pcm_oss.c

linux 内核源代码

				break;
		}
	}
	mutex_unlock(&runtime->oss.params_lock);
	return xfer;

 err:
	mutex_unlock(&runtime->oss.params_lock);
	return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
}

static ssize_t snd_pcm_oss_read2(struct snd_pcm_substream *substream, char *buf, size_t bytes, int in_kernel)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_sframes_t frames, frames1;
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
	char __user *final_dst = (char __user *)buf;
	if (runtime->oss.plugin_first) {
		struct snd_pcm_plugin_channel *channels;
		size_t oss_frame_bytes = (runtime->oss.plugin_last->dst_width * runtime->oss.plugin_last->dst_format.channels) / 8;
		if (!in_kernel)
			buf = runtime->oss.buffer;
		frames = bytes / oss_frame_bytes;
		frames1 = snd_pcm_plug_client_channels_buf(substream, buf, frames, &channels);
		if (frames1 < 0)
			return frames1;
		frames1 = snd_pcm_plug_read_transfer(substream, channels, frames1);
		if (frames1 <= 0)
			return frames1;
		bytes = frames1 * oss_frame_bytes;
		if (!in_kernel && copy_to_user(final_dst, buf, bytes))
			return -EFAULT;
	} else
#endif
	{
		frames = bytes_to_frames(runtime, bytes);
		frames1 = snd_pcm_oss_read3(substream, buf, frames, in_kernel);
		if (frames1 <= 0)
			return frames1;
		bytes = frames_to_bytes(runtime, frames1);
	}
	return bytes;
}

static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __user *buf, size_t bytes)
{
	size_t xfer = 0;
	ssize_t tmp;
	struct snd_pcm_runtime *runtime = substream->runtime;

	if (atomic_read(&substream->mmap_count))
		return -ENXIO;

	if ((tmp = snd_pcm_oss_make_ready(substream)) < 0)
		return tmp;
	mutex_lock(&runtime->oss.params_lock);
	while (bytes > 0) {
		if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) {
			if (runtime->oss.buffer_used == 0) {
				tmp = snd_pcm_oss_read2(substream, runtime->oss.buffer, runtime->oss.period_bytes, 1);
				if (tmp <= 0)
					goto err;
				runtime->oss.bytes += tmp;
				runtime->oss.period_ptr = tmp;
				runtime->oss.buffer_used = tmp;
			}
			tmp = bytes;
			if ((size_t) tmp > runtime->oss.buffer_used)
				tmp = runtime->oss.buffer_used;
			if (copy_to_user(buf, runtime->oss.buffer + (runtime->oss.period_ptr - runtime->oss.buffer_used), tmp)) {
				tmp = -EFAULT;
				goto err;
			}
			buf += tmp;
			bytes -= tmp;
			xfer += tmp;
			runtime->oss.buffer_used -= tmp;
		} else {
			tmp = snd_pcm_oss_read2(substream, (char __force *)buf,
						runtime->oss.period_bytes, 0);
			if (tmp <= 0)
				goto err;
			runtime->oss.bytes += tmp;
			buf += tmp;
			bytes -= tmp;
			xfer += tmp;
		}
	}
	mutex_unlock(&runtime->oss.params_lock);
	return xfer;

 err:
	mutex_unlock(&runtime->oss.params_lock);
	return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp;
}

static int snd_pcm_oss_reset(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;

	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
	if (substream != NULL) {
		snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
		substream->runtime->oss.prepare = 1;
	}
	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
	if (substream != NULL) {
		snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
		substream->runtime->oss.prepare = 1;
	}
	return 0;
}

static int snd_pcm_oss_post(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;
	int err;

	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
	if (substream != NULL) {
		if ((err = snd_pcm_oss_make_ready(substream)) < 0)
			return err;
		snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_START, NULL);
	}
	/* note: all errors from the start action are ignored */
	/* OSS apps do not know, how to handle them */
	return 0;
}

static int snd_pcm_oss_sync1(struct snd_pcm_substream *substream, size_t size)
{
	struct snd_pcm_runtime *runtime;
	ssize_t result = 0;
	long res;
	wait_queue_t wait;

