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 #define FDT_ADDR_T_NONE (-1ULL) 42 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg) 43 #define fdt_size_to_cpu(reg) be64_to_cpu(reg) 44 #else 45 typedef u32 fdt_addr_t; 46 #define FDT_ADDR_T_NONE (-1U) 47 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg) 48 #define fdt_size_to_cpu(reg) be32_to_cpu(reg) 49 #endif 50 51 /* Information obtained about memory from the FDT */ 52 struct fdt_memory { 53 fdt_addr_t start; 54 fdt_addr_t end; 55 }; 56 57 /** 58 * Compat types that we know about and for which we might have drivers. 59 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory 60 * within drivers. 61 */ 62 enum fdt_compat_id { 63 COMPAT_UNKNOWN, 64 COMPAT_NVIDIA_TEGRA20_USB, /* Tegra20 USB port */ 65 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */ 66 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */ 67 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */ 68 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */ 69 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */ 70 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */ 71 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */ 72 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */ 73 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */ 74 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */ 75 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */ 76 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */ 77 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */ 78 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */ 79 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 80 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 81 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 82 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 83 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 84 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 85 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 86 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 87 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */ 88 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 89 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 90 91 COMPAT_COUNT, 92 }; 93 94 /* GPIOs are numbered from 0 */ 95 enum { 96 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 97 98 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 99 }; 100 101 /* This is the state of a GPIO pin as defined by the fdt */ 102 struct fdt_gpio_state { 103 const char *name; /* name of the fdt property defining this */ 104 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 105 u8 flags; /* FDT_GPIO_... flags */ 106 }; 107 108 /* This tells us whether a fdt_gpio_state record is valid or not */ 109 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 110 111 /** 112 * Read the GPIO taking into account the polarity of the pin. 113 * 114 * @param gpio pointer to the decoded gpio 115 * @return value of the gpio if successful, < 0 if unsuccessful 116 */ 117 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 118 119 /** 120 * Write the GPIO taking into account the polarity of the pin. 121 * 122 * @param gpio pointer to the decoded gpio 123 * @return 0 if successful 124 */ 125 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 126 127 /** 128 * Find the next numbered alias for a peripheral. This is used to enumerate 129 * all the peripherals of a certain type. 130 * 131 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 132 * this function will return a pointer to the node the alias points to, and 133 * then update *upto to 1. Next time you call this function, the next node 134 * will be returned. 135 * 136 * All nodes returned will match the compatible ID, as it is assumed that 137 * all peripherals use the same driver. 138 * 139 * @param blob FDT blob to use 140 * @param name Root name of alias to search for 141 * @param id Compatible ID to look for 142 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 143 */ 144 int fdtdec_next_alias(const void *blob, const char *name, 145 enum fdt_compat_id id, int *upto); 146 147 /** 148 * Find the compatible ID for a given node. 149 * 150 * Generally each node has at least one compatible string attached to it. 151 * This function looks through our list of known compatible strings and 152 * returns the corresponding ID which matches the compatible string. 153 * 154 * @param blob FDT blob to use 155 * @param node Node containing compatible string to find 156 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 157 */ 158 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 159 160 /** 161 * Find the next compatible node for a peripheral. 162 * 163 * Do the first call with node = 0. This function will return a pointer to 164 * the next compatible node. Next time you call this function, pass the 165 * value returned, and the next node will be provided. 166 * 167 * @param blob FDT blob to use 168 * @param node Start node for search 169 * @param id Compatible ID to look for (enum fdt_compat_id) 170 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 171 */ 172 int fdtdec_next_compatible(const void *blob, int node, 173 enum fdt_compat_id id); 174 175 /** 176 * Find the next compatible subnode for a peripheral. 177 * 178 * Do the first call with node set to the parent and depth = 0. This 179 * function will return the offset of the next compatible node. Next time 180 * you call this function, pass the node value returned last time, with 181 * depth unchanged, and the next node will be provided. 182 * 183 * @param blob FDT blob to use 184 * @param node Start node for search 185 * @param id Compatible ID to look for (enum fdt_compat_id) 186 * @param depthp Current depth (set to 0 before first call) 187 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 188 */ 189 int fdtdec_next_compatible_subnode(const void *blob, int node, 190 enum fdt_compat_id id, int *depthp); 191 192 /** 193 * Look up an address property in a node and return it as an address. 194 * The property must hold either one address with no trailing data or 195 * one address with a length. This is only tested on 32-bit machines. 