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 98 COMPAT_COUNT, 99 }; 100 101 /* GPIOs are numbered from 0 */ 102 enum { 103 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 104 105 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 106 }; 107 108 /* This is the state of a GPIO pin as defined by the fdt */ 109 struct fdt_gpio_state { 110 const char *name; /* name of the fdt property defining this */ 111 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 112 u8 flags; /* FDT_GPIO_... flags */ 113 }; 114 115 /* This tells us whether a fdt_gpio_state record is valid or not */ 116 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 117 118 /** 119 * Read the GPIO taking into account the polarity of the pin. 120 * 121 * @param gpio pointer to the decoded gpio 122 * @return value of the gpio if successful, < 0 if unsuccessful 123 */ 124 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 125 126 /** 127 * Write the GPIO taking into account the polarity of the pin. 128 * 129 * @param gpio pointer to the decoded gpio 130 * @return 0 if successful 131 */ 132 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 133 134 /** 135 * Find the next numbered alias for a peripheral. This is used to enumerate 136 * all the peripherals of a certain type. 137 * 138 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 139 * this function will return a pointer to the node the alias points to, and 140 * then update *upto to 1. Next time you call this function, the next node 141 * will be returned. 142 * 143 * All nodes returned will match the compatible ID, as it is assumed that 144 * all peripherals use the same driver. 145 * 146 * @param blob FDT blob to use 147 * @param name Root name of alias to search for 148 * @param id Compatible ID to look for 149 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 150 */ 151 int fdtdec_next_alias(const void *blob, const char *name, 152 enum fdt_compat_id id, int *upto); 153 154 /** 155 * Find the compatible ID for a given node. 156 * 157 * Generally each node has at least one compatible string attached to it. 158 * This function looks through our list of known compatible strings and 159 * returns the corresponding ID which matches the compatible string. 160 * 161 * @param blob FDT blob to use 162 * @param node Node containing compatible string to find 163 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 164 */ 165 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 166 167 /** 168 * Find the next compatible node for a peripheral. 169 * 170 * Do the first call with node = 0. This function will return a pointer to 171 * the next compatible node. Next time you call this function, pass the 172 * value returned, and the next node will be provided. 173 * 174 * @param blob FDT blob to use 175 * @param node Start node for search 176 * @param id Compatible ID to look for (enum fdt_compat_id) 177 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 178 */ 179 int fdtdec_next_compatible(const void *blob, int node, 180 enum fdt_compat_id id); 181 182 /** 183 * Find the next compatible subnode for a peripheral. 184 * 185 * Do the first call with node set to the parent and depth = 0. This 186 * function will return the offset of the next compatible node. Next time 187 * you call this function, pass the node value returned last time, with 188 * depth unchanged, and the next node will be provided. 189 * 190 * @param blob FDT blob to use 191 * @param node Start node for search 192 * @param id Compatible ID to look for (enum fdt_compat_id) 193 * @param depthp Current depth (set to 0 before first call) 194 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 195 */ 196 int fdtdec_next_compatible_subnode(const void *blob, int node, 197 enum fdt_compat_id id, int *depthp); 198 199 /** 200 * Look up an address property in a node and return it as an address. 201 * The property must hold either one address with no trailing data or 202 * one address with a length. This is only tested on 32-bit machines. 203 * 204 * @param blob FDT blob 205 * @param node node to examine 206 * @param prop_name name of property to find 207 * @return address, if found, or FDT_ADDR_T_NONE if not 208 */ 209 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 210 const char *prop_name); 211 212 /** 213 * Look up an address property in a node and return it as an address. 214 * The property must hold one address with a length. This is only tested 215 * on 32-bit machines. 216 * 217 * @param blob FDT blob 218 * @param node node to examine 219 * @param prop_name name of property to find 220 * @return address, if found, or FDT_ADDR_T_NONE if not 221 */ 222 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 223 const char *prop_name, fdt_size_t *sizep); 224 225 /** 226 * Look up a 32-bit integer property in a node and return it. The property 227 * must have at least 4 bytes of data. The value of the first cell is 228 * returned. 229 * 230 * @param blob FDT blob 231 * @param node node to examine 232 * @param prop_name name of property to find 233 * @param default_val default value to return if the property is not found 234 * @return integer value, if found, or default_val if not 235 */ 236 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 237 s32 default_val); 238 239 /** 240 * Look up a 64-bit integer property in a node and return it. The property 241 * must have at least 8 bytes of data (2 cells). The first two cells are 242 * concatenated to form a 8 bytes value, where the first cell is top half and 243 * the second cell is bottom half. 244 * 245 * @param blob FDT blob 246 * @param node node to examine 247 * @param prop_name name of property to find 248 * @param default_val default value to return if the property is not found 249 * @return integer value, if found, or default_val if not 250 */ 251 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 252 uint64_t default_val); 253 254 /** 255 * Checks whether a node is enabled. 