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_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 90 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 91 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */ 92 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */ 93 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */ 94 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */ 95 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */ 96 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 97 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 98 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 99 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 100 101 COMPAT_COUNT, 102 }; 103 104 /* GPIOs are numbered from 0 */ 105 enum { 106 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 107 108 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 109 }; 110 111 /* This is the state of a GPIO pin as defined by the fdt */ 112 struct fdt_gpio_state { 113 const char *name; /* name of the fdt property defining this */ 114 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 115 u8 flags; /* FDT_GPIO_... flags */ 116 }; 117 118 /* This tells us whether a fdt_gpio_state record is valid or not */ 119 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 120 121 /** 122 * Read the GPIO taking into account the polarity of the pin. 123 * 124 * @param gpio pointer to the decoded gpio 125 * @return value of the gpio if successful, < 0 if unsuccessful 126 */ 127 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 128 129 /** 130 * Write the GPIO taking into account the polarity of the pin. 131 * 132 * @param gpio pointer to the decoded gpio 133 * @return 0 if successful 134 */ 135 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 136 137 /** 138 * Find the next numbered alias for a peripheral. This is used to enumerate 139 * all the peripherals of a certain type. 140 * 141 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 142 * this function will return a pointer to the node the alias points to, and 143 * then update *upto to 1. Next time you call this function, the next node 144 * will be returned. 145 * 146 * All nodes returned will match the compatible ID, as it is assumed that 147 * all peripherals use the same driver. 148 * 149 * @param blob FDT blob to use 150 * @param name Root name of alias to search for 151 * @param id Compatible ID to look for 152 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 153 */ 154 int fdtdec_next_alias(const void *blob, const char *name, 155 enum fdt_compat_id id, int *upto); 156 157 /** 158 * Find the compatible ID for a given node. 159 * 160 * Generally each node has at least one compatible string attached to it. 161 * This function looks through our list of known compatible strings and 162 * returns the corresponding ID which matches the compatible string. 163 * 164 * @param blob FDT blob to use 165 * @param node Node containing compatible string to find 166 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 167 */ 168 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 169 170 /** 171 * Find the next compatible node for a peripheral. 172 * 173 * Do the first call with node = 0. This function will return a pointer to 174 * the next compatible node. Next time you call this function, pass the 175 * value returned, and the next node will be provided. 176 * 177 * @param blob FDT blob to use 178 * @param node Start node for search 179 * @param id Compatible ID to look for (enum fdt_compat_id) 180 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 181 */ 182 int fdtdec_next_compatible(const void *blob, int node, 183 enum fdt_compat_id id); 184 185 /** 186 * Find the next compatible subnode for a peripheral. 187 * 188 * Do the first call with node set to the parent and depth = 0. This 189 * function will return the offset of the next compatible node. Next time 190 * you call this function, pass the node value returned last time, with 191 * depth unchanged, and the next node will be provided. 192 * 193 * @param blob FDT blob to use 194 * @param node Start node for search 195 * @param id Compatible ID to look for (enum fdt_compat_id) 196 * @param depthp Current depth (set to 0 before first call) 197 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 198 */ 199 int fdtdec_next_compatible_subnode(const void *blob, int node, 200 enum fdt_compat_id id, int *depthp); 201 202 /** 203 * Look up an address property in a node and return it as an address. 204 * The property must hold either one address with no trailing data or 205 * one address with a length. This is only tested 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(const void *blob, int node, 213 const char *prop_name); 214 215 /** 216 * Look up an address property in a node and return it as an address. 217 * The property must hold one address with a length. This is only tested 218 * on 32-bit machines. 219 * 220 * @param blob FDT blob 221 * @param node node to examine 222 * @param prop_name name of property to find 223 * @return address, if found, or FDT_ADDR_T_NONE if not 224 */ 225 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 226 const char *prop_name, fdt_size_t *sizep); 227 228 /** 229 * Look up a 32-bit integer property in a node and return it. The property 230 * must have at least 4 bytes of data. The value of the first cell is 231 * returned. 