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_get - Increase the use count of a pipeline 90 * @entity: The root entity of a pipeline 91 * 92 * Update the use count of all entities in the pipeline and power entities on. 93 * 94 * This function is intended to be called in video node open. It uses 95 * struct media_entity.use_count to track the power status. The use 96 * of this function should be paired with v4l2_pipeline_link_notify(). 97 * 98 * Return 0 on success or a negative error code on failure. 99 */ 100 int v4l2_pipeline_pm_get(struct media_entity *entity); 101 102 /** 103 * v4l2_pipeline_pm_put - Decrease the use count of a pipeline 104 * @entity: The root entity of a pipeline 105 * 106 * Update the use count of all entities in the pipeline and power entities off. 107 * 108 * This function is intended to be called in video node release. It uses 109 * struct media_entity.use_count to track the power status. The use 110 * of this function should be paired with v4l2_pipeline_link_notify(). 111 */ 112 void v4l2_pipeline_pm_put(struct media_entity *entity); 113 114 115 /** 116 * v4l2_pipeline_link_notify - Link management notification callback 117 * @link: The link 118 * @flags: New link flags that will be applied 119 * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*) 120 * 121 * React to link management on powered pipelines by updating the use count of 122 * all entities in the source and sink sides of the link. Entities are powered 123 * on or off accordingly. The use of this function should be paired 124 * with v4l2_pipeline_pm_{get,put}(). 125 * 126 * Return 0 on success or a negative error code on failure. Powering entities 127 * off is assumed to never fail. This function will not fail for disconnection 128 * events. 129 */ 130 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags, 131 unsigned int notification); 132 133 #else /* CONFIG_MEDIA_CONTROLLER */ 134 135 static inline int v4l2_mc_create_media_graph(struct media_device *mdev) 136 { 137 return 0; 138 } 139 140 static inline int v4l_enable_media_source(struct video_device *vdev) 141 { 142 return 0; 143 } 144 145 static inline void v4l_disable_media_source(struct video_device *vdev) 146 { 147 } 148 149 static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q) 150 { 151 return 0; 152 } 153 154 static inline int v4l2_pipeline_pm_get(struct media_entity *entity) 155 { 156 return 0; 157 } 158 159 static inline void v4l2_pipeline_pm_put(struct media_entity *entity) 160 {} 161 162 static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags, 163 unsigned int notification) 164 { 165 return 0; 166 } 167 168 #endif /* CONFIG_MEDIA_CONTROLLER */ 169 #endif /* _V4L2_MC_H */ 170