/*
 * V4L2 Media Controller Driver for Freescale i.MX5/6 SOC
 *
 * Copyright (c) 2016 Mentor Graphics Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/of_graph.h>
#include <linux/of_platform.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mc.h>
#include <video/imx-ipu-v3.h>
#include <media/imx.h>
#include "imx-media.h"

static inline struct imx_media_dev *notifier2dev(struct v4l2_async_notifier *n)
{
        return container_of(n, struct imx_media_dev, subdev_notifier);
}

/*
 * Find an asd by fwnode or device name. This is called during
 * driver load to form the async subdev list and bind them.
 */
static struct v4l2_async_subdev *
find_async_subdev(struct imx_media_dev *imxmd,
                  struct fwnode_handle *fwnode,
                  const char *devname)
{
        struct imx_media_async_subdev *imxasd;
        struct v4l2_async_subdev *asd;

        list_for_each_entry(imxasd, &imxmd->asd_list, list) {
                asd = &imxasd->asd;
                switch (asd->match_type) {
                case V4L2_ASYNC_MATCH_FWNODE:
                        if (fwnode && asd->match.fwnode == fwnode)
                                return asd;
                        break;
                case V4L2_ASYNC_MATCH_DEVNAME:
                        if (devname && !strcmp(asd->match.device_name,
                                               devname))
                                return asd;
                        break;
                default:
                        break;
                }
        }

        return NULL;
}


/*
 * Adds a subdev to the async subdev list. If fwnode is non-NULL, adds
 * the async as a V4L2_ASYNC_MATCH_FWNODE match type, otherwise as
 * a V4L2_ASYNC_MATCH_DEVNAME match type using the dev_name of the
 * given platform_device. This is called during driver load when
 * forming the async subdev list.
 */
int imx_media_add_async_subdev(struct imx_media_dev *imxmd,
                               struct fwnode_handle *fwnode,
                               struct platform_device *pdev)
{
        struct device_node *np = to_of_node(fwnode);
        struct imx_media_async_subdev *imxasd;
        struct v4l2_async_subdev *asd;
        const char *devname = NULL;
        int ret = 0;

        mutex_lock(&imxmd->mutex);

        if (pdev)
                devname = dev_name(&pdev->dev);

        /* return -EEXIST if this asd already added */
        if (find_async_subdev(imxmd, fwnode, devname)) {
                dev_dbg(imxmd->md.dev, "%s: already added %s\n",
                        __func__, np ? np->name : devname);
                ret = -EEXIST;
                goto out;
        }

        imxasd = devm_kzalloc(imxmd->md.dev, sizeof(*imxasd), GFP_KERNEL);
        if (!imxasd) {
                ret = -ENOMEM;
                goto out;
        }
        asd = &imxasd->asd;

        if (fwnode) {
                asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
                asd->match.fwnode = fwnode;
        } else {
                asd->match_type = V4L2_ASYNC_MATCH_DEVNAME;
                asd->match.device_name = devname;
                imxasd->pdev = pdev;
        }

        list_add_tail(&imxasd->list, &imxmd->asd_list);

        imxmd->subdev_notifier.num_subdevs++;

        dev_dbg(imxmd->md.dev, "%s: added %s, match type %s\n",
                __func__, np ? np->name : devname, np ? "FWNODE" : "DEVNAME");

out:
        mutex_unlock(&imxmd->mutex);
        return ret;
}

/*
 * get IPU from this CSI and add it to the list of IPUs
 * the media driver will control.
 */
static int imx_media_get_ipu(struct imx_media_dev *imxmd,
                             struct v4l2_subdev *csi_sd)
{
        struct ipu_soc *ipu;
        int ipu_id;

        ipu = dev_get_drvdata(csi_sd->dev->parent);
        if (!ipu) {
                v4l2_err(&imxmd->v4l2_dev,
                         "CSI %s has no parent IPU!\n", csi_sd->name);
                return -ENODEV;
        }

        ipu_id = ipu_get_num(ipu);
        if (ipu_id > 1) {
                v4l2_err(&imxmd->v4l2_dev, "invalid IPU id %d!\n", ipu_id);
                return -ENODEV;
        }

        if (!imxmd->ipu[ipu_id])
                imxmd->ipu[ipu_id] = ipu;

        return 0;
}

/* async subdev bound notifier */
static int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,
                                  struct v4l2_subdev *sd,
                                  struct v4l2_async_subdev *asd)
{
        struct imx_media_dev *imxmd = notifier2dev(notifier);
        int ret = 0;

        mutex_lock(&imxmd->mutex);

        if (sd->grp_id & IMX_MEDIA_GRP_ID_CSI) {
                ret = imx_media_get_ipu(imxmd, sd);
                if (ret)
                        goto out;
        }

        v4l2_info(&imxmd->v4l2_dev, "subdev %s bound\n", sd->name);
out:
        mutex_unlock(&imxmd->mutex);
        return ret;
}

