device property: Add helper to match multiple connections

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.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220422222351.1297276-2-bjorn.andersson@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/property.c b/drivers/base/property.c
index c0e94cc..08da5ca 100644 (file)
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1218,6 +1218,40 @@ 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)
@@ -1240,6 +1274,37 @@ 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
@@ -1267,3 +1332,47 @@ 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 4cd4b32..de7ff33 100644 (file)
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -447,6 +447,11 @@ 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 */