Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 882 insertions, 0 deletions

diff --git a/sound/usb/caiaq/audio.c b/sound/usb/caiaq/audio.c
new file mode 100644
index 000000000..498175365
--- /dev/null
+++ b/sound/usb/caiaq/audio.c
@@ -0,0 +1,882 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (c) 2006-2008 Daniel Mack, Karsten Wiese
+*/
+
+#include <linux/device.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+#include "device.h"
+#include "audio.h"
+
+#define N_URBS			32
+#define CLOCK_DRIFT_TOLERANCE	5
+#define FRAMES_PER_URB		8
+#define BYTES_PER_FRAME		512
+#define CHANNELS_PER_STREAM	2
+#define BYTES_PER_SAMPLE	3
+#define BYTES_PER_SAMPLE_USB	4
+#define MAX_BUFFER_SIZE		(128*1024)
+#define MAX_ENDPOINT_SIZE	512
+
+#define ENDPOINT_CAPTURE	2
+#define ENDPOINT_PLAYBACK	6
+
+#define MAKE_CHECKBYTE(cdev,stream,i) \
+	(stream << 1) | (~(i / (cdev->n_streams * BYTES_PER_SAMPLE_USB)) & 1)
+
+static const struct snd_pcm_hardware snd_usb_caiaq_pcm_hardware = {
+	.info 		= (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
+			   SNDRV_PCM_INFO_BLOCK_TRANSFER),
+	.formats 	= SNDRV_PCM_FMTBIT_S24_3BE,
+	.rates 		= (SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
+			   SNDRV_PCM_RATE_96000),
+	.rate_min	= 44100,
+	.rate_max	= 0, /* will overwrite later */
+	.channels_min	= CHANNELS_PER_STREAM,
+	.channels_max	= CHANNELS_PER_STREAM,
+	.buffer_bytes_max = MAX_BUFFER_SIZE,
+	.period_bytes_min = 128,
+	.period_bytes_max = MAX_BUFFER_SIZE,
+	.periods_min	= 1,
+	.periods_max	= 1024,
+};
+
+static void
+activate_substream(struct snd_usb_caiaqdev *cdev,
+	           struct snd_pcm_substream *sub)
+{
+	spin_lock(&cdev->spinlock);
+
+	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		cdev->sub_playback[sub->number] = sub;
+	else
+		cdev->sub_capture[sub->number] = sub;
+
+	spin_unlock(&cdev->spinlock);
+}
+
+static void
+deactivate_substream(struct snd_usb_caiaqdev *cdev,
+		     struct snd_pcm_substream *sub)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&cdev->spinlock, flags);
+
+	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		cdev->sub_playback[sub->number] = NULL;
+	else
+		cdev->sub_capture[sub->number] = NULL;
+
+	spin_unlock_irqrestore(&cdev->spinlock, flags);
+}
+
+static int
+all_substreams_zero(struct snd_pcm_substream **subs)
+{
+	int i;
+	for (i = 0; i < MAX_STREAMS; i++)
+		if (subs[i] != NULL)
+			return 0;
+	return 1;
+}
+
+static int stream_start(struct snd_usb_caiaqdev *cdev)
+{
+	int i, ret;
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	dev_dbg(dev, "%s(%p)\n", __func__, cdev);
+
+	if (cdev->streaming)
+		return -EINVAL;
+
+	memset(cdev->sub_playback, 0, sizeof(cdev->sub_playback));
+	memset(cdev->sub_capture, 0, sizeof(cdev->sub_capture));
+	cdev->input_panic = 0;
+	cdev->output_panic = 0;
+	cdev->first_packet = 4;
+	cdev->streaming = 1;
+	cdev->warned = 0;
+
+	for (i = 0; i < N_URBS; i++) {
+		ret = usb_submit_urb(cdev->data_urbs_in[i], GFP_ATOMIC);
+		if (ret) {
+			dev_err(dev, "unable to trigger read #%d! (ret %d)\n",
+				i, ret);
+			cdev->streaming = 0;
+			return -EPIPE;
+		}
+	}
+
+	return 0;
+}
+
+static void stream_stop(struct snd_usb_caiaqdev *cdev)
+{
+	int i;
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	dev_dbg(dev, "%s(%p)\n", __func__, cdev);
+	if (!cdev->streaming)
+		return;
+
+	cdev->streaming = 0;
+
+	for (i = 0; i < N_URBS; i++) {
+		usb_kill_urb(cdev->data_urbs_in[i]);
+
+		if (test_bit(i, &cdev->outurb_active_mask))
