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 */ 103 104 COMPAT_COUNT, 105 }; 106 107 /* GPIOs are numbered from 0 */ 108 enum { 109 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 110 111 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 112 }; 113 114 /* This is the state of a GPIO pin as defined by the fdt */ 115 struct fdt_gpio_state { 116 const char *name; /* name of the fdt property defining this */ 117 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 118 u8 flags; /* FDT_GPIO_... flags */ 119 }; 120 121 /* This tells us whether a fdt_gpio_state record is valid or not */ 122 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 123 124 /** 125 * Read the GPIO taking into account the polarity of the pin. 126 * 127 * @param gpio pointer to the decoded gpio 128 * @return value of the gpio if successful, < 0 if unsuccessful 129 */ 130 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 131 132 /** 133 * Write the GPIO taking into account the polarity of the pin. 134 * 135 * @param gpio pointer to the decoded gpio 136 * @return 0 if successful 137 */ 138 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 139 140 /** 141 * Find the next numbered alias for a peripheral. This is used to enumerate 142 * all the peripherals of a certain type. 143 * 144 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 145 * this function will return a pointer to the node the alias points to, and 146 * then update *upto to 1. Next time you call this function, the next node 147 * will be returned. 148 * 149 * All nodes returned will match the compatible ID, as it is assumed that 150 * all peripherals use the same driver. 151 * 152 * @param blob FDT blob to use 153 * @param name Root name of alias to search for 154 * @param id Compatible ID to look for 155 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 156 */ 157 int fdtdec_next_alias(const void *blob, const char *name, 158 enum fdt_compat_id id, int *upto); 159 160 /** 161 * Find the compatible ID for a given node. 162 * 163 * Generally each node has at least one compatible string attached to it. 164 * This function looks through our list of known compatible strings and 165 * returns the corresponding ID which matches the compatible string. 166 * 167 * @param blob FDT blob to use 168 * @param node Node containing compatible string to find 169 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 170 */ 171 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 172 173 /** 174 * Find the next compatible node for a peripheral. 175 * 176 * Do the first call with node = 0. This function will return a pointer to 177 * the next compatible node. Next time you call this function, pass the 178 * value returned, 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 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 184 */ 185 int fdtdec_next_compatible(const void *blob, int node, 186 enum fdt_compat_id id); 187 188 /** 189 * Find the next compatible subnode for a peripheral. 190 * 191 * Do the first call with node set to the parent and depth = 0. This 192 * function will return the offset of the next compatible node. Next time 193 * you call this function, pass the node value returned last time, with 194 * depth unchanged, and the next node will be provided. 195 * 196 * @param blob FDT blob to use 197 * @param node Start node for search 198 * @param id Compatible ID to look for (enum fdt_compat_id) 199 * @param depthp Current depth (set to 0 before first call) 200 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 201 */ 202 int fdtdec_next_compatible_subnode(const void *blob, int node, 203 enum fdt_compat_id id, int *depthp); 204 205 /** 206 * Look up an address property in a node and return it as an address. 207 * The property must hold either one address with no trailing data or 208 * one address with a length. This is only tested on 32-bit machines. 209 * 210 * @param blob FDT blob 211 * @param node node to examine 212 * @param prop_name name of property to find 213 * @return address, if found, or FDT_ADDR_T_NONE if not 214 */ 215 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 216 const char *prop_name); 217 218 /** 219 * Look up an address property in a node and return it as an address. 220 * The property must hold one address with a length. This is only tested 221 * on 32-bit machines. 222 * 223 * @param blob FDT blob 224 * @param node node to examine 225 * @param prop_name name of property to find 226 * @return address, if found, or FDT_ADDR_T_NONE if not 227 */ 228 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 229 const char *prop_name, fdt_size_t *sizep); 230 231 /** 232 * Look up a 32-bit integer property in a node and return it. The property 233 * must have at least 4 bytes of data. The value of the first cell is 234 * returned. 235 * 236 * @param blob FDT blob 237 * @param node node to examine 238 * @param prop_name name of property to find 239 * @param default_val default value to return if the property is not found 240 * @return integer value, if found, or default_val if not 241 */ 242 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 243 s32 default_val); 244 245 /** 246 * Look up a 64-bit integer property in a node and return it. The property 247 * must have at least 8 bytes of data (2 cells). The first two cells are 248 * concatenated to form a 8 bytes value, where the first cell is top half and 249 * the second cell is bottom half. 250 * 251 * @param blob FDT blob 252 * @param node node to examine 253 * @param prop_name name of property to find 254 * @param default_val default value to return if the property is not found 255 * @return integer value, if found, or default_val if not 256 */ 257 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 258 uint64_t default_val); 259 260 /** 261 * Checks whether a node is enabled. 