4 * Copyright (C) 2010 Nokia Corporation
6 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
7 * Sakari Ailus <sakari.ailus@iki.fi>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #ifndef _MEDIA_ENTITY_H
24 #define _MEDIA_ENTITY_H
26 #include <linux/bitmap.h>
27 #include <linux/bug.h>
28 #include <linux/kernel.h>
29 #include <linux/list.h>
30 #include <linux/media.h>
32 /* Enums used internally at the media controller to represent graphs */
35 * enum media_gobj_type - type of a graph object
37 * @MEDIA_GRAPH_ENTITY: Identify a media entity
38 * @MEDIA_GRAPH_PAD: Identify a media pad
39 * @MEDIA_GRAPH_LINK: Identify a media link
40 * @MEDIA_GRAPH_INTF_DEVNODE: Identify a media Kernel API interface via
43 enum media_gobj_type {
47 MEDIA_GRAPH_INTF_DEVNODE,
50 #define MEDIA_BITS_PER_TYPE 8
51 #define MEDIA_BITS_PER_ID (32 - MEDIA_BITS_PER_TYPE)
52 #define MEDIA_ID_MASK GENMASK_ULL(MEDIA_BITS_PER_ID - 1, 0)
54 /* Structs to represent the objects that belong to a media graph */
57 * struct media_gobj - Define a graph object.
59 * @mdev: Pointer to the struct media_device that owns the object
60 * @id: Non-zero object ID identifier. The ID should be unique
61 * inside a media_device, as it is composed by
62 * %MEDIA_BITS_PER_TYPE to store the type plus
63 * %MEDIA_BITS_PER_ID to store the ID
64 * @list: List entry stored in one of the per-type mdev object lists
66 * All objects on the media graph should have this struct embedded
69 struct media_device *mdev;
71 struct list_head list;
74 #define MEDIA_ENTITY_ENUM_MAX_DEPTH 16
77 * struct media_entity_enum - An enumeration of media entities.
79 * @bmap: Bit map in which each bit represents one entity at struct
80 * media_entity->internal_idx.
81 * @idx_max: Number of bits in bmap
83 struct media_entity_enum {
89 * struct media_entity_graph - Media graph traversal state
91 * @stack: Graph traversal stack; the stack contains information
92 * on the path the media entities to be walked and the
93 * links through which they were reached.
94 * @ent_enum: Visited entities
95 * @top: The top of the stack
97 struct media_entity_graph {
99 struct media_entity *entity;
100 struct list_head *link;
101 } stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
103 struct media_entity_enum ent_enum;
108 * struct media_pipeline - Media pipeline related information
110 * @streaming_count: Streaming start count - streaming stop count
111 * @graph: Media graph walk during pipeline start / stop
113 struct media_pipeline {
115 struct media_entity_graph graph;
119 * struct media_link - A link object part of a media graph.
121 * @graph_obj: Embedded structure containing the media object common data
122 * @list: Linked list associated with an entity or an interface that
124 * @gobj0: Part of a union. Used to get the pointer for the first
125 * graph_object of the link.
126 * @source: Part of a union. Used only if the first object (gobj0) is
127 * a pad. In that case, it represents the source pad.
128 * @intf: Part of a union. Used only if the first object (gobj0) is
130 * @gobj1: Part of a union. Used to get the pointer for the second
131 * graph_object of the link.
132 * @source: Part of a union. Used only if the second object (gobj1) is
133 * a pad. In that case, it represents the sink pad.
134 * @entity: Part of a union. Used only if the second object (gobj1) is
136 * @reverse: Pointer to the link for the reverse direction of a pad to pad
138 * @flags: Link flags, as defined in uapi/media.h (MEDIA_LNK_FL_*)
139 * @is_backlink: Indicate if the link is a backlink.
142 struct media_gobj graph_obj;
143 struct list_head list;
145 struct media_gobj *gobj0;
146 struct media_pad *source;
147 struct media_interface *intf;
150 struct media_gobj *gobj1;
151 struct media_pad *sink;
152 struct media_entity *entity;
154 struct media_link *reverse;
160 * struct media_pad - A media pad graph object.
