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_TEGRA20_I2C, /* Tegra20 i2c */ 66 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */ 67 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */ 68 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */ 69 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */ 70 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */ 71 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */ 72 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */ 73 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */ 74 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */ 75 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 76 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 77 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 78 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 79 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 80 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 81 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 82 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 83 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 84 85 COMPAT_COUNT, 86 }; 87 88 /* GPIOs are numbered from 0 */ 89 enum { 90 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 91 92 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 93 }; 94 95 /* This is the state of a GPIO pin as defined by the fdt */ 96 struct fdt_gpio_state { 97 const char *name; /* name of the fdt property defining this */ 98 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 99 u8 flags; /* FDT_GPIO_... flags */ 100 }; 101 102 /* This tells us whether a fdt_gpio_state record is valid or not */ 103 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 104 105 /** 106 * Read the GPIO taking into account the polarity of the pin. 107 * 108 * @param gpio pointer to the decoded gpio 109 * @return value of the gpio if successful, < 0 if unsuccessful 110 */ 111 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 112 113 /** 114 * Write the GPIO taking into account the polarity of the pin. 115 * 116 * @param gpio pointer to the decoded gpio 117 * @return 0 if successful 118 */ 119 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 120 121 /** 122 * Find the next numbered alias for a peripheral. This is used to enumerate 123 * all the peripherals of a certain type. 124 * 125 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 126 * this function will return a pointer to the node the alias points to, and 127 * then update *upto to 1. Next time you call this function, the next node 128 * will be returned. 129 * 130 * All nodes returned will match the compatible ID, as it is assumed that 131 * all peripherals use the same driver. 132 * 133 * @param blob FDT blob to use 134 * @param name Root name of alias to search for 135 * @param id Compatible ID to look for 136 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 137 */ 138 int fdtdec_next_alias(const void *blob, const char *name, 139 enum fdt_compat_id id, int *upto); 140 141 /** 142 * Find the compatible ID for a given node. 143 * 144 * Generally each node has at least one compatible string attached to it. 145 * This function looks through our list of known compatible strings and 146 * returns the corresponding ID which matches the compatible string. 147 * 148 * @param blob FDT blob to use 149 * @param node Node containing compatible string to find 150 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 151 */ 152 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 153 154 /** 155 * Find the next compatible node for a peripheral. 156 * 157 * Do the first call with node = 0. This function will return a pointer to 158 * the next compatible node. Next time you call this function, pass the 159 * value returned, and the next node will be provided. 160 * 161 * @param blob FDT blob to use 162 * @param node Start node for search 163 * @param id Compatible ID to look for (enum fdt_compat_id) 164 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 165 */ 166 int fdtdec_next_compatible(const void *blob, int node, 167 enum fdt_compat_id id); 168 169 /** 170 * Find the next compatible subnode for a peripheral. 171 * 172 * Do the first call with node set to the parent and depth = 0. This 173 * function will return the offset of the next compatible node. Next time 174 * you call this function, pass the node value returned last time, with 175 * depth unchanged, and the next node will be provided. 176 * 177 * @param blob FDT blob to use 178 * @param node Start node for search 179 * @param id Compatible ID to look for (enum fdt_compat_id) 180 * @param depthp Current depth (set to 0 before first call) 181 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 182 */ 183 int fdtdec_next_compatible_subnode(const void *blob, int node, 184 enum fdt_compat_id id, int *depthp); 185 186 /** 187 * Look up an address property in a node and return it as an address. 188 * The property must hold either one address with no trailing data or 189 * one address with a length. This is only tested on 32-bit machines. 190 * 191 * @param blob FDT blob 192 * @param node node to examine 193 * @param prop_name name of property to find 194 * @return address, if found, or FDT_ADDR_T_NONE if not 195 */ 196 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 197 const char *prop_name); 198 199 /** 200 * Look up a 32-bit integer property in a node and return it. The property 201 * must have at least 4 bytes of data. The value of the first cell is 202 * returned. 