drivers/media/video/cx18/cx18-fileops.c - kernel/msm-5.4 - Gitiles

 /*
  *  cx18 file operation functions
  *
  *  Derived from ivtv-fileops.c
  *
  *  Copyright (C) 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 "cx18-driver.h"
 #include "cx18-fileops.h"
 #include "cx18-i2c.h"
 #include "cx18-queue.h"
 #include "cx18-vbi.h"
 #include "cx18-audio.h"
 #include "cx18-mailbox.h"
 #include "cx18-scb.h"
 #include "cx18-streams.h"
 #include "cx18-controls.h"
 #include "cx18-ioctl.h"
 #include "cx18-cards.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 cx18_claim_stream(struct cx18_open_id *id, int type)
 {
 	struct cx18 *cx = id->cx;
 	struct cx18_stream *s = &cx->streams[type];
 	struct cx18_stream *s_vbi;
 	int vbi_type;

 	if (test_and_set_bit(CX18_F_S_CLAIMED, &s->s_flags)) {
 		/* someone already claimed this stream */
 		if (s->id == id->open_id) {
 			/* yes, this file descriptor did. So that's OK. */
 			return 0;
 		}
 		if (s->id == -1 && type == CX18_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->id = id->open_id;
 			CX18_DEBUG_INFO("Start Read VBI\n");
 			return 0;
 		}
 		/* someone else is using this stream already */
 		CX18_DEBUG_INFO("Stream %d is busy\n", type);
 		return -EBUSY;
 	}
 	s->id = id->open_id;

 	/* CX18_DEC_STREAM_TYPE_MPG needs to claim CX18_DEC_STREAM_TYPE_VBI,
 	   CX18_ENC_STREAM_TYPE_MPG needs to claim CX18_ENC_STREAM_TYPE_VBI
 	   (provided VBI insertion is on and sliced VBI is selected), for all
 	   other streams we're done */
 	if (type == CX18_ENC_STREAM_TYPE_MPG &&
 		   cx->vbi.insert_mpeg && cx->vbi.sliced_in->service_set) {
 		vbi_type = CX18_ENC_STREAM_TYPE_VBI;
 	} else {
 		return 0;
 	}
 	s_vbi = &cx->streams[vbi_type];

 	set_bit(CX18_F_S_CLAIMED, &s_vbi->s_flags);

 	/* mark that it is used internally */
 	set_bit(CX18_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. */
 static void cx18_release_stream(struct cx18_stream *s)
 {
 	struct cx18 *cx = s->cx;
 	struct cx18_stream *s_vbi;

 	s->id = -1;
 	if (s->type == CX18_ENC_STREAM_TYPE_VBI &&
 		test_bit(CX18_F_S_INTERNAL_USE, &s->s_flags)) {
 		/* this stream is still in use internally */
 		return;
 	}
 	if (!test_and_clear_bit(CX18_F_S_CLAIMED, &s->s_flags)) {
 		CX18_DEBUG_WARN("Release stream %s not in use!\n", s->name);
 		return;
 	}

 	cx18_flush_queues(s);

 	/* CX18_ENC_STREAM_TYPE_MPG needs to release CX18_ENC_STREAM_TYPE_VBI,
 	   for all other streams we're done */
 	if (s->type == CX18_ENC_STREAM_TYPE_MPG)
 		s_vbi = &cx->streams[CX18_ENC_STREAM_TYPE_VBI];
 	else
 		return;

 	/* clear internal use flag */
 	if (!test_and_clear_bit(CX18_F_S_INTERNAL_USE, &s_vbi->s_flags)) {
 		/* was already cleared */
 		return;
 	}
 	if (s_vbi->id != -1) {
 		/* VBI stream still claimed by a file descriptor */
 		return;
 	}
 	clear_bit(CX18_F_S_CLAIMED, &s_vbi->s_flags);
 	cx18_flush_queues(s_vbi);
 }

 static void cx18_dualwatch(struct cx18 *cx)
 {
 	struct v4l2_tuner vt;
 	u16 new_bitmap;
 	u16 new_stereo_mode;
 	const u16 stereo_mask = 0x0300;
 	const u16 dual = 0x0200;

 	new_stereo_mode = cx->params.audio_properties & stereo_mask;
 	memset(&vt, 0, sizeof(vt));
 	cx18_call_i2c_clients(cx, VIDIOC_G_TUNER, &vt);
 	if (vt.audmode == V4L2_TUNER_MODE_LANG1_LANG2 &&
 			(vt.rxsubchans & V4L2_TUNER_SUB_LANG2))
 		new_stereo_mode = dual;

 	if (new_stereo_mode == cx->dualwatch_stereo_mode)
 		return;

 	new_bitmap = new_stereo_mode | (cx->params.audio_properties & ~stereo_mask);

 	CX18_DEBUG_INFO("dualwatch: change stereo flag from 0x%x to 0x%x. new audio_bitmask=0x%ux\n",
 			   cx->dualwatch_stereo_mode, new_stereo_mode, new_bitmap);

 	if (cx18_vapi(cx, CX18_CPU_SET_AUDIO_PARAMETERS, 2,
 				cx18_find_handle(cx), new_bitmap) == 0) {
 		cx->dualwatch_stereo_mode = new_stereo_mode;
 		return;
 	}
 	CX18_DEBUG_INFO("dualwatch: changing stereo flag failed\n");
 }


 static struct cx18_buffer *cx18_get_buffer(struct cx18_stream *s, int non_block, int *err)
 {
 	struct cx18 *cx = s->cx;
 	struct cx18_stream *s_vbi = &cx->streams[CX18_ENC_STREAM_TYPE_VBI];
 	struct cx18_buffer *buf;
 	DEFINE_WAIT(wait);

 	*err = 0;
 	while (1) {
 		if (s->type == CX18_ENC_STREAM_TYPE_MPG) {

 			if (time_after(jiffies, cx->dualwatch_jiffies + msecs_to_jiffies(1000))) {
 				cx->dualwatch_jiffies = jiffies;
 				cx18_dualwatch(cx);
 			}
 			if (test_bit(CX18_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
 			    !test_bit(CX18_F_S_APPL_IO, &s_vbi->s_flags)) {
 				while ((buf = cx18_dequeue(s_vbi, &s_vbi->q_full))) {
 					/* byteswap and process VBI data */
 /*					cx18_process_vbi_data(cx, buf, s_vbi->dma_pts, s_vbi->type); */
 					cx18_enqueue(s_vbi, buf, &s_vbi->q_free);
 				}
 			}
 			buf = &cx->vbi.sliced_mpeg_buf;
 			if (buf->readpos != buf->bytesused)
 				return buf;
 		}

