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_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */ 93 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 94 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 95 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 96 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 97 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */ 98 99 COMPAT_COUNT, 100 }; 101 102 /* GPIOs are numbered from 0 */ 103 enum { 104 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 105 106 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 107 }; 108 109 /* This is the state of a GPIO pin as defined by the fdt */ 110 struct fdt_gpio_state { 111 const char *name; /* name of the fdt property defining this */ 112 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 113 u8 flags; /* FDT_GPIO_... flags */ 114 }; 115 116 /* This tells us whether a fdt_gpio_state record is valid or not */ 117 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 118 119 /** 120 * Read the GPIO taking into account the polarity of the pin. 121 * 122 * @param gpio pointer to the decoded gpio 123 * @return value of the gpio if successful, < 0 if unsuccessful 124 */ 125 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 126 127 /** 128 * Write the GPIO taking into account the polarity of the pin. 129 * 130 * @param gpio pointer to the decoded gpio 131 * @return 0 if successful 132 */ 133 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 134 135 /** 136 * Find the next numbered alias for a peripheral. This is used to enumerate 137 * all the peripherals of a certain type. 138 * 139 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 140 * this function will return a pointer to the node the alias points to, and 141 * then update *upto to 1. Next time you call this function, the next node 142 * will be returned. 143 * 144 * All nodes returned will match the compatible ID, as it is assumed that 145 * all peripherals use the same driver. 146 * 147 * @param blob FDT blob to use 148 * @param name Root name of alias to search for 149 * @param id Compatible ID to look for 150 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 151 */ 152 int fdtdec_next_alias(const void *blob, const char *name, 153 enum fdt_compat_id id, int *upto); 154 155 /** 156 * Find the compatible ID for a given node. 157 * 158 * Generally each node has at least one compatible string attached to it. 159 * This function looks through our list of known compatible strings and 160 * returns the corresponding ID which matches the compatible string. 161 * 162 * @param blob FDT blob to use 163 * @param node Node containing compatible string to find 164 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 165 */ 166 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 167 168 /** 169 * Find the next compatible node for a peripheral. 170 * 171 * Do the first call with node = 0. This function will return a pointer to 172 * the next compatible node. Next time you call this function, pass the 173 * value returned, and the next node will be provided. 174 * 175 * @param blob FDT blob to use 176 * @param node Start node for search 177 * @param id Compatible ID to look for (enum fdt_compat_id) 178 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 179 */ 180 int fdtdec_next_compatible(const void *blob, int node, 181 enum fdt_compat_id id); 182 183 /** 184 * Find the next compatible subnode for a peripheral. 185 * 186 * Do the first call with node set to the parent and depth = 0. This 187 * function will return the offset of the next compatible node. Next time 188 * you call this function, pass the node value returned last time, with 189 * depth unchanged, and the next node will be provided. 190 * 191 * @param blob FDT blob to use 192 * @param node Start node for search 193 * @param id Compatible ID to look for (enum fdt_compat_id) 194 * @param depthp Current depth (set to 0 before first call) 195 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 196 */ 197 int fdtdec_next_compatible_subnode(const void *blob, int node, 198 enum fdt_compat_id id, int *depthp); 199 200 /** 201 * Look up an address property in a node and return it as an address. 202 * The property must hold either one address with no trailing data or 203 * one address with a length. This is only tested on 32-bit machines. 204 * 205 * @param blob FDT blob 206 * @param node node to examine 207 * @param prop_name name of property to find 208 * @return address, if found, or FDT_ADDR_T_NONE if not 209 */ 210 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 211 const char *prop_name); 212 213 /** 214 * Look up an address property in a node and return it as an address. 215 * The property must hold one address with a length. This is only tested 216 * on 32-bit machines. 217 * 218 * @param blob FDT blob 219 * @param node node to examine 220 * @param prop_name name of property to find 221 * @return address, if found, or FDT_ADDR_T_NONE if not 222 */ 223 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 224 const char *prop_name, fdt_size_t *sizep); 225 226 /** 227 * Look up a 32-bit integer property in a node and return it. The property 228 * must have at least 4 bytes of data. The value of the first cell is 229 * returned. 