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_GOOGLE_CROS_EC, /* Google CROS_EC Protocol */ 88 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 89 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 90 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */ 91 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */ 92 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */ 93 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */ 94 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 95 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */ 96 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 97 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */ 98 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */ 99 100 COMPAT_COUNT, 101 }; 102 103 /* GPIOs are numbered from 0 */ 104 enum { 105 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 106 107 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 108 }; 109 110 /* This is the state of a GPIO pin as defined by the fdt */ 111 struct fdt_gpio_state { 112 const char *name; /* name of the fdt property defining this */ 113 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 114 u8 flags; /* FDT_GPIO_... flags */ 115 }; 116 117 /* This tells us whether a fdt_gpio_state record is valid or not */ 118 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 119 120 /** 121 * Read the GPIO taking into account the polarity of the pin. 122 * 123 * @param gpio pointer to the decoded gpio 124 * @return value of the gpio if successful, < 0 if unsuccessful 125 */ 126 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 127 128 /** 129 * Write the GPIO taking into account the polarity of the pin. 130 * 131 * @param gpio pointer to the decoded gpio 132 * @return 0 if successful 133 */ 134 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 135 136 /** 137 * Find the next numbered alias for a peripheral. This is used to enumerate 138 * all the peripherals of a certain type. 139 * 140 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 141 * this function will return a pointer to the node the alias points to, and 142 * then update *upto to 1. Next time you call this function, the next node 143 * will be returned. 144 * 145 * All nodes returned will match the compatible ID, as it is assumed that 146 * all peripherals use the same driver. 147 * 148 * @param blob FDT blob to use 149 * @param name Root name of alias to search for 150 * @param id Compatible ID to look for 151 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 152 */ 153 int fdtdec_next_alias(const void *blob, const char *name, 154 enum fdt_compat_id id, int *upto); 155 156 /** 157 * Find the compatible ID for a given node. 158 * 159 * Generally each node has at least one compatible string attached to it. 160 * This function looks through our list of known compatible strings and 161 * returns the corresponding ID which matches the compatible string. 162 * 163 * @param blob FDT blob to use 164 * @param node Node containing compatible string to find 165 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 166 */ 167 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 168 169 /** 170 * Find the next compatible node for a peripheral. 171 * 172 * Do the first call with node = 0. This function will return a pointer to 173 * the next compatible node. Next time you call this function, pass the 174 * value returned, and the next node will be provided. 175 * 176 * @param blob FDT blob to use 177 * @param node Start node for search 178 * @param id Compatible ID to look for (enum fdt_compat_id) 179 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 180 */ 181 int fdtdec_next_compatible(const void *blob, int node, 182 enum fdt_compat_id id); 183 184 /** 185 * Find the next compatible subnode for a peripheral. 186 * 187 * Do the first call with node set to the parent and depth = 0. This 188 * function will return the offset of the next compatible node. Next time 189 * you call this function, pass the node value returned last time, with 190 * depth unchanged, and the next node will be provided. 191 * 192 * @param blob FDT blob to use 193 * @param node Start node for search 194 * @param id Compatible ID to look for (enum fdt_compat_id) 195 * @param depthp Current depth (set to 0 before first call) 196 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 197 */ 198 int fdtdec_next_compatible_subnode(const void *blob, int node, 199 enum fdt_compat_id id, int *depthp); 200 201 /** 202 * Look up an address property in a node and return it as an address. 203 * The property must hold either one address with no trailing data or 204 * one address with a length. This is only tested on 32-bit machines. 205 * 206 * @param blob FDT blob 207 * @param node node to examine 208 * @param prop_name name of property to find 209 * @return address, if found, or FDT_ADDR_T_NONE if not 210 */ 211 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 212 const char *prop_name); 213 214 /** 215 * Look up an address property in a node and return it as an address. 216 * The property must hold one address with a length. This is only tested 217 * on 32-bit machines. 218 * 219 * @param blob FDT blob 220 * @param node node to examine 221 * @param prop_name name of property to find 222 * @return address, if found, or FDT_ADDR_T_NONE if not 223 */ 224 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 225 const char *prop_name, fdt_size_t *sizep); 226 227 /** 228 * Look up a 32-bit integer property in a node and return it. The property 229 * must have at least 4 bytes of data. The value of the first cell is 230 * returned. 