+			usb_kill_urb(cdev->data_urbs_out[i]);
+	}
+
+	cdev->outurb_active_mask = 0;
+}
+
+static int snd_usb_caiaq_substream_open(struct snd_pcm_substream *substream)
+{
+	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	dev_dbg(dev, "%s(%p)\n", __func__, substream);
+	substream->runtime->hw = cdev->pcm_info;
+	snd_pcm_limit_hw_rates(substream->runtime);
+
+	return 0;
+}
+
+static int snd_usb_caiaq_substream_close(struct snd_pcm_substream *substream)
+{
+	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	dev_dbg(dev, "%s(%p)\n", __func__, substream);
+	if (all_substreams_zero(cdev->sub_playback) &&
+	    all_substreams_zero(cdev->sub_capture)) {
+		/* when the last client has stopped streaming,
+		 * all sample rates are allowed again */
+		stream_stop(cdev);
+		cdev->pcm_info.rates = cdev->samplerates;
+	}
+
+	return 0;
+}
+
+static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
+{
+	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
+	deactivate_substream(cdev, sub);
+	return 0;
+}
+
+/* this should probably go upstream */
+#if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
+#error "Change this table"
+#endif
+
+static const unsigned int rates[] = { 5512, 8000, 11025, 16000, 22050, 32000, 44100,
+				48000, 64000, 88200, 96000, 176400, 192000 };
+
+static int snd_usb_caiaq_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	int bytes_per_sample, bpp, ret, i;
+	int index = substream->number;
+	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	dev_dbg(dev, "%s(%p)\n", __func__, substream);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		int out_pos;
+
+		switch (cdev->spec.data_alignment) {
+		case 0:
+		case 2:
+			out_pos = BYTES_PER_SAMPLE + 1;
+			break;
+		case 3:
+		default:
+			out_pos = 0;
+			break;
+		}
+
+		cdev->period_out_count[index] = out_pos;
+		cdev->audio_out_buf_pos[index] = out_pos;
+	} else {
+		int in_pos;
+
+		switch (cdev->spec.data_alignment) {
+		case 0:
+			in_pos = BYTES_PER_SAMPLE + 2;
+			break;
+		case 2:
+			in_pos = BYTES_PER_SAMPLE;
+			break;
+		case 3:
+		default:
+			in_pos = 0;
+			break;
+		}
+
+		cdev->period_in_count[index] = in_pos;
+		cdev->audio_in_buf_pos[index] = in_pos;
+	}
+
+	if (cdev->streaming)
+		return 0;
+
+	/* the first client that opens a stream defines the sample rate
+	 * setting for all subsequent calls, until the last client closed. */
+	for (i=0; i < ARRAY_SIZE(rates); i++)
+		if (runtime->rate == rates[i])
+			cdev->pcm_info.rates = 1 << i;
+
+	snd_pcm_limit_hw_rates(runtime);
+
+	bytes_per_sample = BYTES_PER_SAMPLE;
+	if (cdev->spec.data_alignment >= 2)
+		bytes_per_sample++;
+
+	bpp = ((runtime->rate / 8000) + CLOCK_DRIFT_TOLERANCE)
+		* bytes_per_sample * CHANNELS_PER_STREAM * cdev->n_streams;
+
+	if (bpp > MAX_ENDPOINT_SIZE)
+		bpp = MAX_ENDPOINT_SIZE;
+
+	ret = snd_usb_caiaq_set_audio_params(cdev, runtime->rate,
+					     runtime->sample_bits, bpp);
+	if (ret)
+		return ret;
+
+	ret = stream_start(cdev);
+	if (ret)
+		return ret;
+
+	cdev->output_running = 0;
+	wait_event_timeout(cdev->prepare_wait_queue, cdev->output_running, HZ);
+	if (!cdev->output_running) {
+		stream_stop(cdev);
+		return -EPIPE;
+	}
+
+	return 0;
+}
+
+static int snd_usb_caiaq_pcm_trigger(struct snd_pcm_substream *sub, int cmd)
+{