	runtime = substream->runtime;
	init_waitqueue_entry(&wait, current);
	add_wait_queue(&runtime->sleep, &wait);
#ifdef OSS_DEBUG
	printk("sync1: size = %li\n", size);
#endif
	while (1) {
		result = snd_pcm_oss_write2(substream, runtime->oss.buffer, size, 1);
		if (result > 0) {
			runtime->oss.buffer_used = 0;
			result = 0;
			break;
		}
		if (result != 0 && result != -EAGAIN)
			break;
		result = 0;
		set_current_state(TASK_INTERRUPTIBLE);
		snd_pcm_stream_lock_irq(substream);
		res = runtime->status->state;
		snd_pcm_stream_unlock_irq(substream);
		if (res != SNDRV_PCM_STATE_RUNNING) {
			set_current_state(TASK_RUNNING);
			break;
		}
		res = schedule_timeout(10 * HZ);
		if (signal_pending(current)) {
			result = -ERESTARTSYS;
			break;
		}
		if (res == 0) {
			snd_printk(KERN_ERR "OSS sync error - DMA timeout\n");
			result = -EIO;
			break;
		}
	}
	remove_wait_queue(&runtime->sleep, &wait);
	return result;
}

static int snd_pcm_oss_sync(struct snd_pcm_oss_file *pcm_oss_file)
{
	int err = 0;
	unsigned int saved_f_flags;
	struct snd_pcm_substream *substream;
	struct snd_pcm_runtime *runtime;
	snd_pcm_format_t format;
	unsigned long width;
	size_t size;

	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
	if (substream != NULL) {
		runtime = substream->runtime;
		if (atomic_read(&substream->mmap_count))
			goto __direct;
		if ((err = snd_pcm_oss_make_ready(substream)) < 0)
			return err;
		format = snd_pcm_oss_format_from(runtime->oss.format);
		width = snd_pcm_format_physical_width(format);
		mutex_lock(&runtime->oss.params_lock);
		if (runtime->oss.buffer_used > 0) {
#ifdef OSS_DEBUG
			printk("sync: buffer_used\n");
#endif
			size = (8 * (runtime->oss.period_bytes - runtime->oss.buffer_used) + 7) / width;
			snd_pcm_format_set_silence(format,
						   runtime->oss.buffer + runtime->oss.buffer_used,
						   size);
			err = snd_pcm_oss_sync1(substream, runtime->oss.period_bytes);
			if (err < 0) {
				mutex_unlock(&runtime->oss.params_lock);
				return err;
			}
		} else if (runtime->oss.period_ptr > 0) {
#ifdef OSS_DEBUG
			printk("sync: period_ptr\n");
#endif
			size = runtime->oss.period_bytes - runtime->oss.period_ptr;
			snd_pcm_format_set_silence(format,
						   runtime->oss.buffer,
						   size * 8 / width);
			err = snd_pcm_oss_sync1(substream, size);
			if (err < 0) {
				mutex_unlock(&runtime->oss.params_lock);
				return err;
			}
		}
		/*
		 * The ALSA's period might be a bit large than OSS one.
		 * Fill the remain portion of ALSA period with zeros.
		 */
		size = runtime->control->appl_ptr % runtime->period_size;
		if (size > 0) {
			size = runtime->period_size - size;
			if (runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
				size = (runtime->frame_bits * size) / 8;
				while (size > 0) {
					mm_segment_t fs;
					size_t size1 = size < runtime->oss.period_bytes ? size : runtime->oss.period_bytes;
					size -= size1;
					size1 *= 8;
					size1 /= runtime->sample_bits;
					snd_pcm_format_set_silence(runtime->format,
								   runtime->oss.buffer,
								   size1);
					fs = snd_enter_user();
					snd_pcm_lib_write(substream, (void __user *)runtime->oss.buffer, size1);
					snd_leave_user(fs);
				}
			} else if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
				void __user *buffers[runtime->channels];
				memset(buffers, 0, runtime->channels * sizeof(void *));
				snd_pcm_lib_writev(substream, buffers, size);
			}
		}
		mutex_unlock(&runtime->oss.params_lock);
		/*
		 * finish sync: drain the buffer
		 */
	      __direct:
		saved_f_flags = substream->f_flags;
		substream->f_flags &= ~O_NONBLOCK;
		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DRAIN, NULL);
		substream->f_flags = saved_f_flags;
		if (err < 0)
			return err;
		runtime->oss.prepare = 1;
	}

