fdtdec.h 27.3 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
/*
 * Copyright (c) 2011 The Chromium OS Authors.
 * SPDX-License-Identifier:	GPL-2.0+
 */

#ifndef __fdtdec_h
#define __fdtdec_h

/*
 * This file contains convenience functions for decoding useful and
 * enlightening information from FDTs. It is intended to be used by device
 * drivers and board-specific code within U-Boot. It aims to reduce the
 * amount of FDT munging required within U-Boot itself, so that driver code
 * changes to support FDT are minimized.
 */

#include <libfdt.h>
#include <pci.h>

/*
 * A typedef for a physical address. Note that fdt data is always big
 * endian even on a litle endian machine.
 */
#ifdef CONFIG_PHYS_64BIT
typedef u64 fdt_addr_t;
typedef u64 fdt_size_t;
#define FDT_ADDR_T_NONE (-1ULL)
#define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
#define fdt_size_to_cpu(reg) be64_to_cpu(reg)
#else
typedef u32 fdt_addr_t;
typedef u32 fdt_size_t;
#define FDT_ADDR_T_NONE (-1U)
#define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
#define fdt_size_to_cpu(reg) be32_to_cpu(reg)
#endif

/* Information obtained about memory from the FDT */
struct fdt_memory {
	fdt_addr_t start;
	fdt_addr_t end;
};

/*
 * Information about a resource. start is the first address of the resource
 * and end is the last address (inclusive). The length of the resource will
 * be equal to: end - start + 1.
 */
struct fdt_resource {
	fdt_addr_t start;
	fdt_addr_t end;
};

enum fdt_pci_space {
	FDT_PCI_SPACE_CONFIG = 0,
	FDT_PCI_SPACE_IO = 0x01000000,
	FDT_PCI_SPACE_MEM32 = 0x02000000,
	FDT_PCI_SPACE_MEM64 = 0x03000000,
	FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
	FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
};

#define FDT_PCI_ADDR_CELLS	3
#define FDT_PCI_SIZE_CELLS	2
#define FDT_PCI_REG_SIZE	\
	((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))

/*
 * The Open Firmware spec defines PCI physical address as follows:
 *
 *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
 *
 * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
 * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
 * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
 *
 * where:
 *
 * n:        is 0 if the address is relocatable, 1 otherwise
 * p:        is 1 if addressable region is prefetchable, 0 otherwise
 * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
 *           (for Memory), or below 64KB (for relocatable I/O)
 * ss:       is the space code, denoting the address space
 * bbbbbbbb: is the 8-bit Bus Number
 * ddddd:    is the 5-bit Device Number
 * fff:      is the 3-bit Function Number
 * rrrrrrrr: is the 8-bit Register Number
 * hhhhhhhh: is a 32-bit unsigned number
 * llllllll: is a 32-bit unsigned number
 */
struct fdt_pci_addr {
	u32	phys_hi;
	u32	phys_mid;
	u32	phys_lo;
};

/**
 * Compute the size of a resource.
 *
 * @param res	the resource to operate on
 * @return the size of the resource
 */
static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
{
	return res->end - res->start + 1;
}

/**
 * Compat types that we know about and for which we might have drivers.
 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
 * within drivers.
 */
enum fdt_compat_id {
	COMPAT_UNKNOWN,
	COMPAT_NVIDIA_TEGRA20_USB,	/* Tegra20 USB port */
	COMPAT_NVIDIA_TEGRA30_USB,	/* Tegra30 USB port */
	COMPAT_NVIDIA_TEGRA114_USB,	/* Tegra114 USB port */
	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
	COMPAT_NVIDIA_TEGRA124_PCIE,	/* Tegra 124 PCIe controller */
	COMPAT_NVIDIA_TEGRA30_PCIE,	/* Tegra 30 PCIe controller */
	COMPAT_NVIDIA_TEGRA20_PCIE,	/* Tegra 20 PCIe controller */
	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
					/* Tegra124 XUSB pad controller */
	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */
	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */
	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */
	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
	COMPAT_SANDBOX_HOST_EMULATION,	/* Sandbox emulation of a function */
	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
	COMPAT_INTEL_LPC,		/* Intel Low Pin Count I/F */
	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
	COMPAT_MEMORY_SPD,		/* Memory SPD information */
	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
	COMPAT_INTEL_ICH_SPI,		/* Intel ICH7/9 SPI controller */
	COMPAT_INTEL_QRK_MRC,		/* Intel Quark MRC */
	COMPAT_SOCIONEXT_XHCI,		/* Socionext UniPhier xHCI */

