caiaq-audio.c

linux 内核源代码

			      const struct urb *urb,
			      const struct usb_iso_packet_descriptor *iso)
{
	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
	unsigned char check_byte;
	struct snd_pcm_substream *sub;
	int stream, i;

	spin_lock(&dev->spinlock);
	
	for (i = 0; i < iso->actual_length;) {
		if (i % (dev->n_streams * BYTES_PER_SAMPLE_USB) == 0) {
			for (stream = 0; 
			     stream < dev->n_streams; 
			     stream++, i++) {
				if (dev->first_packet)
					continue;

				check_byte = MAKE_CHECKBYTE(dev, stream, i);
				
				if ((usb_buf[i] & 0x3f) != check_byte)
					dev->input_panic = 1;

				if (usb_buf[i] & 0x80)
					dev->output_panic = 1;
			}
		}
		dev->first_packet = 0;

		for (stream = 0; stream < dev->n_streams; stream++, i++) {
			sub = dev->sub_capture[stream];
			if (sub) {
				struct snd_pcm_runtime *rt = sub->runtime;
				char *audio_buf = rt->dma_area;
				int sz = frames_to_bytes(rt, rt->buffer_size);
				audio_buf[dev->audio_in_buf_pos[stream]++] =
					usb_buf[i];
				dev->period_in_count[stream]++;
				if (dev->audio_in_buf_pos[stream] == sz)
					dev->audio_in_buf_pos[stream] = 0;
			}
		}
	}

	spin_unlock(&dev->spinlock);
}

static void read_in_urb(struct snd_usb_caiaqdev *dev,
			const struct urb *urb,
			const struct usb_iso_packet_descriptor *iso)
{
	if (!dev->streaming)
		return;

	switch (dev->spec.data_alignment) {
	case 0:
		read_in_urb_mode0(dev, urb, iso);
		break;
	case 2:
		read_in_urb_mode2(dev, urb, iso);
		break;
	}

	if (dev->input_panic || dev->output_panic) {
		debug("streaming error detected %s %s\n", 
				dev->input_panic ? "(input)" : "",
				dev->output_panic ? "(output)" : "");
	}

	check_for_elapsed_periods(dev, dev->sub_capture);
}

static void fill_out_urb(struct snd_usb_caiaqdev *dev, 
			 struct urb *urb, 
			 const struct usb_iso_packet_descriptor *iso)
{
	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
	struct snd_pcm_substream *sub;
	int stream, i;

	spin_lock(&dev->spinlock);
	
	for (i = 0; i < iso->length;) {
		for (stream = 0; stream < dev->n_streams; stream++, i++) {
			sub = dev->sub_playback[stream];
			if (sub) {
				struct snd_pcm_runtime *rt = sub->runtime;
				char *audio_buf = rt->dma_area;
				int sz = frames_to_bytes(rt, rt->buffer_size);
				usb_buf[i] =
					audio_buf[dev->audio_out_buf_pos[stream]];
				dev->period_out_count[stream]++;
				dev->audio_out_buf_pos[stream]++;
				if (dev->audio_out_buf_pos[stream] == sz)
					dev->audio_out_buf_pos[stream] = 0;
			} else
				usb_buf[i] = 0;
		}

		/* fill in the check bytes */
		if (dev->spec.data_alignment == 2 &&
		    i % (dev->n_streams * BYTES_PER_SAMPLE_USB) == 
		    	(dev->n_streams * CHANNELS_PER_STREAM))
		    for (stream = 0; stream < dev->n_streams; stream++, i++)
		    	usb_buf[i] = MAKE_CHECKBYTE(dev, stream, i);
	}

	spin_unlock(&dev->spinlock);
	check_for_elapsed_periods(dev, dev->sub_playback);
}

static void read_completed(struct urb *urb)
{
	struct snd_usb_caiaq_cb_info *info = urb->context; 
	struct snd_usb_caiaqdev *dev;
	struct urb *out;
	int frame, len, send_it = 0, outframe = 0;

	if (urb->status || !info)
		return;

	dev = info->dev;
	if (!dev->streaming)
		return;

	out = dev->data_urbs_out[info->index];

