text: /*
   * dvbdev.c
   *
   * Copyright (C) 2000 Ralph  Metzler <ralph@convergence.de>
   *                  & Marcus Metzler <marcus@convergence.de>
   *                    for convergence integrated media GmbH
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public License
   * as published by the Free Software Foundation; either version 2.1
   * of the License, or (at your option) any later version.
   *
   * 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.
   *
   */
  
  #define pr_fmt(fmt) "dvbdev: " fmt
  
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/device.h>
  #include <linux/fs.h>
  #include <linux/cdev.h>
  #include <linux/mutex.h>
  #include "dvbdev.h"
  
  /* Due to enum tuner_pad_index */
  #include <media/tuner.h>
  
  static DEFINE_MUTEX(dvbdev_mutex);
  static int dvbdev_debug;
  
  module_param(dvbdev_debug, int, 0644);
  MODULE_PARM_DESC(dvbdev_debug, "Turn on/off device debugging (default:off).");
  
  #define dprintk(fmt, arg...) do {					\
  	if (dvbdev_debug)						\
  		printk(KERN_DEBUG pr_fmt("%s: " fmt),			\
  		       __func__, ##arg);				\
  } while (0)
  
  static LIST_HEAD(dvb_adapter_list);
  static DEFINE_MUTEX(dvbdev_register_lock);
  
  static const char * const dnames[] = {
  	[DVB_DEVICE_VIDEO] =		"video",
  	[DVB_DEVICE_AUDIO] =		"audio",
  	[DVB_DEVICE_SEC] =		"sec",
  	[DVB_DEVICE_FRONTEND] =		"frontend",
  	[DVB_DEVICE_DEMUX] =		"demux",
  	[DVB_DEVICE_DVR] =		"dvr",
  	[DVB_DEVICE_CA] =		"ca",
  	[DVB_DEVICE_NET] =		"net",
  	[DVB_DEVICE_OSD] =		"osd"
  };
  
  #ifdef CONFIG_DVB_DYNAMIC_MINORS
  #define MAX_DVB_MINORS		256
  #define DVB_MAX_IDS		MAX_DVB_MINORS
  #else
  #define DVB_MAX_IDS		4
  
  static const u8 minor_type[] = {
         [DVB_DEVICE_VIDEO]      = 0,
         [DVB_DEVICE_AUDIO]      = 1,
         [DVB_DEVICE_SEC]        = 2,
         [DVB_DEVICE_FRONTEND]   = 3,
         [DVB_DEVICE_DEMUX]      = 4,
         [DVB_DEVICE_DVR]        = 5,
         [DVB_DEVICE_CA]         = 6,
         [DVB_DEVICE_NET]        = 7,
         [DVB_DEVICE_OSD]        = 8,
  };
  
  #define nums2minor(num, type, id) \
         (((num) << 6) | ((id) << 4) | minor_type[type])
  
  #define MAX_DVB_MINORS		(DVB_MAX_ADAPTERS*64)
  #endif
  
  static struct class *dvb_class;
  
  static struct dvb_device *dvb_minors[MAX_DVB_MINORS];
  static DECLARE_RWSEM(minor_rwsem);
  
  static int dvb_device_open(struct inode *inode, struct file *file)
  {
  	struct dvb_device *dvbdev;
  
  	mutex_lock(&dvbdev_mutex);
  	down_read(&minor_rwsem);
  	dvbdev = dvb_minors[iminor(inode)];
  
  	if (dvbdev && dvbdev->fops) {
  		int err = 0;
  		const struct file_operations *new_fops;
  
  		new_fops = fops_get(dvbdev->fops);
  		if (!new_fops)
  			goto fail;
  		file->private_data = dvbdev;
  		replace_fops(file, new_fops);
  		if (file->f_op->open)
  			err = file->f_op->open(inode, file);
  		up_read(&minor_rwsem);
  		mutex_unlock(&dvbdev_mutex);
  		return err;
  	}
  fail:
  	up_read(&minor_rwsem);
  	mutex_unlock(&dvbdev_mutex);
  	return -ENODEV;
  }
  
  
  static const struct file_operations dvb_device_fops =
  {
  	.owner =	THIS_MODULE,
  	.open =		dvb_device_open,
  	.llseek =	noop_llseek,
  };
  
  static struct cdev dvb_device_cdev;
  
  int dvb_generic_open(struct inode *inode, struct file *file)
  {
  	struct dvb_device *dvbdev = file->private_data;
  
  	if (!dvbdev)
  		return -ENODEV;
  
  	if (!dvbdev->users)
  		return -EBUSY;
  
