drivers/media/pci/cx25821/cx25821-alsa.c - maze/linux - Git at Google

 /*
  *  Driver for the Conexant CX25821 PCIe bridge
  *
  *  Copyright (C) 2009 Conexant Systems Inc.
  *  Authors  <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
  *	Based on SAA713x ALSA driver and CX88 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, version 2
  *
  *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  *
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/vmalloc.h>
 #include <linux/dma-mapping.h>
 #include <linux/pci.h>
 #include <linux/slab.h>

 #include <linux/delay.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/control.h>
 #include <sound/initval.h>
 #include <sound/tlv.h>

 #include "cx25821.h"
 #include "cx25821-reg.h"

 #define AUDIO_SRAM_CHANNEL	SRAM_CH08

 #define dprintk(level, fmt, arg...)				\
 do {								\
 	if (debug >= level)					\
 		pr_info("%s/1: " fmt, chip->dev->name, ##arg);	\
 } while (0)
 #define dprintk_core(level, fmt, arg...)				\
 do {									\
 	if (debug >= level)						\
 		printk(KERN_DEBUG "%s/1: " fmt, chip->dev->name, ##arg); \
 } while (0)

 /****************************************************************************
 	Data type declarations - Can be moded to a header file later
  ****************************************************************************/

 static int devno;

 struct cx25821_audio_buffer {
 	unsigned int bpl;
 	struct btcx_riscmem risc;
 	struct videobuf_dmabuf dma;
 };

 struct cx25821_audio_dev {
 	struct cx25821_dev *dev;
 	struct cx25821_dmaqueue q;

 	/* pci i/o */
 	struct pci_dev *pci;

 	/* audio controls */
 	int irq;

 	struct snd_card *card;

 	unsigned long iobase;
 	spinlock_t reg_lock;
 	atomic_t count;

 	unsigned int dma_size;
 	unsigned int period_size;
 	unsigned int num_periods;

 	struct videobuf_dmabuf *dma_risc;

 	struct cx25821_audio_buffer *buf;

 	struct snd_pcm_substream *substream;
 };


 /****************************************************************************
 			Module global static vars
  ****************************************************************************/

 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
 static bool enable[SNDRV_CARDS] = { 1, [1 ... (SNDRV_CARDS - 1)] = 1 };

 module_param_array(enable, bool, NULL, 0444);
 MODULE_PARM_DESC(enable, "Enable cx25821 soundcard. default enabled.");

 module_param_array(index, int, NULL, 0444);
 MODULE_PARM_DESC(index, "Index value for cx25821 capture interface(s).");

 /****************************************************************************
 				Module macros
  ****************************************************************************/

 MODULE_DESCRIPTION("ALSA driver module for cx25821 based capture cards");
 MODULE_AUTHOR("Hiep Huynh");
 MODULE_LICENSE("GPL");
 MODULE_SUPPORTED_DEVICE("{{Conexant,25821}");	/* "{{Conexant,23881}," */

 static unsigned int debug;
 module_param(debug, int, 0644);
 MODULE_PARM_DESC(debug, "enable debug messages");

 /****************************************************************************
 			Module specific funtions
  ****************************************************************************/
 /* Constants taken from cx88-reg.h */
 #define AUD_INT_DN_RISCI1       (1 <<  0)
 #define AUD_INT_UP_RISCI1       (1 <<  1)
 #define AUD_INT_RDS_DN_RISCI1   (1 <<  2)
 #define AUD_INT_DN_RISCI2       (1 <<  4)	/* yes, 3 is skipped */
 #define AUD_INT_UP_RISCI2       (1 <<  5)
 #define AUD_INT_RDS_DN_RISCI2   (1 <<  6)
 #define AUD_INT_DN_SYNC         (1 << 12)
 #define AUD_INT_UP_SYNC         (1 << 13)
 #define AUD_INT_RDS_DN_SYNC     (1 << 14)
 #define AUD_INT_OPC_ERR         (1 << 16)
 #define AUD_INT_BER_IRQ         (1 << 20)
 #define AUD_INT_MCHG_IRQ        (1 << 21)
 #define GP_COUNT_CONTROL_RESET	0x3

 #define PCI_MSK_AUD_EXT   (1 <<  4)
 #define PCI_MSK_AUD_INT   (1 <<  3)
 /*
  * BOARD Specific: Sets audio DMA
  */

 static int _cx25821_start_audio_dma(struct cx25821_audio_dev *chip)
 {
 	struct cx25821_audio_buffer *buf = chip->buf;
 	struct cx25821_dev *dev = chip->dev;
 	const struct sram_channel *audio_ch =
 	    &cx25821_sram_channels[AUDIO_SRAM_CHANNEL];
 	u32 tmp = 0;

 	/* enable output on the GPIO 0 for the MCLK ADC (Audio) */
 	cx25821_set_gpiopin_direction(chip->dev, 0, 0);

 	/* Make sure RISC/FIFO are off before changing FIFO/RISC settings */
 	cx_clear(AUD_INT_DMA_CTL,
 		 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);

 	/* setup fifo + format - out channel */
 	cx25821_sram_channel_setup_audio(chip->dev, audio_ch, buf->bpl,
 					 buf->risc.dma);

 	/* sets bpl size */
 	cx_write(AUD_A_LNGTH, buf->bpl);

 	/* reset counter */
 	/* GP_COUNT_CONTROL_RESET = 0x3 */
 	cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);
 	atomic_set(&chip->count, 0);

 	/* Set the input mode to 16-bit */
 	tmp = cx_read(AUD_A_CFG);
 	cx_write(AUD_A_CFG, tmp | FLD_AUD_DST_PK_MODE | FLD_AUD_DST_ENABLE |
 		 FLD_AUD_CLK_ENABLE);

