Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 775 insertions, 0 deletions

diff --git a/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c
new file mode 100644
index 000000000..767a227d5
--- /dev/null
+++ b/sound/usb/usx2y/usx2yhwdeppcm.c
@@ -0,0 +1,775 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ */
+
+/* USX2Y "rawusb" aka hwdep_pcm implementation
+
+ Its usb's unableness to atomically handle power of 2 period sized data chuncs
+ at standard samplerates,
+ what led to this part of the usx2y module:
+ It provides the alsa kernel half of the usx2y-alsa-jack driver pair.
+ The pair uses a hardware dependent alsa-device for mmaped pcm transport.
+ Advantage achieved:
+         The usb_hc moves pcm data from/into memory via DMA.
+         That memory is mmaped by jack's usx2y driver.
+         Jack's usx2y driver is the first/last to read/write pcm data.
+         Read/write is a combination of power of 2 period shaping and
+         float/int conversation.
+         Compared to mainline alsa/jack we leave out power of 2 period shaping inside
+         snd-usb-usx2y which needs memcpy() and additional buffers.
+         As a side effect possible unwanted pcm-data coruption resulting of
+         standard alsa's snd-usb-usx2y period shaping scheme falls away.
+         Result is sane jack operation at buffering schemes down to 128frames,
+         2 periods.
+         plain usx2y alsa mode is able to achieve 64frames, 4periods, but only at the
+         cost of easier triggered i.e. aeolus xruns (128 or 256frames,
+         2periods works but is useless cause of crackling).
+
+ This is a first "proof of concept" implementation.
+ Later, functionalities should migrate to more appropriate places:
+ Userland:
+ - The jackd could mmap its float-pcm buffers directly from alsa-lib.
+ - alsa-lib could provide power of 2 period sized shaping combined with int/float
+   conversation.
+   Currently the usx2y jack driver provides above 2 services.
+ Kernel:
+ - rawusb dma pcm buffer transport should go to snd-usb-lib, so also snd-usb-audio
+   devices can use it.
+   Currently rawusb dma pcm buffer transport (this file) is only available to snd-usb-usx2y.
+*/
+
+#include <linux/delay.h>
+#include <linux/gfp.h>
+#include "usbusx2yaudio.c"
+
+#if defined(USX2Y_NRPACKS_VARIABLE) || USX2Y_NRPACKS == 1
+
+#include <sound/hwdep.h>
+
+static int usx2y_usbpcm_urb_capt_retire(struct snd_usx2y_substream *subs)
+{
+	struct urb	*urb = subs->completed_urb;
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+	int		i, lens = 0, hwptr_done = subs->hwptr_done;
+	struct usx2ydev	*usx2y = subs->usx2y;
+	int head;
+
+	if (usx2y->hwdep_pcm_shm->capture_iso_start < 0) { //FIXME
+		head = usx2y->hwdep_pcm_shm->captured_iso_head + 1;
+		if (head >= ARRAY_SIZE(usx2y->hwdep_pcm_shm->captured_iso))
+			head = 0;
+		usx2y->hwdep_pcm_shm->capture_iso_start = head;
+		snd_printdd("cap start %i\n", head);
+	}
+	for (i = 0; i < nr_of_packs(); i++) {
+		if (urb->iso_frame_desc[i].status) { /* active? hmm, skip this */
+			snd_printk(KERN_ERR
+				   "active frame status %i. Most probably some hardware problem.\n",
+				   urb->iso_frame_desc[i].status);
+			return urb->iso_frame_desc[i].status;
+		}
+		lens += urb->iso_frame_desc[i].actual_length / usx2y->stride;
+	}
+	hwptr_done += lens;
+	if (hwptr_done >= runtime->buffer_size)
+		hwptr_done -= runtime->buffer_size;
+	subs->hwptr_done = hwptr_done;
+	subs->transfer_done += lens;
+	/* update the pointer, call callback if necessary */
+	if (subs->transfer_done >= runtime->period_size) {
+		subs->transfer_done -= runtime->period_size;
+		snd_pcm_period_elapsed(subs->pcm_substream);
+	}
+	return 0;
+}
+
+static int usx2y_iso_frames_per_buffer(struct snd_pcm_runtime *runtime,
+					      struct usx2ydev *usx2y)
+{
+	return (runtime->buffer_size * 1000) / usx2y->rate + 1;	//FIXME: so far only correct period_size == 2^x ?
