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_TEGRA30_USB, /* Tegra30 USB port */ 68 COMPAT_NVIDIA_TEGRA114_USB, /* Tegra114 USB port */ 69 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */ 70 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */ 71 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */ 72 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */ 73 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */ 74 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */ 75 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */ 76 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */ 77 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */ 78 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */ 79 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */ 80 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */ 81 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */ 82 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */ 83 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 84 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 85 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 86 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 87 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 88 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 89 COMPAT_GOOGLE_CROS_EC, /* Google CROS_EC Protocol */ 90 COMPAT_GOOGLE_CROS_EC_KEYB, /* Google CROS_EC Keyboard */ 91 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 92 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 93 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */ 94 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */ 95 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */ 96 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */ 97 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */ 98 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 99 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 100 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 101 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 102 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */ 103 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */ 104 105 COMPAT_COUNT, 106 }; 107 108 /* GPIOs are numbered from 0 */ 109 enum { 110 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 111 112 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 113 }; 114 115 /* This is the state of a GPIO pin as defined by the fdt */ 116 struct fdt_gpio_state { 117 const char *name; /* name of the fdt property defining this */ 118 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 119 u8 flags; /* FDT_GPIO_... flags */ 120 }; 121 122 /* This tells us whether a fdt_gpio_state record is valid or not */ 123 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 124 125 /** 126 * Read the GPIO taking into account the polarity of the pin. 127 * 128 * @param gpio pointer to the decoded gpio 129 * @return value of the gpio if successful, < 0 if unsuccessful 130 */ 131 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 132 133 /** 134 * Write the GPIO taking into account the polarity of the pin. 135 * 136 * @param gpio pointer to the decoded gpio 137 * @return 0 if successful 138 */ 139 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 140 141 /** 142 * Find the next numbered alias for a peripheral. This is used to enumerate 143 * all the peripherals of a certain type. 144 * 145 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 146 * this function will return a pointer to the node the alias points to, and 147 * then update *upto to 1. Next time you call this function, the next node 148 * will be returned. 149 * 150 * All nodes returned will match the compatible ID, as it is assumed that 151 * all peripherals use the same driver. 152 * 153 * @param blob FDT blob to use 154 * @param name Root name of alias to search for 155 * @param id Compatible ID to look for 156 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 157 */ 158 int fdtdec_next_alias(const void *blob, const char *name, 159 enum fdt_compat_id id, int *upto); 160 161 /** 162 * Find the compatible ID for a given node. 163 * 164 * Generally each node has at least one compatible string attached to it. 165 * This function looks through our list of known compatible strings and 166 * returns the corresponding ID which matches the compatible string. 167 * 168 * @param blob FDT blob to use 169 * @param node Node containing compatible string to find 170 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 171 */ 172 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 173 174 /** 175 * Find the next compatible node for a peripheral. 176 * 177 * Do the first call with node = 0. This function will return a pointer to 178 * the next compatible node. Next time you call this function, pass the 179 * value returned, 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 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 185 */ 186 int fdtdec_next_compatible(const void *blob, int node, 187 enum fdt_compat_id id); 188 189 /** 190 * Find the next compatible subnode for a peripheral. 191 * 192 * Do the first call with node set to the parent and depth = 0. This 193 * function will return the offset of the next compatible node. Next time 194 * you call this function, pass the node value returned last time, with 195 * depth unchanged, and the next node will be provided. 196 * 197 * @param blob FDT blob to use 198 * @param node Start node for search 199 * @param id Compatible ID to look for (enum fdt_compat_id) 200 * @param depthp Current depth (set to 0 before first call) 201 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 202 */ 203 int fdtdec_next_compatible_subnode(const void *blob, int node, 204 enum fdt_compat_id id, int *depthp); 205 206 /** 207 * Look up an address property in a node and return it as an address. 208 * The property must hold either one address with no trailing data or 209 * one address with a length. This is only tested 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(const void *blob, int node, 217 const char *prop_name); 218 219 /** 220 * Look up an address property in a node and return it as an address. 