From: David Gibson Date: Mon, 17 Dec 2007 03:42:07 +0000 (+1100) Subject: libfdt: Add more documentation (patch the seventh) X-Git-Url: http://git.dujemihanovic.xyz/?a=commitdiff_plain;h=aec7135bc300e3340d18f203347ee00c5b5f68c0;p=u-boot.git libfdt: Add more documentation (patch the seventh) This patch adds more documenting comments to libfdt.h. Specifically, these document the read/write functions (not including fdt_open_into() and fdt_pack(), for now). Signed-off-by: David Gibson --- diff --git a/include/libfdt.h b/include/libfdt.h index ffac678d9e..6c05236858 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -797,23 +797,242 @@ int fdt_finish(void *fdt); int fdt_open_into(const void *fdt, void *buf, int bufsize); int fdt_pack(void *fdt); +/** + * fdt_add_mem_rsv - add one memory reserve map entry + * @fdt: pointer to the device tree blob + * @addres, @size: 64-bit values (native endian) + * + * Adds a reserve map entry to the given blob reserving a region at + * address address of length size. + * + * This function will insert data into the reserve map and will + * therfore change the indexes of some entries in the table. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to + * contain the new reservation entry + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_TRUNCATED, standard meanings + */ int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size); + +/** + * fdt_del_mem_rsv - remove a memory reserve map entry + * @fdt: pointer to the device tree blob + * @n: entry to remove + * + * fdt_del_mem_rsv() removes the n-th memory reserve map entry from + * the blob. + * + * This function will delete data from the reservation table and will + * therfore change the indexes of some entries in the table. + * + * returns: + * 0, on success + * -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there + * are less than n+1 reserve map entries) + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_TRUNCATED, standard meanings + */ int fdt_del_mem_rsv(void *fdt, int n); +/** + * fdt_setprop - create or change a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: pointer to data to set the property value to + * @len: length of the property value + * + * fdt_setprop() sets the value of the named property in the given + * node to the given value and length, creeating the property if it + * does not already exist. + * + * This function may insert or delete data from the blob, and will + * therefore change the offsets of some existing nodes. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to + * contain the new property value + * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_TRUNCATED, standard meanings + */ int fdt_setprop(void *fdt, int nodeoffset, const char *name, const void *val, int len); + +/** + * fdt_setprop_cell - set a property to a single cell value + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @val: 32-bit integer value for the property (native endian) + * + * fdt_setprop_cell() sets the value of the named property in the + * given node to the given cell value (converting to big-endian if + * necessary), or creates a new property with that value if it does + * not already exist. + * + * This function may insert or delete data from the blob, and will + * therefore change the offsets of some existing nodes. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to + * contain the new property value + * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_TRUNCATED, standard meanings + */ 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)); } + +/** + * fdt_setprop_string - set a property to a string value + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to change + * @name: name of the property to change + * @str: string value for the property + * + * fdt_setprop_string() sets the value of the named property in the + * given node to the given string value (using the length of the + * string to determine the new length of the property), or creates a + * new property with that value if it does not already exist. + * + * This function may insert or delete data from the blob, and will + * therefore change the offsets of some existing nodes. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to + * contain the new property value + * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_TRUNCATED, standard meanings + */ #define fdt_setprop_string(fdt, nodeoffset, name, str) \ fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1) + +/** + * fdt_delprop - delete a property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to nop + * @name: name of the property to nop + * + * fdt_del_property() will delete the given property. + * + * This function will delete data from the blob, and will therefore + * change the offsets of some existing nodes. + * + * returns: + * 0, on success + * -FDT_ERR_NOTFOUND, node does not have the named property + * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_TRUNCATED, standard meanings + */ int fdt_delprop(void *fdt, int nodeoffset, const char *name); + +/** + * fdt_add_subnode_namelen - creates a new node 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_add_subnode(), but use only the first namelen + * characters of name as the name of the new node. This is useful for + * creating subnodes based on a portion of a larger string, such as a + * full path. + */ int fdt_add_subnode_namelen(void *fdt, int parentoffset, const char *name, int namelen); + +/** + * fdt_add_subnode - creates a new node + * @fdt: pointer to the device tree blob + * @parentoffset: structure block offset of a node + * @name: name of the subnode to locate + * + * fdt_add_subnode() creates a new node as a subnode of the node at + * structure block offset parentoffset, with the given name (which + * should include the unit address, if any). + * + * This function will insert data into the blob, and will therefore + * change the offsets of some existing nodes. + + * returns: + * structure block offset of the created nodeequested 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_EXISTS, if the node at parentoffset already has a subnode of + * the given name + * -FDT_ERR_NOSPACE, if there is insufficient free space in the + * blob to contain the new node + * -FDT_ERR_NOSPACE + * -FDT_ERR_BADLAYOUT + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_TRUNCATED, standard meanings. + */ int fdt_add_subnode(void *fdt, int parentoffset, const char *name); + +/** + * fdt_del_node - delete a node (subtree) + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node to nop + * + * fdt_del_node() will remove the given node, including all its + * subnodes if any, from the blob. + * + * This function will delete data from the blob, and will therefore + * change the offsets of some existing nodes. + * + * returns: + * 0, on success + * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag + * -FDT_ERR_BADLAYOUT, + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_TRUNCATED, standard meanings + */ int fdt_del_node(void *fdt, int nodeoffset); /**********************************************************************/