162 * @graph_obj: Embedded structure containing the media object common data
163 * @entity: Entity this pad belongs to
164 * @index: Pad index in the entity pads array, numbered from 0 to n
165 * @flags: Pad flags, as defined in uapi/media.h (MEDIA_PAD_FL_*)
168 struct media_gobj graph_obj; /* must be first field in struct */
169 struct media_entity *entity;
175 * struct media_entity_operations - Media entity operations
176 * @link_setup: Notify the entity of link changes. The operation can
177 * return an error, in which case link setup will be
178 * cancelled. Optional.
179 * @link_validate: Return whether a link is valid from the entity point of
180 * view. The media_entity_pipeline_start() function
181 * validates all links by calling this operation. Optional.
183 * Note: Those these callbacks are called with struct media_device.@graph_mutex
186 struct media_entity_operations {
187 int (*link_setup)(struct media_entity *entity,
188 const struct media_pad *local,
189 const struct media_pad *remote, u32 flags);
190 int (*link_validate)(struct media_link *link);
194 * enum media_entity_type - Media entity type
196 * @MEDIA_ENTITY_TYPE_BASE:
197 * The entity isn't embedded in another subsystem structure.
198 * @MEDIA_ENTITY_TYPE_VIDEO_DEVICE:
199 * The entity is embedded in a struct video_device instance.
200 * @MEDIA_ENTITY_TYPE_V4L2_SUBDEV:
201 * The entity is embedded in a struct v4l2_subdev instance.
203 * Media entity objects are often not instantiated directly, but the media
204 * entity structure is inherited by (through embedding) other subsystem-specific
205 * structures. The media entity type identifies the type of the subclass
206 * structure that implements a media entity instance.
208 * This allows runtime type identification of media entities and safe casting to
209 * the correct object type. For instance, a media entity structure instance
210 * embedded in a v4l2_subdev structure instance will have the type
211 * MEDIA_ENTITY_TYPE_V4L2_SUBDEV and can safely be cast to a v4l2_subdev
212 * structure using the container_of() macro.
214 enum media_entity_type {
215 MEDIA_ENTITY_TYPE_BASE,
216 MEDIA_ENTITY_TYPE_VIDEO_DEVICE,
217 MEDIA_ENTITY_TYPE_V4L2_SUBDEV,
221 * struct media_entity - A media entity graph object.
223 * @graph_obj: Embedded structure containing the media object common data.
224 * @name: Entity name.
225 * @obj_type: Type of the object that implements the media_entity.
226 * @function: Entity main function, as defined in uapi/media.h
228 * @flags: Entity flags, as defined in uapi/media.h (MEDIA_ENT_FL_*)
229 * @num_pads: Number of sink and source pads.
230 * @num_links: Total number of links, forward and back, enabled and disabled.
231 * @num_backlinks: Number of backlinks
232 * @internal_idx: An unique internal entity specific number. The numbers are
233 * re-used if entities are unregistered or registered again.
234 * @pads: Pads array with the size defined by @num_pads.
235 * @links: List of data links.
236 * @ops: Entity operations.
237 * @stream_count: Stream count for the entity.
238 * @use_count: Use count for the entity.
239 * @pipe: Pipeline this entity belongs to.
240 * @info: Union with devnode information. Kept just for backward
242 * @major: Devnode major number (zero if not applicable). Kept just
243 * for backward compatibility.
244 * @minor: Devnode minor number (zero if not applicable). Kept just
245 * for backward compatibility.
247 * NOTE: @stream_count and @use_count reference counts must never be
248 * negative, but are signed integers on purpose: a simple WARN_ON(<0) check
249 * can be used to detect reference count bugs that would make them negative.
251 struct media_entity {
252 struct media_gobj graph_obj; /* must be first field in struct */
254 enum media_entity_type obj_type;
263 struct media_pad *pads;
264 struct list_head links;
266 const struct media_entity_operations *ops;
268 /* Reference counts must never be negative, but are signed integers on
269 * purpose: a simple WARN_ON(<0) check can be used to detect reference
270 * count bugs that would make them negative.
275 struct media_pipeline *pipe;
286 * struct media_interface - A media interface graph object.