221 * The property must hold one address with a length. This is only tested 222 * on 32-bit machines. 223 * 224 * @param blob FDT blob 225 * @param node node to examine 226 * @param prop_name name of property to find 227 * @return address, if found, or FDT_ADDR_T_NONE if not 228 */ 229 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 230 const char *prop_name, fdt_size_t *sizep); 231 232 /** 233 * Look up a 32-bit integer property in a node and return it. The property 234 * must have at least 4 bytes of data. The value of the first cell is 235 * returned. 236 * 237 * @param blob FDT blob 238 * @param node node to examine 239 * @param prop_name name of property to find 240 * @param default_val default value to return if the property is not found 241 * @return integer value, if found, or default_val if not 242 */ 243 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 244 s32 default_val); 245 246 /** 247 * Look up a 64-bit integer property in a node and return it. The property 248 * must have at least 8 bytes of data (2 cells). The first two cells are 249 * concatenated to form a 8 bytes value, where the first cell is top half and 250 * the second cell is bottom half. 251 * 252 * @param blob FDT blob 253 * @param node node to examine 254 * @param prop_name name of property to find 255 * @param default_val default value to return if the property is not found 256 * @return integer value, if found, or default_val if not 257 */ 258 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 259 uint64_t default_val); 260 261 /** 262 * Checks whether a node is enabled. 263 * This looks for a 'status' property. If this exists, then returns 1 if 264 * the status is 'ok' and 0 otherwise. If there is no status property, 265 * it returns 1 on the assumption that anything mentioned should be enabled 266 * by default. 267 * 268 * @param blob FDT blob 269 * @param node node to examine 270 * @return integer value 0 (not enabled) or 1 (enabled) 271 */ 272 int fdtdec_get_is_enabled(const void *blob, int node); 273 274 /** 275 * Make sure we have a valid fdt available to control U-Boot. 276 * 277 * If not, a message is printed to the console if the console is ready. 278 * 279 * @return 0 if all ok, -1 if not 280 */ 281 int fdtdec_prepare_fdt(void); 282 283 /** 284 * Checks that we have a valid fdt available to control U-Boot. 285 286 * However, if not then for the moment nothing is done, since this function 287 * is called too early to panic(). 288 * 289 * @returns 0 290 */ 291 int fdtdec_check_fdt(void); 292 293 /** 294 * Find the nodes for a peripheral and return a list of them in the correct 295 * order. This is used to enumerate all the peripherals of a certain type. 296 * 297 * To use this, optionally set up a /aliases node with alias properties for 298 * a peripheral. For example, for usb you could have: 299 * 300 * aliases { 301 * usb0 = "/ehci@c5008000"; 302 * usb1 = "/ehci@c5000000"; 303 * }; 304 * 305 * Pass "usb" as the name to this function and will return a list of two 306 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 307 * 308 * All nodes returned will match the compatible ID, as it is assumed that 309 * all peripherals use the same driver. 310 * 311 * If no alias node is found, then the node list will be returned in the 312 * order found in the fdt. If the aliases mention a node which doesn't 313 * exist, then this will be ignored. If nodes are found with no aliases, 314 * they will be added in any order. 315 * 316 * If there is a gap in the aliases, then this function return a 0 node at 317 * that position. The return value will also count these gaps. 318 * 319 * This function checks node properties and will not return nodes which are 320 * marked disabled (status = "disabled"). 321 * 322 * @param blob FDT blob to use 323 * @param name Root name of alias to search for 324 * @param id Compatible ID to look for 325 * @param node_list Place to put list of found nodes 326 * @param maxcount Maximum number of nodes to find 327 * @return number of nodes found on success, FTD_ERR_... on error 328 */ 329 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 330 enum fdt_compat_id id, int *node_list, int maxcount); 331 332 /* 333 * This function is similar to fdtdec_find_aliases_for_id() except that it 334 * adds to the node_list that is passed in. Any 0 elements are considered 335 * available for allocation - others are considered already used and are 336 * skipped. 337 * 338 * You can use this by calling fdtdec_find_aliases_for_id() with an 339 * uninitialised array, then setting the elements that are returned to -1, 340 * say, then calling this function, perhaps with a different compat id. 341 * Any elements you get back that are >0 are new nodes added by the call 342 * to this function. 343 * 344 * Note that if you have some nodes with aliases and some without, you are 345 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 346 * one compat_id may fill in positions for which you have aliases defined 347 * for another compat_id. When you later call *this* function with the second 348 * compat_id, the alias positions may already be used. A debug warning may 349 * be generated in this case, but it is safest to define aliases for all 350 * nodes when you care about the ordering. 351 */ 352 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 353 enum fdt_compat_id id, int *node_list, int maxcount); 354 355 /* 356 * Get the name for a compatible ID 357 * 358 * @param id Compatible ID to look for 359 * @return compatible string for that id 360 */ 361 const char *fdtdec_get_compatible(enum fdt_compat_id id); 362 363 /* Look up a phandle and follow it to its node. Then return the offset 364 * of that node. 365 * 366 * @param blob FDT blob 367 * @param node node to examine 368 * @param prop_name name of property to find 369 * @return node offset if found, -ve error code on error 370 */ 371 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 372 373 /** 374 * Look up a property in a node and return its contents in an integer 375 * array of given length. The property must have at least enough data for 376 * the array (4*count bytes). It may have more, but this will be ignored. 