uboot/include/fdtdec.h
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   1/* SPDX-License-Identifier: GPL-2.0+ */
   2/*
   3 * Copyright (c) 2011 The Chromium OS Authors.
   4 */
   5
   6#ifndef __fdtdec_h
   7#define __fdtdec_h
   8
   9/*
  10 * This file contains convenience functions for decoding useful and
  11 * enlightening information from FDTs. It is intended to be used by device
  12 * drivers and board-specific code within U-Boot. It aims to reduce the
  13 * amount of FDT munging required within U-Boot itself, so that driver code
  14 * changes to support FDT are minimized.
  15 */
  16
  17#include <linux/libfdt.h>
  18#include <pci.h>
  19
  20/*
  21 * A typedef for a physical address. Note that fdt data is always big
  22 * endian even on a litle endian machine.
  23 */
  24typedef phys_addr_t fdt_addr_t;
  25typedef phys_size_t fdt_size_t;
  26
  27#define FDT_ADDR_T_NONE (-1U)
  28#define FDT_SIZE_T_NONE (-1U)
  29
  30#ifdef CONFIG_PHYS_64BIT
  31#define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
  32#define fdt_size_to_cpu(reg) be64_to_cpu(reg)
  33#define cpu_to_fdt_addr(reg) cpu_to_be64(reg)
  34#define cpu_to_fdt_size(reg) cpu_to_be64(reg)
  35typedef fdt64_t fdt_val_t;
  36#else
  37#define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
  38#define fdt_size_to_cpu(reg) be32_to_cpu(reg)
  39#define cpu_to_fdt_addr(reg) cpu_to_be32(reg)
  40#define cpu_to_fdt_size(reg) cpu_to_be32(reg)
  41typedef fdt32_t fdt_val_t;
  42#endif
  43
  44/* Information obtained about memory from the FDT */
  45struct fdt_memory {
  46        fdt_addr_t start;
  47        fdt_addr_t end;
  48};
  49
  50struct bd_info;
  51
  52#ifdef CONFIG_SPL_BUILD
  53#define SPL_BUILD       1
  54#else
  55#define SPL_BUILD       0
  56#endif
  57
  58#ifdef CONFIG_OF_PRIOR_STAGE
  59extern phys_addr_t prior_stage_fdt_address;
  60#endif
  61
  62/*
  63 * Information about a resource. start is the first address of the resource
  64 * and end is the last address (inclusive). The length of the resource will
  65 * be equal to: end - start + 1.
  66 */
  67struct fdt_resource {
  68        fdt_addr_t start;
  69        fdt_addr_t end;
  70};
  71
  72enum fdt_pci_space {
  73        FDT_PCI_SPACE_CONFIG = 0,
  74        FDT_PCI_SPACE_IO = 0x01000000,
  75        FDT_PCI_SPACE_MEM32 = 0x02000000,
  76        FDT_PCI_SPACE_MEM64 = 0x03000000,
  77        FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
  78        FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
  79};
  80
  81#define FDT_PCI_ADDR_CELLS      3
  82#define FDT_PCI_SIZE_CELLS      2
  83#define FDT_PCI_REG_SIZE        \
  84        ((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
  85
  86/*
  87 * The Open Firmware spec defines PCI physical address as follows:
  88 *
  89 *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
  90 *
  91 * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
  92 * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
  93 * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
  94 *
  95 * where:
  96 *
  97 * n:        is 0 if the address is relocatable, 1 otherwise
  98 * p:        is 1 if addressable region is prefetchable, 0 otherwise
  99 * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
 100 *           (for Memory), or below 64KB (for relocatable I/O)
 101 * ss:       is the space code, denoting the address space
 102 * bbbbbbbb: is the 8-bit Bus Number
 103 * ddddd:    is the 5-bit Device Number
 104 * fff:      is the 3-bit Function Number
 105 * rrrrrrrr: is the 8-bit Register Number
 106 * hhhhhhhh: is a 32-bit unsigned number
 107 * llllllll: is a 32-bit unsigned number
 108 */
 109struct fdt_pci_addr {
 110        u32     phys_hi;
 111        u32     phys_mid;
 112        u32     phys_lo;
 113};
 114
 115extern u8 __dtb_dt_begin[];     /* embedded device tree blob */
 116extern u8 __dtb_dt_spl_begin[]; /* embedded device tree blob for SPL/TPL */
 117
 118/**
 119 * Compute the size of a resource.
 120 *
 121 * @param res   the resource to operate on
 122 * @return the size of the resource
 123 */
 124static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
 125{
 126        return res->end - res->start + 1;
 127}
 128
 129/**
 130 * Compat types that we know about and for which we might have drivers.
 131 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
 132 * within drivers.
