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_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */ 63 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */ 64 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */ 65 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */ 66 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */ 67 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 68 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 69 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 70 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 71 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 72 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 73 COMPAT_GOOGLE_CROS_EC, /* Google CROS_EC Protocol */ 74 COMPAT_GOOGLE_CROS_EC_KEYB, /* Google CROS_EC Keyboard */ 75 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 76 COMPAT_SAMSUNG_EXYNOS5_XHCI, /* Exynos5 XHCI controller */ 77 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 78 COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */ 79 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */ 80 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */ 81 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */ 82 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */ 83 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */ 84 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 85 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 86 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 87 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 88 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */ 89 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */ 90 91 COMPAT_COUNT, 92 }; 93 94 /* GPIOs are numbered from 0 */ 95 enum { 96 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 97 98 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 99 }; 100 101 /* This is the state of a GPIO pin as defined by the fdt */ 102 struct fdt_gpio_state { 103 const char *name; /* name of the fdt property defining this */ 104 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 105 u8 flags; /* FDT_GPIO_... flags */ 106 }; 107 108 /* This tells us whether a fdt_gpio_state record is valid or not */ 109 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 110 111 /** 112 * Read the GPIO taking into account the polarity of the pin. 113 * 114 * @param gpio pointer to the decoded gpio 115 * @return value of the gpio if successful, < 0 if unsuccessful 116 */ 117 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 118 119 /** 120 * Write the GPIO taking into account the polarity of the pin. 121 * 122 * @param gpio pointer to the decoded gpio 123 * @return 0 if successful 124 */ 125 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 126 127 /** 128 * Find the next numbered alias for a peripheral. This is used to enumerate 129 * all the peripherals of a certain type. 130 * 131 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 132 * this function will return a pointer to the node the alias points to, and 133 * then update *upto to 1. Next time you call this function, the next node 134 * will be returned. 135 * 136 * All nodes returned will match the compatible ID, as it is assumed that 137 * all peripherals use the same driver. 138 * 139 * @param blob FDT blob to use 140 * @param name Root name of alias to search for 141 * @param id Compatible ID to look for 142 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 143 */ 144 int fdtdec_next_alias(const void *blob, const char *name, 145 enum fdt_compat_id id, int *upto); 146 147 /** 148 * Find the compatible ID for a given node. 149 * 150 * Generally each node has at least one compatible string attached to it. 151 * This function looks through our list of known compatible strings and 152 * returns the corresponding ID which matches the compatible string. 153 * 154 * @param blob FDT blob to use 155 * @param node Node containing compatible string to find 156 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 157 */ 158 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 159 160 /** 161 * Find the next compatible node for a peripheral. 162 * 163 * Do the first call with node = 0. This function will return a pointer to 164 * the next compatible node. Next time you call this function, pass the 165 * value returned, and the next node will be provided. 166 * 167 * @param blob FDT blob to use 168 * @param node Start node for search 169 * @param id Compatible ID to look for (enum fdt_compat_id) 170 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 171 */ 172 int fdtdec_next_compatible(const void *blob, int node, 173 enum fdt_compat_id id); 174 175 /** 176 * Find the next compatible subnode for a peripheral. 177 * 178 * Do the first call with node set to the parent and depth = 0. This 179 * function will return the offset of the next compatible node. Next time 180 * you call this function, pass the node value returned last time, with 181 * depth unchanged, and the next node will be provided. 182 * 183 * @param blob FDT blob to use 184 * @param node Start node for search 185 * @param id Compatible ID to look for (enum fdt_compat_id) 186 * @param depthp Current depth (set to 0 before first call) 187 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 188 */ 189 int fdtdec_next_compatible_subnode(const void *blob, int node, 190 enum fdt_compat_id id, int *depthp); 191 192 /** 193 * Look up an address property in a node and return it as an address. 194 * The property must hold either one address with no trailing data or 195 * one address with a length. This is only tested on 32-bit machines. 196 * 197 * @param blob FDT blob 198 * @param node node to examine 199 * @param prop_name name of property to find 200 * @return address, if found, or FDT_ADDR_T_NONE if not 201 */ 202 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 203 const char *prop_name); 204 205 /** 206 * Look up an address property in a node and return it as an address. 207 * The property must hold one address with a length. This is only tested 208 * on 32-bit machines. 