audio.c

linux 内核源代码

				audio_devs[dev]->dmap_out->applic_profile = val;
			if (audio_devs[dev]->open_mode & OPEN_READ)
				audio_devs[dev]->dmap_in->applic_profile = val;
			return 0;
		
		case SNDCTL_DSP_GETODELAY:
			dmap = audio_devs[dev]->dmap_out;
			if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
				return -EINVAL;
			if (!(dmap->flags & DMA_ALLOC_DONE))
			{
				val=0;
				break;
			}
		
			spin_lock_irqsave(&dmap->lock,flags);
			/* Compute number of bytes that have been played */
			count = DMAbuf_get_buffer_pointer (dev, dmap, DMODE_OUTPUT);
			if (count < dmap->fragment_size && dmap->qhead != 0)
				count += dmap->bytes_in_use;	/* Pointer wrap not handled yet */
			count += dmap->byte_counter;
		
			/* Substract current count from the number of bytes written by app */
			count = dmap->user_counter - count;
			if (count < 0)
				count = 0;
			spin_unlock_irqrestore(&dmap->lock,flags);
			val = count;
			break;
		
		default:
			return dma_ioctl(dev, cmd, arg);
	}
	return put_user(val, p);
}

void audio_init_devices(void)
{
	/*
	 * NOTE! This routine could be called several times during boot.
	 */
}

void reorganize_buffers(int dev, struct dma_buffparms *dmap, int recording)
{
	/*
	 * This routine breaks the physical device buffers to logical ones.
	 */

	struct audio_operations *dsp_dev = audio_devs[dev];

	unsigned i, n;
	unsigned sr, nc, sz, bsz;

	sr = dsp_dev->d->set_speed(dev, 0);
	nc = dsp_dev->d->set_channels(dev, 0);
	sz = dsp_dev->d->set_bits(dev, 0);

	if (sz == 8)
		dmap->neutral_byte = NEUTRAL8;
	else
		dmap->neutral_byte = NEUTRAL16;

	if (sr < 1 || nc < 1 || sz < 1)
	{
/*		printk(KERN_DEBUG "Warning: Invalid PCM parameters[%d] sr=%d, nc=%d, sz=%d\n", dev, sr, nc, sz);*/
		sr = DSP_DEFAULT_SPEED;
		nc = 1;
		sz = 8;
	}
	
	sz = sr * nc * sz;

	sz /= 8;		/* #bits -> #bytes */
	dmap->data_rate = sz;

	if (!dmap->needs_reorg)
		return;
	dmap->needs_reorg = 0;

	if (dmap->fragment_size == 0)
	{	
		/* Compute the fragment size using the default algorithm */

		/*
		 * Compute a buffer size for time not exceeding 1 second.
		 * Usually this algorithm gives a buffer size for 0.5 to 1.0 seconds
		 * of sound (using the current speed, sample size and #channels).
		 */

		bsz = dmap->buffsize;
		while (bsz > sz)
			bsz /= 2;

		if (bsz == dmap->buffsize)
			bsz /= 2;	/* Needs at least 2 buffers */

		/*
		 *    Split the computed fragment to smaller parts. After 3.5a9
		 *      the default subdivision is 4 which should give better
		 *      results when recording.
		 */

		if (dmap->subdivision == 0)	/* Not already set */
		{
			dmap->subdivision = 4;	/* Init to the default value */

			if ((bsz / dmap->subdivision) > 4096)
				dmap->subdivision *= 2;
			if ((bsz / dmap->subdivision) < 4096)
				dmap->subdivision = 1;
		}
		bsz /= dmap->subdivision;

		if (bsz < 16)
			bsz = 16;	/* Just a sanity check */

		dmap->fragment_size = bsz;
	}
	else
	{
		/*
		 * The process has specified the buffer size with SNDCTL_DSP_SETFRAGMENT or
		 * the buffer size computation has already been done.
		 */
		if (dmap->fragment_size > (dmap->buffsize / 2))
			dmap->fragment_size = (dmap->buffsize / 2);
		bsz = dmap->fragment_size;
	}

	if (audio_devs[dev]->min_fragment)
		if (bsz < (1 << audio_devs[dev]->min_fragment))
			bsz = 1 << audio_devs[dev]->min_fragment;
	if (audio_devs[dev]->max_fragment)
		if (bsz > (1 << audio_devs[dev]->max_fragment))
			bsz = 1 << audio_devs[dev]->max_fragment;
	bsz &= ~0x07;		/* Force size which is multiple of 8 bytes */
#ifdef OS_DMA_ALIGN_CHECK
	OS_DMA_ALIGN_CHECK(bsz);
#endif

	n = dmap->buffsize / bsz;
	if (n > MAX_SUB_BUFFERS)
		n = MAX_SUB_BUFFERS;
	if (n > dmap->max_fragments)
		n = dmap->max_fragments;

