1 /* 2 * Copyright (c) 2011 The Chromium OS Authors. 3 * See file CREDITS for list of people who contributed to this 4 * project. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 19 * MA 02111-1307 USA 20 */ 21 22 #ifndef __fdtdec_h 23 #define __fdtdec_h 24 25 /* 26 * This file contains convenience functions for decoding useful and 27 * enlightening information from FDTs. It is intended to be used by device 28 * drivers and board-specific code within U-Boot. It aims to reduce the 29 * amount of FDT munging required within U-Boot itself, so that driver code 30 * changes to support FDT are minimized. 31 */ 32 33 #include <libfdt.h> 34 35 /* 36 * A typedef for a physical address. Note that fdt data is always big 37 * endian even on a litle endian machine. 38 */ 39 #ifdef CONFIG_PHYS_64BIT 40 typedef u64 fdt_addr_t; 41 typedef u64 fdt_size_t; 42 #define FDT_ADDR_T_NONE (-1ULL) 43 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg) 44 #define fdt_size_to_cpu(reg) be64_to_cpu(reg) 45 #else 46 typedef u32 fdt_addr_t; 47 typedef u32 fdt_size_t; 48 #define FDT_ADDR_T_NONE (-1U) 49 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg) 50 #define fdt_size_to_cpu(reg) be32_to_cpu(reg) 51 #endif 52 53 /* Information obtained about memory from the FDT */ 54 struct fdt_memory { 55 fdt_addr_t start; 56 fdt_addr_t end; 57 }; 58 59 /** 60 * Compat types that we know about and for which we might have drivers. 61 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory 62 * within drivers. 63 */ 64 enum fdt_compat_id { 65 COMPAT_UNKNOWN, 66 COMPAT_NVIDIA_TEGRA20_USB, /* Tegra20 USB port */ 67 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */ 68 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */ 69 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */ 70 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */ 71 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */ 72 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */ 73 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */ 74 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */ 75 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */ 76 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */ 77 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */ 78 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */ 79 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */ 80 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */ 81 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 82 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 83 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 84 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 85 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 86 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 87 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 88 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 89 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */ 90 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */ 91 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */ 92 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 93 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 94 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 95 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 96 97 COMPAT_COUNT, 98 }; 99 100 /* GPIOs are numbered from 0 */ 101 enum { 102 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 103 104 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 105 }; 106 107 /* This is the state of a GPIO pin as defined by the fdt */ 108 struct fdt_gpio_state { 109 const char *name; /* name of the fdt property defining this */ 110 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 111 u8 flags; /* FDT_GPIO_... flags */ 112 }; 113 114 /* This tells us whether a fdt_gpio_state record is valid or not */ 115 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 116 117 /** 118 * Read the GPIO taking into account the polarity of the pin. 119 * 120 * @param gpio pointer to the decoded gpio 121 * @return value of the gpio if successful, < 0 if unsuccessful 122 */ 123 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 124 125 /** 126 * Write the GPIO taking into account the polarity of the pin. 127 * 128 * @param gpio pointer to the decoded gpio 129 * @return 0 if successful 130 */ 131 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 132 133 /** 134 * Find the next numbered alias for a peripheral. This is used to enumerate 135 * all the peripherals of a certain type. 136 * 137 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 138 * this function will return a pointer to the node the alias points to, and 139 * then update *upto to 1. Next time you call this function, the next node 140 * will be returned. 141 * 142 * All nodes returned will match the compatible ID, as it is assumed that 143 * all peripherals use the same driver. 