/*
 * Media device
 *
 * Copyright (C) 2010 Nokia Corporation
 *
 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *           Sakari Ailus <sakari.ailus@iki.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/compat.h>
#include <linux/export.h>
#include <linux/ioctl.h>
#include <linux/media.h>
#include <linux/types.h>

#include <media/media-device.h>
#include <media/media-devnode.h>
#include <media/media-entity.h>

/* -----------------------------------------------------------------------------
 * Userspace API
 */

static int media_device_open(struct file *filp)
{
        return 0;
}

static int media_device_close(struct file *filp)
{
        return 0;
}

static int media_device_get_info(struct media_device *dev,
                                 struct media_device_info __user *__info)
{
        struct media_device_info info;

        memset(&info, 0, sizeof(info));

        strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
        strlcpy(info.model, dev->model, sizeof(info.model));
        strlcpy(info.serial, dev->serial, sizeof(info.serial));
        strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));

        info.media_version = MEDIA_API_VERSION;
        info.hw_revision = dev->hw_revision;
        info.driver_version = dev->driver_version;

        if (copy_to_user(__info, &info, sizeof(*__info)))
                return -EFAULT;
        return 0;
}

static struct media_entity *find_entity(struct media_device *mdev, u32 id)
{
        struct media_entity *entity;
        int next = id & MEDIA_ENT_ID_FLAG_NEXT;

        id &= ~MEDIA_ENT_ID_FLAG_NEXT;

        spin_lock(&mdev->lock);

        media_device_for_each_entity(entity, mdev) {
                if ((entity->id == id && !next) ||
                    (entity->id > id && next)) {
                        spin_unlock(&mdev->lock);
                        return entity;
                }
        }

        spin_unlock(&mdev->lock);

        return NULL;
}

static long media_device_enum_entities(struct media_device *mdev,
                                       struct media_entity_desc __user *uent)
{
        struct media_entity *ent;
        struct media_entity_desc u_ent;

        if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
                return -EFAULT;

        ent = find_entity(mdev, u_ent.id);

        if (ent == NULL)
                return -EINVAL;

        u_ent.id = ent->id;
        if (ent->name) {
                strncpy(u_ent.name, ent->name, sizeof(u_ent.name));
                u_ent.name[sizeof(u_ent.name) - 1] = '\0';
        } else {
                memset(u_ent.name, 0, sizeof(u_ent.name));
        }
        u_ent.type = ent->type;
        u_ent.revision = ent->revision;
        u_ent.flags = ent->flags;
        u_ent.group_id = ent->group_id;
        u_ent.pads = ent->num_pads;
        u_ent.links = ent->num_links - ent->num_backlinks;
        memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
        if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
                return -EFAULT;
        return 0;
}

static void media_device_kpad_to_upad(const struct media_pad *kpad,
                                      struct media_pad_desc *upad)
{
        upad->entity = kpad->entity->id;
        upad->index = kpad->index;
        upad->flags = kpad->flags;
}

static long __media_device_enum_links(struct media_device *mdev,
                                      struct media_links_enum *links)
{
        struct media_entity *entity;

        entity = find_entity(mdev, links->entity);
        if (entity == NULL)
                return -EINVAL;

        if (links->pads) {
                unsigned int p;

                for (p = 0; p < entity->num_pads; p++) {
                        struct media_pad_desc pad;

                        memset(&pad, 0, sizeof(pad));
                        media_device_kpad_to_upad(&entity->pads[p], &pad);
                        if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
                                return -EFAULT;
                }
        }

        if (links->links) {
                struct media_link_desc __user *ulink;
                unsigned int l;

                for (l = 0, ulink = links->links; l < entity->num_links; l++) {
                        struct media_link_desc link;

                        /* Ignore backlinks. */
                        if (entity->links[l].source->entity != entity)
                                continue;

