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#ifdef CONFIG_PHYS_64BIT
  28#define FDT_ADDR_T_NONE (-1U)
  29#define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
  30#define fdt_size_to_cpu(reg) be64_to_cpu(reg)
  31#define cpu_to_fdt_addr(reg) cpu_to_be64(reg)
  32#define cpu_to_fdt_size(reg) cpu_to_be64(reg)
  33typedef fdt64_t fdt_val_t;
  34#else
  35#define FDT_ADDR_T_NONE (-1U)
  36#define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
  37#define fdt_size_to_cpu(reg) be32_to_cpu(reg)
  38#define cpu_to_fdt_addr(reg) cpu_to_be32(reg)
  39#define cpu_to_fdt_size(reg) cpu_to_be32(reg)
  40typedef fdt32_t fdt_val_t;
  41#endif
  42
  43/* Information obtained about memory from the FDT */
  44struct fdt_memory {
  45        fdt_addr_t start;
  46        fdt_addr_t end;
  47};
  48
  49struct bd_info;
  50
  51#ifdef CONFIG_SPL_BUILD
  52#define SPL_BUILD       1
  53#else
  54#define SPL_BUILD       0
  55#endif
  56
  57#ifdef CONFIG_OF_PRIOR_STAGE
  58extern phys_addr_t prior_stage_fdt_address;
  59#endif
  60
  61/*
  62 * Information about a resource. start is the first address of the resource
  63 * and end is the last address (inclusive). The length of the resource will
  64 * be equal to: end - start + 1.
  65 */
  66struct fdt_resource {
  67        fdt_addr_t start;
  68        fdt_addr_t end;
  69};
  70
  71enum fdt_pci_space {
  72        FDT_PCI_SPACE_CONFIG = 0,
  73        FDT_PCI_SPACE_IO = 0x01000000,
  74        FDT_PCI_SPACE_MEM32 = 0x02000000,
  75        FDT_PCI_SPACE_MEM64 = 0x03000000,
  76        FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
  77        FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
  78};
  79
  80#define FDT_PCI_ADDR_CELLS      3
  81#define FDT_PCI_SIZE_CELLS      2
  82#define FDT_PCI_REG_SIZE        \
  83        ((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
  84
  85/*
  86 * The Open Firmware spec defines PCI physical address as follows:
  87 *
  88 *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
  89 *
  90 * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
  91 * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
  92 * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
  93 *
  94 * where:
  95 *
  96 * n:        is 0 if the address is relocatable, 1 otherwise
  97 * p:        is 1 if addressable region is prefetchable, 0 otherwise
  98 * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
  99 *           (for Memory), or below 64KB (for relocatable I/O)
 100 * ss:       is the space code, denoting the address space
 101 * bbbbbbbb: is the 8-bit Bus Number
 102 * ddddd:    is the 5-bit Device Number
 103 * fff:      is the 3-bit Function Number
 104 * rrrrrrrr: is the 8-bit Register Number
 105 * hhhhhhhh: is a 32-bit unsigned number
 106 * llllllll: is a 32-bit unsigned number
 107 */
 108struct fdt_pci_addr {
 109        u32     phys_hi;
 110        u32     phys_mid;
 111        u32     phys_lo;
 112};
 113
 114extern u8 __dtb_dt_begin[];     /* embedded device tree blob */
 115extern u8 __dtb_dt_spl_begin[]; /* embedded device tree blob for SPL/TPL */
 116
 117/**
 118 * Compute the size of a resource.
 119 *
 120 * @param res   the resource to operate on
 121 * @return the size of the resource
 122 */
 123static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
 124{
 125        return res->end - res->start + 1;
 126}
 127
 128/**
 129 * Compat types that we know about and for which we might have drivers.
 130 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
 131 * within drivers.