288 * @graph_obj: embedded graph object
289 * @links: List of links pointing to graph entities
290 * @type: Type of the interface as defined in the
291 * uapi/media/media.h header, e. g.
293 * @flags: Interface flags as defined in uapi/media/media.h
295 struct media_interface {
296 struct media_gobj graph_obj;
297 struct list_head links;
303 * struct media_intf_devnode - A media interface via a device node.
305 * @intf: embedded interface object
306 * @major: Major number of a device node
307 * @minor: Minor number of a device node
309 struct media_intf_devnode {
310 struct media_interface intf;
312 /* Should match the fields at media_v2_intf_devnode */
318 * media_entity_id() - return the media entity graph object id
320 * @entity: pointer to entity
322 static inline u32 media_entity_id(struct media_entity *entity)
324 return entity->graph_obj.id;
328 * media_type() - return the media object type
330 * @gobj: pointer to the media graph object
332 static inline enum media_gobj_type media_type(struct media_gobj *gobj)
334 return gobj->id >> MEDIA_BITS_PER_ID;
338 * media_id() - return the media object ID
340 * @gobj: pointer to the media graph object
342 static inline u32 media_id(struct media_gobj *gobj)
344 return gobj->id & MEDIA_ID_MASK;
348 * media_gobj_gen_id() - encapsulates type and ID on at the object ID
350 * @type: object type as define at enum &media_gobj_type.
351 * @local_id: next ID, from struct &media_device.@id.
353 static inline u32 media_gobj_gen_id(enum media_gobj_type type, u64 local_id)
357 id = type << MEDIA_BITS_PER_ID;
358 id |= local_id & MEDIA_ID_MASK;
364 * is_media_entity_v4l2_video_device() - Check if the entity is a video_device
365 * @entity: pointer to entity
367 * Return: true if the entity is an instance of a video_device object and can
368 * safely be cast to a struct video_device using the container_of() macro, or
371 static inline bool is_media_entity_v4l2_video_device(struct media_entity *entity)
373 return entity && entity->obj_type == MEDIA_ENTITY_TYPE_VIDEO_DEVICE;
377 * is_media_entity_v4l2_subdev() - Check if the entity is a v4l2_subdev
378 * @entity: pointer to entity
380 * Return: true if the entity is an instance of a v4l2_subdev object and can
381 * safely be cast to a struct v4l2_subdev using the container_of() macro, or
384 static inline bool is_media_entity_v4l2_subdev(struct media_entity *entity)
386 return entity && entity->obj_type == MEDIA_ENTITY_TYPE_V4L2_SUBDEV;
390 * __media_entity_enum_init - Initialise an entity enumeration
392 * @ent_enum: Entity enumeration to be initialised
393 * @idx_max: Maximum number of entities in the enumeration
395 * Return: Returns zero on success or a negative error code.
397 __must_check int __media_entity_enum_init(struct media_entity_enum *ent_enum,
401 * media_entity_enum_cleanup - Release resources of an entity enumeration
403 * @ent_enum: Entity enumeration to be released
405 void media_entity_enum_cleanup(struct media_entity_enum *ent_enum);
408 * media_entity_enum_zero - Clear the entire enum
410 * @ent_enum: Entity enumeration to be cleared
412 static inline void media_entity_enum_zero(struct media_entity_enum *ent_enum)
414 bitmap_zero(ent_enum->bmap, ent_enum->idx_max);
418 * media_entity_enum_set - Mark a single entity in the enum
420 * @ent_enum: Entity enumeration
421 * @entity: Entity to be marked
423 static inline void media_entity_enum_set(struct media_entity_enum *ent_enum,
424 struct media_entity *entity)
426 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
429 __set_bit(entity->internal_idx, ent_enum->bmap);
433 * media_entity_enum_clear - Unmark a single entity in the enum
435 * @ent_enum: Entity enumeration
436 * @entity: Entity to be unmarked
438 static inline void media_entity_enum_clear(struct media_entity_enum *ent_enum,
439 struct media_entity *entity)
441 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
444 __clear_bit(entity->internal_idx, ent_enum->bmap);
448 * media_entity_enum_test - Test whether the entity is marked
450 * @ent_enum: Entity enumeration
451 * @entity: Entity to be tested
453 * Returns true if the entity was marked.
