libfdt.h

U-boot源码 ARM7启动代码

 *		-FDT_ERR_BADSTATE,
 *		-FDT_ERR_BADSTRUCTURE,
 *		-FDT_ERR_TRUNCATED, standard meanings
 */
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);
}

/**
 * fdt_getprop - retrieve the value of a given property
 * @fdt: pointer to the device tree blob
 * @nodeoffset: offset of the node whose property to find
 * @name: name of the property to find
 * @lenp: pointer to an integer variable (will be overwritten) or NULL
 *
 * fdt_getprop() retrieves a pointer to the value of the property
 * named 'name' of the node at offset nodeoffset (this will be a
 * pointer to within the device blob itself, not a copy of the value).
 * If lenp is non-NULL, the length of the property value also
 * returned, in the integer pointed to by lenp.
 *
 * returns:
 *	pointer to the property's value
 *		if lenp is non-NULL, *lenp contains the length of the property
 *		value (>=0)
 *	NULL, on error
 *		if lenp is non-NULL, *lenp contains an error code (<0):
 *		-FDT_ERR_NOTFOUND, node does not have named property
 *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
 *		-FDT_ERR_BADMAGIC,
 *		-FDT_ERR_BADVERSION,
 *		-FDT_ERR_BADSTATE,
 *		-FDT_ERR_BADSTRUCTURE,
 *		-FDT_ERR_TRUNCATED, standard meanings
 */
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);
}

/**
 * fdt_get_phandle - retreive the phandle of a given node
 * @fdt: pointer to the device tree blob
 * @nodeoffset: structure block offset of the node
 *
 * fdt_get_phandle() retrieves the phandle of the device tree node at
 * structure block offset nodeoffset.
 *
 * returns:
 *	the phandle of the node at nodeoffset, on succes (!= 0, != -1)
 *	0, if the node has no phandle, or another error occurs
 */
uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);

/**
 * fdt_get_path - determine the full path of a node
 * @fdt: pointer to the device tree blob
 * @nodeoffset: offset of the node whose path to find
 * @buf: character buffer to contain the returned path (will be overwritten)
 * @buflen: size of the character buffer at buf
 *
 * fdt_get_path() computes the full path of the node at offset
 * nodeoffset, and records that path in the buffer at buf.
 *
 * NOTE: This function is expensive, as it must scan the device tree
 * structure from the start to nodeoffset.
 *
 * returns:
 *	0, on success
 *		buf contains the absolute path of the node at
 *		nodeoffset, as a NUL-terminated string.
 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
 *		characters and will not fit in the given buffer.
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);

/**
 * fdt_supernode_atdepth_offset - find a specific ancestor of a node
 * @fdt: pointer to the device tree blob
 * @nodeoffset: offset of the node whose parent to find
 * @supernodedepth: depth of the ancestor to find
 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
 *
 * fdt_supernode_atdepth_offset() finds an ancestor of the given node
 * at a specific depth from the root (where the root itself has depth
 * 0, its immediate subnodes depth 1 and so forth).  So
 *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
 * will always return 0, the offset of the root node.  If the node at
 * nodeoffset has depth D, then:
 *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
 * will return nodeoffset itself.
 *
 * NOTE: This function is expensive, as it must scan the device tree
 * structure from the start to nodeoffset.
 *
 * returns:

 *	structure block offset of the node at node offset's ancestor
 *		of depth supernodedepth (>=0), on success
 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
*	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
				 int supernodedepth, int *nodedepth);

/**
 * fdt_node_depth - find the depth of a given node
 * @fdt: pointer to the device tree blob
 * @nodeoffset: offset of the node whose parent to find
 *
 * fdt_node_depth() finds the depth of a given node.  The root node
 * has depth 0, its immediate subnodes depth 1 and so forth.
 *
 * NOTE: This function is expensive, as it must scan the device tree
 * structure from the start to nodeoffset.
 *
 * returns:
 *	depth of the node at nodeoffset (>=0), on success
 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
int fdt_node_depth(const void *fdt, int nodeoffset);

