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_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 81 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 82 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 83 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 84 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 85 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 86 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 87 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 88 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 89 90 COMPAT_COUNT, 91 }; 92 93 /* GPIOs are numbered from 0 */ 94 enum { 95 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 96 97 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 98 }; 99 100 /* This is the state of a GPIO pin as defined by the fdt */ 101 struct fdt_gpio_state { 102 const char *name; /* name of the fdt property defining this */ 103 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 104 u8 flags; /* FDT_GPIO_... flags */ 105 }; 106 107 /* This tells us whether a fdt_gpio_state record is valid or not */ 108 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 109 110 /** 111 * Read the GPIO taking into account the polarity of the pin. 112 * 113 * @param gpio pointer to the decoded gpio 114 * @return value of the gpio if successful, < 0 if unsuccessful 115 */ 116 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 117 118 /** 119 * Write the GPIO taking into account the polarity of the pin. 120 * 121 * @param gpio pointer to the decoded gpio 122 * @return 0 if successful 123 */ 124 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 125 126 /** 127 * Find the next numbered alias for a peripheral. This is used to enumerate 128 * all the peripherals of a certain type. 129 * 130 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 131 * this function will return a pointer to the node the alias points to, and 132 * then update *upto to 1. Next time you call this function, the next node 133 * will be returned. 134 * 135 * All nodes returned will match the compatible ID, as it is assumed that 136 * all peripherals use the same driver. 137 * 138 * @param blob FDT blob to use 139 * @param name Root name of alias to search for 140 * @param id Compatible ID to look for 141 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 142 */ 143 int fdtdec_next_alias(const void *blob, const char *name, 144 enum fdt_compat_id id, int *upto); 145 146 /** 147 * Find the compatible ID for a given node. 148 * 149 * Generally each node has at least one compatible string attached to it. 150 * This function looks through our list of known compatible strings and 151 * returns the corresponding ID which matches the compatible string. 152 * 153 * @param blob FDT blob to use 154 * @param node Node containing compatible string to find 155 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 156 */ 157 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 158 159 /** 160 * Find the next compatible node for a peripheral. 161 * 162 * Do the first call with node = 0. This function will return a pointer to 163 * the next compatible node. Next time you call this function, pass the 164 * value returned, and the next node will be provided. 165 * 166 * @param blob FDT blob to use 167 * @param node Start node for search 168 * @param id Compatible ID to look for (enum fdt_compat_id) 169 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 170 */ 171 int fdtdec_next_compatible(const void *blob, int node, 172 enum fdt_compat_id id); 173 174 /** 175 * Find the next compatible subnode for a peripheral. 176 * 177 * Do the first call with node set to the parent and depth = 0. This 178 * function will return the offset of the next compatible node. Next time 179 * you call this function, pass the node value returned last time, with 180 * depth unchanged, and the next node will be provided. 181 * 182 * @param blob FDT blob to use 183 * @param node Start node for search 184 * @param id Compatible ID to look for (enum fdt_compat_id) 185 * @param depthp Current depth (set to 0 before first call) 186 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 187 */ 188 int fdtdec_next_compatible_subnode(const void *blob, int node, 189 enum fdt_compat_id id, int *depthp); 190 191 /** 192 * Look up an address property in a node and return it as an address. 193 * The property must hold either one address with no trailing data or 194 * one address with a length. This is only tested on 32-bit machines. 195 * 196 * @param blob FDT blob 197 * @param node node to examine 198 * @param prop_name name of property to find 199 * @return address, if found, or FDT_ADDR_T_NONE if not 200 */ 201 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 202 const char *prop_name); 203 204 /** 205 * Look up an address property in a node and return it as an address. 206 * The property must hold one address with a length. This is only tested 207 * on 32-bit machines. 208 * 209 * @param blob FDT blob 210 * @param node node to examine 211 * @param prop_name name of property to find 212 * @return address, if found, or FDT_ADDR_T_NONE if not 213 */ 214 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node, 215 const char *prop_name, fdt_size_t *sizep); 216 217 /** 218 * Look up a 32-bit integer property in a node and return it. The property 219 * must have at least 4 bytes of data. The value of the first cell is 220 * returned. 