// SPDX-License-Identifier: GPL-2.0-or-later

/*
 * Media Controller ancillary functions
 *
 * Copyright (c) 2016 Mauro Carvalho Chehab <mchehab@kernel.org>
 * Copyright (C) 2016 Shuah Khan <shuahkh@osg.samsung.com>
 * Copyright (C) 2006-2010 Nokia Corporation
 * Copyright (c) 2016 Intel Corporation.
 */

#include <linux/module.h>
#include <linux/pci.h>
#include <linux/usb.h>
#include <media/media-device.h>
#include <media/media-entity.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-mc.h>
#include <media/v4l2-subdev.h>
#include <media/videobuf2-core.h>

int v4l2_mc_create_media_graph(struct media_device *mdev)

{
        struct media_entity *entity;
        struct media_entity *if_vid = NULL, *if_aud = NULL;
        struct media_entity *tuner = NULL, *decoder = NULL;
        struct media_entity *io_v4l = NULL, *io_vbi = NULL, *io_swradio = NULL;
        bool is_webcam = false;
        u32 flags;
        int ret, pad_sink, pad_source;

        if (!mdev)
                return 0;

        media_device_for_each_entity(entity, mdev) {
                switch (entity->function) {
                case MEDIA_ENT_F_IF_VID_DECODER:
                        if_vid = entity;
                        break;
                case MEDIA_ENT_F_IF_AUD_DECODER:
                        if_aud = entity;
                        break;
                case MEDIA_ENT_F_TUNER:
                        tuner = entity;
                        break;
                case MEDIA_ENT_F_ATV_DECODER:
                        decoder = entity;
                        break;
                case MEDIA_ENT_F_IO_V4L:
                        io_v4l = entity;
                        break;
                case MEDIA_ENT_F_IO_VBI:
                        io_vbi = entity;
                        break;
                case MEDIA_ENT_F_IO_SWRADIO:
                        io_swradio = entity;
                        break;
                case MEDIA_ENT_F_CAM_SENSOR:
                        is_webcam = true;
                        break;
                }
        }

        /* It should have at least one I/O entity */
        if (!io_v4l && !io_vbi && !io_swradio) {
                dev_warn(mdev->dev, "Didn't find any I/O entity\n");
                return -EINVAL;
        }

        /*
         * Here, 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 not enough
         * for mc-centric hardware, it is enough for v4l2 interface centric
         * PC-consumer's hardware.
         */
        if (is_webcam) {
                if (!io_v4l) {
                        dev_warn(mdev->dev, "Didn't find a MEDIA_ENT_F_IO_V4L\n");
                        return -EINVAL;
                }

                media_device_for_each_entity(entity, mdev) {
                        if (entity->function != MEDIA_ENT_F_CAM_SENSOR)
                                continue;
                        ret = media_create_pad_link(entity, 0,
                                                    io_v4l, 0,
                                                    MEDIA_LNK_FL_ENABLED);
                        if (ret) {
                                dev_warn(mdev->dev, "Failed to create a sensor link\n");
                                return ret;
                        }
                }
                if (!decoder)
                        return 0;
        }

        /* The device isn't a webcam. So, it should have a decoder */
        if (!decoder) {
                dev_warn(mdev->dev, "Decoder not found\n");
                return -EINVAL;
        }

        /* Link the tuner and IF video output pads */
        if (tuner) {
                if (if_vid) {
                        pad_source = media_get_pad_index(tuner,
                                                         MEDIA_PAD_FL_SOURCE,
                                                         PAD_SIGNAL_ANALOG);
                        pad_sink = media_get_pad_index(if_vid,
                                                       MEDIA_PAD_FL_SINK,
                                                       PAD_SIGNAL_ANALOG);
                        if (pad_source < 0 || pad_sink < 0) {
                                dev_warn(mdev->dev, "Couldn't get tuner and/or PLL pad(s): (%d, %d)\n",
                                         pad_source, pad_sink);
                                return -EINVAL;
                        }
                        ret = media_create_pad_link(tuner, pad_source,
                                                    if_vid, pad_sink,
                                                    MEDIA_LNK_FL_ENABLED);
                        if (ret) {
                                dev_warn(mdev->dev, "Couldn't create tuner->PLL link)\n");
                                return ret;
                        }