+}
+
+/*
+ * prepare urb for playback data pipe
+ *
+ * we copy the data directly from the pcm buffer.
+ * the current position to be copied is held in hwptr field.
+ * since a urb can handle only a single linear buffer, if the total
+ * transferred area overflows the buffer boundary, we cannot send
+ * it directly from the buffer.  thus the data is once copied to
+ * a temporary buffer and urb points to that.
+ */
+static int usx2y_hwdep_urb_play_prepare(struct snd_usx2y_substream *subs,
+					struct urb *urb)
+{
+	int count, counts, pack;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_hwdep_pcm_shm *shm = usx2y->hwdep_pcm_shm;
+	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+
+	if (shm->playback_iso_start < 0) {
+		shm->playback_iso_start = shm->captured_iso_head -
+			usx2y_iso_frames_per_buffer(runtime, usx2y);
+		if (shm->playback_iso_start < 0)
+			shm->playback_iso_start += ARRAY_SIZE(shm->captured_iso);
+		shm->playback_iso_head = shm->playback_iso_start;
+	}
+
+	count = 0;
+	for (pack = 0; pack < nr_of_packs(); pack++) {
+		/* calculate the size of a packet */
+		counts = shm->captured_iso[shm->playback_iso_head].length / usx2y->stride;
+		if (counts < 43 || counts > 50) {
+			snd_printk(KERN_ERR "should not be here with counts=%i\n", counts);
+			return -EPIPE;
+		}
+		/* set up descriptor */
+		urb->iso_frame_desc[pack].offset = shm->captured_iso[shm->playback_iso_head].offset;
+		urb->iso_frame_desc[pack].length = shm->captured_iso[shm->playback_iso_head].length;
+		if (atomic_read(&subs->state) != STATE_RUNNING)
+			memset((char *)urb->transfer_buffer + urb->iso_frame_desc[pack].offset, 0,
+			       urb->iso_frame_desc[pack].length);
+		if (++shm->playback_iso_head >= ARRAY_SIZE(shm->captured_iso))
+			shm->playback_iso_head = 0;
+		count += counts;
+	}
+	urb->transfer_buffer_length = count * usx2y->stride;
+	return 0;
+}
+
+static void usx2y_usbpcm_urb_capt_iso_advance(struct snd_usx2y_substream *subs,
+					      struct urb *urb)
+{
+	struct usb_iso_packet_descriptor *desc;
+	struct snd_usx2y_hwdep_pcm_shm *shm;
+	int pack, head;
+
+	for (pack = 0; pack < nr_of_packs(); ++pack) {
+		desc = urb->iso_frame_desc + pack;
+		if (subs) {
+			shm = subs->usx2y->hwdep_pcm_shm;
+			head = shm->captured_iso_head + 1;
+			if (head >= ARRAY_SIZE(shm->captured_iso))
+				head = 0;
+			shm->captured_iso[head].frame = urb->start_frame + pack;
+			shm->captured_iso[head].offset = desc->offset;
+			shm->captured_iso[head].length = desc->actual_length;
+			shm->captured_iso_head = head;
+			shm->captured_iso_frames++;
+		}
+		desc->offset += desc->length * NRURBS * nr_of_packs();
+		if (desc->offset + desc->length >= SSS)
+			desc->offset -= (SSS - desc->length);
+	}
+}
+
+static int usx2y_usbpcm_usbframe_complete(struct snd_usx2y_substream *capsubs,
+					  struct snd_usx2y_substream *capsubs2,
+					  struct snd_usx2y_substream *playbacksubs,
