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_EXYNOS5_DP, /* Exynos Display port controller */ 83 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */ 84 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */ 85 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 86 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 87 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 88 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 89 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */ 90 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */ 91 92 COMPAT_COUNT, 93 }; 94 95 /* GPIOs are numbered from 0 */ 96 enum { 97 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 98 99 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 100 }; 101 102 /* This is the state of a GPIO pin as defined by the fdt */ 103 struct fdt_gpio_state { 104 const char *name; /* name of the fdt property defining this */ 105 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 106 u8 flags; /* FDT_GPIO_... flags */ 107 }; 108 109 /* This tells us whether a fdt_gpio_state record is valid or not */ 110 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 111 112 /** 113 * Read the GPIO taking into account the polarity of the pin. 114 * 115 * @param gpio pointer to the decoded gpio 116 * @return value of the gpio if successful, < 0 if unsuccessful 117 */ 118 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 119 120 /** 121 * Write the GPIO taking into account the polarity of the pin. 122 * 123 * @param gpio pointer to the decoded gpio 124 * @return 0 if successful 125 */ 126 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 127 128 /** 129 * Find the next numbered alias for a peripheral. This is used to enumerate 130 * all the peripherals of a certain type. 131 * 132 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 133 * this function will return a pointer to the node the alias points to, and 134 * then update *upto to 1. Next time you call this function, the next node 135 * will be returned. 136 * 137 * All nodes returned will match the compatible ID, as it is assumed that 138 * all peripherals use the same driver. 139 * 140 * @param blob FDT blob to use 141 * @param name Root name of alias to search for 142 * @param id Compatible ID to look for 143 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 144 */ 145 int fdtdec_next_alias(const void *blob, const char *name, 146 enum fdt_compat_id id, int *upto); 147 148 /** 149 * Find the compatible ID for a given node. 150 * 151 * Generally each node has at least one compatible string attached to it. 152 * This function looks through our list of known compatible strings and 153 * returns the corresponding ID which matches the compatible string. 154 * 155 * @param blob FDT blob to use 156 * @param node Node containing compatible string to find 157 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 158 */ 159 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 160 161 /** 162 * Find the next compatible node for a peripheral. 163 * 164 * Do the first call with node = 0. This function will return a pointer to 165 * the next compatible node. Next time you call this function, pass the 166 * value returned, and the next node will be provided. 167 * 168 * @param blob FDT blob to use 169 * @param node Start node for search 170 * @param id Compatible ID to look for (enum fdt_compat_id) 171 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 172 */ 173 int fdtdec_next_compatible(const void *blob, int node, 174 enum fdt_compat_id id); 175 176 /** 177 * Find the next compatible subnode for a peripheral. 178 * 179 * Do the first call with node set to the parent and depth = 0. This 180 * function will return the offset of the next compatible node. Next time 181 * you call this function, pass the node value returned last time, with 182 * depth unchanged, and the next node will be provided. 183 * 184 * @param blob FDT blob to use 185 * @param node Start node for search 186 * @param id Compatible ID to look for (enum fdt_compat_id) 187 * @param depthp Current depth (set to 0 before first call) 188 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 189 */ 190 int fdtdec_next_compatible_subnode(const void *blob, int node, 191 enum fdt_compat_id id, int *depthp); 192 193 /** 194 * Look up an address property in a node and return it as an address. 195 * The property must hold either one address with no trailing data or 196 * one address with a length. This is only tested on 32-bit machines. 197 * 198 * @param blob FDT blob 199 * @param node node to examine 200 * @param prop_name name of property to find 201 * @return address, if found, or FDT_ADDR_T_NONE if not 202 */ 203 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 204 const char *prop_name); 205 206 /** 207 * Look up an address property in a node and return it as an address. 208 * The property must hold one address with a length. This is only tested 209 * on 32-bit machines. 210 * 211 * @param blob FDT blob 212 * @param node node to examine 213 * @param prop_name name of property to find 214 * @return address, if found, or FDT_ADDR_T_NONE if not 215 */ 216 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 217 const char *prop_name, fdt_size_t *sizep); 218 219 /** 220 * Look up a 32-bit integer property in a node and return it. The property 221 * must have at least 4 bytes of data. The value of the first cell is 222 * returned. 