dmxdev.c

linux内核源码

/*
 * dmxdev.c - DVB demultiplexer device
 *
 * Copyright (C) 2000 Ralph Metzler & Marcus Metzler
 *		      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/spinlock.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/ioctl.h>
#include <linux/wait.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include "dmxdev.h"

static int debug;

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");

#define dprintk	if (debug) printk

static int dvb_dmxdev_buffer_write(struct dvb_ringbuffer *buf,
				   const u8 *src, size_t len)
{
	ssize_t free;

	if (!len)
		return 0;
	if (!buf->data)
		return 0;

	free = dvb_ringbuffer_free(buf);
	if (len > free) {
		dprintk("dmxdev: buffer overflow\n");
		return -EOVERFLOW;
	}

	return dvb_ringbuffer_write(buf, src, len);
}

static ssize_t dvb_dmxdev_buffer_read(struct dvb_ringbuffer *src,
				      int non_blocking, char __user *buf,
				      size_t count, loff_t *ppos)
{
	size_t todo;
	ssize_t avail;
	ssize_t ret = 0;

	if (!src->data)
		return 0;

	if (src->error) {
		ret = src->error;
		dvb_ringbuffer_flush(src);
		return ret;
	}

	for (todo = count; todo > 0; todo -= ret) {
		if (non_blocking && dvb_ringbuffer_empty(src)) {
			ret = -EWOULDBLOCK;
			break;
		}

		ret = wait_event_interruptible(src->queue,
					       !dvb_ringbuffer_empty(src) ||
					       (src->error != 0));
		if (ret < 0)
			break;

		if (src->error) {
			ret = src->error;
			dvb_ringbuffer_flush(src);
			break;
		}

		avail = dvb_ringbuffer_avail(src);
		if (avail > todo)
			avail = todo;

		ret = dvb_ringbuffer_read(src, (u8 *)buf, avail, 1);
		if (ret < 0)
			break;

		buf += ret;
	}

	return (count - todo) ? (count - todo) : ret;
}

static struct dmx_frontend *get_fe(struct dmx_demux *demux, int type)
{
	struct list_head *head, *pos;

	head = demux->get_frontends(demux);
	if (!head)
		return NULL;
	list_for_each(pos, head)
		if (DMX_FE_ENTRY(pos)->source == type)
			return DMX_FE_ENTRY(pos);

	return NULL;
}

static int dvb_dvr_open(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dmxdev *dmxdev = dvbdev->priv;
	struct dmx_frontend *front;

	dprintk("function : %s\n", __FUNCTION__);

	if (mutex_lock_interruptible(&dmxdev->mutex))
		return -ERESTARTSYS;

	if (dmxdev->exit) {
		mutex_unlock(&dmxdev->mutex);
		return -ENODEV;
	}

	if ((file->f_flags & O_ACCMODE) == O_RDWR) {
		if (!(dmxdev->capabilities & DMXDEV_CAP_DUPLEX)) {
			mutex_unlock(&dmxdev->mutex);
			return -EOPNOTSUPP;
		}
	}

	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
		void *mem;
		if (!dvbdev->readers) {
			mutex_unlock(&dmxdev->mutex);
			return -EBUSY;
		}
		mem = vmalloc(DVR_BUFFER_SIZE);
		if (!mem) {
			mutex_unlock(&dmxdev->mutex);
			return -ENOMEM;
		}
		dvb_ringbuffer_init(&dmxdev->dvr_buffer, mem, DVR_BUFFER_SIZE);
		dvbdev->readers--;
	}

	if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
		dmxdev->dvr_orig_fe = dmxdev->demux->frontend;

		if (!dmxdev->demux->write) {
			mutex_unlock(&dmxdev->mutex);
			return -EOPNOTSUPP;
		}

		front = get_fe(dmxdev->demux, DMX_MEMORY_FE);

		if (!front) {
			mutex_unlock(&dmxdev->mutex);
			return -EINVAL;
		}
		dmxdev->demux->disconnect_frontend(dmxdev->demux);
		dmxdev->demux->connect_frontend(dmxdev->demux, front);
	}
	dvbdev->users++;
	mutex_unlock(&dmxdev->mutex);
	return 0;
}

static int dvb_dvr_release(struct inode *inode, struct file *file)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dmxdev *dmxdev = dvbdev->priv;

	mutex_lock(&dmxdev->mutex);