262 * This looks for a 'status' property. If this exists, then returns 1 if 263 * the status is 'ok' and 0 otherwise. If there is no status property, 264 * it returns 1 on the assumption that anything mentioned should be enabled 265 * by default. 266 * 267 * @param blob FDT blob 268 * @param node node to examine 269 * @return integer value 0 (not enabled) or 1 (enabled) 270 */ 271 int fdtdec_get_is_enabled(const void *blob, int node); 272 273 /** 274 * Make sure we have a valid fdt available to control U-Boot. 275 * 276 * If not, a message is printed to the console if the console is ready. 277 * 278 * @return 0 if all ok, -1 if not 279 */ 280 int fdtdec_prepare_fdt(void); 281 282 /** 283 * Checks that we have a valid fdt available to control U-Boot. 284 285 * However, if not then for the moment nothing is done, since this function 286 * is called too early to panic(). 287 * 288 * @returns 0 289 */ 290 int fdtdec_check_fdt(void); 291 292 /** 293 * Find the nodes for a peripheral and return a list of them in the correct 294 * order. This is used to enumerate all the peripherals of a certain type. 295 * 296 * To use this, optionally set up a /aliases node with alias properties for 297 * a peripheral. For example, for usb you could have: 298 * 299 * aliases { 300 * usb0 = "/ehci@c5008000"; 301 * usb1 = "/ehci@c5000000"; 302 * }; 303 * 304 * Pass "usb" as the name to this function and will return a list of two 305 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 306 * 307 * All nodes returned will match the compatible ID, as it is assumed that 308 * all peripherals use the same driver. 309 * 310 * If no alias node is found, then the node list will be returned in the 311 * order found in the fdt. If the aliases mention a node which doesn't 312 * exist, then this will be ignored. If nodes are found with no aliases, 313 * they will be added in any order. 314 * 315 * If there is a gap in the aliases, then this function return a 0 node at 316 * that position. The return value will also count these gaps. 317 * 318 * This function checks node properties and will not return nodes which are 319 * marked disabled (status = "disabled"). 320 * 321 * @param blob FDT blob to use 322 * @param name Root name of alias to search for 323 * @param id Compatible ID to look for 324 * @param node_list Place to put list of found nodes 325 * @param maxcount Maximum number of nodes to find 326 * @return number of nodes found on success, FTD_ERR_... on error 327 */ 328 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 329 enum fdt_compat_id id, int *node_list, int maxcount); 330 331 /* 332 * This function is similar to fdtdec_find_aliases_for_id() except that it 333 * adds to the node_list that is passed in. Any 0 elements are considered 334 * available for allocation - others are considered already used and are 335 * skipped. 336 * 337 * You can use this by calling fdtdec_find_aliases_for_id() with an 338 * uninitialised array, then setting the elements that are returned to -1, 339 * say, then calling this function, perhaps with a different compat id. 340 * Any elements you get back that are >0 are new nodes added by the call 341 * to this function. 342 * 343 * Note that if you have some nodes with aliases and some without, you are 344 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 345 * one compat_id may fill in positions for which you have aliases defined 346 * for another compat_id. When you later call *this* function with the second 347 * compat_id, the alias positions may already be used. A debug warning may 348 * be generated in this case, but it is safest to define aliases for all 349 * nodes when you care about the ordering. 350 */ 351 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 352 enum fdt_compat_id id, int *node_list, int maxcount); 353 354 /* 355 * Get the name for a compatible ID 356 * 357 * @param id Compatible ID to look for 358 * @return compatible string for that id 359 */ 360 const char *fdtdec_get_compatible(enum fdt_compat_id id); 361 362 /* Look up a phandle and follow it to its node. Then return the offset 363 * of that node. 364 * 365 * @param blob FDT blob 366 * @param node node to examine 367 * @param prop_name name of property to find 368 * @return node offset if found, -ve error code on error 369 */ 370 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 371 372 /** 373 * Look up a property in a node and return its contents in an integer 374 * array of given length. The property must have at least enough data for 375 * the array (4*count bytes). It may have more, but this will be ignored. 376 * 377 * @param blob FDT blob 378 * @param node node to examine 379 * @param prop_name name of property to find 380 * @param array array to fill with data 381 * @param count number of array elements 382 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 383 * or -FDT_ERR_BADLAYOUT if not enough data 384 */ 385 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 386 u32 *array, int count); 387 388 /** 389 * Look up a property in a node and return a pointer to its contents as a 390 * unsigned int array of given length. The property must have at least enough 391 * data for the array ('count' cells). It may have more, but this will be 392 * ignored. The data is not copied. 