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 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */ 85 86 COMPAT_COUNT, 87 }; 88 89 /* GPIOs are numbered from 0 */ 90 enum { 91 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 92 93 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 94 }; 95 96 /* This is the state of a GPIO pin as defined by the fdt */ 97 struct fdt_gpio_state { 98 const char *name; /* name of the fdt property defining this */ 99 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 100 u8 flags; /* FDT_GPIO_... flags */ 101 }; 102 103 /* This tells us whether a fdt_gpio_state record is valid or not */ 104 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 105 106 /** 107 * Read the GPIO taking into account the polarity of the pin. 108 * 109 * @param gpio pointer to the decoded gpio 110 * @return value of the gpio if successful, < 0 if unsuccessful 111 */ 112 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 113 114 /** 115 * Write the GPIO taking into account the polarity of the pin. 116 * 117 * @param gpio pointer to the decoded gpio 118 * @return 0 if successful 119 */ 120 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 121 122 /** 123 * Find the next numbered alias for a peripheral. This is used to enumerate 124 * all the peripherals of a certain type. 125 * 126 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 127 * this function will return a pointer to the node the alias points to, and 128 * then update *upto to 1. Next time you call this function, the next node 129 * will be returned. 130 * 131 * All nodes returned will match the compatible ID, as it is assumed that 132 * all peripherals use the same driver. 133 * 134 * @param blob FDT blob to use 135 * @param name Root name of alias to search for 136 * @param id Compatible ID to look for 137 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 138 */ 139 int fdtdec_next_alias(const void *blob, const char *name, 140 enum fdt_compat_id id, int *upto); 141 142 /** 143 * Find the compatible ID for a given node. 144 * 145 * Generally each node has at least one compatible string attached to it. 146 * This function looks through our list of known compatible strings and 147 * returns the corresponding ID which matches the compatible string. 148 * 149 * @param blob FDT blob to use 150 * @param node Node containing compatible string to find 151 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 152 */ 153 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 154 155 /** 156 * Find the next compatible node for a peripheral. 157 * 158 * Do the first call with node = 0. This function will return a pointer to 159 * the next compatible node. Next time you call this function, pass the 160 * value returned, and the next node will be provided. 161 * 162 * @param blob FDT blob to use 163 * @param node Start node for search 164 * @param id Compatible ID to look for (enum fdt_compat_id) 165 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 166 */ 167 int fdtdec_next_compatible(const void *blob, int node, 168 enum fdt_compat_id id); 169 170 /** 171 * Find the next compatible subnode for a peripheral. 172 * 173 * Do the first call with node set to the parent and depth = 0. This 174 * function will return the offset of the next compatible node. Next time 175 * you call this function, pass the node value returned last time, with 176 * depth unchanged, and the next node will be provided. 177 * 178 * @param blob FDT blob to use 179 * @param node Start node for search 180 * @param id Compatible ID to look for (enum fdt_compat_id) 181 * @param depthp Current depth (set to 0 before first call) 182 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 183 */ 184 int fdtdec_next_compatible_subnode(const void *blob, int node, 185 enum fdt_compat_id id, int *depthp); 186 187 /** 188 * Look up an address property in a node and return it as an address. 189 * The property must hold either one address with no trailing data or 190 * one address with a length. This is only tested on 32-bit machines. 191 * 192 * @param blob FDT blob 193 * @param node node to examine 194 * @param prop_name name of property to find 195 * @return address, if found, or FDT_ADDR_T_NONE if not 196 */ 197 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 198 const char *prop_name); 199 200 /** 201 * Look up a 32-bit integer property in a node and return it. The property 202 * must have at least 4 bytes of data. The value of the first cell is 203 * returned. 204 * 205 * @param blob FDT blob 206 * @param node node to examine 207 * @param prop_name name of property to find 208 * @param default_val default value to return if the property is not found 209 * @return integer value, if found, or default_val if not 210 */ 211 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 212 s32 default_val); 213 214 /** 215 * Look up a 64-bit integer property in a node and return it. The property 216 * must have at least 8 bytes of data (2 cells). The first two cells are 217 * concatenated to form a 8 bytes value, where the first cell is top half and 218 * the second cell is bottom half. 219 * 220 * @param blob FDT blob 221 * @param node node to examine 222 * @param prop_name name of property to find 223 * @param default_val default value to return if the property is not found 224 * @return integer value, if found, or default_val if not 225 */ 226 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 227 uint64_t default_val); 228 229 /** 230 * Checks whether a node is enabled. 