libfdt: Add iterator over properties

Implement a macro based on fdt_first_property_offset and
fdt_next_property_offset that provides a convenience to iterate over all
the properties of a given node.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Simon Glass <sjg@chromium.org>
[dwg: Removed a stray trailing blank line]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Maxime Ripard 2016-07-27 14:55:54 +02:00 committed by David Gibson
parent 902d0f0953
commit d29126c90a
6 changed files with 152 additions and 0 deletions

View file

@ -458,6 +458,33 @@ int fdt_first_property_offset(const void *fdt, int nodeoffset);
*/
int fdt_next_property_offset(const void *fdt, int offset);
/**
* fdt_for_each_property_offset - iterate over all properties of a node
*
* @property_offset: property offset (int, lvalue)
* @fdt: FDT blob (const void *)
* @node: node offset (int)
*
* This is actually a wrapper around a for loop and would be used like so:
*
* fdt_for_each_property_offset(property, fdt, node) {
* Use property
* ...
* }
*
* if ((property < 0) && (property != -FDT_ERR_NOT_FOUND)) {
* Error handling
* }
*
* Note that this is implemented as a macro and property is used as
* iterator in the loop. The node variable can be constant or even a
* literal.
*/
#define fdt_for_each_property_offset(property, fdt, node) \
for (property = fdt_first_property_offset(fdt, node); \
property >= 0; \
property = fdt_next_property_offset(fdt, property))
/**
* fdt_get_property_by_offset - retrieve the property at a given offset
* @fdt: pointer to the device tree blob