 133 */
 134enum fdt_compat_id {
 135        COMPAT_UNKNOWN,
 136        COMPAT_NVIDIA_TEGRA20_EMC,      /* Tegra20 memory controller */
 137        COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
 138        COMPAT_NVIDIA_TEGRA20_NAND,     /* Tegra2 NAND controller */
 139        COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
 140                                        /* Tegra124 XUSB pad controller */
 141        COMPAT_NVIDIA_TEGRA210_XUSB_PADCTL,
 142                                        /* Tegra210 XUSB pad controller */
 143        COMPAT_SAMSUNG_EXYNOS_USB_PHY,  /* Exynos phy controller for usb2.0 */
 144        COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
 145        COMPAT_SAMSUNG_EXYNOS_TMU,      /* Exynos TMU */
 146        COMPAT_SAMSUNG_EXYNOS_MIPI_DSI, /* Exynos mipi dsi */
 147        COMPAT_SAMSUNG_EXYNOS_DWMMC,    /* Exynos DWMMC controller */
 148        COMPAT_GENERIC_SPI_FLASH,       /* Generic SPI Flash chip */
 149        COMPAT_SAMSUNG_EXYNOS_SYSMMU,   /* Exynos sysmmu */
 150        COMPAT_INTEL_MICROCODE,         /* Intel microcode update */
 151        COMPAT_INTEL_QRK_MRC,           /* Intel Quark MRC */
 152        COMPAT_ALTERA_SOCFPGA_DWMAC,    /* SoCFPGA Ethernet controller */
 153        COMPAT_ALTERA_SOCFPGA_DWMMC,    /* SoCFPGA DWMMC controller */
 154        COMPAT_ALTERA_SOCFPGA_DWC2USB,  /* SoCFPGA DWC2 USB controller */
 155        COMPAT_INTEL_BAYTRAIL_FSP,      /* Intel Bay Trail FSP */
 156        COMPAT_INTEL_BAYTRAIL_FSP_MDP,  /* Intel FSP memory-down params */
 157        COMPAT_INTEL_IVYBRIDGE_FSP,     /* Intel Ivy Bridge FSP */
 158        COMPAT_SUNXI_NAND,              /* SUNXI NAND controller */
 159        COMPAT_ALTERA_SOCFPGA_CLK,      /* SoCFPGA Clock initialization */
 160        COMPAT_ALTERA_SOCFPGA_PINCTRL_SINGLE,   /* SoCFPGA pinctrl-single */
 161        COMPAT_ALTERA_SOCFPGA_H2F_BRG,          /* SoCFPGA hps2fpga bridge */
 162        COMPAT_ALTERA_SOCFPGA_LWH2F_BRG,        /* SoCFPGA lwhps2fpga bridge */
 163        COMPAT_ALTERA_SOCFPGA_F2H_BRG,          /* SoCFPGA fpga2hps bridge */
 164        COMPAT_ALTERA_SOCFPGA_F2SDR0,           /* SoCFPGA fpga2SDRAM0 bridge */
 165        COMPAT_ALTERA_SOCFPGA_F2SDR1,           /* SoCFPGA fpga2SDRAM1 bridge */
 166        COMPAT_ALTERA_SOCFPGA_F2SDR2,           /* SoCFPGA fpga2SDRAM2 bridge */
 167        COMPAT_ALTERA_SOCFPGA_FPGA0,            /* SOCFPGA FPGA manager */
 168        COMPAT_ALTERA_SOCFPGA_NOC,              /* SOCFPGA Arria 10 NOC */
 169        COMPAT_ALTERA_SOCFPGA_CLK_INIT,         /* SOCFPGA Arria 10 clk init */
 170
 171        COMPAT_COUNT,
 172};
 173
 174#define MAX_PHANDLE_ARGS 16
 175struct fdtdec_phandle_args {
 176        int node;
 177        int args_count;
 178        uint32_t args[MAX_PHANDLE_ARGS];
 179};
 180
 181/**
 182 * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
 183 *
 184 * This function is useful to parse lists of phandles and their arguments.
 185 *
 186 * Example:
 187 *
 188 * phandle1: node1 {
 189 *      #list-cells = <2>;
 190 * }
 191 *
 192 * phandle2: node2 {
 193 *      #list-cells = <1>;
 194 * }
 195 *
 196 * node3 {
 197 *      list = <&phandle1 1 2 &phandle2 3>;
 198 * }
 199 *
 200 * To get a device_node of the `node2' node you may call this:
 201 * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
 202 *                                &args);
 203 *
 204 * (This function is a modified version of __of_parse_phandle_with_args() from
 205 * Linux 3.18)
 206 *
 207 * @blob:       Pointer to device tree
 208 * @src_node:   Offset of device tree node containing a list
 209 * @list_name:  property name that contains a list
 210 * @cells_name: property name that specifies the phandles' arguments count,
 211 *              or NULL to use @cells_count
 212 * @cells_count: Cell count to use if @cells_name is NULL
 213 * @index:      index of a phandle to parse out
 214 * @out_args:   optional pointer to output arguments structure (will be filled)
 215 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
 216 *      @list_name does not exist, a phandle was not found, @cells_name
 217 *      could not be found, the arguments were truncated or there were too
 218 *      many arguments.
 219 *
 220 */
 221int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
 222                                   const char *list_name,
 223                                   const char *cells_name,
 224                                   int cell_count, int index,
 225                                   struct fdtdec_phandle_args *out_args);
 226
 227/**
 228 * Find the next numbered alias for a peripheral. This is used to enumerate
 229 * all the peripherals of a certain type.
 230 *
 231 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
 232 * this function will return a pointer to the node the alias points to, and
 233 * then update *upto to 1. Next time you call this function, the next node
 234 * will be returned.
 235 *
 236 * All nodes returned will match the compatible ID, as it is assumed that
 237 * all peripherals use the same driver.
 238 *
 239 * @param blob          FDT blob to use
 240 * @param name          Root name of alias to search for
 241 * @param id            Compatible ID to look for
 242 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 243 */
 244int fdtdec_next_alias(const void *blob, const char *name,
 245                enum fdt_compat_id id, int *upto);
 246
 247/**
 248 * Find the compatible ID for a given node.
 249 *
 250 * Generally each node has at least one compatible string attached to it.
 251 * This function looks through our list of known compatible strings and
 252 * returns the corresponding ID which matches the compatible string.
 253 *
 254 * @param blob          FDT blob to use
 255 * @param node          Node containing compatible string to find
 256 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
 257 */
 258enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
 259
 260/**
 261 * Find the next compatible node for a peripheral.
 262 *
 263 * Do the first call with node = 0. This function will return a pointer to
 264 * the next compatible node. Next time you call this function, pass the
 265 * value returned, and the next node will be provided.
 266 *
 267 * @param blob          FDT blob to use
 268 * @param node          Start node for search
 269 * @param id            Compatible ID to look for (enum fdt_compat_id)
 270 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 271 */
 272int fdtdec_next_compatible(const void *blob, int node,
 273                enum fdt_compat_id id);
 274
 275/**
 276 * Find the next compatible subnode for a peripheral.
 277 *
 278 * Do the first call with node set to the parent and depth = 0. This
 279 * function will return the offset of the next compatible node. Next time
 280 * you call this function, pass the node value returned last time, with
 281 * depth unchanged, and the next node will be provided.
