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_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 88 89 COMPAT_COUNT, 90 }; 91 92 /* GPIOs are numbered from 0 */ 93 enum { 94 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 95 96 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 97 }; 98 99 /* This is the state of a GPIO pin as defined by the fdt */ 100 struct fdt_gpio_state { 101 const char *name; /* name of the fdt property defining this */ 102 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 103 u8 flags; /* FDT_GPIO_... flags */ 104 }; 105 106 /* This tells us whether a fdt_gpio_state record is valid or not */ 107 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 108 109 /** 110 * Read the GPIO taking into account the polarity of the pin. 111 * 112 * @param gpio pointer to the decoded gpio 113 * @return value of the gpio if successful, < 0 if unsuccessful 114 */ 115 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 116 117 /** 118 * Write the GPIO taking into account the polarity of the pin. 119 * 120 * @param gpio pointer to the decoded gpio 121 * @return 0 if successful 122 */ 123 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 124 125 /** 126 * Find the next numbered alias for a peripheral. This is used to enumerate 127 * all the peripherals of a certain type. 128 * 129 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 130 * this function will return a pointer to the node the alias points to, and 131 * then update *upto to 1. Next time you call this function, the next node 132 * will be returned. 133 * 134 * All nodes returned will match the compatible ID, as it is assumed that 135 * all peripherals use the same driver. 136 * 137 * @param blob FDT blob to use 138 * @param name Root name of alias to search for 139 * @param id Compatible ID to look for 140 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 141 */ 142 int fdtdec_next_alias(const void *blob, const char *name, 143 enum fdt_compat_id id, int *upto); 144 145 /** 146 * Find the compatible ID for a given node. 147 * 148 * Generally each node has at least one compatible string attached to it. 149 * This function looks through our list of known compatible strings and 150 * returns the corresponding ID which matches the compatible string. 151 * 152 * @param blob FDT blob to use 153 * @param node Node containing compatible string to find 154 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 155 */ 156 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 157 158 /** 159 * Find the next compatible node for a peripheral. 160 * 161 * Do the first call with node = 0. This function will return a pointer to 162 * the next compatible node. Next time you call this function, pass the 163 * value returned, and the next node will be provided. 164 * 165 * @param blob FDT blob to use 166 * @param node Start node for search 167 * @param id Compatible ID to look for (enum fdt_compat_id) 168 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 169 */ 170 int fdtdec_next_compatible(const void *blob, int node, 171 enum fdt_compat_id id); 172 173 /** 174 * Find the next compatible subnode for a peripheral. 175 * 176 * Do the first call with node set to the parent and depth = 0. This 177 * function will return the offset of the next compatible node. Next time 178 * you call this function, pass the node value returned last time, with 179 * depth unchanged, and the next node will be provided. 180 * 181 * @param blob FDT blob to use 182 * @param node Start node for search 183 * @param id Compatible ID to look for (enum fdt_compat_id) 184 * @param depthp Current depth (set to 0 before first call) 185 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 186 */ 187 int fdtdec_next_compatible_subnode(const void *blob, int node, 188 enum fdt_compat_id id, int *depthp); 189 190 /** 191 * Look up an address property in a node and return it as an address. 192 * The property must hold either one address with no trailing data or 193 * one address with a length. This is only tested on 32-bit machines. 194 * 195 * @param blob FDT blob 196 * @param node node to examine 197 * @param prop_name name of property to find 198 * @return address, if found, or FDT_ADDR_T_NONE if not 199 */ 200 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 201 const char *prop_name); 202 203 /** 204 * Look up a 32-bit integer property in a node and return it. The property 205 * must have at least 4 bytes of data. The value of the first cell is 206 * returned. 207 * 208 * @param blob FDT blob 209 * @param node node to examine 210 * @param prop_name name of property to find 211 * @param default_val default value to return if the property is not found 212 * @return integer value, if found, or default_val if not 213 */ 214 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 215 s32 default_val); 216 217 /** 218 * Look up a 64-bit integer property in a node and return it. The property 219 * must have at least 8 bytes of data (2 cells). The first two cells are 220 * concatenated to form a 8 bytes value, where the first cell is top half and 221 * the second cell is bottom half. 222 * 223 * @param blob FDT blob 224 * @param node node to examine 225 * @param prop_name name of property to find 226 * @param default_val default value to return if the property is not found 227 * @return integer value, if found, or default_val if not 228 */ 229 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 230 uint64_t default_val); 231 232 /** 233 * Checks whether a node is enabled. 