                        memset(&link, 0, sizeof(link));
                        media_device_kpad_to_upad(entity->links[l].source,
                                                  &link.source);
                        media_device_kpad_to_upad(entity->links[l].sink,
                                                  &link.sink);
                        link.flags = entity->links[l].flags;
                        if (copy_to_user(ulink, &link, sizeof(*ulink)))
                                return -EFAULT;
                        ulink++;
                }
        }

        return 0;
}

static long media_device_enum_links(struct media_device *mdev,
                                    struct media_links_enum __user *ulinks)
{
        struct media_links_enum links;
        int rval;

        if (copy_from_user(&links, ulinks, sizeof(links)))
                return -EFAULT;

        rval = __media_device_enum_links(mdev, &links);
        if (rval < 0)
                return rval;

        if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
                return -EFAULT;

        return 0;
}

static long media_device_setup_link(struct media_device *mdev,
                                    struct media_link_desc __user *_ulink)
{
        struct media_link *link = NULL;
        struct media_link_desc ulink;
        struct media_entity *source;
        struct media_entity *sink;
        int ret;

        if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
                return -EFAULT;

        /* Find the source and sink entities and link.
         */
        source = find_entity(mdev, ulink.source.entity);
        sink = find_entity(mdev, ulink.sink.entity);

        if (source == NULL || sink == NULL)
                return -EINVAL;

        if (ulink.source.index >= source->num_pads ||
            ulink.sink.index >= sink->num_pads)
                return -EINVAL;

        link = media_entity_find_link(&source->pads[ulink.source.index],
                                      &sink->pads[ulink.sink.index]);
        if (link == NULL)
                return -EINVAL;

        /* Setup the link on both entities. */
        ret = __media_entity_setup_link(link, ulink.flags);

        if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
                return -EFAULT;

        return ret;
}

static long media_device_ioctl(struct file *filp, unsigned int cmd,
                               unsigned long arg)
{
        struct media_devnode *devnode = media_devnode_data(filp);
        struct media_device *dev = to_media_device(devnode);
        long ret;

        switch (cmd) {
        case MEDIA_IOC_DEVICE_INFO:
                ret = media_device_get_info(dev,
                                (struct media_device_info __user *)arg);
                break;

        case MEDIA_IOC_ENUM_ENTITIES:
                ret = media_device_enum_entities(dev,
                                (struct media_entity_desc __user *)arg);
                break;

        case MEDIA_IOC_ENUM_LINKS:
                mutex_lock(&dev->graph_mutex);
                ret = media_device_enum_links(dev,
                                (struct media_links_enum __user *)arg);
                mutex_unlock(&dev->graph_mutex);
                break;

        case MEDIA_IOC_SETUP_LINK:
                mutex_lock(&dev->graph_mutex);
                ret = media_device_setup_link(dev,
                                (struct media_link_desc __user *)arg);
                mutex_unlock(&dev->graph_mutex);
                break;

        default:
                ret = -ENOIOCTLCMD;
        }

        return ret;
}

#ifdef CONFIG_COMPAT

struct media_links_enum32 {
        __u32 entity;
        compat_uptr_t pads; /* struct media_pad_desc * */
        compat_uptr_t links; /* struct media_link_desc * */
        __u32 reserved[4];
};

static long media_device_enum_links32(struct media_device *mdev,
                                      struct media_links_enum32 __user *ulinks)
{
        struct media_links_enum links;
        compat_uptr_t pads_ptr, links_ptr;

        memset(&links, 0, sizeof(links));

        if (get_user(links.entity, &ulinks->entity)
            || get_user(pads_ptr, &ulinks->pads)
            || get_user(links_ptr, &ulinks->links))
                return -EFAULT;

        links.pads = compat_ptr(pads_ptr);
        links.links = compat_ptr(links_ptr);

        return __media_device_enum_links(mdev, &links);
}

#define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)

static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
                                      unsigned long arg)
{
        struct media_devnode *devnode = media_devnode_data(filp);
        struct media_device *dev = to_media_device(devnode);
        long ret;

        switch (cmd) {
        case MEDIA_IOC_DEVICE_INFO:
        case MEDIA_IOC_ENUM_ENTITIES:
        case MEDIA_IOC_SETUP_LINK:
                return media_device_ioctl(filp, cmd, arg);