455 static inline bool media_entity_enum_test(struct media_entity_enum *ent_enum,
456 struct media_entity *entity)
458 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
461 return test_bit(entity->internal_idx, ent_enum->bmap);
465 * media_entity_enum_test - Test whether the entity is marked, and mark it
467 * @ent_enum: Entity enumeration
468 * @entity: Entity to be tested
470 * Returns true if the entity was marked, and mark it before doing so.
473 media_entity_enum_test_and_set(struct media_entity_enum *ent_enum,
474 struct media_entity *entity)
476 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
479 return __test_and_set_bit(entity->internal_idx, ent_enum->bmap);
483 * media_entity_enum_empty - Test whether the entire enum is empty
485 * @ent_enum: Entity enumeration
487 * Returns true if the entity was marked.
489 static inline bool media_entity_enum_empty(struct media_entity_enum *ent_enum)
491 return bitmap_empty(ent_enum->bmap, ent_enum->idx_max);
495 * media_entity_enum_intersects - Test whether two enums intersect
497 * @ent_enum1: First entity enumeration
498 * @ent_enum2: Second entity enumeration
500 * Returns true if entity enumerations e and f intersect, otherwise false.
502 static inline bool media_entity_enum_intersects(
503 struct media_entity_enum *ent_enum1,
504 struct media_entity_enum *ent_enum2)
506 WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max);
508 return bitmap_intersects(ent_enum1->bmap, ent_enum2->bmap,
509 min(ent_enum1->idx_max, ent_enum2->idx_max));
512 #define gobj_to_entity(gobj) \
513 container_of(gobj, struct media_entity, graph_obj)
515 #define gobj_to_pad(gobj) \
516 container_of(gobj, struct media_pad, graph_obj)
518 #define gobj_to_link(gobj) \
519 container_of(gobj, struct media_link, graph_obj)
521 #define gobj_to_link(gobj) \
522 container_of(gobj, struct media_link, graph_obj)
524 #define gobj_to_pad(gobj) \
525 container_of(gobj, struct media_pad, graph_obj)
527 #define gobj_to_intf(gobj) \
528 container_of(gobj, struct media_interface, graph_obj)
530 #define intf_to_devnode(intf) \
531 container_of(intf, struct media_intf_devnode, intf)
534 * media_gobj_create - Initialize a graph object
536 * @mdev: Pointer to the media_device that contains the object
537 * @type: Type of the object
538 * @gobj: Pointer to the graph object
540 * This routine initializes the embedded struct media_gobj inside a
541 * media graph object. It is called automatically if media_*_create()
542 * calls are used. However, if the object (entity, link, pad, interface)
543 * is embedded on some other object, this function should be called before
544 * registering the object at the media controller.
546 void media_gobj_create(struct media_device *mdev,
547 enum media_gobj_type type,
548 struct media_gobj *gobj);
551 * media_gobj_destroy - Stop using a graph object on a media device
553 * @gobj: Pointer to the graph object
555 * This should be called by all routines like media_device_unregister()
556 * that remove/destroy media graph objects.
558 void media_gobj_destroy(struct media_gobj *gobj);
561 * media_entity_pads_init() - Initialize the entity pads
563 * @entity: entity where the pads belong
564 * @num_pads: total number of sink and source pads
565 * @pads: Array of @num_pads pads.
567 * The pads array is managed by the entity driver and passed to
568 * media_entity_pads_init() where its pointer will be stored in the entity
571 * If no pads are needed, drivers could either directly fill
572 * &media_entity->@num_pads with 0 and &media_entity->@pads with NULL or call
573 * this function that will do the same.
575 * As the number of pads is known in advance, the pads array is not allocated
576 * dynamically but is managed by the entity driver. Most drivers will embed the
577 * pads array in a driver-specific structure, avoiding dynamic allocation.
579 * Drivers must set the direction of every pad in the pads array before calling
580 * media_entity_pads_init(). The function will initialize the other pads fields.
