Add M2Tech hiFace USB-SPDIF driver

Add driver for M2Tech hiFace USB-SPDIF interface and compatible devices.

M2Tech hiFace and compatible devices offer a Hi-End S/PDIF Output
Interface, see http://www.m2tech.biz/hiface.html

The supported products are:

  * M2Tech Young
  * M2Tech hiFace
  * M2Tech North Star
  * M2Tech W4S Young
  * M2Tech Corrson
  * M2Tech AUDIA
  * M2Tech SL Audio
  * M2Tech Empirical
  * M2Tech Rockna
  * M2Tech Pathos
  * M2Tech Metronome
  * M2Tech CAD
  * M2Tech Audio Esclusive
  * M2Tech Rotel
  * M2Tech Eeaudio
  * The Chord Company CHORD
  * AVA Group A/S Vitus

Signed-off-by: Antonio Ospite <ao2@amarulasolutions.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

7 files changed, 1006 insertions, 1 deletions

diff --git a/sound/usb/Kconfig b/sound/usb/Kconfig
index 225dfd737265..de9408b83f75 100644
--- a/sound/usb/Kconfig
+++ b/sound/usb/Kconfig
@@ -115,5 +115,36 @@ config SND_USB_6FIRE
           and further help can be found at
           http://sixfireusb.sourceforge.net
 
+config SND_USB_HIFACE
+        tristate "M2Tech hiFace USB-SPDIF driver"
+        select SND_PCM
+        help
+          Select this option to include support for M2Tech hiFace USB-SPDIF
+          interface.
+
+          This driver supports the original M2Tech hiFace and some other
+          compatible devices. The supported products are:
+
+            * M2Tech Young
+            * M2Tech hiFace
+            * M2Tech North Star
+            * M2Tech W4S Young
+            * M2Tech Corrson
+            * M2Tech AUDIA
+            * M2Tech SL Audio
+            * M2Tech Empirical
+            * M2Tech Rockna
+            * M2Tech Pathos
+            * M2Tech Metronome
+            * M2Tech CAD
+            * M2Tech Audio Esclusive
+            * M2Tech Rotel
+            * M2Tech Eeaudio
+            * The Chord Company CHORD
+            * AVA Group A/S Vitus
+
+          To compile this driver as a module, choose M here: the module
+          will be called snd-usb-hiface.
+
 endif   # SND_USB
 
diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index ac256dc4c6be..abe668f660d1 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -23,4 +23,4 @@ obj-$(CONFIG_SND_USB_UA101) += snd-usbmidi-lib.o
 obj-$(CONFIG_SND_USB_USX2Y) += snd-usbmidi-lib.o
 obj-$(CONFIG_SND_USB_US122L) += snd-usbmidi-lib.o
 
-obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/
+obj-$(CONFIG_SND) += misc/ usx2y/ caiaq/ 6fire/ hiface/
diff --git a/sound/usb/hiface/Makefile b/sound/usb/hiface/Makefile
new file mode 100644
index 000000000000..463b136d1d89
--- /dev/null
+++ b/sound/usb/hiface/Makefile
@@ -0,0 +1,2 @@
+snd-usb-hiface-objs := chip.o pcm.o
+obj-$(CONFIG_SND_USB_HIFACE) += snd-usb-hiface.o
diff --git a/sound/usb/hiface/chip.c b/sound/usb/hiface/chip.c
new file mode 100644
index 000000000000..b0dcb3924ce5
--- /dev/null
+++ b/sound/usb/hiface/chip.c
@@ -0,0 +1,297 @@
+/*
+ * Linux driver for M2Tech hiFace compatible devices
+ *
+ * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
+ *
+ * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
+ *           Antonio Ospite <ao2@amarulasolutions.com>
+ *
+ * The driver is based on the work done in TerraTec DMX 6Fire USB
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <sound/initval.h>
+
+#include "chip.h"
+#include "pcm.h"
+
+MODULE_AUTHOR("Michael Trimarchi <michael@amarulasolutions.com>");
+MODULE_AUTHOR("Antonio Ospite <ao2@amarulasolutions.com>");
+MODULE_DESCRIPTION("M2Tech hiFace USB-SPDIF audio driver");
+MODULE_LICENSE("GPL v2");
+MODULE_SUPPORTED_DEVICE("{{M2Tech,Young},"
+                         "{M2Tech,hiFace},"
+                         "{M2Tech,North Star},"
+                         "{M2Tech,W4S Young},"
+                         "{M2Tech,Corrson},"
+                         "{M2Tech,AUDIA},"
+                         "{M2Tech,SL Audio},"
+                         "{M2Tech,Empirical},"
+                         "{M2Tech,Rockna},"
+                         "{M2Tech,Pathos},"
+                         "{M2Tech,Metronome},"
+                         "{M2Tech,CAD},"
+                         "{M2Tech,Audio Esclusive},"