+					  int frame)
+{
+	int err, state;
+	struct urb *urb = playbacksubs->completed_urb;
+
+	state = atomic_read(&playbacksubs->state);
+	if (urb) {
+		if (state == STATE_RUNNING)
+			usx2y_urb_play_retire(playbacksubs, urb);
+		else if (state >= STATE_PRERUNNING)
+			atomic_inc(&playbacksubs->state);
+	} else {
+		switch (state) {
+		case STATE_STARTING1:
+			urb = playbacksubs->urb[0];
+			atomic_inc(&playbacksubs->state);
+			break;
+		case STATE_STARTING2:
+			urb = playbacksubs->urb[1];
+			atomic_inc(&playbacksubs->state);
+			break;
+		}
+	}
+	if (urb) {
+		err = usx2y_hwdep_urb_play_prepare(playbacksubs, urb);
+		if (err)
+			return err;
+		err = usx2y_hwdep_urb_play_prepare(playbacksubs, urb);
+		if (err)
+			return err;
+	}
+
+	playbacksubs->completed_urb = NULL;
+
+	state = atomic_read(&capsubs->state);
+	if (state >= STATE_PREPARED) {
+		if (state == STATE_RUNNING) {
+			err = usx2y_usbpcm_urb_capt_retire(capsubs);
+			if (err)
+				return err;
+		} else if (state >= STATE_PRERUNNING) {
+			atomic_inc(&capsubs->state);
+		}
+		usx2y_usbpcm_urb_capt_iso_advance(capsubs, capsubs->completed_urb);
+		if (capsubs2)
+			usx2y_usbpcm_urb_capt_iso_advance(NULL, capsubs2->completed_urb);
+		err = usx2y_urb_submit(capsubs, capsubs->completed_urb, frame);
+		if (err)
+			return err;
+		if (capsubs2) {
+			err = usx2y_urb_submit(capsubs2, capsubs2->completed_urb, frame);
+			if (err)
+				return err;
+		}
+	}
+	capsubs->completed_urb = NULL;
+	if (capsubs2)
+		capsubs2->completed_urb = NULL;
+	return 0;
+}
+
+static void i_usx2y_usbpcm_urb_complete(struct urb *urb)
+{
+	struct snd_usx2y_substream *subs = urb->context;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *capsubs, *capsubs2, *playbacksubs;
+
+	if (unlikely(atomic_read(&subs->state) < STATE_PREPARED)) {
+		snd_printdd("hcd_frame=%i ep=%i%s status=%i start_frame=%i\n",
+			    usb_get_current_frame_number(usx2y->dev),
+			    subs->endpoint, usb_pipein(urb->pipe) ? "in" : "out",
+			    urb->status, urb->start_frame);
+		return;
+	}
+	if (unlikely(urb->status)) {
+		usx2y_error_urb_status(usx2y, subs, urb);
+		return;
+	}
+
+	subs->completed_urb = urb;
+	capsubs = usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+	capsubs2 = usx2y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
+	playbacksubs = usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+	if (capsubs->completed_urb && atomic_read(&capsubs->state) >= STATE_PREPARED &&
+	    (!capsubs2 || capsubs2->completed_urb) &&
+	    (playbacksubs->completed_urb || atomic_read(&playbacksubs->state) < STATE_PREPARED)) {
+		if (!usx2y_usbpcm_usbframe_complete(capsubs, capsubs2, playbacksubs, urb->start_frame)) {
+			usx2y->wait_iso_frame += nr_of_packs();
+		} else {
+			snd_printdd("\n");
+			usx2y_clients_stop(usx2y);
+		}
+	}
+}
+
+static void usx2y_hwdep_urb_release(struct urb **urb)
+{
+	usb_kill_urb(*urb);
+	usb_free_urb(*urb);
