Re: [PATCH 3/8] device property: Helper to match multiple connections

From: Heikki Krogerus
Date: Thu Dec 30 2021 - 04:26:43 EST


+Andy, Dan and Sakari

On Mon, Dec 27, 2021 at 09:21:11PM -0800, Bjorn Andersson 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-C
> connector. In this case the connector needs to belong to a graph with
> multiple matching remote endpoints, and the TypeC controller needs to be
> able to resolve them both.
>
> Add a new API that allows this kind of lookup.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> ---
> drivers/base/property.c | 94 ++++++++++++++++++++++++++++++++++++++++
> include/linux/property.h | 5 +++
> 2 files changed, 99 insertions(+)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index cbe4fa298413..0aa0296fd991 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -1180,6 +1180,36 @@ 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 (count >= matches_len) {
> + fwnode_handle_put(ep);
> + return count;
> + }
> +
> + node = fwnode_graph_get_remote_port_parent(ep);
> + if (!fwnode_device_is_available(node))
> + continue;
> +
> + ret = match(node, con_id, data);
> + fwnode_handle_put(node);
> +
> + if (ret)
> + matches[count++] = ret;
> + }
> + return count;
> +}
> +
> static void *
> fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id,
> void *data, devcon_match_fn_t match)
> @@ -1202,6 +1232,35 @@ 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;
> + void *ret;
> + int i;
> +
> + for (i = 0; ; i++) {
> + if (count >= matches_len)
> + return count;
> +
> + node = fwnode_find_reference(fwnode, con_id, i);
> + if (IS_ERR(node))
> + break;
> +
> + ret = match(node, NULL, data);
> + fwnode_handle_put(node);
> +
> + if (ret)
> + matches[count++] = ret;
> + }
> +
> + return count;
> +}
> +
> /**
> * fwnode_connection_find_match - Find connection from a device node
> * @fwnode: Device node with the connection
> @@ -1229,3 +1288,38 @@ 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: 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.
> + *
> + * Return: Number of matches resolved, of 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;
> +
> + if (!fwnode || !match || !matches)
> + return -EINVAL;
> +
> + count = fwnode_graph_devcon_matches(fwnode, con_id, data, match,
> + matches, matches_len);
> +
> + return count + fwnode_devcon_matches(fwnode, con_id, data, match,
> + matches + count,
> + matches_len - count);
> +}
> +EXPORT_SYMBOL_GPL(fwnode_connection_find_matches);
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 16f736c698a2..59484ccb260e 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -444,6 +444,11 @@ 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 */
>
> --
> 2.33.1

--
heikki