libfdt/libfdt.h

#ifndef _LIBFDT_H
#define _LIBFDT_H
/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 * libfdt is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 *
 *  a) This library is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of the
 *     License, or (at your option) any later version.
 *
 *     This library is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public
 *     License along with this library; if not, write to the Free
 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *     MA 02110-1301 USA
 *
 * Alternatively,
 *
 *  b) Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *     1. Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *     2. Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <libfdt_env.h>
#include <fdt.h>

#define FDT_FIRST_SUPPORTED_VERSION	0x10
#define FDT_LAST_SUPPORTED_VERSION	0x11

/* Error codes: informative error codes */
#define FDT_ERR_NOTFOUND	1
	/* FDT_ERR_NOTFOUND: The requested node or property does not exist */
#define FDT_ERR_EXISTS		2
	/* FDT_ERR_EXISTS: Attemped to create a node or property which
	 * already exists */
#define FDT_ERR_NOSPACE		3
	/* FDT_ERR_NOSPACE: Operation needed to expand the device
	 * tree, but its buffer did not have sufficient space to
	 * contain the expanded tree. Use fdt_open_into() to move the
	 * device tree to a buffer with more space. */

/* Error codes: codes for bad parameters */
#define FDT_ERR_BADOFFSET	4
	/* FDT_ERR_BADOFFSET: Function was passed a structure block
	 * offset which is out-of-bounds, or which points to an
	 * unsuitable part of the structure for the operation. */
#define FDT_ERR_BADPATH		5
	/* FDT_ERR_BADPATH: Function was passed a badly formatted path
	 * (e.g. missing a leading / for a function which requires an
	 * absolute path) */
#define FDT_ERR_BADSTATE	6
	/* FDT_ERR_BADSTATE: Function was passed an incomplete device
	 * tree created by the sequential-write functions, which is
	 * not sufficiently complete for the requested operation. */

/* Error codes: codes for bad device tree blobs */
#define FDT_ERR_TRUNCATED	7
	/* FDT_ERR_TRUNCATED: Structure block of the given device tree
	 * ends without an FDT_END tag. */
#define FDT_ERR_BADMAGIC	8
	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
	 * device tree at all - it is missing the flattened device
	 * tree magic number. */
#define FDT_ERR_BADVERSION	9
	/* FDT_ERR_BADVERSION: Given device tree has a version which
	 * can't be handled by the requested operation.  For
	 * read-write functions, this may mean that fdt_open_into() is
	 * required to convert the tree to the expected version. */
#define FDT_ERR_BADSTRUCTURE	10
	/* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
	 * structure block or other serious error (e.g. misnested
	 * nodes, or subnodes preceding properties). */
#define FDT_ERR_BADLAYOUT	11
	/* FDT_ERR_BADLAYOUT: For read-write functions, the given
	 * device tree has it's sub-blocks in an order that the
	 * function can't handle (memory reserve map, then structure,
	 * then strings).  Use fdt_open_into() to reorganize the tree
	 * into a form suitable for the read-write operations. */

/* "Can't happen" error indicating a bug in libfdt */
#define FDT_ERR_INTERNAL	12
	/* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
	 * Indicates a bug in libfdt itself. */

#define FDT_ERR_MAX		12

/**********************************************************************/
/* Low-level functions (you probably don't need these)                */
/**********************************************************************/

const void *fdt_offset_ptr(const void *fdt, int offset, int checklen);
static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
{
	return (void *)fdt_offset_ptr(fdt, offset, checklen);
}


#define fdt_offset_ptr_typed(fdt, offset, var) \
	((typeof(var))(fdt_offset_ptr((fdt), (offset), sizeof(*(var)))))
#define fdt_offset_ptr_typed_w(fdt, offset, var) \
	((typeof(var))(fdt_offset_ptr_w((fdt), (offset), sizeof(*(var)))))

uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);

/**********************************************************************/
/* General functions                                                  */
/**********************************************************************/

#define fdt_get_header(fdt, field) \
	(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
#define fdt_magic(fdt) 			(fdt_get_header(fdt, magic))
#define fdt_totalsize(fdt)		(fdt_get_header(fdt, totalsize))
#define fdt_off_dt_struct(fdt)		(fdt_get_header(fdt, off_dt_struct))
#define fdt_off_dt_strings(fdt)		(fdt_get_header(fdt, off_dt_strings))
#define fdt_off_mem_rsvmap(fdt)		(fdt_get_header(fdt, off_mem_rsvmap))
#define fdt_version(fdt)		(fdt_get_header(fdt, version))
#define fdt_last_comp_version(fdt) 	(fdt_get_header(fdt, last_comp_version))
#define fdt_boot_cpuid_phys(fdt) 	(fdt_get_header(fdt, boot_cpuid_phys))
#define fdt_size_dt_strings(fdt) 	(fdt_get_header(fdt, size_dt_strings))
#define fdt_size_dt_struct(fdt)		(fdt_get_header(fdt, size_dt_struct))