223 * 224 * @param blob FDT blob 225 * @param node node to examine 226 * @param prop_name name of property to find 227 * @param default_val default value to return if the property is not found 228 * @return integer value, if found, or default_val if not 229 */ 230 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 231 s32 default_val); 232 233 /** 234 * Look up a 64-bit integer property in a node and return it. The property 235 * must have at least 8 bytes of data (2 cells). The first two cells are 236 * concatenated to form a 8 bytes value, where the first cell is top half and 237 * the second cell is bottom half. 238 * 239 * @param blob FDT blob 240 * @param node node to examine 241 * @param prop_name name of property to find 242 * @param default_val default value to return if the property is not found 243 * @return integer value, if found, or default_val if not 244 */ 245 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 246 uint64_t default_val); 247 248 /** 249 * Checks whether a node is enabled. 250 * This looks for a 'status' property. If this exists, then returns 1 if 251 * the status is 'ok' and 0 otherwise. If there is no status property, 252 * it returns 1 on the assumption that anything mentioned should be enabled 253 * by default. 254 * 255 * @param blob FDT blob 256 * @param node node to examine 257 * @return integer value 0 (not enabled) or 1 (enabled) 258 */ 259 int fdtdec_get_is_enabled(const void *blob, int node); 260 261 /** 262 * Make sure we have a valid fdt available to control U-Boot. 263 * 264 * If not, a message is printed to the console if the console is ready. 265 * 266 * @return 0 if all ok, -1 if not 267 */ 268 int fdtdec_prepare_fdt(void); 269 270 /** 271 * Checks that we have a valid fdt available to control U-Boot. 272 273 * However, if not then for the moment nothing is done, since this function 274 * is called too early to panic(). 275 * 276 * @returns 0 277 */ 278 int fdtdec_check_fdt(void); 279 280 /** 281 * Find the nodes for a peripheral and return a list of them in the correct 282 * order. This is used to enumerate all the peripherals of a certain type. 283 * 284 * To use this, optionally set up a /aliases node with alias properties for 285 * a peripheral. For example, for usb you could have: 286 * 287 * aliases { 288 * usb0 = "/ehci@c5008000"; 289 * usb1 = "/ehci@c5000000"; 290 * }; 291 * 292 * Pass "usb" as the name to this function and will return a list of two 293 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 294 * 295 * All nodes returned will match the compatible ID, as it is assumed that 296 * all peripherals use the same driver. 297 * 298 * If no alias node is found, then the node list will be returned in the 299 * order found in the fdt. If the aliases mention a node which doesn't 300 * exist, then this will be ignored. If nodes are found with no aliases, 301 * they will be added in any order. 302 * 303 * If there is a gap in the aliases, then this function return a 0 node at 304 * that position. The return value will also count these gaps. 305 * 306 * This function checks node properties and will not return nodes which are 307 * marked disabled (status = "disabled"). 308 * 309 * @param blob FDT blob to use 310 * @param name Root name of alias to search for 311 * @param id Compatible ID to look for 312 * @param node_list Place to put list of found nodes 313 * @param maxcount Maximum number of nodes to find 314 * @return number of nodes found on success, FTD_ERR_... on error 315 */ 316 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 317 enum fdt_compat_id id, int *node_list, int maxcount); 318 319 /* 320 * This function is similar to fdtdec_find_aliases_for_id() except that it 321 * adds to the node_list that is passed in. Any 0 elements are considered 322 * available for allocation - others are considered already used and are 323 * skipped. 324 * 325 * You can use this by calling fdtdec_find_aliases_for_id() with an 326 * uninitialised array, then setting the elements that are returned to -1, 327 * say, then calling this function, perhaps with a different compat id. 328 * Any elements you get back that are >0 are new nodes added by the call 329 * to this function. 330 * 331 * Note that if you have some nodes with aliases and some without, you are 332 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 333 * one compat_id may fill in positions for which you have aliases defined 334 * for another compat_id. When you later call *this* function with the second 335 * compat_id, the alias positions may already be used. A debug warning may 336 * be generated in this case, but it is safest to define aliases for all 337 * nodes when you care about the ordering. 338 */ 339 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 340 enum fdt_compat_id id, int *node_list, int maxcount); 341 342 /* 343 * Get the name for a compatible ID 344 * 345 * @param id Compatible ID to look for 346 * @return compatible string for that id 347 */ 348 const char *fdtdec_get_compatible(enum fdt_compat_id id); 349 350 /* Look up a phandle and follow it to its node. Then return the offset 351 * of that node. 352 * 353 * @param blob FDT blob 354 * @param node node to examine 355 * @param prop_name name of property to find 356 * @return node offset if found, -ve error code on error 357 */ 358 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 359 360 /** 361 * Look up a property in a node and return its contents in an integer 362 * array of given length. The property must have at least enough data for 363 * the array (4*count bytes). It may have more, but this will be ignored. 364 * 365 * @param blob FDT blob 366 * @param node node to examine 367 * @param prop_name name of property to find 368 * @param array array to fill with data 369 * @param count number of array elements 370 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 371 * or -FDT_ERR_BADLAYOUT if not enough data 372 */ 373 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 374 u32 *array, int count); 375 376 /** 377 * Look up a property in a node and return a pointer to its contents as a 378 * unsigned int array of given length. The property must have at least enough 379 * data for the array ('count' cells). It may have more, but this will be 380 * ignored. The data is not copied. 