	COMPAT_COUNT,
};

#define MAX_PHANDLE_ARGS 16
struct fdtdec_phandle_args {
	int node;
	int args_count;
	uint32_t args[MAX_PHANDLE_ARGS];
};

/**
 * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
 *
 * This function is useful to parse lists of phandles and their arguments.
 *
 * Example:
 *
 * phandle1: node1 {
 *	#list-cells = <2>;
 * }
 *
 * phandle2: node2 {
 *	#list-cells = <1>;
 * }
 *
 * node3 {
 *	list = <&phandle1 1 2 &phandle2 3>;
 * }
 *
 * To get a device_node of the `node2' node you may call this:
 * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
 *				  &args);
 *
 * (This function is a modified version of __of_parse_phandle_with_args() from
 * Linux 3.18)
 *
 * @blob:	Pointer to device tree
 * @src_node:	Offset of device tree node containing a list
 * @list_name:	property name that contains a list
 * @cells_name:	property name that specifies the phandles' arguments count,
 *		or NULL to use @cells_count
 * @cells_count: Cell count to use if @cells_name is NULL
 * @index:	index of a phandle to parse out
 * @out_args:	optional pointer to output arguments structure (will be filled)
 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
 *	@list_name does not exist, a phandle was not found, @cells_name
 *	could not be found, the arguments were truncated or there were too
 *	many arguments.
 *
 */
int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
				   const char *list_name,
				   const char *cells_name,
				   int cell_count, int index,
				   struct fdtdec_phandle_args *out_args);

/**
 * Find the next numbered alias for a peripheral. This is used to enumerate
 * all the peripherals of a certain type.
 *
 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
 * this function will return a pointer to the node the alias points to, and
 * then update *upto to 1. Next time you call this function, the next node
 * will be returned.
 *
 * All nodes returned will match the compatible ID, as it is assumed that
 * all peripherals use the same driver.
 *
 * @param blob		FDT blob to use
 * @param name		Root name of alias to search for
 * @param id		Compatible ID to look for
 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 */
int fdtdec_next_alias(const void *blob, const char *name,
		enum fdt_compat_id id, int *upto);

/**
 * Find the compatible ID for a given node.
 *
 * Generally each node has at least one compatible string attached to it.
 * This function looks through our list of known compatible strings and
 * returns the corresponding ID which matches the compatible string.
 *
 * @param blob		FDT blob to use
 * @param node		Node containing compatible string to find
 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
 */
enum fdt_compat_id fdtdec_lookup(const void *blob, int node);

/**
 * Find the next compatible node for a peripheral.
 *
 * Do the first call with node = 0. This function will return a pointer to
 * the next compatible node. Next time you call this function, pass the
 * value returned, and the next node will be provided.
 *
 * @param blob		FDT blob to use
 * @param node		Start node for search
 * @param id		Compatible ID to look for (enum fdt_compat_id)
 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 */
int fdtdec_next_compatible(const void *blob, int node,
		enum fdt_compat_id id);

/**
 * Find the next compatible subnode for a peripheral.
 *
 * Do the first call with node set to the parent and depth = 0. This
 * function will return the offset of the next compatible node. Next time
 * you call this function, pass the node value returned last time, with
 * depth unchanged, and the next node will be provided.
 *
 * @param blob		FDT blob to use
 * @param node		Start node for search
 * @param id		Compatible ID to look for (enum fdt_compat_id)
 * @param depthp	Current depth (set to 0 before first call)
 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 */
int fdtdec_next_compatible_subnode(const void *blob, int node,
		enum fdt_compat_id id, int *depthp);

/**
 * Look up an address property in a node and return it as an address.
 * The property must hold either one address with no trailing data or
 * one address with a length. This is only tested on 32-bit machines.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @return address, if found, or FDT_ADDR_T_NONE if not
 */
fdt_addr_t fdtdec_get_addr(const void *blob, int node,
		const char *prop_name);

/**
 * Look up an address property in a node and return it as an address.
 * The property must hold one address with a length. This is only tested
 * on 32-bit machines.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @return address, if found, or FDT_ADDR_T_NONE if not
 */
fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
		const char *prop_name, fdt_size_t *sizep);

