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_TEGRA20_SDMMC, /* Tegra SDMMC controller */ 75 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */ 76 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */ 77 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */ 78 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */ 79 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */ 80 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */ 81 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */ 82 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */ 83 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */ 84 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */ 85 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */ 86 87 COMPAT_COUNT, 88 }; 89 90 /* GPIOs are numbered from 0 */ 91 enum { 92 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ 93 94 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ 95 }; 96 97 /* This is the state of a GPIO pin as defined by the fdt */ 98 struct fdt_gpio_state { 99 const char *name; /* name of the fdt property defining this */ 100 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ 101 u8 flags; /* FDT_GPIO_... flags */ 102 }; 103 104 /* This tells us whether a fdt_gpio_state record is valid or not */ 105 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) 106 107 /** 108 * Read the GPIO taking into account the polarity of the pin. 109 * 110 * @param gpio pointer to the decoded gpio 111 * @return value of the gpio if successful, < 0 if unsuccessful 112 */ 113 int fdtdec_get_gpio(struct fdt_gpio_state *gpio); 114 115 /** 116 * Write the GPIO taking into account the polarity of the pin. 117 * 118 * @param gpio pointer to the decoded gpio 119 * @return 0 if successful 120 */ 121 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val); 122 123 /** 124 * Find the next numbered alias for a peripheral. This is used to enumerate 125 * all the peripherals of a certain type. 126 * 127 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then 128 * this function will return a pointer to the node the alias points to, and 129 * then update *upto to 1. Next time you call this function, the next node 130 * will be returned. 131 * 132 * All nodes returned will match the compatible ID, as it is assumed that 133 * all peripherals use the same driver. 134 * 135 * @param blob FDT blob to use 136 * @param name Root name of alias to search for 137 * @param id Compatible ID to look for 138 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 139 */ 140 int fdtdec_next_alias(const void *blob, const char *name, 141 enum fdt_compat_id id, int *upto); 142 143 /** 144 * Find the compatible ID for a given node. 145 * 146 * Generally each node has at least one compatible string attached to it. 147 * This function looks through our list of known compatible strings and 148 * returns the corresponding ID which matches the compatible string. 149 * 150 * @param blob FDT blob to use 151 * @param node Node containing compatible string to find 152 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match 153 */ 154 enum fdt_compat_id fdtdec_lookup(const void *blob, int node); 155 156 /** 157 * Find the next compatible node for a peripheral. 158 * 159 * Do the first call with node = 0. This function will return a pointer to 160 * the next compatible node. Next time you call this function, pass the 161 * value returned, and the next node will be provided. 162 * 163 * @param blob FDT blob to use 164 * @param node Start node for search 165 * @param id Compatible ID to look for (enum fdt_compat_id) 166 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 167 */ 168 int fdtdec_next_compatible(const void *blob, int node, 169 enum fdt_compat_id id); 170 171 /** 172 * Find the next compatible subnode for a peripheral. 173 * 174 * Do the first call with node set to the parent and depth = 0. This 175 * function will return the offset of the next compatible node. Next time 176 * you call this function, pass the node value returned last time, with 177 * depth unchanged, and the next node will be provided. 178 * 179 * @param blob FDT blob to use 180 * @param node Start node for search 181 * @param id Compatible ID to look for (enum fdt_compat_id) 182 * @param depthp Current depth (set to 0 before first call) 183 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more 184 */ 185 int fdtdec_next_compatible_subnode(const void *blob, int node, 186 enum fdt_compat_id id, int *depthp); 187 188 /** 189 * Look up an address property in a node and return it as an address. 190 * The property must hold either one address with no trailing data or 191 * one address with a length. This is only tested on 32-bit machines. 192 * 193 * @param blob FDT blob 194 * @param node node to examine 195 * @param prop_name name of property to find 196 * @return address, if found, or FDT_ADDR_T_NONE if not 197 */ 198 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 199 const char *prop_name); 200 201 /** 202 * Look up a 32-bit integer property in a node and return it. The property 203 * must have at least 4 bytes of data. The value of the first cell is 204 * returned. 205 * 206 * @param blob FDT blob 207 * @param node node to examine 208 * @param prop_name name of property to find 209 * @param default_val default value to return if the property is not found 210 * @return integer value, if found, or default_val if not 211 */ 212 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 213 s32 default_val); 214 215 /** 216 * Look up a 64-bit integer property in a node and return it. The property 217 * must have at least 8 bytes of data (2 cells). The first two cells are 218 * concatenated to form a 8 bytes value, where the first cell is top half and 219 * the second cell is bottom half. 220 * 221 * @param blob FDT blob 222 * @param node node to examine 223 * @param prop_name name of property to find 224 * @param default_val default value to return if the property is not found 225 * @return integer value, if found, or default_val if not 226 */ 227 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name, 228 uint64_t default_val); 229 230 /** 231 * Checks whether a node is enabled. 