/*
   * 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.
   *
   * You should have received a copy of the GNU Lesser 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/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"
  
  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 if (dvbdev_debug) printk
  
  static LIST_HEAD(dvb_adapter_list);
  static DEFINE_MUTEX(dvbdev_register_lock);
  
  static const char * const dnames[] = {
  	"video", "audio", "sec", "frontend", "demux", "dvr", "ca",
  	"net", "osd"
  };
  
  #ifdef CONFIG_DVB_DYNAMIC_MINORS
  #define MAX_DVB_MINORS		256
  #define DVB_MAX_IDS		MAX_DVB_MINORS
  #else
  #define DVB_MAX_IDS		4
  #define nums2minor(num,type,id)	((num << 6) | (id << 4) | 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_register_media_device(struct dvb_device *dvbdev,
  				      int type, int minor)
  {
  #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
  	int ret = 0, npads;
  
  	if (!dvbdev->adapter->mdev)
  		return;
  
  	dvbdev->entity = kzalloc(sizeof(*dvbdev->entity), GFP_KERNEL);
  	if (!dvbdev->entity)
  		return;
  
  	dvbdev->entity->info.dev.major = DVB_MAJOR;
  	dvbdev->entity->info.dev.minor = minor;
  	dvbdev->entity->name = dvbdev->name;
  
  	switch (type) {
  	case DVB_DEVICE_CA:
  	case DVB_DEVICE_DEMUX:
  	case DVB_DEVICE_FRONTEND:
  		npads = 2;
  		break;
  	case DVB_DEVICE_NET:
  		npads = 0;
  		break;
  	default:
  		npads = 1;
  	}
  
  	if (npads) {
  		dvbdev->pads = kcalloc(npads, sizeof(*dvbdev->pads),
  				       GFP_KERNEL);
  		if (!dvbdev->pads) {
  			kfree(dvbdev->entity);
  			return;
  		}
  	}
  
  	switch (type) {
  	case DVB_DEVICE_FRONTEND:
  		dvbdev->entity->type = MEDIA_ENT_T_DEVNODE_DVB_FE;
  		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
  		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
  		break;
  	case DVB_DEVICE_DEMUX:
  		dvbdev->entity->type = MEDIA_ENT_T_DEVNODE_DVB_DEMUX;
  		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
  		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
  		break;
  	case DVB_DEVICE_DVR:
  		dvbdev->entity->type = MEDIA_ENT_T_DEVNODE_DVB_DVR;
  		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
  		break;
  	case DVB_DEVICE_CA:
  		dvbdev->entity->type = MEDIA_ENT_T_DEVNODE_DVB_CA;
  		dvbdev->pads[0].flags = MEDIA_PAD_FL_SINK;
  		dvbdev->pads[1].flags = MEDIA_PAD_FL_SOURCE;
  		break;
  	case DVB_DEVICE_NET:
  		dvbdev->entity->type = MEDIA_ENT_T_DEVNODE_DVB_NET;
  		break;
  	default:
  		kfree(dvbdev->entity);
  		dvbdev->entity = NULL;
  		return;
  	}
  
  	if (npads)
  		ret = media_entity_init(dvbdev->entity, npads, dvbdev->pads, 0);
  	if (!ret)
  		ret = media_device_register_entity(dvbdev->adapter->mdev,
  						   dvbdev->entity);
  	if (ret < 0) {
  		printk(KERN_ERR
  			"%s: media_device_register_entity failed for %s
  ",
  			__func__, dvbdev->entity->name);
  		kfree(dvbdev->pads);
  		kfree(dvbdev->entity);
  		dvbdev->entity = NULL;
  		return;
  	}
  
  	printk(KERN_DEBUG "%s: media device '%s' registered.
  ",
  		__func__, dvbdev->entity->name);
  #endif
  }
  
  int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev,
  			const struct dvb_device *template, void *priv, int type)
  {
  	struct dvb_device *dvbdev;
  	struct file_operations *dvbdevfops;
  	struct device *clsdev;
  	int minor;
  	int id;
  
  	mutex_lock(&dvbdev_register_lock);
  
  	if ((id = dvbdev_get_free_id (adap, type)) < 0){
  		mutex_unlock(&dvbdev_register_lock);
  		*pdvbdev = NULL;
  		printk(KERN_ERR "%s: couldn't find free device id
  ", __func__);
  		return -ENFILE;
  	}
  
