1 files changed, 756 insertions, 0 deletions

diff --git a/drivers/media/video/cx231xx/cx231xx-audio.c b/drivers/media/video/cx231xx/cx231xx-audio.c
new file mode 100644
index 00000000000..30d13c15739
--- /dev/null
+++ b/drivers/media/video/cx231xx/cx231xx-audio.c
@@ -0,0 +1,756 @@
+/*
+ *  Conexant Cx231xx audio extension
+ *
+ *  Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
+ *       Based on em28xx driver
+ *
+ *
+ *  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.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <linux/init.h>
+#include <linux/sound.h>
+#include <linux/spinlock.h>
+#include <linux/soundcard.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/info.h>
+#include <sound/initval.h>
+#include <sound/control.h>
+#include <media/v4l2-common.h>
+#include "cx231xx.h"
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "activates debug info");
+
+#define dprintk(fmt, arg...) do {                                       \
+                if (debug)                                              \
+                        printk(KERN_INFO "cx231xx-audio %s: " fmt,      \
+                                __func__, ##arg);                       \
+        } while (0)
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
+
+static int cx231xx_isoc_audio_deinit(struct cx231xx *dev)
+{
+        int i;
+
+        dprintk("Stopping isoc\n");
+
+        for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
+                if (dev->adev.urb[i]) {
+                        if (!irqs_disabled())
+                                usb_kill_urb(dev->adev.urb[i]);
+                        else
+                                usb_unlink_urb(dev->adev.urb[i]);
+
+                        usb_free_urb(dev->adev.urb[i]);
+                        dev->adev.urb[i] = NULL;
+
+                        kfree(dev->adev.transfer_buffer[i]);
+                        dev->adev.transfer_buffer[i] = NULL;
+                }
+        }
+
+        return 0;
+}
+
+static int cx231xx_bulk_audio_deinit(struct cx231xx *dev)
+{
+        int i;
+
+        dprintk("Stopping bulk\n");
+
+        for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
+                if (dev->adev.urb[i]) {
+                        if (!irqs_disabled())
+                                usb_kill_urb(dev->adev.urb[i]);
+                        else
+                                usb_unlink_urb(dev->adev.urb[i]);
+
+                        usb_free_urb(dev->adev.urb[i]);
+                        dev->adev.urb[i] = NULL;
+
+                        kfree(dev->adev.transfer_buffer[i]);
+                        dev->adev.transfer_buffer[i] = NULL;
+                }
+        }
+
+        return 0;
+}
+
+static void cx231xx_audio_isocirq(struct urb *urb)
+{
+        struct cx231xx *dev = urb->context;
+        int i;
+        unsigned int oldptr;
+        int period_elapsed = 0;
+        int status;
+        unsigned char *cp;
+        unsigned int stride;
+        struct snd_pcm_substream *substream;
+        struct snd_pcm_runtime *runtime;
+
+        switch (urb->status) {
+        case 0:         /* success */
+        case -ETIMEDOUT:        /* NAK */
+                break;
+        case -ECONNRESET:       /* kill */
+        case -ENOENT:
+        case -ESHUTDOWN:
+                return;
+        default:                /* error */
+                dprintk("urb completition error %d.\n", urb->status);
+                break;
+        }
+
+        if (atomic_read(&dev->stream_started) == 0)
+                return;
+
+        if (dev->adev.capture_pcm_substream) {
+                substream = dev->adev.capture_pcm_substream;
+                runtime = substream->runtime;
+                stride = runtime->frame_bits >> 3;
+
+                for (i = 0; i < urb->number_of_packets; i++) {
+                        int length = urb->iso_frame_desc[i].actual_length /
+                                     stride;
+                        cp = (unsigned char *)urb->transfer_buffer +
+                                              urb->iso_frame_desc[i].offset;
+
+                        if (!length)
+                                continue;
+
+                        oldptr = dev->adev.hwptr_done_capture;
+                        if (oldptr + length >= runtime->buffer_size) {