/*
 * create the media links for all subdevs that registered async.
 * Called after all async subdevs have bound.
 */
static int imx_media_create_links(struct v4l2_async_notifier *notifier)
{
        struct imx_media_dev *imxmd = notifier2dev(notifier);
        struct v4l2_subdev *sd;
        int ret;

        /*
         * Only links are created between subdevices that are known
         * to the async notifier. If there are other non-async subdevices,
         * they were created internally by some subdevice (smiapp is one
         * example). In those cases it is expected the subdevice is
         * responsible for creating those internal links.
         */
        list_for_each_entry(sd, &notifier->done, async_list) {
                switch (sd->grp_id) {
                case IMX_MEDIA_GRP_ID_VDIC:
                case IMX_MEDIA_GRP_ID_IC_PRP:
                case IMX_MEDIA_GRP_ID_IC_PRPENC:
                case IMX_MEDIA_GRP_ID_IC_PRPVF:
                case IMX_MEDIA_GRP_ID_CSI0:
                case IMX_MEDIA_GRP_ID_CSI1:
                        ret = imx_media_create_internal_links(imxmd, sd);
                        if (ret)
                                return ret;
                        /*
                         * the CSIs straddle between the external and the IPU
                         * internal entities, so create the external links
                         * to the CSI sink pads.
                         */
                        if (sd->grp_id & IMX_MEDIA_GRP_ID_CSI)
                                imx_media_create_csi_of_links(imxmd, sd);
                        break;
                default:
                        /* this is an external fwnode subdev */
                        imx_media_create_of_links(imxmd, sd);
                        break;
                }
        }

        return 0;
}

/*
 * adds given video device to given imx-media source pad vdev list.
 * Continues upstream from the pad entity's sink pads.
 */
static int imx_media_add_vdev_to_pad(struct imx_media_dev *imxmd,
                                     struct imx_media_video_dev *vdev,
                                     struct media_pad *srcpad)
{
        struct media_entity *entity = srcpad->entity;
        struct imx_media_pad_vdev *pad_vdev;
        struct list_head *pad_vdev_list;
        struct media_link *link;
        struct v4l2_subdev *sd;
        int i, ret;

        /* skip this entity if not a v4l2_subdev */
        if (!is_media_entity_v4l2_subdev(entity))
                return 0;

        sd = media_entity_to_v4l2_subdev(entity);

        pad_vdev_list = to_pad_vdev_list(sd, srcpad->index);
        if (!pad_vdev_list) {
                v4l2_warn(&imxmd->v4l2_dev, "%s:%u has no vdev list!\n",
                          entity->name, srcpad->index);
                /*
                 * shouldn't happen, but no reason to fail driver load,
                 * just skip this entity.
                 */
                return 0;
        }

        /* just return if we've been here before */
        list_for_each_entry(pad_vdev, pad_vdev_list, list) {
                if (pad_vdev->vdev == vdev)
                        return 0;
        }

        dev_dbg(imxmd->md.dev, "adding %s to pad %s:%u\n",
                vdev->vfd->entity.name, entity->name, srcpad->index);

        pad_vdev = devm_kzalloc(imxmd->md.dev, sizeof(*pad_vdev), GFP_KERNEL);
        if (!pad_vdev)
                return -ENOMEM;

        /* attach this vdev to this pad */
        pad_vdev->vdev = vdev;
        list_add_tail(&pad_vdev->list, pad_vdev_list);

        /* move upstream from this entity's sink pads */
        for (i = 0; i < entity->num_pads; i++) {
                struct media_pad *pad = &entity->pads[i];

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

                list_for_each_entry(link, &entity->links, list) {
                        if (link->sink != pad)
                                continue;
                        ret = imx_media_add_vdev_to_pad(imxmd, vdev,
                                                        link->source);
                        if (ret)
                                return ret;
                }
        }

        return 0;
}

/*
 * For every subdevice, allocate an array of list_head's, one list_head
 * for each pad, to hold the list of video devices reachable from that
 * pad.
 */
static int imx_media_alloc_pad_vdev_lists(struct imx_media_dev *imxmd)
{
        struct list_head *vdev_lists;
        struct media_entity *entity;
        struct v4l2_subdev *sd;
        int i;

        list_for_each_entry(sd, &imxmd->v4l2_dev.subdevs, list) {
                entity = &sd->entity;
                vdev_lists = devm_kcalloc(
                        imxmd->md.dev,
                        entity->num_pads, sizeof(*vdev_lists),
                        GFP_KERNEL);
                if (!vdev_lists)
                        return -ENOMEM;