+	*urb = NULL;
+}
+
+/*
+ * release a substream
+ */
+static void usx2y_usbpcm_urbs_release(struct snd_usx2y_substream *subs)
+{
+	int i;
+
+	snd_printdd("snd_usx2y_urbs_release() %i\n", subs->endpoint);
+	for (i = 0; i < NRURBS; i++)
+		usx2y_hwdep_urb_release(subs->urb + i);
+}
+
+static void usx2y_usbpcm_subs_startup_finish(struct usx2ydev *usx2y)
+{
+	usx2y_urbs_set_complete(usx2y, i_usx2y_usbpcm_urb_complete);
+	usx2y->prepare_subs = NULL;
+}
+
+static void i_usx2y_usbpcm_subs_startup(struct urb *urb)
+{
+	struct snd_usx2y_substream *subs = urb->context;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *prepare_subs = usx2y->prepare_subs;
+	struct snd_usx2y_substream *cap_subs2;
+
+	if (prepare_subs &&
+	    urb->start_frame == prepare_subs->urb[0]->start_frame) {
+		atomic_inc(&prepare_subs->state);
+		if (prepare_subs == usx2y->subs[SNDRV_PCM_STREAM_CAPTURE]) {
+			cap_subs2 = usx2y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
+			if (cap_subs2)
+				atomic_inc(&cap_subs2->state);
+		}
+		usx2y_usbpcm_subs_startup_finish(usx2y);
+		wake_up(&usx2y->prepare_wait_queue);
+	}
+
+	i_usx2y_usbpcm_urb_complete(urb);
+}
+
+/*
+ * initialize a substream's urbs
+ */
+static int usx2y_usbpcm_urbs_allocate(struct snd_usx2y_substream *subs)
+{
+	int i;
+	unsigned int pipe;
+	int is_playback = subs == subs->usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+	struct usb_device *dev = subs->usx2y->dev;
+	struct urb **purb;
+
+	pipe = is_playback ? usb_sndisocpipe(dev, subs->endpoint) :
+			usb_rcvisocpipe(dev, subs->endpoint);
+	subs->maxpacksize = usb_maxpacket(dev, pipe);
+	if (!subs->maxpacksize)
+		return -EINVAL;
+
+	/* allocate and initialize data urbs */
+	for (i = 0; i < NRURBS; i++) {
+		purb = subs->urb + i;
+		if (*purb) {
+			usb_kill_urb(*purb);
+			continue;
+		}
+		*purb = usb_alloc_urb(nr_of_packs(), GFP_KERNEL);
+		if (!*purb) {
+			usx2y_usbpcm_urbs_release(subs);
+			return -ENOMEM;
+		}
+		(*purb)->transfer_buffer = is_playback ?
+			subs->usx2y->hwdep_pcm_shm->playback : (
+				subs->endpoint == 0x8 ?
+				subs->usx2y->hwdep_pcm_shm->capture0x8 :
+				subs->usx2y->hwdep_pcm_shm->capture0xA);
+
+		(*purb)->dev = dev;
+		(*purb)->pipe = pipe;
+		(*purb)->number_of_packets = nr_of_packs();
+		(*purb)->context = subs;
+		(*purb)->interval = 1;
+		(*purb)->complete = i_usx2y_usbpcm_subs_startup;
+	}
+	return 0;
+}
+
+/*
+ * free the buffer
+ */
+static int snd_usx2y_usbpcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+	struct snd_usx2y_substream *cap_subs;
+	struct snd_usx2y_substream *playback_subs;
+	struct snd_usx2y_substream *cap_subs2;
+
+	mutex_lock(&subs->usx2y->pcm_mutex);
+	snd_printdd("%s(%p)\n", __func__, substream);
+
+	cap_subs2 = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE + 2];
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		cap_subs = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+		atomic_set(&subs->state, STATE_STOPPED);
