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_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */ 85 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */ 86 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 87 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 88 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 89 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 90 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */ 91 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */ 92 93 COMPAT_COUNT, 94 }; 95 96 /* GPIOs are numbered from 0 */ 97 enum { 98 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 99 100 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 101 }; 102 103 /* This is the state of a GPIO pin as defined by the fdt */ 104 struct fdt_gpio_state { 105 const char *name; /* name of the fdt property defining this */ 106 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 107 u8 flags; /* FDT_GPIO_... flags */ 108 }; 109 110 /* This tells us whether a fdt_gpio_state record is valid or not */ 111 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 112 113 /** 114 * Read the GPIO taking into account the polarity of the pin. 115 * 116 * @param gpio pointer to the decoded gpio 117 * @return value of the gpio if successful, < 0 if unsuccessful 118 */ 119 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 120 121 /** 122 * Write the GPIO taking into account the polarity of the pin. 123 * 124 * @param gpio pointer to the decoded gpio 125 * @return 0 if successful 126 */ 127 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 128 129 /** 130 * Find the next numbered alias for a peripheral. This is used to enumerate 131 * all the peripherals of a certain type. 132 * 133 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 134 * this function will return a pointer to the node the alias points to, and 135 * then update *upto to 1. Next time you call this function, the next node 136 * will be returned. 137 * 138 * All nodes returned will match the compatible ID, as it is assumed that 139 * all peripherals use the same driver. 140 * 141 * @param blob FDT blob to use 142 * @param name Root name of alias to search for 143 * @param id Compatible ID to look for 144 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 145 */ 146 int fdtdec_next_alias(const void *blob, const char *name, 147 enum fdt_compat_id id, int *upto); 148 149 /** 150 * Find the compatible ID for a given node. 151 * 152 * Generally each node has at least one compatible string attached to it. 153 * This function looks through our list of known compatible strings and 154 * returns the corresponding ID which matches the compatible string. 155 * 156 * @param blob FDT blob to use 157 * @param node Node containing compatible string to find 158 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 159 */ 160 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 161 162 /** 163 * Find the next compatible node for a peripheral. 164 * 165 * Do the first call with node = 0. This function will return a pointer to 166 * the next compatible node. Next time you call this function, pass the 167 * value returned, and the next node will be provided. 168 * 169 * @param blob FDT blob to use 170 * @param node Start node for search 171 * @param id Compatible ID to look for (enum fdt_compat_id) 172 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 173 */ 174 int fdtdec_next_compatible(const void *blob, int node, 175 enum fdt_compat_id id); 176 177 /** 178 * Find the next compatible subnode for a peripheral. 179 * 180 * Do the first call with node set to the parent and depth = 0. This 181 * function will return the offset of the next compatible node. Next time 182 * you call this function, pass the node value returned last time, with 183 * depth unchanged, and the next node will be provided. 184 * 185 * @param blob FDT blob to use 186 * @param node Start node for search 187 * @param id Compatible ID to look for (enum fdt_compat_id) 188 * @param depthp Current depth (set to 0 before first call) 189 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 190 */ 191 int fdtdec_next_compatible_subnode(const void *blob, int node, 192 enum fdt_compat_id id, int *depthp); 193 194 /** 195 * Look up an address property in a node and return it as an address. 196 * The property must hold either one address with no trailing data or 197 * one address with a length. This is only tested on 32-bit machines. 198 * 199 * @param blob FDT blob 200 * @param node node to examine 201 * @param prop_name name of property to find 202 * @return address, if found, or FDT_ADDR_T_NONE if not 203 */ 204 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 205 const char *prop_name); 206 207 /** 208 * Look up an address property in a node and return it as an address. 209 * The property must hold one address with a length. This is only tested 210 * on 32-bit machines. 211 * 212 * @param blob FDT blob 213 * @param node node to examine 214 * @param prop_name name of property to find 215 * @return address, if found, or FDT_ADDR_T_NONE if not 216 */ 217 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 218 const char *prop_name, fdt_size_t *sizep); 219 220 /** 221 * Look up a 32-bit integer property in a node and return it. The property 222 * must have at least 4 bytes of data. The value of the first cell is 223 * returned. 