                        pad_source = media_get_pad_index(if_vid,
                                                         MEDIA_PAD_FL_SOURCE,
                                                         PAD_SIGNAL_ANALOG);
                        pad_sink = media_get_pad_index(decoder,
                                                       MEDIA_PAD_FL_SINK,
                                                       PAD_SIGNAL_ANALOG);
                        if (pad_source < 0 || pad_sink < 0) {
                                dev_warn(mdev->dev, "get decoder and/or PLL pad(s): (%d, %d)\n",
                                         pad_source, pad_sink);
                                return -EINVAL;
                        }
                        ret = media_create_pad_link(if_vid, pad_source,
                                                    decoder, pad_sink,
                                                    MEDIA_LNK_FL_ENABLED);
                        if (ret) {
                                dev_warn(mdev->dev, "couldn't link PLL to decoder\n");
                                return ret;
                        }
                } else {
                        pad_source = media_get_pad_index(tuner,
                                                         MEDIA_PAD_FL_SOURCE,
                                                         PAD_SIGNAL_ANALOG);
                        pad_sink = media_get_pad_index(decoder,
                                                       MEDIA_PAD_FL_SINK,
                                                       PAD_SIGNAL_ANALOG);
                        if (pad_source < 0 || pad_sink < 0) {
                                dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s): (%d, %d)\n",
                                         pad_source, pad_sink);
                                return -EINVAL;
                        }
                        ret = media_create_pad_link(tuner, pad_source,
                                                    decoder, pad_sink,
                                                    MEDIA_LNK_FL_ENABLED);
                        if (ret)
                                return ret;
                }

                if (if_aud) {
                        pad_source = media_get_pad_index(tuner,
                                                         MEDIA_PAD_FL_SOURCE,
                                                         PAD_SIGNAL_AUDIO);
                        pad_sink = media_get_pad_index(if_aud,
                                                       MEDIA_PAD_FL_SINK,
                                                       PAD_SIGNAL_AUDIO);
                        if (pad_source < 0 || pad_sink < 0) {
                                dev_warn(mdev->dev, "couldn't get tuner and/or decoder pad(s) for audio: (%d, %d)\n",
                                         pad_source, pad_sink);
                                return -EINVAL;
                        }
                        ret = media_create_pad_link(tuner, pad_source,
                                                    if_aud, pad_sink,
                                                    MEDIA_LNK_FL_ENABLED);
                        if (ret) {
                                dev_warn(mdev->dev, "couldn't link tuner->audio PLL\n");
                                return ret;
                        }
                } else {
                        if_aud = tuner;
                }

        }

        /* Create demod to V4L, VBI and SDR radio links */
        if (io_v4l) {
                pad_source = media_get_pad_index(decoder, MEDIA_PAD_FL_SOURCE,
                                                 PAD_SIGNAL_DV);
                if (pad_source < 0) {
                        dev_warn(mdev->dev, "couldn't get decoder output pad for V4L I/O\n");
                        return -EINVAL;
                }
                ret = media_create_pad_link(decoder, pad_source,
                                            io_v4l, 0,
                                            MEDIA_LNK_FL_ENABLED);
                if (ret) {
                        dev_warn(mdev->dev, "couldn't link decoder output to V4L I/O\n");
                        return ret;
                }
        }

        if (io_swradio) {
                pad_source = media_get_pad_index(decoder, MEDIA_PAD_FL_SOURCE,
                                                 PAD_SIGNAL_DV);
                if (pad_source < 0) {
                        dev_warn(mdev->dev, "couldn't get decoder output pad for SDR\n");
                        return -EINVAL;
                }
                ret = media_create_pad_link(decoder, pad_source,
                                            io_swradio, 0,
                                            MEDIA_LNK_FL_ENABLED);
                if (ret) {
                        dev_warn(mdev->dev, "couldn't link decoder output to SDR\n");
                        return ret;
                }
        }