209 * 210 * @param blob FDT blob 211 * @param node node to examine 212 * @param prop_name name of property to find 213 * @return address, if found, or FDT_ADDR_T_NONE if not 214 */ 215 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 216 const char *prop_name, fdt_size_t *sizep); 217 218 /** 219 * Look up a 32-bit integer property in a node and return it. The property 220 * must have at least 4 bytes of data. The value of the first cell is 221 * returned. 222 * 223 * @param blob FDT blob 224 * @param node node to examine 225 * @param prop_name name of property to find 226 * @param default_val default value to return if the property is not found 227 * @return integer value, if found, or default_val if not 228 */ 229 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 230 s32 default_val); 231 232 /** 233 * Look up a 64-bit integer property in a node and return it. The property 234 * must have at least 8 bytes of data (2 cells). The first two cells are 235 * concatenated to form a 8 bytes value, where the first cell is top half and 236 * the second cell is bottom half. 237 * 238 * @param blob FDT blob 239 * @param node node to examine 240 * @param prop_name name of property to find 241 * @param default_val default value to return if the property is not found 242 * @return integer value, if found, or default_val if not 243 */ 244 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 245 uint64_t default_val); 246 247 /** 248 * Checks whether a node is enabled. 249 * This looks for a 'status' property. If this exists, then returns 1 if 250 * the status is 'ok' and 0 otherwise. If there is no status property, 251 * it returns 1 on the assumption that anything mentioned should be enabled 252 * by default. 253 * 254 * @param blob FDT blob 255 * @param node node to examine 256 * @return integer value 0 (not enabled) or 1 (enabled) 257 */ 258 int fdtdec_get_is_enabled(const void *blob, int node); 259 260 /** 261 * Make sure we have a valid fdt available to control U-Boot. 262 * 263 * If not, a message is printed to the console if the console is ready. 264 * 265 * @return 0 if all ok, -1 if not 266 */ 267 int fdtdec_prepare_fdt(void); 268 269 /** 270 * Checks that we have a valid fdt available to control U-Boot. 271 272 * However, if not then for the moment nothing is done, since this function 273 * is called too early to panic(). 274 * 275 * @returns 0 276 */ 277 int fdtdec_check_fdt(void); 278 279 /** 280 * Find the nodes for a peripheral and return a list of them in the correct 281 * order. This is used to enumerate all the peripherals of a certain type. 282 * 283 * To use this, optionally set up a /aliases node with alias properties for 284 * a peripheral. For example, for usb you could have: 285 * 286 * aliases { 287 * usb0 = "/ehci@c5008000"; 288 * usb1 = "/ehci@c5000000"; 289 * }; 290 * 291 * Pass "usb" as the name to this function and will return a list of two 292 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 293 * 294 * All nodes returned will match the compatible ID, as it is assumed that 295 * all peripherals use the same driver. 296 * 297 * If no alias node is found, then the node list will be returned in the 298 * order found in the fdt. If the aliases mention a node which doesn't 299 * exist, then this will be ignored. If nodes are found with no aliases, 300 * they will be added in any order. 301 * 302 * If there is a gap in the aliases, then this function return a 0 node at 303 * that position. The return value will also count these gaps. 304 * 305 * This function checks node properties and will not return nodes which are 306 * marked disabled (status = "disabled"). 307 * 308 * @param blob FDT blob to use 309 * @param name Root name of alias to search for 310 * @param id Compatible ID to look for 311 * @param node_list Place to put list of found nodes 312 * @param maxcount Maximum number of nodes to find 313 * @return number of nodes found on success, FTD_ERR_... on error 314 */ 315 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 316 enum fdt_compat_id id, int *node_list, int maxcount); 317 318 /* 319 * This function is similar to fdtdec_find_aliases_for_id() except that it 320 * adds to the node_list that is passed in. Any 0 elements are considered 321 * available for allocation - others are considered already used and are 322 * skipped. 323 * 324 * You can use this by calling fdtdec_find_aliases_for_id() with an 325 * uninitialised array, then setting the elements that are returned to -1, 326 * say, then calling this function, perhaps with a different compat id. 327 * Any elements you get back that are >0 are new nodes added by the call 328 * to this function. 329 * 330 * Note that if you have some nodes with aliases and some without, you are 331 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 332 * one compat_id may fill in positions for which you have aliases defined 333 * for another compat_id. When you later call *this* function with the second 334 * compat_id, the alias positions may already be used. A debug warning may 335 * be generated in this case, but it is safest to define aliases for all 336 * nodes when you care about the ordering. 337 */ 338 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 339 enum fdt_compat_id id, int *node_list, int maxcount); 340 341 /* 342 * Get the name for a compatible ID 343 * 344 * @param id Compatible ID to look for 345 * @return compatible string for that id 346 */ 347 const char *fdtdec_get_compatible(enum fdt_compat_id id); 348 349 /* Look up a phandle and follow it to its node. Then return the offset 350 * of that node. 351 * 352 * @param blob FDT blob 353 * @param node node to examine 354 * @param prop_name name of property to find 355 * @return node offset if found, -ve error code on error 356 */ 357 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 358 359 /** 360 * Look up a property in a node and return its contents in an integer 361 * array of given length. The property must have at least enough data for 362 * the array (4*count bytes). It may have more, but this will be ignored. 