 		/* do we have leftover data? */
 		buf = cx18_dequeue(s, &s->q_io);
 		if (buf)
 			return buf;

 		/* do we have new data? */
 		buf = cx18_dequeue(s, &s->q_full);
 		if (buf) {
 			if (!test_and_clear_bit(CX18_F_B_NEED_BUF_SWAP,
 						&buf->b_flags))
 				return buf;
 			if (s->type == CX18_ENC_STREAM_TYPE_MPG)
 				/* byteswap MPG data */
 				cx18_buf_swap(buf);
 			else {
 				/* byteswap and process VBI data */
 				cx18_process_vbi_data(cx, buf,
 						s->dma_pts, s->type);
 			}
 			return buf;
 		}

 		/* return if end of stream */
 		if (!test_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 			CX18_DEBUG_INFO("EOS %s\n", s->name);
 			return NULL;
 		}

 		/* return if file was opened with O_NONBLOCK */
 		if (non_block) {
 			*err = -EAGAIN;
 			return NULL;
 		}

 		/* wait for more data to arrive */
 		prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
 		/* New buffers might have become available before we were added
 		   to the waitqueue */
 		if (!s->q_full.buffers)
 			schedule();
 		finish_wait(&s->waitq, &wait);
 		if (signal_pending(current)) {
 			/* return if a signal was received */
 			CX18_DEBUG_INFO("User stopped %s\n", s->name);
 			*err = -EINTR;
 			return NULL;
 		}
 	}
 }

 static void cx18_setup_sliced_vbi_buf(struct cx18 *cx)
 {
 	int idx = cx->vbi.inserted_frame % CX18_VBI_FRAMES;

 	cx->vbi.sliced_mpeg_buf.buf = cx->vbi.sliced_mpeg_data[idx];
 	cx->vbi.sliced_mpeg_buf.bytesused = cx->vbi.sliced_mpeg_size[idx];
 	cx->vbi.sliced_mpeg_buf.readpos = 0;
 }

 static size_t cx18_copy_buf_to_user(struct cx18_stream *s,
 		struct cx18_buffer *buf, char __user *ubuf, size_t ucount)
 {
 	struct cx18 *cx = s->cx;
 	size_t len = buf->bytesused - buf->readpos;

 	if (len > ucount)
 		len = ucount;
 	if (cx->vbi.insert_mpeg && s->type == CX18_ENC_STREAM_TYPE_MPG &&
 	    cx->vbi.sliced_in->service_set && buf != &cx->vbi.sliced_mpeg_buf) {
 		const char *start = buf->buf + buf->readpos;
 		const char *p = start + 1;
 		const u8 *q;
 		u8 ch = cx->search_pack_header ? 0xba : 0xe0;
 		int stuffing, i;

 		while (start + len > p) {
 			q = memchr(p, 0, start + len - p);
 			if (q == NULL)
 				break;
 			p = q + 1;
 			if ((char *)q + 15 >= buf->buf + buf->bytesused ||
 			    q[1] != 0 || q[2] != 1 || q[3] != ch)
 				continue;
 			if (!cx->search_pack_header) {
 				if ((q[6] & 0xc0) != 0x80)
 					continue;
 				if (((q[7] & 0xc0) == 0x80 &&
 				     (q[9] & 0xf0) == 0x20) ||
 				    ((q[7] & 0xc0) == 0xc0 &&
 				     (q[9] & 0xf0) == 0x30)) {
 					ch = 0xba;
 					cx->search_pack_header = 1;
 					p = q + 9;
 				}
 				continue;
 			}
 			stuffing = q[13] & 7;
 			/* all stuffing bytes must be 0xff */
 			for (i = 0; i < stuffing; i++)
 				if (q[14 + i] != 0xff)
 					break;
 			if (i == stuffing &&
 			    (q[4] & 0xc4) == 0x44 &&
 			    (q[12] & 3) == 3 &&
 			    q[14 + stuffing] == 0 &&
 			    q[15 + stuffing] == 0 &&
 			    q[16 + stuffing] == 1) {
 				cx->search_pack_header = 0;
 				len = (char *)q - start;
 				cx18_setup_sliced_vbi_buf(cx);
 				break;
 			}
 		}
 	}
 	if (copy_to_user(ubuf, (u8 *)buf->buf + buf->readpos, len)) {
 		CX18_DEBUG_WARN("copy %zd bytes to user failed for %s\n",
 				len, s->name);
 		return -EFAULT;
 	}
 	buf->readpos += len;
 	if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
 	    buf != &cx->vbi.sliced_mpeg_buf)
 		cx->mpg_data_received += len;
 	return len;
 }

 static ssize_t cx18_read(struct cx18_stream *s, char __user *ubuf,
 		size_t tot_count, int non_block)
 {
 	struct cx18 *cx = s->cx;
 	size_t tot_written = 0;
 	int single_frame = 0;

 	if (atomic_read(&cx->ana_capturing) == 0 && s->id == -1) {
 		/* shouldn't happen */
 		CX18_DEBUG_WARN("Stream %s not initialized before read\n",
 				s->name);
 		return -EIO;
 	}

 	/* Each VBI buffer is one frame, the v4l2 API says that for VBI the
 	   frames should arrive one-by-one, so make sure we never output more
 	   than one VBI frame at a time */
 	if (s->type == CX18_ENC_STREAM_TYPE_VBI &&
 	    cx->vbi.sliced_in->service_set)
 		single_frame = 1;

 	for (;;) {
 		struct cx18_buffer *buf;
 		int rc;

 		buf = cx18_get_buffer(s, non_block, &rc);
 		/* if there is no data available... */
 		if (buf == NULL) {
 			/* if we got data, then return that regardless */
 			if (tot_written)
 				break;
 			/* EOS condition */
 			if (rc == 0) {
 				clear_bit(CX18_F_S_STREAMOFF, &s->s_flags);
 				clear_bit(CX18_F_S_APPL_IO, &s->s_flags);
 				cx18_release_stream(s);
 			}
 			/* set errno */
 			return rc;
 		}

 		rc = cx18_copy_buf_to_user(s, buf, ubuf + tot_written,
 				tot_count - tot_written);

