void *blob, const char *prop_name, 499 int default_val); 500 501 /** 502 * Look in the FDT for a config item with the given name 503 * and return whether it exists. 504 * 505 * @param blob FDT blob 506 * @param prop_name property name to look up 507 * @return 1, if it exists, or 0 if not 508 */ 509 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 510 511 /** 512 * Look in the FDT for a config item with the given name and return its value 513 * as a string. 514 * 515 * @param blob FDT blob 516 * @param prop_name property name to look up 517 * @returns property string, NULL on error. 518 */ 519 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 520 521 /* 522 * Look up a property in a node and return its contents in a byte 523 * array of given length. The property must have at least enough data for 524 * the array (count bytes). It may have more, but this will be ignored. 525 * 526 * @param blob FDT blob 527 * @param node node to examine 528 * @param prop_name name of property to find 529 * @param array array to fill with data 530 * @param count number of array elements 531 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 532 * or -FDT_ERR_BADLAYOUT if not enough data 533 */ 534 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 535 u8 *array, int count); 536 537 /** 538 * Look up a property in a node and return a pointer to its contents as a 539 * byte array of given length. The property must have at least enough data 540 * for the array (count bytes). It may have more, but this will be ignored. 541 * The data is not copied. 542 * 543 * @param blob FDT blob 544 * @param node node to examine 545 * @param prop_name name of property to find 546 * @param count number of array elements 547 * @return pointer to byte array if found, or NULL if the property is not 548 * found or there is not enough data 549 */ 550 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 551 const char *prop_name, int count); 552 553 /** 554 * Look up a property in a node which contains a memory region address and 555 * size. Then return a pointer to this address. 556 * 557 * The property must hold one address with a length. This is only tested on 558 * 32-bit machines. 559 * 560 * @param blob FDT blob 561 * @param node node to examine 562 * @param prop_name name of property to find 563 * @param ptrp returns pointer to region, or NULL if no address 564 * @param size returns size of region 565 * @return 0 if ok, -1 on error (propery not found) 566 */ 567 int fdtdec_decode_region(const void *blob, int node, 568 const char *prop_name, void **ptrp, size_t *size); 569 570 /* A flash map entry, containing an offset and length */ 571 struct fmap_entry { 572 uint32_t offset; 573 uint32_t length; 574 }; 575 576 /** 577 * Read a flash entry from the fdt 578 * 579 * @param blob FDT blob 580 * @param node Offset of node to read 581 * @param name Name of node being read 582 * @param entry Place to put offset and size of this node 583 * @return 0 if ok, -ve on error 584 */ 585 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name, 586 struct fmap_entry *entry); 587 #endif 588