 132 */
 133enum fdt_compat_id {
 134        COMPAT_UNKNOWN,
 135        COMPAT_NVIDIA_TEGRA20_EMC,      /* Tegra20 memory controller */
 136        COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
 137        COMPAT_NVIDIA_TEGRA20_NAND,     /* Tegra2 NAND controller */
 138        COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
 139                                        /* Tegra124 XUSB pad controller */
 140        COMPAT_NVIDIA_TEGRA210_XUSB_PADCTL,
 141                                        /* Tegra210 XUSB pad controller */
 142        COMPAT_SMSC_LAN9215,            /* SMSC 10/100 Ethernet LAN9215 */
 143        COMPAT_SAMSUNG_EXYNOS5_SROMC,   /* Exynos5 SROMC */
 144        COMPAT_SAMSUNG_EXYNOS_USB_PHY,  /* Exynos phy controller for usb2.0 */
 145        COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
 146        COMPAT_SAMSUNG_EXYNOS_TMU,      /* Exynos TMU */
 147        COMPAT_SAMSUNG_EXYNOS_MIPI_DSI, /* Exynos mipi dsi */
 148        COMPAT_SAMSUNG_EXYNOS_DWMMC,    /* Exynos DWMMC controller */
 149        COMPAT_GENERIC_SPI_FLASH,       /* Generic SPI Flash chip */
 150        COMPAT_SAMSUNG_EXYNOS_SYSMMU,   /* Exynos sysmmu */
 151        COMPAT_INTEL_MICROCODE,         /* Intel microcode update */
 152        COMPAT_INTEL_QRK_MRC,           /* Intel Quark MRC */
 153        COMPAT_ALTERA_SOCFPGA_DWMAC,    /* SoCFPGA Ethernet controller */
 154        COMPAT_ALTERA_SOCFPGA_DWMMC,    /* SoCFPGA DWMMC controller */
 155        COMPAT_ALTERA_SOCFPGA_DWC2USB,  /* SoCFPGA DWC2 USB controller */
 156        COMPAT_INTEL_BAYTRAIL_FSP,      /* Intel Bay Trail FSP */
 157        COMPAT_INTEL_BAYTRAIL_FSP_MDP,  /* Intel FSP memory-down params */
 158        COMPAT_INTEL_IVYBRIDGE_FSP,     /* Intel Ivy Bridge FSP */
 159        COMPAT_SUNXI_NAND,              /* SUNXI NAND controller */
 160        COMPAT_ALTERA_SOCFPGA_CLK,      /* SoCFPGA Clock initialization */
 161        COMPAT_ALTERA_SOCFPGA_PINCTRL_SINGLE,   /* SoCFPGA pinctrl-single */
 162        COMPAT_ALTERA_SOCFPGA_H2F_BRG,          /* SoCFPGA hps2fpga bridge */
 163        COMPAT_ALTERA_SOCFPGA_LWH2F_BRG,        /* SoCFPGA lwhps2fpga bridge */
 164        COMPAT_ALTERA_SOCFPGA_F2H_BRG,          /* SoCFPGA fpga2hps bridge */
 165        COMPAT_ALTERA_SOCFPGA_F2SDR0,           /* SoCFPGA fpga2SDRAM0 bridge */
 166        COMPAT_ALTERA_SOCFPGA_F2SDR1,           /* SoCFPGA fpga2SDRAM1 bridge */
 167        COMPAT_ALTERA_SOCFPGA_F2SDR2,           /* SoCFPGA fpga2SDRAM2 bridge */
 168        COMPAT_ALTERA_SOCFPGA_FPGA0,            /* SOCFPGA FPGA manager */
 169        COMPAT_ALTERA_SOCFPGA_NOC,              /* SOCFPGA Arria 10 NOC */
 170        COMPAT_ALTERA_SOCFPGA_CLK_INIT,         /* SOCFPGA Arria 10 clk init */
 171
 172        COMPAT_COUNT,
 173};
 174
 175#define MAX_PHANDLE_ARGS 16
 176struct fdtdec_phandle_args {
 177        int node;
 178        int args_count;
 179        uint32_t args[MAX_PHANDLE_ARGS];
 180};
 181
 182/**
 183 * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
 184 *
 185 * This function is useful to parse lists of phandles and their arguments.
 186 *
 187 * Example:
 188 *
 189 * phandle1: node1 {
 190 *      #list-cells = <2>;
 191 * }
 192 *
 193 * phandle2: node2 {
 194 *      #list-cells = <1>;
 195 * }
 196 *
 197 * node3 {
 198 *      list = <&phandle1 1 2 &phandle2 3>;
 199 * }
 200 *
 201 * To get a device_node of the `node2' node you may call this:
 202 * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
 203 *                                &args);
 204 *
 205 * (This function is a modified version of __of_parse_phandle_with_args() from
 206 * Linux 3.18)
 207 *
 208 * @blob:       Pointer to device tree
 209 * @src_node:   Offset of device tree node containing a list
 210 * @list_name:  property name that contains a list
 211 * @cells_name: property name that specifies the phandles' arguments count,
 212 *              or NULL to use @cells_count
 213 * @cells_count: Cell count to use if @cells_name is NULL
 214 * @index:      index of a phandle to parse out
 215 * @out_args:   optional pointer to output arguments structure (will be filled)
 216 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
 217 *      @list_name does not exist, a phandle was not found, @cells_name
 218 *      could not be found, the arguments were truncated or there were too
 219 *      many arguments.
 220 *
 221 */
 222int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
 223                                   const char *list_name,
 224                                   const char *cells_name,
 225                                   int cell_count, int index,
 226                                   struct fdtdec_phandle_args *out_args);
 227
 228/**
 229 * Find the next numbered alias for a peripheral. This is used to enumerate
 230 * all the peripherals of a certain type.
 231 *
 232 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
 233 * this function will return a pointer to the node the alias points to, and
 234 * then update *upto to 1. Next time you call this function, the next node
 235 * will be returned.
 236 *
 237 * All nodes returned will match the compatible ID, as it is assumed that
 238 * all peripherals use the same driver.
 239 *
 240 * @param blob          FDT blob to use
 241 * @param name          Root name of alias to search for
 242 * @param id            Compatible ID to look for
 243 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 244 */
 245int fdtdec_next_alias(const void *blob, const char *name,
 246                enum fdt_compat_id id, int *upto);
 247
 248/**
 249 * Find the compatible ID for a given node.
 250 *
 251 * Generally each node has at least one compatible string attached to it.
 252 * This function looks through our list of known compatible strings and
 253 * returns the corresponding ID which matches the compatible string.