231 * 232 * @param blob FDT blob 233 * @param node node to examine 234 * @param prop_name name of property to find 235 * @param default_val default value to return if the property is not found 236 * @return integer value, if found, or default_val if not 237 */ 238 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 239 s32 default_val); 240 241 /** 242 * Look up a 64-bit integer property in a node and return it. The property 243 * must have at least 8 bytes of data (2 cells). The first two cells are 244 * concatenated to form a 8 bytes value, where the first cell is top half and 245 * the second cell is bottom half. 246 * 247 * @param blob FDT blob 248 * @param node node to examine 249 * @param prop_name name of property to find 250 * @param default_val default value to return if the property is not found 251 * @return integer value, if found, or default_val if not 252 */ 253 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 254 uint64_t default_val); 255 256 /** 257 * Checks whether a node is enabled. 258 * This looks for a 'status' property. If this exists, then returns 1 if 259 * the status is 'ok' and 0 otherwise. If there is no status property, 260 * it returns 1 on the assumption that anything mentioned should be enabled 261 * by default. 262 * 263 * @param blob FDT blob 264 * @param node node to examine 265 * @return integer value 0 (not enabled) or 1 (enabled) 266 */ 267 int fdtdec_get_is_enabled(const void *blob, int node); 268 269 /** 270 * Make sure we have a valid fdt available to control U-Boot. 271 * 272 * If not, a message is printed to the console if the console is ready. 273 * 274 * @return 0 if all ok, -1 if not 275 */ 276 int fdtdec_prepare_fdt(void); 277 278 /** 279 * Checks that we have a valid fdt available to control U-Boot. 280 281 * However, if not then for the moment nothing is done, since this function 282 * is called too early to panic(). 283 * 284 * @returns 0 285 */ 286 int fdtdec_check_fdt(void); 287 288 /** 289 * Find the nodes for a peripheral and return a list of them in the correct 290 * order. This is used to enumerate all the peripherals of a certain type. 291 * 292 * To use this, optionally set up a /aliases node with alias properties for 293 * a peripheral. For example, for usb you could have: 294 * 295 * aliases { 296 * usb0 = "/ehci@c5008000"; 297 * usb1 = "/ehci@c5000000"; 298 * }; 299 * 300 * Pass "usb" as the name to this function and will return a list of two 301 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 302 * 303 * All nodes returned will match the compatible ID, as it is assumed that 304 * all peripherals use the same driver. 305 * 306 * If no alias node is found, then the node list will be returned in the 307 * order found in the fdt. If the aliases mention a node which doesn't 308 * exist, then this will be ignored. If nodes are found with no aliases, 309 * they will be added in any order. 310 * 311 * If there is a gap in the aliases, then this function return a 0 node at 312 * that position. The return value will also count these gaps. 313 * 314 * This function checks node properties and will not return nodes which are 315 * marked disabled (status = "disabled"). 316 * 317 * @param blob FDT blob to use 318 * @param name Root name of alias to search for 319 * @param id Compatible ID to look for 320 * @param node_list Place to put list of found nodes 321 * @param maxcount Maximum number of nodes to find 322 * @return number of nodes found on success, FTD_ERR_... on error 323 */ 324 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 325 enum fdt_compat_id id, int *node_list, int maxcount); 326 327 /* 328 * This function is similar to fdtdec_find_aliases_for_id() except that it 329 * adds to the node_list that is passed in. Any 0 elements are considered 330 * available for allocation - others are considered already used and are 331 * skipped. 332 * 333 * You can use this by calling fdtdec_find_aliases_for_id() with an 334 * uninitialised array, then setting the elements that are returned to -1, 335 * say, then calling this function, perhaps with a different compat id. 336 * Any elements you get back that are >0 are new nodes added by the call 337 * to this function. 338 * 339 * Note that if you have some nodes with aliases and some without, you are 340 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 341 * one compat_id may fill in positions for which you have aliases defined 342 * for another compat_id. When you later call *this* function with the second 343 * compat_id, the alias positions may already be used. A debug warning may 344 * be generated in this case, but it is safest to define aliases for all 345 * nodes when you care about the ordering. 346 */ 347 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 348 enum fdt_compat_id id, int *node_list, int maxcount); 349 350 /* 351 * Get the name for a compatible ID 352 * 353 * @param id Compatible ID to look for 354 * @return compatible string for that id 355 */ 356 const char *fdtdec_get_compatible(enum fdt_compat_id id); 357 358 /* Look up a phandle and follow it to its node. Then return the offset 359 * of that node. 360 * 361 * @param blob FDT blob 362 * @param node node to examine 363 * @param prop_name name of property to find 364 * @return node offset if found, -ve error code on error 365 */ 366 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 367 368 /** 369 * Look up a property in a node and return its contents in an integer 370 * array of given length. The property must have at least enough data for 371 * the array (4*count bytes). It may have more, but this will be ignored. 372 * 373 * @param blob FDT blob 374 * @param node node to examine 375 * @param prop_name name of property to find 376 * @param array array to fill with data 377 * @param count number of array elements 378 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 379 * or -FDT_ERR_BADLAYOUT if not enough data 380 */ 381 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 382 u32 *array, int count); 383 384 /** 385 * Look up a property in a node and return a pointer to its contents as a 386 * unsigned int array of given length. The property must have at least enough 387 * data for the array ('count' cells). It may have more, but this will be 388 * ignored. The data is not copied. 