Hi Daniel and Heikki,
On Thu, Dec 17, 2020 at 11:43:31PM +0000, Daniel Scally wrote:
> From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
>
> 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".
>
> Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> Co-developed-by: Daniel Scally <djrscally@xxxxxxxxx>
> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
> ---
> Changes in v2:
>
> - Changed commit to specify port name prefix as port@
> - Accounted for that rename in *parse_endpoint()
>
> drivers/base/swnode.c | 110 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 109 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 2b90d380039b..0d14d5ebe441 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -540,6 +540,110 @@ 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))) {
> + if (!strncmp(to_swnode(port)->node->name, "port", 4))
> + 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 *old = endpoint;
> + 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, old);
> + if (endpoint) {
> + fwnode_handle_put(port);
> + break;
> + }
> +
> + /* No more endpoints for that port, so stop passing old */
> + old = NULL;
> + }
> +
> + 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);
> + struct fwnode_handle *parent;
> +
> + if (!strcmp(swnode->parent->node->name, "ports"))
> + parent = &swnode->parent->parent->fwnode;
> + else
> + parent = &swnode->parent->fwnode;
If you happen to call this function on a non-port node for whatever reason,
you may end up accessing a pointer that's NULL, can't you? Instead I'd do
something like:
swnode = swnode->parent;
if (swnode && !strcmp(swnode->node->name, "ports"))
swnode = swnode->parent;
return swnode ? software_node_get(&swnode->fwnode) : NULL;
You can also drop parent as a by-product of this.
> +
> + return software_node_get(parent);
> +}
> +
> +static int
> +software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
> + struct fwnode_endpoint *endpoint)
> +{
> + struct swnode *swnode = to_swnode(fwnode);
> + int ret;
> +
> + ret = kstrtou32(swnode->parent->node->name + 5, 10, &endpoint->port);
> + 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 +655,11 @@ 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,
> };
>
> /* -------------------------------------------------------------------------- */
--
Kind regards,
Sakari Ailus
