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 */
 19struct pci_dev;
 20struct 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 */
 40int 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 */
 58int 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 */
 72void 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 */
 86int 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 subdev pad.
 91 *
 92 * @src_sd: pointer to a source subdev
 93 * @sink:  pointer to a subdev 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 subdevice, in its v4l2-async notifier subdev bound
100 * callback, to create 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 */
115int 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 */
139int 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 */
154int 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 */
166void 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 */
184int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
185			      unsigned int notification);
186
187#else /* CONFIG_MEDIA_CONTROLLER */
188
189static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
190{
191	return 0;
192}
193
194static inline int v4l_enable_media_source(struct video_device *vdev)
195{
196	return 0;
197}
198
199static inline void v4l_disable_media_source(struct video_device *vdev)
200{
201}
202
203static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
204{
205	return 0;
206}
207
208static inline int v4l2_pipeline_pm_get(struct media_entity *entity)
209{
210	return 0;
211}
212
213static inline void v4l2_pipeline_pm_put(struct media_entity *entity)
214{}
215
216static 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 */