	if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
		dmxdev->demux->disconnect_frontend(dmxdev->demux);
		dmxdev->demux->connect_frontend(dmxdev->demux,
						dmxdev->dvr_orig_fe);
	}
	if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
		dvbdev->readers++;
		if (dmxdev->dvr_buffer.data) {
			void *mem = dmxdev->dvr_buffer.data;
			mb();
			spin_lock_irq(&dmxdev->lock);
			dmxdev->dvr_buffer.data = NULL;
			spin_unlock_irq(&dmxdev->lock);
			vfree(mem);
		}
	}
	/* TODO */
	dvbdev->users--;
	if(dvbdev->users==-1 && dmxdev->exit==1) {
		fops_put(file->f_op);
		file->f_op = NULL;
		mutex_unlock(&dmxdev->mutex);
		wake_up(&dvbdev->wait_queue);
	} else
		mutex_unlock(&dmxdev->mutex);

	return 0;
}

static ssize_t dvb_dvr_write(struct file *file, const char __user *buf,
			     size_t count, loff_t *ppos)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dmxdev *dmxdev = dvbdev->priv;
	int ret;

	if (!dmxdev->demux->write)
		return -EOPNOTSUPP;
	if ((file->f_flags & O_ACCMODE) != O_WRONLY)
		return -EINVAL;
	if (mutex_lock_interruptible(&dmxdev->mutex))
		return -ERESTARTSYS;

	if (dmxdev->exit) {
		mutex_unlock(&dmxdev->mutex);
		return -ENODEV;
	}
	ret = dmxdev->demux->write(dmxdev->demux, buf, count);
	mutex_unlock(&dmxdev->mutex);
	return ret;
}

static ssize_t dvb_dvr_read(struct file *file, char __user *buf, size_t count,
			    loff_t *ppos)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dmxdev *dmxdev = dvbdev->priv;
	int ret;

	if (dmxdev->exit) {
		mutex_unlock(&dmxdev->mutex);
		return -ENODEV;
	}

	//mutex_lock(&dmxdev->mutex);
	ret = dvb_dmxdev_buffer_read(&dmxdev->dvr_buffer,
				     file->f_flags & O_NONBLOCK,
				     buf, count, ppos);
	//mutex_unlock(&dmxdev->mutex);
	return ret;
}

static inline void dvb_dmxdev_filter_state_set(struct dmxdev_filter
					       *dmxdevfilter, int state)
{
	spin_lock_irq(&dmxdevfilter->dev->lock);
	dmxdevfilter->state = state;
	spin_unlock_irq(&dmxdevfilter->dev->lock);
}

static int dvb_dmxdev_set_buffer_size(struct dmxdev_filter *dmxdevfilter,
				      unsigned long size)
{
	struct dvb_ringbuffer *buf = &dmxdevfilter->buffer;
	void *mem;

	if (buf->size == size)
		return 0;
	if (dmxdevfilter->state >= DMXDEV_STATE_GO)
		return -EBUSY;
	spin_lock_irq(&dmxdevfilter->dev->lock);
	mem = buf->data;
	buf->data = NULL;
	buf->size = size;
	dvb_ringbuffer_flush(buf);
	spin_unlock_irq(&dmxdevfilter->dev->lock);
	vfree(mem);

	if (buf->size) {
		mem = vmalloc(dmxdevfilter->buffer.size);
		if (!mem)
			return -ENOMEM;
		spin_lock_irq(&dmxdevfilter->dev->lock);
		buf->data = mem;
		spin_unlock_irq(&dmxdevfilter->dev->lock);
	}
	return 0;
}

static void dvb_dmxdev_filter_timeout(unsigned long data)
{
	struct dmxdev_filter *dmxdevfilter = (struct dmxdev_filter *)data;

	dmxdevfilter->buffer.error = -ETIMEDOUT;
	spin_lock_irq(&dmxdevfilter->dev->lock);
	dmxdevfilter->state = DMXDEV_STATE_TIMEDOUT;
	spin_unlock_irq(&dmxdevfilter->dev->lock);
	wake_up(&dmxdevfilter->buffer.queue);
}

static void dvb_dmxdev_filter_timer(struct dmxdev_filter *dmxdevfilter)
{
	struct dmx_sct_filter_params *para = &dmxdevfilter->params.sec;

	del_timer(&dmxdevfilter->timer);
	if (para->timeout) {
		dmxdevfilter->timer.function = dvb_dmxdev_filter_timeout;
		dmxdevfilter->timer.data = (unsigned long)dmxdevfilter;
		dmxdevfilter->timer.expires =
		    jiffies + 1 + (HZ / 2 + HZ * para->timeout) / 1000;
		add_timer(&dmxdevfilter->timer);
	}
}

