[v15,01/10] device property: Add remote endpoint to devcon matcher

Commit Message

Pin-yen Lin March 31, 2023, 9:11 a.m. UTC

From: Prashant Malani <[e-mail]>

When searching the device graph for device matches, check the
remote-endpoint itself for a match.

Some drivers register devices for individual endpoints. This allows
the matcher code to evaluate those for a match too, instead
of only looking at the remote parent devices. This is required when a
device supports two mode switches in its endpoints, so we can't simply
register the mode switch with the parent node.

Signed-off-by: Prashant Malani <[e-mail]>
Signed-off-by: Pin-yen Lin <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Sakari Ailus <[e-mail]>
Reviewed-by: Heikki Krogerus <[e-mail]>

---

(no changes since v14)

Changes in v14:
- Collect review tags

Changes in v13:
- Update the kernel doc of fwnode_connection_find_match

Changes in v12:
- Check the availability of the device node in fwnode_graph_devcon_matches
- Ensured valid access to "matches" in fwnode_graph_devcon_matches
- Updated the documentation in fwnode_connection_find_match(es)
- Dropped collected tags due to the new changes

Changes in v11:
- Added missing fwnode_handle_put in drivers/base/property.c

Changes in v10:
- Collected Reviewed-by and Tested-by tags

Changes in v6:
- New in v6

 drivers/base/property.c | 31 ++++++++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 5 deletions(-)

Comments

Stephen Boyd April 7, 2023, 9:54 p.m. UTC | #1

Quoting Pin-yen Lin (2023-03-31 02:11:36)
> From: Prashant Malani <[e-mail]>
>
> When searching the device graph for device matches, check the
> remote-endpoint itself for a match.
>
> Some drivers register devices for individual endpoints. This allows
> the matcher code to evaluate those for a match too, instead
> of only looking at the remote parent devices. This is required when a
> device supports two mode switches in its endpoints, so we can't simply
> register the mode switch with the parent node.

Looking at this in isolation I have no idea what a mode switch is and
how it is related to drivers/base/property.c. Can you expand on this
commit text? Maybe say two "usb typec mode switches"? And maybe include
an example graph node snippet?

Patch

diff --git a/drivers/base/property.c b/drivers/base/property.c
index 083a95791d3b..4426ac2b16ca 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1243,6 +1243,23 @@  static unsigned int fwnode_graph_devcon_matches(const struct fwnode_handle *fwno
 			continue;
 		}
 
+		ret = match(node, con_id, data);
+		fwnode_handle_put(node);
+		if (ret) {
+			if (matches)
+				matches[count] = ret;
+			count++;
+
+			if (matches && count >= matches_len)
+				break;
+		}
+
+		/*
+		 * Some drivers may register devices for endpoints. Check
+		 * the remote-endpoints for matches in addition to the remote
+		 * port parent.
+		 */
+		node = fwnode_graph_get_remote_endpoint(ep);
 		ret = match(node, con_id, data);
 		fwnode_handle_put(node);
 		if (ret) {
@@ -1293,8 +1310,11 @@  static unsigned int fwnode_devcon_matches(const struct fwnode_handle *fwnode,
  * @match: Function to check and convert the connection description
  *
  * Find a connection with unique identifier @con_id between @fwnode and another
- * device node. @match will be used to convert the connection description to
- * data the caller is expecting to be returned.
+ * device node. For fwnode graph connections, the graph endpoints are also
+ * checked. @match will be used to convert the connection description to data
+ * the caller is expecting to be returned.
+ *
+ * Return: The pointer to the matched node, or NULL on error.
  */
 void *fwnode_connection_find_match(const struct fwnode_handle *fwnode,
 				   const char *con_id, void *data,
@@ -1325,9 +1345,10 @@  EXPORT_SYMBOL_GPL(fwnode_connection_find_match);
  * @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.
+ * @fwnode and other device nodes. For fwnode graph connections, the graph
+ * endpoints are also checked. @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.
  *