/**
 * Look at an address property in a node and return the pci address which
 * corresponds to the given type in the form of fdt_pci_addr.
 * The property must hold one fdt_pci_addr with a lengh.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param type		pci address type (FDT_PCI_SPACE_xxx)
 * @param prop_name	name of property to find
 * @param addr		returns pci address in the form of fdt_pci_addr
 * @return 0 if ok, negative on error
 */
int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
		const char *prop_name, struct fdt_pci_addr *addr);

/**
 * Look at the compatible property of a device node that represents a PCI
 * device and extract pci vendor id and device id from it.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param vendor	vendor id of the pci device
 * @param device	device id of the pci device
 * @return 0 if ok, negative on error
 */
int fdtdec_get_pci_vendev(const void *blob, int node,
		u16 *vendor, u16 *device);

/**
 * Look at the pci address of a device node that represents a PCI device
 * and parse the bus, device and function number from it.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param addr		pci address in the form of fdt_pci_addr
 * @param bdf		returns bus, device, function triplet
 * @return 0 if ok, negative on error
 */
int fdtdec_get_pci_bdf(const void *blob, int node,
		struct fdt_pci_addr *addr, pci_dev_t *bdf);

/**
 * Look at the pci address of a device node that represents a PCI device
 * and return base address of the pci device's registers.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param addr		pci address in the form of fdt_pci_addr
 * @param bar		returns base address of the pci device's registers
 * @return 0 if ok, negative on error
 */
int fdtdec_get_pci_bar32(const void *blob, int node,
		struct fdt_pci_addr *addr, u32 *bar);

/**
 * Look up a 32-bit integer property in a node and return it. The property
 * must have at least 4 bytes of data. The value of the first cell is
 * returned.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @param default_val	default value to return if the property is not found
 * @return integer value, if found, or default_val if not
 */
s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
		s32 default_val);

/**
 * Look up a 64-bit integer property in a node and return it. The property
 * must have at least 8 bytes of data (2 cells). The first two cells are
 * concatenated to form a 8 bytes value, where the first cell is top half and
 * the second cell is bottom half.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @param default_val	default value to return if the property is not found
 * @return integer value, if found, or default_val if not
 */
uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
		uint64_t default_val);

/**
 * Checks whether a node is enabled.
 * This looks for a 'status' property. If this exists, then returns 1 if
 * the status is 'ok' and 0 otherwise. If there is no status property,
 * it returns 1 on the assumption that anything mentioned should be enabled
 * by default.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @return integer value 0 (not enabled) or 1 (enabled)
 */
int fdtdec_get_is_enabled(const void *blob, int node);

/**
 * Make sure we have a valid fdt available to control U-Boot.
 *
 * If not, a message is printed to the console if the console is ready.
 *
 * @return 0 if all ok, -1 if not
 */
int fdtdec_prepare_fdt(void);

/**
 * Checks that we have a valid fdt available to control U-Boot.

 * However, if not then for the moment nothing is done, since this function
 * is called too early to panic().
 *
 * @returns 0
 */
int fdtdec_check_fdt(void);

/**
 * Find the nodes for a peripheral and return a list of them in the correct
 * order. This is used to enumerate all the peripherals of a certain type.
 *
 * To use this, optionally set up a /aliases node with alias properties for
 * a peripheral. For example, for usb you could have:
 *
 * aliases {
 *		usb0 = "/ehci@c5008000";
 *		usb1 = "/ehci@c5000000";
 * };
 *
 * Pass "usb" as the name to this function and will return a list of two
 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
 *
 * All nodes returned will match the compatible ID, as it is assumed that
 * all peripherals use the same driver.
 *
 * If no alias node is found, then the node list will be returned in the
 * order found in the fdt. If the aliases mention a node which doesn't
 * exist, then this will be ignored. If nodes are found with no aliases,
 * they will be added in any order.
 *
 * If there is a gap in the aliases, then this function return a 0 node at
 * that position. The return value will also count these gaps.
 *
 * This function checks node properties and will not return nodes which are
 * marked disabled (status = "disabled").
 *
 * @param blob		FDT blob to use
 * @param name		Root name of alias to search for
 * @param id		Compatible ID to look for
 * @param node_list	Place to put list of found nodes
 * @param maxcount	Maximum number of nodes to find
 * @return number of nodes found on success, FTD_ERR_... on error
 */
int fdtdec_find_aliases_for_id(const void *blob, const char *name,
			enum fdt_compat_id id, int *node_list, int maxcount);