+                                unsigned int cnt;
+
+                                cnt = runtime->buffer_size - oldptr;
+                                memcpy(runtime->dma_area + oldptr * stride, cp,
+                                       cnt * stride);
+                                memcpy(runtime->dma_area, cp + cnt * stride,
+                                       length * stride - cnt * stride);
+                        } else {
+                                memcpy(runtime->dma_area + oldptr * stride, cp,
+                                       length * stride);
+                        }
+
+                        snd_pcm_stream_lock(substream);
+
+                        dev->adev.hwptr_done_capture += length;
+                        if (dev->adev.hwptr_done_capture >=
+                                                runtime->buffer_size)
+                                dev->adev.hwptr_done_capture -=
+                                                runtime->buffer_size;
+
+                        dev->adev.capture_transfer_done += length;
+                        if (dev->adev.capture_transfer_done >=
+                                runtime->period_size) {
+                                dev->adev.capture_transfer_done -=
+                                                runtime->period_size;
+                                period_elapsed = 1;
+                        }
+                        snd_pcm_stream_unlock(substream);
+                }
+                if (period_elapsed)
+                        snd_pcm_period_elapsed(substream);
+        }
+        urb->status = 0;
+
+        status = usb_submit_urb(urb, GFP_ATOMIC);
+        if (status < 0) {
+                cx231xx_errdev("resubmit of audio urb failed (error=%i)\n",
+                               status);
+        }
+        return;
+}
+
+static void cx231xx_audio_bulkirq(struct urb *urb)
+{
+        struct cx231xx *dev = urb->context;
+        unsigned int oldptr;
+        int period_elapsed = 0;
+        int status;
+        unsigned char *cp;
+        unsigned int stride;
+        struct snd_pcm_substream *substream;
+        struct snd_pcm_runtime *runtime;
+
+        switch (urb->status) {
+        case 0:         /* success */
+        case -ETIMEDOUT:        /* NAK */
+                break;
+        case -ECONNRESET:       /* kill */
+        case -ENOENT:
+        case -ESHUTDOWN:
+                return;
+        default:                /* error */
+                dprintk("urb completition error %d.\n", urb->status);
+                break;
+        }
+
+        if (atomic_read(&dev->stream_started) == 0)
+                return;
+
+        if (dev->adev.capture_pcm_substream) {
+                substream = dev->adev.capture_pcm_substream;
+                runtime = substream->runtime;
+                stride = runtime->frame_bits >> 3;
+
+                if (1) {
+                        int length = urb->actual_length /
+                                     stride;
+                        cp = (unsigned char *)urb->transfer_buffer;
+
+                        oldptr = dev->adev.hwptr_done_capture;
+                        if (oldptr + length >= runtime->buffer_size) {
+                                unsigned int cnt;
+
+                                cnt = runtime->buffer_size - oldptr;
+                                memcpy(runtime->dma_area + oldptr * stride, cp,
+                                       cnt * stride);
+                                memcpy(runtime->dma_area, cp + cnt * stride,
+                                       length * stride - cnt * stride);
+                        } else {
+                                memcpy(runtime->dma_area + oldptr * stride, cp,
+                                       length * stride);
+                        }
+
+                        snd_pcm_stream_lock(substream);
+
+                        dev->adev.hwptr_done_capture += length;
+                        if (dev->adev.hwptr_done_capture >=
+                                                runtime->buffer_size)
+                                dev->adev.hwptr_done_capture -=
+                                                runtime->buffer_size;
+
+                        dev->adev.capture_transfer_done += length;
+                        if (dev->adev.capture_transfer_done >=