 	/*
 	pr_info("DEBUG: Start audio DMA, %d B/line, cmds_start(0x%x)= %d lines/FIFO, %d periods, %d byte buffer\n",
 		buf->bpl, audio_ch->cmds_start,
 		cx_read(audio_ch->cmds_start + 12)>>1,
 		chip->num_periods, buf->bpl * chip->num_periods);
 	*/

 	/* Enables corresponding bits at AUD_INT_STAT */
 	cx_write(AUD_A_INT_MSK, FLD_AUD_DST_RISCI1 | FLD_AUD_DST_OF |
 		 FLD_AUD_DST_SYNC | FLD_AUD_DST_OPC_ERR);

 	/* Clean any pending interrupt bits already set */
 	cx_write(AUD_A_INT_STAT, ~0);

 	/* enable audio irqs */
 	cx_set(PCI_INT_MSK, chip->dev->pci_irqmask | PCI_MSK_AUD_INT);

 	/* Turn on audio downstream fifo and risc enable 0x101 */
 	tmp = cx_read(AUD_INT_DMA_CTL);
 	cx_set(AUD_INT_DMA_CTL, tmp |
 	       (FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN));

 	mdelay(100);
 	return 0;
 }

 /*
  * BOARD Specific: Resets audio DMA
  */
 static int _cx25821_stop_audio_dma(struct cx25821_audio_dev *chip)
 {
 	struct cx25821_dev *dev = chip->dev;

 	/* stop dma */
 	cx_clear(AUD_INT_DMA_CTL,
 		 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);

 	/* disable irqs */
 	cx_clear(PCI_INT_MSK, PCI_MSK_AUD_INT);
 	cx_clear(AUD_A_INT_MSK, AUD_INT_OPC_ERR | AUD_INT_DN_SYNC |
 		 AUD_INT_DN_RISCI2 | AUD_INT_DN_RISCI1);

 	return 0;
 }

 #define MAX_IRQ_LOOP 50

 /*
  * BOARD Specific: IRQ dma bits
  */
 static char *cx25821_aud_irqs[32] = {
 	"dn_risci1", "up_risci1", "rds_dn_risc1",	/* 0-2 */
 	NULL,						/* reserved */
 	"dn_risci2", "up_risci2", "rds_dn_risc2",	/* 4-6 */
 	NULL,						/* reserved */
 	"dnf_of", "upf_uf", "rds_dnf_uf",		/* 8-10 */
 	NULL,						/* reserved */
 	"dn_sync", "up_sync", "rds_dn_sync",		/* 12-14 */
 	NULL,						/* reserved */
 	"opc_err", "par_err", "rip_err",		/* 16-18 */
 	"pci_abort", "ber_irq", "mchg_irq"		/* 19-21 */
 };

 /*
  * BOARD Specific: Threats IRQ audio specific calls
  */
 static void cx25821_aud_irq(struct cx25821_audio_dev *chip, u32 status,
 			    u32 mask)
 {
 	struct cx25821_dev *dev = chip->dev;

 	if (0 == (status & mask))
 		return;

 	cx_write(AUD_A_INT_STAT, status);
 	if (debug > 1 || (status & mask & ~0xff))
 		cx25821_print_irqbits(dev->name, "irq aud", cx25821_aud_irqs,
 				ARRAY_SIZE(cx25821_aud_irqs), status, mask);

 	/* risc op code error */
 	if (status & AUD_INT_OPC_ERR) {
 		pr_warn("WARNING %s/1: Audio risc op code error\n", dev->name);

 		cx_clear(AUD_INT_DMA_CTL,
 			 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);
 		cx25821_sram_channel_dump_audio(dev,
 				&cx25821_sram_channels[AUDIO_SRAM_CHANNEL]);
 	}
 	if (status & AUD_INT_DN_SYNC) {
 		pr_warn("WARNING %s: Downstream sync error!\n", dev->name);
 		cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);
 		return;
 	}

 	/* risc1 downstream */
 	if (status & AUD_INT_DN_RISCI1) {
 		atomic_set(&chip->count, cx_read(AUD_A_GPCNT));
 		snd_pcm_period_elapsed(chip->substream);
 	}
 }

 /*
  * BOARD Specific: Handles IRQ calls
  */
 static irqreturn_t cx25821_irq(int irq, void *dev_id)
 {
 	struct cx25821_audio_dev *chip = dev_id;
 	struct cx25821_dev *dev = chip->dev;
 	u32 status, pci_status;
 	u32 audint_status, audint_mask;
 	int loop, handled = 0;

 	audint_status = cx_read(AUD_A_INT_STAT);
 	audint_mask = cx_read(AUD_A_INT_MSK);
 	status = cx_read(PCI_INT_STAT);

 	for (loop = 0; loop < 1; loop++) {
 		status = cx_read(PCI_INT_STAT);
 		if (0 == status) {
 			status = cx_read(PCI_INT_STAT);
 			audint_status = cx_read(AUD_A_INT_STAT);
 			audint_mask = cx_read(AUD_A_INT_MSK);

 			if (status) {
 				handled = 1;
 				cx_write(PCI_INT_STAT, status);

 				cx25821_aud_irq(chip, audint_status,
 						audint_mask);
 				break;
 			} else {
 				goto out;
 			}
 		}

 		handled = 1;
 		cx_write(PCI_INT_STAT, status);

 		cx25821_aud_irq(chip, audint_status, audint_mask);
 	}

 	pci_status = cx_read(PCI_INT_STAT);

 	if (handled)
 		cx_write(PCI_INT_STAT, pci_status);

 out:
 	return IRQ_RETVAL(handled);
 }

 static int dsp_buffer_free(struct cx25821_audio_dev *chip)
 {
 	BUG_ON(!chip->dma_size);

 	dprintk(2, "Freeing buffer\n");
 	videobuf_dma_unmap(&chip->pci->dev, chip->dma_risc);
 	videobuf_dma_free(chip->dma_risc);
 	btcx_riscmem_free(chip->pci, &chip->buf->risc);
 	kfree(chip->buf);

 	chip->dma_risc = NULL;
 	chip->dma_size = 0;

 	return 0;
 }

 /****************************************************************************
 				ALSA PCM Interface
  ****************************************************************************/