 282 *
 283 * @param blob          FDT blob to use
 284 * @param node          Start node for search
 285 * @param id            Compatible ID to look for (enum fdt_compat_id)
 286 * @param depthp        Current depth (set to 0 before first call)
 287 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 288 */
 289int fdtdec_next_compatible_subnode(const void *blob, int node,
 290                enum fdt_compat_id id, int *depthp);
 291
 292/*
 293 * Look up an address property in a node and return the parsed address, and
 294 * optionally the parsed size.
 295 *
 296 * This variant assumes a known and fixed number of cells are used to
 297 * represent the address and size.
 298 *
 299 * You probably don't want to use this function directly except to parse
 300 * non-standard properties, and never to parse the "reg" property. Instead,
 301 * use one of the "auto" variants below, which automatically honor the
 302 * #address-cells and #size-cells properties in the parent node.
 303 *
 304 * @param blob  FDT blob
 305 * @param node  node to examine
 306 * @param prop_name     name of property to find
 307 * @param index which address to retrieve from a list of addresses. Often 0.
 308 * @param na    the number of cells used to represent an address
 309 * @param ns    the number of cells used to represent a size
 310 * @param sizep a pointer to store the size into. Use NULL if not required
 311 * @param translate     Indicates whether to translate the returned value
 312 *                      using the parent node's ranges property.
 313 * @return address, if found, or FDT_ADDR_T_NONE if not
 314 */
 315fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
 316                const char *prop_name, int index, int na, int ns,
 317                fdt_size_t *sizep, bool translate);
 318
 319/*
 320 * Look up an address property in a node and return the parsed address, and
 321 * optionally the parsed size.
 322 *
 323 * This variant automatically determines the number of cells used to represent
 324 * the address and size by parsing the provided parent node's #address-cells
 325 * and #size-cells properties.
 326 *
 327 * @param blob  FDT blob
 328 * @param parent        parent node of @node
 329 * @param node  node to examine
 330 * @param prop_name     name of property to find
 331 * @param index which address to retrieve from a list of addresses. Often 0.
 332 * @param sizep a pointer to store the size into. Use NULL if not required
 333 * @param translate     Indicates whether to translate the returned value
 334 *                      using the parent node's ranges property.
 335 * @return address, if found, or FDT_ADDR_T_NONE if not
 336 */
 337fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
 338                int node, const char *prop_name, int index, fdt_size_t *sizep,
 339                bool translate);
 340
 341/*
 342 * Look up an address property in a node and return the parsed address, and
 343 * optionally the parsed size.
 344 *
 345 * This variant automatically determines the number of cells used to represent
 346 * the address and size by parsing the parent node's #address-cells
 347 * and #size-cells properties. The parent node is automatically found.
 348 *
 349 * The automatic parent lookup implemented by this function is slow.
 350 * Consequently, fdtdec_get_addr_size_auto_parent() should be used where
 351 * possible.
 352 *
 353 * @param blob  FDT blob
 354 * @param parent        parent node of @node
 355 * @param node  node to examine
 356 * @param prop_name     name of property to find
 357 * @param index which address to retrieve from a list of addresses. Often 0.
 358 * @param sizep a pointer to store the size into. Use NULL if not required
 359 * @param translate     Indicates whether to translate the returned value
 360 *                      using the parent node's ranges property.
 361 * @return address, if found, or FDT_ADDR_T_NONE if not
 362 */
 363fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
 364                const char *prop_name, int index, fdt_size_t *sizep,
 365                bool translate);
 366
 367/*
 368 * Look up an address property in a node and return the parsed address.
 369 *
 370 * This variant hard-codes the number of cells used to represent the address
 371 * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
 372 * always returns the first address value in the property (index 0).
 373 *
 374 * Use of this function is not recommended due to the hard-coding of cell
 375 * counts. There is no programmatic validation that these hard-coded values
 376 * actually match the device tree content in any way at all. This assumption
 377 * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
 378 * set in the U-Boot build and exercising strict control over DT content to
 379 * ensure use of matching #address-cells/#size-cells properties. However, this
 380 * approach is error-prone; those familiar with DT will not expect the
 381 * assumption to exist, and could easily invalidate it. If the assumption is
 382 * invalidated, this function will not report the issue, and debugging will
 383 * be required. Instead, use fdtdec_get_addr_size_auto_parent().
 384 *
 385 * @param blob  FDT blob
 386 * @param node  node to examine
 387 * @param prop_name     name of property to find
 388 * @return address, if found, or FDT_ADDR_T_NONE if not
 389 */
 390fdt_addr_t fdtdec_get_addr(const void *blob, int node,
 391                const char *prop_name);
 392
 393/*
 394 * Look up an address property in a node and return the parsed address, and
 395 * optionally the parsed size.
 396 *
 397 * This variant hard-codes the number of cells used to represent the address
 398 * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
 399 * always returns the first address value in the property (index 0).
 400 *
 401 * Use of this function is not recommended due to the hard-coding of cell
 402 * counts. There is no programmatic validation that these hard-coded values
 403 * actually match the device tree content in any way at all. This assumption
 404 * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
 405 * set in the U-Boot build and exercising strict control over DT content to
 406 * ensure use of matching #address-cells/#size-cells properties. However, this
 407 * approach is error-prone; those familiar with DT will not expect the
 408 * assumption to exist, and could easily invalidate it. If the assumption is
 409 * invalidated, this function will not report the issue, and debugging will
 410 * be required. Instead, use fdtdec_get_addr_size_auto_parent().
 411 *
 412 * @param blob  FDT blob
 413 * @param node  node to examine
 414 * @param prop_name     name of property to find
 415 * @param sizep a pointer to store the size into. Use NULL if not required
 416 * @return address, if found, or FDT_ADDR_T_NONE if not
 417 */
 418fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
 419                const char *prop_name, fdt_size_t *sizep);
 420
 421/**
 422 * Look at the compatible property of a device node that represents a PCI
 423 * device and extract pci vendor id and device id from it.
