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_ID (32 - MEDIA_BITS_PER_TYPE)
51 #define MEDIA_ID_MASK GENMASK_ULL(MEDIA_BITS_PER_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_ID to store the ID
63 * @list: List entry stored in one of the per-type mdev object lists
65 * All objects on the media graph should have this struct embedded
68 struct media_device
*mdev
;
70 struct list_head list
;
73 #define MEDIA_ENTITY_ENUM_MAX_DEPTH 16
76 * struct media_entity_enum - An enumeration of media entities.
78 * @bmap: Bit map in which each bit represents one entity at struct
79 * media_entity->internal_idx.
80 * @idx_max: Number of bits in bmap
82 struct media_entity_enum
{
88 * struct media_entity_graph - Media graph traversal state
90 * @stack: Graph traversal stack; the stack contains information
91 * on the path the media entities to be walked and the
92 * links through which they were reached.
93 * @ent_enum: Visited entities
94 * @top: The top of the stack
96 struct media_entity_graph
{
98 struct media_entity
*entity
;
99 struct list_head
*link
;
100 } stack
[MEDIA_ENTITY_ENUM_MAX_DEPTH
];
102 struct media_entity_enum ent_enum
;
107 * struct media_pipeline - Media pipeline related information
109 * @streaming_count: Streaming start count - streaming stop count
110 * @graph: Media graph walk during pipeline start / stop
112 struct media_pipeline
{
114 struct media_entity_graph graph
;
118 * struct media_link - A link object part of a media graph.
120 * @graph_obj: Embedded structure containing the media object common data
121 * @list: Linked list associated with an entity or an interface that
123 * @gobj0: Part of a union. Used to get the pointer for the first
124 * graph_object of the link.
125 * @source: Part of a union. Used only if the first object (gobj0) is
126 * a pad. In that case, it represents the source pad.
127 * @intf: Part of a union. Used only if the first object (gobj0) is
129 * @gobj1: Part of a union. Used to get the pointer for the second
130 * graph_object of the link.
131 * @source: Part of a union. Used only if the second object (gobj1) is
132 * a pad. In that case, it represents the sink pad.
133 * @entity: Part of a union. Used only if the second object (gobj1) is
135 * @reverse: Pointer to the link for the reverse direction of a pad to pad
137 * @flags: Link flags, as defined in uapi/media.h (MEDIA_LNK_FL_*)
138 * @is_backlink: Indicate if the link is a backlink.
141 struct media_gobj graph_obj
;
142 struct list_head list
;
144 struct media_gobj
*gobj0
;
145 struct media_pad
*source
;
146 struct media_interface
*intf
;
149 struct media_gobj
*gobj1
;
150 struct media_pad
*sink
;
151 struct media_entity
*entity
;
153 struct media_link
*reverse
;
159 * struct media_pad - A media pad graph object.
161 * @graph_obj: Embedded structure containing the media object common data
162 * @entity: Entity this pad belongs to
163 * @index: Pad index in the entity pads array, numbered from 0 to n
164 * @flags: Pad flags, as defined in uapi/media.h (MEDIA_PAD_FL_*)
167 struct media_gobj graph_obj
; /* must be first field in struct */
168 struct media_entity
*entity
;
174 * struct media_entity_operations - Media entity operations
175 * @link_setup: Notify the entity of link changes. The operation can
176 * return an error, in which case link setup will be
177 * cancelled. Optional.
178 * @link_validate: Return whether a link is valid from the entity point of
179 * view. The media_entity_pipeline_start() function
180 * validates all links by calling this operation. Optional.
182 struct media_entity_operations
{
183 int (*link_setup
)(struct media_entity
*entity
,
184 const struct media_pad
*local
,
185 const struct media_pad
*remote
, u32 flags
);
186 int (*link_validate
)(struct media_link
*link
);
190 * struct media_entity - A media entity graph object.
192 * @graph_obj: Embedded structure containing the media object common data.
193 * @name: Entity name.
194 * @function: Entity main function, as defined in uapi/media.h
196 * @flags: Entity flags, as defined in uapi/media.h (MEDIA_ENT_FL_*)
197 * @num_pads: Number of sink and source pads.
198 * @num_links: Total number of links, forward and back, enabled and disabled.
