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_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 91 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 92 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 93 94 COMPAT_COUNT, 95 }; 96 97 /* GPIOs are numbered from 0 */ 98 enum { 99 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 100 101 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 102 }; 103 104 /* This is the state of a GPIO pin as defined by the fdt */ 105 struct fdt_gpio_state { 106 const char *name; /* name of the fdt property defining this */ 107 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 108 u8 flags; /* FDT_GPIO_... flags */ 109 }; 110 111 /* This tells us whether a fdt_gpio_state record is valid or not */ 112 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 113 114 /** 115 * Read the GPIO taking into account the polarity of the pin. 116 * 117 * @param gpio pointer to the decoded gpio 118 * @return value of the gpio if successful, < 0 if unsuccessful 119 */ 120 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 121 122 /** 123 * Write the GPIO taking into account the polarity of the pin. 124 * 125 * @param gpio pointer to the decoded gpio 126 * @return 0 if successful 127 */ 128 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 129 130 /** 131 * Find the next numbered alias for a peripheral. This is used to enumerate 132 * all the peripherals of a certain type. 133 * 134 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 135 * this function will return a pointer to the node the alias points to, and 136 * then update *upto to 1. Next time you call this function, the next node 137 * will be returned. 138 * 139 * All nodes returned will match the compatible ID, as it is assumed that 140 * all peripherals use the same driver. 141 * 142 * @param blob FDT blob to use 143 * @param name Root name of alias to search for 144 * @param id Compatible ID to look for 145 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 146 */ 147 int fdtdec_next_alias(const void *blob, const char *name, 148 enum fdt_compat_id id, int *upto); 149 150 /** 151 * Find the compatible ID for a given node. 152 * 153 * Generally each node has at least one compatible string attached to it. 154 * This function looks through our list of known compatible strings and 155 * returns the corresponding ID which matches the compatible string. 156 * 157 * @param blob FDT blob to use 158 * @param node Node containing compatible string to find 159 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 160 */ 161 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 162 163 /** 164 * Find the next compatible node for a peripheral. 165 * 166 * Do the first call with node = 0. This function will return a pointer to 167 * the next compatible node. Next time you call this function, pass the 168 * value returned, and the next node will be provided. 169 * 170 * @param blob FDT blob to use 171 * @param node Start node for search 172 * @param id Compatible ID to look for (enum fdt_compat_id) 173 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 174 */ 175 int fdtdec_next_compatible(const void *blob, int node, 176 enum fdt_compat_id id); 177 178 /** 179 * Find the next compatible subnode for a peripheral. 180 * 181 * Do the first call with node set to the parent and depth = 0. This 182 * function will return the offset of the next compatible node. Next time 183 * you call this function, pass the node value returned last time, with 184 * depth unchanged, and the next node will be provided. 185 * 186 * @param blob FDT blob to use 187 * @param node Start node for search 188 * @param id Compatible ID to look for (enum fdt_compat_id) 189 * @param depthp Current depth (set to 0 before first call) 190 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 191 */ 192 int fdtdec_next_compatible_subnode(const void *blob, int node, 193 enum fdt_compat_id id, int *depthp); 194 195 /** 196 * Look up an address property in a node and return it as an address. 197 * The property must hold either one address with no trailing data or 198 * one address with a length. This is only tested on 32-bit machines. 199 * 200 * @param blob FDT blob 201 * @param node node to examine 202 * @param prop_name name of property to find 203 * @return address, if found, or FDT_ADDR_T_NONE if not 204 */ 205 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 206 const char *prop_name); 207 208 /** 209 * Look up an address property in a node and return it as an address. 210 * The property must hold one address with a length. This is only tested 211 * on 32-bit machines. 212 * 213 * @param blob FDT blob 214 * @param node node to examine 215 * @param prop_name name of property to find 216 * @return address, if found, or FDT_ADDR_T_NONE if not 217 */ 218 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 219 const char *prop_name, fdt_size_t *sizep); 220 221 /** 222 * Look up a 32-bit integer property in a node and return it. The property 223 * must have at least 4 bytes of data. The value of the first cell is 224 * returned. 225 * 226 * @param blob FDT blob 227 * @param node node to examine 228 * @param prop_name name of property to find 229 * @param default_val default value to return if the property is not found 230 * @return integer value, if found, or default_val if not 231 */ 232 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 233 s32 default_val); 234 235 /** 236 * Look up a 64-bit integer property in a node and return it. The property 237 * must have at least 8 bytes of data (2 cells). The first two cells are 238 * concatenated to form a 8 bytes value, where the first cell is top half and 239 * the second cell is bottom half. 240 * 241 * @param blob FDT blob 242 * @param node node to examine 243 * @param prop_name name of property to find 244 * @param default_val default value to return if the property is not found 245 * @return integer value, if found, or default_val if not 246 */ 247 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 248 uint64_t default_val); 249 250 /** 251 * Checks whether a node is enabled. 