path: root/drivers/media/dvb-core/dvbdev.c

/*
 * 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"

/* 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 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, &