199 * @num_backlinks: Number of backlinks
200 * @internal_idx: An unique internal entity specific number. The numbers are
201 * re-used if entities are unregistered or registered again.
202 * @pads: Pads array with the size defined by @num_pads.
203 * @links: List of data links.
204 * @ops: Entity operations.
205 * @stream_count: Stream count for the entity.
206 * @use_count: Use count for the entity.
207 * @pipe: Pipeline this entity belongs to.
208 * @info: Union with devnode information. Kept just for backward
210 * @major: Devnode major number (zero if not applicable). Kept just
211 * for backward compatibility.
212 * @minor: Devnode minor number (zero if not applicable). Kept just
213 * for backward compatibility.
215 * NOTE: @stream_count and @use_count reference counts must never be
216 * negative, but are signed integers on purpose: a simple WARN_ON(<0) check
217 * can be used to detect reference count bugs that would make them negative.
219 struct media_entity
{
220 struct media_gobj graph_obj
; /* must be first field in struct */
230 struct media_pad
*pads
;
231 struct list_head links
;
233 const struct media_entity_operations
*ops
;
235 /* Reference counts must never be negative, but are signed integers on
236 * purpose: a simple WARN_ON(<0) check can be used to detect reference
237 * count bugs that would make them negative.
242 struct media_pipeline
*pipe
;
253 * struct media_interface - A media interface graph object.
255 * @graph_obj: embedded graph object
256 * @links: List of links pointing to graph entities
257 * @type: Type of the interface as defined in the
258 * uapi/media/media.h header, e. g.
260 * @flags: Interface flags as defined in uapi/media/media.h
262 struct media_interface
{
263 struct media_gobj graph_obj
;
264 struct list_head links
;
270 * struct media_intf_devnode - A media interface via a device node.
272 * @intf: embedded interface object
273 * @major: Major number of a device node
274 * @minor: Minor number of a device node
276 struct media_intf_devnode
{
277 struct media_interface intf
;
279 /* Should match the fields at media_v2_intf_devnode */
285 * media_entity_id() - return the media entity graph object id
287 * @entity: pointer to entity
289 static inline u32
media_entity_id(struct media_entity
*entity
)
291 return entity
->graph_obj
.id
;
295 * media_type() - return the media object type
297 * @gobj: pointer to the media graph object
299 static inline enum media_gobj_type
media_type(struct media_gobj
*gobj
)
301 return gobj
->id
>> MEDIA_BITS_PER_ID
;
305 * media_id() - return the media object ID
307 * @gobj: pointer to the media graph object
309 static inline u32
media_id(struct media_gobj
*gobj
)
311 return gobj
->id
& MEDIA_ID_MASK
;
315 * media_gobj_gen_id() - encapsulates type and ID on at the object ID
317 * @type: object type as define at enum &media_gobj_type.
318 * @local_id: next ID, from struct &media_device.@id.
320 static inline u32
media_gobj_gen_id(enum media_gobj_type type
, u64 local_id
)
324 id
= type
<< MEDIA_BITS_PER_ID
;
325 id
|= local_id
& MEDIA_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
:
384 * __media_entity_enum_init - Initialise an entity enumeration
386 * @ent_enum: Entity enumeration to be initialised
387 * @idx_max: Maximum number of entities in the enumeration
389 * Return: Returns zero on success or a negative error code.
391 __must_check
int __media_entity_enum_init(struct media_entity_enum
*ent_enum
,
395 * media_entity_enum_cleanup - Release resources of an entity enumeration
397 * @ent_enum: Entity enumeration to be released
399 void media_entity_enum_cleanup(struct media_entity_enum
*ent_enum
);
402 * media_entity_enum_zero - Clear the entire enum
404 * @ent_enum: Entity enumeration to be cleared
406 static inline void media_entity_enum_zero(struct media_entity_enum
*ent_enum
)
408 bitmap_zero(ent_enum
->bmap
, ent_enum
->idx_max
);
412 * media_entity_enum_set - Mark a single entity in the enum
414 * @ent_enum: Entity enumeration
415 * @entity: Entity to be marked
417 static inline void media_entity_enum_set(struct media_entity_enum
*ent_enum
,
418 struct media_entity
*entity
)
420 if (WARN_ON(entity
->internal_idx
>= ent_enum
->idx_max
))
423 __set_bit(entity
->internal_idx
, ent_enum
->bmap
);
427 * media_entity_enum_clear - Unmark a single entity in the enum
429 * @ent_enum: Entity enumeration
430 * @entity: Entity to be unmarked
432 static inline void media_entity_enum_clear(struct media_entity_enum
*ent_enum
,
433 struct media_entity
*entity
)
435 if (WARN_ON(entity
->internal_idx
>= ent_enum
->idx_max
))
438 __clear_bit(entity
->internal_idx
, ent_enum
->bmap
);
442 * media_entity_enum_test - Test whether the entity is marked
444 * @ent_enum: Entity enumeration
445 * @entity: Entity to be tested
447 * Returns true if the entity was marked.