+	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	dev_dbg(dev, "%s(%p) cmd %d\n", __func__, sub, cmd);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		activate_substream(cdev, sub);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		deactivate_substream(cdev, sub);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static snd_pcm_uframes_t
+snd_usb_caiaq_pcm_pointer(struct snd_pcm_substream *sub)
+{
+	int index = sub->number;
+	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
+	snd_pcm_uframes_t ptr;
+
+	spin_lock(&cdev->spinlock);
+
+	if (cdev->input_panic || cdev->output_panic) {
+		ptr = SNDRV_PCM_POS_XRUN;
+		goto unlock;
+	}
+
+	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		ptr = bytes_to_frames(sub->runtime,
+					cdev->audio_out_buf_pos[index]);
+	else
+		ptr = bytes_to_frames(sub->runtime,
+					cdev->audio_in_buf_pos[index]);
+
+unlock:
+	spin_unlock(&cdev->spinlock);
+	return ptr;
+}
+
+/* operators for both playback and capture */
+static const struct snd_pcm_ops snd_usb_caiaq_ops = {
+	.open =		snd_usb_caiaq_substream_open,
+	.close =	snd_usb_caiaq_substream_close,
+	.hw_free =	snd_usb_caiaq_pcm_hw_free,
+	.prepare =	snd_usb_caiaq_pcm_prepare,
+	.trigger =	snd_usb_caiaq_pcm_trigger,
+	.pointer =	snd_usb_caiaq_pcm_pointer,
+};
+
+static void check_for_elapsed_periods(struct snd_usb_caiaqdev *cdev,
+				      struct snd_pcm_substream **subs)
+{
+	int stream, pb, *cnt;
+	struct snd_pcm_substream *sub;
+
+	for (stream = 0; stream < cdev->n_streams; stream++) {
+		sub = subs[stream];
+		if (!sub)
+			continue;
+
+		pb = snd_pcm_lib_period_bytes(sub);
+		cnt = (sub->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
+					&cdev->period_out_count[stream] :
+					&cdev->period_in_count[stream];
+
+		if (*cnt >= pb) {
+			snd_pcm_period_elapsed(sub);
+			*cnt %= pb;
+		}
+	}
+}
+
+static void read_in_urb_mode0(struct snd_usb_caiaqdev *cdev,
+			      const 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;
+
+	if (all_substreams_zero(cdev->sub_capture))
+		return;
+
+	for (i = 0; i < iso->actual_length;) {
+		for (stream = 0; stream < cdev->n_streams; stream++, i++) {
+			sub = cdev->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[cdev->audio_in_buf_pos[stream]++]
+					= usb_buf[i];
+				cdev->period_in_count[stream]++;
+				if (cdev->audio_in_buf_pos[stream] == sz)
+					cdev->audio_in_buf_pos[stream] = 0;
+			}
+		}
+	}
+}
+
+static void read_in_urb_mode2(struct snd_usb_caiaqdev *cdev,
+			      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;
+
+	for (i = 0; i < iso->actual_length;) {
+		if (i % (cdev->n_streams * BYTES_PER_SAMPLE_USB) == 0) {
+			for (stream = 0;
+			     stream < cdev->n_streams;
+			     stream++, i++) {
+				if (cdev->first_packet)
+					continue;
+
+				check_byte = MAKE_CHECKBYTE(cdev, stream, i);
+
+				if ((usb_buf[i] & 0x3f) != check_byte)
+					cdev->input_panic = 1;
+
+				if (usb_buf[i] & 0x80)
+					cdev->output_panic = 1;
+			}
+		}
+		cdev->first_packet = 0;
+
+		for (stream = 0; stream < cdev->n_streams; stream++, i++) {
+			sub = cdev->sub_capture[stream];
+			if (cdev->input_panic)
+				usb_buf[i] = 0;
+
+			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[cdev->audio_in_buf_pos[stream]++] =
+					usb_buf[i];
+				cdev->period_in_count[stream]++;
+				if (cdev->audio_in_buf_pos[stream] == sz)
+					cdev->audio_in_buf_pos[stream] = 0;
+			}
+		}
+	}
+}
+
+static void read_in_urb_mode3(struct snd_usb_caiaqdev *cdev,
+			      const struct urb *urb,
+			      const struct usb_iso_packet_descriptor *iso)
+{
+	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