232 * This looks for a 'status' property. If this exists, then returns 1 if 233 * the status is 'ok' and 0 otherwise. If there is no status property, 234 * it returns 1 on the assumption that anything mentioned should be enabled 235 * by default. 236 * 237 * @param blob FDT blob 238 * @param node node to examine 239 * @return integer value 0 (not enabled) or 1 (enabled) 240 */ 241 int fdtdec_get_is_enabled(const void *blob, int node); 242 243 /** 244 * Make sure we have a valid fdt available to control U-Boot. 245 * 246 * If not, a message is printed to the console if the console is ready. 247 * 248 * @return 0 if all ok, -1 if not 249 */ 250 int fdtdec_prepare_fdt(void); 251 252 /** 253 * Checks that we have a valid fdt available to control U-Boot. 254 255 * However, if not then for the moment nothing is done, since this function 256 * is called too early to panic(). 257 * 258 * @returns 0 259 */ 260 int fdtdec_check_fdt(void); 261 262 /** 263 * Find the nodes for a peripheral and return a list of them in the correct 264 * order. This is used to enumerate all the peripherals of a certain type. 265 * 266 * To use this, optionally set up a /aliases node with alias properties for 267 * a peripheral. For example, for usb you could have: 268 * 269 * aliases { 270 * usb0 = "/ehci@c5008000"; 271 * usb1 = "/ehci@c5000000"; 272 * }; 273 * 274 * Pass "usb" as the name to this function and will return a list of two 275 * nodes offsets: /ehci@c5008000 and ehci@c5000000. 276 * 277 * All nodes returned will match the compatible ID, as it is assumed that 278 * all peripherals use the same driver. 279 * 280 * If no alias node is found, then the node list will be returned in the 281 * order found in the fdt. If the aliases mention a node which doesn't 282 * exist, then this will be ignored. If nodes are found with no aliases, 283 * they will be added in any order. 284 * 285 * If there is a gap in the aliases, then this function return a 0 node at 286 * that position. The return value will also count these gaps. 287 * 288 * This function checks node properties and will not return nodes which are 289 * marked disabled (status = "disabled"). 290 * 291 * @param blob FDT blob to use 292 * @param name Root name of alias to search for 293 * @param id Compatible ID to look for 294 * @param node_list Place to put list of found nodes 295 * @param maxcount Maximum number of nodes to find 296 * @return number of nodes found on success, FTD_ERR_... on error 297 */ 298 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 299 enum fdt_compat_id id, int *node_list, int maxcount); 300 301 /* 302 * This function is similar to fdtdec_find_aliases_for_id() except that it 303 * adds to the node_list that is passed in. Any 0 elements are considered 304 * available for allocation - others are considered already used and are 305 * skipped. 306 * 307 * You can use this by calling fdtdec_find_aliases_for_id() with an 308 * uninitialised array, then setting the elements that are returned to -1, 309 * say, then calling this function, perhaps with a different compat id. 310 * Any elements you get back that are >0 are new nodes added by the call 311 * to this function. 312 * 313 * Note that if you have some nodes with aliases and some without, you are 314 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with 315 * one compat_id may fill in positions for which you have aliases defined 316 * for another compat_id. When you later call *this* function with the second 317 * compat_id, the alias positions may already be used. A debug warning may 318 * be generated in this case, but it is safest to define aliases for all 319 * nodes when you care about the ordering. 320 */ 321 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 322 enum fdt_compat_id id, int *node_list, int maxcount); 323 324 /* 325 * Get the name for a compatible ID 326 * 327 * @param id Compatible ID to look for 328 * @return compatible string for that id 329 */ 330 const char *fdtdec_get_compatible(enum fdt_compat_id id); 331 332 /* Look up a phandle and follow it to its node. Then return the offset 333 * of that node. 334 * 335 * @param blob FDT blob 336 * @param node node to examine 337 * @param prop_name name of property to find 338 * @return node offset if found, -ve error code on error 339 */ 340 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); 341 342 /** 343 * Look up a property in a node and return its contents in an integer 344 * array of given length. The property must have at least enough data for 345 * the array (4*count bytes). It may have more, but this will be ignored. 346 * 347 * @param blob FDT blob 348 * @param node node to examine 349 * @param prop_name name of property to find 350 * @param array array to fill with data 351 * @param count number of array elements 352 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, 353 * or -FDT_ERR_BADLAYOUT if not enough data 354 */ 355 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 356 u32 *array, int count); 357 358 /** 359 * Look up a property in a node and return a pointer to its contents as a 360 * unsigned int array of given length. The property must have at least enough 361 * data for the array ('count' cells). It may have more, but this will be 362 * ignored. The data is not copied. 