+		usx2y_usbpcm_urbs_release(subs);
+		if (!cap_subs->pcm_substream ||
+		    !cap_subs->pcm_substream->runtime ||
+		    cap_subs->pcm_substream->runtime->state < SNDRV_PCM_STATE_PREPARED) {
+			atomic_set(&cap_subs->state, STATE_STOPPED);
+			if (cap_subs2)
+				atomic_set(&cap_subs2->state, STATE_STOPPED);
+			usx2y_usbpcm_urbs_release(cap_subs);
+			if (cap_subs2)
+				usx2y_usbpcm_urbs_release(cap_subs2);
+		}
+	} else {
+		playback_subs = subs->usx2y->subs[SNDRV_PCM_STREAM_PLAYBACK];
+		if (atomic_read(&playback_subs->state) < STATE_PREPARED) {
+			atomic_set(&subs->state, STATE_STOPPED);
+			if (cap_subs2)
+				atomic_set(&cap_subs2->state, STATE_STOPPED);
+			usx2y_usbpcm_urbs_release(subs);
+			if (cap_subs2)
+				usx2y_usbpcm_urbs_release(cap_subs2);
+		}
+	}
+	mutex_unlock(&subs->usx2y->pcm_mutex);
+	return 0;
+}
+
+static void usx2y_usbpcm_subs_startup(struct snd_usx2y_substream *subs)
+{
+	struct usx2ydev *usx2y = subs->usx2y;
+
+	usx2y->prepare_subs = subs;
+	subs->urb[0]->start_frame = -1;
+	smp_wmb();	// Make sure above modifications are seen by i_usx2y_subs_startup()
+	usx2y_urbs_set_complete(usx2y, i_usx2y_usbpcm_subs_startup);
+}
+
+static int usx2y_usbpcm_urbs_start(struct snd_usx2y_substream *subs)
+{
+	int	p, u, err, stream = subs->pcm_substream->stream;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct urb *urb;
+	unsigned long pack;
+
+	if (stream == SNDRV_PCM_STREAM_CAPTURE) {
+		usx2y->hwdep_pcm_shm->captured_iso_head = -1;
+		usx2y->hwdep_pcm_shm->captured_iso_frames = 0;
+	}
+
+	for (p = 0; 3 >= (stream + p); p += 2) {
+		struct snd_usx2y_substream *subs = usx2y->subs[stream + p];
+		if (subs) {
+			err = usx2y_usbpcm_urbs_allocate(subs);
+			if (err < 0)
+				return err;
+			subs->completed_urb = NULL;
+		}
+	}
+
+	for (p = 0; p < 4; p++) {
+		struct snd_usx2y_substream *subs = usx2y->subs[p];
+
+		if (subs && atomic_read(&subs->state) >= STATE_PREPARED)
+			goto start;
+	}
+
+ start:
+	usx2y_usbpcm_subs_startup(subs);
+	for (u = 0; u < NRURBS; u++) {
+		for (p = 0; 3 >= (stream + p); p += 2) {
+			struct snd_usx2y_substream *subs = usx2y->subs[stream + p];
+
+			if (!subs)
+				continue;
+			urb = subs->urb[u];
+			if (usb_pipein(urb->pipe)) {
+				if (!u)
+					atomic_set(&subs->state, STATE_STARTING3);
+				urb->dev = usx2y->dev;
+				for (pack = 0; pack < nr_of_packs(); pack++) {
+					urb->iso_frame_desc[pack].offset = subs->maxpacksize * (pack + u * nr_of_packs());
+					urb->iso_frame_desc[pack].length = subs->maxpacksize;
+				}
+				urb->transfer_buffer_length = subs->maxpacksize * nr_of_packs();
+				err = usb_submit_urb(urb, GFP_KERNEL);
+				if (err < 0) {
+					snd_printk(KERN_ERR "cannot usb_submit_urb() for urb %d, err = %d\n", u, err);
+					err = -EPIPE;
+					goto cleanup;
+				}  else {
+					snd_printdd("%i\n", urb->start_frame);
+					if (!u)