252 * This looks for a 'status' property. If this exists, then returns 1 if 253 * the status is 'ok' and 0 otherwise. If there is no status property, 254 * it returns 1 on the assumption that anything mentioned should be enabled 255 * by default. 256 * 257 * @param blob FDT blob 258 * @param node node to examine 259 * @return integer value 0 (not enabled) or 1 (enabled) 260 */ 261 int fdtdec_get_is_enabled(const void *blob, int node); 262 263 /** 264 * Make sure we have a valid fdt available to control U-Boot. 265 * 266 * If not, a message is printed to the console if the console is ready. 267 * 268 * @return 0 if all ok, -1 if not 269 */ 270 int fdtdec_prepare_fdt(void); 271 272 /** 273 * Checks that we have a valid fdt available to control U-Boot. 274 275 * However, if not then for the moment nothing is done, since this function 276 * is called too early to panic(). 277 * 278 * @returns 0 279 */ 280 int fdtdec_check_fdt(void); 281 282 /** 283 * Find the nodes for a peripheral and return a list of them in the correct 284 * order. This is used to enumerate all the peripherals of a certain type. 285 * 286 * To use this, optionally set up a /aliases node with alias properties for 287 * a peripheral. For example, for usb you could have: 288 * 289 * aliases { 290 * usb0 = "/ehci@c5008000"; 291 * usb1 = "/ehci@c5000000"; 292 * }; 293 * 294 * Pass "usb" as the name to this function and will return a list of two 295 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 296 * 297 * All nodes returned will match the compatible ID, as it is assumed that 298 * all peripherals use the same driver. 299 * 300 * If no alias node is found, then the node list will be returned in the 301 * order found in the fdt. If the aliases mention a node which doesn't 302 * exist, then this will be ignored. If nodes are found with no aliases, 303 * they will be added in any order. 304 * 305 * If there is a gap in the aliases, then this function return a 0 node at 306 * that position. The return value will also count these gaps. 307 * 308 * This function checks node properties and will not return nodes which are 309 * marked disabled (status = "disabled"). 310 * 311 * @param blob FDT blob to use 312 * @param name Root name of alias to search for 313 * @param id Compatible ID to look for 314 * @param node_list Place to put list of found nodes 315 * @param maxcount Maximum number of nodes to find 316 * @return number of nodes found on success, FTD_ERR_... on error 317 */ 318 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 319 enum fdt_compat_id id, int *node_list, int maxcount); 320 321 /* 322 * This function is similar to fdtdec_find_aliases_for_id() except that it 323 * adds to the node_list that is passed in. Any 0 elements are considered 324 * available for allocation - others are considered already used and are 325 * skipped. 326 * 327 * You can use this by calling fdtdec_find_aliases_for_id() with an 328 * uninitialised array, then setting the elements that are returned to -1, 329 * say, then calling this function, perhaps with a different compat id. 330 * Any elements you get back that are >0 are new nodes added by the call 331 * to this function. 332 * 333 * Note that if you have some nodes with aliases and some without, you are 334 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 335 * one compat_id may fill in positions for which you have aliases defined 336 * for another compat_id. When you later call *this* function with the second 337 * compat_id, the alias positions may already be used. A debug warning may 338 * be generated in this case, but it is safest to define aliases for all 339 * nodes when you care about the ordering. 340 */ 341 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 342 enum fdt_compat_id id, int *node_list, int maxcount); 343 344 /* 345 * Get the name for a compatible ID 346 * 347 * @param id Compatible ID to look for 348 * @return compatible string for that id 349 */ 350 const char *fdtdec_get_compatible(enum fdt_compat_id id); 351 352 /* Look up a phandle and follow it to its node. Then return the offset 353 * of that node. 354 * 355 * @param blob FDT blob 356 * @param node node to examine 357 * @param prop_name name of property to find 358 * @return node offset if found, -ve error code on error 359 */ 360 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 361 362 /** 363 * Look up a property in a node and return its contents in an integer 364 * array of given length. The property must have at least enough data for 365 * the array (4*count bytes). It may have more, but this will be ignored. 366 * 367 * @param blob FDT blob 368 * @param node node to examine 369 * @param prop_name name of property to find 370 * @param array array to fill with data 371 * @param count number of array elements 372 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 373 * or -FDT_ERR_BADLAYOUT if not enough data 374 */ 375 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 376 u32 *array, int count); 377 378 /** 379 * Look up a property in a node and return a pointer to its contents as a 380 * unsigned int array of given length. The property must have at least enough 381 * data for the array ('count' cells). It may have more, but this will be 382 * ignored. The data is not copied. 