203 * 204 * @param blob FDT blob 205 * @param node node to examine 206 * @param prop_name name of property to find 207 * @param default_val default value to return if the property is not found 208 * @return integer value, if found, or default_val if not 209 */ 210 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 211 s32 default_val); 212 213 /** 214 * Look up a 64-bit integer property in a node and return it. The property 215 * must have at least 8 bytes of data (2 cells). The first two cells are 216 * concatenated to form a 8 bytes value, where the first cell is top half and 217 * the second cell is bottom half. 218 * 219 * @param blob FDT blob 220 * @param node node to examine 221 * @param prop_name name of property to find 222 * @param default_val default value to return if the property is not found 223 * @return integer value, if found, or default_val if not 224 */ 225 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 226 uint64_t default_val); 227 228 /** 229 * Checks whether a node is enabled. 230 * This looks for a 'status' property. If this exists, then returns 1 if 231 * the status is 'ok' and 0 otherwise. If there is no status property, 232 * it returns 1 on the assumption that anything mentioned should be enabled 233 * by default. 234 * 235 * @param blob FDT blob 236 * @param node node to examine 237 * @return integer value 0 (not enabled) or 1 (enabled) 238 */ 239 int fdtdec_get_is_enabled(const void *blob, int node); 240 241 /** 242 * Make sure we have a valid fdt available to control U-Boot. 243 * 244 * If not, a message is printed to the console if the console is ready. 245 * 246 * @return 0 if all ok, -1 if not 247 */ 248 int fdtdec_prepare_fdt(void); 249 250 /** 251 * Checks that we have a valid fdt available to control U-Boot. 252 253 * However, if not then for the moment nothing is done, since this function 254 * is called too early to panic(). 255 * 256 * @returns 0 257 */ 258 int fdtdec_check_fdt(void); 259 260 /** 261 * Find the nodes for a peripheral and return a list of them in the correct 262 * order. This is used to enumerate all the peripherals of a certain type. 263 * 264 * To use this, optionally set up a /aliases node with alias properties for 265 * a peripheral. For example, for usb you could have: 266 * 267 * aliases { 268 * usb0 = "/ehci@c5008000"; 269 * usb1 = "/ehci@c5000000"; 270 * }; 271 * 272 * Pass "usb" as the name to this function and will return a list of two 273 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 274 * 275 * All nodes returned will match the compatible ID, as it is assumed that 276 * all peripherals use the same driver. 277 * 278 * If no alias node is found, then the node list will be returned in the 279 * order found in the fdt. If the aliases mention a node which doesn't 280 * exist, then this will be ignored. If nodes are found with no aliases, 281 * they will be added in any order. 282 * 283 * If there is a gap in the aliases, then this function return a 0 node at 284 * that position. The return value will also count these gaps. 285 * 286 * This function checks node properties and will not return nodes which are 287 * marked disabled (status = "disabled"). 288 * 289 * @param blob FDT blob to use 290 * @param name Root name of alias to search for 291 * @param id Compatible ID to look for 292 * @param node_list Place to put list of found nodes 293 * @param maxcount Maximum number of nodes to find 294 * @return number of nodes found on success, FTD_ERR_... on error 295 */ 296 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 297 enum fdt_compat_id id, int *node_list, int maxcount); 298 299 /* 300 * This function is similar to fdtdec_find_aliases_for_id() except that it 301 * adds to the node_list that is passed in. Any 0 elements are considered 302 * available for allocation - others are considered already used and are 303 * skipped. 304 * 305 * You can use this by calling fdtdec_find_aliases_for_id() with an 306 * uninitialised array, then setting the elements that are returned to -1, 307 * say, then calling this function, perhaps with a different compat id. 308 * Any elements you get back that are >0 are new nodes added by the call 309 * to this function. 310 * 311 * Note that if you have some nodes with aliases and some without, you are 312 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 313 * one compat_id may fill in positions for which you have aliases defined 314 * for another compat_id. When you later call *this* function with the second 315 * compat_id, the alias positions may already be used. A debug warning may 316 * be generated in this case, but it is safest to define aliases for all 317 * nodes when you care about the ordering. 318 */ 319 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 320 enum fdt_compat_id id, int *node_list, int maxcount); 321 322 /* 323 * Get the name for a compatible ID 324 * 325 * @param id Compatible ID to look for 326 * @return compatible string for that id 327 */ 328 const char *fdtdec_get_compatible(enum fdt_compat_id id); 329 330 /* Look up a phandle and follow it to its node. Then return the offset 331 * of that node. 332 * 333 * @param blob FDT blob 334 * @param node node to examine 335 * @param prop_name name of property to find 336 * @return node offset if found, -ve error code on error 337 */ 338 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 339 340 /** 341 * Look up a property in a node and return its contents in an integer 342 * array of given length. The property must have at least enough data for 343 * the array (4*count bytes). It may have more, but this will be ignored. 344 * 345 * @param blob FDT blob 346 * @param node node to examine 347 * @param prop_name name of property to find 348 * @param array array to fill with data 349 * @param count number of array elements 350 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 351 * or -FDT_ERR_BADLAYOUT if not enough data 352 */ 353 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 354 u32 *array, int count); 355 356 /** 357 * Look up a property in a node and return a pointer to its contents as a 358 * unsigned int array of given length. The property must have at least enough 359 * data for the array ('count' cells). It may have more, but this will be 360 * ignored. The data is not copied. 