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_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 74 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 75 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 76 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 77 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 78 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 79 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 80 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 81 82 COMPAT_COUNT, 83 }; 84 85 /* GPIOs are numbered from 0 */ 86 enum { 87 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 88 89 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 90 }; 91 92 /* This is the state of a GPIO pin as defined by the fdt */ 93 struct fdt_gpio_state { 94 const char *name; /* name of the fdt property defining this */ 95 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 96 u8 flags; /* FDT_GPIO_... flags */ 97 }; 98 99 /* This tells us whether a fdt_gpio_state record is valid or not */ 100 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 101 102 /** 103 * Read the GPIO taking into account the polarity of the pin. 104 * 105 * @param gpio pointer to the decoded gpio 106 * @return value of the gpio if successful, < 0 if unsuccessful 107 */ 108 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 109 110 /** 111 * Write the GPIO taking into account the polarity of the pin. 112 * 113 * @param gpio pointer to the decoded gpio 114 * @return 0 if successful 115 */ 116 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 117 118 /** 119 * Find the next numbered alias for a peripheral. This is used to enumerate 120 * all the peripherals of a certain type. 121 * 122 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 123 * this function will return a pointer to the node the alias points to, and 124 * then update *upto to 1. Next time you call this function, the next node 125 * will be returned. 126 * 127 * All nodes returned will match the compatible ID, as it is assumed that 128 * all peripherals use the same driver. 129 * 130 * @param blob FDT blob to use 131 * @param name Root name of alias to search for 132 * @param id Compatible ID to look for 133 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 134 */ 135 int fdtdec_next_alias(const void *blob, const char *name, 136 enum fdt_compat_id id, int *upto); 137 138 /** 139 * Find the compatible ID for a given node. 140 * 141 * Generally each node has at least one compatible string attached to it. 142 * This function looks through our list of known compatible strings and 143 * returns the corresponding ID which matches the compatible string. 144 * 145 * @param blob FDT blob to use 146 * @param node Node containing compatible string to find 147 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 148 */ 149 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 150 151 /** 152 * Find the next compatible node for a peripheral. 153 * 154 * Do the first call with node = 0. This function will return a pointer to 155 * the next compatible node. Next time you call this function, pass the 156 * value returned, and the next node will be provided. 157 * 158 * @param blob FDT blob to use 159 * @param node Start node for search 160 * @param id Compatible ID to look for (enum fdt_compat_id) 161 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 162 */ 163 int fdtdec_next_compatible(const void *blob, int node, 164 enum fdt_compat_id id); 165 166 /** 167 * Find the next compatible subnode for a peripheral. 168 * 169 * Do the first call with node set to the parent and depth = 0. This 170 * function will return the offset of the next compatible node. Next time 171 * you call this function, pass the node value returned last time, with 172 * depth unchanged, and the next node will be provided. 173 * 174 * @param blob FDT blob to use 175 * @param node Start node for search 176 * @param id Compatible ID to look for (enum fdt_compat_id) 177 * @param depthp Current depth (set to 0 before first call) 178 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 179 */ 180 int fdtdec_next_compatible_subnode(const void *blob, int node, 181 enum fdt_compat_id id, int *depthp); 182 183 /** 184 * Look up an address property in a node and return it as an address. 185 * The property must hold either one address with no trailing data or 186 * one address with a length. This is only tested on 32-bit machines. 187 * 188 * @param blob FDT blob 189 * @param node node to examine 190 * @param prop_name name of property to find 191 * @return address, if found, or FDT_ADDR_T_NONE if not 192 */ 193 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 194 const char *prop_name); 195 196 /** 197 * Look up a 32-bit integer property in a node and return it. The property 198 * must have at least 4 bytes of data. The value of the first cell is 199 * returned. 200 * 201 * @param blob FDT blob 202 * @param node node to examine 203 * @param prop_name name of property to find 204 * @param default_val default value to return if the property is not found 205 * @return integer value, if found, or default_val if not 206 */ 207 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 208 s32 default_val); 209 210 /** 211 * Look up a 64-bit integer property in a node and return it. The property 212 * must have at least 8 bytes of data (2 cells). The first two cells are 213 * concatenated to form a 8 bytes value, where the first cell is top half and 214 * the second cell is bottom half. 215 * 216 * @param blob FDT blob 217 * @param node node to examine 218 * @param prop_name name of property to find 219 * @param default_val default value to return if the property is not found 220 * @return integer value, if found, or default_val if not 221 */ 222 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 223 uint64_t default_val); 224 225 /** 226 * Checks whether a node is enabled. 