230 * 231 * @param blob FDT blob 232 * @param node node to examine 233 * @param prop_name name of property to find 234 * @param default_val default value to return if the property is not found 235 * @return integer value, if found, or default_val if not 236 */ 237 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 238 s32 default_val); 239 240 /** 241 * Look up a 64-bit integer property in a node and return it. The property 242 * must have at least 8 bytes of data (2 cells). The first two cells are 243 * concatenated to form a 8 bytes value, where the first cell is top half and 244 * the second cell is bottom half. 245 * 246 * @param blob FDT blob 247 * @param node node to examine 248 * @param prop_name name of property to find 249 * @param default_val default value to return if the property is not found 250 * @return integer value, if found, or default_val if not 251 */ 252 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 253 uint64_t default_val); 254 255 /** 256 * Checks whether a node is enabled. 257 * This looks for a 'status' property. If this exists, then returns 1 if 258 * the status is 'ok' and 0 otherwise. If there is no status property, 259 * it returns 1 on the assumption that anything mentioned should be enabled 260 * by default. 261 * 262 * @param blob FDT blob 263 * @param node node to examine 264 * @return integer value 0 (not enabled) or 1 (enabled) 265 */ 266 int fdtdec_get_is_enabled(const void *blob, int node); 267 268 /** 269 * Make sure we have a valid fdt available to control U-Boot. 270 * 271 * If not, a message is printed to the console if the console is ready. 272 * 273 * @return 0 if all ok, -1 if not 274 */ 275 int fdtdec_prepare_fdt(void); 276 277 /** 278 * Checks that we have a valid fdt available to control U-Boot. 279 280 * However, if not then for the moment nothing is done, since this function 281 * is called too early to panic(). 282 * 283 * @returns 0 284 */ 285 int fdtdec_check_fdt(void); 286 287 /** 288 * Find the nodes for a peripheral and return a list of them in the correct 289 * order. This is used to enumerate all the peripherals of a certain type. 290 * 291 * To use this, optionally set up a /aliases node with alias properties for 292 * a peripheral. For example, for usb you could have: 293 * 294 * aliases { 295 * usb0 = "/ehci@c5008000"; 296 * usb1 = "/ehci@c5000000"; 297 * }; 298 * 299 * Pass "usb" as the name to this function and will return a list of two 300 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 301 * 302 * All nodes returned will match the compatible ID, as it is assumed that 303 * all peripherals use the same driver. 304 * 305 * If no alias node is found, then the node list will be returned in the 306 * order found in the fdt. If the aliases mention a node which doesn't 307 * exist, then this will be ignored. If nodes are found with no aliases, 308 * they will be added in any order. 309 * 310 * If there is a gap in the aliases, then this function return a 0 node at 311 * that position. The return value will also count these gaps. 312 * 313 * This function checks node properties and will not return nodes which are 314 * marked disabled (status = "disabled"). 315 * 316 * @param blob FDT blob to use 317 * @param name Root name of alias to search for 318 * @param id Compatible ID to look for 319 * @param node_list Place to put list of found nodes 320 * @param maxcount Maximum number of nodes to find 321 * @return number of nodes found on success, FTD_ERR_... on error 322 */ 323 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 324 enum fdt_compat_id id, int *node_list, int maxcount); 325 326 /* 327 * This function is similar to fdtdec_find_aliases_for_id() except that it 328 * adds to the node_list that is passed in. Any 0 elements are considered 329 * available for allocation - others are considered already used and are 330 * skipped. 331 * 332 * You can use this by calling fdtdec_find_aliases_for_id() with an 333 * uninitialised array, then setting the elements that are returned to -1, 334 * say, then calling this function, perhaps with a different compat id. 335 * Any elements you get back that are >0 are new nodes added by the call 336 * to this function. 337 * 338 * Note that if you have some nodes with aliases and some without, you are 339 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 340 * one compat_id may fill in positions for which you have aliases defined 341 * for another compat_id. When you later call *this* function with the second 342 * compat_id, the alias positions may already be used. A debug warning may 343 * be generated in this case, but it is safest to define aliases for all 344 * nodes when you care about the ordering. 345 */ 346 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 347 enum fdt_compat_id id, int *node_list, int maxcount); 348 349 /* 350 * Get the name for a compatible ID 351 * 352 * @param id Compatible ID to look for 353 * @return compatible string for that id 354 */ 355 const char *fdtdec_get_compatible(enum fdt_compat_id id); 356 357 /* Look up a phandle and follow it to its node. Then return the offset 358 * of that node. 359 * 360 * @param blob FDT blob 361 * @param node node to examine 362 * @param prop_name name of property to find 363 * @return node offset if found, -ve error code on error 364 */ 365 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 366 367 /** 368 * Look up a property in a node and return its contents in an integer 369 * array of given length. The property must have at least enough data for 370 * the array (4*count bytes). It may have more, but this will be ignored. 371 * 372 * @param blob FDT blob 373 * @param node node to examine 374 * @param prop_name name of property to find 375 * @param array array to fill with data 376 * @param count number of array elements 377 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 378 * or -FDT_ERR_BADLAYOUT if not enough data 379 */ 380 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 381 u32 *array, int count); 382 383 /** 384 * Look up a property in a node and return a pointer to its contents as a 385 * unsigned int array of given length. The property must have at least enough 386 * data for the array ('count' cells). It may have more, but this will be 387 * ignored. The data is not copied. 