+                         "{M2Tech,Rotel},"
+                         "{M2Tech,Eeaudio},"
+                         "{The Chord Company,CHORD},"
+                         "{AVA Group A/S,Vitus}}");
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-max */
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* Id for card */
+static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP; /* Enable this card */
+
+#define DRIVER_NAME "snd-usb-hiface"
+#define CARD_NAME "hiFace"
+
+module_param_array(index, int, NULL, 0444);
+MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard.");
+module_param_array(id, charp, NULL, 0444);
+MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard.");
+module_param_array(enable, bool, NULL, 0444);
+MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");
+
+static DEFINE_MUTEX(register_mutex);
+
+struct hiface_vendor_quirk {
+        const char *device_name;
+        u8 extra_freq;
+};
+
+static int hiface_chip_create(struct usb_device *device, int idx,
+                              const struct hiface_vendor_quirk *quirk,
+                              struct hiface_chip **rchip)
+{
+        struct snd_card *card = NULL;
+        struct hiface_chip *chip;
+        int ret;
+        int len;
+
+        *rchip = NULL;
+
+        /* if we are here, card can be registered in alsa. */
+        ret = snd_card_create(index[idx], id[idx], THIS_MODULE, sizeof(*chip), &card);
+        if (ret < 0) {
+                dev_err(&device->dev, "cannot create alsa card.\n");
+                return ret;
+        }
+
+        strlcpy(card->driver, DRIVER_NAME, sizeof(card->driver));
+
+        if (quirk && quirk->device_name)
+                strlcpy(card->shortname, quirk->device_name, sizeof(card->shortname));
+        else
+                strlcpy(card->shortname, "M2Tech generic audio", sizeof(card->shortname));
+
+        strlcat(card->longname, card->shortname, sizeof(card->longname));
+        len = strlcat(card->longname, " at ", sizeof(card->longname));
+        if (len < sizeof(card->longname))
+                usb_make_path(device, card->longname + len,
+                              sizeof(card->longname) - len);
+
+        chip = card->private_data;
+        chip->dev = device;
+        chip->card = card;
+
+        *rchip = chip;
+        return 0;
+}
+
+static int hiface_chip_probe(struct usb_interface *intf,
+                             const struct usb_device_id *usb_id)
+{
+        const struct hiface_vendor_quirk *quirk = (struct hiface_vendor_quirk *)usb_id->driver_info;
+        int ret;
+        int i;
+        struct hiface_chip *chip;
+        struct usb_device *device = interface_to_usbdev(intf);
+
+        ret = usb_set_interface(device, 0, 0);
+        if (ret != 0) {
+                dev_err(&device->dev, "can't set first interface for " CARD_NAME " device.\n");
+                return -EIO;
+        }
+
+        /* check whether the card is already registered */
+        chip = NULL;
+        mutex_lock(&register_mutex);
+
+        for (i = 0; i < SNDRV_CARDS; i++)
+                if (enable[i])
+                        break;
+
+        if (i >= SNDRV_CARDS) {
+                dev_err(&device->dev, "no available " CARD_NAME " audio device\n");
+                ret = -ENODEV;
+                goto err;
+        }
+
+        ret = hiface_chip_create(device, i, quirk, &chip);
+        if (ret < 0)
+                goto err;
+
+        snd_card_set_dev(chip->card, &intf->dev);
+
+        ret = hiface_pcm_init(chip, quirk ? quirk->extra_freq : 0);
+        if (ret < 0)
+                goto err_chip_destroy;
+
+        ret = snd_card_register(chip->card);
+        if (ret < 0) {
+                dev_err(&device->dev, "cannot register " CARD_NAME " card\n");
+                goto err_chip_destroy;
+        }
+
+        mutex_unlock(&register_mutex);
+
+        usb_set_intfdata(intf, chip);
+        return 0;
+
+err_chip_destroy:
+        snd_card_free(chip->card);
+err:
+        mutex_unlock(&register_mutex);
+        return ret;
+}
+
+static void hiface_chip_disconnect(struct usb_interface *intf)
+{
+        struct hiface_chip *chip;