  	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
  		if (!dvbdev->readers)
  			return -EBUSY;
  		dvbdev->readers--;
  	} else {
  		if (!dvbdev->writers)
  			return -EBUSY;
  		dvbdev->writers--;
  	}
  
  	dvbdev->users--;
  	return 0;
  }
  EXPORT_SYMBOL(dvb_generic_open);
  
  
  int dvb_generic_release(struct inode *inode, struct file *file)
  {
  	struct dvb_device *dvbdev = file->private_data;
  
  	if (!dvbdev)
  		return -ENODEV;
  
  	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
  		dvbdev->readers++;
  	} else {
  		dvbdev->writers++;
  	}
  
  	dvbdev->users++;
  	return 0;
  }
  EXPORT_SYMBOL(dvb_generic_release);
  
  
  long dvb_generic_ioctl(struct file *file,
  		       unsigned int cmd, unsigned long arg)
  {
  	struct dvb_device *dvbdev = file->private_data;
  
  	if (!dvbdev)
  		return -ENODEV;
  
  	if (!dvbdev->kernel_ioctl)
  		return -EINVAL;
  
  	return dvb_usercopy(file, cmd, arg, dvbdev->kernel_ioctl);
  }
  EXPORT_SYMBOL(dvb_generic_ioctl);
  
  
  static int dvbdev_get_free_id (struct dvb_adapter *adap, int type)
  {
  	u32 id = 0;
  
  	while (id < DVB_MAX_IDS) {
  		struct dvb_device *dev;
  		list_for_each_entry(dev, &adap->device_list, list_head)
  			if (dev->type == type && dev->id == id)
  				goto skip;
  		return id;
  skip:
  		id++;
  	}
  	return -ENFILE;
  }
  
  static void dvb_media_device_free(struct dvb_device *dvbdev)
  {
  #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
  	if (dvbdev->entity) {
  		media_device_unregister_entity(dvbdev->entity);
  		kfree(dvbdev->entity);
  		kfree(dvbdev->pads);
  		dvbdev->entity = NULL;
  		dvbdev->pads = NULL;
  	}
  
  	if (dvbdev->tsout_entity) {
  		int i;
  
  		for (i = 0; i < dvbdev->tsout_num_entities; i++) {
  			media_device_unregister_entity(&dvbdev->tsout_entity[i]);
  			kfree(dvbdev->tsout_entity[i].name);
  		}
  		kfree(dvbdev->tsout_entity);
  		kfree(dvbdev->tsout_pads);
  		dvbdev->tsout_entity = NULL;
  		dvbdev->tsout_pads = NULL;
  
  		dvbdev->tsout_num_entities = 0;
  	}
  
  	if (dvbdev->intf_devnode) {
  		media_devnode_remove(dvbdev->intf_devnode);
  		dvbdev->intf_devnode = NULL;
  	}
  
  	if (dvbdev->adapter->conn) {
  		media_device_unregister_entity(dvbdev->adapter->conn);
  		dvbdev->adapter->conn = NULL;
  		kfree(dvbdev->adapter->conn_pads);
  		dvbdev->adapter->conn_pads = NULL;
  	}
  #endif
  }
  
  #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
  static int dvb_create_tsout_entity(struct dvb_device *dvbdev,
  				    const char *name, int npads)
  {
  	int i, ret = 0;
  
  	dvbdev->tsout_pads = kcalloc(npads, sizeof(*dvbdev->tsout_pads),
  				     GFP_KERNEL);
  	if (!dvbdev->tsout_pads)
  		return -ENOMEM;
  
  	dvbdev->tsout_entity = kcalloc(npads, sizeof(*dvbdev->tsout_entity),
  				       GFP_KERNEL);
  	if (!dvbdev->tsout_entity)
  		return -ENOMEM;
  
  	dvbdev->tsout_num_entities = npads;
  
  	for (i = 0; i < npads; i++) {
  		struct media_pad *pads = &dvbdev->tsout_pads[i];
  		struct media_entity *entity = &dvbdev->tsout_entity[i];
  
  		entity->name = kasprintf(GFP_KERNEL, "%s #%d", name, i);
  		if (!entity->name)
  			return -ENOMEM;
  
  		entity->function = MEDIA_ENT_F_IO_DTV;
  		pads->flags = MEDIA_PAD_FL_SINK;
  
  		ret = media_entity_pads_init(entity, 1, pads);
  		if (ret < 0)
  			return ret;
  
  		ret = media_device_register_entity(dvbdev->adapter->mdev,
  						   entity);
  		if (ret < 0)
  			return ret;
  	}
  	return 0;
  }
  
  #define DEMUX_TSOUT	"demux-tsout"
  #define DVR_TSOUT	"dvr-tsout"
  
  static int dvb_create_media_entity(struct dvb_device *dvbdev,
  				   int type, int demux_sink_pads)
  {
  	int i, ret, npads;
  
  	switch (type) {
  	case DVB_DEVICE_FRONTEND:
  		npads = 2;
  		break;
  	case DVB_DEVICE_DVR:
  		ret = dvb_create_tsout_entity(dvbdev, DVR_TSOUT,
  					      demux_sink_pads);
  		return ret;
  	case DVB_DEVICE_DEMUX:
  		npads = 1 + demux_sink_pads;
  		ret = dvb_create_tsout_entity(dvbdev, DEMUX_TSOUT,
  					      demux_sink_pads);
  		if (ret < 0)
  			return ret;
  		break;
  	case DVB_DEVICE_CA:
  		npads = 2;
  		break;
  	case DVB_DEVICE_NET:
  		/*
  		 * We should be creating entities for the MPE/ULE
  		 * decapsulation hardware (or software implementation).
  		 *
  		 * However, the number of for the MPE/ULE decaps may not be
  		 * fixed. As we don't have yet dynamic support for PADs at
  		 * the Media Controller, let's not create the decap
  		 * entities yet.
  		 */
  		return 0;
  	default:
  		return 0;
  	}
  
  	dvbdev->entity = kzalloc(sizeof(*dvbdev->entity), GFP_KERNEL);
  	if (!dvbdev->entity)
  		return -ENOMEM;
  
  	dvbdev->entity->name = dvbdev->name;
  
  	if (npads) {
  		dvbdev->pads = kcalloc(npads, sizeof(*dvbdev->pads),
  				       GFP_KERNEL);
  		if (!dvbdev->pads)
  			return -ENOMEM;
  	}
  
  	switch (type) {
  	case DVB_DEVICE_FRONTEND:
  		dvbdev->entity->function = MEDIA_ENT_F_DTV_DEMOD;
  		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
  		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
  		break;
  	case DVB_DEVICE_DEMUX:
  		dvbdev->entity->function = MEDIA_ENT_F_TS_DEMUX;
  		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
  		for (i = 1; i < npads; i++)
  			dvbdev->pads[i].flags = MEDIA_PAD_FL_SOURCE;
  		break;
  	case DVB_DEVICE_CA:
  		dvbdev->entity->function = MEDIA_ENT_F_DTV_CA;
  		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
  		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
  		break;
  	default:
  		/* Should never happen, as the first switch prevents it */
  		kfree(dvbdev->entity);
  		kfree(dvbdev->pads);
  		dvbdev->entity = NULL;
  		dvbdev->pads = NULL;
  		return 0;
  	}
  
  	if (npads) {
  		ret = media_entity_pads_init(dvbdev->entity, npads, dvbdev->pads);
  		if (ret)
  			return ret;
  	}
  	ret = media_device_register_entity(dvbdev->adapter->mdev,
  					   dvbdev->entity);
  	if (ret)
  		return ret;
  
  	pr_info("%s: media entity '%s' registered.\n",
  		__func__, dvbdev->entity->name);
  
  	return 0;
  }
  #endif
  
  static int dvb_register_media_device(struct dvb_device *dvbdev,
  				     int type, int minor,
  				     unsigned demux_sink_pads)
  {
  #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
  	struct media_link *link;
  	u32 intf_type;
  	int ret;
  
  	if (!dvbdev->adapter->mdev)
  		return 0;
  
  	ret = dvb_create_media_entity(dvbdev, type, demux_sink_pads);
  	if (ret)
  		return ret;
  
  	switch (type) {
  	case DVB_DEVICE_FRONTEND:
  		intf_type = MEDIA_INTF_T_DVB_FE;
  		break;
  	case DVB_DEVICE_DEMUX:
  		intf_type = MEDIA_INTF_T_DVB_DEMUX;
  		break;
  	case DVB_DEVICE_DVR:
  		intf_type = MEDIA_INTF_T_DVB_DVR;
  		break;
  	case DVB_DEVICE_CA:
  		intf_type = MEDIA_INTF_T_DVB_CA;
  		break;
  	case DVB_DEVICE_NET:
  		intf_type = MEDIA_INTF_T_DVB_NET;
  		break;
  	default:
  		return 0;
  	}
  
  	dvbdev->intf_devnode = media_devnode_create(dvbdev->adapter->mdev,
  						    intf_type, 0,
  						    DVB_MAJOR, minor);
  
  	if (!dvbdev->intf_devnode)
  		return -ENOMEM;
  
  	/*
  	 * Create the "obvious" link, e. g. the ones that represent
  	 * a direct association between an interface and an entity.
  	 * Other links should be created elsewhere, like:
  	 *		DVB FE intf    -> tuner
  	 *		DVB demux intf -> dvr
  	 */
  
  	if (!dvbdev->entity)
  		return 0;
  
  	link = media_create_intf_link(dvbdev->entity, &dvbdev->intf_devnode->intf,
  				      MEDIA_LNK_FL_ENABLED);
  	if (!link)
  		return -ENOMEM;
  #endif
  	return 0;
  }
  
  int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
  			const struct dvb_device *template, void *priv,
  			enum dvb_device_type type, int demux_sink_pads)
  {
  	struct dvb_device *dvbdev;
  	struct file_operations *dvbdevfops;
  	struct device *clsdev;
  	int minor;
  	int id, ret;
  
  	mutex_lock(&dvbdev_register_lock);
  
  	if ((id = dvbdev_get_free_id (adap, type)) < 0){
  		mutex_unlock(&dvbdev_register_lock);
  		*pdvbdev = NULL;
  		pr_err("%s: couldn't find free device id\n", __func__);
  		return -ENFILE;
  	}
  
  	*pdvbdev = dvbdev = kzalloc(sizeof(*dvbdev), GFP_KERNEL);
  
  	if (!dvbdev){
  		mutex_unlock(&dvbdev_register_lock);
  		return -ENOMEM;
  	}
  
  	dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
  
  	if (!dvbdevfops){
  		kfree (dvbdev);
  		mutex_unlock(&dvbdev_register_lock);
  		return -ENOMEM;
  	}
  
  	memcpy(dvbdev, template, sizeof(struct dvb_device));
  	dvbdev->type = type;
  	dvbdev->id = id;
  	dvbdev->adapter = adap;
  	dvbdev->priv = priv;
  	dvbdev->fops = dvbdevfops;
  	init_waitqueue_head (&dvbdev->wait_queue);
  
  	memcpy(dvbdevfops, template->fops, sizeof(struct file_operations));
  	dvbdevfops->owner = adap->module;
  
  	list_add_tail (&dvbdev->list_head, &adap->device_list);
  
  	down_write(&minor_rwsem);
  #ifdef CONFIG_DVB_DYNAMIC_MINORS
  	for (minor = 0; minor < MAX_DVB_MINORS; minor++)
  		if (dvb_minors[minor] == NULL)
  			break;
  
  	if (minor == MAX_DVB_MINORS) {
  		kfree(dvbdevfops);
  		kfree(dvbdev);
  		up_write(&minor_rwsem);
  		mutex_unlock(&dvbdev_register_lock);
  		return -EINVAL;
  	}
  #else
  	minor = nums2minor(adap->num, type, id);
  #endif
  
  	dvbdev->minor = minor;
  	dvb_minors[minor] = dvbdev;
  	up_write(&minor_rwsem);
  
  	ret = dvb_register_media_device(dvbdev, type, minor, demux_sink_pads);
  	if (ret) {
  		pr_err("%s: dvb_register_media_device failed to create the mediagraph\n",
  		      __func__);
  
  		dvb_media_device_free(dvbdev);
  		kfree(dvbdevfops);
  		kfree(dvbdev);
  		up_write(&minor_rwsem);
  		mutex_unlock(&dvbdev_register_lock);
  		return ret;
  	}
  
  	mutex_unlock(&dvbdev_register_lock);
  
  	clsdev = device_create(dvb_class, adap->device,
  			       MKDEV(DVB_MAJOR, minor),
  			       dvbdev, "dvb%d.%s%d", adap->num, dnames[type], id);
  	if (IS_ERR(clsdev)) {
  		pr_err("%s: failed to create device dvb%d.%s%d (%ld)\n",
  		       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
  		return PTR_ERR(clsdev);
  	}
  	dprintk("DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n",
  		adap->num, dnames[type], id, minor, minor);
  
  	return 0;
  }
  EXPORT_SYMBOL(dvb_register_device);
  
  
  void dvb_remove_device(struct dvb_device *dvbdev)
  {
  	if (!dvbdev)
  		return;
  
  	down_write(&minor_rwsem);
  	dvb_minors[dvbdev->minor] = NULL;
  	up_write(&minor_rwsem);
  
  	dvb_media_device_free(dvbdev);
  
  	device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
  
  	list_del (&dvbdev->list_head);
  }
  EXPORT_SYMBOL(dvb_remove_device);
  
  
  void dvb_free_device(struct dvb_device *dvbdev)
  {
  	if (!dvbdev)
  		return;
  
  	kfree (dvbdev->fops);
  	kfree (dvbdev);
  }
  EXPORT_SYMBOL(dvb_free_device);
  
  
  void dvb_unregister_device(struct dvb_device *dvbdev)
  {
  	dvb_remove_device(dvbdev);
  	dvb_free_device(dvbdev);
  }
  EXPORT_SYMBOL(dvb_unregister_device);
  
  
  #ifdef CONFIG_MEDIA_CONTROLLER_DVB
  
  static int dvb_create_io_intf_links(struct dvb_adapter *adap,
  				    struct media_interface *intf,
  				    char *name)
  {
  	struct media_device *mdev = adap->mdev;
  	struct media_entity *entity;
  	struct media_link *link;
  
  	media_device_for_each_entity(entity, mdev) {
  		if (entity->function == MEDIA_ENT_F_IO_DTV) {
  			if (strncmp(entity->name, name, strlen(name)))
  				continue;
  			link = media_create_intf_link(entity, intf,
  						      MEDIA_LNK_FL_ENABLED);
  			if (!link)
  				return -ENOMEM;
  		}
  	}
  	return 0;
  }
  
  int dvb_create_media_graph(struct dvb_adapter *adap,
  			   bool create_rf_connector)
  {
  	struct media_device *mdev = adap->mdev;
  	struct media_entity *entity, *tuner = NULL, *demod = NULL, *conn;
  	struct media_entity *demux = NULL, *ca = NULL;
  	struct media_link *link;
  	struct media_interface *intf;
  	unsigned demux_pad = 0;
  	unsigned dvr_pad = 0;
  	unsigned ntuner = 0, ndemod = 0;
  	int ret;
  	static const char *connector_name = "Television";
  
  	if (!mdev)
  		return 0;
  
  	media_device_for_each_entity(entity, mdev) {
  		switch (entity->function) {
  		case MEDIA_ENT_F_TUNER:
  			tuner = entity;
  			ntuner++;
  			break;
  		case MEDIA_ENT_F_DTV_DEMOD:
  			demod = entity;
  			ndemod++;
  			break;
  		case MEDIA_ENT_F_TS_DEMUX:
  			demux = entity;
  			break;
  		case MEDIA_ENT_F_DTV_CA:
  			ca = entity;
  			break;
  		}
  	}
  
  	/*
  	 * Prepare to signalize to media_create_pad_links() that multiple
  	 * entities of the same type exists and a 1:n or n:1 links need to be
  	 * created.
  	 * NOTE: if both tuner and demod have multiple instances, it is up
  	 * to the caller driver to create such links.
  	 */
  	if (ntuner > 1)
  		tuner = NULL;
  	if (ndemod > 1)
  		demod = NULL;
  
  	if (create_rf_connector) {
  		conn = kzalloc(sizeof(*conn), GFP_KERNEL);
  		if (!conn)
  			return -ENOMEM;
  		adap->conn = conn;
  
  		adap->conn_pads = kzalloc(sizeof(*adap->conn_pads), GFP_KERNEL);
  		if (!adap->conn_pads)
  			return -ENOMEM;
  
  		conn->flags = MEDIA_ENT_FL_CONNECTOR;
  		conn->function = MEDIA_ENT_F_CONN_RF;
  		conn->name = connector_name;
  		adap->conn_pads->flags = MEDIA_PAD_FL_SOURCE;
  
  		ret = media_entity_pads_init(conn, 1, adap->conn_pads);
  		if (ret)
  			return ret;
  
  		ret = media_device_register_entity(mdev, conn);
  		if (ret)
  			return ret;
  
  		if (!ntuner)
  			ret = media_create_pad_links(mdev,
  						     MEDIA_ENT_F_CONN_RF,
  						     conn, 0,
  						     MEDIA_ENT_F_DTV_DEMOD,
  						     demod, 0,
  						     MEDIA_LNK_FL_ENABLED,
  						     false);
  		else
  			ret = media_create_pad_links(mdev,
  						     MEDIA_ENT_F_CONN_RF,
  						     conn, 0,
  						     MEDIA_ENT_F_TUNER,
  						     tuner, TUNER_PAD_RF_INPUT,
  						     MEDIA_LNK_FL_ENABLED,
  						     false);
  		if (ret)
  			return ret;
  	}
  
  	if (ntuner && ndemod) {
  		ret = media_create_pad_links(mdev,
  					     MEDIA_ENT_F_TUNER,
  					     tuner, TUNER_PAD_OUTPUT,
  					     MEDIA_ENT_F_DTV_DEMOD,
  					     demod, 0, MEDIA_LNK_FL_ENABLED,
  					     false);
  		if (ret)
  			return ret;
  	}
  
  	if (ndemod && demux) {
  		ret = media_create_pad_links(mdev,
  					     MEDIA_ENT_F_DTV_DEMOD,
  					     demod, 1,
  					     MEDIA_ENT_F_TS_DEMUX,
  					     demux, 0, MEDIA_LNK_FL_ENABLED,
  					     false);
  		if (ret)
  			return ret;
  	}
  	if (demux && ca) {
  		ret = media_create_pad_link(demux, 1, ca,
  					    0, MEDIA_LNK_FL_ENABLED);
  		if (ret)
  			return ret;
  	}
  
  	/* Create demux links for each ringbuffer/pad */
  	if (demux) {
  		media_device_for_each_entity(entity, mdev) {
  			if (entity->function == MEDIA_ENT_F_IO_DTV) {
  				if (!strncmp(entity->name, DVR_TSOUT,
  				    strlen(DVR_TSOUT))) {
  					ret = media_create_pad_link(demux,
  								++dvr_pad,
  							    entity, 0, 0);
  					if (ret)
  						return ret;
  				}
  				if (!strncmp(entity->name, DEMUX_TSOUT,
  				    strlen(DEMUX_TSOUT))) {
  					ret = media_create_pad_link(demux,
  							      ++demux_pad,
  							    entity, 0, 0);
  					if (ret)
  						return ret;
  				}
  			}
  		}
  	}
  
