/*
   * 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;
  
  	memset(&u_ent, 0, sizeof(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';
  	}
  	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
  ", (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);