+        struct snd_card *card;
+
+        chip = usb_get_intfdata(intf);
+        if (!chip)
+                return;
+
+        card = chip->card;
+
+        /* Make sure that the userspace cannot create new request */
+        snd_card_disconnect(card);
+
+        hiface_pcm_abort(chip);
+        snd_card_free_when_closed(card);
+}
+
+static const struct usb_device_id device_table[] = {
+        {
+                USB_DEVICE(0x04b4, 0x0384),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Young",
+                        .extra_freq = 1,
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x930b),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "hiFace",
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x931b),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "North Star",
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x931c),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "W4S Young",
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x931d),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Corrson",
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x931e),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "AUDIA",
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x931f),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "SL Audio",
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x9320),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Empirical",
+                }
+        },
+        {
+                USB_DEVICE(0x04b4, 0x9321),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Rockna",
+                }
+        },
+        {
+                USB_DEVICE(0x249c, 0x9001),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Pathos",
+                }
+        },
+        {
+                USB_DEVICE(0x249c, 0x9002),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Metronome",
+                }
+        },
+        {
+                USB_DEVICE(0x249c, 0x9006),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "CAD",
+                }
+        },
+        {
+                USB_DEVICE(0x249c, 0x9008),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Audio Esclusive",
+                }
+        },
+        {
+                USB_DEVICE(0x249c, 0x931c),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Rotel",
+                }
+        },
+        {
+                USB_DEVICE(0x249c, 0x932c),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Eeaudio",
+                }
+        },
+        {
+                USB_DEVICE(0x245f, 0x931c),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "CHORD",
+                }
+        },
+        {
+                USB_DEVICE(0x25c6, 0x9002),
+                .driver_info = (unsigned long)&(const struct hiface_vendor_quirk) {
+                        .device_name = "Vitus",
+                }
+        },
+        {}
+};
+
+MODULE_DEVICE_TABLE(usb, device_table);
+
+static struct usb_driver hiface_usb_driver = {
+        .name = DRIVER_NAME,
+        .probe = hiface_chip_probe,
+        .disconnect = hiface_chip_disconnect,
+        .id_table = device_table,
+};
+
+module_usb_driver(hiface_usb_driver);
diff --git a/sound/usb/hiface/chip.h b/sound/usb/hiface/chip.h
new file mode 100644
index 000000000000..189a1371b7c4
--- /dev/null
+++ b/sound/usb/hiface/chip.h
@@ -0,0 +1,30 @@
+/*
+ * Linux driver for M2Tech hiFace compatible devices
+ *
+ * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
+ *
+ * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
+ *           Antonio Ospite <ao2@amarulasolutions.com>
+ *
+ * The driver is based on the work done in TerraTec DMX 6Fire USB
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef HIFACE_CHIP_H
+#define HIFACE_CHIP_H
+
+#include <linux/usb.h>
+#include <sound/core.h>
+
+struct pcm_runtime;
+
+struct hiface_chip {
+        struct usb_device *dev;
+        struct snd_card *card;
+        struct pcm_runtime *pcm;
+};
+#endif /* HIFACE_CHIP_H */
diff --git a/sound/usb/hiface/pcm.c b/sound/usb/hiface/pcm.c
new file mode 100644
index 000000000000..6430ed2a9f65
--- /dev/null
+++ b/sound/usb/hiface/pcm.c
@@ -0,0 +1,621 @@
+/*