        if (io_vbi) {
                pad_source = media_get_pad_index(decoder, MEDIA_PAD_FL_SOURCE,
                                                 PAD_SIGNAL_DV);
                if (pad_source < 0) {
                        dev_warn(mdev->dev, "couldn't get decoder output pad for VBI\n");
                        return -EINVAL;
                }
                ret = media_create_pad_link(decoder, pad_source,
                                            io_vbi, 0,
                                            MEDIA_LNK_FL_ENABLED);
                if (ret) {
                        dev_warn(mdev->dev, "couldn't link decoder output to VBI\n");
                        return ret;
                }
        }

        /* Create links for the media connectors */
        flags = MEDIA_LNK_FL_ENABLED;
        media_device_for_each_entity(entity, mdev) {
                switch (entity->function) {
                case MEDIA_ENT_F_CONN_RF:
                        if (!tuner)
                                continue;
                        pad_sink = media_get_pad_index(tuner, MEDIA_PAD_FL_SINK,
                                                       PAD_SIGNAL_ANALOG);
                        if (pad_sink < 0) {
                                dev_warn(mdev->dev, "couldn't get tuner analog pad sink\n");
                                return -EINVAL;
                        }
                        ret = media_create_pad_link(entity, 0, tuner,
                                                    pad_sink,
                                                    flags);
                        break;
                case MEDIA_ENT_F_CONN_SVIDEO:
                case MEDIA_ENT_F_CONN_COMPOSITE:
                        pad_sink = media_get_pad_index(decoder,
                                                       MEDIA_PAD_FL_SINK,
                                                       PAD_SIGNAL_ANALOG);
                        if (pad_sink < 0) {
                                dev_warn(mdev->dev, "couldn't get decoder analog pad sink\n");
                                return -EINVAL;
                        }
                        ret = media_create_pad_link(entity, 0, decoder,
                                                    pad_sink,
                                                    flags);
                        break;
                default:
                        continue;
                }
                if (ret)
                        return ret;

                flags = 0;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(v4l2_mc_create_media_graph);

int v4l_enable_media_source(struct video_device *vdev)
{
        struct media_device *mdev = vdev->entity.graph_obj.mdev;
        int ret = 0, err;

        if (!mdev)
                return 0;

        mutex_lock(&mdev->graph_mutex);
        if (!mdev->enable_source)
                goto end;
        err = mdev->enable_source(&vdev->entity, &vdev->pipe);
        if (err)
                ret = -EBUSY;
end:
        mutex_unlock(&mdev->graph_mutex);
        return ret;
}
EXPORT_SYMBOL_GPL(v4l_enable_media_source);

void v4l_disable_media_source(struct video_device *vdev)
{
        struct media_device *mdev = vdev->entity.graph_obj.mdev;

        if (mdev) {
                mutex_lock(&mdev->graph_mutex);
                if (mdev->disable_source)
                        mdev->disable_source(&vdev->entity);
                mutex_unlock(&mdev->graph_mutex);
        }
}
EXPORT_SYMBOL_GPL(v4l_disable_media_source);

int v4l_vb2q_enable_media_source(struct vb2_queue *q)
{
        struct v4l2_fh *fh = q->owner;

        if (fh && fh->vdev)
                return v4l_enable_media_source(fh->vdev);
        return 0;
}
EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);

int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
                                    struct media_pad *sink, u32 flags)
{
        struct fwnode_handle *endpoint;

        if (!(sink->flags & MEDIA_PAD_FL_SINK))
                return -EINVAL;

        fwnode_graph_for_each_endpoint(src_sd->fwnode, endpoint) {
                struct fwnode_handle *remote_ep;
                int src_idx, sink_idx, ret;
                struct media_pad *src;

                src_idx = media_entity_get_fwnode_pad(&src_sd->entity,
                                                      endpoint,
                                                      MEDIA_PAD_FL_SOURCE);
                if (src_idx < 0) {
                        dev_dbg(src_sd->dev, "no source pad found for %pfw\n",
                                endpoint);
                        continue;
                }

                remote_ep = fwnode_graph_get_remote_endpoint(endpoint);
                if (!remote_ep) {
                        dev_dbg(src_sd->dev, "no remote ep found for %pfw\n",
                                endpoint);
                        continue;
                }