221 * 222 * @param blob FDT blob 223 * @param node node to examine 224 * @param prop_name name of property to find 225 * @param default_val default value to return if the property is not found 226 * @return integer value, if found, or default_val if not 227 */ 228 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 229 s32 default_val); 230 231 /** 232 * Look up a 64-bit integer property in a node and return it. The property 233 * must have at least 8 bytes of data (2 cells). The first two cells are 234 * concatenated to form a 8 bytes value, where the first cell is top half and 235 * the second cell is bottom half. 236 * 237 * @param blob FDT blob 238 * @param node node to examine 239 * @param prop_name name of property to find 240 * @param default_val default value to return if the property is not found 241 * @return integer value, if found, or default_val if not 242 */ 243 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 244 uint64_t default_val); 245 246 /** 247 * Checks whether a node is enabled. 248 * This looks for a 'status' property. If this exists, then returns 1 if 249 * the status is 'ok' and 0 otherwise. If there is no status property, 250 * it returns 1 on the assumption that anything mentioned should be enabled 251 * by default. 252 * 253 * @param blob FDT blob 254 * @param node node to examine 255 * @return integer value 0 (not enabled) or 1 (enabled) 256 */ 257 int fdtdec_get_is_enabled(const void *blob, int node); 258 259 /** 260 * Make sure we have a valid fdt available to control U-Boot. 261 * 262 * If not, a message is printed to the console if the console is ready. 263 * 264 * @return 0 if all ok, -1 if not 265 */ 266 int fdtdec_prepare_fdt(void); 267 268 /** 269 * Checks that we have a valid fdt available to control U-Boot. 270 271 * However, if not then for the moment nothing is done, since this function 272 * is called too early to panic(). 273 * 274 * @returns 0 275 */ 276 int fdtdec_check_fdt(void); 277 278 /** 279 * Find the nodes for a peripheral and return a list of them in the correct 280 * order. This is used to enumerate all the peripherals of a certain type. 281 * 282 * To use this, optionally set up a /aliases node with alias properties for 283 * a peripheral. For example, for usb you could have: 284 * 285 * aliases { 286 * usb0 = "/ehci@c5008000"; 287 * usb1 = "/ehci@c5000000"; 288 * }; 289 * 290 * Pass "usb" as the name to this function and will return a list of two 291 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 292 * 293 * All nodes returned will match the compatible ID, as it is assumed that 294 * all peripherals use the same driver. 295 * 296 * If no alias node is found, then the node list will be returned in the 297 * order found in the fdt. If the aliases mention a node which doesn't 298 * exist, then this will be ignored. If nodes are found with no aliases, 299 * they will be added in any order. 300 * 301 * If there is a gap in the aliases, then this function return a 0 node at 302 * that position. The return value will also count these gaps. 303 * 304 * This function checks node properties and will not return nodes which are 305 * marked disabled (status = "disabled"). 306 * 307 * @param blob FDT blob to use 308 * @param name Root name of alias to search for 309 * @param id Compatible ID to look for 310 * @param node_list Place to put list of found nodes 311 * @param maxcount Maximum number of nodes to find 312 * @return number of nodes found on success, FTD_ERR_... on error 313 */ 314 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 315 enum fdt_compat_id id, int *node_list, int maxcount); 316 317 /* 318 * This function is similar to fdtdec_find_aliases_for_id() except that it 319 * adds to the node_list that is passed in. Any 0 elements are considered 320 * available for allocation - others are considered already used and are 321 * skipped. 322 * 323 * You can use this by calling fdtdec_find_aliases_for_id() with an 324 * uninitialised array, then setting the elements that are returned to -1, 325 * say, then calling this function, perhaps with a different compat id. 326 * Any elements you get back that are >0 are new nodes added by the call 327 * to this function. 328 * 329 * Note that if you have some nodes with aliases and some without, you are 330 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 331 * one compat_id may fill in positions for which you have aliases defined 332 * for another compat_id. When you later call *this* function with the second 333 * compat_id, the alias positions may already be used. A debug warning may 334 * be generated in this case, but it is safest to define aliases for all 335 * nodes when you care about the ordering. 336 */ 337 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 338 enum fdt_compat_id id, int *node_list, int maxcount); 339 340 /* 341 * Get the name for a compatible ID 342 * 343 * @param id Compatible ID to look for 344 * @return compatible string for that id 345 */ 346 const char *fdtdec_get_compatible(enum fdt_compat_id id); 347 348 /* Look up a phandle and follow it to its node. Then return the offset 349 * of that node. 350 * 351 * @param blob FDT blob 352 * @param node node to examine 353 * @param prop_name name of property to find 354 * @return node offset if found, -ve error code on error 355 */ 356 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 357 358 /** 359 * Look up a property in a node and return its contents in an integer 360 * array of given length. The property must have at least enough data for 361 * the array (4*count bytes). It may have more, but this will be ignored. 362 * 363 * @param blob FDT blob 364 * @param node node to examine 365 * @param prop_name name of property to find 366 * @param array array to fill with data 367 * @param count number of array elements 368 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 369 * or -FDT_ERR_BADLAYOUT if not enough data 370 */ 371 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 372 u32 *array, int count); 373 374 /** 375 * Look up a property in a node and return a pointer to its contents as a 376 * unsigned int array of given length. The property must have at least enough 377 * data for the array ('count' cells). It may have more, but this will be 378 * ignored. The data is not copied. 