377 * 378 * @param blob FDT blob 379 * @param node node to examine 380 * @param prop_name name of property to find 381 * @param array array to fill with data 382 * @param count number of array elements 383 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 384 * or -FDT_ERR_BADLAYOUT if not enough data 385 */ 386 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 387 u32 *array, int count); 388 389 /** 390 * Look up a property in a node and return a pointer to its contents as a 391 * unsigned int array of given length. The property must have at least enough 392 * data for the array ('count' cells). It may have more, but this will be 393 * ignored. The data is not copied. 394 * 395 * Note that you must access elements of the array with fdt32_to_cpu(), 396 * since the elements will be big endian even on a little endian machine. 397 * 398 * @param blob FDT blob 399 * @param node node to examine 400 * @param prop_name name of property to find 401 * @param count number of array elements 402 * @return pointer to array if found, or NULL if the property is not 403 * found or there is not enough data 404 */ 405 const u32 *fdtdec_locate_array(const void *blob, int node, 406 const char *prop_name, int count); 407 408 /** 409 * Look up a boolean property in a node and return it. 410 * 411 * A boolean properly is true if present in the device tree and false if not 412 * present, regardless of its value. 413 * 414 * @param blob FDT blob 415 * @param node node to examine 416 * @param prop_name name of property to find 417 * @return 1 if the properly is present; 0 if it isn't present 418 */ 419 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 420 421 /** 422 * Decode a single GPIOs from an FDT. 423 * 424 * If the property is not found, then the GPIO structure will still be 425 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 426 * provide optional GPIOs. 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 gpio elements to fill from FDT 432 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 433 */ 434 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 435 struct fdt_gpio_state *gpio); 436 437 /** 438 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 439 * terminating item. 440 * 441 * @param blob FDT blob to use 442 * @param node Node to look at 443 * @param prop_name Node property name 444 * @param gpio Array of gpio elements to fill from FDT. This will be 445 * untouched if either 0 or an error is returned 446 * @param max_count Maximum number of elements allowed 447 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 448 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 449 */ 450 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 451 struct fdt_gpio_state *gpio, int max_count); 452 453 /** 454 * Set up a GPIO pin according to the provided gpio information. At present this 455 * just requests the GPIO. 456 * 457 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 458 * deal with optional GPIOs. 459 * 460 * @param gpio GPIO info to use for set up 461 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 462 */ 463 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 464 465 /** 466 * Look in the FDT for a config item with the given name and return its value 467 * as a 32-bit integer. The property must have at least 4 bytes of data. The 468 * value of the first cell is returned. 469 * 470 * @param blob FDT blob to use 471 * @param prop_name Node property name 472 * @param default_val default value to return if the property is not found 473 * @return integer value, if found, or default_val if not 474 */ 475 int fdtdec_get_config_int(const void *blob, const char *prop_name, 476 int default_val); 477 478 /** 479 * Look in the FDT for a config item with the given name 480 * and return whether it exists. 481 * 482 * @param blob FDT blob 483 * @param prop_name property name to look up 484 * @return 1, if it exists, or 0 if not 485 */ 486 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 487 488 /** 489 * Look in the FDT for a config item with the given name and return its value 490 * as a string. 491 * 492 * @param blob FDT blob 493 * @param prop_name property name to look up 494 * @returns property string, NULL on error. 495 */ 496 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 497 498 /* 499 * Look up a property in a node and return its contents in a byte 500 * array of given length. The property must have at least enough data for 501 * the array (count bytes). It may have more, but this will be ignored. 502 * 503 * @param blob FDT blob 504 * @param node node to examine 505 * @param prop_name name of property to find 506 * @param array array to fill with data 507 * @param count number of array elements 508 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 509 * or -FDT_ERR_BADLAYOUT if not enough data 510 */ 511 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 512 u8 *array, int count); 513 514 /** 515 * Look up a property in a node and return a pointer to its contents as a 516 * byte array of given length. The property must have at least enough data 517 * for the array (count bytes). It may have more, but this will be ignored. 518 * The data is not copied. 519 * 520 * @param blob FDT blob 521 * @param node node to examine 522 * @param prop_name name of property to find 523 * @param count number of array elements 524 * @return pointer to byte array if found, or NULL if the property is not 525 * found or there is not enough data 526 */ 527 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 528 const char *prop_name, int count); 529 530 /** 531 * Look up a property in a node which contains a memory region address and 532 * size. Then return a pointer to this address. 533 * 534 * The property must hold one address with a length. This is only tested on 535 * 32-bit machines. 536 * 537 * @param blob FDT blob 538 * @param node node to examine 539 * @param prop_name name of property to find 540 * @param ptrp returns pointer to region, or NULL if no address 541 * @param size returns size of region 542 * @return 0 if ok, -1 on error (propery not found) 543 */ 544 int fdtdec_decode_region(const void *blob, int node, 545 const char *prop_name, void **ptrp, size_t *size); 546 #endif 547