Re: [PATCH v3 07/14] software_node: Add support for fwnode_graph*() family of functions

[Andy Shevchenko]

On Thu, Dec 24, 2020 at 3:14 AM Daniel Scally <djrscally@xxxxxxxxx> wrote:
>
> From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
>
> This implements the remaining .graph_* callbacks in the

.graph_* ==> ->graph_*() ?

> fwnode operations structure for the software nodes. That makes
> the fwnode_graph*() functions available in the drivers also

graph*() -> graph_*() ?

> 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",

> ...)

Looks not good, perhaps move to the previous line, or move port@1 example here?

> 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".

Few nitpicks here and there, after addressing them,
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> Co-developed-by: Daniel Scally <djrscally@xxxxxxxxx>
> Signed-off-by: Daniel Scally <djrscally@xxxxxxxxx>
> ---
> Changes in v3
>         - Changed software_node_get_next_endpoint() to drop the variable
>         named "old"
>         - Used the macros defined in 06/14 instead of magic numbers
>         - Added some comments to explain behaviour a little where it's unclear
>
>  drivers/base/swnode.c | 112 +++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 111 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 2d07eb04c6c8..ff690029060d 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -540,6 +540,112 @@ 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))) {
> +               /*
> +                * ports have naming style "port@n", so we search for children
> +                * that follow that convention (but without assuming anything
> +                * about the index number)
> +                */

> +               if (!strncmp(to_swnode(port)->node->name, "port@",

You may use here corresponding _FMT macro.

> +                            FWNODE_GRAPH_PORT_NAME_PREFIX_LEN))
> +                       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);
> +       int ret;
> +
> +       /* Ports have naming style "port@n", we need to select the n */

> +       ret = kstrtou32(swnode->parent->node->name + FWNODE_GRAPH_PORT_NAME_PREFIX_LEN,

Maybe a temporary variable?

  unsigned int prefix_len = FWNODE_GRAPH_PORT_NAME_PREFIX_LEN;
  ...
  ret = kstrtou32(swnode->parent->node->name + prefix_len,


> +                       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 +657,11 @@ 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