	if (n < 2)
	{
		n = 2;
		bsz /= 2;
	}
	dmap->nbufs = n;
	dmap->bytes_in_use = n * bsz;
	dmap->fragment_size = bsz;
	dmap->max_byte_counter = (dmap->data_rate * 60 * 60) +
			dmap->bytes_in_use;	/* Approximately one hour */

	if (dmap->raw_buf)
	{
		memset(dmap->raw_buf, dmap->neutral_byte, dmap->bytes_in_use);
	}
	
	for (i = 0; i < dmap->nbufs; i++)
	{
		dmap->counts[i] = 0;
	}

	dmap->flags |= DMA_ALLOC_DONE | DMA_EMPTY;
}

static int dma_subdivide(int dev, struct dma_buffparms *dmap, int fact)
{
	if (fact == 0) 
	{
		fact = dmap->subdivision;
		if (fact == 0)
			fact = 1;
		return fact;
	}
	if (dmap->subdivision != 0 || dmap->fragment_size)	/* Too late to change */
		return -EINVAL;

	if (fact > MAX_REALTIME_FACTOR)
		return -EINVAL;

	if (fact != 1 && fact != 2 && fact != 4 && fact != 8 && fact != 16)
		return -EINVAL;

	dmap->subdivision = fact;
	return fact;
}

static int dma_set_fragment(int dev, struct dma_buffparms *dmap, int fact)
{
	int bytes, count;

	if (fact == 0)
		return -EIO;

	if (dmap->subdivision != 0 ||
	    dmap->fragment_size)	/* Too late to change */
		return -EINVAL;

	bytes = fact & 0xffff;
	count = (fact >> 16) & 0x7fff;

	if (count == 0)
		count = MAX_SUB_BUFFERS;
	else if (count < MAX_SUB_BUFFERS)
		count++;

	if (bytes < 4 || bytes > 17)	/* <16 || > 512k */
		return -EINVAL;

	if (count < 2)
		return -EINVAL;

	if (audio_devs[dev]->min_fragment > 0)
		if (bytes < audio_devs[dev]->min_fragment)
			bytes = audio_devs[dev]->min_fragment;

	if (audio_devs[dev]->max_fragment > 0)
		if (bytes > audio_devs[dev]->max_fragment)
			bytes = audio_devs[dev]->max_fragment;

#ifdef OS_DMA_MINBITS
	if (bytes < OS_DMA_MINBITS)
		bytes = OS_DMA_MINBITS;
#endif

	dmap->fragment_size = (1 << bytes);
	dmap->max_fragments = count;

	if (dmap->fragment_size > dmap->buffsize)
		dmap->fragment_size = dmap->buffsize;

	if (dmap->fragment_size == dmap->buffsize &&
	    audio_devs[dev]->flags & DMA_AUTOMODE)
		dmap->fragment_size /= 2;	/* Needs at least 2 buffers */

	dmap->subdivision = 1;	/* Disable SNDCTL_DSP_SUBDIVIDE */
	return bytes | ((count - 1) << 16);
}

static int dma_ioctl(int dev, unsigned int cmd, void __user *arg)
{
	struct dma_buffparms *dmap_out = audio_devs[dev]->dmap_out;
	struct dma_buffparms *dmap_in = audio_devs[dev]->dmap_in;
	struct dma_buffparms *dmap;
	audio_buf_info info;
	count_info cinfo;
	int fact, ret, changed, bits, count, err;
	unsigned long flags;

	switch (cmd) 
	{
		case SNDCTL_DSP_SUBDIVIDE:
			ret = 0;
			if (get_user(fact, (int __user *)arg))
				return -EFAULT;
			if (audio_devs[dev]->open_mode & OPEN_WRITE)
				ret = dma_subdivide(dev, dmap_out, fact);
			if (ret < 0)
				return ret;
			if (audio_devs[dev]->open_mode != OPEN_WRITE ||
				(audio_devs[dev]->flags & DMA_DUPLEX &&
					audio_devs[dev]->open_mode & OPEN_READ))
				ret = dma_subdivide(dev, dmap_in, fact);
			if (ret < 0)
				return ret;
			break;