232 * 233 * @param blob FDT blob 234 * @param node node to examine 235 * @param prop_name name of property to find 236 * @param default_val default value to return if the property is not found 237 * @return integer value, if found, or default_val if not 238 */ 239 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 240 s32 default_val); 241 242 /** 243 * Look up a 64-bit integer property in a node and return it. The property 244 * must have at least 8 bytes of data (2 cells). The first two cells are 245 * concatenated to form a 8 bytes value, where the first cell is top half and 246 * the second cell is bottom half. 247 * 248 * @param blob FDT blob 249 * @param node node to examine 250 * @param prop_name name of property to find 251 * @param default_val default value to return if the property is not found 252 * @return integer value, if found, or default_val if not 253 */ 254 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 255 uint64_t default_val); 256 257 /** 258 * Checks whether a node is enabled. 259 * This looks for a 'status' property. If this exists, then returns 1 if 260 * the status is 'ok' and 0 otherwise. If there is no status property, 261 * it returns 1 on the assumption that anything mentioned should be enabled 262 * by default. 263 * 264 * @param blob FDT blob 265 * @param node node to examine 266 * @return integer value 0 (not enabled) or 1 (enabled) 267 */ 268 int fdtdec_get_is_enabled(const void *blob, int node); 269 270 /** 271 * Make sure we have a valid fdt available to control U-Boot. 272 * 273 * If not, a message is printed to the console if the console is ready. 274 * 275 * @return 0 if all ok, -1 if not 276 */ 277 int fdtdec_prepare_fdt(void); 278 279 /** 280 * Checks that we have a valid fdt available to control U-Boot. 281 282 * However, if not then for the moment nothing is done, since this function 283 * is called too early to panic(). 284 * 285 * @returns 0 286 */ 287 int fdtdec_check_fdt(void); 288 289 /** 290 * Find the nodes for a peripheral and return a list of them in the correct 291 * order. This is used to enumerate all the peripherals of a certain type. 292 * 293 * To use this, optionally set up a /aliases node with alias properties for 294 * a peripheral. For example, for usb you could have: 295 * 296 * aliases { 297 * usb0 = "/ehci@c5008000"; 298 * usb1 = "/ehci@c5000000"; 299 * }; 300 * 301 * Pass "usb" as the name to this function and will return a list of two 302 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 303 * 304 * All nodes returned will match the compatible ID, as it is assumed that 305 * all peripherals use the same driver. 306 * 307 * If no alias node is found, then the node list will be returned in the 308 * order found in the fdt. If the aliases mention a node which doesn't 309 * exist, then this will be ignored. If nodes are found with no aliases, 310 * they will be added in any order. 311 * 312 * If there is a gap in the aliases, then this function return a 0 node at 313 * that position. The return value will also count these gaps. 314 * 315 * This function checks node properties and will not return nodes which are 316 * marked disabled (status = "disabled"). 317 * 318 * @param blob FDT blob to use 319 * @param name Root name of alias to search for 320 * @param id Compatible ID to look for 321 * @param node_list Place to put list of found nodes 322 * @param maxcount Maximum number of nodes to find 323 * @return number of nodes found on success, FTD_ERR_... on error 324 */ 325 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 326 enum fdt_compat_id id, int *node_list, int maxcount); 327 328 /* 329 * This function is similar to fdtdec_find_aliases_for_id() except that it 330 * adds to the node_list that is passed in. Any 0 elements are considered 331 * available for allocation - others are considered already used and are 332 * skipped. 333 * 334 * You can use this by calling fdtdec_find_aliases_for_id() with an 335 * uninitialised array, then setting the elements that are returned to -1, 336 * say, then calling this function, perhaps with a different compat id. 337 * Any elements you get back that are >0 are new nodes added by the call 338 * to this function. 339 * 340 * Note that if you have some nodes with aliases and some without, you are 341 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 342 * one compat_id may fill in positions for which you have aliases defined 343 * for another compat_id. When you later call *this* function with the second 344 * compat_id, the alias positions may already be used. A debug warning may 345 * be generated in this case, but it is safest to define aliases for all 346 * nodes when you care about the ordering. 347 */ 348 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 349 enum fdt_compat_id id, int *node_list, int maxcount); 350 351 /* 352 * Get the name for a compatible ID 353 * 354 * @param id Compatible ID to look for 355 * @return compatible string for that id 356 */ 357 const char *fdtdec_get_compatible(enum fdt_compat_id id); 358 359 /* Look up a phandle and follow it to its node. Then return the offset 360 * of that node. 361 * 362 * @param blob FDT blob 363 * @param node node to examine 364 * @param prop_name name of property to find 365 * @return node offset if found, -ve error code on error 366 */ 367 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 368 369 /** 370 * Look up a property in a node and return its contents in an integer 371 * array of given length. The property must have at least enough data for 372 * the array (4*count bytes). It may have more, but this will be ignored. 373 * 374 * @param blob FDT blob 375 * @param node node to examine 376 * @param prop_name name of property to find 377 * @param array array to fill with data 378 * @param count number of array elements 379 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 380 * or -FDT_ERR_BADLAYOUT if not enough data 381 */ 382 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 383 u32 *array, int count); 384 385 /** 386 * Look up a property in a node and return a pointer to its contents as a 387 * unsigned int array of given length. The property must have at least enough 388 * data for the array ('count' cells). It may have more, but this will be 389 * ignored. The data is not copied. 