231 * This looks for a 'status' property. If this exists, then returns 1 if 232 * the status is 'ok' and 0 otherwise. If there is no status property, 233 * it returns 1 on the assumption that anything mentioned should be enabled 234 * by default. 235 * 236 * @param blob FDT blob 237 * @param node node to examine 238 * @return integer value 0 (not enabled) or 1 (enabled) 239 */ 240 int fdtdec_get_is_enabled(const void *blob, int node); 241 242 /** 243 * Make sure we have a valid fdt available to control U-Boot. 244 * 245 * If not, a message is printed to the console if the console is ready. 246 * 247 * @return 0 if all ok, -1 if not 248 */ 249 int fdtdec_prepare_fdt(void); 250 251 /** 252 * Checks that we have a valid fdt available to control U-Boot. 253 254 * However, if not then for the moment nothing is done, since this function 255 * is called too early to panic(). 256 * 257 * @returns 0 258 */ 259 int fdtdec_check_fdt(void); 260 261 /** 262 * Find the nodes for a peripheral and return a list of them in the correct 263 * order. This is used to enumerate all the peripherals of a certain type. 264 * 265 * To use this, optionally set up a /aliases node with alias properties for 266 * a peripheral. For example, for usb you could have: 267 * 268 * aliases { 269 * usb0 = "/ehci@c5008000"; 270 * usb1 = "/ehci@c5000000"; 271 * }; 272 * 273 * Pass "usb" as the name to this function and will return a list of two 274 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 275 * 276 * All nodes returned will match the compatible ID, as it is assumed that 277 * all peripherals use the same driver. 278 * 279 * If no alias node is found, then the node list will be returned in the 280 * order found in the fdt. If the aliases mention a node which doesn't 281 * exist, then this will be ignored. If nodes are found with no aliases, 282 * they will be added in any order. 283 * 284 * If there is a gap in the aliases, then this function return a 0 node at 285 * that position. The return value will also count these gaps. 286 * 287 * This function checks node properties and will not return nodes which are 288 * marked disabled (status = "disabled"). 289 * 290 * @param blob FDT blob to use 291 * @param name Root name of alias to search for 292 * @param id Compatible ID to look for 293 * @param node_list Place to put list of found nodes 294 * @param maxcount Maximum number of nodes to find 295 * @return number of nodes found on success, FTD_ERR_... on error 296 */ 297 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 298 enum fdt_compat_id id, int *node_list, int maxcount); 299 300 /* 301 * This function is similar to fdtdec_find_aliases_for_id() except that it 302 * adds to the node_list that is passed in. Any 0 elements are considered 303 * available for allocation - others are considered already used and are 304 * skipped. 305 * 306 * You can use this by calling fdtdec_find_aliases_for_id() with an 307 * uninitialised array, then setting the elements that are returned to -1, 308 * say, then calling this function, perhaps with a different compat id. 309 * Any elements you get back that are >0 are new nodes added by the call 310 * to this function. 311 * 312 * Note that if you have some nodes with aliases and some without, you are 313 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 314 * one compat_id may fill in positions for which you have aliases defined 315 * for another compat_id. When you later call *this* function with the second 316 * compat_id, the alias positions may already be used. A debug warning may 317 * be generated in this case, but it is safest to define aliases for all 318 * nodes when you care about the ordering. 319 */ 320 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 321 enum fdt_compat_id id, int *node_list, int maxcount); 322 323 /* 324 * Get the name for a compatible ID 325 * 326 * @param id Compatible ID to look for 327 * @return compatible string for that id 328 */ 329 const char *fdtdec_get_compatible(enum fdt_compat_id id); 330 331 /* Look up a phandle and follow it to its node. Then return the offset 332 * of that node. 333 * 334 * @param blob FDT blob 335 * @param node node to examine 336 * @param prop_name name of property to find 337 * @return node offset if found, -ve error code on error 338 */ 339 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 340 341 /** 342 * Look up a property in a node and return its contents in an integer 343 * array of given length. The property must have at least enough data for 344 * the array (4*count bytes). It may have more, but this will be ignored. 345 * 346 * @param blob FDT blob 347 * @param node node to examine 348 * @param prop_name name of property to find 349 * @param array array to fill with data 350 * @param count number of array elements 351 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 352 * or -FDT_ERR_BADLAYOUT if not enough data 353 */ 354 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 355 u32 *array, int count); 356 357 /** 358 * Look up a property in a node and return a pointer to its contents as a 359 * unsigned int array of given length. The property must have at least enough 360 * data for the array ('count' cells). It may have more, but this will be 361 * ignored. The data is not copied. 362 * 363 * Note that you must access elements of the array with fdt32_to_cpu(), 364 * since the elements will be big endian even on a little endian machine. 