 254 *
 255 * @param blob          FDT blob to use
 256 * @param node          Node containing compatible string to find
 257 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
 258 */
 259enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
 260
 261/**
 262 * Find the next compatible node for a peripheral.
 263 *
 264 * Do the first call with node = 0. This function will return a pointer to
 265 * the next compatible node. Next time you call this function, pass the
 266 * value returned, and the next node will be provided.
 267 *
 268 * @param blob          FDT blob to use
 269 * @param node          Start node for search
 270 * @param id            Compatible ID to look for (enum fdt_compat_id)
 271 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 272 */
 273int fdtdec_next_compatible(const void *blob, int node,
 274                enum fdt_compat_id id);
 275
 276/**
 277 * Find the next compatible subnode for a peripheral.
 278 *
 279 * Do the first call with node set to the parent and depth = 0. This
 280 * function will return the offset of the next compatible node. Next time
 281 * you call this function, pass the node value returned last time, with
 282 * depth unchanged, and the next node will be provided.
 283 *
 284 * @param blob          FDT blob to use
 285 * @param node          Start node for search
 286 * @param id            Compatible ID to look for (enum fdt_compat_id)
 287 * @param depthp        Current depth (set to 0 before first call)
 288 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 289 */
 290int fdtdec_next_compatible_subnode(const void *blob, int node,
 291                enum fdt_compat_id id, int *depthp);
 292
 293/*
 294 * Look up an address property in a node and return the parsed address, and
 295 * optionally the parsed size.
 296 *
 297 * This variant assumes a known and fixed number of cells are used to
 298 * represent the address and size.
 299 *
 300 * You probably don't want to use this function directly except to parse
 301 * non-standard properties, and never to parse the "reg" property. Instead,
 302 * use one of the "auto" variants below, which automatically honor the
 303 * #address-cells and #size-cells properties in the parent node.
 304 *
 305 * @param blob  FDT blob
 306 * @param node  node to examine
 307 * @param prop_name     name of property to find
 308 * @param index which address to retrieve from a list of addresses. Often 0.
 309 * @param na    the number of cells used to represent an address
 310 * @param ns    the number of cells used to represent a size
 311 * @param sizep a pointer to store the size into. Use NULL if not required
 312 * @param translate     Indicates whether to translate the returned value
 313 *                      using the parent node's ranges property.
 314 * @return address, if found, or FDT_ADDR_T_NONE if not
 315 */
 316fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
 317                const char *prop_name, int index, int na, int ns,
 318                fdt_size_t *sizep, bool translate);
 319
 320/*
 321 * Look up an address property in a node and return the parsed address, and
 322 * optionally the parsed size.
 323 *
 324 * This variant automatically determines the number of cells used to represent
 325 * the address and size by parsing the provided parent node's #address-cells
 326 * and #size-cells properties.
 327 *
 328 * @param blob  FDT blob
 329 * @param parent        parent node of @node
 330 * @param node  node to examine
 331 * @param prop_name     name of property to find
 332 * @param index which address to retrieve from a list of addresses. Often 0.
 333 * @param sizep a pointer to store the size into. Use NULL if not required
 334 * @param translate     Indicates whether to translate the returned value
 335 *                      using the parent node's ranges property.
 336 * @return address, if found, or FDT_ADDR_T_NONE if not
 337 */
 338fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
 339                int node, const char *prop_name, int index, fdt_size_t *sizep,
 340                bool translate);
 341
 342/*
 343 * Look up an address property in a node and return the parsed address, and
 344 * optionally the parsed size.
 345 *
 346 * This variant automatically determines the number of cells used to represent
 347 * the address and size by parsing the parent node's #address-cells
 348 * and #size-cells properties. The parent node is automatically found.
 349 *
 350 * The automatic parent lookup implemented by this function is slow.
 351 * Consequently, fdtdec_get_addr_size_auto_parent() should be used where
 352 * possible.
 353 *
 354 * @param blob  FDT blob
 355 * @param parent        parent node of @node
 356 * @param node  node to examine
 357 * @param prop_name     name of property to find
 358 * @param index which address to retrieve from a list of addresses. Often 0.
 359 * @param sizep a pointer to store the size into. Use NULL if not required
 360 * @param translate     Indicates whether to translate the returned value
 361 *                      using the parent node's ranges property.
 362 * @return address, if found, or FDT_ADDR_T_NONE if not
 363 */
 364fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
 365                const char *prop_name, int index, fdt_size_t *sizep,
 366                bool translate);
 367
 368/*
 369 * Look up an address property in a node and return the parsed address.
 370 *
 371 * This variant hard-codes the number of cells used to represent the address
 372 * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
 373 * always returns the first address value in the property (index 0).
 374 *
 375 * Use of this function is not recommended due to the hard-coding of cell
 376 * counts. There is no programmatic validation that these hard-coded values
 377 * actually match the device tree content in any way at all. This assumption
 378 * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
 379 * set in the U-Boot build and exercising strict control over DT content to
 380 * ensure use of matching #address-cells/#size-cells properties. However, this
 381 * approach is error-prone; those familiar with DT will not expect the
 382 * assumption to exist, and could easily invalidate it. If the assumption is
 383 * invalidated, this function will not report the issue, and debugging will
 384 * be required. Instead, use fdtdec_get_addr_size_auto_parent().