 424 *
 425 * @param blob          FDT blob
 426 * @param node          node to examine
 427 * @param vendor        vendor id of the pci device
 428 * @param device        device id of the pci device
 429 * @return 0 if ok, negative on error
 430 */
 431int fdtdec_get_pci_vendev(const void *blob, int node,
 432                u16 *vendor, u16 *device);
 433
 434/**
 435 * Look at the pci address of a device node that represents a PCI device
 436 * and return base address of the pci device's registers.
 437 *
 438 * @param dev           device to examine
 439 * @param addr          pci address in the form of fdt_pci_addr
 440 * @param bar           returns base address of the pci device's registers
 441 * @return 0 if ok, negative on error
 442 */
 443int fdtdec_get_pci_bar32(const struct udevice *dev, struct fdt_pci_addr *addr,
 444                         u32 *bar);
 445
 446/**
 447 * Look at the bus range property of a device node and return the pci bus
 448 * range for this node.
 449 * The property must hold one fdt_pci_addr with a length.
 450 * @param blob          FDT blob
 451 * @param node          node to examine
 452 * @param res           the resource structure to return the bus range
 453 * @return 0 if ok, negative on error
 454 */
 455
 456int fdtdec_get_pci_bus_range(const void *blob, int node,
 457                             struct fdt_resource *res);
 458
 459/**
 460 * Look up a 32-bit integer property in a node and return it. The property
 461 * must have at least 4 bytes of data. The value of the first cell is
 462 * returned.
 463 *
 464 * @param blob  FDT blob
 465 * @param node  node to examine
 466 * @param prop_name     name of property to find
 467 * @param default_val   default value to return if the property is not found
 468 * @return integer value, if found, or default_val if not
 469 */
 470s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
 471                s32 default_val);
 472
 473/**
 474 * Unsigned version of fdtdec_get_int. The property must have at least
 475 * 4 bytes of data. The value of the first cell is returned.
 476 *
 477 * @param blob  FDT blob
 478 * @param node  node to examine
 479 * @param prop_name     name of property to find
 480 * @param default_val   default value to return if the property is not found
 481 * @return unsigned integer value, if found, or default_val if not
 482 */
 483unsigned int fdtdec_get_uint(const void *blob, int node, const char *prop_name,
 484                        unsigned int default_val);
 485
 486/**
 487 * Get a variable-sized number from a property
 488 *
 489 * This reads a number from one or more cells.
 490 *
 491 * @param ptr   Pointer to property
 492 * @param cells Number of cells containing the number
 493 * @return the value in the cells
 494 */
 495u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
 496
 497/**
 498 * Look up a 64-bit integer property in a node and return it. The property
 499 * must have at least 8 bytes of data (2 cells). The first two cells are
 500 * concatenated to form a 8 bytes value, where the first cell is top half and
 501 * the second cell is bottom half.
 502 *
 503 * @param blob  FDT blob
 504 * @param node  node to examine
 505 * @param prop_name     name of property to find
 506 * @param default_val   default value to return if the property is not found
 507 * @return integer value, if found, or default_val if not
 508 */
 509uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 510                uint64_t default_val);
 511
 512/**
 513 * Checks whether a node is enabled.
 514 * This looks for a 'status' property. If this exists, then returns 1 if
 515 * the status is 'ok' and 0 otherwise. If there is no status property,
 516 * it returns 1 on the assumption that anything mentioned should be enabled
 517 * by default.
 518 *
 519 * @param blob  FDT blob
 520 * @param node  node to examine
 521 * @return integer value 0 (not enabled) or 1 (enabled)
 522 */
 523int fdtdec_get_is_enabled(const void *blob, int node);
 524
 525/**
 526 * Make sure we have a valid fdt available to control U-Boot.
 527 *
 528 * If not, a message is printed to the console if the console is ready.
 529 *
 530 * @return 0 if all ok, -1 if not
 531 */
 532int fdtdec_prepare_fdt(void);
 533
 534/**
 535 * Checks that we have a valid fdt available to control U-Boot.
 536
 537 * However, if not then for the moment nothing is done, since this function
 538 * is called too early to panic().
 539 *
 540 * @returns 0
 541 */
 542int fdtdec_check_fdt(void);
 543
 544/**
 545 * Find the nodes for a peripheral and return a list of them in the correct
 546 * order. This is used to enumerate all the peripherals of a certain type.
 547 *
 548 * To use this, optionally set up a /aliases node with alias properties for
 549 * a peripheral. For example, for usb you could have:
 550 *
 551 * aliases {
 552 *              usb0 = "/ehci@c5008000";
 553 *              usb1 = "/ehci@c5000000";
 554 * };
 555 *
 556 * Pass "usb" as the name to this function and will return a list of two
 557 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
 558 *
 559 * All nodes returned will match the compatible ID, as it is assumed that
 560 * all peripherals use the same driver.
 561 *
 562 * If no alias node is found, then the node list will be returned in the
 563 * order found in the fdt. If the aliases mention a node which doesn't
 564 * exist, then this will be ignored. If nodes are found with no aliases,
 565 * they will be added in any order.
 566 *
 567 * If there is a gap in the aliases, then this function return a 0 node at
 568 * that position. The return value will also count these gaps.
 569 *
 570 * This function checks node properties and will not return nodes which are
 571 * marked disabled (status = "disabled").
 572 *
 573 * @param blob          FDT blob to use
 574 * @param name          Root name of alias to search for
 575 * @param id            Compatible ID to look for
 576 * @param node_list     Place to put list of found nodes
 577 * @param maxcount      Maximum number of nodes to find
 578 * @return number of nodes found on success, FDT_ERR_... on error
 579 */
 580int fdtdec_find_aliases_for_id(const void *blob, const char *name,
 581                        enum fdt_compat_id id, int *node_list, int maxcount);
 582
 583/*
 584 * This function is similar to fdtdec_find_aliases_for_id() except that it
 585 * adds to the node_list that is passed in. Any 0 elements are considered
 586 * available for allocation - others are considered already used and are
 587 * skipped.
