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/bitops.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 struct media_pipeline {
78 * struct media_link - A link object part of a media graph.
80 * @graph_obj: Embedded structure containing the media object common data
81 * @list: Linked list associated with an entity or an interface that
83 * @gobj0: Part of a union. Used to get the pointer for the first
84 * graph_object of the link.
85 * @source: Part of a union. Used only if the first object (gobj0) is
86 * a pad. In that case, it represents the source pad.
87 * @intf: Part of a union. Used only if the first object (gobj0) is
89 * @gobj1: Part of a union. Used to get the pointer for the second
90 * graph_object of the link.
91 * @source: Part of a union. Used only if the second object (gobj1) is
92 * a pad. In that case, it represents the sink pad.
93 * @entity: Part of a union. Used only if the second object (gobj1) is
95 * @reverse: Pointer to the link for the reverse direction of a pad to pad
97 * @flags: Link flags, as defined in uapi/media.h (MEDIA_LNK_FL_*)
98 * @is_backlink: Indicate if the link is a backlink.
101 struct media_gobj graph_obj;
102 struct list_head list;
104 struct media_gobj *gobj0;
105 struct media_pad *source;
106 struct media_interface *intf;
109 struct media_gobj *gobj1;
110 struct media_pad *sink;
111 struct media_entity *entity;
113 struct media_link *reverse;
119 * struct media_pad - A media pad graph object.
121 * @graph_obj: Embedded structure containing the media object common data
122 * @entity: Entity this pad belongs to
123 * @index: Pad index in the entity pads array, numbered from 0 to n
124 * @flags: Pad flags, as defined in uapi/media.h (MEDIA_PAD_FL_*)
127 struct media_gobj graph_obj; /* must be first field in struct */
128 struct media_entity *entity;
134 * struct media_entity_operations - Media entity operations
135 * @link_setup: Notify the entity of link changes. The operation can
136 * return an error, in which case link setup will be
137 * cancelled. Optional.
138 * @link_validate: Return whether a link is valid from the entity point of
139 * view. The media_entity_pipeline_start() function
140 * validates all links by calling this operation. Optional.
142 struct media_entity_operations {
143 int (*link_setup)(struct media_entity *entity,
144 const struct media_pad *local,
145 const struct media_pad *remote, u32 flags);
146 int (*link_validate)(struct media_link *link);
150 * struct media_entity - A media entity graph object.
152 * @graph_obj: Embedded structure containing the media object common data.
153 * @name: Entity name.
154 * @function: Entity main function, as defined in uapi/media.h
156 * @flags: Entity flags, as defined in uapi/media.h (MEDIA_ENT_FL_*)
157 * @num_pads: Number of sink and source pads.
158 * @num_links: Total number of links, forward and back, enabled and disabled.
159 * @num_backlinks: Number of backlinks
160 * @internal_idx: An unique internal entity specific number. The numbers are
161 * re-used if entities are unregistered or registered again.
162 * @pads: Pads array with the size defined by @num_pads.
163 * @links: List of data links.
164 * @ops: Entity operations.
165 * @stream_count: Stream count for the entity.
166 * @use_count: Use count for the entity.
167 * @pipe: Pipeline this entity belongs to.
168 * @info: Union with devnode information. Kept just for backward
170 * @major: Devnode major number (zero if not applicable). Kept just
171 * for backward compatibility.
172 * @minor: Devnode minor number (zero if not applicable). Kept just
173 * for backward compatibility.
175 * NOTE: @stream_count and @use_count reference counts must never be
176 * negative, but are signed integers on purpose: a simple WARN_ON(<0) check
177 * can be used to detect reference count bugs that would make them negative.
179 struct media_entity {
180 struct media_gobj graph_obj; /* must be first field in struct */
190 struct media_pad *pads;
191 struct list_head links;
193 const struct media_entity_operations *ops;
195 /* Reference counts must never be negative, but are signed integers on
196 * purpose: a simple WARN_ON(<0) check can be used to detect reference
197 * count bugs that would make them negative.
202 struct media_pipeline *pipe;
213 * struct media_interface - A media interface graph object.