                /* attach to the subdev's host private pointer */
                sd->host_priv = vdev_lists;

                for (i = 0; i < entity->num_pads; i++)
                        INIT_LIST_HEAD(to_pad_vdev_list(sd, i));
        }

        return 0;
}

/* form the vdev lists in all imx-media source pads */
static int imx_media_create_pad_vdev_lists(struct imx_media_dev *imxmd)
{
        struct imx_media_video_dev *vdev;
        struct media_link *link;
        int ret;

        ret = imx_media_alloc_pad_vdev_lists(imxmd);
        if (ret)
                return ret;

        list_for_each_entry(vdev, &imxmd->vdev_list, list) {
                link = list_first_entry(&vdev->vfd->entity.links,
                                        struct media_link, list);
                ret = imx_media_add_vdev_to_pad(imxmd, vdev, link->source);
                if (ret)
                        return ret;
        }

        return 0;
}

/* async subdev complete notifier */
static int imx_media_probe_complete(struct v4l2_async_notifier *notifier)
{
        struct imx_media_dev *imxmd = notifier2dev(notifier);
        int ret;

        mutex_lock(&imxmd->mutex);

        ret = imx_media_create_links(notifier);
        if (ret)
                goto unlock;

        ret = imx_media_create_pad_vdev_lists(imxmd);
        if (ret)
                goto unlock;

        ret = v4l2_device_register_subdev_nodes(&imxmd->v4l2_dev);
unlock:
        mutex_unlock(&imxmd->mutex);
        if (ret)
                return ret;

        return media_device_register(&imxmd->md);
}

static const struct v4l2_async_notifier_operations imx_media_subdev_ops = {
        .bound = imx_media_subdev_bound,
        .complete = imx_media_probe_complete,
};

/*
 * adds controls to a video device from an entity subdevice.
 * Continues upstream from the entity's sink pads.
 */
static int imx_media_inherit_controls(struct imx_media_dev *imxmd,
                                      struct video_device *vfd,
                                      struct media_entity *entity)
{
        int i, ret = 0;

        if (is_media_entity_v4l2_subdev(entity)) {
                struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);

                dev_dbg(imxmd->md.dev,
                        "adding controls to %s from %s\n",
                        vfd->entity.name, sd->entity.name);

                ret = v4l2_ctrl_add_handler(vfd->ctrl_handler,
                                            sd->ctrl_handler,
                                            NULL);
                if (ret)
                        return ret;
        }

        /* move upstream */
        for (i = 0; i < entity->num_pads; i++) {
                struct media_pad *pad, *spad = &entity->pads[i];

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

                pad = media_entity_remote_pad(spad);
                if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
                        continue;

                ret = imx_media_inherit_controls(imxmd, vfd, pad->entity);
                if (ret)
                        break;
        }

        return ret;
}

static int imx_media_link_notify(struct media_link *link, u32 flags,
                                 unsigned int notification)
{
        struct media_entity *source = link->source->entity;
        struct imx_media_pad_vdev *pad_vdev;
        struct list_head *pad_vdev_list;
        struct imx_media_dev *imxmd;
        struct video_device *vfd;
        struct v4l2_subdev *sd;
        int pad_idx, ret;

        ret = v4l2_pipeline_link_notify(link, flags, notification);
        if (ret)
                return ret;

        /* don't bother if source is not a subdev */
        if (!is_media_entity_v4l2_subdev(source))
                return 0;

        sd = media_entity_to_v4l2_subdev(source);
        pad_idx = link->source->index;

        imxmd = dev_get_drvdata(sd->v4l2_dev->dev);

        pad_vdev_list = to_pad_vdev_list(sd, pad_idx);
        if (!pad_vdev_list) {
                /* shouldn't happen, but no reason to fail link setup */
                return 0;
        }

        /*
         * Before disabling a link, reset controls for all video
         * devices reachable from this link.
         *
         * After enabling a link, refresh controls for all video
         * devices reachable from this link.
         */
        if (notification == MEDIA_DEV_NOTIFY_PRE_LINK_CH &&
            !(flags & MEDIA_LNK_FL_ENABLED)) {
                list_for_each_entry(pad_vdev, pad_vdev_list, list) {
                        vfd = pad_vdev->vdev->vfd;
                        dev_dbg(imxmd->md.dev,
                                "reset controls for %s\n",
                                vfd->entity.name);
                        v4l2_ctrl_handler_free(vfd->ctrl_handler);
                        v4l2_ctrl_handler_init(vfd->ctrl_handler, 0);
                }
        } else if (notification == MEDIA_DEV_NOTIFY_POST_LINK_CH &&
                   (link->flags & MEDIA_LNK_FL_ENABLED)) {
                list_for_each_entry(pad_vdev, pad_vdev_list, list) {
                        vfd = pad_vdev->vdev->vfd;
                        dev_dbg(imxmd->md.dev,
                                "refresh controls for %s\n",
                                vfd->entity.name);
                        ret = imx_media_inherit_controls(imxmd, vfd,
                                                         &vfd->entity);
                        if (ret)
                                break;
                }
        }

