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/kernel.h>
28 #include <linux/list.h>
29 #include <linux/media.h>
31 /* Enums used internally at the media controller to represent graphs */
34 * enum media_gobj_type - type of a graph object
36 * @MEDIA_GRAPH_ENTITY: Identify a media entity
37 * @MEDIA_GRAPH_PAD: Identify a media pad
38 * @MEDIA_GRAPH_LINK: Identify a media link
39 * @MEDIA_GRAPH_INTF_DEVNODE: Identify a media Kernel API interface via
42 enum media_gobj_type {
46 MEDIA_GRAPH_INTF_DEVNODE,
49 #define MEDIA_BITS_PER_TYPE 8
50 #define MEDIA_BITS_PER_LOCAL_ID (32 - MEDIA_BITS_PER_TYPE)
51 #define MEDIA_LOCAL_ID_MASK GENMASK(MEDIA_BITS_PER_LOCAL_ID - 1, 0)
53 /* Structs to represent the objects that belong to a media graph */
56 * struct media_gobj - Define a graph object.
58 * @mdev: Pointer to the struct media_device that owns the object
59 * @id: Non-zero object ID identifier. The ID should be unique
60 * inside a media_device, as it is composed by
61 * MEDIA_BITS_PER_TYPE to store the type plus
62 * MEDIA_BITS_PER_LOCAL_ID to store a per-type ID
63 * (called as "local 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
75 #define MEDIA_ENTITY_ENUM_MAX_ID 64
78 * The number of pads can't be bigger than the number of entities,
79 * as the worse-case scenario is to have one entity linked up to
80 * MEDIA_ENTITY_ENUM_MAX_ID - 1 entities.
82 #define MEDIA_ENTITY_MAX_PADS (MEDIA_ENTITY_ENUM_MAX_ID - 1)
85 * struct media_entity_enum - An enumeration of media entities.
87 * @prealloc_bmap: Pre-allocated space reserved for media entities if the
88 * total number of entities does not exceed
89 * MEDIA_ENTITY_ENUM_MAX_ID.
90 * @bmap: Bit map in which each bit represents one entity at struct
91 * media_entity->internal_idx.
92 * @idx_max: Number of bits in bmap
94 struct media_entity_enum {
95 DECLARE_BITMAP(prealloc_bmap, MEDIA_ENTITY_ENUM_MAX_ID);
101 * struct media_entity_graph - Media graph traversal state
103 * @stack: Graph traversal stack; the stack contains information
104 * on the path the media entities to be walked and the
105 * links through which they were reached.
106 * @ent_enum: Visited entities
107 * @top: The top of the stack
109 struct media_entity_graph {
111 struct media_entity *entity;
112 struct list_head *link;
113 } stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
115 struct media_entity_enum ent_enum;
120 * struct media_pipeline - Media pipeline related information
122 * @graph: Media graph walk during pipeline start / stop
124 struct media_pipeline {
125 struct media_entity_graph graph;
129 * struct media_link - A link object part of a media graph.
131 * @graph_obj: Embedded structure containing the media object common data
132 * @list: Linked list associated with an entity or an interface that
134 * @gobj0: Part of a union. Used to get the pointer for the first
135 * graph_object of the link.
136 * @source: Part of a union. Used only if the first object (gobj0) is
137 * a pad. In that case, it represents the source pad.
138 * @intf: Part of a union. Used only if the first object (gobj0) is
140 * @gobj1: Part of a union. Used to get the pointer for the second
141 * graph_object of the link.
142 * @source: Part of a union. Used only if the second object (gobj1) is
143 * a pad. In that case, it represents the sink pad.
144 * @entity: Part of a union. Used only if the second object (gobj1) is
146 * @reverse: Pointer to the link for the reverse direction of a pad to pad
148 * @flags: Link flags, as defined in uapi/media.h (MEDIA_LNK_FL_*)
149 * @is_backlink: Indicate if the link is a backlink.
152 struct media_gobj graph_obj;
153 struct list_head list;
155 struct media_gobj *gobj0;
156 struct media_pad *source;
157 struct media_interface *intf;
160 struct media_gobj *gobj1;
161 struct media_pad *sink;
162 struct media_entity *entity;
164 struct media_link *reverse;
170 * struct media_pad - A media pad graph object.