393 * 394 * Note that you must access elements of the array with fdt32_to_cpu(), 395 * since the elements will be big endian even on a little endian machine. 396 * 397 * @param blob FDT blob 398 * @param node node to examine 399 * @param prop_name name of property to find 400 * @param count number of array elements 401 * @return pointer to array if found, or NULL if the property is not 402 * found or there is not enough data 403 */ 404 const u32 *fdtdec_locate_array(const void *blob, int node, 405 const char *prop_name, int count); 406 407 /** 408 * Look up a boolean property in a node and return it. 409 * 410 * A boolean properly is true if present in the device tree and false if not 411 * present, regardless of its value. 412 * 413 * @param blob FDT blob 414 * @param node node to examine 415 * @param prop_name name of property to find 416 * @return 1 if the properly is present; 0 if it isn't present 417 */ 418 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 419 420 /** 421 * Decode a single GPIOs from an FDT. 422 * 423 * If the property is not found, then the GPIO structure will still be 424 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 425 * provide optional GPIOs. 426 * 427 * @param blob FDT blob to use 428 * @param node Node to look at 429 * @param prop_name Node property name 430 * @param gpio gpio elements to fill from FDT 431 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 432 */ 433 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 434 struct fdt_gpio_state *gpio); 435 436 /** 437 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 438 * terminating item. 439 * 440 * @param blob FDT blob to use 441 * @param node Node to look at 442 * @param prop_name Node property name 443 * @param gpio Array of gpio elements to fill from FDT. This will be 444 * untouched if either 0 or an error is returned 445 * @param max_count Maximum number of elements allowed 446 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 447 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 448 */ 449 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 450 struct fdt_gpio_state *gpio, int max_count); 451 452 /** 453 * Set up a GPIO pin according to the provided gpio information. At present this 454 * just requests the GPIO. 455 * 456 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 457 * deal with optional GPIOs. 458 * 459 * @param gpio GPIO info to use for set up 460 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 461 */ 462 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 463 464 /** 465 * Look in the FDT for a config item with the given name and return its value 466 * as a 32-bit integer. The property must have at least 4 bytes of data. The 467 * value of the first cell is returned. 468 * 469 * @param blob FDT blob to use 470 * @param prop_name Node property name 471 * @param default_val default value to return if the property is not found 472 * @return integer value, if found, or default_val if not 473 */ 474 int fdtdec_get_config_int(const void *blob, const char *prop_name, 475 int default_val); 476 477 /** 478 * Look in the FDT for a config item with the given name 479 * and return whether it exists. 480 * 481 * @param blob FDT blob 482 * @param prop_name property name to look up 483 * @return 1, if it exists, or 0 if not 484 */ 485 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 486 487 /** 488 * Look in the FDT for a config item with the given name and return its value 489 * as a string. 490 * 491 * @param blob FDT blob 492 * @param prop_name property name to look up 493 * @returns property string, NULL on error. 494 */ 495 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 496 497 /* 498 * Look up a property in a node and return its contents in a byte 499 * array of given length. The property must have at least enough data for 500 * the array (count bytes). It may have more, but this will be ignored. 501 * 502 * @param blob FDT blob 503 * @param node node to examine 504 * @param prop_name name of property to find 505 * @param array array to fill with data 506 * @param count number of array elements 507 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 508 * or -FDT_ERR_BADLAYOUT if not enough data 509 */ 510 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 511 u8 *array, int count); 512 513 /** 514 * Look up a property in a node and return a pointer to its contents as a 515 * byte array of given length. The property must have at least enough data 516 * for the array (count bytes). It may have more, but this will be ignored. 517 * The data is not copied. 518 * 519 * @param blob FDT blob 520 * @param node node to examine 521 * @param prop_name name of property to find 522 * @param count number of array elements 523 * @return pointer to byte array if found, or NULL if the property is not 524 * found or there is not enough data 525 */ 526 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 527 const char *prop_name, int count); 528 529 /** 530 * Look up a property in a node which contains a memory region address and 531 * size. Then return a pointer to this address. 532 * 533 * The property must hold one address with a length. This is only tested on 534 * 32-bit machines. 535 * 536 * @param blob FDT blob 537 * @param node node to examine 538 * @param prop_name name of property to find 539 * @param ptrp returns pointer to region, or NULL if no address 540 * @param size returns size of region 541 * @return 0 if ok, -1 on error (propery not found) 542 */ 543 int fdtdec_decode_region(const void *blob, int node, 544 const char *prop_name, void **ptrp, size_t *size); 545 #endif 546