 385 *
 386 * @param blob  FDT blob
 387 * @param node  node to examine
 388 * @param prop_name     name of property to find
 389 * @return address, if found, or FDT_ADDR_T_NONE if not
 390 */
 391fdt_addr_t fdtdec_get_addr(const void *blob, int node,
 392                const char *prop_name);
 393
 394/*
 395 * Look up an address property in a node and return the parsed address, and
 396 * optionally the parsed size.
 397 *
 398 * This variant hard-codes the number of cells used to represent the address
 399 * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
 400 * always returns the first address value in the property (index 0).
 401 *
 402 * Use of this function is not recommended due to the hard-coding of cell
 403 * counts. There is no programmatic validation that these hard-coded values
 404 * actually match the device tree content in any way at all. This assumption
 405 * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
 406 * set in the U-Boot build and exercising strict control over DT content to
 407 * ensure use of matching #address-cells/#size-cells properties. However, this
 408 * approach is error-prone; those familiar with DT will not expect the
 409 * assumption to exist, and could easily invalidate it. If the assumption is
 410 * invalidated, this function will not report the issue, and debugging will
 411 * be required. Instead, use fdtdec_get_addr_size_auto_parent().
 412 *
 413 * @param blob  FDT blob
 414 * @param node  node to examine
 415 * @param prop_name     name of property to find
 416 * @param sizep a pointer to store the size into. Use NULL if not required
 417 * @return address, if found, or FDT_ADDR_T_NONE if not
 418 */
 419fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
 420                const char *prop_name, fdt_size_t *sizep);
 421
 422/**
 423 * Look at the compatible property of a device node that represents a PCI
 424 * device and extract pci vendor id and device id from it.
 425 *
 426 * @param blob          FDT blob
 427 * @param node          node to examine
 428 * @param vendor        vendor id of the pci device
 429 * @param device        device id of the pci device
 430 * @return 0 if ok, negative on error
 431 */
 432int fdtdec_get_pci_vendev(const void *blob, int node,
 433                u16 *vendor, u16 *device);
 434
 435/**
 436 * Look at the pci address of a device node that represents a PCI device
 437 * and return base address of the pci device's registers.
 438 *
 439 * @param dev           device to examine
 440 * @param addr          pci address in the form of fdt_pci_addr
 441 * @param bar           returns base address of the pci device's registers
 442 * @return 0 if ok, negative on error
 443 */
 444int fdtdec_get_pci_bar32(const struct udevice *dev, struct fdt_pci_addr *addr,
 445                         u32 *bar);
 446
 447/**
 448 * Look at the bus range property of a device node and return the pci bus
 449 * range for this node.
 450 * The property must hold one fdt_pci_addr with a length.
 451 * @param blob          FDT blob
 452 * @param node          node to examine
 453 * @param res           the resource structure to return the bus range
 454 * @return 0 if ok, negative on error
 455 */
 456
 457int fdtdec_get_pci_bus_range(const void *blob, int node,
 458                             struct fdt_resource *res);
 459
 460/**
 461 * Look up a 32-bit integer property in a node and return it. The property
 462 * must have at least 4 bytes of data. The value of the first cell is
 463 * returned.
 464 *
 465 * @param blob  FDT blob
 466 * @param node  node to examine
 467 * @param prop_name     name of property to find
 468 * @param default_val   default value to return if the property is not found
 469 * @return integer value, if found, or default_val if not
 470 */
 471s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
 472                s32 default_val);
 473
 474/**
 475 * Unsigned version of fdtdec_get_int. The property must have at least
 476 * 4 bytes of data. The value of the first cell is returned.
 477 *
 478 * @param blob  FDT blob
 479 * @param node  node to examine
 480 * @param prop_name     name of property to find
 481 * @param default_val   default value to return if the property is not found
 482 * @return unsigned integer value, if found, or default_val if not
 483 */
 484unsigned int fdtdec_get_uint(const void *blob, int node, const char *prop_name,
 485                        unsigned int default_val);
 486
 487/**
 488 * Get a variable-sized number from a property
 489 *
 490 * This reads a number from one or more cells.
 491 *
 492 * @param ptr   Pointer to property
 493 * @param cells Number of cells containing the number
 494 * @return the value in the cells
 495 */
 496u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
 497
 498/**
 499 * Look up a 64-bit integer property in a node and return it. The property
 500 * must have at least 8 bytes of data (2 cells). The first two cells are
 501 * concatenated to form a 8 bytes value, where the first cell is top half and
 502 * the second cell is bottom half.
 503 *
 504 * @param blob  FDT blob
 505 * @param node  node to examine
 506 * @param prop_name     name of property to find
 507 * @param default_val   default value to return if the property is not found
 508 * @return integer value, if found, or default_val if not
 509 */
 510uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 511                uint64_t default_val);
 512
 513/**
 514 * Checks whether a node is enabled.
 515 * This looks for a 'status' property. If this exists, then returns 1 if
 516 * the status is 'ok' and 0 otherwise. If there is no status property,
 517 * it returns 1 on the assumption that anything mentioned should be enabled
 518 * by default.
