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