172 * @graph_obj: Embedded structure containing the media object common data
173 * @entity: Entity this pad belongs to
174 * @index: Pad index in the entity pads array, numbered from 0 to n
175 * @flags: Pad flags, as defined in uapi/media.h (MEDIA_PAD_FL_*)
178 struct media_gobj graph_obj; /* must be first field in struct */
179 struct media_entity *entity;
185 * struct media_entity_operations - Media entity operations
186 * @link_setup: Notify the entity of link changes. The operation can
187 * return an error, in which case link setup will be
188 * cancelled. Optional.
189 * @link_validate: Return whether a link is valid from the entity point of
190 * view. The media_entity_pipeline_start() function
191 * validates all links by calling this operation. Optional.
193 struct media_entity_operations {
194 int (*link_setup)(struct media_entity *entity,
195 const struct media_pad *local,
196 const struct media_pad *remote, u32 flags);
197 int (*link_validate)(struct media_link *link);
201 * struct media_entity - A media entity graph object.
203 * @graph_obj: Embedded structure containing the media object common data.
204 * @name: Entity name.
205 * @function: Entity main function, as defined in uapi/media.h
207 * @flags: Entity flags, as defined in uapi/media.h (MEDIA_ENT_FL_*)
208 * @num_pads: Number of sink and source pads.
209 * @num_links: Total number of links, forward and back, enabled and disabled.
210 * @num_backlinks: Number of backlinks
211 * @internal_idx: An unique internal entity specific number. The numbers are
212 * re-used if entities are unregistered or registered again.
213 * @pads: Pads array with the size defined by @num_pads.
214 * @links: List of data links.
215 * @ops: Entity operations.
216 * @stream_count: Stream count for the entity.
217 * @use_count: Use count for the entity.
218 * @pipe: Pipeline this entity belongs to.
219 * @info: Union with devnode information. Kept just for backward
221 * @major: Devnode major number (zero if not applicable). Kept just
222 * for backward compatibility.
223 * @minor: Devnode minor number (zero if not applicable). Kept just
224 * for backward compatibility.
226 * NOTE: @stream_count and @use_count reference counts must never be
227 * negative, but are signed integers on purpose: a simple WARN_ON(<0) check
228 * can be used to detect reference count bugs that would make them negative.
230 struct media_entity {
231 struct media_gobj graph_obj; /* must be first field in struct */
241 struct media_pad *pads;
242 struct list_head links;
244 const struct media_entity_operations *ops;
246 /* Reference counts must never be negative, but are signed integers on
247 * purpose: a simple WARN_ON(<0) check can be used to detect reference
248 * count bugs that would make them negative.
253 struct media_pipeline *pipe;
264 * struct media_interface - A media interface graph object.
266 * @graph_obj: embedded graph object
267 * @links: List of links pointing to graph entities
268 * @type: Type of the interface as defined in the
269 * uapi/media/media.h header, e. g.
271 * @flags: Interface flags as defined in uapi/media/media.h
273 struct media_interface {
274 struct media_gobj graph_obj;
275 struct list_head links;
281 * struct media_intf_devnode - A media interface via a device node.
283 * @intf: embedded interface object
284 * @major: Major number of a device node
285 * @minor: Minor number of a device node
287 struct media_intf_devnode {
288 struct media_interface intf;
290 /* Should match the fields at media_v2_intf_devnode */
296 * media_entity_id() - return the media entity graph object id
298 * @entity: pointer to entity
300 static inline u32 media_entity_id(struct media_entity *entity)
302 return entity->graph_obj.id;
306 * media_type() - return the media object type
308 * @gobj: pointer to the media graph object
310 static inline enum media_gobj_type media_type(struct media_gobj *gobj)
312 return gobj->id >> MEDIA_BITS_PER_LOCAL_ID;
315 static inline u32 media_localid(struct media_gobj *gobj)
317 return gobj->id & MEDIA_LOCAL_ID_MASK;
320 static inline u32 media_gobj_gen_id(enum media_gobj_type type, u32 local_id)
324 id = type << MEDIA_BITS_PER_LOCAL_ID;
325 id |= local_id & MEDIA_LOCAL_ID_MASK;
331 * is_media_entity_v4l2_io() - identify if the entity main function
334 * @entity: pointer to entity
336 * Return: true if the entity main function is one of the V4L2 I/O types
337 * (video, VBI or SDR radio); false otherwise.