381 * 382 * Note that you must access elements of the array with fdt32_to_cpu(), 383 * since the elements will be big endian even on a little endian machine. 384 * 385 * @param blob FDT blob 386 * @param node node to examine 387 * @param prop_name name of property to find 388 * @param count number of array elements 389 * @return pointer to array if found, or NULL if the property is not 390 * found or there is not enough data 391 */ 392 const u32 *fdtdec_locate_array(const void *blob, int node, 393 const char *prop_name, int count); 394 395 /** 396 * Look up a boolean property in a node and return it. 397 * 398 * A boolean properly is true if present in the device tree and false if not 399 * present, regardless of its value. 400 * 401 * @param blob FDT blob 402 * @param node node to examine 403 * @param prop_name name of property to find 404 * @return 1 if the properly is present; 0 if it isn't present 405 */ 406 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 407 408 /** 409 * Decode a single GPIOs from an FDT. 410 * 411 * If the property is not found, then the GPIO structure will still be 412 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 413 * provide optional GPIOs. 414 * 415 * @param blob FDT blob to use 416 * @param node Node to look at 417 * @param prop_name Node property name 418 * @param gpio gpio elements to fill from FDT 419 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 420 */ 421 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 422 struct fdt_gpio_state *gpio); 423 424 /** 425 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 426 * terminating item. 427 * 428 * @param blob FDT blob to use 429 * @param node Node to look at 430 * @param prop_name Node property name 431 * @param gpio Array of gpio elements to fill from FDT. This will be 432 * untouched if either 0 or an error is returned 433 * @param max_count Maximum number of elements allowed 434 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 435 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 436 */ 437 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 438 struct fdt_gpio_state *gpio, int max_count); 439 440 /** 441 * Set up a GPIO pin according to the provided gpio information. At present this 442 * just requests the GPIO. 443 * 444 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 445 * deal with optional GPIOs. 446 * 447 * @param gpio GPIO info to use for set up 448 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 449 */ 450 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 451 452 /** 453 * Look in the FDT for a config item with the given name and return its value 454 * as a 32-bit integer. The property must have at least 4 bytes of data. The 455 * value of the first cell is returned. 456 * 457 * @param blob FDT blob to use 458 * @param prop_name Node property name 459 * @param default_val default value to return if the property is not found 460 * @return integer value, if found, or default_val if not 461 */ 462 int fdtdec_get_config_int(const void *blob, const char *prop_name, 463 int default_val); 464 465 /** 466 * Look in the FDT for a config item with the given name 467 * and return whether it exists. 468 * 469 * @param blob FDT blob 470 * @param prop_name property name to look up 471 * @return 1, if it exists, or 0 if not 472 */ 473 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 474 475 /** 476 * Look in the FDT for a config item with the given name and return its value 477 * as a string. 478 * 479 * @param blob FDT blob 480 * @param prop_name property name to look up 481 * @returns property string, NULL on error. 482 */ 483 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 484 485 /* 486 * Look up a property in a node and return its contents in a byte 487 * array of given length. The property must have at least enough data for 488 * the array (count bytes). It may have more, but this will be ignored. 489 * 490 * @param blob FDT blob 491 * @param node node to examine 492 * @param prop_name name of property to find 493 * @param array array to fill with data 494 * @param count number of array elements 495 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 496 * or -FDT_ERR_BADLAYOUT if not enough data 497 */ 498 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 499 u8 *array, int count); 500 501 /** 502 * Look up a property in a node and return a pointer to its contents as a 503 * byte array of given length. The property must have at least enough data 504 * for the array (count bytes). It may have more, but this will be ignored. 505 * The data is not copied. 506 * 507 * @param blob FDT blob 508 * @param node node to examine 509 * @param prop_name name of property to find 510 * @param count number of array elements 511 * @return pointer to byte array if found, or NULL if the property is not 512 * found or there is not enough data 513 */ 514 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 515 const char *prop_name, int count); 516 517 /** 518 * Look up a property in a node which contains a memory region address and 519 * size. Then return a pointer to this address. 520 * 521 * The property must hold one address with a length. This is only tested on 522 * 32-bit machines. 523 * 524 * @param blob FDT blob 525 * @param node node to examine 526 * @param prop_name name of property to find 527 * @param ptrp returns pointer to region, or NULL if no address 528 * @param size returns size of region 529 * @return 0 if ok, -1 on error (propery not found) 530 */ 531 int fdtdec_decode_region(const void *blob, int node, 532 const char *prop_name, void **ptrp, size_t *size); 533 #endif 534