static int dvb_dmxdev_section_callback(const u8 *buffer1, size_t buffer1_len,
				       const u8 *buffer2, size_t buffer2_len,
				       struct dmx_section_filter *filter,
				       enum dmx_success success)
{
	struct dmxdev_filter *dmxdevfilter = filter->priv;
	int ret;

	if (dmxdevfilter->buffer.error) {
		wake_up(&dmxdevfilter->buffer.queue);
		return 0;
	}
	spin_lock(&dmxdevfilter->dev->lock);
	if (dmxdevfilter->state != DMXDEV_STATE_GO) {
		spin_unlock(&dmxdevfilter->dev->lock);
		return 0;
	}
	del_timer(&dmxdevfilter->timer);
	dprintk("dmxdev: section callback %02x %02x %02x %02x %02x %02x\n",
		buffer1[0], buffer1[1],
		buffer1[2], buffer1[3], buffer1[4], buffer1[5]);
	ret = dvb_dmxdev_buffer_write(&dmxdevfilter->buffer, buffer1,
				      buffer1_len);
	if (ret == buffer1_len) {
		ret = dvb_dmxdev_buffer_write(&dmxdevfilter->buffer, buffer2,
					      buffer2_len);
	}
	if (ret < 0) {
		dvb_ringbuffer_flush(&dmxdevfilter->buffer);
		dmxdevfilter->buffer.error = ret;
	}
	if (dmxdevfilter->params.sec.flags & DMX_ONESHOT)
		dmxdevfilter->state = DMXDEV_STATE_DONE;
	spin_unlock(&dmxdevfilter->dev->lock);
	wake_up(&dmxdevfilter->buffer.queue);
	return 0;
}

static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len,
				  const u8 *buffer2, size_t buffer2_len,
				  struct dmx_ts_feed *feed,
				  enum dmx_success success)
{
	struct dmxdev_filter *dmxdevfilter = feed->priv;
	struct dvb_ringbuffer *buffer;
	int ret;

	spin_lock(&dmxdevfilter->dev->lock);
	if (dmxdevfilter->params.pes.output == DMX_OUT_DECODER) {
		spin_unlock(&dmxdevfilter->dev->lock);
		return 0;
	}

	if (dmxdevfilter->params.pes.output == DMX_OUT_TAP)
		buffer = &dmxdevfilter->buffer;
	else
		buffer = &dmxdevfilter->dev->dvr_buffer;
	if (buffer->error) {
		spin_unlock(&dmxdevfilter->dev->lock);
		wake_up(&buffer->queue);
		return 0;
	}
	ret = dvb_dmxdev_buffer_write(buffer, buffer1, buffer1_len);
	if (ret == buffer1_len)
		ret = dvb_dmxdev_buffer_write(buffer, buffer2, buffer2_len);
	if (ret < 0) {
		dvb_ringbuffer_flush(buffer);
		buffer->error = ret;
	}
	spin_unlock(&dmxdevfilter->dev->lock);
	wake_up(&buffer->queue);
	return 0;
}

/* stop feed but only mark the specified filter as stopped (state set) */
static int dvb_dmxdev_feed_stop(struct dmxdev_filter *dmxdevfilter)
{
	dvb_dmxdev_filter_state_set(dmxdevfilter, DMXDEV_STATE_SET);

	switch (dmxdevfilter->type) {
	case DMXDEV_TYPE_SEC:
		del_timer(&dmxdevfilter->timer);
		dmxdevfilter->feed.sec->stop_filtering(dmxdevfilter->feed.sec);
		break;
	case DMXDEV_TYPE_PES:
		dmxdevfilter->feed.ts->stop_filtering(dmxdevfilter->feed.ts);
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

/* start feed associated with the specified filter */
static int dvb_dmxdev_feed_start(struct dmxdev_filter *filter)
{
	dvb_dmxdev_filter_state_set(filter, DMXDEV_STATE_GO);

	switch (filter->type) {
	case DMXDEV_TYPE_SEC:
		return filter->feed.sec->start_filtering(filter->feed.sec);
	case DMXDEV_TYPE_PES:
		return filter->feed.ts->start_filtering(filter->feed.ts);
	default:
		return -EINVAL;
	}

	return 0;
}

/* restart section feed if it has filters left associated with it,
   otherwise release the feed */
static int dvb_dmxdev_feed_restart(struct dmxdev_filter *filter)
{
	int i;
	struct dmxdev *dmxdev = filter->dev;
	u16 pid = filter->params.sec.pid;