		case SNDCTL_DSP_GETISPACE:
		case SNDCTL_DSP_GETOSPACE:
			dmap = dmap_out;
			if (cmd == SNDCTL_DSP_GETISPACE && !(audio_devs[dev]->open_mode & OPEN_READ))
				return -EINVAL;
			if (cmd == SNDCTL_DSP_GETOSPACE && !(audio_devs[dev]->open_mode & OPEN_WRITE))
				return -EINVAL;
			if (cmd == SNDCTL_DSP_GETISPACE && audio_devs[dev]->flags & DMA_DUPLEX)
				dmap = dmap_in;
			if (dmap->mapping_flags & DMA_MAP_MAPPED)
				return -EINVAL;
			if (!(dmap->flags & DMA_ALLOC_DONE))
				reorganize_buffers(dev, dmap, (cmd == SNDCTL_DSP_GETISPACE));
			info.fragstotal = dmap->nbufs;
			if (cmd == SNDCTL_DSP_GETISPACE)
				info.fragments = dmap->qlen;
			else 
			{
				if (!DMAbuf_space_in_queue(dev))
					info.fragments = 0;
				else
				{
					info.fragments = DMAbuf_space_in_queue(dev);
					if (audio_devs[dev]->d->local_qlen) 
					{
						int tmp = audio_devs[dev]->d->local_qlen(dev);
						if (tmp && info.fragments)
							tmp--;	/*
								 * This buffer has been counted twice
								 */
						info.fragments -= tmp;
					}
				}
			}
			if (info.fragments < 0)
				info.fragments = 0;
			else if (info.fragments > dmap->nbufs)
				info.fragments = dmap->nbufs;

			info.fragsize = dmap->fragment_size;
			info.bytes = info.fragments * dmap->fragment_size;

			if (cmd == SNDCTL_DSP_GETISPACE && dmap->qlen)
				info.bytes -= dmap->counts[dmap->qhead];
			else 
			{
				info.fragments = info.bytes / dmap->fragment_size;
				info.bytes -= dmap->user_counter % dmap->fragment_size;
			}
			if (copy_to_user(arg, &info, sizeof(info)))
				return -EFAULT;
			return 0;

		case SNDCTL_DSP_SETTRIGGER:
			if (get_user(bits, (int __user *)arg))
				return -EFAULT;
			bits &= audio_devs[dev]->open_mode;
			if (audio_devs[dev]->d->trigger == NULL)
				return -EINVAL;
			if (!(audio_devs[dev]->flags & DMA_DUPLEX) && (bits & PCM_ENABLE_INPUT) &&
				(bits & PCM_ENABLE_OUTPUT))
				return -EINVAL;

			if (bits & PCM_ENABLE_INPUT)
			{
				spin_lock_irqsave(&dmap_in->lock,flags);
				changed = (audio_devs[dev]->enable_bits ^ bits) & PCM_ENABLE_INPUT;
				if (changed && audio_devs[dev]->go) 
				{
					reorganize_buffers(dev, dmap_in, 1);
					if ((err = audio_devs[dev]->d->prepare_for_input(dev,
						     dmap_in->fragment_size, dmap_in->nbufs)) < 0) {
						spin_unlock_irqrestore(&dmap_in->lock,flags);
						return -err;
					}
					dmap_in->dma_mode = DMODE_INPUT;
					audio_devs[dev]->enable_bits |= PCM_ENABLE_INPUT;
					DMAbuf_activate_recording(dev, dmap_in);
				} else
					audio_devs[dev]->enable_bits &= ~PCM_ENABLE_INPUT;
				spin_unlock_irqrestore(&dmap_in->lock,flags);
			}
			if (bits & PCM_ENABLE_OUTPUT)
			{
				spin_lock_irqsave(&dmap_out->lock,flags);
				changed = (audio_devs[dev]->enable_bits ^ bits) & PCM_ENABLE_OUTPUT;
				if (changed &&
				    (dmap_out->mapping_flags & DMA_MAP_MAPPED || dmap_out->qlen > 0) &&
				    audio_devs[dev]->go) 
				{
					if (!(dmap_out->flags & DMA_ALLOC_DONE))
						reorganize_buffers(dev, dmap_out, 0);
					dmap_out->dma_mode = DMODE_OUTPUT;
					audio_devs[dev]->enable_bits |= PCM_ENABLE_OUTPUT;
					dmap_out->counts[dmap_out->qhead] = dmap_out->fragment_size;
					DMAbuf_launch_output(dev, dmap_out);
				} else
					audio_devs[dev]->enable_bits &= ~PCM_ENABLE_OUTPUT;
				spin_unlock_irqrestore(&dmap_out->lock,flags);
			}
#if 0
			if (changed && audio_devs[dev]->d->trigger)
				audio_devs[dev]->d->trigger(dev, bits * audio_devs[dev]->go);
#endif				
			/* Falls through... */

		case SNDCTL_DSP_GETTRIGGER:
			ret = audio_devs[dev]->enable_bits;
			break;

		case SNDCTL_DSP_SETSYNCRO:
			if (!audio_devs[dev]->d->trigger)
				return -EINVAL;
			audio_devs[dev]->d->trigger(dev, 0);
			audio_devs[dev]->go = 0;
			return 0;