+                                runtime->period_size) {
+                                dev->adev.capture_transfer_done -=
+                                                runtime->period_size;
+                                period_elapsed = 1;
+                        }
+                        snd_pcm_stream_unlock(substream);
+                }
+                if (period_elapsed)
+                        snd_pcm_period_elapsed(substream);
+        }
+        urb->status = 0;
+
+        status = usb_submit_urb(urb, GFP_ATOMIC);
+        if (status < 0) {
+                cx231xx_errdev("resubmit of audio urb failed (error=%i)\n",
+                               status);
+        }
+        return;
+}
+
+static int cx231xx_init_audio_isoc(struct cx231xx *dev)
+{
+        int i, errCode;
+        int sb_size;
+
+        cx231xx_info("%s: Starting ISO AUDIO transfers\n", __func__);
+
+        sb_size = CX231XX_ISO_NUM_AUDIO_PACKETS * dev->adev.max_pkt_size;
+
+        for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
+                struct urb *urb;
+                int j, k;
+
+                dev->adev.transfer_buffer[i] = kmalloc(sb_size, GFP_ATOMIC);
+                if (!dev->adev.transfer_buffer[i])
+                        return -ENOMEM;
+
+                memset(dev->adev.transfer_buffer[i], 0x80, sb_size);
+                urb = usb_alloc_urb(CX231XX_ISO_NUM_AUDIO_PACKETS, GFP_ATOMIC);
+                if (!urb) {
+                        cx231xx_errdev("usb_alloc_urb failed!\n");
+                        for (j = 0; j < i; j++) {
+                                usb_free_urb(dev->adev.urb[j]);
+                                kfree(dev->adev.transfer_buffer[j]);
+                        }
+                        return -ENOMEM;
+                }
+
+                urb->dev = dev->udev;
+                urb->context = dev;
+                urb->pipe = usb_rcvisocpipe(dev->udev,
+                                                dev->adev.end_point_addr);
+                urb->transfer_flags = URB_ISO_ASAP;
+                urb->transfer_buffer = dev->adev.transfer_buffer[i];
+                urb->interval = 1;
+                urb->complete = cx231xx_audio_isocirq;
+                urb->number_of_packets = CX231XX_ISO_NUM_AUDIO_PACKETS;
+                urb->transfer_buffer_length = sb_size;
+
+                for (j = k = 0; j < CX231XX_ISO_NUM_AUDIO_PACKETS;
+                        j++, k += dev->adev.max_pkt_size) {
+                        urb->iso_frame_desc[j].offset = k;
+                        urb->iso_frame_desc[j].length = dev->adev.max_pkt_size;
+                }
+                dev->adev.urb[i] = urb;
+        }
+
+        for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
+                errCode = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
+                if (errCode < 0) {
+                        cx231xx_isoc_audio_deinit(dev);
+                        return errCode;
+                }
+        }
+
+        return errCode;
+}
+
+static int cx231xx_init_audio_bulk(struct cx231xx *dev)
+{
+        int i, errCode;
+        int sb_size;
+
+        cx231xx_info("%s: Starting BULK AUDIO transfers\n", __func__);
+
+        sb_size = CX231XX_NUM_AUDIO_PACKETS * dev->adev.max_pkt_size;
+
+        for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
+                struct urb *urb;
+                int j;
+
+                dev->adev.transfer_buffer[i] = kmalloc(sb_size, GFP_ATOMIC);
+                if (!dev->adev.transfer_buffer[i])
+                        return -ENOMEM;
+
+                memset(dev->adev.transfer_buffer[i], 0x80, sb_size);
+                urb = usb_alloc_urb(CX231XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
+                if (!urb) {
+                        cx231xx_errdev("usb_alloc_urb failed!\n");
+                        for (j = 0; j < i; j++) {
+                                usb_free_urb(dev->adev.urb[j]);
+                                kfree(dev->adev.transfer_buffer[j]);
+                        }
+                        return -ENOMEM;
+                }
+
+                urb->dev = dev->udev;
+                urb->context = dev;
+                urb->pipe = usb_rcvbulkpipe(dev->udev,
+                                                dev->adev.end_point_addr);
