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 * 95 * This function searches for fwnode endpoint connections from a source 96 * subdevice to a single sink pad, and if suitable connections are found, 97 * translates them into media links to that pad. The function can be 98 * called by the sink subdevice, in its v4l2-async notifier subdev bound 99 * callback, to create links from a bound source subdevice. 100 * 101 * .. note:: 102 * 103 * Any sink subdevice that calls this function must implement the 104 * .get_fwnode_pad media operation in order to verify endpoints passed 105 * to the sink are owned by the sink. 106 * 107 * Return 0 on success or a negative error code on failure. 108 */ 109 int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd, 110 struct media_pad *sink); 111 112 /** 113 * v4l2_create_fwnode_links - Create fwnode-based links from a source 114 * subdev to a sink subdev. 115 * 116 * @src_sd - pointer to a source subdevice 117 * @sink_sd - pointer to a sink subdevice 118 * 119 * This function searches for any and all fwnode endpoint connections 120 * between source and sink subdevices, and translates them into media 121 * links. The function can be called by the sink subdevice, in its 122 * v4l2-async notifier subdev bound callback, to create all links from 123 * a bound source subdevice. 124 * 125 * .. note:: 126 * 127 * Any sink subdevice that calls this function must implement the 128 * .get_fwnode_pad media operation in order to verify endpoints passed 129 * to the sink are owned by the sink. 130 * 131 * Return 0 on success or a negative error code on failure. 132 */ 133 int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd, 134 struct v4l2_subdev *sink_sd); 135 136 /** 137 * v4l2_pipeline_pm_get - Increase the use count of a pipeline 138 * @entity: The root entity of a pipeline 139 * 140 * Update the use count of all entities in the pipeline and power entities on. 141 * 142 * This function is intended to be called in video node open. It uses 143 * struct media_entity.use_count to track the power status. The use 144 * of this function should be paired with v4l2_pipeline_link_notify(). 145 * 146 * Return 0 on success or a negative error code on failure. 147 */ 148 int v4l2_pipeline_pm_get(struct media_entity *entity); 149 150 /** 151 * v4l2_pipeline_pm_put - Decrease the use count of a pipeline 152 * @entity: The root entity of a pipeline 153 * 154 * Update the use count of all entities in the pipeline and power entities off. 155 * 156 * This function is intended to be called in video node release. It uses 157 * struct media_entity.use_count to track the power status. The use 158 * of this function should be paired with v4l2_pipeline_link_notify(). 159 */ 160 void v4l2_pipeline_pm_put(struct media_entity *entity); 161 162 163 /** 164 * v4l2_pipeline_link_notify - Link management notification callback 165 * @link: The link 166 * @flags: New link flags that will be applied 167 * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*) 168 * 169 * React to link management on powered pipelines by updating the use count of 170 * all entities in the source and sink sides of the link. Entities are powered 171 * on or off accordingly. The use of this function should be paired 172 * with v4l2_pipeline_pm_{get,put}(). 173 * 174 * Return 0 on success or a negative error code on failure. Powering entities 175 * off is assumed to never fail. This function will not fail for disconnection 176 * events. 177 */ 178 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags, 179 unsigned int notification); 180 181 #else /* CONFIG_MEDIA_CONTROLLER */ 182 183 static inline int v4l2_mc_create_media_graph(struct media_device *mdev) 184 { 185 return 0; 186 } 187 188 static inline int v4l_enable_media_source(struct video_device *vdev) 189 { 190 return 0; 191 } 192 193 static inline void v4l_disable_media_source(struct video_device *vdev) 194 { 195 } 196 197 static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q) 198 { 199 return 0; 200 } 201 202 static inline int v4l2_pipeline_pm_get(struct media_entity *entity) 203 { 204 return 0; 205 } 206 207 static inline void v4l2_pipeline_pm_put(struct media_entity *entity) 208 {} 209 210 static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags, 211 unsigned int notification) 212 { 213 return 0; 214 } 215 216 #endif /* CONFIG_MEDIA_CONTROLLER */ 217 #endif /* _V4L2_MC_H */ 218