1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * v4l2-mc.h - Media Controller V4L2 types and prototypes
4 *
5 * Copyright (C) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
6 * Copyright (C) 2006-2010 Nokia Corporation
7 * Copyright (c) 2016 Intel Corporation.
8 */
9
10 #ifndef _V4L2_MC_H
11 #define _V4L2_MC_H
12
13 #include <media/media-device.h>
14 #include <media/v4l2-dev.h>
15 #include <linux/types.h>
16
17 /* We don't need to include pci.h or usb.h here */
18 struct pci_dev;
19 struct usb_device;
20
21 #ifdef CONFIG_MEDIA_CONTROLLER
22 /**
23 * v4l2_mc_create_media_graph() - create Media Controller links at the graph.
24 *
25 * @mdev: pointer to the &media_device struct.
26 *
27 * Add links between the entities commonly found on PC customer's hardware at
28 * the V4L2 side: camera sensors, audio and video PLL-IF decoders, tuners,
29 * analog TV decoder and I/O entities (video, VBI and Software Defined Radio).
30 *
31 * .. note::
32 *
33 * Webcams are modelled on a very simple way: the sensor is
34 * connected directly to the I/O entity. All dirty details, like
35 * scaler and crop HW are hidden. While such mapping is enough for v4l2
36 * interface centric PC-consumer's hardware, V4L2 subdev centric camera
37 * hardware should not use this routine, as it will not build the right graph.
38 */
39 int v4l2_mc_create_media_graph(struct media_device *mdev);
40
41 /**
42 * v4l_enable_media_source() - Hold media source for exclusive use
43 * if free
44 *
45 * @vdev: pointer to struct video_device
46 *
47 * This interface calls enable_source handler to determine if
48 * media source is free for use. The enable_source handler is
49 * responsible for checking is the media source is free and
50 * start a pipeline between the media source and the media
51 * entity associated with the video device. This interface
52 * should be called from v4l2-core and dvb-core interfaces
53 * that change the source configuration.
54 *
55 * Return: returns zero on success or a negative error code.
56 */
57 int v4l_enable_media_source(struct video_device *vdev);
58
59 /**
60 * v4l_disable_media_source() - Release media source
61 *
62 * @vdev: pointer to struct video_device
63 *
64 * This interface calls disable_source handler to release
65 * the media source. The disable_source handler stops the
66 * active media pipeline between the media source and the
67 * media entity associated with the video device.
68 *
69 * Return: returns zero on success or a negative error code.
70 */
71 void v4l_disable_media_source(struct video_device *vdev);
72
73 /*
74 * v4l_vb2q_enable_media_tuner - Hold media source for exclusive use
75 * if free.
76 * @q - pointer to struct vb2_queue
77 *
78 * Wrapper for v4l_enable_media_source(). This function should
79 * be called from v4l2-core to enable the media source with
80 * pointer to struct vb2_queue as the input argument. Some
81 * v4l2-core interfaces don't have access to video device and
82 * this interface finds the struct video_device for the q and
83 * calls v4l_enable_media_source().
84 */
85 int v4l_vb2q_enable_media_source(struct vb2_queue *q);
86
87
88 /**
89 * v4l2_pipeline_pm_use - Update the use count of an entity
90 * @entity: The entity
91 * @use: Use (1) or stop using (0) the entity
92 *
93 * Update the use count of all entities in the pipeline and power entities on or
94 * off accordingly.
95 *
96 * This function is intended to be called in video node open (use ==
97 * 1) and release (use == 0). It uses struct media_entity.use_count to
98 * track the power status. The use of this function should be paired
99 * with v4l2_pipeline_link_notify().
100 *
101 * Return 0 on success or a negative error code on failure. Powering entities
102 * off is assumed to never fail. No failure can occur when the use parameter is
103 * set to 0.
104 */
105 int v4l2_pipeline_pm_use(struct media_entity *entity, int use);
106
107
108 /**
109 * v4l2_pipeline_link_notify - Link management notification callback
110 * @link: The link
111 * @flags: New link flags that will be applied
112 * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*)
113 *
114 * React to link management on powered pipelines by updating the use count of
115 * all entities in the source and sink sides of the link. Entities are powered
116 * on or off accordingly. The use of this function should be paired
117 * with v4l2_pipeline_pm_use().
118 *
119 * Return 0 on success or a negative error code on failure. Powering entities
120 * off is assumed to never fail. This function will not fail for disconnection
121 * events.
122 */
123 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
124 unsigned int notification);
125
126 #else /* CONFIG_MEDIA_CONTROLLER */
127
128 static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
129 {
130 return 0;
131 }
132
133 static inline int v4l_enable_media_source(struct video_device *vdev)
134 {
135 return 0;
136 }
137
138 static inline void v4l_disable_media_source(struct video_device *vdev)
139 {
140 }
141
142 static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
143 {
144 return 0;
145 }
146
147 static inline int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
148 {
149 return 0;
150 }
151
152 static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
153 unsigned int notification)
154 {
155 return 0;
156 }
157
158 #endif /* CONFIG_MEDIA_CONTROLLER */
159 #endif /* _V4L2_MC_H */