/*
 * This function is similar to fdtdec_find_aliases_for_id() except that it
 * adds to the node_list that is passed in. Any 0 elements are considered
 * available for allocation - others are considered already used and are
 * skipped.
 *
 * You can use this by calling fdtdec_find_aliases_for_id() with an
 * uninitialised array, then setting the elements that are returned to -1,
 * say, then calling this function, perhaps with a different compat id.
 * Any elements you get back that are >0 are new nodes added by the call
 * to this function.
 *
 * Note that if you have some nodes with aliases and some without, you are
 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
 * one compat_id may fill in positions for which you have aliases defined
 * for another compat_id. When you later call *this* function with the second
 * compat_id, the alias positions may already be used. A debug warning may
 * be generated in this case, but it is safest to define aliases for all
 * nodes when you care about the ordering.
 */
int fdtdec_add_aliases_for_id(const void *blob, const char *name,
			enum fdt_compat_id id, int *node_list, int maxcount);

/**
 * Get the alias sequence number of a node
 *
 * This works out whether a node is pointed to by an alias, and if so, the
 * sequence number of that alias. Aliases are of the form <base><num> where
 * <num> is the sequence number. For example spi2 would be sequence number
 * 2.
 *
 * @param blob		Device tree blob (if NULL, then error is returned)
 * @param base		Base name for alias (before the underscore)
 * @param node		Node to look up
 * @param seqp		This is set to the sequence number if one is found,
 *			but otherwise the value is left alone
 * @return 0 if a sequence was found, -ve if not
 */
int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
			 int *seqp);

/**
 * Get the offset of the given chosen node
 *
 * This looks up a property in /chosen containing the path to another node,
 * then finds the offset of that node.
 *
 * @param blob		Device tree blob (if NULL, then error is returned)
 * @param name		Property name, e.g. "stdout-path"
 * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
 */
int fdtdec_get_chosen_node(const void *blob, const char *name);

/*
 * Get the name for a compatible ID
 *
 * @param id		Compatible ID to look for
 * @return compatible string for that id
 */
const char *fdtdec_get_compatible(enum fdt_compat_id id);

/* Look up a phandle and follow it to its node. Then return the offset
 * of that node.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @return node offset if found, -ve error code on error
 */
int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);

/**
 * Look up a property in a node and return its contents in an integer
 * array of given length. The property must have at least enough data for
 * the array (4*count bytes). It may have more, but this will be ignored.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param array		array to fill with data
 * @param count		number of array elements
 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
 *		or -FDT_ERR_BADLAYOUT if not enough data
 */
int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
		u32 *array, int count);

/**
 * Look up a property in a node and return its contents in an integer
 * array of given length. The property must exist but may have less data that
 * expected (4*count bytes). It may have more, but this will be ignored.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param array		array to fill with data
 * @param count		number of array elements
 * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
 *		property is not found
 */
int fdtdec_get_int_array_count(const void *blob, int node,
			       const char *prop_name, u32 *array, int count);

/**
 * Look up a property in a node and return a pointer to its contents as a
 * unsigned int array of given length. The property must have at least enough
 * data for the array ('count' cells). It may have more, but this will be
 * ignored. The data is not copied.
 *
 * Note that you must access elements of the array with fdt32_to_cpu(),
 * since the elements will be big endian even on a little endian machine.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param count		number of array elements
 * @return pointer to array if found, or NULL if the property is not
 *		found or there is not enough data
 */
const u32 *fdtdec_locate_array(const void *blob, int node,
			       const char *prop_name, int count);

/**
 * Look up a boolean property in a node and return it.
 *
 * A boolean properly is true if present in the device tree and false if not
 * present, regardless of its value.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @return 1 if the properly is present; 0 if it isn't present
 */
int fdtdec_get_bool(const void *blob, int node, const char *prop_name);

/**
 * Look in the FDT for a config item with the given name and return its value
 * as a 32-bit integer. The property must have at least 4 bytes of data. The
 * value of the first cell is returned.
 *
 * @param blob		FDT blob to use
 * @param prop_name	Node property name
 * @param default_val	default value to return if the property is not found
 * @return integer value, if found, or default_val if not
 */
int fdtdec_get_config_int(const void *blob, const char *prop_name,
		int default_val);

/**
 * Look in the FDT for a config item with the given name
 * and return whether it exists.
 *
 * @param blob		FDT blob
 * @param prop_name	property name to look up
 * @return 1, if it exists, or 0 if not
 */
int fdtdec_get_config_bool(const void *blob, const char *prop_name);