 519 *
 520 * @param blob  FDT blob
 521 * @param node  node to examine
 522 * @return integer value 0 (not enabled) or 1 (enabled)
 523 */
 524int fdtdec_get_is_enabled(const void *blob, int node);
 525
 526/**
 527 * Make sure we have a valid fdt available to control U-Boot.
 528 *
 529 * If not, a message is printed to the console if the console is ready.
 530 *
 531 * @return 0 if all ok, -1 if not
 532 */
 533int fdtdec_prepare_fdt(void);
 534
 535/**
 536 * Checks that we have a valid fdt available to control U-Boot.
 537
 538 * However, if not then for the moment nothing is done, since this function
 539 * is called too early to panic().
 540 *
 541 * @returns 0
 542 */
 543int fdtdec_check_fdt(void);
 544
 545/**
 546 * Find the nodes for a peripheral and return a list of them in the correct
 547 * order. This is used to enumerate all the peripherals of a certain type.
 548 *
 549 * To use this, optionally set up a /aliases node with alias properties for
 550 * a peripheral. For example, for usb you could have:
 551 *
 552 * aliases {
 553 *              usb0 = "/ehci@c5008000";
 554 *              usb1 = "/ehci@c5000000";
 555 * };
 556 *
 557 * Pass "usb" as the name to this function and will return a list of two
 558 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
 559 *
 560 * All nodes returned will match the compatible ID, as it is assumed that
 561 * all peripherals use the same driver.
 562 *
 563 * If no alias node is found, then the node list will be returned in the
 564 * order found in the fdt. If the aliases mention a node which doesn't
 565 * exist, then this will be ignored. If nodes are found with no aliases,
 566 * they will be added in any order.
 567 *
 568 * If there is a gap in the aliases, then this function return a 0 node at
 569 * that position. The return value will also count these gaps.
 570 *
 571 * This function checks node properties and will not return nodes which are
 572 * marked disabled (status = "disabled").
 573 *
 574 * @param blob          FDT blob to use
 575 * @param name          Root name of alias to search for
 576 * @param id            Compatible ID to look for
 577 * @param node_list     Place to put list of found nodes
 578 * @param maxcount      Maximum number of nodes to find
 579 * @return number of nodes found on success, FDT_ERR_... on error
 580 */
 581int fdtdec_find_aliases_for_id(const void *blob, const char *name,
 582                        enum fdt_compat_id id, int *node_list, int maxcount);
 583
 584/*
 585 * This function is similar to fdtdec_find_aliases_for_id() except that it
 586 * adds to the node_list that is passed in. Any 0 elements are considered
 587 * available for allocation - others are considered already used and are
 588 * skipped.
 589 *
 590 * You can use this by calling fdtdec_find_aliases_for_id() with an
 591 * uninitialised array, then setting the elements that are returned to -1,
 592 * say, then calling this function, perhaps with a different compat id.
 593 * Any elements you get back that are >0 are new nodes added by the call
 594 * to this function.
 595 *
 596 * Note that if you have some nodes with aliases and some without, you are
 597 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
 598 * one compat_id may fill in positions for which you have aliases defined
 599 * for another compat_id. When you later call *this* function with the second
 600 * compat_id, the alias positions may already be used. A debug warning may
 601 * be generated in this case, but it is safest to define aliases for all
 602 * nodes when you care about the ordering.
 603 */
 604int fdtdec_add_aliases_for_id(const void *blob, const char *name,
 605                        enum fdt_compat_id id, int *node_list, int maxcount);
 606
 607/**
 608 * Get the alias sequence number of a node
 609 *
 610 * This works out whether a node is pointed to by an alias, and if so, the
 611 * sequence number of that alias. Aliases are of the form <base><num> where
 612 * <num> is the sequence number. For example spi2 would be sequence number
 613 * 2.
 614 *
 615 * @param blob          Device tree blob (if NULL, then error is returned)
 616 * @param base          Base name for alias (before the underscore)
 617 * @param node          Node to look up
 618 * @param seqp          This is set to the sequence number if one is found,
 619 *                      but otherwise the value is left alone
 620 * @return 0 if a sequence was found, -ve if not
 621 */
 622int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
 623                         int *seqp);
 624
 625/**
 626 * Get the highest alias number for susbystem.
 627 *
 628 * It parses all aliases and find out highest recorded alias for subsystem.
 629 * Aliases are of the form <base><num> where <num> is the sequence number.
 630 *
 631 * @param blob          Device tree blob (if NULL, then error is returned)
 632 * @param base          Base name for alias susbystem (before the number)
 633 *
 634 * @return 0 highest alias ID, -1 if not found
 635 */
 636int fdtdec_get_alias_highest_id(const void *blob, const char *base);
 637
 638/**
 639 * Get a property from the /chosen node
 640 *
 641 * @param blob          Device tree blob (if NULL, then NULL is returned)
 642 * @param name          Property name to look up
 643 * @return Value of property, or NULL if it does not exist
 644 */
 645const char *fdtdec_get_chosen_prop(const void *blob, const char *name);
 646
 647/**
 648 * Get the offset of the given /chosen node
 649 *
 650 * This looks up a property in /chosen containing the path to another node,
 651 * then finds the offset of that node.