 /*
  * Digital hardware definition
  */
 #define DEFAULT_FIFO_SIZE	384
 static struct snd_pcm_hardware snd_cx25821_digital_hw = {
 	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP_VALID,
 	.formats = SNDRV_PCM_FMTBIT_S16_LE,

 	.rates = SNDRV_PCM_RATE_48000,
 	.rate_min = 48000,
 	.rate_max = 48000,
 	.channels_min = 2,
 	.channels_max = 2,
 	/* Analog audio output will be full of clicks and pops if there
 	   are not exactly four lines in the SRAM FIFO buffer.  */
 	.period_bytes_min = DEFAULT_FIFO_SIZE / 3,
 	.period_bytes_max = DEFAULT_FIFO_SIZE / 3,
 	.periods_min = 1,
 	.periods_max = AUDIO_LINE_SIZE,
 	/* 128 * 128 = 16384 = 1024 * 16 */
 	.buffer_bytes_max = (AUDIO_LINE_SIZE * AUDIO_LINE_SIZE),
 };

 /*
  * audio pcm capture open callback
  */
 static int snd_cx25821_pcm_open(struct snd_pcm_substream *substream)
 {
 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	int err;
 	unsigned int bpl = 0;

 	if (!chip) {
 		pr_err("DEBUG: cx25821 can't find device struct. Can't proceed with open\n");
 		return -ENODEV;
 	}

 	err = snd_pcm_hw_constraint_pow2(runtime, 0,
 					 SNDRV_PCM_HW_PARAM_PERIODS);
 	if (err < 0)
 		goto _error;

 	chip->substream = substream;

 	runtime->hw = snd_cx25821_digital_hw;

 	if (cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size !=
 	    DEFAULT_FIFO_SIZE) {
 		/* since there are 3 audio Clusters */
 		bpl = cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size / 3;
 		bpl &= ~7;	/* must be multiple of 8 */

 		if (bpl > AUDIO_LINE_SIZE)
 			bpl = AUDIO_LINE_SIZE;

 		runtime->hw.period_bytes_min = bpl;
 		runtime->hw.period_bytes_max = bpl;
 	}

 	return 0;
 _error:
 	dprintk(1, "Error opening PCM!\n");
 	return err;
 }

 /*
  * audio close callback
  */
 static int snd_cx25821_close(struct snd_pcm_substream *substream)
 {
 	return 0;
 }

 /*
  * hw_params callback
  */
 static int snd_cx25821_hw_params(struct snd_pcm_substream *substream,
 				 struct snd_pcm_hw_params *hw_params)
 {
 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
 	struct videobuf_dmabuf *dma;

 	struct cx25821_audio_buffer *buf;
 	int ret;

 	if (substream->runtime->dma_area) {
 		dsp_buffer_free(chip);
 		substream->runtime->dma_area = NULL;
 	}

 	chip->period_size = params_period_bytes(hw_params);
 	chip->num_periods = params_periods(hw_params);
 	chip->dma_size = chip->period_size * params_periods(hw_params);

 	BUG_ON(!chip->dma_size);
 	BUG_ON(chip->num_periods & (chip->num_periods - 1));

 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
 	if (NULL == buf)
 		return -ENOMEM;

 	if (chip->period_size > AUDIO_LINE_SIZE)
 		chip->period_size = AUDIO_LINE_SIZE;

 	buf->bpl = chip->period_size;

 	dma = &buf->dma;
 	videobuf_dma_init(dma);
 	ret = videobuf_dma_init_kernel(dma, PCI_DMA_FROMDEVICE,
 			(PAGE_ALIGN(chip->dma_size) >> PAGE_SHIFT));
 	if (ret < 0)
 		goto error;

 	ret = videobuf_dma_map(&chip->pci->dev, dma);
 	if (ret < 0)
 		goto error;

 	ret = cx25821_risc_databuffer_audio(chip->pci, &buf->risc, dma->sglist,
 			chip->period_size, chip->num_periods, 1);
 	if (ret < 0) {
 		pr_info("DEBUG: ERROR after cx25821_risc_databuffer_audio()\n");
 		goto error;
 	}

 	/* Loop back to start of program */
 	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | RISC_CNT_INC);
 	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
 	buf->risc.jmp[2] = cpu_to_le32(0);	/* bits 63-32 */

 	chip->buf = buf;
 	chip->dma_risc = dma;

 	substream->runtime->dma_area = chip->dma_risc->vaddr;
 	substream->runtime->dma_bytes = chip->dma_size;
 	substream->runtime->dma_addr = 0;

 	return 0;

 error:
 	kfree(buf);
 	return ret;
 }

 /*
  * hw free callback
  */
 static int snd_cx25821_hw_free(struct snd_pcm_substream *substream)
 {
 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);

 	if (substream->runtime->dma_area) {
 		dsp_buffer_free(chip);
 		substream->runtime->dma_area = NULL;
 	}

 	return 0;
 }

 /*
  * prepare callback
  */
 static int snd_cx25821_prepare(struct snd_pcm_substream *substream)
 {
 	return 0;
 }

 /*
  * trigger callback
  */
 static int snd_cx25821_card_trigger(struct snd_pcm_substream *substream,
 				    int cmd)
 {
 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
 	int err = 0;

 	/* Local interrupts are already disabled by ALSA */
 	spin_lock(&chip->reg_lock);

