include/media/v4l2-mc.h

   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 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  */
 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
 189 static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
 190 {
 191         return 0;
 192 }
 193
 194 static inline int v4l_enable_media_source(struct video_device *vdev)
 195 {
 196         return 0;
 197 }
 198
 199 static inline void v4l_disable_media_source(struct video_device *vdev)
 200 {
 201 }
 202
 203 static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
 204 {
 205         return 0;
 206 }
 207
 208 static inline int v4l2_pipeline_pm_get(struct media_entity *entity)
 209 {
 210         return 0;
 211 }
 212
 213 static inline void v4l2_pipeline_pm_put(struct media_entity *entity)
 214 {}
 215
 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 */