582 int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
583 struct media_pad *pads);
586 * media_entity_cleanup() - free resources associated with an entity
588 * @entity: entity where the pads belong
590 * This function must be called during the cleanup phase after unregistering
591 * the entity (currently, it does nothing).
593 static inline void media_entity_cleanup(struct media_entity *entity) {};
596 * media_create_pad_link() - creates a link between two entities.
598 * @source: pointer to &media_entity of the source pad.
599 * @source_pad: number of the source pad in the pads array
600 * @sink: pointer to &media_entity of the sink pad.
601 * @sink_pad: number of the sink pad in the pads array.
602 * @flags: Link flags, as defined in include/uapi/linux/media.h.
604 * Valid values for flags:
605 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be
606 * used to transfer media data. When two or more links target a sink pad,
607 * only one of them can be enabled at a time.
609 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't
610 * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then
611 * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is
616 * Before calling this function, media_entity_pads_init() and
617 * media_device_register_entity() should be called previously for both ends.
619 __must_check int media_create_pad_link(struct media_entity *source,
620 u16 source_pad, struct media_entity *sink,
621 u16 sink_pad, u32 flags);
624 * media_create_pad_links() - creates a link between two entities.
626 * @mdev: Pointer to the media_device that contains the object
627 * @source_function: Function of the source entities. Used only if @source is
629 * @source: pointer to &media_entity of the source pad. If NULL, it will use
630 * all entities that matches the @sink_function.
631 * @source_pad: number of the source pad in the pads array
632 * @sink_function: Function of the sink entities. Used only if @sink is NULL.
633 * @sink: pointer to &media_entity of the sink pad. If NULL, it will use
634 * all entities that matches the @sink_function.
635 * @sink_pad: number of the sink pad in the pads array.
636 * @flags: Link flags, as defined in include/uapi/linux/media.h.
637 * @allow_both_undefined: if true, then both @source and @sink can be NULL.
638 * In such case, it will create a crossbar between all entities that
639 * matches @source_function to all entities that matches @sink_function.
640 * If false, it will return 0 and won't create any link if both @source
641 * and @sink are NULL.
643 * Valid values for flags:
644 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be
645 * used to transfer media data. If multiple links are created and this
646 * flag is passed as an argument, only the first created link will have
649 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't
650 * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then
651 * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is
654 * It is common for some devices to have multiple source and/or sink entities
655 * of the same type that should be linked. While media_create_pad_link()
656 * creates link by link, this function is meant to allow 1:n, n:1 and even
657 * cross-bar (n:n) links.
659 * NOTE: Before calling this function, media_entity_pads_init() and
660 * media_device_register_entity() should be called previously for the entities
663 int media_create_pad_links(const struct media_device *mdev,
664 const u32 source_function,
665 struct media_entity *source,
666 const u16 source_pad,
667 const u32 sink_function,
668 struct media_entity *sink,
671 const bool allow_both_undefined);
673 void __media_entity_remove_links(struct media_entity *entity);
676 * media_entity_remove_links() - remove all links associated with an entity
678 * @entity: pointer to &media_entity
680 * Note: this is called automatically when an entity is unregistered via
681 * media_device_register_entity().
683 void media_entity_remove_links(struct media_entity *entity);
686 * __media_entity_setup_link - Configure a media link without locking
687 * @link: The link being configured
688 * @flags: Link configuration flags
690 * The bulk of link setup is handled by the two entities connected through the
691 * link. This function notifies both entities of the link configuration change.
693 * If the link is immutable or if the current and new configuration are
694 * identical, return immediately.
696 * The user is expected to hold link->source->parent->mutex. If not,
697 * media_entity_setup_link() should be used instead.
699 int __media_entity_setup_link(struct media_link *link, u32 flags);
702 * media_entity_setup_link() - changes the link flags properties in runtime
704 * @link: pointer to &media_link
705 * @flags: the requested new link flags
707 * The only configurable property is the %MEDIA_LNK_FL_ENABLED link flag
708 * flag to enable/disable a link. Links marked with the
709 * %MEDIA_LNK_FL_IMMUTABLE link flag can not be enabled or disabled.