449 static inline bool media_entity_enum_test(struct media_entity_enum
*ent_enum
,
450 struct media_entity
*entity
)
452 if (WARN_ON(entity
->internal_idx
>= ent_enum
->idx_max
))
455 return test_bit(entity
->internal_idx
, ent_enum
->bmap
);
459 * media_entity_enum_test - Test whether the entity is marked, and mark it
461 * @ent_enum: Entity enumeration
462 * @entity: Entity to be tested
464 * Returns true if the entity was marked, and mark it before doing so.
467 media_entity_enum_test_and_set(struct media_entity_enum
*ent_enum
,
468 struct media_entity
*entity
)
470 if (WARN_ON(entity
->internal_idx
>= ent_enum
->idx_max
))
473 return __test_and_set_bit(entity
->internal_idx
, ent_enum
->bmap
);
477 * media_entity_enum_empty - Test whether the entire enum is empty
479 * @ent_enum: Entity enumeration
481 * Returns true if the entity was marked.
483 static inline bool media_entity_enum_empty(struct media_entity_enum
*ent_enum
)
485 return bitmap_empty(ent_enum
->bmap
, ent_enum
->idx_max
);
489 * media_entity_enum_intersects - Test whether two enums intersect
491 * @ent_enum1: First entity enumeration
492 * @ent_enum2: Second entity enumeration
494 * Returns true if entity enumerations e and f intersect, otherwise false.
496 static inline bool media_entity_enum_intersects(
497 struct media_entity_enum
*ent_enum1
,
498 struct media_entity_enum
*ent_enum2
)
500 WARN_ON(ent_enum1
->idx_max
!= ent_enum2
->idx_max
);
502 return bitmap_intersects(ent_enum1
->bmap
, ent_enum2
->bmap
,
503 min(ent_enum1
->idx_max
, ent_enum2
->idx_max
));
506 #define gobj_to_entity(gobj) \
507 container_of(gobj, struct media_entity, graph_obj)
509 #define gobj_to_pad(gobj) \
510 container_of(gobj, struct media_pad, graph_obj)
512 #define gobj_to_link(gobj) \
513 container_of(gobj, struct media_link, graph_obj)
515 #define gobj_to_link(gobj) \
516 container_of(gobj, struct media_link, graph_obj)
518 #define gobj_to_pad(gobj) \
519 container_of(gobj, struct media_pad, graph_obj)
521 #define gobj_to_intf(gobj) \
522 container_of(gobj, struct media_interface, graph_obj)
524 #define intf_to_devnode(intf) \
525 container_of(intf, struct media_intf_devnode, intf)
528 * media_gobj_create - Initialize a graph object
530 * @mdev: Pointer to the media_device that contains the object
531 * @type: Type of the object
532 * @gobj: Pointer to the graph object
534 * This routine initializes the embedded struct media_gobj inside a
535 * media graph object. It is called automatically if media_*_create()
536 * calls are used. However, if the object (entity, link, pad, interface)
537 * is embedded on some other object, this function should be called before
538 * registering the object at the media controller.
540 void media_gobj_create(struct media_device
*mdev
,
541 enum media_gobj_type type
,
542 struct media_gobj
*gobj
);
545 * media_gobj_destroy - Stop using a graph object on a media device
547 * @gobj: Pointer to the graph object
549 * This should be called by all routines like media_device_unregister()
550 * that remove/destroy media graph objects.
552 void media_gobj_destroy(struct media_gobj
*gobj
);
555 * media_entity_pads_init() - Initialize the entity pads
557 * @entity: entity where the pads belong
558 * @num_pads: total number of sink and source pads
559 * @pads: Array of @num_pads pads.