+	struct device *dev = caiaqdev_to_dev(cdev);
+	int stream, i;
+
+	/* paranoia check */
+	if (iso->actual_length % (BYTES_PER_SAMPLE_USB * CHANNELS_PER_STREAM))
+		return;
+
+	for (i = 0; i < iso->actual_length;) {
+		for (stream = 0; stream < cdev->n_streams; stream++) {
+			struct snd_pcm_substream *sub = cdev->sub_capture[stream];
+			char *audio_buf = NULL;
+			int c, n, sz = 0;
+
+			if (sub && !cdev->input_panic) {
+				struct snd_pcm_runtime *rt = sub->runtime;
+				audio_buf = rt->dma_area;
+				sz = frames_to_bytes(rt, rt->buffer_size);
+			}
+
+			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
+				/* 3 audio data bytes, followed by 1 check byte */
+				if (audio_buf) {
+					for (n = 0; n < BYTES_PER_SAMPLE; n++) {
+						audio_buf[cdev->audio_in_buf_pos[stream]++] = usb_buf[i+n];
+
+						if (cdev->audio_in_buf_pos[stream] == sz)
+							cdev->audio_in_buf_pos[stream] = 0;
+					}
+
+					cdev->period_in_count[stream] += BYTES_PER_SAMPLE;
+				}
+
+				i += BYTES_PER_SAMPLE;
+
+				if (usb_buf[i] != ((stream << 1) | c) &&
+				    !cdev->first_packet) {
+					if (!cdev->input_panic)
+						dev_warn(dev, " EXPECTED: %02x got %02x, c %d, stream %d, i %d\n",
+							 ((stream << 1) | c), usb_buf[i], c, stream, i);
+					cdev->input_panic = 1;
+				}
+
+				i++;
+			}
+		}
+	}
+
+	if (cdev->first_packet > 0)
+		cdev->first_packet--;
+}
+
+static void read_in_urb(struct snd_usb_caiaqdev *cdev,
+			const struct urb *urb,
+			const struct usb_iso_packet_descriptor *iso)
+{
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	if (!cdev->streaming)
+		return;
+
+	if (iso->actual_length < cdev->bpp)
+		return;
+
+	switch (cdev->spec.data_alignment) {
+	case 0:
+		read_in_urb_mode0(cdev, urb, iso);
+		break;
+	case 2:
+		read_in_urb_mode2(cdev, urb, iso);
+		break;
+	case 3:
+		read_in_urb_mode3(cdev, urb, iso);
+		break;
+	}
+
+	if ((cdev->input_panic || cdev->output_panic) && !cdev->warned) {
+		dev_warn(dev, "streaming error detected %s %s\n",
+				cdev->input_panic ? "(input)" : "",
+				cdev->output_panic ? "(output)" : "");
+		cdev->warned = 1;
+	}
+}
+
+static void fill_out_urb_mode_0(struct snd_usb_caiaqdev *cdev,
+				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;
+
+	for (i = 0; i < iso->length;) {
+		for (stream = 0; stream < cdev->n_streams; stream++, i++) {
+			sub = cdev->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[cdev->audio_out_buf_pos[stream]];
+				cdev->period_out_count[stream]++;
+				cdev->audio_out_buf_pos[stream]++;
+				if (cdev->audio_out_buf_pos[stream] == sz)
+					cdev->audio_out_buf_pos[stream] = 0;
+			} else
+				usb_buf[i] = 0;
+		}
+
+		/* fill in the check bytes */
+		if (cdev->spec.data_alignment == 2 &&
+		    i % (cdev->n_streams * BYTES_PER_SAMPLE_USB) ==
+		        (cdev->n_streams * CHANNELS_PER_STREAM))
+			for (stream = 0; stream < cdev->n_streams; stream++, i++)
+				usb_buf[i] = MAKE_CHECKBYTE(cdev, stream, i);
+	}
+}
+
+static void fill_out_urb_mode_3(struct snd_usb_caiaqdev *cdev,
+				struct urb *urb,
+				const struct usb_iso_packet_descriptor *iso)
+{
+	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
+	int stream, i;
+
+	for (i = 0; i < iso->length;) {
+		for (stream = 0; stream < cdev->n_streams; stream++) {
+			struct snd_pcm_substream *sub = cdev->sub_playback[stream];
+			char *audio_buf = NULL;
+			int c, n, sz = 0;
+
+			if (sub) {
+				struct snd_pcm_runtime *rt = sub->runtime;