 652 *
 653 * @param blob          Device tree blob (if NULL, then error is returned)
 654 * @param name          Property name, e.g. "stdout-path"
 655 * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
 656 */
 657int fdtdec_get_chosen_node(const void *blob, const char *name);
 658
 659/*
 660 * Get the name for a compatible ID
 661 *
 662 * @param id            Compatible ID to look for
 663 * @return compatible string for that id
 664 */
 665const char *fdtdec_get_compatible(enum fdt_compat_id id);
 666
 667/* Look up a phandle and follow it to its node. Then return the offset
 668 * of that node.
 669 *
 670 * @param blob          FDT blob
 671 * @param node          node to examine
 672 * @param prop_name     name of property to find
 673 * @return node offset if found, -ve error code on error
 674 */
 675int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
 676
 677/**
 678 * Look up a property in a node and return its contents in an integer
 679 * array of given length. The property must have at least enough data for
 680 * the array (4*count bytes). It may have more, but this will be ignored.
 681 *
 682 * @param blob          FDT blob
 683 * @param node          node to examine
 684 * @param prop_name     name of property to find
 685 * @param array         array to fill with data
 686 * @param count         number of array elements
 687 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
 688 *              or -FDT_ERR_BADLAYOUT if not enough data
 689 */
 690int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
 691                u32 *array, int count);
 692
 693/**
 694 * Look up a property in a node and return its contents in an integer
 695 * array of given length. The property must exist but may have less data that
 696 * expected (4*count bytes). It may have more, but this will be ignored.
 697 *
 698 * @param blob          FDT blob
 699 * @param node          node to examine
 700 * @param prop_name     name of property to find
 701 * @param array         array to fill with data
 702 * @param count         number of array elements
 703 * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
 704 *              property is not found
 705 */
 706int fdtdec_get_int_array_count(const void *blob, int node,
 707                               const char *prop_name, u32 *array, int count);
 708
 709/**
 710 * Look up a property in a node and return a pointer to its contents as a
 711 * unsigned int array of given length. The property must have at least enough
 712 * data for the array ('count' cells). It may have more, but this will be
 713 * ignored. The data is not copied.
 714 *
 715 * Note that you must access elements of the array with fdt32_to_cpu(),
 716 * since the elements will be big endian even on a little endian machine.
 717 *
 718 * @param blob          FDT blob
 719 * @param node          node to examine
 720 * @param prop_name     name of property to find
 721 * @param count         number of array elements
 722 * @return pointer to array if found, or NULL if the property is not
 723 *              found or there is not enough data
 724 */
 725const u32 *fdtdec_locate_array(const void *blob, int node,
 726                               const char *prop_name, int count);
 727
 728/**
 729 * Look up a boolean property in a node and return it.
 730 *
 731 * A boolean properly is true if present in the device tree and false if not
 732 * present, regardless of its value.
 733 *
 734 * @param blob  FDT blob
 735 * @param node  node to examine
 736 * @param prop_name     name of property to find
 737 * @return 1 if the properly is present; 0 if it isn't present
 738 */
 739int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
 740
 741/*
 742 * Count child nodes of one parent node.
 743 *
 744 * @param blob  FDT blob
 745 * @param node  parent node
 746 * @return number of child node; 0 if there is not child node
 747 */
 748int fdtdec_get_child_count(const void *blob, int node);
 749
 750/**
 751 * Look in the FDT for a config item with the given name and return its value
 752 * as a 32-bit integer. The property must have at least 4 bytes of data. The
 753 * value of the first cell is returned.
 754 *
 755 * @param blob          FDT blob to use
 756 * @param prop_name     Node property name
 757 * @param default_val   default value to return if the property is not found
 758 * @return integer value, if found, or default_val if not
 759 */
 760int fdtdec_get_config_int(const void *blob, const char *prop_name,
 761                int default_val);
 762
 763/**
 764 * Look in the FDT for a config item with the given name
 765 * and return whether it exists.
 766 *
 767 * @param blob          FDT blob
 768 * @param prop_name     property name to look up
 769 * @return 1, if it exists, or 0 if not
 770 */
 771int fdtdec_get_config_bool(const void *blob, const char *prop_name);
 772
 773/**
 774 * Look in the FDT for a config item with the given name and return its value
 775 * as a string.
 776 *
 777 * @param blob          FDT blob
 778 * @param prop_name     property name to look up
 779 * @returns property string, NULL on error.
 780 */
 781char *fdtdec_get_config_string(const void *blob, const char *prop_name);
 782
 783/*
 784 * Look up a property in a node and return its contents in a byte
 785 * array of given length. The property must have at least enough data for
 786 * the array (count bytes). It may have more, but this will be ignored.
 787 *
 788 * @param blob          FDT blob
 789 * @param node          node to examine
 790 * @param prop_name     name of property to find
 791 * @param array         array to fill with data
 792 * @param count         number of array elements
 793 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
 794 *              or -FDT_ERR_BADLAYOUT if not enough data
 795 */
 796int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
 797                u8 *array, int count);
 798
 799/**
 800 * Look up a property in a node and return a pointer to its contents as a
 801 * byte array of given length. The property must have at least enough data
 802 * for the array (count bytes). It may have more, but this will be ignored.