227 * This looks for a 'status' property. If this exists, then returns 1 if 228 * the status is 'ok' and 0 otherwise. If there is no status property, 229 * it returns 1 on the assumption that anything mentioned should be enabled 230 * by default. 231 * 232 * @param blob FDT blob 233 * @param node node to examine 234 * @return integer value 0 (not enabled) or 1 (enabled) 235 */ 236 int fdtdec_get_is_enabled(const void *blob, int node); 237 238 /** 239 * Make sure we have a valid fdt available to control U-Boot. 240 * 241 * If not, a message is printed to the console if the console is ready. 242 * 243 * @return 0 if all ok, -1 if not 244 */ 245 int fdtdec_prepare_fdt(void); 246 247 /** 248 * Checks that we have a valid fdt available to control U-Boot. 249 250 * However, if not then for the moment nothing is done, since this function 251 * is called too early to panic(). 252 * 253 * @returns 0 254 */ 255 int fdtdec_check_fdt(void); 256 257 /** 258 * Find the nodes for a peripheral and return a list of them in the correct 259 * order. This is used to enumerate all the peripherals of a certain type. 260 * 261 * To use this, optionally set up a /aliases node with alias properties for 262 * a peripheral. For example, for usb you could have: 263 * 264 * aliases { 265 * usb0 = "/ehci@c5008000"; 266 * usb1 = "/ehci@c5000000"; 267 * }; 268 * 269 * Pass "usb" as the name to this function and will return a list of two 270 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 271 * 272 * All nodes returned will match the compatible ID, as it is assumed that 273 * all peripherals use the same driver. 274 * 275 * If no alias node is found, then the node list will be returned in the 276 * order found in the fdt. If the aliases mention a node which doesn't 277 * exist, then this will be ignored. If nodes are found with no aliases, 278 * they will be added in any order. 279 * 280 * If there is a gap in the aliases, then this function return a 0 node at 281 * that position. The return value will also count these gaps. 282 * 283 * This function checks node properties and will not return nodes which are 284 * marked disabled (status = "disabled"). 285 * 286 * @param blob FDT blob to use 287 * @param name Root name of alias to search for 288 * @param id Compatible ID to look for 289 * @param node_list Place to put list of found nodes 290 * @param maxcount Maximum number of nodes to find 291 * @return number of nodes found on success, FTD_ERR_... on error 292 */ 293 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 294 enum fdt_compat_id id, int *node_list, int maxcount); 295 296 /* 297 * This function is similar to fdtdec_find_aliases_for_id() except that it 298 * adds to the node_list that is passed in. Any 0 elements are considered 299 * available for allocation - others are considered already used and are 300 * skipped. 301 * 302 * You can use this by calling fdtdec_find_aliases_for_id() with an 303 * uninitialised array, then setting the elements that are returned to -1, 304 * say, then calling this function, perhaps with a different compat id. 305 * Any elements you get back that are >0 are new nodes added by the call 306 * to this function. 307 * 308 * Note that if you have some nodes with aliases and some without, you are 309 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 310 * one compat_id may fill in positions for which you have aliases defined 311 * for another compat_id. When you later call *this* function with the second 312 * compat_id, the alias positions may already be used. A debug warning may 313 * be generated in this case, but it is safest to define aliases for all 314 * nodes when you care about the ordering. 315 */ 316 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 317 enum fdt_compat_id id, int *node_list, int maxcount); 318 319 /* 320 * Get the name for a compatible ID 321 * 322 * @param id Compatible ID to look for 323 * @return compatible string for that id 324 */ 325 const char *fdtdec_get_compatible(enum fdt_compat_id id); 326 327 /* Look up a phandle and follow it to its node. Then return the offset 328 * of that node. 329 * 330 * @param blob FDT blob 331 * @param node node to examine 332 * @param prop_name name of property to find 333 * @return node offset if found, -ve error code on error 334 */ 335 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 336 337 /** 338 * Look up a property in a node and return its contents in an integer 339 * array of given length. The property must have at least enough data for 340 * the array (4*count bytes). It may have more, but this will be ignored. 341 * 342 * @param blob FDT blob 343 * @param node node to examine 344 * @param prop_name name of property to find 345 * @param array array to fill with data 346 * @param count number of array elements 347 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 348 * or -FDT_ERR_BADLAYOUT if not enough data 349 */ 350 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 351 u32 *array, int count); 352 353 /** 354 * Look up a property in a node and return a pointer to its contents as a 355 * unsigned int array of given length. The property must have at least enough 356 * data for the array ('count' cells). It may have more, but this will be 357 * ignored. The data is not copied. 