388 * 389 * Note that you must access elements of the array with fdt32_to_cpu(), 390 * since the elements will be big endian even on a little endian machine. 391 * 392 * @param blob FDT blob 393 * @param node node to examine 394 * @param prop_name name of property to find 395 * @param count number of array elements 396 * @return pointer to array if found, or NULL if the property is not 397 * found or there is not enough data 398 */ 399 const u32 *fdtdec_locate_array(const void *blob, int node, 400 const char *prop_name, int count); 401 402 /** 403 * Look up a boolean property in a node and return it. 404 * 405 * A boolean properly is true if present in the device tree and false if not 406 * present, regardless of its value. 407 * 408 * @param blob FDT blob 409 * @param node node to examine 410 * @param prop_name name of property to find 411 * @return 1 if the properly is present; 0 if it isn't present 412 */ 413 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 414 415 /** 416 * Decode a single GPIOs from an FDT. 417 * 418 * If the property is not found, then the GPIO structure will still be 419 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 420 * provide optional GPIOs. 421 * 422 * @param blob FDT blob to use 423 * @param node Node to look at 424 * @param prop_name Node property name 425 * @param gpio gpio elements to fill from FDT 426 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 427 */ 428 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 429 struct fdt_gpio_state *gpio); 430 431 /** 432 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 433 * terminating item. 434 * 435 * @param blob FDT blob to use 436 * @param node Node to look at 437 * @param prop_name Node property name 438 * @param gpio Array of gpio elements to fill from FDT. This will be 439 * untouched if either 0 or an error is returned 440 * @param max_count Maximum number of elements allowed 441 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 442 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 443 */ 444 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 445 struct fdt_gpio_state *gpio, int max_count); 446 447 /** 448 * Set up a GPIO pin according to the provided gpio information. At present this 449 * just requests the GPIO. 450 * 451 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 452 * deal with optional GPIOs. 453 * 454 * @param gpio GPIO info to use for set up 455 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 456 */ 457 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 458 459 /** 460 * Look in the FDT for a config item with the given name and return its value 461 * as a 32-bit integer. The property must have at least 4 bytes of data. The 462 * value of the first cell is returned. 463 * 464 * @param blob FDT blob to use 465 * @param prop_name Node property name 466 * @param default_val default value to return if the property is not found 467 * @return integer value, if found, or default_val if not 468 */ 469 int fdtdec_get_config_int(const void *blob, const char *prop_name, 470 int default_val); 471 472 /** 473 * Look in the FDT for a config item with the given name 474 * and return whether it exists. 475 * 476 * @param blob FDT blob 477 * @param prop_name property name to look up 478 * @return 1, if it exists, or 0 if not 479 */ 480 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 481 482 /** 483 * Look in the FDT for a config item with the given name and return its value 484 * as a string. 485 * 486 * @param blob FDT blob 487 * @param prop_name property name to look up 488 * @returns property string, NULL on error. 489 */ 490 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 491 492 /* 493 * Look up a property in a node and return its contents in a byte 494 * array of given length. The property must have at least enough data for 495 * the array (count bytes). It may have more, but this will be ignored. 496 * 497 * @param blob FDT blob 498 * @param node node to examine 499 * @param prop_name name of property to find 500 * @param array array to fill with data 501 * @param count number of array elements 502 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 503 * or -FDT_ERR_BADLAYOUT if not enough data 504 */ 505 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 506 u8 *array, int count); 507 508 /** 509 * Look up a property in a node and return a pointer to its contents as a 510 * byte array of given length. The property must have at least enough data 511 * for the array (count bytes). It may have more, but this will be ignored. 512 * The data is not copied. 513 * 514 * @param blob FDT blob 515 * @param node node to examine 516 * @param prop_name name of property to find 517 * @param count number of array elements 518 * @return pointer to byte array if found, or NULL if the property is not 519 * found or there is not enough data 520 */ 521 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 522 const char *prop_name, int count); 523 524 /** 525 * Look up a property in a node which contains a memory region address and 526 * size. Then return a pointer to this address. 527 * 528 * The property must hold one address with a length. This is only tested on 529 * 32-bit machines. 530 * 531 * @param blob FDT blob 532 * @param node node to examine 533 * @param prop_name name of property to find 534 * @param ptrp returns pointer to region, or NULL if no address 535 * @param size returns size of region 536 * @return 0 if ok, -1 on error (propery not found) 537 */ 538 int fdtdec_decode_region(const void *blob, int node, 539 const char *prop_name, void **ptrp, size_t *size); 540 #endif 541