 588 *
 589 * You can use this by calling fdtdec_find_aliases_for_id() with an
 590 * uninitialised array, then setting the elements that are returned to -1,
 591 * say, then calling this function, perhaps with a different compat id.
 592 * Any elements you get back that are >0 are new nodes added by the call
 593 * to this function.
 594 *
 595 * Note that if you have some nodes with aliases and some without, you are
 596 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
 597 * one compat_id may fill in positions for which you have aliases defined
 598 * for another compat_id. When you later call *this* function with the second
 599 * compat_id, the alias positions may already be used. A debug warning may
 600 * be generated in this case, but it is safest to define aliases for all
 601 * nodes when you care about the ordering.
 602 */
 603int fdtdec_add_aliases_for_id(const void *blob, const char *name,
 604                        enum fdt_compat_id id, int *node_list, int maxcount);
 605
 606/**
 607 * Get the alias sequence number of a node
 608 *
 609 * This works out whether a node is pointed to by an alias, and if so, the
 610 * sequence number of that alias. Aliases are of the form <base><num> where
 611 * <num> is the sequence number. For example spi2 would be sequence number
 612 * 2.
 613 *
 614 * @param blob          Device tree blob (if NULL, then error is returned)
 615 * @param base          Base name for alias (before the underscore)
 616 * @param node          Node to look up
 617 * @param seqp          This is set to the sequence number if one is found,
 618 *                      but otherwise the value is left alone
 619 * @return 0 if a sequence was found, -ve if not
 620 */
 621int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
 622                         int *seqp);
 623
 624/**
 625 * Get the highest alias number for susbystem.
 626 *
 627 * It parses all aliases and find out highest recorded alias for subsystem.
 628 * Aliases are of the form <base><num> where <num> is the sequence number.
 629 *
 630 * @param blob          Device tree blob (if NULL, then error is returned)
 631 * @param base          Base name for alias susbystem (before the number)
 632 *
 633 * @return 0 highest alias ID, -1 if not found
 634 */
 635int fdtdec_get_alias_highest_id(const void *blob, const char *base);
 636
 637/**
 638 * Get a property from the /chosen node
 639 *
 640 * @param blob          Device tree blob (if NULL, then NULL is returned)
 641 * @param name          Property name to look up
 642 * @return Value of property, or NULL if it does not exist
 643 */
 644const char *fdtdec_get_chosen_prop(const void *blob, const char *name);
 645
 646/**
 647 * Get the offset of the given /chosen node
 648 *
 649 * This looks up a property in /chosen containing the path to another node,
 650 * then finds the offset of that node.
 651 *
 652 * @param blob          Device tree blob (if NULL, then error is returned)
 653 * @param name          Property name, e.g. "stdout-path"
 654 * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
 655 */
 656int fdtdec_get_chosen_node(const void *blob, const char *name);
 657
 658/*
 659 * Get the name for a compatible ID
 660 *
 661 * @param id            Compatible ID to look for
 662 * @return compatible string for that id
 663 */
 664const char *fdtdec_get_compatible(enum fdt_compat_id id);
 665
 666/* Look up a phandle and follow it to its node. Then return the offset
 667 * of that node.
 668 *
 669 * @param blob          FDT blob
 670 * @param node          node to examine
 671 * @param prop_name     name of property to find
 672 * @return node offset if found, -ve error code on error
 673 */
 674int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
 675
 676/**
 677 * Look up a property in a node and return its contents in an integer
 678 * array of given length. The property must have at least enough data for
 679 * the array (4*count bytes). It may have more, but this will be ignored.
 680 *
 681 * @param blob          FDT blob
 682 * @param node          node to examine
 683 * @param prop_name     name of property to find
 684 * @param array         array to fill with data
 685 * @param count         number of array elements
 686 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
 687 *              or -FDT_ERR_BADLAYOUT if not enough data
 688 */
 689int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
 690                u32 *array, int count);
 691
 692/**
 693 * Look up a property in a node and return its contents in an integer
 694 * array of given length. The property must exist but may have less data that
 695 * expected (4*count bytes). It may have more, but this will be ignored.
 696 *
 697 * @param blob          FDT blob
 698 * @param node          node to examine
 699 * @param prop_name     name of property to find
 700 * @param array         array to fill with data
 701 * @param count         number of array elements
 702 * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
 703 *              property is not found
 704 */
 705int fdtdec_get_int_array_count(const void *blob, int node,
 706                               const char *prop_name, u32 *array, int count);
 707
 708/**
 709 * Look up a property in a node and return a pointer to its contents as a
 710 * unsigned int array of given length. The property must have at least enough
 711 * data for the array ('count' cells). It may have more, but this will be
 712 * ignored. The data is not copied.
 713 *
 714 * Note that you must access elements of the array with fdt32_to_cpu(),
 715 * since the elements will be big endian even on a little endian machine.
 716 *
 717 * @param blob          FDT blob
 718 * @param node          node to examine
 719 * @param prop_name     name of property to find
 720 * @param count         number of array elements
 721 * @return pointer to array if found, or NULL if the property is not
 722 *              found or there is not enough data
 723 */
 724const u32 *fdtdec_locate_array(const void *blob, int node,
 725                               const char *prop_name, int count);
 726
 727/**
 728 * Look up a boolean property in a node and return it.
 729 *
 730 * A boolean properly is true if present in the device tree and false if not
 731 * present, regardless of its value.
 732 *
 733 * @param blob  FDT blob
 734 * @param node  node to examine
 735 * @param prop_name     name of property to find
 736 * @return 1 if the properly is present; 0 if it isn't present
 737 */
 738int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
 739
 740/*
 741 * Count child nodes of one parent node.
 742 *
 743 * @param blob  FDT blob
 744 * @param node  parent node
 745 * @return number of child node; 0 if there is not child node
 746 */
 747int fdtdec_get_child_count(const void *blob, int node);
 748
 749/**
 750 * Look in the FDT for a config item with the given name and return its value
 751 * as a 32-bit integer. The property must have at least 4 bytes of data. The
 752 * value of the first cell is returned.