383 * 384 * Note that you must access elements of the array with fdt32_to_cpu(), 385 * since the elements will be big endian even on a little endian machine. 386 * 387 * @param blob FDT blob 388 * @param node node to examine 389 * @param prop_name name of property to find 390 * @param count number of array elements 391 * @return pointer to array if found, or NULL if the property is not 392 * found or there is not enough data 393 */ 394 const u32 *fdtdec_locate_array(const void *blob, int node, 395 const char *prop_name, int count); 396 397 /** 398 * Look up a boolean property in a node and return it. 399 * 400 * A boolean properly is true if present in the device tree and false if not 401 * present, regardless of its value. 402 * 403 * @param blob FDT blob 404 * @param node node to examine 405 * @param prop_name name of property to find 406 * @return 1 if the properly is present; 0 if it isn't present 407 */ 408 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 409 410 /** 411 * Decode a single GPIOs from an FDT. 412 * 413 * If the property is not found, then the GPIO structure will still be 414 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 415 * provide optional GPIOs. 416 * 417 * @param blob FDT blob to use 418 * @param node Node to look at 419 * @param prop_name Node property name 420 * @param gpio gpio elements to fill from FDT 421 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 422 */ 423 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 424 struct fdt_gpio_state *gpio); 425 426 /** 427 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 428 * terminating item. 429 * 430 * @param blob FDT blob to use 431 * @param node Node to look at 432 * @param prop_name Node property name 433 * @param gpio Array of gpio elements to fill from FDT. This will be 434 * untouched if either 0 or an error is returned 435 * @param max_count Maximum number of elements allowed 436 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 437 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 438 */ 439 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 440 struct fdt_gpio_state *gpio, int max_count); 441 442 /** 443 * Set up a GPIO pin according to the provided gpio information. At present this 444 * just requests the GPIO. 445 * 446 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 447 * deal with optional GPIOs. 448 * 449 * @param gpio GPIO info to use for set up 450 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 451 */ 452 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 453 454 /** 455 * Look in the FDT for a config item with the given name and return its value 456 * as a 32-bit integer. The property must have at least 4 bytes of data. The 457 * value of the first cell is returned. 458 * 459 * @param blob FDT blob to use 460 * @param prop_name Node property name 461 * @param default_val default value to return if the property is not found 462 * @return integer value, if found, or default_val if not 463 */ 464 int fdtdec_get_config_int(const void *blob, const char *prop_name, 465 int default_val); 466 467 /** 468 * Look in the FDT for a config item with the given name 469 * and return whether it exists. 470 * 471 * @param blob FDT blob 472 * @param prop_name property name to look up 473 * @return 1, if it exists, or 0 if not 474 */ 475 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 476 477 /** 478 * Look in the FDT for a config item with the given name and return its value 479 * as a string. 480 * 481 * @param blob FDT blob 482 * @param prop_name property name to look up 483 * @returns property string, NULL on error. 484 */ 485 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 486 487 /* 488 * Look up a property in a node and return its contents in a byte 489 * array of given length. The property must have at least enough data for 490 * the array (count bytes). It may have more, but this will be ignored. 491 * 492 * @param blob FDT blob 493 * @param node node to examine 494 * @param prop_name name of property to find 495 * @param array array to fill with data 496 * @param count number of array elements 497 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 498 * or -FDT_ERR_BADLAYOUT if not enough data 499 */ 500 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 501 u8 *array, int count); 502 503 /** 504 * Look up a property in a node and return a pointer to its contents as a 505 * byte array of given length. The property must have at least enough data 506 * for the array (count bytes). It may have more, but this will be ignored. 507 * The data is not copied. 508 * 509 * @param blob FDT blob 510 * @param node node to examine 511 * @param prop_name name of property to find 512 * @param count number of array elements 513 * @return pointer to byte array if found, or NULL if the property is not 514 * found or there is not enough data 515 */ 516 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 517 const char *prop_name, int count); 518 519 /** 520 * Look up a property in a node which contains a memory region address and 521 * size. Then return a pointer to this address. 522 * 523 * The property must hold one address with a length. This is only tested on 524 * 32-bit machines. 525 * 526 * @param blob FDT blob 527 * @param node node to examine 528 * @param prop_name name of property to find 529 * @param ptrp returns pointer to region, or NULL if no address 530 * @param size returns size of region 531 * @return 0 if ok, -1 on error (propery not found) 532 */ 533 int fdtdec_decode_region(const void *blob, int node, 534 const char *prop_name, void **ptrp, size_t *size); 535 #endif 536