	/* read the recently received packet and send back one which has
	 * the same layout */
	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
		if (urb->iso_frame_desc[frame].status)
			continue;

		len = urb->iso_frame_desc[outframe].actual_length;
		out->iso_frame_desc[outframe].length = len;
		out->iso_frame_desc[outframe].actual_length = 0;
		out->iso_frame_desc[outframe].offset = BYTES_PER_FRAME * frame;
		
		if (len > 0) {
			fill_out_urb(dev, out, &out->iso_frame_desc[outframe]);
			read_in_urb(dev, urb, &urb->iso_frame_desc[frame]);
			send_it = 1;
		}

		outframe++;
	}

	if (send_it) {
		out->number_of_packets = FRAMES_PER_URB;
		out->transfer_flags = URB_ISO_ASAP;
		usb_submit_urb(out, GFP_ATOMIC);
	}
	
	/* re-submit inbound urb */
	for (frame = 0; frame < FRAMES_PER_URB; frame++) {
		urb->iso_frame_desc[frame].offset = BYTES_PER_FRAME * frame;
		urb->iso_frame_desc[frame].length = BYTES_PER_FRAME;
		urb->iso_frame_desc[frame].actual_length = 0;
	}
	
	urb->number_of_packets = FRAMES_PER_URB;
	urb->transfer_flags = URB_ISO_ASAP;
	usb_submit_urb(urb, GFP_ATOMIC);
}

static void write_completed(struct urb *urb)
{
	struct snd_usb_caiaq_cb_info *info = urb->context;
	struct snd_usb_caiaqdev *dev = info->dev;

	if (!dev->output_running) {
		dev->output_running = 1;
		wake_up(&dev->prepare_wait_queue);
	}
}

static struct urb **alloc_urbs(struct snd_usb_caiaqdev *dev, int dir, int *ret)
{
	int i, frame;
	struct urb **urbs;
	struct usb_device *usb_dev = dev->chip.dev;
	unsigned int pipe;

	pipe = (dir == SNDRV_PCM_STREAM_PLAYBACK) ? 
		usb_sndisocpipe(usb_dev, ENDPOINT_PLAYBACK) :
		usb_rcvisocpipe(usb_dev, ENDPOINT_CAPTURE);

	urbs = kmalloc(N_URBS * sizeof(*urbs), GFP_KERNEL);
	if (!urbs) {
		log("unable to kmalloc() urbs, OOM!?\n");
		*ret = -ENOMEM;
		return NULL;
	}

	for (i = 0; i < N_URBS; i++) {
		urbs[i] = usb_alloc_urb(FRAMES_PER_URB, GFP_KERNEL);
		if (!urbs[i]) {
			log("unable to usb_alloc_urb(), OOM!?\n");
			*ret = -ENOMEM;
			return urbs;
		}

		urbs[i]->transfer_buffer = 
			kmalloc(FRAMES_PER_URB * BYTES_PER_FRAME, GFP_KERNEL);
		if (!urbs[i]->transfer_buffer) {
			log("unable to kmalloc() transfer buffer, OOM!?\n");
			*ret = -ENOMEM;
			return urbs;
		}
		
		for (frame = 0; frame < FRAMES_PER_URB; frame++) {
			struct usb_iso_packet_descriptor *iso = 
				&urbs[i]->iso_frame_desc[frame];
			
			iso->offset = BYTES_PER_FRAME * frame;
			iso->length = BYTES_PER_FRAME;
		}
		
		urbs[i]->dev = usb_dev;
		urbs[i]->pipe = pipe;
		urbs[i]->transfer_buffer_length = FRAMES_PER_URB 
						* BYTES_PER_FRAME;
		urbs[i]->context = &dev->data_cb_info[i];
		urbs[i]->interval = 1;
		urbs[i]->transfer_flags = URB_ISO_ASAP;
		urbs[i]->number_of_packets = FRAMES_PER_URB;
		urbs[i]->complete = (dir == SNDRV_PCM_STREAM_CAPTURE) ?
					read_completed : write_completed;
	}