365 * 366 * @param blob FDT blob 367 * @param node node to examine 368 * @param prop_name name of property to find 369 * @param count number of array elements 370 * @return pointer to array if found, or NULL if the property is not 371 * found or there is not enough data 372 */ 373 const u32 *fdtdec_locate_array(const void *blob, int node, 374 const char *prop_name, int count); 375 376 /** 377 * Look up a boolean property in a node and return it. 378 * 379 * A boolean properly is true if present in the device tree and false if not 380 * present, regardless of its value. 381 * 382 * @param blob FDT blob 383 * @param node node to examine 384 * @param prop_name name of property to find 385 * @return 1 if the properly is present; 0 if it isn't present 386 */ 387 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 388 389 /** 390 * Decode a single GPIOs from an FDT. 391 * 392 * If the property is not found, then the GPIO structure will still be 393 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 394 * provide optional GPIOs. 395 * 396 * @param blob FDT blob to use 397 * @param node Node to look at 398 * @param prop_name Node property name 399 * @param gpio gpio elements to fill from FDT 400 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 401 */ 402 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 403 struct fdt_gpio_state *gpio); 404 405 /** 406 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 407 * terminating item. 408 * 409 * @param blob FDT blob to use 410 * @param node Node to look at 411 * @param prop_name Node property name 412 * @param gpio Array of gpio elements to fill from FDT. This will be 413 * untouched if either 0 or an error is returned 414 * @param max_count Maximum number of elements allowed 415 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 416 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 417 */ 418 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 419 struct fdt_gpio_state *gpio, int max_count); 420 421 /** 422 * Set up a GPIO pin according to the provided gpio information. At present this 423 * just requests the GPIO. 424 * 425 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 426 * deal with optional GPIOs. 427 * 428 * @param gpio GPIO info to use for set up 429 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 430 */ 431 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 432 433 /** 434 * Look in the FDT for a config item with the given name and return its value 435 * as a 32-bit integer. The property must have at least 4 bytes of data. The 436 * value of the first cell is returned. 437 * 438 * @param blob FDT blob to use 439 * @param prop_name Node property name 440 * @param default_val default value to return if the property is not found 441 * @return integer value, if found, or default_val if not 442 */ 443 int fdtdec_get_config_int(const void *blob, const char *prop_name, 444 int default_val); 445 446 /** 447 * Look in the FDT for a config item with the given name 448 * and return whether it exists. 449 * 450 * @param blob FDT blob 451 * @param prop_name property name to look up 452 * @return 1, if it exists, or 0 if not 453 */ 454 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 455 456 /** 457 * Look in the FDT for a config item with the given name and return its value 458 * as a string. 459 * 460 * @param blob FDT blob 461 * @param prop_name property name to look up 462 * @returns property string, NULL on error. 463 */ 464 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 465 466 /* 467 * Look up a property in a node and return its contents in a byte 468 * array of given length. The property must have at least enough data for 469 * the array (count bytes). It may have more, but this will be ignored. 470 * 471 * @param blob FDT blob 472 * @param node node to examine 473 * @param prop_name name of property to find 474 * @param array array to fill with data 475 * @param count number of array elements 476 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 477 * or -FDT_ERR_BADLAYOUT if not enough data 478 */ 479 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 480 u8 *array, int count); 481 482 /** 483 * Look up a property in a node and return a pointer to its contents as a 484 * byte array of given length. The property must have at least enough data 485 * for the array (count bytes). It may have more, but this will be ignored. 486 * The data is not copied. 487 * 488 * @param blob FDT blob 489 * @param node node to examine 490 * @param prop_name name of property to find 491 * @param count number of array elements 492 * @return pointer to byte array if found, or NULL if the property is not 493 * found or there is not enough data 494 */ 495 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 496 const char *prop_name, int count); 497 498 /** 499 * Look up a property in a node which contains a memory region address and 500 * size. Then return a pointer to this address. 501 * 502 * The property must hold one address with a length. This is only tested on 503 * 32-bit machines. 504 * 505 * @param blob FDT blob 506 * @param node node to examine 507 * @param prop_name name of property to find 508 * @param ptrp returns pointer to region, or NULL if no address 509 * @param size returns size of region 510 * @return 0 if ok, -1 on error (propery not found) 511 */ 512 int fdtdec_decode_region(const void *blob, int node, 513 const char *prop_name, void **ptrp, size_t *size); 514 #endif 515