+                urb->transfer_flags = 0;
+                urb->transfer_buffer = dev->adev.transfer_buffer[i];
+                urb->complete = cx231xx_audio_bulkirq;
+                urb->transfer_buffer_length = sb_size;
+
+                dev->adev.urb[i] = urb;
+
+        }
+
+        for (i = 0; i < CX231XX_AUDIO_BUFS; i++) {
+                errCode = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
+                if (errCode < 0) {
+                        cx231xx_bulk_audio_deinit(dev);
+                        return errCode;
+                }
+        }
+
+        return errCode;
+}
+
+static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
+                                        size_t size)
+{
+        struct snd_pcm_runtime *runtime = subs->runtime;
+
+        dprintk("Allocating vbuffer\n");
+        if (runtime->dma_area) {
+                if (runtime->dma_bytes > size)
+                        return 0;
+
+                vfree(runtime->dma_area);
+        }
+        runtime->dma_area = vmalloc(size);
+        if (!runtime->dma_area)
+                return -ENOMEM;
+
+        runtime->dma_bytes = size;
+
+        return 0;
+}
+
+static struct snd_pcm_hardware snd_cx231xx_hw_capture = {
+        .info = SNDRV_PCM_INFO_BLOCK_TRANSFER   |
+            SNDRV_PCM_INFO_MMAP                 |
+            SNDRV_PCM_INFO_INTERLEAVED          |
+            SNDRV_PCM_INFO_MMAP_VALID,
+
+        .formats = SNDRV_PCM_FMTBIT_S16_LE,
+
+        .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
+
+        .rate_min = 48000,
+        .rate_max = 48000,
+        .channels_min = 2,
+        .channels_max = 2,
+        .buffer_bytes_max = 62720 * 8,  /* just about the value in usbaudio.c */
+        .period_bytes_min = 64,         /* 12544/2, */
+        .period_bytes_max = 12544,
+        .periods_min = 2,
+        .periods_max = 98,              /* 12544, */
+};
+
+static int snd_cx231xx_capture_open(struct snd_pcm_substream *substream)
+{
+        struct cx231xx *dev = snd_pcm_substream_chip(substream);
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        int ret = 0;
+
+        dprintk("opening device and trying to acquire exclusive lock\n");
+
+        if (!dev) {
+                cx231xx_errdev("BUG: cx231xx can't find device struct."
+                               " Can't proceed with open\n");
+                return -ENODEV;
+        }
+
+        /* Sets volume, mute, etc */
+        dev->mute = 0;
+
+        /* set alternate setting for audio interface */
+        /* 1 - 48000 samples per sec */
+        mutex_lock(&dev->lock);
+        if (dev->USE_ISO)
+                ret = cx231xx_set_alt_setting(dev, INDEX_AUDIO, 1);
+        else
+                ret = cx231xx_set_alt_setting(dev, INDEX_AUDIO, 0);
+        mutex_unlock(&dev->lock);
+        if (ret < 0) {
+                cx231xx_errdev("failed to set alternate setting !\n");
+
+                return ret;
+        }
+
+        runtime->hw = snd_cx231xx_hw_capture;
+
+        mutex_lock(&dev->lock);
+        /* inform hardware to start streaming */
+        ret = cx231xx_capture_start(dev, 1, Audio);
+
+        dev->adev.users++;
+        mutex_unlock(&dev->lock);
+
+        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+        dev->adev.capture_pcm_substream = substream;
+        runtime->private_data = dev;
+
+        return 0;
+}
+
+static int snd_cx231xx_pcm_close(struct snd_pcm_substream *substream)
+{
+        int ret;
+        struct cx231xx *dev = snd_pcm_substream_chip(substream);
+
+        dprintk("closing device\n");
+
+        /* inform hardware to stop streaming */
+        mutex_lock(&dev->lock);
+        ret = cx231xx_capture_start(dev, 0, Audio);
+
+        /* set alternate setting for audio interface */
+        /* 1 - 48000 samples per sec */
+        ret = cx231xx_set_alt_setting(dev, INDEX_AUDIO, 0);
+        if (ret < 0) {
+                cx231xx_errdev("failed to set alternate setting !\n");
+
+                mutex_unlock(&dev->lock);
+                return ret;
+        }
+
+        dev->mute = 1;
+        dev->adev.users--;
+        mutex_unlock(&dev->lock);
+
+        if (dev->adev.users == 0 && dev->adev.shutdown == 1) {
+                dprintk("audio users: %d\n", dev->adev.users);