363 * 364 * Note that you must access elements of the array with fdt32_to_cpu(), 365 * since the elements will be big endian even on a little endian machine. 366 * 367 * @param blob FDT blob 368 * @param node node to examine 369 * @param prop_name name of property to find 370 * @param count number of array elements 371 * @return pointer to array if found, or NULL if the property is not 372 * found or there is not enough data 373 */ 374 const u32 *fdtdec_locate_array(const void *blob, int node, 375 const char *prop_name, int count); 376 377 /** 378 * Look up a boolean property in a node and return it. 379 * 380 * A boolean properly is true if present in the device tree and false if not 381 * present, regardless of its value. 382 * 383 * @param blob FDT blob 384 * @param node node to examine 385 * @param prop_name name of property to find 386 * @return 1 if the properly is present; 0 if it isn't present 387 */ 388 int fdtdec_get_bool(const void *blob, int node, const char *prop_name); 389 390 /** 391 * Decode a single GPIOs from an FDT. 392 * 393 * If the property is not found, then the GPIO structure will still be 394 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to 395 * provide optional GPIOs. 396 * 397 * @param blob FDT blob to use 398 * @param node Node to look at 399 * @param prop_name Node property name 400 * @param gpio gpio elements to fill from FDT 401 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. 402 */ 403 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 404 struct fdt_gpio_state *gpio); 405 406 /** 407 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 408 * terminating item. 409 * 410 * @param blob FDT blob to use 411 * @param node Node to look at 412 * @param prop_name Node property name 413 * @param gpio Array of gpio elements to fill from FDT. This will be 414 * untouched if either 0 or an error is returned 415 * @param max_count Maximum number of elements allowed 416 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 417 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 418 */ 419 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name, 420 struct fdt_gpio_state *gpio, int max_count); 421 422 /** 423 * Set up a GPIO pin according to the provided gpio information. At present this 424 * just requests the GPIO. 425 * 426 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to 427 * deal with optional GPIOs. 428 * 429 * @param gpio GPIO info to use for set up 430 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error 431 */ 432 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); 433 434 /** 435 * Look in the FDT for a config item with the given name and return its value 436 * as a 32-bit integer. The property must have at least 4 bytes of data. The 437 * value of the first cell is returned. 438 * 439 * @param blob FDT blob to use 440 * @param prop_name Node property name 441 * @param default_val default value to return if the property is not found 442 * @return integer value, if found, or default_val if not 443 */ 444 int fdtdec_get_config_int(const void *blob, const char *prop_name, 445 int default_val); 446 447 /** 448 * Look in the FDT for a config item with the given name 449 * and return whether it exists. 450 * 451 * @param blob FDT blob 452 * @param prop_name property name to look up 453 * @return 1, if it exists, or 0 if not 454 */ 455 int fdtdec_get_config_bool(const void *blob, const char *prop_name); 456 457 /** 458 * Look in the FDT for a config item with the given name and return its value 459 * as a string. 460 * 461 * @param blob FDT blob 462 * @param prop_name property name to look up 463 * @returns property string, NULL on error. 464 */ 465 char *fdtdec_get_config_string(const void *blob, const char *prop_name); 466 467 /* 468 * Look up a property in a node and return its contents in a byte 469 * array of given length. The property must have at least enough data for 470 * the array (count bytes). It may have more, but this will be ignored. 471 * 472 * @param blob FDT blob 473 * @param node node to examine 474 * @param prop_name name of property to find 475 * @param array array to fill with data 476 * @param count number of array elements 477 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, 478 * or -FDT_ERR_BADLAYOUT if not enough data 479 */ 480 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, 481 u8 *array, int count); 482 483 /** 484 * Look up a property in a node and return a pointer to its contents as a 485 * byte array of given length. The property must have at least enough data 486 * for the array (count bytes). It may have more, but this will be ignored. 487 * The data is not copied. 488 * 489 * @param blob FDT blob 490 * @param node node to examine 491 * @param prop_name name of property to find 492 * @param count number of array elements 493 * @return pointer to byte array if found, or NULL if the property is not 494 * found or there is not enough data 495 */ 496 const u8 *fdtdec_locate_byte_array(const void *blob, int node, 497 const char *prop_name, int count); 498 499 /** 500 * Look up a property in a node which contains a memory region address and 501 * size. Then return a pointer to this address. 502 * 503 * The property must hold one address with a length. This is only tested on 504 * 32-bit machines. 505 * 506 * @param blob FDT blob 507 * @param node node to examine 508 * @param prop_name name of property to find 509 * @param ptrp returns pointer to region, or NULL if no address 510 * @param size returns size of region 511 * @return 0 if ok, -1 on error (propery not found) 512 */ 513 int fdtdec_decode_region(const void *blob, int node, 514 const char *prop_name, void **ptrp, size_t *size); 515 #endif 516