+						usx2y->wait_iso_frame = urb->start_frame;
+				}
+				urb->transfer_flags = 0;
+			} else {
+				atomic_set(&subs->state, STATE_STARTING1);
+				break;
+			}
+		}
+	}
+	err = 0;
+	wait_event(usx2y->prepare_wait_queue, !usx2y->prepare_subs);
+	if (atomic_read(&subs->state) != STATE_PREPARED)
+		err = -EPIPE;
+
+ cleanup:
+	if (err) {
+		usx2y_subs_startup_finish(usx2y);	// Call it now
+		usx2y_clients_stop(usx2y);	// something is completely wrong > stop everything
+	}
+	return err;
+}
+
+#define USX2Y_HWDEP_PCM_PAGES	\
+	PAGE_ALIGN(sizeof(struct snd_usx2y_hwdep_pcm_shm))
+
+/*
+ * prepare callback
+ *
+ * set format and initialize urbs
+ */
+static int snd_usx2y_usbpcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+	struct usx2ydev *usx2y = subs->usx2y;
+	struct snd_usx2y_substream *capsubs = subs->usx2y->subs[SNDRV_PCM_STREAM_CAPTURE];
+	int err = 0;
+
+	snd_printdd("snd_usx2y_pcm_prepare(%p)\n", substream);
+
+	mutex_lock(&usx2y->pcm_mutex);
+
+	if (!usx2y->hwdep_pcm_shm) {
+		usx2y->hwdep_pcm_shm = alloc_pages_exact(USX2Y_HWDEP_PCM_PAGES,
+							 GFP_KERNEL);
+		if (!usx2y->hwdep_pcm_shm) {
+			err = -ENOMEM;
+			goto up_prepare_mutex;
+		}
+		memset(usx2y->hwdep_pcm_shm, 0, USX2Y_HWDEP_PCM_PAGES);
+	}
+
+	usx2y_subs_prepare(subs);
+	// Start hardware streams
+	// SyncStream first....
+	if (atomic_read(&capsubs->state) < STATE_PREPARED) {
+		if (usx2y->format != runtime->format) {
+			err = usx2y_format_set(usx2y, runtime->format);
+			if (err < 0)
+				goto up_prepare_mutex;
+		}
+		if (usx2y->rate != runtime->rate) {
+			err = usx2y_rate_set(usx2y, runtime->rate);
+			if (err < 0)
+				goto up_prepare_mutex;
+		}
+		snd_printdd("starting capture pipe for %s\n", subs == capsubs ?
+			    "self" : "playpipe");
+		err = usx2y_usbpcm_urbs_start(capsubs);
+		if (err < 0)
+			goto up_prepare_mutex;
+	}
+
+	if (subs != capsubs) {
+		usx2y->hwdep_pcm_shm->playback_iso_start = -1;
+		if (atomic_read(&subs->state) < STATE_PREPARED) {
+			while (usx2y_iso_frames_per_buffer(runtime, usx2y) >
+			       usx2y->hwdep_pcm_shm->captured_iso_frames) {
+				snd_printdd("Wait: iso_frames_per_buffer=%i,captured_iso_frames=%i\n",
+					    usx2y_iso_frames_per_buffer(runtime, usx2y),
+					    usx2y->hwdep_pcm_shm->captured_iso_frames);
+				if (msleep_interruptible(10)) {
+					err = -ERESTARTSYS;
+					goto up_prepare_mutex;
+				}
+			}
+			err = usx2y_usbpcm_urbs_start(subs);
+			if (err < 0)
+				goto up_prepare_mutex;
+		}
+		snd_printdd("Ready: iso_frames_per_buffer=%i,captured_iso_frames=%i\n",
+			    usx2y_iso_frames_per_buffer(runtime, usx2y),
+			    usx2y->hwdep_pcm_shm->captured_iso_frames);
+	} else {
+		usx2y->hwdep_pcm_shm->capture_iso_start = -1;
+	}
+
+ up_prepare_mutex:
+	mutex_unlock(&usx2y->pcm_mutex);
+	return err;
+}
+
+static const struct snd_pcm_hardware snd_usx2y_4c = {
+	.info =			(SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