+                dprintk("disabling audio stream!\n");
+                dev->adev.shutdown = 0;
+                dprintk("released lock\n");
+                if (atomic_read(&dev->stream_started) > 0) {
+                        atomic_set(&dev->stream_started, 0);
+                        schedule_work(&dev->wq_trigger);
+                }
+        }
+        return 0;
+}
+
+static int snd_cx231xx_hw_capture_params(struct snd_pcm_substream *substream,
+                                         struct snd_pcm_hw_params *hw_params)
+{
+        unsigned int channels, rate, format;
+        int ret;
+
+        dprintk("Setting capture parameters\n");
+
+        ret = snd_pcm_alloc_vmalloc_buffer(substream,
+                                           params_buffer_bytes(hw_params));
+        format = params_format(hw_params);
+        rate = params_rate(hw_params);
+        channels = params_channels(hw_params);
+
+        /* TODO: set up cx231xx audio chip to deliver the correct audio format,
+           current default is 48000hz multiplexed => 96000hz mono
+           which shouldn't matter since analogue TV only supports mono */
+        return 0;
+}
+
+static int snd_cx231xx_hw_capture_free(struct snd_pcm_substream *substream)
+{
+        struct cx231xx *dev = snd_pcm_substream_chip(substream);
+
+        dprintk("Stop capture, if needed\n");
+
+        if (atomic_read(&dev->stream_started) > 0) {
+                atomic_set(&dev->stream_started, 0);
+                schedule_work(&dev->wq_trigger);
+        }
+
+        return 0;
+}
+
+static int snd_cx231xx_prepare(struct snd_pcm_substream *substream)
+{
+        struct cx231xx *dev = snd_pcm_substream_chip(substream);
+
+        dev->adev.hwptr_done_capture = 0;
+        dev->adev.capture_transfer_done = 0;
+
+        return 0;
+}
+
+static void audio_trigger(struct work_struct *work)
+{
+        struct cx231xx *dev = container_of(work, struct cx231xx, wq_trigger);
+
+        if (atomic_read(&dev->stream_started)) {
+                dprintk("starting capture");
+                if (is_fw_load(dev) == 0)
+                        cx25840_call(dev, core, load_fw);
+                if (dev->USE_ISO)
+                        cx231xx_init_audio_isoc(dev);
+                else
+                        cx231xx_init_audio_bulk(dev);
+        } else {
+                dprintk("stopping capture");
+                cx231xx_isoc_audio_deinit(dev);
+        }
+}
+
+static int snd_cx231xx_capture_trigger(struct snd_pcm_substream *substream,
+                                       int cmd)
+{
+        struct cx231xx *dev = snd_pcm_substream_chip(substream);
+        int retval;
+
+        spin_lock(&dev->adev.slock);
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+                atomic_set(&dev->stream_started, 1);
+                break;
+        case SNDRV_PCM_TRIGGER_STOP:
+                atomic_set(&dev->stream_started, 0);
+                break;
+        default:
+                retval = -EINVAL;
+        }
+        spin_unlock(&dev->adev.slock);
+
+        schedule_work(&dev->wq_trigger);
+
+        return 0;
+}
+
+static snd_pcm_uframes_t snd_cx231xx_capture_pointer(struct snd_pcm_substream
+                                                     *substream)
+{
+        struct cx231xx *dev;
+        unsigned long flags;
+        snd_pcm_uframes_t hwptr_done;
+
+        dev = snd_pcm_substream_chip(substream);
+
+        spin_lock_irqsave(&dev->adev.slock, flags);
+        hwptr_done = dev->adev.hwptr_done_capture;
+        spin_unlock_irqrestore(&dev->adev.slock, flags);
+
+        return hwptr_done;
+}
+
+static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
+                                             unsigned long offset)
+{
+        void *pageptr = subs->runtime->dma_area + offset;
+
+        return vmalloc_to_page(pageptr);
+}
+
+static struct snd_pcm_ops snd_cx231xx_pcm_capture = {
+        .open = snd_cx231xx_capture_open,
+        .close = snd_cx231xx_pcm_close,
+        .ioctl = snd_pcm_lib_ioctl,
+        .hw_params = snd_cx231xx_hw_capture_params,
+        .hw_free = snd_cx231xx_hw_capture_free,
+        .prepare = snd_cx231xx_prepare,
+        .trigger = snd_cx231xx_capture_trigger,
+        .pointer = snd_cx231xx_capture_pointer,
+        .page = snd_pcm_get_vmalloc_page,
+};
+
+static int cx231xx_audio_init(struct cx231xx *dev)
