This patch adds some more documenting comments to libfdt.h. Specifically this documents all the write-in-place functions.

Signed-off-by: David Gibson david@gibson.dropbear.id.au ---

I've applied and pushed two documentation patches from David Gibson, taken from the dtc/libfdt repository. This brings us back in sync with the master libfdt.

This patch was from Mon, 17 Dec 2007 14:41:52 +1100

include/libfdt.h | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 104 insertions(+), 0 deletions(-)

diff --git a/include/libfdt.h b/include/libfdt.h index 6b2fb92..b4bed61 100644 --- a/include/libfdt.h +++ b/include/libfdt.h @@ -655,8 +655,65 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset, /* Write-in-place functions */ /**********************************************************************/

+/** + * fdt_setprop_inplace - change a property's value, but not its size + * @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 replace the property value with + * @len: length of the property value + * + * fdt_setprop_inplace() replaces the value of a given property with + * the data in val, of length len. This function cannot change the + * size of a property, and so will only work if len is equal to the + * current length of the property. + * + * This function will alter only the bytes in the blob which contain + * the given property value, and will not alter or move any other part + * of the tree. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, if len is not equal to the property's current length + * -FDT_ERR_NOTFOUND, node does not have the 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 + */ int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name, const void *val, int len); + +/** + * fdt_setprop_inplace_cell - change the value of a single-cell 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: cell (32-bit integer) value to replace the property with + * + * fdt_setprop_inplace_cell() replaces the value of a given property + * with the 32-bit integer cell value in val, converting val to + * big-endian if necessary. This function cannot change the size of a + * property, and so will only work if the property already exists and + * has length 4. + * + * This function will alter only the bytes in the blob which contain + * the given property value, and will not alter or move any other part + * of the tree. + * + * returns: + * 0, on success + * -FDT_ERR_NOSPACE, if the property's length is not equal to 4 + * -FDT_ERR_NOTFOUND, node does not have the 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 + */ static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset, const char *name, uint32_t val) { @@ -664,7 +721,54 @@ static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset, return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val)); }

+/** + * fdt_nop_property - replace a property with nop tags + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node whose property to nop + * @name: name of the property to nop + * + * fdt_nop_property() will replace a given property's representation + * in the blob with FDT_NOP tags, effectively removing it from the + * tree. + * + * This function will alter only the bytes in the blob which contain + * the property, and will not alter or move any other part of the + * tree. + * + * 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_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, + * -FDT_ERR_TRUNCATED, standard meanings + */ int fdt_nop_property(void *fdt, int nodeoffset, const char *name); + +/** + * fdt_nop_node - replace a node (subtree) with nop tags + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of the node to nop + * + * fdt_nop_node() will replace a given node's representation in the + * blob, including all its subnodes, if any, with FDT_NOP tags, + * effectively removing it from the tree. + * + * This function will alter only the bytes in the blob which contain + * the node and its properties and subnodes, and will not alter or + * move any other part of the tree. + * + * returns: + * 0, on success + * -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 + */ int fdt_nop_node(void *fdt, int nodeoffset);

/**********************************************************************/