  	*pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), 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);
  
  	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)) {
  		printk(KERN_ERR "%s: failed to create device dvb%d.%s%d (%ld)
  ",
  		       __func__, adap->num, dnames[type], id, PTR_ERR(clsdev));
  		return PTR_ERR(clsdev);
  	}
  	dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)
  ",
  		adap->num, dnames[type], id, minor, minor);
  
  	dvb_register_media_device(dvbdev, type, minor);
  
  	return 0;
  }
  EXPORT_SYMBOL(dvb_register_device);
  
  
  void dvb_unregister_device(struct dvb_device *dvbdev)
  {
  	if (!dvbdev)
  		return;
  
  	down_write(&minor_rwsem);
  	dvb_minors[dvbdev->minor] = NULL;
  	up_write(&minor_rwsem);
  
  	device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor));
  
  #if defined(CONFIG_MEDIA_CONTROLLER_DVB)
  	if (dvbdev->entity) {
  		media_device_unregister_entity(dvbdev->entity);
  		kfree(dvbdev->entity);
  		kfree(dvbdev->pads);
  	}
  #endif
  
  	list_del (&dvbdev->list_head);
  	kfree (dvbdev->fops);
  	kfree (dvbdev);
  }
  EXPORT_SYMBOL(dvb_unregister_device);
  
  
  #ifdef CONFIG_MEDIA_CONTROLLER_DVB
  void dvb_create_media_graph(struct dvb_adapter *adap)
  {
  	struct media_device *mdev = adap->mdev;
  	struct media_entity *entity, *tuner = NULL, *fe = NULL;
  	struct media_entity *demux = NULL, *dvr = NULL, *ca = NULL;
  
  	if (!mdev)
  		return;
  
  	media_device_for_each_entity(entity, mdev) {
  		switch (entity->type) {
  		case MEDIA_ENT_T_V4L2_SUBDEV_TUNER:
  			tuner = entity;
  			break;
  		case MEDIA_ENT_T_DEVNODE_DVB_FE:
  			fe = entity;
  			break;
  		case MEDIA_ENT_T_DEVNODE_DVB_DEMUX:
  			demux = entity;
  			break;
  		case MEDIA_ENT_T_DEVNODE_DVB_DVR:
  			dvr = entity;
  			break;
  		case MEDIA_ENT_T_DEVNODE_DVB_CA:
  			ca = entity;
  			break;
  		}
  	}
  
  	if (tuner && fe)
  		media_entity_create_link(tuner, 0, fe, 0, 0);
  
  	if (fe && demux)
  		media_entity_create_link(fe, 1, demux, 0, MEDIA_LNK_FL_ENABLED);
  
  	if (demux && dvr)
  		media_entity_create_link(demux, 1, dvr, 0, MEDIA_LNK_FL_ENABLED);
  
  	if (demux && ca)
  		media_entity_create_link(demux, 1, ca, 0, MEDIA_LNK_FL_ENABLED);
  }
  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);
  
  	printk(KERN_INFO "DVB: registering new adapter (%s)
  ", 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) {
  		printk(KERN_ERR "dvb-core: unable to get major %d
  ", DVB_MAJOR);
  		return retval;
  	}
  
  	cdev_init(&dvb_device_cdev, &dvb_device_fops);
  	if ((retval = cdev_add(&dvb_device_cdev, dev, MAX_DVB_MINORS)) != 0) {
  		printk(KERN_ERR "dvb-core: unable register character device
  ");
  		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");