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