361 * 362 * Note that you must access elements of the array with fdt32_to_cpu(), 363 * since the elements will be big endian even on a little endian machine. 364 * 365 * @param blob FDT blob 366 * @param node node to examine 367 * @param prop_name name of property to find 368 * @param count number of array elements 369 * @return pointer to array if found, or NULL if the property is not 370 * found or there is not enough data 371 */ 372 const u32 *fdtdec_locate_array(const void *blob, int node, 373 const char *prop_name, int count); 374 375 /** 376 * Look up a boolean property in a node and return it. 377 * 378 * A boolean properly is true if present in the device tree and false if not 379 * present, regardless of its value. 380 * 381 * @param blob FDT blob 382 * @param node node to examine 383 * @param prop_name name of property to find 384 * @return 1 if the properly is present; 0 if it isn't present 385 */ 386 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 387 388 /** 389 * Decode a single GPIOs from an FDT. 390 * 391 * If the property is not found, then the GPIO structure will still be 392 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 393 * provide optional GPIOs. 394 * 395 * @param blob FDT blob to use 396 * @param node Node to look at 397 * @param prop_name Node property name 398 * @param gpio gpio elements to fill from FDT 399 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 400 */ 401 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 402 struct fdt_gpio_state *gpio); 403 404 /** 405 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 406 * terminating item. 407 * 408 * @param blob FDT blob to use 409 * @param node Node to look at 410 * @param prop_name Node property name 411 * @param gpio Array of gpio elements to fill from FDT. This will be 412 * untouched if either 0 or an error is returned 413 * @param max_count Maximum number of elements allowed 414 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 415 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 416 */ 417 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 418 struct fdt_gpio_state *gpio, int max_count); 419 420 /** 421 * Set up a GPIO pin according to the provided gpio information. At present this 422 * just requests the GPIO. 423 * 424 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 425 * deal with optional GPIOs. 426 * 427 * @param gpio GPIO info to use for set up 428 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 429 */ 430 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 431 432 /** 433 * Look in the FDT for a config item with the given name and return its value 434 * as a 32-bit integer. The property must have at least 4 bytes of data. The 435 * value of the first cell is returned. 436 * 437 * @param blob FDT blob to use 438 * @param prop_name Node property name 439 * @param default_val default value to return if the property is not found 440 * @return integer value, if found, or default_val if not 441 */ 442 int fdtdec_get_config_int(const void *blob, const char *prop_name, 443 int default_val); 444 445 /** 446 * Look in the FDT for a config item with the given name 447 * and return whether it exists. 448 * 449 * @param blob FDT blob 450 * @param prop_name property name to look up 451 * @return 1, if it exists, or 0 if not 452 */ 453 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 454 455 /** 456 * Look in the FDT for a config item with the given name and return its value 457 * as a string. 458 * 459 * @param blob FDT blob 460 * @param prop_name property name to look up 461 * @returns property string, NULL on error. 462 */ 463 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 464 465 /* 466 * Look up a property in a node and return its contents in a byte 467 * array of given length. The property must have at least enough data for 468 * the array (count bytes). It may have more, but this will be ignored. 469 * 470 * @param blob FDT blob 471 * @param node node to examine 472 * @param prop_name name of property to find 473 * @param array array to fill with data 474 * @param count number of array elements 475 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 476 * or -FDT_ERR_BADLAYOUT if not enough data 477 */ 478 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 479 u8 *array, int count); 480 481 /** 482 * Look up a property in a node and return a pointer to its contents as a 483 * byte array of given length. The property must have at least enough data 484 * for the array (count bytes). It may have more, but this will be ignored. 485 * The data is not copied. 486 * 487 * @param blob FDT blob 488 * @param node node to examine 489 * @param prop_name name of property to find 490 * @param count number of array elements 491 * @return pointer to byte array if found, or NULL if the property is not 492 * found or there is not enough data 493 */ 494 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 495 const char *prop_name, int count); 496 497 /** 498 * Look up a property in a node which contains a memory region address and 499 * size. Then return a pointer to this address. 500 * 501 * The property must hold one address with a length. This is only tested on 502 * 32-bit machines. 503 * 504 * @param blob FDT blob 505 * @param node node to examine 506 * @param prop_name name of property to find 507 * @param ptrp returns pointer to region, or NULL if no address 508 * @param size returns size of region 509 * @return 0 if ok, -1 on error (propery not found) 510 */ 511 int fdtdec_decode_region(const void *blob, int node, 512 const char *prop_name, void **ptrp, size_t *size); 513 #endif 514