+ * Linux driver for M2Tech hiFace compatible devices
+ *
+ * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
+ *
+ * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
+ *           Antonio Ospite <ao2@amarulasolutions.com>
+ *
+ * The driver is based on the work done in TerraTec DMX 6Fire USB
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/slab.h>
+#include <sound/pcm.h>
+
+#include "pcm.h"
+#include "chip.h"
+
+#define OUT_EP          0x2
+#define PCM_N_URBS      8
+#define PCM_PACKET_SIZE 4096
+#define PCM_BUFFER_SIZE (2 * PCM_N_URBS * PCM_PACKET_SIZE)
+
+struct pcm_urb {
+        struct hiface_chip *chip;
+
+        struct urb instance;
+        struct usb_anchor submitted;
+        u8 *buffer;
+};
+
+struct pcm_substream {
+        spinlock_t lock;
+        struct snd_pcm_substream *instance;
+
+        bool active;
+        snd_pcm_uframes_t dma_off;    /* current position in alsa dma_area */
+        snd_pcm_uframes_t period_off; /* current position in current period */
+};
+
+enum { /* pcm streaming states */
+        STREAM_DISABLED, /* no pcm streaming */
+        STREAM_STARTING, /* pcm streaming requested, waiting to become ready */
+        STREAM_RUNNING,  /* pcm streaming running */
+        STREAM_STOPPING
+};
+
+struct pcm_runtime {
+        struct hiface_chip *chip;
+        struct snd_pcm *instance;
+
+        struct pcm_substream playback;
+        bool panic; /* if set driver won't do anymore pcm on device */
+
+        struct pcm_urb out_urbs[PCM_N_URBS];
+
+        struct mutex stream_mutex;
+        u8 stream_state; /* one of STREAM_XXX */
+        u8 extra_freq;
+        wait_queue_head_t stream_wait_queue;
+        bool stream_wait_cond;
+};
+
+static const unsigned int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000,
+                                      352800, 384000 };
+static const struct snd_pcm_hw_constraint_list constraints_extra_rates = {
+        .count = ARRAY_SIZE(rates),
+        .list = rates,
+        .mask = 0,
+};
+
+static const struct snd_pcm_hardware pcm_hw = {
+        .info = SNDRV_PCM_INFO_MMAP |
+                SNDRV_PCM_INFO_INTERLEAVED |
+                SNDRV_PCM_INFO_BLOCK_TRANSFER |
+                SNDRV_PCM_INFO_PAUSE |
+                SNDRV_PCM_INFO_MMAP_VALID |
+                SNDRV_PCM_INFO_BATCH,
+
+        .formats = SNDRV_PCM_FMTBIT_S32_LE,
+
+        .rates = SNDRV_PCM_RATE_44100 |
+                SNDRV_PCM_RATE_48000 |
+                SNDRV_PCM_RATE_88200 |
+                SNDRV_PCM_RATE_96000 |
+                SNDRV_PCM_RATE_176400 |
+                SNDRV_PCM_RATE_192000,
+
+        .rate_min = 44100,
+        .rate_max = 192000, /* changes in hiface_pcm_open to support extra rates */
+        .channels_min = 2,
+        .channels_max = 2,
+        .buffer_bytes_max = PCM_BUFFER_SIZE,
+        .period_bytes_min = PCM_PACKET_SIZE,
+        .period_bytes_max = PCM_BUFFER_SIZE,
+        .periods_min = 2,
+        .periods_max = 1024
+};
+
+/* message values used to change the sample rate */
+#define HIFACE_SET_RATE_REQUEST 0xb0
+
+#define HIFACE_RATE_44100  0x43
+#define HIFACE_RATE_48000  0x4b
+#define HIFACE_RATE_88200  0x42
+#define HIFACE_RATE_96000  0x4a
+#define HIFACE_RATE_176400 0x40
+#define HIFACE_RATE_192000 0x48
+#define HIFACE_RATE_352000 0x58
+#define HIFACE_RATE_384000 0x68
+
+static int hiface_pcm_set_rate(struct pcm_runtime *rt, unsigned int rate)
+{
+        struct usb_device *device = rt->chip->dev;
+        u16 rate_value;
+        int ret;
+
+        /* We are already sure that the rate is supported here thanks to
+         * ALSA constraints
+         */
+        switch (rate) {
+        case 44100:
+                rate_value = HIFACE_RATE_44100;
+                break;
+        case 48000:
+                rate_value = HIFACE_RATE_48000;
+                break;
+        case 88200:
+                rate_value = HIFACE_RATE_88200;
+                break;
+        case 96000:
+                rate_value = HIFACE_RATE_96000;
+                break;
+        case 176400:
+                rate_value = HIFACE_RATE_176400;
+                break;
+        case 192000:
+                rate_value = HIFACE_RATE_192000;
+                break;
+        case 352000:
+                rate_value = HIFACE_RATE_352000;
+                break;
+        case 384000:
+                rate_value = HIFACE_RATE_384000;
+                break;
+        default:
+                dev_err(&device->dev, "Unsupported rate %d\n", rate);
+                return -EINVAL;
+        }
+
+        /*
+         * USBIO: Vendor 0xb0(wValue=0x0043, wIndex=0x0000)
+         * 43 b0 43 00 00 00 00 00
+         * USBIO: Vendor 0xb0(wValue=0x004b, wIndex=0x0000)
+         * 43 b0 4b 00 00 00 00 00
+         * This control message doesn't have any ack from the
+         * other side
+         */
+        ret = usb_control_msg(device, usb_sndctrlpipe(device, 0),
+                              HIFACE_SET_RATE_REQUEST,
+                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
+                              rate_value, 0, NULL, 0, 100);
+        if (ret < 0) {
+                dev_err(&device->dev, "Error setting samplerate %d.\n", rate);
+                return ret;
+        }
+
+        return 0;
+}
+
+static struct pcm_substream *hiface_pcm_get_substream(struct snd_pcm_substream
+                                                      *alsa_sub)
+{
+        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
+        struct device *device = &rt->chip->dev->dev;
+
+        if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
+                return &rt->playback;
+
+        dev_err(device, "Error getting pcm substream slot.\n");
+        return NULL;
+}
+
+/* call with stream_mutex locked */
+static void hiface_pcm_stream_stop(struct pcm_runtime *rt)
+{
+        int i, time;
+
+        if (rt->stream_state != STREAM_DISABLED) {
+                rt->stream_state = STREAM_STOPPING;
+
+                for (i = 0; i < PCM_N_URBS; i++) {
+                        time = usb_wait_anchor_empty_timeout(
+                                        &rt->out_urbs[i].submitted, 100);
+                        if (!time)
+                                usb_kill_anchored_urbs(
+                                        &rt->out_urbs[i].submitted);
+                        usb_kill_urb(&rt->out_urbs[i].instance);
+                }
+
+                rt->stream_state = STREAM_DISABLED;
+        }
+}
+
+/* call with stream_mutex locked */
+static int hiface_pcm_stream_start(struct pcm_runtime *rt)
+{
+        int ret = 0;
+        int i;
+
+        if (rt->stream_state == STREAM_DISABLED) {
+
+                /* reset panic state when starting a new stream */
+                rt->panic = false;
+
+                /* submit our out urbs zero init */
+                rt->stream_state = STREAM_STARTING;
+                for (i = 0; i < PCM_N_URBS; i++) {
+                        memset(rt->out_urbs[i].buffer, 0, PCM_PACKET_SIZE);
+                        usb_anchor_urb(&rt->out_urbs[i].instance,
+                                       &rt->out_urbs[i].submitted);
+                        ret = usb_submit_urb(&rt->out_urbs[i].instance,
+                                             GFP_ATOMIC);
+                        if (ret) {
+                                hiface_pcm_stream_stop(rt);
+                                return ret;
+                        }
+                }
+
+                /* wait for first out urb to return (sent in in urb handler) */
+                wait_event_timeout(rt->stream_wait_queue, rt->stream_wait_cond,
+                                   HZ);
+                if (rt->stream_wait_cond) {
+                        struct device *device = &rt->chip->dev->dev;
+                        dev_dbg(device, "%s: Stream is running wakeup event\n",
+                                 __func__);
+                        rt->stream_state = STREAM_RUNNING;
+                } else {
+                        hiface_pcm_stream_stop(rt);
+                        return -EIO;
+                }
+        }
+        return ret;
+}
+
+/* The hardware wants word-swapped 32-bit values */
+static void memcpy_swahw32(u8 *dest, u8 *src, unsigned int n)
+{
+        unsigned int i;
+
