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_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 79 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 80 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 81 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 82 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 83 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 84 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 85 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 86 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 87 88 COMPAT_COUNT, 89 }; 90 91 /* GPIOs are numbered from 0 */ 92 enum { 93 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 94 95 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 96 }; 97 98 /* This is the state of a GPIO pin as defined by the fdt */ 99 struct fdt_gpio_state { 100 const char *name; /* name of the fdt property defining this */ 101 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 102 u8 flags; /* FDT_GPIO_... flags */ 103 }; 104 105 /* This tells us whether a fdt_gpio_state record is valid or not */ 106 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 107 108 /** 109 * Read the GPIO taking into account the polarity of the pin. 110 * 111 * @param gpio pointer to the decoded gpio 112 * @return value of the gpio if successful, < 0 if unsuccessful 113 */ 114 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 115 116 /** 117 * Write the GPIO taking into account the polarity of the pin. 118 * 119 * @param gpio pointer to the decoded gpio 120 * @return 0 if successful 121 */ 122 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 123 124 /** 125 * Find the next numbered alias for a peripheral. This is used to enumerate 126 * all the peripherals of a certain type. 127 * 128 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 129 * this function will return a pointer to the node the alias points to, and 130 * then update *upto to 1. Next time you call this function, the next node 131 * will be returned. 132 * 133 * All nodes returned will match the compatible ID, as it is assumed that 134 * all peripherals use the same driver. 135 * 136 * @param blob FDT blob to use 137 * @param name Root name of alias to search for 138 * @param id Compatible ID to look for 139 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 140 */ 141 int fdtdec_next_alias(const void *blob, const char *name, 142 enum fdt_compat_id id, int *upto); 143 144 /** 145 * Find the compatible ID for a given node. 146 * 147 * Generally each node has at least one compatible string attached to it. 148 * This function looks through our list of known compatible strings and 149 * returns the corresponding ID which matches the compatible string. 150 * 151 * @param blob FDT blob to use 152 * @param node Node containing compatible string to find 153 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 154 */ 155 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 156 157 /** 158 * Find the next compatible node for a peripheral. 159 * 160 * Do the first call with node = 0. This function will return a pointer to 161 * the next compatible node. Next time you call this function, pass the 162 * value returned, and the next node will be provided. 163 * 164 * @param blob FDT blob to use 165 * @param node Start node for search 166 * @param id Compatible ID to look for (enum fdt_compat_id) 167 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 168 */ 169 int fdtdec_next_compatible(const void *blob, int node, 170 enum fdt_compat_id id); 171 172 /** 173 * Find the next compatible subnode for a peripheral. 174 * 175 * Do the first call with node set to the parent and depth = 0. This 176 * function will return the offset of the next compatible node. Next time 177 * you call this function, pass the node value returned last time, with 178 * depth unchanged, and the next node will be provided. 179 * 180 * @param blob FDT blob to use 181 * @param node Start node for search 182 * @param id Compatible ID to look for (enum fdt_compat_id) 183 * @param depthp Current depth (set to 0 before first call) 184 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 185 */ 186 int fdtdec_next_compatible_subnode(const void *blob, int node, 187 enum fdt_compat_id id, int *depthp); 188 189 /** 190 * Look up an address property in a node and return it as an address. 191 * The property must hold either one address with no trailing data or 192 * one address with a length. This is only tested on 32-bit machines. 193 * 194 * @param blob FDT blob 195 * @param node node to examine 196 * @param prop_name name of property to find 197 * @return address, if found, or FDT_ADDR_T_NONE if not 198 */ 199 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 200 const char *prop_name); 201 202 /** 203 * Look up a 32-bit integer property in a node and return it. The property 204 * must have at least 4 bytes of data. The value of the first cell is 205 * returned. 206 * 207 * @param blob FDT blob 208 * @param node node to examine 209 * @param prop_name name of property to find 210 * @param default_val default value to return if the property is not found 211 * @return integer value, if found, or default_val if not 212 */ 213 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 214 s32 default_val); 215 216 /** 217 * Look up a 64-bit integer property in a node and return it. The property 218 * must have at least 8 bytes of data (2 cells). The first two cells are 219 * concatenated to form a 8 bytes value, where the first cell is top half and 220 * the second cell is bottom half. 