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		err = _cx25821_start_audio_dma(chip);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		err = _cx25821_stop_audio_dma(chip);
 		break;
 	default:
 		err = -EINVAL;
 		break;
 	}

 	spin_unlock(&chip->reg_lock);

 	return err;
 }

 /*
  * pointer callback
  */
 static snd_pcm_uframes_t snd_cx25821_pointer(struct snd_pcm_substream
 					     *substream)
 {
 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	u16 count;

 	count = atomic_read(&chip->count);

 	return runtime->period_size * (count & (runtime->periods - 1));
 }

 /*
  * page callback (needed for mmap)
  */
 static struct page *snd_cx25821_page(struct snd_pcm_substream *substream,
 				     unsigned long offset)
 {
 	void *pageptr = substream->runtime->dma_area + offset;

 	return vmalloc_to_page(pageptr);
 }

 /*
  * operators
  */
 static struct snd_pcm_ops snd_cx25821_pcm_ops = {
 	.open = snd_cx25821_pcm_open,
 	.close = snd_cx25821_close,
 	.ioctl = snd_pcm_lib_ioctl,
 	.hw_params = snd_cx25821_hw_params,
 	.hw_free = snd_cx25821_hw_free,
 	.prepare = snd_cx25821_prepare,
 	.trigger = snd_cx25821_card_trigger,
 	.pointer = snd_cx25821_pointer,
 	.page = snd_cx25821_page,
 };

 /*
  * ALSA create a PCM device:  Called when initializing the board.
  * Sets up the name and hooks up the callbacks
  */
 static int snd_cx25821_pcm(struct cx25821_audio_dev *chip, int device,
 			   char *name)
 {
 	struct snd_pcm *pcm;
 	int err;

 	err = snd_pcm_new(chip->card, name, device, 0, 1, &pcm);
 	if (err < 0) {
 		pr_info("ERROR: FAILED snd_pcm_new() in %s\n", __func__);
 		return err;
 	}
 	pcm->private_data = chip;
 	pcm->info_flags = 0;
 	strcpy(pcm->name, name);
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_cx25821_pcm_ops);

 	return 0;
 }

 /****************************************************************************
 			Basic Flow for Sound Devices
  ****************************************************************************/

 /*
  * PCI ID Table - 14f1:8801 and 14f1:8811 means function 1: Audio
  * Only boards with eeprom and byte 1 at eeprom=1 have it
  */

 static DEFINE_PCI_DEVICE_TABLE(cx25821_audio_pci_tbl) = {
 	{0x14f1, 0x0920, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
 	{0,}
 };

 MODULE_DEVICE_TABLE(pci, cx25821_audio_pci_tbl);

 /*
  * Alsa Constructor - Component probe
  */
 static int cx25821_audio_initdev(struct cx25821_dev *dev)
 {
 	struct snd_card *card;
 	struct cx25821_audio_dev *chip;
 	int err;

 	if (devno >= SNDRV_CARDS) {
 		pr_info("DEBUG ERROR: devno >= SNDRV_CARDS %s\n", __func__);
 		return -ENODEV;
 	}

 	if (!enable[devno]) {
 		++devno;
 		pr_info("DEBUG ERROR: !enable[devno] %s\n", __func__);
 		return -ENOENT;
 	}

 	err = snd_card_create(index[devno], id[devno], THIS_MODULE,
 			sizeof(struct cx25821_audio_dev), &card);
 	if (err < 0) {
 		pr_info("DEBUG ERROR: cannot create snd_card_new in %s\n",
 			__func__);
 		return err;
 	}

 	strcpy(card->driver, "cx25821");

 	/* Card "creation" */
 	chip = card->private_data;
 	spin_lock_init(&chip->reg_lock);

 	chip->dev = dev;
 	chip->card = card;
 	chip->pci = dev->pci;
 	chip->iobase = pci_resource_start(dev->pci, 0);

 	chip->irq = dev->pci->irq;

 	err = request_irq(dev->pci->irq, cx25821_irq,
 			  IRQF_SHARED, chip->dev->name, chip);

 	if (err < 0) {
 		pr_err("ERROR %s: can't get IRQ %d for ALSA\n", chip->dev->name,
 			dev->pci->irq);
 		goto error;
 	}

 	err = snd_cx25821_pcm(chip, 0, "cx25821 Digital");
 	if (err < 0) {
 		pr_info("DEBUG ERROR: cannot create snd_cx25821_pcm %s\n",
 			__func__);
 		goto error;
 	}

 	snd_card_set_dev(card, &chip->pci->dev);

 	strcpy(card->shortname, "cx25821");
 	sprintf(card->longname, "%s at 0x%lx irq %d", chip->dev->name,
 		chip->iobase, chip->irq);
 	strcpy(card->mixername, "CX25821");

 	pr_info("%s/%i: ALSA support for cx25821 boards\n", card->driver,
 		devno);

 	err = snd_card_register(card);
 	if (err < 0) {
 		pr_info("DEBUG ERROR: cannot register sound card %s\n",
 			__func__);
 		goto error;
 	}

 	dev->card = card;
 	devno++;
 	return 0;

 error:
 	snd_card_free(card);
 	return err;
 }

 /****************************************************************************
 				LINUX MODULE INIT
  ****************************************************************************/

 static int cx25821_alsa_exit_callback(struct device *dev, void *data)
 {
 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 	struct cx25821_dev *cxdev = get_cx25821(v4l2_dev);

 	snd_card_free(cxdev->card);
 	return 0;
 }

 static void cx25821_audio_fini(void)
 {
 	struct device_driver *drv = driver_find("cx25821", &pci_bus_type);
 	int ret;

 	ret = driver_for_each_device(drv, NULL, NULL, cx25821_alsa_exit_callback);
 	if (ret)
 		pr_err("%s failed to find a cx25821 driver.\n", __func__);
 }

 static int cx25821_alsa_init_callback(struct device *dev, void *data)
 {
 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 	struct cx25821_dev *cxdev = get_cx25821(v4l2_dev);

 	cx25821_audio_initdev(cxdev);
 	return 0;
 }

 /*
  * Module initializer
  *
  * Loops through present saa7134 cards, and assigns an ALSA device
  * to each one
  *
  */
 static int cx25821_alsa_init(void)
 {
 	struct device_driver *drv = driver_find("cx25821", &pci_bus_type);

 	return driver_for_each_device(drv, NULL, NULL, cx25821_alsa_init_callback);