#define __fdt_set_hdr(name) \
	static inline void fdt_set_##name(void *fdt, uint32_t val) \
	{ \
		struct fdt_header *fdth = fdt; \
		fdth->name = cpu_to_fdt32(val); \
	}
__fdt_set_hdr(magic);
__fdt_set_hdr(totalsize);
__fdt_set_hdr(off_dt_struct);
__fdt_set_hdr(off_dt_strings);
__fdt_set_hdr(off_mem_rsvmap);
__fdt_set_hdr(version);
__fdt_set_hdr(last_comp_version);
__fdt_set_hdr(boot_cpuid_phys);
__fdt_set_hdr(size_dt_strings);
__fdt_set_hdr(size_dt_struct);
#undef __fdt_set_hdr

/**
 * fdt_check_header - sanity check a device tree or possible device tree
 * @fdt: pointer to data which might be a flattened device tree
 *
 * fdt_check_header() checks that the given buffer contains what
 * appears to be a flattened device tree with sane information in its
 * header.
 *
 * returns:
 *     0, if the buffer appears to contain a valid device tree
 *     -FDT_ERR_BADMAGIC,
 *     -FDT_ERR_BADVERSION,
 *     -FDT_ERR_BADSTATE, standard meanings, as above
 */
int fdt_check_header(const void *fdt);

/**
 * fdt_move - move a device tree around in memory
 * @fdt: pointer to the device tree to move
 * @buf: pointer to memory where the device is to be moved
 * @bufsize: size of the memory space at buf
 *
 * fdt_move() relocates, if possible, the device tree blob located at
 * fdt to the buffer at buf of size bufsize.  The buffer may overlap
 * with the existing device tree blob at fdt.  Therefore,
 *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
 * should always succeed.
 *
 * returns:
 *     0, on success
 *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
 *     -FDT_ERR_BADMAGIC,
 *     -FDT_ERR_BADVERSION,
 *     -FDT_ERR_BADSTATE, standard meanings
 */
int fdt_move(const void *fdt, void *buf, int bufsize);

/**********************************************************************/
/* Read-only functions                                                */
/**********************************************************************/

/**
 * fdt_string - retreive a string from the strings block of a device tree
 * @fdt: pointer to the device tree blob
 * @stroffset: offset of the string within the strings block (native endian)
 *
 * fdt_string() retrieves a pointer to a single string from the
 * strings block of the device tree blob at fdt.
 *
 * returns:
 *     a pointer to the string, on success
 *     NULL, if stroffset is out of bounds
 */
const char *fdt_string(const void *fdt, int stroffset);

/**
 * fdt_num_mem_rsv - retreive the number of memory reserve map entries
 * @fdt: pointer to the device tree blob
 *
 * Returns the number of entries in the device tree blob's memory
 * reservation map.  This does not include the terminating 0,0 entry
 * or any other (0,0) entries reserved for expansion.
 *
 * returns:
 *     the number of entries
 */
int fdt_num_mem_rsv(const void *fdt);

/**
 * fdt_get_mem_rsv - retreive one memory reserve map entry
 * @fdt: pointer to the device tree blob
 * @address, @size: pointers to 64-bit variables
 *
 * On success, *address and *size will contain the address and size of
 * the n-th reserve map entry from the device tree blob, in
 * native-endian format.
 *
 * returns:
 *     0, on success
 *     -FDT_ERR_BADMAGIC,
 *     -FDT_ERR_BADVERSION,
 *     -FDT_ERR_BADSTATE, standard meanings
 */
int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);

/**
 * fdt_subnode_offset_namelen - find a subnode based on substring
 * @fdt: pointer to the device tree blob
 * @parentoffset: structure block offset of a node
 * @name: name of the subnode to locate
 * @namelen: number of characters of name to consider
 *
 * Identical to fdt_subnode_offset(), but only examine the first
 * namelen characters of name for matching the subnode name.  This is
 * useful for finding subnodes based on a portion of a larger string,
 * such as a full path.
 */
int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
			       const char *name, int namelen);
/**
 * fdt_subnode_offset - find a subnode of a given node
 * @fdt: pointer to the device tree blob
 * @parentoffset: structure block offset of a node
 * @name: name of the subnode to locate
 *
 * fdt_subnode_offset() finds a subnode of the node at structure block
 * offset parentoffset with the given name.  name may include a unit
 * address, in which case fdt_subnode_offset() will find the subnode
 * with that unit address, or the unit address may be omitted, in
 * which case fdt_subnode_offset() will find an arbitrary subnode
 * whose name excluding unit address matches the given name.
 *
 * returns:
 *	structure block offset of the requested subnode (>=0), on success
 *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
 *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
 *      -FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE,
 *	-FDT_ERR_TRUNCATED, standard meanings.
 */
int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);

/**
 * fdt_path_offset - find a tree node by its full path
 * @fdt: pointer to the device tree blob
 * @path: full path of the node to locate
 *
 * fdt_path_offset() finds a node of a given path in the device tree.
 * Each path component may omit the unit address portion, but the
 * results of this are undefined if any such path component is
 * ambiguous (that is if there are multiple nodes at the relevant
 * level matching the given component, differentiated only by unit
 * address).
 *
 * returns:
 *	structure block offset of the node with the requested path (>=0), on success
 *	-FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
 *	-FDT_ERR_NOTFOUND, if the requested node does not exist
 *      -FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE,
 *	-FDT_ERR_TRUNCATED, standard meanings.
 */
int fdt_path_offset(const void *fdt, const char *path);

/**
 * fdt_get_name - retreive the name of a given node
 * @fdt: pointer to the device tree blob
 * @nodeoffset: structure block offset of the starting node
 * @len: pointer to an intger variable (will be overwritten) or NULL
 *
 * fdt_get_name() retrieves the name (including unit address) of the
 * device tree node at structure block offset nodeoffset.  If len is
 * non-NULL, the length of this name is also returned, in the integer
 * pointed to by len.
 *
 * returns:
 *	pointer to the node's name, on success
 *		*len contains the length of that name (>=0)
 *	NULL, on error
 *		*len contains an error code (<0):
 *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 *		-FDT_ERR_BADMAGIC,
 *		-FDT_ERR_BADVERSION,
 *		-FDT_ERR_BADSTATE, standard meanings
 */
const char *fdt_get_name(const void *fdt, int nodeoffset, int *len);

const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
					    const char *name, int *lenp);

static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
						      const char *name,
						      int *lenp)
{
	return (struct fdt_property *)fdt_get_property(fdt, nodeoffset,
						       name, lenp);
}

const void *fdt_getprop(const void *fdt, int nodeoffset,
			const char *name, int *lenp);
static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
				  const char *name, int *lenp)
{
	return (void *)fdt_getprop(fdt, nodeoffset, name, lenp);
}

int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);

int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
				 int supernodedepth, int *nodedepth);
int fdt_node_depth(const void *fdt, int nodeoffset);
int fdt_parent_offset(const void *fdt, int nodeoffset);

int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
				  const char *propname,
				  const void *propval, int proplen);

int fdt_node_check_compatible(const void *fdt, int nodeoffset,
			      const char *compatible);
int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
				  const char *compatible);

/**********************************************************************/
/* Write-in-place functions                                           */
/**********************************************************************/

int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
			const void *val, int len);

#define fdt_setprop_inplace_typed(fdt, nodeoffset, name, val) \
	({ \
		typeof(val) x = val; \
		fdt_setprop_inplace(fdt, nodeoffset, name, &x, sizeof(x)); \
	})

int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
int fdt_nop_node(void *fdt, int nodeoffset);

/**********************************************************************/
/* Sequential write functions                                         */
/**********************************************************************/

int fdt_create(void *buf, int bufsize);
int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
int fdt_finish_reservemap(void *fdt);
int fdt_begin_node(void *fdt, const char *name);
int fdt_property(void *fdt, const char *name, const void *val, int len);
#define fdt_property_typed(fdt, name, val) \
	({ \
		typeof(val) x = (val); \
		fdt_property((fdt), (name), &x, sizeof(x)); \
	})
#define fdt_property_string(fdt, name, str) \
	fdt_property(fdt, name, str, strlen(str)+1)
int fdt_end_node(void *fdt);
int fdt_finish(void *fdt);

/**********************************************************************/
/* Read-write functions                                               */
/**********************************************************************/

int fdt_open_into(const void *fdt, void *buf, int bufsize);
int fdt_pack(void *fdt);

int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
int fdt_del_mem_rsv(void *fdt, int n);

int fdt_setprop(void *fdt, int nodeoffset, const char *name,
		const void *val, int len);
#define fdt_setprop_typed(fdt, nodeoffset, name, val) \
	({ \
		typeof(val) x = (val); \
		fdt_setprop((fdt), (nodeoffset), (name), &x, sizeof(x)); \
	})
#define fdt_setprop_string(fdt, nodeoffset, name, str) \
	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
int fdt_delprop(void *fdt, int nodeoffset, const char *name);
int fdt_add_subnode_namelen(void *fdt, int parentoffset,
			    const char *name, int namelen);
int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
int fdt_del_node(void *fdt, int nodeoffset);

/**********************************************************************/
/* Debugging / informational functions                                */
/**********************************************************************/

const char *fdt_strerror(int errval);

#endif /* _LIBFDT_H */