 753 *
 754 * @param blob          FDT blob to use
 755 * @param prop_name     Node property name
 756 * @param default_val   default value to return if the property is not found
 757 * @return integer value, if found, or default_val if not
 758 */
 759int fdtdec_get_config_int(const void *blob, const char *prop_name,
 760                int default_val);
 761
 762/**
 763 * Look in the FDT for a config item with the given name
 764 * and return whether it exists.
 765 *
 766 * @param blob          FDT blob
 767 * @param prop_name     property name to look up
 768 * @return 1, if it exists, or 0 if not
 769 */
 770int fdtdec_get_config_bool(const void *blob, const char *prop_name);
 771
 772/**
 773 * Look in the FDT for a config item with the given name and return its value
 774 * as a string.
 775 *
 776 * @param blob          FDT blob
 777 * @param prop_name     property name to look up
 778 * @returns property string, NULL on error.
 779 */
 780char *fdtdec_get_config_string(const void *blob, const char *prop_name);
 781
 782/*
 783 * Look up a property in a node and return its contents in a byte
 784 * array of given length. The property must have at least enough data for
 785 * the array (count bytes). It may have more, but this will be ignored.
 786 *
 787 * @param blob          FDT blob
 788 * @param node          node to examine
 789 * @param prop_name     name of property to find
 790 * @param array         array to fill with data
 791 * @param count         number of array elements
 792 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
 793 *              or -FDT_ERR_BADLAYOUT if not enough data
 794 */
 795int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
 796                u8 *array, int count);
 797
 798/**
 799 * Look up a property in a node and return a pointer to its contents as a
 800 * byte array of given length. The property must have at least enough data
 801 * for the array (count bytes). It may have more, but this will be ignored.
 802 * The data is not copied.
 803 *
 804 * @param blob          FDT blob
 805 * @param node          node to examine
 806 * @param prop_name     name of property to find
 807 * @param count         number of array elements
 808 * @return pointer to byte array if found, or NULL if the property is not
 809 *              found or there is not enough data
 810 */
 811const u8 *fdtdec_locate_byte_array(const void *blob, int node,
 812                             const char *prop_name, int count);
 813
 814/**
 815 * Obtain an indexed resource from a device property.
 816 *
 817 * @param fdt           FDT blob
 818 * @param node          node to examine
 819 * @param property      name of the property to parse
 820 * @param index         index of the resource to retrieve
 821 * @param res           returns the resource
 822 * @return 0 if ok, negative on error
 823 */
 824int fdt_get_resource(const void *fdt, int node, const char *property,
 825                     unsigned int index, struct fdt_resource *res);
 826
 827/**
 828 * Obtain a named resource from a device property.
 829 *
 830 * Look up the index of the name in a list of strings and return the resource
 831 * at that index.
 832 *
 833 * @param fdt           FDT blob
 834 * @param node          node to examine
 835 * @param property      name of the property to parse
 836 * @param prop_names    name of the property containing the list of names
 837 * @param name          the name of the entry to look up
 838 * @param res           returns the resource
 839 */
 840int fdt_get_named_resource(const void *fdt, int node, const char *property,
 841                           const char *prop_names, const char *name,
 842                           struct fdt_resource *res);
 843
 844/* Display timings from linux include/video/display_timing.h */
 845enum display_flags {
 846        DISPLAY_FLAGS_HSYNC_LOW         = 1 << 0,
 847        DISPLAY_FLAGS_HSYNC_HIGH        = 1 << 1,
 848        DISPLAY_FLAGS_VSYNC_LOW         = 1 << 2,
 849        DISPLAY_FLAGS_VSYNC_HIGH        = 1 << 3,
 850
 851        /* data enable flag */
 852        DISPLAY_FLAGS_DE_LOW            = 1 << 4,
 853        DISPLAY_FLAGS_DE_HIGH           = 1 << 5,
 854        /* drive data on pos. edge */
 855        DISPLAY_FLAGS_PIXDATA_POSEDGE   = 1 << 6,
 856        /* drive data on neg. edge */
 857        DISPLAY_FLAGS_PIXDATA_NEGEDGE   = 1 << 7,
 858        DISPLAY_FLAGS_INTERLACED        = 1 << 8,
 859        DISPLAY_FLAGS_DOUBLESCAN        = 1 << 9,
 860        DISPLAY_FLAGS_DOUBLECLK         = 1 << 10,
 861};
 862
 863/*
 864 * A single signal can be specified via a range of minimal and maximal values
 865 * with a typical value, that lies somewhere inbetween.
 866 */
 867struct timing_entry {
 868        u32 min;
 869        u32 typ;
 870        u32 max;
 871};
 872
 873/*
 874 * Single "mode" entry. This describes one set of signal timings a display can
 875 * have in one setting. This struct can later be converted to struct videomode
 876 * (see include/video/videomode.h). As each timing_entry can be defined as a
 877 * range, one struct display_timing may become multiple struct videomodes.
 878 *
 879 * Example: hsync active high, vsync active low
 880 *
 881 *                                  Active Video
 882 * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
 883 *        |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
 884 *        |          |   porch  |                    |   porch   |
 885 *
 886 * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
 887 *
 888 * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
 889 */
 890struct display_timing {
 891        struct timing_entry pixelclock;
 892
 893        struct timing_entry hactive;            /* hor. active video */
 894        struct timing_entry hfront_porch;       /* hor. front porch */
 895        struct timing_entry hback_porch;        /* hor. back porch */
 896        struct timing_entry hsync_len;          /* hor. sync len */
 897
 898        struct timing_entry vactive;            /* ver. active video */
 899        struct timing_entry vfront_porch;       /* ver. front porch */
 900        struct timing_entry vback_porch;        /* ver. back porch */
 901        struct timing_entry vsync_len;          /* ver. sync len */
 902
 903        enum display_flags flags;               /* display flags */
 904        bool hdmi_monitor;                      /* is hdmi monitor? */
 905};
 906
 907/**
 908 * fdtdec_decode_display_timing() - decode display timings
 909 *
 910 * Decode display timings from the supplied 'display-timings' node.