196 * 197 * @param blob FDT blob 198 * @param node node to examine 199 * @param prop_name name of property to find 200 * @return address, if found, or FDT_ADDR_T_NONE if not 201 */ 202 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 203 const char *prop_name); 204 205 /** 206 * Look up a 32-bit integer property in a node and return it. The property 207 * must have at least 4 bytes of data. The value of the first cell is 208 * returned. 209 * 210 * @param blob FDT blob 211 * @param node node to examine 212 * @param prop_name name of property to find 213 * @param default_val default value to return if the property is not found 214 * @return integer value, if found, or default_val if not 215 */ 216 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 217 s32 default_val); 218 219 /** 220 * Look up a 64-bit integer property in a node and return it. The property 221 * must have at least 8 bytes of data (2 cells). The first two cells are 222 * concatenated to form a 8 bytes value, where the first cell is top half and 223 * the second cell is bottom half. 224 * 225 * @param blob FDT blob 226 * @param node node to examine 227 * @param prop_name name of property to find 228 * @param default_val default value to return if the property is not found 229 * @return integer value, if found, or default_val if not 230 */ 231 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 232 uint64_t default_val); 233 234 /** 235 * Checks whether a node is enabled. 236 * This looks for a 'status' property. If this exists, then returns 1 if 237 * the status is 'ok' and 0 otherwise. If there is no status property, 238 * it returns 1 on the assumption that anything mentioned should be enabled 239 * by default. 240 * 241 * @param blob FDT blob 242 * @param node node to examine 243 * @return integer value 0 (not enabled) or 1 (enabled) 244 */ 245 int fdtdec_get_is_enabled(const void *blob, int node); 246 247 /** 248 * Make sure we have a valid fdt available to control U-Boot. 249 * 250 * If not, a message is printed to the console if the console is ready. 251 * 252 * @return 0 if all ok, -1 if not 253 */ 254 int fdtdec_prepare_fdt(void); 255 256 /** 257 * Checks that we have a valid fdt available to control U-Boot. 258 259 * However, if not then for the moment nothing is done, since this function 260 * is called too early to panic(). 261 * 262 * @returns 0 263 */ 264 int fdtdec_check_fdt(void); 265 266 /** 267 * Find the nodes for a peripheral and return a list of them in the correct 268 * order. This is used to enumerate all the peripherals of a certain type. 269 * 270 * To use this, optionally set up a /aliases node with alias properties for 271 * a peripheral. For example, for usb you could have: 272 * 273 * aliases { 274 * usb0 = "/ehci@c5008000"; 275 * usb1 = "/ehci@c5000000"; 276 * }; 277 * 278 * Pass "usb" as the name to this function and will return a list of two 279 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 280 * 281 * All nodes returned will match the compatible ID, as it is assumed that 282 * all peripherals use the same driver. 283 * 284 * If no alias node is found, then the node list will be returned in the 285 * order found in the fdt. If the aliases mention a node which doesn't 286 * exist, then this will be ignored. If nodes are found with no aliases, 287 * they will be added in any order. 288 * 289 * If there is a gap in the aliases, then this function return a 0 node at 290 * that position. The return value will also count these gaps. 291 * 292 * This function checks node properties and will not return nodes which are 293 * marked disabled (status = "disabled"). 294 * 295 * @param blob FDT blob to use 296 * @param name Root name of alias to search for 297 * @param id Compatible ID to look for 298 * @param node_list Place to put list of found nodes 299 * @param maxcount Maximum number of nodes to find 300 * @return number of nodes found on success, FTD_ERR_... on error 301 */ 302 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 303 enum fdt_compat_id id, int *node_list, int maxcount); 304 305 /* 306 * This function is similar to fdtdec_find_aliases_for_id() except that it 307 * adds to the node_list that is passed in. Any 0 elements are considered 308 * available for allocation - others are considered already used and are 309 * skipped. 310 * 311 * You can use this by calling fdtdec_find_aliases_for_id() with an 312 * uninitialised array, then setting the elements that are returned to -1, 313 * say, then calling this function, perhaps with a different compat id. 314 * Any elements you get back that are >0 are new nodes added by the call 315 * to this function. 316 * 317 * Note that if you have some nodes with aliases and some without, you are 318 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 319 * one compat_id may fill in positions for which you have aliases defined 320 * for another compat_id. When you later call *this* function with the second 321 * compat_id, the alias positions may already be used. A debug warning may 322 * be generated in this case, but it is safest to define aliases for all 323 * nodes when you care about the ordering. 324 */ 325 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 326 enum fdt_compat_id id, int *node_list, int maxcount); 327 328 /* 329 * Get the name for a compatible ID 330 * 331 * @param id Compatible ID to look for 332 * @return compatible string for that id 333 */ 334 const char *fdtdec_get_compatible(enum fdt_compat_id id); 335 336 /* Look up a phandle and follow it to its node. Then return the offset 337 * of that node. 338 * 339 * @param blob FDT blob 340 * @param node node to examine 341 * @param prop_name name of property to find 342 * @return node offset if found, -ve error code on error 343 */ 344 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 345 346 /** 347 * Look up a property in a node and return its contents in an integer 348 * array of given length. The property must have at least enough data for 349 * the array (4*count bytes). It may have more, but this will be ignored. 