[media] media: add functions to allow creating interfaces

Interfaces are different than entities: they represent a
Kernel<->userspace interaction, while entities represent a
piece of hardware/firmware/software that executes a function.

Let's distinguish them by creating a separate structure to
store the interfaces.

Later patches should change the existing drivers and logic
to split the current interface embedded inside the entity
structure (device nodes) into a separate object of the graph.

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

2 files changed, 50 insertions, 0 deletions

diff --git a/include/media/media-device.h b/include/media/media-device.h
index 05414e351f8e..3b14394d5701 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -44,6 +44,7 @@ struct device;
  * @entity_id:  Unique ID used on the last entity registered
  * @pad_id:     Unique ID used on the last pad registered
  * @link_id:    Unique ID used on the last link registered
+ * @intf_devnode_id: Unique ID used on the last interface devnode registered
  * @entities:   List of registered entities
  * @lock:       Entities list lock
  * @graph_mutex: Entities graph operation lock
@@ -73,6 +74,7 @@ struct media_device {
         u32 entity_id;
         u32 pad_id;
         u32 link_id;
+        u32 intf_devnode_id;
 
         struct list_head entities;
 
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index a493dd9910f4..4d5fc91c4134 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -36,11 +36,14 @@
  * @MEDIA_GRAPH_ENTITY:         Identify a media entity
  * @MEDIA_GRAPH_PAD:            Identify a media pad
  * @MEDIA_GRAPH_LINK:           Identify a media link
+ * @MEDIA_GRAPH_INTF_DEVNODE:   Identify a media Kernel API interface via
+ *                              a device node
  */
 enum media_gobj_type {
         MEDIA_GRAPH_ENTITY,
         MEDIA_GRAPH_PAD,
         MEDIA_GRAPH_LINK,
+        MEDIA_GRAPH_INTF_DEVNODE,
 };
 
 #define MEDIA_BITS_PER_TYPE             8
@@ -141,6 +144,34 @@ struct media_entity {
         } info;
 };
 
+/**
+ * struct media_intf_devnode - Define a Kernel API interface
+ *
+ * @graph_obj:          embedded graph object
+ * @type:               Type of the interface as defined at the
+ *                      uapi/media/media.h header, e. g.
+ *                      MEDIA_INTF_T_*
+ * @flags:              Interface flags as defined at uapi/media/media.h
+ */
+struct media_interface {
+        struct media_gobj               graph_obj;
+        u32                             type;
+        u32                             flags;
+};
+
+/**
+ * struct media_intf_devnode - Define a Kernel API interface via a device node
+ *
+ * @intf:       embedded interface object
+ * @major:      Major number of a device node
+ * @minor:      Minor number of a device node
+ */
+struct media_intf_devnode {
+        struct media_interface          intf;
+        u32                             major;
+        u32                             minor;
+};
+
 static inline u32 media_entity_type(struct media_entity *entity)
 {
         return entity->type & MEDIA_ENT_TYPE_MASK;
@@ -205,6 +236,18 @@ struct media_entity_graph {
 #define gobj_to_link(gobj) \
                 container_of(gobj, struct media_link, graph_obj)
 
+#define gobj_to_link(gobj) \
+                container_of(gobj, struct media_link, graph_obj)
+
+#define gobj_to_pad(gobj) \
+                container_of(gobj, struct media_pad, graph_obj)
+
+#define gobj_to_intf(gobj) \
+                container_of(gobj, struct media_interface, graph_obj)
+
+#define intf_to_devnode(intf) \
+                container_of(intf, struct media_intf_devnode, intf)
+
 void media_gobj_init(struct media_device *mdev,
                     enum media_gobj_type type,
                     struct media_gobj *gobj);
@@ -236,6 +279,11 @@ __must_check int media_entity_pipeline_start(struct media_entity *entity,
                                              struct media_pipeline *pipe);
 void media_entity_pipeline_stop(struct media_entity *entity);
 
+struct media_intf_devnode *media_devnode_create(struct media_device *mdev,
+                                                u32 type, u32 flags,
+                                                u32 major, u32 minor,
+                                                gfp_t gfp_flags);
+void media_devnode_remove(struct media_intf_devnode *devnode);
 #define media_entity_call(entity, operation, args...)                   \
         (((entity)->ops && (entity)->ops->operation) ?                  \
          (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)