 }

 late_initcall(cx25821_alsa_init);
 module_exit(cx25821_audio_fini);
	/*
	* Driver for the Conexant CX25821 PCIe bridge
	*
	* Copyright (C) 2009 Conexant Systems Inc.
	* Authors <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
	* Based on SAA713x ALSA driver and CX88 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, version 2
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/device.h>
	#include <linux/interrupt.h>
	#include <linux/vmalloc.h>
	#include <linux/dma-mapping.h>
	#include <linux/pci.h>
	#include <linux/slab.h>

	#include <linux/delay.h>
	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/control.h>
	#include <sound/initval.h>
	#include <sound/tlv.h>

	#include "cx25821.h"
	#include "cx25821-reg.h"

	#define AUDIO_SRAM_CHANNEL SRAM_CH08

	#define dprintk(level, fmt, arg...) \
	do { \
	if (debug >= level) \
	pr_info("%s/1: " fmt, chip->dev->name, ##arg); \
	} while (0)
	#define dprintk_core(level, fmt, arg...) \
	do { \
	if (debug >= level) \
	printk(KERN_DEBUG "%s/1: " fmt, chip->dev->name, ##arg); \
	} while (0)

	/****************************************************************************
	Data type declarations - Can be moded to a header file later
	****************************************************************************/

	static int devno;

	struct cx25821_audio_buffer {
	unsigned int bpl;
	struct btcx_riscmem risc;
	struct videobuf_dmabuf dma;
	};

	struct cx25821_audio_dev {
	struct cx25821_dev *dev;
	struct cx25821_dmaqueue q;

	/* pci i/o */
	struct pci_dev *pci;

	/* audio controls */
	int irq;

	struct snd_card *card;

	unsigned long iobase;
	spinlock_t reg_lock;
	atomic_t count;

	unsigned int dma_size;
	unsigned int period_size;
	unsigned int num_periods;

	struct videobuf_dmabuf *dma_risc;

	struct cx25821_audio_buffer *buf;

	struct snd_pcm_substream *substream;
	};


	/****************************************************************************
	Module global static vars
	****************************************************************************/

	static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */
	static char id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; / ID for this card */
	static bool enable[SNDRV_CARDS] = { 1, [1 ... (SNDRV_CARDS - 1)] = 1 };

	module_param_array(enable, bool, NULL, 0444);
	MODULE_PARM_DESC(enable, "Enable cx25821 soundcard. default enabled.");

	module_param_array(index, int, NULL, 0444);
	MODULE_PARM_DESC(index, "Index value for cx25821 capture interface(s).");

	/****************************************************************************
	Module macros
	****************************************************************************/

	MODULE_DESCRIPTION("ALSA driver module for cx25821 based capture cards");
	MODULE_AUTHOR("Hiep Huynh");
	MODULE_LICENSE("GPL");
	MODULE_SUPPORTED_DEVICE("{{Conexant,25821}"); /* "{{Conexant,23881}," */

	static unsigned int debug;
	module_param(debug, int, 0644);
	MODULE_PARM_DESC(debug, "enable debug messages");

	/****************************************************************************
	Module specific funtions
	****************************************************************************/
	/* Constants taken from cx88-reg.h */
	#define AUD_INT_DN_RISCI1 (1 << 0)
	#define AUD_INT_UP_RISCI1 (1 << 1)
	#define AUD_INT_RDS_DN_RISCI1 (1 << 2)
	#define AUD_INT_DN_RISCI2 (1 << 4) /* yes, 3 is skipped */
	#define AUD_INT_UP_RISCI2 (1 << 5)
	#define AUD_INT_RDS_DN_RISCI2 (1 << 6)
	#define AUD_INT_DN_SYNC (1 << 12)
	#define AUD_INT_UP_SYNC (1 << 13)
	#define AUD_INT_RDS_DN_SYNC (1 << 14)
	#define AUD_INT_OPC_ERR (1 << 16)
	#define AUD_INT_BER_IRQ (1 << 20)
	#define AUD_INT_MCHG_IRQ (1 << 21)
	#define GP_COUNT_CONTROL_RESET 0x3

	#define PCI_MSK_AUD_EXT (1 << 4)
	#define PCI_MSK_AUD_INT (1 << 3)
	/*
	* BOARD Specific: Sets audio DMA
	*/

	static int _cx25821_start_audio_dma(struct cx25821_audio_dev *chip)
	{
	struct cx25821_audio_buffer *buf = chip->buf;
	struct cx25821_dev *dev = chip->dev;
	const struct sram_channel *audio_ch =
	&cx25821_sram_channels[AUDIO_SRAM_CHANNEL];
	u32 tmp = 0;

	/* enable output on the GPIO 0 for the MCLK ADC (Audio) */
	cx25821_set_gpiopin_direction(chip->dev, 0, 0);

	/* Make sure RISC/FIFO are off before changing FIFO/RISC settings */
	cx_clear(AUD_INT_DMA_CTL,
	FLD_AUD_DST_A_RISC_EN \| FLD_AUD_DST_A_FIFO_EN);

	/* setup fifo + format - out channel */
	cx25821_sram_channel_setup_audio(chip->dev, audio_ch, buf->bpl,
	buf->risc.dma);

	/* sets bpl size */
	cx_write(AUD_A_LNGTH, buf->bpl);

	/* reset counter */
	/* GP_COUNT_CONTROL_RESET = 0x3 */
	cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);
	atomic_set(&chip->count, 0);

	/* Set the input mode to 16-bit */
	tmp = cx_read(AUD_A_CFG);
	cx_write(AUD_A_CFG, tmp \| FLD_AUD_DST_PK_MODE \| FLD_AUD_DST_ENABLE \|
	FLD_AUD_CLK_ENABLE);

