V4L/DVB (7786): cx18: new driver for the Conexant CX23418 MPEG encoder chip

Many thanks to Steve Toth from Hauppauge and Nattu Dakshinamurthy from
Conexant for their support. I am in particular thankful to Hauppauge
since without their help this driver would not exist. It should also
be noted that Steve did the work to get the DVB part up and running.
Thank you!

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Steven Toth <stoth@hauppauge.com>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: G. Andrew Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 711 insertions, 0 deletions

diff --git a/drivers/media/video/cx18/cx18-fileops.c b/drivers/media/video/cx18/cx18-fileops.c
new file mode 100644
index 000000000000..69303065a294
--- /dev/null
+++ b/drivers/media/video/cx18/cx18-fileops.c
@@ -0,0 +1,711 @@
+/*
+ *  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. */
+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. */
+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->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 *)&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->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->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++) {
+			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->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->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");
+}