561 * The pads array is managed by the entity driver and passed to
562 * media_entity_pads_init() where its pointer will be stored in the entity
565 * If no pads are needed, drivers could either directly fill
566 * &media_entity->@num_pads with 0 and &media_entity->@pads with NULL or call
567 * this function that will do the same.
569 * As the number of pads is known in advance, the pads array is not allocated
570 * dynamically but is managed by the entity driver. Most drivers will embed the
571 * pads array in a driver-specific structure, avoiding dynamic allocation.
573 * Drivers must set the direction of every pad in the pads array before calling
574 * media_entity_pads_init(). The function will initialize the other pads fields.
576 int media_entity_pads_init(struct media_entity
*entity
, u16 num_pads
,
577 struct media_pad
*pads
);
580 * media_entity_cleanup() - free resources associated with an entity
582 * @entity: entity where the pads belong
584 * This function must be called during the cleanup phase after unregistering
585 * the entity (currently, it does nothing).
587 static inline void media_entity_cleanup(struct media_entity
*entity
) {};
590 * media_create_pad_link() - creates a link between two entities.
592 * @source: pointer to &media_entity of the source pad.
593 * @source_pad: number of the source pad in the pads array
594 * @sink: pointer to &media_entity of the sink pad.
595 * @sink_pad: number of the sink pad in the pads array.
596 * @flags: Link flags, as defined in include/uapi/linux/media.h.
598 * Valid values for flags:
599 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be
600 * used to transfer media data. When two or more links target a sink pad,
601 * only one of them can be enabled at a time.
603 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't
604 * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then
605 * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is
610 * Before calling this function, media_entity_pads_init() and
611 * media_device_register_entity() should be called previously for both ends.
613 __must_check
int media_create_pad_link(struct media_entity
*source
,
614 u16 source_pad
, struct media_entity
*sink
,
615 u16 sink_pad
, u32 flags
);
618 * media_create_pad_links() - creates a link between two entities.
620 * @mdev: Pointer to the media_device that contains the object
621 * @source_function: Function of the source entities. Used only if @source is
623 * @source: pointer to &media_entity of the source pad. If NULL, it will use
624 * all entities that matches the @sink_function.
625 * @source_pad: number of the source pad in the pads array
626 * @sink_function: Function of the sink entities. Used only if @sink is NULL.
627 * @sink: pointer to &media_entity of the sink pad. If NULL, it will use
628 * all entities that matches the @sink_function.
629 * @sink_pad: number of the sink pad in the pads array.
630 * @flags: Link flags, as defined in include/uapi/linux/media.h.
631 * @allow_both_undefined: if true, then both @source and @sink can be NULL.
632 * In such case, it will create a crossbar between all entities that
633 * matches @source_function to all entities that matches @sink_function.
634 * If false, it will return 0 and won't create any link if both @source
635 * and @sink are NULL.
637 * Valid values for flags:
638 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be
639 * used to transfer media data. If multiple links are created and this
640 * flag is passed as an argument, only the first created link will have
643 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't
644 * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then
645 * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is
648 * It is common for some devices to have multiple source and/or sink entities
649 * of the same type that should be linked. While media_create_pad_link()
650 * creates link by link, this function is meant to allow 1:n, n:1 and even
651 * cross-bar (n:n) links.
653 * NOTE: Before calling this function, media_entity_pads_init() and
654 * media_device_register_entity() should be called previously for the entities
657 int media_create_pad_links(const struct media_device
*mdev
,
658 const u32 source_function
,
659 struct media_entity
*source
,
660 const u16 source_pad
,
661 const u32 sink_function
,
662 struct media_entity
*sink
,
665 const bool allow_both_undefined
);
667 void __media_entity_remove_links(struct media_entity
*entity
);
670 * media_entity_remove_links() - remove all links associated with an entity
672 * @entity: pointer to &media_entity
674 * Note: this is called automatically when an entity is unregistered via
675 * media_device_register_entity().
677 void media_entity_remove_links(struct media_entity
*entity
);
680 * __media_entity_setup_link - Configure a media link without locking
681 * @link: The link being configured
682 * @flags: Link configuration flags
684 * The bulk of link setup is handled by the two entities connected through the
685 * link. This function notifies both entities of the link configuration change.