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 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 229 uint64_t default_val); 230 231 /** 232 * Checks whether a node is enabled. 233 * This looks for a 'status' property. If this exists, then returns 1 if 234 * the status is 'ok' and 0 otherwise. If there is no status property, 235 * it returns 1 on the assumption that anything mentioned should be enabled 236 * by default. 237 * 238 * @param blob FDT blob 239 * @param node node to examine 240 * @return integer value 0 (not enabled) or 1 (enabled) 241 */ 242 int fdtdec_get_is_enabled(const void *blob, int node); 243 244 /** 245 * Make sure we have a valid fdt available to control U-Boot. 246 * 247 * If not, a message is printed to the console if the console is ready. 248 * 249 * @return 0 if all ok, -1 if not 250 */ 251 int fdtdec_prepare_fdt(void); 252 253 /** 254 * Checks that we have a valid fdt available to control U-Boot. 255 256 * However, if not then for the moment nothing is done, since this function 257 * is called too early to panic(). 258 * 259 * @returns 0 260 */ 261 int fdtdec_check_fdt(void); 262 263 /** 264 * Find the nodes for a peripheral and return a list of them in the correct 265 * order. This is used to enumerate all the peripherals of a certain type. 266 * 267 * To use this, optionally set up a /aliases node with alias properties for 268 * a peripheral. For example, for usb you could have: 269 * 270 * aliases { 271 * usb0 = "/ehci@c5008000"; 272 * usb1 = "/ehci@c5000000"; 273 * }; 274 * 275 * Pass "usb" as the name to this function and will return a list of two 276 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 277 * 278 * All nodes returned will match the compatible ID, as it is assumed that 279 * all peripherals use the same driver. 280 * 281 * If no alias node is found, then the node list will be returned in the 282 * order found in the fdt. If the aliases mention a node which doesn't 283 * exist, then this will be ignored. If nodes are found with no aliases, 284 * they will be added in any order. 285 * 286 * If there is a gap in the aliases, then this function return a 0 node at 287 * that position. The return value will also count these gaps. 288 * 289 * This function checks node properties and will not return nodes which are 290 * marked disabled (status = "disabled"). 291 * 292 * @param blob FDT blob to use 293 * @param name Root name of alias to search for 294 * @param id Compatible ID to look for 295 * @param node_list Place to put list of found nodes 296 * @param maxcount Maximum number of nodes to find 297 * @return number of nodes found on success, FTD_ERR_... on error 298 */ 299 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 300 enum fdt_compat_id id, int *node_list, int maxcount); 301 302 /* 303 * This function is similar to fdtdec_find_aliases_for_id() except that it 304 * adds to the node_list that is passed in. Any 0 elements are considered 305 * available for allocation - others are considered already used and are 306 * skipped. 307 * 308 * You can use this by calling fdtdec_find_aliases_for_id() with an 309 * uninitialised array, then setting the elements that are returned to -1, 310 * say, then calling this function, perhaps with a different compat id. 311 * Any elements you get back that are >0 are new nodes added by the call 312 * to this function. 313 * 314 * Note that if you have some nodes with aliases and some without, you are 315 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 316 * one compat_id may fill in positions for which you have aliases defined 317 * for another compat_id. When you later call *this* function with the second 318 * compat_id, the alias positions may already be used. A debug warning may 319 * be generated in this case, but it is safest to define aliases for all 320 * nodes when you care about the ordering. 321 */ 322 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 323 enum fdt_compat_id id, int *node_list, int maxcount); 324 325 /* 326 * Get the name for a compatible ID 327 * 328 * @param id Compatible ID to look for 329 * @return compatible string for that id 330 */ 331 const char *fdtdec_get_compatible(enum fdt_compat_id id); 332 333 /* Look up a phandle and follow it to its node. Then return the offset 334 * of that node. 335 * 336 * @param blob FDT blob 337 * @param node node to examine 338 * @param prop_name name of property to find 339 * @return node offset if found, -ve error code on error 340 */ 341 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 342 343 /** 344 * Look up a property in a node and return its contents in an integer 345 * array of given length. The property must have at least enough data for 346 * the array (4*count bytes). It may have more, but this will be ignored. 347 * 348 * @param blob FDT blob 349 * @param node node to examine 350 * @param prop_name name of property to find 351 * @param array array to fill with data 352 * @param count number of array elements 353 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 354 * or -FDT_ERR_BADLAYOUT if not enough data 355 */ 356 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 357 u32 *array, int count); 358 359 /** 360 * Look up a property in a node and return a pointer to its contents as a 361 * unsigned int array of given length. The property must have at least enough 362 * data for the array ('count' cells). It may have more, but this will be 363 * ignored. The data is not copied. 