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authorDavid Gibson <david@gibson.dropbear.id.au>2007-12-17 14:41:52 +1100
committerGerald Van Baren <vanbaren@cideas.com>2008-01-08 15:03:34 -0500
commit9d4450b5adc36623e9c1de1f92539db77ad0c57e (patch)
treecd6559de9ec8fe450d3c7296900f20c407974327 /include
parentb60af3d4c1680487ee37e11aa1b3db6dec04d8f0 (diff)
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libfdt: Add more documentation (patch the sixth)
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>
Diffstat (limited to 'include')
-rw-r--r--include/libfdt.h104
1 files changed, 104 insertions, 0 deletions
diff --git a/include/libfdt.h b/include/libfdt.h
index 8050049..ffac678 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);
/**********************************************************************/