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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * v4l2-mc.h - Media Controller V4L2 types and prototypes
+ *
+ * Copyright (C) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
+ * Copyright (C) 2006-2010 Nokia Corporation
+ * Copyright (c) 2016 Intel Corporation.
+ */
+
+#ifndef _V4L2_MC_H
+#define _V4L2_MC_H
+
+#include <media/media-device.h>
+#include <media/v4l2-dev.h>
+#include <media/v4l2-subdev.h>
+#include <linux/types.h>
+
+/* We don't need to include pci.h or usb.h here */
+struct pci_dev;
+struct usb_device;
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+/**
+ * v4l2_mc_create_media_graph() - create Media Controller links at the graph.
+ *
+ * @mdev: pointer to the &media_device struct.
+ *
+ * Add links between the entities commonly found on PC customer's hardware at
+ * the V4L2 side: camera sensors, audio and video PLL-IF decoders, tuners,
+ * analog TV decoder and I/O entities (video, VBI and Software Defined Radio).
+ *
+ * .. note::
+ *
+ * Webcams are modelled on a very simple way: the sensor is
+ * connected directly to the I/O entity. All dirty details, like
+ * scaler and crop HW are hidden. While such mapping is enough for v4l2
+ * interface centric PC-consumer's hardware, V4L2 subdev centric camera
+ * hardware should not use this routine, as it will not build the right graph.
+ */
+int v4l2_mc_create_media_graph(struct media_device *mdev);
+
+/**
+ * v4l_enable_media_source() - Hold media source for exclusive use
+ * if free
+ *
+ * @vdev: pointer to struct video_device
+ *
+ * This interface calls enable_source handler to determine if
+ * media source is free for use. The enable_source handler is
+ * responsible for checking is the media source is free and
+ * start a pipeline between the media source and the media
+ * entity associated with the video device. This interface
+ * should be called from v4l2-core and dvb-core interfaces
+ * that change the source configuration.
+ *
+ * Return: returns zero on success or a negative error code.
+ */
+int v4l_enable_media_source(struct video_device *vdev);
+
+/**
+ * v4l_disable_media_source() - Release media source
+ *
+ * @vdev: pointer to struct video_device
+ *
+ * This interface calls disable_source handler to release
+ * the media source. The disable_source handler stops the
+ * active media pipeline between the media source and the
+ * media entity associated with the video device.
+ *
+ * Return: returns zero on success or a negative error code.
+ */
+void v4l_disable_media_source(struct video_device *vdev);
+
+/*
+ * v4l_vb2q_enable_media_tuner - Hold media source for exclusive use
+ * if free.
+ * @q - pointer to struct vb2_queue
+ *
+ * Wrapper for v4l_enable_media_source(). This function should
+ * be called from v4l2-core to enable the media source with
+ * pointer to struct vb2_queue as the input argument. Some
+ * v4l2-core interfaces don't have access to video device and
+ * this interface finds the struct video_device for the q and
+ * calls v4l_enable_media_source().
+ */
+int v4l_vb2q_enable_media_source(struct vb2_queue *q);
+
+/**
+ * v4l2_create_fwnode_links_to_pad - Create fwnode-based links from a
+ * source subdev to a sink subdev pad.
+ *
+ * @src_sd: pointer to a source subdev
+ * @sink: pointer to a subdev sink pad
+ *
+ * This function searches for fwnode endpoint connections from a source
+ * subdevice to a single sink pad, and if suitable connections are found,
+ * translates them into media links to that pad. The function can be
+ * called by the sink subdevice, in its v4l2-async notifier subdev bound
+ * callback, to create links from a bound source subdevice.
+ *
+ * .. note::
+ *
+ * Any sink subdevice that calls this function must implement the
+ * .get_fwnode_pad media operation in order to verify endpoints passed
+ * to the sink are owned by the sink.
+ *
+ * Return 0 on success or a negative error code on failure.
+ */
+int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
+ struct media_pad *sink);
+
+/**
+ * v4l2_create_fwnode_links - Create fwnode-based links from a source
+ * subdev to a sink subdev.
+ *
+ * @src_sd: pointer to a source subdevice
+ * @sink_sd: pointer to a sink subdevice
+ *
+ * This function searches for any and all fwnode endpoint connections
+ * between source and sink subdevices, and translates them into media
+ * links. The function can be called by the sink subdevice, in its
+ * v4l2-async notifier subdev bound callback, to create all links from
+ * a bound source subdevice.
+ *
+ * .. note::
+ *
+ * Any sink subdevice that calls this function must implement the
+ * .get_fwnode_pad media operation in order to verify endpoints passed
+ * to the sink are owned by the sink.
+ *
+ * Return 0 on success or a negative error code on failure.
+ */
+int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
+ struct v4l2_subdev *sink_sd);
+
+/**
+ * v4l2_pipeline_pm_get - Increase the use count of a pipeline
+ * @entity: The root entity of a pipeline
+ *
+ * Update the use count of all entities in the pipeline and power entities on.
+ *
+ * This function is intended to be called in video node open. It uses
+ * struct media_entity.use_count to track the power status. The use
+ * of this function should be paired with v4l2_pipeline_link_notify().
+ *
+ * Return 0 on success or a negative error code on failure.
+ */
+int v4l2_pipeline_pm_get(struct media_entity *entity);
+
+/**
+ * v4l2_pipeline_pm_put - Decrease the use count of a pipeline
+ * @entity: The root entity of a pipeline
+ *
+ * Update the use count of all entities in the pipeline and power entities off.
+ *
+ * This function is intended to be called in video node release. It uses
+ * struct media_entity.use_count to track the power status. The use
+ * of this function should be paired with v4l2_pipeline_link_notify().
+ */
+void v4l2_pipeline_pm_put(struct media_entity *entity);
+
+
+/**
+ * v4l2_pipeline_link_notify - Link management notification callback
+ * @link: The link
+ * @flags: New link flags that will be applied
+ * @notification: The link's state change notification type (MEDIA_DEV_NOTIFY_*)
+ *
+ * React to link management on powered pipelines by updating the use count of
+ * all entities in the source and sink sides of the link. Entities are powered
+ * on or off accordingly. The use of this function should be paired
+ * with v4l2_pipeline_pm_{get,put}().
+ *
+ * Return 0 on success or a negative error code on failure. Powering entities
+ * off is assumed to never fail. This function will not fail for disconnection
+ * events.
+ */
+int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
+ unsigned int notification);
+
+#else /* CONFIG_MEDIA_CONTROLLER */
+
+static inline int v4l2_mc_create_media_graph(struct media_device *mdev)
+{
+ return 0;
+}
+
+static inline int v4l_enable_media_source(struct video_device *vdev)
+{
+ return 0;
+}
+
+static inline void v4l_disable_media_source(struct video_device *vdev)
+{
+}
+
+static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
+{
+ return 0;
+}
+
+static inline int v4l2_pipeline_pm_get(struct media_entity *entity)
+{
+ return 0;
+}
+
+static inline void v4l2_pipeline_pm_put(struct media_entity *entity)
+{}
+
+static inline int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
+ unsigned int notification)
+{
+ return 0;
+}
+
+#endif /* CONFIG_MEDIA_CONTROLLER */
+#endif /* _V4L2_MC_H */