+        for (i = 0; i < n / 4; i++)
+                ((u32 *)dest)[i] = swahw32(((u32 *)src)[i]);
+}
+
+/* call with substream locked */
+/* returns true if a period elapsed */
+static bool hiface_pcm_playback(struct pcm_substream *sub, struct pcm_urb *urb)
+{
+        struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
+        struct device *device = &urb->chip->dev->dev;
+        u8 *source;
+        unsigned int pcm_buffer_size;
+
+        WARN_ON(alsa_rt->format != SNDRV_PCM_FORMAT_S32_LE);
+
+        pcm_buffer_size = snd_pcm_lib_buffer_bytes(sub->instance);
+
+        if (sub->dma_off + PCM_PACKET_SIZE <= pcm_buffer_size) {
+                dev_dbg(device, "%s: (1) buffer_size %#x dma_offset %#x\n", __func__,
+                         (unsigned int) pcm_buffer_size,
+                         (unsigned int) sub->dma_off);
+
+                source = alsa_rt->dma_area + sub->dma_off;
+                memcpy_swahw32(urb->buffer, source, PCM_PACKET_SIZE);
+        } else {
+                /* wrap around at end of ring buffer */
+                unsigned int len;
+
+                dev_dbg(device, "%s: (2) buffer_size %#x dma_offset %#x\n", __func__,
+                         (unsigned int) pcm_buffer_size,
+                         (unsigned int) sub->dma_off);
+
+                len = pcm_buffer_size - sub->dma_off;
+
+                source = alsa_rt->dma_area + sub->dma_off;
+                memcpy_swahw32(urb->buffer, source, len);
+
+                source = alsa_rt->dma_area;
+                memcpy_swahw32(urb->buffer + len, source,
+                               PCM_PACKET_SIZE - len);
+        }
+        sub->dma_off += PCM_PACKET_SIZE;
+        if (sub->dma_off >= pcm_buffer_size)
+                sub->dma_off -= pcm_buffer_size;
+
+        sub->period_off += PCM_PACKET_SIZE;
+        if (sub->period_off >= alsa_rt->period_size) {
+                sub->period_off %= alsa_rt->period_size;
+                return true;
+        }
+        return false;
+}
+
+static void hiface_pcm_out_urb_handler(struct urb *usb_urb)
+{
+        struct pcm_urb *out_urb = usb_urb->context;
+        struct pcm_runtime *rt = out_urb->chip->pcm;
+        struct pcm_substream *sub;
+        bool do_period_elapsed = false;
+        unsigned long flags;
+        int ret;
+
+        if (rt->panic || rt->stream_state == STREAM_STOPPING)
+                return;
+
+        if (unlikely(usb_urb->status == -ENOENT ||      /* unlinked */
+                     usb_urb->status == -ENODEV ||      /* device removed */
+                     usb_urb->status == -ECONNRESET ||  /* unlinked */
+                     usb_urb->status == -ESHUTDOWN)) {  /* device disabled */
+                goto out_fail;
+        }
+
+        if (rt->stream_state == STREAM_STARTING) {
+                rt->stream_wait_cond = true;
+                wake_up(&rt->stream_wait_queue);
+        }
+
+        /* now send our playback data (if a free out urb was found) */
+        sub = &rt->playback;
+        spin_lock_irqsave(&sub->lock, flags);
+        if (sub->active)
+                do_period_elapsed = hiface_pcm_playback(sub, out_urb);
+        else
+                memset(out_urb->buffer, 0, PCM_PACKET_SIZE);
+
+        spin_unlock_irqrestore(&sub->lock, flags);
+
+        if (do_period_elapsed)
+                snd_pcm_period_elapsed(sub->instance);
+
+        ret = usb_submit_urb(&out_urb->instance, GFP_ATOMIC);
+        if (ret < 0)
+                goto out_fail;
+
+        return;
+
+out_fail:
+        rt->panic = true;
+}
+
+static int hiface_pcm_open(struct snd_pcm_substream *alsa_sub)
+{
+        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
+        struct pcm_substream *sub = NULL;
+        struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
+        int ret;
+
+        if (rt->panic)
+                return -EPIPE;
+
+        mutex_lock(&rt->stream_mutex);
+        alsa_rt->hw = pcm_hw;
+
+        if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
+                sub = &rt->playback;
+
+        if (!sub) {
+                struct device *device = &rt->chip->dev->dev;
+                mutex_unlock(&rt->stream_mutex);