687 * If the link is immutable or if the current and new configuration are
688 * identical, return immediately.
690 * The user is expected to hold link->source->parent->mutex. If not,
691 * media_entity_setup_link() should be used instead.
693 int __media_entity_setup_link(struct media_link
*link
, u32 flags
);
696 * media_entity_setup_link() - changes the link flags properties in runtime
698 * @link: pointer to &media_link
699 * @flags: the requested new link flags
701 * The only configurable property is the %MEDIA_LNK_FL_ENABLED link flag
702 * flag to enable/disable a link. Links marked with the
703 * %MEDIA_LNK_FL_IMMUTABLE link flag can not be enabled or disabled.
705 * When a link is enabled or disabled, the media framework calls the
706 * link_setup operation for the two entities at the source and sink of the
707 * link, in that order. If the second link_setup call fails, another
708 * link_setup call is made on the first entity to restore the original link
711 * Media device drivers can be notified of link setup operations by setting the
712 * media_device::link_notify pointer to a callback function. If provided, the
713 * notification callback will be called before enabling and after disabling
716 * Entity drivers must implement the link_setup operation if any of their links
717 * is non-immutable. The operation must either configure the hardware or store
718 * the configuration information to be applied later.
720 * Link configuration must not have any side effect on other links. If an
721 * enabled link at a sink pad prevents another link at the same pad from
722 * being enabled, the link_setup operation must return -EBUSY and can't
723 * implicitly disable the first enabled link.
725 * NOTE: the valid values of the flags for the link is the same as described
726 * on media_create_pad_link(), for pad to pad links or the same as described
727 * on media_create_intf_link(), for interface to entity links.
729 int media_entity_setup_link(struct media_link
*link
, u32 flags
);
732 * media_entity_find_link - Find a link between two pads
733 * @source: Source pad
736 * Return a pointer to the link between the two entities. If no such link
737 * exists, return NULL.
739 struct media_link
*media_entity_find_link(struct media_pad
*source
,
740 struct media_pad
*sink
);
743 * media_entity_remote_pad - Find the pad at the remote end of a link
744 * @pad: Pad at the local end of the link
746 * Search for a remote pad connected to the given pad by iterating over all
747 * links originating or terminating at that pad until an enabled link is found.
749 * Return a pointer to the pad at the remote end of the first found enabled
750 * link, or NULL if no enabled link has been found.
752 struct media_pad
*media_entity_remote_pad(struct media_pad
*pad
);
755 * media_entity_get - Get a reference to the parent module
757 * @entity: The entity
759 * Get a reference to the parent media device module.
761 * The function will return immediately if @entity is NULL.
763 * Return a pointer to the entity on success or NULL on failure.
765 struct media_entity
*media_entity_get(struct media_entity
*entity
);
767 __must_check
int media_entity_graph_walk_init(
768 struct media_entity_graph
*graph
, struct media_device
*mdev
);
771 * media_entity_graph_walk_cleanup - Release resources used by graph walk.
773 * @graph: Media graph structure that will be used to walk the graph
775 void media_entity_graph_walk_cleanup(struct media_entity_graph
*graph
);
778 * media_entity_put - Release the reference to the parent module
780 * @entity: The entity
782 * Release the reference count acquired by media_entity_get().
784 * The function will return immediately if @entity is NULL.
786 void media_entity_put(struct media_entity
*entity
);
789 * media_entity_graph_walk_start - Start walking the media graph at a given entity
790 * @graph: Media graph structure that will be used to walk the graph
791 * @entity: Starting entity
793 * Before using this function, media_entity_graph_walk_init() must be
794 * used to allocate resources used for walking the graph. This
795 * function initializes the graph traversal structure to walk the
796 * entities graph starting at the given entity. The traversal
797 * structure must not be modified by the caller during graph
798 * traversal. After the graph walk, the resources must be released
799 * using media_entity_graph_walk_cleanup().
801 void media_entity_graph_walk_start(struct media_entity_graph
*graph
,
802 struct media_entity
*entity
);
805 * media_entity_graph_walk_next - Get the next entity in the graph
806 * @graph: Media graph structure
808 * Perform a depth-first traversal of the given media entities graph.
810 * The graph structure must have been previously initialized with a call to
811 * media_entity_graph_walk_start().
