cx18-fileops.c

来自「trident tm5600的linux驱动」· C语言 代码 · 共 770 行 · 第 1/2 页

/*
 *  cx18 file operation functions
 *
 *  Derived from ivtv-fileops.c
 *
 *  Copyright (C) 2007  Hans Verkuil <[e-mail]>
 *
 *  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;
	u32 h;

	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);

	h = cx18_find_handle(cx);
	if (h == CX18_INVALID_TASK_HANDLE) {
		CX18_DEBUG_INFO("dualwatch: can't find valid task handle\n");
		return;
	}

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

#if 0
static void cx18_update_pgm_info(struct cx18 *cx)
{
	u32 wr_idx = (cx18_read_enc(cx, cx->pgm_info_offset)
			- cx->pgm_info_offset - 4) / 24;
	int cnt;
	int i = 0;

	if (wr_idx >= cx->pgm_info_num) {
		CX18_DEBUG_WARN("Invalid PGM index %d (>= %d)\n", wr_idx, cx->pgm_info_num);
		return;
	}
	cnt = (wr_idx + cx->pgm_info_num - cx->pgm_info_write_idx) % cx->pgm_info_num;
	while (i < cnt) {
		int idx = (cx->pgm_info_write_idx + i) % cx->pgm_info_num;
		struct v4l2_enc_idx_entry *e = cx->pgm_info + idx;
		u32 addr = cx->pgm_info_offset + 4 + idx * 24;
		const int mapping[] = { V4L2_ENC_IDX_FRAME_P, V4L2_ENC_IDX_FRAME_I, V4L2_ENC_IDX_FRAME_B, 0 };

		e->offset = cx18_read_enc(cx, addr + 4)
				+ ((u64)cx18_read_enc(cx, addr + 8) << 32);
		if (e->offset > cx->mpg_data_received)
			break;
		e->offset += cx->vbi_data_inserted;
		e->length = cx18_read_enc(cx, addr);
		e->pts = cx18_read_enc(cx, addr + 16)
			 + ((u64)(cx18_read_enc(cx, addr + 20) & 1) << 32);
		e->flags = mapping[cx18_read_enc(cx, addr + 12) & 3];
		i++;
	}
	cx->pgm_info_write_idx = (cx->pgm_info_write_idx + i) % cx->pgm_info_num;
}
#endif

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 0
			/* Process pending program info updates and pending
			   VBI data */
			cx18_update_pgm_info(cx);
#endif

			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 (!atomic_read(&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;