 911 * See doc/device-tree-bindings/video/display-timing.txt for binding
 912 * information.
 913 *
 914 * @param blob          FDT blob
 915 * @param node          'display-timing' node containing the timing subnodes
 916 * @param index         Index number to read (0=first timing subnode)
 917 * @param config        Place to put timings
 918 * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
 919 */
 920int fdtdec_decode_display_timing(const void *blob, int node, int index,
 921                                 struct display_timing *config);
 922
 923/**
 924 * fdtdec_setup_mem_size_base() - decode and setup gd->ram_size and
 925 * gd->ram_start
 926 *
 927 * Decode the /memory 'reg' property to determine the size and start of the
 928 * first memory bank, populate the global data with the size and start of the
 929 * first bank of memory.
 930 *
 931 * This function should be called from a boards dram_init(). This helper
 932 * function allows for boards to query the device tree for DRAM size and start
 933 * address instead of hard coding the value in the case where the memory size
 934 * and start address cannot be detected automatically.
 935 *
 936 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
 937 * invalid
 938 */
 939int fdtdec_setup_mem_size_base(void);
 940
 941/**
 942 * fdtdec_setup_mem_size_base_lowest() - decode and setup gd->ram_size and
 943 * gd->ram_start by lowest available memory base
 944 *
 945 * Decode the /memory 'reg' property to determine the lowest start of the memory
 946 * bank bank and populate the global data with it.
 947 *
 948 * This function should be called from a boards dram_init(). This helper
 949 * function allows for boards to query the device tree for DRAM size and start
 950 * address instead of hard coding the value in the case where the memory size
 951 * and start address cannot be detected automatically.
 952 *
 953 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
 954 * invalid
 955 */
 956int fdtdec_setup_mem_size_base_lowest(void);
 957
 958/**
 959 * fdtdec_setup_memory_banksize() - decode and populate gd->bd->bi_dram
 960 *
 961 * Decode the /memory 'reg' property to determine the address and size of the
 962 * memory banks. Use this data to populate the global data board info with the
 963 * phys address and size of memory banks.
 964 *
 965 * This function should be called from a boards dram_init_banksize(). This
 966 * helper function allows for boards to query the device tree for memory bank
 967 * information instead of hard coding the information in cases where it cannot
 968 * be detected automatically.
 969 *
 970 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
 971 * invalid
 972 */
 973int fdtdec_setup_memory_banksize(void);
 974
 975/**
 976 * fdtdec_set_ethernet_mac_address() - set MAC address for default interface
 977 *
 978 * Looks up the default interface via the "ethernet" alias (in the /aliases
 979 * node) and stores the given MAC in its "local-mac-address" property. This
 980 * is useful on platforms that store the MAC address in a custom location.
 981 * Board code can call this in the late init stage to make sure that the
 982 * interface device tree node has the right MAC address configured for the
 983 * Ethernet uclass to pick it up.
 984 *
 985 * Typically the FDT passed into this function will be U-Boot's control DTB.
 986 * Given that a lot of code may be holding offsets to various nodes in that
 987 * tree, this code will only set the "local-mac-address" property in-place,
 988 * which means that it needs to exist and have space for the 6-byte address.
 989 * This ensures that the operation is non-destructive and does not invalidate
 990 * offsets that other drivers may be using.
 991 *
 992 * @param fdt FDT blob
 993 * @param mac buffer containing the MAC address to set
 994 * @param size size of MAC address
 995 * @return 0 on success or a negative error code on failure
 996 */
 997int fdtdec_set_ethernet_mac_address(void *fdt, const u8 *mac, size_t size);
 998
 999/**
1000 * fdtdec_set_phandle() - sets the phandle of a given node
1001 *
1002 * @param blob          FDT blob
1003 * @param node          offset in the FDT blob of the node whose phandle is to
1004 *                      be set
1005 * @param phandle       phandle to set for the given node
1006 * @return 0 on success or a negative error code on failure
1007 */
1008static inline int fdtdec_set_phandle(void *blob, int node, uint32_t phandle)
1009{
1010        return fdt_setprop_u32(blob, node, "phandle", phandle);
1011}
1012
1013/**
1014 * fdtdec_add_reserved_memory() - add or find a reserved-memory node
1015 *
1016 * If a reserved-memory node already exists for the given carveout, a phandle
1017 * for that node will be returned. Otherwise a new node will be created and a
1018 * phandle corresponding to it will be returned.
1019 *
1020 * See Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
1021 * for details on how to use reserved memory regions.
1022 *
1023 * As an example, consider the following code snippet:
1024 *
1025 *     struct fdt_memory fb = {
1026 *         .start = 0x92cb3000,
1027 *         .end = 0x934b2fff,
1028 *     };
1029 *     uint32_t phandle;
1030 *
1031 *     fdtdec_add_reserved_memory(fdt, "framebuffer", &fb, &phandle, false);
1032 *
1033 * This results in the following subnode being added to the top-level
1034 * /reserved-memory node:
1035 *
1036 *     reserved-memory {
1037 *         #address-cells = <0x00000002>;
1038 *         #size-cells = <0x00000002>;
1039 *         ranges;
1040 *
1041 *         framebuffer@92cb3000 {
1042 *             reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>;
1043 *             phandle = <0x0000004d>;
1044 *         };
1045 *     };
1046 *
1047 * If the top-level /reserved-memory node does not exist, it will be created.
1048 * The phandle returned from the function call can be used to reference this
1049 * reserved memory region from other nodes.
1050 *
1051 * See fdtdec_set_carveout() for a more elaborate example.
1052 *
1053 * @param blob          FDT blob
1054 * @param basename      base name of the node to create
1055 * @param carveout      information about the carveout region
1056 * @param phandlep      return location for the phandle of the carveout region
1057 *                      can be NULL if no phandle should be added
1058 * @param no_map        add "no-map" property if true
1059 * @return 0 on success or a negative error code on failure
1060 */
1061int fdtdec_add_reserved_memory(void *blob, const char *basename,
1062                               const struct fdt_memory *carveout,
1063                               uint32_t *phandlep, bool no_map);
1064
1065/**
1066 * fdtdec_get_carveout() - reads a carveout from an FDT
1067 *
1068 * Reads information about a carveout region from an FDT. The carveout is a
1069 * referenced by its phandle that is read from a given property in a given
1070 * node.
