1 /* 2 * v4l2-mc.h - Media Controller V4L2 types and prototypes 3 * 4 * Copyright (C) 2016 Mauro Carvalho Chehab <mchehab@kernel.org> 5 * Copyright (C) 2006-2010 Nokia Corporation 6 * Copyright (c) 2016 Intel Corporation. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 */ 18 19 #ifndef _V4L2_MC_H 20 #define _V4L2_MC_H 21 22 #include <media/media-device.h> 23 #include <media/v4l2-dev.h> 24 #include <linux/types.h> 25 26 /* We don't need to include pci.h or usb.h here */ 27 struct pci_dev; 28 struct usb_device; 29 30 #ifdef CONFIG_MEDIA_CONTROLLER 31 /** 32 * v4l2_mc_create_media_graph() - create Media Controller links at the graph. 33 * 34 * @mdev: pointer to the &media_device struct. 35 * 36 * Add links between the entities commonly found on PC customer's hardware at 37 * the V4L2 side: camera sensors, audio and video PLL-IF decoders, tuners, 38 * analog TV decoder and I/O entities (video, VBI and Software Defined Radio). 39 * 40 * .. note:: 41 * 42 * Webcams are modelled on a very simple way: the sensor is 43 * connected directly to the I/O entity. All dirty details, like 44 * scaler and crop HW are hidden. While such mapping is enough for v4l2 45 * interface centric PC-consumer's hardware, V4L2 subdev centric camera 46 * hardware should not use this routine, as it will not build the right graph. 47 */ 48 int v4l2_mc_create_media_graph(struct media_device *mdev); 49 50 /** 51 * v4l_enable_media_source() - Hold media source for exclusive use 52 * if free 53 * 54 * @vdev: pointer to struct video_device 55 * 56 * This interface calls enable_source handler to determine if 57 * media source is free for use. The enable_source handler is 58 * responsible for checking is the media source is free and 59 * start a pipeline between the media source and the media 60 * entity associated with the video device. This interface 61 * should be called from v4l2-core and dvb-core interfaces 62 * that change the source configuration. 63 * 64 * Return: returns zero on success or a negative error code. 65 */ 66 int v4l_enable_media_source(struct video_device *vdev); 67 68 /** 69 * v4l_disable_media_source() - Release media source 70 * 71 * @vdev: pointer to struct video_device 72 * 73 * This interface calls disable_source handler to release 74 * the media source. The disable_source handler stops the 75 * active media pipeline between the media source and the 76 * media entity associated with the video device. 77 * 78 * Return: returns zero on success or a negative error code. 79 */ 80 void v4l_disable_media_source(struct video_device *vdev); 81 82 /* 83 * v4l_vb2q_enable_media_tuner - Hold media source for exclusive use 84 * if free. 85 * @q - pointer to struct vb2_queue 86 * 87 * Wrapper for v4l_enable_media_source(). This function should 88 * be called from v4l2-core to enable the media source with 89 * pointer to struct vb2_queue as the input argument. Some 90 * v4l2-core interfaces don't have access to video device and 91 * this interface finds the struct video_device for the q and 92 * calls v4l_enable_media_source(). 93 */ 94 int v4l_vb2q_enable_media_source(struct vb2_queue *q); 95 96 97 /** 98 * v4l2_pipeline_pm_use - Update the use count of an entity 99 * @entity: The entity 100 * @use: Use (1) or stop using (0) the entity 101 * 102 * Update the use count of all entities in the pipeline and power entities on or 103 * off accordingly. 104 * 105 * This function is intended to be called in video node open (use == 106 * 1) and release (use == 0). It uses struct media_entity.use_count to 107 * track the power status. The use of this function should be paired 108 * with v4l2_pipeline_link_notify(). 109 * 110 * Return 0 on success or a negative error code on failure. Powering entities 111 * off is assumed to never fail. No failure can occur when the use parameter is 112 * set to 0. 113 */ 114 int v4l2_pipeline_pm_use(struct media_entity *entity, int use); 115 116 117 /** 118 * v4l2_pipeline_link_notify - Link management notification callback 119 * @link: The link 120 * @flags: New link flags that will be applied 121 * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*) 122 * 123 * React to link management on powered pipelines by updating the use count of 124 * all entities in the source and sink sides of the link. Entities are powered 125 * on or off accordingly. The use of this function should be paired 126 * with v4l2_pipeline_pm_use(). 127 * 128 * Return 0 on success or a negative error code on failure. Powering entities 129 * off is assumed to never fail. This function will not fail for disconnection 130 * events. 131 */ 132 int v4l2_pipeline_link_notify(struct media_link *link, u32 flags, 133 unsigned int notification); 134 135 #else /* CONFIG_MEDIA_CONTROLLER */ 136 137 static inline int v4l2_mc_create_media_graph(struct media_device *mdev) 138 { 139 return 0; 140 } 141 142 static inline int v4l_enable_media_source(struct video_device *vdev) 143 { 144 return 0; 145 } 146 147 static inline void v4l_disable_media_source(struct video_device *vdev) 148 { 149 } 150 151 static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q) 152 { 153 return 0; 154 } 155 156 static inline int v4l2_pipeline_pm_use(struct media_entity *entity, int use) 157 { 158 return 0; 159 } 160 161 static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags, 162 unsigned int notification) 163 { 164 return 0; 165 } 166 167 #endif /* CONFIG_MEDIA_CONTROLLER */ 168 #endif /* _V4L2_MC_H */ 169