339 static inline bool is_media_entity_v4l2_io(struct media_entity *entity)
344 switch (entity->function) {
345 case MEDIA_ENT_F_IO_V4L:
346 case MEDIA_ENT_F_IO_VBI:
347 case MEDIA_ENT_F_IO_SWRADIO:
355 * is_media_entity_v4l2_subdev - return true if the entity main function is
356 * associated with the V4L2 API subdev usage
358 * @entity: pointer to entity
360 * This is an ancillary function used by subdev-based V4L2 drivers.
361 * It checks if the entity function is one of functions used by a V4L2 subdev,
362 * e. g. camera-relatef functions, analog TV decoder, TV tuner, V4L2 DSPs.
364 static inline bool is_media_entity_v4l2_subdev(struct media_entity *entity)
369 switch (entity->function) {
370 case MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN:
371 case MEDIA_ENT_F_CAM_SENSOR:
372 case MEDIA_ENT_F_FLASH:
373 case MEDIA_ENT_F_LENS:
374 case MEDIA_ENT_F_ATV_DECODER:
375 case MEDIA_ENT_F_TUNER:
383 __must_check int __media_entity_enum_init(struct media_entity_enum *ent_enum,
385 void media_entity_enum_cleanup(struct media_entity_enum *e);
388 * media_entity_enum_zero - Clear the entire enum
390 * @e: Entity enumeration to be cleared
392 static inline void media_entity_enum_zero(struct media_entity_enum *ent_enum)
394 bitmap_zero(ent_enum->bmap, ent_enum->idx_max);
398 * media_entity_enum_set - Mark a single entity in the enum
400 * @e: Entity enumeration
401 * @entity: Entity to be marked
403 static inline void media_entity_enum_set(struct media_entity_enum *ent_enum,
404 struct media_entity *entity)
406 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
409 __set_bit(entity->internal_idx, ent_enum->bmap);
413 * media_entity_enum_clear - Unmark a single entity in the enum
415 * @e: Entity enumeration
416 * @entity: Entity to be unmarked
418 static inline void media_entity_enum_clear(struct media_entity_enum *ent_enum,
419 struct media_entity *entity)
421 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
424 __clear_bit(entity->internal_idx, ent_enum->bmap);
428 * media_entity_enum_test - Test whether the entity is marked
430 * @e: Entity enumeration
431 * @entity: Entity to be tested
433 * Returns true if the entity was marked.
435 static inline bool media_entity_enum_test(struct media_entity_enum *ent_enum,
436 struct media_entity *entity)
438 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
441 return test_bit(entity->internal_idx, ent_enum->bmap);
445 * media_entity_enum_test - Test whether the entity is marked, and mark it
447 * @e: Entity enumeration
448 * @entity: Entity to be tested
450 * Returns true if the entity was marked, and mark it before doing so.
452 static inline bool media_entity_enum_test_and_set(
453 struct media_entity_enum *ent_enum, struct media_entity *entity)
455 if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
458 return __test_and_set_bit(entity->internal_idx, ent_enum->bmap);
462 * media_entity_enum_test - Test whether the entire enum is empty
464 * @e: Entity enumeration
465 * @entity: Entity to be tested
467 * Returns true if the entity was marked.
469 static inline bool media_entity_enum_empty(struct media_entity_enum *ent_enum)
471 return bitmap_empty(ent_enum->bmap, ent_enum->idx_max);
475 * media_entity_enum_intersects - Test whether two enums intersect
477 * @e: First entity enumeration
478 * @f: Second entity enumeration
480 * Returns true if entity enumerations e and f intersect, otherwise false.