	for (i = 0; i < dmxdev->filternum; i++)
		if (dmxdev->filter[i].state >= DMXDEV_STATE_GO &&
		    dmxdev->filter[i].type == DMXDEV_TYPE_SEC &&
		    dmxdev->filter[i].params.sec.pid == pid) {
			dvb_dmxdev_feed_start(&dmxdev->filter[i]);
			return 0;
		}

	filter->dev->demux->release_section_feed(dmxdev->demux,
						 filter->feed.sec);

	return 0;
}

static int dvb_dmxdev_filter_stop(struct dmxdev_filter *dmxdevfilter)
{
	if (dmxdevfilter->state < DMXDEV_STATE_GO)
		return 0;

	switch (dmxdevfilter->type) {
	case DMXDEV_TYPE_SEC:
		if (!dmxdevfilter->feed.sec)
			break;
		dvb_dmxdev_feed_stop(dmxdevfilter);
		if (dmxdevfilter->filter.sec)
			dmxdevfilter->feed.sec->
			    release_filter(dmxdevfilter->feed.sec,
					   dmxdevfilter->filter.sec);
		dvb_dmxdev_feed_restart(dmxdevfilter);
		dmxdevfilter->feed.sec = NULL;
		break;
	case DMXDEV_TYPE_PES:
		if (!dmxdevfilter->feed.ts)
			break;
		dvb_dmxdev_feed_stop(dmxdevfilter);
		dmxdevfilter->dev->demux->
		    release_ts_feed(dmxdevfilter->dev->demux,
				    dmxdevfilter->feed.ts);
		dmxdevfilter->feed.ts = NULL;
		break;
	default:
		if (dmxdevfilter->state == DMXDEV_STATE_ALLOCATED)
			return 0;
		return -EINVAL;
	}

	dvb_ringbuffer_flush(&dmxdevfilter->buffer);
	return 0;
}

static inline int dvb_dmxdev_filter_reset(struct dmxdev_filter *dmxdevfilter)
{
	if (dmxdevfilter->state < DMXDEV_STATE_SET)
		return 0;

	dmxdevfilter->type = DMXDEV_TYPE_NONE;
	dvb_dmxdev_filter_state_set(dmxdevfilter, DMXDEV_STATE_ALLOCATED);
	return 0;
}

static int dvb_dmxdev_filter_start(struct dmxdev_filter *filter)
{
	struct dmxdev *dmxdev = filter->dev;
	void *mem;
	int ret, i;

	if (filter->state < DMXDEV_STATE_SET)
		return -EINVAL;

	if (filter->state >= DMXDEV_STATE_GO)
		dvb_dmxdev_filter_stop(filter);

	if (!filter->buffer.data) {
		mem = vmalloc(filter->buffer.size);
		if (!mem)
			return -ENOMEM;
		spin_lock_irq(&filter->dev->lock);
		filter->buffer.data = mem;
		spin_unlock_irq(&filter->dev->lock);
	}

	dvb_ringbuffer_flush(&filter->buffer);

	switch (filter->type) {
	case DMXDEV_TYPE_SEC:
	{
		struct dmx_sct_filter_params *para = &filter->params.sec;
		struct dmx_section_filter **secfilter = &filter->filter.sec;
		struct dmx_section_feed **secfeed = &filter->feed.sec;

		*secfilter = NULL;
		*secfeed = NULL;


		/* find active filter/feed with same PID */
		for (i = 0; i < dmxdev->filternum; i++) {
			if (dmxdev->filter[i].state >= DMXDEV_STATE_GO &&
			    dmxdev->filter[i].type == DMXDEV_TYPE_SEC &&
			    dmxdev->filter[i].params.sec.pid == para->pid) {
				*secfeed = dmxdev->filter[i].feed.sec;
				break;
			}
		}

		/* if no feed found, try to allocate new one */
		if (!*secfeed) {
			ret = dmxdev->demux->allocate_section_feed(dmxdev->demux,
								   secfeed,
								   dvb_dmxdev_section_callback);
			if (ret < 0) {
				printk("DVB (%s): could not alloc feed\n",
				       __FUNCTION__);
				return ret;
			}

			ret = (*secfeed)->set(*secfeed, para->pid, 32768,
					      (para->flags & DMX_CHECK_CRC) ? 1 : 0);
			if (ret < 0) {
				printk("DVB (%s): could not set feed\n",
				       __FUNCTION__);
				dvb_dmxdev_feed_restart(filter);
				return ret;
			}