+				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
+				 SNDRV_PCM_INFO_MMAP_VALID),
+	.formats =                 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_3LE,
+	.rates =                   SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000,
+	.rate_min =                44100,
+	.rate_max =                48000,
+	.channels_min =            2,
+	.channels_max =            4,
+	.buffer_bytes_max =	(2*128*1024),
+	.period_bytes_min =	64,
+	.period_bytes_max =	(128*1024),
+	.periods_min =		2,
+	.periods_max =		1024,
+	.fifo_size =              0
+};
+
+static int snd_usx2y_usbpcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_usx2y_substream	*subs =
+		((struct snd_usx2y_substream **)
+		 snd_pcm_substream_chip(substream))[substream->stream];
+	struct snd_pcm_runtime	*runtime = substream->runtime;
+
+	if (!(subs->usx2y->chip_status & USX2Y_STAT_CHIP_MMAP_PCM_URBS))
+		return -EBUSY;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		runtime->hw = snd_usx2y_2c;
+	else
+		runtime->hw = (subs->usx2y->subs[3] ? snd_usx2y_4c : snd_usx2y_2c);
+	runtime->private_data = subs;
+	subs->pcm_substream = substream;
+	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME, 1000, 200000);
+	return 0;
+}
+
+static int snd_usx2y_usbpcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usx2y_substream *subs = runtime->private_data;
+
+	subs->pcm_substream = NULL;
+	return 0;
+}
+
+static const struct snd_pcm_ops snd_usx2y_usbpcm_ops = {
+	.open =		snd_usx2y_usbpcm_open,
+	.close =	snd_usx2y_usbpcm_close,
+	.hw_params =	snd_usx2y_pcm_hw_params,
+	.hw_free =	snd_usx2y_usbpcm_hw_free,
+	.prepare =	snd_usx2y_usbpcm_prepare,
+	.trigger =	snd_usx2y_pcm_trigger,
+	.pointer =	snd_usx2y_pcm_pointer,
+};
+
+static int usx2y_pcms_busy_check(struct snd_card *card)
+{
+	struct usx2ydev	*dev = usx2y(card);
+	struct snd_usx2y_substream *subs;
+	int i;
+
+	for (i = 0; i < dev->pcm_devs * 2; i++) {
+		subs = dev->subs[i];
+		if (subs && subs->pcm_substream &&
+		    SUBSTREAM_BUSY(subs->pcm_substream))
+			return -EBUSY;
+	}
+	return 0;
+}
+
+static int snd_usx2y_hwdep_pcm_open(struct snd_hwdep *hw, struct file *file)
+{
+	struct snd_card *card = hw->card;
+	int err;
+
+	mutex_lock(&usx2y(card)->pcm_mutex);
+	err = usx2y_pcms_busy_check(card);
+	if (!err)
+		usx2y(card)->chip_status |= USX2Y_STAT_CHIP_MMAP_PCM_URBS;
+	mutex_unlock(&usx2y(card)->pcm_mutex);
+	return err;
+}
+
+static int snd_usx2y_hwdep_pcm_release(struct snd_hwdep *hw, struct file *file)
+{
+	struct snd_card *card = hw->card;
+	int err;
+
+	mutex_lock(&usx2y(card)->pcm_mutex);
+	err = usx2y_pcms_busy_check(card);
+	if (!err)
+		usx2y(hw->card)->chip_status &= ~USX2Y_STAT_CHIP_MMAP_PCM_URBS;
+	mutex_unlock(&usx2y(card)->pcm_mutex);
+	return err;
+}
+
+static void snd_usx2y_hwdep_pcm_vm_open(struct vm_area_struct *area)
+{
+}
+
+static void snd_usx2y_hwdep_pcm_vm_close(struct vm_area_struct *area)
