drivers/media/usb/cx231xx/cx231xx-audio.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Conexant Cx231xx audio extension
  *
  *  Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
  *       Based on em28xx driver
  */

 #include "cx231xx.h"
 #include <linux/kernel.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>

 static int debug;
 module_param(debug, int, 0644);
 MODULE_PARM_DESC(debug, "activates debug info");

 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;

 static int cx231xx_isoc_audio_deinit(struct cx231xx *dev)
 {
 	int i;

 	dev_dbg(dev->dev, "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;

 	dev_dbg(dev->dev, "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;

 	if (dev->state & DEV_DISCONNECTED)
 		return;

 	switch (urb->status) {
 	case 0:		/* success */
 	case -ETIMEDOUT:	/* NAK */
 		break;
 	case -ECONNRESET:	/* kill */
 	case -ENOENT:
 	case -ESHUTDOWN:
 		return;
 	default:		/* error */
 		dev_dbg(dev->dev, "urb completion 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++) {
 			unsigned long flags;
 			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_irqsave(substream, flags);

 			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_irqrestore(substream, flags);
 		}
 		if (period_elapsed)
 			snd_pcm_period_elapsed(substream);
 	}
 	urb->status = 0;

 	status = usb_submit_urb(urb, GFP_ATOMIC);
 	if (status < 0) {
 		dev_err(dev->dev,
 			"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;

 	if (dev->state & DEV_DISCONNECTED)
 		return;

 	switch (urb->status) {
 	case 0:		/* success */
 	case -ETIMEDOUT:	/* NAK */
 		break;
 	case -ECONNRESET:	/* kill */
 	case -ENOENT:
 	case -ESHUTDOWN:
 		return;
 	default:		/* error */
 		dev_dbg(dev->dev, "urb completion 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) {
 			unsigned long flags;
 			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_irqsave(substream, flags);

 			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_irqrestore(substream, flags);
 		}
 		if (period_elapsed)
 			snd_pcm_period_elapsed(substream);
 	}
 	urb->status = 0;

 	status = usb_submit_urb(urb, GFP_ATOMIC);
 	if (status < 0) {
 		dev_err(dev->dev,
 			"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;

 	dev_dbg(dev->dev,
 		"%s: Starting ISO AUDIO transfers\n", __func__);

 	if (dev->state & DEV_DISCONNECTED)
 		return -ENODEV;

 	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) {
 			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;

 	dev_dbg(dev->dev,
 		"%s: Starting BULK AUDIO transfers\n", __func__);

 	if (dev->state & DEV_DISCONNECTED)
 		return -ENODEV;

 	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) {
 			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;
 	struct cx231xx *dev = snd_pcm_substream_chip(subs);

 	dev_dbg(dev->dev, "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 const 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;

 	dev_dbg(dev->dev,
 		"opening device and trying to acquire exclusive lock\n");

 	if (dev->state & DEV_DISCONNECTED) {
 		dev_err(dev->dev,
 			"Can't open. the device was removed.\n");
 		return -ENODEV;
 	}

 	/* 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) {
 		dev_err(dev->dev,
 			"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);

 	dev_dbg(dev->dev, "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) {
 		dev_err(dev->dev,
 			"failed to set alternate setting !\n");

 		mutex_unlock(&dev->lock);
 		return ret;
 	}

 	dev->adev.users--;
 	if (substream->runtime->dma_area) {
 		dev_dbg(dev->dev, "freeing\n");
 		vfree(substream->runtime->dma_area);
 		substream->runtime->dma_area = NULL;
 	}
 	mutex_unlock(&dev->lock);

 	if (dev->adev.users == 0 && dev->adev.shutdown == 1) {
 		dev_dbg(dev->dev, "audio users: %d\n", dev->adev.users);
 		dev_dbg(dev->dev, "disabling audio stream!\n");
 		dev->adev.shutdown = 0;
 		dev_dbg(dev->dev, "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)
 {
 	struct cx231xx *dev = snd_pcm_substream_chip(substream);
 	int ret;

 	dev_dbg(dev->dev, "Setting capture parameters\n");

 	ret = snd_pcm_alloc_vmalloc_buffer(substream,
 					   params_buffer_bytes(hw_params));
 #if 0
 	/* 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 */
 	unsigned int channels, rate, format;

 	format = params_format(hw_params);
 	rate = params_rate(hw_params);
 	channels = params_channels(hw_params);
 #endif

 	return ret;
 }

 static int snd_cx231xx_hw_capture_free(struct snd_pcm_substream *substream)
 {
 	struct cx231xx *dev = snd_pcm_substream_chip(substream);

 	dev_dbg(dev->dev, "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)) {
 		dev_dbg(dev->dev, "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 {
 		dev_dbg(dev->dev, "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 = 0;

 	if (dev->state & DEV_DISCONNECTED)
 		return -ENODEV;