363 * 364 * @param blob FDT blob 365 * @param node node to examine 366 * @param prop_name name of property to find 367 * @param array array to fill with data 368 * @param count number of array elements 369 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 370 * or -FDT_ERR_BADLAYOUT if not enough data 371 */ 372 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 373 u32 *array, int count); 374 375 /** 376 * Look up a property in a node and return a pointer to its contents as a 377 * unsigned int array of given length. The property must have at least enough 378 * data for the array ('count' cells). It may have more, but this will be 379 * ignored. The data is not copied. 380 * 381 * Note that you must access elements of the array with fdt32_to_cpu(), 382 * since the elements will be big endian even on a little endian machine. 383 * 384 * @param blob FDT blob 385 * @param node node to examine 386 * @param prop_name name of property to find 387 * @param count number of array elements 388 * @return pointer to array if found, or NULL if the property is not 389 * found or there is not enough data 390 */ 391 const u32 *fdtdec_locate_array(const void *blob, int node, 392 const char *prop_name, int count); 393 394 /** 395 * Look up a boolean property in a node and return it. 396 * 397 * A boolean properly is true if present in the device tree and false if not 398 * present, regardless of its value. 399 * 400 * @param blob FDT blob 401 * @param node node to examine 402 * @param prop_name name of property to find 403 * @return 1 if the properly is present; 0 if it isn't present 404 */ 405 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 406 407 /** 408 * Decode a single GPIOs from an FDT. 409 * 410 * If the property is not found, then the GPIO structure will still be 411 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 412 * provide optional GPIOs. 413 * 414 * @param blob FDT blob to use 415 * @param node Node to look at 416 * @param prop_name Node property name 417 * @param gpio gpio elements to fill from FDT 418 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 419 */ 420 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 421 struct fdt_gpio_state *gpio); 422 423 /** 424 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 425 * terminating item. 426 * 427 * @param blob FDT blob to use 428 * @param node Node to look at 429 * @param prop_name Node property name 430 * @param gpio Array of gpio elements to fill from FDT. This will be 431 * untouched if either 0 or an error is returned 432 * @param max_count Maximum number of elements allowed 433 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 434 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 435 */ 436 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 437 struct fdt_gpio_state *gpio, int max_count); 438 439 /** 440 * Set up a GPIO pin according to the provided gpio information. At present this 441 * just requests the GPIO. 442 * 443 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 444 * deal with optional GPIOs. 445 * 446 * @param gpio GPIO info to use for set up 447 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 448 */ 449 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 450 451 /** 452 * Look in the FDT for a config item with the given name and return its value 453 * as a 32-bit integer. The property must have at least 4 bytes of data. The 454 * value of the first cell is returned. 455 * 456 * @param blob FDT blob to use 457 * @param prop_name Node property name 458 * @param default_val default value to return if the property is not found 459 * @return integer value, if found, or default_val if not 460 */ 461 int fdtdec_get_config_int(const void *blob, const char *prop_name, 462 int default_val); 463 464 /** 465 * Look in the FDT for a config item with the given name 466 * and return whether it exists. 467 * 468 * @param blob FDT blob 469 * @param prop_name property name to look up 470 * @return 1, if it exists, or 0 if not 471 */ 472 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 473 474 /** 475 * Look in the FDT for a config item with the given name and return its value 476 * as a string. 477 * 478 * @param blob FDT blob 479 * @param prop_name property name to look up 480 * @returns property string, NULL on error. 481 */ 482 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 483 484 /* 485 * Look up a property in a node and return its contents in a byte 486 * array of given length. The property must have at least enough data for 487 * the array (count bytes). It may have more, but this will be ignored. 488 * 489 * @param blob FDT blob 490 * @param node node to examine 491 * @param prop_name name of property to find 492 * @param array array to fill with data 493 * @param count number of array elements 494 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 495 * or -FDT_ERR_BADLAYOUT if not enough data 496 */ 497 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 498 u8 *array, int count); 499 500 /** 501 * Look up a property in a node and return a pointer to its contents as a 502 * byte array of given length. The property must have at least enough data 503 * for the array (count bytes). It may have more, but this will be ignored. 504 * The data is not copied. 505 * 506 * @param blob FDT blob 507 * @param node node to examine 508 * @param prop_name name of property to find 509 * @param count number of array elements 510 * @return pointer to byte array if found, or NULL if the property is not 511 * found or there is not enough data 512 */ 513 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 514 const char *prop_name, int count); 515 516 /** 517 * Look up a property in a node which contains a memory region address and 518 * size. Then return a pointer to this address. 519 * 520 * The property must hold one address with a length. This is only tested on 521 * 32-bit machines. 522 * 523 * @param blob FDT blob 524 * @param node node to examine 525 * @param prop_name name of property to find 526 * @param ptrp returns pointer to region, or NULL if no address 527 * @param size returns size of region 528 * @return 0 if ok, -1 on error (propery not found) 529 */ 530 int fdtdec_decode_region(const void *blob, int node, 531 const char *prop_name, void **ptrp, size_t *size); 532 #endif 533