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@xxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxxxxx>");
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__ */
--
1.8.1.5
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