234 * This looks for a 'status' property. If this exists, then returns 1 if 235 * the status is 'ok' and 0 otherwise. If there is no status property, 236 * it returns 1 on the assumption that anything mentioned should be enabled 237 * by default. 238 * 239 * @param blob FDT blob 240 * @param node node to examine 241 * @return integer value 0 (not enabled) or 1 (enabled) 242 */ 243 int fdtdec_get_is_enabled(const void *blob, int node); 244 245 /** 246 * Make sure we have a valid fdt available to control U-Boot. 247 * 248 * If not, a message is printed to the console if the console is ready. 249 * 250 * @return 0 if all ok, -1 if not 251 */ 252 int fdtdec_prepare_fdt(void); 253 254 /** 255 * Checks that we have a valid fdt available to control U-Boot. 256 257 * However, if not then for the moment nothing is done, since this function 258 * is called too early to panic(). 259 * 260 * @returns 0 261 */ 262 int fdtdec_check_fdt(void); 263 264 /** 265 * Find the nodes for a peripheral and return a list of them in the correct 266 * order. This is used to enumerate all the peripherals of a certain type. 267 * 268 * To use this, optionally set up a /aliases node with alias properties for 269 * a peripheral. For example, for usb you could have: 270 * 271 * aliases { 272 * usb0 = "/ehci@c5008000"; 273 * usb1 = "/ehci@c5000000"; 274 * }; 275 * 276 * Pass "usb" as the name to this function and will return a list of two 277 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 278 * 279 * All nodes returned will match the compatible ID, as it is assumed that 280 * all peripherals use the same driver. 281 * 282 * If no alias node is found, then the node list will be returned in the 283 * order found in the fdt. If the aliases mention a node which doesn't 284 * exist, then this will be ignored. If nodes are found with no aliases, 285 * they will be added in any order. 286 * 287 * If there is a gap in the aliases, then this function return a 0 node at 288 * that position. The return value will also count these gaps. 289 * 290 * This function checks node properties and will not return nodes which are 291 * marked disabled (status = "disabled"). 292 * 293 * @param blob FDT blob to use 294 * @param name Root name of alias to search for 295 * @param id Compatible ID to look for 296 * @param node_list Place to put list of found nodes 297 * @param maxcount Maximum number of nodes to find 298 * @return number of nodes found on success, FTD_ERR_... on error 299 */ 300 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 301 enum fdt_compat_id id, int *node_list, int maxcount); 302 303 /* 304 * This function is similar to fdtdec_find_aliases_for_id() except that it 305 * adds to the node_list that is passed in. Any 0 elements are considered 306 * available for allocation - others are considered already used and are 307 * skipped. 308 * 309 * You can use this by calling fdtdec_find_aliases_for_id() with an 310 * uninitialised array, then setting the elements that are returned to -1, 311 * say, then calling this function, perhaps with a different compat id. 312 * Any elements you get back that are >0 are new nodes added by the call 313 * to this function. 314 * 315 * Note that if you have some nodes with aliases and some without, you are 316 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 317 * one compat_id may fill in positions for which you have aliases defined 318 * for another compat_id. When you later call *this* function with the second 319 * compat_id, the alias positions may already be used. A debug warning may 320 * be generated in this case, but it is safest to define aliases for all 321 * nodes when you care about the ordering. 322 */ 323 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 324 enum fdt_compat_id id, int *node_list, int maxcount); 325 326 /* 327 * Get the name for a compatible ID 328 * 329 * @param id Compatible ID to look for 330 * @return compatible string for that id 331 */ 332 const char *fdtdec_get_compatible(enum fdt_compat_id id); 333 334 /* Look up a phandle and follow it to its node. Then return the offset 335 * of that node. 336 * 337 * @param blob FDT blob 338 * @param node node to examine 339 * @param prop_name name of property to find 340 * @return node offset if found, -ve error code on error 341 */ 342 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 343 344 /** 345 * Look up a property in a node and return its contents in an integer 346 * array of given length. The property must have at least enough data for 347 * the array (4*count bytes). It may have more, but this will be ignored. 348 * 349 * @param blob FDT blob 350 * @param node node to examine 351 * @param prop_name name of property to find 352 * @param array array to fill with data 353 * @param count number of array elements 354 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 355 * or -FDT_ERR_BADLAYOUT if not enough data 356 */ 357 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 358 u32 *array, int count); 359 360 /** 361 * Look up a property in a node and return a pointer to its contents as a 362 * unsigned int array of given length. The property must have at least enough 363 * data for the array ('count' cells). It may have more, but this will be 364 * ignored. The data is not copied. 365 * 366 * Note that you must access elements of the array with fdt32_to_cpu(), 367 * since the elements will be big endian even on a little endian machine. 