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