215 * @graph_obj: embedded graph object
216 * @links: List of links pointing to graph entities
217 * @type: Type of the interface as defined in the
218 * uapi/media/media.h header, e. g.
220 * @flags: Interface flags as defined in uapi/media/media.h
222 struct media_interface {
223 struct media_gobj graph_obj;
224 struct list_head links;
230 * struct media_intf_devnode - A media interface via a device node.
232 * @intf: embedded interface object
233 * @major: Major number of a device node
234 * @minor: Minor number of a device node
236 struct media_intf_devnode {
237 struct media_interface intf;
239 /* Should match the fields at media_v2_intf_devnode */
245 * media_entity_id() - return the media entity graph object id
247 * @entity: pointer to entity
249 static inline u32 media_entity_id(struct media_entity *entity)
251 return entity->graph_obj.id;
255 * media_type() - return the media object type
257 * @gobj: pointer to the media graph object
259 static inline enum media_gobj_type media_type(struct media_gobj *gobj)
261 return gobj->id >> MEDIA_BITS_PER_LOCAL_ID;
264 static inline u32 media_localid(struct media_gobj *gobj)
266 return gobj->id & MEDIA_LOCAL_ID_MASK;
269 static inline u32 media_gobj_gen_id(enum media_gobj_type type, u32 local_id)
273 id = type << MEDIA_BITS_PER_LOCAL_ID;
274 id |= local_id & MEDIA_LOCAL_ID_MASK;
280 * is_media_entity_v4l2_io() - identify if the entity main function
283 * @entity: pointer to entity
285 * Return: true if the entity main function is one of the V4L2 I/O types
286 * (video, VBI or SDR radio); false otherwise.
288 static inline bool is_media_entity_v4l2_io(struct media_entity *entity)
293 switch (entity->function) {
294 case MEDIA_ENT_F_IO_V4L:
295 case MEDIA_ENT_F_IO_VBI:
296 case MEDIA_ENT_F_IO_SWRADIO:
304 * is_media_entity_v4l2_subdev - return true if the entity main function is
305 * associated with the V4L2 API subdev usage
307 * @entity: pointer to entity
309 * This is an ancillary function used by subdev-based V4L2 drivers.
310 * It checks if the entity function is one of functions used by a V4L2 subdev,
311 * e. g. camera-relatef functions, analog TV decoder, TV tuner, V4L2 DSPs.
313 static inline bool is_media_entity_v4l2_subdev(struct media_entity *entity)
318 switch (entity->function) {
319 case MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN:
320 case MEDIA_ENT_F_CAM_SENSOR:
321 case MEDIA_ENT_F_FLASH:
322 case MEDIA_ENT_F_LENS:
323 case MEDIA_ENT_F_ATV_DECODER:
324 case MEDIA_ENT_F_TUNER:
332 #define MEDIA_ENTITY_ENUM_MAX_DEPTH 16
333 #define MEDIA_ENTITY_ENUM_MAX_ID 64
336 * The number of pads can't be bigger than the number of entities,
337 * as the worse-case scenario is to have one entity linked up to
338 * MEDIA_ENTITY_ENUM_MAX_ID - 1 entities.
340 #define MEDIA_ENTITY_MAX_PADS (MEDIA_ENTITY_ENUM_MAX_ID - 1)
342 struct media_entity_graph {
344 struct media_entity *entity;
345 struct list_head *link;
346 } stack[MEDIA_ENTITY_ENUM_MAX_DEPTH];
348 DECLARE_BITMAP(entities, MEDIA_ENTITY_ENUM_MAX_ID);
352 #define gobj_to_entity(gobj) \
353 container_of(gobj, struct media_entity, graph_obj)
355 #define gobj_to_pad(gobj) \
356 container_of(gobj, struct media_pad, graph_obj)
358 #define gobj_to_link(gobj) \
359 container_of(gobj, struct media_link, graph_obj)
361 #define gobj_to_link(gobj) \
362 container_of(gobj, struct media_link, graph_obj)
364 #define gobj_to_pad(gobj) \
365 container_of(gobj, struct media_pad, graph_obj)
367 #define gobj_to_intf(gobj) \
368 container_of(gobj, struct media_interface, graph_obj)
370 #define intf_to_devnode(intf) \
371 container_of(intf, struct media_intf_devnode, intf)
374 * media_gobj_create - Initialize a graph object
376 * @mdev: Pointer to the media_device that contains the object
377 * @type: Type of the object
378 * @gobj: Pointer to the graph object
380 * This routine initializes the embedded struct media_gobj inside a
381 * media graph object. It is called automatically if media_*_create()
382 * calls are used. However, if the object (entity, link, pad, interface)
383 * is embedded on some other object, this function should be called before
384 * registering the object at the media controller.
