// SPDX-License-Identifier: GPL-2.0
/*
 * Xilinx Video IP Composite Device
 *
 * Copyright (C) 2013-2015 Ideas on Board
 * Copyright (C) 2013-2015 Xilinx, Inc.
 *
 * Contacts: Hyun Kwon <hyun.kwon@xilinx.com>
 *           Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 */

#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <media/v4l2-async.h>
#include <media/v4l2-common.h>
#include <media/v4l2-device.h>
#include <media/v4l2-fwnode.h>

#include "xilinx-dma.h"
#include "xilinx-vipp.h"

#define XVIPP_DMA_S2MM                          0
#define XVIPP_DMA_MM2S                          1

/**
 * struct xvip_graph_entity - Entity in the video graph
 * @asd: subdev asynchronous registration information
 * @entity: media entity, from the corresponding V4L2 subdev
 * @subdev: V4L2 subdev
 */
struct xvip_graph_entity {
        struct v4l2_async_subdev asd; /* must be first */
        struct media_entity *entity;
        struct v4l2_subdev *subdev;
};

static inline struct xvip_graph_entity *
to_xvip_entity(struct v4l2_async_subdev *asd)
{
        return container_of(asd, struct xvip_graph_entity, asd);
}

/* -----------------------------------------------------------------------------
 * Graph Management
 */

static struct xvip_graph_entity *
xvip_graph_find_entity(struct xvip_composite_device *xdev,
                       const struct fwnode_handle *fwnode)
{
        struct xvip_graph_entity *entity;
        struct v4l2_async_subdev *asd;

        list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
                entity = to_xvip_entity(asd);
                if (entity->asd.match.fwnode == fwnode)
                        return entity;
        }

        return NULL;
}

static int xvip_graph_build_one(struct xvip_composite_device *xdev,
                                struct xvip_graph_entity *entity)
{
        u32 link_flags = MEDIA_LNK_FL_ENABLED;
        struct media_entity *local = entity->entity;
        struct media_entity *remote;
        struct media_pad *local_pad;
        struct media_pad *remote_pad;
        struct xvip_graph_entity *ent;
        struct v4l2_fwnode_link link;
        struct fwnode_handle *ep = NULL;
        int ret = 0;

        dev_dbg(xdev->dev, "creating links for entity %s\n", local->name);

        while (1) {
                /* Get the next endpoint and parse its link. */
                ep = fwnode_graph_get_next_endpoint(entity->asd.match.fwnode,
                                                    ep);
                if (ep == NULL)
                        break;

                dev_dbg(xdev->dev, "processing endpoint %p\n", ep);

                ret = v4l2_fwnode_parse_link(ep, &link);
                if (ret < 0) {
                        dev_err(xdev->dev, "failed to parse link for %p\n",
                                ep);
                        continue;
                }

                /* Skip sink ports, they will be processed from the other end of
                 * the link.
                 */
                if (link.local_port >= local->num_pads) {
                        dev_err(xdev->dev, "invalid port number %u for %p\n",
                                link.local_port, link.local_node);
                        v4l2_fwnode_put_link(&link);
                        ret = -EINVAL;
                        break;
                }

                local_pad = &local->pads[link.local_port];

                if (local_pad->flags & MEDIA_PAD_FL_SINK) {
                        dev_dbg(xdev->dev, "skipping sink port %p:%u\n",
                                link.local_node, link.local_port);
                        v4l2_fwnode_put_link(&link);
                        continue;
                }

                /* Skip DMA engines, they will be processed separately. */
                if (link.remote_node == of_fwnode_handle(xdev->dev->of_node)) {
                        dev_dbg(xdev->dev, "skipping DMA port %p:%u\n",
                                link.local_node, link.local_port);
                        v4l2_fwnode_put_link(&link);
                        continue;
                }

                /* Find the remote entity. */
                ent = xvip_graph_find_entity(xdev, link.remote_node);
                if (ent == NULL) {
                        dev_err(xdev->dev, "no entity found for %p\n",
                                link.remote_node);
                        v4l2_fwnode_put_link(&link);
                        ret = -ENODEV;
                        break;
                }

                remote = ent->entity;

                if (link.remote_port >= remote->num_pads) {
                        dev_err(xdev->dev, "invalid port number %u on %p\n",
                                link.remote_port, link.remote_node);
                        v4l2_fwnode_put_link(&link);
                        ret = -EINVAL;
                        break;
                }

                remote_pad = &remote->pads[link.remote_port];

                v4l2_fwnode_put_link(&link);

