Add two graph helper functions. display_entity_build_notifier() builds an entity notifier from an entities graph represented as a flat array, typically passed from platform data. display_entity_link_graph() can then be used to create media controller links between all entities in the graph.
Signed-off-by: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com --- drivers/video/display/display-core.c | 107 +++++++++++++++++++++++++++++++ drivers/video/display/display-notifier.c | 51 +++++++++++++++ include/video/display.h | 20 ++++++ 3 files changed, 178 insertions(+)
diff --git a/drivers/video/display/display-core.c b/drivers/video/display/display-core.c index bb18723..c3b47d3 100644 --- a/drivers/video/display/display-core.c +++ b/drivers/video/display/display-core.c @@ -10,6 +10,7 @@ * published by the Free Software Foundation. */
+#include <linux/device.h> #include <linux/export.h> #include <linux/kernel.h> #include <linux/module.h> @@ -313,6 +314,112 @@ void display_entity_unregister(struct display_entity *entity) } EXPORT_SYMBOL_GPL(display_entity_unregister);
+/* ----------------------------------------------------------------------------- + * Graph Helpers + */ + +static int display_entity_link_entity(struct device *dev, + struct display_entity *entity, + struct list_head *entities) +{ + const struct display_entity_graph_data *graph = entity->match->data; + u32 link_flags = MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED; + struct media_entity *local = &entity->entity; + unsigned int i; + int ret = 0; + + dev_dbg(dev, "creating links for entity %s\n", local->name); + + for (i = 0; i < entity->entity.num_pads; ++i) { + const struct display_entity_source_data *source; + struct media_pad *local_pad = &local->pads[i]; + struct media_entity *remote = NULL; + struct media_pad *remote_pad; + struct display_entity *ent; + + dev_dbg(dev, "processing pad %u\n", i); + + /* Skip source pads, they will be processed from the other end + * of the link. + */ + if (local_pad->flags & MEDIA_PAD_FL_SOURCE) { + dev_dbg(dev, "skipping source pad %s:%u\n", + local->name, i); + continue; + } + + /* Find the remote entity. If not found, just skip the link as + * it goes out of scope of the entities handled by the notifier. + */ + source = &graph->sources[i]; + list_for_each_entry(ent, entities, list) { + if (strcmp(source->name, dev_name(ent->dev)) == 0) { + remote = &ent->entity; + break; + } + } + + if (remote == NULL) { + dev_dbg(dev, "no entity found for %s\n", source->name); + continue; + } + + if (source->port >= remote->num_pads) { + dev_err(dev, "invalid port number %u on %s\n", + source->port, source->name); + ret = -EINVAL; + break; + } + + remote_pad = &remote->pads[source->port]; + + /* Create the media link. */ + dev_dbg(dev, "creating %s:%u -> %s:%u link\n", + remote->name, remote_pad->index, + local->name, local_pad->index); + + ret = media_entity_create_link(remote, remote_pad->index, + local, local_pad->index, + link_flags); + if (ret < 0) { + dev_err(dev, "failed to create %s:%u -> %s:%u link\n", + remote->name, remote_pad->index, + local->name, local_pad->index); + break; + } + } + + return ret; +} + +/** + * display_entity_link_graph - Link all entities in a graph + * @dev: device used to print debugging and error messages + * @entities: list of display entities in the graph + * + * This function creates media controller links for all entities in a graph + * based on graph link data. It relies on the entities match data pointers + * having been initialized by the display_entity_build_notifier() function when + * building the notifier and thus can't be used when the notifier is built in a + * different way. + * + * Return 0 on success or a negative error code otherwise. + */ +int display_entity_link_graph(struct device *dev, struct list_head *entities) +{ + struct display_entity *entity; + int ret; + + list_for_each_entry(entity, entities, list) { + ret = display_entity_link_entity(dev, entity, entities); + if (ret < 0) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(display_entity_link_graph); + MODULE_AUTHOR("Laurent Pinchart laurent.pinchart@ideasonboard.com"); MODULE_DESCRIPTION("Display Core"); MODULE_LICENSE("GPL"); diff --git a/drivers/video/display/display-notifier.c b/drivers/video/display/display-notifier.c index c9210ec..2d752b3 100644 --- a/drivers/video/display/display-notifier.c +++ b/drivers/video/display/display-notifier.c @@ -220,6 +220,57 @@ void display_entity_unregister_notifier(struct display_entity_notifier *notifier } EXPORT_SYMBOL_GPL(display_entity_unregister_notifier);
+/** + * display_entity_build_notifier - build a notifier from graph data + * @notifier: display entity notifier to be built + * @graph: graph data + * + * Before registering a notifier drivers must initialize the notifier's list of + * entities. This helper function simplifies building the list of entities for + * drivers that use an array of struct display_entity_graph_data to describe the + * entities graph. + * + * The function allocates an array of struct display_entity_match, initialize it + * from graph data, and sets the notifier entities and num_entities fields. + * + * The entities array is allocated using the managed memory allocation API on + * the notifier device, which must be initialized before calling this function. + * + * Return 0 on success or a negative error code on error. + */ +int display_entity_build_notifier(struct display_entity_notifier *notifier, + const struct display_entity_graph_data *graph) +{ + struct display_entity_match *entities; + unsigned int num_entities; + unsigned int i; + + for (num_entities = 0; graph[num_entities].name; ++num_entities) { + } + + if (num_entities == 0) + return -EINVAL; + + entities = devm_kzalloc(notifier->dev, sizeof(*notifier->entities) * + num_entities, GFP_KERNEL); + if (entities == NULL) + return -ENOMEM; + + for (i = 0; i < num_entities; ++i) { + struct display_entity_match *match = &entities[i]; + + match->type = DISPLAY_ENTITY_BUS_PLATFORM; + match->match.platform.name = graph[i].name; + match->data = &graph[i]; + } + + notifier->num_entities = num_entities; + notifier->entities = entities; + + return 0; +} +EXPORT_SYMBOL_GPL(display_entity_build_notifier); + /* ----------------------------------------------------------------------------- * Entity Registration */ diff --git a/include/video/display.h b/include/video/display.h index 2063694..58ff0d1 100644 --- a/include/video/display.h +++ b/include/video/display.h @@ -159,6 +159,7 @@ enum display_entity_bus_type { * @match.platform.name: platform device name * @match.dt.node: DT node * @list: link match objects waiting to be matched + * @data: driver private data, not touched by the core */ struct display_entity_match { enum display_entity_bus_type type; @@ -169,6 +170,7 @@ struct display_entity_match { } match;
struct list_head list; + const void *data; };
/** @@ -206,4 +208,22 @@ void display_entity_unregister_notifier(struct display_entity_notifier *notifier int display_entity_add(struct display_entity *entity); void display_entity_remove(struct display_entity *entity);
+/* ----------------------------------------------------------------------------- + * Graph Helpers + */ + +struct display_entity_source_data { + const char *name; + unsigned int port; +}; + +struct display_entity_graph_data { + const char *name; + const struct display_entity_source_data *sources; +}; + +int display_entity_build_notifier(struct display_entity_notifier *notifier, + const struct display_entity_graph_data *graph); +int display_entity_link_graph(struct device *dev, struct list_head *entities); + #endif /* __DISPLAY_H__ */