[PATCH v3 02/13] device property: Add fwnode_graph_get_next_port_endpoint()

[Bartosz Golaszewski]

On Fri, 3 Jul 2026 13:03:03 +0200, Chen-Yu Tsai <wenst at chromium.org> said:
> Due to design constraints of the power sequencing API, the consumer
> must first be sure that the other side is actually a provider, or it
> will continually get -EPROBE_DEFER when requesting the power
> sequencing descriptor.
>
> In the upcoming USB power sequencing integration, the USB hub driver
> first needs to check whether a graph connection exists, and whether
> the other side of the connection is a supported connector type. The
> USB port is tied to a "port" firmware node, and this new helper will
> be used to get the endpoint under the known "port" firmware node.
>
> Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
> ---
> Changes since v2:
> - Dropped unused |ep| variable
> - Rewrote as do {} while()
> - Dropped WARN() use
> ---
>  drivers/base/property.c  | 25 +++++++++++++++++++++++++
>  include/linux/property.h |  2 ++
>  2 files changed, 27 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 3e3e19ef66a9..7e7ad3635806 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -1099,6 +1099,31 @@ int fwnode_irq_get_byname(const struct fwnode_handle *fwnode, const char *name)
>  }
>  EXPORT_SYMBOL(fwnode_irq_get_byname);
>
> +/**
> + * fwnode_graph_get_next_port_endpoint - Get next endpoint firmware node in port
> + * @port: Pointer to the target port firmware node
> + * @prev: Previous endpoint node or %NULL to get the first
> + *
> + * The caller is responsible for calling fwnode_handle_put() on the returned
> + * fwnode pointer. Note that this function also puts a reference to @prev
> + * unconditionally.
> + *
> + * Return: an endpoint firmware node pointer or %NULL if no more endpoints

I think the correct keyword is Returns: followed by a newline.

> + * are available.
> + */
> +struct fwnode_handle *fwnode_graph_get_next_port_endpoint(const struct fwnode_handle *port,
> +							  struct fwnode_handle *prev)
> +{
> +	do {
> +		prev = fwnode_get_next_child_node(port, prev);
> +		if (fwnode_name_eq(prev, "endpoint"))
> +			break;
> +	} while (prev);
> +
> +	return prev;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_graph_get_next_port_endpoint);
> +
>  /**
>   * fwnode_graph_get_next_endpoint - Get next endpoint firmware node
>   * @fwnode: Pointer to the parent firmware node
> diff --git a/include/linux/property.h b/include/linux/property.h
> index e04901c0bd8f..931e703393cb 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -506,6 +506,8 @@ int fwnode_get_phy_mode(const struct fwnode_handle *fwnode);
>  void __iomem *fwnode_iomap(struct fwnode_handle *fwnode, int index);
>
>  struct fwnode_handle *fwnode_graph_get_port_by_id(struct fwnode_handle *fwnode, u32 id);
> +struct fwnode_handle *fwnode_graph_get_next_port_endpoint(
> +	const struct fwnode_handle *port, struct fwnode_handle *prev);
>  struct fwnode_handle *fwnode_graph_get_next_endpoint(
>  	const struct fwnode_handle *fwnode, struct fwnode_handle *prev);
>  struct fwnode_handle *
> --
> 2.55.0.rc0.799.gd6f94ed593-goog
>
>

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski at oss.qualcomm.com>