+                dev_err(device, "Invalid stream type\n");
+                return -EINVAL;
+        }
+
+        if (rt->extra_freq) {
+                alsa_rt->hw.rates |= SNDRV_PCM_RATE_KNOT;
+                alsa_rt->hw.rate_max = 384000;
+
+                /* explicit constraints needed as we added SNDRV_PCM_RATE_KNOT */
+                ret = snd_pcm_hw_constraint_list(alsa_sub->runtime, 0,
+                                                 SNDRV_PCM_HW_PARAM_RATE,
+                                                 &constraints_extra_rates);
+                if (ret < 0) {
+                        mutex_unlock(&rt->stream_mutex);
+                        return ret;
+                }
+        }
+
+        sub->instance = alsa_sub;
+        sub->active = false;
+        mutex_unlock(&rt->stream_mutex);
+        return 0;
+}
+
+static int hiface_pcm_close(struct snd_pcm_substream *alsa_sub)
+{
+        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
+        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
+        unsigned long flags;
+
+        if (rt->panic)
+                return 0;
+
+        mutex_lock(&rt->stream_mutex);
+        if (sub) {
+                hiface_pcm_stream_stop(rt);
+
+                /* deactivate substream */
+                spin_lock_irqsave(&sub->lock, flags);
+                sub->instance = NULL;
+                sub->active = false;
+                spin_unlock_irqrestore(&sub->lock, flags);
+
+        }
+        mutex_unlock(&rt->stream_mutex);
+        return 0;
+}
+
+static int hiface_pcm_hw_params(struct snd_pcm_substream *alsa_sub,
+                                struct snd_pcm_hw_params *hw_params)
+{
+        return snd_pcm_lib_alloc_vmalloc_buffer(alsa_sub,
+                                                params_buffer_bytes(hw_params));
+}
+
+static int hiface_pcm_hw_free(struct snd_pcm_substream *alsa_sub)
+{
+        return snd_pcm_lib_free_vmalloc_buffer(alsa_sub);
+}
+
+static int hiface_pcm_prepare(struct snd_pcm_substream *alsa_sub)
+{
+        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
+        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
+        struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
+        int ret;
+
+        if (rt->panic)
+                return -EPIPE;
+        if (!sub)
+                return -ENODEV;
+
+        mutex_lock(&rt->stream_mutex);
+
+        sub->dma_off = 0;
+        sub->period_off = 0;
+
+        if (rt->stream_state == STREAM_DISABLED) {
+
+                ret = hiface_pcm_set_rate(rt, alsa_rt->rate);
+                if (ret) {
+                        mutex_unlock(&rt->stream_mutex);
+                        return ret;
+                }
+                ret = hiface_pcm_stream_start(rt);
+                if (ret) {
+                        mutex_unlock(&rt->stream_mutex);
+                        return ret;
+                }
+        }
+        mutex_unlock(&rt->stream_mutex);
+        return 0;
+}
+
+static int hiface_pcm_trigger(struct snd_pcm_substream *alsa_sub, int cmd)
+{
+        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
+        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
+
+        if (rt->panic)
+                return -EPIPE;
+        if (!sub)
+                return -ENODEV;
+
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+                spin_lock_irq(&sub->lock);
+                sub->active = true;
+                spin_unlock_irq(&sub->lock);
+                return 0;
+
+        case SNDRV_PCM_TRIGGER_STOP:
+        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+                spin_lock_irq(&sub->lock);
+                sub->active = false;
+                spin_unlock_irq(&sub->lock);
+                return 0;
+
+        default:
+                return -EINVAL;
+        }
+}
+
+static snd_pcm_uframes_t hiface_pcm_pointer(struct snd_pcm_substream *alsa_sub)
+{
+        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
+        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
+        unsigned long flags;
+        snd_pcm_uframes_t dma_offset;
+