        case MEDIA_IOC_ENUM_LINKS32:
                mutex_lock(&dev->graph_mutex);
                ret = media_device_enum_links32(dev,
                                (struct media_links_enum32 __user *)arg);
                mutex_unlock(&dev->graph_mutex);
                break;

        default:
                ret = -ENOIOCTLCMD;
        }

        return ret;
}
#endif /* CONFIG_COMPAT */

static const struct media_file_operations media_device_fops = {
        .owner = THIS_MODULE,
        .open = media_device_open,
        .ioctl = media_device_ioctl,
#ifdef CONFIG_COMPAT
        .compat_ioctl = media_device_compat_ioctl,
#endif /* CONFIG_COMPAT */
        .release = media_device_close,
};

/* -----------------------------------------------------------------------------
 * sysfs
 */

static ssize_t show_model(struct device *cd,
                          struct device_attribute *attr, char *buf)
{
        struct media_device *mdev = to_media_device(to_media_devnode(cd));

        return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
}

static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);

/* -----------------------------------------------------------------------------
 * Registration/unregistration
 */

static void media_device_release(struct media_devnode *mdev)
{
}

/**
 * media_device_register - register a media device
 * @mdev:       The media device
 *
 * The caller is responsible for initializing the media device before
 * registration. The following fields must be set:
 *
 * - dev must point to the parent device
 * - model must be filled with the device model name
 */
int __must_check media_device_register(struct media_device *mdev)
{
        int ret;

        if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
                return -EINVAL;

        mdev->entity_id = 1;
        INIT_LIST_HEAD(&mdev->entities);
        spin_lock_init(&mdev->lock);
        mutex_init(&mdev->graph_mutex);

        /* Register the device node. */
        mdev->devnode.fops = &media_device_fops;
        mdev->devnode.parent = mdev->dev;
        mdev->devnode.release = media_device_release;
        ret = media_devnode_register(&mdev->devnode);
        if (ret < 0)
                return ret;

        ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
        if (ret < 0) {
                media_devnode_unregister(&mdev->devnode);
                return ret;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(media_device_register);

/**
 * media_device_unregister - unregister a media device
 * @mdev:       The media device
 *
 */
void media_device_unregister(struct media_device *mdev)
{
        struct media_entity *entity;
        struct media_entity *next;

        list_for_each_entry_safe(entity, next, &mdev->entities, list)
                media_device_unregister_entity(entity);

        device_remove_file(&mdev->devnode.dev, &dev_attr_model);
        media_devnode_unregister(&mdev->devnode);
}
EXPORT_SYMBOL_GPL(media_device_unregister);

/**
 * media_device_register_entity - Register an entity with a media device
 * @mdev:       The media device
 * @entity:     The entity
 */
int __must_check media_device_register_entity(struct media_device *mdev,
                                              struct media_entity *entity)
{
        /* Warn if we apparently re-register an entity */
        WARN_ON(entity->parent != NULL);
        entity->parent = mdev;

        spin_lock(&mdev->lock);
        if (entity->id == 0)
                entity->id = mdev->entity_id++;
        else
                mdev->entity_id = max(entity->id + 1, mdev->entity_id);
        list_add_tail(&entity->list, &mdev->entities);
        spin_unlock(&mdev->lock);

        return 0;
}
EXPORT_SYMBOL_GPL(media_device_register_entity);

/**
 * media_device_unregister_entity - Unregister an entity
 * @entity:     The entity
 *
 * If the entity has never been registered this function will return
 * immediately.
 */
void media_device_unregister_entity(struct media_entity *entity)
{
        struct media_device *mdev = entity->parent;

        if (mdev == NULL)
                return;

        spin_lock(&mdev->lock);
        list_del(&entity->list);
        spin_unlock(&mdev->lock);
        entity->parent = NULL;
}
EXPORT_SYMBOL_GPL(media_device_unregister_entity);