390 * 391 * Note that you must access elements of the array with fdt32_to_cpu(), 392 * since the elements will be big endian even on a little endian machine. 393 * 394 * @param blob FDT blob 395 * @param node node to examine 396 * @param prop_name name of property to find 397 * @param count number of array elements 398 * @return pointer to array if found, or NULL if the property is not 399 * found or there is not enough data 400 */ 401 const u32 *fdtdec_locate_array(const void *blob, int node, 402 const char *prop_name, int count); 403 404 /** 405 * Look up a boolean property in a node and return it. 406 * 407 * A boolean properly is true if present in the device tree and false if not 408 * present, regardless of its value. 409 * 410 * @param blob FDT blob 411 * @param node node to examine 412 * @param prop_name name of property to find 413 * @return 1 if the properly is present; 0 if it isn't present 414 */ 415 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 416 417 /** 418 * Decode a single GPIOs from an FDT. 419 * 420 * If the property is not found, then the GPIO structure will still be 421 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 422 * provide optional GPIOs. 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 gpio elements to fill from FDT 428 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 429 */ 430 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 431 struct fdt_gpio_state *gpio); 432 433 /** 434 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 435 * terminating item. 436 * 437 * @param blob FDT blob to use 438 * @param node Node to look at 439 * @param prop_name Node property name 440 * @param gpio Array of gpio elements to fill from FDT. This will be 441 * untouched if either 0 or an error is returned 442 * @param max_count Maximum number of elements allowed 443 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 444 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 445 */ 446 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 447 struct fdt_gpio_state *gpio, int max_count); 448 449 /** 450 * Set up a GPIO pin according to the provided gpio information. At present this 451 * just requests the GPIO. 452 * 453 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 454 * deal with optional GPIOs. 455 * 456 * @param gpio GPIO info to use for set up 457 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 458 */ 459 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 460 461 /** 462 * Look in the FDT for a config item with the given name and return its value 463 * as a 32-bit integer. The property must have at least 4 bytes of data. The 464 * value of the first cell is returned. 465 * 466 * @param blob FDT blob to use 467 * @param prop_name Node property name 468 * @param default_val default value to return if the property is not found 469 * @return integer value, if found, or default_val if not 470 */ 471 int fdtdec_get_config_int(const void *blob, const char *prop_name, 472 int default_val); 473 474 /** 475 * Look in the FDT for a config item with the given name 476 * and return whether it exists. 477 * 478 * @param blob FDT blob 479 * @param prop_name property name to look up 480 * @return 1, if it exists, or 0 if not 481 */ 482 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 483 484 /** 485 * Look in the FDT for a config item with the given name and return its value 486 * as a string. 487 * 488 * @param blob FDT blob 489 * @param prop_name property name to look up 490 * @returns property string, NULL on error. 491 */ 492 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 493 494 /* 495 * Look up a property in a node and return its contents in a byte 496 * array of given length. The property must have at least enough data for 497 * the array (count bytes). It may have more, but this will be ignored. 498 * 499 * @param blob FDT blob 500 * @param node node to examine 501 * @param prop_name name of property to find 502 * @param array array to fill with data 503 * @param count number of array elements 504 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 505 * or -FDT_ERR_BADLAYOUT if not enough data 506 */ 507 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 508 u8 *array, int count); 509 510 /** 511 * Look up a property in a node and return a pointer to its contents as a 512 * byte array of given length. The property must have at least enough data 513 * for the array (count bytes). It may have more, but this will be ignored. 514 * The data is not copied. 515 * 516 * @param blob FDT blob 517 * @param node node to examine 518 * @param prop_name name of property to find 519 * @param count number of array elements 520 * @return pointer to byte array if found, or NULL if the property is not 521 * found or there is not enough data 522 */ 523 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 524 const char *prop_name, int count); 525 526 /** 527 * Look up a property in a node which contains a memory region address and 528 * size. Then return a pointer to this address. 529 * 530 * The property must hold one address with a length. This is only tested on 531 * 32-bit machines. 532 * 533 * @param blob FDT blob 534 * @param node node to examine 535 * @param prop_name name of property to find 536 * @param ptrp returns pointer to region, or NULL if no address 537 * @param size returns size of region 538 * @return 0 if ok, -1 on error (propery not found) 539 */ 540 int fdtdec_decode_region(const void *blob, int node, 541 const char *prop_name, void **ptrp, size_t *size); 542 #endif 543