 		if (buf != &cx->vbi.sliced_mpeg_buf) {
 			if (buf->readpos == buf->bytesused) {
 				cx18_buf_sync_for_device(s, buf);
 				cx18_enqueue(s, buf, &s->q_free);
 				cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5,
 					s->handle,
 					(void __iomem *)&cx->scb->cpu_mdl[buf->id] -
 					  cx->enc_mem,
 					1, buf->id, s->buf_size);
 			} else
 				cx18_enqueue(s, buf, &s->q_io);
 		} else if (buf->readpos == buf->bytesused) {
 			int idx = cx->vbi.inserted_frame % CX18_VBI_FRAMES;

 			cx->vbi.sliced_mpeg_size[idx] = 0;
 			cx->vbi.inserted_frame++;
 			cx->vbi_data_inserted += buf->bytesused;
 		}
 		if (rc < 0)
 			return rc;
 		tot_written += rc;

 		if (tot_written == tot_count || single_frame)
 			break;
 	}
 	return tot_written;
 }

 static ssize_t cx18_read_pos(struct cx18_stream *s, char __user *ubuf,
 		size_t count, loff_t *pos, int non_block)
 {
 	ssize_t rc = count ? cx18_read(s, ubuf, count, non_block) : 0;
 	struct cx18 *cx = s->cx;

 	CX18_DEBUG_HI_FILE("read %zd from %s, got %zd\n", count, s->name, rc);
 	if (rc > 0)
 		pos += rc;
 	return rc;
 }

 int cx18_start_capture(struct cx18_open_id *id)
 {
 	struct cx18 *cx = id->cx;
 	struct cx18_stream *s = &cx->streams[id->type];
 	struct cx18_stream *s_vbi;

 	if (s->type == CX18_ENC_STREAM_TYPE_RAD) {
 		/* you cannot read from these stream types. */
 		return -EPERM;
 	}

 	/* Try to claim this stream. */
 	if (cx18_claim_stream(id, s->type))
 		return -EBUSY;

 	/* If capture is already in progress, then we also have to
 	   do nothing extra. */
 	if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
 	    test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 		set_bit(CX18_F_S_APPL_IO, &s->s_flags);
 		return 0;
 	}

 	/* Start VBI capture if required */
 	s_vbi = &cx->streams[CX18_ENC_STREAM_TYPE_VBI];
 	if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
 	    test_bit(CX18_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
 	    !test_and_set_bit(CX18_F_S_STREAMING, &s_vbi->s_flags)) {
 		/* Note: the CX18_ENC_STREAM_TYPE_VBI is claimed
 		   automatically when the MPG stream is claimed.
 		   We only need to start the VBI capturing. */
 		if (cx18_start_v4l2_encode_stream(s_vbi)) {
 			CX18_DEBUG_WARN("VBI capture start failed\n");

 			/* Failure, clean up and return an error */
 			clear_bit(CX18_F_S_STREAMING, &s_vbi->s_flags);
 			clear_bit(CX18_F_S_STREAMING, &s->s_flags);
 			/* also releases the associated VBI stream */
 			cx18_release_stream(s);
 			return -EIO;
 		}
 		CX18_DEBUG_INFO("VBI insertion started\n");
 	}

 	/* Tell the card to start capturing */
 	if (!cx18_start_v4l2_encode_stream(s)) {
 		/* We're done */
 		set_bit(CX18_F_S_APPL_IO, &s->s_flags);
 		/* Resume a possibly paused encoder */
 		if (test_and_clear_bit(CX18_F_I_ENC_PAUSED, &cx->i_flags))
 			cx18_vapi(cx, CX18_CPU_CAPTURE_PAUSE, 1, s->handle);
 		return 0;
 	}

 	/* failure, clean up */
 	CX18_DEBUG_WARN("Failed to start capturing for stream %s\n", s->name);

 	/* Note: the CX18_ENC_STREAM_TYPE_VBI is released
 	   automatically when the MPG stream is released.
 	   We only need to stop the VBI capturing. */
 	if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
 	    test_bit(CX18_F_S_STREAMING, &s_vbi->s_flags)) {
 		cx18_stop_v4l2_encode_stream(s_vbi, 0);
 		clear_bit(CX18_F_S_STREAMING, &s_vbi->s_flags);
 	}
 	clear_bit(CX18_F_S_STREAMING, &s->s_flags);
 	cx18_release_stream(s);
 	return -EIO;
 }

 ssize_t cx18_v4l2_read(struct file *filp, char __user *buf, size_t count,
 		loff_t *pos)
 {
 	struct cx18_open_id *id = filp->private_data;
 	struct cx18 *cx = id->cx;
 	struct cx18_stream *s = &cx->streams[id->type];
 	int rc;

 	CX18_DEBUG_HI_FILE("read %zd bytes from %s\n", count, s->name);

 	mutex_lock(&cx->serialize_lock);
 	rc = cx18_start_capture(id);
 	mutex_unlock(&cx->serialize_lock);
 	if (rc)
 		return rc;
 	return cx18_read_pos(s, buf, count, pos, filp->f_flags & O_NONBLOCK);
 }

 unsigned int cx18_v4l2_enc_poll(struct file *filp, poll_table *wait)
 {
 	struct cx18_open_id *id = filp->private_data;
 	struct cx18 *cx = id->cx;
 	struct cx18_stream *s = &cx->streams[id->type];
 	int eof = test_bit(CX18_F_S_STREAMOFF, &s->s_flags);

 	/* Start a capture if there is none */
 	if (!eof && !test_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 		int rc;

 		mutex_lock(&cx->serialize_lock);
 		rc = cx18_start_capture(id);
 		mutex_unlock(&cx->serialize_lock);
 		if (rc) {
 			CX18_DEBUG_INFO("Could not start capture for %s (%d)\n",
 					s->name, rc);
 			return POLLERR;
 		}
 		CX18_DEBUG_FILE("Encoder poll started capture\n");
 	}

 	/* add stream's waitq to the poll list */
 	CX18_DEBUG_HI_FILE("Encoder poll\n");
 	poll_wait(filp, &s->waitq, wait);

 	if (s->q_full.length || s->q_io.length)
 		return POLLIN | POLLRDNORM;
 	if (eof)
 		return POLLHUP;
 	return 0;
 }

 void cx18_stop_capture(struct cx18_open_id *id, int gop_end)
 {
 	struct cx18 *cx = id->cx;
 	struct cx18_stream *s = &cx->streams[id->type];

 	CX18_DEBUG_IOCTL("close() of %s\n", s->name);

 	/* 'Unclaim' this stream */

 	/* Stop capturing */
 	if (test_bit(CX18_F_S_STREAMING, &s->s_flags)) {
 		struct cx18_stream *s_vbi =
 			&cx->streams[CX18_ENC_STREAM_TYPE_VBI];