+				audio_buf = rt->dma_area;
+				sz = frames_to_bytes(rt, rt->buffer_size);
+			}
+
+			for (c = 0; c < CHANNELS_PER_STREAM; c++) {
+				for (n = 0; n < BYTES_PER_SAMPLE; n++) {
+					if (audio_buf) {
+						usb_buf[i+n] = audio_buf[cdev->audio_out_buf_pos[stream]++];
+
+						if (cdev->audio_out_buf_pos[stream] == sz)
+							cdev->audio_out_buf_pos[stream] = 0;
+					} else {
+						usb_buf[i+n] = 0;
+					}
+				}
+
+				if (audio_buf)
+					cdev->period_out_count[stream] += BYTES_PER_SAMPLE;
+
+				i += BYTES_PER_SAMPLE;
+
+				/* fill in the check byte pattern */
+				usb_buf[i++] = (stream << 1) | c;
+			}
+		}
+	}
+}
+
+static inline void fill_out_urb(struct snd_usb_caiaqdev *cdev,
+				struct urb *urb,
+				const struct usb_iso_packet_descriptor *iso)
+{
+	switch (cdev->spec.data_alignment) {
+	case 0:
+	case 2:
+		fill_out_urb_mode_0(cdev, urb, iso);
+		break;
+	case 3:
+		fill_out_urb_mode_3(cdev, urb, iso);
+		break;
+	}
+}
+
+static void read_completed(struct urb *urb)
+{
+	struct snd_usb_caiaq_cb_info *info = urb->context;
+	struct snd_usb_caiaqdev *cdev;
+	struct device *dev;
+	struct urb *out = NULL;
+	int i, frame, len, send_it = 0, outframe = 0;
+	unsigned long flags;
+	size_t offset = 0;
+
+	if (urb->status || !info)
+		return;
+
+	cdev = info->cdev;
+	dev = caiaqdev_to_dev(cdev);
+
+	if (!cdev->streaming)
+		return;
+
+	/* find an unused output urb that is unused */
+	for (i = 0; i < N_URBS; i++)
+		if (test_and_set_bit(i, &cdev->outurb_active_mask) == 0) {
+			out = cdev->data_urbs_out[i];
+			break;
+		}
+
+	if (!out) {
+		dev_err(dev, "Unable to find an output urb to use\n");
+		goto requeue;
+	}
+
+	/* 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 = offset;
+		offset += len;
+
+		if (len > 0) {
+			spin_lock_irqsave(&cdev->spinlock, flags);
+			fill_out_urb(cdev, out, &out->iso_frame_desc[outframe]);
+			read_in_urb(cdev, urb, &urb->iso_frame_desc[frame]);
+			spin_unlock_irqrestore(&cdev->spinlock, flags);
+			check_for_elapsed_periods(cdev, cdev->sub_playback);
+			check_for_elapsed_periods(cdev, cdev->sub_capture);
+			send_it = 1;
+		}
+
+		outframe++;
+	}
+
+	if (send_it) {
+		out->number_of_packets = outframe;
+		usb_submit_urb(out, GFP_ATOMIC);
+	} else {
+		struct snd_usb_caiaq_cb_info *oinfo = out->context;
+		clear_bit(oinfo->index, &cdev->outurb_active_mask);
+	}
+
+requeue:
+	/* 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;
+	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 *cdev = info->cdev;
+
+	if (!cdev->output_running) {
+		cdev->output_running = 1;
+		wake_up(&cdev->prepare_wait_queue);
+	}
+
+	clear_bit(info->index, &cdev->outurb_active_mask);
+}
+
+static struct urb **alloc_urbs(struct snd_usb_caiaqdev *cdev, int dir, int *ret)
+{
+	int i, frame;
+	struct urb **urbs;
+	struct usb_device *usb_dev = cdev->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_array(N_URBS, sizeof(*urbs), GFP_KERNEL);
+	if (!urbs) {
+		*ret = -ENOMEM;
+		return NULL;
+	}
+
+	for (i = 0; i < N_URBS; i++) {
+		urbs[i] = usb_alloc_urb(FRAMES_PER_URB, GFP_KERNEL);
+		if (!urbs[i]) {
+			*ret = -ENOMEM;
+			return urbs;
+		}
+
+		urbs[i]->transfer_buffer =
+			kmalloc_array(BYTES_PER_FRAME, FRAMES_PER_URB,
+				      GFP_KERNEL);
+		if (!urbs[i]->transfer_buffer) {
+			*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 = &cdev->data_cb_info[i];
+		urbs[i]->interval = 1;
+		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 snd_usb_caiaq_audio_init(struct snd_usb_caiaqdev *cdev)