+        if (rt->panic || !sub)
+                return SNDRV_PCM_STATE_XRUN;
+
+        spin_lock_irqsave(&sub->lock, flags);
+        dma_offset = sub->dma_off;
+        spin_unlock_irqrestore(&sub->lock, flags);
+        return bytes_to_frames(alsa_sub->runtime, dma_offset);
+}
+
+static struct snd_pcm_ops pcm_ops = {
+        .open = hiface_pcm_open,
+        .close = hiface_pcm_close,
+        .ioctl = snd_pcm_lib_ioctl,
+        .hw_params = hiface_pcm_hw_params,
+        .hw_free = hiface_pcm_hw_free,
+        .prepare = hiface_pcm_prepare,
+        .trigger = hiface_pcm_trigger,
+        .pointer = hiface_pcm_pointer,
+        .page = snd_pcm_lib_get_vmalloc_page,
+        .mmap = snd_pcm_lib_mmap_vmalloc,
+};
+
+static int hiface_pcm_init_urb(struct pcm_urb *urb,
+                               struct hiface_chip *chip,
+                               unsigned int ep,
+                               void (*handler)(struct urb *))
+{
+        urb->chip = chip;
+        usb_init_urb(&urb->instance);
+
+        urb->buffer = kzalloc(PCM_PACKET_SIZE, GFP_KERNEL);
+        if (!urb->buffer)
+                return -ENOMEM;
+
+        usb_fill_bulk_urb(&urb->instance, chip->dev,
+                          usb_sndbulkpipe(chip->dev, ep), (void *)urb->buffer,
+                          PCM_PACKET_SIZE, handler, urb);
+        init_usb_anchor(&urb->submitted);
+
+        return 0;
+}
+
+void hiface_pcm_abort(struct hiface_chip *chip)
+{
+        struct pcm_runtime *rt = chip->pcm;
+
+        if (rt) {
+                rt->panic = true;
+
+                mutex_lock(&rt->stream_mutex);
+                hiface_pcm_stream_stop(rt);
+                mutex_unlock(&rt->stream_mutex);
+        }
+}
+
+static void hiface_pcm_destroy(struct hiface_chip *chip)
+{
+        struct pcm_runtime *rt = chip->pcm;
+        int i;
+
+        for (i = 0; i < PCM_N_URBS; i++)
+                kfree(rt->out_urbs[i].buffer);
+
+        kfree(chip->pcm);
+        chip->pcm = NULL;
+}
+
+static void hiface_pcm_free(struct snd_pcm *pcm)
+{
+        struct pcm_runtime *rt = pcm->private_data;
+
+        if (rt)
+                hiface_pcm_destroy(rt->chip);
+}
+
+int hiface_pcm_init(struct hiface_chip *chip, u8 extra_freq)
+{
+        int i;
+        int ret;
+        struct snd_pcm *pcm;
+        struct pcm_runtime *rt;
+
+        rt = kzalloc(sizeof(*rt), GFP_KERNEL);
+        if (!rt)
+                return -ENOMEM;
+
+        rt->chip = chip;
+        rt->stream_state = STREAM_DISABLED;
+        if (extra_freq)
+                rt->extra_freq = 1;
+
+        init_waitqueue_head(&rt->stream_wait_queue);
+        mutex_init(&rt->stream_mutex);
+        spin_lock_init(&rt->playback.lock);
+
+        for (i = 0; i < PCM_N_URBS; i++)
+                hiface_pcm_init_urb(&rt->out_urbs[i], chip, OUT_EP,
+                                    hiface_pcm_out_urb_handler);
+
+        ret = snd_pcm_new(chip->card, "USB-SPDIF Audio", 0, 1, 0, &pcm);
+        if (ret < 0) {
+                kfree(rt);
+                dev_err(&chip->dev->dev, "Cannot create pcm instance\n");
+                return ret;
+        }
+
+        pcm->private_data = rt;
+        pcm->private_free = hiface_pcm_free;
+
+        strlcpy(pcm->name, "USB-SPDIF Audio", sizeof(pcm->name));
+        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_ops);
+
+        rt->instance = pcm;
+
+        chip->pcm = rt;
+        return 0;
+}
diff --git a/sound/usb/hiface/pcm.h b/sound/usb/hiface/pcm.h
new file mode 100644
index 000000000000..77edd7c12e19
--- /dev/null
+++ b/sound/usb/hiface/pcm.h
@@ -0,0 +1,24 @@
+/*
+ * Linux driver for M2Tech hiFace compatible devices
+ *
+ * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
+ *
+ * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
+ *           Antonio Ospite <ao2@amarulasolutions.com>
+ *
+ * The driver is based on the work done in TerraTec DMX 6Fire USB
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef HIFACE_PCM_H
+#define HIFACE_PCM_H
+
+struct hiface_chip;
+
+int hiface_pcm_init(struct hiface_chip *chip, u8 extra_freq);
+void hiface_pcm_abort(struct hiface_chip *chip);
+#endif /* HIFACE_PCM_H */