 		CX18_DEBUG_INFO("close stopping capture\n");
 		/* Special case: a running VBI capture for VBI insertion
 		   in the mpeg stream. Need to stop that too. */
 		if (id->type == CX18_ENC_STREAM_TYPE_MPG &&
 		    test_bit(CX18_F_S_STREAMING, &s_vbi->s_flags) &&
 		    !test_bit(CX18_F_S_APPL_IO, &s_vbi->s_flags)) {
 			CX18_DEBUG_INFO("close stopping embedded VBI capture\n");
 			cx18_stop_v4l2_encode_stream(s_vbi, 0);
 		}
 		if (id->type == CX18_ENC_STREAM_TYPE_VBI &&
 		    test_bit(CX18_F_S_INTERNAL_USE, &s->s_flags))
 			/* Also used internally, don't stop capturing */
 			s->id = -1;
 		else
 			cx18_stop_v4l2_encode_stream(s, gop_end);
 	}
 	if (!gop_end) {
 		clear_bit(CX18_F_S_APPL_IO, &s->s_flags);
 		clear_bit(CX18_F_S_STREAMOFF, &s->s_flags);
 		cx18_release_stream(s);
 	}
 }

 int cx18_v4l2_close(struct inode *inode, struct file *filp)
 {
 	struct cx18_open_id *id = filp->private_data;
 	struct cx18 *cx = id->cx;
 	struct cx18_stream *s = &cx->streams[id->type];

 	CX18_DEBUG_IOCTL("close() of %s\n", s->name);

 	v4l2_prio_close(&cx->prio, &id->prio);

 	/* Easy case first: this stream was never claimed by us */
 	if (s->id != id->open_id) {
 		kfree(id);
 		return 0;
 	}

 	/* 'Unclaim' this stream */

 	/* Stop radio */
 	mutex_lock(&cx->serialize_lock);
 	if (id->type == CX18_ENC_STREAM_TYPE_RAD) {
 		/* Closing radio device, return to TV mode */
 		cx18_mute(cx);
 		/* Mark that the radio is no longer in use */
 		clear_bit(CX18_F_I_RADIO_USER, &cx->i_flags);
 		/* Switch tuner to TV */
 		cx18_call_i2c_clients(cx, VIDIOC_S_STD, &cx->std);
 		/* Select correct audio input (i.e. TV tuner or Line in) */
 		cx18_audio_set_io(cx);
 		if (atomic_read(&cx->ana_capturing) > 0) {
 			/* Undo video mute */
 			cx18_vapi(cx, CX18_CPU_SET_VIDEO_MUTE, 2, s->handle,
 				cx->params.video_mute |
 					(cx->params.video_mute_yuv << 8));
 		}
 		/* Done! Unmute and continue. */
 		cx18_unmute(cx);
 		cx18_release_stream(s);
 	} else {
 		cx18_stop_capture(id, 0);
 	}
 	kfree(id);
 	mutex_unlock(&cx->serialize_lock);
 	return 0;
 }

 static int cx18_serialized_open(struct cx18_stream *s, struct file *filp)
 {
 	struct cx18 *cx = s->cx;
 	struct cx18_open_id *item;

 	CX18_DEBUG_FILE("open %s\n", s->name);

 	/* Allocate memory */
 	item = kmalloc(sizeof(struct cx18_open_id), GFP_KERNEL);
 	if (NULL == item) {
 		CX18_DEBUG_WARN("nomem on v4l2 open\n");
 		return -ENOMEM;
 	}
 	item->cx = cx;
 	item->type = s->type;
 	v4l2_prio_open(&cx->prio, &item->prio);

 	item->open_id = cx->open_id++;
 	filp->private_data = item;

 	if (item->type == CX18_ENC_STREAM_TYPE_RAD) {
 		/* Try to claim this stream */
 		if (cx18_claim_stream(item, item->type)) {
 			/* No, it's already in use */
 			kfree(item);
 			return -EBUSY;
 		}

 		if (!test_bit(CX18_F_I_RADIO_USER, &cx->i_flags)) {
 			if (atomic_read(&cx->ana_capturing) > 0) {
 				/* switching to radio while capture is
 				   in progress is not polite */
 				cx18_release_stream(s);
 				kfree(item);
 				return -EBUSY;
 			}
 		}

 		/* Mark that the radio is being used. */
 		set_bit(CX18_F_I_RADIO_USER, &cx->i_flags);
 		/* We have the radio */
 		cx18_mute(cx);
 		/* Switch tuner to radio */
 		cx18_call_i2c_clients(cx, AUDC_SET_RADIO, NULL);
 		/* Select the correct audio input (i.e. radio tuner) */
 		cx18_audio_set_io(cx);
 		/* Done! Unmute and continue. */
 		cx18_unmute(cx);
 	}
 	return 0;
 }

 int cx18_v4l2_open(struct inode *inode, struct file *filp)
 {
 	int res, x, y = 0;
 	struct cx18 *cx = NULL;
 	struct cx18_stream *s = NULL;
 	int minor = iminor(inode);

 	/* Find which card this open was on */
 	spin_lock(&cx18_cards_lock);
 	for (x = 0; cx == NULL && x < cx18_cards_active; x++) {
 		/* find out which stream this open was on */
 		for (y = 0; y < CX18_MAX_STREAMS; y++) {
 			if (cx18_cards[x] == NULL)
 				continue;
 			s = &cx18_cards[x]->streams[y];
 			if (s->v4l2dev && s->v4l2dev->minor == minor) {
 				cx = cx18_cards[x];
 				break;
 			}
 		}
 	}
 	spin_unlock(&cx18_cards_lock);

 	if (cx == NULL) {
 		/* Couldn't find a device registered
 		   on that minor, shouldn't happen! */
 		printk(KERN_WARNING "No cx18 device found on minor %d\n",
 				minor);
 		return -ENXIO;
 	}

 	mutex_lock(&cx->serialize_lock);
 	if (cx18_init_on_first_open(cx)) {
 		CX18_ERR("Failed to initialize on minor %d\n", minor);
 		mutex_unlock(&cx->serialize_lock);
 		return -ENXIO;
 	}
 	res = cx18_serialized_open(s, filp);
 	mutex_unlock(&cx->serialize_lock);
 	return res;
 }