386 void media_gobj_create(struct media_device *mdev,
387 enum media_gobj_type type,
388 struct media_gobj *gobj);
391 * media_gobj_destroy - Stop using a graph object on a media device
393 * @gobj: Pointer to the graph object
395 * This should be called by all routines like media_device_unregister()
396 * that remove/destroy media graph objects.
398 void media_gobj_destroy(struct media_gobj *gobj);
401 * media_entity_pads_init() - Initialize the entity pads
403 * @entity: entity where the pads belong
404 * @num_pads: total number of sink and source pads
405 * @pads: Array of @num_pads pads.
407 * The pads array is managed by the entity driver and passed to
408 * media_entity_pads_init() where its pointer will be stored in the entity
411 * If no pads are needed, drivers could either directly fill
412 * &media_entity->@num_pads with 0 and &media_entity->@pads with NULL or call
413 * this function that will do the same.
415 * As the number of pads is known in advance, the pads array is not allocated
416 * dynamically but is managed by the entity driver. Most drivers will embed the
417 * pads array in a driver-specific structure, avoiding dynamic allocation.
419 * Drivers must set the direction of every pad in the pads array before calling
420 * media_entity_pads_init(). The function will initialize the other pads fields.
422 int media_entity_pads_init(struct media_entity *entity, u16 num_pads,
423 struct media_pad *pads);
426 * media_entity_cleanup() - free resources associated with an entity
428 * @entity: entity where the pads belong
430 * This function must be called during the cleanup phase after unregistering
431 * the entity (currently, it does nothing).
433 static inline void media_entity_cleanup(struct media_entity *entity) {};
436 * media_create_pad_link() - creates a link between two entities.
438 * @source: pointer to &media_entity of the source pad.
439 * @source_pad: number of the source pad in the pads array
440 * @sink: pointer to &media_entity of the sink pad.
441 * @sink_pad: number of the sink pad in the pads array.
442 * @flags: Link flags, as defined in include/uapi/linux/media.h.
444 * Valid values for flags:
445 * A %MEDIA_LNK_FL_ENABLED flag indicates that the link is enabled and can be
446 * used to transfer media data. When two or more links target a sink pad,
447 * only one of them can be enabled at a time.
449 * A %MEDIA_LNK_FL_IMMUTABLE flag indicates that the link enabled state can't
450 * be modified at runtime. If %MEDIA_LNK_FL_IMMUTABLE is set, then
451 * %MEDIA_LNK_FL_ENABLED must also be set since an immutable link is
456 * Before calling this function, media_entity_pads_init() and
457 * media_device_register_entity() should be called previously for both ends.
459 __must_check int media_create_pad_link(struct media_entity *source,
460 u16 source_pad, struct media_entity *sink,
461 u16 sink_pad, u32 flags);
462 void __media_entity_remove_links(struct media_entity *entity);
465 * media_entity_remove_links() - remove all links associated with an entity
467 * @entity: pointer to &media_entity
469 * Note: this is called automatically when an entity is unregistered via
470 * media_device_register_entity().
472 void media_entity_remove_links(struct media_entity *entity);
475 * __media_entity_setup_link - Configure a media link without locking
476 * @link: The link being configured
477 * @flags: Link configuration flags
479 * The bulk of link setup is handled by the two entities connected through the
480 * link. This function notifies both entities of the link configuration change.