389 * 390 * Note that you must access elements of the array with fdt32_to_cpu(), 391 * since the elements will be big endian even on a little endian machine. 392 * 393 * @param blob FDT blob 394 * @param node node to examine 395 * @param prop_name name of property to find 396 * @param count number of array elements 397 * @return pointer to array if found, or NULL if the property is not 398 * found or there is not enough data 399 */ 400 const u32 *fdtdec_locate_array(const void *blob, int node, 401 const char *prop_name, int count); 402 403 /** 404 * Look up a boolean property in a node and return it. 405 * 406 * A boolean properly is true if present in the device tree and false if not 407 * present, regardless of its value. 408 * 409 * @param blob FDT blob 410 * @param node node to examine 411 * @param prop_name name of property to find 412 * @return 1 if the properly is present; 0 if it isn't present 413 */ 414 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 415 416 /** 417 * Decode a single GPIOs from an FDT. 418 * 419 * If the property is not found, then the GPIO structure will still be 420 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 421 * provide optional GPIOs. 422 * 423 * @param blob FDT blob to use 424 * @param node Node to look at 425 * @param prop_name Node property name 426 * @param gpio gpio elements to fill from FDT 427 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 428 */ 429 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 430 struct fdt_gpio_state *gpio); 431 432 /** 433 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 434 * terminating item. 435 * 436 * @param blob FDT blob to use 437 * @param node Node to look at 438 * @param prop_name Node property name 439 * @param gpio Array of gpio elements to fill from FDT. This will be 440 * untouched if either 0 or an error is returned 441 * @param max_count Maximum number of elements allowed 442 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 443 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 444 */ 445 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 446 struct fdt_gpio_state *gpio, int max_count); 447 448 /** 449 * Set up a GPIO pin according to the provided gpio information. At present this 450 * just requests the GPIO. 451 * 452 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 453 * deal with optional GPIOs. 454 * 455 * @param gpio GPIO info to use for set up 456 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 457 */ 458 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 459 460 /** 461 * Look in the FDT for a config item with the given name and return its value 462 * as a 32-bit integer. The property must have at least 4 bytes of data. The 463 * value of the first cell is returned. 464 * 465 * @param blob FDT blob to use 466 * @param prop_name Node property name 467 * @param default_val default value to return if the property is not found 468 * @return integer value, if found, or default_val if not 469 */ 470 int fdtdec_get_config_int(const void *blob, const char *prop_name, 471 int default_val); 472 473 /** 474 * Look in the FDT for a config item with the given name 475 * and return whether it exists. 476 * 477 * @param blob FDT blob 478 * @param prop_name property name to look up 479 * @return 1, if it exists, or 0 if not 480 */ 481 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 482 483 /** 484 * Look in the FDT for a config item with the given name and return its value 485 * as a string. 486 * 487 * @param blob FDT blob 488 * @param prop_name property name to look up 489 * @returns property string, NULL on error. 490 */ 491 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 492 493 /* 494 * Look up a property in a node and return its contents in a byte 495 * array of given length. The property must have at least enough data for 496 * the array (count bytes). It may have more, but this will be ignored. 497 * 498 * @param blob FDT blob 499 * @param node node to examine 500 * @param prop_name name of property to find 501 * @param array array to fill with data 502 * @param count number of array elements 503 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 504 * or -FDT_ERR_BADLAYOUT if not enough data 505 */ 506 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 507 u8 *array, int count); 508 509 /** 510 * Look up a property in a node and return a pointer to its contents as a 511 * byte array of given length. The property must have at least enough data 512 * for the array (count bytes). It may have more, but this will be ignored. 513 * The data is not copied. 514 * 515 * @param blob FDT blob 516 * @param node node to examine 517 * @param prop_name name of property to find 518 * @param count number of array elements 519 * @return pointer to byte array if found, or NULL if the property is not 520 * found or there is not enough data 521 */ 522 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 523 const char *prop_name, int count); 524 525 /** 526 * Look up a property in a node which contains a memory region address and 527 * size. Then return a pointer to this address. 528 * 529 * The property must hold one address with a length. This is only tested on 530 * 32-bit machines. 531 * 532 * @param blob FDT blob 533 * @param node node to examine 534 * @param prop_name name of property to find 535 * @param ptrp returns pointer to region, or NULL if no address 536 * @param size returns size of region 537 * @return 0 if ok, -1 on error (propery not found) 538 */ 539 int fdtdec_decode_region(const void *blob, int node, 540 const char *prop_name, void **ptrp, size_t *size); 541 #endif 542