144 * 145 * @param blob FDT blob to use 146 * @param name Root name of alias to search for 147 * @param id Compatible ID to look for 148 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 149 */ 150 int fdtdec_next_alias(const void *blob, const char *name, 151 enum fdt_compat_id id, int *upto); 152 153 /** 154 * Find the compatible ID for a given node. 155 * 156 * Generally each node has at least one compatible string attached to it. 157 * This function looks through our list of known compatible strings and 158 * returns the corresponding ID which matches the compatible string. 159 * 160 * @param blob FDT blob to use 161 * @param node Node containing compatible string to find 162 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 163 */ 164 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 165 166 /** 167 * Find the next compatible node for a peripheral. 168 * 169 * Do the first call with node = 0. This function will return a pointer to 170 * the next compatible node. Next time you call this function, pass the 171 * value returned, and the next node will be provided. 172 * 173 * @param blob FDT blob to use 174 * @param node Start node for search 175 * @param id Compatible ID to look for (enum fdt_compat_id) 176 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 177 */ 178 int fdtdec_next_compatible(const void *blob, int node, 179 enum fdt_compat_id id); 180 181 /** 182 * Find the next compatible subnode for a peripheral. 183 * 184 * Do the first call with node set to the parent and depth = 0. This 185 * function will return the offset of the next compatible node. Next time 186 * you call this function, pass the node value returned last time, with 187 * depth unchanged, and the next node will be provided. 188 * 189 * @param blob FDT blob to use 190 * @param node Start node for search 191 * @param id Compatible ID to look for (enum fdt_compat_id) 192 * @param depthp Current depth (set to 0 before first call) 193 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 194 */ 195 int fdtdec_next_compatible_subnode(const void *blob, int node, 196 enum fdt_compat_id id, int *depthp); 197 198 /** 199 * Look up an address property in a node and return it as an address. 200 * The property must hold either one address with no trailing data or 201 * one address with a length. This is only tested on 32-bit machines. 202 * 203 * @param blob FDT blob 204 * @param node node to examine 205 * @param prop_name name of property to find 206 * @return address, if found, or FDT_ADDR_T_NONE if not 207 */ 208 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 209 const char *prop_name); 210 211 /** 212 * Look up an address property in a node and return it as an address. 213 * The property must hold one address with a length. This is only tested 214 * on 32-bit machines. 215 * 216 * @param blob FDT blob 217 * @param node node to examine 218 * @param prop_name name of property to find 219 * @return address, if found, or FDT_ADDR_T_NONE if not 220 */ 221 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 222 const char *prop_name, fdt_size_t *sizep); 223 224 /** 225 * Look up a 32-bit integer property in a node and return it. The property 226 * must have at least 4 bytes of data. The value of the first cell is 227 * returned. 228 * 229 * @param blob FDT blob 230 * @param node node to examine 231 * @param prop_name name of property to find 232 * @param default_val default value to return if the property is not found 233 * @return integer value, if found, or default_val if not 234 */ 235 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 236 s32 default_val); 237 238 /** 239 * Look up a 64-bit integer property in a node and return it. The property 240 * must have at least 8 bytes of data (2 cells). The first two cells are 241 * concatenated to form a 8 bytes value, where the first cell is top half and 242 * the second cell is bottom half. 243 * 244 * @param blob FDT blob 245 * @param node node to examine 246 * @param prop_name name of property to find 247 * @param default_val default value to return if the property is not found 248 * @return integer value, if found, or default_val if not 249 */ 250 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 251 uint64_t default_val); 252 253 /** 254 * Checks whether a node is enabled. 255 * This looks for a 'status' property. If this exists, then returns 1 if 256 * the status is 'ok' and 0 otherwise. If there is no status property, 257 * it returns 1 on the assumption that anything mentioned should be enabled 258 * by default. 259 * 260 * @param blob FDT blob 261 * @param node node to examine 262 * @return integer value 0 (not enabled) or 1 (enabled) 263 */ 264 int fdtdec_get_is_enabled(const void *blob, int node); 265 266 /** 267 * Make sure we have a valid fdt available to control U-Boot. 268 * 269 * If not, a message is printed to the console if the console is ready. 270 * 271 * @return 0 if all ok, -1 if not 272 */ 273 int fdtdec_prepare_fdt(void); 274 275 /** 276 * Checks that we have a valid fdt available to control U-Boot. 277 278 * However, if not then for the moment nothing is done, since this function 279 * is called too early to panic(). 