	/*
	pr_info("DEBUG: Start audio DMA, %d B/line, cmds_start(0x%x)= %d lines/FIFO, %d periods, %d byte buffer\n",
	buf->bpl, audio_ch->cmds_start,
	cx_read(audio_ch->cmds_start + 12)>>1,
	chip->num_periods, buf->bpl * chip->num_periods);
	*/

	/* Enables corresponding bits at AUD_INT_STAT */
	cx_write(AUD_A_INT_MSK, FLD_AUD_DST_RISCI1 \| FLD_AUD_DST_OF \|
	FLD_AUD_DST_SYNC \| FLD_AUD_DST_OPC_ERR);

	/* Clean any pending interrupt bits already set */
	cx_write(AUD_A_INT_STAT, ~0);

	/* enable audio irqs */
	cx_set(PCI_INT_MSK, chip->dev->pci_irqmask \| PCI_MSK_AUD_INT);

	/* Turn on audio downstream fifo and risc enable 0x101 */
	tmp = cx_read(AUD_INT_DMA_CTL);
	cx_set(AUD_INT_DMA_CTL, tmp \|
	(FLD_AUD_DST_A_RISC_EN \| FLD_AUD_DST_A_FIFO_EN));

	mdelay(100);
	return 0;
	}

	/*
	* BOARD Specific: Resets audio DMA
	*/
	static int _cx25821_stop_audio_dma(struct cx25821_audio_dev *chip)
	{
	struct cx25821_dev *dev = chip->dev;

	/* stop dma */
	cx_clear(AUD_INT_DMA_CTL,
	FLD_AUD_DST_A_RISC_EN \| FLD_AUD_DST_A_FIFO_EN);

	/* disable irqs */
	cx_clear(PCI_INT_MSK, PCI_MSK_AUD_INT);
	cx_clear(AUD_A_INT_MSK, AUD_INT_OPC_ERR \| AUD_INT_DN_SYNC \|
	AUD_INT_DN_RISCI2 \| AUD_INT_DN_RISCI1);

	return 0;
	}

	#define MAX_IRQ_LOOP 50

	/*
	* BOARD Specific: IRQ dma bits
	*/
	static char *cx25821_aud_irqs[32] = {
	"dn_risci1", "up_risci1", "rds_dn_risc1", /* 0-2 */
	NULL, /* reserved */
	"dn_risci2", "up_risci2", "rds_dn_risc2", /* 4-6 */
	NULL, /* reserved */
	"dnf_of", "upf_uf", "rds_dnf_uf", /* 8-10 */
	NULL, /* reserved */
	"dn_sync", "up_sync", "rds_dn_sync", /* 12-14 */
	NULL, /* reserved */
	"opc_err", "par_err", "rip_err", /* 16-18 */
	"pci_abort", "ber_irq", "mchg_irq" /* 19-21 */
	};

	/*
	* BOARD Specific: Threats IRQ audio specific calls
	*/
	static void cx25821_aud_irq(struct cx25821_audio_dev *chip, u32 status,
	u32 mask)
	{
	struct cx25821_dev *dev = chip->dev;

	if (0 == (status & mask))
	return;

	cx_write(AUD_A_INT_STAT, status);
	if (debug > 1 \|\| (status & mask & ~0xff))
	cx25821_print_irqbits(dev->name, "irq aud", cx25821_aud_irqs,
	ARRAY_SIZE(cx25821_aud_irqs), status, mask);

	/* risc op code error */
	if (status & AUD_INT_OPC_ERR) {
	pr_warn("WARNING %s/1: Audio risc op code error\n", dev->name);

	cx_clear(AUD_INT_DMA_CTL,
	FLD_AUD_DST_A_RISC_EN \| FLD_AUD_DST_A_FIFO_EN);
	cx25821_sram_channel_dump_audio(dev,
	&cx25821_sram_channels[AUDIO_SRAM_CHANNEL]);
	}
	if (status & AUD_INT_DN_SYNC) {
	pr_warn("WARNING %s: Downstream sync error!\n", dev->name);
	cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);
	return;
	}

	/* risc1 downstream */
	if (status & AUD_INT_DN_RISCI1) {
	atomic_set(&chip->count, cx_read(AUD_A_GPCNT));
	snd_pcm_period_elapsed(chip->substream);
	}
	}

	/*
	* BOARD Specific: Handles IRQ calls
	*/
	static irqreturn_t cx25821_irq(int irq, void *dev_id)
	{
	struct cx25821_audio_dev *chip = dev_id;
	struct cx25821_dev *dev = chip->dev;
	u32 status, pci_status;
	u32 audint_status, audint_mask;
	int loop, handled = 0;

	audint_status = cx_read(AUD_A_INT_STAT);
	audint_mask = cx_read(AUD_A_INT_MSK);
	status = cx_read(PCI_INT_STAT);

	for (loop = 0; loop < 1; loop++) {
	status = cx_read(PCI_INT_STAT);
	if (0 == status) {
	status = cx_read(PCI_INT_STAT);
	audint_status = cx_read(AUD_A_INT_STAT);
	audint_mask = cx_read(AUD_A_INT_MSK);

	if (status) {
	handled = 1;
	cx_write(PCI_INT_STAT, status);

	cx25821_aud_irq(chip, audint_status,
	audint_mask);
	break;
	} else {
	goto out;
	}
	}

	handled = 1;
	cx_write(PCI_INT_STAT, status);

	cx25821_aud_irq(chip, audint_status, audint_mask);
	}

	pci_status = cx_read(PCI_INT_STAT);

	if (handled)
	cx_write(PCI_INT_STAT, pci_status);

	out:
	return IRQ_RETVAL(handled);
	}

	static int dsp_buffer_free(struct cx25821_audio_dev *chip)
	{
	BUG_ON(!chip->dma_size);

	dprintk(2, "Freeing buffer\n");
	videobuf_dma_unmap(&chip->pci->dev, chip->dma_risc);
	videobuf_dma_free(chip->dma_risc);
	btcx_riscmem_free(chip->pci, &chip->buf->risc);
	kfree(chip->buf);

	chip->dma_risc = NULL;
	chip->dma_size = 0;

	return 0;
	}

	/****************************************************************************
	ALSA PCM Interface
	****************************************************************************/