224 * 225 * @param blob FDT blob 226 * @param node node to examine 227 * @param prop_name name of property to find 228 * @param default_val default value to return if the property is not found 229 * @return integer value, if found, or default_val if not 230 */ 231 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 232 s32 default_val); 233 234 /** 235 * Look up a 64-bit integer property in a node and return it. The property 236 * must have at least 8 bytes of data (2 cells). The first two cells are 237 * concatenated to form a 8 bytes value, where the first cell is top half and 238 * the second cell is bottom half. 239 * 240 * @param blob FDT blob 241 * @param node node to examine 242 * @param prop_name name of property to find 243 * @param default_val default value to return if the property is not found 244 * @return integer value, if found, or default_val if not 245 */ 246 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 247 uint64_t default_val); 248 249 /** 250 * Checks whether a node is enabled. 251 * This looks for a 'status' property. If this exists, then returns 1 if 252 * the status is 'ok' and 0 otherwise. If there is no status property, 253 * it returns 1 on the assumption that anything mentioned should be enabled 254 * by default. 255 * 256 * @param blob FDT blob 257 * @param node node to examine 258 * @return integer value 0 (not enabled) or 1 (enabled) 259 */ 260 int fdtdec_get_is_enabled(const void *blob, int node); 261 262 /** 263 * Make sure we have a valid fdt available to control U-Boot. 264 * 265 * If not, a message is printed to the console if the console is ready. 266 * 267 * @return 0 if all ok, -1 if not 268 */ 269 int fdtdec_prepare_fdt(void); 270 271 /** 272 * Checks that we have a valid fdt available to control U-Boot. 273 274 * However, if not then for the moment nothing is done, since this function 275 * is called too early to panic(). 276 * 277 * @returns 0 278 */ 279 int fdtdec_check_fdt(void); 280 281 /** 282 * Find the nodes for a peripheral and return a list of them in the correct 283 * order. This is used to enumerate all the peripherals of a certain type. 284 * 285 * To use this, optionally set up a /aliases node with alias properties for 286 * a peripheral. For example, for usb you could have: 287 * 288 * aliases { 289 * usb0 = "/ehci@c5008000"; 290 * usb1 = "/ehci@c5000000"; 291 * }; 292 * 293 * Pass "usb" as the name to this function and will return a list of two 294 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 295 * 296 * All nodes returned will match the compatible ID, as it is assumed that 297 * all peripherals use the same driver. 298 * 299 * If no alias node is found, then the node list will be returned in the 300 * order found in the fdt. If the aliases mention a node which doesn't 301 * exist, then this will be ignored. If nodes are found with no aliases, 302 * they will be added in any order. 303 * 304 * If there is a gap in the aliases, then this function return a 0 node at 305 * that position. The return value will also count these gaps. 306 * 307 * This function checks node properties and will not return nodes which are 308 * marked disabled (status = "disabled"). 309 * 310 * @param blob FDT blob to use 311 * @param name Root name of alias to search for 312 * @param id Compatible ID to look for 313 * @param node_list Place to put list of found nodes 314 * @param maxcount Maximum number of nodes to find 315 * @return number of nodes found on success, FTD_ERR_... on error 316 */ 317 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 318 enum fdt_compat_id id, int *node_list, int maxcount); 319 320 /* 321 * This function is similar to fdtdec_find_aliases_for_id() except that it 322 * adds to the node_list that is passed in. Any 0 elements are considered 323 * available for allocation - others are considered already used and are 324 * skipped. 325 * 326 * You can use this by calling fdtdec_find_aliases_for_id() with an 327 * uninitialised array, then setting the elements that are returned to -1, 328 * say, then calling this function, perhaps with a different compat id. 329 * Any elements you get back that are >0 are new nodes added by the call 330 * to this function. 331 * 332 * Note that if you have some nodes with aliases and some without, you are 333 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 334 * one compat_id may fill in positions for which you have aliases defined 335 * for another compat_id. When you later call *this* function with the second 336 * compat_id, the alias positions may already be used. A debug warning may 337 * be generated in this case, but it is safest to define aliases for all 338 * nodes when you care about the ordering. 339 */ 340 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 341 enum fdt_compat_id id, int *node_list, int maxcount); 342 343 /* 344 * Get the name for a compatible ID 345 * 346 * @param id Compatible ID to look for 347 * @return compatible string for that id 348 */ 349 const char *fdtdec_get_compatible(enum fdt_compat_id id); 350 351 /* Look up a phandle and follow it to its node. Then return the offset 352 * of that node. 353 * 354 * @param blob FDT blob 355 * @param node node to examine 356 * @param prop_name name of property to find 357 * @return node offset if found, -ve error code on error 358 */ 359 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 360 361 /** 362 * Look up a property in a node and return its contents in an integer 363 * array of given length. The property must have at least enough data for 364 * the array (4*count bytes). It may have more, but this will be ignored. 365 * 366 * @param blob FDT blob 367 * @param node node to examine 368 * @param prop_name name of property to find 369 * @param array array to fill with data 370 * @param count number of array elements 371 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 372 * or -FDT_ERR_BADLAYOUT if not enough data 373 */ 374 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 375 u32 *array, int count); 376 377 /** 378 * Look up a property in a node and return a pointer to its contents as a 379 * unsigned int array of given length. The property must have at least enough 380 * data for the array ('count' cells). It may have more, but this will be 381 * ignored. The data is not copied. 