                /* Create the media link. */
                dev_dbg(xdev->dev, "creating %s:%u -> %s:%u link\n",
                        local->name, local_pad->index,
                        remote->name, remote_pad->index);

                ret = media_create_pad_link(local, local_pad->index,
                                               remote, remote_pad->index,
                                               link_flags);
                if (ret < 0) {
                        dev_err(xdev->dev,
                                "failed to create %s:%u -> %s:%u link\n",
                                local->name, local_pad->index,
                                remote->name, remote_pad->index);
                        break;
                }
        }

        fwnode_handle_put(ep);
        return ret;
}

static struct xvip_dma *
xvip_graph_find_dma(struct xvip_composite_device *xdev, unsigned int port)
{
        struct xvip_dma *dma;

        list_for_each_entry(dma, &xdev->dmas, list) {
                if (dma->port == port)
                        return dma;
        }

        return NULL;
}

static int xvip_graph_build_dma(struct xvip_composite_device *xdev)
{
        u32 link_flags = MEDIA_LNK_FL_ENABLED;
        struct device_node *node = xdev->dev->of_node;
        struct media_entity *source;
        struct media_entity *sink;
        struct media_pad *source_pad;
        struct media_pad *sink_pad;
        struct xvip_graph_entity *ent;
        struct v4l2_fwnode_link link;
        struct device_node *ep = NULL;
        struct xvip_dma *dma;
        int ret = 0;

        dev_dbg(xdev->dev, "creating links for DMA engines\n");

        while (1) {
                /* Get the next endpoint and parse its link. */
                ep = of_graph_get_next_endpoint(node, ep);
                if (ep == NULL)
                        break;

                dev_dbg(xdev->dev, "processing endpoint %pOF\n", ep);

                ret = v4l2_fwnode_parse_link(of_fwnode_handle(ep), &link);
                if (ret < 0) {
                        dev_err(xdev->dev, "failed to parse link for %pOF\n",
                                ep);
                        continue;
                }

                /* Find the DMA engine. */
                dma = xvip_graph_find_dma(xdev, link.local_port);
                if (dma == NULL) {
                        dev_err(xdev->dev, "no DMA engine found for port %u\n",
                                link.local_port);
                        v4l2_fwnode_put_link(&link);
                        ret = -EINVAL;
                        break;
                }

                dev_dbg(xdev->dev, "creating link for DMA engine %s\n",
                        dma->video.name);

                /* Find the remote entity. */
                ent = xvip_graph_find_entity(xdev, link.remote_node);
                if (ent == NULL) {
                        dev_err(xdev->dev, "no entity found for %pOF\n",
                                to_of_node(link.remote_node));
                        v4l2_fwnode_put_link(&link);
                        ret = -ENODEV;
                        break;
                }

                if (link.remote_port >= ent->entity->num_pads) {
                        dev_err(xdev->dev, "invalid port number %u on %pOF\n",
                                link.remote_port,
                                to_of_node(link.remote_node));
                        v4l2_fwnode_put_link(&link);
                        ret = -EINVAL;
                        break;
                }

                if (dma->pad.flags & MEDIA_PAD_FL_SOURCE) {
                        source = &dma->video.entity;
                        source_pad = &dma->pad;
                        sink = ent->entity;
                        sink_pad = &sink->pads[link.remote_port];
                } else {
                        source = ent->entity;
                        source_pad = &source->pads[link.remote_port];
                        sink = &dma->video.entity;
                        sink_pad = &dma->pad;
                }

                v4l2_fwnode_put_link(&link);

                /* Create the media link. */
                dev_dbg(xdev->dev, "creating %s:%u -> %s:%u link\n",
                        source->name, source_pad->index,
                        sink->name, sink_pad->index);

                ret = media_create_pad_link(source, source_pad->index,
                                               sink, sink_pad->index,
                                               link_flags);
                if (ret < 0) {
                        dev_err(xdev->dev,
                                "failed to create %s:%u -> %s:%u link\n",
                                source->name, source_pad->index,
                                sink->name, sink_pad->index);
                        break;
                }
        }

        of_node_put(ep);
        return ret;
}

static int xvip_graph_notify_complete(struct v4l2_async_notifier *notifier)
{
        struct xvip_composite_device *xdev =
                container_of(notifier, struct xvip_composite_device, notifier);
        struct xvip_graph_entity *entity;
        struct v4l2_async_subdev *asd;
        int ret;

        dev_dbg(xdev->dev, "notify complete, all subdevs registered\n");

        /* Create links for every entity. */
        list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
                entity = to_xvip_entity(asd);
                ret = xvip_graph_build_one(xdev, entity);
                if (ret < 0)
                        return ret;
        }

        /* Create links for DMA channels. */
        ret = xvip_graph_build_dma(xdev);
        if (ret < 0)
                return ret;

        ret = v4l2_device_register_subdev_nodes(&xdev->v4l2_dev);
        if (ret < 0)
                dev_err(xdev->dev, "failed to register subdev nodes\n");

        return media_device_register(&xdev->media_dev);
}

static int xvip_graph_notify_bound(struct v4l2_async_notifier *notifier,
                                   struct v4l2_subdev *subdev,
                                   struct v4l2_async_subdev *unused)
{
        struct xvip_composite_device *xdev =
                container_of(notifier, struct xvip_composite_device, notifier);
        struct xvip_graph_entity *entity;
        struct v4l2_async_subdev *asd;