256 * This looks for a 'status' property. If this exists, then returns 1 if 257 * the status is 'ok' and 0 otherwise. If there is no status property, 258 * it returns 1 on the assumption that anything mentioned should be enabled 259 * by default. 260 * 261 * @param blob FDT blob 262 * @param node node to examine 263 * @return integer value 0 (not enabled) or 1 (enabled) 264 */ 265 int fdtdec_get_is_enabled(const void *blob, int node); 266 267 /** 268 * Make sure we have a valid fdt available to control U-Boot. 269 * 270 * If not, a message is printed to the console if the console is ready. 271 * 272 * @return 0 if all ok, -1 if not 273 */ 274 int fdtdec_prepare_fdt(void); 275 276 /** 277 * Checks that we have a valid fdt available to control U-Boot. 278 279 * However, if not then for the moment nothing is done, since this function 280 * is called too early to panic(). 281 * 282 * @returns 0 283 */ 284 int fdtdec_check_fdt(void); 285 286 /** 287 * Find the nodes for a peripheral and return a list of them in the correct 288 * order. This is used to enumerate all the peripherals of a certain type. 289 * 290 * To use this, optionally set up a /aliases node with alias properties for 291 * a peripheral. For example, for usb you could have: 292 * 293 * aliases { 294 * usb0 = "/ehci@c5008000"; 295 * usb1 = "/ehci@c5000000"; 296 * }; 297 * 298 * Pass "usb" as the name to this function and will return a list of two 299 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 300 * 301 * All nodes returned will match the compatible ID, as it is assumed that 302 * all peripherals use the same driver. 303 * 304 * If no alias node is found, then the node list will be returned in the 305 * order found in the fdt. If the aliases mention a node which doesn't 306 * exist, then this will be ignored. If nodes are found with no aliases, 307 * they will be added in any order. 308 * 309 * If there is a gap in the aliases, then this function return a 0 node at 310 * that position. The return value will also count these gaps. 311 * 312 * This function checks node properties and will not return nodes which are 313 * marked disabled (status = "disabled"). 314 * 315 * @param blob FDT blob to use 316 * @param name Root name of alias to search for 317 * @param id Compatible ID to look for 318 * @param node_list Place to put list of found nodes 319 * @param maxcount Maximum number of nodes to find 320 * @return number of nodes found on success, FTD_ERR_... on error 321 */ 322 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 323 enum fdt_compat_id id, int *node_list, int maxcount); 324 325 /* 326 * This function is similar to fdtdec_find_aliases_for_id() except that it 327 * adds to the node_list that is passed in. Any 0 elements are considered 328 * available for allocation - others are considered already used and are 329 * skipped. 330 * 331 * You can use this by calling fdtdec_find_aliases_for_id() with an 332 * uninitialised array, then setting the elements that are returned to -1, 333 * say, then calling this function, perhaps with a different compat id. 334 * Any elements you get back that are >0 are new nodes added by the call 335 * to this function. 336 * 337 * Note that if you have some nodes with aliases and some without, you are 338 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 339 * one compat_id may fill in positions for which you have aliases defined 340 * for another compat_id. When you later call *this* function with the second 341 * compat_id, the alias positions may already be used. A debug warning may 342 * be generated in this case, but it is safest to define aliases for all 343 * nodes when you care about the ordering. 344 */ 345 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 346 enum fdt_compat_id id, int *node_list, int maxcount); 347 348 /** 349 * Get the alias sequence number of a node 350 * 351 * This works out whether a node is pointed to by an alias, and if so, the 352 * sequence number of that alias. Aliases are of the form <base><num> where 353 * <num> is the sequence number. For example spi2 would be sequence number 354 * 2. 355 * 356 * @param blob Device tree blob (if NULL, then error is returned) 357 * @param base Base name for alias (before the underscore) 358 * @param node Node to look up 359 * @param seqp This is set to the sequence number if one is found, 360 * but otherwise the value is left alone 361 * @return 0 if a sequence was found, -ve if not 362 */ 363 int fdtdec_get_alias_seq(const void *blob, const char *base, int node, 364 int *seqp); 365 366 /* 367 * Get the name for a compatible ID 368 * 369 * @param id Compatible ID to look for 370 * @return compatible string for that id 371 */ 372 const char *fdtdec_get_compatible(enum fdt_compat_id id); 373 374 /* Look up a phandle and follow it to its node. Then return the offset 375 * of that node. 376 * 377 * @param blob FDT blob 378 * @param node node to examine 379 * @param prop_name name of property to find 380 * @return node offset if found, -ve error code on error 381 */ 382 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 383 384 /** 385 * Look up a property in a node and return its contents in an integer 386 * array of given length. The property must have at least enough data for 387 * the array (4*count bytes). It may have more, but this will be ignored. 388 * 389 * @param blob FDT blob 390 * @param node node to examine 391 * @param prop_name name of property to find 392 * @param array array to fill with data 393 * @param count number of array elements 394 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 395 * or -FDT_ERR_BADLAYOUT if not enough data 396 */ 397 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 398 u32 *array, int count); 399 400 /** 401 * Look up a property in a node and return a pointer to its contents as a 402 * unsigned int array of given length. The property must have at least enough 403 * data for the array ('count' cells). It may have more, but this will be 404 * ignored. The data is not copied. 405 * 406 * Note that you must access elements of the array with fdt32_to_cpu(), 407 * since the elements will be big endian even on a little endian machine. 