	/*
	* Digital hardware definition
	*/
	#define DEFAULT_FIFO_SIZE 384
	static struct snd_pcm_hardware snd_cx25821_digital_hw = {
	.info = SNDRV_PCM_INFO_MMAP \| SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER \| SNDRV_PCM_INFO_MMAP_VALID,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,

	.rates = SNDRV_PCM_RATE_48000,
	.rate_min = 48000,
	.rate_max = 48000,
	.channels_min = 2,
	.channels_max = 2,
	/* Analog audio output will be full of clicks and pops if there
	are not exactly four lines in the SRAM FIFO buffer. */
	.period_bytes_min = DEFAULT_FIFO_SIZE / 3,
	.period_bytes_max = DEFAULT_FIFO_SIZE / 3,
	.periods_min = 1,
	.periods_max = AUDIO_LINE_SIZE,
	/* 128 * 128 = 16384 = 1024 * 16 */
	.buffer_bytes_max = (AUDIO_LINE_SIZE * AUDIO_LINE_SIZE),
	};

	/*
	* audio pcm capture open callback
	*/
	static int snd_cx25821_pcm_open(struct snd_pcm_substream *substream)
	{
	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err;
	unsigned int bpl = 0;

	if (!chip) {
	pr_err("DEBUG: cx25821 can't find device struct. Can't proceed with open\n");
	return -ENODEV;
	}

	err = snd_pcm_hw_constraint_pow2(runtime, 0,
	SNDRV_PCM_HW_PARAM_PERIODS);
	if (err < 0)
	goto _error;

	chip->substream = substream;

	runtime->hw = snd_cx25821_digital_hw;

	if (cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size !=
	DEFAULT_FIFO_SIZE) {
	/* since there are 3 audio Clusters */
	bpl = cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size / 3;
	bpl &= ~7; /* must be multiple of 8 */

	if (bpl > AUDIO_LINE_SIZE)
	bpl = AUDIO_LINE_SIZE;

	runtime->hw.period_bytes_min = bpl;
	runtime->hw.period_bytes_max = bpl;
	}

	return 0;
	_error:
	dprintk(1, "Error opening PCM!\n");
	return err;
	}

	/*
	* audio close callback
	*/
	static int snd_cx25821_close(struct snd_pcm_substream *substream)
	{
	return 0;
	}

	/*
	* hw_params callback
	*/
	static int snd_cx25821_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *hw_params)
	{
	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
	struct videobuf_dmabuf *dma;

	struct cx25821_audio_buffer *buf;
	int ret;

	if (substream->runtime->dma_area) {
	dsp_buffer_free(chip);
	substream->runtime->dma_area = NULL;
	}

	chip->period_size = params_period_bytes(hw_params);
	chip->num_periods = params_periods(hw_params);
	chip->dma_size = chip->period_size * params_periods(hw_params);

	BUG_ON(!chip->dma_size);
	BUG_ON(chip->num_periods & (chip->num_periods - 1));

	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
	if (NULL == buf)
	return -ENOMEM;

	if (chip->period_size > AUDIO_LINE_SIZE)
	chip->period_size = AUDIO_LINE_SIZE;

	buf->bpl = chip->period_size;

	dma = &buf->dma;
	videobuf_dma_init(dma);
	ret = videobuf_dma_init_kernel(dma, PCI_DMA_FROMDEVICE,
	(PAGE_ALIGN(chip->dma_size) >> PAGE_SHIFT));
	if (ret < 0)
	goto error;

	ret = videobuf_dma_map(&chip->pci->dev, dma);
	if (ret < 0)
	goto error;

	ret = cx25821_risc_databuffer_audio(chip->pci, &buf->risc, dma->sglist,
	chip->period_size, chip->num_periods, 1);
	if (ret < 0) {
	pr_info("DEBUG: ERROR after cx25821_risc_databuffer_audio()\n");
	goto error;
	}

	/* Loop back to start of program */
	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP \| RISC_IRQ1 \| RISC_CNT_INC);
	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
	buf->risc.jmp[2] = cpu_to_le32(0); /* bits 63-32 */

	chip->buf = buf;
	chip->dma_risc = dma;

	substream->runtime->dma_area = chip->dma_risc->vaddr;
	substream->runtime->dma_bytes = chip->dma_size;
	substream->runtime->dma_addr = 0;

	return 0;

	error:
	kfree(buf);
	return ret;
	}

	/*
	* hw free callback
	*/
	static int snd_cx25821_hw_free(struct snd_pcm_substream *substream)
	{
	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);

	if (substream->runtime->dma_area) {
	dsp_buffer_free(chip);
	substream->runtime->dma_area = NULL;
	}

	return 0;
	}

	/*
	* prepare callback
	*/
	static int snd_cx25821_prepare(struct snd_pcm_substream *substream)
	{
	return 0;
	}

	/*
	* trigger callback
	*/
	static int snd_cx25821_card_trigger(struct snd_pcm_substream *substream,
	int cmd)
	{
	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
	int err = 0;