        /* Locate the entity corresponding to the bound subdev and store the
         * subdev pointer.
         */
        list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
                entity = to_xvip_entity(asd);

                if (entity->asd.match.fwnode != subdev->fwnode)
                        continue;

                if (entity->subdev) {
                        dev_err(xdev->dev, "duplicate subdev for node %p\n",
                                entity->asd.match.fwnode);
                        return -EINVAL;
                }

                dev_dbg(xdev->dev, "subdev %s bound\n", subdev->name);
                entity->entity = &subdev->entity;
                entity->subdev = subdev;
                return 0;
        }

        dev_err(xdev->dev, "no entity for subdev %s\n", subdev->name);
        return -EINVAL;
}

static const struct v4l2_async_notifier_operations xvip_graph_notify_ops = {
        .bound = xvip_graph_notify_bound,
        .complete = xvip_graph_notify_complete,
};

static int xvip_graph_parse_one(struct xvip_composite_device *xdev,
                                struct fwnode_handle *fwnode)
{
        struct fwnode_handle *remote;
        struct fwnode_handle *ep = NULL;
        int ret = 0;

        dev_dbg(xdev->dev, "parsing node %p\n", fwnode);

        while (1) {
                struct xvip_graph_entity *xge;

                ep = fwnode_graph_get_next_endpoint(fwnode, ep);
                if (ep == NULL)
                        break;

                dev_dbg(xdev->dev, "handling endpoint %p\n", ep);

                remote = fwnode_graph_get_remote_port_parent(ep);
                if (remote == NULL) {
                        ret = -EINVAL;
                        goto err_notifier_cleanup;
                }

                fwnode_handle_put(ep);

                /* Skip entities that we have already processed. */
                if (remote == of_fwnode_handle(xdev->dev->of_node) ||
                    xvip_graph_find_entity(xdev, remote)) {
                        fwnode_handle_put(remote);
                        continue;
                }

                xge = v4l2_async_notifier_add_fwnode_subdev(
                        &xdev->notifier, remote,
                        struct xvip_graph_entity);
                fwnode_handle_put(remote);
                if (IS_ERR(xge)) {
                        ret = PTR_ERR(xge);
                        goto err_notifier_cleanup;
                }
        }

        return 0;

err_notifier_cleanup:
        v4l2_async_notifier_cleanup(&xdev->notifier);
        fwnode_handle_put(ep);
        return ret;
}

static int xvip_graph_parse(struct xvip_composite_device *xdev)
{
        struct xvip_graph_entity *entity;
        struct v4l2_async_subdev *asd;
        int ret;

        /*
         * Walk the links to parse the full graph. Start by parsing the
         * composite node and then parse entities in turn. The list_for_each
         * loop will handle entities added at the end of the list while walking
         * the links.
         */
        ret = xvip_graph_parse_one(xdev, of_fwnode_handle(xdev->dev->of_node));
        if (ret < 0)
                return 0;

        list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
                entity = to_xvip_entity(asd);
                ret = xvip_graph_parse_one(xdev, entity->asd.match.fwnode);
                if (ret < 0) {
                        v4l2_async_notifier_cleanup(&xdev->notifier);
                        break;
                }
        }

        return ret;
}

static int xvip_graph_dma_init_one(struct xvip_composite_device *xdev,
                                   struct device_node *node)
{
        struct xvip_dma *dma;
        enum v4l2_buf_type type;
        const char *direction;
        unsigned int index;
        int ret;

        ret = of_property_read_string(node, "direction", &direction);
        if (ret < 0)
                return ret;

        if (strcmp(direction, "input") == 0)
                type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        else if (strcmp(direction, "output") == 0)
                type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
        else
                return -EINVAL;

        of_property_read_u32(node, "reg", &index);

        dma = devm_kzalloc(xdev->dev, sizeof(*dma), GFP_KERNEL);
        if (dma == NULL)
                return -ENOMEM;

        ret = xvip_dma_init(xdev, dma, type, index);
        if (ret < 0) {
                dev_err(xdev->dev, "%pOF initialization failed\n", node);
                return ret;
        }

        list_add_tail(&dma->list, &xdev->dmas);

        xdev->v4l2_caps |= type == V4L2_BUF_TYPE_VIDEO_CAPTURE
                         ? V4L2_CAP_VIDEO_CAPTURE : V4L2_CAP_VIDEO_OUTPUT;

        return 0;
}

static int xvip_graph_dma_init(struct xvip_composite_device *xdev)
{
        struct device_node *ports;
        struct device_node *port;
        int ret;