1071 *
1072 * @param blob          FDT blob
1073 * @param node          name of a node
1074 * @param name          name of the property in the given node that contains
1075 *                      the phandle for the carveout
1076 * @param index         index of the phandle for which to read the carveout
1077 * @param carveout      return location for the carveout information
1078 * @return 0 on success or a negative error code on failure
1079 */
1080int fdtdec_get_carveout(const void *blob, const char *node, const char *name,
1081                        unsigned int index, struct fdt_memory *carveout);
1082
1083/**
1084 * fdtdec_set_carveout() - sets a carveout region for a given node
1085 *
1086 * Sets a carveout region for a given node. If a reserved-memory node already
1087 * exists for the carveout, the phandle for that node will be reused. If no
1088 * such node exists, a new one will be created and a phandle to it stored in
1089 * a specified property of the given node.
1090 *
1091 * As an example, consider the following code snippet:
1092 *
1093 *     const char *node = "/host1x@50000000/dc@54240000";
1094 *     struct fdt_memory fb = {
1095 *         .start = 0x92cb3000,
1096 *         .end = 0x934b2fff,
1097 *     };
1098 *
1099 *     fdtdec_set_carveout(fdt, node, "memory-region", 0, "framebuffer", &fb);
1100 *
1101 * dc@54200000 is a display controller and was set up by the bootloader to
1102 * scan out the framebuffer specified by "fb". This would cause the following
1103 * reserved memory region to be added:
1104 *
1105 *     reserved-memory {
1106 *         #address-cells = <0x00000002>;
1107 *         #size-cells = <0x00000002>;
1108 *         ranges;
1109 *
1110 *         framebuffer@92cb3000 {
1111 *             reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>;
1112 *             phandle = <0x0000004d>;
1113 *         };
1114 *     };
1115 *
1116 * A "memory-region" property will also be added to the node referenced by the
1117 * offset parameter.
1118 *
1119 *     host1x@50000000 {
1120 *         ...
1121 *
1122 *         dc@54240000 {
1123 *             ...
1124 *             memory-region = <0x0000004d>;
1125 *             ...
1126 *         };
1127 *
1128 *         ...
1129 *     };
1130 *
1131 * @param blob          FDT blob
1132 * @param node          name of the node to add the carveout to
1133 * @param prop_name     name of the property in which to store the phandle of
1134 *                      the carveout
1135 * @param index         index of the phandle to store
1136 * @param name          base name of the reserved-memory node to create
1137 * @param carveout      information about the carveout to add
1138 * @return 0 on success or a negative error code on failure
1139 */
1140int fdtdec_set_carveout(void *blob, const char *node, const char *prop_name,
1141                        unsigned int index, const char *name,
1142                        const struct fdt_memory *carveout);
1143
1144/**
1145 * Set up the device tree ready for use
1146 */
1147int fdtdec_setup(void);
1148
1149/**
1150 * Perform board-specific early DT adjustments
1151 */
1152int fdtdec_board_setup(const void *fdt_blob);
1153
1154#if CONFIG_IS_ENABLED(MULTI_DTB_FIT)
1155/**
1156 * fdtdec_resetup()  - Set up the device tree again
1157 *
1158 * The main difference with fdtdec_setup() is that it returns if the fdt has
1159 * changed because a better match has been found.
1160 * This is typically used for boards that rely on a DM driver to detect the
1161 * board type. This function sould be called by the board code after the stuff
1162 * needed by board_fit_config_name_match() to operate porperly is available.
1163 * If this functions signals that a rescan is necessary, the board code must
1164 * unbind all the drivers using dm_uninit() and then rescan the DT with
1165 * dm_init_and_scan().
1166 *
1167 * @param rescan Returns a flag indicating that fdt has changed and rescanning
1168 *               the fdt is required
1169 *
1170 * @return 0 if OK, -ve on error
1171 */
1172int fdtdec_resetup(int *rescan);
1173#endif
1174
1175/**
1176 * Board-specific FDT initialization. Returns the address to a device tree blob.
1177 * Called when CONFIG_OF_BOARD is defined, or if CONFIG_OF_SEPARATE is defined
1178 * and the board implements it.
1179 */
1180void *board_fdt_blob_setup(void);
1181
1182/*
1183 * Decode the size of memory
1184 *
1185 * RAM size is normally set in a /memory node and consists of a list of
1186 * (base, size) cells in the 'reg' property. This information is used to
1187 * determine the total available memory as well as the address and size
1188 * of each bank.
1189 *
1190 * Optionally the memory configuration can vary depending on a board id,
1191 * typically read from strapping resistors or an EEPROM on the board.
1192 *
1193 * Finally, memory size can be detected (within certain limits) by probing
1194 * the available memory. It is safe to do so within the limits provides by
1195 * the board's device tree information. This makes it possible to produce
1196 * boards with different memory sizes, where the device tree specifies the
1197 * maximum memory configuration, and the smaller memory configuration is
1198 * probed.
1199 *
1200 * This function decodes that information, returning the memory base address,
1201 * size and bank information. See the memory.txt binding for full
1202 * documentation.
1203 *
1204 * @param blob          Device tree blob
1205 * @param area          Name of node to check (NULL means "/memory")
1206 * @param board_id      Board ID to look up
1207 * @param basep         Returns base address of first memory bank (NULL to
1208 *                      ignore)
1209 * @param sizep         Returns total memory size (NULL to ignore)
1210 * @param bd            Updated with the memory bank information (NULL to skip)
1211 * @return 0 if OK, -ve on error
1212 */
1213int fdtdec_decode_ram_size(const void *blob, const char *area, int board_id,
1214                           phys_addr_t *basep, phys_size_t *sizep,
1215                           struct bd_info *bd);
1216
1217#endif
1218