[U-Boot] [PATCH 02/14] fdt: Add functions to access phandles, arrays and bools

[David Gibson <david@gibson.dropbear.id.au>]

On Mon, Nov 28, 2011 at 11:41:32AM -0700, Stephen Warren wrote:
> On 11/23/2011 08:54 PM, Simon Glass wrote:
> > Add a function to lookup a property which is a phandle in a node, and
> > another to read a fixed-length integer array from an fdt property.
> > Also add a function to read boolean properties.
> > 
> > Signed-off-by: Simon Glass <sjg@chromium.org>
> 
> Looking at the U-Boot custodians web page, you need to send the core DT
> changes (well, probably anything DT related) to Jerry Van Baren.
> 
> > +/**
> > + * Look up a property in a node and return its contents in an integer
> > + * array of given length. The property must have at least enough data for
> > + * the array (4*count bytes). It may have more, but this will be ignored.
> > + *
> > + * @param blob		FDT blob
> > + * @param node		node to examine
> > + * @param prop_name	name of property to find
> > + * @param array		array to fill with data
> > + * @param count		number of array elements
> > + * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
> > + *		or -FDT_ERR_BADLAYOUT if not enough data
> > + */
> > +int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
> > +		int *array, int count);
> 
> The kernel's equivalent of this function retrieves an array of U32s. Is
> one version more correct than the other?

Using u32 is a better idea.  The property formats are all defined in
terms of fixed width elements, so using a vague width type like int to
interact with it is a bad idea.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson