/*
 * 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.
 *
 */

#undef pr_fmt
#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/i2c.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 <media/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);
		kfree(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) {
			kfree(dvbdev->entity);
			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 |
				      MEDIA_LNK_FL_IMMUTABLE);
	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 = kmemdup(template->fops, sizeof(*dvbdevfops), 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);

	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);
		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));
		dvb_media_device_free(dvbdev);
		kfree(dvbdevfops);
		kfree(dvbdev);
		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 |
						      MEDIA_LNK_FL_IMMUTABLE);
			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, pad_source, pad_sink;
	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 {
			pad_sink = media_get_pad_index(tuner, true,
						       PAD_SIGNAL_ANALOG);
			if (pad_sink < 0)
				return -EINVAL;
			ret = media_create_pad_links(mdev,
						     MEDIA_ENT_F_CONN_RF,
						     conn, 0,
						     MEDIA_ENT_F_TUNER,
						     tuner, pad_sink,
						     MEDIA_LNK_FL_ENABLED,
						     false);
		}
		if (ret)
			return ret;
	}

	if (ntuner && ndemod) {
		/* NOTE: first found tuner source pad presumed correct */
		pad_source = media_get_pad_index(tuner, false,
						 PAD_SIGNAL_ANALOG);
		if (pad_source < 0)
			return -EINVAL;
		ret = media_create_pad_links(mdev,
					     MEDIA_ENT_F_TUNER,
					     tuner, pad_source,
					     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 |
						      MEDIA_LNK_FL_IMMUTABLE);
			if (!link)
				return -ENOMEM;
		}

		if (intf->type == MEDIA_INTF_T_DVB_FE && tuner) {
			link = media_create_intf_link(tuner, intf,
						      MEDIA_LNK_FL_ENABLED |
						      MEDIA_LNK_FL_IMMUTABLE);
			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 |
						      MEDIA_LNK_FL_IMMUTABLE);
			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);

#ifdef CONFIG_MEDIA_CONTROLLER_DVB
	mutex_init(&adap->mdev_lock);
#endif

	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 dependency
   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;
}

#if IS_ENABLED(CONFIG_I2C)
struct i2c_client *dvb_module_probe(const char *module_name,
				    const char *name,
				    struct i2c_adapter *adap,
				    unsigned char addr,
				    void *platform_data)
{
	struct i2c_client *client;
	struct i2c_board_info *board_info;

	board_info = kzalloc(sizeof(*board_info), GFP_KERNEL);
	if (!board_info)
		return NULL;

	if (name)
		strscpy(board_info->type, name, I2C_NAME_SIZE);
	else
		strscpy(board_info->type, module_name, I2C_NAME_SIZE);

	board_info->addr = addr;
	board_info->platform_data = platform_data;
	request_module(module_name);
	client = i2c_new_client_device(adap, board_info);
	if (!i2c_client_has_driver(client)) {
		kfree(board_info);
		return NULL;
	}

	if (!try_module_get(client->dev.driver->owner)) {
		i2c_unregister_device(client);
		client = NULL;
	}

	kfree(board_info);
	return client;
}
EXPORT_SYMBOL_GPL(dvb_module_probe);

void dvb_module_release(struct i2c_client *client)
{
	if (!client)
		return;

	module_put(client->dev.driver->owner);
	i2c_unregister_device(client);
}
EXPORT_SYMBOL_GPL(dvb_module_release);
#endif

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);
	printk(KERN_ERR "WARNING: You are using an experimental version of the media stack.\n\tAs the driver is backported to an older kernel, it doesn't offer\n\tenough quality for its usage in production.\n\tUse it with care.\nLatest git patches (needed if you report a bug to linux-media@vger.kernel.org):\n\t0b276e470a4d43e1365d3eb53c608a3d208cabd4 media: coda: fix macroblocks count control usage\n\tac746729178bd7c08bb7e5242df92bd01593a732 media: rkisp1: params: fix wrong bits settings\n\t147d211cc9b4d753148d1640a1758b25edfbf437 media: cedrus: Fix H265 status definitions\n");

	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");