	/* Local interrupts are already disabled by ALSA */
	spin_lock(&chip->reg_lock);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	err = _cx25821_start_audio_dma(chip);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	err = _cx25821_stop_audio_dma(chip);
	break;
	default:
	err = -EINVAL;
	break;
	}

	spin_unlock(&chip->reg_lock);

	return err;
	}

	/*
	* pointer callback
	*/
	static snd_pcm_uframes_t snd_cx25821_pointer(struct snd_pcm_substream
	*substream)
	{
	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	u16 count;

	count = atomic_read(&chip->count);

	return runtime->period_size * (count & (runtime->periods - 1));
	}

	/*
	* page callback (needed for mmap)
	*/
	static struct page snd_cx25821_page(struct snd_pcm_substream substream,
	unsigned long offset)
	{
	void *pageptr = substream->runtime->dma_area + offset;

	return vmalloc_to_page(pageptr);
	}

	/*
	* operators
	*/
	static struct snd_pcm_ops snd_cx25821_pcm_ops = {
	.open = snd_cx25821_pcm_open,
	.close = snd_cx25821_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = snd_cx25821_hw_params,
	.hw_free = snd_cx25821_hw_free,
	.prepare = snd_cx25821_prepare,
	.trigger = snd_cx25821_card_trigger,
	.pointer = snd_cx25821_pointer,
	.page = snd_cx25821_page,
	};

	/*
	* ALSA create a PCM device: Called when initializing the board.
	* Sets up the name and hooks up the callbacks
	*/
	static int snd_cx25821_pcm(struct cx25821_audio_dev *chip, int device,
	char *name)
	{
	struct snd_pcm *pcm;
	int err;

	err = snd_pcm_new(chip->card, name, device, 0, 1, &pcm);
	if (err < 0) {
	pr_info("ERROR: FAILED snd_pcm_new() in %s\n", __func__);
	return err;
	}
	pcm->private_data = chip;
	pcm->info_flags = 0;
	strcpy(pcm->name, name);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_cx25821_pcm_ops);

	return 0;
	}

	/****************************************************************************
	Basic Flow for Sound Devices
	****************************************************************************/

	/*
	* PCI ID Table - 14f1:8801 and 14f1:8811 means function 1: Audio
	* Only boards with eeprom and byte 1 at eeprom=1 have it
	*/

	static DEFINE_PCI_DEVICE_TABLE(cx25821_audio_pci_tbl) = {
	{0x14f1, 0x0920, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
	{0,}
	};

	MODULE_DEVICE_TABLE(pci, cx25821_audio_pci_tbl);

	/*
	* Alsa Constructor - Component probe
	*/
	static int cx25821_audio_initdev(struct cx25821_dev *dev)
	{
	struct snd_card *card;
	struct cx25821_audio_dev *chip;
	int err;

	if (devno >= SNDRV_CARDS) {
	pr_info("DEBUG ERROR: devno >= SNDRV_CARDS %s\n", __func__);
	return -ENODEV;
	}

	if (!enable[devno]) {
	++devno;
	pr_info("DEBUG ERROR: !enable[devno] %s\n", __func__);
	return -ENOENT;
	}

	err = snd_card_create(index[devno], id[devno], THIS_MODULE,
	sizeof(struct cx25821_audio_dev), &card);
	if (err < 0) {
	pr_info("DEBUG ERROR: cannot create snd_card_new in %s\n",
	__func__);
	return err;
	}

	strcpy(card->driver, "cx25821");

	/* Card "creation" */
	chip = card->private_data;
	spin_lock_init(&chip->reg_lock);

	chip->dev = dev;
	chip->card = card;
	chip->pci = dev->pci;
	chip->iobase = pci_resource_start(dev->pci, 0);

	chip->irq = dev->pci->irq;

	err = request_irq(dev->pci->irq, cx25821_irq,
	IRQF_SHARED, chip->dev->name, chip);

	if (err < 0) {
	pr_err("ERROR %s: can't get IRQ %d for ALSA\n", chip->dev->name,
	dev->pci->irq);
	goto error;
	}

	err = snd_cx25821_pcm(chip, 0, "cx25821 Digital");
	if (err < 0) {
	pr_info("DEBUG ERROR: cannot create snd_cx25821_pcm %s\n",
	__func__);
	goto error;
	}

	snd_card_set_dev(card, &chip->pci->dev);

	strcpy(card->shortname, "cx25821");
	sprintf(card->longname, "%s at 0x%lx irq %d", chip->dev->name,
	chip->iobase, chip->irq);
	strcpy(card->mixername, "CX25821");

	pr_info("%s/%i: ALSA support for cx25821 boards\n", card->driver,
	devno);

	err = snd_card_register(card);
	if (err < 0) {
	pr_info("DEBUG ERROR: cannot register sound card %s\n",
	__func__);
	goto error;
	}

	dev->card = card;
	devno++;
	return 0;

	error:
	snd_card_free(card);
	return err;
	}

	/****************************************************************************
	LINUX MODULE INIT
	****************************************************************************/

	static int cx25821_alsa_exit_callback(struct device dev, void data)
	{
	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
	struct cx25821_dev *cxdev = get_cx25821(v4l2_dev);

	snd_card_free(cxdev->card);
	return 0;
	}

	static void cx25821_audio_fini(void)
	{
	struct device_driver *drv = driver_find("cx25821", &pci_bus_type);
	int ret;

	ret = driver_for_each_device(drv, NULL, NULL, cx25821_alsa_exit_callback);
	if (ret)
	pr_err("%s failed to find a cx25821 driver.\n", __func__);
	}

	static int cx25821_alsa_init_callback(struct device dev, void data)
	{
	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
	struct cx25821_dev *cxdev = get_cx25821(v4l2_dev);

	cx25821_audio_initdev(cxdev);
	return 0;
	}

	/*
	* Module initializer
	*
	* Loops through present saa7134 cards, and assigns an ALSA device
	* to each one
	*
	*/
	static int cx25821_alsa_init(void)
	{
	struct device_driver *drv = driver_find("cx25821", &pci_bus_type);

	return driver_for_each_device(drv, NULL, NULL, cx25821_alsa_init_callback);

	}

	late_initcall(cx25821_alsa_init);
	module_exit(cx25821_audio_fini);