408 * 409 * @param blob FDT blob 410 * @param node node to examine 411 * @param prop_name name of property to find 412 * @param count number of array elements 413 * @return pointer to array if found, or NULL if the property is not 414 * found or there is not enough data 415 */ 416 const u32 *fdtdec_locate_array(const void *blob, int node, 417 const char *prop_name, int count); 418 419 /** 420 * Look up a boolean property in a node and return it. 421 * 422 * A boolean properly is true if present in the device tree and false if not 423 * present, regardless of its value. 424 * 425 * @param blob FDT blob 426 * @param node node to examine 427 * @param prop_name name of property to find 428 * @return 1 if the properly is present; 0 if it isn't present 429 */ 430 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 431 432 /** 433 * Decode a single GPIOs from an FDT. 434 * 435 * If the property is not found, then the GPIO structure will still be 436 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 437 * provide optional GPIOs. 438 * 439 * @param blob FDT blob to use 440 * @param node Node to look at 441 * @param prop_name Node property name 442 * @param gpio gpio elements to fill from FDT 443 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 444 */ 445 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 446 struct fdt_gpio_state *gpio); 447 448 /** 449 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 450 * terminating item. 451 * 452 * @param blob FDT blob to use 453 * @param node Node to look at 454 * @param prop_name Node property name 455 * @param gpio Array of gpio elements to fill from FDT. This will be 456 * untouched if either 0 or an error is returned 457 * @param max_count Maximum number of elements allowed 458 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 459 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 460 */ 461 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 462 struct fdt_gpio_state *gpio, int max_count); 463 464 /** 465 * Set up a GPIO pin according to the provided gpio information. At present this 466 * just requests the GPIO. 467 * 468 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 469 * deal with optional GPIOs. 470 * 471 * @param gpio GPIO info to use for set up 472 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 473 */ 474 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 475 476 /** 477 * Look in the FDT for a config item with the given name and return its value 478 * as a 32-bit integer. The property must have at least 4 bytes of data. The 479 * value of the first cell is returned. 480 * 481 * @param blob FDT blob to use 482 * @param prop_name Node property name 483 * @param default_val default value to return if the property is not found 484 * @return integer value, if found, or default_val if not 485 */ 486 int fdtdec_get_config_int(const void *blob, const char *prop_name, 487 int default_val); 488 489 /** 490 * Look in the FDT for a config item with the given name 491 * and return whether it exists. 492 * 493 * @param blob FDT blob 494 * @param prop_name property name to look up 495 * @return 1, if it exists, or 0 if not 496 */ 497 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 498 499 /** 500 * Look in the FDT for a config item with the given name and return its value 501 * as a string. 502 * 503 * @param blob FDT blob 504 * @param prop_name property name to look up 505 * @returns property string, NULL on error. 506 */ 507 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 508 509 /* 510 * Look up a property in a node and return its contents in a byte 511 * array of given length. The property must have at least enough data for 512 * the array (count bytes). It may have more, but this will be ignored. 513 * 514 * @param blob FDT blob 515 * @param node node to examine 516 * @param prop_name name of property to find 517 * @param array array to fill with data 518 * @param count number of array elements 519 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 520 * or -FDT_ERR_BADLAYOUT if not enough data 521 */ 522 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 523 u8 *array, int count); 524 525 /** 526 * Look up a property in a node and return a pointer to its contents as a 527 * byte array of given length. The property must have at least enough data 528 * for the array (count bytes). It may have more, but this will be ignored. 529 * The data is not copied. 530 * 531 * @param blob FDT blob 532 * @param node node to examine 533 * @param prop_name name of property to find 534 * @param count number of array elements 535 * @return pointer to byte array if found, or NULL if the property is not 536 * found or there is not enough data 537 */ 538 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 539 const char *prop_name, int count); 540 541 /** 542 * Look up a property in a node which contains a memory region address and 543 * size. Then return a pointer to this address. 544 * 545 * The property must hold one address with a length. This is only tested on 546 * 32-bit machines. 547 * 548 * @param blob FDT blob 549 * @param node node to examine 550 * @param prop_name name of property to find 551 * @param ptrp returns pointer to region, or NULL if no address 552 * @param size returns size of region 553 * @return 0 if ok, -1 on error (propery not found) 554 */ 555 int fdtdec_decode_region(const void *blob, int node, 556 const char *prop_name, void **ptrp, size_t *size); 557 558 /* A flash map entry, containing an offset and length */ 559 struct fmap_entry { 560 uint32_t offset; 561 uint32_t length; 562 }; 563 564 /** 565 * Read a flash entry from the fdt 566 * 567 * @param blob FDT blob 568 * @param node Offset of node to read 569 * @param name Name of node being read 570 * @param entry Place to put offset and size of this node 571 * @return 0 if ok, -ve on error 572 */ 573 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name, 574 struct fmap_entry *entry); 575 #endif 576