482 static inline bool media_entity_enum_intersects(
483 struct media_entity_enum *ent_enum1,
484 struct media_entity_enum *ent_enum2)
486 WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max);
488 return bitmap_intersects(ent_enum1->bmap, ent_enum2->bmap,
489 min(ent_enum1->idx_max, ent_enum2->idx_max));
492 #define gobj_to_entity(gobj) \
493 container_of(gobj, struct media_entity, graph_obj)
495 #define gobj_to_pad(gobj) \
496 container_of(gobj, struct media_pad, graph_obj)
498 #define gobj_to_link(gobj) \
499 container_of(gobj, struct media_link, graph_obj)
501 #define gobj_to_link(gobj) \
502 container_of(gobj, struct media_link, graph_obj)
504 #define gobj_to_pad(gobj) \
505 container_of(gobj, struct media_pad, graph_obj)
507 #define gobj_to_intf(gobj) \
508 container_of(gobj, struct media_interface, graph_obj)
510 #define intf_to_devnode(intf) \
511 container_of(intf, struct media_intf_devnode, intf)
514 * media_gobj_create - Initialize a graph object
516 * @mdev: Pointer to the media_device that contains the object
517 * @type: Type of the object
518 * @gobj: Pointer to the graph object
520 * This routine initializes the embedded struct media_gobj inside a
521 * media graph object. It is called automatically if media_*_create()
522 * calls are used. However, if the object (entity, link, pad, interface)
523 * is embedded on some other object, this function should be called before
524 * registering the object at the media controller.
526 void media_gobj_create(struct media_device *mdev,
527 enum media_gobj_type type,
528 struct media_gobj *gobj);
531 * media_gobj_destroy - Stop using a graph object on a media device
533 * @gobj: Pointer to the graph object
535 * This should be called by all routines like media_device_unregister()
536 * that remove/destroy media graph objects.
538 void media_gobj_destroy(struct media_gobj *gobj);
541 * media_entity_pads_init() - Initialize the entity pads
543 * @entity: entity where the pads belong
544 * @num_pads: total number of sink and source pads
545 * @pads: Array of @num_pads pads.
547 * The pads array is managed by the entity driver and passed to
548 * media_entity_pads_init() where its pointer will be stored in the entity
551 * If no pads are needed, drivers could either directly fill
552 * &media_entity->@num_pads with 0 and &media_entity->@pads with NULL or call
553 * this function that will do the same.
555 * As the number of pads is known in advance, the pads array is not allocated
556 * dynamically but is managed by the entity driver. Most drivers will embed the
557 * pads array in a driver-specific structure, avoiding dynamic allocation.
559 * Drivers must set the direction of every pad in the pads array before calling
560 * media_entity_pads_init(). The function will initialize the other pads fields.
562 int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
563 struct media_pad *pads);
566 * media_entity_cleanup() - free resources associated with an entity
568 * @entity: entity where the pads belong
570 * This function must be called during the cleanup phase after unregistering
571 * the entity (currently, it does nothing).
573 static inline void media_entity_cleanup(struct media_entity *entity) {};
576 * media_create_pad_link() - creates a link between two entities.
578 * @source: pointer to &media_entity of the source pad.
579 * @source_pad: number of the source pad in the pads array
580 * @sink: pointer to &media_entity of the sink pad.
581 * @sink_pad: number of the sink pad in the pads array.
582 * @flags: Link flags, as defined in include/uapi/linux/media.h.
584 * Valid values for flags:
585 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be
586 * used to transfer media data. When two or more links target a sink pad,
587 * only one of them can be enabled at a time.
589 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't
590 * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then
591 * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is
596 * Before calling this function, media_entity_pads_init() and
597 * media_device_register_entity() should be called previously for both ends.
599 __must_check int media_create_pad_link(struct media_entity *source,
600 u16 source_pad, struct media_entity *sink,
601 u16 sink_pad, u32 flags);
602 void __media_entity_remove_links(struct media_entity *entity);
605 * media_entity_remove_links() - remove all links associated with an entity
607 * @entity: pointer to &media_entity
609 * Note: this is called automatically when an entity is unregistered via
610 * media_device_register_entity().
612 void media_entity_remove_links(struct media_entity *entity);
615 * __media_entity_setup_link - Configure a media link without locking
616 * @link: The link being configured
617 * @flags: Link configuration flags
619 * The bulk of link setup is handled by the two entities connected through the
620 * link. This function notifies both entities of the link configuration change.