        ports = of_get_child_by_name(xdev->dev->of_node, "ports");
        if (ports == NULL) {
                dev_err(xdev->dev, "ports node not present\n");
                return -EINVAL;
        }

        for_each_child_of_node(ports, port) {
                ret = xvip_graph_dma_init_one(xdev, port);
                if (ret < 0) {
                        of_node_put(port);
                        return ret;
                }
        }

        return 0;
}

static void xvip_graph_cleanup(struct xvip_composite_device *xdev)
{
        struct xvip_dma *dmap;
        struct xvip_dma *dma;

        v4l2_async_notifier_unregister(&xdev->notifier);
        v4l2_async_notifier_cleanup(&xdev->notifier);

        list_for_each_entry_safe(dma, dmap, &xdev->dmas, list) {
                xvip_dma_cleanup(dma);
                list_del(&dma->list);
        }
}

static int xvip_graph_init(struct xvip_composite_device *xdev)
{
        int ret;

        /* Init the DMA channels. */
        ret = xvip_graph_dma_init(xdev);
        if (ret < 0) {
                dev_err(xdev->dev, "DMA initialization failed\n");
                goto done;
        }

        /* Parse the graph to extract a list of subdevice DT nodes. */
        ret = xvip_graph_parse(xdev);
        if (ret < 0) {
                dev_err(xdev->dev, "graph parsing failed\n");
                goto done;
        }

        if (list_empty(&xdev->notifier.asd_list)) {
                dev_err(xdev->dev, "no subdev found in graph\n");
                ret = -ENOENT;
                goto done;
        }

        /* Register the subdevices notifier. */
        xdev->notifier.ops = &xvip_graph_notify_ops;

        ret = v4l2_async_notifier_register(&xdev->v4l2_dev, &xdev->notifier);
        if (ret < 0) {
                dev_err(xdev->dev, "notifier registration failed\n");
                goto done;
        }

        ret = 0;

done:
        if (ret < 0)
                xvip_graph_cleanup(xdev);

        return ret;
}

/* -----------------------------------------------------------------------------
 * Media Controller and V4L2
 */

static void xvip_composite_v4l2_cleanup(struct xvip_composite_device *xdev)
{
        v4l2_device_unregister(&xdev->v4l2_dev);
        media_device_unregister(&xdev->media_dev);
        media_device_cleanup(&xdev->media_dev);
}

static int xvip_composite_v4l2_init(struct xvip_composite_device *xdev)
{
        int ret;

        xdev->media_dev.dev = xdev->dev;
        strscpy(xdev->media_dev.model, "Xilinx Video Composite Device",
                sizeof(xdev->media_dev.model));
        xdev->media_dev.hw_revision = 0;

        media_device_init(&xdev->media_dev);

        xdev->v4l2_dev.mdev = &xdev->media_dev;
        ret = v4l2_device_register(xdev->dev, &xdev->v4l2_dev);
        if (ret < 0) {
                dev_err(xdev->dev, "V4L2 device registration failed (%d)\n",
                        ret);
                media_device_cleanup(&xdev->media_dev);
                return ret;
        }

        return 0;
}

/* -----------------------------------------------------------------------------
 * Platform Device Driver
 */

static int xvip_composite_probe(struct platform_device *pdev)
{
        struct xvip_composite_device *xdev;
        int ret;

        xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL);
        if (!xdev)
                return -ENOMEM;

        xdev->dev = &pdev->dev;
        INIT_LIST_HEAD(&xdev->dmas);
        v4l2_async_notifier_init(&xdev->notifier);

        ret = xvip_composite_v4l2_init(xdev);
        if (ret < 0)
                return ret;

        ret = xvip_graph_init(xdev);
        if (ret < 0)
                goto error;

        platform_set_drvdata(pdev, xdev);

        dev_info(xdev->dev, "device registered\n");

        return 0;

error:
        xvip_composite_v4l2_cleanup(xdev);
        return ret;
}

static int xvip_composite_remove(struct platform_device *pdev)
{
        struct xvip_composite_device *xdev = platform_get_drvdata(pdev);

        xvip_graph_cleanup(xdev);
        xvip_composite_v4l2_cleanup(xdev);

        return 0;
}

static const struct of_device_id xvip_composite_of_id_table[] = {
        { .compatible = "xlnx,video" },
        { }
};
MODULE_DEVICE_TABLE(of, xvip_composite_of_id_table);

static struct platform_driver xvip_composite_driver = {
        .driver = {
                .name = "xilinx-video",
                .of_match_table = xvip_composite_of_id_table,
        },
        .probe = xvip_composite_probe,
        .remove = xvip_composite_remove,
};

module_platform_driver(xvip_composite_driver);

MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("Xilinx Video IP Composite Driver");
MODULE_LICENSE("GPL v2");