711 * When a link is enabled or disabled, the media framework calls the
712 * link_setup operation for the two entities at the source and sink of the
713 * link, in that order. If the second link_setup call fails, another
714 * link_setup call is made on the first entity to restore the original link
717 * Media device drivers can be notified of link setup operations by setting the
718 * media_device::link_notify pointer to a callback function. If provided, the
719 * notification callback will be called before enabling and after disabling
722 * Entity drivers must implement the link_setup operation if any of their links
723 * is non-immutable. The operation must either configure the hardware or store
724 * the configuration information to be applied later.
726 * Link configuration must not have any side effect on other links. If an
727 * enabled link at a sink pad prevents another link at the same pad from
728 * being enabled, the link_setup operation must return -EBUSY and can't
729 * implicitly disable the first enabled link.
731 * NOTE: the valid values of the flags for the link is the same as described
732 * on media_create_pad_link(), for pad to pad links or the same as described
733 * on media_create_intf_link(), for interface to entity links.
735 int media_entity_setup_link(struct media_link *link, u32 flags);
738 * media_entity_find_link - Find a link between two pads
739 * @source: Source pad
742 * Return a pointer to the link between the two entities. If no such link
743 * exists, return NULL.
745 struct media_link *media_entity_find_link(struct media_pad *source,
746 struct media_pad *sink);
749 * media_entity_remote_pad - Find the pad at the remote end of a link
750 * @pad: Pad at the local end of the link
752 * Search for a remote pad connected to the given pad by iterating over all
753 * links originating or terminating at that pad until an enabled link is found.
755 * Return a pointer to the pad at the remote end of the first found enabled
756 * link, or NULL if no enabled link has been found.
758 struct media_pad *media_entity_remote_pad(struct media_pad *pad);
761 * media_entity_get - Get a reference to the parent module
763 * @entity: The entity
765 * Get a reference to the parent media device module.
767 * The function will return immediately if @entity is NULL.
769 * Return a pointer to the entity on success or NULL on failure.
771 struct media_entity *media_entity_get(struct media_entity *entity);
773 __must_check int media_entity_graph_walk_init(
774 struct media_entity_graph *graph, struct media_device *mdev);
777 * media_entity_graph_walk_cleanup - Release resources used by graph walk.
779 * @graph: Media graph structure that will be used to walk the graph
781 void media_entity_graph_walk_cleanup(struct media_entity_graph *graph);
784 * media_entity_put - Release the reference to the parent module
786 * @entity: The entity
788 * Release the reference count acquired by media_entity_get().
790 * The function will return immediately if @entity is NULL.
792 void media_entity_put(struct media_entity *entity);
795 * media_entity_graph_walk_start - Start walking the media graph at a given entity
796 * @graph: Media graph structure that will be used to walk the graph
797 * @entity: Starting entity
799 * Before using this function, media_entity_graph_walk_init() must be
800 * used to allocate resources used for walking the graph. This
801 * function initializes the graph traversal structure to walk the
802 * entities graph starting at the given entity. The traversal
803 * structure must not be modified by the caller during graph
804 * traversal. After the graph walk, the resources must be released
805 * using media_entity_graph_walk_cleanup().
807 void media_entity_graph_walk_start(struct media_entity_graph *graph,
808 struct media_entity *entity);
811 * media_entity_graph_walk_next - Get the next entity in the graph
812 * @graph: Media graph structure
814 * Perform a depth-first traversal of the given media entities graph.
816 * The graph structure must have been previously initialized with a call to
817 * media_entity_graph_walk_start().
819 * Return the next entity in the graph or NULL if the whole graph have been
822 struct media_entity *
823 media_entity_graph_walk_next(struct media_entity_graph *graph);
826 * media_entity_pipeline_start - Mark a pipeline as streaming
827 * @entity: Starting entity
828 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
830 * Mark all entities connected to a given entity through enabled links, either
831 * directly or indirectly, as streaming. The given pipeline object is assigned to
832 * every entity in the pipeline and stored in the media_entity pipe field.
834 * Calls to this function can be nested, in which case the same number of
835 * media_entity_pipeline_stop() calls will be required to stop streaming. The
836 * pipeline pointer must be identical for all nested calls to
837 * media_entity_pipeline_start().