 	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;
 		break;
 	}
 	spin_unlock(&dev->adev.slock);

 	schedule_work(&dev->wq_trigger);

 	return retval;
 }

 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 const 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;
 	}

 	dev_dbg(dev->dev,
 		"probing for cx231xx non standard usbaudio\n");

 	err = snd_card_new(dev->dev, 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)
 		goto err_free_card;

 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
 			&snd_cx231xx_pcm_capture);
 	pcm->info_flags = 0;
 	pcm->private_data = dev;
 	strscpy(pcm->name, "Conexant cx231xx Capture", sizeof(pcm->name));
 	strscpy(card->driver, "Cx231xx-Audio", sizeof(card->driver));
 	strscpy(card->shortname, "Cx231xx Audio", sizeof(card->shortname));
 	strscpy(card->longname, "Conexant cx231xx Audio", sizeof(card->longname));

 	INIT_WORK(&dev->wq_trigger, audio_trigger);

 	err = snd_card_register(card);
 	if (err < 0)
 		goto err_free_card;

 	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];

 	if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) {
 		err = -ENODEV;
 		goto err_free_card;
 	}

 	adev->end_point_addr =
 	    uif->altsetting[0].endpoint[isoc_pipe].desc.
 			bEndpointAddress;

 	adev->num_alt = uif->num_altsetting;
 	dev_info(dev->dev,
 		"audio EndPoint Addr 0x%x, Alternate settings: %i\n",
 		adev->end_point_addr, adev->num_alt);
 	adev->alt_max_pkt_size = kmalloc_array(32, adev->num_alt, GFP_KERNEL);
 	if (!adev->alt_max_pkt_size) {
 		err = -ENOMEM;
 		goto err_free_card;
 	}

 	for (i = 0; i < adev->num_alt; i++) {
 		u16 tmp;

 		if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) {
 			err = -ENODEV;
 			goto err_free_pkt_size;
 		}

 		tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc.
 				wMaxPacketSize);
 		adev->alt_max_pkt_size[i] =
 		    (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1);
 		dev_dbg(dev->dev,
 			"audio alternate setting %i, max size= %i\n", i,
 			adev->alt_max_pkt_size[i]);
 	}

 	return 0;

 err_free_pkt_size:
 	kfree(adev->alt_max_pkt_size);
 err_free_card:
 	snd_card_free(card);

 	return err;
 }

 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);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Conexant Cx231xx audio extension
	*
	* Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
	* Based on em28xx driver
	*/

	#include "cx231xx.h"
	#include <linux/kernel.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>

	static int debug;
	module_param(debug, int, 0644);
	MODULE_PARM_DESC(debug, "activates debug info");

	static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;

	static int cx231xx_isoc_audio_deinit(struct cx231xx *dev)
	{
	int i;

	dev_dbg(dev->dev, "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;

	dev_dbg(dev->dev, "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;

	if (dev->state & DEV_DISCONNECTED)
	return;

	switch (urb->status) {
	case 0: /* success */
	case -ETIMEDOUT: /* NAK */
	break;
	case -ECONNRESET: /* kill */
	case -ENOENT:
	case -ESHUTDOWN:
	return;
	default: /* error */
	dev_dbg(dev->dev, "urb completion 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++) {
	unsigned long flags;
	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_irqsave(substream, flags);

	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_irqrestore(substream, flags);
	}
	if (period_elapsed)
	snd_pcm_period_elapsed(substream);
	}
	urb->status = 0;

	status = usb_submit_urb(urb, GFP_ATOMIC);
	if (status < 0) {
	dev_err(dev->dev,
	"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;

	if (dev->state & DEV_DISCONNECTED)
	return;

	switch (urb->status) {
	case 0: /* success */
	case -ETIMEDOUT: /* NAK */
	break;
	case -ECONNRESET: /* kill */
	case -ENOENT:
	case -ESHUTDOWN:
	return;
	default: /* error */
	dev_dbg(dev->dev, "urb completion 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) {
	unsigned long flags;
	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_irqsave(substream, flags);

	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_irqrestore(substream, flags);
	}
	if (period_elapsed)
	snd_pcm_period_elapsed(substream);
	}
	urb->status = 0;

	status = usb_submit_urb(urb, GFP_ATOMIC);
	if (status < 0) {
	dev_err(dev->dev,
	"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;

	dev_dbg(dev->dev,
	"%s: Starting ISO AUDIO transfers\n", __func__);

	if (dev->state & DEV_DISCONNECTED)
	return -ENODEV;

