Re: [PATCH v5 1/7] device property: Add helper to match multiple connections

[Andy Shevchenko]

On Sat, Apr 23, 2022 at 1:25 AM Bjorn Andersson
<bjorn.andersson@xxxxxxxxxx> wrote:
>
> In some cases multiple connections with the same connection id
> needs to be resolved from a fwnode graph.
>
> One such example is when separate hardware is used for performing muxing
> and/or orientation switching of the SuperSpeed and SBU lines in a USB
> Type-C connector. In this case the connector needs to belong to a graph
> with multiple matching remote endpoints, and the Type-C controller needs
> to be able to resolve them both.
>
> Add a new API that allows this kind of lookup.

LGTM now,
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
thanks!

> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
>
> Changes since v4:
> - Added "Add" to patch subject
> - Added "(Optional)" kernel-doc of fwnode_connection_find_matches()
>
>  drivers/base/property.c  | 109 +++++++++++++++++++++++++++++++++++++++
>  include/linux/property.h |   5 ++
>  2 files changed, 114 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 36401cfe432c..babab8cec7a0 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -1201,6 +1201,40 @@ fwnode_graph_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
>         return NULL;
>  }
>
> +static unsigned int fwnode_graph_devcon_matches(struct fwnode_handle *fwnode,
> +                                               const char *con_id, void *data,
> +                                               devcon_match_fn_t match,
> +                                               void **matches,
> +                                               unsigned int matches_len)
> +{
> +       struct fwnode_handle *node;
> +       struct fwnode_handle *ep;
> +       unsigned int count = 0;
> +       void *ret;
> +
> +       fwnode_graph_for_each_endpoint(fwnode, ep) {
> +               if (matches && count >= matches_len) {
> +                       fwnode_handle_put(ep);
> +                       break;
> +               }
> +
> +               node = fwnode_graph_get_remote_port_parent(ep);
> +               if (!fwnode_device_is_available(node)) {
> +                       fwnode_handle_put(node);
> +                       continue;
> +               }
> +
> +               ret = match(node, con_id, data);
> +               fwnode_handle_put(node);
> +               if (ret) {
> +                       if (matches)
> +                               matches[count] = ret;
> +                       count++;
> +               }
> +       }
> +       return count;
> +}
> +
>  static void *
>  fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
>                     void *data, devcon_match_fn_t match)
> @@ -1223,6 +1257,37 @@ fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
>         return NULL;
>  }
>
> +static unsigned int fwnode_devcon_matches(struct fwnode_handle *fwnode,
> +                                         const char *con_id, void *data,
> +                                         devcon_match_fn_t match,
> +                                         void **matches,
> +                                         unsigned int matches_len)
> +{
> +       struct fwnode_handle *node;
> +       unsigned int count = 0;
> +       unsigned int i;
> +       void *ret;
> +
> +       for (i = 0; ; i++) {
> +               if (matches && count >= matches_len)
> +                       break;
> +
> +               node = fwnode_find_reference(fwnode, con_id, i);
> +               if (IS_ERR(node))
> +                       break;
> +
> +               ret = match(node, NULL, data);
> +               fwnode_handle_put(node);
> +               if (ret) {
> +                       if (matches)
> +                               matches[count] = ret;
> +                       count++;
> +               }
> +       }
> +
> +       return count;
> +}
> +
>  /**
>   * fwnode_connection_find_match - Find connection from a device node
>   * @fwnode: Device node with the connection
> @@ -1250,3 +1315,47 @@ void *fwnode_connection_find_match(struct fwnode_handle *fwnode,
>         return fwnode_devcon_match(fwnode, con_id, data, match);
>  }
>  EXPORT_SYMBOL_GPL(fwnode_connection_find_match);
> +
> +/**
> + * fwnode_connection_find_matches - Find connections from a device node
> + * @fwnode: Device node with the connection
> + * @con_id: Identifier for the connection
> + * @data: Data for the match function
> + * @match: Function to check and convert the connection description
> + * @matches: (Optional) array of pointers to fill with matches
> + * @matches_len: Length of @matches
> + *
> + * Find up to @matches_len connections with unique identifier @con_id between
> + * @fwnode and other device nodes. @match will be used to convert the
> + * connection description to data the caller is expecting to be returned
> + * through the @matches array.
> + * If @matches is NULL @matches_len is ignored and the total number of resolved
> + * matches is returned.
> + *
> + * Return: Number of matches resolved, or negative errno.
> + */
> +int fwnode_connection_find_matches(struct fwnode_handle *fwnode,
> +                                  const char *con_id, void *data,
> +                                  devcon_match_fn_t match,
> +                                  void **matches, unsigned int matches_len)
> +{
> +       unsigned int count_graph;
> +       unsigned int count_ref;
> +
> +       if (!fwnode || !match)
> +               return -EINVAL;
> +
> +       count_graph = fwnode_graph_devcon_matches(fwnode, con_id, data, match,
> +                                                 matches, matches_len);
> +
> +       if (matches) {
> +               matches += count_graph;
> +               matches_len -= count_graph;
> +       }
> +
> +       count_ref = fwnode_devcon_matches(fwnode, con_id, data, match,
> +                                         matches, matches_len);
> +
> +       return count_graph + count_ref;
> +}
> +EXPORT_SYMBOL_GPL(fwnode_connection_find_matches);
> diff --git a/include/linux/property.h b/include/linux/property.h
> index fc24d45632eb..a5b429d623f6 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -451,6 +451,11 @@ static inline void *device_connection_find_match(struct device *dev,
>         return fwnode_connection_find_match(dev_fwnode(dev), con_id, data, match);
>  }
>
> +int fwnode_connection_find_matches(struct fwnode_handle *fwnode,
> +                                  const char *con_id, void *data,
> +                                  devcon_match_fn_t match,
> +                                  void **matches, unsigned int matches_len);
> +
>  /* -------------------------------------------------------------------------- */
>  /* Software fwnode support - when HW description is incomplete or missing */
>
> --
> 2.35.1
>


-- 
With Best Regards,
Andy Shevchenko