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 <media/v4l2-subdev.h>
16 #include <linux/types.h>
17
18 /* We don't need to include pci.h or usb.h here */
19 struct pci_dev;
20 struct usb_device;
21
22 #ifdef CONFIG_MEDIA_CONTROLLER
23 /**
24 * v4l2_mc_create_media_graph() - create Media Controller links at the graph.
25 *
26 * @mdev: pointer to the &media_device struct.
27 *
28 * Add links between the entities commonly found on PC customer's hardware at
29 * the V4L2 side: camera sensors, audio and video PLL-IF decoders, tuners,
30 * analog TV decoder and I/O entities (video, VBI and Software Defined Radio).
31 *
32 * .. note::
33 *
34 * Webcams are modelled on a very simple way: the sensor is
35 * connected directly to the I/O entity. All dirty details, like
36 * scaler and crop HW are hidden. While such mapping is enough for v4l2
37 * interface centric PC-consumer's hardware, V4L2 subdev centric camera
38 * hardware should not use this routine, as it will not build the right graph.
39 */
40 int v4l2_mc_create_media_graph(struct media_device *mdev);
41
42 /**
43 * v4l_enable_media_source() - Hold media source for exclusive use
44 * if free
45 *
46 * @vdev: pointer to struct video_device
47 *
48 * This interface calls enable_source handler to determine if
49 * media source is free for use. The enable_source handler is
50 * responsible for checking is the media source is free and
51 * start a pipeline between the media source and the media
52 * entity associated with the video device. This interface
53 * should be called from v4l2-core and dvb-core interfaces
54 * that change the source configuration.
55 *
56 * Return: returns zero on success or a negative error code.
57 */
58 int v4l_enable_media_source(struct video_device *vdev);
59
60 /**
61 * v4l_disable_media_source() - Release media source
62 *
63 * @vdev: pointer to struct video_device
64 *
65 * This interface calls disable_source handler to release
66 * the media source. The disable_source handler stops the
67 * active media pipeline between the media source and the
68 * media entity associated with the video device.
69 *
70 * Return: returns zero on success or a negative error code.
71 */
72 void v4l_disable_media_source(struct video_device *vdev);
73
74 /*
75 * v4l_vb2q_enable_media_tuner - Hold media source for exclusive use
76 * if free.
77 * @q - pointer to struct vb2_queue
78 *
79 * Wrapper for v4l_enable_media_source(). This function should
80 * be called from v4l2-core to enable the media source with
81 * pointer to struct vb2_queue as the input argument. Some
82 * v4l2-core interfaces don't have access to video device and
83 * this interface finds the struct video_device for the q and
84 * calls v4l_enable_media_source().
85 */
86 int v4l_vb2q_enable_media_source(struct vb2_queue *q);
87
88 /**
89 * v4l2_create_fwnode_links_to_pad - Create fwnode-based links from a
90 * source subdev to a sink pad.
91 *
92 * @src_sd: pointer to a source subdev
93 * @sink: pointer to a sink pad
94 * @flags: the link flags
95 *
96 * This function searches for fwnode endpoint connections from a source
97 * subdevice to a single sink pad, and if suitable connections are found,
98 * translates them into media links to that pad. The function can be
99 * called by the sink, in its v4l2-async notifier bound callback, to create
100 * links from a bound source subdevice.
101 *
102 * The @flags argument specifies the link flags. The caller shall ensure that
103 * the flags are valid regardless of the number of links that may be created.
104 * For instance, setting the MEDIA_LNK_FL_ENABLED flag will cause all created
105 * links to be enabled, which isn't valid if more than one link is created.
106 *
107 * .. note::
108 *
109 * Any sink subdevice that calls this function must implement the
110 * .get_fwnode_pad media operation in order to verify endpoints passed
111 * to the sink are owned by the sink.
112 *
113 * Return 0 on success or a negative error code on failure.
114 */
115 int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
116 struct media_pad *sink, u32 flags);
117
118 /**
119 * v4l2_create_fwnode_links - Create fwnode-based links from a source
120 * subdev to a sink subdev.
121 *
122 * @src_sd: pointer to a source subdevice
123 * @sink_sd: pointer to a sink subdevice
124 *
125 * This function searches for any and all fwnode endpoint connections
126 * between source and sink subdevices, and translates them into media
127 * links. The function can be called by the sink subdevice, in its
128 * v4l2-async notifier subdev bound callback, to create all links from
129 * a bound source subdevice.
130 *
131 * .. note::
132 *
133 * Any sink subdevice that calls this function must implement the
134 * .get_fwnode_pad media operation in order to verify endpoints passed
135 * to the sink are owned by the sink.
136 *
137 * Return 0 on success or a negative error code on failure.
138 */
139 int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
140 struct v4l2_subdev *sink_sd);
141
142 /**
143 * v4l2_pipeline_pm_get - Increase the use count of a pipeline
144 * @entity: The root entity of a pipeline
145 *
146 * Update the use count of all entities in the pipeline and power entities on.
147 *
148 * This function is intended to be called in video node open. It uses
149 * struct media_entity.use_count to track the power status. The use
150 * of this function should be paired with v4l2_pipeline_link_notify().
151 *
152 * Return 0 on success or a negative error code on failure.
153 */
154 int v4l2_pipeline_pm_get(struct media_entity *entity);
155
156 /**
157 * v4l2_pipeline_pm_put - Decrease the use count of a pipeline
158 * @entity: The root entity of a pipeline
159 *
160 * Update the use count of all entities in the pipeline and power entities off.
161 *
162 * This function is intended to be called in video node release. It uses
163 * struct media_entity.use_count to track the power status. The use
164 * of this function should be paired with v4l2_pipeline_link_notify().
165 */
166 void v4l2_pipeline_pm_put(struct media_entity *entity);
167
168
169 /**
170 * v4l2_pipeline_link_notify - Link management notification callback
171 * @link: The link
172 * @flags: New link flags that will be applied
173 * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*)
174 *
175 * React to link management on powered pipelines by updating the use count of
176 * all entities in the source and sink sides of the link. Entities are powered
177 * on or off accordingly. The use of this function should be paired
178 * with v4l2_pipeline_pm_{get,put}().
179 *
180 * Return 0 on success or a negative error code on failure. Powering entities
181 * off is assumed to never fail. This function will not fail for disconnection
182 * events.
183 */
184 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
185 unsigned int notification);
186
187 #else /* CONFIG_MEDIA_CONTROLLER */
188
v4l2_mc_create_media_graph(struct media_device * mdev)189 static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
190 {
191 return 0;
192 }
193
v4l_enable_media_source(struct video_device * vdev)194 static inline int v4l_enable_media_source(struct video_device *vdev)
195 {
196 return 0;
197 }
198
v4l_disable_media_source(struct video_device * vdev)199 static inline void v4l_disable_media_source(struct video_device *vdev)
200 {
201 }
202
v4l_vb2q_enable_media_source(struct vb2_queue * q)203 static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
204 {
205 return 0;
206 }
207
v4l2_pipeline_pm_get(struct media_entity * entity)208 static inline int v4l2_pipeline_pm_get(struct media_entity *entity)
209 {
210 return 0;
211 }
212
v4l2_pipeline_pm_put(struct media_entity * entity)213 static inline void v4l2_pipeline_pm_put(struct media_entity *entity)
214 {}
215
v4l2_pipeline_link_notify(struct media_link * link,u32 flags,unsigned int notification)216 static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
217 unsigned int notification)
218 {
219 return 0;
220 }
221
222 #endif /* CONFIG_MEDIA_CONTROLLER */
223 #endif /* _V4L2_MC_H */
224