 void cx18_mute(struct cx18 *cx)
 {
 	if (atomic_read(&cx->ana_capturing))
 		cx18_vapi(cx, CX18_CPU_SET_AUDIO_MUTE, 2,
 				cx18_find_handle(cx), 1);
 	CX18_DEBUG_INFO("Mute\n");
 }

 void cx18_unmute(struct cx18 *cx)
 {
 	if (atomic_read(&cx->ana_capturing)) {
 		cx18_msleep_timeout(100, 0);
 		cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 2,
 				cx18_find_handle(cx), 12);
 		cx18_vapi(cx, CX18_CPU_SET_AUDIO_MUTE, 2,
 				cx18_find_handle(cx), 0);
 	}
 	CX18_DEBUG_INFO("Unmute\n");
 }
	/*
	* cx18 file operation functions
	*
	* Derived from ivtv-fileops.c
	*
	* Copyright (C) 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 "cx18-driver.h"
	#include "cx18-fileops.h"
	#include "cx18-i2c.h"
	#include "cx18-queue.h"
	#include "cx18-vbi.h"
	#include "cx18-audio.h"
	#include "cx18-mailbox.h"
	#include "cx18-scb.h"
	#include "cx18-streams.h"
	#include "cx18-controls.h"
	#include "cx18-ioctl.h"
	#include "cx18-cards.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 cx18_claim_stream(struct cx18_open_id *id, int type)
	{
	struct cx18 *cx = id->cx;
	struct cx18_stream *s = &cx->streams[type];
	struct cx18_stream *s_vbi;
	int vbi_type;

	if (test_and_set_bit(CX18_F_S_CLAIMED, &s->s_flags)) {
	/* someone already claimed this stream */
	if (s->id == id->open_id) {
	/* yes, this file descriptor did. So that's OK. */
	return 0;
	}
	if (s->id == -1 && type == CX18_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->id = id->open_id;
	CX18_DEBUG_INFO("Start Read VBI\n");
	return 0;
	}
	/* someone else is using this stream already */
	CX18_DEBUG_INFO("Stream %d is busy\n", type);
	return -EBUSY;
	}
	s->id = id->open_id;

	/* CX18_DEC_STREAM_TYPE_MPG needs to claim CX18_DEC_STREAM_TYPE_VBI,
	CX18_ENC_STREAM_TYPE_MPG needs to claim CX18_ENC_STREAM_TYPE_VBI
	(provided VBI insertion is on and sliced VBI is selected), for all
	other streams we're done */
	if (type == CX18_ENC_STREAM_TYPE_MPG &&
	cx->vbi.insert_mpeg && cx->vbi.sliced_in->service_set) {
	vbi_type = CX18_ENC_STREAM_TYPE_VBI;
	} else {
	return 0;
	}
	s_vbi = &cx->streams[vbi_type];

	set_bit(CX18_F_S_CLAIMED, &s_vbi->s_flags);

	/* mark that it is used internally */
	set_bit(CX18_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. */
	static void cx18_release_stream(struct cx18_stream *s)
	{
	struct cx18 *cx = s->cx;
	struct cx18_stream *s_vbi;

	s->id = -1;
	if (s->type == CX18_ENC_STREAM_TYPE_VBI &&
	test_bit(CX18_F_S_INTERNAL_USE, &s->s_flags)) {
	/* this stream is still in use internally */
	return;
	}
	if (!test_and_clear_bit(CX18_F_S_CLAIMED, &s->s_flags)) {
	CX18_DEBUG_WARN("Release stream %s not in use!\n", s->name);
	return;
	}

	cx18_flush_queues(s);

	/* CX18_ENC_STREAM_TYPE_MPG needs to release CX18_ENC_STREAM_TYPE_VBI,
	for all other streams we're done */
	if (s->type == CX18_ENC_STREAM_TYPE_MPG)
	s_vbi = &cx->streams[CX18_ENC_STREAM_TYPE_VBI];
	else
	return;

	/* clear internal use flag */
	if (!test_and_clear_bit(CX18_F_S_INTERNAL_USE, &s_vbi->s_flags)) {
	/* was already cleared */
	return;
	}
	if (s_vbi->id != -1) {
	/* VBI stream still claimed by a file descriptor */
	return;
	}
	clear_bit(CX18_F_S_CLAIMED, &s_vbi->s_flags);
	cx18_flush_queues(s_vbi);
	}

	static void cx18_dualwatch(struct cx18 *cx)
	{
	struct v4l2_tuner vt;
	u16 new_bitmap;
	u16 new_stereo_mode;
	const u16 stereo_mask = 0x0300;
	const u16 dual = 0x0200;

	new_stereo_mode = cx->params.audio_properties & stereo_mask;
	memset(&vt, 0, sizeof(vt));
	cx18_call_i2c_clients(cx, VIDIOC_G_TUNER, &vt);
	if (vt.audmode == V4L2_TUNER_MODE_LANG1_LANG2 &&
	(vt.rxsubchans & V4L2_TUNER_SUB_LANG2))
	new_stereo_mode = dual;

	if (new_stereo_mode == cx->dualwatch_stereo_mode)
	return;

	new_bitmap = new_stereo_mode \| (cx->params.audio_properties & ~stereo_mask);

	CX18_DEBUG_INFO("dualwatch: change stereo flag from 0x%x to 0x%x. new audio_bitmask=0x%ux\n",
	cx->dualwatch_stereo_mode, new_stereo_mode, new_bitmap);

	if (cx18_vapi(cx, CX18_CPU_SET_AUDIO_PARAMETERS, 2,
	cx18_find_handle(cx), new_bitmap) == 0) {
	cx->dualwatch_stereo_mode = new_stereo_mode;
	return;
	}
	CX18_DEBUG_INFO("dualwatch: changing stereo flag failed\n");
	}


	static struct cx18_buffer cx18_get_buffer(struct cx18_stream s, int non_block, int *err)
	{
	struct cx18 *cx = s->cx;
	struct cx18_stream *s_vbi = &cx->streams[CX18_ENC_STREAM_TYPE_VBI];
	struct cx18_buffer *buf;
	DEFINE_WAIT(wait);

	*err = 0;
	while (1) {
	if (s->type == CX18_ENC_STREAM_TYPE_MPG) {

	if (time_after(jiffies, cx->dualwatch_jiffies + msecs_to_jiffies(1000))) {
	cx->dualwatch_jiffies = jiffies;
	cx18_dualwatch(cx);
	}
	if (test_bit(CX18_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
	!test_bit(CX18_F_S_APPL_IO, &s_vbi->s_flags)) {
	while ((buf = cx18_dequeue(s_vbi, &s_vbi->q_full))) {
	/* byteswap and process VBI data */
	/* cx18_process_vbi_data(cx, buf, s_vbi->dma_pts, s_vbi->type); */
	cx18_enqueue(s_vbi, buf, &s_vbi->q_free);
	}
	}
	buf = &cx->vbi.sliced_mpeg_buf;
	if (buf->readpos != buf->bytesused)
	return buf;
	}

