[U-Boot] [PATCH v2 5/9] libfdt: Add iterator over properties

Stefan Agner stefan at agner.ch
Fri Jun 10 04:51:23 CEST 2016


On 2016-05-27 02:13, Maxime Ripard wrote:
> 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 at free-electrons.com>
> ---
>  include/libfdt.h | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)

Reviewed-by: Stefan Agner <stefan at agner.ch>

There would be already be several opportunities in existing code to use
that :-)

> 
> diff --git a/include/libfdt.h b/include/libfdt.h
> index 74b1d149c2dd..4e8eb9ede3a4 100644
> --- a/include/libfdt.h
> +++ b/include/libfdt.h
> @@ -441,6 +441,30 @@ int fdt_first_property_offset(const void *fdt,
> int nodeoffset);
>  int fdt_next_property_offset(const void *fdt, int offset);
>  
>  /**
> + * fdt_for_each_property - iterate over all properties of a node
> + * @fdt:	FDT blob (const void *)
> + * @node:	node offset (int)
> + * @property:	property offset (int)
> + *
> + * This is actually a wrapper around a for loop and would be used like so:
> + *
> + *	fdt_for_each_property(fdt, node, property) {
> + *		...
> + *		use property
> + *		...
> + *	}
> + *
> + * Note that this is implemented as a macro and property is used as
> + * iterator in the loop. It should therefore be a locally allocated
> + * variable. The node variable on the other hand is never modified, so
> + * it can be constant or even a literal.
> + */
> +#define fdt_for_each_property(fdt, node, property)		\
> +	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
>   * @offset: offset of the property to retrieve


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