        return ret;
}

static const struct media_device_ops imx_media_md_ops = {
        .link_notify = imx_media_link_notify,
};

static int imx_media_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *node = dev->of_node;
        struct imx_media_async_subdev *imxasd;
        struct v4l2_async_subdev **subdevs;
        struct imx_media_dev *imxmd;
        int num_subdevs, i, ret;

        imxmd = devm_kzalloc(dev, sizeof(*imxmd), GFP_KERNEL);
        if (!imxmd)
                return -ENOMEM;

        dev_set_drvdata(dev, imxmd);

        strlcpy(imxmd->md.model, "imx-media", sizeof(imxmd->md.model));
        imxmd->md.ops = &imx_media_md_ops;
        imxmd->md.dev = dev;

        mutex_init(&imxmd->mutex);

        imxmd->v4l2_dev.mdev = &imxmd->md;
        strlcpy(imxmd->v4l2_dev.name, "imx-media",
                sizeof(imxmd->v4l2_dev.name));

        media_device_init(&imxmd->md);

        ret = v4l2_device_register(dev, &imxmd->v4l2_dev);
        if (ret < 0) {
                v4l2_err(&imxmd->v4l2_dev,
                         "Failed to register v4l2_device: %d\n", ret);
                goto cleanup;
        }

        dev_set_drvdata(imxmd->v4l2_dev.dev, imxmd);

        INIT_LIST_HEAD(&imxmd->asd_list);
        INIT_LIST_HEAD(&imxmd->vdev_list);

        ret = imx_media_add_of_subdevs(imxmd, node);
        if (ret) {
                v4l2_err(&imxmd->v4l2_dev,
                         "add_of_subdevs failed with %d\n", ret);
                goto unreg_dev;
        }

        ret = imx_media_add_internal_subdevs(imxmd);
        if (ret) {
                v4l2_err(&imxmd->v4l2_dev,
                         "add_internal_subdevs failed with %d\n", ret);
                goto unreg_dev;
        }

        num_subdevs = imxmd->subdev_notifier.num_subdevs;

        /* no subdevs? just bail */
        if (num_subdevs == 0) {
                ret = -ENODEV;
                goto unreg_dev;
        }

        subdevs = devm_kcalloc(imxmd->md.dev, num_subdevs, sizeof(*subdevs),
                               GFP_KERNEL);
        if (!subdevs) {
                ret = -ENOMEM;
                goto unreg_dev;
        }

        i = 0;
        list_for_each_entry(imxasd, &imxmd->asd_list, list)
                subdevs[i++] = &imxasd->asd;

        /* prepare the async subdev notifier and register it */
        imxmd->subdev_notifier.subdevs = subdevs;
        imxmd->subdev_notifier.ops = &imx_media_subdev_ops;
        ret = v4l2_async_notifier_register(&imxmd->v4l2_dev,
                                           &imxmd->subdev_notifier);
        if (ret) {
                v4l2_err(&imxmd->v4l2_dev,
                         "v4l2_async_notifier_register failed with %d\n", ret);
                goto del_int;
        }

        return 0;

del_int:
        imx_media_remove_internal_subdevs(imxmd);
unreg_dev:
        v4l2_device_unregister(&imxmd->v4l2_dev);
cleanup:
        media_device_cleanup(&imxmd->md);
        return ret;
}

static int imx_media_remove(struct platform_device *pdev)
{
        struct imx_media_dev *imxmd =
                (struct imx_media_dev *)platform_get_drvdata(pdev);

        v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n");

        v4l2_async_notifier_unregister(&imxmd->subdev_notifier);
        imx_media_remove_internal_subdevs(imxmd);
        v4l2_device_unregister(&imxmd->v4l2_dev);
        media_device_unregister(&imxmd->md);
        media_device_cleanup(&imxmd->md);

        return 0;
}

static const struct of_device_id imx_media_dt_ids[] = {
        { .compatible = "fsl,imx-capture-subsystem" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx_media_dt_ids);

static struct platform_driver imx_media_pdrv = {
        .probe          = imx_media_probe,
        .remove         = imx_media_remove,
        .driver         = {
                .name   = "imx-media",
                .of_match_table = imx_media_dt_ids,
        },
};

module_platform_driver(imx_media_pdrv);

MODULE_DESCRIPTION("i.MX5/6 v4l2 media controller driver");
MODULE_AUTHOR("Steve Longerbeam <steve_longerbeam@mentor.com>");
MODULE_LICENSE("GPL");