Re: [PATCH 2/2] device property: Add fwnode_property_get_reference_optional_args

Andy Shevchenko
2025-04-08T08:39:57Z

On Mon, Apr 07, 2025 at 06:37:14PM -0400, Sean Anderson wrote:
> Add a fwnode variant of of_parse_phandle_with_optional_args to allow
> nargs_prop to be absent from the referenced node. This improves
> compatibility for references where the devicetree might not always have
> nargs_prop.

...

> +/**
> + * fwnode_property_get_reference_optional_args() - Find a reference with optional arguments
> + * @fwnode: Firmware node where to look for the reference
> + * @prop: The name of the property
> + * @nargs_prop: The name of the property telling the number of

Use space instead of TAB as it's already too long to make it aligned with the
rest.

> + * arguments in the referred node.
> + * @index: Index of the reference, from zero onwards.
> + * @args: Result structure with reference and integer arguments.
> + * May be NULL.
> + *
> + * Obtain a reference based on a named property in an fwnode, with
> + * integer arguments. If @nargs_prop is absent from the referenced node, then
> + * number of arguments is be assumed to be 0.
> + *
> + * The caller is responsible for calling fwnode_handle_put() on the returned
> + * @args->fwnode pointer.
> + *
> + * Return: %0 on success
> + * %-ENOENT when the index is out of bounds, the index has an empty
> + * reference or the property was not found
> + * %-EINVAL on parse error
> + */
> +int fwnode_property_get_reference_optional_args(const struct fwnode_handle *fwnode,
> + const char *prop,
> + const char *nargs_prop,
> + unsigned int index,
> + struct fwnode_reference_args *args)
> +{
> + int ret;

> + if (IS_ERR_OR_NULL(fwnode))
> + return -ENOENT;

This is incorrect most likely, see below.

> + ret = fwnode_call_int_op(fwnode, get_reference_args, prop, nargs_prop,
> + 0, index, args);
> + if (ret == 0)
> + return ret;
> +
> + if (IS_ERR_OR_NULL(fwnode->secondary))
> + return ret;

Here no such error code shadowing, and TBH I do not like the shadowing without
real need.

> + return fwnode_call_int_op(fwnode->secondary, get_reference_args, prop, nargs_prop,
> + 0, index, args);
> +}

--
With Best Regards,
Andy Shevchenko