/**
 * fdt_parent_offset - find the parent of a given node
 * @fdt: pointer to the device tree blob
 * @nodeoffset: offset of the node whose parent to find
 *
 * fdt_parent_offset() locates the parent node of a given node (that
 * is, it finds the offset of the node which contains the node at
 * nodeoffset as a subnode).
 *
 * NOTE: This function is expensive, as it must scan the device tree
 * structure from the start to nodeoffset, *twice*.
 *
 * returns:
 *	stucture block offset of the parent of the node at nodeoffset
 *		(>=0), on success
 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
int fdt_parent_offset(const void *fdt, int nodeoffset);

/**
 * fdt_node_offset_by_prop_value - find nodes with a given property value
 * @fdt: pointer to the device tree blob
 * @startoffset: only find nodes after this offset
 * @propname: property name to check
 * @propval: property value to search for
 * @proplen: length of the value in propval
 *
 * fdt_node_offset_by_prop_value() returns the offset of the first
 * node after startoffset, which has a property named propname whose
 * value is of length proplen and has value equal to propval; or if
 * startoffset is -1, the very first such node in the tree.
 *
 * To iterate through all nodes matching the criterion, the following
 * idiom can be used:
 *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
 *					       propval, proplen);
 *	while (offset != -FDT_ERR_NOTFOUND) {
 *		// other code here
 *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
 *						       propval, proplen);
 *	}
 *
 * Note the -1 in the first call to the function, if 0 is used here
 * instead, the function will never locate the root node, even if it
 * matches the criterion.
 *
 * returns:
 *	structure block offset of the located node (>= 0, >startoffset),
 *		 on success
 *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
 *		tree after startoffset
 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
				  const char *propname,
				  const void *propval, int proplen);

/**
 * fdt_node_offset_by_phandle - find the node with a given phandle
 * @fdt: pointer to the device tree blob
 * @phandle: phandle value
 *
 * fdt_node_offset_by_prop_value() returns the offset of the node
 * which has the given phandle value.  If there is more than one node
 * in the tree with the given phandle (an invalid tree), results are
 * undefined.
 *
 * returns:
 *	structure block offset of the located node (>= 0), on success
 *	-FDT_ERR_NOTFOUND, no node with that phandle exists
 *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);

/**
 * fdt_node_check_compatible: check a node's compatible property
 * @fdt: pointer to the device tree blob
 * @nodeoffset: offset of a tree node
 * @compatible: string to match against
 *
 *
 * fdt_node_check_compatible() returns 0 if the given node contains a
 * 'compatible' property with the given string as one of its elements,
 * it returns non-zero otherwise, or on error.
 *
 * returns:
 *	0, if the node has a 'compatible' property listing the given string
 *	1, if the node has a 'compatible' property, but it does not list
 *		the given string
 *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
 * 	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
int fdt_node_check_compatible(const void *fdt, int nodeoffset,
			      const char *compatible);

/**
 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
 * @fdt: pointer to the device tree blob
 * @startoffset: only find nodes after this offset
 * @compatible: 'compatible' string to match against
 *
 * fdt_node_offset_by_compatible() returns the offset of the first
 * node after startoffset, which has a 'compatible' property which
 * lists the given compatible string; or if startoffset is -1, the
 * very first such node in the tree.
 *
 * To iterate through all nodes matching the criterion, the following
 * idiom can be used:
 *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
 *	while (offset != -FDT_ERR_NOTFOUND) {
 *		// other code here
 *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
 *	}
 *
 * Note the -1 in the first call to the function, if 0 is used here
 * instead, the function will never locate the root node, even if it
 * matches the criterion.
 *
 * returns:
 *	structure block offset of the located node (>= 0, >startoffset),
 *		 on success
 *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
 *		tree after startoffset
 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
 *	-FDT_ERR_BADMAGIC,
 *	-FDT_ERR_BADVERSION,
 *	-FDT_ERR_BADSTATE,
 *	-FDT_ERR_BADSTRUCTURE, standard meanings
 */
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);
static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
					   const char *name, uint32_t val)
{
	val = cpu_to_fdt32(val);
	return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val));
}

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);
static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
{
	val = cpu_to_fdt32(val);
	return fdt_property(fdt, name, &val, sizeof(val));
}
#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);
static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
				   uint32_t val)
{
	val = cpu_to_fdt32(val);
	return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val));
}
#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 */