368 * 369 * @param blob FDT blob 370 * @param node node to examine 371 * @param prop_name name of property to find 372 * @param count number of array elements 373 * @return pointer to array if found, or NULL if the property is not 374 * found or there is not enough data 375 */ 376 const u32 *fdtdec_locate_array(const void *blob, int node, 377 const char *prop_name, int count); 378 379 /** 380 * Look up a boolean property in a node and return it. 381 * 382 * A boolean properly is true if present in the device tree and false if not 383 * present, regardless of its value. 384 * 385 * @param blob FDT blob 386 * @param node node to examine 387 * @param prop_name name of property to find 388 * @return 1 if the properly is present; 0 if it isn't present 389 */ 390 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 391 392 /** 393 * Decode a single GPIOs from an FDT. 394 * 395 * If the property is not found, then the GPIO structure will still be 396 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 397 * provide optional GPIOs. 398 * 399 * @param blob FDT blob to use 400 * @param node Node to look at 401 * @param prop_name Node property name 402 * @param gpio gpio elements to fill from FDT 403 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 404 */ 405 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 406 struct fdt_gpio_state *gpio); 407 408 /** 409 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 410 * terminating item. 411 * 412 * @param blob FDT blob to use 413 * @param node Node to look at 414 * @param prop_name Node property name 415 * @param gpio Array of gpio elements to fill from FDT. This will be 416 * untouched if either 0 or an error is returned 417 * @param max_count Maximum number of elements allowed 418 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 419 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 420 */ 421 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 422 struct fdt_gpio_state *gpio, int max_count); 423 424 /** 425 * Set up a GPIO pin according to the provided gpio information. At present this 426 * just requests the GPIO. 427 * 428 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 429 * deal with optional GPIOs. 430 * 431 * @param gpio GPIO info to use for set up 432 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 433 */ 434 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 435 436 /** 437 * Look in the FDT for a config item with the given name and return its value 438 * as a 32-bit integer. The property must have at least 4 bytes of data. The 439 * value of the first cell is returned. 440 * 441 * @param blob FDT blob to use 442 * @param prop_name Node property name 443 * @param default_val default value to return if the property is not found 444 * @return integer value, if found, or default_val if not 445 */ 446 int fdtdec_get_config_int(const void *blob, const char *prop_name, 447 int default_val); 448 449 /** 450 * Look in the FDT for a config item with the given name 451 * and return whether it exists. 452 * 453 * @param blob FDT blob 454 * @param prop_name property name to look up 455 * @return 1, if it exists, or 0 if not 456 */ 457 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 458 459 /** 460 * Look in the FDT for a config item with the given name and return its value 461 * as a string. 462 * 463 * @param blob FDT blob 464 * @param prop_name property name to look up 465 * @returns property string, NULL on error. 466 */ 467 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 468 469 /* 470 * Look up a property in a node and return its contents in a byte 471 * array of given length. The property must have at least enough data for 472 * the array (count bytes). It may have more, but this will be ignored. 473 * 474 * @param blob FDT blob 475 * @param node node to examine 476 * @param prop_name name of property to find 477 * @param array array to fill with data 478 * @param count number of array elements 479 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 480 * or -FDT_ERR_BADLAYOUT if not enough data 481 */ 482 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 483 u8 *array, int count); 484 485 /** 486 * Look up a property in a node and return a pointer to its contents as a 487 * byte array of given length. The property must have at least enough data 488 * for the array (count bytes). It may have more, but this will be ignored. 489 * The data is not copied. 490 * 491 * @param blob FDT blob 492 * @param node node to examine 493 * @param prop_name name of property to find 494 * @param count number of array elements 495 * @return pointer to byte array if found, or NULL if the property is not 496 * found or there is not enough data 497 */ 498 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 499 const char *prop_name, int count); 500 501 /** 502 * Look up a property in a node which contains a memory region address and 503 * size. Then return a pointer to this address. 504 * 505 * The property must hold one address with a length. This is only tested on 506 * 32-bit machines. 507 * 508 * @param blob FDT blob 509 * @param node node to examine 510 * @param prop_name name of property to find 511 * @param ptrp returns pointer to region, or NULL if no address 512 * @param size returns size of region 513 * @return 0 if ok, -1 on error (propery not found) 514 */ 515 int fdtdec_decode_region(const void *blob, int node, 516 const char *prop_name, void **ptrp, size_t *size); 517 #endif 518