482 * If the link is immutable or if the current and new configuration are
483 * identical, return immediately.
485 * The user is expected to hold link->source->parent->mutex. If not,
486 * media_entity_setup_link() should be used instead.
488 int __media_entity_setup_link(struct media_link *link, u32 flags);
491 * media_entity_setup_link() - changes the link flags properties in runtime
493 * @link: pointer to &media_link
494 * @flags: the requested new link flags
496 * The only configurable property is the %MEDIA_LNK_FL_ENABLED link flag
497 * flag to enable/disable a link. Links marked with the
498 * %MEDIA_LNK_FL_IMMUTABLE link flag can not be enabled or disabled.
500 * When a link is enabled or disabled, the media framework calls the
501 * link_setup operation for the two entities at the source and sink of the
502 * link, in that order. If the second link_setup call fails, another
503 * link_setup call is made on the first entity to restore the original link
506 * Media device drivers can be notified of link setup operations by setting the
507 * media_device::link_notify pointer to a callback function. If provided, the
508 * notification callback will be called before enabling and after disabling
511 * Entity drivers must implement the link_setup operation if any of their links
512 * is non-immutable. The operation must either configure the hardware or store
513 * the configuration information to be applied later.
515 * Link configuration must not have any side effect on other links. If an
516 * enabled link at a sink pad prevents another link at the same pad from
517 * being enabled, the link_setup operation must return -EBUSY and can't
518 * implicitly disable the first enabled link.
520 * NOTE: the valid values of the flags for the link is the same as described
521 * on media_create_pad_link(), for pad to pad links or the same as described
522 * on media_create_intf_link(), for interface to entity links.
524 int media_entity_setup_link(struct media_link *link, u32 flags);
527 * media_entity_find_link - Find a link between two pads
528 * @source: Source pad
531 * Return a pointer to the link between the two entities. If no such link
532 * exists, return NULL.
534 struct media_link *media_entity_find_link(struct media_pad *source,
535 struct media_pad *sink);
538 * media_entity_remote_pad - Find the pad at the remote end of a link
539 * @pad: Pad at the local end of the link
541 * Search for a remote pad connected to the given pad by iterating over all
542 * links originating or terminating at that pad until an enabled link is found.
544 * Return a pointer to the pad at the remote end of the first found enabled
545 * link, or NULL if no enabled link has been found.
547 struct media_pad *media_entity_remote_pad(struct media_pad *pad);
550 * media_entity_get - Get a reference to the parent module
552 * @entity: The entity
554 * Get a reference to the parent media device module.
556 * The function will return immediately if @entity is NULL.
558 * Return a pointer to the entity on success or NULL on failure.
560 struct media_entity *media_entity_get(struct media_entity *entity);
563 * media_entity_put - Release the reference to the parent module
565 * @entity: The entity
567 * Release the reference count acquired by media_entity_get().
569 * The function will return immediately if @entity is NULL.
571 void media_entity_put(struct media_entity *entity);
574 * media_entity_graph_walk_start - Start walking the media graph at a given entity
575 * @graph: Media graph structure that will be used to walk the graph
576 * @entity: Starting entity
578 * This function initializes the graph traversal structure to walk the entities
579 * graph starting at the given entity. The traversal structure must not be
580 * modified by the caller during graph traversal. When done the structure can
583 void media_entity_graph_walk_start(struct media_entity_graph *graph,
584 struct media_entity *entity);
587 * media_entity_graph_walk_next - Get the next entity in the graph
588 * @graph: Media graph structure
590 * Perform a depth-first traversal of the given media entities graph.
592 * The graph structure must have been previously initialized with a call to
593 * media_entity_graph_walk_start().
595 * Return the next entity in the graph or NULL if the whole graph have been
598 struct media_entity *
599 media_entity_graph_walk_next(struct media_entity_graph *graph);
602 * media_entity_pipeline_start - Mark a pipeline as streaming
603 * @entity: Starting entity
604 * @pipe: Media pipeline to be assigned to all entities in the pipeline.
