Re: [PATCH v4 08/15] software_node: Add support for fwnode_graph*() family of functions

Andy Shevchenko
2021-01-04T10:23:45Z

On Sun, Jan 03, 2021 at 11:12:28PM +0000, Daniel Scally wrote:
> From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>
> This implements the remaining .graph_*() callbacks in the fwnode
> operations structure for the software nodes. That makes the
> fwnode_graph_*() functions available in the drivers also when software
> nodes are used.
>
> The implementation tries to mimic the "OF graph" as much as possible, but
> there is no support for the "reg" device property. The ports will need to
> have the index in their name which starts with "port@" (for example
> "port@0", "port@1", ...) and endpoints will use the index of the software
> node that is given to them during creation. The port nodes can also be
> grouped under a specially named "ports" subnode, just like in DT, if
> necessary.
>
> The remote-endpoints are reference properties under the endpoint nodes
> that are named "remote-endpoint".

Couple of nitpicks below (can be considered as follow up, depends on yours and
maintainer wishes).

> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Co-developed-by: Daniel Scally <djrscally@gmail.com>
> Signed-off-by: Daniel Scally <djrscally@gmail.com>
> ---
> Changes in v4:
>
> - Replaced the FWNODE_GRAPH_PORT_NAME_PREFIX_LEN macro with
> strlen("port@") throughout
> - Added a check to software_node_graph_parse_endpoint() to ensure
> the name of the endpoint's parent matches the expected port@n
> format
>
> drivers/base/swnode.c | 116 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 115 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 1f43c51b431e..82f9d6326110 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -540,6 +540,116 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
> return 0;
> }
>
> +static struct fwnode_handle *
> +swnode_graph_find_next_port(const struct fwnode_handle *parent,
> + struct fwnode_handle *port)
> +{
> + struct fwnode_handle *old = port;
> +
> + while ((port = software_node_get_next_child(parent, old))) {
> + /*
> + * fwnode ports have naming style "port@", so we search for any
> + * children that follow that convention.
> + */
> + if (!strncmp(to_swnode(port)->node->name, "port@",
> + strlen("port@")))
> + return port;
> + old = port;
> + }
> +
> + return NULL;
> +}
> +
> +static struct fwnode_handle *
> +software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
> + struct fwnode_handle *endpoint)
> +{
> + struct swnode *swnode = to_swnode(fwnode);
> + struct fwnode_handle *parent;
> + struct fwnode_handle *port;
> +
> + if (!swnode)
> + return NULL;
> +
> + if (endpoint) {
> + port = software_node_get_parent(endpoint);
> + parent = software_node_get_parent(port);
> + } else {
> + parent = software_node_get_named_child_node(fwnode, "ports");
> + if (!parent)
> + parent = software_node_get(&swnode->fwnode);
> +
> + port = swnode_graph_find_next_port(parent, NULL);
> + }
> +
> + for (; port; port = swnode_graph_find_next_port(parent, port)) {
> + endpoint = software_node_get_next_child(port, endpoint);
> + if (endpoint) {
> + fwnode_handle_put(port);
> + break;
> + }
> + }
> +
> + fwnode_handle_put(parent);
> +
> + return endpoint;
> +}
> +
> +static struct fwnode_handle *
> +software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
> +{
> + struct swnode *swnode = to_swnode(fwnode);
> + const struct software_node_ref_args *ref;
> + const struct property_entry *prop;
> +
> + if (!swnode)
> + return NULL;
> +
> + prop = property_entry_get(swnode->node->properties, "remote-endpoint");
> + if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
> + return NULL;
> +
> + ref = prop->pointer;
> +
> + return software_node_get(software_node_fwnode(ref[0].node));
> +}
> +
> +static struct fwnode_handle *
> +software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
> +{
> + struct swnode *swnode = to_swnode(fwnode);
> +
> + swnode = swnode->parent;
> + if (swnode && !strcmp(swnode->node->name, "ports"))
> + swnode = swnode->parent;
> +
> + return swnode ? software_node_get(&swnode->fwnode) : NULL;
> +}
> +
> +static int
> +software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
> + struct fwnode_endpoint *endpoint)
> +{
> + struct swnode *swnode = to_swnode(fwnode);
> + const char *parent_name = swnode->parent->node->name;
> + int ret;
> +
> + if (!(strlen(parent_name) > strlen("port@")) ||

A nit:

if (strlen("port@") >= strlen(parent_name) ||

better to read

> + strncmp(parent_name, "port@", strlen("port@")))
> + return -EINVAL;
> +
> + /* Ports have naming style "port@n", we need to select the n */
> + ret = kstrtou32(parent_name + strlen("port@"),
> + 10, &endpoint->port);

A nit:

ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port);

(perhaps you need to adjust your editor settings, this still fits 80)

> + if (ret)
> + return ret;
> +
> + endpoint->id = swnode->id;
> + endpoint->local_fwnode = fwnode;
> +
> + return 0;
> +}
> +
> static const struct fwnode_operations software_node_ops = {
> .get = software_node_get,
> .put = software_node_put,
> @@ -551,7 +661,11 @@ static const struct fwnode_operations software_node_ops = {
> .get_parent = software_node_get_parent,
> .get_next_child_node = software_node_get_next_child,
> .get_named_child_node = software_node_get_named_child_node,
> - .get_reference_args = software_node_get_reference_args
> + .get_reference_args = software_node_get_reference_args,
> + .graph_get_next_endpoint = software_node_graph_get_next_endpoint,
> + .graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
> + .graph_get_port_parent = software_node_graph_get_port_parent,
> + .graph_parse_endpoint = software_node_graph_parse_endpoint,
> };
>
> /* -------------------------------------------------------------------------- */
> --
> 2.25.1
>

--
With Best Regards,
Andy Shevchenko