/**
 * Look in the FDT for a config item with the given name and return its value
 * as a string.
 *
 * @param blob          FDT blob
 * @param prop_name     property name to look up
 * @returns property string, NULL on error.
 */
char *fdtdec_get_config_string(const void *blob, const char *prop_name);

/*
 * Look up a property in a node and return its contents in a byte
 * array of given length. The property must have at least enough data for
 * the array (count bytes). It may have more, but this will be ignored.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param array		array to fill with data
 * @param count		number of array elements
 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
 *		or -FDT_ERR_BADLAYOUT if not enough data
 */
int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
		u8 *array, int count);

/**
 * Look up a property in a node and return a pointer to its contents as a
 * byte array of given length. The property must have at least enough data
 * for the array (count bytes). It may have more, but this will be ignored.
 * The data is not copied.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param count		number of array elements
 * @return pointer to byte array if found, or NULL if the property is not
 *		found or there is not enough data
 */
const u8 *fdtdec_locate_byte_array(const void *blob, int node,
			     const char *prop_name, int count);

/**
 * Look up a property in a node which contains a memory region address and
 * size. Then return a pointer to this address.
 *
 * The property must hold one address with a length. This is only tested on
 * 32-bit machines.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param basep		Returns base address of region
 * @param size		Returns size of region
 * @return 0 if ok, -1 on error (property not found)
 */
int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
			 fdt_addr_t *basep, fdt_size_t *sizep);

enum fmap_compress_t {
	FMAP_COMPRESS_NONE,
	FMAP_COMPRESS_LZO,
};

enum fmap_hash_t {
	FMAP_HASH_NONE,
	FMAP_HASH_SHA1,
	FMAP_HASH_SHA256,
};

/* A flash map entry, containing an offset and length */
struct fmap_entry {
	uint32_t offset;
	uint32_t length;
	uint32_t used;			/* Number of bytes used in region */
	enum fmap_compress_t compress_algo;	/* Compression type */
	enum fmap_hash_t hash_algo;		/* Hash algorithm */
	const uint8_t *hash;			/* Hash value */
	int hash_size;				/* Hash size */
};

/**
 * Read a flash entry from the fdt
 *
 * @param blob		FDT blob
 * @param node		Offset of node to read
 * @param name		Name of node being read
 * @param entry		Place to put offset and size of this node
 * @return 0 if ok, -ve on error
 */
int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
			   struct fmap_entry *entry);

/**
 * Obtain an indexed resource from a device property.
 *
 * @param fdt		FDT blob
 * @param node		node to examine
 * @param property	name of the property to parse
 * @param index		index of the resource to retrieve
 * @param res		returns the resource
 * @return 0 if ok, negative on error
 */
int fdt_get_resource(const void *fdt, int node, const char *property,
		     unsigned int index, struct fdt_resource *res);

/**
 * Obtain a named resource from a device property.
 *
 * Look up the index of the name in a list of strings and return the resource
 * at that index.
 *
 * @param fdt		FDT blob
 * @param node		node to examine
 * @param property	name of the property to parse
 * @param prop_names	name of the property containing the list of names
 * @param name		the name of the entry to look up
 * @param res		returns the resource
 */
int fdt_get_named_resource(const void *fdt, int node, const char *property,
			   const char *prop_names, const char *name,
			   struct fdt_resource *res);

/**
 * Decode a named region within a memory bank of a given type.
 *
 * This function handles selection of a memory region. The region is
 * specified as an offset/size within a particular type of memory.
 *
 * The properties used are:
 *
 *	<mem_type>-memory<suffix> for the name of the memory bank
 *	<mem_type>-offset<suffix> for the offset in that bank
 *
 * The property value must have an offset and a size. The function checks
 * that the region is entirely within the memory bank.5
 *
 * @param blob		FDT blob
 * @param node		Node containing the properties (-1 for /config)
 * @param mem_type	Type of memory to use, which is a name, such as
 *			"u-boot" or "kernel".
 * @param suffix	String to append to the memory/offset
 *			property names
 * @param basep		Returns base of region
 * @param sizep		Returns size of region
 * @return 0 if OK, -ive on error
 */
int fdtdec_decode_memory_region(const void *blob, int node,
				const char *mem_type, const char *suffix,
				fdt_addr_t *basep, fdt_size_t *sizep);
#endif