606 * Mark all entities connected to a given entity through enabled links, either
607 * directly or indirectly, as streaming. The given pipeline object is assigned to
608 * every entity in the pipeline and stored in the media_entity pipe field.
610 * Calls to this function can be nested, in which case the same number of
611 * media_entity_pipeline_stop() calls will be required to stop streaming. The
612 * pipeline pointer must be identical for all nested calls to
613 * media_entity_pipeline_start().
615 __must_check int media_entity_pipeline_start(struct media_entity *entity,
616 struct media_pipeline *pipe);
619 * media_entity_pipeline_stop - Mark a pipeline as not streaming
620 * @entity: Starting entity
622 * Mark all entities connected to a given entity through enabled links, either
623 * directly or indirectly, as not streaming. The media_entity pipe field is
626 * If multiple calls to media_entity_pipeline_start() have been made, the same
627 * number of calls to this function are required to mark the pipeline as not
630 void media_entity_pipeline_stop(struct media_entity *entity);
633 * media_devnode_create() - creates and initializes a device node interface
635 * @mdev: pointer to struct &media_device
636 * @type: type of the interface, as given by MEDIA_INTF_T_* macros
637 * as defined in the uapi/media/media.h header.
638 * @flags: Interface flags as defined in uapi/media/media.h.
639 * @major: Device node major number.
640 * @minor: Device node minor number.
642 * Return: if succeeded, returns a pointer to the newly allocated
643 * &media_intf_devnode pointer.
645 struct media_intf_devnode *
646 __must_check media_devnode_create(struct media_device *mdev,
648 u32 major, u32 minor);
650 * media_devnode_remove() - removes a device node interface
652 * @devnode: pointer to &media_intf_devnode to be freed.
654 * When a device node interface is removed, all links to it are automatically
657 void media_devnode_remove(struct media_intf_devnode *devnode);
661 * media_create_intf_link() - creates a link between an entity and an interface
663 * @entity: pointer to %media_entity
664 * @intf: pointer to %media_interface
665 * @flags: Link flags, as defined in include/uapi/linux/media.h.
668 * Valid values for flags:
669 * The %MEDIA_LNK_FL_ENABLED flag indicates that the interface is connected to
670 * the entity hardware. That's the default value for interfaces. An
671 * interface may be disabled if the hardware is busy due to the usage
672 * of some other interface that it is currently controlling the hardware.
673 * A typical example is an hybrid TV device that handle only one type of
674 * stream on a given time. So, when the digital TV is streaming,
675 * the V4L2 interfaces won't be enabled, as such device is not able to
676 * also stream analog TV or radio.
680 * Before calling this function, media_devnode_create() should be called for
681 * the interface and media_device_register_entity() should be called for the
682 * interface that will be part of the link.
684 __must_check media_create_intf_link(struct media_entity *entity,
685 struct media_interface *intf,
688 * __media_remove_intf_link() - remove a single interface link
690 * @link: pointer to &media_link.
692 * Note: this is an unlocked version of media_remove_intf_link()
694 void __media_remove_intf_link(struct media_link *link);
697 * media_remove_intf_link() - remove a single interface link
699 * @link: pointer to &media_link.
701 * Note: prefer to use this one, instead of __media_remove_intf_link()
703 void media_remove_intf_link(struct media_link *link);
706 * __media_remove_intf_links() - remove all links associated with an interface
708 * @intf: pointer to &media_interface
710 * Note: this is an unlocked version of media_remove_intf_links().
712 void __media_remove_intf_links(struct media_interface *intf);
714 * media_remove_intf_links() - remove all links associated with an interface
716 * @intf: pointer to &media_interface
720 * this is called automatically when an entity is unregistered via
721 * media_device_register_entity() and by media_devnode_remove().
723 * Prefer to use this one, instead of __media_remove_intf_links().
725 void media_remove_intf_links(struct media_interface *intf);
728 #define media_entity_call(entity, operation, args...) \
729 (((entity)->ops && (entity)->ops->operation) ? \
730 (entity)->ops->operation((entity) , ##args) : -ENOIOCTLCMD)