                /*
                 * ask the sink to verify it owns the remote endpoint,
                 * and translate to a sink pad.
                 */
                sink_idx = media_entity_get_fwnode_pad(sink->entity,
                                                       remote_ep,
                                                       MEDIA_PAD_FL_SINK);
                fwnode_handle_put(remote_ep);

                if (sink_idx < 0 || sink_idx != sink->index) {
                        dev_dbg(src_sd->dev,
                                "sink pad index mismatch or error (is %d, expected %u)\n",
                                sink_idx, sink->index);
                        continue;
                }

                /*
                 * the source endpoint corresponds to one of its source pads,
                 * the source endpoint connects to an endpoint at the sink
                 * entity, and the sink endpoint corresponds to the sink
                 * pad requested, so we have found an endpoint connection
                 * that works, create the media link for it.
                 */

                src = &src_sd->entity.pads[src_idx];

                /* skip if link already exists */
                if (media_entity_find_link(src, sink)) {
                        dev_dbg(src_sd->dev,
                                "link %s:%d -> %s:%d already exists\n",
                                src_sd->entity.name, src_idx,
                                sink->entity->name, sink_idx);
                        continue;
                }

                dev_dbg(src_sd->dev, "creating link %s:%d -> %s:%d\n",
                        src_sd->entity.name, src_idx,
                        sink->entity->name, sink_idx);

                ret = media_create_pad_link(&src_sd->entity, src_idx,
                                            sink->entity, sink_idx, flags);
                if (ret) {
                        dev_err(src_sd->dev,
                                "link %s:%d -> %s:%d failed with %d\n",
                                src_sd->entity.name, src_idx,
                                sink->entity->name, sink_idx, ret);

                        fwnode_handle_put(endpoint);
                        return ret;
                }
        }

        return 0;
}
EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links_to_pad);

int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
                             struct v4l2_subdev *sink_sd)
{
        unsigned int i;

        for (i = 0; i < sink_sd->entity.num_pads; i++) {
                struct media_pad *pad = &sink_sd->entity.pads[i];
                int ret;

                if (!(pad->flags & MEDIA_PAD_FL_SINK))
                        continue;

                ret = v4l2_create_fwnode_links_to_pad(src_sd, pad, 0);
                if (ret)
                        return ret;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(v4l2_create_fwnode_links);

/* -----------------------------------------------------------------------------
 * Pipeline power management
 *
 * Entities must be powered up when part of a pipeline that contains at least
 * one open video device node.
 *
 * To achieve this use the entity use_count field to track the number of users.
 * For entities corresponding to video device nodes the use_count field stores
 * the users count of the node. For entities corresponding to subdevs the
 * use_count field stores the total number of users of all video device nodes
 * in the pipeline.
 *
 * The v4l2_pipeline_pm_{get, put}() functions must be called in the open() and
 * close() handlers of video device nodes. It increments or decrements the use
 * count of all subdev entities in the pipeline.
 *
 * To react to link management on powered pipelines, the link setup notification
 * callback updates the use count of all entities in the source and sink sides
 * of the link.
 */

/*
 * pipeline_pm_use_count - Count the number of users of a pipeline
 * @entity: The entity
 *
 * Return the total number of users of all video device nodes in the pipeline.
 */
static int pipeline_pm_use_count(struct media_entity *entity,
        struct media_graph *graph)
{
        int use = 0;

        media_graph_walk_start(graph, entity);

        while ((entity = media_graph_walk_next(graph))) {
                if (is_media_entity_v4l2_video_device(entity))
                        use += entity->use_count;
        }

        return use;
}

/*
 * pipeline_pm_power_one - Apply power change to an entity
 * @entity: The entity
 * @change: Use count change
 *
 * Change the entity use count by @change. If the entity is a subdev update its
 * power state by calling the core::s_power operation when the use count goes
 * from 0 to != 0 or from != 0 to 0.
 *
 * Return 0 on success or a negative error code on failure.
 */
static int pipeline_pm_power_one(struct media_entity *entity, int change)
{
        struct v4l2_subdev *subdev;
        int ret;