	/* do we have leftover data? */
	buf = cx18_dequeue(s, &s->q_io);
	if (buf)
	return buf;

	/* do we have new data? */
	buf = cx18_dequeue(s, &s->q_full);
	if (buf) {
	if (!test_and_clear_bit(CX18_F_B_NEED_BUF_SWAP,
	&buf->b_flags))
	return buf;
	if (s->type == CX18_ENC_STREAM_TYPE_MPG)
	/* byteswap MPG data */
	cx18_buf_swap(buf);
	else {
	/* byteswap and process VBI data */
	cx18_process_vbi_data(cx, buf,
	s->dma_pts, s->type);
	}
	return buf;
	}

	/* return if end of stream */
	if (!test_bit(CX18_F_S_STREAMING, &s->s_flags)) {
	CX18_DEBUG_INFO("EOS %s\n", s->name);
	return NULL;
	}

	/* return if file was opened with O_NONBLOCK */
	if (non_block) {
	*err = -EAGAIN;
	return NULL;
	}

	/* wait for more data to arrive */
	prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
	/* New buffers might have become available before we were added
	to the waitqueue */
	if (!s->q_full.buffers)
	schedule();
	finish_wait(&s->waitq, &wait);
	if (signal_pending(current)) {
	/* return if a signal was received */
	CX18_DEBUG_INFO("User stopped %s\n", s->name);
	*err = -EINTR;
	return NULL;
	}
	}
	}

	static void cx18_setup_sliced_vbi_buf(struct cx18 *cx)
	{
	int idx = cx->vbi.inserted_frame % CX18_VBI_FRAMES;

	cx->vbi.sliced_mpeg_buf.buf = cx->vbi.sliced_mpeg_data[idx];
	cx->vbi.sliced_mpeg_buf.bytesused = cx->vbi.sliced_mpeg_size[idx];
	cx->vbi.sliced_mpeg_buf.readpos = 0;
	}

	static size_t cx18_copy_buf_to_user(struct cx18_stream *s,
	struct cx18_buffer buf, char __user ubuf, size_t ucount)
	{
	struct cx18 *cx = s->cx;
	size_t len = buf->bytesused - buf->readpos;

	if (len > ucount)
	len = ucount;
	if (cx->vbi.insert_mpeg && s->type == CX18_ENC_STREAM_TYPE_MPG &&
	cx->vbi.sliced_in->service_set && buf != &cx->vbi.sliced_mpeg_buf) {
	const char *start = buf->buf + buf->readpos;
	const char *p = start + 1;
	const u8 *q;
	u8 ch = cx->search_pack_header ? 0xba : 0xe0;
	int stuffing, i;

	while (start + len > p) {
	q = memchr(p, 0, start + len - p);
	if (q == NULL)
	break;
	p = q + 1;
	if ((char *)q + 15 >= buf->buf + buf->bytesused \|\|
	q[1] != 0 \|\| q[2] != 1 \|\| q[3] != ch)
	continue;
	if (!cx->search_pack_header) {
	if ((q[6] & 0xc0) != 0x80)
	continue;
	if (((q[7] & 0xc0) == 0x80 &&
	(q[9] & 0xf0) == 0x20) \|\|
	((q[7] & 0xc0) == 0xc0 &&
	(q[9] & 0xf0) == 0x30)) {
	ch = 0xba;
	cx->search_pack_header = 1;
	p = q + 9;
	}
	continue;
	}
	stuffing = q[13] & 7;
	/* all stuffing bytes must be 0xff */
	for (i = 0; i < stuffing; i++)
	if (q[14 + i] != 0xff)
	break;
	if (i == stuffing &&
	(q[4] & 0xc4) == 0x44 &&
	(q[12] & 3) == 3 &&
	q[14 + stuffing] == 0 &&
	q[15 + stuffing] == 0 &&
	q[16 + stuffing] == 1) {
	cx->search_pack_header = 0;
	len = (char *)q - start;
	cx18_setup_sliced_vbi_buf(cx);
	break;
	}
	}
	}
	if (copy_to_user(ubuf, (u8 *)buf->buf + buf->readpos, len)) {
	CX18_DEBUG_WARN("copy %zd bytes to user failed for %s\n",
	len, s->name);
	return -EFAULT;
	}
	buf->readpos += len;
	if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
	buf != &cx->vbi.sliced_mpeg_buf)
	cx->mpg_data_received += len;
	return len;
	}

	static ssize_t cx18_read(struct cx18_stream s, char __user ubuf,
	size_t tot_count, int non_block)
	{
	struct cx18 *cx = s->cx;
	size_t tot_written = 0;
	int single_frame = 0;

	if (atomic_read(&cx->ana_capturing) == 0 && s->id == -1) {
	/* shouldn't happen */
	CX18_DEBUG_WARN("Stream %s not initialized before read\n",
	s->name);
	return -EIO;
	}

	/* Each VBI buffer is one frame, the v4l2 API says that for VBI the
	frames should arrive one-by-one, so make sure we never output more
	than one VBI frame at a time */
	if (s->type == CX18_ENC_STREAM_TYPE_VBI &&
	cx->vbi.sliced_in->service_set)
	single_frame = 1;

	for (;;) {
	struct cx18_buffer *buf;
	int rc;

	buf = cx18_get_buffer(s, non_block, &rc);
	/* if there is no data available... */
	if (buf == NULL) {
	/* if we got data, then return that regardless */
	if (tot_written)
	break;
	/* EOS condition */
	if (rc == 0) {
	clear_bit(CX18_F_S_STREAMOFF, &s->s_flags);
	clear_bit(CX18_F_S_APPL_IO, &s->s_flags);
	cx18_release_stream(s);
	}
	/* set errno */
	return rc;
	}

	rc = cx18_copy_buf_to_user(s, buf, ubuf + tot_written,
	tot_count - tot_written);