	*ret = 0;
	return urbs;
}

static void free_urbs(struct urb **urbs)
{
	int i;

	if (!urbs)
		return;

	for (i = 0; i < N_URBS; i++) {
		if (!urbs[i])
			continue;
		
		usb_kill_urb(urbs[i]);
		kfree(urbs[i]->transfer_buffer);
		usb_free_urb(urbs[i]);
	}

	kfree(urbs);
}

int __devinit snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *dev)
{
	int i, ret;

	dev->n_audio_in  = max(dev->spec.num_analog_audio_in, 
			       dev->spec.num_digital_audio_in) / 
				CHANNELS_PER_STREAM;
	dev->n_audio_out = max(dev->spec.num_analog_audio_out,
			       dev->spec.num_digital_audio_out) / 
				CHANNELS_PER_STREAM;
	dev->n_streams = max(dev->n_audio_in, dev->n_audio_out);

	debug("dev->n_audio_in = %d\n", dev->n_audio_in);
	debug("dev->n_audio_out = %d\n", dev->n_audio_out);
	debug("dev->n_streams = %d\n", dev->n_streams);

	if (dev->n_streams > MAX_STREAMS) {
		log("unable to initialize device, too many streams.\n");
		return -EINVAL;
	}

	ret = snd_pcm_new(dev->chip.card, dev->product_name, 0, 
			dev->n_audio_out, dev->n_audio_in, &dev->pcm);

	if (ret < 0) {
		log("snd_pcm_new() returned %d\n", ret);
		return ret;
	}

	dev->pcm->private_data = dev;
	strcpy(dev->pcm->name, dev->product_name);

	memset(dev->sub_playback, 0, sizeof(dev->sub_playback));
	memset(dev->sub_capture, 0, sizeof(dev->sub_capture));
	
	memcpy(&dev->pcm_info, &snd_usb_caiaq_pcm_hardware,
			sizeof(snd_usb_caiaq_pcm_hardware));

	/* setup samplerates */
	dev->samplerates = dev->pcm_info.rates;
	switch (dev->chip.usb_id) {
	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AK1):
	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL3):
		dev->samplerates |= SNDRV_PCM_RATE_88200;
		dev->samplerates |= SNDRV_PCM_RATE_192000;
		break;
	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO8DJ):
		dev->samplerates |= SNDRV_PCM_RATE_88200;
		break;
	}

	snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_PLAYBACK, 
				&snd_usb_caiaq_ops);
	snd_pcm_set_ops(dev->pcm, SNDRV_PCM_STREAM_CAPTURE, 
				&snd_usb_caiaq_ops);

	snd_pcm_lib_preallocate_pages_for_all(dev->pcm,
					SNDRV_DMA_TYPE_CONTINUOUS,
					snd_dma_continuous_data(GFP_KERNEL),
					MAX_BUFFER_SIZE, MAX_BUFFER_SIZE);

	dev->data_cb_info =
		kmalloc(sizeof(struct snd_usb_caiaq_cb_info) * N_URBS, 
					GFP_KERNEL);

	if (!dev->data_cb_info)
		return -ENOMEM;

	for (i = 0; i < N_URBS; i++) {
		dev->data_cb_info[i].dev = dev;
		dev->data_cb_info[i].index = i;
	}
	
	dev->data_urbs_in = alloc_urbs(dev, SNDRV_PCM_STREAM_CAPTURE, &ret);
	if (ret < 0) {
		kfree(dev->data_cb_info);
		free_urbs(dev->data_urbs_in);
		return ret;
	}
	
	dev->data_urbs_out = alloc_urbs(dev, SNDRV_PCM_STREAM_PLAYBACK, &ret);
	if (ret < 0) {
		kfree(dev->data_cb_info);
		free_urbs(dev->data_urbs_in);
		free_urbs(dev->data_urbs_out);
		return ret;
	}

	return 0;
}

void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *dev)
{
	debug("snd_usb_caiaq_audio_free (%p)\n", dev);
	stream_stop(dev);
	free_urbs(dev->data_urbs_in);
	free_urbs(dev->data_urbs_out);
	kfree(dev->data_cb_info);
}