        subdev = is_media_entity_v4l2_subdev(entity)
               ? media_entity_to_v4l2_subdev(entity) : NULL;

        if (entity->use_count == 0 && change > 0 && subdev != NULL) {
                ret = v4l2_subdev_call(subdev, core, s_power, 1);
                if (ret < 0 && ret != -ENOIOCTLCMD)
                        return ret;
        }

        entity->use_count += change;
        WARN_ON(entity->use_count < 0);

        if (entity->use_count == 0 && change < 0 && subdev != NULL)
                v4l2_subdev_call(subdev, core, s_power, 0);

        return 0;
}

/*
 * pipeline_pm_power - Apply power change to all entities in a pipeline
 * @entity: The entity
 * @change: Use count change
 *
 * Walk the pipeline to update the use count and the power state of all non-node
 * entities.
 *
 * Return 0 on success or a negative error code on failure.
 */
static int pipeline_pm_power(struct media_entity *entity, int change,
        struct media_graph *graph)
{
        struct media_entity *first = entity;
        int ret = 0;

        if (!change)
                return 0;

        media_graph_walk_start(graph, entity);

        while (!ret && (entity = media_graph_walk_next(graph)))
                if (is_media_entity_v4l2_subdev(entity))
                        ret = pipeline_pm_power_one(entity, change);

        if (!ret)
                return ret;

        media_graph_walk_start(graph, first);

        while ((first = media_graph_walk_next(graph))
               && first != entity)
                if (is_media_entity_v4l2_subdev(first))
                        pipeline_pm_power_one(first, -change);

        return ret;
}

static int v4l2_pipeline_pm_use(struct media_entity *entity, unsigned int use)
{
        struct media_device *mdev = entity->graph_obj.mdev;
        int change = use ? 1 : -1;
        int ret;

        mutex_lock(&mdev->graph_mutex);

        /* Apply use count to node. */
        entity->use_count += change;
        WARN_ON(entity->use_count < 0);

        /* Apply power change to connected non-nodes. */
        ret = pipeline_pm_power(entity, change, &mdev->pm_count_walk);
        if (ret < 0)
                entity->use_count -= change;

        mutex_unlock(&mdev->graph_mutex);

        return ret;
}

int v4l2_pipeline_pm_get(struct media_entity *entity)
{
        return v4l2_pipeline_pm_use(entity, 1);
}
EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_get);

void v4l2_pipeline_pm_put(struct media_entity *entity)
{
        /* Powering off entities shouldn't fail. */
        WARN_ON(v4l2_pipeline_pm_use(entity, 0));
}
EXPORT_SYMBOL_GPL(v4l2_pipeline_pm_put);

int v4l2_pipeline_link_notify(struct media_link *link, u32 flags,
                              unsigned int notification)
{
        struct media_graph *graph = &link->graph_obj.mdev->pm_count_walk;
        struct media_entity *source = link->source->entity;
        struct media_entity *sink = link->sink->entity;
        int source_use;
        int sink_use;
        int ret = 0;

        source_use = pipeline_pm_use_count(source, graph);
        sink_use = pipeline_pm_use_count(sink, graph);

        if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
            !(flags & MEDIA_LNK_FL_ENABLED)) {
                /* Powering off entities is assumed to never fail. */
                pipeline_pm_power(source, -sink_use, graph);
                pipeline_pm_power(sink, -source_use, graph);
                return 0;
        }

        if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
                (flags & MEDIA_LNK_FL_ENABLED)) {

                ret = pipeline_pm_power(source, sink_use, graph);
                if (ret < 0)
                        return ret;

                ret = pipeline_pm_power(sink, source_use, graph);
                if (ret < 0)
                        pipeline_pm_power(source, -sink_use, graph);
        }

        return ret;
}
EXPORT_SYMBOL_GPL(v4l2_pipeline_link_notify);