 803 * The data is not copied.
 804 *
 805 * @param blob          FDT blob
 806 * @param node          node to examine
 807 * @param prop_name     name of property to find
 808 * @param count         number of array elements
 809 * @return pointer to byte array if found, or NULL if the property is not
 810 *              found or there is not enough data
 811 */
 812const u8 *fdtdec_locate_byte_array(const void *blob, int node,
 813                             const char *prop_name, int count);
 814
 815/**
 816 * Obtain an indexed resource from a device property.
 817 *
 818 * @param fdt           FDT blob
 819 * @param node          node to examine
 820 * @param property      name of the property to parse
 821 * @param index         index of the resource to retrieve
 822 * @param res           returns the resource
 823 * @return 0 if ok, negative on error
 824 */
 825int fdt_get_resource(const void *fdt, int node, const char *property,
 826                     unsigned int index, struct fdt_resource *res);
 827
 828/**
 829 * Obtain a named resource from a device property.
 830 *
 831 * Look up the index of the name in a list of strings and return the resource
 832 * at that index.
 833 *
 834 * @param fdt           FDT blob
 835 * @param node          node to examine
 836 * @param property      name of the property to parse
 837 * @param prop_names    name of the property containing the list of names
 838 * @param name          the name of the entry to look up
 839 * @param res           returns the resource
 840 */
 841int fdt_get_named_resource(const void *fdt, int node, const char *property,
 842                           const char *prop_names, const char *name,
 843                           struct fdt_resource *res);
 844
 845/* Display timings from linux include/video/display_timing.h */
 846enum display_flags {
 847        DISPLAY_FLAGS_HSYNC_LOW         = 1 << 0,
 848        DISPLAY_FLAGS_HSYNC_HIGH        = 1 << 1,
 849        DISPLAY_FLAGS_VSYNC_LOW         = 1 << 2,
 850        DISPLAY_FLAGS_VSYNC_HIGH        = 1 << 3,
 851
 852        /* data enable flag */
 853        DISPLAY_FLAGS_DE_LOW            = 1 << 4,
 854        DISPLAY_FLAGS_DE_HIGH           = 1 << 5,
 855        /* drive data on pos. edge */
 856        DISPLAY_FLAGS_PIXDATA_POSEDGE   = 1 << 6,
 857        /* drive data on neg. edge */
 858        DISPLAY_FLAGS_PIXDATA_NEGEDGE   = 1 << 7,
 859        DISPLAY_FLAGS_INTERLACED        = 1 << 8,
 860        DISPLAY_FLAGS_DOUBLESCAN        = 1 << 9,
 861        DISPLAY_FLAGS_DOUBLECLK         = 1 << 10,
 862};
 863
 864/*
 865 * A single signal can be specified via a range of minimal and maximal values
 866 * with a typical value, that lies somewhere inbetween.
 867 */
 868struct timing_entry {
 869        u32 min;
 870        u32 typ;
 871        u32 max;
 872};
 873
 874/*
 875 * Single "mode" entry. This describes one set of signal timings a display can
 876 * have in one setting. This struct can later be converted to struct videomode
 877 * (see include/video/videomode.h). As each timing_entry can be defined as a
 878 * range, one struct display_timing may become multiple struct videomodes.
 879 *
 880 * Example: hsync active high, vsync active low
 881 *
 882 *                                  Active Video
 883 * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
 884 *        |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
 885 *        |          |   porch  |                    |   porch   |
 886 *
 887 * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
 888 *
 889 * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
 890 */
 891struct display_timing {
 892        struct timing_entry pixelclock;
 893
 894        struct timing_entry hactive;            /* hor. active video */
 895        struct timing_entry hfront_porch;       /* hor. front porch */
 896        struct timing_entry hback_porch;        /* hor. back porch */
 897        struct timing_entry hsync_len;          /* hor. sync len */
 898
 899        struct timing_entry vactive;            /* ver. active video */
 900        struct timing_entry vfront_porch;       /* ver. front porch */
 901        struct timing_entry vback_porch;        /* ver. back porch */
 902        struct timing_entry vsync_len;          /* ver. sync len */
 903
 904        enum display_flags flags;               /* display flags */
 905        bool hdmi_monitor;                      /* is hdmi monitor? */
 906};
 907
 908/**
 909 * fdtdec_decode_display_timing() - decode display timings
 910 *
 911 * Decode display timings from the supplied 'display-timings' node.
 912 * See doc/device-tree-bindings/video/display-timing.txt for binding
 913 * information.
 914 *
 915 * @param blob          FDT blob
 916 * @param node          'display-timing' node containing the timing subnodes
 917 * @param index         Index number to read (0=first timing subnode)
 918 * @param config        Place to put timings
 919 * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
 920 */
 921int fdtdec_decode_display_timing(const void *blob, int node, int index,
 922                                 struct display_timing *config);
 923
 924/**
 925 * fdtdec_setup_mem_size_base() - decode and setup gd->ram_size and
 926 * gd->ram_start
 927 *
 928 * Decode the /memory 'reg' property to determine the size and start of the
 929 * first memory bank, populate the global data with the size and start of the
 930 * first bank of memory.