+{
+}
+
+static vm_fault_t snd_usx2y_hwdep_pcm_vm_fault(struct vm_fault *vmf)
+{
+	unsigned long offset;
+	void *vaddr;
+
+	offset = vmf->pgoff << PAGE_SHIFT;
+	vaddr = (char *)((struct usx2ydev *)vmf->vma->vm_private_data)->hwdep_pcm_shm + offset;
+	vmf->page = virt_to_page(vaddr);
+	get_page(vmf->page);
+	return 0;
+}
+
+static const struct vm_operations_struct snd_usx2y_hwdep_pcm_vm_ops = {
+	.open = snd_usx2y_hwdep_pcm_vm_open,
+	.close = snd_usx2y_hwdep_pcm_vm_close,
+	.fault = snd_usx2y_hwdep_pcm_vm_fault,
+};
+
+static int snd_usx2y_hwdep_pcm_mmap(struct snd_hwdep *hw, struct file *filp, struct vm_area_struct *area)
+{
+	unsigned long	size = (unsigned long)(area->vm_end - area->vm_start);
+	struct usx2ydev	*usx2y = hw->private_data;
+
+	if (!(usx2y->chip_status & USX2Y_STAT_CHIP_INIT))
+		return -EBUSY;
+
+	/* if userspace tries to mmap beyond end of our buffer, fail */
+	if (size > USX2Y_HWDEP_PCM_PAGES) {
+		snd_printd("%lu > %lu\n", size, (unsigned long)USX2Y_HWDEP_PCM_PAGES);
+		return -EINVAL;
+	}
+
+	if (!usx2y->hwdep_pcm_shm)
+		return -ENODEV;
+
+	area->vm_ops = &snd_usx2y_hwdep_pcm_vm_ops;
+	area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+	area->vm_private_data = hw->private_data;
+	return 0;
+}
+
+static void snd_usx2y_hwdep_pcm_private_free(struct snd_hwdep *hwdep)
+{
+	struct usx2ydev *usx2y = hwdep->private_data;
+
+	if (usx2y->hwdep_pcm_shm)
+		free_pages_exact(usx2y->hwdep_pcm_shm, USX2Y_HWDEP_PCM_PAGES);
+}
+
+int usx2y_hwdep_pcm_new(struct snd_card *card)
+{
+	int err;
+	struct snd_hwdep *hw;
+	struct snd_pcm *pcm;
+	struct usb_device *dev = usx2y(card)->dev;
+
+	if (nr_of_packs() != 1)
+		return 0;
+
+	err = snd_hwdep_new(card, SND_USX2Y_USBPCM_ID, 1, &hw);
+	if (err < 0)
+		return err;
+
+	hw->iface = SNDRV_HWDEP_IFACE_USX2Y_PCM;
+	hw->private_data = usx2y(card);
+	hw->private_free = snd_usx2y_hwdep_pcm_private_free;
+	hw->ops.open = snd_usx2y_hwdep_pcm_open;
+	hw->ops.release = snd_usx2y_hwdep_pcm_release;
+	hw->ops.mmap = snd_usx2y_hwdep_pcm_mmap;
+	hw->exclusive = 1;
+	sprintf(hw->name, "/dev/bus/usb/%03d/%03d/hwdeppcm", dev->bus->busnum, dev->devnum);
+
+	err = snd_pcm_new(card, NAME_ALLCAPS" hwdep Audio", 2, 1, 1, &pcm);
+	if (err < 0)
+		return err;
+
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_usx2y_usbpcm_ops);
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_usx2y_usbpcm_ops);
+
+	pcm->private_data = usx2y(card)->subs;
+	pcm->info_flags = 0;
+
+	sprintf(pcm->name, NAME_ALLCAPS" hwdep Audio");
+	snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream,
+				   SNDRV_DMA_TYPE_CONTINUOUS,
+				   NULL,
+				   64*1024, 128*1024);
+	snd_pcm_set_managed_buffer(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
+				   SNDRV_DMA_TYPE_CONTINUOUS,
+				   NULL,
+				   64*1024, 128*1024);
+
+	return 0;
+}
+
+#else
+
+int usx2y_hwdep_pcm_new(struct snd_card *card)
+{
+	return 0;
+}
+
+#endif