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