280 * 281 * @returns 0 282 */ 283 int fdtdec_check_fdt(void); 284 285 /** 286 * Find the nodes for a peripheral and return a list of them in the correct 287 * order. This is used to enumerate all the peripherals of a certain type. 288 * 289 * To use this, optionally set up a /aliases node with alias properties for 290 * a peripheral. For example, for usb you could have: 291 * 292 * aliases { 293 * usb0 = "/ehci@c5008000"; 294 * usb1 = "/ehci@c5000000"; 295 * }; 296 * 297 * Pass "usb" as the name to this function and will return a list of two 298 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 299 * 300 * All nodes returned will match the compatible ID, as it is assumed that 301 * all peripherals use the same driver. 302 * 303 * If no alias node is found, then the node list will be returned in the 304 * order found in the fdt. If the aliases mention a node which doesn't 305 * exist, then this will be ignored. If nodes are found with no aliases, 306 * they will be added in any order. 307 * 308 * If there is a gap in the aliases, then this function return a 0 node at 309 * that position. The return value will also count these gaps. 310 * 311 * This function checks node properties and will not return nodes which are 312 * marked disabled (status = "disabled"). 313 * 314 * @param blob FDT blob to use 315 * @param name Root name of alias to search for 316 * @param id Compatible ID to look for 317 * @param node_list Place to put list of found nodes 318 * @param maxcount Maximum number of nodes to find 319 * @return number of nodes found on success, FTD_ERR_... on error 320 */ 321 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 322 enum fdt_compat_id id, int *node_list, int maxcount); 323 324 /* 325 * This function is similar to fdtdec_find_aliases_for_id() except that it 326 * adds to the node_list that is passed in. Any 0 elements are considered 327 * available for allocation - others are considered already used and are 328 * skipped. 329 * 330 * You can use this by calling fdtdec_find_aliases_for_id() with an 331 * uninitialised array, then setting the elements that are returned to -1, 332 * say, then calling this function, perhaps with a different compat id. 333 * Any elements you get back that are >0 are new nodes added by the call 334 * to this function. 335 * 336 * Note that if you have some nodes with aliases and some without, you are 337 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 338 * one compat_id may fill in positions for which you have aliases defined 339 * for another compat_id. When you later call *this* function with the second 340 * compat_id, the alias positions may already be used. A debug warning may 341 * be generated in this case, but it is safest to define aliases for all 342 * nodes when you care about the ordering. 343 */ 344 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 345 enum fdt_compat_id id, int *node_list, int maxcount); 346 347 /* 348 * Get the name for a compatible ID 349 * 350 * @param id Compatible ID to look for 351 * @return compatible string for that id 352 */ 353 const char *fdtdec_get_compatible(enum fdt_compat_id id); 354 355 /* Look up a phandle and follow it to its node. Then return the offset 356 * of that node. 357 * 358 * @param blob FDT blob 359 * @param node node to examine 360 * @param prop_name name of property to find 361 * @return node offset if found, -ve error code on error 362 */ 363 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 364 365 /** 366 * Look up a property in a node and return its contents in an integer 367 * array of given length. The property must have at least enough data for 368 * the array (4*count bytes). It may have more, but this will be ignored. 369 * 370 * @param blob FDT blob 371 * @param node node to examine 372 * @param prop_name name of property to find 373 * @param array array to fill with data 374 * @param count number of array elements 375 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 376 * or -FDT_ERR_BADLAYOUT if not enough data 377 */ 378 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 379 u32 *array, int count); 380 381 /** 382 * Look up a property in a node and return a pointer to its contents as a 383 * unsigned int array of given length. The property must have at least enough 384 * data for the array ('count' cells). It may have more, but this will be 385 * ignored. The data is not copied. 386 * 387 * Note that you must access elements of the array with fdt32_to_cpu(), 388 * since the elements will be big endian even on a little endian machine. 389 * 390 * @param blob FDT blob 391 * @param node node to examine 392 * @param prop_name name of property to find 393 * @param count number of array elements 394 * @return pointer to array if found, or NULL if the property is not 395 * found or there is not enough data 396 */ 397 const u32 *fdtdec_locate_array(const void *blob, int node, 398 const char *prop_name, int count); 399 400 /** 401 * Look up a boolean property in a node and return it. 402 * 403 * A boolean properly is true if present in the device tree and false if not 404 * present, regardless of its value. 