364 * 365 * Note that you must access elements of the array with fdt32_to_cpu(), 366 * since the elements will be big endian even on a little endian machine. 367 * 368 * @param blob FDT blob 369 * @param node node to examine 370 * @param prop_name name of property to find 371 * @param count number of array elements 372 * @return pointer to array if found, or NULL if the property is not 373 * found or there is not enough data 374 */ 375 const u32 *fdtdec_locate_array(const void *blob, int node, 376 const char *prop_name, int count); 377 378 /** 379 * Look up a boolean property in a node and return it. 380 * 381 * A boolean properly is true if present in the device tree and false if not 382 * present, regardless of its value. 383 * 384 * @param blob FDT blob 385 * @param node node to examine 386 * @param prop_name name of property to find 387 * @return 1 if the properly is present; 0 if it isn't present 388 */ 389 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 390 391 /** 392 * Decode a single GPIOs from an FDT. 393 * 394 * If the property is not found, then the GPIO structure will still be 395 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 396 * provide optional GPIOs. 397 * 398 * @param blob FDT blob to use 399 * @param node Node to look at 400 * @param prop_name Node property name 401 * @param gpio gpio elements to fill from FDT 402 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 403 */ 404 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 405 struct fdt_gpio_state *gpio); 406 407 /** 408 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 409 * terminating item. 410 * 411 * @param blob FDT blob to use 412 * @param node Node to look at 413 * @param prop_name Node property name 414 * @param gpio Array of gpio elements to fill from FDT. This will be 415 * untouched if either 0 or an error is returned 416 * @param max_count Maximum number of elements allowed 417 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 418 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 419 */ 420 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 421 struct fdt_gpio_state *gpio, int max_count); 422 423 /** 424 * Set up a GPIO pin according to the provided gpio information. At present this 425 * just requests the GPIO. 426 * 427 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 428 * deal with optional GPIOs. 429 * 430 * @param gpio GPIO info to use for set up 431 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 432 */ 433 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 434 435 /** 436 * Look in the FDT for a config item with the given name and return its value 437 * as a 32-bit integer. The property must have at least 4 bytes of data. The 438 * value of the first cell is returned. 439 * 440 * @param blob FDT blob to use 441 * @param prop_name Node property name 442 * @param default_val default value to return if the property is not found 443 * @return integer value, if found, or default_val if not 444 */ 445 int fdtdec_get_config_int(const void *blob, const char *prop_name, 446 int default_val); 447 448 /** 449 * Look in the FDT for a config item with the given name 450 * and return whether it exists. 451 * 452 * @param blob FDT blob 453 * @param prop_name property name to look up 454 * @return 1, if it exists, or 0 if not 455 */ 456 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 457 458 /** 459 * Look in the FDT for a config item with the given name and return its value 460 * as a string. 461 * 462 * @param blob FDT blob 463 * @param prop_name property name to look up 464 * @returns property string, NULL on error. 465 */ 466 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 467 468 /* 469 * Look up a property in a node and return its contents in a byte 470 * array of given length. The property must have at least enough data for 471 * the array (count bytes). It may have more, but this will be ignored. 472 * 473 * @param blob FDT blob 474 * @param node node to examine 475 * @param prop_name name of property to find 476 * @param array array to fill with data 477 * @param count number of array elements 478 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 479 * or -FDT_ERR_BADLAYOUT if not enough data 480 */ 481 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 482 u8 *array, int count); 483 484 /** 485 * Look up a property in a node and return a pointer to its contents as a 486 * byte array of given length. The property must have at least enough data 487 * for the array (count bytes). It may have more, but this will be ignored. 488 * The data is not copied. 489 * 490 * @param blob FDT blob 491 * @param node node to examine 492 * @param prop_name name of property to find 493 * @param count number of array elements 494 * @return pointer to byte array if found, or NULL if the property is not 495 * found or there is not enough data 496 */ 497 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 498 const char *prop_name, int count); 499 500 /** 501 * Look up a property in a node which contains a memory region address and 502 * size. Then return a pointer to this address. 503 * 504 * The property must hold one address with a length. This is only tested on 505 * 32-bit machines. 506 * 507 * @param blob FDT blob 508 * @param node node to examine 509 * @param prop_name name of property to find 510 * @param ptrp returns pointer to region, or NULL if no address 511 * @param size returns size of region 512 * @return 0 if ok, -1 on error (propery not found) 513 */ 514 int fdtdec_decode_region(const void *blob, int node, 515 const char *prop_name, void **ptrp, size_t *size); 516 #endif 517