	if (buf != &cx->vbi.sliced_mpeg_buf) {
	if (buf->readpos == buf->bytesused) {
	cx18_buf_sync_for_device(s, buf);
	cx18_enqueue(s, buf, &s->q_free);
	cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5,
	s->handle,
	(void __iomem *)&cx->scb->cpu_mdl[buf->id] -
	cx->enc_mem,
	1, buf->id, s->buf_size);
	} else
	cx18_enqueue(s, buf, &s->q_io);
	} else if (buf->readpos == buf->bytesused) {
	int idx = cx->vbi.inserted_frame % CX18_VBI_FRAMES;

	cx->vbi.sliced_mpeg_size[idx] = 0;
	cx->vbi.inserted_frame++;
	cx->vbi_data_inserted += buf->bytesused;
	}
	if (rc < 0)
	return rc;
	tot_written += rc;

	if (tot_written == tot_count \|\| single_frame)
	break;
	}
	return tot_written;
	}

	static ssize_t cx18_read_pos(struct cx18_stream s, char __user ubuf,
	size_t count, loff_t *pos, int non_block)
	{
	ssize_t rc = count ? cx18_read(s, ubuf, count, non_block) : 0;
	struct cx18 *cx = s->cx;

	CX18_DEBUG_HI_FILE("read %zd from %s, got %zd\n", count, s->name, rc);
	if (rc > 0)
	pos += rc;
	return rc;
	}

	int cx18_start_capture(struct cx18_open_id *id)
	{
	struct cx18 *cx = id->cx;
	struct cx18_stream *s = &cx->streams[id->type];
	struct cx18_stream *s_vbi;

	if (s->type == CX18_ENC_STREAM_TYPE_RAD) {
	/* you cannot read from these stream types. */
	return -EPERM;
	}

	/* Try to claim this stream. */
	if (cx18_claim_stream(id, s->type))
	return -EBUSY;

	/* If capture is already in progress, then we also have to
	do nothing extra. */
	if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) \|\|
	test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
	set_bit(CX18_F_S_APPL_IO, &s->s_flags);
	return 0;
	}

	/* Start VBI capture if required */
	s_vbi = &cx->streams[CX18_ENC_STREAM_TYPE_VBI];
	if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
	test_bit(CX18_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
	!test_and_set_bit(CX18_F_S_STREAMING, &s_vbi->s_flags)) {
	/* Note: the CX18_ENC_STREAM_TYPE_VBI is claimed
	automatically when the MPG stream is claimed.
	We only need to start the VBI capturing. */
	if (cx18_start_v4l2_encode_stream(s_vbi)) {
	CX18_DEBUG_WARN("VBI capture start failed\n");

	/* Failure, clean up and return an error */
	clear_bit(CX18_F_S_STREAMING, &s_vbi->s_flags);
	clear_bit(CX18_F_S_STREAMING, &s->s_flags);
	/* also releases the associated VBI stream */
	cx18_release_stream(s);
	return -EIO;
	}
	CX18_DEBUG_INFO("VBI insertion started\n");
	}

	/* Tell the card to start capturing */
	if (!cx18_start_v4l2_encode_stream(s)) {
	/* We're done */
	set_bit(CX18_F_S_APPL_IO, &s->s_flags);
	/* Resume a possibly paused encoder */
	if (test_and_clear_bit(CX18_F_I_ENC_PAUSED, &cx->i_flags))
	cx18_vapi(cx, CX18_CPU_CAPTURE_PAUSE, 1, s->handle);
	return 0;
	}

	/* failure, clean up */
	CX18_DEBUG_WARN("Failed to start capturing for stream %s\n", s->name);

	/* Note: the CX18_ENC_STREAM_TYPE_VBI is released
	automatically when the MPG stream is released.
	We only need to stop the VBI capturing. */
	if (s->type == CX18_ENC_STREAM_TYPE_MPG &&
	test_bit(CX18_F_S_STREAMING, &s_vbi->s_flags)) {
	cx18_stop_v4l2_encode_stream(s_vbi, 0);
	clear_bit(CX18_F_S_STREAMING, &s_vbi->s_flags);
	}
	clear_bit(CX18_F_S_STREAMING, &s->s_flags);
	cx18_release_stream(s);
	return -EIO;
	}

	ssize_t cx18_v4l2_read(struct file filp, char __user buf, size_t count,
	loff_t *pos)
	{
	struct cx18_open_id *id = filp->private_data;
	struct cx18 *cx = id->cx;
	struct cx18_stream *s = &cx->streams[id->type];
	int rc;

	CX18_DEBUG_HI_FILE("read %zd bytes from %s\n", count, s->name);

	mutex_lock(&cx->serialize_lock);
	rc = cx18_start_capture(id);
	mutex_unlock(&cx->serialize_lock);
	if (rc)
	return rc;
	return cx18_read_pos(s, buf, count, pos, filp->f_flags & O_NONBLOCK);
	}

	unsigned int cx18_v4l2_enc_poll(struct file filp, poll_table wait)
	{
	struct cx18_open_id *id = filp->private_data;
	struct cx18 *cx = id->cx;
	struct cx18_stream *s = &cx->streams[id->type];
	int eof = test_bit(CX18_F_S_STREAMOFF, &s->s_flags);

	/* Start a capture if there is none */
	if (!eof && !test_bit(CX18_F_S_STREAMING, &s->s_flags)) {
	int rc;

	mutex_lock(&cx->serialize_lock);
	rc = cx18_start_capture(id);
	mutex_unlock(&cx->serialize_lock);
	if (rc) {
	CX18_DEBUG_INFO("Could not start capture for %s (%d)\n",
	s->name, rc);
	return POLLERR;
	}
	CX18_DEBUG_FILE("Encoder poll started capture\n");
	}

	/* add stream's waitq to the poll list */
	CX18_DEBUG_HI_FILE("Encoder poll\n");
	poll_wait(filp, &s->waitq, wait);

	if (s->q_full.length \|\| s->q_io.length)
	return POLLIN \| POLLRDNORM;
	if (eof)
	return POLLHUP;
	return 0;
	}

	void cx18_stop_capture(struct cx18_open_id *id, int gop_end)
	{
	struct cx18 *cx = id->cx;
	struct cx18_stream *s = &cx->streams[id->type];

	CX18_DEBUG_IOCTL("close() of %s\n", s->name);

	/* 'Unclaim' this stream */

	/* Stop capturing */
	if (test_bit(CX18_F_S_STREAMING, &s->s_flags)) {
	struct cx18_stream *s_vbi =
	&cx->streams[CX18_ENC_STREAM_TYPE_VBI];