358 * 359 * Note that you must access elements of the array with fdt32_to_cpu(), 360 * since the elements will be big endian even on a little endian machine. 361 * 362 * @param blob FDT blob 363 * @param node node to examine 364 * @param prop_name name of property to find 365 * @param count number of array elements 366 * @return pointer to array if found, or NULL if the property is not 367 * found or there is not enough data 368 */ 369 const u32 *fdtdec_locate_array(const void *blob, int node, 370 const char *prop_name, int count); 371 372 /** 373 * Look up a boolean property in a node and return it. 374 * 375 * A boolean properly is true if present in the device tree and false if not 376 * present, regardless of its value. 377 * 378 * @param blob FDT blob 379 * @param node node to examine 380 * @param prop_name name of property to find 381 * @return 1 if the properly is present; 0 if it isn't present 382 */ 383 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 384 385 /** 386 * Decode a single GPIOs from an FDT. 387 * 388 * If the property is not found, then the GPIO structure will still be 389 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 390 * provide optional GPIOs. 391 * 392 * @param blob FDT blob to use 393 * @param node Node to look at 394 * @param prop_name Node property name 395 * @param gpio gpio elements to fill from FDT 396 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 397 */ 398 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 399 struct fdt_gpio_state *gpio); 400 401 /** 402 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 403 * terminating item. 404 * 405 * @param blob FDT blob to use 406 * @param node Node to look at 407 * @param prop_name Node property name 408 * @param gpio Array of gpio elements to fill from FDT. This will be 409 * untouched if either 0 or an error is returned 410 * @param max_count Maximum number of elements allowed 411 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 412 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 413 */ 414 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 415 struct fdt_gpio_state *gpio, int max_count); 416 417 /** 418 * Set up a GPIO pin according to the provided gpio information. At present this 419 * just requests the GPIO. 420 * 421 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 422 * deal with optional GPIOs. 423 * 424 * @param gpio GPIO info to use for set up 425 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 426 */ 427 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 428 429 /** 430 * Look in the FDT for a config item with the given name and return its value 431 * as a 32-bit integer. The property must have at least 4 bytes of data. The 432 * value of the first cell is returned. 433 * 434 * @param blob FDT blob to use 435 * @param prop_name Node property name 436 * @param default_val default value to return if the property is not found 437 * @return integer value, if found, or default_val if not 438 */ 439 int fdtdec_get_config_int(const void *blob, const char *prop_name, 440 int default_val); 441 442 /** 443 * Look in the FDT for a config item with the given name 444 * and return whether it exists. 445 * 446 * @param blob FDT blob 447 * @param prop_name property name to look up 448 * @return 1, if it exists, or 0 if not 449 */ 450 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 451 452 /** 453 * Look in the FDT for a config item with the given name and return its value 454 * as a string. 455 * 456 * @param blob FDT blob 457 * @param prop_name property name to look up 458 * @returns property string, NULL on error. 459 */ 460 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 461 462 /* 463 * Look up a property in a node and return its contents in a byte 464 * array of given length. The property must have at least enough data for 465 * the array (count bytes). It may have more, but this will be ignored. 466 * 467 * @param blob FDT blob 468 * @param node node to examine 469 * @param prop_name name of property to find 470 * @param array array to fill with data 471 * @param count number of array elements 472 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 473 * or -FDT_ERR_BADLAYOUT if not enough data 474 */ 475 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 476 u8 *array, int count); 477 478 /** 479 * Look up a property in a node and return a pointer to its contents as a 480 * byte array of given length. The property must have at least enough data 481 * for the array (count bytes). It may have more, but this will be ignored. 482 * The data is not copied. 483 * 484 * @param blob FDT blob 485 * @param node node to examine 486 * @param prop_name name of property to find 487 * @param count number of array elements 488 * @return pointer to byte array if found, or NULL if the property is not 489 * found or there is not enough data 490 */ 491 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 492 const char *prop_name, int count); 493 494 /** 495 * Look up a property in a node which contains a memory region address and 496 * size. Then return a pointer to this address. 497 * 498 * The property must hold one address with a length. This is only tested on 499 * 32-bit machines. 500 * 501 * @param blob FDT blob 502 * @param node node to examine 503 * @param prop_name name of property to find 504 * @param ptrp returns pointer to region, or NULL if no address 505 * @param size returns size of region 506 * @return 0 if ok, -1 on error (propery not found) 507 */ 508 int fdtdec_decode_region(const void *blob, int node, 509 const char *prop_name, void **ptrp, size_t *size); 510 #endif 511