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