	CX18_DEBUG_INFO("close stopping capture\n");
	/* Special case: a running VBI capture for VBI insertion
	in the mpeg stream. Need to stop that too. */
	if (id->type == CX18_ENC_STREAM_TYPE_MPG &&
	test_bit(CX18_F_S_STREAMING, &s_vbi->s_flags) &&
	!test_bit(CX18_F_S_APPL_IO, &s_vbi->s_flags)) {
	CX18_DEBUG_INFO("close stopping embedded VBI capture\n");
	cx18_stop_v4l2_encode_stream(s_vbi, 0);
	}
	if (id->type == CX18_ENC_STREAM_TYPE_VBI &&
	test_bit(CX18_F_S_INTERNAL_USE, &s->s_flags))
	/* Also used internally, don't stop capturing */
	s->id = -1;
	else
	cx18_stop_v4l2_encode_stream(s, gop_end);
	}
	if (!gop_end) {
	clear_bit(CX18_F_S_APPL_IO, &s->s_flags);
	clear_bit(CX18_F_S_STREAMOFF, &s->s_flags);
	cx18_release_stream(s);
	}
	}

	int cx18_v4l2_close(struct inode inode, struct file filp)
	{
	struct cx18_open_id *id = filp->private_data;
	struct cx18 *cx = id->cx;
	struct cx18_stream *s = &cx->streams[id->type];

	CX18_DEBUG_IOCTL("close() of %s\n", s->name);

	v4l2_prio_close(&cx->prio, &id->prio);

	/* Easy case first: this stream was never claimed by us */
	if (s->id != id->open_id) {
	kfree(id);
	return 0;
	}

	/* 'Unclaim' this stream */

	/* Stop radio */
	mutex_lock(&cx->serialize_lock);
	if (id->type == CX18_ENC_STREAM_TYPE_RAD) {
	/* Closing radio device, return to TV mode */
	cx18_mute(cx);
	/* Mark that the radio is no longer in use */
	clear_bit(CX18_F_I_RADIO_USER, &cx->i_flags);
	/* Switch tuner to TV */
	cx18_call_i2c_clients(cx, VIDIOC_S_STD, &cx->std);
	/* Select correct audio input (i.e. TV tuner or Line in) */
	cx18_audio_set_io(cx);
	if (atomic_read(&cx->ana_capturing) > 0) {
	/* Undo video mute */
	cx18_vapi(cx, CX18_CPU_SET_VIDEO_MUTE, 2, s->handle,
	cx->params.video_mute \|
	(cx->params.video_mute_yuv << 8));
	}
	/* Done! Unmute and continue. */
	cx18_unmute(cx);
	cx18_release_stream(s);
	} else {
	cx18_stop_capture(id, 0);
	}
	kfree(id);
	mutex_unlock(&cx->serialize_lock);
	return 0;
	}

	static int cx18_serialized_open(struct cx18_stream s, struct file filp)
	{
	struct cx18 *cx = s->cx;
	struct cx18_open_id *item;

	CX18_DEBUG_FILE("open %s\n", s->name);

	/* Allocate memory */
	item = kmalloc(sizeof(struct cx18_open_id), GFP_KERNEL);
	if (NULL == item) {
	CX18_DEBUG_WARN("nomem on v4l2 open\n");
	return -ENOMEM;
	}
	item->cx = cx;
	item->type = s->type;
	v4l2_prio_open(&cx->prio, &item->prio);

	item->open_id = cx->open_id++;
	filp->private_data = item;

	if (item->type == CX18_ENC_STREAM_TYPE_RAD) {
	/* Try to claim this stream */
	if (cx18_claim_stream(item, item->type)) {
	/* No, it's already in use */
	kfree(item);
	return -EBUSY;
	}

	if (!test_bit(CX18_F_I_RADIO_USER, &cx->i_flags)) {
	if (atomic_read(&cx->ana_capturing) > 0) {
	/* switching to radio while capture is
	in progress is not polite */
	cx18_release_stream(s);
	kfree(item);
	return -EBUSY;
	}
	}

	/* Mark that the radio is being used. */
	set_bit(CX18_F_I_RADIO_USER, &cx->i_flags);
	/* We have the radio */
	cx18_mute(cx);
	/* Switch tuner to radio */
	cx18_call_i2c_clients(cx, AUDC_SET_RADIO, NULL);
	/* Select the correct audio input (i.e. radio tuner) */
	cx18_audio_set_io(cx);
	/* Done! Unmute and continue. */
	cx18_unmute(cx);
	}
	return 0;
	}

	int cx18_v4l2_open(struct inode inode, struct file filp)
	{
	int res, x, y = 0;
	struct cx18 *cx = NULL;
	struct cx18_stream *s = NULL;
	int minor = iminor(inode);

	/* Find which card this open was on */
	spin_lock(&cx18_cards_lock);
	for (x = 0; cx == NULL && x < cx18_cards_active; x++) {
	/* find out which stream this open was on */
	for (y = 0; y < CX18_MAX_STREAMS; y++) {
	if (cx18_cards[x] == NULL)
	continue;
	s = &cx18_cards[x]->streams[y];
	if (s->v4l2dev && s->v4l2dev->minor == minor) {
	cx = cx18_cards[x];
	break;
	}
	}
	}
	spin_unlock(&cx18_cards_lock);

	if (cx == NULL) {
	/* Couldn't find a device registered
	on that minor, shouldn't happen! */
	printk(KERN_WARNING "No cx18 device found on minor %d\n",
	minor);
	return -ENXIO;
	}

	mutex_lock(&cx->serialize_lock);
	if (cx18_init_on_first_open(cx)) {
	CX18_ERR("Failed to initialize on minor %d\n", minor);
	mutex_unlock(&cx->serialize_lock);
	return -ENXIO;
	}
	res = cx18_serialized_open(s, filp);
	mutex_unlock(&cx->serialize_lock);
	return res;
	}

	void cx18_mute(struct cx18 *cx)
	{
	if (atomic_read(&cx->ana_capturing))
	cx18_vapi(cx, CX18_CPU_SET_AUDIO_MUTE, 2,
	cx18_find_handle(cx), 1);
	CX18_DEBUG_INFO("Mute\n");
	}

	void cx18_unmute(struct cx18 *cx)
	{
	if (atomic_read(&cx->ana_capturing)) {
	cx18_msleep_timeout(100, 0);
	cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 2,
	cx18_find_handle(cx), 12);
	cx18_vapi(cx, CX18_CPU_SET_AUDIO_MUTE, 2,
	cx18_find_handle(cx), 0);
	}
	CX18_DEBUG_INFO("Unmute\n");
	}