839 __must_check int media_entity_pipeline_start(struct media_entity *entity,
840 struct media_pipeline *pipe);
842 * __media_entity_pipeline_start - Mark a pipeline as streaming
844 * @entity: Starting entity
845 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
847 * Note: This is the non-locking version of media_entity_pipeline_start()
849 __must_check int __media_entity_pipeline_start(struct media_entity *entity,
850 struct media_pipeline *pipe);
853 * media_entity_pipeline_stop - Mark a pipeline as not streaming
854 * @entity: Starting entity
856 * Mark all entities connected to a given entity through enabled links, either
857 * directly or indirectly, as not streaming. The media_entity pipe field is
860 * If multiple calls to media_entity_pipeline_start() have been made, the same
861 * number of calls to this function are required to mark the pipeline as not
864 void media_entity_pipeline_stop(struct media_entity *entity);
867 * __media_entity_pipeline_stop - Mark a pipeline as not streaming
869 * @entity: Starting entity
871 * Note: This is the non-locking version of media_entity_pipeline_stop()
873 void __media_entity_pipeline_stop(struct media_entity *entity);
876 * media_devnode_create() - creates and initializes a device node interface
878 * @mdev: pointer to struct &media_device
879 * @type: type of the interface, as given by MEDIA_INTF_T_* macros
880 * as defined in the uapi/media/media.h header.
881 * @flags: Interface flags as defined in uapi/media/media.h.
882 * @major: Device node major number.
883 * @minor: Device node minor number.
885 * Return: if succeeded, returns a pointer to the newly allocated
886 * &media_intf_devnode pointer.
888 struct media_intf_devnode *
889 __must_check media_devnode_create(struct media_device *mdev,
891 u32 major, u32 minor);
893 * media_devnode_remove() - removes a device node interface
895 * @devnode: pointer to &media_intf_devnode to be freed.
897 * When a device node interface is removed, all links to it are automatically
900 void media_devnode_remove(struct media_intf_devnode *devnode);
904 * media_create_intf_link() - creates a link between an entity and an interface
906 * @entity: pointer to %media_entity
907 * @intf: pointer to %media_interface
908 * @flags: Link flags, as defined in include/uapi/linux/media.h.
911 * Valid values for flags:
912 * The %MEDIA_LNK_FL_ENABLED flag indicates that the interface is connected to
913 * the entity hardware. That's the default value for interfaces. An
914 * interface may be disabled if the hardware is busy due to the usage
915 * of some other interface that it is currently controlling the hardware.
916 * A typical example is an hybrid TV device that handle only one type of
917 * stream on a given time. So, when the digital TV is streaming,
918 * the V4L2 interfaces won't be enabled, as such device is not able to
919 * also stream analog TV or radio.
923 * Before calling this function, media_devnode_create() should be called for
924 * the interface and media_device_register_entity() should be called for the
925 * interface that will be part of the link.
927 __must_check media_create_intf_link(struct media_entity *entity,
928 struct media_interface *intf,
931 * __media_remove_intf_link() - remove a single interface link
933 * @link: pointer to &media_link.
935 * Note: this is an unlocked version of media_remove_intf_link()
937 void __media_remove_intf_link(struct media_link *link);
940 * media_remove_intf_link() - remove a single interface link
942 * @link: pointer to &media_link.
944 * Note: prefer to use this one, instead of __media_remove_intf_link()
946 void media_remove_intf_link(struct media_link *link);
949 * __media_remove_intf_links() - remove all links associated with an interface
951 * @intf: pointer to &media_interface
953 * Note: this is an unlocked version of media_remove_intf_links().
955 void __media_remove_intf_links(struct media_interface *intf);
958 * media_remove_intf_links() - remove all links associated with an interface
960 * @intf: pointer to &media_interface
964 * this is called automatically when an entity is unregistered via
965 * media_device_register_entity() and by media_devnode_remove().
967 * Prefer to use this one, instead of __media_remove_intf_links().
969 void media_remove_intf_links(struct media_interface *intf);
971 #define media_entity_call(entity, operation, args...) \
972 (((entity)->ops && (entity)->ops->operation) ? \
973 (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)