	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
	if (substream != NULL) {
		if ((err = snd_pcm_oss_make_ready(substream)) < 0)
			return err;
		runtime = substream->runtime;
		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DROP, NULL);
		if (err < 0)
			return err;
		runtime->oss.buffer_used = 0;
		runtime->oss.prepare = 1;
	}
	return 0;
}

static int snd_pcm_oss_set_rate(struct snd_pcm_oss_file *pcm_oss_file, int rate)
{
	int idx;

	for (idx = 1; idx >= 0; --idx) {
		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
		struct snd_pcm_runtime *runtime;
		if (substream == NULL)
			continue;
		runtime = substream->runtime;
		if (rate < 1000)
			rate = 1000;
		else if (rate > 192000)
			rate = 192000;
		if (runtime->oss.rate != rate) {
			runtime->oss.params = 1;
			runtime->oss.rate = rate;
		}
	}
	return snd_pcm_oss_get_rate(pcm_oss_file);
}

static int snd_pcm_oss_get_rate(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.rate;
}

static int snd_pcm_oss_set_channels(struct snd_pcm_oss_file *pcm_oss_file, unsigned int channels)
{
	int idx;
	if (channels < 1)
		channels = 1;
	if (channels > 128)
		return -EINVAL;
	for (idx = 1; idx >= 0; --idx) {
		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
		struct snd_pcm_runtime *runtime;
		if (substream == NULL)
			continue;
		runtime = substream->runtime;
		if (runtime->oss.channels != channels) {
			runtime->oss.params = 1;
			runtime->oss.channels = channels;
		}
	}
	return snd_pcm_oss_get_channels(pcm_oss_file);
}

static int snd_pcm_oss_get_channels(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.channels;
}

static int snd_pcm_oss_get_block_size(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.period_bytes;
}

static int snd_pcm_oss_get_formats(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;
	int err;
	int direct;
	struct snd_pcm_hw_params *params;
	unsigned int formats = 0;
	struct snd_mask format_mask;
	int fmt;

	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	if (atomic_read(&substream->mmap_count))
		direct = 1;
	else
		direct = substream->oss.setup.direct;
	if (!direct)
		return AFMT_MU_LAW | AFMT_U8 |
		       AFMT_S16_LE | AFMT_S16_BE |
		       AFMT_S8 | AFMT_U16_LE |
		       AFMT_U16_BE |
			AFMT_S32_LE | AFMT_S32_BE |
			AFMT_S24_LE | AFMT_S24_LE |
			AFMT_S24_PACKED;
	params = kmalloc(sizeof(*params), GFP_KERNEL);
	if (!params)
		return -ENOMEM;
	_snd_pcm_hw_params_any(params);
	err = snd_pcm_hw_refine(substream, params);
	format_mask = *hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT); 
	kfree(params);
	snd_assert(err >= 0, return err);
	for (fmt = 0; fmt < 32; ++fmt) {
		if (snd_mask_test(&format_mask, fmt)) {
			int f = snd_pcm_oss_format_to(fmt);
			if (f >= 0)
				formats |= f;
		}
	}
	return formats;
}

static int snd_pcm_oss_set_format(struct snd_pcm_oss_file *pcm_oss_file, int format)
{
	int formats, idx;
	
	if (format != AFMT_QUERY) {
		formats = snd_pcm_oss_get_formats(pcm_oss_file);
		if (formats < 0)
			return formats;
		if (!(formats & format))
			format = AFMT_U8;
		for (idx = 1; idx >= 0; --idx) {
			struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
			struct snd_pcm_runtime *runtime;
			if (substream == NULL)
				continue;
			runtime = substream->runtime;
			if (runtime->oss.format != format) {
				runtime->oss.params = 1;
				runtime->oss.format = format;
			}
		}
	}
	return snd_pcm_oss_get_format(pcm_oss_file);
}

static int snd_pcm_oss_get_format(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.format;
}

static int snd_pcm_oss_set_subdivide1(struct snd_pcm_substream *substream, int subdivide)
{
	struct snd_pcm_runtime *runtime;

	if (substream == NULL)
		return 0;
	runtime = substream->runtime;
	if (subdivide == 0) {
		subdivide = runtime->oss.subdivision;
		if (subdivide == 0)
			subdivide = 1;
		return subdivide;
	}
	if (runtime->oss.subdivision || runtime->oss.fragshift)
		return -EINVAL;
	if (subdivide != 1 && subdivide != 2 && subdivide != 4 &&
	    subdivide != 8 && subdivide != 16)
		return -EINVAL;
	runtime->oss.subdivision = subdivide;
	runtime->oss.params = 1;
	return subdivide;
}

static int snd_pcm_oss_set_subdivide(struct snd_pcm_oss_file *pcm_oss_file, int subdivide)
{
	int err = -EINVAL, idx;

	for (idx = 1; idx >= 0; --idx) {
		struct snd_pcm_substream *substream = pcm_oss_file->streams[idx];
		if (substream == NULL)
			continue;
		if ((err = snd_pcm_oss_set_subdivide1(substream, subdivide)) < 0)
			return err;
	}