405 * 406 * @param blob FDT blob 407 * @param node node to examine 408 * @param prop_name name of property to find 409 * @return 1 if the properly is present; 0 if it isn't present 410 */ 411 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 412 413 /** 414 * Decode a single GPIOs from an FDT. 415 * 416 * If the property is not found, then the GPIO structure will still be 417 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 418 * provide optional GPIOs. 419 * 420 * @param blob FDT blob to use 421 * @param node Node to look at 422 * @param prop_name Node property name 423 * @param gpio gpio elements to fill from FDT 424 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 425 */ 426 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 427 struct fdt_gpio_state *gpio); 428 429 /** 430 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 431 * terminating item. 432 * 433 * @param blob FDT blob to use 434 * @param node Node to look at 435 * @param prop_name Node property name 436 * @param gpio Array of gpio elements to fill from FDT. This will be 437 * untouched if either 0 or an error is returned 438 * @param max_count Maximum number of elements allowed 439 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 440 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 441 */ 442 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 443 struct fdt_gpio_state *gpio, int max_count); 444 445 /** 446 * Set up a GPIO pin according to the provided gpio information. At present this 447 * just requests the GPIO. 448 * 449 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 450 * deal with optional GPIOs. 451 * 452 * @param gpio GPIO info to use for set up 453 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 454 */ 455 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 456 457 /** 458 * Look in the FDT for a config item with the given name and return its value 459 * as a 32-bit integer. The property must have at least 4 bytes of data. The 460 * value of the first cell is returned. 461 * 462 * @param blob FDT blob to use 463 * @param prop_name Node property name 464 * @param default_val default value to return if the property is not found 465 * @return integer value, if found, or default_val if not 466 */ 467 int fdtdec_get_config_int(const void *blob, const char *prop_name, 468 int default_val); 469 470 /** 471 * Look in the FDT for a config item with the given name 472 * and return whether it exists. 473 * 474 * @param blob FDT blob 475 * @param prop_name property name to look up 476 * @return 1, if it exists, or 0 if not 477 */ 478 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 479 480 /** 481 * Look in the FDT for a config item with the given name and return its value 482 * as a string. 483 * 484 * @param blob FDT blob 485 * @param prop_name property name to look up 486 * @returns property string, NULL on error. 487 */ 488 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 489 490 /* 491 * Look up a property in a node and return its contents in a byte 492 * array of given length. The property must have at least enough data for 493 * the array (count bytes). It may have more, but this will be ignored. 494 * 495 * @param blob FDT blob 496 * @param node node to examine 497 * @param prop_name name of property to find 498 * @param array array to fill with data 499 * @param count number of array elements 500 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 501 * or -FDT_ERR_BADLAYOUT if not enough data 502 */ 503 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 504 u8 *array, int count); 505 506 /** 507 * Look up a property in a node and return a pointer to its contents as a 508 * byte array of given length. The property must have at least enough data 509 * for the array (count bytes). It may have more, but this will be ignored. 510 * The data is not copied. 511 * 512 * @param blob FDT blob 513 * @param node node to examine 514 * @param prop_name name of property to find 515 * @param count number of array elements 516 * @return pointer to byte array if found, or NULL if the property is not 517 * found or there is not enough data 518 */ 519 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 520 const char *prop_name, int count); 521 522 /** 523 * Look up a property in a node which contains a memory region address and 524 * size. Then return a pointer to this address. 525 * 526 * The property must hold one address with a length. This is only tested on 527 * 32-bit machines. 528 * 529 * @param blob FDT blob 530 * @param node node to examine 531 * @param prop_name name of property to find 532 * @param ptrp returns pointer to region, or NULL if no address 533 * @param size returns size of region 534 * @return 0 if ok, -1 on error (propery not found) 535 */ 536 int fdtdec_decode_region(const void *blob, int node, 537 const char *prop_name, void **ptrp, size_t *size); 538 #endif 539