379 * 380 * Note that you must access elements of the array with fdt32_to_cpu(), 381 * since the elements will be big endian even on a little endian machine. 382 * 383 * @param blob FDT blob 384 * @param node node to examine 385 * @param prop_name name of property to find 386 * @param count number of array elements 387 * @return pointer to array if found, or NULL if the property is not 388 * found or there is not enough data 389 */ 390 const u32 *fdtdec_locate_array(const void *blob, int node, 391 const char *prop_name, int count); 392 393 /** 394 * Look up a boolean property in a node and return it. 395 * 396 * A boolean properly is true if present in the device tree and false if not 397 * present, regardless of its value. 398 * 399 * @param blob FDT blob 400 * @param node node to examine 401 * @param prop_name name of property to find 402 * @return 1 if the properly is present; 0 if it isn't present 403 */ 404 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 405 406 /** 407 * Decode a single GPIOs from an FDT. 408 * 409 * If the property is not found, then the GPIO structure will still be 410 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 411 * provide optional GPIOs. 412 * 413 * @param blob FDT blob to use 414 * @param node Node to look at 415 * @param prop_name Node property name 416 * @param gpio gpio elements to fill from FDT 417 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 418 */ 419 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 420 struct fdt_gpio_state *gpio); 421 422 /** 423 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 424 * terminating item. 425 * 426 * @param blob FDT blob to use 427 * @param node Node to look at 428 * @param prop_name Node property name 429 * @param gpio Array of gpio elements to fill from FDT. This will be 430 * untouched if either 0 or an error is returned 431 * @param max_count Maximum number of elements allowed 432 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 433 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 434 */ 435 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 436 struct fdt_gpio_state *gpio, int max_count); 437 438 /** 439 * Set up a GPIO pin according to the provided gpio information. At present this 440 * just requests the GPIO. 441 * 442 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 443 * deal with optional GPIOs. 444 * 445 * @param gpio GPIO info to use for set up 446 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 447 */ 448 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 449 450 /** 451 * Look in the FDT for a config item with the given name and return its value 452 * as a 32-bit integer. The property must have at least 4 bytes of data. The 453 * value of the first cell is returned. 454 * 455 * @param blob FDT blob to use 456 * @param prop_name Node property name 457 * @param default_val default value to return if the property is not found 458 * @return integer value, if found, or default_val if not 459 */ 460 int fdtdec_get_config_int(const void *blob, const char *prop_name, 461 int default_val); 462 463 /** 464 * Look in the FDT for a config item with the given name 465 * and return whether it exists. 466 * 467 * @param blob FDT blob 468 * @param prop_name property name to look up 469 * @return 1, if it exists, or 0 if not 470 */ 471 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 472 473 /** 474 * Look in the FDT for a config item with the given name and return its value 475 * as a string. 476 * 477 * @param blob FDT blob 478 * @param prop_name property name to look up 479 * @returns property string, NULL on error. 480 */ 481 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 482 483 /* 484 * Look up a property in a node and return its contents in a byte 485 * array of given length. The property must have at least enough data for 486 * the array (count bytes). It may have more, but this will be ignored. 487 * 488 * @param blob FDT blob 489 * @param node node to examine 490 * @param prop_name name of property to find 491 * @param array array to fill with data 492 * @param count number of array elements 493 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 494 * or -FDT_ERR_BADLAYOUT if not enough data 495 */ 496 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 497 u8 *array, int count); 498 499 /** 500 * Look up a property in a node and return a pointer to its contents as a 501 * byte array of given length. The property must have at least enough data 502 * for the array (count bytes). It may have more, but this will be ignored. 503 * The data is not copied. 504 * 505 * @param blob FDT blob 506 * @param node node to examine 507 * @param prop_name name of property to find 508 * @param count number of array elements 509 * @return pointer to byte array if found, or NULL if the property is not 510 * found or there is not enough data 511 */ 512 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 513 const char *prop_name, int count); 514 515 /** 516 * Look up a property in a node which contains a memory region address and 517 * size. Then return a pointer to this address. 518 * 519 * The property must hold one address with a length. This is only tested on 520 * 32-bit machines. 521 * 522 * @param blob FDT blob 523 * @param node node to examine 524 * @param prop_name name of property to find 525 * @param ptrp returns pointer to region, or NULL if no address 526 * @param size returns size of region 527 * @return 0 if ok, -1 on error (propery not found) 528 */ 529 int fdtdec_decode_region(const void *blob, int node, 530 const char *prop_name, void **ptrp, size_t *size); 531 #endif 532