		case SNDCTL_DSP_GETIPTR:
			if (!(audio_devs[dev]->open_mode & OPEN_READ))
				return -EINVAL;
			spin_lock_irqsave(&dmap_in->lock,flags);
			cinfo.bytes = dmap_in->byte_counter;
			cinfo.ptr = DMAbuf_get_buffer_pointer(dev, dmap_in, DMODE_INPUT) & ~3;
			if (cinfo.ptr < dmap_in->fragment_size && dmap_in->qtail != 0)
				cinfo.bytes += dmap_in->bytes_in_use;	/* Pointer wrap not handled yet */
			cinfo.blocks = dmap_in->qlen;
			cinfo.bytes += cinfo.ptr;
			if (dmap_in->mapping_flags & DMA_MAP_MAPPED)
				dmap_in->qlen = 0;	/* Reset interrupt counter */
			spin_unlock_irqrestore(&dmap_in->lock,flags);
			if (copy_to_user(arg, &cinfo, sizeof(cinfo)))
				return -EFAULT;
			return 0;

		case SNDCTL_DSP_GETOPTR:
			if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
				return -EINVAL;

			spin_lock_irqsave(&dmap_out->lock,flags);
			cinfo.bytes = dmap_out->byte_counter;
			cinfo.ptr = DMAbuf_get_buffer_pointer(dev, dmap_out, DMODE_OUTPUT) & ~3;
			if (cinfo.ptr < dmap_out->fragment_size && dmap_out->qhead != 0)
				cinfo.bytes += dmap_out->bytes_in_use;	/* Pointer wrap not handled yet */
			cinfo.blocks = dmap_out->qlen;
			cinfo.bytes += cinfo.ptr;
			if (dmap_out->mapping_flags & DMA_MAP_MAPPED)
				dmap_out->qlen = 0;	/* Reset interrupt counter */
			spin_unlock_irqrestore(&dmap_out->lock,flags);
			if (copy_to_user(arg, &cinfo, sizeof(cinfo)))
				return -EFAULT;
			return 0;

		case SNDCTL_DSP_GETODELAY:
			if (!(audio_devs[dev]->open_mode & OPEN_WRITE))
				return -EINVAL;
			if (!(dmap_out->flags & DMA_ALLOC_DONE))
			{
				ret=0;
				break;
			}
			spin_lock_irqsave(&dmap_out->lock,flags);
			/* Compute number of bytes that have been played */
			count = DMAbuf_get_buffer_pointer (dev, dmap_out, DMODE_OUTPUT);
			if (count < dmap_out->fragment_size && dmap_out->qhead != 0)
				count += dmap_out->bytes_in_use;	/* Pointer wrap not handled yet */
			count += dmap_out->byte_counter;
			/* Substract current count from the number of bytes written by app */
			count = dmap_out->user_counter - count;
			if (count < 0)
				count = 0;
			spin_unlock_irqrestore(&dmap_out->lock,flags);
			ret = count;
			break;

		case SNDCTL_DSP_POST:
			if (audio_devs[dev]->dmap_out->qlen > 0)
				if (!(audio_devs[dev]->dmap_out->flags & DMA_ACTIVE))
					DMAbuf_launch_output(dev, audio_devs[dev]->dmap_out);
			return 0;

		case SNDCTL_DSP_GETBLKSIZE:
			dmap = dmap_out;
			if (audio_devs[dev]->open_mode & OPEN_WRITE)
				reorganize_buffers(dev, dmap_out, (audio_devs[dev]->open_mode == OPEN_READ));
			if (audio_devs[dev]->open_mode == OPEN_READ ||
			    (audio_devs[dev]->flags & DMA_DUPLEX &&
			     audio_devs[dev]->open_mode & OPEN_READ))
				reorganize_buffers(dev, dmap_in, (audio_devs[dev]->open_mode == OPEN_READ));
			if (audio_devs[dev]->open_mode == OPEN_READ)
				dmap = dmap_in;
			ret = dmap->fragment_size;
			break;

		case SNDCTL_DSP_SETFRAGMENT:
			ret = 0;
			if (get_user(fact, (int __user *)arg))
				return -EFAULT;
			if (audio_devs[dev]->open_mode & OPEN_WRITE)
				ret = dma_set_fragment(dev, dmap_out, fact);
			if (ret < 0)
				return ret;
			if (audio_devs[dev]->open_mode == OPEN_READ ||
			    (audio_devs[dev]->flags & DMA_DUPLEX &&
			     audio_devs[dev]->open_mode & OPEN_READ))
				ret = dma_set_fragment(dev, dmap_in, fact);
			if (ret < 0)
				return ret;
			if (!arg) /* don't know what this is good for, but preserve old semantics */
				return 0;
			break;

		default:
			if (!audio_devs[dev]->d->ioctl)
				return -EINVAL;
			return audio_devs[dev]->d->ioctl(dev, cmd, arg);
	}
	return put_user(ret, (int __user *)arg);
}