622 * If the link is immutable or if the current and new configuration are
623 * identical, return immediately.
625 * The user is expected to hold link->source->parent->mutex. If not,
626 * media_entity_setup_link() should be used instead.
628 int __media_entity_setup_link(struct media_link *link, u32 flags);
631 * media_entity_setup_link() - changes the link flags properties in runtime
633 * @link: pointer to &media_link
634 * @flags: the requested new link flags
636 * The only configurable property is the %MEDIA_LNK_FL_ENABLED link flag
637 * flag to enable/disable a link. Links marked with the
638 * %MEDIA_LNK_FL_IMMUTABLE link flag can not be enabled or disabled.
640 * When a link is enabled or disabled, the media framework calls the
641 * link_setup operation for the two entities at the source and sink of the
642 * link, in that order. If the second link_setup call fails, another
643 * link_setup call is made on the first entity to restore the original link
646 * Media device drivers can be notified of link setup operations by setting the
647 * media_device::link_notify pointer to a callback function. If provided, the
648 * notification callback will be called before enabling and after disabling
651 * Entity drivers must implement the link_setup operation if any of their links
652 * is non-immutable. The operation must either configure the hardware or store
653 * the configuration information to be applied later.
655 * Link configuration must not have any side effect on other links. If an
656 * enabled link at a sink pad prevents another link at the same pad from
657 * being enabled, the link_setup operation must return -EBUSY and can't
658 * implicitly disable the first enabled link.
660 * NOTE: the valid values of the flags for the link is the same as described
661 * on media_create_pad_link(), for pad to pad links or the same as described
662 * on media_create_intf_link(), for interface to entity links.
664 int media_entity_setup_link(struct media_link *link, u32 flags);
667 * media_entity_find_link - Find a link between two pads
668 * @source: Source pad
671 * Return a pointer to the link between the two entities. If no such link
672 * exists, return NULL.
674 struct media_link *media_entity_find_link(struct media_pad *source,
675 struct media_pad *sink);
678 * media_entity_remote_pad - Find the pad at the remote end of a link
679 * @pad: Pad at the local end of the link
681 * Search for a remote pad connected to the given pad by iterating over all
682 * links originating or terminating at that pad until an enabled link is found.
684 * Return a pointer to the pad at the remote end of the first found enabled
685 * link, or NULL if no enabled link has been found.
687 struct media_pad *media_entity_remote_pad(struct media_pad *pad);
690 * media_entity_get - Get a reference to the parent module
692 * @entity: The entity
694 * Get a reference to the parent media device module.
696 * The function will return immediately if @entity is NULL.
698 * Return a pointer to the entity on success or NULL on failure.
700 struct media_entity *media_entity_get(struct media_entity *entity);
702 __must_check int media_entity_graph_walk_init(
703 struct media_entity_graph *graph, struct media_device *mdev);
704 void media_entity_graph_walk_cleanup(struct media_entity_graph *graph);
707 * media_entity_put - Release the reference to the parent module
709 * @entity: The entity
711 * Release the reference count acquired by media_entity_get().
713 * The function will return immediately if @entity is NULL.
715 void media_entity_put(struct media_entity *entity);
718 * media_entity_graph_walk_start - Start walking the media graph at a given entity
719 * @graph: Media graph structure that will be used to walk the graph
720 * @entity: Starting entity
722 * Before using this function, media_entity_graph_walk_init() must be
723 * used to allocate resources used for walking the graph. This
724 * function initializes the graph traversal structure to walk the
725 * entities graph starting at the given entity. The traversal
726 * structure must not be modified by the caller during graph
727 * traversal. After the graph walk, the resources must be released
728 * using media_entity_graph_walk_cleanup().
730 void media_entity_graph_walk_start(struct media_entity_graph *graph,
731 struct media_entity *entity);
734 * media_entity_graph_walk_next - Get the next entity in the graph
735 * @graph: Media graph structure
737 * Perform a depth-first traversal of the given media entities graph.
739 * The graph structure must have been previously initialized with a call to
740 * media_entity_graph_walk_start().