+{
+	int i, ret;
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	cdev->n_audio_in  = max(cdev->spec.num_analog_audio_in,
+			       cdev->spec.num_digital_audio_in) /
+				CHANNELS_PER_STREAM;
+	cdev->n_audio_out = max(cdev->spec.num_analog_audio_out,
+			       cdev->spec.num_digital_audio_out) /
+				CHANNELS_PER_STREAM;
+	cdev->n_streams = max(cdev->n_audio_in, cdev->n_audio_out);
+
+	dev_dbg(dev, "cdev->n_audio_in = %d\n", cdev->n_audio_in);
+	dev_dbg(dev, "cdev->n_audio_out = %d\n", cdev->n_audio_out);
+	dev_dbg(dev, "cdev->n_streams = %d\n", cdev->n_streams);
+
+	if (cdev->n_streams > MAX_STREAMS) {
+		dev_err(dev, "unable to initialize device, too many streams.\n");
+		return -EINVAL;
+	}
+
+	if (cdev->n_streams < 1) {
+		dev_err(dev, "bogus number of streams: %d\n", cdev->n_streams);
+		return -EINVAL;
+	}
+
+	ret = snd_pcm_new(cdev->chip.card, cdev->product_name, 0,
+			cdev->n_audio_out, cdev->n_audio_in, &cdev->pcm);
+
+	if (ret < 0) {
+		dev_err(dev, "snd_pcm_new() returned %d\n", ret);
+		return ret;
+	}
+
+	cdev->pcm->private_data = cdev;
+	strscpy(cdev->pcm->name, cdev->product_name, sizeof(cdev->pcm->name));
+
+	memset(cdev->sub_playback, 0, sizeof(cdev->sub_playback));
+	memset(cdev->sub_capture, 0, sizeof(cdev->sub_capture));
+
+	memcpy(&cdev->pcm_info, &snd_usb_caiaq_pcm_hardware,
+			sizeof(snd_usb_caiaq_pcm_hardware));
+
+	/* setup samplerates */
+	cdev->samplerates = cdev->pcm_info.rates;
+	switch (cdev->chip.usb_id) {
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AK1):
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_RIGKONTROL3):
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_SESSIONIO):
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_GUITARRIGMOBILE):
+		cdev->samplerates |= SNDRV_PCM_RATE_192000;
+		fallthrough;
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO2DJ):
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO4DJ):
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_AUDIO8DJ):
+	case USB_ID(USB_VID_NATIVEINSTRUMENTS, USB_PID_TRAKTORAUDIO2):
+		cdev->samplerates |= SNDRV_PCM_RATE_88200;
+		break;
+	}
+
+	snd_pcm_set_ops(cdev->pcm, SNDRV_PCM_STREAM_PLAYBACK,
+				&snd_usb_caiaq_ops);
+	snd_pcm_set_ops(cdev->pcm, SNDRV_PCM_STREAM_CAPTURE,
+				&snd_usb_caiaq_ops);
+	snd_pcm_set_managed_buffer_all(cdev->pcm, SNDRV_DMA_TYPE_VMALLOC,
+				       NULL, 0, 0);
+
+	cdev->data_cb_info =
+		kmalloc_array(N_URBS, sizeof(struct snd_usb_caiaq_cb_info),
+					GFP_KERNEL);
+
+	if (!cdev->data_cb_info)
+		return -ENOMEM;
+
+	cdev->outurb_active_mask = 0;
+	BUILD_BUG_ON(N_URBS > (sizeof(cdev->outurb_active_mask) * 8));
+
+	for (i = 0; i < N_URBS; i++) {
+		cdev->data_cb_info[i].cdev = cdev;
+		cdev->data_cb_info[i].index = i;
+	}
+
+	cdev->data_urbs_in = alloc_urbs(cdev, SNDRV_PCM_STREAM_CAPTURE, &ret);
+	if (ret < 0) {
+		kfree(cdev->data_cb_info);
+		free_urbs(cdev->data_urbs_in);
+		return ret;
+	}
+
+	cdev->data_urbs_out = alloc_urbs(cdev, SNDRV_PCM_STREAM_PLAYBACK, &ret);
+	if (ret < 0) {
+		kfree(cdev->data_cb_info);
+		free_urbs(cdev->data_urbs_in);
+		free_urbs(cdev->data_urbs_out);
+		return ret;
+	}
+
+	return 0;
+}
+
+void snd_usb_caiaq_audio_free(struct snd_usb_caiaqdev *cdev)
+{
+	struct device *dev = caiaqdev_to_dev(cdev);
+
+	dev_dbg(dev, "%s(%p)\n", __func__, cdev);
+	stream_stop(cdev);
+	free_urbs(cdev->data_urbs_in);
+	free_urbs(cdev->data_urbs_out);
+	kfree(cdev->data_cb_info);
+}
+