350 * 351 * @param blob FDT blob 352 * @param node node to examine 353 * @param prop_name name of property to find 354 * @param array array to fill with data 355 * @param count number of array elements 356 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 357 * or -FDT_ERR_BADLAYOUT if not enough data 358 */ 359 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 360 u32 *array, int count); 361 362 /** 363 * Look up a property in a node and return a pointer to its contents as a 364 * unsigned int array of given length. The property must have at least enough 365 * data for the array ('count' cells). It may have more, but this will be 366 * ignored. The data is not copied. 367 * 368 * Note that you must access elements of the array with fdt32_to_cpu(), 369 * since the elements will be big endian even on a little endian machine. 370 * 371 * @param blob FDT blob 372 * @param node node to examine 373 * @param prop_name name of property to find 374 * @param count number of array elements 375 * @return pointer to array if found, or NULL if the property is not 376 * found or there is not enough data 377 */ 378 const u32 *fdtdec_locate_array(const void *blob, int node, 379 const char *prop_name, int count); 380 381 /** 382 * Look up a boolean property in a node and return it. 383 * 384 * A boolean properly is true if present in the device tree and false if not 385 * present, regardless of its value. 386 * 387 * @param blob FDT blob 388 * @param node node to examine 389 * @param prop_name name of property to find 390 * @return 1 if the properly is present; 0 if it isn't present 391 */ 392 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 393 394 /** 395 * Decode a single GPIOs from an FDT. 396 * 397 * If the property is not found, then the GPIO structure will still be 398 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 399 * provide optional GPIOs. 400 * 401 * @param blob FDT blob to use 402 * @param node Node to look at 403 * @param prop_name Node property name 404 * @param gpio gpio elements to fill from FDT 405 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 406 */ 407 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 408 struct fdt_gpio_state *gpio); 409 410 /** 411 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 412 * terminating item. 413 * 414 * @param blob FDT blob to use 415 * @param node Node to look at 416 * @param prop_name Node property name 417 * @param gpio Array of gpio elements to fill from FDT. This will be 418 * untouched if either 0 or an error is returned 419 * @param max_count Maximum number of elements allowed 420 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 421 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 422 */ 423 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 424 struct fdt_gpio_state *gpio, int max_count); 425 426 /** 427 * Set up a GPIO pin according to the provided gpio information. At present this 428 * just requests the GPIO. 429 * 430 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 431 * deal with optional GPIOs. 432 * 433 * @param gpio GPIO info to use for set up 434 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 435 */ 436 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 437 438 /** 439 * Look in the FDT for a config item with the given name and return its value 440 * as a 32-bit integer. The property must have at least 4 bytes of data. The 441 * value of the first cell is returned. 442 * 443 * @param blob FDT blob to use 444 * @param prop_name Node property name 445 * @param default_val default value to return if the property is not found 446 * @return integer value, if found, or default_val if not 447 */ 448 int fdtdec_get_config_int(const void *blob, const char *prop_name, 449 int default_val); 450 451 /** 452 * Look in the FDT for a config item with the given name 453 * and return whether it exists. 454 * 455 * @param blob FDT blob 456 * @param prop_name property name to look up 457 * @return 1, if it exists, or 0 if not 458 */ 459 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 460 461 /** 462 * Look in the FDT for a config item with the given name and return its value 463 * as a string. 464 * 465 * @param blob FDT blob 466 * @param prop_name property name to look up 467 * @returns property string, NULL on error. 468 */ 469 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 470 471 /* 472 * Look up a property in a node and return its contents in a byte 473 * array of given length. The property must have at least enough data for 474 * the array (count bytes). It may have more, but this will be ignored. 475 * 476 * @param blob FDT blob 477 * @param node node to examine 478 * @param prop_name name of property to find 479 * @param array array to fill with data 480 * @param count number of array elements 481 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 482 * or -FDT_ERR_BADLAYOUT if not enough data 483 */ 484 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 485 u8 *array, int count); 486 487 /** 488 * Look up a property in a node and return a pointer to its contents as a 489 * byte array of given length. The property must have at least enough data 490 * for the array (count bytes). It may have more, but this will be ignored. 491 * The data is not copied. 492 * 493 * @param blob FDT blob 494 * @param node node to examine 495 * @param prop_name name of property to find 496 * @param count number of array elements 497 * @return pointer to byte array if found, or NULL if the property is not 498 * found or there is not enough data 499 */ 500 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 501 const char *prop_name, int count); 502 503 /** 504 * Look up a property in a node which contains a memory region address and 505 * size. Then return a pointer to this address. 506 * 507 * The property must hold one address with a length. This is only tested on 508 * 32-bit machines. 509 * 510 * @param blob FDT blob 511 * @param node node to examine 512 * @param prop_name name of property to find 513 * @param ptrp returns pointer to region, or NULL if no address 514 * @param size returns size of region 515 * @return 0 if ok, -1 on error (propery not found) 516 */ 517 int fdtdec_decode_region(const void *blob, int node, 518 const char *prop_name, void **ptrp, size_t *size); 519 #endif 520