On 28-12-21, 09:04, Bjorn Andersson wrote: > On Tue 28 Dec 05:09 PST 2021, Dmitry Baryshkov wrote: > > > On 28/12/2021 08:21, 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; > > > +} > > > > This API doesn't let it's user know if there are more matches found in the > > device tree or not. I'd suggest to add 'count' mode that would return the > > amount of found matches if (matches == NULL) && (matches_len == 0). But the API does call each match > > Unfortunately in this code path we don't know how to "free" the objects > returned by match(), e.g. see how typec_switch_match() returns wrapper > of a refcounted device. > > So we must return all the match results to the caller to it can free > things up based on its knowledge of what matches[] actually contains.. ACPI walk has similar APIs, I can think of acpi_walk_namespace() which I have used in past and does similar walk in namespace but for devices and calls the match() -- ~Vinod