+{
+        struct cx231xx_audio *adev = &dev->adev;
+        struct snd_pcm *pcm;
+        struct snd_card *card;
+        static int devnr;
+        int err;
+        struct usb_interface *uif;
+        int i, isoc_pipe = 0;
+
+        if (dev->has_alsa_audio != 1) {
+                /* This device does not support the extension (in this case
+                   the device is expecting the snd-usb-audio module or
+                   doesn't have analog audio support at all) */
+                return 0;
+        }
+
+        cx231xx_info("cx231xx-audio.c: probing for cx231xx "
+                     "non standard usbaudio\n");
+
+        err = snd_card_create(index[devnr], "Cx231xx Audio", THIS_MODULE,
+                              0, &card);
+        if (err < 0)
+                return err;
+
+        spin_lock_init(&adev->slock);
+        err = snd_pcm_new(card, "Cx231xx Audio", 0, 0, 1, &pcm);
+        if (err < 0) {
+                snd_card_free(card);
+                return err;
+        }
+
+        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
+                        &snd_cx231xx_pcm_capture);
+        pcm->info_flags = 0;
+        pcm->private_data = dev;
+        strcpy(pcm->name, "Conexant cx231xx Capture");
+        snd_card_set_dev(card, &dev->udev->dev);
+        strcpy(card->driver, "Cx231xx-Audio");
+        strcpy(card->shortname, "Cx231xx Audio");
+        strcpy(card->longname, "Conexant cx231xx Audio");
+
+        INIT_WORK(&dev->wq_trigger, audio_trigger);
+
+        err = snd_card_register(card);
+        if (err < 0) {
+                snd_card_free(card);
+                return err;
+        }
+        adev->sndcard = card;
+        adev->udev = dev->udev;
+
+        /* compute alternate max packet sizes for Audio */
+        uif =
+            dev->udev->actconfig->interface[dev->current_pcb_config.
+                                            hs_config_info[0].interface_info.
+                                            audio_index + 1];
+
+        adev->end_point_addr =
+            le16_to_cpu(uif->altsetting[0].endpoint[isoc_pipe].desc.
+                        bEndpointAddress);
+
+        adev->num_alt = uif->num_altsetting;
+        cx231xx_info("EndPoint Addr 0x%x, Alternate settings: %i\n",
+                     adev->end_point_addr, adev->num_alt);
+        adev->alt_max_pkt_size = kmalloc(32 * adev->num_alt, GFP_KERNEL);
+
+        if (adev->alt_max_pkt_size == NULL) {
+                cx231xx_errdev("out of memory!\n");
+                return -ENOMEM;
+        }
+
+        for (i = 0; i < adev->num_alt; i++) {
+                u16 tmp =
+                    le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc.
+                                wMaxPacketSize);
+                adev->alt_max_pkt_size[i] =
+                    (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1);
+                cx231xx_info("Alternate setting %i, max size= %i\n", i,
+                             adev->alt_max_pkt_size[i]);
+        }
+
+        return 0;
+}
+
+static int cx231xx_audio_fini(struct cx231xx *dev)
+{
+        if (dev == NULL)
+                return 0;
+
+        if (dev->has_alsa_audio != 1) {
+                /* This device does not support the extension (in this case
+                   the device is expecting the snd-usb-audio module or
+                   doesn't have analog audio support at all) */
+                return 0;
+        }
+
+        if (dev->adev.sndcard) {
+                snd_card_free(dev->adev.sndcard);
+                kfree(dev->adev.alt_max_pkt_size);
+                dev->adev.sndcard = NULL;
+        }
+
+        return 0;
+}
+
+static struct cx231xx_ops audio_ops = {
+        .id = CX231XX_AUDIO,
+        .name = "Cx231xx Audio Extension",
+        .init = cx231xx_audio_init,
+        .fini = cx231xx_audio_fini,
+};
+
+static int __init cx231xx_alsa_register(void)
+{
+        return cx231xx_register_extension(&audio_ops);
+}
+
+static void __exit cx231xx_alsa_unregister(void)
+{
+        cx231xx_unregister_extension(&audio_ops);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Srinivasa Deevi <srinivasa.deevi@conexant.com>");
+MODULE_DESCRIPTION("Cx231xx Audio driver");
+
+module_init(cx231xx_alsa_register);
+module_exit(cx231xx_alsa_unregister);