  	/* Create interface links for FE->tuner, DVR->demux and CA->ca */
  	media_device_for_each_intf(intf, mdev) {
  		if (intf->type == MEDIA_INTF_T_DVB_CA && ca) {
  			link = media_create_intf_link(ca, intf,
  						      MEDIA_LNK_FL_ENABLED);
  			if (!link)
  				return -ENOMEM;
  		}
  
  		if (intf->type == MEDIA_INTF_T_DVB_FE && tuner) {
  			link = media_create_intf_link(tuner, intf,
  						      MEDIA_LNK_FL_ENABLED);
  			if (!link)
  				return -ENOMEM;
  		}
  #if 0
  		/*
  		 * Indirect link - let's not create yet, as we don't know how
  		 *		   to handle indirect links, nor if this will
  		 *		   actually be needed.
  		 */
  		if (intf->type == MEDIA_INTF_T_DVB_DVR && demux) {
  			link = media_create_intf_link(demux, intf,
  						      MEDIA_LNK_FL_ENABLED);
  			if (!link)
  				return -ENOMEM;
  		}
  #endif
  		if (intf->type == MEDIA_INTF_T_DVB_DVR) {
  			ret = dvb_create_io_intf_links(adap, intf, DVR_TSOUT);
  			if (ret)
  				return ret;
  		}
  		if (intf->type == MEDIA_INTF_T_DVB_DEMUX) {
  			ret = dvb_create_io_intf_links(adap, intf, DEMUX_TSOUT);
  			if (ret)
  				return ret;
  		}
  	}
  	return 0;
  }
  EXPORT_SYMBOL_GPL(dvb_create_media_graph);
  #endif
  
  static int dvbdev_check_free_adapter_num(int num)
  {
  	struct list_head *entry;
  	list_for_each(entry, &dvb_adapter_list) {
  		struct dvb_adapter *adap;
  		adap = list_entry(entry, struct dvb_adapter, list_head);
  		if (adap->num == num)
  			return 0;
  	}
  	return 1;
  }
  
  static int dvbdev_get_free_adapter_num (void)
  {
  	int num = 0;
  
  	while (num < DVB_MAX_ADAPTERS) {
  		if (dvbdev_check_free_adapter_num(num))
  			return num;
  		num++;
  	}
  
  	return -ENFILE;
  }
  
  
  int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
  			 struct module *module, struct device *device,
  			 short *adapter_nums)
  {
  	int i, num;
  
  	mutex_lock(&dvbdev_register_lock);
  
  	for (i = 0; i < DVB_MAX_ADAPTERS; ++i) {
  		num = adapter_nums[i];
  		if (num >= 0  &&  num < DVB_MAX_ADAPTERS) {
  		/* use the one the driver asked for */
  			if (dvbdev_check_free_adapter_num(num))
  				break;
  		} else {
  			num = dvbdev_get_free_adapter_num();
  			break;
  		}
  		num = -1;
  	}
  
  	if (num < 0) {
  		mutex_unlock(&dvbdev_register_lock);
  		return -ENFILE;
  	}
  
  	memset (adap, 0, sizeof(struct dvb_adapter));
  	INIT_LIST_HEAD (&adap->device_list);
  
  	pr_info("DVB: registering new adapter (%s)\n", name);
  
  	adap->num = num;
  	adap->name = name;
  	adap->module = module;
  	adap->device = device;
  	adap->mfe_shared = 0;
  	adap->mfe_dvbdev = NULL;
  	mutex_init (&adap->mfe_lock);
  
  	list_add_tail (&adap->list_head, &dvb_adapter_list);
  
  	mutex_unlock(&dvbdev_register_lock);
  
  	return num;
  }
  EXPORT_SYMBOL(dvb_register_adapter);
  
  
  int dvb_unregister_adapter(struct dvb_adapter *adap)
  {
  	mutex_lock(&dvbdev_register_lock);
  	list_del (&adap->list_head);
  	mutex_unlock(&dvbdev_register_lock);
  	return 0;
  }
  EXPORT_SYMBOL(dvb_unregister_adapter);
  
  /* if the miracle happens and "generic_usercopy()" is included into
     the kernel, then this can vanish. please don't make the mistake and
     define this as video_usercopy(). this will introduce a dependecy
     to the v4l "videodev.o" module, which is unnecessary for some
     cards (ie. the budget dvb-cards don't need the v4l module...) */
  int dvb_usercopy(struct file *file,
  		     unsigned int cmd, unsigned long arg,
  		     int (*func)(struct file *file,
  		     unsigned int cmd, void *arg))
  {
  	char    sbuf[128];
  	void    *mbuf = NULL;
  	void    *parg = NULL;
  	int     err  = -EINVAL;
  