 931 *
 932 * This function should be called from a boards dram_init(). This helper
 933 * function allows for boards to query the device tree for DRAM size and start
 934 * address instead of hard coding the value in the case where the memory size
 935 * and start address cannot be detected automatically.
 936 *
 937 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
 938 * invalid
 939 */
 940int fdtdec_setup_mem_size_base(void);
 941
 942/**
 943 * fdtdec_setup_mem_size_base_lowest() - decode and setup gd->ram_size and
 944 * gd->ram_start by lowest available memory base
 945 *
 946 * Decode the /memory 'reg' property to determine the lowest start of the memory
 947 * bank bank and populate the global data with it.
 948 *
 949 * This function should be called from a boards dram_init(). This helper
 950 * function allows for boards to query the device tree for DRAM size and start
 951 * address instead of hard coding the value in the case where the memory size
 952 * and start address cannot be detected automatically.
 953 *
 954 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
 955 * invalid
 956 */
 957int fdtdec_setup_mem_size_base_lowest(void);
 958
 959/**
 960 * fdtdec_setup_memory_banksize() - decode and populate gd->bd->bi_dram
 961 *
 962 * Decode the /memory 'reg' property to determine the address and size of the
 963 * memory banks. Use this data to populate the global data board info with the
 964 * phys address and size of memory banks.
 965 *
 966 * This function should be called from a boards dram_init_banksize(). This
 967 * helper function allows for boards to query the device tree for memory bank
 968 * information instead of hard coding the information in cases where it cannot
 969 * be detected automatically.
 970 *
 971 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
 972 * invalid
 973 */
 974int fdtdec_setup_memory_banksize(void);
 975
 976/**
 977 * fdtdec_set_ethernet_mac_address() - set MAC address for default interface
 978 *
 979 * Looks up the default interface via the "ethernet" alias (in the /aliases
 980 * node) and stores the given MAC in its "local-mac-address" property. This
 981 * is useful on platforms that store the MAC address in a custom location.
 982 * Board code can call this in the late init stage to make sure that the
 983 * interface device tree node has the right MAC address configured for the
 984 * Ethernet uclass to pick it up.
 985 *
 986 * Typically the FDT passed into this function will be U-Boot's control DTB.
 987 * Given that a lot of code may be holding offsets to various nodes in that
 988 * tree, this code will only set the "local-mac-address" property in-place,
 989 * which means that it needs to exist and have space for the 6-byte address.
 990 * This ensures that the operation is non-destructive and does not invalidate
 991 * offsets that other drivers may be using.
 992 *
 993 * @param fdt FDT blob
 994 * @param mac buffer containing the MAC address to set
 995 * @param size size of MAC address
 996 * @return 0 on success or a negative error code on failure
 997 */
 998int fdtdec_set_ethernet_mac_address(void *fdt, const u8 *mac, size_t size);
 999
1000/**
1001 * fdtdec_set_phandle() - sets the phandle of a given node
1002 *
1003 * @param blob          FDT blob
1004 * @param node          offset in the FDT blob of the node whose phandle is to
1005 *                      be set
1006 * @param phandle       phandle to set for the given node
1007 * @return 0 on success or a negative error code on failure
1008 */
1009static inline int fdtdec_set_phandle(void *blob, int node, uint32_t phandle)
1010{
1011        return fdt_setprop_u32(blob, node, "phandle", phandle);
1012}
1013
1014/**
1015 * fdtdec_add_reserved_memory() - add or find a reserved-memory node
1016 *
1017 * If a reserved-memory node already exists for the given carveout, a phandle
1018 * for that node will be returned. Otherwise a new node will be created and a
1019 * phandle corresponding to it will be returned.
1020 *
1021 * See Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
1022 * for details on how to use reserved memory regions.
1023 *
1024 * As an example, consider the following code snippet:
1025 *
1026 *     struct fdt_memory fb = {
1027 *         .start = 0x92cb3000,
1028 *         .end = 0x934b2fff,
1029 *     };
1030 *     uint32_t phandle;
1031 *
1032 *     fdtdec_add_reserved_memory(fdt, "framebuffer", &fb, &phandle);
1033 *
1034 * This results in the following subnode being added to the top-level
1035 * /reserved-memory node:
1036 *
1037 *     reserved-memory {
1038 *         #address-cells = <0x00000002>;
1039 *         #size-cells = <0x00000002>;
1040 *         ranges;
1041 *
1042 *         framebuffer@92cb3000 {
1043 *             reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>;
1044 *             phandle = <0x0000004d>;
1045 *         };
1046 *     };
1047 *
1048 * If the top-level /reserved-memory node does not exist, it will be created.
1049 * The phandle returned from the function call can be used to reference this
1050 * reserved memory region from other nodes.
1051 *
1052 * See fdtdec_set_carveout() for a more elaborate example.
1053 *
1054 * @param blob          FDT blob
1055 * @param basename      base name of the node to create
1056 * @param carveout      information about the carveout region
1057 * @param phandlep      return location for the phandle of the carveout region
1058 *                      can be NULL if no phandle should be added
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);
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