813 * Return the next entity in the graph or NULL if the whole graph have been
816 struct media_entity
*
817 media_entity_graph_walk_next(struct media_entity_graph
*graph
);
820 * media_entity_pipeline_start - Mark a pipeline as streaming
821 * @entity: Starting entity
822 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
824 * Mark all entities connected to a given entity through enabled links, either
825 * directly or indirectly, as streaming. The given pipeline object is assigned to
826 * every entity in the pipeline and stored in the media_entity pipe field.
828 * Calls to this function can be nested, in which case the same number of
829 * media_entity_pipeline_stop() calls will be required to stop streaming. The
830 * pipeline pointer must be identical for all nested calls to
831 * media_entity_pipeline_start().
833 __must_check
int media_entity_pipeline_start(struct media_entity
*entity
,
834 struct media_pipeline
*pipe
);
837 * media_entity_pipeline_stop - Mark a pipeline as not streaming
838 * @entity: Starting entity
840 * Mark all entities connected to a given entity through enabled links, either
841 * directly or indirectly, as not streaming. The media_entity pipe field is
844 * If multiple calls to media_entity_pipeline_start() have been made, the same
845 * number of calls to this function are required to mark the pipeline as not
848 void media_entity_pipeline_stop(struct media_entity
*entity
);
851 * media_devnode_create() - creates and initializes a device node interface
853 * @mdev: pointer to struct &media_device
854 * @type: type of the interface, as given by MEDIA_INTF_T_* macros
855 * as defined in the uapi/media/media.h header.
856 * @flags: Interface flags as defined in uapi/media/media.h.
857 * @major: Device node major number.
858 * @minor: Device node minor number.
860 * Return: if succeeded, returns a pointer to the newly allocated
861 * &media_intf_devnode pointer.
863 struct media_intf_devnode
*
864 __must_check
media_devnode_create(struct media_device
*mdev
,
866 u32 major
, u32 minor
);
868 * media_devnode_remove() - removes a device node interface
870 * @devnode: pointer to &media_intf_devnode to be freed.
872 * When a device node interface is removed, all links to it are automatically
875 void media_devnode_remove(struct media_intf_devnode
*devnode
);
879 * media_create_intf_link() - creates a link between an entity and an interface
881 * @entity: pointer to %media_entity
882 * @intf: pointer to %media_interface
883 * @flags: Link flags, as defined in include/uapi/linux/media.h.
886 * Valid values for flags:
887 * The %MEDIA_LNK_FL_ENABLED flag indicates that the interface is connected to
888 * the entity hardware. That's the default value for interfaces. An
889 * interface may be disabled if the hardware is busy due to the usage
890 * of some other interface that it is currently controlling the hardware.
891 * A typical example is an hybrid TV device that handle only one type of
892 * stream on a given time. So, when the digital TV is streaming,
893 * the V4L2 interfaces won't be enabled, as such device is not able to
894 * also stream analog TV or radio.
898 * Before calling this function, media_devnode_create() should be called for
899 * the interface and media_device_register_entity() should be called for the
900 * interface that will be part of the link.
902 __must_check
media_create_intf_link(struct media_entity
*entity
,
903 struct media_interface
*intf
,
906 * __media_remove_intf_link() - remove a single interface link
908 * @link: pointer to &media_link.
910 * Note: this is an unlocked version of media_remove_intf_link()
912 void __media_remove_intf_link(struct media_link
*link
);
915 * media_remove_intf_link() - remove a single interface link
917 * @link: pointer to &media_link.
919 * Note: prefer to use this one, instead of __media_remove_intf_link()
921 void media_remove_intf_link(struct media_link
*link
);
924 * __media_remove_intf_links() - remove all links associated with an interface
926 * @intf: pointer to &media_interface
928 * Note: this is an unlocked version of media_remove_intf_links().
930 void __media_remove_intf_links(struct media_interface
*intf
);
933 * media_remove_intf_links() - remove all links associated with an interface
935 * @intf: pointer to &media_interface
939 * this is called automatically when an entity is unregistered via
940 * media_device_register_entity() and by media_devnode_remove().
942 * Prefer to use this one, instead of __media_remove_intf_links().
944 void media_remove_intf_links(struct media_interface
*intf
);
946 #define media_entity_call(entity, operation, args...) \
947 (((entity)->ops && (entity)->ops->operation) ? \
948 (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)