742 * Return the next entity in the graph or NULL if the whole graph have been
745 struct media_entity *
746 media_entity_graph_walk_next(struct media_entity_graph *graph);
749 * media_entity_pipeline_start - Mark a pipeline as streaming
750 * @entity: Starting entity
751 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
753 * Mark all entities connected to a given entity through enabled links, either
754 * directly or indirectly, as streaming. The given pipeline object is assigned to
755 * every entity in the pipeline and stored in the media_entity pipe field.
757 * Calls to this function can be nested, in which case the same number of
758 * media_entity_pipeline_stop() calls will be required to stop streaming. The
759 * pipeline pointer must be identical for all nested calls to
760 * media_entity_pipeline_start().
762 __must_check int media_entity_pipeline_start(struct media_entity *entity,
763 struct media_pipeline *pipe);
766 * media_entity_pipeline_stop - Mark a pipeline as not streaming
767 * @entity: Starting entity
769 * Mark all entities connected to a given entity through enabled links, either
770 * directly or indirectly, as not streaming. The media_entity pipe field is
773 * If multiple calls to media_entity_pipeline_start() have been made, the same
774 * number of calls to this function are required to mark the pipeline as not
777 void media_entity_pipeline_stop(struct media_entity *entity);
780 * media_devnode_create() - creates and initializes a device node interface
782 * @mdev: pointer to struct &media_device
783 * @type: type of the interface, as given by MEDIA_INTF_T_* macros
784 * as defined in the uapi/media/media.h header.
785 * @flags: Interface flags as defined in uapi/media/media.h.
786 * @major: Device node major number.
787 * @minor: Device node minor number.
789 * Return: if succeeded, returns a pointer to the newly allocated
790 * &media_intf_devnode pointer.
792 struct media_intf_devnode *
793 __must_check media_devnode_create(struct media_device *mdev,
795 u32 major, u32 minor);
797 * media_devnode_remove() - removes a device node interface
799 * @devnode: pointer to &media_intf_devnode to be freed.
801 * When a device node interface is removed, all links to it are automatically
804 void media_devnode_remove(struct media_intf_devnode *devnode);
808 * media_create_intf_link() - creates a link between an entity and an interface
810 * @entity: pointer to %media_entity
811 * @intf: pointer to %media_interface
812 * @flags: Link flags, as defined in include/uapi/linux/media.h.
815 * Valid values for flags:
816 * The %MEDIA_LNK_FL_ENABLED flag indicates that the interface is connected to
817 * the entity hardware. That's the default value for interfaces. An
818 * interface may be disabled if the hardware is busy due to the usage
819 * of some other interface that it is currently controlling the hardware.
820 * A typical example is an hybrid TV device that handle only one type of
821 * stream on a given time. So, when the digital TV is streaming,
822 * the V4L2 interfaces won't be enabled, as such device is not able to
823 * also stream analog TV or radio.
827 * Before calling this function, media_devnode_create() should be called for
828 * the interface and media_device_register_entity() should be called for the
829 * interface that will be part of the link.
831 __must_check media_create_intf_link(struct media_entity *entity,
832 struct media_interface *intf,
835 * __media_remove_intf_link() - remove a single interface link
837 * @link: pointer to &media_link.
839 * Note: this is an unlocked version of media_remove_intf_link()
841 void __media_remove_intf_link(struct media_link *link);
844 * media_remove_intf_link() - remove a single interface link
846 * @link: pointer to &media_link.
848 * Note: prefer to use this one, instead of __media_remove_intf_link()
850 void media_remove_intf_link(struct media_link *link);
853 * __media_remove_intf_links() - remove all links associated with an interface
855 * @intf: pointer to &media_interface
857 * Note: this is an unlocked version of media_remove_intf_links().
859 void __media_remove_intf_links(struct media_interface *intf);
861 * media_remove_intf_links() - remove all links associated with an interface
863 * @intf: pointer to &media_interface
867 * this is called automatically when an entity is unregistered via
868 * media_device_register_entity() and by media_devnode_remove().
870 * Prefer to use this one, instead of __media_remove_intf_links().
872 void media_remove_intf_links(struct media_interface *intf);
875 #define media_entity_call(entity, operation, args...) \
876 (((entity)->ops && (entity)->ops->operation) ? \
877 (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)