  	/*  Copy arguments into temp kernel buffer  */
  	switch (_IOC_DIR(cmd)) {
  	case _IOC_NONE:
  		/*
  		 * For this command, the pointer is actually an integer
  		 * argument.
  		 */
  		parg = (void *) arg;
  		break;
  	case _IOC_READ: /* some v4l ioctls are marked wrong ... */
  	case _IOC_WRITE:
  	case (_IOC_WRITE | _IOC_READ):
  		if (_IOC_SIZE(cmd) <= sizeof(sbuf)) {
  			parg = sbuf;
  		} else {
  			/* too big to allocate from stack */
  			mbuf = kmalloc(_IOC_SIZE(cmd), GFP_KERNEL);
  			if (NULL == mbuf)
  				return -ENOMEM;
  			parg = mbuf;
  		}
  
  		err = -EFAULT;
  		if (copy_from_user(parg, (void __user *)arg, _IOC_SIZE(cmd)))
  			goto out;
  		break;
  	}
  
  	/* call driver */
  	if ((err = func(file, cmd, parg)) == -ENOIOCTLCMD)
  		err = -ENOTTY;
  
  	if (err < 0)
  		goto out;
  
  	/*  Copy results into user buffer  */
  	switch (_IOC_DIR(cmd))
  	{
  	case _IOC_READ:
  	case (_IOC_WRITE | _IOC_READ):
  		if (copy_to_user((void __user *)arg, parg, _IOC_SIZE(cmd)))
  			err = -EFAULT;
  		break;
  	}
  
  out:
  	kfree(mbuf);
  	return err;
  }
  
  static int dvb_uevent(struct device *dev, struct kobj_uevent_env *env)
  {
  	struct dvb_device *dvbdev = dev_get_drvdata(dev);
  
  	add_uevent_var(env, "DVB_ADAPTER_NUM=%d", dvbdev->adapter->num);
  	add_uevent_var(env, "DVB_DEVICE_TYPE=%s", dnames[dvbdev->type]);
  	add_uevent_var(env, "DVB_DEVICE_NUM=%d", dvbdev->id);
  	return 0;
  }
  
  static char *dvb_devnode(struct device *dev, umode_t *mode)
  {
  	struct dvb_device *dvbdev = dev_get_drvdata(dev);
  
  	return kasprintf(GFP_KERNEL, "dvb/adapter%d/%s%d",
  		dvbdev->adapter->num, dnames[dvbdev->type], dvbdev->id);
  }
  
  
  static int __init init_dvbdev(void)
  {
  	int retval;
  	dev_t dev = MKDEV(DVB_MAJOR, 0);
  
  	if ((retval = register_chrdev_region(dev, MAX_DVB_MINORS, "DVB")) != 0) {
  		pr_err("dvb-core: unable to get major %d\n", DVB_MAJOR);
  		return retval;
  	}
  
  	cdev_init(&dvb_device_cdev, &dvb_device_fops);
  	if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
  		pr_err("dvb-core: unable register character device\n");
  		goto error;
  	}
  
  	dvb_class = class_create(THIS_MODULE, "dvb");
  	if (IS_ERR(dvb_class)) {
  		retval = PTR_ERR(dvb_class);
  		goto error;
  	}
  	dvb_class->dev_uevent = dvb_uevent;
  	dvb_class->devnode = dvb_devnode;
  	return 0;
  
  error:
  	cdev_del(&dvb_device_cdev);
  	unregister_chrdev_region(dev, MAX_DVB_MINORS);
  	return retval;
  }
  
  
  static void __exit exit_dvbdev(void)
  {
  	class_destroy(dvb_class);
  	cdev_del(&dvb_device_cdev);
  	unregister_chrdev_region(MKDEV(DVB_MAJOR, 0), MAX_DVB_MINORS);
  }
  
  subsys_initcall(init_dvbdev);
  module_exit(exit_dvbdev);
  
  MODULE_DESCRIPTION("DVB Core Driver");
  MODULE_AUTHOR("Marcus Metzler, Ralph Metzler, Holger Waechtler");
  MODULE_LICENSE("GPL");
  