	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) {
	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;

	dev_dbg(dev->dev,
	"%s: Starting BULK AUDIO transfers\n", __func__);

	if (dev->state & DEV_DISCONNECTED)
	return -ENODEV;

	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) {
	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;
	struct cx231xx *dev = snd_pcm_substream_chip(subs);

	dev_dbg(dev->dev, "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 const 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;

	dev_dbg(dev->dev,
	"opening device and trying to acquire exclusive lock\n");

	if (dev->state & DEV_DISCONNECTED) {
	dev_err(dev->dev,
	"Can't open. the device was removed.\n");
	return -ENODEV;
	}

	/* 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) {
	dev_err(dev->dev,
	"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);

	dev_dbg(dev->dev, "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) {
	dev_err(dev->dev,
	"failed to set alternate setting !\n");

	mutex_unlock(&dev->lock);
	return ret;
	}

	dev->adev.users--;
	if (substream->runtime->dma_area) {
	dev_dbg(dev->dev, "freeing\n");
	vfree(substream->runtime->dma_area);
	substream->runtime->dma_area = NULL;
	}
	mutex_unlock(&dev->lock);

	if (dev->adev.users == 0 && dev->adev.shutdown == 1) {
	dev_dbg(dev->dev, "audio users: %d\n", dev->adev.users);
	dev_dbg(dev->dev, "disabling audio stream!\n");
	dev->adev.shutdown = 0;
	dev_dbg(dev->dev, "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)
	{
	struct cx231xx *dev = snd_pcm_substream_chip(substream);
	int ret;

	dev_dbg(dev->dev, "Setting capture parameters\n");

	ret = snd_pcm_alloc_vmalloc_buffer(substream,
	params_buffer_bytes(hw_params));
	#if 0
	/* 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 */
	unsigned int channels, rate, format;

	format = params_format(hw_params);
	rate = params_rate(hw_params);
	channels = params_channels(hw_params);
	#endif

	return ret;
	}

	static int snd_cx231xx_hw_capture_free(struct snd_pcm_substream *substream)
	{
	struct cx231xx *dev = snd_pcm_substream_chip(substream);

	dev_dbg(dev->dev, "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)) {
	dev_dbg(dev->dev, "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 {
	dev_dbg(dev->dev, "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 = 0;

	if (dev->state & DEV_DISCONNECTED)
	return -ENODEV;

	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;
	break;
	}
	spin_unlock(&dev->adev.slock);

	schedule_work(&dev->wq_trigger);

	return retval;
	}

	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 const 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;
	}

	dev_dbg(dev->dev,
	"probing for cx231xx non standard usbaudio\n");

	err = snd_card_new(dev->dev, 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)
	goto err_free_card;

	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE,
	&snd_cx231xx_pcm_capture);
	pcm->info_flags = 0;
	pcm->private_data = dev;
	strscpy(pcm->name, "Conexant cx231xx Capture", sizeof(pcm->name));
	strscpy(card->driver, "Cx231xx-Audio", sizeof(card->driver));
	strscpy(card->shortname, "Cx231xx Audio", sizeof(card->shortname));
	strscpy(card->longname, "Conexant cx231xx Audio", sizeof(card->longname));

	INIT_WORK(&dev->wq_trigger, audio_trigger);

	err = snd_card_register(card);
	if (err < 0)
	goto err_free_card;

	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];

	if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) {
	err = -ENODEV;
	goto err_free_card;
	}

	adev->end_point_addr =
	uif->altsetting[0].endpoint[isoc_pipe].desc.
	bEndpointAddress;

	adev->num_alt = uif->num_altsetting;
	dev_info(dev->dev,
	"audio EndPoint Addr 0x%x, Alternate settings: %i\n",
	adev->end_point_addr, adev->num_alt);
	adev->alt_max_pkt_size = kmalloc_array(32, adev->num_alt, GFP_KERNEL);
	if (!adev->alt_max_pkt_size) {
	err = -ENOMEM;
	goto err_free_card;
	}

	for (i = 0; i < adev->num_alt; i++) {
	u16 tmp;

	if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) {
	err = -ENODEV;
	goto err_free_pkt_size;
	}

	tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc.
	wMaxPacketSize);
	adev->alt_max_pkt_size[i] =
	(tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1);
	dev_dbg(dev->dev,
	"audio alternate setting %i, max size= %i\n", i,
	adev->alt_max_pkt_size[i]);
	}

	return 0;

	err_free_pkt_size:
	kfree(adev->alt_max_pkt_size);
	err_free_card:
	snd_card_free(card);

	return err;
	}

	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);