path: root/drivers/media/pci/ivtv/ivtv-fileops.c

/*
    file operation functions
    Copyright (C) 2003-2004  Kevin Thayer <nufan_wfk at yahoo.com>
    Copyright (C) 2004  Chris Kennedy <c@groovy.org>
    Copyright (C) 2005-2007  Hans Verkuil <hverkuil@xs4all.nl>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 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 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 "ivtv-driver.h"
#include "ivtv-fileops.h"
#include "ivtv-i2c.h"
#include "ivtv-queue.h"
#include "ivtv-udma.h"
#include "ivtv-irq.h"
#include "ivtv-vbi.h"
#include "ivtv-mailbox.h"
#include "ivtv-routing.h"
#include "ivtv-streams.h"
#include "ivtv-yuv.h"
#include "ivtv-ioctl.h"
#include "ivtv-cards.h"
#include "ivtv-firmware.h"
#include <media/v4l2-event.h>
#include <media/saa7115.h>

/* This function tries to claim the stream for a specific file descriptor.
   If no one else is using this stream then the stream is claimed and
   associated VBI streams are also automatically claimed.
   Possible error returns: -EBUSY if someone else has claimed
   the stream or 0 on success. */
static int ivtv_claim_stream(struct ivtv_open_id *id, int type)
{
	struct ivtv *itv = id->itv;
	struct ivtv_stream *s = &itv->streams[type];
	struct ivtv_stream *s_vbi;
	int vbi_type;

	if (test_and_set_bit(IVTV_F_S_CLAIMED, &s->s_flags)) {
		/* someone already claimed this stream */
		if (s->fh == &id->fh) {
			/* yes, this file descriptor did. So that's OK. */
			return 0;
		}
		if (s->fh == NULL && (type == IVTV_DEC_STREAM_TYPE_VBI ||
					 type == IVTV_ENC_STREAM_TYPE_VBI)) {
			/* VBI is handled already internally, now also assign
			   the file descriptor to this stream for external
			   reading of the stream. */
			s->fh = &id->fh;
			IVTV_DEBUG_INFO("Start Read VBI\n");
			return 0;
		}
		/* someone else is using this stream already */
		IVTV_DEBUG_INFO("Stream %d is busy\n", type);
		return -EBUSY;
	}
	s->fh = &id->fh;
	if (type == IVTV_DEC_STREAM_TYPE_VBI) {
		/* Enable reinsertion interrupt */
		ivtv_clear_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
	}

	/* IVTV_DEC_STREAM_TYPE_MPG needs to claim IVTV_DEC_STREAM_TYPE_VBI,
	   IVTV_ENC_STREAM_TYPE_MPG needs to claim IVTV_ENC_STREAM_TYPE_VBI
	   (provided VBI insertion is on and sliced VBI is selected), for all
	   other streams we're done */
	if (type == IVTV_DEC_STREAM_TYPE_MPG) {
		vbi_type = IVTV_DEC_STREAM_TYPE_VBI;
	} else if (type == IVTV_ENC_STREAM_TYPE_MPG &&
		   itv->vbi.insert_mpeg && !ivtv_raw_vbi(itv)) {
		vbi_type = IVTV_ENC_STREAM_TYPE_VBI;
	} else {
		return 0;
	}
	s_vbi = &itv->streams[vbi_type];

	if (!test_and_set_bit(IVTV_F_S_CLAIMED, &s_vbi->s_flags)) {
		/* Enable reinsertion interrupt */
		if (vbi_type == IVTV_DEC_STREAM_TYPE_VBI)
			ivtv_clear_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
	}
	/* mark that it is used internally */
	set_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags);
	return 0;
}

/* This function releases a previously claimed stream. It will take into
   account associated VBI streams. */
void ivtv_release_stream(struct ivtv_stream *s)
{
	struct ivtv *itv = s->itv;
	struct ivtv_stream *s_vbi;

	s->fh = NULL;
	if ((s->type == IVTV_DEC_STREAM_TYPE_VBI || s->type == IVTV_ENC_STREAM_TYPE_VBI) &&
		test_bit(IVTV_F_S_INTERNAL_USE, &s->s_flags)) {
		/* this stream is still in use internally */
		return;
	}
	if (!test_and_clear_bit(IVTV_F_S_CLAIMED, &s->s_flags)) {
		IVTV_DEBUG_WARN("Release stream %s not in use!\n", s->name);
		return;
	}

	ivtv_flush_queues(s);

	/* disable reinsertion interrupt */
	if (s->type == IVTV_DEC_STREAM_TYPE_VBI)
		ivtv_set_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);

	/* IVTV_DEC_STREAM_TYPE_MPG needs to release IVTV_DEC_STREAM_TYPE_VBI,
	   IVTV_ENC_STREAM_TYPE_MPG needs to release IVTV_ENC_STREAM_TYPE_VBI,
	   for all other streams we're done */
	if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
		s_vbi = &itv->streams[IVTV_DEC_STREAM_TYPE_VBI];
	else if (s->type == IVTV_ENC_STREAM_TYPE_MPG)
		s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
	else
		return;

	/* clear internal use flag */
	if (!test_and_clear_bit(IVTV_F_S_INTERNAL_USE