382 * 383 * Note that you must access elements of the array with fdt32_to_cpu(), 384 * since the elements will be big endian even on a little endian machine. 385 * 386 * @param blob FDT blob 387 * @param node node to examine 388 * @param prop_name name of property to find 389 * @param count number of array elements 390 * @return pointer to array if found, or NULL if the property is not 391 * found or there is not enough data 392 */ 393 const u32 *fdtdec_locate_array(const void *blob, int node, 394 const char *prop_name, int count); 395 396 /** 397 * Look up a boolean property in a node and return it. 398 * 399 * A boolean properly is true if present in the device tree and false if not 400 * present, regardless of its value. 401 * 402 * @param blob FDT blob 403 * @param node node to examine 404 * @param prop_name name of property to find 405 * @return 1 if the properly is present; 0 if it isn't present 406 */ 407 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 408 409 /** 410 * Decode a single GPIOs from an FDT. 411 * 412 * If the property is not found, then the GPIO structure will still be 413 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 414 * provide optional GPIOs. 415 * 416 * @param blob FDT blob to use 417 * @param node Node to look at 418 * @param prop_name Node property name 419 * @param gpio gpio elements to fill from FDT 420 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 421 */ 422 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 423 struct fdt_gpio_state *gpio); 424 425 /** 426 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 427 * terminating item. 428 * 429 * @param blob FDT blob to use 430 * @param node Node to look at 431 * @param prop_name Node property name 432 * @param gpio Array of gpio elements to fill from FDT. This will be 433 * untouched if either 0 or an error is returned 434 * @param max_count Maximum number of elements allowed 435 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 436 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 437 */ 438 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 439 struct fdt_gpio_state *gpio, int max_count); 440 441 /** 442 * Set up a GPIO pin according to the provided gpio information. At present this 443 * just requests the GPIO. 444 * 445 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 446 * deal with optional GPIOs. 447 * 448 * @param gpio GPIO info to use for set up 449 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 450 */ 451 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 452 453 /** 454 * Look in the FDT for a config item with the given name and return its value 455 * as a 32-bit integer. The property must have at least 4 bytes of data. The 456 * value of the first cell is returned. 457 * 458 * @param blob FDT blob to use 459 * @param prop_name Node property name 460 * @param default_val default value to return if the property is not found 461 * @return integer value, if found, or default_val if not 462 */ 463 int fdtdec_get_config_int(const void *blob, const char *prop_name, 464 int default_val); 465 466 /** 467 * Look in the FDT for a config item with the given name 468 * and return whether it exists. 469 * 470 * @param blob FDT blob 471 * @param prop_name property name to look up 472 * @return 1, if it exists, or 0 if not 473 */ 474 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 475 476 /** 477 * Look in the FDT for a config item with the given name and return its value 478 * as a string. 479 * 480 * @param blob FDT blob 481 * @param prop_name property name to look up 482 * @returns property string, NULL on error. 483 */ 484 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 485 486 /* 487 * Look up a property in a node and return its contents in a byte 488 * array of given length. The property must have at least enough data for 489 * the array (count bytes). It may have more, but this will be ignored. 490 * 491 * @param blob FDT blob 492 * @param node node to examine 493 * @param prop_name name of property to find 494 * @param array array to fill with data 495 * @param count number of array elements 496 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 497 * or -FDT_ERR_BADLAYOUT if not enough data 498 */ 499 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 500 u8 *array, int count); 501 502 /** 503 * Look up a property in a node and return a pointer to its contents as a 504 * byte array of given length. The property must have at least enough data 505 * for the array (count bytes). It may have more, but this will be ignored. 506 * The data is not copied. 507 * 508 * @param blob FDT blob 509 * @param node node to examine 510 * @param prop_name name of property to find 511 * @param count number of array elements 512 * @return pointer to byte array if found, or NULL if the property is not 513 * found or there is not enough data 514 */ 515 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 516 const char *prop_name, int count); 517 518 /** 519 * Look up a property in a node which contains a memory region address and 520 * size. Then return a pointer to this address. 521 * 522 * The property must hold one address with a length. This is only tested on 523 * 32-bit machines. 524 * 525 * @param blob FDT blob 526 * @param node node to examine 527 * @param prop_name name of property to find 528 * @param ptrp returns pointer to region, or NULL if no address 529 * @param size returns size of region 530 * @return 0 if ok, -1 on error (propery not found) 531 */ 532 int fdtdec_decode_region(const void *blob, int node, 533 const char *prop_name, void **ptrp, size_t *size); 534 #endif 535